bluuebunny/crossref_metadata_2025 huggingface dataset:
Personalized mathematical model of endotoxin-induced inflammatory responses in young men and associated changes in heart rate variability
Authors: Brady R. , Frank-Ito D.O. , Tran H.T. , Janum S. , Møller K. , Brix S. , Ottesen J.T. , Mehlsen J. , Olufsen M.S.
Published: September 2018

The objective of this study was to develop a personalized inflammatory model and estimate subject-specific parameters that could be related to changes in heart rate variability (HRV), a measure that can be obtained non-invasively in real time. An inflammatory model was developed and calibrated to measurements of interleukin-6 (IL-6), tumor necrosis factor (TNF-alpha), interleukin-8 (IL-8) and interleukin-10 (IL-10) over 8 hours in 20 subjects administered a low dose of lipopolysaccharide. For this model, we estimated 11 subject-specific parameters for all 20 subjects. Estimated parameters were correlated with changes in HRV, computed from ECG measurements using a built-in HRV module available in Labchart. Results revealed that patients could be separated into two groups expressing normal and abnormal responses to endotoxin. Abnormal responders exhibited increased HRV, most likely as a result of increased vagal firing. The observed correlation between the inflammatory response and HRV brings us a step further towards understanding if HRV predictions can be used as a marker for inflammation. Analyzing HRV parameters provides an easy, non-invasively obtained measure that can be used to assess the state of the subject, potentially translating to identifying a non-invasive marker that can be used to detect the onset of sepsis.
Catching platelets from the bloodflow: the role of the conformation of von Willebrand factor
Authors: Belyaev Aleksey V.
Published: September 2018

The mechanics of platelet initial adhesion due to interactions between GPIb receptor with von Willebrand factor (vWf) multimers is essential for thrombus growth and the regulation of this process. Multimeric structure of vWf is known to make adhesion sensitive to the hydrodynamic conditions, providing intensive platelet aggregation in bulk fluid for high shear rates. But it is still unclear how it affects the dynamics of platelet motion near vessel walls and efficiency of their adhesion to surfaces. Our goal is to resolve the principal issues in the mechanics of platelet initial attachmentviaGPIb-vWf bonds in near-wall flow conditions: when the platelet tends to roll or slide and how this dynamics depends on the size, conformation and adhesive properties of the vWf multimers. We employ a 3D computer model based on a combination of the Lattice Boltzmann method with mesoscopic particle dynamics for explicit simulation of vWf-mediated blood platelet adhesion in shear flow. Our results reveal the link between the mechanics of platelet initial adhesion and the physico-chemical properties of vWf multimers. This has implications in further theoretical investigation of thrombus growth dynamics, as well as the interpretation of in vitro experimental data.
Interaction solutions between soliton and periodic wave for the foam-drainage equation
Authors: Zhang Zhi-Yong , Ma Kai-Hua
Published: September 2018

The foam-drainage equation is a model for the drainage of liquid in a foam. In this work, we present two different types of interaction solutions of the foam-drainage equation both analytically and graphically, including soliton-hyperbolic tangent wave and soliton-cotangent wave. The properties of the interaction solutions are analysed.
Optimal online algorithms for the portfolio selection problem, bi-directional trading and -search with interrelated prices
Authors: Schroeder Pascal , Kacem Imed , Schmidt Günter
Published: September 2018

In this work we investigate theportfolio selection problem(P1) andbi-directional trading(P2) when prices are interrelated. Zhanget al.(J. Comb. Optim.23(2012) 159–166) provided the algorithm UND which solves one variant of P2. We are interested in solutions which are optimal from a worst-case perspective. For P1, we prove the worst-case input sequence and derive the algorithmoptimal portfolio for interrelated prices(OPIP). We then prove the competitive ratio and optimality. We use the idea of OPIP to solve P2 and derive the algorithm calledoptimal conversion for interrelated prices(OCIP). Using OCIP, we also design optimal online algorithms forbi-directional search(P3) calledbi-directional UND(BUND) andoptimal online search for unknown relative price bounds(RUN). We run numerical experiments and conclude that OPIP and OCIP perform well compared to other algorithms even if prices do not behave adverse.
An extended approach for manufacturing strategy process base on organization performance through Fuzzy QFD
Authors: Pooya Alireza , Tabrizi Moghadam Elaheh Valinezhd
Published: September 2018

This paper provides an extended model base on the Quality Function Deployment (QFD) framework to develop a manufacturing strategy process through linking manufacturing competitive factors with organization performance. Performance factors will guarantee alignment between manufacturing strategy and organization strategy. Performance analysis using entropy methods and the improvement ratio in all stages of this model is an advantage. A further advantage of model is the quantity control of correlation between manufacturing competitive factors, which causes factors to achieve higher rank such that their development will proceed the development of other competitive factors and increase the values of selected performance factors; similarly, quantity control of the correlation between manufacturing strategy decisions will increase effectiveness of this model in prioritizing manufacturing strategy development. The proposed model in this paper is implemented in an automotive rubber profile manufacturer in Iran. The results of application of the model are provided at the end of the article.
Knowledge and Practices Regarding Polycystic Ovary Syndrome among Physicians in Europe, North America, and Internationally: An Online Questionnaire-Based Study
Authors: Gibson-Helm Melanie , Dokras Anuja , Karro Helle , Piltonen Terhi , Teede Helena
Published: September 2018

Background To inform knowledge translation by identifying evidence–practice gaps in polycystic ovary syndrome (PCOS) care and variations between disciplines and across world regions via an online, anonymous, devised questionnaire distributed via professional societies and completed by 1,495 physicians (2015–2016).

