bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serpentinization, Deformation, and Seismic Anisotropy in the Subduction Mantle Wedge
Authors: Horn Charis , Bouilhol Pierre , Skemer Philip 
Published: April 2020

AbstractAntigorite is a hydrous sheet silicate with strongly anisotropic seismic and rheological properties. Hydrous minerals such as antigorite have been invoked to explain numerous geologic observations within subduction zones including intermediate‐depth earthquakes, arc volcanism, the persistent weakness of the subduction interface, trench‐parallel S wave splitting, and episodic tremor and slip. To understand how the presence of antigorite‐bearing rocks affects observations of seismic anisotropy, three mylonites from the Kohistan palaeo‐island arc in Pakistan were analysed using electron backscatter diffraction. A fourth sample, which displayed optical evidence for crystallographically controlled replacements of olivine, was also investigated using electron backscatter diffraction to identify potential topotactic relationships. The resulting data were used to model the bulk seismic properties of antigorite‐rich rocks. The mylonitic samples exhibit incredibly strong bulk anisotropy (10–20% for the antigorite + olivine). Within the nominally undeformed protomylonite, two topotactic relationships were observed: (1) (010)ant//(100)ol with [100]ant//[001]ol and (2) (010)ant//(100)ol with [100]ant//[010]ol. However, the strength of a texture formed by topotactic replacement is markedly weaker than the strength of the textures observed in mylonitic samples. Since antigorite is thought to be rheologically weak, we hypothesise that microstructures formed from topotactic reactions will be progressively overprinted as deformation is localised in regions with greater percentages of serpentine. Regions of highly sheared serpentine, therefore, have the potential to strongly influence seismic wave speeds in subduction settings. The presence of deformed antigorite in a dipping structure is one explanation for observations of both the magnitude and splitting pattern of seismic waves in subduction zones.
Evidence of Bermuda Hot and Wet Upwelling From Novel Three‐Dimensional Global Mantle Electrical Conductivity Image
Authors: Li Shiwen , Weng Aihua , Zhang Yanhui , Schultz Adam , Li Yabin , Tang Yu , Zou Zonglin , Zhou Zikun 
Published: April 2020

AbstractA model of electrical conductivity in the mid–mantle transition zone was obtained with improved constraints. An L1‐norm regularization inversion algorithm is proposed here that reduces the influence of noisy data on three‐dimensional geomagnetic depth sounding inversion from C‐responses. Here the regularization is implemented by using an L1‐norm to measure the predicted data error, which is normalized by the C‐response covariance, but an L2‐norm is used to measure the regularization term associated with model parameters. The limited‐memory quasi‐Newton method (L‐BFGS) is used to invert for the three‐dimensional electrical conductivity model. The model is discretized by curved rectangular prisms in spherical coordinates. Sensitivity tests show that for good‐quality data contaminated by Gaussian noise, L1 inversion, which could perform as well as L2 inversion, can adequately recover the main features of the electrical conductivity structure within the region of data coverage. When data errors are drawn from an exponential distribution, L1 inversion obtains relatively reliable reconstruction of the electrical structure, even when the noise level is comparable to that of actual C‐responses. C‐responses from 129 low‐latitude and midlatitude geomagnetic observatories are inverted using L1‐norm minimization of the data error. The resulting model reveals an electrically conductive feature in the lower mantle transition zone and upper lower mantle that is broadly coincident with that found in previous studies. The reduced influence of data with large variances on L1‐norm misfits, along with inclusion of responses estimated from more observatories, makes L1 inversion more clearly identify these deep conductive features while identifying previously obscured anoconductive zones. A feature of particular interest is the high electrical conductivity anomaly beneath the Bermuda‐Sargasso Sea region in the mid–mantle transition zone and the uppermost lower mantle. Rock physics analysis indicates that the anomaly is most possibly caused by the wet upwelling material with excessive ~650 K higher temperature, suggesting a narrow tail with a broad head.
A New Data Set of Thermospheric Molecular Oxygen From the Global‐scale Observations of the Limb and Disk (GOLD) Mission
Authors: Lumpe J. D. , McClintock W. E. , Evans J. S. , Correira J. , Veibell V. , Beland S. , Eastes R. 
Published: April 2020

