bluuebunny/crossref_metadata_2025 huggingface dataset:
Application in deep vertical groundbeds of linear flexible anodes
Authors: Tremolada Simone , Martinelli Giorgio
Published: October 2019

This paper is about a case of application of a new anode system in a vertical groundbed in Italy for the impressed current cathodic protection of gas distribution pipelines. This system offers significant advantages for the installation of impressed current cathodic protection groundbeds with easy and timesaving procedures, accurate Quality Check on the factory-made conductive connections and optimization of the current distribution. The reduction of anode resistance versus soil enables a relevant energy saving. The product is flexible even in current output and expected design life. It is possible to select parameters, like the Mixed Metal Oxide titanium anode diameter, the feeding cable insulation, the distance and number of joints between the anode and the cable to realize a specific product fit for purpose. The reduced diameter of this anode system will enable to design new wells with consistently reduced borehole diameter. Further cost optimization can be reached by concentrating the length of the active part of the anodic system, this resulting in a reduced perforation depth. Deep Vertical Groundbed (DVG) calculations for the design of new groundbeds are presented in details with examples of a traditional string of MMO titanium anodes and linear flexible anode as alternative options.
Biomass - alternative renewable energy source and its conversion for hydrogen rich gas production
Authors: David Elena , Kopac Janez , Armeanu Adrian , Niculescu Violeta , Sandru Claudia , Badescu Viorel
Published: October 2019

This paper presnts biomass as a renewable energy source and defines the resources as well as the ways through biomass energy is converted into fuels, the technologies used for extracting the energy from biomass as well as the advantages and disadvantages that appear by using of biomass as a energy source. In addition,it is known hydrogen is an important alternative energy vector and a bridge to a sustainable way fot the energy future. Hydrogen is an energy carrier and can be obtained by different production technologies from a large variety of primary energy sources. At present, many researches are focused on getting energy from biomass, a sustainable and non-polluting way to replace fossil fuels, because the biomass can be considered as the best option with high potential, which meets energy requirements and could insure fuel supply in the future. Biomass and residual biomass can be used to produce hydrogen rich gas sustainably. Biomass pyrolysis and gasification offers an efficiency and economical route for the renewable hydrogen production and this is also discussed in the paper.
A holistic approach for the optimization of offshore wind farm layouts considering cable layouts
Authors: Ulku Ilayda , Alabas-Uslu Cigdem
Published: October 2019

A wind farm, mainly, is composed of a set of turbines, one or more transmitters and a set of electrical cable connections between turbines and transmitters. Determination of turbine locations within the farm to maximize total power generation is called turbine location (TL) problem. Relative turbine positions affect the amount of overall energy because of wake effects. Determination of cable connections among turbines and transmitters to collect produced energy by turbines at transmitters is called cable layout (CL) problem. While TL problem is directly effective on the total energy production in the farm, CL problem indirectly affects the total energy due to the power losses. In the literature, TL and CL problems are solved sequentially where the layout found by solving of TL is used as an input of CL problem. To minimize wake effects in TL problem, distances between turbine pairs should be increased, however, as the distances are increased the cable cost increases in CL problem. A new mathematical model is developed to deal with simultaneously solving of TL and CL problems. A set of test instances are used to show the performance of the proposed model. The experiments show the practical use of the proposed holistic model.
Development of a statistical forecasting model for PM2.5 in Macau based on clustering of backward trajectories
Authors: Xie Tong , Mok Kai Meng , Yuen Ka Veng , Hoi Ka In
Published: October 2019

A daily PM2.5 forecasting model based on multiple linear regression (MLR) and backward trajectory clustering of HYSPLIT was designed for its application to small cities where PM2.5 level is easily affected by regional transport. The objective of this study is to investigate the regions that affect the fine particulate concentration of Macau and to develop an effective forecasting system to enhance the capture of PM2.5 episodes. By clustering the HYSPLIT 24-hr backward trajectories originated at Macau from 2015 to 2017, five potential transportation paths of PM2.5 were found. A cluster based statistical model was developed and trained with air quality and meteorological data of2015 and 2016. Then, the trained model was evaluated with data of 2017. Comparing to an ordinary model without backward trajectory clustering, the cluster based PM2.5 forecasting model yielded similar general forecast performance in 2017. However, the critical success index of the cluster based model was 11% higher than that of the ordinary model. This means the cluster based model has better model performance in PM2.5 concentration prediction and it is more important for the health of the public.
Assessment of Natural Radioactivity Level and Annual Effective Dose of Amber Rice Samples Cultivated in the South of Iraq
Authors: Younis Abdulridha S. , Tawfiq Nada F.
Published: October 2019

In this work, the activity concentrations of naturally occurring radioactive material including 238U, 232Th, and 40K were measured of some amber rice samples cultivated in southern Baghdad and Al Najaf governorate and used in Baghdad governorate, Iraq in 2018, using gamma-ray spectrometer with NaI (Tl) detector. The results show that the activity concentrations for 238U ranged from (2.68 to 10.81) Bq/kg with average 5.94 Bq/kg, 232Th ranged from (B.D.L to 3.37) Bq/kg with average 2.65 Bq/kg, and for 40K ranged from (4.48 to 35.7) Bq/kg with average 16.84 Bq/kg. The annual effective dose from rice consumption by adults for 238U, 232Th, and 40K ranged from (0.41 to 1.6) x10-5 Sv/y with average 0.9 x10-5 Sv/y, (B.D.L to 0.42) x10-5 Sv/y with average 0.2 x10-5 Sv/y, and (0.17 to 1.2) x10-5 Sv/y with average 0.45 x10-5 Sv/y respectively. All values of the average specific activities are less than the global average values of ICRP, and the annual effective dose from rice consumption by adults was lower than the permissible limit of (1 m Sv/y) recommended by the International Commission on Radiological Protection.
Bioelimination of sulfur from high-sulfur coal by selected strains of microorganisms
Authors: Samet Raushan , Zhubanova Azhar , Akimbekov Nuraly , Qiao Xiaohui , Kadyrzhanova Anel
Published: October 2019

