bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of the Working Parameters of the Biomass Boiler
Authors: Rimár Miroslav , Kulikova Olha , Kulikov Andrii
Published: November 2020

The modern day trend is associated with the green energy. Thermochemical conversion is the commonly used way of extraction energy from the biomass. Nevertheless, the thermochemical processes of the combustion are not totally known. The simulation model of the woodchips boiler was made to understand the processes inside. Simulation model was made for Ansys Fluent 2019. Combustion model consist of two combustion stages: 1st – combustion of volatile compounds, 2nd – combustion of the solid parts. The simulation was validated by the series measurements at the boiler HERZ firemytic 80 BioControl.
Simulation Fluidity Test for Semisolid Squeeze Casting
Authors: Pastirčák Richard , Martinec Denis
Published: November 2020

The paper deals with semi solid squeeze casting technology. Fluidity tests were designed for the selected technology. The shape of the test casting was designed in the shape of test bars with different thicknesses and also in the shape of a stepped casting. The thickness of the individual elements was chosen on the basis of a selected / preferred numbers R10 EN STN 17. As a result, the thickness of the elements was 2.0, 2.5, 3.15, 4.0, 5.0 and 6.3 mm. Designed fluidity tests were verified by using ProCast simulation software. The selected process parameters were: operating pressure 80 MPa, mold temperature 200 °C, piston speed 30 mm.s-1. The experimental material was an AlSi7Mg0.3 alloy with a different solid phase content. The initial solid amount were 50, 55 and 60 %. The effect of solidus and liquidus, temperature distribution and pressure was monitored during the evaluation of fluidity.
Multiphase Flow in the Gap Between Two Rotating Cylinders
Authors: Kozubková Milada , Jablonská Jana , Bojko Marian , Pochylý František , Fialová Simona
Published: November 2020

The research of liquids composed of two (or more) mutually immiscible components is a new emerging area. These liquids represent new materials, which can be utilized as lubricants, liquid seals or as fluid media in biomechanical devices. The investigation of the problem of immiscible liquids started some years ago and soon it was evident that it will have a great application potential. Recently, there has been an effort to use ferromagnetic or magnetorheological fluids in the construction of dumpers or journal bearings. Their advantage is a significant change in dynamic viscosity depending on magnetic induction. In combination with immiscible liquids, qualitatively new liquids can be developed for future technologies. In our case, immiscible fluids increase the dynamic properties of the journal hydrodynamic bearing. The article focuses on the stability of single-phase and subsequently multiphase flow of liquids in the gap between two concentric cylinders, one of which rotates. The aim of the analysis was to study the effect of viscosity and density on the stability/instability of the flow, which is manifested by Taylor vortices. Methods of experimental and mathematical analysis were used for the analysis in order to verify mathematical models of laminar and turbulent flow of immiscible liquids.
Cavitation Flow of Oil and Water Through the Nozzle
Authors: Bojko Marian , Kozubková Milada , Jablonská Jana
Published: November 2020

The hydraulic equipment and elements are designed so that the flow is not significantly affected by the content of gases in the fluid. In the case of cavitation, there is a change in the volumetric amount of gas, which in water is due to the air and water vapour present, and in the case of oils, especially the air content. This phenomenon causes a significant change in the loss coefficient of the element. The problem of cavitation is solved in the literature for water flow, for other hydraulic fluids (e.g. hydraulic oils operated at different temperatures) the problem is still not solved to a sufficient extent. The article deals with the issue of cavitation in systems in which different types of liquids are used. In the introduction, the physical properties of the used liquids are evaluated, because they significantly influence the origin and development of cavitation. Subsequently, an experimental device with a transparent nozzle is described, on which the measurement. The dependence of the loss coefficient and the cavitation number on the Reynolds number is evaluated. Cavitation is evaluated by a high-speed camera, where it is possible to monitor the behaviour of the cavitation cloud.
Vortices inside a single-stage axial air turbine captured by Particle Image Velocimetry
Authors: Duda Daniel , Yanovych Vitalii , Uruba Václav , Němec Martin , Žitek Pavel
Published: November 2020

Particle Image Velocimetry (PIV) is an experimental method of fluid research resulting into a spatially resolved two-dimensional velocity field. We measured the velocity inside a single-stage axial test turbine at the Czech Aerospace Research Centre. We studied the axial × tangential plane just behind the rotor wheel at the tip radius under three regimes: underloaded, designed and overloaded ones. We found individual vortices in the instantaneous snapshots and we analyze their properties statistically.
On the Recirculation Zone Behind a Cylinder of Finite Length with Subcritical Aspect Ratio
Authors: Procházka Pavel , Uruba Václav
Published: November 2020

The Particle Image Velocimetry is utilized to investigate flow behind a cylinder of finite length with subcritical value of Aspect Ratio (AR). The cylinder is submitted to uniform freestream with very low intensity of turbulence and thin laminar boundary layer. The flow field cannot be expected as 2D even for time-averaged quantities. The Strouhal number is evaluated in various planes of measurement. The wake is fully turbulent and is composed of many streamwise and spanwise-oriented structures. Such complex flow is very convenient to be subjected to dynamical decomposition analysis.
Behandlungsmöglichkeiten nach fehlgeschlagenen Osteosynthesen am Femurschaft mit Pseudarthrosen und Torsionsdifferenzen
Authors: Rüther Johannes , Geßlein Markus , Bail Hermann Josef
Published: November 2020

