bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attenuation coefficient in the energy range 14–36 keV of 3D printing materials for physical breast phantoms
Authors: Mettivier Giovanni , Sarno Antonio , Varallo Antonio , Russo Paolo 
Published: August 2022

Abstract

Objective. To measure the monoenergetic x-ray linear attenuation coefficient, μ, of fused deposition modeling (FDM) colored 3D printing materials (ABS, PLAwhite, PLAorange, PET and NYLON), used as adipose, glandular or skin tissue substitutes for manufacturing physical breast phantoms. Approach. Attenuation data (at 14, 18, 20, 24, 28, 30 and 36 keV) were acquired at Elettra synchrotron radiation facility, with step-wedge objects, using the Lambert–Beer law and a CCD imaging detector. Test objects were 3D printed using the Ultimaker 3 FDM printer. PMMA, Nylon-6 and high-density polyethylene step objects were also investigated for the validation of the proposed methodology. Printing uniformity was assessed via monoenergetic and polyenergetic imaging (32 kV, W/Rh). Main results. Maximum absolute deviation of μ for PMMA, Nylon-6 and HD-PE was 5.0%, with reference to literature data. For ABS and NYLON, μ differed by less than 6.1% and 7.1% from that of adipose tissue, respectively; for PET and PLAorange the difference was less than 11.3% and 6.3% from glandular tissue, respectively. PLAorange is a good substitute of skin (differences from −9.4% to +1.2%). Hence, ABS and NYLON filaments are suitable adipose tissue substitutes, while PET and PLAorange mimick the glandular tissue. PLAwhite could be printed at less than 100% infill density for matching the attenuation of glandular tissue, using the measured density calibration curve. The printing mesh was observed for sample thicknesses less than 60 mm, imaged in the direction normal to the printing layers. Printing dimensional repeatability and reproducibility was less 1%. Significance. For the first time an experimental determination was provided of the linear attenuation coefficient of common 3D printing filament materials with estimates of μ at all energies in the range 14–36 keV, for their use in mammography, breast tomosynthesis and breast computed tomography investigations.
Accuracy enhancement in reflective pulse oximetry by considering wavelength-dependent pathlengths
Authors: Badiola Idoia , Blazek Vladimir , Jagadeesh Kumar V , George Boby , Leonhardt Steffen , Hoog Antink Christoph 
Published: August 2022

Abstract

Objective. Noninvasive measurement of oxygen saturation (SpO
2) using transmissive photoplethysmography (tPPG) is clinically accepted and widely employed. However, reflective photoplethysmography (rPPG)—currently present in smartwatches—has not become equally accepted, partially because the pathlengths of the red and infrared PPGs are patient-dependent. Thus, even the most popular ‘Ratio of Modulation’ (R) method requires patient-dependent calibration to reduce the errors in the measurement of SpO
2 using rPPGs. Approach. In this paper, a correction factor or ‘pathlength ratio’ β is introduced in an existing calibration-free algorithm that compensates the patient-dependent pathlength variations, and improved accuracy is obtained in the measurement of SpO
2 using rPPGs. The proposed pathlength ratio β is derived through the analytical model of a rPPG signal. Using the new expression and data obtained from a human hypoxia study wherein arterial oxygen saturation values acquired through Blood Gas Analysis were employed as a reference, β is determined. Main results. The results of the analysis show that a specific combination of the β and the measurements on the pulsating part of the natural logarithm of the red and infrared PPG signals yields a reduced root-mean-square error (RMSE). It is shown that the average RMSE in measuring SpO
2 values reduces to 1 %. Significance. The human hypoxia study data used for this work, obtained in a previous study, covers SpO
2 values in the range from 70 % to 100 %, and thus shows that the pathlength ratio β proposed here works well in the range of clinical interest. This work demonstrates that the calibration-free method applicable for transmission type PPGs can be extended to determine SpO
2 using reflective PPGs with the incorporation of the correction factor β. Our algorithm significantly reduces the number of parameters needed for the estimation, while keeping the RMSE below the clinically accepted 2 %.
Mutual coherence function based topological charge detection in a Gaussian vortex beam optical communication system
Authors: Eyyuboğlu Halil Tanyer 
Published: August 2022

