bluuebunny/crossref_metadata_2025 huggingface dataset:
Average density of states of amorphous Hamiltonians: role of phonon mediated coupling of nano-clusters
Authors: Shukla Pragya
Published: January 2022

Based on a description of an amorphous solid as a collection of coupled nanosize molecular clusters referred as basic blocks, we analyse the statistical properties of its Hamiltonian. The information is then used to derive the ensemble averaged density of the vibrational states (non-phonon) which turns out to be a Gaussian in the bulk of the spectrum and an Airy function in the low frequency regime. A comparison with experimental data for six glasses confirms validity of our theoretical predictions.
Silver nanoparticles embedded 2D g-C3N4 nanosheets toward excellent photocatalytic hydrogen evolution under visible light
Authors: Deng Xiyu , Kuang Xinya , Zeng Jiyang , Zi Baoye , Ma Yiwen , Yan Ruihan , Zhang Jin , Xiao Bin , Liu Qingju
Published: January 2022

Photocatalytic water splitting is considered to be a feasible method to replace traditional energy. However, most of the catalysts have unsatisfactory performance. In this work, we used a hydrothermal process to grow Ag nanoparticles in situ on g-C3N4 nanosheets, and then a high performance catalyst (Ag–g–C3N4) under visible light was obtained. The Ag nanoparticles obtained by this process are amorphous and exhibit excellent catalytic activity. At the same time, the local plasmon resonance effect of Ag can effectively enhance the absorption intensity of visible light by the catalyst. The hydrogen production rate promote to 1035 μmol g−1 h−1 after loaded 0.6 wt% of Ag under the visible light, which was 313 times higher than that of pure g-C3N4 (3.3 μmol g−1 h−1). This hydrogen production rate is higher than most previously reported catalysts which loaded with Ag or Pt. The excellent activity of Ag-g-C3N4 is benefited from the Ag nanoparticles and special interaction in each other. Through various analysis and characterization methods, it is shown that the synergy between Ag and g-C3N4 can effectively promote the separation of carriers and the transfer of electrons. Our work proves that Ag-g-C3N4 is a promising catalyst to make full use of solar energy.
Transport and losses of fusion-born alpha particles in the presence of tearing modes using the new Toroidal Accelerated Particle Simulator (TAPaS)
Authors: Zarzoso David , del-Castillo-Negrete Diego , Lacroix Rémi , Bernard Pierre-Eric , Touzet Stanislas
Published: January 2022

The transport and losses of fusion-born alpha particles are studied in the presence of a single-helicity tearing mode, characterized by (

m
=
2
,
n
=
1

). The analysis is performed by means of the recently developed Toroidal Accelerated Particle Simulator (TAPaS). Although such modes have usually been believed to result only in a local flattening of the radial profiles, it is shown that the density profile can exhibit a global modification leading to significant losses of alpha particles. This is due to the fact that, although the magnetic field does not exhibit any chaotic behaviour, the trajectories of alpha particles do, as revealed by their Poincaré maps. Such results are in qualitative agreement with past observations and simulations of energetic particles generated by neutral beam injection in TFTR, DIII-D and AUG tokamaks. In-depth analysis is carried out to characterize the impact of the tearing mode on the transport and losses of fusion-born alpha-particles with a realistic density profile. The impact of the amplitude is evidenced. Moreover, the effect of the island rotation frequency is assessed based on a detailed analysis of the linear resonances in phase-space, in agreement with the simulation results. Finally, the probability density function of the exit time has been computed and the transport of alpha particles has been found to be anomalous.
Cross-beam energy transfer saturation: ion heating and pump depletion
Authors: Hansen A M , Nguyen K L , Turnbull D , Albright B J , Follett R K , Huff R , Katz J , Mastrosimone D , Milder A L , Yin L , Palastro J P , Froula D H
Published: January 2022

Cross-beam energy transfer (CBET) was measured in two regimes where the energy transfer saturation mechanism was determined by the plasma and laser beam conditions. Linear kinetic CBET theory agrees well with the measured energy transfer in all experimental configurations and at all probe beam intensities when accounting for pump depletion and the plasma conditions measured using Thomson-scattering. Simultaneous CBET and Thomson-scattering measurements enabled uncertainties in the plasma conditions to be isolated from CBET theory, which allowed the saturation mechanisms to be identified. In the perpendicular-beam configuration the saturation mode was through ion heating, which resulted from ion trapping in the driven waves and subsequent ion-ion collisional heating. In the co-propagating beam configuration there was minimal ion heating and the saturation mode was through pump depletion.
Multi-scroll fractional-order chaotic system and finite-time synchronization
Authors: Yan Shaohui , Wang Qiyu , Wang Ertong , Sun Xi , Song Zhenlong
Published: January 2022

