bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge and attitude of South-Indian smokers towards smoking associated health risk
Authors: Madiyal Ananya , Ajila Vidya , Babu G. Subhas , Hegde Shruthi
Published: April 2020

Aim: To assess the knowledge and attitude of South-Indian smokers towards health effects of smoking and their intentions to quit.

Study design: A cross sectional questionnaire based survey was conducted among 550 smokers hailing from South India who reported to the out-patient department of the dental hospital.

Results: Highest incidence of smoking in men was seen in those who received moderate level of education and those residing in rural areas. In female smokers, the highest incidence was seen in those residing in urban areas (53.8%) with a high level of education (38.4%). We found that males continued their habit mainly to destress while females used it to socialize. Majority of the participants were aware that smoking causes a host of problems in the oral cavity and 68.18% were aware that passive smoking was injurious to the body. Most of the responders admitted to having observed warnings on tobacco products and were willing to quit the habit with help from their dentists.

Conclusion: Smokers are at risk for various diseases that include the cardiovascular, respiratory and reproductive systems as well as the oral cavity. This study sheds light on the level of awareness among current tobacco users and the areas of deficiency in patient education which should be addressed by clinicians.
Effect of Music Therapy on Pain and Quality of Life among Cancer Survivors
Authors: Bareh Samrika , D'silva Fatima
Published: April 2020

Background: Cancer is one of the ten leading cause of death in India. Cancer patients usually present with moderate to severe pain which results usually from the cancer itself or from their treatment .To counteract pain complementary therapies are used along with the medical treatment. The most common used in the clinical setting is Music therapy; which is found to have a positive effect on the physical and psychological response of the patients.

Objectives: To find the effectiveness of Music therapy on Pain and Quality of life among Cancer survivors.

Material and Method : A quasi experimental research design was adopted for the study. The data were collected using demographic proforma, Numerical Pain rating scale and McGill Quality of life Questionnaire. 50 subjects with moderate to severe pain were identified and were randomly allocated into experimental (25) and control group (25). Experimental groups (25) received Music therapy for 15-20 mins twice a day for a period of 5 days. The control group (25) received no intervention. Pain was assessed twice a day, before and after the intervention for 5 th th days and QoL was assessed on the 6th and 10th day for both the groups..

Results: Majority of the subjects19 (38%) were between the age groups of 41-50 years and most of them 29 (58%) were males. Among the females the most common cancer was breast 12 (24%) and among males it was lungs 10 (20%). Most of the subjects 23(46%) had stage –II cancer, and 28(56%) were on radiation therapy. With regard to treatment, majority 29(58%) were on treatment for a duration of 1-3 months. The study also revealed a significant difference in the level of pain after the music intervention (p<0.05) and a significant improvement in the Quality of life especially affecting the physical and psychological domain (p<0.05). No significant association was found between pain, QoL and selected demographic variables (p<0.05)

Conclusion: Music therapy was found to be an effective complementary therapy in reducing the level of pain and improving the QoL of the cancer survivors.
Loop-mediated isothermal amplification (LAMP) : A rapid molecular diagnosis technique for detection of human pathogens
Authors: Chakraborty Gunimala , Karunasagar Indrani , Chakraborty Anirban
Published: April 2020

Delivery of quality healthcare in case of an infectious disease depends on how efficiently and how quickly the responsible pathogens are detected from the samples. Molecular methods can detect the presence of pathogens in a rapid and sensitive manner. Over the years, a number of such assays have been developed. However, these methods, although highly reliable and efficient, require use of expensive equipment, reagents, and trained personnel. Therefore, development of molecular assays that are simple, rapid, cost-effective, yet sensitive, is highly warranted to ensure efficient management or treatment strategies. Loop-mediated isothermal amplification (LAMP), a technique invented in the year 2000, is a novel method that amplifies DNA at isothermal conditions. Since its invention, this technique has been one of the most extensively used molecular diagnostic tools in the field of diagnostics offering rapid, accurate and cost-effective diagnosis of infectious diseases. Using the LAMP principle, many commercial kits have been developed in the last decade for a variety of human pathogens including bacteria, viruses and parasites. Currently LAMP assay is being considered as an effective diagnostic tool for use in developing countries because of its simple working protocol, allowing even an onsite application. The focus of this review is to describe the salient features of this technique the current status of development of LAMP assays with an emphasis on the pathogens of clinical significance.
DOUBLE JEOPARDY : PATHOLOGICAL FRACTURE AND NONUNION OF PROXIMAL HUMERUS DUE TO CHONDROCALCINOSIS
Authors: Shetty Vikram , Shetty Siddharth M , Ballal Arjun , Kamani Mayur M , Shetty B Jayaprakash
Published: April 2020

Fractures of the humerus constitute 5% to 8% of fractures and most have an uneventful healing, but occasionally non-unions of the fracture with joint stiffness of shoulder and/or elbow and prolonged debilitating pain may be encountered. Predisposing conditions usually are osteoporosis, obesity, alcoholism and smoking. Comminuted or segmental fractures, soft tissue interposition at the fracture site, improper fixation and infection may also result in non-union.

