bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Control Laws Based on Inverted Decoupling and Linear Matrix Inequality for a Turboprop Engine
Authors: Chen Huairong , Wang Xi , Zhu Meiyin , Gu Nannan , Yang Shubo
Published: January 2020

This paper proposes a systematic approach to design control laws for a turboprop engine. The proposed approach includes interactions decoupling and control laws design based on linear matrix inequality (LMI). First, since the main objective of the turboprop engine control system is to ensure propeller-absorbed power at a constant propeller speed, the linear model of a turboprop engine can be linearized into a two-input two-output (TITO) plants, and there exist the interactions between two control loops. Because inverted decoupling can well retain the dynamic characteristics of the original system, it is used to decouple the interactions so that the TITO plant can be divided into two single-input single-output plants, that is, gas-generator shaft speed is controlled by fuel flowrate and power turbine shaft speed is controlled by blade angle. Then, the control laws are designed separately for each control loop by solving the LMI group derived from static output feedback (SOF) and regional pole placement. Finally, the proposed approach is implemented on a two-spool turboprop engine (TSTPE) integrated model. The simulation results show that there exist strong interactions between two control loops of TSTPE, applying inverted decoupling to decouple these interactions is effective, and the gas-generator shaft speed and the power turbine speed can track their commands with appropriate performance by controlling the fuel flowrate and blade angle under the action of the designed control laws and inverted decoupling.
Facile Preparation of a Surface-Enriched Pt Layer Over Pd/C as an Efficient Oxygen Reduction Catalyst With Enhanced Activity and Stability
Authors: Bhuvanendran Narayanamoorthy , Ravichandran Sabarinathan , Xu Qian , Pasupathi Sivakumar , Su Huaneng
Published: January 2020

Pt-enriched surface layer formation on Vulcan carbon-supported Pd (Pt@Pd/C) was successfully prepared through a simple and one-pot formic acid reduction approach without any stabilizing agent. The electrocatalytic performance of Pt@Pd/C catalyst toward an oxygen reduction reaction (ORR) in alkaline medium was studied and also compared with standard carbon-supported Pt (Pt/C) and Pd (Pd/C) catalysts. The Pt@Pd/C exhibits higher electrochemical active surface area (74.7 m2/g) and mass activity (1.38 mA/µg) than Pt/C, Pd/C, and contending with standard reported catalysts. In durability tests, Pt@Pd/C showed negligible loss of intrinsic activity (∼10%) after 10,000 cycles which confirmed improved stability than Pt-based catalysts for ORR in KOH medium. This improved electrocatalytic performance could be attributed to their structural characteristics of the Pt-enriched surface layer on Pd/C-core and the compressive lattice strain on Pt. The present investigation demonstrates the simple preparation procedure for surface-enriched Pt on Pd/C and its improved performance for ORR, suggesting that it is a promising contender to benchmark ORR catalysts for alkaline fuel cells.
An Extended Eddy-Preserving Scheme for Strong Vortical Flows
Authors: Yang Liu , Jiang Yao , Nadarajah Siva
Published: January 2020

The eddy-preserving limiter has been demonstrated to outperform the conventional van Albada limiter for monotone upstream-centered schemes for conservation laws (MUSCL) for vortical flows. It reduces the dissipation by inactivating the conventional van Albada limiter in the interpolation of velocity components on the swirl plane of the vortex. In this work, we extend the limiter for the interpolation of pressure since a minimum pressure often exists along the axis of a free vortex. Three-dimensional vortex advection cases are employed to demonstrate the effects of the novel scheme. An extended eddy-preserving limiter scheme has been demonstrated to further improve the preservation of the pressure extrema. Finally, the scheme is applied to flow through a draft tube and the numerical results are compared against experimental data.
A Computational Technique to Evaluate the Relative Influence of Internal and External Cooling on Overall Effectiveness
Authors: Bryant Carol E. , Rutledge James L.
Published: January 2020

Gas turbine components are protected via a coolant that travels through internal passageways before being ejected as external film cooling. Modern computational approaches facilitate the simulation of the conjugate heat transfer that takes place within turbine components, allowing the prediction of the actual metal temperature, nondimensionalized as overall effectiveness. Efforts aimed at improving cooling are often focused on either the internal cooling or the film cooling; however, the common coolant flow means that the internal and external cooling schemes are linked and the coolant holes themselves provide another convective path for heat transfer to the coolant. The relative influence of internal cooling, external cooling, and convection through the film cooling holes on overall effectiveness is not well understood. Computational fluid dynamics (CFD) simulations were performed to isolate each cooling mechanism, and thereby determine their relative contributions to overall effectiveness. The conjugate CFD model was a flat plate with five staggered rows of shaped film cooling holes. Unique boundary conditions were used to isolate the cooling mechanisms. The internal surface was modeled with and without heat transfer on the internal face in order to isolate the effects of plenum cooling. Convection through the coolant holes was isolated by making the inside of the film cooling holes adiabatic to evaluate the influence of the internal cooling provided by the cooling holes themselves. Finally, the effect of film cooling was removed through the novel use of an outlet boundary condition at the exit of each hole that allowed the internal coolant flow without external coolant ejection.
Plasma etching of wide bandgap and ultrawide bandgap semiconductors
Authors: Pearton Stephen J. , Douglas Erica A. , Shul Randy J. , Ren Fan
Published: January 2020

