bluuebunny/crossref_metadata_2025 huggingface dataset:
Deming’s Quality Management Practices by Small Businesses in Rural Areas
Authors: Rabiatul Adawiyah Wiwiek , Agus Pramuka Bambang , Sholikhah Zahrotush
Published: November 2020

Deming’s Philosophy is a famous thought among Quality Management scholars and practitioner. The theory consists of 14 principles providing guidelines for appropriate firms’ quality behavior and practices. Deming proposes that an organization shall experience high-quality service by lowering non-value added activities, such as scrap, rework, and conflicts, while increasing customers’ loyalty. There is an overwhelming allegation on the apparent effect of Deming’s theory on quality management theory and practices worldwide, mostly in larger organizations of developed countries. Few studies have discussed the relevance of Deming theories in small business management practices in developing countries. Moreover, there is a stigma among small business practitioners that all western originated management theories are less applicable in their context. At the same time, the currently available literature on Deming management methods is mostly a description of the 14 points. This study aims at elaborating the small businesses owners’/ managers’ understanding of Deming’s fourteen points. The rising numbers of Small Medium Enterprises in Indonesia is a positive sign of local economic development in the Industrial revolution 4.0. To remain competitive, SMEs are forced to be a quality focus and consistently innovate. The sample of the study was 335 SMEs’ owners/ managers in Banyumas Central Java, Indonesia. Authors used descriptive statistics to analyze the data — results based on descriptive analysis. The result of the study confirmed the practics of Deming’s theory among SMEs in Indonesia. Majority of respondents had a good understanding of the theory and felt the benefits of the theory while adopting it.
Problematic of Local Head Regulation As a Local Law Products in The Framework of National Legal Development
Authors: Aziz Nasihuddin Abdul , Sudrajat Tedi , Handayani Sri Wahyu
Published: November 2020

In Indonesia, the main discusssion in the dynamics of local autonomy is the establishment of local law product after the discussion of general elections. How come? Article 18 paragraph (6) of the 1945 Constitution regulates that in the framework of implementing autonomy and co-administration duties, the local Government has the right to stipulate local regulations and other regulations. Practically, other regulations can be form as local head regulation and many kind of legal policy which made by head of local government. It can be imagined, how many local law products were established in one year in 34 provinces and 265 cities/regency. In this perspective, it is important to raises the object of Local Head Regulations as a miniature of government duties as a derivative of the Local Regulation. The problems which arrise is what is the position of local head regulation in the national legal development. This paper was conduct by doctrinal approach. The specifications which used is descriptive analysis by inventorying and identifying problems that related to harmonization and synchronization of local law products based on Law Number 12 Year 2011 concerning the Establishment of Regulations and Law Number 23 Year 2014 concerning Local Government. Analysing method is normative qualitative by using gramatical and systematic interpretation.In this study, it was found that local head regulation is a part of local law products in the form of legal policy which called as beleidregels. Based on that form, if there any substantive problems from the legal policy so it could not be tested in the legal procedure because the legal policy was made based by the freedom of government. Thats why the government should create an alternative solution to solve the substantive problems from the local head regulation as a legal policy.
Traditional Transport Tools as Supporters of the Regional Economy through Tourism and Culture Activities
Authors: Gultom E R
Published: November 2020

Some regions in Indonesia such as West Sumatra, Yogyakarta, Jakarta and other regions, often found traditional Bendi transportation which is used to transport people or goods from one place to the agreed destination. Apart from functioning as a public transportation tool, Bendi also has an important role in tourism, which is used around to transport tourists both from within and outside the country. The activity carried out by Bendi can increase the income of the local people who use Bendi as a regional tourism promotion tool. How is the existence of a Traditional Transport Tool in the midst of modern transportation in Indonesia?; How is this traditional Bendi transport regulated in Indonesia’s national regulations? and What is the support of traditional Bendi transportation for regional economic development where its position is as a means of transportation? Is the subject matter in writing this paper. The research method used is normative, using secondary data and primary data as supporters, through interviews with some observers of traditional transport equipment. Then it will be analyzed descriptively. The conclusion obtained is that in a certain area, there are provisions for regional regulations that regulate the existence of these Bendi traditional transportation equipment, such as in the Yogyakarta area. Traditional Bendi transportation support as a supporter of the regional economy through tourism activities is very large, such as those found in the Yogyakarta area, where Bendi is always there to surround tourist areas that deliver domestic and foreign tourists in visiting tourist areas, as well as in West Sumatra, Padang, Bendi still exists even though it is rare, but it is still used as a tourism and cultural transport tool.
An integrated data-driven solar wind – CME numerical framework for space weather forecasting
Authors: Narechania Nishant M. , Nikolić Ljubomir , Freret Lucie , De Sterck Hans , Groth Clinton P. T.
Published: November 2020