AbstractThe Global‐scale Observations of the Limb and Disk (GOLD) instrument was launched on 25 January 2018 onboard the SES‐14 commercial communications satellite and began nominal science operations in October 2018. Operating from geostationary orbit at 47.5°W longitude, GOLD images the Earth's thermosphere and ionosphere in the far‐ultraviolet (132–162 nm), measuring critical geophysical parameters by continuously scanning the Earth's disk and limb 18 hours per day. GOLD also performs stellar occultation measurements using bright type O and B stars. Up to 10 occultations per day are obtained at latitudes ranging from 60°S to 45°N and two fixed longitudes, ~33°E and ~128°W. The occultation data provide a direct measurement of atmospheric absorption in the O2 Schumann Runge continuum, which is used to retrieve the O2 density profile from 130‐ to 200‐km altitude. This paper describes the GOLD occultation measurement technique and the operational retrieval algorithm used to derive the Level 2 O2DEN data product. The spatial, temporal, and local time sampling of the GOLD O2 data product is summarized, and the data quality, retrieval errors, and validation plans are discussed. Occultations are observed under both daytime and nighttime conditions, providing the O2 density over a complete range of local times. GOLD retrievals have an estimated precision of 10% and a vertical resolution of 5–10 km, depending on altitude. The data have sufficient accuracy and resolution to provide scientifically useful constraints on the O2 abundance and variability. Initial comparisons show qualitative agreement, but also notable differences, between the GOLD O2 data and the Naval Research Laboratory Mass Spectrometer Incoherent Scatter Radar (NRLMSISE‐00) empirical model predictions.
Role of M1-polarized tumor-associated macrophages in the prognosis of advanced ovarian cancer patients
Authors: Macciò Antonio , Gramignano Giulia , Cherchi Maria Cristina , Tanca Luciana , Melis Luca , Madeddu Clelia 
Published: April 2020

AbstractThe identification of prognostic and predictive markers is crucial for choosing the most appropriate management method for ovarian cancer patients. We aimed to assess the prognostic role of tumor-associated macrophage (TAM) polarization in advanced ovarian cancer patients. We carried out a prospective observational study that included 140 consecutive patients with advanced-stage high-grade serous ovarian cancer as well as patients with other histotypes of ovarian cancer and patients with ovarian metastasis from other sites between June 2013 and December 2018. Patients were enrolled at the time of laparoscopic surgery before receiving any antineoplastic treatment. We found that patients with high-grade serous papillary ovarian cancers had a prevalence of M1 TAMs, a higher M1/M2 ratio, and a longer overall survival (OS) and progression-free survival (PFS) than other patients. Regression analysis confirmed that there was a significant positive association between the M1/M2 ratio and an improved OS, PFS and platinum-free interval (PFI), both in the entire population and in patients stratified according to tumor type and initial surgery. Kaplan-Meier analysis was performed after the patients were divided into 2 groups according to the median M1/M2 ratio and revealed that patients with a high M1/M2 ratio had a higher OS, PFS and PFI than those with a low M1/M2 ratio. In conclusion, the prognostic and predictive role of TAM polarization in the tumor microenvironment could be of great clinical relevance and may allow the early identification of patients who are likely to respond to therapy. Further studies in a larger prospective sample are warranted.
DUSP2 regulates extracellular vesicle‐VEGF‐C secretion and pancreatic cancer early dissemination
Authors: Wang Chu‐An , Chang I‐Heng , Hou Pei‐Chi , Tai Yu‐Jing , Li Wan‐Ning , Hsu Pei‐Ling , Wu Shang‐Rung , Chiu Wen‐Tai , Li Chien‐Feng , Shan Yan‐Shen , Tsai Shaw‐Jenq 
Published: April 2020