In this study, low-rank lignite coal sample collected from Lenger coal deposit (Turkestan province) in Kazakhstan was subjected to desulfurization by using three bacterial strains isolated from soil with silt and coal itself. The molecular identification of the 16S rRNA gene revealed that the isolated bacteria wereAtlantibactersp.,Pseudomonassp.,Bacillussp. denoted as S1, S2, and T1, respectively.Pseudomonassp. showed the best result in removing organic sulfur (93%) and total sulfur (52%), whileBacillussp. was effective in removing pyritic sulfur (19%) compared to other strains. However,Atlantibactersp. had no significant influence on sulfur content after treatment, thereby reducing its chances to be used in decreasing sulfur content in lignite in future investigations. Additionally, this research would be valuable to develop an innovative biotechnological method for producing an environmentally friendly briquetted smokeless fuel from lignite.
Study of the destructive activity of microorganisms isolated from soil contaminated by pesticides
Authors: Malik Azhar , Abdieva Gulzhamal , Ualieva Perizat , Akimbekov Nuraly
Published: October 2019

Chemical pollution of natural and agricultural habitats is a growing global problem and a serious threat to the sustainability and health of people. Among various chemical ecotoxicants of anthropogenic origin, organochlorine pesticides are among the most stable and dangerous for the environment and humans. Pesticides are chemical plant protection products, the intensive and not always justified the use of which has led to the fact that recently they are also considered among the most dangerous pollutants. One of the serious environmental problems is the pollution of natural objects with organic pesticides with high toxicity and persistence. Toxic substances can enter the environment and pose a threat to all living organisms, including the microbial population of the soil. Microorganisms isolated from ecosystems exposed to long-term treatment with pesticides can quickly decompose these compounds. The problem related to the decomposition of pesticide residues in the soil is an important environmental issue. Microorganisms are able to most effectively decompose xenobiotic substances foreign to the biosphere. The ability of microorganisms to decompose pesticides is associated with biochemical reactions and a high level of their adaptation. In this study, the microbial diversity of the soil in the territories adjacent to the pesticide burial sites was studied.
Concevoir une formation par concordance pour développer le raisonnement professionnel : quelles étapes faut-il parcourir ?
Authors: Charlin Bernard , Deschênes Marie-France , Dumas Jean-Pierre , Lecours Julie , Vincent Anne-Marie , Kassis Jeannine , Guertin Louis , Gagnon Robert , Robert Diane , Foucault Amélie , Lubarsky Stuart , Fernandez Nicolas
Published: October 2019

Contexte : Développer le raisonnement est une nécessité dans la formation des professionnels de la santé. La formation par concordance (FpC) est une approche pédagogique qui place les apprenants dans des situations authentiques. Les questions posées sont celles que se posent les professionnels dans leur pratique et les réponses sont comparées à celles qu’ont données les membres d’un panel de référence. But : Décrire les variables dont il est nécessaire de tenir compte pour concevoir une FpC. Méthodes : Ces variables sont au nombre de six : 1) les buts de l’activité pédagogique ; 2) la nature de la tâche ; 3) le contenu et le niveau de complexité ; 4) le panel de référence ; 5) les rétroactions ; 6) l’environnement numérique d’apprentissage. Résultats : Les exemples illustrés dans cet article permettent de constater la versatilité de cette approche pour mettre l’accent sur les divers éléments critiques au raisonnement de diverses professions. Conclusion : Les exemples présentés illustrent comment il est possible de mettre au point des outils de FpC qui se prêtent à l’amélioration à chaque itération. Il est désormais possible d’imaginer qu’un jour cette approche à la formation fera partie importante de toute formation professionnelle.
Schwindel, von der Fahreignung mit Führerschein zum
Führerschein ohne Fahreignung: Sind die aktuellen Leitlinien
gerechtfertigt?
Authors: Huppert Doreen , Brandt Thomas
Published: October 2019

Die seit dem Jahre 2014 gültigen und verpflichtend anzuwendenden
Begutachtungsleitlinien zur Fahreignung von Patienten mit Schwindel und
Gleichgewichtsstörungen (dort „Störungen des Gleichgewichtssinnes“ genannt)
werden kritisch diskutiert. Bei allem Respekt vor der sorgfältigen Arbeit der
Expertenkommission, die die Begutachtungsleitlinien erstellt hat – die
international nicht ihresgleichen haben – halten wir eine Überarbeitung der
geltenden Leitlinien für erforderlich. Die Auflagen für Schwindel und
Gleichgewichtsstörungen sind unserer Ansicht nach aufgrund der langjährigen
Arbeit im Deutschen Schwindel und Gleichgewichtszentrum der LMU München zu
streng und die geforderten beschwerdefreien Intervalle zu lang.