The development of numerical models and tools which have operational space weather potential is an increasingly important area of research. This study presents recent Canadian efforts toward the development of a numerical framework for Sun-to-Earth simulations of solar wind disturbances. This modular three-dimensional (3D) simulation framework is based on a semi-empirical data-driven approach to describe the solar corona and an MHD-based description of the heliosphere. In the present configuration, the semi-empirical component uses the potential field source surface (PFSS) and Schatten current sheet (SCS) models to derive the coronal magnetic field based on observed magnetogram data. Using empirical relations, solar wind properties are associated with this coronal magnetic field. Together with a coronal mass ejection (CME) model, this provides inner boundary conditions for a global MHD model which is used to describe interplanetary propagation of the solar wind and CMEs. The proposed MHD numerical approach makes use of advanced numerical techniques. The 3D MHD code employs a finite-volume discretization procedure with limited piecewise linear reconstruction to solve the governing partial-differential equations. The equations are solved on a body-fitted hexahedral multi-block cubed-sphere mesh and an efficient iterative Newton method is used for time-invariant simulations and an explicit time-marching scheme is applied for unsteady cases. Additionally, an efficient anisotropic block-based refinement technique provides significant reductions in the size of the computational mesh by locally refining the grid in selected directions as dictated by the flow physics. The capabilities of the framework for accurately capturing solar wind structures and forecasting solar wind properties at Earth are demonstrated. Furthermore, a comparison with previously reported results and future space weather forecasting challenges are discussed.
Long-term studies of photospheric magnetic fields on the Sun
Authors: Pevtsov Alexei A. , Bertello Luca , Nagovitsyn Yury A. , Tlatov Andrey G. , Pipin Valery V.
Published: November 2020

We briefly review the history of observations of magnetic fields on the Sun, and describe early magnetograps for full disk measurements. Changes in instruments and detectors, the cohort of observers, the knowledge base etc may result in non-uniformity of the long-term synoptic datasets. Still, such data are critical for detecting and understanding the long-term trends in solar activity. We demonstrate the value of historical data using studies of active region tilt (Joy’s law) and the evolution of polar field and its reversal. Using the longest dataset of sunspot field strength measurements from Mount Wilson Observatory (1917-present) supplemented by shorter datasets from Pulkovo (1956–1997) and Crimean (1956-present) observatories we demonstrate that the magnetic properties of sunspots did not change over the last hundred years. We also show that the relationship between the sunspot area and its magnetic flux can be used to extend the studies of magnetic field in sunspots to periods with no direct magnetic field measurements. Finally, we show how more recent full disk observations of the vector magnetic field can be used to study the long-term (solar cycle) variations in magnetic helicity on the Sun.
Lung Cancer Screening by Low-Dose Computed Tomography: Part 2 – Key Elements for Programmatic Implementation of Lung Cancer Screening
Authors: Delorme Stefan , Kaaks Rudolf
Published: November 2020

Purpose For screening with low-dose CT (LDCT) to be effective, the benefits must outweigh the potential risks. In large lung cancer screening studies, a mortality reduction of approx. 20 % has been reported, which requires several organizational elements to be achieved in practice.

Materials and Methods The elements to be set up are an effective invitation strategy, uniform and quality-assured assessment criteria, and computer-assisted evaluation tools resulting in a nodule management algorithm to assign each nodule the needed workup intensity. For patients with confirmed lung cancer, immediate counseling and guideline-compliant treatment in tightly integrated regional expert centers with expert skills are required. First, pulmonology contacts as well as CT facilities should be available in the participant’s neighborhood. IT infrastructure, linkage to clinical cancer registries, quality management as well as epidemiologic surveillance are also required.

Results An effective organization of screening will result in an articulated structure of both widely distributed pulmonology offices as the participants’ primary contacts and CT facilities as well as central expert facilities for supervision of screening activities, individual clarification of suspicious findings, and treatment of proven cancer.

Conclusion In order to ensure that the benefits of screening more than outweigh the potential harms and that it will be accepted by the public, a tightly organized structure is needed to ensure wide availability of pulmonologists as first contacts and CT facilities with expert skills and high-level equipment concentrated in central facilities.

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Citation Format
Erianthridin Induces Non-small Cell Lung Cancer Cell Apoptosis through the Suppression of Extracellular Signal-regulated Kinase Activity
Authors: Boonjing Sirima , Pothongsrisit Sutthaorn , Wattanathamsan Onsurang , Sritularak Boonchoo , Pongrakhananon Varisa
Published: November 2020

Due to the high mortality of lung cancer, natural derivative compounds have been promoted as versatile sources for anticancer drug discovery. Erianthridin, a phenanthrene compound isolated from Dendrobium formosum, exhibits intriguing apoptosis-inducing effects in non-small cell lung cancer cells. Apoptotic nuclei staining assays showed that apoptotic cells with DNA fragmentation and apoptotic bodies were apparent, and an increase in annexin V-FITC-positive cells were found in cells treated with erianthridin. The apoptosis protein markers for cleaved caspase-3 and cleaved poly-ADP-ribose polymerase were significantly upregulated in response to erianthridin. A mechanistic investigation revealed that erianthridin was able to attenuate extracellular signal-regulated kinase activity and thereby mediate apoptosis through the modulation of Bcl-2 family protein levels. U0126, an extracellular signal-regulated kinase inhibitor, augmented the apoptosis-inducing effect of erianthridin; in contrast, overexpression of exogenous extracellular signal-regulated kinase substantially abrogated erianthridin activity. Furthermore, an in vitro 3D tumorigenesis assay showed that erianthridin was able to potentially suppress lung cancer cell proliferation. This study is the first to report a promising cytotoxic effect of erianthridin, which provides preclinical evidence for further research and development of this compound.
Plasmacytoma Masquerading as Meningioma
Authors: Erdem Münibe Büşra , Çakmak Pınar , Akyürek Nalan , Dogulu Fikret
Published: November 2020