Abstract
We investigate a topological charge (TC) detection schema for an optical communication system employing Gaussian vortex beam (GVB). In this scenario, the transmitter maps the electrical message symbols to the TCs of GVBs. Thus obtained optical signal propagates in turbulent atmosphere arriving at the receiver, where a detection process is implemented to determine the TC of GVB by correlating the imaginary part of the mutual coherence function (MCF) of the incoming beam against the stored profiles. The feasibility of such a schema is firstly established by examining and comparing the analytical formulation of MCF and that of random phase screen setup. The latter is then used to explore the success rate and boundaries of this particular detection schema. Our results show that the proposed detection schema can operate with a error rate of 5% at a link length of 5.5 km and atmospheric turbulence structure constant of 10−14.
Study on the magnetic origin in p-type ferromagnetic semiconductor (Ga,Fe)Sb: ab initio calculations
Authors: Akroud Karima , Tahar Kadri Mohamed , Belkhir Hafid , Zanat Kamel 
Published: August 2022

Abstract
The electronic and magnetic properties of Ga
1−x

Fe

x

Sb (x=0.125, 0.25, 0.5) have been investigated using the first-principles calculations based on density functional theory (DFT) and DFT plus on-site repulsion scheme (DFT+U). We found that the Coulomb U parameter plays an important role in predicting the correct stable magnetic order. Using the DFT+U method, the ferromagnetic (FM) ordering is found to be the magnetic ground state for both concentrations 12.5% and 25%, where the DFT failed without on-site repulsion U-term correction. This failure of semi-local DFT functionals is the fingerprint of the correlated nature of Fe-3d electrons. This result is in good agreement with experiment. Increasing Fe concentration up to 50% changing the magnetic ground state from FM to antiferromagnetic (AF) phase. We have used the Heyd-Scuseria-Ernzerhof (HSE) method to calculate the unfolded band structure of supercell for Ga
1−x

Fe

x

Sb for x=0.125, in both FM and AF phases. The location of Fe-3d states in the calculation of the unfolded band structure showed a good accordance with recent resonance photoemission spectroscopy (RPES) experimental results. We have found that hole carriers have an important role at Fermi level E

F
. The rules of thumb to predict the stability of the ferromagnetism in Fe doped GaSb FMS have been discussed.
Influence of pedestal radiation on the H–L transition using krypton seeded discharges at ASDEX Upgrade
Authors: David P. , Bernert M. , Cavedon M. , Harrer G. , Eich T. , ASDEX Upgrade Team the 
Published: August 2022

Abstract
Krypton can be a tool to refine and analyse the H–L power threshold in detail, as a proxy for L–H threshold, taking into account radiative losses in the region where the H–L transition takes place and, thus, decouple the power flux over the pedestal top to the one over the separatrix. The commonly used ITPA 2008 L–H threshold scaling does not account for radiation but it is often assumed that it should be compared to the net power crossing the separatrix. Yet, dedicated analyses are still lacking. At ASDEX Upgrade, krypton radiates dominantly at the very edge of the confined plasma (ρ
pol between 0.97 and 1.01). Recent results show that L–H and H–L transitions are initiated close to ρ
pol = 0.98. As such, the bulk of krypton radiation is between the separatrix and a potential source location for the transition. Scans in krypton seeding level and heating power have been performed to study and compare the influence of the powers radiated from inside the separatrix and the pedestal top on the plasma confinement state. The heating power is compared to the usual L–H power scaling but corrected by either of these two radiations for seeded H–L transitions. The power scaling is shown to remain valid for higher input and radiated powers, up to 3–5 times the non-seeded L–H power threshold of AUG, when the radiation inside the separatrix is subtracted from the input power. Additionally, kinetic and radiation profiles are used to run TRANSP analyses to compare the edge ion heat to past studies from unseeded discharges. Using this physical parameter gives a reference point from a very different parameter range of input and radiated powers, densities and back, instead of forward, transition.
Machine learning on FPGA for event selection
Authors: Furletov S. , Barbosa F. , Belfore L. , Dickover C. , Fanelli C. , Furletova Y. , Jokhovets L. , Lawrence D. , Romanov D. 
Published: August 2022