A fracture of neck of the right humerus (dominant limb) in a young lady failed to unite following internal fixation and lead to atrophic non-union with implant loosening, which initially was suspected to be due to poor fixation and or infection, but histopathological evaluation on two separate occasions of the fracture site revealed a picture of Chondrocalcinosis (CC). CC is a condition wherein deposition of calcium pyrophosphate dihydrate (CPPD) crystals occurs within articular cartilage and synovial tissue and is associated with joint pain leading to arthritis. The presence of these CPPD crystal has not been mentioned in the bone or at fracture sites in the literature, The histopathological evidence of CPPD at the fracture site in this case of humerus non-union did not establish whether the fracture was due to the pathology or the CPPD got deposited at the fracture site and was a cause of non-union.
Diagnostic Application of Fractal Dimension Analysis of Bone Invasion in Oral Malignancy—A Preliminary Retrospective Study
Authors: Archana M , Sadaksharam Jayachandran
Published: April 2020

Introduction

Fractal dimension (FD) analysis gives a numerical measure of the degree of boundary irregularity or surface roughness of an object and is based on quantitative analysis of features in an image. It quantifies the trabecular pattern of bone by analyzing the trabecular bone and bone marrow detecting the early changes in alveolar bone mineral content. The aim of this study is to assess the alveolar bone density by FD analysis in digital orthopantomograms (OPGs) showing bony erosion.

Materials and Methods

The OPGs of 10 patients from the archives of Department of Oral Medicine and Radiology were included in this retrospective study. The radiographs were selected based on set inclusion and exclusion criteria. FD analysis through box counting (using ImageJ software) was applied to the digital radiographs to establish a noninvasive evaluation of bone structure. The FD values obtained were recorded.

Results

The FD values were recorded and the data were analyzed. FD values showed statistical significance with p <0.05.

Conclusion

With the number of samples analyzed and the results obtained, it can be concluded that FD analysis is an innovative method which can be used for early diagnosis of bony invasion in oral cancer. It can serve as a guide to dental surgeons in identifying the extent of bony invasion and can help in determining the margins of surgical resection of oral malignancy. This will prove to be a useful tool in surgical planning of oral malignancy.
Comparison of physical activity as an obesity-related behavior between immigrants and native-born US adults
Authors: Alese Joyce T. , Alese Olatunji B.
Published: April 2020

Non-communicable diseases and chronic conditions such as obesity constitute significant public health issues in the United States (US) and globally. A major proximal determinant of obesity is physical activity, and related behavior. Limited data however exists comparing physical activity levels of US immigrants with those of native-born adults. This study aimed to compare US immigrants and native-born adults regarding associations of physical activity behavior and obesity. We analyzed data from the Health Information National Trends Survey. Outcomes of interest were various indicators of physical activity. Bivariate analyses and multivariate logistic regression models were utilized in describing demographics, weight distribution, and associations between variables of interest. A total of 3,185 individuals participated in the survey. Male to female ratio was 1.6 and 17% of the participants were immigrants. The mean age was 51 years (SD ± 15) for immigrants and 55 years (SD ± 16) for native-born respondents. Among immigrants, the racial distribution was 55.3% Hispanic, 18.9% Asian, 14.7% White, 9.9% Black, and 1.3% other races. Immigrants were less likely than non-immigrants to spend 6 h or more a day on sedentary leisure activities (adjusted OR = 0.64; 95% CI: 0.42–0.97;p = 0.0350). Also, immigrants were more likely than non-immigrants to engage in physical activity of at least moderate intensity, at least once a week (adjusted OR = 1.48; 95% CI: 1.07–2.05;p = 0.0192). Compared to native-born adults, US immigrants appear to have healthier lifestyles regarding physical activity behavior. Strategies to sustain such tendencies among immigrants will promote health and reduce overall risks of obesity and other chronic diseases in the US. Researchers, practitioners and policy makers should develop targeted strategies and focus attention on keeping immigrants in the loop of positive health behavior, while encouraging US adults to engage in more physical activity. Further studies are needed to determine the effects of various socio-economic, demographic and cultural factors that impact proximal determinants of obesity.
A close examination of the role and needed expertise of brokers in bridging and building science policy boundaries in environmental decision making
Authors: Duncan Ronlyn , Robson-Williams Melissa , Edwards Sarah
Published: April 2020

Knowledge brokers are often portrayed as neutral intermediaries that act as a necessary conduit between the spheres of science and policy. Conceived largely as a task in packaging, brokers are expected to link knowledge producers and users and objectively translate science into policy-useable knowledge. The research presented in this paper shows how brokering can be far more active and precarious. We present findings from semi-structured interviews with practitioners working with community-based groups involved in collaborative water planning in New Zealand’s South Island region of Canterbury. Working in a highly conflicted situation, our brokers had to navigate different knowledges and epistemic practices, highly divergent values and grapple with uncertainties to deliver recommendations for regional authorities to set water quality and quantity limits. Conceiving science and policy as interlinked, mutually constitutive and co-produced at multiple levels, rather than as separate domains, shows how the brokers of this study were not only bridging or blurring science policy boundaries to integrate and translate knowledges. They were also building boundaries between science and policy to foster credibility and legitimacy for themselves as scientists and the knowledge they were brokering. This research identifies further under-explored aspects of brokering expertise, namely, the multiple dimensions of brokering, transdisciplinary skills and expertise, ‘absorptive’ uncertainty management and knowledge translation practices.
RETRACTED ARTICLE: Creating an optimal environment for distance learning in higher education: discovering leadership issues
Authors: Beketova Elena , Leontyeva Irina , Zubanova Svetlana , Gryaznukhin Aleksandr , Movchun Vasily
Published: April 2020

