bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation and characterization of local Azotobacter isolate) producing bio-plastics and consuming waste vegetable oils
Authors: Gatea I H , Sabr A B , Abdul Wahed E A , Abbas A H , Halob A A , Mahmood M S
Published: December 2019

Polyhyroxyalkanotes (PHAs) are a family of polyhydroxyesters synthesized by numerous bacteria as an intracellular carbon and energy storage compound under nutrient-limiting conditions with excess carbon. An extensive screening program was previously done to isolate a promising bacterial isolate capable of polyhydroxyalkanoate (PHA) production. Polyhydroxalkanoates are biodegradable thermo polyesters like poly-β-hydroxybutyrate (PHB), which can be produced intracellularly as carbon and energy reserves. In this present study, out of 35 isolates, as many as 12 isolates were found to accumulate PHA which isolated from the oil and plastic contaminated soils, collected from different contaminated sites in Baghdad. However only one bacterial colony is selected among others based on maximum PHA yield (4.8g/L) after 48 hrs of incubation at 30°C with 54 % of PHA. Bacteria from this colony was characterized by morphological, biochemical and identified as Azotobater. The maximum PHA yield was recorded under the dry weight basis with 3% of corn oil wastes as the sole carbon source. However, Sudan black stained cells showed the presence of large quantities of granules in the cell cytoplasm when viewed under microscope. The polymer was extracted for the purpose of studying its physical and chemical properties.
The Companion effect between Salicylic acid and Glutamine on the growth and yield of water-stressed cucumber (Cucumis sativus L. )
Authors: Hamid Z H , Mansoor R J
Published: December 2019

Trial was conducted in greenhouse of the Department of biology / College of Science/University of Diyala during autumn season 2016. The study included two levels of water stress ( S1
/Irrigation for 14 minutes and S2
/ Irrigation for 7 minutes/7 ml of water per minute ), three foliar application levels of Salicylic acid SA (0, 75, 150) mg. L−1 and three foliar application levels of Glutamine acid G (0, 1000, 2000) mg. L−1. Some growth indicators viz., (Plant height, Stem diameter, Relative growth rate and Plant Yield were registered. The experiment was designed as a factorial experiment using an RCBD design with three replicates. Water stress decreased the means of all studied indicators, Plant height record 232.44 cm, Stem diameter 8.28mm, Relative growth rate 0.019 g.day−1 and yield 1358 gm plant−1 at the first stress level (Irrigation for 14 minutes / S1
) while the means of the indicators decreased to183.82 cm, 7.41 mm, 0.016 g day−1 and 972 g plant−1, respectively at the second stress level (Irrigation for 7 minutes / S2
). Salicylic acid and Glutamine acid increased all the studied indicators. the third level of salicylic and Glutamine spraying (150 mg. L−1, 2000 mg. L−1 ) has exceeded the second level (75 mg. L−1, 1000 mg. L−1 ). The role of Salicylic acid and Glutamine acid was positive to decrease the passive effect of water stress, Plant height record 236.17 cm, Stem diameter 8.57mm, Relative growth rate 0.021 g.day−1 and yield 1893 gm plant−1(the percentage of increase was 37.57%, 40.95%, 50.00%, 179.62%, respectively), also the triple interaction between the second stress level(S2
) and the spraying at high levels the Salicylic acid and Glutamine SA3 G3 was positive to decrease the effect of water deficit stress, 262.00 cm, 9.22 mm, 0.024g.day−1 and yield 2317gm plant−1 (percentages of increase were 75.05%,58.97%,100.00%and286.17%, respectively).
Impact of the inclination angle of a blade of the geokhod cutting body on the energy intensity of rock destruction
Authors: Aksenov V V , Efremenkov A B , Sadovets V Yu , Pashkov D A , Efremenkov V A
Published: December 2019

The article presents the dependence of the energy intensity of rock destruction on the inclination angle of blade of geokhod cutting body for the destruction of low hardness rocks. To formulate the research tasks, the main provisions of the geokhod technology for making workings are presented; the features of the new class of mining equipment, geokhod, are given. The research relevance is formulated. To determine the energy intensity of the rocks destruction, the method of calculating the power and geometric parameters of the geokhod blade cutting body was chosen. An algorithm has been developed for calculating the energy intensity of rock destruction, on the basis of which a computer program has been developed for determining the power parameters of the geokhod blade cutting body. In addition, the article presents well-founded forms of face, which appear as a result of destruction with the blade cutting body of the geokhod. To determine the influence of the inclination angle of the geokhod blade cutting body on the energy intensity of destruction, the geometrical parameters of the blade cutting body and the parameters of the mining and technical conditions of the mine working were justified. As a result of the study, it was revealed that the energy intensity of rock destruction with the blade cutting body decreases unevenly as the inclination angle of the blade towards the reverse cone increases.
Technological parameters for the production of steel and titanium blanks by the method of helical rolling
Authors: Belyakov V N , Naumova O S
Published: December 2019

