bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncertainty quantification and sensitivity studies on Thorium-fueled reactors
Authors: Party Eliot , Doligez Xavier , Dessagne Philippe , Kerveno Maëlle , Henning Greg
Published: September 2020

This paper shows how Total Monte Carlo (TMC) method and Perturbation Theory (PT) can be applied to quantify uncertainty due to nuclear data on reactor static calculations of integral parameters such as keff and βeff. This work focuses on thorium fueled reactors and it aims to rank different cross sections uncertainty regarding criticality calculations. The consistency of the two methods are first studied. The cross sections set used for the TMC method is computed to build adequate correlation matrices. Those matrices are then multiplied by the sensitivity coefficients obtained thanks to the PT to obtain global uncertainties that are compared to the ones calculated by the TMC method. Results in good agreement allow us to use correlation matrix from the state of the art nuclear data library (JEFF 3-3) that provide insight of uncertainty on keff and βeff for thorium fueled Pressurized Water Reactors. Finally, maximum uncertainties on cross sections are estimated to reach a target uncertainty on integral parameters. It is shown that a strong reduction of the current uncertainty is needed and consequently, new measurements and evaluations have to be performed.
Citizen science in radiation research
Authors: Gustavsson Cecilia , Andersson-Sundén Erik , Barker Abigail , Hjalmarsson Anders , Lantz Mattias , Lundén Karl , Pomp Stephan
Published: September 2020

A growing trend in science is that research institutions reach out to members of the public for participating in research. The reasons for outreach are many, spanning from the desire to collect and/or analyse large sets of data efficiently, to the idea of including the general public on a very fundamental level in science-making and ultimately decision-making. The presented project is curriculum-based and carried out in 240 lower secondary school classes (pupils of age 13-16). The task, as designed by the participating universities, is to collect mushrooms, soil and animal droppings from different parts of Sweden, do preliminary sample preparation and analyses and send the samples to the university institutions for radioactivity measurement. Behind the project is a desire to compare today’s levels of137Cs with those deposited right after the Chernobyl accident in 1986, but also to study the exchange of caesium between organisms as well as the impacts of biological and geological processes on uptake and retention. The scientific outcome is a geodatabase with the137Cs activity (Bq/m2) present in the Swedish environment, where radioactivity data can be linked to the species (fungi, competing species, animals foraging), forest type, land type, land use and other environmental factors. The science question is of interest to the general public as foraging for mushrooms, as well as spending recreational time in forests is widely popular in Sweden. In this article, we will discuss the current status of the project and the observations we have made about how well the public can participate in scientific research. Focus will be on organization of the project, such as logistics, preparation of supportive material, feedback and communication between researchers and schools. We will present observations about the impact the project has had on the participants, based on quantitative and qualitative evaluations.
Listening to the quantum vacuum: a perspective on the dynamical Casimir effect
Authors: Paraoanu Gheorghe Sorin , Johansson Göran
Published: September 2020

Modern quantum field theory has offered us a very intriguing picture of empty space. The vacuum state is no longer an inert, motionless state. We are instead dealing with an entity teeming with fluctuations that continuously produce virtual particles popping in and out of existence. The dynamical Casimir effect is a paradigmatic phenomenon, whereby these particles are converted into real particles (photons) by changing the boundary conditions of the field. It was predicted 50 years ago by Gerald T. Moore and it took more than 40 years until the first experimental verification.
The route problem of multimodal transportation with timetable under uncertainty: multi-objective robust optimization model and heuristic approach
Authors: Peng Yong , Yong Pengcheng , Luo Yijuan
Published: September 2020

The uncertainty of transportation duration between nodes is an inherent characteristic and should be concerned in the routing optimization of the multimodal transportation network to guarantee the reliability of delivery time. The interval number is used to deal with the uncertainty of transportation duration, and the multi-objective robust optimization model is established which covers the transportation duration and the cost. To solve the combinatorial optimization problem of this study, Non-Dominated Sorting Genetic Algorithm-II (NSGA-II) is designed, which integrates the (μ + λ) selection method elite retention and the external filing elite retention. Our findings verify the efficiency of the proposed approach by analyzing the diversity, distribution and convergence of the frontier solutions. Finally, near-optimal solutions are obtained with the proposed algorithm in the numerical example. The present study can provide decision reference for multimodal transportation carriers in making transportation plan under uncertainty.
4 Fachleute – 4 Strategien: Diskopathien beim Hund
Authors: Düver Pia , Challande-Kathmann Iris , Börner Doris , Zohmann Andreas
Published: September 2020

Für die Entscheidung, ob eine Diskopathie (Diskusprolaps, Bandscheibenvorfall) chirurgisch oder konservativ behandelt werden muss, ist eine vorhergehende genaue diagnostische Abklärung unabdingbar. Um das Ziel der Wiedererlangung eines normalen Gangbildes und guter Lebensqualität für den Patienten zu unterstützen und zu erreichen, stehen uns zahlreiche therapeutische Möglichkeiten zur Verfügung. Da diese oft in Kombination die beste Wirkung entfalten, ist eine interdisziplinäre Zusammenarbeit in enger Abstimmung anzustreben.
Kann man die Asymmetrie des Pferdes durch den Reiter behandeln?
Authors: Hallring Maria , Börner Doris
Published: September 2020

