bluuebunny/crossref_metadata_2025 huggingface dataset:
Tailoring the optical properties of PC/ZnS nanocomposite by γ radiation
Authors: Bahareth Radiyah A. , Barakat Mai ME. , Alhodaib Aiyeshah , Aldawood Saad , Nouh Samir A.
Published: May 2021

Chemical coprecipitation methodology in atmospheric air has been used to prepare Zinc sulfide (ZnS) nanoparticles (NPs); EDTA-ethylenediamine was used as stabilizing agent. Then ex-situ casting technique was used to synthesis nanocomposite (NCP) from Polycarbonate polymer (PC) and the synthesized ZnS NPs. Detection analysis of XRD records demonstrated that synthesized ZnS adjusts cubic zinc blend construction of lattice constant matches 5.345 Å and an average grain size 4nm. PC/ZnS NCP samples were irradiated with doses of gamma radiation in the range 25‑230 kGy. The modifications in optical parameters of the irradiated NCP samples were investigated using UV spectroscopic analysis and CIE color variation technique. Tauc's model and optical dielectric loss assisted in estimating the optical band gap (Eg) and to recognize the type of electronic transition.Egdecreased from 3.83 to 3.00 eV upon increasing the radiation dosesγup to 230 kGy; demonstrating the enhancement of the amorphous phase in the NCP. This was conveyed by an increase in the refractive index. Moreover, the color variations were explored using UV transmission spectra and the CIELAB color space methodology. Theγradiation causes a reduction in green and blue color components, conveyed by an increase in whiteness. This led to a noteworthy color variation that is applicable in marketable imitation on printing press.
Integrating decision making conditions into DEA models
Authors: Zehi Rokhsaneh Yousef , Mustafa Adli
Published: May 2021

Data Envelopment Analysis (DEA) is a popular non-parametric technique for the assessment of efficiency of a set of homogeneous decision making units (DMUs) with the same set of inputs and outputs. In the conventional DEA models, it is assumed that all variables are fully controllable. However, in the real-world applications of DEA, some of the variables are completely uncontrollable or partially controllable. In this paper, we are concerned about partially controllable variables which are called semi-discretionary variables. In DEA models, in the presence of semi-discretionary variables, decision makers have partial control on these variables and the proportional changes are possible to some extent. Previous DEA models with semi-discretionary variables consider a certain level of control on the variables which is fixed and it is given by decision makers or a higher authority. Since this level is usually given by experts, it is possible that in some cases all experts may not come up with an agreement, so in this paper we consider variable instead of fixed level of control on each semi-discretionary variable. In the presence of semi-discretionary variables, the proportional changes in inputs and out-puts may not be feasible and as a result the obtained target value by conventional DEA models is not achievable for an inefficient DMU. Thus, we propose a bi-objective model to evaluate DMUs when modifying a variable to its target value should be managed by decision makers in a voting system. One of the advantages of the proposed model is including decision making conditions directly into a DEA model.
Online-Kurse mit Freude und Verstand geben
Authors: Larsen Valerie
Published: May 2021

Ob Geburtsvorbereitungskurs oder Rückbildungskurs: Präsenzveranstaltungen sind eine Wunschvorstellung, die sich in Zeiten von Corona nicht uneingeschränkt umsetzten lässt. Durch die Pandemie stellen sich viele Probleme, die den Alltag freiberuflicher Hebammen stark beeinflussen. Die Autorin vermittelt anschaulich, wie sich gute und originäre Hebammenarbeit auch im digitalen Kursraum realisieren und ansprechend gestalten lässt.
Als Hebamme freiberuflich arbeiten
Authors: Stamm Anja , Kuntz Heidi
Published: May 2021

Die überwiegende Mehrheit der rund 24 000 Hebammen in Deutschland arbeitet ganz oder teilweise freiberuflich. Der Artikel beleuchtet, worauf es beim Start in die Selbstständigkeit ankommt. Eine freiberufliche Hebamme vermittelt, welche Herausforderungen und Chancen mit der Selbstständigkeit verbunden sind.
The Ratio of the Distal Femur Width to the Tibial Plateau Width with Advancing Age
Authors: Schlatterer Daniel Robert , Kessler Raymond , Donahue Jeffrey , Amersi Arish , Robinson Weston , Khakharia Saurabh
Published: May 2021

Historically, intraoperative analysis of knee fracture procedures relied upon a fluoroscopic reduction assessment by the surgeon. This is a subjective assessment due to the lack of linear measurement reference data. Compared with the knee, the ankle and wrist have well-established bony anatomical relationships to guide reduction assessment during fracture treatment. The purpose of this study was to (1) determine the width ratios in the knee (plateau to femur) with aging, and (2) determine knee width changes with aging. One-hundred and fifty consecutive uninjured knee radiographs were reviewed. In all age groups, the width ratio of the articular distal femoral (ADF) to the articular tibial plateau (ATP) is greater than 1.0 and between 1.03 and 1.05. The tibia plateau width is on average 9.34 mm wider and the femoral width is 8.0 mm wider in the 61 to 80 age group than the ATP and the ADF in the younger age groups. In conclusion, the articular tibial plateau width and the articular distal femoral width are nearly equal across ages 20 to 80 years. An absolute articular width value by age cannot be assigned because articular widths change with aging.
National Decline in Knee Fusions Performed for Salvage of Chronic Periprosthetic Total Knee Infections
Authors: Rajaee Sean S. , Kavolus Joseph J. , Hayden Brett L. , Estok Daniel M.
Published: May 2021