Current literature does not provide exhaustive information about leadership as part of teaching and learning. The distance learning format creates a platform for developing leadership skills. However, this form of education is often confused with the denial of the importance of education and the ideas of “unschooling”, which leads to a negative attitude in society towards extramural forms of study. This study demonstrates the value of distance learning in the education system, and describes specific leadership skills that can be improved through distance learning. The study disproves unconfirmed judgments and clichés about detachment, loneliness, and the degradation of communicative competencies among distance learning students. The study as well outlines the impact of extramural forms of study on the development of inclusiveness and tolerance for self-expression in educational classes. Thus, it has been proven that distance learning has a positive influence on skills development.
A novel broadband capacitor voltage divider for measurement of ultrafast square high voltage pulse transmitted in transmission line
Authors: Wei Bing , Liu Hongwei , Liang Jinhui , Yuan Jianqiang , Xie Weiping
Published: April 2020

This paper studies a new type of broadband capacitive voltage divider, which is used to measure the high voltage square wave pulse with sub-nanosecond front in a transmission line. The low-frequency characteristics of traditional capacitive dividers are extended by adding sampling resistors, and the high-frequency gain caused by stray capacitors of sampling resistors is eliminated by adding compensation capacitors, which greatly broadens the bandwidth of capacitive dividers. The findings show that when the sampling resistance is 6.1 kΩ and 12 kΩ and the equivalent grounding capacitance is about 15 pF and 30 pF, respectively, the bandwidth of the divider is 180 kHz to 2 GHz and 100 kHz to 2 GHz, which can meet the test requirements of the high voltage square wave pulse with sub-nanosecond front and dozens of nanosecond pulse width.
ISIS Penning source extraction studies reveal the 3-dimensional Child–Langmuir effect
Authors: Faircloth D. , Tarvainen O. , Lawrie S. , Sarmento T. , Savard N. , Abel R. , Macgregor J. , Whitehead M. , Wood T. , Cahill C.
Published: April 2020

The standard 1X ISIS negative Penning surface plasma source has reliably produced an H− beam for ISIS operations for 35 years. In order to meet the 60 mA, 2 ms, and 50 Hz beam current and duty cycle required for the front end test stand (Letchford et al., in Proceedings of IPAC2015, Richmond, VA, USA, 2015), a 2X scaled source has been developed [Faircloth et al., AIP Conf. Proc. 2052, 050004 (2018)]. The 2X source has a plasma chamber twice the linear dimensions of the 1X source. This paper investigates the comparison between different emission areas (plasma electrode aperture dimensions) for both the 1X and 2X sources. Slit and circular extraction schemes are studied. A 3D Child–Langmuir relationship is observed where the space charge limited current density depends on the aspect ratio of the extraction aperture.
Effect of the Reynolds number on the aeroacoustic fields of a transitional supersonic jet
Authors: Ozawa Y. , Nonomura T. , Oyama A. , Asai K.
Published: April 2020

The Reynolds number effect on the aeroacoustic fields of a supersonic jet was experimentally investigated via particle image velocimetry (PIV), schlieren visualization, and near-field acoustic measurements. Cold supersonic jets under ideally expanded conditions at a Mach number of 2.0 were produced with the Reynolds number, based on the diameter of the nozzle exit, ranging from 105 to 106. This study focuses on the laminar-to-turbulent transition of a supersonic jet, including a transitional condition (Re ≈ 105). The PIV results of the high-Reynolds-number jet (Re = 106), which exhibited a fully turbulent shear layer at the nozzle exit, show a linear growth of the shear layer width. Conversely, a significant increase in the turbulent fluctuations and a drastic change in the shear-layer-growth rate were observed near the transition region in the case of the low-Reynolds-number jet (Re = 105). The schlieren visualization and acoustic measurements imply that the turbulent fluctuations of the transition generated strong Mach waves. The effect of disturbing the nozzle flow was also investigated because the laminar-to-turbulent transition is sensitive to the initial disturbance. A physical disturbance added in the inlet of the low-Reynolds-number jet (Re = 105) can promote an earlier transition and suppress a significant increase in the turbulence fluctuations outside the nozzle. The changes in the flow fields due to the disturbance result in a decrease in the sound pressure level. Therefore, the aeroacoustic fields of the low-Reynolds-number jet with the disturbance show similar trends to those of the high-Reynolds-number jet (Re = 106), which already exhibited a fully turbulent shear layer at the nozzle exit.
Universal superposition codes: Capacity regions of compound quantum broadcast channel with confidential messages
Authors: Boche Holger , Janßen Gisbert , Saeedinaeeni Sajad
Published: April 2020