Methods Multivariable logistic regression analyses generated adjusted odds ratios (OR) and 95% confidence intervals (CI) for associations between outcome measures and world region, specialty, annual patients with PCOS, age, and sex.

Results Features corresponding to Rotterdam diagnostic criteria were well recognized (e.g., irregular menstrual cycles by 99% of physicians), but psychological implications were recognized only by 29 to 64%. Reproductive endocrinologists were more likely to use Rotterdam diagnostic criteria (OR: 3.1; 95% CI: 2.3–4.3; p < 0.007) than obstetrician-gynecologists. Reproductive (OR: 2.0; 95% CI: 1.5–2.8; p < 0.007) and medical endocrinologists (OR: 3.1; 95% CI: 1.7–5.7; p < 0.007) were more likely to recommend lifestyle management than obstetrician-gynecologists. Physicians in Europe (OR: 4.7; 95% CI: 3.5–6.1; p < 0.007) and other regions (OR: 4.0; 95% CI: 2.8–5.9; p < 0.007) were more likely to use Rotterdam diagnostic criteria than physicians in North America.

Conclusion Knowledge gaps in PCOS care to be addressed internationally include physician awareness of the breadth of PCOS features, application of diagnostic criteria, and recommending lifestyle management effectively.
What Can You Find about Polycystic Ovary Syndrome (PCOS) Online? Assessing Online Information on PCOS: Quality, Content, and User-Friendliness
Authors: Chiu Wei-Ling , Kuczynska-Burggraf Millicent , Gibson-Helm Melanie , Teede Helena , Vincent Amanda , Boyle Jacqueline
Published: September 2018

Background Polycystic ovary syndrome (PCOS) is a common yet complex condition, where education is vital. It predominantly affects reproductive-aged women, the age group with peak use of the Internet, now a major source of health information. Women with PCOS are dissatisfied with care, and the lack of useful online information is a key concern.

Methods Using a rigorous and systematic methodology, we examined the quality, information content, and user-friendliness of online information about PCOS. Internet searches were conducted in Australia and the United Kingdom in December 2015 using Google, Bing, and Yahoo with different browsers, operating systems, and domain names. A total of 75 Web sites were evaluated and categorized.

Results The majority of Web sites were commercial (41%) and not-for-profit (76%) and were aimed at women only. Less than a third of the Web sites were externally accredited. Commercial Web sites and Web sites targeting only women had the lowest quality scores, while professional-society Web sites and Web sites targeting only HPs scored the highest in quality. Accredited Web sites had higher quality and user-friendliness scores than nonaccredited Web sites.

Conclusion The majority of PCOS Web sites were commercially derived, targeted women, and were not accredited. There is a significant lack of quality, easy-to-read, evidence-based information online for women with PCOS.
Informing Translation: The Accuracy of Information on Websites for Lifestyle Management of Polycystic Ovary Syndrome
Authors: Htet Thaw , Cassar S. , Kuczynska-Burggraf Millicent , Gibson-Helm Melanie , Chiu Wei-Ling , Stepto N. , Moran Lisa , Boyle Jacqueline
Published: September 2018

Lifestyle (diet, physical activity [PA], and/or behavioral) interventions are recommended for all women with polycystic ovary syndrome (PCOS) in international guidelines. The internet is a widely used health information resource. However, the accuracy of lifestyle information on PCOS websites is unknown and is reviewed here to inform translation of the international guideline on PCOS. An internet search was conducted with three search engines across different web browsers and countries. Accuracy was assessed through a checklist of 29 questions based on international guidelines for diet, PA, or weight management for the general population and for PCOS with higher scores indicating greater accuracy. Fifteen websites were eligible out of 72 (20%). The total accuracy score was 56 ± 13 (mean ± standard deviation; potential range: −29 to 87) comprising 23 ± 6 for diet (−11 to 33), 15 ± 5 for PA (−9 to 27), and 14 ± 3 for weight management (−8 to 24). A moderate proportion of websites provided general information on appropriate diet (40–80%) or weight management strategies (47–60%), but only 10 to 40% of websites provided information on core foods, discretionary foods, exercise quantity/intensity, energy deficits, or behavioral strategies. Limited websites on PCOS contain information on lifestyle management. The majority provided information on general diet, PA, and weight recommendations but less information on practical implementation of lifestyle change as an identified translation gap for the international guideline on PCOS.
Large-Scale Evidence-Based Guideline Development Engaging the International PCOS Community
Authors: Misso Marie , Tassone Eliza , Costello Michael , Dokras Anuja , Laven Joop , Moran Lisa , Teede Helena ,   on behalf of the International PCOS Network
Published: September 2018

The evidence-based guideline for the assessment and management of polycystic ovary syndrome (PCOS) integrates the best available evidence with international, multidisciplinary clinical expertise and consumer preferences to provide health professionals, consumers, and policy makers with high-quality, comprehensive guidance about diagnosing and managing PCOS. Here, we outline the rigorous and systematic process, defined a priori and documented to be reproducible, to minimize bias and maintain transparency, in alignment with the Appraisal of Guidelines for Research and Evaluation (AGREE II) criteria and incorporating the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework that render this PCOS evidence-based guideline credible, trustworthy, reliable, and useable.
Value of Ki-67 Labeling Index in Predicting Recurrence of WHO Grade I Cranial Base Meningiomas
Authors: Matias Jose Gabrielle , Jusue-Torres Ignacio , Martin Brendan , Bajaj Ankush , Borys Ewa , Melian Edward , Barton Kevin , Anderson Douglas E. , Prabhu Vikram C.
Published: September 2018

Objectives Assess impact of Ki-67 labeling index (LI; Ki-67 LI) on risk of recurrence or progression of WHO grade I meningiomas.