Solitary bone plasmacytoma is a rare disease in the skull. We present a 70-year-old patient who presented with a skull deformity due to the left parietooccipital tumor. Neurological examination found no deficit. The systemic scanning revealed no additional lesion. The surgery was planned, and the tumor was removed totally with the marginal bone around it. Histopathological examination confirmed solitary bone plasmacytoma. The patient is being followed-up without recurrence or progression to multiple myeloma. As the calvarial solitary bone plasmacytomas can be easily misdiagnosed preoperatively, the detailed examination of the CT features may be helpful for the planning and course of the surgery.
Clinical and Genetic Varieties of Gaucher Disease in Iraqi Children
Authors: Ibraheem Mohammad Fadhil , Ahmed Shaymaa Jamal
Published: November 2020

Gaucher disease (GD), which is due to a deficiency in the lysosomal enzyme β-glucocerebrosidase, is a rare genetic disorder. It is characterized by a wide variety of clinical manifestations and severity of symptoms, making it difficult to manage. A cross-sectional hospital-based genetic study was undertaken with 32 pediatric patients. We recruited 21 males and 11 females diagnosed with GD, with a male-to-female ratio of 1.91:1. The mean age of the study population was 8.79 ± 4.37 years with an age range from 8 months to 17 years. We included patients on clinical evaluation from 2011 to 2019. An enzyme assay test was used to measure β-glucosidase enzyme activity in leukocytes and the GBA gene study was performed by polymerase chain reaction technique. We found GD type 1 in 27 (84.37%) participants, GD type 3 in five (15.63%) participants, while none classified as GD type 2. The dominant mutation in GD 1 was N370S in 81.5%, of which two-thirds were homozygous. The second common mutation in this type of disease (L444P) was present in nine cases (40.9%), two of whom were homozygous (9.9%). Meanwhile, R463C was present in six cases (27.27%), of whom one was homozygous. In GD 3, the dominant mutation was L444P as seen in 80% of the patients followed by N370S and R463C in 20%. This study shows that the most common mutant allele in this study was N370S, followed by L444P. Further large-scale studies with more advanced designs are recommended to explore the sequences of GBA genes.
Characterizing dynamics of time series via Hill-index complexity measure
Authors: Peng Kun , Shang Pengjian , Yin Yi
Published: November 2020

The ordinal patterns of time series provide a variety of information about the dynamic characteristics of the underlying process. With the ordinal symbolic approach, recently, a permutation-based Hill’s diversity index has been proposed as a useful tool for complex system analysis. However, this method just measures the complexity of the system from the perspective of uncertainty, while the underlying structural information of the system dynamics can hardly be captured. To overcome this deficiency, this paper introduces a Hill-index complexity measure (HICM). The numerical applications suggest that the proposed HICM has greater discriminating power than the conventional statistical complexity measure (SCM). With parameter r, even between chaotic systems with extremely similar dynamics, HICM can make a clear differentiation, which can barely be achieved by SCM. Besides, HICM with appropriate r is relatively more robust against noise than SCM. In the empirical application to financial markets, the approach adopted in this paper could differentiate the stage of stock market development. Combined with multidimensional scaling based on the dynamic time wrapping distance, the method could reveal the potential similarities among the stock market dynamics and give a refined classification of these world indices.
Non-uniform longitudinal current density induced power saturation in GaAs-based high power diode lasers
Authors: Arslan S. , Swertfeger R. B. , Fricke J. , Ginolas A. , Stölmacker C. , Wenzel H. , Crump P. A. , Patra S. K. , Deri R. J. , Boisselle M. C. , Pope D. L. , Leisher P. O.
Published: November 2020

The output power of modern 975 nm GaAs-based broad area diode lasers is limited by increasing carrier and photon losses at high bias. We use experiment and one-dimensional calculations on these devices to reveal that higher current densities (and hence higher local recombination rates and higher losses) arise near the front facet due to spatial hole burning and that the non-uniformity is strongly affected by laser geometry, which is more severe for longer resonators and less severe for higher front facet reflectivity. Specifically, we use devices with a segmented p-contact to directly measure the current distribution along the resonator and compare this with laser simulation. Devices with a 6 mm resonator show 29% more current at the front than back, twice as large as the 15% current non-uniformity in devices with a 3 mm resonator. In contrast, increased front facet reflectivity (20% rather than 0.8%) is shown to almost halve the current non-uniformity from 29% to 18% in devices with a 6 mm resonator and reduces power saturation. Although the magnitude of current non-uniformity in experiment and theory is broadly consistent, in experiment, an additional divergence is seen in current flow (and hence recombination rate) near the facets, and earlier power saturation occurs. We discuss the possible saturation mechanisms that are not included in the simulation.
Compensation in (2¯01) homoepitaxial β-Ga2O3 thin films grown by metalorganic vapor-phase epitaxy
Authors: Eisner Brian A. , Ranga Praneeth , Bhattacharyya Arkka , Krishnamoorthy Sriram , Scarpulla Michael A.
Published: November 2020