The article is devoted to the technology of producing steel and titanium blanks by the method of cross-helical rolling. The grades of the investigated alloys and technological processing modes are given. Studies of the effect of rolling parameters (deformation temperature, feed angle) on the production of round billets are presented. The general nature of the influence of technological factors of the process on the conditions of metal deformation is established. The change in the microstructure of titanium alloys after hot deformation was investigated. The expediency of using this method is substantiated.
Determination of external impacts on the bearing unit of the geokhod
Authors: Dronov A A , Beglyakov V Yu , Aksenov V V , Efremenkov A B , Efremenkov V A
Published: December 2019

The mathematical model of interaction of the bearing unit of the geokhod with geoenvironment and related systems was developed. The model takes into account the variability of the bearing unit of the geokhod and opens up the possibilities for further determining the inter-actions of the elements of the bearing unit of the geokhod with each other.
Methods of pulsed local action on magnetic mechanical state of ferromagnetic shape memory alloy
Authors: Gorbatenko N I , Grechikhin V V , Kraevskiy I S , Kudrya A V , Yufanova A L
Published: December 2019

The task of controlling a positioning system drive with the active element of ferromagnetic shape memory alloy has been considered. The task is to provide the length increment of the active element by a given value from the resultant action – the pulse of magnetic field (or pulse series) with definite amplitude and duration. Methods of solving the task – the methods of tracking and scanning modes of the pulse reversal of the active element – have been suggested. To implement the method of scanning magnetization reversal, it is necessary to introduce a feedback link to reduce the positioning error due to the discrete nature of the effect and have information about the deformation of the element. A specific feature of tracking magnetic reversal is the use of experimental information to exclude overregulation. In testing process, an iterative process has been carried out to correct the mathematical model of deformation, using experimental data. To study the method, a software module has been developed in the LabVIEW graphical programming environment. The data obtained show that application of the method allows to increase the accuracy of controlling positioning systems based on ferromagnetic shape memory alloy.
Exergetic analysis of heat pump units for various climate conditions
Authors: Malyshev A A , Malinina O S , Arendateleva S I , Zawadzki I M
Published: December 2019

The article deals with exergetic analysis of a heat pump for climate of Russian North-West. The dependencies between the parts of the pump and its general characteristic are shown. The influence of ambient temperature, condensation temperature, and low-grade heat source on the working efficiency of heat pump units is analyzed. The changes in thermodynamic characteristics of the heat pump at ambient temperature decreasing form 0°C to –15°C are identified. The coefficient of performance is seen to decrease two times, the coefficient of transformation – by 1.4 times; overall exergetic coefficient of performance increases by 18 %. Working efficiency and coefficient of performance of the unit in general, and the ones of compressor, compensator, evaporator and thermal expansion valve are determined. The results of the research are of use for increasing efficiency of heat pumps.
Experimental research on a phase slip and pressure loss during boiling of the refrigerant R134a in a mini-channel
Authors: Malyshev A A , Kouadio K F , Letenkov O V , Zawadzki I M
Published: December 2019

This article is devoted to the development of a methodology for calculating the hydrodynamic characteristics of liquids boiling in mini-channels. In contrast to the well-known methods, the proposed methodology is based on the use of the true volumetric steam content and prediction of two-phase flow regimes in the field of a steady flow. The article presents experimental data on the true volumetric steam content, pressure loss, and two-phase flow pattern in mini-channels
Determination of the admissible intervals of the input technological parameters that provide the necessary values of the parameters – acceptance criteria
Authors: Popov S A
Published: December 2019

An inverse optimization problem is considered to determine the optimal intervals of the input technological parameters. The solution is based on multi-response technological process models for the multi-dimensional area of input and output parameters. Expressions for calculating the coefficients of the multi-response models are given. It is shown how the intervals of admissible values of the input technological parameters are built. As an optimality criterion, the percentage of yield of products is used, parameters – acceptance criteria.
Technological method of assessing the quality of adhesion of the coating to the basis of the tool material during indentation with the exposure time of loading the sample
Authors: Shvetsov I V , Mokritsky B Y , Zhelnov D V
Published: December 2019

Techniques of assessing the quality of adhesion of the coating to the base of a tool material during penetration of the indenter with the sample loading time exposure have been considered. Data of efficient tool hardening have been given. Comparative tests of the tool subjected to various kinds of hardening thermoplastic processing show relative increase in its performance. Within the given work, we understand the quality of tools as the correspondence of controlled parameters of physical mechanical characteristics of tools to those values which define the performance properties of a metal cutting tool, or, comparing them, it is possible to prefer those which have performance advantages.
Wood moisture accounting in creep equations
Authors: Varenik K A , Varenik A S , Sanzharovsky R S , Labudin B V
Published: December 2019

Wood as a structural material differs from other materials used in construction and industry, high variability of its properties. This is due, among other things, to the action of various variable factors – moisture content, temperature, inclination of fibers and others. The influence of wood moisture is especially strong – as a result of moistening the strength of wood considerably decreases in comparison with durability in absolutely dry condition. In addition, wood is a significantly nonlinear structural material. Non-linearity is manifested both in short-term and prolonged loading. Research of wood in time can be divided into two directions: longterm durability of wood and creep of wood. Modern models of wood creep are based on linear theories. Analysis of experimental data of various researchers on wood creep, has shown that the area of linear creep is observed at rather low levels of loading. At medium and high levels of experimental loading the existing models of linear wood creep theory do not correspond to experimental data. All this points to the actuality of the development of methods of calculating wooden structures for creep (linear and nonlinear), taking into account the wood moisture.
Methods for processing structures based on solid solutions of AIIIBV compounds
Authors: Zhelannov A V , Seleznev B I , Fedorov D G
Published: December 2019