Study Design Retrospective study of adult patients who underwent resection of cranial base meningioma between 2004 and 2016.

Results 272 patients fulfilled criteria for inclusion in the study. Average age was 61.8 years; 196 (72%) were females. Simpson's grade 1 resection was noted in 77 patients (32%), grade 2 in 39 (16%), grade 3 in 36 (15%), and grade 4 in 88 (37%). The Ki-67 LI was low (1–4%) in 214 (78.7%), intermediate (5–9%) in 44 (16.2%), and high (>10%) in 14 (5.2%). Median follow-up was 39 months (IQR: 16–71 months); 221 (87.1%) tumors remained stable or did not recur, 19 (7.4%) recurred, and 14 (5.5%) progressed. Compared with tumors with low Ki-67 LI, those with intermediate Ki-67 LI had 2.47 times (2.47 [1.09–5.59], p = 0.03), and those with high Ki-67 LI had 3.38 times (3.38 [1.16–9.89], p = 0.03) higher risk of recurrence or progression. Tumors with Ki-67 LI > 4% had a shorter time to recurrence or progression (p = 0.01). Recurrence or progression-free survival rates at 3, 5, and 10 years for tumors with low Ki-67 LI were 95%, 89%, and 75%, respectively; tumors with intermediate Ki-67 LI, 87%, 69%, and 52%, respectively; tumors with high Ki-67 LI, 78%, 49%, and 49%, respectively.

Conclusions Following surgical resection of a WHO grade I cranial base meningioma, Ki-67 LI > 4% may predict an increased risk of recurrence or progression of residual tumor.
Transplante de microbiota fecal no tratamento da infecção por Clostridium difficile recorrente—uma revisão
Authors: Meneses Rômulo , Filardi Kaique , Bagano Patricia , Machado Rafaela , Fernandes Sandra
Published: September 2018

A infecção por Clostridium difficile (ICD) tem se tornado uma das maiores complicações associadas ao uso de antibióticos sistêmicos. Os antimicrobianos quebram o equilíbrio da flora intestinal colônica, predispondo o indivíduo a infecção por cepas oportunistas, como a ICD, que pode ocasionar, caracteristicamente, um quadro de diarreia e colite. O tratamento padrão para estes casos consiste no uso de metronidazol ou vancomicina por um período de 10 a 14 dias. Porém, estima-se que cerca de 5 a 35% destes pacientes apresentarão falha terapêutica, com novos quadros de ICD. As opções de tratamento para a ICD recorrente permanecem limitadas, mas com terapias promissoras sendo constantemente pesquisadas. O uso de fezes obtidas de um doador saudável para a realização de transplante de microbiota fecal (TMF) vem ganhando espaço nos diversos centros de saúde, com taxas de sucesso reportadas entre 80 e 100%. No entanto, a experiência acerca do assunto ainda permanece limitada, com necessidade de estudos que permitam a criação de um protocolo específico para a realização do TMF.
Cochlear Implantation: An Overview
Authors: Deep Nicholas , Dowling Eric , Jethanamest Daniel , Carlson Matthew
Published: September 2018

A cochlear implant (CI) is a surgically implanted device for the treatment of severe to profound sensorineural hearing loss in children and adults. It works by transducing acoustic energy into an electrical signal, which is used to stimulate surviving spiral ganglion cells of the auditory nerve. The past 2 decades have witnessed an exponential rise in the number of CI surgeries performed. Continual developments in programming strategies, device design, and minimally traumatic surgical technique have demonstrated the safety and efficacy of CI surgery. As a result, candidacy guidelines have expanded to include both pre and postlingually deaf children as young as 1 year of age, and those with greater degrees of residual hearing. A growing proportion of patients are undergoing CI for off-label or nontraditional indications including single-sided deafness, retrocochlear hearing loss, asymmetrical sensorineural hearing loss (SNHL) in adults and children with at least 1 ear that is better than performance cut-off for age, and children less than 12 months of age. Herein, we review CI design, clinical evaluation, indications, operative technique, and outcomes. We also discuss the expanding indications for CI surgery as it relates to lateral skull base pathology, comparing CI to auditory brainstem implants, and address the concerns with obtaining magnetic resonance imaging (MRI) in CI recipients.
Economic crisis and mental health – findings from Greece
Authors: Christodoulou N.
Published: September 2018

Background: The direct and indirect effects of the economic crisis in Greece have resulted in inequalities, poverty and unemployment. Public health services, social care and welfare have been both severely curtailed and overstretched by increased demand due to higher private care costs and the refugee crisis. For society’s most vulnerable this is beyond an economic crisis, it is a humanitarian crisis. Method: In this narrative review we report a continued rise in suicides, persistent mental health problems in the population, and continued systemic problems despite some successful reforms and slowing of the economic deterioration. Synergistic effects are identified between pre-existing systemic weaknesses, the effects of the crisis, and the effects of austerity. Outlook: Psychiatrists should promote evidence- based interventions, for example preventing mental illness by supporting vulnerable groups and by reducing inequalities. Evidence-based heurism is advocated for, in the interest of outcome. Psychiatrists also have a political role in tackling stigma towards mental illness, refugees and other vulnerable groups, and in promoting resilience and solidarity.
Die Begriffe der Depression und Melancholie im Werk von Johann Christian August Heinroth (1773-1843)
Authors: Steinberg H.
Published: September 2018