ABSTRACTEarly dissemination is a unique characteristic and a detrimental process of pancreatic ductal adenocarcinoma (PDAC); however, the underlying mechanism remains largely unknown. Here, we investigate the role of dual‐specificity phosphatase‐2 (DUSP2)‐vascular endothelial growth factor‐C (VEGF‐C) axis in mediating PDAC lymphangiogenesis and lymphovascular invasion. Expression of DUSP2 is greatly suppressed in PDAC, which results in increased aberrant expression of extracellular vesicle (EV)‐associated VEGF‐C secretion. EV‐VEGF‐C exerts paracrine effects on lymphatic endothelial cells and autocrine effects on cancer cells, resulting in the lymphovascular invasion of cancer cells. Tissue‐specific knockout of Dusp2 in mouse pancreas recapitulates PDAC phenotype and lymphovascular invasion. Mechanistically, loss‐of‐DUSP2 enhances proprotein convertase activity and vesicle trafficking to promote the release of the mature form of EV‐VEGF‐C. Collectively, these findings represent a conceptual advance in understanding pancreatic cancer lymphovascular invasion and suggest that loss‐of‐DUSP2‐mediated VEGF‐C processing may play important roles in early dissemination of pancreatic cancer.Abbreviations: DUSP2: dual‐specificity phosphatase‐2; VEGF‐C: vascular endothelial growth factor‐C; EV: extracellular vesicles; PDAC: pancreatic ductal adenocarcinoma; KD: knockdown
High-temperature creep and damage of metallic materials
Authors: Arutyunyan A R , Arutyunyan R A , Saitova R R 
Published: April 2020

Abstract
The problem of creep and long-term strength of metallic materials and alloys is considered. This problem is demanded in such important fields of modern engineering, as thermal and nuclear power plants, aircraft and spacecraft, etc. The damage conception was introduced in the mechanics of materials to describe long-term strength under conditions of high-temperature creep. In this paper is proposed to determine the damage parameter changes from experimental high-temperature creep curves. Therefore, only one kinetic equation for the creep rate for the case of a compressible medium is formulated. The continuity parameter is determined from this kinetic equation and depends on the creep rate and creep deformation. Similarly, the changes in the continuity parameter are determined by the Rabotnov solution. It was obtained that for the case of a compressible medium, a more intense accumulation of damage and, correspondingly, fracture processes are observed, compared with the Rabotnov solution.
Influence of supersonic flow on nonlinear oscillations of a cylindrical shell
Authors: Baghdasaryan G Y , Mikilyan M A , Vardanyan I A , Panteleev A V 
Published: April 2020

Abstract
In this paper we consider nonlinear oscillations of an isotropic cylindrical shallow shell in a supersonic gas flow. The study is carried out with considering both types of nonlinearity: the geometric and the aerodynamic. By taking into account the asymmetric (quadratic) nonlinearity, we come to a conclusion that in certain velocity intervals the amplitude-velocity dependence is a multi-valued function. It is shown, that there exist so-called zones of silence – the intervals of the steaming flow velocity, where undamped flutter oscillations cannot be induced. Here we give some of our most important and significant results, which follow from the influence of a supersonic gas flow on the nature of nonlinear oscillations of the investigated aeroelastic system: a) the larger the relative radius of the shell, the wider the silence zone; b) the amplitude of oscillations, depending on the flow velocity, is a monotonously decreasing function in the region to the left of the silence zone and tends to zero at the left boundary of the zone; at the right boundary of the zone the amplitude increases abruptly to a certain finite value and then it monotonously decreases; c) in the case of thin shells with an increase in the velocity of the flow we observe the following: flutter oscillations mode persists up to a certain velocity value (the “upper” critical velocity), where the oscillations “break off” and the unperturbed state of the shell restores. When the velocity decreases, the unperturbed state is stable as long as the velocity is greater than the critical flutter velocity (the “lower” critical velocity), at which the amplitude of flutter oscillations increases abruptly to a certain value and keeps increasing with further velocity decrease; d) in the case of sufficiently thin shells, the zone of silence is a semi-infinite region.
Influence of boundary conditions on the aero-thermo-elastic stability of a closed cylindrical shell
Authors: Baghdasaryan G Y , Mikilyan M A , Vardanyan I A , Danoyan E H , Melikyan K 
Published: April 2020

