bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrafast spectroscopic investigation on fluorescent carbon nanodots: the role of passivation
Authors: Sciortino Alice , Gazzetto Michela , Soriano Maria Laura , Cannas Marco , Cárdenas Soledad , Cannizzo Andrea , Messina Fabrizio
Published: July 2019

Femtosecond spectroscopy allows to clarify the role of passivation on the fluorescence of carbon nanodots and reveals the lack of interplay between core and surface electronic states.
Fluorination on non-photolabile dppz ligands for improving Ru(ii) complex-based photoactivated chemotherapy
Authors: Boerhan Rena , Sun Weize , Tian Na , Wang Youchao , Lu Jian , Li Chao , Cheng Xuexin , Wang Xuesong , Zhou Qianxiong
Published: July 2019

Fluorination on the retaining ligand of Ru(ii) PACT agents enhanced phototoxicity but diminished dark cytotoxicity compared with the parent complex, more favorable for PACT application.
A nanoporous metal–organic framework as a renewable size-selective hydrogen-bonding catalyst in water
Authors: Liu Yanhong , Ma Ju , Wu Pengyan , Zheng Jia-Jia , Tian Xueqin , Jiang Min , He Yumei , Dong Han , Wang Jian
Published: July 2019

A new squaramide-containing nanoporous MOF as a bifunctional hydrogen-bond catalyst exhibits high size-selectivity and good renewability for a Michael addition reaction in water.
Correction: Dissolved organic matter in Lake Superior: insights into the effects of extraction methods on chemical composition
Authors: Li Hongyu , Minor Elizabeth C.
Published: July 2019

Correction for ‘Dissolved organic matter in Lake Superior: insights into the effects of extraction methods on chemical composition’ by Hongyu Li et al., Environ. Sci.: Processes Impacts, 2015, 17, 1829–1840.
Elemental analysis of copper alloys with laser-ablation spark-induced breakdown spectroscopy based on a fiber laser operated at 30 kHz pulse repetition rate
Authors: Jiang Yinhua , Li Runhua , Chen Yuqi
Published: July 2019

The analytical sensitivity of a compact LIBS system consisting of a fiber laser and a fiber spectrometer was successfully improved by the spark discharge.
Read-across predictions of nanoparticle hazard endpoints: a mathematical optimization approach
Authors: Varsou Dimitra-Danai , Afantitis Antreas , Melagraki Georgia , Sarimveis Haralambos
Published: July 2019

Development of a novel read-across methodology for the prediction of toxicity related endpoints of nanoparticles based on genetic algorithms.
Atomic structures of RNA nanotubes and their comparison with DNA nanotubes
Authors: Naskar Supriyo , Joshi Himanshu , Chakraborty Banani , Seeman Nadrian C. , Maiti Prabal K.
Published: July 2019

We present a computational framework to model RNA nanotubes with an underlying theoretical model to estimate their mechanical properties.
Two-dimensional layered materials: from mechanical and coupling properties towards applications in electronics
Authors: Zhan Hao , Guo Dan , Xie GuoXin
Published: July 2019

With the increasing interest in nanodevices based on two-dimensional layered materials (2DLMs) after the birth of graphene, the mechanical and coupling properties of these materials, which play an important role in determining the performance and life of nanodevices, have drawn increasingly more attention.
Bio-inspired immobilization of low-fouling phospholipid polymers via a simple dipping process: a comparative study of phenol, catechol and gallol as tethering groups
Authors: Cheng Bohan , Ishihara Kazuhiko , Ejima Hirotaka
Published: July 2019

Low-fouling phospholipid polymer was conjugated with bio-inspired tethering groups. Immobilization efficiencies of these polymers onto various surfaces were investigated.
The journey of self-healing and shape memory polyurethanes from bench to translational research
Authors: Menon Aishwarya V. , Madras Giridhar , Bose Suryasarathi
Published: July 2019