The definition of fractional calculus is introduced into the 5D chaotic system, and the 5D fractional-order chaotic system is obtained. The new 5D fractional-order chaotic system has no equilibrium, multi-scroll hidden attractor and multi-stability. By analyzing the time-domain waveform, phase diagram, bifurcation diagram and complexity, it is found that the system has no equilibrium but is very sensitive to parameters and initial values. With the variation of different parameters, the system can produce attractors of different scroll types accompanied by bursting oscillation. Secondly, the multi-stability of the hidden attractor is studied. Different initial values lead to the coexistence of attractors of different scroll number, which shows the advantages of the system. The correctness and realizability of the fractional-order chaotic system are proved by analog circuit and physical implement. Finally, because of the high security of multi-scroll attractor and hidden attractor, finite-time synchronization based on the fractional-order chaotic system is studied, which has a good application prospect in the field of secure communication.
Nonmagnetic scattering induced suppression of superfluid density in Bi-2212
Authors: Sk Tasaul , Rakshit Doyel , Ghosh Ajay Kumar
Published: January 2022

Nonlinear current-voltage (IV) characteristics of Bi-2212 observed in the presence of the nonmagnetic impurity have been explained incorporating the idea of Berezinskii-Kosterlitz - Thouless (BKT). An exponent (η) is extracted as a function of temperature (T) for several Bi2−x
Sr2 CaCu2−x
Zn
x
O8+δ
(Bi-2212) superconducting samples. Within the framework of the Ambegaokar-Halperin-Nelson-Siggia (AHNS) theory we have extracted the superfluid phase stiffness (SPS) as a function of T. A scaling between the SPS and critical temperature is observed. Strong suppression by the nonmagnetic impurity has been explained using the idea of localized phase fluctuations in the superconducting planes.
Generation of stable and tunable optical frequency linked to a radio frequency by use of a high finesse cavity and its application in absorption spectroscopy
Authors: Zhou Yueting , Zhao Gang , Liu Jianxin , Yan Xiaojuan , Li Zhixin , Ma Weiguang , Jia Suotang
Published: January 2022

The laser frequency could be linked to an radio frequency through an external cavity by the combination of Pound–Drever–Hall and Devoe–Brewer locking techniques. A stable and tunable optical frequency at wavelength of 1.5 μm obtained by a cavity with high finesse of 96000 and a fiber laser has been demonstrated, calibrated by a commercial optical frequency comb. The locking performances have been analyzed by in-loop and out-loop noises, indicating that the absolute frequency instability could be down to 50 kHz over 1 s and keep to less than 110 kHz over 2.5 h. Then, the application of this stabilized laser to the direct absorption spectroscopy has been performed. With the help of balanced detection, the detection sensitivity, in terms of optical density, can reach to 9.4 × 10−6.
Interaction between plasma and electromagnetic field in ion source of 10 cm ECR ion thruster
Authors: Mou Hao , Jin Yi-Zhou , Yang Juan , Xia Xu , Fu Yu-Liang
Published: January 2022

Through diagnosing the plasma density and calculating the intensity of microwave electric field, four 10 cm electron cyclotron resonance (ECR) ion sources with different magnetic field structures are studied to reveal the inside interaction between the plasma, magnetic field and microwave electric field. From the diagnosing result it can be found that the plasma density distribution is controlled by the plasma generation and electron loss volumes associated with the magnetic field and microwave power level. Based on the cold plasma hypothesis and diagnosing result, the microwave electric field intensity distribution in the plasma is calculated. The result shows that the plasma will significantly change the distribution of the microwave electric field intensity to form a bow shape. From the boundary region of the shape to the center, the electric field intensity varies from higher to lower and the diagnosed density inversely changes. If the bow and its inside lower electric field intensity region are close to the screen grid, the performance of ion beam extracting will be better. The study can provide useful information for the creating of 10 cm ECR ion source and understanding its mechanism.
The pointing model of 4.5-m small radio telescope at NARIT
Authors: Namkham N , Chanwedchasart N , Jaroenjittichai P , Prasert N
Published: January 2022

The efficiency of a radio telescope decisively depends on its pointing accuracy. Telescope’s pointing model (PM) contains repeatable errors due to the antenna control system’s imperfections, which can be corrected during observation. The 4.5m Small Radio Telescope (SRT’s) has been developed for education and experiments at Astropark, National Astronomical Research Institute of Thailand (NARIT), Chiang Mai (18°N 51’ 5” and 98°E 57’ 27”). We have implemented a 10-cm optical camera system installed on the SRT’s antenna structure to measure the offset of individual pointing covering all sky direction, which then are modeled, and the telescope’s PM is obtained. Here, we report preliminary results of SRT’s PM, where we obtain for each epoch -551.116 and -3811.549 arcsec for Azimuth encoder offset, and 1217.105 and -3343.866 arcsec for Elevation encoder offset. More accurate results can be obtained with better sky coverage observation.
Astrometric observations of water maser sources toward the Galactic Center with VLBI
Authors: Sakai D , Oyama T , Nagayama T , Kobayashi H , Honma M
Published: January 2022

