bluuebunny/crossref_metadata_2025 huggingface dataset:
The widest Hα survey of accreting protoplanets around nearby transition disks
Authors: Zurlo A. , Cugno G. , Montesinos M. , Perez S. , Canovas H. , Casassus S. , Christiaens V. , Cieza L. , Huelamo N.
Published: December 2019

Context. The mechanisms of planet formation are still under debate. We know little about how planets form, even if more than 4000 exoplanets have been detected to date. Recent investigations target the cot of newly born planets: the protoplanetary disk. At the first stages of their life, exoplanets still accrete material from the gas-rich disk in which they are embedded. Transitional disks are indeed disks that show peculiarities, such as gaps, spiral arms, and rings, which can be connected to the presence of substellar companions.

Aims. To investigate what is responsible for these features, we selected all the known transitional disks in the solar neighborhood (<200 pc) that are visible from the southern hemisphere. We conducted a survey of 11 transitional disks with the SPHERE instrument at the Very Large Telescope. This is the largest Hα survey that has been conducted so far to look for protoplanets. The observations were performed with the Hα filter of ZIMPOL in order to target protoplanets that are still in the accretion stage. All the selected targets are very young stars, less than 20 Myr, and show low extinction in the visible.

Methods. We reduced the ZIMPOL pupil stabilized data by applying the method of the angular spectral differential imaging (ASDI), which combines both techniques. The datacubes are composed of the Cnt_Hα and the narrow band filter Hα, which are taken simultaneously to permit the suppression of the speckle pattern. The principal component analysis method was employed for the reduction of the data. For each dataset, we derived the 5σ contrast limit and converted it in upper limits on the accretion luminosity.

Results. We do not detect any new accreting substellar companions around the targeted transition disks down to an average contrast of 12 magnitudes at 0.′′2 from the central star. We have recovered the signal of the accreting M star companion around the star HD 142527. We have detected and resolved, for the first time in visible light, the quadruple system HD 98800. For every other system, we can exclude the presence of massive actively accreting companions, assuming that the accretion is not episodic and that the extinction is negligible. The mean accretion luminosity limit is 10−6 L⊙ at a separation of 0.′′2 from the host.
Tidal evolution of circumbinary systems with arbitrary eccentricities: applications for Kepler systems
Authors: Zoppetti F. A. , Leiva A. M. , Beaugé C.
Published: December 2019

We present an extended version of the Constant Time Lag analytical approach for the tidal evolution of circumbinary planets introduced in our previous work. The model is self-consistent, in the sense that all tidal interactions between pairs are computed, regardless of their size. We derive analytical expressions for the variational equations governing the spin and orbital evolution, which are expressed as high-order elliptical expansions in the semimajor axis ratio but retain closed form in terms of the binary and planetary eccentricities. These are found to reproduce the results of the numerical simulations with arbitrary eccentricities very well, as well as reducing to our previous results in the low-eccentric case. Our model is then applied to the well-characterised Kepler circumbinary systems by analysing the tidal timescales and unveiling the tidal flow around each different system. In all cases we find that the spins reach stationary values much faster than the characteristic timescale of the orbital evolution, indicating that all Kepler circumbinary planets are expected to be in a sub-synchronous state. On the other hand, all systems are located in a tidal flow leading to outward migration; thus the proximity of the planets to the orbital instability limit may have been even greater in the past. Additionally, Kepler systems may have suffered a significant tidally induced eccentricity damping, which may be related to their proximity to the capture eccentricity. To help understand the predictions of our model, we also offer a simple geometrical interpretation of our results.
Lasers de forte puissance : vers l’avènement de fibres optiques à aire effective extrême
Authors: Leconte Baptiste , Bigot Laurent , Roy Philippe , Jamier Raphael , Dauliat Romain , Malleville Marie-Alicia , Quiquempois Yves , El Hamzaoui Hicham , Vanvincq Olivier
Published: December 2019

Les systèmes lasers fibrés sont au coeur de nombreuses recherches académiques et constituent un marché annuel mondial dépassant le milliard d’euros. L’augmentation de la puissance en sortie de ces dispositifs a été rendue possible grâce à une innovation permanente portant sur la géométrie de fibres, les matériaux qui les constituent et les méthodes de synthèse associées. Après un bref rappel historique, nous rappelons quelques éléments de contexte et présentons quelques avancées récentes en matière de fibres à très grandes aires effectives.
Raccordement des fibres optiques à l’habitat - FTTH
Authors: Mur Jean-Michel
Published: December 2019

Le déploiement de la fibre optique jusqu’à l’habitat (fiber to the home – FTTH) a des conséquences (on pourrait parler de défis à relever) comme la création des fibres UIT-T G.657, une pénurie de main-d’oeuvre, de nouveaux réseaux optiques passifs et des évolutions des équipements. Tour d’horizon…
Kommentar zur AWMF-S2k-Leitlinie von 2018 zur Prä-Expositions-Prophylaxe der HIV-Infektion (PrEP)
Authors: Nagel Stefan
Published: December 2019