Femurschaftfrakturen sind komplikationsträchtige Verletzungen. Die exakte Reposition der Fragmente, weichteilschonendes Operieren und stabile Osteosyntheseverfahren stellen hohe Anforderungen dar. Kommt es zur Pseudarthrosenbildung, ist in jedem Fall ein individueller Behandlungsplan zu erstellen. Frakturen mit erhaltender Biologie und geringem Knochenverlust lassen sich durch vergleichsweise einfache Techniken zur Durchbauung bringen. Die infizierte Defektpseudarthrose stellt die aufwendigste Komplikation dar. Hierbei muss einerseits die Osteitis saniert werden, andererseits müssen Knochen und Weichteile rekonstruiert werden. Vielfach ist hier ein interdisziplinäres Vorgehen zwischen Unfallchirurg, Gefäßchirurg und plastischem Chirurgen erforderlich. Besonderes Augenmerk muss auf die Führung des Patienten gelegt werden. Behandlungsverläufe von vielen Monaten sind keine Seltenheit. Durch eine korrekte Erstbehandlung lassen sich viele Komplikationen vermeiden, daher sind an die erste Operation genauso hohe Anforderungen zu stellen wie an die weitere Behandlung der Pseudarthrose. Die postoperative Torsionsfehlstellung nach antegrader Marknagelosteosynthese ist eine häufig unterschätze Komplikation mit erheblichen Folgen. Eine intra- und postoperative Kontrolle der Torsion sollte obligat durchgeführt und dokumentiert werden.
Molar Pregnancy in Cesarean Section Scar: A Case Report and Literature Review
Authors: Daggez Mine , Dolanbay Mehmet
Published: November 2020

Molar pregnancy in cesarean scar is an extremely rare condition. It has a high risk of uterine rupture and bleeding. There is a small number of case reports in the literature, so the optimal diagnostic algorithms and management are not clear. We reported a 25-year-old woman who presented to our clinic with amenorrhea for 40 days and vaginal bleeding for 3 days. Transvaginal ultrasonography and serum human chorionic gonadotropin (hCG) level raised suspicion of a molar cesarean scar pregnancy (CSP). Magnetic resonance imaging (MRI) was conducted for further knowledge of the characteristics of the mass. Careful suction curettage under ultrasound guidance was performed. The histologic examination of the tissue confirmed a partial hydatidiform mole. The differential diagnosis between CSP and molar CSP is extremely challenging. Serum hCG, sonogram, and MRI are our tools, but none of them suffice for a definitive diagnosis. Histological examination of the postoperative sample is still the gold standard for the diagnosis of molar CSP; however, MRI can assist in planning the necessary interventions.
Tapering body stiffness shortens upper gastrointestinal examination via transoral insertion with ultrathin endoscope
Authors: Ono Satoshi , Ito Shun , Maejima Kyohei , Hosaka Shosuke , Umeki Kiyotaka , Sato Shin-ichiro
Published: November 2020

Background and study aims Ultrathin endoscopes are commonly used for surveillance esophagogastroduodenoscopy (EGD) to reduce discomfort associated with scope insertion. However, the flexibility of an ultrathin endoscope is a trade-off between reducing discomfort and lengthening examination time.

Patients and methods The EG17-J10 (EG17) is a novel ultrathin endoscope characterized by its tapering body stiffness; however, the flexibility of its tip is comparable to that of the traditional ultrathin endoscope EG16-K10 (EG16). We compared EGD examination time between EG17 and EG16. A total of 319 examinees who underwent EGD from November 2019 to January 2020 at the Chiba-Nishi General Hospital were enrolled. Six examinees were excluded due to past history of surgical resection of the upper gastrointestinal tract or too much food residues; 313 examinees (EG17, 209; EG16,104) were retrospectively analyzed. The examination time was divided into three periods: esophageal insertion time (ET), gastroduodenal insertion time (GDT), and surveillance time of the stomach (ST). The total amount of ET, GDT, and ST was defined as total examination time (TT).

Results TT of EGD using EG17 was significantly shorter compared to EGD using EG16 (222.7 ± 68.9 vs. 245.7 ± 78.5 seconds) (P = 0.004). Among the three periods of examination time, ET (66.7 ± 24.1 vs. 76.0 ± 24.1 seconds) (P = 0.001) and GDT (47.9 ± 17.4 vs. 55.2 ± 35.2 seconds) (P = 0.007) of EGD using EG17 were significantly shorter compared to EGD using EG16, except for ST (108.1 ± 51.5.1 vs. 114.5 ± 50.1 seconds) (P = 0.148).

Conclusion An ultrathin endoscope with tapering body stiffness can shorten EGD examination time, mainly due to the shortening of insertion time.
The Swinging Flashlight Test – Flawed Execution and Interpretation in Ophthalmological Routine
Authors: Beisse Flemming , Ring Alina , Wilhelm Helmut , Beisse Christina
Published: November 2020

Background The swinging flashlight test is a standard diagnostic procedure to detect relative afferent pupillary defects. The advantages of the test lie within its objectivity and minimal effort. However, its value depends on its correct execution and interpretation. This questionnaire-based survey investigates whether this is given among German speaking ophthalmologists.