Die geltenden Begutachtungsleitlinien schreiben für Fahrer der
Fahrerlaubnisklasse Gruppe 1 („Privatfahrer“) zum Beispiel vor:

1) bei M. Menière (Attacken ohne Prodromi) eine Attackenfreiheit von 2 Jahren,
bevor Autofahren wieder möglich ist;

2) bei vestibulärer Migräne ohne Prodromi eine Attackenfreiheit von 3 Jahren.

Für Fahrer der Fahrerlaubnisklassen Gruppe 1 und 2 („Berufsfahrer“) gilt:

3) bei bilateraler Vestibulopathie in der Regel keine Fahreignung;

4) bei zentral-vestibulären Schwindelformen bzw. Okulomotorikstörungen wie
Downbeat- oder Upbeat-Nystagmussyndromen ebenfalls in der Regel keine
Fahreignung;

5) bei funktionellen (psychogenen) Schwindelformen (z. B. phobischer
Schwankschwindel) ist die Fahreignung für Fahrer der Fahrerlaubnisklasse Gruppe
1 nicht gegeben, wenn Schwindel beim Fahren auftritt, für Fahrer der
Fahrerlaubnisklasse Gruppe 2 besteht in der Regel keine Fahreignung. Bei vielen
Patienten mit episodischem oder chronischem Schwindel sind jedoch die Symptome
so gering, dass sie die Fahrtüchtigkeit nicht relevant einschränken oder bei
einer Schwindelattacke eine kontrollierte Beendigung des aktiven Fahrens
erlauben. Im Vergleich dazu sind die Auflagen für andere Erkrankungen, die mit
anfallsartigen Kognitions- und Bewusstseinsstörungen einhergehen wie den
Epilepsien, weniger streng (für Fahrer der Fahrerlaubnisklasse Gruppe 1
anfallsfreie Intervalle in Abhängigkeit von der Art bzw. Auslösung des Anfalls 3
Monate bis 1 Jahr), obwohl bei diesen die Fahrtüchtigkeit im Anfall sicher nicht
gegeben ist.
Aktuelle Therapiekonzepte bei oberflächlichen malignen
Tumoren
Authors: Scholz Simone Luisa , Eckstein Anja , Dekowski Dirk , Esser Joachim , Westekemper Henrike , Steuhl Klaus P.
Published: October 2019

In dieser Übersichtsarbeit werden die diagnostischen und therapeutischen
Möglichkeiten bei den häufigsten malignen oberflächlichen Tumoren abgehandelt,
hierzu gehören Basalzellkarzinome, konjunktivale Lymphome,
Plattenepithelkarzinome und maligne Melanome und deren Vorstufen. Entscheidend
für die richtige Diagnostik und Therapie ist eine ausführliche Anamnese,
Spaltlampenuntersuchung und Fotodokumentation des Tumorbefunds. Aber auch
regelmäßige Kontrollen nach erfolgter Therapie sind unabdingbar.

Das Basalzellkarzinom ist der häufigste Tumor der periokulären Haut. Histologisch
werden 3 Subtypen (nodulär, superfiziell, Morpheatyp) unterschieden. Eine
vollständige Exzision mit entsprechendem Sicherheitsabstand ist immer
anzustreben.

Das Lymphom ist der häufigste maligne primäre Tumor der Augenhöhle und der
okulären Adnexe. Es kann sowohl primär als auch sekundär, im Rahmen einer
lymphatischen Systemerkrankung, als auch ein- oder beidseitig auftreten. Das
MALT-Lymphom (MALT: Mucosa associated lymphoid tissue) betrifft am häufigsten
die Konjunktiven mit 20–33 %. Therapeutisch wird standardmäßig eine perkutane
Bestrahlung des Tumors angewandt.

Die Plattenepithelkarzinome der Bindehaut und deren Vorstufen (CIN I-III) stellen
ebenfalls eine der häufigsten Tumorentitäten am Auge dar. Eine vollständige
Tumorexzision ist immer anzustreben, jedoch aufgrund der häufig großflächigen
Ausbreitung nicht möglich. Für eine gute Tumorkontrolle sind nach R1-Resektion
daher adjuvante Therapien mit Mitomycin C (MMC) oder eine Radiotherapie mit
Rutheniumapplikator oder Protonenbestrahlung notwendig.

Das Bindehautmelanom ist selten, es kann jedoch lebensbedrohlich sein. Die primär
erworbene Melanose (PEM) mit Atypien (PEM I-III) hat je nach Schweregrad ein
erhöhtes Entartungsrisiko, dies macht eine Therapie mit Mitomycin-C-Augentropfen
notwendig. Bei Verdacht auf einen malignen Prozess ist immer eine Exzision
mittels Non-Touch-Technik anzustreben, damit das Streuungsrisiko von Tumorzellen
gering bleibt. Zusätzlich ist, abhängig von Lokalisation und Ausbreitung eines
Melanoms, immer eine adjuvante Therapie mittels Rutheniumapplikator oder
Protonentherapie notwendig.
Smoldering-Divertikulitis – doch eine Form der chronisch-rezidivierenden Divertikulitis mit guter Operationsindikation?
Authors: Rink Andreas D. , Nousinanou Maria Eleni , Hahn Jasmina , Dikermann Michael , Paul Claudia , Vestweber Karl-Heinz
Published: October 2019

Zusammenfasung

Hintergrund Die Indikation zur elektiven Sigmaresektion bei der rezidivierenden unkomplizierten Divertikulitis wird zurückhaltend gestellt. Eine Sonderform dieser Erkrankungsmanifestation wird im amerikanischen Schrifttum als „Smoldering-Diverticulitis“ (SmD) beschrieben, bei der symptomatische Schübe als Folge einer einem „Schwelbrand“ vergleichbaren persistierenden Entzündung in enger zeitlicher Abfolge auftreten. Das Ziel der Untersuchung bestand in der Evaluation der Sinnhaftigkeit der Operation in dieser Untergruppe.