The technologies of plasma-chemical etching of AlxGa1-xN epitaxial layers in chlo-rine-containing mixtures, which allow forming a microrelief on the surface of a semiconductor in the range from tens of nanometers to tens of micrometers, are presented. The modes of selective etching of GaN layers with respect to AlxGa1-xN (x = 0.25) are determined.
Study on Size Error Compensation of Connecting Bracket Based on Fused Deposition Modeling
Authors: Li Shibo , Liu Tingting , Xiao Xingzhi , Hu Weiyue , Liao Wenhe
Published: December 2019

In the integrated additive manufacturing of electronic products, the connecting bracket is a typical fixed structure for embedding electronic components such as PCBs, sensors, batteries, etc. The dimensional accuracy of column spacing affects the stability of embedded components directly. In this paper, aiming at the printing error of connecting bracket column spacing during the Fused Deposition Modeling (FDM), the printing error compensation is studied via the single factor experiments. The impact of design size on printing error is analyzed, and the printing error compensation model is established. Based on the FDM printing process of the connecting bracket, the main influencing factors of the printing error are analyzed. The results show that the column spacing printing error is the result of the combination of the dimension error of column printing, the dimension error of base printing and the motion error of the machine. Finally, based on the error compensation model, the compensated connection bracket is printed and the PCBs embedding verification is performed. The PCB can be embedded steadily, which indicates that the established model has higher precision.
Analyzing Resistance of Al-10Si-5Mg Alloy from Stress Corrosion Cracking for Ocean Current Turbine Applications
Authors: Matarru Andre Amba , Syahid Muhammad , Yoesgiantoro Donny , Hadi Syahril
Published: December 2019

Stress Corrosion Cracking in Marine Applications, especially Ocean Current Turbines must be overcome. Al-10Si-5Mg Alloy which is based on the nature of flexibility and strength, is expected to survive from the SCC. The purpose of this paper is to examine the indications of SCC from immersed specimens in the 3.5% NaCl Solution + Aquades solution, then give varying deflections on the 3 Point Bending Testing. The other tests are harness testing, tensile testing, and macro visualization. The method is experimental for Al-10Si material in addition to a 5% Mg at casting. There are 9 specimens, namely 3 specimens from each of the 3 load values, namely 252 MPa (deflection (y)=2mm), 378 MPa (y=3mm), and 504 MPa (y=4mm). The results provide evidence that when the specimens were submerged with varying stresses, the absence of broken material was obtained even though there were indications of cracking and corrosion. Then the specimen that gets a high stress, becomes more susceptible to fracture due to the predominant cracking effect when compared to low standing specimens (σy=4 mm < σy=3 mm < σy=2 mm). So by the resistance to SCC, the Al-10Si-5Mg alloy can be recommended as an Ocean Current Turbine Blade material.
CNC Planing Process for Turbine Twisted Blade Profile
Authors: Ding Tao , Li Jia , Jin Yongquan , Zhang Juncheng
Published: December 2019

In this paper, a multi-axis follow-up CNC planing process for twisted blade profile is proposed to reduce the machining cost and achieve high machining efficiency. Firstly, the planing process of the turbine twisted blade is analysed to determine the planing shaping movements; then the machine layout and CNC planing system needed to realize the shaping movements are constructed; then the implementation method of the multi-axis follow-up function which is unique to the CNC planing system is studied; Finally, a proof experiment of this machining process has been done to verify its feasibility.
The Microstructural Evolution of a Cold Rolled AlSi9Mg Aluminum Alloy after Semi-Solid Isothermal Treatment Process
Authors: Wang Yongfei , Zhao Shengdun , Guo Yi , Li Shuangjiang , Fan Xiaoguang
Published: December 2019

The key factor in semi-solid metal forming process is the preparation of semi-solid billet with fine and spherical microstructure. The recrystallization and partial melting (RAP) process consists of cold deformation and semi-solid isothermal treatment (SSIT) is a promising method, because that many alloys are always supplied in the deformed state. In this work, a cold rolled AlSi9Mg aluminum alloy was used directly to fabricate semi-solid billets. During the RAP process, samples cut from the cold rolled AlSi9Mg aluminum alloy were treated with different isothermal holding temperatures and times, and the effects of isothermal treatment parameters on the microstructures of AlSi9Mg alloy semi-solid billets were investigated. The results show that, with increasing the isothemal holding temperature and time, the average grain size of solid grains is gradually increased, the spheroidization degrees of solid grains are sharply increased and then follows by a slight improvement. The high-quality semi-solid billets can be prepared with SSIT process at 570 °C for 5~10 min.
Prediction of a residual operating life of engines
Authors: Bazhenov Y , Bazhenov M
Published: December 2019