In this critical review, we have enlisted a comprehensive summary of different approaches that have been used over the past decade to synthesize self-healing polyurethanes including “close then heal” and “shape memory assisted self-healing” concept.
Facile synthesis of NF/ZnOx and NF/CoOx nanostructures for high performance supercapacitor electrode materials
Authors: Kumar Yedluri Anil , Reddy Araveeti Eswar , Bak Jin-Soo , Cho In-Ho , Kim Hee-Je
Published: July 2019

NF/ZnOx nanocone and NF/CoOx nanoparticle electrode materials were fabricated on a nickel foam surface using a simple chemical bath deposition approach and assessed as an electrode material for high-performance supercapacitors.
Synthesis of graphene quantum dot-stabilized gold nanoparticles and their application
Authors: Chen Weifeng , Shen Jialu , Chen Shaona , Yan Jiaying , Zhang Nuonuo , Zheng Kaibo , Liu Xiang
Published: July 2019

Herein, we report an in situ synthesis of graphene quantum dots (GQDs), which have been synthesized from only starch and water and stabilize AuNPs in water.
In vitro and in vivo evaluation of benzathine foscarnet microcrystals as a potential intravitreal drug depot
Authors: Wang Jiaxing , Tao Yong , Feng Jing , Niu Yidong , Liu Jichao , Huang Yanbin
Published: July 2019

Benzathine foscarnet microcrystals as a potential intravitreal drug depot.
Enzymatic characterization and molecular mechanism of a novel aspartokinase mutant M372I/T379W fromCorynebacterium pekinense
Authors: Gao Yunna , Han Caijing , Liu Chunlei , Wang Ji , Zhao Lan , Fang Li , Min Weihong
Published: July 2019

A novel aspartokinase mutant M372I/T379W fromCorynebacterium pekinensewas constructed by using site-directed mutagenesis.
Excellent microwave absorption properties based on a composite of one dimensional Mo2C@C nanorods and a PVDF matrix
Authors: Li Chao-Qin , Shen Xun , Ding Ruo-Cheng , Wang Guang-Sheng
Published: July 2019

A Mo2C@C/PVDF composite with excellent absorption performance has been synthesized. The results indicate that the maximum reflection loss can reach −39.0 dB, and the absorbing bandwidth is up to 3.1 GHz at a thickness of 2.0 mm.
Utilization of catecholic functionality in natural safrole and eugenol to synthesize mussel-inspired polymers
Authors: Alhaffar Mouheddin T. , Akhtar Mohammad N. , Ali Shaikh A.
Published: July 2019

Naturally occurring safroleIupon epoxidation gave safrole oxideII, which underwent polymerization using a Lewis acid initiator/catalyst of triphenylmethylphosphonium bromide/triisobutylaluminum to afford new polyetherIIIin excellent yields.
Cross-linked sulfonated poly(ether ether ketone) electrolytes bearing pendent imidazole groups for high temperature proton exchange membrane fuel cells
Authors: Jiang Jingjing , Zhu Xingye , Qian Huidong , Xu Jianfeng , Yue Zhouying , Zou Zhiqing , Yang Hui
Published: July 2019

A series of ionic-covalently cross-linked SPEEK bearing imidazole groups have been synthesized for high temperature fuel cells.
Photo actuation of liquid crystalline elastomer nanocomposites incorporated with gold nanoparticles based on surface plasmon resonance
Authors: Xu Jiaojiao , Chen Shuang , Yang Wenlong , Qin Ban , Wang Xiuxiu , Wang Yuchang , Cao Maosheng , Gao Yachen , Li Chensha , Dong Yinmao
Published: July 2019

We developed a nano-gold incorporated liquid crystalline elastomer nanocomposite which demonstrated significant photo actuation and nonlinear optic properties, and thus is potential in the application of smart devices and laser technologies.
Morphology controllable synthesis of PtNi concave nanocubes enclosed by high-index facets supported on porous graphene for enhanced hydrogen evolution reaction
Authors: Yang Juntao , Ning Guoqing , Yu Lei , Wang Yao , Luan Chenglong , Fan Aixin , Zhang Xin , Liu Yujie , Dong Yin , Dai Xiaoping
Published: July 2019