Methods A multiple-choice questionnaire with 14 questions on the use of the swinging flashlight test was designed. It was presented to German speaking ophthalmology specialists (primary data) and orthoptists (secondary data) on specialist conferences or by telephone interviews.

Results 249 ophthalmologists and 76 orthoptists participated in the survey. Only 2% of ophthalmologists answered all 14 questions correctly. On average 66% (range 29 – 100%) of the questions were answered correctly by the ophthalmologists. The question with the lowest result had a rate of 19%, the question with the highest result was correctly answered by 95%. The orthoptists achieved similar results.

Conclusion The rate of correct answers appears disturbingly low. The swinging flashlight test being a basic tool and an obligatory test in a number of guidelines should rather be performed nearly error-free. In light of the high error rates, misdiagnoses and treatment errors must be feared. Better training seems necessary.
Ophthalmological Management of Patients with Pituitary Adenomas
Authors: Küchlin Sebastian , Lagrèze Wolf Alexander
Published: November 2020

Pituitary tumours are a common cause of functional impairment and degeneration of the anterior visual pathway. Depending on localization and size, they clinically manifest as initially reversible visual field defects. As part of interdisciplinary tumour management, ophthalmologic examinations are of particular importance concerning diagnostics, indication for tumour resection and documentation of functional surgical results. Based on the relationship between clinical dysfunction and manifest atrophy, together with the patientʼs age and the duration of symptoms, the ophthalmologist can provide insights into the postoperative visual prognosis. Under good conditions, surgical tumour resection often results in significant improvements to visual fields and acuity. Long-term ophthalmological controls are required in cases of persistent visual loss, radiotherapy or tumour remnants abutting the visual pathway.
A Molecular Stereostructure Descriptor Based On Spherical Projection
Authors: Zhang Shuo-Qing , Hong Xin , Xu Li-Cheng , Li Xin , Tang Miao-Jiong , Yuan Luo-Tian , Zheng Jia-Yu
Published: November 2020

Description of molecular stereostructure is critical for the machine learning prediction of asymmetric catalysis. Herein we report a spherical projection descriptor of molecular stereostructure (SPMS), which allows precise representation of the molecular van der Waals (vdW) surface. The key features of SPMS descriptor are presented using the examples of chiral phosphoric acid, and the machine learning application is demonstrated in Denmark’s dataset of asymmetric thiol addition to N-acylimines. In addition, SPMS descriptor also offers a color-coded diagram that provides straightforward chemical interpretation of the steric environment.
Impaired Platelet Function in Sept8-Deficient Mice In Vitro
Authors: Jurk Kerstin , Neubauer Katharina , Petermann Victoria , Kumm Elena , Zieger Barbara
Published: November 2020

Septins (Septs) are a widely expressed protein family of 13 mammalian members, recognized as a unique component of the cytoskeleton. In human platelets, we previously described that SEPT4 and SEPT8 are localized surrounding α-granules and move to the platelet surface after activation, indicating a possible role in platelet physiology. In this study, we investigated the impact of Sept8 on platelet function in vitro using Sept8-deficient mouse platelets. Deletion of Sept8 in mouse platelets caused a pronounced defect in activation of the fibrinogen receptor integrin αIIbβ3, α-granule exocytosis, and aggregation, especially in response to the glycoprotein VI agonist convulxin. In contrast, δ-granule and lysosome exocytosis of Sept8-deficient platelets was comparable to wild-type platelets. Sept8-deficient platelet binding to immobilized fibrinogen under static conditions was diminished and spreading delayed. The procoagulant activity of Sept8-deficient platelets was reduced in response to convulxin as determined by lactadherin binding. Also thrombin generation was decreased relative to controls. Thus, Sept8 is required for efficient integrin αIIbβ3 activation, α-granule release, platelet aggregation, and contributes to platelet-dependent thrombin generation. These results revealed Sept8 as a modulator of distinct platelet functions involved in primary and secondary hemostatic processes.
Augmenting the Clinical Data Sources for Enigmatic Diseases: A Cross-Sectional Study of Self-Tracking Data and Clinical Documentation in Endometriosis
Authors: Ensari Ipek , Pichon Adrienne , Lipsky-Gorman Sharon , Bakken Suzanne , Elhadad Noémie
Published: November 2020

Background Self-tracking through mobile health technology can augment the electronic health record (EHR) as an additional data source by providing direct patient input. This can be particularly useful in the context of enigmatic diseases and further promote patient engagement.

Objectives This study aimed to investigate the additional information that can be gained through direct patient input on poorly understood diseases, beyond what is already documented in the EHR.

Methods This was an observational study including two samples with a clinically confirmed endometriosis diagnosis. We analyzed data from 6,925 women with endometriosis using a research app for tracking endometriosis to assess prevalence of self-reported pain problems, between- and within-person variability in pain over time, endometriosis-affected tasks of daily function, and self-management strategies. We analyzed data from 4,389 patients identified through a large metropolitan hospital EHR to compare pain problems with the self-tracking app and to identify unique data elements that can be contributed via patient self-tracking.