The primary purpose of this study was to study and compare rates of two salvage operations for patients with chronically infected total knee arthroplasties: (1) knee arthrodesis and (2) above knee amputation (AKA). An analysis was performed comparing the inpatient hospital characteristics and complications between the two procedures. Secondarily, we presented rates of all surgically treated periprosthetic total knee infections over a 6-year period. Using the Nationwide Inpatient Sample, we identified all patients with a periprosthetic infection (International Classification of Diseases, Ninth Revision [ICD-9] 996.66) from 2009 to 2014. Subsequently, we identified surgically treated total knee infections through the following ICD-9 codes: 00.80 (all component revision), 00.84 (liner exchange), 80.06 (removal of prosthesis), 84.17 (AKA), and 81.22 (knee fusion). From 2009 to 2014, the annual incidence of surgically treated total knee periprosthetic infections increased by 34.9% nationally, while the annual incidence of primary total knees increased by only 13.9%. Salvage operations (AKA and knee fusion) represented 5.8% of all surgically treated infections. The rate of knee fusions decreased from 1.9% of surgically treated infections in 2009 to 1.4% in 2014 (p < 0.05), while the rate of AKA stayed steady at 4.5% of cases over the 6-year period. Length of stay was significantly shorter in the knee fusion group (7.9 vs. 10.8 days, p < 0.05), but total hospital costs were higher (33,016 vs. 24,933, p < 0.05). In the multivariable adjusted model, patients undergoing knee fusion had significantly decreased odds of being discharged to skilled nursing facility (odds ratio: 0.42, 95% confidence interval: 0.31–0.58). The annual incidence of surgically treated periprosthetic total knee infections is increasing. The rate of knee arthrodesis for chronic periprosthetic total knee infections is decreasing. Reasons for this downward trend in knee fusions should be evaluated carefully as knee fusions have shown to have the potential advantage of improved mobility and decreased patient morbidity for chronic PJI. The level of evidence is III.
Impact of COVID-19 Pandemic during the Lockdown on the Traumatic Brain Injury—An Institutional Experience
Authors: Nayak Nitish , Singh Prashant Raj , Sharma Raghvendra Kumar , Gupta Surendra Kumar , Gandhoke Charandeep Singh , Sharma Anil Kumar
Published: May 2021

Background Traumatic brain injuries (TBIs) contribute to a significant socioeconomic impact, primarily affecting the lower-income sections of the society. The COVID-19 pandemic has resulted in a marked reduction in in-patient attendance. We are highlighting the impact of lockdown in neurotrauma cases in our institution compared to the prelockdown period.

Methods We have done the retrospective review of the patients admitted due to TBI in prelockdown (January 14–March 21, 2020) and lockdown period (March 25–May 31, 2020) for the same duration of the 68 days at our tertiary institution. We have included demographic characteristics (age, sex), mode of injury, the severity of TBI, radiological diagnosis (computed tomography scan), and treatment obtained in our study. We compared the data for percentage (%) reduction of TBI cases and factors responsible for it during the lockdown period.

Result A total of 166 patients were included in both groups. TBI’s most common mechanism was road traffic accident, but we observed an increase in self-fall (16.9% vs. 38.1%) and assault (11.2% vs. 19%) during the lockdown period. We have noted that moderate TBI increased during the lockdown period by 17%. Overall, there is a reduction of 67% in TBI cases during the lockdown period.

Conclusion The COVID pandemic has limited road traffic activity, and strict implementation of lockdown has restricted the infection and has reduced the neurotrauma emergencies. Simultaneously, moderate TBI cases have increased because of the lack of transportation facility and delay in the management of mild TBI cases.
Discharge dynamics of a nanosecond pulsed helium/argon nanosecond atmospheric pressure glow discharge
Authors: Walsten A. , Xu K. , Sanderson C. , Ballmann C. , Matyas D.
Published: May 2021

A nanosecond pulsed atmospheric pressure dielectric barrier glow discharge in helium with 1% of argon was studied. The effects of the electric field, frequency, and gas mixture ratio on the temporal behavior of the plasma discharge were captured with an ICCD camera. Special interest was given to the timing and scale of the secondary or return stroke. It was found that the external electric field can control the occurrence of the return stroke in a dielectric barrier discharge. If the electric field is high enough, the return stroke occurs earlier than previously observed in other works. Increasing frequency leads to faster discharge initiation times for both the primary and secondary discharges. Increasing the argon ratio of the mixture leads to an increased intensity of the primary discharge, a decrease in the intensity of the secondary discharge, and a delay in the timing of the primary discharge.
MHD simulation of supersonic FRC merging corrected by non-invasive magnetic measurements
Authors: Kobayashi D. , Asai T. , Takahashi Ts. , Watanabe T. , Yoshino T. , Harashima D. , Dettrick S. , Mok Y. , Gota H.
Published: May 2021