Results of the executed researches on prediction of an individual residual operating life of engines are pre-sented in article. Prediction is based on the diagnostic information on technical condition of engines ob-tained during the carrying out their maintenance and repair. The analytical equation, the describing regu-larities of change of diagnostic parameters on an operating time and its graphic interpretation are given. The forecasting technique of a residual operating life of mechanisms of engines with use of the lower fidu-cial bound of distribution of their practices to the limiting condition is offered. The technique is approved on the example of forecasting of a residual operating life of cylinder-piston group of the ZMZ-40524.10 engine.
Multicriteria optimization in the study of active vehicle safety.
Authors: Markovnina A.I. , Makarov V.S. , Belyakov V.V.
Published: December 2019

Ensuring road safety is a paramount task to be solved by specialists in the field of automobile transport. It affects all aspects of the Driver-Car-Road-Environment system and is aimed at increasing the degree of protection of road users from traffic accidents, at reducing the degree of road traffic injuries and reducing the risk of mortality. Similar functions for ensuring road safety are performed by the active safety systems of the car, including intelligent driver assistance systems and assistants. With all the variety of possibilities of equipping automobiles with complex systems, there is a need to assess the feasibility and profitability of installing a particular complex of systems. For this, it is proposed to apply multi-criteria assessment methods. At the same time, the possibility of multi-parameter optimization according to two or more criteria is considered, respectively, several approaches to solving the problem are described. As a result, a concept is developed that is close to universal, in assessing the active safety systems of a car and intelligent systems.
Composition research of generator gas for application as motor fuel
Authors: Plotnikov S.A. , Biryukov A.L. , Zubakin A.S-
Published: December 2019

The problem of the lack of currently approved methodology for determining chemical composition of generator gas and the effect of gas composition when using it as a motor fuel on the operational and environmental performance of an internal combustion engine is discussed. A method for determining chemical composition of generator gas has been developed and tested, in which it is proposed to measure mass concentrations (volume fractions) of the determined components in the generator gas by the indicator (linear-colour) method. Experimental studies were carried out to determine chemical composition of the generator gas according to the developed technique. The studies were carried out on an experimental gas generator of original design, the novelty of which is confirmed by a patent for the invention. Charcoal and wood chocks were used as raw materials for production of generator gas. The composition of the generator gas in a parametric gas generator depends on the type of fuel (raw material), the temperature in the gasification zone, the number and spatial location of the injectors included in the operation and varies in the content of combustible components: H2 from 7% to 18%; CnHm - from 0.1% to 0.3%; CO - from 18% to 31%; CH4 - from 2% to 2.5%. The content of ballast in the generator gas also changes, so the O2 content is from 0.2% to 1.9%; N2 - from 48% to 57.3%; CO2 - from 3.2% to 10%. Experimental studies have confirmed the sufficient accuracy of the proposed methods.
Optimization of perlite steels mechanical properties for car fasteners stamping
Authors: Kuzmin A.N. , Filippov A.A. , Pachurin G.V. , Goncharova D.A.
Published: December 2019

The car fasteners made of pearlitic steels by cold stamping method are to meet special requirements for their structural and mechanical characteristics.

The hardware is made of hot-rolled steel, which cannot be used straight after the delivery for fasteners manufacturing due to the poor quality of the structure and surface layer. Therefore, calibrated rolled stock gets heat treatment before drawing. In addition, hardware of strength class 8.8 and higher obtained from alloy steels using cold heading machines are subjected to temper hardening, which often leads to surface decarburization, cracking and distortion of finished products, that afflicts labor and energy efficiency, and, thus, the final cost of production.

The article suggests a method for 35X and 38XA pearlitic steels stock treatment excluding recrystallization annealing, rod-like items temper hardening, and including isothermal operation to prevent decarburization, risks and distortion. Passing through the die, hardening the surface due to volume strain and thread rolling impart to M8 bolts and studs the mechanical properties corresponding to strength grades 8.8 and 9.8.

This study also has practical application, it allows manufacturers to determine the appropriate mode for producing automotive fasteners.
Accelerometer-Measured Physical Activity at Work and Need for Recovery: A Compositional Analysis of Cross-sectional Data
Authors: Stevens Matthew L , Crowley Patrick , Rasmussen Charlotte L , Hallman David M , Mortensen Ole S , Nygård Clas-Håkan , Holtermann Andreas
Published: December 2019

Objectives

Previous research has shown strong associations between occupational physical activity (OPA) and need for recovery (NFR). However this research has only utilized self-reported measures of OPA which may be biased. Thus, there is a need for investigating if the previously documented association between self-reported OPA and NFR can be found when using technical measures of OPA. There is also the need to investigate whether older workers are particularly susceptible to increased NFR, since age-related declines in physical capacity mean that it is likely these workers will have a higher NFR for a given physical activity. The aim of this study was to investigate the association between technically measured OPA and NFR, and whether this relationship is modified by age.