Zusätzlich zu den bisherigen Präventionsmethoden stellt die Prä-Expositions-Prophylaxe (PrEP) eine neuartige und wirksame Vorgehensweise zur Vorbeugung einer HIV-Infektion dar. Sie ergänzt die bisherigen Methoden des Kondomgebrauchs sowie des Schutzes durch eine effektive Unterdrückung der Viruslast mittels medikamentöser Behandlung (Schutz durch Behandlung). Ziel ist, eine weitere Reduktion der Neuinfektionszahlen durch die vorbeugende Einnahme einer antiretroviralen Medikation bei bisher HIV-negativen Personen mit entsprechenden Risiken zu erreichen. Für dieses Vorgehen gibt die 2018 konsentierte AWMF-S2k-Leitlinie Empfehlungen sowohl zum Vorgehen im Vorfeld (Diagnostik, Indikation, Verschreibung, Beratung) als auch zur eigentlichen Behandlung mit dem Kombinationspräparat Emtricitabin/Tenofovirdisoproxil (TDF/FTC) als auch zum begleitenden medizinischen Monitoring im Verlauf der Behandlung bezüglich medikationsbedingter Risiken und Risiken des Auftretens anderer sexuell übertragbarer Erkrankungen.
Perspektive eines HIV-Behandlers auf die PrEP
Authors: Schellberg Sven
Published: December 2019

Sven Schellberg ist als Arzt in der Novopraxis tätig, einer HIV-Schwerpunktpraxis in Berlin. Er ist immer häufiger mit Patient_innen konfrontiert, die nach der PrEP fragen. Er würdigt die Gründe, warnt aber auch vor einer manchmal allzu unkritischen „Medikalisierung schwuler Sexualität“. Und er wünscht sich, dass offene Gespräche über sexuelles Verhalten und sexuelles Wohlbefinden, über HIV- und STI-Prävention nicht nur in HIV-Schwerpunktpraxen, sondern ganz selbstverständlich auch in anderen Arztpraxen stattfinden. Doch das scheint viel zu oft noch ein Tabu zu sein.
Testicular–Epididymal Dissociation: Vas and Vessels May “Lead up the Garden Path”
Authors: Papageorgiou Eleni , Mantovani Alberto , Monti Elena , Brain Caroline , Smeulders Naima , Cherian Abraham
Published: December 2019

The vas deferens and spermatic vessels entering the inguinal canal through the internal inguinal ring is thought to exclude an intra-abdominal testis. We present a case of high bilateral intra-abdominal testes on a 46,XY boy despite the vas deferens and good-sized vessels passing through the deep rings.

Data were collected from clinical records, radiology (ultrasound, magnetic resonance imaging [MRI]), and endocrine blood tests.

This case underlines the importance of following the pathway of embryological descent of the testis cranially as well as caudally during diagnostic laparoscopy, to avoid missing this rare anatomical variant.
Evaluation of Serum Ferritin as a Prognostic Marker in Acute Hemorrhagic Stroke
Authors: Rajendran Sowri Rajan , Periyasamy Sivakumar , Manjuladevi Moonishaa Thiyagarajan , George Neethu
Published: December 2019

Background Acute hemorrhagic stroke (AHS) resulting from intracerebral hemorrhage (ICH) is a rampant neurological disorder with devastating consequences, particularly in Indians. Recently, serum ferritin levels have been related to adverse cardiovascular and stroke outcomes. We aimed to evaluate the prognostic utility of serum ferritin in AHS.

Materials and Methods Admission serum ferritin levels were estimated in 50 AHS patients with primary supratentorial hemorrhage. Study subjects were categorized based on their prognostic scores in modified Rankin scale (mRS) assessment. Ferritin levels were compared across the study groups, correlated with mRS and other ICH severity indicators.

Results Serum ferritin and other ICH severity indices such as Glasgow coma scale (GCS) and ICH volume were significantly altered in the mRS groups by the end of 7th and 30th days of hospitalization. Elevated ferritin levels, ICH volume together with decreased GCS, characterized the groups with adverse prognosis. Serum ferritin moderately correlated with GCS (r= –0.643), ICH volume (r= 0.562), and had significantly higher correlations with long-term prognostic scores of 7th day mRS (r= 0.802) and 30th day mRS (r= 0.916).

Conclusion  Elevated admission serum ferritin levels indicate poor AHS short-term and long-term outcomes, thereby making serum ferritin a possible prognostic index for the same.
Successful Management of Esophageal Perforation with Self-Expandable Metal Stent following Pneumatic Dilation for Achalasia Cardia
Authors: Verma Abhai , Mohindra Samir , Saraswat Vivek Anand , Ghoshal Uday Chand
Published: December 2019

Achalasia cardia is the most common cause of motor dysphagia. Pneumatic dilation (PD) of lower esophageal sphincter remains the cornerstone of treatment. However, it is associated with esophageal perforation in some cases. We present a case of esophageal perforation following PD of achalasia cardia which was successfully managed with esophageal stent.
Prevalence of Hearing Loss and Associated Factors in School-Age Individuals in an Urban Area of Northeast Brazil
Authors: Nunes Aryelly Dayane Silva , Balen Sheila Andreoli , Souza Dyego Leandro Bezerra , Barbosa Isabelle Ribeiro
Published: December 2019

Introduction Hearing loss interferes in the development of language and verbal capacities, which causes learning difficulties and deleterious effects.