We derive universal codes for transmission of broadcast and confidential messages over classical-quantum–quantum and fully quantum channels. These codes are robust to channel uncertainties considered in the compound model. To construct these codes, we generalize random codes for transmission of public messages to derive a universal superposition coding for the compound quantum broadcast channel. As an application, we give a multi-letter characterization of regions corresponding to the capacity of the compound quantum broadcast channel for transmitting broadcast and confidential messages simultaneously. This is done for two types of broadcast messages, one called public and the other common.
Optimization of ruthenium as a buffer layer for non-collinear antiferromagnetic Mn3X films
Authors: Kurdi S. , Zilske P. , Xu X. D. , Frentrup M. , Vickers M. E. , Sakuraba Y. , Reiss G. , Barber Z. H. , Koo J. W.
Published: April 2020

Two thin film deposition routes were studied for the growth of high quality single crystalline Ru (0001) epitaxial films on c-Al2O3 substrates using radio frequency-magnetron sputtering. Such films are very important as buffer layers for the deposition of epitaxial non-collinear antiferromagnetic Mn3X films. The first route involved depositing Ru at 700 °C, leading to a smooth 30 nm thick film. Although, high resolution x-ray diffraction revealed twinned Ru film orientations, in situ post-annealing eliminated one orientation, leaving the film orientation aligned with the substrate, with no in-plane lattice rotation and a large lattice mismatch (13.6%). The second route involved the deposition of Ru at room temperature followed by in situ post-annealing at 700 °C. Transmission electron microscopy confirmed a very high quality of these films, free of crystal twinning, and a 30° in-plane lattice rotation relative to the substrate, resulting in a small in-plane lattice mismatch of –1.6%. X-ray reflectivity demonstrated smooth surfaces for films down to 7 nm thickness. 30 nm thick high quality single-crystalline Mn3Ga and Mn3Sn films were grown on top of the Ru buffer deposited using the second route as a first step to realize Mn3X films for antiferromagnetic spintronics applications.
Ultrafast vibrational dynamics of a trigonal planar anionic probe in ionic liquids (ILs): A two-dimensional infrared (2DIR) spectroscopic investigation
Authors: Guchhait Biswajit , Tibbetts Clara A. , Tracy Kathryn M. , Luther Bradley M. , Krummel Amber T.
Published: April 2020

A major impediment limiting the widespread application of ionic liquids (ILs) is their high shear viscosity. Incorporation of a tricyanomethanide (TCM−) anion in ILs leads to low shear viscosity and improvement of several characteristics suitable for large scale applications. However, properties including interactions of TCM− with the local environment and dynamics of TCM− have not been thoroughly investigated. Herein, we have studied the ultrafast dynamics of TCM− in several imidazolium ILs using linear IR and two-dimensional infrared spectroscopy techniques. The spectral diffusion dynamics of the CN stretching modes of TCM− in all ILs exhibit a nonexponential behavior with a short time component of ∼2 ps and a long time component spanning ∼9 ps to 14 ps. The TCM− vibrational probe reports a significantly faster relaxation of ILs compared to those observed previously using linear vibrational probes, such as thiocyanate and selenocyanate. Our results indicate a rapid relaxation of the local ion-cage structure embedding the vibrational probe in the ILs. The faster relaxation suggests that the lifetime of the local ion-cage structure decreases in the presence of TCM− in the ILs. Linear IR spectroscopic results show that the hydrogen-bonding interaction between TCM− and imidazolium cations in ILs is much weaker. Shorter ion-cage lifetimes together with weaker hydrogen-bonding interactions account for the low shear viscosity of TCM− based ILs compared to commonly used ILs. In addition, this study demonstrates that TCM− can be used as a potential vibrational reporter to study the structure and dynamics of ILs and other molecular systems.
Improvement of uneven charge distribution on piezoelectric circular diaphragm with notched-substrate
Authors: Han Yu , Li Yuanbo , Yang Yangyiwei , Li Minghao , Yang Tongqing
Published: April 2020

Vibration-based energy harvesting using piezoelectric circular diaphragms (PCDs) has drawn much attention in recent decades because of their compatibility with various operation modes. However, it has been revealed that their output distribution over the electrode surface is highly uneven, with less output generated around the edge. In this work, we present a possible structure of a PCD, which consists of a notched substrate (notched PCD), a PZT-5H disk, and an annular mass, in which the charge output around the edge of the PCD can be enhanced. Moreover, the difference in charge production between the outer region (the region with less charge) and the inner region (the region with high charge) is reduced so that the output distribution of the PCD is improved. In the notched-PCD, the perimeter region of the PCD is better utilized, which leads to a higher output power. Finite element analysis is performed in order to provide further information about how the notched substrates affect the output distribution on the PCD: the more the notches on the substrate, the more the extra charge generated on the PZT-5H disk. The experimental results also present the increases in the total output power of the notched PCD compared to the PCD without notches. In addition, there are two peaks in the normalized output power curve, the values of which are 1.6 corresponding to 9 mW for the output (with 10-notched PCD) and 1.8 corresponding to 10 mW for the output (with 4-notched PCD).
Quantum mechanical analysis of 2D transition metal dichalcogenide material based vertical heterojunction tunnel FET
Authors: Paul Tanmoy Kumar , Khosru Quazi Deen Mohd
Published: April 2020