„Reite dein Pferd vorwärts und richte es gerade!“ In diesem Zitat des Reitmeisters Gustav Steinbrecht kommt zum Ausdruck, wie wichtig die Geraderichtung und damit die Balance des Pferdes unter dem Reiter ist. Ein gerades Pferd kann es allerdings nur geben, wenn auch der Reiter und das bindende Glied zwischen Reiter und Pferd – der Sattel – ausbalanciert sind. Ist dieses nicht der Fall, entstehen physikalische Kräfte, die zu Schmerzen und Krankheiten bei Reiter und Pferd führen können. Der Sattel muss also nicht nur zum Pferd passen, sondern unbedingt auch zum Reiter. Warum ist das so und wie kann man diesem Anspruch Rechnung tragen?
Long-Term Clinical Outcome in Elderly Patients Undergoing Mitral Valve Repair
Authors: Götte Julia , Zittermann Armin , Hakim-Meibodi Kavous , Hata Masatoshi , Schramm Rene , Bleiziffer Sabine , Parsa Mohammed Amin , Gummert Jan , Renner Andre
Published: September 2020

Background Long-term data on patients over 75 years undergoing mitral valve (MV) repair are scarce. At our high-volume institution, we, therefore, aimed to evaluate mortality, stroke risk, and reoperation rates in these patients.

Methods We investigated clinical outcomes in 372 patients undergoing MV repair with (n = 115) or without (n = 257) tricuspid valve repair. The primary endpoint was the probability of survival up to a maximum follow-up of 9 years. Secondary clinical endpoints were stroke and reoperation of the MV during follow-up. Univariate and multivariable Cox regression analysis was performed to assess independent predictors of mortality. Mortality was also compared with the age- and sex-adjusted general population.

Results During a median follow-up period of 37 months (range: 0.1–108 months), 90 patients died. The following parameters were independently associated with mortality: double valve repair (hazard ratio, confidence interval [HR, 95% CI]: 2.15, 1.37–3.36), advanced age (HR: 1.07, CI: 1.01–1.14 per year), diabetes (HR: 1.97, CI: 1.13–3.43), preoperative New York Heart Association (NYHA) functional class (HR: 1.41, CI: 1.01–1.97 per class), and operative creatininemax levels (HR: 1.32, CI: 1.13–1.55 per mg/dL). The risk of stroke in the isolated MV and double valve repair groups at postoperative year 5 was 5.0 and 4.1%, respectively (p = 0.65). The corresponding values for the risk of reoperation were 4.0 and 7.0%, respectively (p = 0.36). Nine-year survival was comparable with the general population (53.2 vs. 53.1%).

Conclusion Various independent risk factors for mortality in elderly MV repair patients could be identified, but overall survival rates were similar to those of the general population. Consequently, our data indicates that repairing the MV in elderly patients represents a suitable and safe surgical approach.
Emergency Surgery during COVID-19: Lessons Learned
Authors: Bhattacharjee Hemanga K. , Chaliyadan Shafneed , Verma Eshan , Kumaran Keerthi , Bhargava Priyank , Singh Abhishek , Maitra Souvik , Parshad Rajinder
Published: September 2020

Introduction The ongoing coronavirus disease-2019 (COVID-19) pandemic has disrupted health services throughout the world. It has brought in several new challenges to deal with surgical emergencies. Herein, we report two suspected cases of COVID-19 that were operated during this “lockdown” period and highlight the protocols we followed and lessons we learned from this situation.

Result Two patients from “red zones” for COVID-19 pandemic presented with acute abdomen, one a 64-year male, who presented with perforation peritonitis and another, a 57-year male with acute intestinal obstruction due to sigmoid volvulus. They also had associated COVID-19 symptoms. COVID-19 test could not be done at the time of their presentation to the hospital. Patients underwent emergency exploratory laparotomy assuming them to be positive for the infection. Surgical team was donned with full coverall personal protective equipment. Sudden and uncontrolled egression intraperitoneal free gas was avoided, Echelon flex 60 staplers were used to resect the volvulus without allowing the gas from the volvulus to escape; mesocolon was divided using vascular reload of the stapler, no electrosurgical devices were used to avoid the aerosolization of viral particles. Colostomy was done in both the patients. Both the patients turned out to be negative for COVID-19 subsequently and discharged from hospital in stable condition.

Conclusion Surgeons need to adapt to safely execute emergency surgical procedures during this period of COVID-19 pandemic. Preparedness is of paramount importance. Full precautionary measures should be taken when dealing with any suspected case.
Report of the First Training the Colonoscopy Trainers Courses Held in India
Authors: Basumani Pandurangan , Donnelly Mark Thomas , Riley Stuart Anthony , Thoufeeq Md. , Ravi Ramakrishnan
Published: September 2020

Background and Aim Training the colonoscopy trainers (TCT) courses have become widespread in the United Kingdom and elsewhere but have never taken place in India. This is an account of the first such course delivered in India with an attempt to demonstrate its impact on the training knowledge and abilities of the delegates.

Materials and Methods Twelve independent colonoscopists, all with a training remit, underwent a structured 2-day TCT course. They were asked retrospectively to self-assess their knowledge and training skills across a number of metrics using a 1–10 scale, before and after attending the course.