In this study, a newly developed correction method with external magnetic measurements for the magnetohydrodynamics (MHD) simulation of the collisional merging formation of a field-reversed configuration (FRC) realized the estimation of the internal structure of the FRCs without invasive internal measurements. In the collisional merging formation of FRCs, an FRC is formed via merging of two initial FRC-like plasmoids at supersonic/Alfvénic velocity. An invasive diagnostic may also interfere with the collisional merging formation process. A two-dimensional resistive MHD simulation was conducted to evaluate the global behavior and internal structure of FRCs in the collisional merging formation process without invasive measurements. This code simulated the initial formation and collisional merging processes of FRCs including discharge circuits. However, the translation velocity and the pressure of initial FRCs did not simultaneously agree with the experimental values because the magnetic pressure gradient in each formation region could not be reproduced without the artificial adjustment of the initial condition. The experimentally measured current distribution was given as the initial condition of the circuit calculation in the developed correction method. The initial FRCs were successfully translated at the translation velocity and plasma pressure in the corrected simulation, both of which were equivalent to the experiments. The properties of the merged FRCs in the experiments such as volume, total temperature, and average electron density were reproduced in the corrected simulation. The detailed radial profile of the internal magnetic field of the FRC was also measured and found to agree very well with the simulation results.
Matrix detector to determine the spatial distribution of VUV-radiation from plasma diode
Authors: Babenko Ie. V. , Hrechko Ya. O. , Azarenkov N. A. , Sereda I. N. , Ryabchikov D. L.
Published: May 2021

The study of the vacuum ultraviolet (VUV) distribution has been carried out with help of the multiple-ionized tin plasma of the high-current pulse diode. The VUV spatial distribution has been determined with the help of a matrix detector. The matrix with 21 copper photocathodes registered VUV pulses with a time resolution of 4 ns. The VUV radiation has been observed as a series of pulses in the first three half-periods of the discharge current oscillations. Based on VUV spatial distribution, the detailed radiating plasma dynamic has been obtained. Analysis of the plasma dynamics has revealed the features of the generating zones for long (1 μs) and short peak (100–200 ns) radiation pulses and the additional radiating zones in the second and third half-periods.
Energy-angle distribution of the ions in the RF sheath of ICRH antennas
Authors: Elias M. , Curreli D. , Myra J. R.
Published: May 2021

Radio-frequency sheaths forming at the surface of ion cyclotron resonance heating (ICRH) actuators in fusion experiments are associated with enhanced impurity sputtering from ICRH plasma-facing components (PFCs). The minimization of impurity fluxes from the ICRH PFC is a vital task for the usage of ICRH systems. Capturing the ion kinetics is important for an accurate description of plasma–material interactions, because the ion dynamics plays a crucial role in RF sheaths. Here, we present a hybrid particle-in-cell (hPIC) model able to capture the kinetic behavior of the ions. We analyze the kinetic ion energy-angle distributions (IEADs) impacting the RF antenna and its dependence on different plasma and RF sheath parameters. In particular, the IEAD dependence on RF frequency and magnetic field alignment is investigated. Using hPIC, we simulated a case emulating the latest experimental campaign from JET. The simulation showed that under specific plasma and RF parameters, the kinetic motion of ions results in a cusp formation in the IEAD.
Suppression of the vacuum space-charge effect in fs-photoemission by a retarding electrostatic front lens
Authors: Schönhense G. , Kutnyakhov D. , Pressacco F. , Heber M. , Wind N. , Agustsson S. Y. , Babenkov S. , Vasilyev D. , Fedchenko O. , Chernov S. , Rettig L. , Schönhense B. , Wenthaus L. , Brenner G. , Dziarzhytski S. , Palutke S. , Mahatha S. K. , Schirmel N. , Redlin H. , Manschwetus B. , Hartl I. , Matveyev Yu. , Gloskovskii A. , Schlueter C. , Shokeen V. , Duerr H. , Allison T. K. , Beye M. , Rossnagel K. , Elmers H. J. , Medjanik K.
Published: May 2021

The performance of time-resolved photoemission experiments at fs-pulsed photon sources is ultimately limited by the e–e Coulomb interaction, downgrading energy and momentum resolution. Here, we present an approach to effectively suppress space-charge artifacts in momentum microscopes and photoemission microscopes. A retarding electrostatic field generated by a special objective lens repels slow electrons, retaining the k-image of the fast photoelectrons. The suppression of space-charge effects scales with the ratio of the photoelectron velocities of fast and slow electrons. Fields in the range from −20 to −1100 V/mm for Ekin = 100 eV to 4 keV direct secondaries and pump-induced slow electrons back to the sample surface. Ray tracing simulations reveal that this happens within the first 40 to 3 μm above the sample surface for Ekin = 100 eV to 4 keV. An optimized front-lens design allows switching between the conventional accelerating and the new retarding mode. Time-resolved experiments at Ekin = 107 eV using fs extreme ultraviolet probe pulses from the free-electron laser FLASH reveal that the width of the Fermi edge increases by just 30 meV at an incident pump fluence of 22 mJ/cm2 (retarding field −21 V/mm). For an accelerating field of +2 kV/mm and a pump fluence of only 5 mJ/cm2, it increases by 0.5 eV (pump wavelength 1030 nm). At the given conditions, the suppression mode permits increasing the slow-electron yield by three to four orders of magnitude. The feasibility of the method at high energies is demonstrated without a pump beam at Ekin = 3830 eV using hard x rays from the storage ring PETRA III. The approach opens up a previously inaccessible regime of pump fluences for photoemission experiments.
IR and metasurface based mm-wave camera
Authors: Lundgren Johan , Gustafsson Mats , Sjöberg Daniel , Nilsson Martin
Published: May 2021