In this work, a single layer n-doped MoS2 and p-doped WTe2 based vertical heterojunction tunnel FET has been investigated through a well-organized quantum mechanical approach. The key outcome is the design criteria of the device for low subthreshold swing keeping its length as short as possible. Inter-coupled real space model Hamiltonian of the device is formed by introducing the coupling energy of the WTe2 valence band and the MoS2 conduction band in the overlap region. Here, MATLAB based self-consistent analysis is used to numerically solve the device by coupling Schrödinger and Poisson equations taking into account the plane dependence of permittivity in 2D transition metal dichalcogenide materials. For 15 nm channel overlap length and 15 nm gate extension length, a subthreshold slope of as low as 10 mV/decade has been obtained. For 20 nm channel overlap length, an ON current of 18 µA/μm has been obtained as well. The effect of the top gate extension, overlap length, and dielectric layer thickness over the ON and OFF state currents has been explained from the viewpoint of device physics. Thus, the framework presented will help designers to optimize the device for improved performance.
Hybrid chemical bath deposition-CdS/sputter-Zn(O,S) alternative buffer for Cu2ZnSn(S,Se)4 based solar cells
Authors: Kogler Willi , Schnabel Thomas , Ahlswede Erik , Taskesen Teoman , Gütay Levent , Hauschild Dirk , Weinhardt Lothar , Heske Clemens , Seeger Jasmin , Hetterich Michael , Powalla Michael
Published: April 2020

To replace the conventionally used CdS buffers in Cu2ZnSn(S,Se)4 (CZTSSe) based thin-film solar cells, sputtered Zn(O,S) buffer layers have been investigated. Zn(O,S) layers with three different [O]/([O] + [S]) ratios (0.4, 0.7, and 0.8)—and a combination of Zn(O,S) and CdS (“hybrid buffer layer”) were studied. In comparison to the CdS reference, the external quantum efficiency (EQE) of the Zn(O,S)-buffered devices increases in the short- and long-wavelength regions of the spectrum. However, the average EQE ranges below that of the CdS reference, and the devices show a low open-circuit voltage (VOC). By adding a very thin CdS layer (5 nm) between the absorber and the Zn(O,S) buffer, the VOC loss is completely avoided. Using thicker intermediate CdS layers result in a further device improvement, with VOC values above those of the CdS reference. X-ray photoelectron spectroscopy (XPS) measurements suggest that the thin CdS layer prevents damage to the absorber surface during the sputter deposition of the Zn(O,S) buffer. With the hybrid buffer configuration, a record VOC deficit, i.e., a minimum difference between bandgap energy Eg (divided by the elementary charge q) and VOC (Eg/q – VOC) of 519 mV could be obtained, i.e., the lowest value reported for kesterite solar cells to date. Thus, the hybrid buffer configuration is a promising approach to overcome one of the main bottlenecks of kesterite-based solar cells, while simultaneously also reducing the amount of cadmium needed in the device.
Quantum dots of two-dimensional Ruddlesden–Popper organic–inorganic hybrid perovskite with high optical limiting properties
Authors: J. Varma Sreekanth , Cherusseri Jayesh , Li Jinxin , Kumar Jitesh , Barrios Elizabeth , Thomas Jayan
Published: April 2020

Hybrid perovskites have been investigated for various potential applications because of their tunable optical properties. In this paper, we report the synthesis of quantum dots (QDs) of two-dimensional (2D) Ruddlesden–Popper (RP) hybrid perovskite using a top-down approach. The QDs of the developed 2D RP perovskite exhibit high and sharp photoluminescence in the ultraviolet region. The sharp peak in the absorption spectrum and the intense photoluminescence in the ultraviolet region indicate strong quantum confinement in these particles, which is further confirmed by x-ray photoelectron spectroscopy. These QDs show superior nonlinear optical scattering and absorption properties with the optical z-scan technique and strong nonlinear absorption property with the photoacoustic z-scan technique. Evaluating the nonlinear optical properties using two complementary techniques provides a deeper understanding of the nonlinear mechanism involved in the optical limiting process. The two-photon absorption coefficient obtained by optical z-scan is 7.2 × 102 cm/GW, which is larger than that of most perovskite nanocrystals and nanosheets. Our studies, therefore, reveal a new class of material, 2D RP perovskite QDs, which show important nonlinear properties that are important for optical limiting applications.
Numerical study on the attenuation effect on the blast wave of encircling a high explosive with granular media
Authors: Sugiyama Yuta , Homae Tomotaka , Matsumura Tomoharu , Wakabayashi Kunihiko
Published: April 2020