Methoden Aus einem eigenen Kollektiv von 393 prospektiv erfassten Patienten mit minimalinvasiv intendierter Sigmaresektion bei Divertikulitis wurden 44 Patienten mit dem klinischen Bild einer SmD identifiziert und bezüglich operativer Morbidität und der Lebensqualitätsveränderung (Gastrointestinaler Lebensqualitätsindex (GLQI)) mit einer Gruppe von Patienten mit Operationen wegen perforierter Divertikulitiden verglichen (n = 95).

Ergebnisse Es zeigte sich eine vergleichbare Morbidität der Operation bei kürzeren Operationszeiten in der SmD-Gruppe (159 (65–301) vs. 174 (100–443) Minuten, p = 0,031). Sechs Monate postoperativ fand sich für die SmD-Patienten eine signifikante Verbesserung der Lebensqualität (GLQI 115 (72–143) im Vergleich zur präoperativen Situation (GLQI 98 (56–139), p = 0,018), während sich für die Kontrollgruppe nur ein nicht signifikanter Anstieg der präoperativ weniger reduzierten Lebensqualität zeigte. Fast 80 % der Patienten waren mit dem Ergebnis zufrieden.

Schlussfolgerung Die Untersuchung zeigt, dass bei dem klinischen Bild der engmaschig-rezidivierenden (Smoldering-) Divertikulitis eine Operation zur Verbesserung der Lebensqualität sinnvoll sein kann.
An insight into Clostridium difficile infection: a single-center retrospective case-control study
Authors: Haddad Fady G. , Zaidan Julie , Polavarapu Abhishek , Khan Hafiz , Khan Asif , Mudduluru Bindu Madhavi , Saabiye Joseph , Lukanovic Slobodanka , Demissie Seleshi , Mulrooney Stephen , Khalil Ambreen
Published: October 2019

Background Clostridium difficile infection (CDI) has become a worldwide health problem in view of its significant incidence and medical and economic impact on the health system. Prior studies have been undergone about risk factors and disease characteristics. We wanted to study the characteristics, prognostic factors associated with CDI at our institute, as well as a new prognostic factor.

Methods Our study aimed at describing the risk factors, patient characteristics, and outcomes associated with healthcare facility–acquired CDI (HCFA-CDI) and community-acquired CDI (CA-CDI). We intended to identify the factors associated with worse outcomes. We evaluated the characteristics associated with CDI over 3 years. We also evaluated a simple neutrophil-lymphocyte ratio (NLR) and its predictive value for worse outcomes.

Results Six hundred patients were enrolled (333 in a control group; 171 in the HCFA-CDI group and 96 in the CA-CDI group). NLR > 5 predicted increased mortality and intensive care unit transfer in all CDI if done as early as day 2 after CDI diagnosis. In HCFA-CDI, NLR > 5 predicted a higher ICU transfer if done as early as day 1 post-diagnosis and with increased mortality as early as day 2 post-diagnosis. In CA-CDI, NLR > 5 predicted a higher mortality and ICU transfer if done at least 4 days after diagnosis. Moreover, every 10-unit increase in NLR was associated with a significant increase in mortality and ICU transfer in patients with CDI.

Conclusion A timely use of NLR can be used as a mean to predict worse outcomes, namely ICU transfer and mortality, in patients with CDI.
Catalyst-Free [2,3]-Sigmatropic Rearrangement Reactions of Photochemically Generated Ammonium Ylides
Authors: Li Fang , He Feifei , Koenigs Rene M.
Published: October 2019

The rearrangement reaction of ammonium ylides furnishes valuable α,α-disubstituted amino esters. In this work, we describe the visible-light photolysis reaction of aryldiazoacetates in the presence of tertiary amines that react via a free ammonium ylide in a sigmatropic rearrangement reaction to provide amino esters in moderate to very good yields (33 examples, up to 97% yield).
Optimal ultra-miniature polarimeters in silicon photonic integrated circuits
Authors: Lin Zhongjin , Rusch Leslie A. , Chen Yuxuan , Shi Wei
Published: October 2019

Measurement of the state of polarization of light is essential in a vast number of applications, such as quantum and classical communications, remote sensing, astronomy, and biomedical diagnostics. Nanophotonic structures and integrated photonic circuits can, in many circumstances, replace conventional discrete optical components for miniature polarimeters and chip-scale polarimetry systems and thus significantly improve robustness while minimizing the footprint and cost. We propose and experimentally demonstrate two silicon photonic four-photodetector (PD) division-of-amplitude polarimeters (4PD-DOAPs) using a complementary metal–oxide–semiconductor-compatible photonic fabrication process. The first design targets minimizing the number of optical components. The second design makes use of a slightly more complex circuit design to achieve an optimal frame for measurements; this measurement frame minimizes and equalizes estimation variances in the presence of the additive white Gaussian noise and the signal dependent shot noise. Further theoretical examination reveals that within the optimal measurement frames for Stokes polarimeters, the DOAP with four PDs has the minimal equally weighted variance compared to those with a greater number of PDs.
Dehydrogenation of the liquid organic hydrogen carrier system 2-methylindole/2-methylindoline/2-methyloctahydroindole on Pt(111)
Authors: Bachmann Philipp , Steinhauer Johann , Späth Florian , Düll Fabian , Bauer Udo , Eschenbacher Roman , Hemauer Felix , Scheuermeyer Marlene , Bösmann Andreas , Büttner Miriam , Neiß Christian , Görling Andreas , Wasserscheid Peter , Steinrück Hans-Peter , Papp Christian
Published: October 2019