Methods

This study utilized data from the Danish Physical Activity Cohort with Objective Measurements cohort—comprising Danish workers (n = 840) from the cleaning, manufacturing, and transportation sectors. OPA was measured by accelerometers attached to the thigh and upper back for at least one work day and classified into four physical behaviour categories (sedentary, standing, light, or moderate/vigorous). NFR was measured using a shortened version of the Danish NFR scale. Analysis was conducted using linear regression and isotemporal substitution analyses for compositional data.

Results

The overall association between OPA and NFR was statistically significant in the unadjusted model (P < 0.001), but not when adjusted for age, sex, occupation, and shift work (P = 0.166). Isotemporal substitution showed small but significant reductions in NFR when increasing sedentary time relative to other behaviours (adjusted: ΔNFR = −0.010 [−0.019; −0.001]). There were no significant interactions between age and OPA (P = 0.409).

Conclusions

This study found significant associations between OPA and NFR, but the effect sizes were small. Reallocating 30 min to sedentary behaviours from other behaviours was associated with a reduced NFR, but the effect size may not be practically relevant. Moreover, no clear modifying effects of age were identified.
Predictive value of non-invasive right ventricle to pulmonary circulation coupling in systemic lupus erythematosus patients with pulmonary arterial hypertension
Authors: Guo Xiaoxiao , Lai Jinzhi , Wang Hui , Tian Zhuang , Wang Qian , Zhao Jiuliang , Li MengTao , Fang Quan , Fang Ligang , Liu Yongtai , Zeng Xiaofeng
Published: December 2019

Aims

Pulmonary arterial hypertension (PAH) is a serious and devastating complication of systemic lupus erythematosus (SLE), especially when the right ventricle (RV) fails. Whether the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) measured by echocardiography as a simple surrogate of RV to pulmonary circulation (PC) coupling predicts the outcome of SLE-associated PAH has not been investigated.

Methods and results

Between February 2010 and August 2015, 112 consecutive patients with a diagnosis of SLE-associated PAH confirmed by right heart catheterization were enrolled prospectively. The endpoint was a composite of all-cause mortality and clinical worsening. Baseline clinical characteristics and echocardiographic assessment were analysed. Among all the patients, 47 (42%) patients experienced the endpoint (mean follow-up period 18.1 ± 12.0 months), including 20 patients who died during a median follow-up period of 48.5 months. Multivariable Cox regression analysis showed that TAPSE/PASP ratio [hazard ratio (HR) 0.004, P = 0.017] and 6-min walk distance (6MWD) (HR 0.997, P = 0.036) were the independent predictors for the endpoint. A three-group prediction risk was created based on combined assessment of the TAPSE/PASP ratio and 6MWD relative to their cut-off values. The patients with the worse RV-PC coupling (TAPSE/PASP <0.184 mm/mmHg) and the lower 6MWD (<395 m) had the highest risk (HR 4.62, confidence interval 2.27–9.41, P < 0.001) of experiencing the endpoint.

Conclusion

The TAPSE/PASP ratio, combined with 6MWD, provides clinical and prognostic insights into patients with SLE-associated PAH. A low TAPSE/PASP and low 6MWD identifies the subgroup of patients with high risk of poor prognosis.
Chromosome-scale assembly comparison of the Korean Reference Genome KOREF from PromethION and PacBio with Hi-C mapping information
Authors: Kim Hui-Su , Jeon Sungwon , Kim Changjae , Kim Yeon Kyung , Cho Yun Sung , Kim Jungeun , Blazyte Asta , Manica Andrea , Lee Semin , Bhak Jong
Published: December 2019

Background

Long DNA reads produced by single-molecule and pore-based sequencers are more suitable for assembly and structural variation discovery than short-read DNA fragments. For de novo assembly, Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) are the favorite options. However, PacBio's SMRT sequencing is expensive for a full human genome assembly and costs more than $40,000 US for 30× coverage as of 2019. ONT PromethION sequencing, on the other hand, is 1/12 the price of PacBio for the same coverage. This study aimed to compare the cost-effectiveness of ONT PromethION and PacBio's SMRT sequencing in relation to the quality.

Findings

We performed whole-genome de novo assemblies and comparison to construct an improved version of KOREF, the Korean reference genome, using sequencing data produced by PromethION and PacBio. With PromethION, an assembly using sequenced reads with 64× coverage (193 Gb, 3 flowcell sequencing) resulted in 3,725 contigs with N50s of 16.7 Mb and a total genome length of 2.8 Gb. It was comparable to a KOREF assembly constructed using PacBio at 62× coverage (188 Gb, 2,695 contigs, and N50s of 17.9 Mb). When we applied Hi-C–derived long-range mapping data, an even higher quality assembly for the 64× coverage was achieved, resulting in 3,179 scaffolds with an N50 of 56.4 Mb.