The precise patterning of front-side mesas, backside vias, and selective removal of ternary alloys are all needed for power device fabrication in the various wide bandgap (AlGaN/GaN, SiC) and ultrawide bandgap (high Al-content alloys, boron nitride, Ga2O3, diamond) semiconductor technologies. The plasma etching conditions used are generally ion-assisted because of the strong bond strengths in these materials, and this creates challenges for the choice of masks in order to have sufficient selectivity over the semiconductor and to avoid mask erosion and micromasking issues. It can also be challenging to achieve practical etch rates without creating excessive damage in the patterned surface. The authors review the optimum choices for plasma chemistries for each of the semiconductors and acknowledge the pioneering work of John Coburn, who first delineated the ion-assisted etch mechanism.
The small-slope approximation for layered, fluid seafloors
Authors: Jackson Darrell , Olson Derek R.
Published: January 2020

The small-slope approximation (SSA) for rough-interface scattering is most commonly applied to the upper boundary of either impenetrable media or uniform half-space media, but has been recently developed for layered media in the acoustic and electromagnetic cases. The present work gives an overview of three forms of the SSA for layered media. The first has been previously presented in the acoustics literature. The second is from the electromagnetics literature and in the present work is converted to the fluid-sediment problem. A missing proof is supplied of a key consistency condition demanded of the small-slope ansatz. As is usual, these small-slope results are expressed in k-space. A third SSA for layered seafloors follows from conversion of the usual half-space formulation from k-space to coordinate space. This form turns out to be useful for reverberation simulations. The three different approaches are compared with respect to scattering strength and the coherent reflection coefficient, but an assessment of their relative merits will require comparison with exact calculations.
Myoelectric Responses of Lower-Body Muscles Performing Squat and Lunge Exercise Variations Adopting Visual Feedback With a Laser Sensor
Authors: Paz Gabriel Andrade , Almeida Lohanne , Ruiz Larissa , Casseres Sabrina , Xavier Giovanna , Lucas João , Santana Haroldo Gualter , Miranda Humberto , Bonnette Scott , Willardson Jeffrey
Published: January 2020

Study design: Cross-over study. Context: The squat, single-leg squat, forward lunge, and reverse lunge are fundamental movements often performed in activities of daily living, sports competitions, and sport-specific training. Objective: The purpose of this study was to investigate the effect of visual feedback with a laser sensor (VFLS) versus a control condition on the myoelectric activity (surface electromyography [sEMG]) of the vastus medialis oblique (VMO), vastus lateralis, gluteus medius (Gmed), and erector spinae muscles during the performance of several squat variations with bodyweight. Methods: Nineteen female college students (20 [2.5] y, 165.3 [10.2] cm, 66.4 [4.1] kg, 2 [1.2] y of resistance training experience) with a background in strength or sports training volunteered to participate in this study. Over 4 separate visits, subjects performed 2 sets of 10 repetitions of a squat variation exercise in random order (ie, squat, single-leg squat, forward lunge, and reverse lunge). The first set of a given squat variation condition was considered a control set, and then after 3-minute rest, a second set was performed with VFLS. Results: Significant decreases in VMO and Gmed myoelectric activity were observed during the VFLS set versus the control set for the forward lunge exercise (P = .03). No differences were observed between the control set and VFLS set in the sEMG normalized signal for all muscles analyzed for the squat and single-leg squat, respectively. However, the sample entropy of the sEMG signal for the erector spinae became more irregular during the VFLS set versus the control set for the squat exercise (P = .01), whereas the Gmed presented a more irregular sEMG signal during the VFLS set versus the control set for the single-leg squat (P = .08). Conclusion: Laser sensor biofeedback may induce significant decreases in VMO and Gmed activation performing forward lunge exercise. Therefore, laser sensor biofeedback may induce a reduction in muscle activity of neutralizers muscles during a few squat bodyweight variations (bilateral, single-leg, forward, and reverse lunge).
Cerebellar oscillations driven by synaptic pruning deficits of cerebellar climbing fibers contribute to tremor pathophysiology
Authors: Pan Ming-Kai , Li Yong-Shi , Wong Shi-Bing , Ni Chun-Lun , Wang Yi-Mei , Liu Wen-Chuan , Lu Liang-Yin , Lee Jye-Chang , Cortes Etty P. , Vonsattel Jean-Paul G. , Sun Qian , Louis Elan D. , Faust Phyllis L. , Kuo Sheng-Han
Published: January 2020

Excessive cerebellar oscillations, resulting from GluRδ2-dependent pruning deficits of climbing fiber–to–Purkinje cell synapses, drive tremor.
Weighing in on asthma
Authors: Brunner Patrick M.
Published: January 2020

Immune activation and microbiota alterations are accentuated in obese asthmatics.
High Levels of Serum Angiopoietin 2 and Angiopoietin 2/1 Ratio at the Critical Stage of Dengue Hemorrhagic Fever in Patients and Association with Clinical and Biochemical Parameters
Authors: Mapalagamage Maheshi , Handunnetti Shiroma M. , Wickremasinghe Ananda Rajitha , Premawansa Gayani , Thillainathan Sharmila , Fernando Tharanga , Kanapathippillai Karunayokiny , De Silva Aruna Dharshan , Premawansa Sunil
Published: January 2020