Statistical Analysis Scores were analyzed by the Wilcoxon’s two-tail test

Results Delegates training knowledge and skills improved significantly across all seven metrics (p < 0.01 for all).

Conclusion The TCT is highly suitable in the Indian endoscopic environment and very effective in improving the training knowledge and skills of even experienced colonoscopists.
The Evolution of the Free Fibula Flap for Head and Neck Reconstruction: 21 Years of Experience with 128 Flaps
Authors: Fliss Ehud , Yanko Ravit , Bracha Gal , Teman Roy , Amir Aharon , Horowitz Gilad , Muhanna Nidal , Fliss Dan M. , Gur Eyal , Zaretski Arik
Published: September 2020

Background The free fibula flap is commonly referred to as a “workhorse” for head and neck reconstruction. During our 21-year experience with this flap, we have performed several changes in preoperative planning, operative technique, and postoperative follow-up.

Patients and Methods A retrospective cohort study designed to analyze the cohort of patients who underwent free fibula transfer for head and neck reconstruction. Demographics, medical background, operative data, and postoperative outcome were collected. The changes we performed in preoperative planning, operative technique, and postoperative follow-up were assessed and their impact on outcome discussed.

Results During 1998 to 2019 a total of 128 free fibula flaps were transferred for head and neck reconstruction. When comparing the patients treated in the early years to those who were treated in recent years we found no statistically significant difference in minor or major nonmicrosurgical complications in the recipient and donor site and in the rate of take backs due to microsurgical reasons. However total flap failure rate improved from 28% in early years to 8% in recent years (p = 0.012).

Conclusion During this 21-year period, we performed several changes in our practice. This included the use of a three-dimensional (3D) prefabricated model of the mandible, a shift toward side-table osteotomies, increasing the rate of osteofascial flaps in contrast to osteocutaneous flaps and the use of an implantable Doppler. These changes, together with a learning curve of the surgical team, significantly improved our overall success rates.
Malignant Gastrointestinal Obstruction: Options for Decompression and Nutrition
Authors: Litwin Robert J. , Chan Johanna L. , Huang Steven Y.
Published: September 2020

Malignant bowel obstruction (MBO) is a relatively common condition affecting patients with advanced malignancy. Therapeutic interventions should be aimed at maintaining quality of life. Given the lack of prospective controlled studies in this patient population, patient management is often based on local practice patterns and anecdotal experience. To foster a collaborative approach among the members of the patient care team involving internal medicine, oncology, palliative care, clinical nutrition, surgery, gastroenterology, and interventional radiology physicians, it is important to improve our understanding of MBO. The purpose of this article is to describe the clinical presentation, pathophysiology, as well as medical, surgical, and nonsurgical palliative options available to patients with MBO for purposes of decompression and nutrition.
So near, so far, so what is social distancing? A fundamental ontological account of a mobile place brand
Authors: Rossolatos George
Published: September 2020

This paper offers a social phenomenological reading of the globally binding practice of ‘social distancing’ in light of the precautionary measures against the spreading of the Covid-19 virus. Amid speculation about the far-reaching effects of temporarily applicable measures and foresights about the advent of an ethos that has been heralded by the media as the ‘new normal’, the ubiquitous phenomenon of social distancing calls for a fundamental ontological elucidation. The purported hermeneutic that is situated in the broader place branding and experiential marketing literatures places Covid-19 in the shoes of Being, and, therefore, imagines how Being would behave ontologically if it were a virus. By arguing that the virus does operate like Being, five theses are put forward as experiential interpretive categories with regard to the ontological status of Covid-19. The adopted approach makes the following contributions to the extant literature: First, it addresses a wholly new phenomenon in place branding, namely a pre-branded place whose meaning is non-negotiable, globally applicable and seemingly equivalent to pure void. Second, it advances the application of phenomenological research in place branding and experiential consumption by highlighting the aptness of the so far peripheral (in the marketing discipline) strand of Heideggerian fundamental ontology. Third, it extends the meaning of place in the place branding literature, by showing how spatialization is the outcome of temporalization, in line with the adopted phenomenological perspective.
Analysis of fluctuation conductivity in Y1−хCdxBa2Cu3O7−δ (x = 0−0.4)
Authors: Aliyev V. M. , Selim-zade R. I. , Ragimov J. A. , Omelchenko L. V. , Petrenko E. V.
Published: September 2020

The effect that the partial substitution of Cd for Y has on the mechanism of excess conductivity formation in polycrystalline Y1−хCdxBa2Cu3O7−δ with x = 0 (Y1), 0.1 (Y2), 0.3 (Y3), and 0.4 (Y4) is investigated. The resistivity ρ of the samples increases markedly with increasing x, and the critical temperature of the superconducting (SC) state transition, Tc, decreases. The mechanism responsible for the formation of fluctuation conductivity, σ'(T), is considered within the framework of the Aslamazov–Larkin theory near Tc. The Ginzburg temperature (TG), the critical temperature in the mean-field approximation (Tcmf), the temperature of the 3D–2D crossover (T0), and T01, which limits the region of the SC fluctuations from above, are determined. It is shown that doping with Cd at x = 0−0.4 increases the coherence length along the c axis, ξc(0), by 2.7 times, and the distance between the CuO2 planes, d01, by 2.2 times. The temperature dependences of the pseudogap (PG), Δ*(T), are determined by analyzing the excess conductivity within the framework of the local pair model. It is found that with an increase in substitution, the maximum value of the PG Δ*(Tpair) decreases from 250.2 to 215.7 K, while the real value of the PG, measured at TG,Δ*(TG), increases from 217.4 to 224.2 K.
Electronic structure of an elbow junction in carbon nanotubes
Authors: Mironov G. I.
Published: September 2020