This study explored the practicality of a two-phase flow model for granular media in elucidating the attenuation mechanism of the blast wave. To validate the model, the numerical data were compared with the results of the previous experiments in terms of the interaction between the planar shock wave and particle layer, dispersal of steel particles saturated with a liquid explosive after the detonation of the explosive, and attenuation effect of the particle layer on the blast wave. Results of the validation confirmed good agreement and consistency between both data. Next, the attenuation effect on the blast wave created by a spherical pentolite by encircling the high explosive with a particle layer of sand was investigated, where the main parameter for comparison was the particle layer thickness. Here, a thicker particle layer further attenuated the blast wave, whereas a thinner one was accelerated to a velocity exceeding the sound speed of air, which generates a secondary shock wave ahead of the particle layer and behind the incident shock wave. When the secondary shock wave was coupled with the incident shock wave, the blast wave strength was locally recovered. To quantitatively comprehend the attenuation mechanism of the particle layer on the blast wave, the total energy transfer between the particle layer and air was computed. Results revealed a strong correlation between the blast wave strength and the amount of energy transferred between the particle layer and air and to the flow structures generated by the particle motion.
Thermo-elastic model for the prediction of thermodynamic properties of high temperature phase change materials under confinement: Isobaric and isochoric regimes
Authors: Hernández-Cooper Ernesto M. , Otero José A. , Chong-Quero J. Enrique
Published: April 2020

Thermal energy storage through encapsulation of phase change materials is critical for the efficient usage of renewable energy. In this paper, a model is proposed to include thermal and pressure induced density changes in a confined phase change material. To the best of the authors’ knowledge, the local energy balance at the interface and the total mass balance that couple thermal and pressure induced density changes during melting of confined phase change materials are proposed for the first time. The proposed model is solved for a KNO3 salt and several values of the elastic constant in order to probe the phase transition in the whole pressure domain. The behavior of the thermodynamic variables is investigated for other kinds of salts used in high temperature thermal energy storage applications and in the high pressure regime. In all the examples shown, and when the phase change process takes place close to the isochoric regime, the effects of temperature dependent densities are found to be enhanced by pressure induced density changes. However, close to the isobaric regime, the effects of temperature dependent densities are almost negligible. Finally, the thermal energy stored during the melting process is obtained. Close to the isochoric regime, and depending on the types of boundary conditions, the sensible heat stored is found to be enhanced by thermal expansion, while the latent heat absorbed is significantly reduced.
Fluid–structure interaction simulation based on immersed boundary-lattice Boltzmann flux solver and absolute nodal coordinate formula
Authors: Liu Fan , Liu Gang , Shu Chang
Published: April 2020

Large deformation fluid–structure interaction (FSI) is a typical nonlinear problem in aero elastics. Engineering applications can be found in aviation, marine engineering, and bio-fluid mechanics. A three-dimensional (3D) parallel FSI solver based on an immersed boundary-lattice Boltzmann flux solver (IB-LBFS) and absolute nodal coordinate formula (ANCF) is established. The computational efficiency of the parallel IB-LBFS with moving boundaries is improved by several acceleration techniques, including Euler–Lagrangian interpolation matrix parallel assembling and sparse matrix solving methods. Structure dynamics simulation discretized in high-order ANCF elements distinctly reduces the number of finite elements compared with the standard finite element method. A multiple body dynamics (MBD) solver including a rigid body, ANCF cable elements, and ANCF plate elements is developed. The IB-LBFS, MBD solver, and coupled FSI solver are tested by the corresponding validation examples. A framework of solving 3D FSI problems of complex multiple flexible structures with large deformation in incompressible flow is presented. An implicit boundary condition enforced method is applied to achieve a strong coupling approach. For application demonstration, the inflation process of several types of parachute systems is simulated in which different Young’s moduli of the parachute canopy are considered. The interaction between dynamic deformation and an unsteady vortex is obtained and discussed.
Residual entropy model for predicting the viscosities of dense fluid mixtures
Authors: Binti Mohd Taib Malyanah , Trusler J. P. Martin
Published: April 2020

In this work, we have investigated the mono-variant relationship between the reduced viscosity and residual entropy in pure fluids and in binary mixtures of hydrocarbons and hydrocarbons with dissolved carbon dioxide. The mixtures considered were octane + dodecane, decane + carbon dioxide, and 1,3-dimethylbenzene (m-xylene) + carbon dioxide. The reduced viscosity was calculated according to the definition of Bell, while the residual entropy was calculated from accurate multi-parameter Helmholtz-energy equations of state and, for mixtures, the multi-fluid Helmholtz energy approximation. The mono-variant dependence of reduced viscosity upon residual molar entropy was observed for the pure fluids investigated, and by incorporating two scaling factors (one for reduced viscosity and the other for residual molar entropy), the data were represented by a single universal curve. To apply this method to mixtures, the scaling factors were determined from a mole-fraction weighted sum of the pure-component values. This simple model was found to work well for the systems investigated. The average absolute relative deviation (AARD) was observed to be between 1% and 2% for pure components and a mixture of similar hydrocarbons. Larger deviations, with AARDs of up to 15%, were observed for the asymmetric mixtures, but this compares favorably with other methods for predicting the viscosity of such systems. We conclude that the residual-entropy concept can be used to estimate the viscosity of mixtures of similar molecules with high reliability and that it offers a useful engineering approximation even for asymmetric mixtures.
Dissipative particle dynamics for systems with polar species: Interactions in dielectric media
Authors: Gavrilov Alexey A.
Published: April 2020