Abstract
Real-time data processing is a frontier field in experimental particle physics. The application of FPGAs at the trigger level is used by many current and planned experiments (CMS, LHCb, Belle2, PANDA). Usually they use conventional processing algorithms. LHCb has implemented Machine Learning (ML) elements for real-time data processing with a triggered readout system that runs most of the ML algorithms on a computer farm. The work described in this article aims to test the ML-FPGA algorithms for streaming data acquisition. There are many experiments working in this area and they have a lot in common, but there are many specific solutions for detector and accelerator parameters that are worth exploring further. This report describes the purpose of the work and progress in evaluating the ML-FPGA application.
Optimal design and HOM damping of a 500 MHz 5-cell copper cavity for SAPS
Authors: Zhu J. , Li X. , Yu J. , Lu Z. , Liu Y. , Chen S. , Long W. , Wu B. , Zhang C. , Liu S. 
Published: August 2022

Abstract
In order to meet the requirements of the Southern Advanced Photon Source (SAPS), a slot-coupled π-mode 5-cell copper cavity with higher order mode (HOM) damping was proposed and developed. In this study, we present the optimal design of a 5-cell copper cavity and an investigation of HOM impedances. A prototype of 5-cell copper cavity based on this design was manufactured. The RF characteristics of 5-cell copper cavity have been tested. The results show that a flat accelerating electric field is obtained, with a coupling coefficient of 1.7% and a shunt impedance more than 19.5 MΩ/m. To damp these HOMs with high impedance, two inductive HOM couplers and two capacitive HOM couplers were designed. Finally, the impedances of all the HOMs are below the threshold of coupled-bunch instabilities (CBI) for SAPS.
Research on a back-illuminated CMOS sensor for LUV imaging
Authors: Liu W. , Ji L. , Qiu H.Y. , Lou Z. , Cai M.S. , Zhou H.J. , Huo T.L. 
Published: August 2022

Abstract
The Lyman UV (LUV) band possesses several unique characteristics that make it useful to study the properties of the interstellar medium and the circum-galactic medium (CGM) surrounding nearby galaxies. MCP detectors are sensitive in the LUV band and can be used as imagers and photon counters in space missions. Instead of MCP, this paper describes a new CMOS imaging system that can be applied to astronomical observations in the LUV band. We adopted a special back-side illuminated CMOS as the image sensor. Using it, we developed a LUV imaging system based on FPGA technology. With the assistance of a synchrotron radiation platform, the properties of the CMOS imaging system were measured and calibrated within the wavelength range from 105 nm to 130 nm. By calibrating gain, photon current, electron number and photon number parameters, we derived the quantum efficiency curve for this wavelength range. Such a development provides a new method to detect and image Lyman UV radiations.
Influence of heat treatment on the mechanical properties of alkali-activated fly ash-based binders with marble dust substitution
Authors: Ionescu B A , Mircea C , Chira M , Lăzărescu A-V 
Published: August 2022

Abstract
Marble waste contains a high level of calcium, which is obtained from the cutting process in marble production. The properties of geopolymer binders are influenced not only by the amount of alkali activators, their ratio, the molarity used, and the Si and Al content of the mineral additives used in the mixture, but also by the duration of the heat treatment and the heat treatment temperature. This study aimed to produce alkali-activated geopolymer binders based on fly ash and marble dust. Alkali-activated geopolymer pastes were made both with heat treatment for 24h at 70°C and without heat treatment at (23±2) °C. Structural analysis by optical microscopy revealed, in the case of heat-treated samples, the formation of pores with an average size of 1÷1.5 mm, much larger than in the case of samples without heat treatment.
Increasing the sustainability of construction sector by developing new products based on biomass and renewable polymers - bibliometric analysis
Authors: Istoan R , Manea L D , Plesa L , Tintisan M L 
Published: August 2022