Homoepitaxial growth of β-Ga2O3 using metalorganic vapor-phase epitaxy (MOVPE) on several different crystal orientations has previously been studied, but growth on the (2¯01) plane has remained comparatively unexplored. To investigate this, we grew Si-doped and unintentionally doped (UID) homoepitaxial layers simultaneously on Sn-doped (2¯01) and (010) substrates under conditions optimized for (010) growth. We report herein on results from current–voltage and capacitance–voltage (IV and CV) and deep level transient spectroscopy (DLTS) characterization of Schottky diodes fabricated on these samples. Devices on (010) display nearly ideal Schottky diode JV and CV behaviors while for (2¯01) evidence of complete depletion of >2 μm thickness, UID epilayers are observed. The (2¯01) UID diodes exhibited Mott–Gurney space charge-limited transport and were completely depleted even at zero bias. Doping (2¯01) samples heavily with Si was sufficient to overcome background compensation and reproduce near-ideal diode behavior. DLTS data from these doped devices show, in addition to typical negative majority-carrier transients, positive transients with a broad energy distribution, possibly indicating traps on structural defects or surface states. An etch pit analysis under SEM revealed intricate structures of the grown layers. Cross-sectional TEM characterization of a (2¯01) sample revealed a high density of structural defects within the epitaxial layer, likely stacking faults. Hypotheses for the origins of the compensation in (2¯01) β-Ga2O3 homoepitaxial MOVPE growth under (010) growth conditions are discussed; the most likely explanation is the presence of defect states introduced by the stacking faults visible under TEM.
Effect of NaOH and precursor concentration on size and magnetic properties of FeCo nanoparticles synthesized using the polyol method
Authors: Park J. H. , Park C. , Lee K. S. , Suh S. J.
Published: November 2020

In this study, the effects of NaOH and precursor concentration on the particle size and magnetic properties of FeCo nanoparticles are investigated. Results suggest that an optimized ratio of NaOH molar concentration [OH] to precursor molar concentration [M] is required to obtain a small particle size, high saturation magnetization, and low coercivity. When the [OH]/[M] ratio was greater than 40, the FeCo nanoparticles aggregated, whereas when the [OH]/[M] ratio was less than 20, FeCo + CoFe2O4 nanoparticles were obtained due to unstable reduction reactions. When [OH]/[M] was 40, the 387 nm FeCo nanoparticles showed the highest saturation magnetization and lowest coercivity, which are the best conditions for achieving high permeability. In contrast, the complex permeability of the 173 nm FeCo nanoparticles was higher than that of the 387 nm FeCo nanoparticles owing to the decrease in the demagnetization effect in the high frequency band. This confirmed that the particle size had a greater effect on the complex permeability than that on the saturation magnetization and coercivity in GHz ranges.
Terahertz photoresistivity of a high-mobility 3D topological insulator based on a strained HgTe film
Authors: Savchenko M. L. , Otteneder M. , Dmitriev I. A. , Mikhailov N. N. , Kvon Z. D. , Ganichev S. D.
Published: November 2020

We report on a detailed study of terahertz (THz) photoresistivity in a strained HgTe three-dimensional topological insulator (3D TI) for all Fermi level positions: inside the conduction and valence bands and in the bulk gap. In the presence of a magnetic field, we detect a resonance corresponding to the cyclotron resonance (CR) in the top surface Dirac fermions (DFs) and examine the nontrivial dependence of the surface state cyclotron mass on the Fermi level position. We also detect additional resonant features at moderate electron densities and demonstrate that they are caused by the mixing of surface DFs and bulk electrons. At high electron densities, we observe THz radiation-induced 1/B-periodic low-field magneto-oscillations coupled to harmonics of the CR and demonstrate that they have a common origin with microwave-induced resistance oscillations previously observed in high mobility GaAs-based heterostructures. This observation attests the superior quality of a 2D electron system formed by helical surface states in strained HgTe films.
A deep unsupervised clustering-based post-processing framework for high-fidelity Cerenkov luminescence tomography
Authors: Cao Xin , Zhang Jun , Yang Jianan , Fan Chunxiao , Zhao Fengjun , Zhou Wei , Wang Lin , Geng Guohua , Zhou Mingquan , Chen Xueli
Published: November 2020