Conclusion

The pore-based PromethION approach provided a high-quality chromosome-scale human genome assembly at a low cost with long maximum contig and scaffold lengths and was more cost-effective than PacBio at comparable quality measurements.
On the use of the coda of seismic noise autocorrelations to compute H/V spectral ratios
Authors: Tchawe F N , Froment B , Campillo M , Margerin L
Published: December 2019

The horizontal to vertical spectral ratio (HVSR) of seismic ambient noise has been proven to be a fast and efficient method for characterizing the 1-D resonance frequency of the local subsurface in a practical framework. Over the last decades, theories have been developed in order to extend the exploitation of HVSR beside the frequency of its first peak, notably the diffuse field assumption (DFA) which links the HVSR to the Green’s function of the local medium assuming the diffuseness of the seismic ambient noise wavefield. However, the underlying assumption of the seismic ambient noise being a diffuse, equipartitioned field may not be satisfied under certain circumstances. In order to exploit the contribution of scattering in forging diffuse wave fields, we leverage the advantages of coda waves and present a novel procedure for computing the HVSR, using the coda part of ambient noise correlations. We applied this technique to data gathered at the plio-quaternary sedimentary basin of Argostoli, Greece. Results on this data set show the potential of the method to improve the temporal stability of the HVSR measurements compared to the classical computation, and the fit with the theoretical HVSR curve derived from the DFA theory. These results suggest that this procedure could help in extracting physical information from the HVSR and thus could lead to an extended use of these measurements to characterize the mechanical properties of the medium.
What can P-wave polarization direction data tell us about subsurface velocity structures?
Authors: Jing Xili , Li Li
Published: December 2019

As seismic waves propagate in the Earth, the directions of particle motions are affected by the media that they encounter, and thus seismic wave polarization direction carries the information on the media. So far there remains unclear about what can be inferred from the P-wave polarization direction data. For clarifying it, we discuss the mapping relation between polarization direction and velocity distribution. It is found that the velocity model cannot be derived uniquely from the polarization direction data. By analysing the relation between slowness vectors of the seismic ray at the source and the receiver, we find that relative velocity gradient is the physical quantity that describes the capability to deflect seismic rays in a continuous medium. The equation describing the relation between polarization direction and relative velocity gradient is given. For imaging relative velocity gradients, we derive the calculation formula for the partial derivative of polarization direction with respect to velocity gradient parameters. Synthetic experiments are conducted. The test results demonstrate that the absolute velocity model cannot be recovered from P-wave polarization direction data, but the relative velocity gradient model can. Polarization direction tomography gives a way to build gradient maps for the geometric characteristic of the subsurface velocity structures.
3-D shear wave velocity model of the lithosphere below the Sardinia–Corsica continental block based on Rayleigh-wave phase velocities
Authors: Magrini Fabrizio , Diaferia Giovanni , Fadel Islam , Cammarano Fabio , van der Meijde Mark , Boschi Lapo
Published: December 2019

Rayleigh-wave dispersion curves from both ambient noise and teleseismic events allow us to provide the first high-resolution 3-D shear wave velocity (VS) model of the crust and upper mantle below the Sardinia–Corsica microplate, an important continental block for understanding the evolution of the central-western Mediterranean. For a wide range of periods (from 3 to ∼30 s), the phase velocities of the study area are systematically higher than those measured within the Italian peninsula, in agreement with a colder geotherm. Relative and absolute variations in the VS allow us to detect a very heterogeneous upper crust down to 8 km, as opposed to a relatively homogeneous middle and lower crust. The isosurface at 4.1 km s−1 is consistent with a rather flat Moho at a depth of 28.0 ± 1.8 km (2σ). The lithospheric mantle is relatively cold, and we constrain the thermal lithosphere–asthenosphere boundary at ∼100 km. We find our estimate consistent with a continental geotherm based on a surface heat flow of 60 mW m−2. Our results suggest that most of the lithosphere endured the complex history of deformation experienced by the study area and imply, in general, that deep tectonic processes do not easily destabilize the deeper portion of the continental lithosphere, despite leaving a clear surface signature.
A solid/fluid substitution scheme constrained by pore-scale numerical simulations
Authors: Sun Yongyang , Gurevich Boris , Glubokovskikh Stanislav , Lebedev Maxim , Squelch Andrew , Arns Christoph , Guo Junxin
Published: December 2019

Estimating the effects of pore filling material on the elastic moduli or velocities of porous and fractured rocks attracts widespread attention. This effect can be modelled by a recently proposed triple-porosity scheme, which quantifies this effect from parameters of the pressure dependency of the elastic properties of the dry rock. This scheme divides total porosity into three parts: compliant, intermediate and stiff. Each type of pores is assumed to be spheroidal and characterized by a single aspect ratio. However, the implementation of this model requires the asymptotic values of the elastic moduli at much higher pressures where only non-closable pores remain open. Those pressures are beyond the capacity of most rock physics laboratories and can even crush typical sandstone samples. Experimental data at such pressures are usually unavailable. To address this issue, we introduce pore-scale numerical simulations in conjunction with effective medium theories (EMT) to compute the asymptotic values directly from the microtomographic images. This workflow reduces the uncertainty of model predictions on the geometric information of stiff pores and strengthens the predictive power and usefulness of the model without any adjustable parameters. Applying this to a Bentheim sandstone fully filled with liquid and solid octadecane gives a reasonable match between model predictions and laboratory measurements. This success verifies the accuracy and applicability of the model and indicates its potential in further exploitation and characterization of heavy oil reservoirs and other similar reservoirs.
Reclaiming Children after the Armenian Genocide: Neutral House in Istanbul
Authors: Gzoyan Edita , Galustyan Regina , Khachatryan Shushan
Published: December 2019