Objective To analyze the prevalence and associated factors for hearing loss in school-age individuals of the municipality of Natal, state of Rio Grande do Norte, Northeast Brazil.

Methods Cross-sectional study that evaluated 238 school-age individuals (6–17 years old) in municipal public schools. Meatoscopy was performed and school-age individuals answered the questions “Do you think that you hear well?” and “Do you have earaches?”. Auditory evaluation was performed with a Telessaúde audiometer. The responsible adults answered socioeconomic, speech and audiology aspects and risk factors for hearing loss questionnaire.

Results The prevalence of hearing loss was 16% (11.7–21.4%); 16% reported not to hear well, 18.9% reported earaches, and 26.1% presented altered meatoscopy. The prevalence of hearing loss was higher in school-age individuals who reported hearing difficulties, in children between the ages of 6 and 12, and with altered meatoscopy results (p < 0.05). Airway infection (PR = 3.37; 95% confidence interval [CI]: 1.48–7.68) was found as a risk factor associated with hearing loss, remaining significant in the multivariate model (PR = 6.79; 95%CI: 1.98–23.26; p = 0.002).

Conclusions Hearing loss in this sample is above the values reported in other studies performed in Brazil for this age group. This highlights the necessity of better structure of speech and audiology attention, so that auditory health promotion actions can be systematized for this population.
Endoscopic Full Thickness Resection for Duodenal Neuroendocrine Tumor
Authors:   Harwani Y,   Tamboliya G,   Gajera N
Published: December 2019

Introduction  Recently endoscopic full thickness resection (EFTR) device with inbuilt Ovesco clip and mounted snare has been introduced for lower gastrointestinal lesions but its feasibility for upper gastrointestinal lesions is still doubted and is not commercially available. We performed EFTR by using Ovesco clip followed by snare polypectomy for one cm duodenal neuroendocrine tumor (NET) which is 1.5-cm proximal to papilla.

Case 55-year-old male was incidentally detected to have biopsy proven 1 cm well-differentiated duodenal NET, 1.5-cm proximal to papilla in duodenum with positive DOTA positron emission tomography–computed tomography (PET–CT) scan. Endoscopic ultrasound suggestive of 9 mm × 4 mm lesion arising from submucosa and adherent to mascularis propria. Surgical treatment in the form of Whipple’s procedure, endoscopic submucosal dissection (ESD) and EFTR all modalities of treatment were discussed with patient. EFTR was preferred over ESD considering its small size and adherence to muscularis propria.

Discussion  Duodenal NET have to be removed irrespective of size and symptoms as they have potential to metastasize. Surgical duodenectomy or Whipple’s procedure are major surgical procedures which are associated with considerable morbidity for asymptomatic small (less than 2 cm) duodenal NET. ESD and EFTR are suitable options for small duodenal lesions. ESD may be challenging for lesion spread beyond submucosa and may lead to perforation of the bowel. Perforation in second part of the duodenum may lead to serious consequences. Compared to ESD, EFTR is a simple technique based on band and cut technique used for endoscopic mucosal resection (EMR) and safe for such type of patients.

Conclusion  EFTR is a suitable option than Whipple’s procedure for lesions up to 2 cm in duodenum, can be preferred over ESD for lesions spread beyond submucosa. EFTR is a relatively simple and safe technique.
Ultrasound assessment of the myofascial trigger point. A systematic review
Authors: G. López San Miguel , I. Barbe Mendibil , B. Torres Chica , J. Ríos Diaz
Published: December 2019

Introduction Myofascial pain syndrome is an important and prevalent public health problem. The lack of consensus on the diagnostic criteria, together with the scarce reliability of the manual detection of the manual detection of myofascial trigger points (MTrPs) point to the need to develop objective methods to enable confirmation of the presence of MTrPs. Ultrasound is an accessible method which enables the assessment of tissue properties in real time, helping to characterize the MTrP, understand its physiopathology and define its diagnosis.

Aims To identify observational studies researching the use of ultrasound in the assessment of MTrPs. Also, to learn about and compile the advances in the study of the characteristics of MTrPs and their sonographic diagnosis.

Material and Methods A systematic review was performed by two independent reviewers, searching biomedical databases using terms related with “ultrasound” and “trigger points”. Observational studies were selected evaluating the characteristics of MTrPs. Subsequently, an analysis of the diagnostic quality of studies was performed using the QAREL scale and a study of the methodological quality took place based on the Downs and Black scale. Furthermore, an assessment of the reproducibility of the acquirement of images was performed, via the analysis of the description of the ultrasound method. The risk of bias was evaluated according to the Cochrane guidelines.

Results 18 studies based on B Mode methods, elastography and Doppler, were included in the review. The anatomic regions which were most explored were the cervical area and the upper limb, evaluated in 14 of the 18 papers. The most common muscle was the upper trapezius (61%). Two articles were located corresponding to the lumbar region and one article concerned the lower limb. The analysis of the sonographic method showed a low level, 5 of the 9 items did not overcome 17% of fulfillment, in 3 papers the frequency was below 6%. The QAREL scale also displayed low levels, only 3 items out of 11. Inter-evaluator blinding, correct testing and statistical methods were fulfilled in over 50%. The mean score obtained by the studies in the Downs and Black scale was 5.4 points out of 10, ranging between 2 and 7 points. The risk of bias according to the Cochrane guidelines was mid- to high.