Cerenkov Luminescence Tomography (CLT) is a promising optical molecular imaging technology. It involves the three-dimensional reconstruction of the distribution of radionuclide probes inside a single object to indicate a tumor's localization and distribution. However, reconstruction using CLT suffers from severe ill-posedness, resulting in numerous artifacts within the reconstructed images. These artifacts influence the visual effect and may misguide the medical professional (diagnostician), resulting in a wrong diagnosis. Here, we proposed a deep unsupervised clustering-based post-processing framework to eliminate artifacts and facilitate high-fidelity CLT. First, an initial reconstructed image was obtained by a specific reconstruction method. Second, voxel data were generated based on the initial reconstructed result. Third, these voxels were divided into three groups, and only the group with the highest mean intensity was chosen as the final reconstructed result. A group of numerical simulation and in vivo mouse-based experiments were conducted to assess the presented framework's feasibility and potential. The results indicated that the proposed framework could reduce the number of artifacts effectively. The reconstructed image's shape and distribution were more similar to the actual light source than those obtained without the proposed framework.
Biobank networking and globalisation: perspectives and practices of Australian biobanks
Authors: Light Edwina , Wiersma Miriam , Dive Lisa , Kerridge Ian , Lipworth Wendy , Stewart Cameron , Kowal Emma , Marlton Paula , Critchley Christine
Published: November 2020

Objective This study examined the practices and attitudes of Australian biobanks regarding access to samples and data, as well as local and global networking with other biobanks. Methods This was a mixed-methods study, including an online survey of Australian biobank administrators and qualitative interviews with survey participants. The survey examined the criteria applied when considering requests to share or network. The interviews explored attitudes and practices regarding sharing and networking. Results Most (90.9%; 30/33) biobanks offered access to their samples and data to others, principally for research (90.6%; 29/32). The most common criteria used to evaluate access requests included ethical oversight (84.8%; 28/33), scientific merit (84.8%; 28/33) and intended use (81.8%; 27/33). Just over two-thirds (69.7%; 23/33) of biobanks participated in Australian networks, and 39.1% (9/23) participated in global networks. Networking took the form of both sharing standardised operating procedures and policies (60.9%) and sharing samples and data (43.5%). Thirteen of the 16 interviewees participated in networks. Motivations for sharing included scientific necessity, sharing expertise and standardising operations and governance. Significant barriers to networking remain, including insufficient resources, inconsistent regulations and procedures, and cultural and political issues to do with the conduct of research. Conclusions Many Australian biobanks are already active participants in various types of global biobanking. If biobanks are to expand and make the most of their involvement in global networks, then important barriers need to be overcome. What is known about the topic? Biobanks that store human tissue and associated data are increasingly forming local, national and global networks. These networks create opportunities for enhancing the utility and sustainability of biobanks, but also raise considerable technical, legal and ethical challenges. What does this paper add? This paper reports findings from a mixed-methods study of Australian biobanks and reveals contemporary practices and perspectives concerning sample and data sharing, as well as local and global networking. It found most Australian biobanks currently take part in these activities. What are the implications for practitioners? Many Australian biobanks are networking in various ways across regional and national borders. A better understanding of current practices and views on significant and emerging issues is relevant to the diverse range of biobank stakeholders involved in any agenda to expand biobank networking, including patients, consumers, clinicians, scientists, policy makers and regulators.
Does the C
Authors: Winter Klaus , Garcia Milton , Virgo Aurelio , Ceballos Jorge , Holtum Joseph A. M.
Published: November 2020

We examined whether crassulacean acid metabolism (CAM) is present in Trianthema portulacastrum L. (Aizoaceae), a pantropical, salt-tolerant C4 annual herb with atriplicoid-type Kranz anatomy in leaves but not in stems. The leaves of T. portulacastrum are slightly succulent and the stems are fleshy, similar to some species of Portulaca, the only genus known in which C4 and CAM co-occur. Low- level nocturnal acidification typical of weakly expressed, predominantly constitutive CAM was measured in plants grown for their entire life-cycle in an outdoor raised garden box. Acidification was greater in stems than in leaves. Plants showed net CO2 uptake only during the light irrespective of soil water availability. However, nocturnal traces of CO2 exchange exhibited curved kinetics of reduced CO2 loss during the middle of the night consistent with low-level CAM. Trianthema becomes the second genus of vascular land plants in which C4 and features of CAM have been demonstrated to co-occur in the same plant and the first C4 plant with CAM-type acidification described for the Aizoaceae. Traditionally the stems of herbs are not sampled in screening studies. Small herbs with mildly succulent leaves and fleshy stems might be a numerically significant component of CAM biodiversity.
Politics, Ethnicity and the Postcolonial Nation
Authors: Esposito Eleonora
Published: November 2020

This book explores the politics of ethnicity and nationalism in the Caribbean from a critical discourse-analytical perspective. Focusing on political communication in Trinidad and Tobago, it offers unique socio-political insights into one of the most complex and diverse countries of the Archipelago. Through a detailed reconstruction of Kamla Persad-Bissessar’s 2010 victorious run for office, this book offers ample empirical evidence of the multimodal discursive strategies that held the key to the success of the first woman PM candidate and her inter-ethnic coalition bid to overcome political tribalism in the country. In parallel, it explores the implications and challenges of the postcolonial Trinbagonian national project, caught between pluralism and creolization. Through its innovative, context-dependent and interdisciplinary CDS approach, this book breaks new ground in Caribbean Studies while at the same time broadening the horizons of the Euro-American tradition of Political Discourse Studies to address the complexities of global postcoloniality.
Exciton Vortices in Two-Dimensional Hybrid Perovskite Monolayers*
Authors: Chen Yingda , Zhang Dong , Chang Kai
Published: November 2020