Longitudinal changes of serum angiopoietin 1 (Ang-1) and angiopoietin 2 (Ang-2) associated with endothelial stability in dengue patients with different disease stages were studied. Serum Ang-1 and Ang-2 levels were measured in confirmed dengue fever (DF) patients on admission (DFA,
n
 = 40) and discharge (DFD,
n
 = 20); in dengue hemorrhagic fever (DHF) patients on admission (DHFA,
n
 = 40), at critical stage (DHFC,
n
 = 36), and on discharge (DHFD,
n
 = 20); and in healthy controls (HC,
n
 = 25).
Prospective Evaluation of the mariPOC Test for Detection of Clostridioides difficile Glutamate Dehydrogenase and Toxins A/B
Authors: Savolainen Roosa , Koskinen Juha M. , Mentula Silja , Koskinen Janne O. , Kaukoranta Suvi-Sirkku
Published: January 2020

The objective of this study was to evaluate a novel automated random-access test, mariPOC CDI (ArcDia Ltd., Finland), for the detection of
Clostridioides difficile
glutamate dehydrogenase (GDH) and toxins A and B directly from fecal specimens. The mariPOC test was compared with both the GenomEra
C. difficile
PCR assay (Abacus Diagnostica Oy, Finland) and the TechLab C. diff Quik Chek Complete (Alere Inc.; now Abbot) membrane enzyme immunoassay (MEIA). Culture and the Xpert
C. difficile
assay (Cepheid Inc.
A Conserved Acidic-Cluster Motif in SERINC5 Confers Partial Resistance to Antagonism by HIV-1 Nef
Authors: Stoneham Charlotte A. , Ramirez Peter W. , Singh Rajendra , Suarez Marissa , Debray Andrew , Lim Christopher , Jia Xiaofei , Xiong Yong , Guatelli John
Published: January 2020

Cellular membrane proteins in the SERINC family, especially SERINC5, inhibit the infectivity of retroviral virions. This inhibition is counteracted by retroviral proteins, specifically, HIV-1 Nef, MLV glycoGag, and EIAV S2. One consequence of such a host-pathogen “arms race” is a compensatory change in the host antiviral protein as it evolves to escape the effects of viral antagonists. This is often reflected in a genetic signature, positive selection, which is conspicuously missing in
SERINC5
. Here we show that despite this lack of genetic evidence, a sequence in SERINC5 nonetheless provides relative resistance to antagonism by HIV-1 Nef.
Formation of the main sulfide zone at Unki Mine, Shurugwi Subchamber of the Great Dyke, Zimbabwe: Constraints from petrography and sulfide compositions
Authors: Chaumba Jeff B. , Musa Caston T.
Published: January 2020

The major platinum group element (PGE) occurrence in the Great Dyke of Zimbabwe, the main sulfide zone, is a tabular stratabound layer hosted in pyroxenites, and it is broadly similar in form throughout the length of the Great Dyke. We conducted a petrographic and sulfide composition study on a sulfide-enriched zone from the contact of the mafic sequence–ultramafic sequence through the main sulfide zone at Unki Mine in the Shurugwi Subchamber to its underlying footwall rocks to place some constraints on the origin of the rocks.

Pyrrhotite, pentlandite, chalcopyrite, and pyrite are the base metal sulfides that were encountered during the study. Pyrrhotite, pentlandite, and chalcopyrite typically occurred as inclusions in both primary (orthopyroxene, plagioclase, and clinopyroxene) and secondary (amphibole and chlorite) silicate phases, whereas pyrite was observed in only three samples, where it occurred in association with pyrrhotite. The concentrations of PGEs in the base metal sulfides were nearly all at or below minimum detection limits. The intercumulus nature of some of these sulfides in the investigated sequence suggests that they were likely formed during the crystallization history of these rocks. The occurrence of pyrite, which we interpret to be an alteration phase, suggests that a late-stage event, likely formed during hydrothermal alteration, helped to concentrate the mineralization at Unki Mine. In some cases, however, these sulfides occur partially surrounding some chromite and silicate phases. Thus, some sulfides in the Unki Mine area were likely formed early in the crystallization history of the Great Dyke, whereas others were formed late during hydrothermal processes. Low concentrations of PGEs such as platinum (Pt), palladium (Pd), and rhodium (Rh) in base metal sulfides imply that the PGEs in the main sulfide zone and Unki Mine are hosted either in silicates and/or platinum group minerals. Very low Co contents in pentlandites in the rocks under investigation are interpreted to imply that very limited Fe substitution by Co, and also of Ni by Co, occurred. Broadly comparable trends, with minor variations of Fe in pyrrhotite, of Co and Ni in pentlandite, and of Cu in chalcopyrite, for example, likely reflect magmatic processes. The concentrations of these metals in base metal sulfides vary sympathetically, indicating that their original magmatic signatures were subsequently affected by hydrothermal fluids. The spiked pattern displayed by the variations in the percent modal proportions of the base metal sulfides across the entire investigated stratigraphic section is interpreted to reflect remobilization of the sulfides during hydrothermal alteration. Depletions in some elements, which occur near the base and at the top of the investigated succession, are likely a result of this hydrothermal alteration.
Dynamic models of earthquake rupture along branch faults of the eastern San Gorgonio Pass region in California using complex fault structure
Authors: Douilly Roby , Oglesby David D. , Cooke Michele L. , Hatch Jennifer L.
Published: January 2020