Conclusion Important steps have been taken in the study of the sonograhic characteristics of the MTrP, however, we are still far from standardizing the use of the same as a diagnostic method. The poor results in the quality analysis of the present study suggest caution in the interpretation of the present findings. Future research is necessary, including different anatomic regions, analytic methods, better defined exploration protocols and more robust reliability studies for the different methods available.
Design and validation of a ten nanosecond resolved resistive thermometer for Gaussian laser beam heating
Authors: Wang Letian , Paeng Dongwoo , Jin Zeqing , Zhang He , Kim Y. S. , Rho Yoonsoo , Eliceiri Matthew , Grigoropoulos Costas P.
Published: December 2019

Pulsed laser processing plays a crucial role in additive manufacturing and nanomaterial processing. However, probing the transient temperature field during the pulsed laser interaction with the processed materials is challenging as it requires both high spatial and temporal resolution. Previous transient thermometry studies have measured neither sub-100 µm spatial resolution nor sub-10 ns temporal resolution. The temperature field induced by Gaussian laser beam profiles has also not been accounted for. Here, we demonstrate a 9 ns rise time, 50 µm sized Pt thin-film sensor for probing the temperature field generated by a nanosecond pulsed laser on a semiconductor thin film. The measurement error sources and associated improvements in the thin film fabrication, sensor patterning, and electrical circuitry are discussed. We carried out the first experimental and theoretical analysis of spatial resolution and accuracy for measuring a Gaussian pulse on the serpentine structure. Transparent silica and sapphire substrates, as well as 7–45 nm insulation layer thicknesses, are compared for sensing accuracy and temporal resolution. Finally, the measured absolute temperature magnitude is validated through the laser-induced melting of the 40 nm thick amorphous silicon film. Preliminary study shows its potential application for probing heat conduction among ultrathin films.
Dynamics of analog logic-gate networks for machine learning
Authors: Shani Itamar , Shaughnessy Liam , Rzasa John , Restelli Alessandro , Hunt Brian R. , Komkov Heidi , Lathrop Daniel P.
Published: December 2019

We describe the continuous-time dynamics of networks implemented on Field Programable Gate Arrays (FPGAs). The networks can perform Boolean operations when the FPGA is in the clocked (digital) mode; however, we run the programed FPGA in the unclocked (analog) mode. Our motivation is to use these FPGA networks as ultrafast machine-learning processors, using the technique of reservoir computing. We study both the undriven dynamics and the input response of these networks as we vary network design parameters, and we relate the dynamics to accuracy on two machine-learning tasks.
Tracking disturbances in transitional and turbulent flows: Coherent structures
Authors: Sengupta Tapan K. , Sharma Pushpender K. , Sengupta Aditi , Suman Vajjala K.
Published: December 2019

Tracking transitional and turbulent flows requires methods other than the classical techniques, which capture coherent structures via locating pressure minima, after the disturbance field has evolved to late-transitional and turbulent flow stages. Keeping it in mind, transition to turbulence of zero pressure gradient flow is studied, following two routes of excitation, by solving the three-dimensional Navier-Stokes equation in derived variable formulation, with vorticity as one of the dependent variables. For such flows, disturbance structures should be traced from the receptivity to the coherent structure stage for the fully developed turbulent flow. The coherent structures in turbulent flows are identified by the Q- and λ2-criteria, based on the occurrence of pressure minima at the vortex cores. In the proposed study here, the zero pressure gradient boundary layer is excited (i) at the wall with a monochromatic source and (ii) causing transition to turbulence, by a convecting vortex in the free stream. The main aim here is to trace the incipient disturbances from the onset to the turbulent state in terms of physical quantities, such as the disturbance mechanical energy introduced by Sengupta et al. [“Vortex-induced instability of an incompressible wall-bounded shear layer,” J. Fluid Mech. 493, 277–286 (2003)] and disturbance enstrophy transport equation, as proposed by Sengupta et al. [“An enstrophy-based linear and nonlinear receptivity theory,” Phys. Fluids 30(5), 054106 (2018)]. Such methods are capable of tracing disturbance structures from the onset to the evolved stage. We compare these methods with Q- and λ2-criteria to trace disturbance evolution.
Relationships between seed bank composition and an invasive plant in a floodplain wetland of the Murray–Darling Basin
Authors: Vivian L. M. , Godfree R. C.
Published: December 2019