Morphology-controllable synthesis of PtNi CNCs enclosed by HIFs supported on PG for enhanced HER.
Unusual formation of hollow NiCoO2 sub-microspheres by oxygen functional group dominated thermally induced mass relocation towards efficient lithium storage
Authors: Wang Zhengluo , Denis Dienguila Kionga , Zhao Zhiwei , Sun Xuan , Zhang Jinyang , Hou Linrui , Yuan Changzhou
Published: July 2019

The unique oxygen functional group dominated thermally induced mass relocation strategy was first purposefully explored for controllable synthesis of uniform NiCoO2 hollow spheres with enhanced lithium-storage behaviors for LIBs.
Supramacromolecular injectable hydrogels by crystallization-driven self-assembly of carbohydrate-conjugated poly(2-isopropyloxazoline)s for biomedical applications
Authors: Nishimura Tomoki , Sumi Naoki , Mukai Sada-atsu , Sasaki Yoshihiro , Akiyoshi Kazunari
Published: July 2019

An approach for the fabrication of self-healing injectable hydrogels based on the crystallization-driven self-assembly of carbohydrate-conjugated poly(2-isopropyloxazoline)s is demonstrated.
Efficacy Study of a Social Communication and Self-Regulation Intervention for School-Age Children With Autism Spectrum Disorder: A Randomized Controlled Trial
Authors: Nowell Sallie W. , Watson Linda R. , Boyd Brian , Klinger Laura G.
Published: July 2019

Purpose

This study aimed to examine the initial efficacy of a parent-assisted blended intervention combining components of Structured TEACCHing and Social Thinking, designed to increase social communication and self-regulation concept knowledge in 1st and 2nd graders (
n
= 17) diagnosed with autism spectrum disorder (ASD) and their parents.

Method

A randomized delayed treatment control group design with pre- and postintervention assessments of both parents and children was implemented within a community practice setting. Two follow-up assessments at 3 and 6 months postintervention were also completed.

Results

Overall, results indicate that the intervention is efficacious in teaching social communication and self-regulation concept knowledge to children with ASD and their parents. Both parents and children demonstrated an increase in social communication and self-regulation knowledge after participating in the Growing, Learning, and Living With Autism Group as compared to a delayed treatment control group. The effects of the intervention did not extend to parent–child interactions coded from video recordings. Child treatment effects were maintained at the 3- and 6-month follow-up assessments.

Conclusions

Preliminary efficacy of the Growing, Learning, and Living With Autism Group was established. Based on parent report at the conclusion of the intervention, this is a socially valid intervention for teaching social communication and self-regulation skills to school-age children with ASD.

Supplemental Material

https://doi.org/10.23641/asha.8637236
Design of adaptive model predictive control for a class of uncertain non‐linear dynamic systems: stability, convergence, and robustness analysis
Authors: Bolandi Hossein , Saki Saman
Published: July 2019

Aside from relying on the robustness of the model predictive control (MPC) against model uncertainties, tracking performance degradation in the transient time is an inevitable challenge which is the main motivation of the adaptive MPC (AMPC). To that aim, in this study, a fast online identification scheme is suggested to identify a suitable linear state‐space model used in the control algorithm. Then, the authors prove the convergence of the identification error sequence using Lyapunov candidate function in the time domain and also, in the frequency domain (graph topology) point of view. Also, due to the dependency of the convergence error on the initial selection of the identification model, the authors introduce a stability and convergence ball as a function of generalised stability margin and the v‐gap criteria. Then, the stability and feasibility of the proposed AMPC is guaranteed when using the identified linear model at each sampling time. Moreover, the identification error convergence applies a constraint on the MPC in which, with a suitable selection of the update rate, MPC cost function is been relaxed from the constraint. In the simulations, the authors consider two examples of highly non‐linear dynamic systems. In both cases the proposed control strategy gives satisfactory conclusions.
Meta‐surface enabled hepta‐band compact antenna for wearable applications
Authors: Alam Maksud , Siddique Mainuddin , Kanaujia Binod K. , Beg Mirza T. , Kumar Sachin , Rambabu Karumudi
Published: July 2019