During the Armenian Genocide the Turkish Government forcibly converted and assimilated Armenian children. The defeat of the Ottoman Empire in WWI brought the opportunity to retrieve such children, whose identities and future became a battleground between Armenians and Turks. This article addresses the fate of these child-survivors, many of whom, after being rescued, continued to deny their Armenian identities. The article presents a history of Neutral House, a unique organization established in Istanbul to return these children to their nation.
Optimizing image-based protocol to monitor macroepibenthic communities colonizing artificial structures
Authors: Taormina Bastien , Marzloff Martin P , Desroy Nicolas , Caisey Xavier , Dugornay Olivier , Metral Thiesse Emmanuelle , Tancray Aurélien , Carlier Antoine
Published: December 2019

Underwater imagery is increasingly used as an effective and repeatable method to monitor benthic ecosystems. Nevertheless, extracting ecologically relevant information from a large amount of raw images remains a time-consuming and somewhat laborious challenge. Thus, underwater imagery processing needs to strike a compromise between time-efficient image annotation and accuracy in quantifying benthic community composition. Designing and implementing robust image sampling and image annotation protocols are therefore critical to rationally address these trade-offs between ecological accuracy and processing time. The aim of this study was to develop and to optimize a reliable image scoring strategy based on the point count method using imagery data acquired on tide-swept macroepibenthic communities. Using a stepwise approach, we define an underwater imagery processing protocol that is effective in terms of (i) time allocated to overall image, (ii) reaching a satisfactory accuracy to estimate the occurrence of dominant benthic taxa, and (iii) adopting a sufficient taxonomic resolution to describe changes in community composition. We believe that our method is well adapted to investigate the composition of epibenthic communities on artificial reefs and can be useful in surveying colonization of other human structures (wind turbine foundations, pipelines, etc.) in coastal areas. Our strategy meets the increasing demand for inexpensive and time-effective tools for monitoring changes in benthic communities in a context of increasing coastal artificialization pressures.
Genetic diversity and offspring fitness in the red and white fruit color morphs of the wild strawberry Fragaria pentaphylla
Authors: Chen Lu-Xi , Xu Su-Ting , Ding Wei-Hang , Li Jun-Min , Alpert Peter
Published: December 2019

Aims

Fruit color polymorphisms are widespread in plants, but what maintains them is largely unclear. One hypothesis is that some morphs are preferred by dispersers while others have higher pre- or postdispersal fitness. This leads to the prediction that fruit color morphs will differ in pre- or postdispersal fitness.

Methods

We compared genetic and clonal diversity, mating system, morphological traits that might be associated with resistance to freezing, and germination, survival and seed production of progeny of the red and white fruit morphs in a population of a diploid, wild strawberry, Fragaria pentaphylla, from south-central China.

Important Findings

The red morph was much more abundant than the white but did not show higher genetic diversity as measured by observed and effective numbers of alleles, Shannon information index, or expected or observed heterozygosities. AMOVA showed that most of the genetic variation in the population was within rather than between morphs. Morphs did not differ in mating system parameters, and no significant biparental inbreeding was found in either morph. Gene flow between two morphs was high (Nm = 6.89). Seeds of the red morph germinated about 2 days earlier and had a 40% higher rate of germination than those of the white morph, but survival of seedlings and seed production by surviving offspring did not differ between morphs. The whole postdispersal fitness of the red morph was about two times higher than that of the white morph. Red morphs had hairier petioles but not more surface wax on leaves. Overall, results showed partial evidence for difference in pre- and postdispersal fitness between fruit color morphs in F. pentaphylla. Differences in fitness independent of dispersal may thus partially account for fruit color polymorphism in all cases.
To pee or not to pee: severe discomfort in a young air traveller
Authors: Lim Grace Hui Chin , Lim Bryan Chang Wei , Flaherty Gerard Thomas
Published: December 2019

This is the first manuscript relating to paruresis in the travel medicine literature. It describes a case of a 30-year-old man who is unable to urinate on board commercial air flights. The case is described and recommendations for management are advanced.
Testing the relativistic Doppler boost hypothesis for supermassive binary black holes candidates via broad emission line profiles
Authors: Song Zihao , Ge Junqiang , Lu Youjun , Ji Xiang
Published: December 2019

Optical periodicity QSOs found by transient surveys are suggested to be subparsec supermassive binary black holes (BBHs). An intriguing interpretation for the periodicity of some of those QSOs is that the continuum is radiated from the accretion disc associated with the BBH secondary component and modulated by the periodical rotation of the secondary via Doppler-boost effect. Close to edge-on orbital orientation can lead to more significant Doppler-boost effect and thus are preferred for these systems, which is distinct from those normal type-1 QSOs with more or less face-on orientations. Therefore, the profiles of broad lines emitted from these Doppler-modulated systems may be significantly different from other systems that are not Doppler modulated. We investigate the properties of the broad emission lines of optical-periodicity QSOs, including both a sample of QSOs that can be interpreted by the Doppler-modulated effects and a sample that cannot. We find that there is no obvious difference in the profiles and other properties of various (stacked) broad emission lines of these two samples, though a simple broad line region model would suggest significant differences. Our finding raises a challenge to the Doppler boost hypothesis for some of those BBHs candidates with optical periodicity.
Dust masses and grain size distributions of a sample of Galactic pulsar wind nebulae
Authors: Priestley F D , Barlow M J , De Looze I , Chawner H
Published: December 2019