Seed banks are an important characteristic of wetland plant assemblages, enabling the storage of dormant propagules through wet and dry periods until the next favourable period for growth and reproduction. In this study, we use a seed bank emergence experiment to investigate whether the seed bank of a grassy floodplain wetland located in Australia’s Murray–Darling Basin has been impacted by the invasion of Juncus ingens N.A. Wakef. River regulation and altered flood regimes have encouraged the spread of this species throughout grassy wetland areas, particularly at Barmah Forest, a Ramsar Convention-listed wetland of international significance in Victoria. We particularly focus on changes in the seed bank of an ecologically important, but declining, floodplain grass, Pseudoraphis spinescens (R.Br.) Vickery, and implications for restoration. We found that sites invaded by J. ingens had a higher density of emerged J. ingens plants, a lower density of P. spinescens and a lower overall native species richness. J. ingens-dominated sites were also characterised by a significantly deeper maximum flood depth than P. spinescens-dominated sites. The overall density of P. spinescens plants emerging from the soil was very low in comparison to most other species, and largely restricted to shallow sites where the species was already present. This suggests that restoration efforts may need to focus on encouraging vegetative regrowth from existing grassy swards, rather than expecting recovery from a viable seed bank, and highlights the importance of conserving the remaining P. spinescens patches at Barmah Forest.
High-performance, semiconducting membrane composed of ultrathin, single-crystal organic semiconductors
Authors: Makita Tatsuyuki , Kumagai Shohei , Kumamoto Akihito , Mitani Masato , Tsurumi Junto , Hakamatani Ryohei , Sasaki Mari , Okamoto Toshihiro , Ikuhara Yuichi , Watanabe Shun , Takeya Jun
Published: December 2019

Significance

Organic thin film transistors (OTFTs) are promising building blocks in next-generation electronic devices due to the compatibility with the solution process of organic semiconductors (OSCs). Generally, OTFT processes inevitably face the serious issue that the available substrates are limited to those that are solution-process compatible. In a striking contrast to conventional OTFT fabrication processes, we successfully demonstrate simple water exfoliation together with a transfer method for solution-processed organic single-crystal semiconductors. An ideal single-crystalline form can be maintained during the process, which results in excellent electronic performance. The methodology presented in this study allows the ideal production of OTFTs on a wide range of destination substrates with sufficient scalability and expands the possibility for OSCs to be employed in printed electronic devices.
Principles of forest biotechnology.
Authors: Meilan R. , Kirst M.
Published: December 2019

This chapter describes the principles of forest biotechnology. To genetically engineer a tree, a single, transformed cell must be regenerated into a whole plant. Agrobacterium tumefaciens is commonly used as a vehicle to transform (introduce genetic material) into the chromosome of a plant cell, but other approaches, such as biolistics, are available. The two general approaches to regenerating a plant are organogenesis and embryogenesis. The latter is the preferred route but has only been accomplished with a limited number of tree species, and is a labour-intensive and time-consuming process.
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with ISCIII, March 2019
Authors: Viallon Joële , Moussay Philippe , Wielgosz Robert , Abad Patricia , Nunez-Corcuera Beatriz , Miguel Jose Miguel de , Morillo Pilar
Published: December 2019

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of the Instituto de Salud Carlos III (ISCIII) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Spatial-symmetry violating electromagnetic fields corrected by nonlinear Lagrangian
Authors: Shibata Kazunori
Published: December 2019

We investigate a general nonlinear electromagnetic Lagrangian belonging to a subclass of the Plebański class. Depending on the form of nonlinear Lagrangian model, in an electrostatic problem, not only the electric field but also the electric flux density can vary from that given by linear classical electromagnetism. The variance is a correction which stems from the nonlinearity of Lagrangian. The nonlinear correction is a divergence-free field and possesses a mathematical vector potential. By considering a two charge system with a non-perturbative approach, we derive a necessary condition on nonlinear Lagrangian such that the nonlinear correction of the electric flux density becomes zero in the entire space. Several frequently considered nonlinear Lagrangian models do not satisfy this condition. As another important result, we show that the vector potential of the nonlinear correction violates mirror symmetry.
Influence of low-temperature atmospheric pressure plasma on the vital functions of microorganisms
Authors: Savinov V P , Yakunin V G , Karpukhina O V , Inozemtsev A N , Timoshenko V Y , Riaby V A
Published: December 2019

Experimental research on inactivating various types of microorganisms with low-temperature plasma at atmospheric pressure demonstrates great advantages of this method. It is shown that when treating the cells with cold plasma for 3 minutes by using a compact plasma source (plasmatron) a partial or complete disruption of the functional activity of Paramecium caudatum cells occurs. We have found out that plasma treatment for 5 minutes suppresses completely the vital functions of pathogenic microorganisms such as Mucor, Fusarium, Aspergillus and Bacillus mesentericus cells.
Electromagnetic and gravitational waves conversion in a nonlinear dielectric medium by intense light source irradiation
Authors: Pustovoit V I , Gladyshev V O , Gorelik V S , Kauts V L , Kayutenko A V , Morozov A N , Fomin I V , Sharandin E A , Gladysheva T M , Portnov D I
Published: December 2019

Various types of gravity wave sources were considered in this paper. It is proposed to use the effect of mutual conversion of electromagnetic and gravitational waves in a nonlinear optical dielectric medium irradiated by an intensive light source as a perspective method of generating gravitational-wave radiation.
Change in baric properties with decreasing size of germanium nanocrystal
Authors: Magomedov M N
Published: December 2019