The Central Molecular Zone (CMZ) in the Galactic Center region shows outstanding non-circular motion unlike the Galactic disk. Although several models describing this non-circular motion are proposed, an uniform kinematic model of the CMZ orbit is not appeared. Three dimensional velocity information including proper motions will be critical to constrain the orbital models of the CMZ because most of models proposed are devised to reproduce the line-of-sight velocity pro les of the molecular clouds in this region. To reveal the dynamics of the Galactic center region, we conducted VLBI astrometric observations of 22 GHz water maser sources toward the Galactic center with VERA. By measuring parallaxes and proper motions, we can identify whether each source is actually located in the CMZ or not, and identify the three dimensional positions and velocities in the non-circular orbit if the source is located in the CMZ. We show the results of astrometric study for several maser sources associated with molecular clouds toward the Galactic center including Sgr B2 complex and Sgr D HII region. The parallax measurement toward Sgr B2 obtained the parallax of 0.133 0:038 mas, and its proper motions indicated that Sgr B2 complex is moving toward the positive Galactic longitude with V = 100 km s−1 relative to Sgr A*.
Cumulants of the chiral order parameter in a nonequilibrium Bjorken expansion with a QCD critical point
Authors: Saikhum Poramin , Herold Christoph , Mohd Yusoff Mohamad Lukman Aidid
Published: January 2022

To understand experimentally obtained net-proton number cumulants in the search for the QCD critical point, we study a dynamical model based on an effective quark-meson Lagrangian with chiral symmetry. We investigate the evolution of the expanding medium created in a heavy-ion collision using a spatially homogeneous fluid and a time-dependent order parameter, the sigma field evolved by a Langevin equation. We extract cumulants of the sigma field along a parametrized freeze-out curve and match the obtained freeze-out points to corresponding beam energies. These cumulants can be related to cumulants of the net-proton number through the sigma-proton coupling to provide a qualitative comparison to experimental data from STAR’s beam energy scan program. We demonstrate that the presence of the spinodal or mixed phase region around the first-order chiral phase transition allows for a wide interval of cumulants at the lowest beam energies.
Fabrication of SnO2 by RF magnetron sputtering for electron transport layer of planar perovskite solar cells
Authors: Thanimkan R , Namnuan B , Chatraphorn S
Published: January 2022

The requirements of electron transport layer (ETL) for high efficiency Perovskite solar cells (PSCs) are, for example, appropriate band energy alignment, high electron mobility, high optical transmittance, high stability, and easy processing. SnO2 has attracted more attention as ETL for PSCs because it has diverse advantages, e.g., wide bandgap energy, excellent optical and chemical stability, high transparency, high electron mobility, and easy preparation. The SnO2 ETL was fabricated by RF magnetron sputtering technique to ensure the chemical composition and uniform layer thickness when compared to the use of chemical solution via spin-coating method. The RF power was varied from 60 - 150 W. The Ar sputtering gas pressure was varied from 1 × 10−3 - 6 × 10−3 mbar while keeping O2 partial pressure at 1 × 10−4 mbar. The thickness of SnO2 layer decreases as the Ar gas pressure increases resulting in the increase of sheet resistance. The surface morphology and optical transmission of the SnO2 ETL were investigated. It was found that the optimum thickness of SnO2 layer was approximately 35 - 40 nm. The best device shows Jsc = 27.4 mA/cm2, Voc = 1.03 V, fill factor = 0.63, and efficiency = 17.7%.
Magnetic and electrochemical properties of nickel oxide microstructures prepared by hydrothermal method
Authors: Boonraksa N , Maensiri S , Swatsitang E , Wongsaprom K
Published: January 2022

Nickel oxide microstructures were succesfully synthesized by hydrothermal method. The structure, morphology, surface and porosity of the NiO hexagonal plates indicated the formation of NiO without appearing any secondary phases, occupying the typical cubic structure. The ferromagnetic behaviour was examined by vibrating sample magnetometer (VSM). The sample exhibited ferromagnetic behaviour at room-temperature with the magnetic moment value of ~ 160 memu/g. The cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) anylysis were used to examine the electrochemical capacitance of the sample. The specific capacitance of the sample at a current density of 1 A/g was obtained to be 174.14 F/g. The cycle stability was excellent usability 76.6% after 500 cycles at a current density of 5 A/g.
Development and study on mechanical properties of small diameter artificial blood vessel by using electrospinning and 3d printing
Authors: Sukchanta A , Kummanee P , Nuansing W
Published: January 2022

The small diameter artificial blood vessel is synthesized with a diameter less than or equal to 6 millimetres. This technique has been used in coronary artery bypass grafting to treat coronary artery disease. Currently, the problem of coronary artery disease is still common, in addition to aortic aneurysm caused by the incompatibility of mechanical properties between the artificial blood vessel and the local blood vessel in the patient’s body. This research aims to solve the aforementioned problems using electrospinning and 3D printing technologies, as many types of materials are supported, all parameters are easy to change, and the cost is low. In this report, we describe a design for a small diameter polylactic acid (PLA) vascular graft fabricated by electrospinning with solutions of PLA in AC/DMF (1:1) 10, 12 and 15% w/v at 4 mm. The electrospun PLA nanofibers are tested for their morphology, contact angle, and seam strength. As the results, the fibres are still no same direction alignment due to insufficient rotation speed. The filament holding force is in the range of 1.90-2.71 N and the contact angles are greater than 90° because the samples are not wettable and have hydrophobic property. Further on, we will investigate other required properties, such as cell culture and other mechanical properties. Furthermore, we will compare the results with 3D printed artificial blood vessels with small diameter.
Energy conversion of electrostrictive poly(vinylidene fluoride-co-hexafluoropropylene)/Graphene composites
Authors: Ruadroew R , Thainiramit P , Putson C
Published: January 2022

