bluuebunny/crossref_metadata_2025 huggingface dataset:
An efficient and practical aerobic oxidation of benzylic methylenes by recyclable N-hydroxyimide
Authors: Wang Jian , Zhang Cheng , Ye Xiao-Qing , Du Wenting , Zeng Shenxin , Xu Jian-Hong , Yin Hong
Published: January 2021

An efficient and practical benzylic aerobic oxidation catalyzed by cheap and simple N-hydroxyimide organocatalyst has been achieved with high yields and broad substrate scope.
H-USY and H-ZSM-5 zeolites as catalysts for HDPE conversion under a hydrogen reductive atmosphere
Authors: Costa Cátia S. , Muñoz Marta , Ribeiro M. Rosário , Silva João M.
Published: January 2021

This work uses thermogravimetric analysis to investigate the influence of acidity and accessibility in the catalytic conversion of HDPE under hydrogen atmosphere over parent and Ni-based H-USY and H-ZSM-5 zeolites.
Correction: High-capacitance polyurethane ionogels for low-voltage operated organic transistors and pressure sensors
Authors: Tabi Grace Dansoa , Kim Joo Sung , Nketia-Yawson Benjamin , Kim Do Hwan , Noh Yong-Young
Published: January 2021

Correction for ‘High-capacitance polyurethane ionogels for low-voltage operated organic transistors and pressure sensors’ by Grace Dansoa Tabi et al., J. Mater. Chem. C, 2020, 8, 17107–17113, DOI: 10.1039/D0TC02364G.
Temporal modulation of the NF-κB RelA network in response to different types of DNA damage
Authors: Campbell Amy E. , Ferraz Franco Catarina , Su Ling-I , Corbin Emma K. , Perkins Simon , Kalyuzhnyy Anton , Jones Andrew R. , Brownridge Philip J. , Perkins Neil D. , Eyers Claire E.
Published: January 2021

Different types of DNA damage can initiate phosphorylation-mediated signalling cascades that result in stimulus specific pro- or anti-apoptotic cellular responses. Amongst its many roles, the NF-κB transcription factor RelA is central to these DNA damage response pathways. However, we still lack understanding of the co-ordinated signalling mechanisms that permit different DNA damaging agents to induce distinct cellular outcomes through RelA. Here, we use label-free quantitative phosphoproteomics to examine the temporal effects of exposure of U2OS cells to either etoposide (ETO) or hydroxyurea (HU) by monitoring the phosphorylation status of RelA and its protein binding partners. Although few stimulus-specific differences were identified in the constituents of phosphorylated RelA interactome after exposure to these DNA damaging agents, we observed subtle, but significant, changes in their phosphorylation states, as a function of both type and duration of treatment. The DNA double strand break (DSB)-inducing ETO invoked more rapid, sustained responses than HU, with regulated targets primarily involved in transcription, cell division and canonical DSB repair. Kinase substrate prediction of ETO-regulated phosphosites suggest abrogation of CDK and ERK1 signalling, in addition to the known induction of ATM/ATR. In contrast, HU-induced replicative stress mediated temporally dynamic regulation, with phosphorylated RelA binding partners having roles in rRNA/mRNA processing and translational initiation, many of which contained a 14-3-3ε binding motif, and were putative substrates of the dual specificity kinase CLK1. Our data thus point to differential regulation of key cellular processes and the involvement of distinct signalling pathways in modulating DNA damage-specific functions of RelA.
Stable development of travel business in the Odessa region: Estimate using multivariate statistical analysis
Authors: Matskul Valerii , Kovalyov Anatoliy , Chernyshev Valentyn , Okara Diana
Published: January 2021

The article examines the level of sustainable development of the travel business in the Odessa region of Ukraine. This level is evaluated as a latent indicator, which is characterized by a certain set of signs-symptoms. The methodology used for modeling is Partial Least Squares-Path Modelling (or PLS-PM) and the method Time-Wise Multi-Way Principal Component Analysis. This approach allowed us to identify and evaluate latent and explicit factors affecting the sustainable development of travel business in the Odessa region.
Creating efficiency model of higher education institutions
Authors: Janikova Jana
Published: January 2021

The paper deals with assessing the efficiency of the faculties of universities of applied sciences. A model based on Data Envelopment Analysis was created, using specifically the CCR alternative. It is an input-oriented method, assuming the constant returns to scale. The model was subsequently validated on an example of a specific university. The results clearly show that the model was able to determine how and to which extent a given faculty is effective. It also provides the assessor with a tool to manage the efficiency of the faculty, as it is able to identify the causes of possible ineffectiveness. Further research focuses on the model´s applicability in the environment of all universities of applied sciences ideally all over the world.
Chronobiologische Ernährung – wann ist es Zeit zu essen? – Dinner Cancelling oder Breakfast Skipping?
Authors: Stange Rainer
Published: January 2021