The author has performed a theoretical analysis of the electronic structure of an elbow junction in single-walled “armchair” (4,4) and “zigzag” (7,0) carbon nanotubes consisting of 131 carbon atoms, as well as in pure carbon “armchair” (4,4) nanotubes consisting of 128 atoms, and “zigzag” nanotubes consisting of 126 atoms. It is shown that in the case of the elbow junction under study, a metal-semiconductor transition does not take place.
Australian chlorofluorocarbon (CFC) emissions: 1960–2017
Authors: Fraser Paul J. , Dunse Bronwyn L. , Krummel Paul B. , Steele L. Paul , Derek Nada , Mitrevski Blagoj , Allison Colin E. , Loh Zoë , Manning Alistair J. , Redington Alison , Rigby Matthew
Published: September 2020

Environmental contextChlorofluorocarbons (CFCs) are potent greenhouse and stratospheric ozone depleting trace gases. Their atmospheric concentrations are in decline, thanks to global production and consumption controls imposed by the Montreal Protocol. In recent years, the rates of decline of CFC atmospheric concentrations, especially for CFC-11 (CCl3F), are not as large as anticipated under the Protocol, resulting in renewed efforts to estimate CFC consumption and/or emissions to possibly identify new or poorly quantified sources.
AbstractAustralian emissions of chlorofluorocarbons (CFCs) have been estimated from atmospheric CFC observations by both inverse modelling and interspecies correlation techniques, and from CFC production, import and consumption data compiled by industry and government. Australian and global CFC emissions show similar temporal behaviour, with emissions peaking in the late-1980s and then declining by ~10% per year through to the present. Australian CFC emissions since 1978 account for less than 1% of global emissions and therefore make a correspondingly small contribution to stratospheric ozone depletion. The current CFC emissions in Australia are likely from ‘banks’ of closed-cell foams, and refrigeration–air conditioning equipment now more than 20 years old. There is no evidence of renewed consumption or emissions of CFCs in Australia. The reduction in CFC emissions has made a significant contribution to reducing Australian greenhouse gas emissions.
Explorations in the relations between reference, syntactic
constructions and prosody
Authors: Klein Janina , Jullien Stéphane , Fox Gwendoline
Published: September 2020

Based on a cross-sectional corpus of 14
mother-child conversations (aged 2;2 to 2;4), this chapter explores
children’s sensitivity to both formal linguistic features and
discourse-pragmatic factors. We considered various issues. The first
was the sensitivity of young children to discourse through a
syntactic construction closely related to discourse and information
structure, i.e., dislocations (see Lambrecht, 1994, for adults, and De Cat, 2007, for
children). The second was the fact that the occurrence of a
referring expression in a syntactic construction was due not only to
discourse-pragmatic characteristics but also to the constraints
imposed by the nature of certain verb frames. The third was young
children’s sensitivity to discourse, examined through variation in
the prosodic contours of referring expressions. Our results indicate
that the children’s use of dislocation is sensitive to
discourse-pragmatic contexts in a way comparable to that of the
adults and that prosody varies with discourse-pragmatic
characteristics. In addition, the nature of the verb frames studied
was also shown to influence children’s choice of referring
expressions.
Infinitely degenerate exact Ricci-flat solutions in f(R) gravity
Authors: Xavier Semin , Mathew Jose , Shankaranarayanan S
Published: September 2020

We obtain an infinite number of exact static, Ricci-flat spherically symmetric vacuum solutions for a class of f(R) theories of gravity. We analytically derive two exact vacuum black-hole solutions for the same class of f(R) theories. The two black-hole solutions have the event-horizon at the same point; however, their asymptotic features are different. Our results suggest that no-hair theorem may not hold for generic modified gravity theories. We discuss the implications of our work to distinguish modified gravity theories from general relativity in gravitational wave detections.
Looping pendulum: theoretical and experimental studies
Authors: Wen Qinghao , Huang Xiucai , Zhang Yansheng , Ong Etienne
Published: September 2020

This work focuses on exploring the phenomenon of looping pendulum proposed by ‘International Young Physicists’ Tournament in 2019, specifically, the various types of loops observed and the physical conditions for a loop to be successful. Firstly, we establish a theoretical model for three distinct stages of the motion observed in the phenomenon, i.e. slipping, non-slipping, and pulling phenomena. We then construct a numerical algorithm for simulation studies so as to predict the looping trajectory, which is significantly influenced by the mass ratio between the masses, the initial release angle of the small mass and the initial distance between the small mass and the tangential point on the rod. Phase plots, which illustrate how varying some of these parameters will affect the type of loop produced, are generated. The theoretical looping trajectories and phase plots are verified experimentally. A qualitative analysis of the common trajectories observed and the successful trends in the phase plots are presented to provide further insights on the physics of this phenomenon. The findings presented in this paper reveal some properties of the looping pendulum and help us to gain a better understanding of its physical behavior.
Interatomic resonant Auger effect in N2O
Authors: Deinert Sascha , Schrodt Alexander , Hartmann Gregor , Achner Alexander , Artemyev Anton N , Ehresmann Arno , Hans Andreas , Ilchen Markus , Glaser Leif , Scholz Frank , Seltmann Jörn , Viefhaus Jens , Demekhin Philipp V , Knie André
Published: September 2020