Abstract
In this paper, in a linear formulation, the stability problem of a closed cylindrical shell under the influence of an inhomogeneous temperature field and a supersonic gas stream flowing around the shell is considered. The stability conditions for the unperturbed state of the aero-thermo-elastic system under consideration are obtained. It was shown for different boundary conditions that by the combined action of the temperature field and the flowing stream, the stability process can be controlled and the critical flutter velocity can be substantially changed using the temperature field. The following most significant results were obtained: 1) in the case of a homogeneous temperature field, if the edges of the shell freely move in the longitudinal direction: a) a constant temperature field practically does not affect the value of the critical velocity νcr
; b) the critical velocity function νcr
, depending on the number of circumferential waves n, has a minimum point; 2) in the case of a homogeneous temperature field, if the edges of the shell are fixed: a) for negative values of T
0, the lower the temperature, the wider the stability region; b) for positive values of T
0 up to a certain temperature value the stability region narrows, after which, with increasing temperature it expands; c) starting from a certain temperature value

T

0

*

for all

T

0

>

T

0

*

the system is unstable for any 0 < ν < ν
*, and with increasing speed (ν > ν
*) the system becomes stable, and the larger the radius of the shell, the smaller this value

T

0

*

; 3) in the case of a temperature field inhomogeneous over the thickness of the shell, if the edges of the shell move freely in the longitudinal direction: a) when Θ > 0 the critical velocity increases significantly and the minimum point of the function νcr
(n) moves towards the lower values of n; b) when Θ < 0 the opposite is observed; 4) in the case of a temperature field inhomogeneous over thickness of the shell, if the edges of the shell are fixed: a) the stability region expands with increasing |Θ|; b) for a fixed value of the gradient Θ, an increase in the radius of the shell R leads to an expansion of the stability region; 5) fixing the edges of the shell leads to a significant increase in the value of the critical velocity of the flowing stream.
Nonstationary torsion problems for the finite cylinder partly coupled with rigid base
Authors: Demydov O V , Popov V G 
Published: April 2020

Abstract
The axisymmetric dynamic problems of determining the stress state in the vicinity of the delamination in a finite cylinder partly coupled with the rigid base were solved. In contrast to the traditional solution methods based on the use of the integral Laplace transform, the proposed method consists in the difference approximation only of the time derivative. As a result, the original problem is replaced by a sequence of homogeneous boundary value problems for the Helmholtz equation that reduce to the Fredholm integral equation of the second kind. The numerical solution found made it possible to obtain an approximate formula for calculating the stress intensity factor.
Influence of surface effects on stress state in a body with two circular holes
Authors: Gandilyan D.V. , Ustinov K.B. 
Published: April 2020

Abstract
The problem of two equal holes in a plane under uniform comprehensive tension is considered with accounting effects of surface elasticity. The problem is solved in the approximation of plane strain by using bipolar coordinates and series expansion. The problem may be of interest for the case of rather close holes. In this case, despite rather simple geometry, rather strong effects of the difference between surface and volumetric properties may be expected due to small distance between holes.
Localisation of guided wave in stratified elastic reflector sandwiched between two elastic semi-spaces
Authors: Ghazaryan K B , Ghazaryan R A , Papyan A A , Ohanyan S K 
Published: April 2020

Abstract
The guided shear wave localisation is considered in the problem of reflection and refraction through bi–material stratified elastic reflector perfectly sandwiched between two elastic semi–spaces. Bi-material stratified reflector consists of finite number periodically arranged and perfectly bonded elastic sub-layers. A shear wave incident at the interface of layer from the first semi–space will give rise to a guided wave in reflector, a reflected shear wave in the same semi-space and a refracted shear wave in the second semi–space. It is shown that guided wave amplitude is localized at the neighbourhood of the layer interface adjacent to the incidence elastic semi-space and monotonously attenuates with increasing of cell number, if the frequencies of incident wave are in the stopband ranges.
Anti-plane stressed state uniformly piece-homogeneous space with a periodic system of parallel semi-infinite interfacial cracks
Authors: Hakobyan V N , Grigoryan A H 
Published: April 2020

Abstract
In the present work, the exact solutions for two problems of the antiplane stress state of a uniformly piecewise homogeneous space formed by alternately joining two heterogeneous layers of equal thickness from different materials, which is weakened on the junction planes of layers by a periodic system of parallel semi-infinite tunnel cracks are obtained. In the first of these problems, it is assumed that stresses are given on the crack banks, and in the second problem, that stresses are given on one of the crack banks and displacements on the other.
Analytical prediction of thermal stresses in composite shells
Authors: Janakiraman A , Velmurugan R , Jayaganthan R , Rajasingh G 
Published: April 2020