This study proposes a new hepta‐band antenna that consists of an inductive ground plane and slots loaded patch for the multiband body‐worn scenario. The phase distribution is optimised by considering a 7 × 7 array of periodic square patches on the metallic ground‐backed substrate in such a way that resonant modes of patch slots interact with the resonant modes of meta‐resonators of inductive ground to achieve hepta‐band behaviour with desired radiation characteristics. Each unit cell corresponds to a phase shift of 3.6° out of available phase distribution of 180°. The seven bands are targeted at 1.8, 2.45, 2.96, 3.5, 3.8, 4.2, and 4.5 GHz which supports GSM (1.8 GHz), WLAN (2.4 GHz), LTE (2.5 GHz), Wi‐MAX (3.5 GHz), sub‐6 GHz 5G band (3.4‐4.2 GHz), navigation (2.96 GHz), and satellite (4.5 GHz) applications. It is also demonstrated that an inductive ground plane can be used to get reduced SAR and increased FBR, making antenna useful for wearable applications. The proposed antenna has a patch size of 28.84 × 28.84 mm upon a 0.4 mm thick substrate of permittivity 4.3. Inductive ground is made of via‐free periodic square patches each of size 5 × 5 mm on the 2.6 mm thick metallic ground‐backed substrate.
Ship detection and recognition combing one‐dimensional range profile with SAR image
Authors: Li Yang , Cheng Miaomiao , Peng Xiangjun , Zhuo Bangsheng , Li Feng
Published: July 2019

Target detection and recognition are two important parts in image processing. As it is known to authors, target detection in synthetic aperture radar (SAR) image is usually processed on two‐dimension, which is more complex than one‐dimension. Here, the target detection in SAR image is achieved by two levels of one‐dimensional target detection. Then, the range profiles of the suspected targets are obtained while the target region is detected. Based on the obtained range profiles, features are extracted and the classifier is used to distinguish the targets and others. Finally, a method of target recognition based on mid‐level features is used here. Authors’ method is applied on SAR ship data and the result shows that authors’ proposed method works well on target detection.
Near‐space hypersonic target coherent integration algorithm based on search compensation
Authors: Li Lin , Wang Guohong , Zhang Xiangyu , Xin Tingting
Published: July 2019

A near‐space hypersonic target coherent integration algorithm based on search compensation is proposed for the problem of range gate stride and Doppler extension. The algorithm first estimates the target radial velocity and Doppler rate by searching, and then completes coherent integration of echo signal via distance and phase compensation according to the estimated values. The simulation results show that the algorithm can effectively solve the problem of range gate stride and Doppler extension, suppress noise, and increase gain. The integration effect of the proposed algorithm is obviously superior to the classical moving target detection (MTD) algorithm.
Spectroscopic binaries RV Tauri and DF Cygni
Authors: Manick Rajeev , Kamath Devika , Van Winckel Hans , Jorissen Alain , Sekaran Sanjay , Bowman Dominic M. , Oomen Glenn-Michael , Kluska Jacques , Bollen Dylan , Waelkens Christoffel
Published: July 2019

Context. Some RV Tauri stars show a long-term photometric variability in their mean magnitudes. DF Cygni (DF Cyg), the only RV Tauri star in the original Kepler field, and the prototype RV Tauri (RV Tau) are two such stars.

Aims. The focus of this paper is on two famous but still poorly understood RV Tauri stars: RV Tau and DF Cyg. We aim to confirm their suspected binary nature and derive their orbital elements to investigate the impact of their orbits on the evolution of these systems. This research is embedded in a wider endeavour to study binary evolution of low- and intermediate-mass stars.

Methods. The high amplitude pulsations were cleaned from the radial-velocity data to better constrain the orbital motion, allowing us to obtain accurate orbital parameters. We also analysed the photometric time series of both stars using a Lomb-Scargle periodogram. We used Gaia Data Release 2 (DR2) parallaxes in combination with the spectral energy distributions (SEDs) to compute their luminosities. These luminosities were complemented with the ones we computed using a period-luminosity-colour (PLC) relation for RV Tauri stars. The ratio of the circumstellar infrared (IR) flux to the photospheric flux obtained from the SEDs was used to estimate the orbital inclination of each system.