In this work, we develop a method for simulating polar species in the dissipative particle dynamics (DPD) method. The main idea behind the method is to treat each bead as a dumb-bell, i.e., two sub-beads kept at a fixed distance, instead of a point-like particle. The relation between the bead dipole moment and the bulk dielectric permittivity was obtained. The interaction force of single charges in polar liquid showed that the effective dielectric permittivity is somewhat smaller than that obtained for the bulk case at large separation between the charges. In order to understand the reasons behind the observed drop in the dielectric permittivity, we calculate the electric field of an isolated charge in a polar liquid; no permittivity drop is observed for this case. We can assume that the behavior observed for the force is due to the fact that the probing point is always associated with the charged bead, which is a force center, which essentially leads to a non-homogeneous density distribution around it on average; this is not the case when the field is measured. The interaction of a single charge with an interface between two liquids with different permittivities was studied after that; the model is found to correctly reproduce the “mirror image” effects. Finally, we show why it is necessary to treat the polar species in DPD explicitly by investigating the behavior of a charged colloidal particle at a liquid–liquid interface.
Explicit unsteady Navier–Stokes solutions and their analysis via local vortex criteria
Authors: Pedergnana Tiemo , Oettinger David , P. Langlois Gabriel , Haller George
Published: April 2020

We construct a class of spatially polynomial velocity fields that are exact solutions of the planar unsteady Navier–Stokes equation. These solutions can be used as simple benchmarks for testing numerical methods or verifying the feasibility of flow-feature identification principles. We use examples from the constructed solution family to illustrate the deficiencies of streamline-based feature detection and those of the Okubo–Weiss criterion, which is the common two-dimensional version of the broadly used Q-, Δ-, λ2-, and λci-criteria for vortex-detection. Our planar polynomial solutions also extend directly to explicit, three-dimensional unsteady Navier–Stokes solutions with a symmetry.
Deep learning-based reconstruction of the structure of heterogeneous composites from their temperature fields
Authors: Wu Haiyi , Zhang Hongwei , Hu Guoqing , Qiao Rui
Published: April 2020

Inverse problems involving transport phenomena are ubiquitous in engineering practice, but their solution is often challenging. In this work, we build a data-driven deep learning model to predict the heterogeneous distribution of circle-shaped fillers in two-dimensional thermal composites using the temperature field in the composite as an input. The deep learning model is based on convolutional neural networks with a U-shape architecture and encoding–decoding processes. The temperature field is cast into images of 128 × 128 pixels. When the true temperature at each pixel is given, the trained model can predict the distribution of fillers with an average accuracy of over 0.979. When the true temperature is only available at 0.88% of the pixels inside the composite, the model can predict the distribution of fillers with an average accuracy of 0.94, if the temperature at the unknown pixels is obtained through the Laplace interpolation. Even if the true temperature is only available at pixels on the boundary of the composite, the average prediction accuracy of the deep learning model can still reach 0.80; the prediction accuracy of the model can be improved by incorporating true temperature in regions where the model has low prediction confidence.
TRAVIS—A free analyzer for trajectories from molecular simulation
Authors: Brehm M. , Thomas M. , Gehrke S. , Kirchner B.
Published: April 2020

TRAVIS (“Trajectory Analyzer and Visualizer”) is a program package for post-processing and analyzing trajectories from molecular dynamics and Monte Carlo simulations, mostly focused on molecular condensed phase systems. It is an open source free software licensed under the GNU GPL, is platform independent, and does not require any external libraries. Nine years after the original publication of TRAVIS, we highlight some of the recent new functions and features in this article. At the same time, we shortly present some of the underlying algorithms in TRAVIS, which contribute to make trajectory analysis more efficient. Some modern visualization techniques such as Sankey diagrams are also demonstrated. Many analysis functions are implemented, covering structural analyses, dynamical analyses, and functions for predicting vibrational spectra from molecular dynamics simulations. While some of the analyses are known since several decades, others are very recent. For example, TRAVIS has been used to compute the first ab initio predictions in the literature of bulk phase vibrational circular dichroism spectra, bulk phase Raman optical activity spectra, and bulk phase resonance Raman spectra within the last few years.
Thermally tunable whispering-gallery mode cavities for magneto-optics
Authors: Vincent Serge , Jiang Xin , Russell Philip , Vollmer Frank
Published: April 2020

We report the experimental realization of magneto-optical coupling between whispering-gallery modes in a germanate (56GeO2-31PbO-9Na2O-4Ga2O3) microspherical cavity due to the Faraday effect. An encapsulated gold conductor heats the resonator and tunes the quasi-transverse electric (TE) and quasi-transverse magnetic (TM) polarized modes with an efficiency of ∼ 65 fm/V at a peak-to-peak bias voltage of 4 V. The signal parameters for a number of heating regimes are quantified to confirm sensitivity to the generated magnetic field. The quasi-TE and quasi-TM resonance frequencies stably converge near the device's heating rate limit (equivalently, bias voltage limit) in order to minimize inherent geometrical birefringence. This functionality optimizes Faraday rotation and thus enables the observation of subsequent magneto-optics.
Developmental programming: intrauterine caloric restriction promotes upregulation of mitochondrial sirtuin with mild effects on oxidative parameters in the ovaries and testes of offspring
Authors: Dal Magro B. M. , Stone V. , Klein C. P. , Maurmann R. M. , Saccomori A. B. , dos Santos B. G. , August P. M. , Rodrigues K. S. , Conrado L. , de Sousa F. A. B. , Dreimeier D. , Mello F. , Matté C.
Published: April 2020