Ob eine Kalorie am Morgen einer Kalorie am Abend entspricht, steht derzeit in der Diskussion. Hintergrund istder Zusammenhang zirkadianer Rhythmen mit Ernährungund Stoffwechsel. Frühe Forschungsergebnissehaben gezeigt, dass endokrinologische und thermogenetischeReaktionen auf die Energiezufuhr von der Tageszeitabhängen. Daraus resultierte u. a. die Beobachtung,dass eine Reduktionskost bei Übergewichtigen zugrößeren Gewichtsverlusten führt, wenn der Schwerpunktder Energieaufnahme morgens liegt.Fastenformen wie intermittierendes Fasten, Intervallfastenoder Frühstücksfasten erfreuen sich derzeit großer Beliebtheit, während noch viele Fragen im Sinne der EBM offen sind. Dennoch kann Intervallfasten in der Praxisdem jeweiligen Chronotyp entsprechend unter Beobachtungrelativ einfach dokumentierbarer klinischer Parameter angewendet werden. Erfolge stellen sich beitäglich praktiziertem Intervallfasten meist in 2–3 Wochenein.
Predictors of the Size and Surgical Freedom of the Trans-Cribriform and Trans-Clival Corridors, a Radiographic Analysis
Authors: Aljuboori Zaid , Nuru Mohammed , Sharma Mayur , Andaluz Norberto
Published: January 2021

Introduction The transcribriform and transclival corridors are endoscopic endonasal approaches used to treat pathologies of the skull base. We present a predictive model that uses the clival length and ethmoidal width to predict the size and surgical freedom (SF) of these corridors.

Methods Adult facial computed tomography scans were reviewed. Exclusion criteria included patients <18 years of age or radiographic evidence of trauma, neoplasm, or congenital deformities of the skull base. The images were analyzed using OsiriX MD (Bernex, Switzerland). Patients' demographics, clival length, ethmoidal width, surface area, and others were collected. Linear regression was used to create prediction models for the size and SF of the transclival and transcribriform corridors.

Results A total of 103 patients were included with an average age of 44.9 years and 47% males. Females had a smaller clival surface area (8 vs. 9.2 cm2, p = 0.001). For transclival corridor, clival length correlated positively with SF in the sagittal plane (rho = 0.44, p < 0.05) and negatively with SF in the coronal plane (rho = − 0.2, p < 0.05). For transcribriform corridor, ethmoidal width correlated positively with SF in the coronal plane (rho = 0.74, p < 0.05), and negatively with SF in the sagittal plane (rho = − 0.2, p < 0.05).

Conclusion A significant variability of the bony anatomy of the anterior and central skull base was found. The use of clival length and ethmoidal width as part of preoperative surgical planning might help to overcome the anatomical variability which could affect the adequacy of surgical corridors.
Aggressive Treatment Including Endonasal Surgical Sequestrectomy with Vascularized Nasoseptal Flap Can Improve Outcomes of Skull Base Osteoradionecrosis
Authors: Cho Sung-Woo , Han Sang Y. , Song Yoonjae , Kim Jeong-Whun , Kim Hyun J. , Kim Dong-Young , Rhee Chae-Seo , Bae Yun J. , Kim Ji-hoon , Wu Hong-Gyun , Bang Jae S. , Won Tae-Bin
Published: January 2021

Objective Skull base osteoradionecrosis (SB-ORN) is a serious, potentially lethal complication of radiation therapy. We aimed to review the clinical characteristics and outcomes of SB-ORN according to the extent of treatment.

Design Retrospective analysis design was used for this study.

Setting The study was conducted in two tertiary care hospitals.

Participants Patients included who had been clinically diagnosed with SB-ORN from January 2006 to 2017.

Main Outcome Measures Clinical characteristics, including demographics, predisposing factors, presenting symptoms, radiological findings, treatment modalities, and treatment outcomes, were reviewed. Treatment was classified into conservative and aggressive types. Aggressive treatment included radical surgical removal of soft tissue and bony sequestrum with the placement of vascularized tissue. Treatment outcome was analyzed in terms of clinical control, survival, and carotid artery blow out.

Results Fifteen patients (11 males and 4 females) were identified during the study period. Eight patients were managed conservatively, whereas seven patients were managed with aggressive treatment. The 2-year survival was 75% in the aggressive treatment group and 15% in the conservative group (log-rank, p = 0.049). The estimated 2-year blow out free rate was 46.7% for the conservative group and 100% for the aggressive group (log-rank, p = 0.100).

Conclusion In patients with SB-ORN, aggressive management, including surgical removal of sequestrum and coverage with a pedicled flap, is associated with increased survival.
Between technochauvinism and human-centrism: Can algorithms improve decision-making in democratic politics?
Authors: König Pascal D. , Wenzelburger Georg
Published: January 2021

The promise of algorithmic decision-making (ADM) lies in its capacity to support or replace human decision-making based on a superior ability to solve specific cognitive tasks. Applications have found their way into various domains of decision-making—and even find appeal in the realm of politics. Against the backdrop of widespread dissatisfaction with politicians in established democracies, there are even calls for replacing politicians with machines. Our discipline has hitherto remained surprisingly silent on these issues. The present article argues that it is important to have a clear grasp of when and how ADM is compatible with political decision-making. While algorithms may help decision-makers in the evidence-based selection of policy instruments to achieve pre-defined goals, bringing ADM to the heart of politics, where the guiding goals are set, is dangerous. Democratic politics, we argue, involves a kind of learning that is incompatible with the learning and optimization performed by algorithmic systems.
Electro-thermal co-design of
β
-(AlxGa1-x)2O3/Ga2O3 modulation doped field effect transistors
Authors: Chatterjee Bikramjit , Song Yiwen , Lundh James Spencer , Zhang Yuewei , Xia Zhanbo , Islam Zahabul , Leach Jacob , McGray Craig , Ranga Praneeth , Krishnamoorthy Sriram , Haque Aman , Rajan Siddharth , Choi Sukwon
Published: January 2021