We have developed a technique to measure low-power electromagnetic fields from mm-wave devices non-intrusively by combining a metasurface, designed to absorb power and focus the radiated power in a thermally isolated region, with an infrared (IR) camera. The metasurface consists of thermally isolated elements of low mass and highly emissive material for maximal IR conversion of the incident wave. The IR camera captures the converted energy and indirectly images the incident electromagnetic field on the metasurface. The setup combines multi-scale, multi-physical processes to conduct measurements of the incident electromagnetic fields in real time. In this work, the technique is presented and discussed. Measurements are carried out to demonstrate the technique and image the electromagnetic field of a radiating device. The results compare well with simulations, and the technique can measure the low power density levels of consumer devices and provide a general visualization of electromagnetic fields in a live setting.
Photodissociation of [Ar–N2]+ induced by near-IR femtosecond laser fields by ion-trap time-of-flight mass spectrometry
Authors: Suzuki Takahiro , Kanya Reika , Yamanouchi Kaoru
Published: May 2021

Photodissociation of [Ar–N2]+ induced by a near-IR (800 nm) femtosecond laser pulse is investigated using ion-trap time-of-flight mass spectrometry. The intra-complex charge transfer proceeding in the course of the decomposition of the electronically excited Ar+(2P3/2)⋯N2(X1Σg+), prepared by the photoexcitation of the electronic ground Ar(1S0)⋯N2+(X2Σg+), is probed by the ion yields of Ar+ and N2+. The yield ratio γ of N2+ with respect to the sum of the yields of Ar+ and N2+ is determined to be γ = 0.62, which is much larger than γ ∼ 0.2 determined before when the photodissociation is induced by a nano-second laser pulse in the shorter wavelength region between 270 and 650 nm. This enhancement of γ at 800 nm and the dependence of γ on the excitation wavelength are interpreted by numerical simulations, in which the adiabatic population transfer from Ar+(2P3/2)⋯N2(X1Σg+) to Ar(1S0)⋯N2+(X2Σg+) at the avoided crossings is accompanied by the vibrational excitation in the N2+(X2Σg+) moiety followed by the intra-complex vibrational energy transfer from the N2+(X2Σg+) moiety to the intra-complex vibrational mode leading to the dissociation.
A perspective on the next generation of invisibility cloaks—Intelligent cloaks
Authors: Qian Chao , Chen Hongsheng
Published: May 2021

Invisibility has been a long-standing topic, owing to its crucial importance in both academia and industry. At the close of the last century, the advent of metamaterials unprecedentedly ignited the enthusiasm toward pursuing invisibility cloaks, but despite two decades of research, it has yet to mature into a practical method. In this Perspective, we first present a review of conventional and state-of-the-art invisibility methodologies, as well as their intrinsic challenges. To take a further step, we focus on the conjunction of two burgeoning disciplines—metamaterials and deep learning—to facilitate an intelligent self-adaptive invisibility cloak for dynamic surroundings. Finally, future directions are described, which include possible development directions and other practice-oriented metadevices driven by deep learning.
The nonlinear initiation of side-branching by activator-inhibitor-substrate (Turing) morphogenesis
Authors: Yochelis Arik
Published: May 2021

An understanding of the underlying mechanism of side-branching is paramount in controlling and/or therapeutically treating mammalian organs, such as lungs, kidneys, and glands. Motivated by an activator-inhibitor-substrate approach that is conjectured to dominate the initiation of side-branching in a pulmonary vascular pattern, I demonstrate a distinct transverse front instability in which new fingers grow out of an oscillatory breakup dynamics at the front line without any typical length scale. These two features are attributed to unstable peak solutions in 1D that subcritically emanate from Turing bifurcation and that exhibit repulsive interactions. The results are based on a bifurcation analysis and numerical simulations and provide a potential strategy toward also developing a framework of side-branching for other biological systems, such as plant roots and cellular protrusions.
Regulating autologous stem cell interventions in Australia: updated review of the direct-to-consumer advertising restrictions
Authors: Rudge Chris , Ghinea Narcyz , Munsie Megan , Stewart Cameron
Published: May 2021

Objective This paper provides an update and overview of the law governing direct-to-consumer (DTC) advertising of autologous stem cell interventions (ASCIs) in Australia. It follows significant changes to the advertising regulations made in 2018. Methods The paper reviews the three primary sources or ‘centres’ of law regulating ASCIs in Australia, together with the relevant guidance documents that supplement these sources. It provides analysis of how the post-2018 advertising regulations, contained in the Therapeutic Goods Act 1989 (Cwlth), apply to all ‘biologicals’, including ASCIs. It demonstrates how these three sources of law interact with one another and outlines the new tiered offence regime that applies to contraventions of these prohibitions. Results The analysis demonstrates that DTC advertising of ASCIs in Australia is strictly controlled, with primary legislation prohibiting the advertising of biologicals altogether. Conclusions The polycentric legal regime regulating biologicals in Australia clearly makes DTC advertising of ASCIs unlawful. Health practitioners who promote ASCIs, either online, in print or in other media forms, may be penalised in different ways and by different authorities. What is known about the topic? Although several analyses have examined the regulation of ASCIs in Australia, no analysis has studied the reforms made in 2018 relating to the advertising of biologicals. As such, this analysis contributes a fresh examination of these relatively recent reforms. What does this paper add? This analysis clarifies the effects of these new advertising regulations, providing clear guidance on the relevant legal provisions for the benefit of health practitioners and health professionals more generally. What are the implications for practitioners? Health practitioners, especially those who offer ASCIs, should be aware that civil and criminal penalties are likely to be imposed on individuals who promote biologicals in Australia by any means.
Immersion in a minority language
Authors: Ní Chlochasaigh Karen , Shiel Gerry , Ó Duibhir Pádraig
Published: May 2021