The interatomic resonant Auger effect in N2O is investigated experimentally and theoretically. We observe variations of the ratio between the yields of 1s-photoionization of the central and terminal nitrogen atom in the photon energy range across the O 1s → π* excitation. The present ab initio calculations of electronic structure and dynamics attribute these variations to the Fano interference between the direct N 1s-photoionizations and the resonant O 1s → π* excitation followed by Auger decays into the respective core–shell continua. The theory reveals that this interatomic core–hole-transfer effect is governed entirely by an energy transfer mechanism, and not by charge transfer.
Electron scattering studies of BF and BF2
Authors: Gupta Dhanoj , Choi Heechol , Song Mi-Young , Singh Suvam , Antony Bobby , Chakrabarti Kalyan , Yoon Jung-Sik , Tennyson Jonathan
Published: September 2020

The present article reports calculated elastic, differential, momentum transfer and excitation cross section for electron scattering from BF and BF2 radicals using the ab initio R-matrix method. The calculations are performed with complete active space—configuration interaction and static exchange models for both targets to yield scattering cross sections and resonance parameters. Elastic and momentum transfer cross sections are also calculated using the spherical complex optical potential method to cover a wide energy range. The total ionization cross section is also reported from ionization threshold to 5 keV. The calculated cross sections for these neutral species are important for BF3 plasma and are reported for the first time to the best of our knowledge except ionization.
Comparative studies of the degrees of orientation of CO molecules pumped by intense femtosecond two-color pulses based on high-order harmonic generation and Coulomb explosion imaging
Authors: Minemoto Shinichirou , Komatsubara Wataru , Sakai Hirofumi
Published: September 2020

With an intense femtosecond two-color pulse optimized for the generation of even-order harmonics from CO molecules, we directly measure the actual degrees of orientation by utilizing the Coulomb explosion imaging technique with appropriate probe polarization. We find that the macroscopic orientation of CO molecules is negligible even when significant even-order harmonics are observed. This finding shows that the generation of even-order harmonics cannot be ascribed to the macroscopic orientation of CO molecules. The rotational wave packet of CO molecules created with an intense femtosecond two-color pulse is thought to be in an uninvestigated quantum state, which cannot be explained by the theoretical model based on the Born–Oppenheimer approximation, without inversion symmetry at any of the three steps of high-order harmonic generation, leading to the generation of even-order harmonics.
Chaotic dynamics of a non-Hermitian kicked particle
Authors: Huang Kai-qian , Wang Jiaozi , Zhao Wen-Lei , Liu Jie
Published: September 2020

We investigate both the classical and quantum dynamics of a kicked particle with

P
T

symmetry. In chaotic situation, the mean energy of the real parts of momentum linearly increases with time, and that of the imaginary momentum exponentially increases. There exists a breakdown time for chaotic diffusion, which is obtained both analytically and numerically. The quantum diffusion of this non-Hermitian system follows the classically chaotic diffusion of Hermitian case during the Ehrenfest time, after which it is completely suppressed. Interestingly, the Ehrenfest time decreases with the decrease of effective Planck constant or the increase of the strength of the non-Hermitian kicking potential. The exponential growth of the quantum out-of-time-order correlators (OTOC) during the initially short time interval characterizes the feature of the exponential diffusion of imaginary trajectories. The long time behavior of OTOC reflects the dynamical localization of quantum diffusion. The dynamical behavior of inverse participation ratio can quantify the

P
T

symmetry breaking, for which the rule of the phase transition points is numerically obtained.
A rotating machinery fault diagnosis method using composite multiscale fuzzy distribution entropy and minimal error of convex hull approximation
Authors: Zhao Xianzhu , Cheng Junsheng , Wang Ping , Yang Yu
Published: September 2020

Rotating machinery plays an increasingly crucial role in mechanical systems. For its normal operation, a novel fault diagnosis method is proposed in this paper, using composite multiscale fuzzy distribution entropy (CMFDE) and minimal error of convex hull approximation (MECHA). In this paper, CMFDE is utilized to extract essential information and measure time series complexity for vibration signals. Results indicate the CMFDE has less information loss and better stability. Then, to fulfill the classification tasks, the first several main features obtained by principal components analysis are fed into the proposed MECHA-based classifier. Results show MECHA has better classification performance. Using the laboratory data, we validate the feasibility and superiority of the proposed fault diagnosis method through two cases consisting of different fault types or fault severity degrees.
Recyclable free-polymer transfer of nano-grain MoS2 film onto arbitrary substrates
Authors: Woo Gunhoo , Kim Hyeong-U , Yoo Hocheon , Kim Taesung
Published: September 2020