Der Leipziger Psychiater Johann Christian August Heinroth definierte den Inhalt des Begriffes Depression neu zur rein symptomatischen Beschreibung einer allgemein traurigen, niedergedrückten Stimmung und damit als recht klar umrissenes psychopathologisches Phänomen. Dieser so vor allem in seinem Lehrbuch von 1818 eingeführte Terminus blieb im Fortgang der Geschichte der Psychiatrie mit dieser Bedeutung erhalten. Davon zu unterscheiden nutzte er zur Bezeichnung der depressiven Erkrankung des Gemüts, das er entsprechend der Vermögenspsychologie neben dem Geist und dem Willen als eine der Grundkräfte der Seele auffasste, innerhalb seiner eigenen, in der Reflexion entstandenen kategorialen Krankheitsklassifikation indes den vorhandenen Begriff der Melancholie.
Biomechanical Evaluation of Suture Anchor versus Transosseous Tunnel Patellar Tendon Repair Techniques
Authors: Sherman Seth L. , Black Brandee , Mooberry Matthew A. , Freeman Katie L. , Gulbrandsen Trevor R. , Milles Jeffrey L. , Evans Laura , Flood David , Pfeiffer Ferris
Published: September 2018

The objective of this study is to compare the cyclic loading strength and ultimate failure load in suture anchor repair versus transosseous tunnel repair of patellar tendons using a cadaver model. Twelve cadaveric patella specimens were used (six matched pairs). Dual-energy X-ray absorptiometry (DXA) measurements were performed to ensure equal bone quality among groups. All right knees were assigned to the suture anchor repair group (n = 6), whereas all left knees were assigned to the transosseous bone tunnel group (n = 6). Suture type and repair configuration were equivalent. After the respective procedures were performed, each patella was mounted into a gripping jig. Tensile load was applied at a rate of 1 Hz between magnitudes of 50 and 150 N, 50 and 200 N, 50 and 250 N, and tensile load at a rate of 0.1 mm/s until failure. Failure was defined as a sharp deviation in the linear load versus displacement curve, and failure mode was recorded. DXA measurements demonstrated equivalence of bone quality between the two groups (p > 0.05). During cyclic load testing, there was only a statistically significant difference between the groups with regard to cyclic loading at the 50 to 200 N loading cycle (p = 0.010). There was no statistically significant difference between the groups with regard to ultimate load to failure (p = 0.43). Failure mode within the suture anchor cohort occurred through anchor pullout except for one, which failed through the tendon. All specimens within the transosseous cohort failed through the midsubstance of the tendon except for one, which failed through suture breakage. Suture anchor repair demonstrated a similar biomechanical profile regarding cyclic loading and ultimate load to failure when compared with “gold standard” transosseous tunnel patellar tendon repair with a trend toward less gapping in the suture anchor group. Using suture anchors for repair of the patella tendon has similar biomechanical properties to transpatellar tunnels but may provide other clinical advantages.
Phase synchronization on spatially embedded duplex networks with total cost constraint
Authors: Niu Ruiwu , Wu Xiaoqun , Lu Jun-an , Feng Jianwen
Published: September 2018

Synchronization on multiplex networks has attracted increasing attention in the past few years. We investigate collective behaviors of Kuramoto oscillators on single layer and duplex spacial networks with total cost restriction, which was introduced by Li et al. [Phys. Rev. Lett. 104, 018701 (2010)] and termed as the Li network afterwards. We first explore how the topology of the network influences synchronizability of Kuramoto oscillators on single layer Li networks and find that the closer the Li network is to a regular lattice, the more difficult for it to evolve into synchronization. Then, we investigate synchronizability of duplex Li networks and find that the existence of inter-layer interaction can greatly enhance inter-layer and global synchronizability. When the inter-layer coupling strength is larger than a certain critical value, inter-layer synchronization will always occur. Furthermore, on single layer Li networks, nodes with larger degrees reach global synchronization more easily than those with smaller degrees, while on duplex Li networks, due to inter-layer interaction, this phenomenon becomes much less obvious. The results are important for us to gain insight into collective behaviors of many real-world complex systems which inherently possess multiplex architecture.
Affinity, kinetics, and pathways of anisotropic ligands binding to hydrophobic model pockets
Authors: Weiß R. Gregor , Chudoba Richard , Setny Piotr , Dzubiella Joachim
Published: September 2018

Using explicit-water molecular dynamics simulations of a generic pocket-ligand model, we investigate how chemical and shape anisotropy of small ligands influences the affinities, kinetic rates, and pathways for their association with hydrophobic binding sites. In particular, we investigate aromatic compounds, all of similar molecular size, but distinct by various hydrophilic or hydrophobic residues. We demonstrate that the most hydrophobic sections are in general desolvated primarily upon binding to the cavity, suggesting that specific hydration of the different chemical units can steer the orientation pathways via a “hydrophobic torque.” Moreover, we find that ligands with bimodal orientation fluctuations have significantly increased kinetic barriers for binding compared to the kinetic barriers previously observed for spherical ligands due to translational fluctuations. We exemplify that these kinetic barriers, which are ligand specific, impact both binding and unbinding times for which we observe considerable differences between our studied ligands.
Super steep-switching (SS ≈ 2 mV/decade) phase-FinFET with Pb(Zr0.52Ti0.48)O3 threshold switching device
Authors: Shin Jaemin , Ko Eunah , Park June , Kim Seung-Geun , Lee Jae Woo , Yu Hyun-Yong , Shin Changhwan
Published: September 2018