When the earliest Irish language immersion schools outside Irish-speaking (Gaeltacht) areas were established, students were likely to come from relatively high socioeconomic backgrounds. While research has shown positive outcomes for these students, less is known about the outcomes of immersion education for students from areas of social disadvantage. Of 145 Irish immersion primary schools in the Republic of Ireland in 2016, 13 (8%) served low socioeconomic status (SES) communities. The current study examined the achievements of Grade 3 (n. = 283) and Grade 6 (n. = 235) students in these schools on nationally-standardised tests of English reading and mathematics. Their scores are compared to those of students attending schools in areas of disadvantage nationally. Immersion students in Grade 3 achieved lower mean scores on both English reading and mathematics when compared with their low-SES English-medium peers. However, Grade 6 students achieved at about the same level in mathematics and outperformed their low-SES peers nationally in English reading.
Anomalous effects of dielectric coated plasmonic metal nanoparticles on solar absorption enhancement in perovskite thin films
Authors: Shen Chenglong , Deng Liren , Wang Ningning , Huang Yu
Published: May 2021

Localized surface plasmon resonances in metallic nanostructures have been extensively harnessed for light absorption enhancement in various solar cells, including perovskite solar cells (PSCs). For stabilization and functionalization, plasmonic metal nanostructures are often coated with dielectric shells. In this work, we numerically investigate the effects of dielectric coated plasmonic metal nanoparticles (NPs) on solar absorption enhancement in perovskite thin films. To our surprise, a further absorption enhancement compared with the films embedding bare Ag NPs can be achieved when using thin dielectric coating of high refractive index, while an absorption reduction in comparison with bare perovskite thin films may take place when the embedded Ag NPs are coated with thick dielectric shells of low refractive index. The physics behind is addressed within classic electrodynamics. These anomalous effects extend our knowledge of PSCs, providing guidelines for optimized design of plasmonic solar cells.
Target domains in nanometric Permalloy disks with columnar structure
Authors: Ponomareva Svetlana , Morel Robert , Joisten Hélène , Sabon Philippe , Dieny Bernard
Published: May 2021

We conducted a thorough experimental and numerical study of the micromagnetic properties of Permalloy (Ni80Fe20) microdisks exhibiting target domain structures at remanence. Vortex configurations are quite common in such microdisks and correspond to an in-plane (IP) flux closure configuration of cylindrical symmetry with an out-of-plane (OOP) magnetized core. In contrast, target domain configuration are observed in thicker microdisks and are characterized by a vortex configuration of the IP component of the magnetization superposed to an OOP component of magnetization which oscillates as a function of the distance to the microdisk center resulting in the formation of concentric domains. The ratio of the OOP oscillatory component of the magnetization to the IP vortex one increases with the thickness of the microdisk. Hysteresis loops were measured under IP and OOP field. The results at remanence and under magnetic field could be interpreted by micromagnetic simulations in which the microdisks were described as an assembly of partially coupled columns representing the granular nanostructure of the films from which the microdisks were patterned. Quite original magnetization processes take place in these microdisks exhibiting target domain remanent configuration. These include in particular entire flipping of the domain configuration and annihilation/creation of ring domains.
Plasma–graphene interactions: combined effects of positive ions, vacuum-ultraviolet photons, and metastable species
Authors: Vinchon P , Glad X , Bigras G Robert , Sarkissian A , Martel R , Stafford L
Published: May 2021

This study compares the impact of different plasma environments on the damage formation dynamics of polycrystalline monolayer graphene films on SiO2/Si substrates and investigates the combined effects often observed in low-pressure argon plasmas. After careful characterization of the discharge properties by Langmuir probes and optical absorption spectroscopy, three operating conditions were selected to promote graphene irradiation by either positive ions, metastable species, or vacuum-ultraviolet (VUV) photons. In all cases, hyperspectral Raman imaging of graphene reveals plasma-induced damage. In addition, defect generation is systematically slower at grain boundaries (GBs) than within the grains, a behavior ascribed to a preferential self-healing of plasma-induced defects at GBs. The evolution of selected Raman band parameters is also correlated with the energy fluence provided to the graphene lattice by very-low-energy ions. From such correlation, it is shown that the presence of VUV photons enhances the defect formation dynamics through additional energy transfer. On the other hand, the presence of metastable species first impedes the defect generation and then promotes it for higher lattice disorder. While this impediment can be linked to an enhanced defect migration and self-healing at nanocrystallite boundaries in graphene, such effect vanishes in more heavily-damaged films.
Temperature activated conductivity of Ge2Sb2Te5: connection to the variation of Fermi level and implications on resistance drift
Authors: Vorobyov Y , Ermachikhin A , Yakubov A , Trusov E , Fedyanina M , Lazarenko P , Kozyukhin S
Published: May 2021