This study investigates energy-conversion properties of the electrostrictive polymer, poly(vinylidene fluoride-co-hexafluoropropylene), P(VDF-HFP), filled with graphene nanosheets (GNPs). The composites (i.e., P(VDF-HFP) and GNPs) were fabricated by using the solution casting method. The dielectric constant of these electrostrictive materials was measured to observe the energy conversion property with different frequencies using an LCR meter. Their mechanical properties were measured using a photonic sensor with varying various input vibrations and electric fields to calculate their electrostrictive coefficients. These characterized results revealed that dielectric constants and electrostrictive coefficients were significantly increased when GNPs fillers were filled higher. For the electrical property, the generating current, which was measured across these polymer films, increased proportionally with respect to the adding GNPs. In this obtained result, the main finding of P(VDF-HFP)/GNPs composites is a promising electrostrictive material for applications of electromechanical energy conversions in many smart-material systems.
The archaeomagnetic field recorded in ancient kiln walls in Si Satchanalai, Sukhothai
Authors: Supakulopas R
Published: January 2022

Archaeological dating is crucial in archaeology as it is a key to understand human history. However, traditional dating methods used by archaeologists such as potassium-argon dating and luminescence dating can provide ambiguous age results, e.g., argon loss during the dating returns young apparent ages. Therefore, I plan to establish an archaeomagnetic secular variation (ASV) curve to resolve this problem and use the ASV curve as an alternative tool to date archaeological artefacts. However, archaeomagnetic data in Thailand are absent from literature. Therefore, the ASV curve cannot be constructed from the archaeomagnetic data for this locality. To provide archaeomagnetic data to construct the ASV curve, the directions of the Earth’s magnetic field recorded in kiln walls from Ban Ko Noi (KN123, age 1,370 ± 100 A.D.), Si Satchanalai were measured. The mean declination and inclination of 49.6° and 32.6° with 95% confidence limit of 5.4° were determined from 10 samples from kiln KN123. Mean directions from this study were also compared with the directions of the Earth’s magnetic field in Thailand during 1,370 A.D. from the global archaeomagnetic field model ARCH3k.1. Declination and inclination from this study show significant departure from the field predicted by the ARCH3k.1 model.
Investigation on optical integration between LED Mid-IR light sources and Si-based waveguides for sensing applications
Authors: Jaturaphagorn Pawaphat , Chaisakul Papichaya , Chattham Nattaporn , Limsuwan Pichet
Published: January 2022

Research on mid-IR silicon-based waveguides has recently received strong interest. Particularly, this paper focuses on one of the critical issues in micron-scale photonic integrated circuits, which is to efficiently couple a mid-IR LED (light emitting diode) light source to an external micron-scale waveguide. The optical coupling scheme is crucial for the exploitation of LED light sources in waveguide-based spectroscopic sensing applications. This paper reports optical coupling scheme between an LED mid-IR light source and a silicon rich silicon nitride (SiN) waveguide that could enable the use of LED-based light sources. Finally, the detection limit of the investigated device for carbon dioxide gas detection is calculated.
Development of non-invasive alcohol analyzer using Photoplethysmographytle
Authors: Sanguansri Pornnapa , Apiwong-Ngam Nattapat , Ngamjarurojana Athipong , Choopun Supab
Published: January 2022

Photoplethysmography (PPG) is one of the optical signals commonly used in clinical research for measuring the vital signs. Previously, PPG is often used as an indicator for detecting blood volume changes in the micro-vascular. The advantages of PPG signal mentioned in studies are non-invasive, lower operation cost, and the simplicity of the procedure. Although some the components of the PPG signal are not fully understood, it is generally accepted that it can provide valuable information in clinical study. Thus, it is interesting for finding a relation between PPG signal and blood alcohol concentration. The objective of this study is to classify two groups of ten-volunteer: (1) group of people who consumed alcohol and (2) non-consumed alcohol, by using the difference of PPG signals in these two groups and compared the results with fuel-cell breath alcohol analyzer. A set of PPG reflection data is recorded from optical sensors including the wavelength light of the red light and the infrared light from the fingertip of individuals. In additional, the changes of each signals for distinguishing two groups of volunteers are examined. The set of data is computed and analysed to find the correlation coefficient between significant variables in statistic domain. The analysis techniques are included (1) slope of the signals over time, (2) peak to peak of the heart rate, and (3) deep of waveform valley after rotation for training generalized linear (GLM) classifiers to create classification models. The accuracy of GLM classification can be obtained up to 87.50%. This suggests that PPG technique with our lab prototype has a potential for screening test to classify people who consumed alcohol and non-consumed alcohol.
LDLA14: a 14 Gbps optical transceiver ASIC in 55 nm for NICA multi purpose detector project
Authors: Chen Q. , Guo D. , Zhao C. , Arteche R. , Ceballos C. , Fang N. , Gan Y. , Guo Z. , Murin Y. , Sun X. , Yi L.
Published: January 2022