We study theoretically the exciton Bose–Einstein condensation and exciton vortices in a two-dimensional (2D) perovskite (PEA)2PbI4 monolayer. Combining the first-principles calculations and the Keldysh model, the exciton binding energy of in a (PEA)2PbI4 monolayer can approach hundreds of meV, which make it possible to observe the excitonic effect at room temperature. Due to the large exciton binding energy, and hence the high density of excitons, we find that the critical temperature of the exciton condensation could approach the liquid nitrogen regime. In the presence of perpendicular electric fields, the dipole-dipole interaction between excitons is found to drive the condensed excitons confined in (PEA)2PbI4 monolayer flakes into patterned vortices, as the evolution time of vortex patterns is comparable to the exciton lifetime.
On the connection between bound and scattering states of finite square-well potentials: a unified approach
Authors: Morrison Ian , Ekey Robert , Biaggio Ivan , Mitchell Brandon
Published: November 2020

We discuss a general description of the solutions to the 1D time-independent Schrödinger equation that does not a priori distinguish between scattering states and bound states and emphasizes and reinforces their relationship and connection to each other. This manuscript also introduces the concept of transfer matrices, which it presents as a logical extension of the traditional approach to evaluating 1D potentials. Using the transfer matrix method and a finite step approximation allows for a simple and straight-forward numerical solution of arbitrary 1D potentials. It also separates the process of solving the Schrödinger equation from selecting physically relevant solutions, which is a critical skill in quantum mechanics and is at the core of physics problems in general.
Sliding down a rough curved hill
Authors: Ivchenko Vladimir
Published: November 2020

In this paper, we analyse the process of a particle sliding down an arbitrary curved hill in the presence of friction. We show that in this case, the kinetic friction force turns out to be effectively dependent on the speed. We find that the final speed for each concave (convex) profile should be less (greater) than that for the corresponding inclined plane. In the limit of extremely small final speed or profiles of the hill close to linear, the final speed does not depend on the shape of the trajectory even in the presence of kinetic friction. As an illustrative example, we perform the calculation of the final speed for a concave hill in the form of a quarter circle. We also derive the shape of the curved hill profile for which a body can slide down at a constant speed.
Kinetics of metastable N2(A3Σu

+
, v) molecules in high-pressure nonequilibrium plasmas
Authors: Jans E R , Raskar S , Yang X , Adamovich I V
Published: November 2020

Absolute, time-resolved populations of N2(A3Σu
  +, v = 0–5) vibrational levels in high-pressure ns pulse discharge plasmas are measured by Tunable Diode Laser Absorption Spectroscopy (TDLAS). The diffuse plasma is generated by a repetitively pulsed, double dielectric barrier, ns discharge across a 10 mm gap in a plane-to-plane geometry, at pressures of up to 400 Torr. The results of TDLAS measurements in nitrogen and in H2–N2, O2–N2, and NO–N2 plasmas are compared with kinetic modeling predictions, identifying the mechanisms of N2(A3Σu
  +) generation and decay during the discharge pulses and in the afterglow. Comparison with the modeling predictions indicates that electron impact dissociation of N2 from the ground electronic state significantly underpredicts the yield of N atoms. The present data suggest that N2 dissociation in the plasma also occurs during the energy pooling process in collisions of two N2(A3Σu
  +) molecules. The results also show that high-pressure, high repetition rate, volume-scalable ns pulse discharges can be used for efficient generation of atomic species for plasma chemical and plasma catalysis syntheses. In an NO–N2 mixture, it is shown that the N2(A3Σu
  +) decay is controlled by the rapid energy transfer to NO, resulting in its electronic excitation and UV emission (NO γ bands). The diagnostics used in the present work can be used for the accurate characterization of both high-pressure, low-temperature gas discharge plasmas and high-temperature nonequilibrium flows generated in pulsed facilities such as shock tubes and expansion tunnels.
Magnetorheological damper with multi-grooves on piston for damping force enhancement
Authors: Liu Gaoyu , Gao Fei , Liao Wei-Hsin
Published: November 2020

Due to low power consumption and fast response, magnetorheological (MR) dampers are widely used in various engineering applications. To enhance the performances, efforts have been made to increase the field dependent force with the same power consumption. However, the fluid viscous force is also increased significantly, which is undesirable in practical use. To tackle this problem, the focus of this paper is to design, simulate, and test an MR damper with multi-grooves (small multiple annular flow gaps) on piston for performance enhancement. First, the detailed design of the proposed MR damper is provided. Then, a coupled field model to describe the characteristics of MR fluid in different regions of MR damper is derived. Based on this model, multiphysics simulations are performed using COMSOL Multiphysics. Parametric analysis of the number and width of multi-grooves is also conducted. Experimental results of the two MR dampers without and with multi-grooves are given and compared with the simulation results. The advantages of MR damper with multi-grooves over the one without multi-grooves and the accuracy of the coupled field model are validated by experiments and simulations. This is the first time that the advantages of MR damper with multi-grooves are validated by experiments. Compared with MR damper without multi-grooves, MR damper with multi-grooves has larger damping force and controllable force range, as well as less increment of fluid viscous force while keeping the same increase of field dependent force. The performance of MR damper with multi-grooves could be further improved by increasing the number and decreasing the width of multi-grooves.
A new design of magnetic circuits in magnetorheological dampers for simple structure subjected to small stroke and low damping force
Authors: Lee Tae-Hoon , Kang Byung-Hyuk , Kim Gi-Woo , Choi Seung-Bok
Published: November 2020