Among other N-heterocycles, indole and its substituted derivatives, such as methylindoles, are considered promising Liquid Organic Hydrogen Carriers (LOHCs) for the storage of renewable energy. We used X-ray photoelectron spectroscopy (XPS), temperature programmed desorption (TPD), and density-functional theory (DFT) to investigate the low temperature adsorption and consecutive dehydrogenation reaction during heating of 2-methylindole, 2-methylindoline, and 2-methyloctahydroindole on Pt(111) and their viability as the LOHC system. In the photoemission experiments, for all Hx-2-methylindoles, we find deprotonation at the NH bond starting between 240 and 300 K, resulting in a 2-methylindolide species. Simultaneously or before this reaction step, the dehydrogenation of 2-methyloctahydroindole via 2-methylindoline and 2-methylindole intermediates is observed. For 2-methyloctahydroindole, we also find π-allyl intermediates above 230 K. Starting at ∼390 K, decomposition of the remaining 2-methylindolide species takes place under the conditions of our surface science experiments. DFT calculations give insight into the relative energies of the various species, reaction intermediates, and their isomers both in the gas phase and on the Pt(111) surface.
3D Fourier imaging based on 2D heterodyne detection at THz frequencies
Authors: Yuan Hui , Voß Daniel , Lisauskas Alvydas , Mundy David , Roskos Hartmut G.
Published: October 2019

Holographic imaging techniques, which exploit the coherence properties of light, enable the reconstruction of the 3D scenery being viewed. While the standard approaches for the recording of holographic images require the superposition of scattered light with a reference field, heterodyne detection techniques enable direct measurement of the amplitude and relative phase of the electric light field. Here, we explore heterodyne Fourier imaging and its capabilities using active illumination with continuous-wave radiation at 300 GHz and a raster-scanned antenna-coupled field-effect transistor (TeraFET) for phase-sensitive detection. We demonstrate that the numerical reconstruction of the scenery provides access to depth resolution together with the capability to numerically refocus the image and the capability to detect an object obscured by another object in the beam path. In addition, the digital refocusing capability allows us to employ Fourier imaging also in the case of small lens-object distances (virtual imaging regime), thus allowing high spatial frequencies to pass through the lens, which results in enhanced lateral resolution.
Phase field simulation of grain size effects on the phase coexistence and magnetostrictive behavior near the ferromagnetic morphotropic phase boundary
Authors: Hu Cheng-Chao , Zhang Zhao , Yang Tian-Nan , Shi Yang-Guang , Cheng Xiao-Xing , Ni Jun-Jie , Hao Ji-Gong , Rao Wei-Feng , Chen Long-Qing
Published: October 2019

The grain size effects on the phase coexistence and magnetostrictive response of Tb1−xDyxFe2 polycrystals near the ferromagnetic morphotropic phase boundary (MPB) are revealed through phase-field modeling. It shows that phase coexistence is a universal phenomenon in polycrystals for both ferromagnetic and ferroelectric MPB and that the range of compositions for phase coexistence increases with decreasing grain sizes. A large, reversible, and anhysteretic magnetostrictive response at low external fields is also found in the fine-grained polycrystals around the ferromagnetic MPB, which offers us a route to developing nanocrystalline magnetostrictive materials.
THz field detection in graphene using deep neural networks
Authors: Kilic Velat , Foster Mark A. , Khurgin Jacob B.
Published: October 2019

We propose a graphene-based terahertz detection scheme capable of measuring not only pulse energy but also electric field shape. The scheme leverages strong nonlinear velocity saturation characteristics of graphene in combination with envelope-carrier phase offset imposed by propagation of the pulses through the dispersive medium to produce shape-dependent electric charge. These charges can then be easily detected by conventional electronics, and as numerical calculations show, the original pulse shape can be recovered with the help of deep neural networks.
Numerical study of amplitude modulation in the atmospheric boundary layer at very high Reynolds number
Authors: Ren Hehe , Laima Shujin , Li Hui
Published: October 2019

Wall model large eddy simulations (WMLES) are carried out to investigate the amplitude modulation exerted on near-wall small-scale motions by outer layer large-scale motions in the atmospheric boundary layer at high Reynolds number O(106–107). The properties of the mean and fluctuating velocities show good agreement with those found in previous studies. Furthermore, the positions at which there is no amplitude modulation found in the present study are consistent with those found in previous studies. A new phenomenon is observed, namely, that the value of the negative maximum correlation at high Reynolds number is smaller than that at low and moderate Reynolds number. Further investigation shows that the negative maximum correlation decreases with increasing Reynolds number, which could be explained by intermittency effects. There is good agreement of the correlation for different values of the Reynolds number when scaled with outer variables, which confirms that the large boundary-layer-height-scaled events that inhabit the logarithmic region are the source of amplitude modulation. This is confirmed by the locations of other characteristic points, which are independent of Reynolds number. In contrast, when scaled with inner variables, these characteristic points have a strong linear dependence on Reynolds number. Furthermore, the reversal in sign of the correlation corresponds to the crossover points of small-scale turbulent intensity and the local peak in the energy distribution, which gives the first and secondary crossover points a specific physical meaning. Finally, we provide an overview of the energy distribution, which gives an intuitive view of the outer peak energy site.
Forecasting short-term dynamics of shallow cumuli using dynamic mode decomposition
Authors: Manning Jeff , Baldick Ross
Published: October 2019