Ultra-wide bandgap β-gallium oxide (Ga2O3) devices are of considerable interest with potential applications in both power electronics and radio frequency devices. However, current Ga2O3 device technologies are limited by the material's low intrinsic electron mobility and thermal conductivity. The former problem can be addressed by employing modulation-doped β-(AlxGa1−x)2O3/Ga2O3 heterostructures in the device architecture. In this work, (AlxGa1−x)2O3/Ga2O3 modulation-doped field effect transistors (MODFETs) have been investigated from a thermal perspective. Thermoreflectance thermal imaging was used to characterize the self-heating of the MODFETs. The (Al0.18Ga0.82)2O3 thermal conductivity (3.1–3.6 W/mK) was determined using a frequency domain thermoreflectance technique. Electro-thermal modeling was used to discern the effect of design parameters such as substrate orientation and channel length on the device self-heating behavior. Various thermal management schemes were evaluated using the electro-thermal device model. From an electro-thermal co-design perspective, the improvement in electrical performance followed by the mitigation of self-heating was also studied. For example, by employing a Ga2O3-on-SiC composite wafer, which was fabricated in this work, a 50% increase in power handling capability can be achieved as compared to a homoepitaxial device. Furthermore, flip-chip heterointegration and double-sided cooling approaches can lead to more than 2× improvement in the power handling capability. Using an augmented double-sided cooling design that includes nanocrystalline diamond passivation, a 5× improvement in the power handling capability can be accomplished, indicating the potential of the technology upon implementation of a suitable thermal management scheme.
Interdiffusion reliability and resistivity scaling of intermetallic compounds as advanced interconnect materials
Authors: Chen Linghan , Kumar Sushant , Yahagi Masataka , Ando Daisuke , Sutou Yuji , Gall Daniel , Sundararaman Ravishankar , Koike Junichi
Published: January 2021

Intermetallic compounds have been proposed as potential interconnect materials for advanced semiconductor devices. This study reports the interdiffusion reliability and resistivity scaling of three low-resistivity intermetallic compounds (Cu2Mg, CuAl2, and NiAl) formed on thermally grown SiO2. Experimental observations and thermodynamic calculations indicated good interdiffusion reliability with CuAl2 and NiAl but not with Cu2Mg. This was due to slow reaction between Al and SiO2 in conjunction with strong chemical bonds of Cu–Al and Ni–Al. As for resistivity scaling, all three intermetallic compounds showed better resistivity scalability than Cu. Resistivity of the thin films was measured and characteristic parameters were obtained by curve fitting using a classical scattering model. First-principles calculations were carried out to determine the electron mean free path and bulk resistivity in order to explain the resistivity scaling. The results showed the importance of having optimum microstructure features, i.e., low-defect-density surface, interface, and grain boundaries in addition to optimum material properties, i.e., a short mean free path and low bulk resistivity. CuAl2 and NiAl appeared to satisfy the interdiffusion and resistivity conditions and be promising candidates to replace Cu interconnections for future devices.
Acoustic subsurface-atomic force microscopy: Three-dimensional imaging at the nanoscale
Authors: Sharahi Hossein J. , Janmaleki Mohsen , Tetard Laurene , Kim Seonghwan , Sadeghian Hamed , Verbiest Gerard J.
Published: January 2021

The development of acoustic subsurface atomic force microscopy, which promises three-dimensional imaging with single-digit nanometer resolution by the introduction of ultrasound actuations to a conventional atomic force microscope, has come a long way since its inception in the early 1990s. Recent advances provide a quantitative understanding of the different experimentally observed contrast mechanisms, which paves the way for future applications. In this Perspective, we first review the different subsurface atomic force microscope modalities: ultrasonic force microscopy, atomic force acoustic microscopy, heterodyne force microscopy, mode-synthesizing atomic force microscopy, and near-field picosecond ultrasonic microscopy. Then, we highlight and resolve a debate existing in the literature on the importance of the chosen ultrasound excitation frequencies with respect to the resonance frequencies of the cantilever and the observed contrast mechanisms. Finally, we discuss remaining open problems in the field and motivate the importance of new actuators, near-field picosecond ultrasonics, and integration with other techniques to achieve multi-functional non-destructive three-dimensional imaging at the nanoscale.
Leakage current reduction in n-GaN/p-Si (100) heterojunction solar cells
Authors: Saron K. M. A. , Ibrahim M. , Hashim M. R. , Taha T. A. , Elfadill Nezar G. , Mkawi E. M. , Allam Nageh K.
Published: January 2021

We report on the growth of n-GaN/p-Si heterojunction solar cells via thermal chemical vapor deposition on Si (100) substrates at different growth temperatures (900, 950, and 1000 °C). The influence of growth temperature on the morphological, structural, optical, and electrical properties of GaN films has been elucidated. Increasing the growth temperature was found to reduce the internal stress and improve the material's crystallinity as confirmed via x-ray diffraction and Raman spectroscopy analyses. The photoluminescence spectra exhibit strong near band edge peaks in the range between 375 and 366 nm, with the peak intensity increasing with increasing the growth temperature. The current–voltage (J–V) characteristics of the assembled heterojunction solar cells showed the reverse leakage current to decrease with increasing the growth temperature. Consequently, the solar cell fabricated using the films grown at 1000 °C exhibits higher conversion efficiency (8.17%) than those grown at 950 °C (5.15%) and 900 °C (2.48%), respectively. This work shows that the structural, optical, and photovoltaic properties of the grown n-GaN/p-Si heterojunction solar cell structures are strongly influenced by the growth temperature.
Article Commentary: Confronting COVID, Racism, and Addiction: The Association of Multidisciplinary Education and Research in Substance use and Addiction (AMERSA)
Authors: Mountain-Ray Shannon , Finnell Deborah , Roy Payel , Northup Rebecca , MacLane-Baeder Doreen
Published: January 2021