Results Pelvic pain was the most prevalent problem in the self-tracking sample (57.3%), followed by gastrointestinal-related (55.9%) and lower back (49.2%) pain. Unique problems that were captured by self-tracking included pain in ovaries (43.7%) and uterus (37.2%). Pain experience was highly variable both across and within participants over time. Within-person variation accounted for 58% of the total variance in pain scores, and was large in magnitude, based on the ratio of within- to between-person variability (0.92) and the intraclass correlation (0.42). Work was the most affected daily function task (49%), and there was significant within- and between-person variability in self-management effectiveness. Prevalence rates in the EHR were significantly lower, with abdominal pain being the most prevalent (36.5%).

Conclusion For enigmatic diseases, patient self-tracking as an additional data source complementary to EHR can enable learning from the patient to more accurately and comprehensively evaluate patient health history and status.
The Benefits of the Supercharged Ileocolic Flap in Patients Who Underwent Total Esophagectomy and Gastrectomy
Authors: Marchi Filippo , Kang Shih Ching , Cheong David Chon Fok , Hung Shao Yu , Wang Szu Han , Chiu Ting Han , Chen Yu Ting , Tsao Chung Kan
Published: November 2020

Background Patients who undergo total esophagectomy and gastrectomy present a challenging scenario for reconstructive surgeons. Several techniques have been described. However, the best choice is still a matter of debate. We aim to report our experience with the supercharged ileocolic flap, then to compare the long-term functional outcomes in cancer and caustic injury patients. We investigate the safest route of transposition and demonstrate the importance of supercharging the flap. Last, we perform a literature review to compare our results with the ones reported in the literature.

Methods A total of 36 patients underwent the supercharged ileocolic flap procedure. The details reviewed included the type of defect, flap characteristic, route of transposition, complications, patient survival, and swallowing evaluation. Survival and long-term function preservation were considered as the main outcomes. A secondary end-point was the identification of the safest route of transposition. We extracted the pertinent literature on supercharged bowel flaps from 1995 to July 2020

Results All flaps survived; only two flaps were partially lost. Thirty-three percent of the cohort experienced postoperative complications; the most common was leakage of the cervical anastomosis (17%), followed by neck wound infection (8%). The 5-year dysphagia-free survival rate was 87% in corrosive injury patients and 78% in cancer patients. The mean time to be free from dysphagia after surgery was 25.12 ± 4.55 months for corrosive patients and 39.56 ± 9.45 months for cancer patients (p = 0.118). The safest route of transposition was retrosternal extra-mediastinal. From the literature review, the data from 11 studies were extracted.

Conclusion The supercharged ileocolic flap is a robust option for total esophageal replacement when the stomach is not available and the retrosternal route is the safest for transposition. The functional outcomes are excellent, with acceptable morbidity and a good life expectancy, either in cancer and noncancer patients. Supercharging the flap is recommended.
Rooming-in for Infants at Risk for Neonatal Abstinence Syndrome: Outcomes 5 Years following Its Introduction as the Standard of Care at One Hospital
Authors: Newman Adam Isaiah , Mauer-Vakil Dane , Coo Helen , Newton Lynn , Wilkerson Emily , McKnight Sarah , Brogly Susan B.
Published: November 2020

Objective The practice of rooming-in for opioid-dependent infants was introduced as the standard of care at our hospital following a pilot study which demonstrated that such infants had shorter lengths of stay and were less likely to require pharmacological treatment. We sought to determine whether these benefits have continued, and whether outcomes support continuing to use rooming-in as standard care.

Study Design Opioid-dependent infants delivered at 36 weeks gestation or later between January 1, 2015, and December 31, 2019, were eligible for rooming-in. Charts were reviewed and data were extracted regarding maternal and infant conditions, whether neonatal pharmacological treatment was required, and total length of hospital stay. Outcomes were compared with two historical groups reported in a previous pilot study: 24 healthy near-term opioid-dependent newborns who were admitted directly to the neonatal intensive care unit (NICU) prior to the introduction of rooming-in (May 1, 2012–May 31, 2013), and 20 similar opioid-dependent infants who were the first to room-in at our hospital (September 1, 2013–September 30, 2014).

Results Only 3.5% of 57 infants who roomed-in during the 5-year study period required pharmacological treatment, compared with 15% who roomed-in during the first year of the program's introduction and 83.3% who had been admitted directly to the NICU. The median length of stay remained 5 days for infants rooming-in, compared with 24 days for opioid-dependent infants in the cohort admitted to the NICU.

Conclusion Early observations of the benefits of rooming-in on neonatal outcomes were sustained. Infants allowed to room-in were significantly less likely to require initiation of pharmacotherapy and a prolonged hospital stay than similar infants prior to the implementation of rooming-in as standard care. A large proportion of the infants who might have benefited from rooming-in required admission to the NICU for reasons other than neonatal abstinence syndrome (NAS).