The non-Arrhenius behaviour of Ge2Sb2Te5 conductivity is attributed to the non-linear temperature dependence of the Fermi level, assuming extended state conduction by free holes. The temperature-dependent Fermi level is shown to alter values of activation energy and prefactor for conductivity so that their exact determination becomes impossible using the conductivity data alone. However, if one assumes the temperature dependence of the Fermi level to be a parabolic function. Then, two of three model parameters can be retrieved; to obtain the third parameter one has to make an assumption about the value of prefactor for conductivity. Applying the proposed analysis scheme to Ge2Sb2Te5, reasonable values of Fermi level position are obtained and the change of Fermi level as a result of resistance drift phenomenon is demonstrated.
Continuous manipulation of acoustic wavefront using a programmable acoustic metasurface
Authors: Gong Kemeng , Zhou Xin , Ouyang Huajiang , Mo Jiliang
Published: May 2021

Conventional passive acoustic metasurfaces (AMSs) can hardly reconfigure their topologies or structural parameters, which limits their wide applications. In this paper, a programmable AMS which contains an array of reconfigurable subwavelength unit cells, regulated by a set of stepper motors with lead screws and a cost-effective control system is presented. The unit of the AMS is composed of a parallel one-dimensional daisy-chained slit with five Helmholtz resonators. The phase shift of the transmission wave through the AMS units can be precisely controlled over the full phase range and continuously tuned by varying the slit width at high transmission efficiency. Benefitting from such a mechanism, the designed AMS is able to achieve continuous versatile wave manipulation functions in simulation and in experiment by engineering the phase and amplitude of transmission waves, including tuneable acoustic refraction, tuneable acoustic focusing and tuneable acoustic self-bending. Thus, this proposed AMS holds a great potential for a wide range of applications including diagnostic sonography, active non-destructive evaluation, acoustic holography, noncontact micro-particles manipulation and energy harvesting.
Structure driven magnetic correlations and magnetodielectric coupling in 6H-perovskite Ba3DyRu2O9
Authors: Chhillar S , Mukherjee K , Yadav C S
Published: May 2021

The 6H-perovskites Ba3(R/M)Ru2O9 (R = rare Earth, M = transition metal) exhibit complex magnetism and have been extensively studied recently for their magnetodielectric (MD) properties. Here, we present a detailed study of structural, magnetic, thermodynamic and MD properties of a 6H-perovskite Ba3DyRu2O9. This compound is found to undergo long range antiferromagnetic ordering below ∼5.8 K (T
N), along with the presence of metamagnetic transition at low temperatures. The heat capacity shows two additional anomalies at ∼28 K (T
1) and ∼33 K (T
2), besides the anomaly at T
N. Signature of these anomalies is also visible in the derivative of magnetization curve. The dielectric response also shows weak anomalies around T
1 and T
2 at zero field whereas anomaly at T
2 gets suppressed at 80 kOe. The observed MD coupling of ∼2%–4% at 80 kOe field below ∼30 K temperature range, is among the highest values observed for the compounds of this family. Low temperature crystal structures of the compound show sharp distortion of Ru2O9 octahedra near T
2. Our study points toward the emergence of structurally driven spin correlations of Ru moments resulting in the observed MD coupling in this compound.
Fabrication and optical behavior of AuCuSi amorphous alloy film
Authors: Jia Hao , Xu Tianding , Yao Wang , Cao Qingping , Wang Xiaodong , Jiang Jian-Zhong , Zhang Dongxian
Published: May 2021

Amorphous alloys (AAs) are promising materials due to their unique properties and have been applied in various biomaterial coatings and micro-electro-mechanical systems. However, they have seldom been applied in the optical nano-device. Here, we systematically investigate morphology, microstructure, mechanical and optical properties of an Au–Cu–Si AA and successfully design and fabricate a broadband optical absorber using the Au–Cu–Si AA. Such device achieves an average absorption up to about 95% from 500 to 1500 nm with a thickness less than 300 nm. This is of significance for exploration the feasibility of AAs application in the field of optical nano-devices.
Performance improvements in all-solution processed inverted QLEDs realized by inserting an electron blocking layer
Authors: Zheng Weiye , Song Dandan , Zhao Suling , Qiao Bo , Xu Zheng , Chen Junfei , Liu Guoxu , Shen Chongyu
Published: May 2021

Highly efficient, all-solution processed inverted quantum dot light-emitting diodes (QLEDs) are demonstrated by employing 1,3,5-tri(m-pyrid-3-yl-phenyl)benzene (TmPyPB) layer as electron blocking layer. Electron injection from ZnO electron transport layer to quantum dots (QDs) emission layer (EML) can be adjusted by thickness of TmPyPB layer, enabling the balanced charge carriers in QDs EML. With optimal thickness of this TmPyPB adjuster, 59.7% increment in the device current efficiency (from 8.2 to 13.1 cd A−1) and 46.2% improvement in the maximum luminance (from 31916 to 46674 cd m−2) are achieved, compared with those of the control QLED which has double hole transport layer structure. On the other hand, we find luminescence quenching process, which often happens at the interface of ZnO nanoparticles and QDs, is not obvious in our QLEDs, in which the ZnO layer is fabricated in precursor method, and this conclusion is verified through Time Resolution Photoluminescence test. In a word, this strategy provides a direction for optimizing charge carrier balance in all-solution processed inverted QLED.
Diffraction in time of an entangled non-relativistic quantum particle
Authors: Umul Yusuf Ziya
Published: May 2021