Clean transfer of transition metal dichalcogenides (TMDs) film is highly desirable, as intrinsic properties of TMDs may be degraded in a conventional wet transfer process using a polymer-based resist and toxic chemical solvent. Residues from the resists often remain on the transferred TMDs, thereby causing a significant variation in their electrical and optical characteristics. Therefore, an alternative to the conventional wet transfer method is needed—one in which no residue is left behind. Herein, we report that our molybdenum disulfide (MoS2) films synthesized by plasma-enhanced chemical vapor deposition can be easily transferred onto arbitrary substrates (such as SiO2/Si, polyimide, fluorine-doped tin oxide, and polyethersulfone) by using water alone, i.e. without residues or chemical solvents. The transferred MoS2 film retains its original morphology and physical properties, which are investigated by optical microscopy, atomic force microscopy, Raman, x-ray photoelectron spectroscopy, and surface tension analysis. Furthermore, we demonstrate multiple recycling of the resist-free transfer for the nano-grain MoS2 film. Using the proposed water-assisted and recyclable transfer, MoS2/p-doped Si wafer photodiode was fabricated, and the opto-electric properties of the photodiode were characterized to demonstrate the feasibility of the proposed method.
Animal tissue-based quantitative comparison of dual-energy CT to SPR conversion methods using high-resolution gel dosimetry
Authors: Niepel K B , Stanislawski M , Wuerl M , Doerringer F , Pinto M , Dietrich O , Ertl-Wagner B , Lalonde A , Bouchard H , Pappas E , Yohannes I , Hillbrand M , Landry G , Parodi K
Published: September 2020

Dual-energy computed tomography (DECT) has been shown to allow for more accurate ion therapy treatment planning by improving the estimation of tissue stopping power ratio (SPR) relative to water, among other tissue properties. In this study, we measured and compared the accuracy of SPR values derived using both dual- and single-energy CT (SECT) based on different published conversion algorithms. For this purpose, a phantom setup containing either fresh animal soft tissue samples (beef, pork) and a water reference or tissue equivalent plastic materials was designed and irradiated in a clinical proton therapy facility. Dosimetric polymer gel was positioned downstream of the samples to obtain a three-dimensional proton range distribution with high spatial resolution. The mean proton range in gel for each tissue relative to the water sample was converted to a SPR value. Additionally, the homogeneous samples were probed with a variable water column encompassed by two ionization chambers to benchmark the SPR accuracy of the gel dosimetry. The SPR values measured with both methods were consistent with a mean deviation of 0.2%, but the gel dosimetry captured range variations up to 5 mm within individual samples.

Across all fresh tissue samples the SECT approach yielded significantly greater mean absolute deviations from the SPR deduced using gel range measurements, with an average difference of 1.2%, compared to just 0.3% for the most accurate DECT-based algorithm. These results show a significant advantage of DECT over SECT for stopping power prediction in a realistic setting, and for the first time allow to compare a large set of methods under the same conditions.
A review of simulation codes and approaches for radiation chemistry
Authors: Plante Ianik
Published: September 2020

Historically, the field of radiation chemistry began shortly after the discovery of radioactivity, and its development has been closely related to discoveries in other related fields such as radiation and nuclear physics. Radiolysis of water and radiation chemistry have been very important in elucidating how radiation affects living matter and how it induces DNA damage. Nowadays, we recognize the importance of chemistry to understanding the effects of radiation on cells; however, it took several decades to obtain this insight, and much is still unknown. The radiolysis of water and aqueous solutions have been the subject of much experimental and theoretical research for many decades.

One important concept closely related to radiation chemistry is radiation track structure. Track structure results from early physical and physicochemical events that lead to a highly non-homogenous distribution of radiolytic species. Because ionizing radiation creates unstable species that are distributed non-homogenously, the use of conventional reaction kinetics methods does not describe this chemistry well. In recent years, several methods have been developed for simulating radiation chemistry. In this review, we give a brief history of the field and the development of the simulation codes. We review the current methods used to simulate radiolysis of water and radiation chemistry, and we describe several radiation chemistry codes and their applications.
Deep level defects and their instability in PLD-grown IGZO (In2Ga2Zn5O11) thin films studied by thermally stimulated current spectroscopy
Authors: Wang Buguo , Look David , Anders Jason , Leedy Kevin , Schuette Michael
Published: September 2020

InGaZnO (IGZO) is an excellent semiconductor material for thin-film transistors (TFTs) used in direct-current and radio-frequency (RF) switching applications, especially since it can be grown at low temperatures on a wide variety of substrates. IGZO thin films with a composition of InGaZnO4 have been deposited and used as channel layers in TFTs for many applications to date; however, IGZO compositions can also be easily changed to vary their properties. These different compositions of IGZO may have different defect properties. In this study, we report the growth of IGZO with composition of In2O3:Ga2O3:5ZnO (In2Ga2Zn5O11) by pulsed laser deposition (PLD) and its electronic defects studied by thermally stimulated current (TSC) spectroscopy. It was found that the as-grown sample has a DC activation energy of 0.62 eV, and four major traps with activation energies between ∼0.16–0.50 eV and one at ∼0.90 eV. Electrical properties and the deep traps of PLD-grown IGZO thin film were found to be varied by post-processing conditions such as thermal history and measurement conditions such as the bias and light exposure applied to the samples. The instabilities induced by these conditions can be explained by structural and stoichiometric features—the ZnO4 tetrahedra and GaO6 octahedra in the structure may become distorted, caused by oxidation or reduction, so that the different defect states could be changed and/or lattice energy variations from the distortion can be observed. This work demonstrates that current-based trap emission, such as that associated with TSC, can effectively reveal electronic defects in highly-resistive semiconductor materials, especially those that are not amenable to capacitance-based techniques, such as deep-level transient spectroscopy, and provide an effective manner to study the trap instabilities in IGZO.
Decreasing the V
th shift of InGaZnO thin-film transistors under positive and negative bias stress using SU-8 as etch-stop and passivation layer
Authors: Lopez Castillo M A , Toledo-Guizar P G , Andraca Adame J A , Garcia R , Hernandez Cuevas F J , Aleman M , Hernandez-Como N
Published: September 2020