The COVID-19 pandemic, the ongoing opioid epidemic, rise in substance use, and social and political unrest in the US and globally has impacted how substance use-related health needs are addressed. These issues were driving forces in planning AMERSA's 44th annual conference. True to the multidisciplinary spirit, and with diversity goals and advocacy at the forefront of mind, “together we rise” became the beacon for the AMERSA 2020 conference. This commentary provides an overview of the conference proceedings, topics that were highly relevant for clinicians, educators, researcher, and advocates for change. Abstracts of paper and poster presentations are also provided (Supplemental Material).
Small noncoding vault RNA modulates synapse formation by amplifying MAPK signaling
Authors: Wakatsuki Shuji , Takahashi Yoko , Shibata Megumi , Adachi Naoki , Numakawa Tadahiro , Kunugi Hiroshi , Araki Toshiyuki
Published: January 2021

The small noncoding vault RNA (vtRNA) is a component of the vault complex, a ribonucleoprotein complex found in most eukaryotes. Emerging evidence suggests that vtRNAs may be involved in the regulation of a variety of cellular functions when unassociated with the vault complex. Here, we demonstrate a novel role for vtRNA in synaptogenesis. Using an in vitro synapse formation model, we show that murine vtRNA (mvtRNA) promotes synapse formation by modulating the MAPK signaling pathway. mvtRNA is transported to the distal region of neurites as part of the vault complex. Interestingly, mvtRNA is released from the vault complex in the neurite by a mitotic kinase Aurora-A–dependent phosphorylation of MVP, a major protein component of the vault complex. mvtRNA binds to and activates MEK1 and thereby enhances MEK1-mediated ERK activation in neurites. These results suggest the existence of a regulatory mechanism of the MAPK signaling pathway by vtRNAs as a new molecular basis for synapse formation.
An Arf/Rab cascade controls the growth and invasiveness of glioblastoma
Authors: Kulasekaran Gopinath , Chaineau Mathilde , Piscopo Valerio Emilio Crescenzo , Verginelli Federica , Fotouhi Maryam , Girard Martine , Tang Yeman , Dali Rola , Lo Rita , Stifani Stefano , McPherson Peter S.
Published: January 2021

Glioblastoma is the most common and deadly malignant brain cancer. We now demonstrate that loss of function of the endosomal GTPase Rab35 in human brain tumor initiating cells (BTICs) increases glioblastoma growth and decreases animal survival following BTIC implantation in mouse brains. Mechanistically, we identify that the GTPase Arf5 interacts with the guanine nucleotide exchange factor (GEF) for Rab35, DENND1/connecdenn, and allosterically enhances its GEF activity toward Rab35. Knockdown of either Rab35 or Arf5 increases cell migration, invasiveness, and self-renewal in culture and enhances the growth and invasiveness of BTIC-initiated brain tumors in mice. RNAseq of the tumors reveals up-regulation of the tumor-promoting transcription factor SPOCD1, and disruption of the Arf5/Rab35 axis in glioblastoma cells leads to strong activation of the epidermal growth factor receptor, with resulting enhancement of SPOCD1 levels. These discoveries reveal an unexpected cascade between an Arf and a Rab and indicate a role for the cascade, and thus endosomal trafficking, in brain tumors.
Low cost technology for the fabrication of anti-counterfeiting microtaggants
Authors: Tomescu Roxana , Parvulescu Catalin , Cristea Dana , Comanescu Brandus , Pelteacu Mihaela
Published: January 2021

One of the most important responsibility of manufacturers is to protect their products against counterfeiting. Currently there are a large variety of protection methods based on security tags that can be attached to the products such as holographic labels, nanoparticles, encrypted messages, barcodes etc. The research in this area focuses on the possibility of adding extra security elements (ex: nanoparticles) or complicating the designs of the classical holographic labels. Here we present a simple and low-cost technology for the fabrication of metal microtaggants with different types of security elements engraved, such as holographic background with different visual effects and micro-texts, and etched alphanumerical elements. The main advantages of these structures are the possibility to combine different types of security elements and the relatively small dimension, in the hundreds of micrometres range, making them significantly hard to identify with the naked eye. Our structures can be incorporated into paints, inks, paper, or simply attached on the surface of the product.
Rectifying and spin filtering behavior of aluminum doped silicon carbide nanoribbons: the first principles study
Authors: Rahmani-Ivriq Nasim , Ahmadkhan Kordbacheh Amirhossein
Published: January 2021