A magnetorheological (MR) damper is popularly applied for vibration control owing to its fast response and the easy controllability of the field-dependent damping force. However, most of the existing MR dampers developed so far possess design complexity and a high manufacturing cost due to complicated coil structures. To resolve these drawbacks of the existing MR dampers, a novel magnetic circuit positioned separately from the piston head of MR damper with a simple structure is proposed in this work. As a first step, a design configuration using the operating principle of the magnetic circuit is demonstrated, and subsequently, the magnetic analysis of MR damper is carried out through an analytical approach and the finite element method. In the magnetic analysis, the magnetic flux density is numerically calculated at various piston locations with different applied currents. After determining the principal design parameters of the proposed MR damper, experimental validation to demonstrate the concept of the new magnetic circuit is performed. The effect of the piston stroke length on the damping force is evaluated as a function of the current. In addition, it is discussed that the proposed MR damper can provide much higher control range of the damping force than conventional types of MR dampers in a low level of damping force.
Voltage response of three ionic polymer pressure sensors based on ion migration at different ambient humidities
Authors: Li Shiping , Liu Hu , Zhu Zicai , Sun Xiaofei , Tang Zhenhua , Guo Yan , Hu Qiao , Zhang Yong
Published: November 2020

Besides bending sensor, ionic polymer materials can work as pressure sensor based on ion migration and show more potential in engineering application. To explore a better ionic polymer material for pressure sensor, three typical ionic polymer materials, Nafion, poly(vinylidene fluoride)/ionic liquid (IL/PVDF) composite, thermoplastic polyurethane/ionic liquid (IL/TPU) composite, were selected to comparatively investigate the sensing properties under an applied pressure. Ionic polymer pressure sensors with circular truncated cone structure were developed by casting method. Their voltage responses were evaluated by a self-made test platform under a series of step force. The voltage sensitivity and the stability were obtained by performing the tests at different ambient humidity levels. The sensitivity of Nafion sensor was influenced by the ambient humidity heavily, which increased from 8.97 mV N−1 (28.17 mV MPa−1) to 31.11 mV N−1 (97.69 mV MPa−1) as the relative humidity (RH) increasing from 30% RH to 90% RH. In comparison, the voltage responses of IL/TPU sensor and IL/PVDF sensor were rarely influenced by the humidity because of the stability of IL, but strongly related to the content of IL. As the IL content increasing from 30 wt.% to 50 wt.%, the sensitivity of IL/TPU sensor increased from 5.65 mV N−1 (17.74 mV MPa−1) to 16.55 mV N−1 (51.97 mV MPa−1), that of IL/PVDF sensor increased from 14.12 mV N−1 (44.33 mV MPa−1) to 32.23 mV N−1 (101.20 mV MPa−1) monotonously. The underlying mechanisms were revealed based on water exchange in air and ion transport theory qualitatively. IL/PVDF sensor with 50 wt.% IL content shows the best sensing performance in air and is promising for practical application.
Magnetorheology of exotic magnetic mesostructures generated under triaxial unsteady magnetic fields
Authors: Terkel Matthew , de Vicente Juan
Published: November 2020

Traditionally, the rheological properties of magnetorheological (MR) fluids are investigated under uniaxial steady (DC) fields. These basic fields promote the aggregation of magnetically attractive particles into chain-like structures aligned in the field driven direction. In this manuscript we show how triaxial unsteady fields can generate a variety of exotic mesostructures and influence the rheological response of the MR fluids. We bridge understanding the rheological response to each unique particle structure through videomicroscopy, x-ray microtomography and rheometry tests. Small-amplitude oscillatory shear and steady shear tests lay out an unmistakable argument for MR enhancement with both elevated storage modulus and yield stress responses following a sequence of steady uniaxial and unsteady fields. We demonstrate that structures assembled through time-averaged particle interactions or typical dipole–dipole magnetostatic interactions, especially when columnar structures are strengthened through lateral chain coalescence, can boost rheological response.
Terahertz tunable optical dual-functional slow light reflector based on gold-graphene metamaterials
Authors: Xu Hui , Chen Zhiquan , He Zhihui , Nie Guozheng , Li Deqiong
Published: November 2020

Tunable terahertz optical dual-functional slow light reflector based on gold-graphene metamaterials has been designed and the proposed structure can achieve a good optical reflection effect and slow light effect. The tunable function can be dynamically controlled by applying a voltage to the gold and it can achieve a good effect for selecting reflection band. In more detail, the gold in this device can enable us to dynamically tune the Fermi level of graphene, thus this device can achieve a good tunable effect. Compared with other structures, the graphene monolayer in this structure is simpler and forms a complete band distribution, laying a solid foundation for the subsequent implementation of the device. Through the derivation and analysis of the optical equivalent-cavity coupled mode theory, the theoretical fitting transmission and reflection of this device can be obtained, and they are in good agreement with the numerical results. Furthermore, the slow light effect of this device has been analyzed and it is found that this device has a better slow light performance. This investigation is expected to provide a theoretical basis for the realization of tunable slow light reflectors.
Irreversibility, heat and information flows induced by non-reciprocal interactions
Authors: Loos Sarah A M , Klapp Sabine H L
Published: November 2020