Geologic data suggest that the Coachella Valley segment of the southern San Andreas fault (southern California, USA) is past its average recurrence time period. At its northern edge, this right-lateral fault segment branches into the Mission Creek and Banning strands of the San Andreas fault. Depending on how rupture propagates through this region, there is the possibility of a throughgoing rupture that could lead to the channeling of damaging seismic energy into the Los Angeles Basin. The fault structures and potential rupture scenarios on these two strands differ significantly, which highlights the need to determine which strand provides a more likely rupture path and the circumstances that control this rupture path. In this study, we examine the effect of different assumptions about fault geometry and initial stress pattern on the dynamic rupture process to test multiple rupture scenarios and thus investigate the most likely path(s) of a rupture that starts on the Coachella Valley segment. We consider three types of fault geometry based on the Southern California Earthquake Center Community Fault Model, and we create a three-dimensional finite-element mesh for each of them. These three meshes are then incorporated into the finite-element method code FaultMod to compute a physical model for the rupture dynamics. We use a slip-weakening friction law, and consider different assumptions of background stress, such as constant tractions and regional stress regimes with different orientations. Both the constant and regional stress distributions show that rupture from the Coachella Valley segment is more likely to branch to the Mission Creek than to the Banning fault strand. The fault connectivity at this branch system seems to have a significant impact on the likelihood of a throughgoing rupture, with potentially significant impacts for ground motion and seismic hazard both locally and in the greater Los Angeles metropolitan area.
Intimate partner violence and childhood illnesses in Cambodia: a cross-sectional study
Authors: Nakphong Michelle Kao , von Ehrenstein Ondine S
Published: January 2020

Background

Around a quarter of Cambodian women reported being victim to intimate partner violence (IPV) from their current partner. Children’s exposure to familial IPV impacts psychosocial well-being and emerging research indicates associations with physical health.

Objective

Investigate associations between maternal experience of IPV and common childhood illnesses in Cambodia.

Design, setting, participants

Analysis of the Cambodia Demographic and Health Survey (2000, 2005, 2014) using logistic regression, including 5025 children under 5 years of age whose mothers responded to questions about experience of emotional, physical and sexual violence by current partner.

Main outcome measures

Report of diarrhoea, acute respiratory infection (ARI) or fever, respectively, in children in the two weeks preceding the survey.

Results

Children of mothers with experience of any type of IPV had estimated elevated odds of diarrhoea (adjusted OR (aOR)=1.65, 95% CI 1.39 to 1.97), estimated odds of ARI (aOR=1.78, 95% CI 1.47 to 2.16) and estimated odds of fever (aOR=1.51, 95% CI 1.31 to 1.76) compared with children of mothers without reported IPV experience. Exposure to any form of IPV corresponded to an estimated 2.65 times higher odds (95% CI 2.01 to 3.51) for reporting having both diarrhoea and ARI.

Conclusions

Our findings support the notion that children’s susceptibility to diarrhoea, ARI and fever may be affected by mothers’ experience of IPV, including emotional violence. Maternal and child health programmes should train healthcare professionals to identify domestic violence and children at risk, and link victims to appropriate health and legal services.
Volatile anaesthetic for treatment of respiratory failure from status asthmaticus requiring extracorporeal membrane oxygenation
Authors: LaGrew Joseph E , Olsen Kevin Robert , Frantz Amanda
Published: January 2020

A 37-year-old male smoker with asthma presented with status asthmaticus refractory to terbutaline, intravenous magnesium, continuous bronchodilators, steroids, heliox and theophylline infusion. He was intubated on hospital day 2 and cannulated for veno-venous extracorporeal membrane oxygenation (V-V ECMO) on hospital day 3 for refractory respiratory acidosis secondary to hypercapnia and hypoxemia despite maximum medical management over 4 days. He was started on inhaled isoflurane with improvement in peak airway pressures and respiratory acidosis, allowing for prompt weaning from V-V ECMO and extubation. Inhaled volatile anaesthetics exert a direct action on bronchiole smooth muscle causing relaxation with significant effect despite severely impaired pulmonary function. This treatment in patients on ECMO may allow for earlier decannulation and decreased risk of coagulopathy, ECMO circuit failure, infection, renal failure, pulmonary haemorrhage and central nervous system haemorrhage. However, major limitations exist in delivering volatile anaesthetics, which may make use inefficient and costly despite efficacy.
Novel technique of fixing intracorneal rings segments after migration
Authors: Agarwal Prateek , Subudhi Praveen , Mithal Neha
Published: January 2020

A 38-year-old patient with a history of non-progressive keratoconus in the left eye presented to us with an uncorrected visual acuity of 20/400, which improved to 20/60 with pinhole. We planned for intracorneal rings segment in the left eye. Postoperatively uncorrected visual acuity improved to 20/30. The patient presented 2 weeks later with severely decreased vision to 20/100 and migration of intracorneal rings were noted with both the rings riding side by side. The patient gave history of vigorous eye rubbing. The rings were repositioned with the help of Sinskey hooks and superior ring was anchored with 10-nylon suture passed through the ring hole to the corneal stroma. Two more sutures were placed radial to the circumference of inferior ring to prevent its migration. The sutures were removed after 1 month and the patient was followed up with stable position of the rings for the next 6 months . The uncorrected visual acuity improved to 20/40.
OCTA characterisation of microvascular retinal alterations in patients with central serous chorioretinopathy
Authors: Battista Marco , Borrelli Enrico , Parravano Mariacristina , Gelormini Francesco , Tedeschi Massimiliano , De Geronimo Daniele , Sacconi Riccardo , Querques Lea , Bandello Francesco , Querques Giuseppe
Published: January 2020

Purpose

This study aimed to describe the characteristics of microvascular retinal alterations in eyes with chronic central serous chorioretinopathy (CSC) employing optical coherence tomography angiography (OCTA) analysis.