In this paper, spin transport properties of aluminum-doped zigzag silicon carbide nanoribbons (Al-ZSiC NRs) are investigated using the first-principle calculations and the nonequilibrium Green’s function method. The results show an approximately perfect spin filtering (100%) for three considered models and undoped structure at ferromagnetic state in the presence of bias voltage. In particular, a weak negative differential resistance (NDR) phenomenon can be obtained in a certain system when replacing the edge Si atom with the Al-doping atom. Indeed, edge states play a crucial role in spin-dependent transport and magnetic properties of ZSiC NRs, such as the NDR effect. Furthermore, the significant rectifying ratio (RR) is obtained under bias voltage only for one given configuration. When the same spin states overlap in the bias window (BW), spin-dependent transmission and the spin current display a non-zero value; however, the mismatch of the same spin states within the BW region causes to vanish the transmission spectra. The controllable manipulation of threshold voltage, spin filtering efficiency, NDR behavior, and RR effect can be achieved by substituting of silicon with Al atom in ZSiC NRs. These results shed new light on our understanding of silicon carbide-based nanodevices with appealing spintronic applications.
Resonance phase and geometric phase integrated diffusion metasurface for broadband scattering control
Authors: Ying-Jie Wang , Ke Chen , Fang-Kun Zhou , Jiang-Xiao Tian , Yu-Feng Fu , Ping Chen
Published: January 2021

In this paper, we demonstrate a binary diffusion metasurface with a broadband radar cross section (RCS) reduction performance based on the integration of resonance and geometric phase manipulation. The working principle of such a metasurface was investigated and the general criterion for the electromagnetic (EM) responses of the meta-atom was derived. In particular, we deployed a split metallic ellipse ring with a beam along the short axis and its counterpart with a 90° inclined angle as the binary elements to construct the diffusion metasurface. EM responses of the proposed anisotropic meta-atom were explored in the framework of the equivalent circuit model. The inherent resonance phases of the meta-atom along its two symmetric axes were adjusted by changing its structural parameters. Then, we integrated the manipulation of the resonance phase and geometric phase together and designed a metasurface that can achieve broadband specular RCS reduction (more than −10 dB) from 4.3 GHz to 16.5 GHz. The RCS reduction performance of the metasurface is polarization-independent and shows a certain degree of stability under oblique incidence. For verification, a prototype with optimized structural parameters was fabricated and the measured results coincide well with the simulated results. Our work provides a convenient approach to realize a binary diffusion metasurface for the purpose of broadband RCS reduction.
Self-powered and temperature-tunable infrared-visible photodetector based on a VO2/Si heterojunction
Authors: Hassan Zamir Ul , Siddique Razwan , Sajjad Syeda Amna , Umer Zeshan Adeel , Bukhari Shujaht , Anwar-Ul-Haq Muhammad , Rafique Mohsin , Raza Syed Raza Ali
Published: January 2021

In this work, a type-III heterojunction based on a pulsed-laser-deposited vanadium dioxide (VO2) and p-type silicon (p-Si) substrate is realized. The device shows a large self-powered and room-temperature photoresponse to IR (950 nm), green (515 nm) and blue (456 nm) LEDs. A short-circuit current (I
sc) of ∼3 µA and an open-circuit voltage (V
oc) of ∼−120 mV are observed under IR LED illumination. The work function data in literature along with the sign of V
oc measurement is used to sketch the energy band diagram of the heterojunction. The temperature-dependent I
sc properties of the junction, contrary to conventional photodetectors, show an initial rise and then a sharp transition from maximum (3.5 μA) to almost zero near 337 K, corresponding to a metal–insulator phase transition, paving the way for photodetectors with temperature-tunable photoresponsivity.
Effect of nanoparticle shape on therapeutic temperature distribution during magnetic hyperthermia
Authors: Tang Yundong , Flesch Rodolfo C C , Jin Tao , Gao Yueming , He Minhua
Published: January 2021

Treatment temperature distribution is a crucial factor for magnetic hyperthermia, since it directly determines the treatment effect related to the apoptosis situation of malignant cells. The shape of magnetic nanoparticles (MNPs) is one of many factors that can affect the treatment temperature during therapy. This paper conducts a comparative study on three different shapes of MNPs by considering the effective area percentage of treatment temperature distribution. The treatment temperature for a proposed model is predicted by solving bio-heat transfer equations, which take the power dissipation of MNPs as the input and consider a temperature-dependent blood perfusion rate in these equations at the same time. The simulation results demonstrate that the treatment temperature distribution can be effectively improved when the temperature-dependent blood perfusion rate is used for the simulation with respect to a constant case. In addition, the MNPs with higher regular shape can lead to a better result than a lower case in the treatment temperature distribution when the same condition is considered for therapy.
All-MOCVD-grown gallium nitride diodes with ultra-low resistance tunnel junctions
Authors: Hasan Syed M N , Gunning Brendan P , J.-Eddine Zane , Chandrasekar Hareesh , Crawford Mary H , Armstrong Andrew , Rajan Siddharth , Arafin Shamsul
Published: January 2021

We carefully investigate three important effects including postgrowth activation annealing, delta (δ) dose and magnesium (Mg) buildup delay as well as experimentally demonstrate their influence on the electrical properties of GaN homojunction p–n diodes with a tunnel junction (TJ). The diodes were monolithically grown by metalorganic chemical vapor deposition (MOCVD) in a single growth step. By optimizing the annealing parameters for Mg activation, δ-dose for both donors and acceptors at TJ interfaces, and p
+-GaN layer thickness, a significant improvement in tunneling properties is achieved. For the TJs embedded within the continuously-grown, all-MOCVD GaN diode structures, ultra-low voltage penalties of 158 mV and 490 mV are obtained at current densities of 20 A cm−2 and 100 A cm−2, respectively. The diodes with the engineered TJs show a record-low differential resistivity of 1.6 × 10−4 Ω cm2 at 5 kA cm−2.
MoSi2N4 single-layer: a novel two-dimensional material with outstanding mechanical, thermal, electronic and optical properties
Authors: Bafekry A , Faraji M , Hoat D M , Shahrokhi M , Fadlallah M M , Shojaei F , Feghhi S A H , Ghergherehchi M , Gogova D
Published: January 2021