The application of dynamic mode decomposition to clear-sky index forecasting of shadowing effects of convective fair-weather cumulus clouds is presented. Cloud dynamics are captured by sequences of visible-light photographic video frames. This method can be more easily applied to the modeling of cloud evolution than traditional fluid-based methods and can enhance the existing frozen-cloud advection methods. Its use is demonstrated for an actual fair-weather cumulus cloud image sequence and compared to an advection-only forecast. It is concluded that the method shows promise for very short-term clear-sky index forecasting for up to 7 minute horizons.
Evaluation of measurement uncertainty for a high-precision angle comparator with a vacuum preloaded structure
Authors: Xia Yangqiu , Wu Zhilin , Huang Ming , Li Mengyang , Tang Qiang
Published: October 2019

Angle measurement is widely used in various fields of science and technology. With the development of technology, the measurement uncertainty of angle metrology becomes more and more demanding. To achieve high-precision calibration of a high-precision angle comparator with a sub-arc-second level, a method of angle position error calibration and measurement uncertainty evaluation based on no material reference was established. Firstly, the structure of the angle comparator with a vacuum preloaded air bearing driven by an ultrasonic motor drive and the construction of the whole calibration system are briefly introduced. Then, the basic principle, algorithm and error separation principle of angle calibration based on the optical angle measurement method were studied, and the test process is introduced. Finally, the measurement results and error sources were analyzed, the measurement uncertainty model was established and the measurement uncertainty was evaluated. The experimental results show that the high-precision angle comparator with a vacuum preloaded structure has an angle position error of 0.12″ and a measurement uncertainty of 0.05″ (k  =  2). Through many experiments, it is shown that the measurement system has a stable high-precision calibration capability with a sub-arc-second level for circular division artifacts.
A mathematical optimization model for spatial adjustments of dose distributions in high dose-rate brachytherapy
Authors: Morén Björn , Larsson Torbjörn , Tedgren Åsa Carlsson
Published: October 2019

High dose-rate brachytherapy is a modality of radiation therapy used for cancer treatment, in which the radiation source is placed within the body. The treatment goal is to give a high enough dose to the tumour while sparing nearby healthy tissue and organs (organs-at-risk). The most common criteria for evaluating dose distributions are dosimetric indices. For the tumour, such an index is the portion of the volume that receives at least a specified dose level (e.g. the prescription dose), while for organs-at-risk it is instead the portion of the volume that receives at most a specified dose level. Dosimetric indices are aggregate criteria and do not consider spatial properties of the dose distribution. Further, there are neither any established evaluation criteria for characterizing spatial properties, nor have such properties been studied in the context of mathematical optimization of brachytherapy. Spatial properties are however of clinical relevance and therefore dose plans are sometimes adjusted manually to improve them. We propose an optimization model for reducing the prevalence of contiguous volumes with a too high dose (hot spots) or a too low dose (cold spots) in a tentative dose plan. This model is independent of the process of constructing the tentative plan. We conduct computational experiments with tentative plans obtained both from optimization models and from clinical practice. The objective function considers pairs of dose points and each pair is given a distance-based penalty if the dose is either too high or too low at both dose points. Constraints are included to retain dosimetric indices at acceptable levels. Our model is designed to automate the manual adjustment step in the planning process. In the automatic adjustment step large-scale optimization models are solved. We show reductions of the volumes of the largest hot and cold spots, and the computing times are feasible in clinical practice.
Continuous-variable ramp quantum secret sharing with Gaussian states and operations
Authors: Habibidavijani Masoud , Sanders Barry C
Published: October 2019

We aim to quantify and mitigate quantum-information leakage in continuous-variable quantum secret sharing (CV QSS). Here we introduce a technique for certifying CV ramp quantum secret-sharing (RQSS) schemes in the framework of quantum interactive-proof systems. We devise pseudocodes in order to represent the sequence of steps taken to solve the certification problem. Furthermore, we derive the expression for quantum mutual information between the quantum secret extracted by any multi-player structure and the share held by the referee corresponding to the Tyc–Rowe–Sanders CV QSS scheme. We solve by converting the Tyc–Rowe–Sanders position representation for the state into a Wigner function from which the covariance matrix can be found, then insert the covariance matrix into the standard formula for CR quantum mutual information to obtain quantum mutual information in terms of squeezing. Our quantum mutual information result quantifies the leakage of the RQSS schemes.
Electromagnetically induced transparency at optical nanofiber–cesium vapor interface*
Authors: Liu Rui-Juan , Su Dian-Qiang , Song Zi-Xuan , Ji Zhong-Hua , Zhao Yan-Ting
Published: October 2019

Optical nanofiber (ONF) is a special tool for effectively controlling coupling of light and atoms. In this paper, we study the ladder-type electromagnetically induced transparent (EIT) under ultralow power level in a warm cesium vapor by observing the transmission of ONF that couples the 6S → 6P Cs atoms in the presence of a 6P → 8S control beam through the same fiber. The linewidth and transmission of the EIT signal are investigated at different intensities of the control laser. In addition, we theoretically study the nonlinear interaction at the ONF interface using the multi-level density matrix equations, and obtain good agreements between theory and experiments. The results may have great significance for further study of optical nonlinear effect at low power level.
One-dimensional structure made of periodic slabs of SiO2/InSb offering tunable wide band gap at terahertz frequency range
Authors: Razi Sepehr , Ghasemi Fatemeh
Published: October 2019