Methods

We collected data from 472 eyes with chronic CSC from 336 patients who had OCTA obtained. Each OCTA image was graded by two readers to assess the presence of microvascular retinal alterations, including regions of vascular rarefaction/retinal hypoperfusion, enlargement of the foveal avascular zone (FAZ) and presence of telangiectasias or microaneurysms. Volume spectral domain optical coherence tomography (SD-OCT) scans were obtained through the macula and the OCT was correlated with the OCTA findings in eyes with retinal vascular alterations.

Results

OCTA displayed microvascular retinal alterations in 18 out of 474 eyes (3.6%) from 14 patients (13 male and 1 female; mean±SD age was 54.7±11.1 years). One eye displayed the presence of retinal telangiectasias, while 17 out of 18 eyes were graded as having areas of retinal vascular rarefactions, and 3 out of 17 eyes were also characterised by an enlargement of the FAZ. The parafoveal region was the location most involved by retinal vascular changes (66,7%), followed by foveal (22,2%) and perifoveal (11.1%) regions, respectively.

Conclusion

Although CSC is known to represent a choroidal disorder, retinal vascular alterations may be present in these eyes and OCTA may represent a useful tool to identify and describe them.
Women’s leadership in academic medicine: a systematic review of extent, condition and interventions
Authors: Alwazzan Lulu , Al-Angari Samiah S
Published: January 2020

Objectives

Because culture reflects leadership, the making of diverse and inclusive medical schools begins with diversity among leaders. The inclusion of women leaders remains elusive, warranting a systematic exploration of scholarship in this area. We ask: (1) What is the extent of women’s leadership in academic medicine? (2) What factors influence women’s leadership? (3) What is the impact of leadership development programmes?

Design

Systematic review.

Data sources

A systematic search of six online databases (OvidMEDLINE, EMBASE, CINAHL, PsycINFO, the Cochrane Library and ERIC) from the earliest date available to April 2018 was conducted. Bridging searches were conducted from April 2018 until October 2019.

Eligibility criteria

(1) Peer-reviewed; (2) English; (3) Quantitative studies (prospective and retrospective cohort, cross-sectional and preintervention/postintervention); evaluating (4) The extent of women’s leadership at departmental, college and graduate programme levels; (5) Factors influencing women’s leadership; (6) Leadership development programmes. Quantitative studies that explored women’s leadership in journal editorial boards and professional societies and qualitative study designs were excluded.

Data extraction and synthesis

Two reviewers screened retrieved data of abstracts and full-texts for eligibility, assessment and extracted study-level data independently. The included studies were objectively appraised using the Medical Education Research Quality Study Instrument with an inter-rater reliability of (κ=0.93).

Results

Of 4024 records retrieved, 40 studies met the inclusion criteria. The extent of women’s leadership was determined through gender distribution of leadership positions. Women’s leadership emergence was hindered by institutional requirements such as research productivity and educational credentials, while women’s enactment of leadership was hindered by lack of policy implementation. Leadership development programmes had a positive influence on women’s individual enactment of leadership and on medical schools’ cultures.

Conclusions

Scholarship on women’s leadership inadvertently produced institute-centric rather than women-centric research. More robust contextualised scholarship is needed to provide practical-recommendations; drawing on existing conceptual frameworks and using more rigorous research methods.
Development of a trajectory planning algorithm for a 4-DoF rockbreaker based on hydraulic flow rate limits
Authors: Tremblay Louis-Francis Y. , Arsenault Marc , Zeinali Meysar
Published: January 2020

In this paper, a novel trajectory planning methodology is proposed for use within a semi-automated hydraulic rockbreaker system. The objective of the proposed method is to minimize the trajectory duration while hydraulic fluid flow rate limits are respected. Within the trajectory planning methodology, a point-to-point path planning approach based on the decoupling of the motion of the rockbreaker’s first joint is compared with an alternative approach based on Cartesian straight-line motion. Each of these path types is parameterized as a function of time based on an imposed trajectory profile that ensures smooth rockbreaker motions. A constrained nonlinear optimization problem is formulated and solved with the trajectory duration as the objective function while constraints are applied to ensure that flow rate limits through the rockbreaker’s proportional valves and hydraulic pump are not exceeded. The proposed methodology is successfully implemented to compute a set of representative trajectories, with the path planning approach based on the decoupling of the motion of the rockbreaker’s first joint consistently producing shorter trajectory durations.
The Casimir-Polder interaction of an atom and real graphene sheet: Verification of the Nernst heat theorem
Authors: Klimchitskaya G. L.
Published: January 2020