Abstract
To increase the sustainability of the construction sector, one of the most important research directions in recent years has been the development of new building materials. As the construction industry is considered one of the most polluted sectors, the focus of researchers is to find new ways to shift away from traditional materials towards green materials. Those are usually derived from waste or unlimited natural-organic resources and have the role to reduce the environmental impact of the construction sector. Reaching the objective of a sustainable industry through the process of developing sustainable building materials is not about restricting the total amount of construction but paying more attention to how the new materials are designed and the traditional materials are rethought, as clean and energy efficient alternatives. The utilization of biomass in the composition of building materials present the new products as low-embodied energy materials that reduce energy use and greenhouse gas emissions. Based on this premise, the research will provide a bibliometric analysis of the studies carried out in the last years.
Study on behaviour of electrical insulating materials combined with conductive elements
Authors: Buică G , Antonov A E , Beiu C , Pasculescu D , Sipos C 
Published: August 2022

Abstract
The study presents the research results on the identification of technical and safety requirements specific to work equipment made of electrical insulation materials combined with conductive elements, to guarantee safety in use. The identification of the technical and safety requirements specific to the work equipment that is provided with electrically insulating materials combined with conductive elements was carried out, taking into account the safety conditions that must be guaranteed from the design and manufacturing phase. The national technical norms for live work stipulate that the work equipment used for electrical installations must be certified from the point of view of safety and health at work. Research study shows the behavior of various electrical insulation materials combined with conductive elements under the influence of mechanical, electrical, thermal and environmental factors to verify and certify the safety function that must be guaranteed in use. The research results consist of the development of the experimentation and evaluation methodology concerning the legal regulations in force and the evaluation of compliance with the technical and safety requirements identified for work equipment that is provided with electrical insulation materials combined with conductive elements - occupational health of workers and a safe work environment.
Investigation of microstructural development in mortars with recycled paper ash used as cement replacement, using NMR relaxometry
Authors: Tintisan M L , Siomin A C , Moldovean M , Zaharie A M , Istoan R , Jumate E , Manea D L , Fechete R 
Published: August 2022

Abstract
For the investigation of porous media with applications in the field of civil engineering on concrete and mortar, NMR technology is used, with emphasis on the sensitivity of 1H hydrogen protons to pore filling fluids. NMR technology was used to highlight the changes that replacing cement with recycled paper ash powder in mortar recipes brings at a molecular level. The samples are analyzed during 56 days, at predetermined deadlines depending on the evolution of cement compounds hydration. Ability of recycled paper ash to replace cement in its role as binder is analyzed and the results obtained from mechanical tests are correlated with the structure and volume of pores in the control samples. Mixture compositions and C–S–H characteristics are calculated based on NMR signal intensities and relaxation analysis.
Identifying the structure of a plaster mortar mixtures on the basis of NMR investigations
Authors: Siomin A C , Tintisan M L , Zaharie A , Moldoveanu M , Manea D L , Jumate E , Fechete R 
Published: August 2022

Abstract
Starting from the concept of sustainable development, the research program aims to establish a waste management by reducing the construction materials used in the preparation of plaster mortars. Thus, the chosen material, respectively the used paint plays an important role in replacing the main components of the plaster mortar recipe. Following the research in the laboratory of the Faculty of Construction, it was concluded that used paint can replace water or cement in the recipe in different percentages, a fact recorded in an article published in early 2022 [1]. In the future, this research can help reduce the raw materials used to make plaster mortars, an ambitious plan and a step towards the transition to the circular economy. By reducing the amount of raw materials by recycling used paint, we protect the environment. During the investigations, the 3 mortar recipes: CSIV, CSIV10C, CSIV20P are presented from the point of view of nuclear magnetic resonance NMR. According to the research program, the tracking of behavior over time was done by analyzing the samples at 3 days, 7 days and 28 days.
Olive vegetation waters (OVWs): characteristics, treatments and environmental problems
Authors: De Luca P , Sicilia V , Candamano S , Macario A 
Published: August 2022