Abstract
The use of fibre-reinforced plastics or FRPs in various industries, such as aviation, automobiles, renewable energy, etc. has drastically increased over the past decades, owing to the significant strength to weight ratios they offer. The design phase of such components must also factor in thermal loads. Thermal expansions and contractions, when restricted, lead to the buildup of stresses in a material. The distribution of these stresses across the layers of a composite tube has been dealt with here with the help of an analytical study, taking into account any radially varying user-defined temperature profile. On account of geometry, the cases handled are axisymmetric and therefore, shear stresses aren’t considered.
Deformation behavior and resistance to fracture of glass-fabric pipes subjected to complex loading with torque and internal hydrostatic pressure
Authors: Karapetyan K A , Valesyan S Sh , Muradyan N S 
Published: April 2020

Abstract
The results of fracture resistance and deformation behavior of thin-walled glass-plastics pipes subjected to internal hydrostatic pressure and torque at the conditions of complex and separate loading are considered.
As a result of the obtained data comparative analysis, the practical guidelines are stated pointing to the optimal design of tubular constructional products made of reinforced plastics operating at the conditions of internal pressure and torque.
On modelling inelastic deformation of permeable rocks with accounting time-dependent effects
Authors: Karev V I , Klimov D M , Kovalenko Yu F , Ustinov K B 
Published: April 2020

Abstract
A model has been developed for describing stress state and filtration of rocks that include creep-like effects. The model describes elastic-inelastic transition, and further deformation in inelastic region. The key point consists in accounting for anisotropy of elastic, ultimate and filtration properties. The model is particularized for the properties of rocks of one of oil deposits of Russia.
The problem of stationary thermoelasticity for a piecewise homogeneous transversely isotropic space under the influence of a heat flux specified at infinity is considered
Authors: Kryvyi O , Morozov Y 
Published: April 2020

Abstract
An exact solution to the problem of thermoelasticity about interfacial circular inclusion, which is in complete adhesion with different transversely isotropic half-spaces, is constructed. Analytical dependencies are obtained between the parameters of the linear displacement of the inclusion and the characteristics of the force and temperature fields. The order of the singularity of surges and displacements near the inclusion is determined. Expressions are obtained for the stress intensity factor at the inclusion boundary, as well as the numerical dependences of these coefficients on the polar angle, temperature, and load.
Techno-Economic Analysis Small Biodiesel Plant from Palm Sludge Oil
Authors: Wicaksono A , Widayat  , Saptadi S 
Published: April 2020

Abstract
This research aims for the production of biodiesel (methyl ester) with the raw material of palm sludge oil (PSO) and perform a feasibility analysis through the parameters of Net Present Value, Internal Rate of Return (compare to bank interests rate), and Simple Payback Period on the small industrial scale 50-70 litters the biodiesel production obtained 91.30% yield from. Biodiesel can replace diesel oil as a fuel boiler for industrial use based on the quality parameters analysed, including methyl ester content, calorie value, flash point, viscosity and density. The economics analysis includes shows this business feasible to be applied.
Plasma Technology in Cold Storage for Shelf Life Extension of Fresh Fish
Authors: Hartadi Y , Nur M , Fajar B 
Published: April 2020

Abstract
Low temperature storage or cold storage to prevent bacteria and microorganisms from growing on food. Maintaining the quality of fresh fish when stored above freezing temperatures requires special treatment to maintain the quality and prolong the storage. The use of ozone as disinfectant could be a solution to the decreasing quality of fresh fish. The combination of ozone technology with cold storage gives a great advantage in storing fish in fresh conditions. The use of ozone generating plasma technology in cold storage offers a space for increased energy efficiency and economic value by using three time less energy use intensity than cold storage without plasma technology, which means that the plasma technology in cold storage provides a three-fold benefit in terms of energy costs per kilogram of fresh fish per day. A prolonged shelf life as well as a decrease of energy use intensity is very important in food distribution chain, especially for fresh fish that are vulnerable to damage.