This paper presents the design and test results of a 14 Gbps optical transceiver ASIC (LDLA14) fabricated in a 55 nm CMOS technology for NICA Multi Purpose Detector (MPD) project. The LDLA14 is a single-channel bidirectional (1Tx + 1Rx) optical transceiver ASIC, including a Laser Driver (LD) module and a Limiting Amplifier (LA) module. It would drive the Vertical Cavity Surface Emitting Laser (VCSEL) of Transmitter Optical Sub-Assembly (TOSA) and receive signals from Photo Diode (PD) of Receiver Optical Sub-Assembly (ROSA), respectively. In the LDLA14, a novel structure of capacitive coupling pre-emphasis is proposed in the output driver of LD to obtain peaking effect without sacrifice the modulation current swing. A shared inductor technology and a Continuous Time Linear Equalizer (CTLE) pre-emphasis structure are added in the output buffer of LA to improve the quality of the output eye diagram. The dimension of LDLA14 is 1.5 mm × 1.3 mm, and the power consumption is 178 mW. The Peak-to-Peak Jitter (PPJ) and Root-Mean-Square Jitter (RMSJ) of the 14 Gbps optical eye diagram of LD in the Tx direction are 22.5 ps and 3.5 ps, respectively. The PPJ and RMSJ of the 14 Gbps electrical eye diagram of LA in the Rx direction are 23.1 ps and 4.7 ps, respectively. The BER tests have been conducted in Tx, Rx directions and the Tx-Rx loop condition, and the BER less than 10−12 is achieved in all tests.
Scintillation and optical properties of xenon-doped liquid argon
Authors: Vogl C. , Schwarz M. , Stribl X. , Grießing J. , Krause P. , Schönert S.
Published: January 2022

Liquid argon (LAr) is a common choice as detection medium in particle physics and rare-event searches. Challenges of LAr scintillation light detection include its short emission wavelength, long scintillation time and short attenuation length. The addition of small amounts of xenon to LAr is known to improve the scintillation and optical properties. We present a characterization campaign on xenon-doped liquid argon (XeDLAr) with target xenon concentrations ranging from 0 to 300 ppm by mass encompassing the measurement of the photoelectron yieldY, effective triplet lifetimeτ3and effective attenuation lengthλatt. The measurements were conducted in the Subterranean Cryogenic ARgon Facility,Scarf, a 1 t (XeD)LAr test stand in the shallow underground laboratory (UGL) of TU-Munich. These three scintillation and optical parameters were observed simultaneously with a single setup, theLegendLiquid Argon Monitoring Apparatus,Llama. The actual xenon concentrations in the liquid and gaseous phases were determined with the Impurity DEtector For Investigation of Xenon,Idefix, a mass spectrometer setup, and successful doping was confirmed. At the highest dopant concentration we find a doubling ofY, a tenfold reduction ofτ3to ∼90 ns and a tenfold increase ofλattto over 6 m.
Development of an Operational Framework for Flood Risk Management
Authors: Herath HMM , Wijesekera NTS , Rajapakse RLHL
Published: January 2022

Uncertainty is inherent to the decision-making process of flood risk management, and hence uncertainty management has been identified as crucial in the decision-making process. Flood management has been transformed towards flood risk management highlighting the stakeholder integration and adaptation to extreme flood events. Therefore, the development of multifunctional land uses over floodplains considering the multiple objectives of the stakeholders have become a key to manage uncertainty incorporated with flood risk management. Integration of multiple stakeholders in the decision-making process has been a challenging task. Therefore, spatial planning as a collaborative planning tool has become very important to manage flood risk. Operationalization of flood risk management is mainly governed by the characteristics of the planning processes and it is also coined with the governance context of each locality. However, the importance of the role of spatial planning in flood risk management is still hidden. Further, there is no common framework developed for structuring the complexity of the planning process. Therefore, this research attempts to develop a framework for the operationalization of flood risk management. The conceptual framework was developed based on a comprehensive literature review. Analytic Hierarchy Process (AHP) has been used and integrated with the Delphi technique to identify and calibrate the criteria and the sub-criteria of the framework. The developed framework has been validated with a case study. This research has been concluded that sixteen characteristics of the decision-making process contribute to the operationalization of flood risk management.
Experimental and Numerical Investigations into Temperature Distributions and VOC Conversion Rate of RTO
Authors: Liu Jingyin , Peng Zhijun
Published: January 2022

As regulations for controlling VOCs (Volatile Organic Compounds) emissions have become more and more stringent, RTO (Regenerative Thermal Oxidizer) which involves heat exchange and storage, combustion and reaction processes has to be further optimised for enhancing the VOC treatment efficiency and reducing energy consumption. In this paper, influences of operating temperature distributions and internal flow fields on gas-out VOC concentration have been studied with experimental investigation and CFD numerical simulation. Experimental results shows that combustion temperature (around the combustor) plays more critical role than thermal storage bed temperature for affecting VOC flow-out concentration. By examining the internal flow and temperature distributions, modelling results demonstrate that fast heat transfer takes place in thermal ceramic beds and high temperature areas are formed around the combustor. At about 20 seconds after a bed working for gas-in flow, the heat transfer has demonstrated obvious attenuating. The research suggests that it is very challenging for simultaneously maintaining low gas-out VOC concentration and keeping low fuel consumption and low combustion temperature in RTOs.
Selection of Energy Upgrades for Canadian Single-Detached Residential Households Based on Occupancy Profile
Authors: Kamal M R , Riyadh M M , Zahid R , Rana A , Kamali M , Sultana S R , Hewage K , Alam M S , Sadiq R
Published: January 2022