The diffraction process of an entangled non-relativistic quantum particle in time domain is investigated. The scenario consists of two entangled spin-0 particles and a quantum shutter, which is opened at an initial time. The particles are traveling in two opposite sides and expressed with a single wave function. The integral solution of the Schrödinger equation is considered for two particles case. The initial condition is expressed in terms of an entangled wave function. The time-diffracted matter wave is obtained in terms of the Fresnel integral. The effect of the phenomenon of diffraction in time is examined numerically for the entangled system of two particles.
Proposition of a new approach for calculating the efficiency of domestic gas cooking appliances
Authors: Moreira Rosana Medeiros , Oliveira Elcio Cruz de
Published: May 2021

The process of measuring the performance of gas cooking appliances is based on the simple calculation of the arithmetic mean between the results obtained from different burners, without any metrological rigour related to the behavior of the data. This study proposes a new methodology and compares it against the traditional one. The proposed approach evaluates whether data are far apart on the normality, treats outliers and calculates the efficiency from the position measure inversely weighted by the dispersion measure of each burner. For the datasets studied, there may be divergences between the results found for the efficiency calculation when treated by the traditional approach and the proposed approach. However, this study recommends a detailed analysis of the algorithms used, in order to better understand the reason for the divergences found; as well as the implementation of measurement uncertainty calculation, in order to evaluate the partial overlap between specification ranges.
Quality infrastructure and innovation in the Brazilian information technology services: evidence from the National Innovation Survey
Authors: Reis Marcello Carvalho dos , Almeida Maria Fatima Ludovico de
Published: May 2021

The objective of this work is to contribute to the advancement of knowledge about the innovation capacity of information technology service companies in Brazil, with emphasis on the role of the quality infrastructure functions in strengthening this capacity. We have drawn the data from the National Innovation Survey 2014 (Pintec 2014) to answer how the companies in this sector perceive the importance of quality infrastructure functions in their cycles of innovation, to highlight the benefits derived from the existence of such infrastructure in Brazil.
Self-assessment model for testing and calibration laboratories based on ISO/IEC 17025:2017 requirements
Authors: Belezia Luciano Carlos , Almeida Maria Fatima Ludovico de
Published: May 2021

This paper aims to propose a self-assessment model for evaluating the competence, impartiality, and consistent operation of testing and calibration laboratories, based on ISO/IEC 17025:2017 requirements. During the research, an attempt was made to demonstrate the applicability of the proposed model through the development of a case study in one of the Brazilian Navy’s Testing and Calibration Laboratories. The main outcome of this research is an innovative self-assessment model for testing and calibration laboratories, with a view to supporting decisions for achieving accreditation. Notably, the results of the empirical study demonstrate that it is feasible to determine the readiness level of the Navy’s Laboratory in compliance with the requirements of the mentioned standard. Also, they allowed identifying opportunities for improvement of the current management system of the Laboratory.
Hardness Reference Blocks as Certified Reference Materials to be supplied by Inmetro to the Market
Authors: Filho Jorge Trota , Oliveira Sérgio Pinheiro de , Fratari Rômulo Queiroz
Published: May 2021

Reference materials for the Rockwell, Brinell and Vickers hardness scales are fundamental for the Brazilian industrial sector. Mechanical property Hardness is the most common mechanical test used for quality control of raw materials in finished products as well as in research and development of new products and materials. A description of the main findings of two studies and the revalidation of the last on the demand of hardness reference blocks in Brazil is presented. This paper shows national demand of hardness reference blocks could be supplied on a large scale by Inmetro´s Force Laboratory.
Developing virtual instruments in Excel for metrology teaching and training
Authors: Banegas J M , Cámara E , Orué M
Published: May 2021

The use of technology to improve education – either in the classroom or online – is highly positive, making possible to expand the learning experience beyond the classroom or laboratory. In this paper, different technologies are explored focusing in their applicability for metrology training. Then a new approach is proposed, developing different virtual instruments in Excel. This tool allows easy use both for the teacher and the student, is portable between different platforms with a simple file sharing, and is highly applicable to metrology.
The redefined SI and the electromagnetic quantities in detail – part I: current and voltage
Authors: Landim R P , Carvalho H R , de Oliveira V C
Published: May 2021

This paper describes the electromagnetic units after the SI redefinition and the details regarding how they are realized. It is divided into two parts. In this first part, we review the state-of-the art performance, the physical principles, diagrams, electrical circuits, equations and uncertainties of the ampere and volt realizations.
Quantification of Ca, K, Mg, Zn and Fe elements in grape leaves from different regions of Iraq by atomic absorption spectroscopy
Authors: Albakaa A R M , Ameen D S M , Abed N K , Jabbar Z A , Musaa L A
Published: May 2021