According to the developmental origins of health and disease (DOHaD) hypothesis, changes in the maternal environment are known to reprogram the metabolic response of offspring. Known for its redox modulation, caloric restriction extends the lifespan of some species, which contributes to diminished cellular damage. Little is known about the effects of gestational caloric restriction, in terms of antioxidant parameters and molecular mechanisms of action, on the reproductive organs of offspring. This study assessed the effects of moderate (20%) caloric restriction on redox status parameters, molecular expression of sirtuin (SIRT) 1 and SIRT3 and histopathological markers in the ovaries and testes of adult rats that were subjected to gestational caloric restriction. Although enzyme activity was increased, ovaries from female pups contained high levels of oxidants, whereas testes from male pups had decreased antioxidant enzyme defences, as evidenced by diminished glyoxalase I activity and reduced glutathione content. Expression of SIRT3, a deacetylase enzyme related to cellular bioenergetics, was increased in both ovaries and testes. Previous studies have suggested that, in ovaries, diminished antioxidant metabolism can lead to premature ovarian failure. Unfortunately, there is little information regarding the redox profile in the testis. This study is the first to assess the redox network in both ovaries and testes, suggesting that, although intrauterine caloric restriction improves molecular mechanisms, it has a negative effect on the antioxidant network and redox status of reproductive organs of young adult rats.
Soil biochemical activities after the application of pyroligneous acid to soil
Authors: Cardelli Roberto , Becagli Michelangelo , Marchini Fausto , Saviozzi Alessandro
Published: April 2020

Pyroligneous acid (PA) is produced during the combustion of woody biomass and is a complex aqueous fraction resulting from the thermochemical rupture of the components of vegetable biomass. We evaluated the effect of PA on the soil microbial community and activity in order to assess the applicability of this acid in soil and to gather further information on the mechanisms of its toxicity or stimulation. Five concentrations of PA solution (0, 0.5, 1, 2 and 5%) were selected to monitor the biochemical parameters of the soil. The respirometric test showed that the increase in the evolved carbon dioxide-carbon (C) was not due to a release of the native organic C from the soil, but only from the organic compounds of PA. The highest values of microbial biomass content were found in the soil treated with the lowest PA doses, but decreased with increased doses. At higher application doses (2 and 5%), there was a decrease in most enzymatic activities and a loss of soil quality. When PA was applied in doses of up to 1%, our results indicated no negative effects on soil biology and that there was even an improvement.
Improved elevated temperature mechanical properties of graphene-reinforced pure aluminium matrix composites
Authors: Turan Muhammet Emre , Aydin Fatih
Published: April 2020

In this study, graphene nanoplatelets (0.25 and 0.5 wt-%) reinforced aluminium matrix composites were synthesised. Microstructures of composites were investigated by X-ray diffraction, scanning electron microscope and transmission electron microscope. Hardness was measured according to the Vickers test method. Tensile tests were performed at both room (25°C) and elevated temperatures (150°C and 250°C). Results showed that hardness was improved with direct addition of graphene. Microstructure of composites was free of macro defects. Yield and tensile strength behaviours of pure aluminium were increased with the addition of graphene especially at room temperature. Graphene-reinforced samples have higher compressive residual stress. From the outer surface to inner surface, transition from compressive to tensile residual stress was observed for samples.
Building the nation in Southern Sudan: state emblems, symbols and national identity
Authors: Ylönen Aleksi
Published: April 2020

This article discusses a selection of state emblems, national symbols and national identity in Southern Sudan. The emblems and symbols are used to provide meaning to a nation in the making and serve as pillars for common national identification to guide the formation of national identity. In essence, they represent the top-down process of politically dominant societal actors’ attempt to effect nation building by seeking to promote their desired type of national identity. Drawing on field observations and analysis aimed at examining aspects of state symbols and national identity, the article shows that the meanings attached to the adopted state emblems and national symbols can be inclusionary or exclusionary and may encourage unity or division. It argues that any attempt to promote unifying and cohesive national identity following a long and divisive armed conflict, as in the case of Southern Sudan, requires the adoption of inclusive and positively meaningful state emblems and national symbols.
Mitochondria as intracellular signaling platforms in health and disease
Authors: Tan Jay X. , Finkel Toren
Published: April 2020

Mitochondria, long viewed solely in the context of bioenergetics, are increasingly emerging as critical hubs for intracellular signaling. Due to their bacterial origin, mitochondria possess their own genome and carry unique lipid components that endow these organelles with specialized properties to help orchestrate multiple signaling cascades. Mitochondrial signaling modulates diverse pathways ranging from metabolism to redox homeostasis to cell fate determination. Here, we review recent progress in our understanding of how mitochondria serve as intracellular signaling platforms with a particular emphasis on lipid-mediated signaling, innate immune activation, and retrograde signaling. We further discuss how these signaling properties might potentially be exploited to develop new therapeutic strategies for a range of age-related conditions.