Optical features of a semiconductor–dielectric photonic crystal are studied theoretically. Alternating layers of micrometer sized SiO2/InSb slabs are considered as building blocks of the proposed ideal crystal. By inserting additional layers and disrupting the regularity, two more defective crystals are also proposed. Photonic band structure of the ideal crystal and its dependence on the structural parameters are explored at the first step. Transmittance of the defective crystals and its changes with the thicknesses of the layers are studied. After extracting the optimum values for the thicknesses of the unit cells of the crystals, the optical response of the proposed structures at different temperatures and incident angles are investigated. Changes of the defect layers’ induced mode(s) are discussed by taking into consideration of the temperature dependence of the InSb layer permittivity. The results clearly reflect the high potential of the proposed crystals to be used at high temperature terahertz technology as a promising alternative to their electronic counterparts.
Resonant multiple wave solutions to some integrable soliton equations*
Authors: Liu Jian-Gen , Yang Xiao-Jun , Feng Yi-Ying
Published: October 2019

To transform the exponential traveling wave solutions to bilinear differential equations, a sufficient and necessary condition is proposed. Motivated by the condition, we extend the results to the (2+1)-dimensional Kadomtsev–Petviashvili (KP) equation, the (3+1)-dimensional generalized Kadomtsev–Petviashvili (g-KP) equation, and the B-type Kadomtsev–Petviashvili (BKP) equation. Aa a result, we obtain some new resonant multiple wave solutions through the parameterization for wave numbers and frequencies via some linear combinations of exponential traveling waves. Finally, these new resonant type solutions can be displayed in graphs to illustrate the resonant behaviors of multiple wave solutions.
Design and optimization of microstructure optical fiber sensor based on bimetal plasmon mode interaction*
Authors: Wu Meng , Liu Xin-Yu , Zhou Gui-Yao , Xia Chang-Ming , Li Bo-Yao , Hou Zhi-Yun
Published: October 2019

A surface plasmon resonance (SPR) sensor with two orthogonal open loops based on microstructured optical fibers (MOFs) is introduced. The interaction between core mode and surface plasmon polariton (SPP) mode produced by two different metal films is studied. Full vector finite element method is used to analyze the coupling and sensing characteristics. The results show that there are three loss peaks near the Au/Ag film, and multi-peak calibration is achieved. Because of the positive and negative sensitivity of the amplitude, the sensor has strong anti-interference capability when the external environment changes. The sensor can detect the refractive index between 1.37 and 1.40, and the working wavelength is between 1600 nm and 2400 nm. Because the sensor has some excellent characteristics, it can be used in biochemical sensing, environmental detection, and other related fields.
Pattern selection of three components Gray-Scott model
Authors: Rahim Huzaif , Iqbal Naveed , Cong Cong , Ding Zejun
Published: October 2019

The reaction-diffusion system demonstrates a variety of dynamical behaviours, and has become a standard model for explaining complex Turing patterns. In this work we have performed the analytical analysis of the three components Gray-Scott reaction-diffusion system. The analytical conditions for Turing instability about the homogeneous steady state has been derived. The linear stability is theoretically discussed. To determine the nature of pattern amplitude equation is derived by using weakly nonlinear analysis, which enumerates about the rich dynamical behaviour of this model, e.g. spot-, strip- and hexagon-patterns.
Extinction and persistence of a stochastic SIRS model with nonlinear incidence rate and transfer from infectious to susceptible
Authors: Zhang Qiuhua , Zhou Kai
Published: October 2019

In this paper, we propose a stochastic SIRS model with nonlinear incidence rate and transfer from infectious to susceptible. We first give the existence and uniqueness of the positive solution for this system. Moreover, the extinction of the disease and the persistence in the mean are established in the terms of a threshold value.
A new discriminant model for Parkinson’s disease based on logistic regression
Authors: Guo Pengcheng , Li Wei , Su Zhongyu
Published: October 2019

Although Parkinson’s Disease has significantly affected patients’ normal family and life, it’s difficult to find the correlations of many kinds of indicators and an effective way of diagnosing timely. In this paper, an efficient Discriminant Analysis model based on Logistic Regression is provided to give the reduction of Parkinson’s patients’ indicators and diagnose whether or not you have the disease. Firstly, Principal Component Analysis and Clustering Analysis are implemented to reduce the data dimension of Parkinson’s indicators and give the reductive clusters to complete the feature extraction. The 22 physical indicators data of 195 patients is efficiently 3 main components and 4 clusters. Secondly, according to the extracted features and discriminant analysis based on Logistic Regression, the new discriminant function is established. At last, Python programming is designed to input the characteristic values and output whether or not have the disease to finish the efficient computer implementation of this model. Its result that the accuracy of 195 Parkinson cases of discrimination is 100% has verified the efficiency of this model.
Evolution of cooperation driven by individual disguise in the public goods game with pool punishment
Authors: Wang Qiang , Chen Xiaojie
Published: October 2019

The phenomenon of individual disguise is pervasive in the real world. But in theory it is unclear what roles it plays in the evolution of cooperation. In this work we introduce individual disguise into a public goods game with pool punishment, and we assume that defectors choose to probabilistically disguise to escape punishment in interaction groups. By using the replicator equations, we show that the introduction of individual disguise hinders public cooperation in the conditions of low fine and low disguise cost no matter whether second-order punishment is considered or not. Besides, we find that the positive role of punishment is completely undermined in the absence of second-order punishment, whereas the situation is improved in the presence of second-order punishment.
An implicit integration factor method for a kind of spatial fractional diffusion equations
Authors: Zhao Yongliang , Zhu Peiyong , Gu Xianming , Zhao Xile , Jian Huanyan
Published: October 2019