Key Points
Legal issues in automated vehicles: critically considering the potential role of consent and interactive digital interfaces
Authors: Pattinson Jo-Ann , Chen Haibo , Basu Subhajit
Published: November 2020

Some of the first ‘automated’ vehicles to be deployed on our roads will require a system of shared driving with a human driver. While this creates technical and operational challenges, the law must also facilitate such a transfer. One method may be to obtain the driver’s consent to share operational responsibility and to delineate legal responsibility between vehicle and driver in the event of an accident. Consent is a voluntary agreement where an individual is aware of the potential consequences of their consent, including the risks. The driver of a partially automated vehicle must be informed of potential risks before giving consent to share operational responsibility. This paper will refer to the inherent dangers associated with shared operational responsibility, in particular where there has been a request for the driver to take back control from the automated vehicle during the journey. Drivers are likely to experience delay in regaining situational awareness, making such operational transfers hazardous. It is argued that where an interactive digital interface is used to convey information, such as driver responsibility, risk and legal terms, drivers may fail to sufficiently process such communications due to fundamental weaknesses in human–machine interaction. The use of an interactive digital interface alone may be inadequate to effectively communicate information to drivers. If the problems identified are not addressed, it is argued that driver consent may be inconsequential, and fail to facilitate a predicable demarcation of legal responsibility between automated vehicles and drivers. Ongoing research into automated vehicle driver training is considered as part of the preparation required to design driver education to a level whereby drivers may be able to sufficiently understand the responsibilities involved in operating a partially automated vehicle, which has implications for future driver training, licensing and certification.
Evaluation of anisotropic correction models for diffuse solar irradiance measured by the MEO shadow ring method
Authors: Dal Pai Alexandre , Dal Pai Enzo , Sarnighausen Valéria Cristina Rodrigues , Escobedo João Francisco
Published: November 2020

Diffuse solar radiation is measured using a pyranometer positioned under the shadow of a ring. The function of the ring is to block direct solar radiation. However, the ring also blocks a portion of the diffuse solar radiation, and therefore, the diffuse radiation needs corrections. The most well-known assembly in the literature on the shading ring method is the Drumond assembly. This study aims to determine the effectiveness of three methods of correction of diffuse irradiance measured with shadow bands: the LeBaron method, the Battles method, and the Dal Pai method. The Laboratory of Solar Radiometry of Botucatu provided global, direct, and diffuse solar irradiances. The laboratory measures diffuse solar radiation using the Melo–Escobedo–Oliveira (MEO) shading ring method, a different setup compared to Drummond's setup. The period used for the study comprised the years 1996 to 2005. The results showed that LeBaron and Battles correction models with the original coefficients are not suitable for correction of diffuse irradiance in Botucatu. According to MBE (Mean Bias Error) and RMSE (Root Mean Square Error), the statistical indicators, LeBaron and Battles with adjusted coefficients, and Dal Pai correction models are indicated to correct the diffuse irradiance in Botucatu measured under an MEO shading ring. For monthly applications, the LeBaron model with adjusted coefficients is recommended. Although this model is more complex from the operational point of view, it better explains anisotropic effects, especially for the winter months.
Quantum cutting-induced near-infrared luminescence of Yb3+ and Er3+ in a layer structured perovskite film
Authors: Ishii Ayumi , Miyasaka Tsutomu
Published: November 2020

Quantum cutting is an attractive optical phenomenon where one high-energy photon is converted into two low-energy photons, resulting in photoluminescence quantum yields (PLQYs) above 100%. In this report, we demonstrate a novel approach to enhance the quantum cutting energy transfer from an all-inorganic perovskite (CsPbCl3) to ytterbium (Yb3+) and erbium (Er3+) ions as near-infrared (NIR) emitters by using the highly orientated crystalline film. Yb3+ ions are fixed in the neighborhood of the CsPbCl3 lattice by preparing a one-to-one layer arrangement consisting of quasi-2D CsPbCl3 perovskite and Yb3+ layers. The successful preparation of layer arrangements resulted in the highly sensitized luminescence of Yb3+ by CsPbCl3 with NIR PLQYs exceeding 130%, which is attributed to quantum cutting. In addition, Er3+ luminescence at 1540 nm is acquired by the co-existence of Er3+ with Yb3+ in a layer, which is a result of the intralayer metal-to-metal energy transfer from Yb3+ activated by CsPbCl3 via the interlayer quantum cutting process. The PLQY of Er3+ luminescence reaches to 12.6%, which is the highest value ever observed for Er3+ compounds, resulting from the efficient interlayer quantum cutting process over 100% and the following intralayer resonance metal to metal energy transfer with the efficiency over 80%.
Carrier localization in self-organized quantum dots: An interplay between quantum and solid mechanics
Authors: Kosarev Alexander , Chaldyshev Vladimir V.
Published: November 2020

Localization of carriers in a self-organized quantum dot is a problem of quantum mechanics to be solved with the localizing potential for electrons and holes determined by the geometry, chemical composition, and built-in mechanical stress–strain field. We show that changes in the aspect ratio of a buried pyramidal quantum dot result in a substantial redistribution of the mechanical field components, which in turn provides certain non-trivial conditions for the strongest carrier localization at any given volume of the quantum dot.
Species of accidental woody epiphytes vary between host trees in Tasmanian wet forests
Authors: Winoto-Lewin Yanti , Kirkpatrick Jamie B.
Published: November 2020