A Pb(Zr0.52Ti0.48)O3 (PZT) threshold-switching (TS) device with abrupt resistive switching (∼5 to 6 orders) at a threshold voltage of ∼1.1 V and high off-state resistance (approximately 1 × 1010 Ω) is demonstrated. The thermal, productive, and operational reliability of the PZT TS device is investigated. Furthermore, a PZT-based phase transition fin-shaped field-effect-transistor (phase-FinFET) is demonstrated. Compared against a baseline FinFET, the PZT-based phase-FinFET improves the on/off current ratio by a factor of 27.5 and exhibits an extremely abrupt steep-switching characteristic (subthreshold slope of ∼2 mV/decade at 300 K).
Tetrahedral framework of inverse opal photonic crystals defines the optical response and photonic band gap
Authors: Lonergan Alex , McNulty David , O'Dwyer Colm
Published: September 2018

By forming anatase TiO2 inverse opals by infiltration of an opal photonic crystal, we demonstrate that the optical response and angle-resolved blue-shift of the band-gap of the inverse opal structure are defined by a particular three-dimensional structure of the infilled voids. The optical structure of TiO2 inverse opals usually displays significant deviation from its physical structure and from the theoretically predicted position of the photonic band-gap. Following rigorous structural characterization of the parent opal template and TiO2 inverse opals, alternative explanations for the signature of optical transmission through inverse opals are proposed. These approaches posit that, for light-matter interaction, an inverse opal is not precisely the inverse of an opal. Accurate parameters for the structure and material properties can be obtained by invoking a Bragg FCC selection rule-forbidden (-211) plane, which is not a realistic model for diffraction in the IO. Alternatively, by assuming optical interactions with just the periodic arrangement of tetrahedral filled interstitial sites in the structure of the inverse opal, a complete reconciliation with the spectral blue-shift with the angle, photonic band gap, and material parameters is obtained when a reduced unit cell is defined based on interstitial void filling. The analysis suggests a reduced interplanar spacing (d = 1/√3 D, for pore diameter D), based on the actual structure of an inverse opal in general, rather than a definition based on the inverse of an FCC packed opal. This approach provides an accurate and general description for predicting the spectral response and material parameters of ordered inverse opal photonic crystal materials.
Study of the fractality of magnetized plasma using an MHD shell model driven by solar wind data
Authors: Domínguez Macarena , Nigro Giuseppina , Muñoz Víctor , Carbone Vincenzo
Published: September 2018

An MHD shell model is used to describe the dissipative events that take place in magnetized plasmas. We analyze the activity of the time series of the magnetic energy dissipation rate obtained in the MHD shell model, which evolves under two forcing regimes: quiet and active states. To this purpose, we use solar wind data as the forcing terms of the shell model, covering solar maximum and solar minimum periods. Then, we calculate the fractal dimension of the solar wind data for the thirteen years of the 23rd solar cycle and we compare this with the energy dissipation time series obtained from the shell model description. We discuss the correlation between the fractal dimension of the solar wind data and the corresponding energy dissipation rate.
Metrological large range magnetic force microscopy
Authors: Dai Gaoliang , Hu Xiukun , Sievers Sibylle , Fernández Scarioni Alexander , Neu Volker , Fluegge Jens , Schumacher Hans Werner
Published: September 2018

A new metrological large range magnetic force microscope (Met. LR-MFM) has been developed. In its design, the scanner motion is measured by using three laser interferometers along the x, y, and z axes. Thus, the scanner position and the lift height of the MFM can be accurately and traceably determined with subnanometer accuracy, allowing accurate and traceable MFM measurements. The Met. LR-MFM has a measurement range of 25 mm × 25 mm × 5 mm, larger than conventional MFMs by almost three orders of magnitude. It is capable of measuring samples from the nanoscale to the macroscale, and thus, it has the potential to bridge different magnetic field measurement tools having different spatially resolved scales. Three different measurement strategies referred to as Topo&MFM, MFMXY, and MFMZ have been developed. The Topo&MFM is designed for measuring topography and MFM phase images, similar to conventional MFMs. The MFMXY differs from the Topo&MFM as it does not measure the topography profile of surfaces at the second and successive lines, thus reducing tip wear and saving measurement time. The MFMZ allows the imaging of the stray field in the xz- or yz-planes. A number of measurement examples on a multilayered thin film reference sample made of [Co(0.4 nm)/Pt(0.9 nm)]100 and on a patterned magnetic multilayer [Co(0.4 nm)/Pt(0.9 nm)]10 with stripes with a 9.9 μm line width and 20 μm periodicity are demonstrated, indicating excellent measurement performance.
Electromagnetic wave transmittance control using self-organized plasma lattice metamaterial
Authors: Matlis Eric H. , Corke Thomas C. , Neiswander Brian , Hoffman Anthony J.
Published: September 2018