Very recently, the 2D form of MoSi2N4 has been successfully fabricated (Hong et al 2020 Science
369 670). Motivated by these recent experimental results, we investigate the structural, mechanical, thermal, electronic and optical properties of the MoSi2N4 monolayer. The mechanical study confirms the stability of the MoSi2N4 monolayer. The Young’s modulus decreases by ∼30%, while the Poisson’s ratio increases by ∼30% compared to the corresponding values of graphene. In addition, the MoSi2N4 monolayer’s work function is very similar to that of phosphorene and MoS2 monolayers. The electronic structure shows that the MoSi2N4 monolayer is an indirect semiconductor with a band gaps of 1.79 (2.35) eV using the GGA (HSE06) functional. The thermoelectric performance of the MoSi2N4 monolayer has been revealed and a figure of merit slightly larger than unity at high temperatures is calculated. The optical analysis shows that the first absorption peak for in-plane polarization is located in the visible range of the spectrum, therefore, the MoSi2N4 monolayer is a promising candidate for advanced optoelectronic nanodevices. In summary, the fascinating MoSi2N4 monoloayer is a promising 2D material for many applications due to its unique physical properties.
Pulsed laser ablation of binary compounds: effect of time delay in component evaporation on ablation plume expansion
Authors: Morozov A A , Starinskiy S V , Bulgakov A V
Published: January 2021

Pulsed laser ablation of compound materials often occurs with delayed evaporation of a less volatile component; however, the effect of the delay on ablation plume expansion remains virtually unexplored. Here, we have performed an experimental and theoretical study of the delayed evaporation effect using an example of a plume produced by nanosecond laser ablation of a gold–silver alloy in a vacuum and comparing it with ablation of pure gold and silver targets. The plume expansion dynamics are investigated by time-of-flight (TOF) mass spectrometry and direct simulation Monte Carlo (DSMC), while the laser-induced target evaporation is analyzed using a thermal model. A dramatic effect of the delay time on the average kinetic energy of the plume particles, especially for the less volatile gold, is demonstrated and the main collisional processes governing the two-component plume expansion under the conditions of delayed evaporation are revealed. Based on comparison of experimental and DSMC data, the delay of the gold evaporation onset is estimated as approximately 0.6 ns. The delayed evaporation is therefore an important factor for correct interpretation of TOF measurements in ablation plumes with components of different volatilities.
Ternary flower-sphere-like MnO2-graphite/reduced graphene oxide nanocomposites for supercapacitor
Authors: Yao Jun , Jia Yongfeng , Han Qingli , Yang Daotong , Pan Qingjiang , Yao Shanshan , Li Jiuming , Duan Limei , Liu Jinghai
Published: January 2021

Chemical fabrication of a nanocomposite structure for electrode materials to regulate the ion diffusion channels and charge transfer resistances and Faradaic active sites is a versatile strategy towards building a high-performance supercapacitor. Here, a new ternary flower-sphere-like nanocomposite MnO2-graphite (MG)/reduced graphene oxide (RGO) was designed using the RGO as a coating for the MG. MnO2-graphite (MnO2-4) was obtained by KMnO4 oxidizing the pretreated graphite in an acidic medium (pH = 4). The GO coating was finally reduced by the NaBH4 to prepare the ternary nanocomposite MG. The microstructures and pore sizes were investigated by x-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and nitrogen adsorption/desorption. The electrochemical properties of MG were systematically investigated by the cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy in Na2SO4 solution. The MG as an electrode material for supercapacitor exhibits a specific capacitance of 478.2 and 454.6 F g−1 at a current density of 1.0 and 10.0 A g−1, respectively. In addition, the capacitance retention was 90% after 8,000 cycles. The ternary nanocomposite enhanced electrochemical performance originates from the specific flower-sphere-like morphology and coating architecture bringing higher specific surface area and lower charge transfer resistance (Rct).
Valley manipulation in monolayer transition metal dichalcogenides and their hybrid systems: status and challenges
Authors: Zhao Siwen , Li Xiaoxi , Dong Baojuan , Wang Huide , Wang Hanwen , Zhang Yupeng , Han Zheng , Zhang Han
Published: January 2021

Recently, the emerging conceptual valley-related devices have attracted much attention due to the progress on generating, controlling, and detecting the valley degree of freedom in the transition metal dichalcogenide (TMD) monolayers. In general, it is known that achieving valley degree of freedom with long valley lifetime is crucial in the implementation of valleytronic devices. Here, we provide a brief introduction of the basic understandings of valley degree of freedom. We as well review the recent experimental advancement in the modulation of valley degree of freedom. The strategies include optical/magnetic/electric field tuning, moiré patterns, plasmonic metasurface, defects and strain engineering. In addition, we summarize the corresponding mechanisms, which can help to obtain large degree of polarization and long valley lifetimes in monolayer TMDs. Based on these methods, two-dimensional valley-optoelectronic systems based on TMD heterostructures can be constructed, providing opportunities for such as the new paradigm in data processing and transmission. Challenges and perspectives on the development of valleytronics are highlighted as well.
Substantial reduction of the anisotropy in the critical current densities J
c of Ni-doped CaKFe4As4 single crystals by chemical and irradiation-induced disorder
Authors: Haberkorn N , Xu M , Meier W R , Schmidt J , Suárez S , Bud’ko S L , Canfield P C
Published: January 2021