Little is known about accidental epiphytes in Australian temperate forests. In western Tasmania, we determined whether: (1) the occurrence and abundance of accidental epiphytes increases with moisture availability and the size of host; (2) the species of host affects the occurrence of individual taxa of accidental epiphytes; (3) moist microhabitats favour accidental epiphytes. We recorded the accidental woody epiphytes on 21 trees in each of 20 locations and measured attributes of the host and the location and attachment height of the individual epiphytes. Epiphyte occurrence, but not abundance, was associated with the basal area of host tree, January rainfall and the taxon of the host. Eucalypts, gymnosperms and tree ferns were the outstanding hosts. The rainforest tree Nothofagus cunninghamii occurred as an epiphyte on eucalypts more than expected, while Proteaceae species occurred less than expected. In contrast, there was a strong positive association between the gymnosperm Athrotaxis selaginoides as a host and Proteaceae as epiphytes, possible reflecting their joint status as palaeoendemics. Accidental epiphytes were concentrated on the west and south-west of trees and near their bases, further indicating a strong effect of moisture availability on their occurrence. Our results reinforce the importance of conserving old growth forest to maintain ecosystem complexity.
Physiological implications of climate change for a critically endangered Australian marsupial
Authors: Cooper Christine Elizabeth , Withers Philip Carew , Turner James Malcolm
Published: November 2020

Extreme weather events (e.g. heatwaves and droughts) can expose animals to environmental conditions outside of their zones of physiological tolerance, and even resistance, and impact long-term viability of populations and species. We examined the thermal and hygric physiology of the critically endangered western ringtail possum (Pseudocheirus occidentalis), a member of a family of marsupial folivores (Pseudocheiridae) that appear particularly vulnerable to environmental extremes. Basal metabolic rate and other standard physiological variables measured at an ambient temperature of 30°C conformed to values for other marsupials. At lower temperatures, body temperature decreased slightly, and metabolic rate increased significantly at 5°C. At higher temperatures, possums experienced mild hyperthermia and increased evaporative heat loss by licking rather than panting. Their point of relative water economy (–8.7°C) was more favourable than other pseudocheirid possums and the koala (Phascolarctos cinereus). We predict that western ringtail possums should tolerate low ambient temperatures well and be more physiologically tolerant of hot and dry conditions than common (Pseudocheirus peregrinus) and particularly green (Pseudochirops archeri) ringtail possums, and koalas. Our physiological data can be incorporated into mechanistic species distribution models to test our hypothesis that western ringtail possums should physiologically tolerate the climate of habitat further inland than their current distribution, and withstand moderate impacts of climate change in the south-west of Western Australia.
Simulation of the Ronchi test for arbitrary wave aberrations in imaging systems
Authors: Hassani Khosrow
Published: November 2020

The Ronchi test is a simple qualitative method to identify aberrations in imaging systems: a binary grating is superimposed on its own image formed by the system to produce patterns, known as Ronchigrams, that manifest the aberrations in the system. In practice, the experimentally recorded Ronchigrams are compared with model-based simulations to infer the types and amounts of wave aberrations. In this article an effective algorithm to simulate the Ronchigrams in an imaging system under arbitrary third-order wave aberrations is introduced. The method uses simple coordinate interpolation to transfer the grating transmittance from the object to the image space. High-quality Ronchigrams for all types of wave aberrations can easily be produced. For demonstration purposes, experimental Ronchigrams obtained in real imaging systems are also provided and compared with the simulations. The results show that this technique can both be used as an educational tool, and also in a real test setup.
Fourier transform method for the electrostatic self-energy of a solid sphere with uniform volume charge density
Authors: Ciftja Orion
Published: November 2020

The problem of a solid sphere with uniform volume charge density is encountered in virtually all undergraduate calculus-based physics textbooks dealing with the topic of electromagnetism. This example illustrates well the use of Gauss’s law and from there one can easily derive all the quantities of interest such as electrostatic field, potential, self-energy, and so on. Undergraduate physics majors are also well aware of the theory of Fourier transforms from having taken mathematics courses. Nevertheless, despite its great utility, the Fourier transform method is rarely mentioned as a powerful tool to solve physics problems at this level. To address this shortcoming, in this work we propose a possible scenario which may allow an instructor to introduce this powerful method to a proper undergraduate audience without any major pedagogical drawback. The case study that we choose is that of a solid sphere with uniform volume charge density. Specifically, we show the calculation of its electrostatic self-energy by using Fourier transform techniques. The main idea of this work is to draw reader’s attention to the versatility of the approach that can, in principle, be applied to other more geometrically complicated bodies where Gauss’s law does not lead to simple solutions. Concurrently, this work also provides instructional approaches that intertwine content-specific and pedagogical viewpoints that can be useful to all undergraduate students and teachers who wish to enhance their command of the subject.
A neural-network based framework of developing cross interaction in alloy embedded-atom method potentials: application to Zr–Nb alloy
Authors: Lin Bo , Wang Jincheng , Li Junjie , Wang Zhijun
Published: November 2020