The use of energy efficient building systems can play a key role in reducing energy consumption and the adverse impacts of greenhouse gas (GHG) emission. The occupancy profile of residential dwellings has a notable influence on the effectiveness of selecting appropriate energy upgrade retrofits. Building simulation models can be integrated to determine the impact of independent occupancy profile in realizing a building’s carbon mitigation target. In this paper, the most desirable energy upgrade retrofits are suggested for three different occupancy profiles by considering important economic parameters, such as the initial investment, payback period and environmental parameter such as GHG emissions. The three occupancy profiles considered were a single adult, couple without children and couple with children. For this purpose, a calibrated energy model was developed for a single-detached family household in British Columbia, Canada, which was equipped with power sensors for monitoring the real time energy data. From the calibrated energy model, three different energy upgrade retrofits (solar, window, and wall/roof insulation) were modelled for the occupancy profiles chosen and the most suitable energy upgrades were suggested. The results show that solar panels contributed the most in energy cost reduction and upgraded windows had the least GHG emission. With suitable financial initiative, the combination of all the three energy upgrades can be the best option in terms of environment and economy.
Effect of Zeolite on the Compressive Strength of Concrete with Different Types of Cement
Authors: Sudarsono I , Wahyudi S I , Adi H P , Ikval M D
Published: January 2022

Concrete is a material component in coastal area construction. With the increasing demand for concrete for construction purposes, there have been various innovations in concrete mixtures to improve the quality of the concrete, including the compressive strength value of concrete. In the concrete mixture, the researchers also add additive to the concrete mixture, one alternative is natural zeolite which is widely found in the earth. Research by testing concrete samples with variations of the zeolite mixture 0%, 15%, and 25% uses cement type V. The test results are then compared with the results of other studies using different types of cement. Comparative studies of zeolite concrete test with different types of cement show that the optimum proportion of zeolite is around 10% to 20% of the weight of cement to get the best compressive strength value.
Barrier knock-down weir as an alternative technology for irrigation
Authors: Parwanti A , Wahyudi S I , Ni’am M F
Published: January 2022

Sand bags are one of the technologies still widely used to elevate water level. The sand bags are arranged in order to dam the river flow and to irrigate agricultural land, especially during the dry season. In line with its utilization, water supply of this technology is still less effective, thus, alternative technology is needed. This study aimed to test Barrier Knock-Down as an alternative technology that can be assembled and stored. This study was a quantitative research conducted by testing the prototypes. The tests were carried out using a monitor instrument Diver, piezometer. The tests of comparison were conducted in 4 types: Type 1, it was an L shape filled with sand+water; Type 2 was I shape filled with sand+water; Type 3 was an I shape filled with water; Type 4 was in an L shape filled with water. From the results of the study, type 1 is the best method for weir irrigation technology because of its ability to resist vertical and horizontal force than other types. Type 1-an L shape filled with sand+water with the value of safety factor rolling stability 5,28 and shear stability 2,23. Experiment result a stable elevation value in weir, did not experience a shift.
Gabion as a coastal protection structure: a case study in Panjang Island Indonesia
Authors: Adi H P , Wahyudi S I , Soebagyo A
Published: January 2022

Panjang Island is a small island in Jepara, Indonesia which is very vulnerable to coastal damage due to crashing waves. Therefore, presence of coastal protection structure is essentially important. Gabion structure was constructed to protect this coastal area. Considering the age, the existing gabion structure needed assessment and analysis to ensure its performance in term of protecting the coastal area. This study aimed at assessing and analyzing the performance of the existing gabion structure. Data of the study were collected through observing the condition of the structure. Assessment was carried out by scaling 1 (minor) to 5 (severe damage). Results of the analysis showed that the value of stability to overturning was 3.96, while the stability to shearing was 2.07, the structure stability was in safe category. Soil pressure under the structure in σ max. was 0.39 kg/cm2, while σ min was 0.16 kg/cm2, which means safe. The condition of gabion as a coastal protection structure in section 1 was partially damaged with a moderate level of damage, in section 2, the damage was revealed to be a minor level of damage, while in section 3, the damage was in a minor level of damage.
Analysis of Construction Implementation Time and Cost Scheduling by Adjusting Budget Changes Due to the Covid-19 Pandemic (Case Study on the Randugunting Dam Construction Project)
Authors: Setiyono B , Wahyudi S I , Adi H P
Published: January 2022