In order to expand the InGaZnO (IGZO) technology to several applications other than displays, including integrated circuits with certain complexity, it is necessary to mitigate the V
th shift under bias stress. For this purpose, the use of a passivated semiconductor channel has demonstrated its effectiveness in improving the V
th reliability. In this work, staggered bottom gate IGZO thin-film transistors were fabricated using a 450 nm SU-8 2000.5 film as a passivation and etch-stop layer. The thin-film transistors (TFTs) were fabricated by a full lithography process and the SU-8 film determined the maximum processing temperature of 200 °C. Positive and negative bias stress were performed during 1200 s on 150 μm/40 μm (W/L) TFTs stressed at low field (2 MV cm−1) and high field (4 MV cm−1) leading to a maximum V
th shift of 0.12 V and −0.38 V, respectively. The negative V
th shift was associated to an undesired mechanism dominated by hydrogen migration. The spin coated SU-8 passivation layer demonstrated higher device stability and it can be also used for future interconnection between transistors.
A Kretschmann setup at acoustic frequencies for studying molecular vibration
Authors: Simone Giuseppina , de Ruijter Pim
Published: September 2020

In this study, simultaneous measurement of surface plasmon resonance (SPR) and surface enhanced Raman scattering (SERS) on flat metallic surfaces was demonstrated in a setup based on the Kretschmann configuration at acoustic frequency. This asset facilitates matching the photon and the surface plasmon polaritons wavevectors by tunneling the photon in the total internal reflection geometry and we demonstrate the compensation for the absence of hotspots typical on rough surfaces. The optomechanical asset allows detecting the two signals and prevents their interference. Experimental and numerical analyses were done for characterizing the two signals. The results emphasize the enhancement of the electromagnetic field at the surface, which provides high sensitivity for detecting the signals coming from the Raman probe molecules such as Congo red and thiols such as cysteamine. The combination of simultaneous SPR–SERS microspectroscopy at low frequencies opens up interesting prospects that facilitate experimental conditions using standard SPR setups, with a dramatic reduction in sensor cost.
Optical and dielectric spectroscopic analysis of SmMn2O5
Authors: Ahmad J , Bukhari S H , Khan J A , Jamil M T , Nissar U , BiBi S , Sultan T
Published: September 2020

Polycrystalline SmMn2O5 has been synthesized by using sol-gel auto combustion tecnique. X-ray diffraction (XRD) pattern reflects the single phase formation of orthorhombic structure with Pbam space group. In the frequency range of (30–1000 cm−1) reflectivity spectrum reveals the 14 infrared active phonons out of 36, which are already pridicted theoretically. We have estimated the optical energy band gap (E
g
) ≃ 1.5 eV from UV–visible absorption spectrum. Temperature dependent (293-533 K) DC electrical characterization up to 40 V suggests semiconducting nature of the material. The temperature dependent impedance spectroscopy within a broader frequency range of (20 Hz—3 GHz) shows decreasing behavior of dielectric constant and tangent loss while AC conductivity increasing with the rise in frequency and temperature suggest the strong frequency dispersion and relaxational behavior of the material. The activation energy calculation from AC conductivity is in good agreement with semiconducting material energy band gap.
An algorithm for determining the state of a non-stationary dynamic system for assessing fire safety control in an enterprise by the method of integrated indicators
Authors: Masaev S N , Minkin A N , Edimichev D A
Published: September 2020

Analysis of the scientific literature showed that a lot of work is devoted to assessing the effectiveness of fire safety management in an enterprise. It is worth noting that today there is no universal method for the integrated assessment of fire safety management, taking into account the interconnectedness of all enterprise subsystems and the influence of environmental factors. One of the original approaches to assessing the effectiveness of the fire safety management system is the method of integral indicators. The method of integral indicators is used in the algorithm for analyzing the state of a dynamic non-stationary system for assessing fire safety management in an enterprise. The algorithm is implemented in the author’s complex of programs described in the text of the article. In the simulation, an analysis of 1.2 million values is performed on a well-studied economic object with the spaces identified at each time step: actual data, control and environmental parameters. In the experiment, the basic mode of operation of the enterprise does not contain the implementation of a fire safety management strategy. The research showed significant changes in the values of the integral indicator characterizing the state of the enterprise during the implementation of the fire safety management system at the enterprise.
Explore the feasibility of fabricating pure copper parts with low-laser energy by selective laser melting
Authors: Lingqin Xia , Guang Chen , Luyu Zheng , Pan Lu
Published: September 2020