The equation of state P(v/v
o) and the baric dependences of both the lattice and the surface properties for germanium macro- and nanocrystals were calculated using the Mie-Lennard-Jones pairwise interatomic potential and the RP-model of a nanocrystal. It is shown that at a certain value of the relative volume (v/v
o)0, the isothermal dependences P(v/v
o) for the macro- intersect with those for the nanocrystal. At the intersection point (at (v/v
o)0), the surface pressure becomes zero. The value (v/v
o)0 decreases both with an isomorphic-isomeric rise in temperature, and with an isomorphically-isothermal decrease in the number of atoms in a nanocrystal, or with an isomeric-isothermal deviation of the shape of the nanocrystal from the energy-optimal shape (a cube for the RP-model). Based on the equation of state obtained, the change in 23 properties of Ge was studied both at an isochoric (v/v
o = 1) and at an isobaric (P = 0) decrease in the number of atoms in a nanocrystal at temperatures of 100, 300, and 1000 K.
Metallographic research into the quality of X15N27T3MR-VD steel wire (EP700-VD)
Authors: Averina Yu M , Naumkina V A , Nedashkovsky K I , Nikolaenko O A , Semenova A V
Published: December 2019

The purpose of this paper is to report on the results of metallographic research into the quality of X15N27T3MR-VD steel wire (EP700-VD). The reason for the research was an oxidized zone with intergranular cracking which had been detected on the surface of the wire. To remove the defects, a variety of chemical methods were applied to the surface. As the research shows, after the chemical treatment methods such as winding springs, blowing them with corundum, etching in a mixture of HNO3 and HF, and electropolishing were applied to the surface, the defects were removed completely.
Symmetrical slot line with a dielectric insert in the slot
Authors: Klyuev S B , Nefyodov E I , Potapov A A
Published: December 2019

The electrodynamic properties of a symmetric slot line with a dielectric insert are investigated. A numerical analysis of the transmission line is performed using the finite element method. The dispersion matrix elements of the transmission line are presented. It is shown that the model of a symmetric slot line with a dielectric insert can extend the operating frequency band more than 2 times.
Practical uses of high-durability DC arc plasmatrons
Authors: Yakunin V G , Riaby V A , Savinov V P
Published: December 2019

The novel DC arc plasmatrons, with tungsten rod cathodes and nozzle anodes, and ways of their application are described in this article. The initial successful device was a T-plasmatron with a T-form of its gas-flow channels. Its specific anode erosion rate was lowered by four orders of magnitude, as compared with traditional arc plasmatrons. The result of a specific anode design, arranging technological gas and plasma-forming gas interactions, decreased this parameter to 4·10−10 g/C. This plasmatron was used in several technological processes, including cleaning the flow of Diesel engine exhaust, etching, and depositing different materials. After these experiments, the A-plasmatron was created, which had a generally axisymmetric form with a three-times greater ability for technological gas activation as compared with the T-plasmatron. The A-plasmatron was also used in the above-mentioned technological processes and demonstrated higher possibilities for each process. The extremely clean plasma flow of this plasmatron was studied using integral and local plasma diagnostic results, which have indicated its acceptable application for several processes, including the rather effective and interesting biomedical interactions with human wounds, vegetables, white straw crops and their products.
Simulation of deformation processes in upsetting
Authors: Solomonov K N , Tishchuk L I
Published: December 2019

The article describes an analysis of universal and specialized software complexes. We consider the «equi-theory» used for simulating the metal flow pattern. The software complex EQUI is applied to computer simulation of the metal flow pattern. We show how it is used for complex multi-contour workpieces.
Polydisperse vapour-droplet mixture dynamics model with phase transitions, fragmentation, and coagulation of droplets
Authors: Tukmakov A L , Tonkonog V G , Tukmakova N A , Arslanova S V
Published: December 2019

This work presents mathematical model and numerical method for polydisperse vapour-droplet mixture current description. A system of Euler equations for the carrier medium and disperse phase motion is solved via Mac-Cormack’s explicit method based on operator dimensional splitting and deferred correction scheme. The results of vapour-droplet flow calculations in cylindrical conduits are shown.
Irreversible protein transformation of multi-component animal raw materials systems under the influence of microbiological and technical factors
Authors: Boldyrev V , Ivankin A , Oliferenko G , Baburina M , Vostrikova N , Kulikovskii A , Tunieva E
Published: December 2019

In order to change the composition of natural food systems based on animal raw materials, we studied some features of thermodynamic changes of proteins under the influence of technological factors in the presence of biocultures. We revealed the important features of the influence of denaturation temperature and enthalpy of thermal transitions of myofibrillary proteins used in the technology of obtaining sodium chloride products, which is important for the effective optimization of parameters for obtaining high-quality products.
Numerical calculation of asymmetric antireflection microstructures spectral transmission dependency on polarization
Authors: Bushunov A A , Tarabrin M K , Lazarev V A
Published: December 2019

In this paper we performed a numerical analysis of middle infrared antireflection microstructures with elliptical holes. We used COMSOL Multiphysics finite element method analysis commercial software. The calculation results revealed the qualitative influence of structure surface imperfections and non-symmetry on transmission spectra for different polarizations. This fact has to be taken into account for the design of polarization-independent antireflection microstructures.
Numerical analysis of three-dimensional leukemia model’s equilibrium points
Authors: Domashenko Sofia , Alekhin Fedor
Published: December 2019