Interaction potentials are critical to molecular dynamics simulations on fundamental mechanisms at atomic scales. Combination of well-developed single-element empirical potentials via cross interaction (CI) is an important and effective way to develop alloy embedded-atom method (EAM) potentials. In this work, based on neural-network (NN) models, firstly we proposed a framework to construct CI potential functions via utilizing single-element potentials. The framework contained four steps: (1) extracting characteristic points from single-element potential functions, (2) constructing CI functions by cubic spline interpolation, (3) evaluating the accuracy of CI functions by referring to first-principle (FP) data, and (4) searching for reasonable CI functions via NN models. Then with this framework, we developed a Zr–Nb alloy CI potential utilizing the MA-III (pure Zr potential developed by Mendelev and Ackland in 2007) and the Fellinger, Park and Wilkins (FPW) (pure Nb potential developed by FPW in 2010) potentials as single-element parts. The calculated results with this Zr–Nb alloy potential showed that: (1) the newly developed CI potential functions could simultaneously present the potential-function features of Zr and Nb; (2) the normalized energy–volume curves of L12 Zr3Nb, B2 ZrNb and L12 ZrNb3 calculated by this CI potential reasonably agreed with FP results; (3) the referred MA-III Zr and FPW Nb potentials can satisfactorily reproduce the priority of prismatic slip in Zr and the tension–compression asymmetry of 〈111〉{112} slip in Nb, while other ab initio developed Zr–Nb alloy potentials cannot. Our study indicates that, this NN based framework can take full advantage of single-element potentials, and is very convenient to develop EAM potentials of alloys; moreover, the new-developed Zr–Nb alloy EAM potential can reasonably describe the complicated deformation behaviors in Zr–Nb systems.
Molecular beam magnetic resonance coupled with a cryogenically cooled, pulsed laser vaporization source and time-of-flight mass spectrometry
Authors: Fuchs Thomas M , Schäfer Rolf
Published: November 2020

A molecular beam magnetic resonance apparatus designed for the study of polyatomic molecules and small metal clusters is described. In contrast to atoms, vibrational and rotational excitation in clusters and molecules invoke spin relaxation upon a change of magnetic flux density. To prevent this, a pulsed laser vaporization source with a cryogenically cooled nozzle is utilized to minimize thermal excitation and a magnet setup has been designed to diminish magnetic field fluctuations. The apparatus is evaluated by Stern–Gerlach and resonance experiments on an atomic europium beam with the identical pulsed laser vaporization source.
Resonance-based bandwidth Fourier decomposition method for gearbox fault diagnosis
Authors: Deng Minqiang , Deng Aidong , Zhu Jing , Shi Yaowei , Liu Yang , Chen Qiang
Published: November 2020

This paper aims to investigate the response mechanism of faulty gears, and further proposes a resonance-based bandwidth Fourier decomposition (RBBFD) method for gearbox fault identification. To reveal the vibration patterns of the gear-pair system, a dynamic model with time-varying stiffness is established to obtain the transient response excited by local damage. The analysis results demonstrate that the impulse response of a faulty gear is essentially carried by the natural frequency instead of the widely recognized meshing frequency and its harmonies. After that, the RBBFD method is developed based on the dynamic characteristics. In the proposed method, the resonance frequencies of the gear system are estimated according to the maximum point distribution of the Fourier spectrum, and then the Fourier spectrum bandwidth optimization algorithm is introduced to decompose the vibration signal into mono-components centered on the estimated natural frequencies. A new criterion termed the characteristic frequency ratio is utilized to measure the fault-related degree of the decomposed modes, and the fault type is identified by Hilbert demodulation. The effectiveness of RBBFD is verified through two diagnostic cases. The comparison with several state-of-art works validates the superiority of the proposed method in gearbox fault diagnosis.
A particle debonding model considering interface nanoscale damage effect
Authors: Liu Yu , Chen Jieshi , Dong Xianghuai
Published: November 2020

The debonding of the inclusions or second phase particles from matrix which is controlled by energy and stress condition is an important source of voids nucleation in engineering materials. In this paper, firstly it is confirmed that energy condition for debonding can easily be satisfied for micron scale particles in plastic deformation by numerical simulation; then a stress controlled debonding model introducing the effect of nanoscale damage of the interface is proposed; then the parameters of the model are determined by fitting the published experimental data. Unlike traditional debonding models, the proposed model can reasonably predict the size effect that the debonding strain will increase with the decrease of particle size at micron scale, which was observed by experiments.
Evaluation of eddy current distortion and field inhomogeneity distortion corrections in MR diffusion imaging using log-demons DIR method
Authors: Arsenault Theodore , Yin Fang Fang , Chino Junzo , Craciunescu Oana , Chang Jim Zheng
Published: November 2020