We calculate dust spectral energy distributions (SEDs) for a range of grain sizes and compositions, using physical properties appropriate for five pulsar wind nebulae (PWNe) from which dust emission associated with the ejecta has been detected. By fitting the observed dust SED with our models, with the number of grains of different sizes as the free parameters, we are able to determine the grain size distribution and total dust mass in each PWN. We find that all five PWNe require large ($\ge 0.1 \, {\rm \mu m}$) grains to make up the majority of the dust mass, with strong evidence for the presence of micron-sized or larger grains. Only two PWNe contain non-negligible quantities of small ($\lt 0.01 \, {\rm \mu m}$) grains. The size distributions are generally well-represented by broken power laws, although our uncertainties are too large to rule out alternative shapes. We find a total dust mass of $0.02\rm {-}0.28 \, {\rm M}_\odot$ for the Crab Nebula, depending on the composition and distance from the synchrotron source, in agreement with recent estimates. For three objects in our sample, the PWN synchrotron luminosity is insufficient to power the observed dust emission, and additional collisional heating is required, either from warm, dense gas as found in the Crab Nebula, or higher temperature shocked material. For G54.1+0.3, the dust is heated by nearby OB stars rather than the PWN. Inferred dust masses vary significantly depending on the details of the assumed heating mechanism, but in all cases large mass fractions of micron-sized grains are required.
Temozolomide radiochemotherapy for high-grade glioma patients with hemodialysis: a case series of 7 patients
Authors: Muto Jun , Matsutani Tomoo , Matsuda Ryosuke , Kinoshita Masashi , Oikawa Mitsuteru , Pallud Johan , Sasaki Hikaru
Published: December 2019

Background

The pharmacokinetics of temozolomide (TMZ) in patients with severe renal impairments (creatinine clearance, <36 mL/min/m2) or in hemodialysis (HD) patients has not been investigated. TMZ and its metabolic products are mainly excreted in urine, as retention of these in the body may result in increased adverse events in HD patients.

Methods

Seven HD patients with high-grade gliomas from 6 institutions were included in the study. Patient characteristics, treatment schedule, clinical course, pathological/molecular findings, and adverse events were evaluated.

Results

The histopathological diagnoses were isocitrate dehydrogenase (IDH) wild-type glioblastoma in 4 cases, not other specified (NOS) glioblastoma in 2 cases, and IDH-mutant anaplastic astrocytoma in 1 case. Five of the 7 patients completed radiotherapy (48-60 Gy) with concomitant TMZ (75 mg/m2) followed by adjuvant 5-day TMZ (150 mg/m2) every 28 days. During the entire course of treatment with TMZ, severe (Common Terminology Criteria for Adverse Events [CTCAE] ≥ Grade 3) lymphocytopenia occurred in 57%, neutropenia in 0%, and thrombocytopenia in 14% of the patients. Generally, the frequency and degree of myelosuppression do not increase in HD patients with high-grade gliomas. Two of the 7 (28.5%) patients died of infectious disease despite having no direct correlation to myelosuppression; that is similar to the death rate of 21.9% resulting from infection in HD patients in Japan.

Conclusions

Decreasing the dose of TMZ might not be required in HD patients with high-grade gliomas during concomitant radiochemotherapy and maintenance therapy. However, careful clinical and hematological observation is required to avoid critical hematotoxicity and infection.
Portion size estimation in dietary assessment: a systematic review of existing tools, their strengths and limitations
Authors: Amoutzopoulos Birdem , Page Polly , Roberts Caireen , Roe Mark , Cade Janet , Steer Toni , Baker Ruby , Hawes Tabitha , Galloway Catherine , Yu Dove , Almiron-Roig Eva
Published: December 2019

Context

Overestimation or underestimation of portion size leads to measurement error during dietary assessment.

Objective

To identify portion size estimation elements (PSEEs) and evaluate their relative efficacy in relation to dietary assessment, and assess the quality of studies validating PSEEs.

Data Selection and Extraction

Electronic databases, internet sites, and cross-references of published records were searched, generating 16 801 initial records, from which 334 records were reviewed and 542 PSEEs were identified, comprising 5% 1-dimensional tools (eg, food guides), 46% 2-dimensional tools (eg, photographic atlases), and 49% 3-dimensional tools (eg, household utensils). Out of 334 studies, 21 validated a PSEE (compared PSEE to actual food amounts) and 13 compared PSEEs with other PSEEs.

Conclusion

Quality assessment showed that only a few validation studies were of high quality. According to the findings of validation and comparison studies, food image–based PSEEs were more accurate than food models and household utensils. Key factors to consider when selecting a PSEE include efficiency of the PSEE and its applicability to targeted settings and populations.