A kind of spatial fractional diffusion equations in this paper are studied. Firstly, an L1 formula is employed for the spatial discretization of the equations. Then, a second order scheme is derived based on the resulting semi-discrete ordinary differential system by using the implicit integration factor method, which is a class of efficient semi-implicit temporal scheme. Numerical results show that the proposed scheme is accurate even for the discontinuous coefficients.
Effect and correction of segregation error in coal size distribution estimation by image analysis on a conveyor belt
Authors: Zhang Zelin , Hu Qi , Zhang Zhiwei , Wang Li
Published: October 2019

Online monitoring of rock size is of great significance for mining and mineral processing, and machine vision is regarded as the most suitable approach. Segregation error of coal piles is inherent in image-based size distribution estimation, leading to the difference between surface size distribution and overall size distribution. In this research, we analysed the segregation error and proposed a correction method for image-based size distribution estimation of coal piles on a conveyor belt. The paint spraying of rock particles makes the compare of actual surface size distribution and overall size distribution possible. Rosin-Rammler particle characteristic equation was used to build the correction model to reduce the segregation error in size distribution estimation. Test results indicated that the corrected overall size distribution is close to the actual overall size distribution, and the maximal absolute error reduces from 19.98% to 2.04%. This investigation is useful and valuable for the optimization and improvement of image-based size distribution estimation of coal piles on a conveyor.
Stabilization of a heat-like equation in rectangle domain
Authors: Ding Xing , Zhou Zhongcheng
Published: October 2019

In this paper, we discuss the stabilization of the heat-like equation in rectangle domain with boundary control. We firstly transfer the heat-like equation in 2D into series of heat equations in 1D via eigenfunction expansion, then, by using the normal backstepping transformation, we obtain the existence and estimate for series of kernel functions in transformations. Finally, combined with the states and controls estimate of series of heat equations, we finally obtain the exponential and finite time stabilization of the heat-like equation in 2D.
Uniform convergence analysis of finite difference approximations on adaptive mesh for general singular perturbed problems
Authors: Wang Antao , Sun Linan
Published: October 2019

In this paper we consider a more general singular perturbation problem, that is, −εu″(x) − a(x)u’(x) + b(x)u (x) = f(x) (0<ε≪1) on an adaptive grid. The mesh is constructed adaptively by equidistributing a monitor function based on the arc-length of the approximated solutions. Our analysis provide insight into the convergence behaviour on such mesh, and the posterior error estimates of piecewise linear interpolation about the approximate solution is investigated and an ε-uniform error estimate for the first-order upwind discretization of general singular perturbed problem is derived at last. We extend the relevant results of the document to a more general case.
Seismic waveform inversion using a neural network-based forward
Authors: Fu Hongsun , Zhang Yan , Ma Mingyue
Published: October 2019

The purpose of seismic waveform inversion is to obtain a geological model that is optimally fitted to the predicted seismic record and the measured seismic record. Since the forward model is repeatedly called during the inversion process, in order to improve efficiency, an efficient forward calculation method must be employed. In this study, we take a 2D wave equation as an example and propose a deep learning method as a forward model to minimize the prediction error value of seismic records. And the velocity inversion test of the Marmousi model is carried out by conjugate gradient method. Numerical experiments show that compared with the traditional finite difference method, the method can greatly reduce the calculation amount and improve the calculation efficiency.
Study on the reflection characteristics of the composite structure coupled with periodic plasma and frequency selective surface
Authors: Li Chuanbao , Hou Zhongyu
Published: October 2019

This paper proposes and prepares a composite structure composed of periodic plasma structure and three-dimensional (three-layer) metal period structure. The printed circuit board (PCB)-based frequency selective surface (FSS) is a double-layer conjugate structure. The periodic plasma structure consists of six horizontally aligned T8 fluorescent tubes. The composite structure exhibits some characteristics of plasma photonic crystal. The effects of periodic plasma structure, metal grids above periodic plasma and polarization angle on the reflection of metal periodic structure are studied in this paper. Experimental results show that FSS of the composite structure causes the reflection of electromagnetic wave to drop by 6.3 dB at 2.0 GHz compared with the composite structure without FSS. When the polarization angle is 30 degrees, the metal grids above the periodic plasma can further reduce electromagnetic wave reflection, and the reflection of a composite structure with metal grids is about 14dB lower than that of structure without metal grids at 1.89GHz. In addition, when the polarization angle changes from 0 degree to 30 degrees, the reflection of electromagnetic wave drops by 9.3 dB at the absorption peak.
Development of a body force model for a marine reactor in heaving motion
Authors: Li Weitong , Yu Lei , Rao Yuxian , Wang Cong
Published: October 2019

In the marine environment, sea wave affects the reactor coolant periodically through the additional forces. In this paper, a modified mathematical model is proposed and applied in the RELAP5/3.2 code in order to simulate the marine heaving condition. Then the influence mechanism of heaving motion and natural circulation features for an integral natural circulation reactor are analysed and discussed. The results show that the original flow distribution of prototype reactor is broken, however, the natural circulation is not interrupted. What’s more, the calculation shows that large amplitude and long period of heaving motion bring out violent oscillation, which is referential to the safety analysis of the reactor core.