Pure copper is widely used for complex shapes, high thermal conductivity and good conductivity parts, such as heat exchangers, welding nozzles, injection molds, and various conductive parts. However, traditional manufacturing techniques are difficult to design complex pure copper parts into the most effective thermal and conductive structure. Selective Laser melting(SLM) can fabricate parts with complex shapes directly. However, due to the characteristics of easy oxidation, high optical reflectivity and high thermal conductivity, 3D printing pure copper by SLM is extremely challenging. In this study, the feasibility of fabricating pure copper by low-laser energy was studied by both numerical simulation and printing experiments, and the characteristics of the molten pool (molten pool structure, temperature flow and velocity flow) were studied. The results showed that due to its high thermal conductivity, heat spread out quickly in the molten pool, temperature rise rate and cooling rate reached as high as 1.36 × 107 K S−1, 2.99 × 105 K S−1 respectively. And it took only about 1.7 × 10–4 S for the process time of powder melting and solidification. Additionally, by reducing the particle size, the absorption rate for pure copper was improved, pure copper parts were successfully fabricated with low-laser energy: laser power 500 W, hatching space 0.07 mm, layer thickness 0.03 mm, laser scanning velocity 2500 mm s−1.
Stabilization of an iridium oxygen evolution catalyst by titanium oxides
Authors: Kasian Olga , Li Tong , Mingers Andrea M , Schweinar Kevin , Savan Alan , Ludwig Alfred , Mayrhofer Karl
Published: September 2020

The anodic oxygen evolution reaction (OER) has significant importance in many electrochemical technologies. In proton exchange membrane water electrolyzers it plays a pivotal role for electrochemical energy conversion, yet sluggish kinetics and the corrosive environment during operation still compel significant advances in electrode materials to enable a widespread application. Up-to-date Iridium is known as the best catalyst material for the OER in acidic media due to its relatively high activity and long-term stability. However, scarcity of iridium drives the development of strategies for its efficient utilization. One promising way would be the formation of mixtures in which the noble catalyst element is dispersed in the non-noble matrix of more stable metals or metal oxides. A promising valve metal oxide is TiOx, yet the degree to which performance can be optimized by composition is still unresolved. Thus, using a scanning flow cell connected to an inductively coupled plasma mass spectrometer, we examined the activity and stability for the OER of an oxidized Ir–Ti thin film material library covering the composition range from 20–70 at.% of Ir. We find that regardless of the composition the rate of Ir dissolution is observed to be lower than that of thermally prepared IrO2. Moreover, mixtures containing at least 50 at.% of Ir exhibit reactivity comparable to IrO2. Their superior performance is discussed with complementary information obtained from atomic scale and electronic structure analysis using atom probe tomography and x-ray photoelectron spectroscopy. Overall, our data shows that Ir–Ti mixtures can be promising OER catalysts with both high activity and high stability.
The transport properties of Cl-decorated arsenene controlled by electric field
Authors: Li Bowen , Zhu Lin , Wu Chunyan , Cheng Huanyu , Yao Kailun
Published: September 2020

The large contact resistance is an insurmountable problem for the Schottky contact between the semiconducting two-dimensional channel material and the metal electrode. One solution to the Schottky contact issue is to decrease the contact resistance. Here, by using the first-principles calculations combined with the non-equilibrium Green’s function technique, we find that when monolayer arsenene is covalently bonded with chlorine adatoms, it can transform from the intrinsic semiconductor to metal, which greatly improves its conductivity. Moreover, in the double-layer structure, the Cl adatoms can hop from one layer to the other by applying a vertical electric field. Their interlayer translation can turn arsenene and metallic electrodes from Schottky contact to Ohmic contact, then the resistance is greatly reduced, producing significant switching effects. The highest on/off ratio is as large as 638 at zero bias voltage, which can be utilized as nonvolatile high-density memory and logic operation devices based on arsenene homojunction.
Recent trends in nanothermites: Fabrication, characteristics and applications
Authors: Kabra Shruti , Gharde Swaroop , Gore Prakash M , Jain Sunil , Khire Vrushali H , Kandasubramanian Balasubramanian
Published: September 2020

Energetic materials (EMs) are a group of distinctive materials that release an enormous amount of amassed chemical energy in a short time when incited by external mechanical or thermal factors. They comprise of propellants, explosives, and pyrotechnics. Unlike conventional micro-energetic materials, nano energetic materials (nEMs), due to their smaller particle size ranging from 1–100 nm, exhibit higher specific surface area (~10–50 m2 g−1), reduced ignition temperatures from 2350 K to approx.1000 K for particle size from 100 μm to 100 nm respectively, higher energy densities (up to 50 MJ kg−1), burning rates ~30.48 mm s−1 at 6.894 kPa with specific impulses up to 542 s (5320 m s−1), low impact sensitivity (<4–35 J). Such exceptional properties of nano energetic composites, i.e., thermites (a combination of metal-fuel/metal oxide particles), find applications, namely in, munitions, pyrotechnics, energetic micro-electromechanical system (MEMS) chips. This review provides valuable insight into the synthesis methods of nano energetic composite systems (e.g., Al/CuO, Al/KMnO4, Al/Fe2O3, Al/SnO2, Silicon-based systems), their characteristic properties, behavior under certain conditions and applications. Furthermore, the review converses about the advancements made in the last few decades by many researchers, along with the technological gaps that need to be addressed for futuristic applications.