We demonstrate that the anisotropy in the critical current densities, J
c, of CaK(Fe1−x
Ni
x
)4As4 (x = 0, 0.015, 0.025, and 0.030) single crystals reduces with increasing chemical and irradiation-induced disorder. The magnetic field dependences of J
c are analyzed by performing magnetization measurements with H applied parallel and perpendicular to the crystallographic c-axis. The results show that undoped crystals display large anisotropies in J
c due to an enhancement of the vortex pinning with H applied parallel to the crystallographic ab-planes. This anisotropy reduces substantially as Ni addition increases. Moreover, we found that random disorder introduced by proton irradiation enhances mainly the vortex pinning for H parallel to the c-axis. Consequently, using adequate fluencies, the vortex pinning at low temperatures in both undoped and doped samples becomes close to isotropic. These results make the CaKFe4As4 system promising for applications that require isotropic J
c under magnetic fields.
Modeling study on high-temperature superconducting bulk’s growth anisotropy effect on magnetization and levitation properties in applied magnetic fields
Authors: Zheng Jun , Chen Nan , Zhang Weifeng , Deng Zigang
Published: January 2021

Fabricated by top-seeded melt-texture methods, high-temperature superconducting (HTS) bulk, such as YBaCuO bulk exhibits anisotropic properties of the critical current density J
c spatial distribution in growth sector regions and growth sector boundaries (GSBs). It was found that the YBaCuO bulk arrangement optimization considering the J
c spatial distribution above a permanent magnet guideway (PMG) enhances the levitation performance of the HTS magnetic levitation (maglev) system according to the past experiments. Therefore, from the point of view of practical applications, a theoretical model describing this HTS growth anisotropy is required to reproduce its effect on HTS maglev properties. In this study, we proposed an updated J
c spatial function with an adjustment parameter to better describe HTS bulk’s growth anisotropy. Its Cartesian form is suitable for differently shaped bulk superconductors. We subsequently established a 3D simulation model of an HTS–PMG maglev system and completed the calculations of both the levitation force and decay of two different bulk arrangements above the PMG. The calculation results are consistent with the experimental results, which verifies the reliability of the 3D HTS–PMG maglev model and J
c spatial function. Further, all results show that a more stable HTS levitation with a larger levitation force is generated in the case where the GSB is aligned with the longitudinal direction of the PMG’s largest magnetic field. This provides a reference for HTS maglev designs. Furthermore, the modeling can be a useful tool for optimizing the HTS–PMG maglev system for several scenarios.
Spectral red-shift of solid high-order harmonic generation combining a fundamental field and a terahertz field
Authors: Pan Xue-Fei , Li Bo , Huo Xiao-Xin , Zhang Jun , Liu Xue-Shen
Published: January 2021

High-order harmonic generation (HHG) from a solid by combining a fundamental field and a terahertz field is investigated by solving the time-dependent Schrödinger equation. The numerical results illustrate that the red-shift from odd harmonics is more obvious in the combined field than the fundamental field. We have also investigated solid HHG with different relative phases. We find that the HHG spectra exhibit a larger red-shift from odd harmonics for the relative phase φ = 0 and the red-shift from odd harmonics is gradually weakened by increasing the relative phase. For the relative phase φ = π, the red-shift of solid HHG disappears and only odd harmonic order can be observed. The time-dependent population imaging picture is used to illustrate the physical mechanism of the red-shift in solid HHG.
Vector soliton generation from a compact all-polarization-maintaining fiber laser
Authors: Wu Zhichao , Zhan Bingye , Li Lu , Huang Tianye , Wei Qian , Zhang Dazhong , Shum Perry Ping
Published: January 2021

We investigate polarization-locked vector solitons (PLVSs) arising in an all-polarization-maintaining (PM) soliton fiber laser mode-locked by a carbon nanotube. The laser can operate stably in both Q-switched and mode-locked states with different pump power. Under the PLVS condition, we observe a string of peak-dip-pair sidebands after polarization-resolving measurement, indicating the strong and regular energy exchange between the two polarized orthogonal components, which evidently distinguishes this all-PM fiber laser from conventional single-mode fiber-based vector cavities. By dispersion compensating, vector dissipative solitons are also successfully obtained. The cavity structure is greatly simplified and stabilized by a hybrid fiber component and shows excellent long-term stability.
Pozzolanic Properties of Agro Waste Ashes for Potential Cement Replacement Predicted using ANN
Authors: Manikanta C , Manikandan P , Duraimurugan S , Elavenil S , Vasugi V
Published: January 2021