To investigate the feasibility of the log-demons deformable image registration (DIR) method to correct eddy current and field inhomogeneity distortions while preserving diffusion tensor information. Diffusion-weighted images (DWIs) are susceptible to distortions caused by eddy current and echo-planar imaging (EPI) gradients. We propose a post-acquisition correction algorithm using the log-demons DIR technique for eddy current and field inhomogeneity distortions of DWI. The new correction technique was applied to DWI acquired using a diffusion phantom and the multiple acquisitions for standardization of structural imaging validation and evaluation (MASSIVE) brain database. This method is compared to previous methods using cross-correlation, mutual information (MI). In the phantom study, the log-demons algorithm reduced eddy current and field inhomogeneity distortions while preserving diffusion tensor information when compared to affine and demon’s registration techniques. Analysis of the tensor metrics using percent difference and the root mean square of the apparent diffusion coefficient and fractional anisotropy found that the log-demons algorithm outperforms the other algorithms in terms of preserving diffusion information. In the MASSIVE study, the average MI of all slices increased for both eddy current and field inhomogeneity distortion correction. The average absolute differences of all slices between corrected images with opposing gradients were also on average decreased. This work indicates that the log-demons DIR algorithm is feasible to reduce eddy current and field inhomogeneity distortions while preserving quantitative diffusion information.
Quantitative analysis of bony birth canal for periacetabular osteotomy patient by template fitting
Authors: Shao Long , Li Heng , Liu Xinxin , Wang Yanjun , Shi Liujia , Ai Danni , Fan Jingfan , Song Hong , Zhang Hong , Yang Jian
Published: November 2020

Periacetabular osteotomy (PAO) is a joint preservation procedure for developmental dysplasia of the hip. Such a procedure requires osteotomy of the medial wall of the acetabulum, which may cause the narrow of the bony birth canal and increase the risk of complications during the childbirth process in the future. Using quantitative analysis of the bony birth canal to determine the risk of complications for the childbirth process remains a challenging task. The purpose of this paper is to explore a new 3D CT measurement method to quantify the narrowest parameters of the bony birth canal of the female patients with hip dysplasia before and after unilateral PAO surgery. By analyzing the impact of PAO surgery on the bony birth canal, the patient’s risk of complications during the childbirth process in the future can be estimated, and it can be utilized for doctors to determine the impact of unilateral PAO for choosing appropriate delivery method. In this paper, a mean shape of the preoperative pelvises is obtained by using the statistical shape model algorithm, and the mean shape includes pelvic shape features of all the preoperative pelvises, and it can be utilized as the standard pelvic template. A bidirectional iterative algorithm is used to generate a standard bony birth canal path template. Then, the pelvic registration and principal plane deformation constraint are utilized to calculate the optimal bony birth canal path. The proposed method is verified in 31 cases of CT data with the approval of the institutional review board. The test data contain preoperative and postoperative CT images. Compared with the benchmark method, the measurement accuracy of the narrowest position and diameter of the bony birth canal is improved by 65% and 78%, respectively. In addition, the processing speed is increased by 32%. Experimental results demonstrate that the proposed method has high accuracy and validity for quantifying the bony birth canal. The proposed method can measure the anatomical parameters of the bony birth canal accurately. In addition, the doctor can make optimal planning for childbirth with the help of the quantitative analysis of the bony birth canal.
A scan driver including light emission control integrated by metal-oxide thin-film transistors
Authors: Liu Chun , Lin Yi-Zhen , Wu Wei-Jing , Zhou Lei , Xu Miao , Wang Lei , Peng Jun-Biao
Published: November 2020

This paper presents a new scan driver including a light emission control module, which is fabricated by metal oxide thin-film transistors (TFTs) with back channel etched structures. The proposed scan driver employs the capacitor coupling effect and two-step-resetting method to output SCAN and EM signals simultaneously. Therefore, there is no need to design the scan driver circuit and the light emission control circuit separately, which saves the resources of peripheral driving signals and area of TFT integrated circuits. Thirty stages of the proposed scan driver are fabricated on a glass substrate to verify its function. Experimental results show that each stage can output full-swing waveforms for SCAN and EM signals, which have little distortion and exhibit good stability with a 10 us pulse width. The measured power consumption per stage of the proposed scan driver is 85 µW at a clock frequency of 33.4 kHz.
Electronic Maxwell’s equations
Authors: Li Mingjie , Shi Peng , Du Luping , Yuan Xiaocong
Published: November 2020

To date, the wave nature of electron has been widely researched, together with its similarity to optics. To unify electronic waves and electromagnetic waves, we establish four equations analogous to Maxwell’s equations by expressing the Dirac equation in terms of the quaternions. We develop some fundamental theories from the electronic version of Maxwell’s equations. In practice, solving electron wave problem is convenient without appearance of quantum operators such as Pauli matrices. The benefit is its potential in the analysis and applications of diverse electron beams, for example, phase-shift control. Moreover, physical quantities represented by electronic vector fields are notably similar to those in optics, making it possible to apply some ideas developed in optics in the research of electron.
Symmetry-protection of multiphoton states of light
Authors: Lasa-Alonso Jon , Molezuelas-Ferreras Martín , Miguel Varga J J , García-Etxarri Aitzol , Giedke Géza , Molina-Terriza Gabriel
Published: November 2020

In this manuscript we analyze the emergence of protected multiphoton states in scattering problems with cylindrical symmetry. In order to do that, we first provide a formal definition of the concept of postselected symmetry-protection. We show that the notion of symmetry-protection is not limited to one- or two-photon states, on the contrary, it can be formally extended to the multiphoton case. In addition, we prove for the case of cylindrical symmetry that all possible multiphoton protected states are constructed from a small set of one- and two-photon states. Finally, we point out possible applications that symmetry-protected states may have in quantum communications, concretely, in the construction of decoherence-free subspaces.