We find the low-temperature behavior of the Casimir-Polder free energy and entropy for an atom interacting with real graphene sheet possessing nonzero energy gap and chemical potential. Employing the formalism of the polarization tensor, it is shown that the Casimir-Polder entropy goes to zero by the power law with vanishing temperature, i.e., the Nernst heat theorem is satisfied. This result is discussed in connection with the problems connected with account of free charge carriers in the Lifshitz theory.
Casimir effect for biaxial anisotropic plates with surface conductivity
Authors: Emelianova N. , Fialkovsky I. V. , Khusnutdinov N.
Published: January 2020

The Casimir energy is constructed for a system consisting of two semi-infinite slabs of anisotropic material. Each of them is characterized by bulk complex dielectric permittivity tensor and surface conductivity on the free boundary. We found general form of the scattering matrix and Fresnel coefficients for each part of the system by solving Maxwell equations in the anisotropic media.
On the (im)possibility of Casimir repulsion between Chern-Simons surfaces
Authors: Vassilevich Dmitri
Published: January 2020

We critically review the possibilities of a repulsive Casimir interaction between materials which carry Chern-Simons surface actions for the electromagnetic field.
Revisiting the Casimir energy with general boundary conditions and applications in 1D crystals
Authors: Muñoz-Castañeda J. M. , Bordag M. , Santamaría-Sanz L.
Published: January 2020

We obtain new expressions for the Casimir energy between plates that are mimicked by the most general possible boundary conditions allowed by the principles of quantum field theory. This result enables to provide the quantum vacuum energy for scalar fields propagating under the influence of a one-dimensional crystal represented by a periodic potential formed by an infinite array of identical potentials with compact support.
On finite temperature Casimir effect for Dirac lattices
Authors: Pirozhenko Irina
Published: January 2020

We consider polarizable sheets modeled by a lattice of delta function potentials. The Casimir interaction of two such lattices is calculated at nonzero temperature. The heat kernel expansion for periodic singular background is discussed in relation with the high temperature asymptote of the free energy.
Shock-wave propagation in an isothermal slightly-compressible bubbly viscoelastic fluid flow
Authors: Chukkol Yusuf Buba , Muminov Mukhiddin
Published: January 2020

In this work, weakly nonlinear wave equation in mono-dispersed, isothermal, bubbly, slightly compressible viscoelastic liquid is derived, using reduction perturbation method. The constitutive equation is based on the second-grade fluid model. Viscosity, relaxation, retardation and surface tension are considered under isothermal condition, which modifies the Rayleigh–Plesset equation for compressible liquid. A kink traveling wave solution is obtained using the tangent hyperbolic method combined with the Riccati equation. Graphical representation of the solution is given and analyzed with different parameter values.
Synthesis, structures and reduction chemistry of monophthalocyanine scandium hydroxides
Authors: Ganga-Sah Yumeela , Tajbakhsh Elahe , Platel Rachel H. , Zhou Wen , Leznoff Daniel B.
Published: January 2020

The preparation and structural characterization of a pair of scandium(III) phthalocyanine hydroxide complexes were achieved by reaction of PcScCl with alkali metal alkoxides, likely via hydrolysis of soluble PcSc-alkoxide intermediates. A Sc[Formula: see text]Li[Formula: see text]-OH)[Formula: see text] cubane supported by two distorted Pc rings of the form (PcSc)[Formula: see text]-OH)[Formula: see text]Li[Formula: see text](THF)(DME) was isolated from the reaction of PcScCl with LiO[Formula: see text]Pr, while a simpler alkali-metal-free [Pc[Formula: see text]Sc[Formula: see text]-OH)[Formula: see text](THF)] was obtained from addition of NaO[Formula: see text]Bu; both structures are reminiscent of bent metallocenes, with dihedral angles between the two Pc rings of 50.8 and 37.7[Formula: see text]respectively. A soluble PcScOH material can also be obtained directly via hydrolysis of insoluble PcScCl in approximately 95:5 THF:water. Reduction of the Pc ring of PcScCl using KC[Formula: see text] is reversible and generates Pc[Formula: see text] and Pc[Formula: see text]-containing materials that were characterized via UV-vis spectroscopy and, where appropriate EPR and [Formula: see text]H NMR spectroscopy; analogous reductions of the PcScOH-based species were irreversible. Exposure of the air-sensitive, reduced PcScCl-based species to ambient atmosphere generated PcScOH materials analogous to the direct hydrolysis route.
Sand injection and polygonal faulting in the Great South Basin, New Zealand
Authors: Chenrai Piyaphong , Huuse Mads
Published: January 2020

Subsurface sediment remobilization phenomena, including sand injection complexes and mud volcano systems, have been recognized to play a significant role in basinal fluid flow and in some cases are an important part of petroleum systems. Seismic-scale wing-like anomalies, interpreted as sand injections based on their similarities with North Sea examples, have been identified within the upper Paleocene sediments of the Great South Basin, New Zealand. The structures were observed on three-dimensional seismic data at about 2.5–2.7 s two-way time beneath the seabed. The sand injections occur below a well-developed polygonal fault system within the uppermost Paleocene sediments. The wing-shaped sand injections are often located near the downward extent of polygonal fault tips, possibly implying that the injections affected polygonal fault formation. This is the first time that a seismic-scale sand injection complex has been described in the southeastern hemisphere. The study adds to an emerging realization that sand injection complexes occur in many deep-water basins and has direct implications for basin evolution and hydrocarbon exploration in the Great South Basin.
Clinical Rehabilitation Effect of Postoperative Lower-Limb Training on the Patients Undergoing OLIF Surgery: A Retrospective Study
Authors: Wang Haoming , Huo Yachong , Zhao Yachao , Zhang Botong , Yang Dalong , Yang Sidong , Ding Wenyuan
Published: January 2020