The Randugunting Dam, located in Blora Regency, is planned to have a capacity of 10.40 million m and is expected to irrigate an area of 630 Ha, providing a raw water supply of 0.15 m/second. The construction activity of the Randugunting Dam is one of the construction works that has been affected by the Covid-19 pandemic, namely cash flow is hampered. Therefore we need an analysis of cash flow management scenarios and determining strategies for handling the impact of the pandemic on implementation. The data used in this study is the result of interviews with the project implementation team for the Randugunting Dam construction, and data on the project cost budget. Cash flow management analysis is carried out by applying 3 scenarios, namely: scenario 1 (fixed time), scenario 2 (slowed down time), and scenario 3 (accelerated time). The analysis was carried out with the help of the Microsoft Project 2010. The determination of the handling strategy in this study used the DSS (Decision Support System) method, and the SWOT (Strength, Weakness, Opportunity, and Threat). The results of the study chose scenario 3, which is to speed up the time of 6 months. Acceleration is done by increasing the working time. The annual cost required is higher than scenario 1 (fixed time) and 2 (delayed time by 7 months), but the building is completed faster and can be used immediately. The strategy generated by SWOT analysis is Diversity Strategy and produces 8 (eight) strategies. Diversity Strategy is a strategy by maximizing internal strength factors (S), namely increasing the internal capabilities of project implementers and avoiding external threat factors (T), especially related to the Covid-19 pandemic.
Drainage System of Tegalsari Polder for Handling Flood and Tide in Tegal City Indonesia
Authors: Yuswo M , Wahyudi S I , Soedarsono  , Boogard F C , Boer E
Published: January 2022

Although in 2019 the local government of Tegal city Indonesia had constructed a retention basin at drainage system of Siwatu, Tegal Barat, Tegal city with a catchment area of 226 ha, the areas around the system still experienced flood and inundation. This study belonged to a descriptive qualitative research aimed to evaluate the performances of Siwatu drainage system and Tegalsari retention basin. Data of the study included field data and technical data from institutions. Based on the 15-year rainfall data (2014 – 2018) from Pemali - Comal PSDA Office, Central Java Province, Indonesia, the statistical parameters of Cs: 0.0027, Ck: 1.904, Sd: 15.91, Cv: 0.144 were obtained and so Gumbel method distribution was applied in the study, the return period rainfall of 10 years was 138 mm, the flood discharge for Qr.10 years was 9.63 m3/sec., the addition of long storage was 8×2,50×500 m, and the combination of pump addition was of 1 m3/sec. with the long storage of 8×2.00×500 m. By implementing one of the alternative choices, either flood or inundation could be resolved.
Analysis of The Carrying Capacity of Tourism Area in Maron Mangrove Edu Park (MMEP) Semarang
Authors: Poedjiastoeti H , Widyasamratri H , Arista C D
Published: January 2022

Ecotourism area which relies on natural conditions and local resources such as plants is required to preserve its existing resources as the main attraction. Number of visitors can be parameter of its development. Tourist visits which exceed capacity has the potential to bring negative impact to the ecotourism as a whole. Therefore, recognizing the capacity of the area is important in order that tourism and conservation activities can synergize and go hand in hand. This study aimed at analyzing the carrying capacity of Maron Mangrove Edu Park (MMEP). Data of the study were collected by surveying visitors of MMEP, interviewing the management and directly observing the site of the study. Data were analyzed based on the concept of carrying capacity. Result of the study showed that the ecotourism area was able to accommodate only 50 people/day. The average number of visitors per day were still under the maximum carrying capacity, thus it was still “safe”. To increase visits of tourists, optimization of the area based on the concept of sustainable tourism were required and could be implemented by improving access to the location, infrastructure and quality of waste management.
Natural dilution and distribution of ammonia of groundwater in Kuta Alam sub-district, Banda Aceh city 16 years post tsunami
Authors: Siddiq S , Saiful  , Arahman N
Published: January 2022

The 2004 earthquake off the west coast of Aceh caused a catastrophic tsunami. The massive influx of seawater into the land affected the environment, especially groundwater. Kuta Alam was one of the sub-districts worst affected by the tsunami. In 2005 and 2006, the quality of groundwater degraded due to, among others, the content of ammonia compounds. Increasing the population density after city reconstruction became a problem for the environment as domestic waste also pollutes the groundwater. This study proved that while 2 of the 3 research samples showed a decrease in the level of ammonia compounds in groundwater. One sampling in a densely populated area showed an increase of ammonia concentration. In areas that are not densely populated, ammonia compounds have diluted to an acceptable level, but an increase was found in densely populated areas. This indicated that the pollution was most likely occur around high population area. Proofing through a simple linear regression analysis showed a strong correlation between the content of ammonia compounds and population density.
Innovation to zero emissions: nuclear energy trough nonproliferation and environment protection- Romanian experience for GEN 4
Authors: Valeca M , Valeca S , Giosanu D
Published: January 2022