Grapes grow in various regions of Iraq, regions have been selected Baqubah, Al Khalesah, Nasiriyah and Sulaymaniyah, to determine the Ca, K, Mg, Zn, and Fe concentrations in their leaves for its nutritional importance using atomic absorption spectroscopy (A.A.S.). Two procedures were used for sample preparation (one of their new) and their accuracy data was evaluated, no significant differences at 97% level of confidence were found by comparison the dataset results for two methods. It has been found that Ca, K, Mg, Zn and Fe metal ion concentration are in the range of (806.9 – 2815.2), (7092.2 – 11058.7), (3708.7 – 5434.8), (17.2 – 30.8) and (114.8 – 3083) μg.g-1, respectively and follow the order K>>Mg>Ca>>Fe>Zn. However, the metal contents in vine leaves from Al Khalesah and Baqubah were relatively high in comparing to those of Sulaymaniyah and Nasiriyah. Fe metal content significantly differs from region to region and the highest concentration was found in grape leaves from Baqubah region (2890.9 – 3083.0 μg.g–1), Nasiriyah (2314.8 - 2331.3 μg.g–1), Al Khalesah (205.7 – 237.2 μg.g–1), while the lowest from Sulaymaniyah (110.9 – 114.8 μg.g-1). Thus, through the variation in the concentration of trophic metals in grape leaves from one region to another and their lack of similarity, irregularity, and incongruence, it can be concluded that the different concentration of elements depends on the quality of the soil, the irrigation water, and the climate and atmosphere (The nature of environment).
Research and application of full electronic control testing technology for chemical flooding in Daqing Oilfield
Authors: Guangle Gao , Haicheng Li , Chongjiang Liu , Lijuan Wang , Meng Cai , Jundong Tang , xingliang Song , Yu Han
Published: May 2021

chemical flooding and separate injection has entered the stage of large-scale popularization and application. With the deepening of development, the number of separate injection wells is increasing year by year, and the test workload is increasing continuously. Because the test and adjustment period of chemical flooding wells is shorter than that of water flooding, the test workload and test pressure are further increased The electric sealing and fishing technology is adopted to realize the electric control direct reading in the whole process of sealing, bailing and adjustment of chemical flooding wells, and the efficiency of measurement and adjustment is further improved. This paper introduces the process principle, technical characteristics and application effect of electric sealing and fishing technology of chemical drive. Fund supported projects: National Science and technology major project 2016zx05054 “Daqing placanticline extra high water cut oilfield EOR demonstration project”.
Application of Particle Swarm Fuzzy-Smith PID in Temperature Control of Bag Filter
Authors: Wei Yuanfang , Cheng Fa , Tang Na , He Xin
Published: May 2021

The temperature control of the bag filter is a non-linear control system with large time lag and too complicated environmental factors. Therefore, building an accurate model is very difficult and thus unable to perform precise control. Currently, fuzzy PID methods are mostly used. However, fuzzy PID relies too much on expert experience. After the parameter value is set, it cannot be adjusted with the change of the input error, and the dynamic performance is poor. In this article, optimizing the scale factors Kp, Ki, Kd and quantization factors Ke, Kec in fuzzy PID control by particle swarm optimization. Besides, smith control aimed to eliminate the effect of time lag and then using MATLAB to verify the effectiveness of the algorithm. Experiments show that particle swarm optimization fuzzy PID has faster response speed, smaller overshoot, and shorter time to reach a steady state.
Research on Automatic Bit Feeding Control System with Constant Weight on Bit Based on Fuzzy Predictive Control
Authors: Liu Guangxing , Zhang Yige , Cao Xilin
Published: May 2021

According to the automatic bit feeding system of oil drilling rig has basic characteristics such as multi-variable, time-varying and nonlinear, an automatic bit feeding control system with constant weight on bit (WOB) based on fuzzy predictive control is proposed. The fuzzy predictive controller of WOB is designed, and the future output of the system is predicted by predictive control, and the output value of the system is close to the given value of WOB as much as possible by fuzzy control. The simulation results show that the response speed of the system is improved, which meets the requirements of small error and high precision, and has a certain guiding significance for the actual design and application.
Interpretation and evaluation of the electrical thickness of 0.2m high-resolution logging series
Authors: Xiuqin Li
Published: May 2021

This article compares and evaluates the electrical thickness interpretation results of the 0.2 m high-resolution logging series and the currently applied DLSII logging series. The author finds that there is no difference in their external thickness electrical measurement interpretations. However, the interpretation thickness and number of layers of the high-resolution logging series with an effective thickness of 0.2 m have increased slightly, and the oil layer group Gaotaizi, which is mainly thin and poor layers, has increased. This conclusion laid a foundation for the promotion and application of the 0.2m high-resolution logging series.
Review of automatic fire water monitor system
Authors: Duan Linfeng , Hou Xinguo
Published: May 2021

The fire protection technology of large space building based on fire water monitor is a research hotspot in the field of fire protection technology. Aiming at the related contents and existing problems of the current fire water monitor research, this paper introduces the working principle and characteristics of the automatic fire water monitor system, and summarizes the research on the fire detection and positioning of the automatic fire water monitor system, the jet trajectory of the fire water monitor and the fire water monitor control system. This paper summarizes the research methods and shortcomings of fire detection positioning, fire water monitor jet trajectory and fire water monitor control system, and puts forward suggestions and prospects.