The results of numerical analysis of a mathematical model for chronic myelogenous leukemia (CML) equilibrium points quantity are presented. Considering a control example, the condition for the system without bistable equilibrium points was reached, so the system is supposed to have only those equilibrium points which is are asymptotically stable.
Research of the isofrequency temperature dependences of the Raman spectra near the phase transition point in quartz
Authors: Gorelik V S , Demeshkin F S , Pyatyshev A Yu
Published: December 2019

The work analyzes the isofrequency temperature dependences of Raman scattering near the phase transition point in quartz. Theoretical dependences for the spectral intensity of inelastic light scattering are derived. Coefficients for these dependencies were obtained on the basis of experimental data.
Some phase peculiarity in reflection of EM wave from boundaries between two isotropic media
Authors: Skripnik F V , Zadorozhnyi N A , Korogodina E V , Timchenko S L
Published: December 2019

A method of interferometric registration of the phase change of a polarized EM wave reflected from the boundaries between dielectric media is proposed. The method is suitable for determining how the phases of the waves reflected from the boundaries between isotropic media are affected by changes in the polarization plane and the angle of incidence of the wave. The interference pattern from two types of linearly polarized waves, one polarized in the plane of incidence (p-wave), another in a perpendicular plane (s-wave), was observed as interference of thin films in reflected light. This observation showed that the phase of the reflected s-wave from an optically denser medium was changed to the opposite for all tested angles of incidence. On the contrary, the phase of the reflected p-wave depends on the angle of incidence. The phase of reflected p-wave does not change for the range of the incidence angles from 0 to the Brewster angle (αB
) and becomes opposite for the range between αB
and π/2.
Rationalization of plasma piston’s particles parameters in a coaxial railgun
Authors: Sharaborova E S , Gerasimov Yu V , Maslov A G
Published: December 2019

This article is devoted to collisionless plasma particle motion in a coaxial railgun bore. Numerical modeling results showed that 2 types of motion can be realized in this system. Plasma particle parameters such as mass and charge were rationalized according to the types of motion and their roles in throwing body acceleration. The most effective parameters of the whole system were obtained.
Solution of thermoelasticity problems for solids of revolution with transversal isotropic feature and a body force
Authors: Ivanychev D A , Levina E Y
Published: December 2019

The paper describes a method for determining a stress-strain state of transversally isotropic solids of revolution, which are simultaneously influenced by external load and a body force within a steady-state temperature field. The final condition of the body is determined by the combination of these 3 factors, which are also affecting each other. The boundary conditions method is applied to determine the final condition influenced by exposure to an external load and temperature; the inverse method is applied to determine the condition affected by and resulted from influence of the body force. Methodologies were developed to form the bases of internal and boundary conditions related by isomorphism, and the relations that define them were formulated. Problems were solved for a circular cylinder of rock and for a solid of revolution with nontrivial form. The results are presented graphically.
Observation of the Talbot carpet for waves on the liquid surfac
Authors: Morozov A N , Moskvina I V , Skuibin B G , Smirnov E V
Published: December 2019

In this paper, the first observation of the Talbot effect for waves on the surface of a liquid is made. The diffraction of flat surface waves in a ditch with water on a diffraction grating containing 8 slits made it possible to obtain a clear image of the Talbot carpet on the surface of the water behind the grating. The Talbot length observed in the experiment coincides with the data of theoretical calculations.
Demonstration of special relativity effects with specialized software
Authors: Kashnikov A V , Gusmanova A A , Kiktenko E O
Published: December 2019

A software development project designed to demonstrate some effects of the special theory of relativity (STR) is considered. The software visualizes a uniform relativistic motion of one inertial reference frame, associated with a rocket, relative to another inertial reference frame, associated with the ground. The main idea behind the visualization is to reduce the speed of light down to perceived value, such that relativistic time dilation and relativistic length contraction effects can be explored. The basic mathematical expressions describing the model are given, and the interface of the software is presented. It is expected that the developed software will help to provide intuition behind relativistic mechanics for students starting their immersion in this topic.
Collective excitations in two-dimensional fluid with dipole-like repulsive interactions
Authors: Mistryukova L A , Kryuchkov N P , Khrapak S A , Golyak I S , Yurchenko S O
Published: December 2019

Collective excitations in a two-dimensional fluid with repulsive dipole-like interactions are systematically studied by molecular dynamics simulations. A two-oscillator model is used to reconstruct dispersion curves and to measure q-gap boundary values in the dispersion relation of the transverse (shear) mode. Functional form for the dependence of the q-gap boundary value on the coupling parameter is suggested. The results obtained can be used in future investigations of collective excitations in fluids, especially in two-dimensional cases.
The use of HTS-tape as a sample for a laboratory workshop
Authors: Goshin P V , Infimovsky Yu Yu , Motylev V A , Sokolov R A , Urakov D V
Published: December 2019

The suitability of the process use HST tape in the development of a laboratory workshop on general physics course. A sample transfer test bench for the HST tape included: a vessel with liquid nitrogen, a stabilized power supply, a microvoltmeter to measure the potential difference on the sample, a thermocouple (copper/copper-nickel) and a millivoltmeter to measure thermoelectric effect. The temperature of the sample and the potential difference on it were measured simultaneously.
Waste anthropogenic minerals in the circular economy
Authors: Cieplińska A , Szymanek A
Published: December 2019