A reconfigurable glow discharge plasma lattice structure is examined for its ability to interact with and suppress electromagnetic (EM) wave energy with wavelengths on the order of centimeters. The plasma lattice is formed in the air gap between a double dielectric electrode arrangement that formed a rectangular cross-section channel. The lattice consists of columns that span the gap between the electrodes. The spacing between the plasma columns in the lattice results from a surface charge instability that is controllable by a combination of channel height, AC voltage, and gas pressure. The lattice number is highly repeatable and predictable following packing theory. The effect of the plasma lattice spacing on the transmittance of O(cm) wavelength EM waves was investigated. Excellent agreement was found between the experiments and simulations, with S21 transmittance reduced by up to 75%. In addition, experiments in which the EM waves were oriented at an oblique angle to the plasma lattice incident axis were performed. This documented a narrow-band absorption that was predicted from an anisotropic medium permittivity tensor analysis. These experiments also indicated a negative index of refraction of the oblique EM waves for the plasma lattice that provided further evidence of its anisotropic behavior.
First demonstration of improved capsule implosions by reducing radiation preheat in uranium vs gold hohlraums
Authors: Dewald E. L. , Tommasini R. , Meezan N. B. , Landen O. L. , Khan S. , Rygg R. , Field J. , Moore A. S. , Sayre D. , MacKinnon A. J. , Berzak Hopkins L. F. , Divol L. , Le Pape S. , Pak A. , Thomas C. A. , Farrell M. , Nikroo A. , Hurricane O.
Published: September 2018

In indirectly-driven Inertial Confinement Fusion (ICF) implosions, supra-thermal M-band (>2 keV) radiation from principally 4–3 resonance line transitions generated during laser irradiation at the peak power of Au hohlraum walls can preheat the fusion capsule and reduce compressional pressure. Higher Z, un-lined depleted uranium (DU) hohlraums were used for the first time in ICF implosions on the National Ignition Facility (NIF) to reduce M-band radiation levels while keeping the total radiation flux similar to Au hohlraums. First implosions in DU demonstrate an increase in in-flight density (+15%) of high density carbon capsules, and hence in stagnated hot spot temperature (+15%), hot spot x-ray (+200%) and fusion neutron yields (+100%) compared to Au hohlraums. We show analytically that these changes are consistent with the observed 40% reduction in M-band x-ray flux in DU, and are in agreement with 2D hydrodynamic simulations. This result had a major impact on ICF research on the NIF where a significant fraction of high neutron yield implosions are currently using un-lined DU hohlraums.
Rheological consequences of wet and dry friction in a dumbbell model with hydrodynamic interactions and internal viscosity
Authors: Kailasham R. , Chakrabarti Rajarshi , Prakash J. Ravi
Published: September 2018

The effect of fluctuating internal viscosity and hydrodynamic interactions on a range of rheological properties of dilute polymer solutions is examined using a finitely extensible dumbbell model for a polymer. Brownian dynamics simulations are used to compute both transient and steady state viscometric functions in shear flow. The results enable a careful differentiation of the influence, on rheological properties, of solvent-mediated friction from that of a dissipative mechanism that is independent of solvent viscosity. In particular, hydrodynamic interactions have a significant influence on the magnitude of the stress jump at the inception of shear flow, and on the transient viscometric functions, but a negligible effect on the steady state viscometric functions at high shear rates. Zero-shear rate viscometric functions of free-draining dumbbells remain essentially independent of the internal viscosity parameter, as predicted by the Gaussian approximation, but the inclusion of hydrodynamic interactions induces a dependence on both the hydrodynamic interaction and the internal viscosity parameter. Large values of the internal viscosity parameter lead to linear viscoelastic predictions that mimic the behavior of rigid dumbbell solutions. On the other hand, steady-shear viscometric functions at high shear rates differ in general from those for rigid dumbbells, depending crucially on the finite extensibility of the dumbbell spring.
Orbital-free density functional theory simulation of collective dynamics coupling in liquid Sn
Authors: del Rio Beatriz G. , Chen Mohan , González Luis E. , Carter Emily A.
Published: September 2018

The appearance of a second excitation mode in the longitudinal and transverse collective dynamics of a series of liquid metals has been observed recently, either by inelastic X-ray scattering (IXS) or by first-principles molecular dynamics (FPMD). The phenomenon’s origin is still uncertain, although some theories have been used with relative success to reproduce the FPMD results as a means to find an explanation for it (e.g., mode-coupling (MC) theory in liquid zinc [B. G. del Rio and L. E. González, Phys. Rev. B 95, 224201 (2017)]). For liquid tin (l-Sn), the second excitation mode in the dynamic structure factor and longitudinal current spectrum was observed by IXS [S. Hosokawa et al., J. Phys.: Condens. Matter 25, 112101 (2013)]. By performing orbital-free density functional theory MD simulations of l-Sn, we confirm the existence of a second excitation mode in the longitudinal and transverse collective dynamics and provide a theoretical explanation based on MC theory. Moreover, we introduce a new binary term in MC theory to better capture the negative minima present in the memory functions of the collective dynamics. These results confirm that the origin of the second excitation mode exhibited by the longitudinal and transverse collective dynamics in some liquid metals involves an indirect coupling of the longitudinal and transverse modes.
Electric-field control of bound states and optical spectrum in window-coupled quantum waveguides
Authors: Olendski O.
Published: September 2018