We study the thermodynamic properties induced by non-reciprocal interactions between stochastic degrees of freedom in time- and space-continuous systems. We show that, under fairly general conditions, non-reciprocal coupling alone implies a steady energy flow through the system, i.e., non-equilibrium. Projecting out the non-reciprocally coupled degrees of freedom renders non-Markovian, one-variable Langevin descriptions with complex types of memory, for which we find a generalized second law involving information flow. We demonstrate that non-reciprocal linear interactions can be used to engineer non-monotonic memory, which is typical for, e.g., time-delayed feedback control, and is automatically accompanied with a nonzero information flow through the system. Furthermore, already a single non-reciprocally coupled degree of freedom can extract energy from a single heat bath (at isothermal conditions), and can thus be viewed as a minimal version of a time-continuous, autonomous ‘Maxwell demon’. We also show that for appropriate parameter settings, the non-reciprocal system has characteristic features of active matter, such as a positive energy input on the level of the fluctuating trajectories without global particle transport.
Dynamic focusing of laser driven positron jets by self-generated fields
Authors: Kim J , Link A , Canning D , Fitzsimmons P , Fooks J A , Kerr S , Ma T , Manuel M J-E , Mariscal D , Wallace R , Williams G J , Willingale L , Beg F N , Chen H
Published: November 2020

Focusing effect of laser-driven positron jets by self-generated target sheath fields has been observed for the first time experimentally and the results are supported by the computational studies. In the experiment, OMEGA EP short-pulse (0.7 ps, 500 J) irradiates mm-size gold targets with a concave back surface and reference flat-surface targets. Both targets exhibited positrons with quasi-monoenergetic energy peaks while targets with concave curvature also showed increased number of positrons at the detector. The data is consistent with hybrid-PIC simulations confirming that the time-varying electric fields driven by electrons escaping from the target significantly change the trajectories of positrons. These simulations show a small radius of curvature on the rear side increases the relative focusing effect and the positrons to electrons ratio in the escaping plasma. For the smallest radius of curvature, positron jets that are up to 10 times denser can be achieved.
Spectroscopic properties of Δ baryons
Authors: Menapara Chandni , Shah Zalak , Kumar Rai Ajay
Published: November 2020

The resonance state of the

baryon, which exists in four isospin (

) states, has been studied using the hypercentral constituent quark model (hCQM) with a simple linear potential with added first order correction. The calculated data ranges for 1S-5S, 1P-5P, 1D-4D and 1F-2F are given, with possible spin-parity assignments for all the states. The magnetic moments have also been obtained for all four configurations. The

decay channel width has been calculated for a few states. The linear nature of the data has been verified through Regge trajectories.
Diffuseness effect and radial basis function network for optimizing α decay calculations *
Authors: Ma Na-Na , Bao Xiao-Jun , Zhang Hong-Fei
Published: November 2020

A radial basis function network (RBFN) approach is adopted for the first time to optimize the calculation of

decay half-life in the generalized liquid drop model (GLDM), while concurrently incorporating the surface diffuseness effect. The calculations presented herein agree closely with the experimental half-lives for 68 superheavy nuclei (SHN), achieving a remarkable reduction of 40% in the root-mean-square (rms) deviations of half-lives. Furthermore, using the RBFN method, the half-lives for four SHN isotopes, 252-288Rf, 272-310Fl, 286-316119, and 292-318120, are predicted using the improved GLDM with the diffuseness correction and the decay energies from WS4 and FRDM as inputs. Therefore, we conclude that the diffuseness effect should be embodied in the proximity energy. Moreover, increased application of neural network methods in nuclear reaction studies is encouraged.
Commissioning of the CALIFA Barrel Calorimeter of the R3B Experiment at FAIR
Authors: Cabanelas P , Alvarez-Pol H , Boillos J M , Casarejos E , Cederkall J , Cortina D , Feijoo M , Galaviz D , Galiana E , Gernhäuser R , Golubev P , González D , Hartig A-L , Heinz A , Johansson H , Klenze P , Knyazev A , Kröll T , Nacher E , Park J , Perea A , Ponnath L , Rhee H-B , Rodríguez-Sánchez J L , Suerder C , Tengblad O , Teubig P
Published: November 2020

CALIFA is the high efficiency and energy resolution calorimeter for the R3B experiment at FAIR, intended for detecting high energy charged particles and γ-rays in inverse kinematics direct reactions. It surrounds the reaction target in a segmented configuration of Barrel and Forward End-Cap pieces. The CALIFA Barrel consists of 1952 detection units made of CsI(Tl) long-shaped scintillator crystals, and it is being commissioned during the Phase0 experiments at FAIR. The first setup for the CALIFA Barrel commissioning is presented here. Results of detector performance with γ-rays are obtained, and show that the system fulfills the design requirements.