The UN Intergovernmental Panel on Climate Change (NY 2019) has concluded that nations must move more swiftly to reduce emissions of carbon dioxide, methane, and other greenhouse gases to avoid the most devastating effects of global warming. The paper presents nuclear energy as part of the solution. Due to the fact that the population is concerned about nuclear proliferation, plant safety and radiation protection, the paper presents the Romanian experience regarding the reduction of the risk of proliferation as well as the project of the 4th generation reactor ALFRED. One of the most important steps in assessing the candidate materials for Generation IV reactors is the material performance under neutron irradiation. In this respect, the paper also presents the results of the evaluations on some potential materials to be used in fast lead cooled reactors.
Influence of boundary conditions on the optimization of a geothermal heat pump studied using a thermodynamic model
Authors: Arz A , Minghini A , Feidt M , Costea M , Moyne C
Published: January 2022

This paper is the logical follow-up to a work [1] whose results were presented at the 28th French Thermal Congress which was to be held in Belfort in 2020. The model developed at that time is completed in this proposal to consider the specificity of the geothermal heat pump. This is a machine operating upon a mechanical vapor compression cycle, the limit of which is an inverse Carnot cycle. Its specificity consists of a cold loop at the source with the geothermal exchanger and the evaporator, then a hot loop at the sink with the condenser and a floor heat exchanger in the application considered here. We are particularly concerned with the optimal sizing of these heat exchangers through their effectiveness. The parametric sensitivity of this distribution to various boundary conditions is studied, especially by focusing on different conditions at the source: (1) imposed soil temperature, corresponding to a Dirichlet condition, (2) imposed heat flux (including adiabatic case), corresponding to a Neumann condition, (3) imposed mechanical power consumed by the heat pump, and (4) imposed coefficient of performance COP, to all cases being associated a finite thermal capacity in thermal contact with the geothermal exchanger operating in steady-state conditions.
Study concerning the thermal energy balance in an internal combustion engine
Authors: Popa Rm , Borborean AT , Stoica V , Ionel I
Published: January 2022

In this scientific report the steps for achieving the energy balance on a test engine Daewoo 1.6 liter in 4 cylinders, with 4 valves per cylinder, its power being77 kW, are presented. The engine was connected to a hydraulic brake during the tests. The energy balance was established, based on measurements applied on the stand test, focusing to determine the lost heat and to conceive a Sankey diagram, accordingly. Two sets of measurements were performed and based on them the heat losses were determined and two Sankey diagrams were depicted. The lost heat through the cooling fluid is determined by measuring the cooling water flow rate and its inlet and outlet temperature. The lost heat through the exhaust gases is determined by the difference between the enthalpy of the exhaust gases and the enthalpy of fresh air. The lost heat due to incomplete chemical combustion is determined by analyzing the composition of the exhaust gases. The measurements are centralized on a graphic user interface, supported by a NI Compact RIO platform.
Estimating the impact of a new bridge over the river Danube
Authors: Vilcan Adrian , Nicolae Viorel , Martin Ivana , Istrate Mihaela
Published: January 2022

The impact of a new bridge over the Danube was estimated using a 3-step road transport model, as at the time no multimodal model was available. Different forecasts have been considered for both scenarios without the project and with the project. Also, sensitivity tests have been carried out in order to assess the impact of various bridge tolls. At the end, time savings and emissions have been estimated.
Electric bus platform for urban mobility
Authors: Tudor E , Marinescu A , Prejbeanu R , Vintila A , Tudorache T , Marinescu D G , Neagu D O , Vasile I , Sburlan I C
Published: January 2022

Today, the technology of automatic battery charging based on Wireless Power Transfer (WPT) for the electric mass transit industry involving electric trains, buses and trams, is being used more and more. The modern solution described in this paper proposes an innovative technology for mixed charging of electric buses, either by wireless charging for 2-3 minutes in selected stations, or by plug-in charging at the end of the bus line, which results in only minimal energy storage on board - practically enough to get to the next charging station. The reduction of the weight of the battery packs determines the increase of the number of passengers transported, but also a reduction of the purchase price of the bus, without reducing the performances. The conversion can cost about half the price of new electric buses, depending on the condition of the vehicle and the extent of the work. This solution can be applied especially for the conversion of Diesel buses into electric buses which is not only sustainable, but also significantly better in terms of investment and operational costs, comparing with the purchase of new electric buses.
Comparative Analysis of Pitching Prediction Algorithms
Authors: Antonov D. , Zaitsev O. , Litvinenko Yu.
Published: January 2022

Two algorithms are described in the paper; one of them is the Kalman filter, which is based on the use of a pitching mathematical model, and the second uses a neural network in which the model is considered unknown. The results of the algorithms sensitivity analysis to the parameters of the model and its influence on the potential accuracy of prediction are presented. A stationary narrow-band second-order Markov process is used as a model of the ship pitching, which was used to form the input signal of the algorithms. Also, the results of the algorithms simulation in predicting real data are presented.
Estimation of the Nuclear Magnetic Gyroscope Sensitivity to Inertial Influences
Authors: Zavitaev A.S. , Evstifeev M. I.
Published: January 2022

The factors influencing the stability of the zero offset of a nuclear magnetic gyroscope (NMG) are considered. As a result, an equation for the connection of these parameters with changes arising in the course of inertial influences on the NMG body has been created. In addition, the displacements caused by vibration effects on the NMG under operating conditions are analyzed. Based on these data, the changes in NMG accuracy are calculated and conclusions are drawn about the effectiveness of the NMG design.