The properties of the bound states of two quantum waveguides coupled via the window of the width s in their common boundary are calculated under the assumption that the transverse electric field E is applied to the structure. It is shown that the increase in the electric intensity brings closer to each other fundamental propagation thresholds of the opening and the arms. As a result, the ground state, which in the absence of the field exists at any nonzero s, exhibits the energy E0 decrease for the growing E and in the high-field regime E0 stays practically the same regardless of the size of the connecting region. It is predicted that the critical window widths scrn, n=1,2,…, at which new excited localized orbitals emerge, strongly depend on the transverse voltage; in particular, the field leads to the increase in scrn, and, for quite strong electric intensities, the critical width unrestrictedly diverges. This remarkable feature of the electric-field-induced switching of the bound states can be checked, for example, by the change of the optical properties of the structure when the gate voltage is applied; namely, both the oscillator strength and absorption spectrum exhibit a conspicuous maximum on their E dependence and turn to zero when the electric intensity reaches its critical value. Comparative analysis of the two-dimensional (2D) and 3D geometries reveals their qualitative similarity and quantitative differences.
Effects of radiation reaction on laser proton acceleration in the bubble regime
Authors: Wu Yitong , Ji Liangliang , Zhang Lingang , Guo Zhao , Feng Bo , Geng Xuesong , Yu Qin , Wang Nengwen , Zhang Xiaomei , Shen Baifei , Li Ruxin
Published: September 2018

We investigated laser proton acceleration in the bubble regime when radiation reaction (RR) effects become non-negligible. By using particle-in-cell simulations, it is shown that in addition to the bubble field, the RR trapped electrons form another charge-separation field, leading to fast acceleration of the background protons at the early stage. However, for insufficient laser intensities, the reduced bubble field and acceleration length originating from the laser depletion by gamma-photon emission do not allow for trapping and further acceleration of the protons. The final proton energy is significantly smaller than the one when RR is not considered. This effect can be mitigated by tuning the peak laser intensity (hence the pulse duration) for certain laser energy and plasma density. By increasing the laser intensity (shortening the pulse duration), we found that protons pre-accelerated by the RR-induced charge separation field gain enough momenta such that they are picked-up by the bubble field and continuously accelerated. In this case, the bubble field is also strong enough to trap protons located in the bubble front. Eventually, two groups of protons are effectively accelerated, resulting in a bump in the proton spectrum. These results can be used to design the future proton acceleration experiments in upcoming 100 PW laser facilities.
Methodology for detection of photovoltaic systems underperformance operation based on the correlation of irradiance estimates of neighboring systems
Authors: Popovic Ivan , Radovanovic Ilija
Published: September 2018

The methodology for the detection of under-performance operation of neighbouring photovoltaic systems is presented. The methodology compares the estimations of the total horizontal solar irradiance obtained from a group of photovoltaic systems. The estimations can be obtained from the direct measurement of the solar irradiance or indirectly by utilizing the group of methods for the processing of electrical signals at the output of the photovoltaic system. Inter-system comparison is performed solely during the system operation under the detected clear-sky conditions, as this atmospheric condition in a predictable manner affects the incident solar irradiance at the arbitrary surface area. We assume that the measurement or the estimation of the total horizontal solar irradiance in close proximity area under the particular clear-sky condition is expected to produce comparable results. In order to provide the comparable estimations, the methodology introduces the system efficiency factor to address various influences on the operation of the photovoltaic system, which are not easily addressable in analytical form. These influences are related to different physical, installation, and operational properties of the photovoltaic system, including aging, manufacturing tolerances, and other technology-related properties. The methods for the empirical assessment of the system efficiency factor as well as for the correlation-related processing are also given as a part of the proposed methodology. The utilization of the methodology for the detection of the under-performance operation is verified through the presented case study.
Reinterpretation of the electronic absorption spectrum of the methylene amidogen radical (H2CN)
Authors: Abbott Adam S. , Glick Zach L. , Schaefer Henry F.
Published: September 2018

The peculiar electronic absorption spectrum of H2CN has been of great interest to experiment. Herein, this system is studied extensively by applying theoretical methods to the ground and low-lying excited electronic states. Employing a large breadth of high-level ab initio computations, including coupled cluster [CCSD(T) and CCSDT(Q)] and multireference configuration interaction [MRCISD+Q] methods, we comprehensively demonstrate that the most recent experimental and theoretical interpretations of the electronic spectrum of H2CN are in error. The previous assignments of the two broad features in the spectrum as the origin 000 (∼35 050 cm−1) and 402 (∼35 600 cm−1) B̃ 2A1←X̃ 2B2 transitions are both found to be incorrect. The presently reported transition energies suggest that the higher energy band near 35 600 cm−1 is the true origin band. Additionally, from the computed anharmonic vibrational frequencies of the X̃ 2B2 and B̃ 2A1 states, we show that this ∼550 cm−1 band spacing cannot be attributed to a simple vibronic transition, as claimed by the 402 assignment. Possible alternative explanations for the appearance of the lower intensity band near 35 050 cm−1 are discussed.
Antireflection-assisted all-dielectric terahertz metamaterial polarization converter
Authors: Zi Jianchen , Xu Quan , Wang Qiu , Tian Chunxiu , Li Yanfeng , Zhang Xixiang , Han Jiaguang , Zhang Weili
Published: September 2018