Background. In this study, it was aimed to investigate the clinical rehabilitation effect of lower-limb training on the patients that undergo oblique lumbar interbody fusion (OLIF) procedures. Methods. The eligible participants undergoing OLIF procedures between 01/2017 and 07/2019 were identified. All the patients underwent one-segment fusion operation (L3-4 or L4-5). Based on whether the participants received postoperative rehabilitation training, they were divided into two groups: intervention group and control group. Postoperatively, the participants in the intervention group were trained with lower-extremity rehabilitation exercise and maintained for three months. All participants got reexamined at the first postoperative week, the second postoperative week, the first postoperative month, and the third postoperative month (last follow-up). Comparisons were made in terms of the lower-extremity muscle force, visual analogue scale (VAS) score, lumbar JOA score, Oswestry disability index (ODI), the incidence of deep venous thrombosis (DVT), and patient satisfaction. Results. Seventy-seven participants in the intervention group (32 males and 45 females) and 82 in the control group (39 males and 43 females) were incorporated in this study. The median age of the participants was 57 years (39∼73) in the intervention group and 54 years (35∼71) in the control group. No statistical significance between the two groups was found (P>0.05). ODI score was less in the intervention group as compared to the control group in the first week after surgery (P=0.029). VAS and JOA scores were better in the intervention group in the first two weeks after surgery (P<0.05). DVT incidence in the intervention group was lower than the control group at final follow-up (P=0.037). Both group participants have achieved good grading in muscle force rehabilitation but no significant differences between the two groups. Additionally, satisfaction was higher in the intervention group than the control group. Conclusions. In summary, postoperative lower-extremity rehabilitation exercise can effectively accelerate patients’ health recovery from the OLIF surgery and increase their satisfaction.
The Simulation of a Surface Plasmon Resonance Metallic Grating for Maximizing THz Sensitivity in Refractive Index Sensor Application
Authors: Sathukarn Asmar , Jia yi Chia , Boonruang Sakoolkan , Horprathum Mati , Tantiwanichapan Khwanchai , Prasertsuk Kiattiwut , Thanapirom Chayut , Kusolthossakul Woraprach , Kasamsook Kittipong
Published: January 2020

Nowadays, the simplicity of both designing and fabrication process of a terahertz (THz) resonator-based sensing technique leads to its ongoing development. The consumable THz resonator needs to be easily integrated into an existing terahertz time domain spectroscopy (THz TDS) measurement system. It should also be able to be fabricated in a mass scale with a low production cost. In this work, a metal-coated surface plasmon resonance- (SPR-) based sensor is simulated and designed as a low-cost refractive index sensor utilizing rigorous coupled wave analysis (RCWA). To demonstrate our methodology, we design a gold-coated grating with a polydimethylsiloxane (PDMS) as a substrate, in order to perform quantitative analysis of gasoline-toluene mixture composition, which has a refraction index variation of 0.1 at THz frequency. The grating period is tuned such that its surface plasmon resonance (SPR) frequency matches with the peak frequency of the THz TDS system. Moreover, other grating parameters, i.e., a filling factor and a grating depth, are optimized to increase the sensor sensitivity and sharpen the resonance dip. High sensitivity up to 500 GHz/RIU with a refractive index resolution up to 0.01 is numerically revealed. The H-field of the designed grating is then evaluated to indicate a strong SPR excitation. The well-developed designed grating introduces a promising, low-cost, and easily fabricated THz refractive index sensor.
Polypyrrole-Chitosan-CaFe2O4 Layer Sensor for Detection of Anionic and Cationic Dye Using Surface Plasmon Resonance
Authors: Sadrolhosseini Amir Reza , Nia Pooria Moozarm , Shafie Suhaidi , Shameli Kamyar , Mahdi Mohd Adzir
Published: January 2020

A polypyrrole-chitosan-calcium ferrite nanocomposite was prepared using the electrodeposition method. The prepared layer was characterized by using Fourier transform infrared spectroscopy, the X-ray diffraction technique, and field emission electron microscopy. The thickness of the thin layers was in the range of 2.8 nm to 59.5 nm, and the refractive index of the composite layer was in the range of 1.66131+0.156i to 1.62734+0.167i. Detection and removal of cationic and anionic dyes, such as methylene blue and methylene orange, are subject of great interest for protecting environmental water. The layer composite was used to detect methylene orange and methylene blue using the surface plasmon resonance technique. Consequently, the polypyrrole-chitosan-calcium-ferrite composite layer interacted with the anionic and cationic dyes. The resonance angle shift for the detection of the cationic dye was larger than the resonance angle shift for the anionic dye. The sensor limit was achieved from a sensogram at about 0.01 ppm.
Study on the Deocclusion of the Visibility Window of Traffic Signs on a Curved Highway
Authors: Xiao Jian , Zhao Jian , Yang Liulin , He Juanxia , Li Yu , Li Yuxiao
Published: January 2020