Abstract
The present work aims to analyze the various aspects relating to olive-vegetative waters (OVW) with particular reference to environmental problems. As is known, olive-vegetation waters are one of the most polluting by-products of the oil industry. They are produced in large quantities and have a polluting potential. For this reason, an in-depth and detailed analysis of the production chain is reported up to the correct and lawful disposal of the olive-vegetation waters. The chemical characteristics of vegetation waters are described, with particular reference to polyphenols, which are the most important compounds present in vegetation waters. The treatments, enhancement, perspectives and possible uses in agriculture are reported.
Recycling plastic wastes in order to obtain new building materials
Authors: Plesa L , Manea L D , Istoan R 
Published: August 2022

Abstract
This paper presents the development of new types of construction materials using plastic waste. According to the European Court, plastic waste from various sectors such as the automotive, electronics, agriculture and construction sectors is a growing problem and is damaging to both terrestrial and marine media. Thus, every year, between 4.8 and 12.7 million tons of plastics reach the oceans. According to most of the research studies, plastic wastes have the potential to replace the natural aggregate at specific percentages. This paper proposes the reuse of this waste as reinforcement in masonry mortars, using plastic waste in various proportions. The experimental program follows the characteristics of masonry mortars both in terms of the behaviour of fresh mortar and in terms of mechanical strength. The results obtained showed a better performance of mortars reinforced with plastic strips, both in terms of flexural strength and compressive strength.
Flexible sensor based on multi-walled carbon nanotube-SnO2 nanocomposite material for hydrogen detection
Authors: Aleksanyan Mikayel S , Sayunts Artak G , Shahkhatuni Gevorg H , Simonyan Zarine G , Aroutiounian Vladimir M , Shahnazaryan Gohar E 
Published: August 2022

Abstract
This study aimed to develop a high-performance hydrogen flexible sensor based on multi-walled carbon nanotube (MWCNT):SnO2 material. The MWCNT:SnO2 thin film was deposited onto a flexible polyimide substrate by the electron-beam deposition method to perform the low temperature detection of hydrogen. The thickness and surface morphology of the sensing layers have been determined by the thickness measuring profilometer and the scanning electron microscope (SEM), respectively. The flexible MWCNT:SnO2 sensor exhibited excellent sensitive characteristics to hydrogen in a range of 25–3000 ppm. H2 sensing parameters like sensor response, recovery, and response times were investigated at different operating temperatures. The minimum response and recovery times of the sensor corresponding to 1000 ppm H2 concentrations were found to be 37 and 554 s, respectively. The investigated sensing parameters demonstrate that this work can provide the possibility of a versatile route to fabricate flexible hydrogen sensor with high sensitivity and selectivity, which demonstrates its great potential in hydrogen leakage monitoring.
State of the Art Review: Vascular Remodeling in Hypertension
Authors: Rizzoni Damiano , Agabiti-Rosei Claudia , De Ciuceis Carolina 
Published: August 2022

Abstract
Although the gold-standard method for the assessment of structural alteration in small resistance arteries is the evaluation of the MLR by micromyography in bioptic tissues, new, noninvasive techniques are presently under development, focusing mainly on the evaluation of WLR in retinal arterioles. These approaches represent a promising and interesting future perspective. Appropriate antihypertensive treatment is able to prevent the development of microvascular alterations or to induce their regression. Also, conductance arteries may be affected by a remodeling process in hypertension, and a cross-talk may exist between structural changes in the small and large arteries.
In conclusion, the evaluation of microvascular structure is ready for clinical prime time, and it could, in the future, represent an evaluation to be performed in the majority of hypertensive patients, to better stratify cardiovascular risk and better evaluate the effects of antihypertensive therapy. However, for this purpose, we need a clear demonstration of the prognostic relevance of noninvasive measures of microvascular structure, in basal conditions and during treatment.
Vascular remodeling may be frequently observed in hypertension, as well as in obesity and diabetes mellitus. An increased media to lumen ratio (MLR) or wall to lumen ratio (WLR) in microvessels is the hallmark of hypertension, and may impair organ flow reserve, being relevant in the maintenance and, probably, also in the progressive worsening of hypertensive disease, as well as in the development of hypertension-mediated organ damage/cardiovascular events. The molecular mechanisms underlying the development of vascular remodeling are only partly understood.