We present a transmissive all-dielectric terahertz (THz) metamaterial half-wave plate with a double-working-layer structure. One layer works as a half-wave plate to enable polarization conversion of the incident THz wave, and the other layer functions as an antireflection layer to improve the transmission. The device is made of pure silicon only and can realize a high-performance polarization conversion at the designed THz frequency. Numerical simulations have been performed to show how the polarization properties of the THz wave can be adjusted by the structural parameters of the metamaterial. With appropriate structural parameters, the transmission for cross-polarization can reach 90%, and the polarization conversion rate can reach almost 100% at the designed operation frequency of 1 THz in simulation. Several samples have been fabricated and characterized, and the experimental results show a cross-polarized transmission of about 80% and a polarization conversion rate of almost 100% and agree well with the simulations.
Coulomb localization in orbital degenerate, doped Mott insulators
Authors: Avella Adolfo , Oleś Andrzej M. , Horsch Peter
Published: September 2018

We study electron localization in a three-band extended Hubbard model describing the t2g electrons of doped vanadium perovskites such as La1−xCaxVO3, where Ca defects are represented by Coulomb potentials. The main goal of this paper is to explore what happens when long-range electron-electron (e-e) interactions are switched on. The electronic structure of these doped Mott-Hubbard insulators is calculated using the unrestricted Hartree-Fock approximation that allows to perform the required statistical averages over many distinct defect realizations. The Mott gap is found to persist up to large doping and the defect states, appearing inside of it, are seen to develop a defect states gap centered at the Fermi energy. The internal kinetic energy of the doped holes, forming spin-orbital polarons bound to the defects, induces the defect states gap even in the absence of e-e interactions. Such kinetic gap survives disorder fluctuations and is amplified by long-range e-e interactions. A study of the inverse participation ratio reveals the small size of such spin-orbital polarons and provides an explanation for the persistence of spin and orbital order up to high doping.
Ultrasonic bandgaps in composite laminates: Experimental observation and Floquet-Bloch wave analysis
Authors: Ishii Yosuke , Biwa Shiro
Published: September 2018

The ultrasonic bandgap characteristics of fiber-reinforced composite laminates are studied experimentally and theoretically. The transmission spectra of obliquely incident ultrasonic waves are obtained experimentally for 16-ply carbon/epoxy composite laminates having interleaf layers at interlaminar interfaces. Compared to the conventional composite laminates, these interleaved composite laminates exhibit clearer bandgaps in the transmission spectra and enable closer examination of their features. The transmission spectra for different incident angles are favorably reproduced by the theoretical plane wave transmission analysis based on the spring-type interlaminar interface model. The Floquet-Bloch wave analysis for the corresponding periodic structures is also employed to elucidate the ultrasonic bandgap mechanism in the composite laminates.
Force-free motion of a cold plasma during the current quench
Authors: Kiramov D. I. , Breizman B. N.
Published: September 2018

Cold disruptive plasma tends to move during the current quench. Its motion is essentially force-free since the current quench timescale is resistive rather than Alfvénic. In contrast to the hot vertical displacement events, the frozen-in condition is violated in the cold plasma case, and the plasma motion is not governed by magnetic flux conservation but rather by its dissipation. We present a numerical model of the cold plasma dynamics. This model predicts electromagnetic loads on the vacuum vessel, the plasma flow and density evolution, and the plasma centroid evolution. Our calculations include poloidal wall currents. We demonstrate their significant contribution to the force acting on the vacuum vessel.
Impact of the ferroelectric layer thickness on the resistive switching characteristics of ferroelectric/dielectric structures
Authors: Silva J. M. B. , Silva J. P. B. , Sekhar K. C. , Pereira M. , Gomes M. J. M.
Published: September 2018

In the present work, the effect of the ferroelectric layer thickness on the resistive switching (RS) characteristics of 0.5 Ba(Zr0.2Ti0.8)O3-0.5 (Ba0.7Ca0.3)TiO3 (BCZT)/HfO2:Al2O3 (HAO) structures deposited on Pt-Si substrates in a metal-dielectric-ferroelectric-metal configuration is investigated. The polarization-electric field hysteresis loops disclose the ferroelectric nature of the Pt/BCZT/HAO/Au structures and reveal that the remnant polarization and the coercive field decrease with the increase in the BCZT ferroelectric layer thickness. Furthermore, the RS behavior is observed in Pt/BCZT/HAO/Au structures and is attributed to the barrier variation at the BCZT/HAO interface caused by the ferroelectric polarization flipping. Besides, it is also shown that the RS ratio and the switching field can be tuned by the thickness of the ferroelectric layer. This work intends to be a first step to build an alternative stack that provides an efficient way to develop dielectric-ferroelectric structures for RS memory devices with low power consumption.
Superconductivity in new oxyanion superconductors: TlSr4Cu2Oz(SO4)1-x(CrO4)x
Authors: Lee H. K.
Published: September 2018

TlSr4Cu2Oz(SO4)1-x(CrO4)x (x = 0 – 1.0) polycrystalline samples were prepared by using a solid state reaction technique to investigate the effect of Cr substitution for S on the phase formation and the superconducting properties of the recently isolated superconducting compound TlSr4Cu2Oz(SO4). X-ray powder diffraction measurements showed that almost-single phase samples with tetragonal (P4/mmm) structure were obtained in a range of 0 ≤ x ≤ 1.0. The magnetic transition temperatures were 74 K, 73K, and 76 K for the x = 0, 0.5, and 1.0 samples, respectively. The observed superconductivity was of bulk nature.