Highway navigation is often affected by complex topography, and the flat curve plays an important role in the horizontal alignment design of a highway. Many curves are formed, where visibility could be decreased. Thus, the indicative function of a traffic sign plays a crucial role in ensuring driving safety at the curve. Due to the blocked visibility, the probability of the traffic sign occlusion at the curve of operating highways is quite high. It is urgent to consider the clearing obstructions around traffic signs at curves during highway construction. In this study, the potential of visual occlusion for traffic signs on curved highways was investigated. Firstly, the driver’s visibility window that contains traffic signs was defined and criteria of visual occlusion were proposed. Secondly, a geometric occlusion design formula was established to mimic the visual recognition process of traffic signs on a curved highway, yielding the formula to calculate the visibility window. Finally, the occlusion design formula was applied into a case study of the Beijing-Hong Kong-Macau Expressway (Hunan section), in which visibility windows were calculated and analyzed. The obtained results verified the correctness and effectiveness of the occlusion design formula developed in this study.
Discovering Insightful Rules among Truck Crash Characteristics using Apriori Algorithm
Authors: Hong Jungyeol , Tamakloe Reuben , Park Dongjoo
Published: January 2020

This study aims to discover hidden patterns and potential relationships in risk factors in freight truck crash data. Existing studies mainly used parametric models to analyze the causes of freight vehicle crashes. However, predetermined assumptions and underlying relationships between independent and dependent variables have been cited as its limitations. To overcome these limitations and provide a better understanding of factors that lead to truck crashes on the expressways, we applied the Association Rules Mining (ARM) technique, which is a nonparametric method. ARM quantifies the interrelationships between the antecedents and consequents of truck-involved crashes and provides researchers with the most influential set of factors that leads to crashes. We utilized a freight vehicle-involved crash data consisting of 19,038 crashes that occurred on the Korean expressways from 2008 to 2017 for this investigation. From the data, 90,951 association rules were generated through ARM employing the Apriori algorithm. The lift values estimated by the Apriori algorithm showed the strength of association between risk factors, and based on the estimated lift values, we identified key crash contributory factors that lead to truck-involved crashes at various segment types, under different weather conditions, considering the driver’s age, crash type, driver’s faults, vehicle size, and roadway geometry type. From the generated rules, we demonstrated that overspeeding with medium-weight trucks was highly associated with crashes during the rainy weather, whereas drowsy driving during the evening was correlated with crashes during fine weather. Segment-related crashes were mainly associated with driver’s faults and roadway geometry. Our results present useful insights and suggestions that can be used by transport stakeholders, including policymakers and researchers, to create relevant policies that will help reduce freight truck crashes on the expressways.
Improvement of Heavy Load Robot Positioning Accuracy by Combining a Model-Based Identification for Geometric Parameters and an Optimized Neural Network for the Compensation of Nongeometric Errors
Authors: Wang Yuxiang , Chen Zhangwei , Zu Hongfei , Zhang Xiang , Mao Chentao , Wang Zhirong
Published: January 2020

The positioning accuracy of a robot is of great significance in advanced robotic manufacturing systems. This paper proposes a novel calibration method for improving robot positioning accuracy. First of all, geometric parameters are identified on the basis of the product of exponentials (POE) formula. The errors of the reduction ratio and the coupling ratio are identified at the same time. Then, joint stiffness identification is carried out by adding a load to the end-effector. Finally, residual errors caused by nongeometric parameters are compensated by a multilayer perceptron neural network (MLPNN) based on beetle swarm optimization algorithm. The calibration is implemented on a SIASUN SR210D robot manipulator. Results show that the proposed method possesses better performance in terms of faster convergence and higher precision.
Aggressive Disease Course of Multiple Myeloma with Concomitant ALK-Negative Anaplastic Large Cell Lymphoma: A Case Report with an Unusual Presentation
Authors: Staderini Michela , Mannelli Lara , Antonioli Elisabetta , Puccini Benedetta , Berti Valentina , Mungai Francesco , Vergoni Federica , Carrai Valentina , Rigacci Luigi , Bosi Alberto
Published: January 2020

ALK-negative anaplastic large cell lymphoma is a rare T-cell neoplasm with an aggressive course requiring prompt diagnostic work-up and treatment. Few cases of concomitant multiple myeloma and T-cell neoplasm are described in the literature, mainly regarding primary cutaneous anaplastic large cell lymphoma. We present the case of a 65-year-old man, simultaneously diagnosed with ALK-negative anaplastic large cell lymphoma with extranodal localization in the gastrocnemius muscle (stage 1AE) and IgG lambda multiple myeloma (ISS 2, Durie-Salmon stage 3A). Both diseases required therapeutic intervention due to the high proliferative index of lymphoma and the presence of bone lesions attributable to myeloma. The therapeutic program initially included chemotherapy (cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisone; CHOEP), radiotherapy on the leg, bortezomib, and then consolidation with autologous hematopoietic stem cell transplantation. Despite being on bortezomib treatment and waiting for transplantation, the patient experienced an early myeloma progression that turned out to be refractory to second-line lenalidomide-based treatment. To our knowledge, this is the first case of concurrent diagnosis of extranodal ALK-negative anaplastic large cell lymphoma of the muscle and multiple myeloma. Simultaneous onset can be challenging for clinicians as both diseases may have an aggressive course requiring multiple treatments with increased risk of toxicity and complicated management.