The article presents the possibility of using calcareous wastes to produce alternative sorbents for flue gas desulphurization. Calcareous wastes from chemical plants produced during the propylene oxide production process were used. In order to assess the potential of stored waste, they were subjected to comprehensive physical and chemical tests: the chemical, morphological, structural, fractional composition and reactivity were determined. Due to the nature of its formation, lime waste was subjected to electromagnetic activation to improve its sorption properties. The impact of activation on physico-chemical properties was also determined. The verification of the tests carried out on a micro scale was the flue gas desulphurisation test performed on a real object using the activation technology in an electromagnetic mill. The aim of the test was to obtain similar results of flue gas desulphurisation with the use of a waste sorbent for the lime milk used in this method.
Problems with identification of vortex rings when using anemometry measurements.
Authors: Gruszka Konrad , Durajski Artur , Niegodajew Paweł , Bęben Mateusz , Elsner Witold , Gnatowska Renata , Šofer Michal
Published: December 2019

Measurement of key vortex rings properties with the use of anemometry techniques is not so straightforward due to the angular dispersion of these structures and in consequence change of their trajectories as they move downstream. Owing to the fact that in available literature no much attention is paid to this issue, there is still a need to address this problem. In the present work we show some preliminary data which allowed to quantify the dispersion of vortex rings when these propagate over a distance up eight orifice diameters. The presented results indicate that the vortex structures generated at a certain frequency are characterized by increasing unrepeatability and angular dispersion as a function of distance from the generator. This leads to difficulties in their identification because their position in respect to the fixed position of the hot-wire probe changes.
Some chosen aspects of CFB boilers operation
Authors: Kobyłecki Rafał , Zarzycki Robert , Bis Zbigniew
Published: December 2019

Central Europe, particularly Poland, has been one of the areas of intensive development of fluidized bed combustion technology for over 25 years. This paper deals with a brief discussion on the results of industrial tests carried out by the authors and focused on the reduction of nitrogen oxide emission, solids deposition and unburned carbon content in the fly ashes. Some selected data has been presented and come remarks and counteractions to improve the operation of industrial large-scale circulating fluidized bed boilers are given.
Study of the influence of the electrophysical properties of ZnO nanorods grown on glass on their gas-sensitive properties
Authors: Petrov V V , Abdullin Kh A , Starnikova A P , Varzarev Yu N
Published: December 2019

The article discusses the sensory properties of an array of ZnO-based nanorods, which were used as sensitive elements of carbon (II) oxide sensors. By hydrothermal synthesis, arrays of ZnO nanorods were grown on glass, which had an average transverse size of up to 40 nm and a height of up to 660 nm. Formed rods had a predominantly vertical orientation. Metal contacts were formed over the array of nanorods. Studies of the electrophysical properties showed that the temperature dependence of the conductivity of the formed structure has a hysteresis at temperatures above 160 ° C, and the current-voltage characteristic is close to linear. The gas sensitive properties of the ZnO array of nanorods were investigated to carbon monoxide (II) with a concentration of 20-100 ppm at operating temperatures from 20 to 270 ° C. It has been shown that the sensor response is strongly influenced by the rate of blowing the array with nanorod air or the test gas.
Atomic layer etching of Silicon Oxide
Authors: Kuzmenko V. , Miakonkikh A. , Rudenko K.
Published: December 2019

The atomic layer etching process for Silicon oxide is studied. The process consists of deposition step and activation step separated by pumping and purging steps. The deposition step is performed in C4F8 plasma and produces a polymer fluorocarbon film with 0.2-3 nm thickness. Then activation step is performed in Argon or Oxygen plasma with DC bias applied to the waferholder. Accelerated ions enhance reaction of fluorine atoms of the polymer film with underlaying Silicon oxide which leads to controllable saturated etching.
On the dendrite growth simulation during multitrack selective laser melting process
Authors: Dubrov A V , Mirzade F Kh , Dubrov V D
Published: December 2019

The evolution of the microstructure in the selective laser melting (SLM) process is investigated in the framework of a multiscale approach. The kinetic equation for the phase-field (order parameter) coupled with the energy transfer equation is used to describe the crystallization processes. To study the effect of technological parameters on the microstructure of the synthesized product, and to establish a connection between the models of macro- and micro-scale through the temperature gradient, numerical studies of macro processes in the formation of a series of parallel SLM tracks were carried out. It is shown that the adjustment of the laser power level changes the temperature dynamics in the test areas, which, in turn, through the changed temperature gradients affects the evolution of the microstructure in the micro-scale model. The calculations showed that the implemented numerical model qualitatively describes the kinetics of crystallization and formation of microstructures in the SLM process.
Substrate-removed flip-chip photodiode array based on InAsSbP/InAs double heterostructure
Authors: Karandashev S A , Klimov A A , Kunkov R E , Lavrov A A , Lukhmyrina T S , Matveev B A , Remennyi M A , Usikova A A
Published: December 2019

N-InAsSbP/InAs/P-InAsSbP double heterostructures have been grown onto n+-InAs substrate and further processed into 2×2 photodiode array containing no n+-InAs. C-V, spectral response as well as mid-IR photoluminescence and electroluminescence in the 77-300 K temperature range have been measured and used for photodiode characterization including D*(λ) and BLIP temperature evaluation.