Every year, cement demand increases due to infrastructural development in our country, which indirectly increases global warming since the manufacturing of Portland cement emits a large volume of carbon dioxide into the atmosphere. Hence, the demand of using Portland cement should be reduced by using various types of mineral admixtures as a replacement to Cement. In India, every year agricultural sector produces a large volume of waste by-products like corncob, rice husk, sugarcane bagasse, bamboo leaves etc., which could be burnt in a controlled environment and the resulted ashes could be used as partial replacement to Cement. The pozzolanic activity of agro-waste ashes like rice husk ash, cocoa fruit shell ash, corncob ash, bamboo leaves ash, sugarcane bagasse ash have been tested and compared using the strength activity test, the saturated lime test and the Frattini test with the implementation of Artificial Intelligence using Neural Network was carried out. It is observed that Rice husk ash, corncob ash, bamboo leaf ash, sugar cane bagasse ash have the potential to be replaced for Cement while cocoa fruit shell ash does not have the expected pozzolanic activity. The predicted pozzolanic strength property of the different agro-waste ashes with the utilization of Artificial Neural Network was observed to correspond with experimental values.
Remaining useful life estimation of a Product
Authors: Murali Krishna K , Janardhan Reddy Dr K
Published: January 2021

A sudden failure of a product or a component may result in loss of valuable data or interruption in the task being carried out. In order to eliminate these kind of scenarios and to avoid unnecessary investments on the used products, the remaining life need to be predicted/estimated. In this work, a comprehensive two-phase approach is proposed. In the first stage phase, statistically analyzing the behavior of components for reuse, a well-known reliability assessment method, the Weibull analysis, is applied to the time-to-failure data to assess the mean life of components. In the second phase, the degradation and condition monitoring data are analyzed by developing an Artificial Neural Network model (ANN model). This project is aimed on estimating the remaining useful life of washing machine and LED bulb
Restricted Ridge Regression estimator as a parameter estimation in multiple linear regression model for multicollinearity case
Authors: Rumere F A O , Soemartojo S M , Widyaningsih Y
Published: January 2021

Multiple Linear Regression analysis is one of the techniques in statistics that is used to analyse the relationship between a dependent variable and two or more independent (regressor) variables. Ordinary Least Square method is commonly used to estimate the parameters. Most frequently occurring problem in multiple linear regression analysis is the presence of multicollinearity. Multicollinearity in the least square estimation produces estimation with a large variance, so another method is needed to overcome the multicollinearity. The method is called ridge regression. In this method, a constant bias ridgekis added toX′Xmatrix. A study had developed the method by using the prior information of the parameter β and introduced the Restricted Ridge Regression method. Prior information of the parameter β was defined as a non-sample information arising from past experiences and the opinions of an expert with similar situations and containing the same parameters β. This study explains the use of Restricted Ridge Regression method in overcoming the multicollinearity in regression model. Based on an application on a data set, β of Restricted Ridge Regression has smallest mean square error (MSE) than β of Ordinary Least Square.
Predicting readmission risk after coronary artery bypass graft surgery using logistic regression model
Authors: Febriani V , Lestari D , Mardiyati S , Devila S
Published: January 2021

Coronary Artery Bypass Graft (CABG) post-operative readmission has a high incidence rate compared to other health cases. This particular case contributes to an increase in morbidity and hospital costs of patients. Therefore, an appropriate prediction model is needed while the model can be beneficial to the health financing institutions. There are many risk factors that will be used to predict CABG post-operative readmission. Of the many risk factors observed, some factors that have a significant influence on construction the Logistic Regression model will be determined. This model is developed to generate probabilities which are then called Created Readmission Risk Scores (CRRS).
Odd graceful labeling on the Ilalang graph (Sn
, 3) it’s variation
Authors: Amri Z , Irvan I , Maryanti I , Sumardi H
Published: January 2021

A graph called odd graceful graph if there is an injective mapping f:V(G) → {0,1,2,…,2q − 1} such that for each edge xy 6 E(G) labeled by |f(u) − f(v)|, and the results willform a label on the edge {1,3,5, …,2q − 1} which is bijective. Variabel q is the number of edges. This paper purpose is to construct the formula of odd graceful labelling on the ilalang graph (Sn
, 3) and it’s variation.
The relation between prior knowledge and students’ mathematics reflective thinking ability
Authors: Muntazhimah M , Turmudi T , Prabawanto S
Published: January 2021

The reflective thinking ability is one of the higher order thinking skills (HOTS), and mathematics reflective thinking is one of the abilities needed in learning mathematics. This study aims to reveal the relation between prior knowledge and mathematics reflective thinking ability which studied by quantitative method. Data collection used instruments of mathematics reflective thinking test. Samples in this study were students of class VIII at junior high school. The results showed that there was a positive relation between prior knowledge and students’ mathematics reflective thinking ability with the correlation coefficient 0.49. The regression equation shows that each addition of one prior knowledge score was followed by change in increase in students’ mathematics reflective thinking ability by 0.5539. It can be concluded that the prerequisite material as a prior knowledge must be thoroughly learned so as to have a large contribution to the success of learning further material.
Development of learning device oriented problem based learning to improve student’s mathematical problem solving skill
Authors: Siagian T A , Armanto D , Siagian P
Published: January 2021

This research study is research and development learning devices. The purpose of this study were: 1) Developed problem-based on learning tools with criteria are valid, practical, and effective; 2) Described the improvement of mathematical problem solving skills of student using learning device based on problem based learning developed. Learning device development using 4-D model which developed by Thiagarajan, Semmel and Semmel, was done in two stages: 1) the development of learning devices; and 2) testing devices. The subject in this study were students of class X SMAN 1 Pematangsiantar, while the objects is the PBL developed, mathematical problem solving skill students. The results were obtained: 1) The learning devices based on PBL that developed have valid criteria, practical and effective; 2) There is an increased ability of mathematical problem solving skill of student using learning device based PBL developed.