Results. DF Cyg and RV Tau are binaries with spectroscopic orbital periods of 784 ± 16 days and 1198 ± 17 days, respectively. These orbital periods are found to be similar to the long-term periodic variability in the photometry, indicating that binarity indeed explains the long-term photometric variability. The SEDs of these systems indicate the presence of a circumbinary disc. Our line of sight grazes the dusty disc, which causes the photometric flux from the star to extinct periodically with the orbital period. Our derived orbital inclinations enabled us to obtain accurate companion masses for DF Cyg and RV Tau, and these were found to be 0.6 ± 0.1 M⊙ and 0.7 ± 0.1 M⊙, respectively. The derived luminosities suggest that RV Tau is a post asymptotic giant branch (post-AGB) binary, while DF Cyg is likely a post red giant branch (post-RGB) binary. Analysis of the Kepler photometry of DF Cyg revealed a power spectrum with side lobes around the fundamental pulsation frequency. This modulation corresponds to the spectroscopic orbital period and hence to the long-term photometric period. Finally we report on the evidence of high velocity absorption features related to the Hα profile in both objects, indicating outflows launched from around the companion.
Polarization reversal of scattered thermal dust emission in protoplanetary disks at submillimetre wavelengths
Authors: Brunngräber R. , Wolf S.
Published: July 2019

Investigation of the polarized light of protoplanetary disks is key for constraining dust properties, disk morphology, and embedded magnetic fields. However, different polarization mechanisms and the diversity of dust grain shapes and compositions lead to ambiguities in the polarization pattern. The so-called “self-scattering” of thermal, re-emitted radiation in the infrared and millimetre and submillimetre wavelengths is discussed as a major polarization mechanism. If the net flux of the radiation field is in the radial direction, it is commonly assumed that the polarization pattern produced by scattering in a protoplanetary disk shows concentric rings for disks seen in face-on orientation. We show that a change of 90° of the polarization vector orientation may occur and mimic the typical pattern of dichroic emission of dust grains aligned by a toroidal magnetic field in disks seen close to face-on. Furthermore, this effect of polarization reversal is a fast-changing function of wavelength and grain size, and is thus a powerful tool to constrain grain composition and size distribution present in protoplanetary disks. In addition, the effect may also provide unique constraints for the disk inclination, especially if the disk is seen close to face-on.
Estimate of intrinsic safety of capacitive circuits
Authors: Hladkov Oleksandr , Mnukhin Anatolii , Stasevich Rishard
Published: July 2019

A universal method has been developed and tested for computer estimate of intrinsic safety of inductive capacitive circuits, which takes into account the most hazardous discharge type by contact closure and the regression dependences are obtained of minimal igniting energy on discharge time in a capacitive circuit and the comparison is made of results with available experimental dependences. A regression equation is received which connects minimal igniting energy and discharge time as well as voltage of a capacitive circuit. The comparison of the results with available experimental dependencies is made. The intrinsic safety parameters are defined which leads to decrease of risk for explosion and freely burning fire in a coal mine.
An effective way to rock mass preparation on metallic and nonmetallic quarries Ukraine
Authors: Ishchenko Kostiantyn , Konoval Volodymyr , Lohvyna Liudmyla
Published: July 2019

A method in experimental studies and industrial-polygon particular conditions justifying the choice of a rational design of an explosive charge. The comparative results of the evaluation of the stress wave’s amplitudes studies and the character of crushing hard media from the explosion of the charge explosives-variable and constant cross section. The dependences of the particle size distribution of various designs explosive charges destroyed by the explosion are constructed. In industrial conditions, the rationale for the explosive boreholes location according to the massif structure. Adjusted boreholes location grid on rational parameters blasting unit, determined using a novel method of breaking rock complex structure. A new design of a combined borehole charge of variable cross section has been proposed. Industrial tests performed and evaluation of the effectiveness of the proposed method blasting locally fractured rocks and ore deposits on non-metallic minerals. Recommendations on their use are given.
Determination of the maximum allowable distance between the roller conveyors of a tubular belt conveyor
Authors: Kiriia Ruslan , Mishchenko Tamara
Published: July 2019

The article developed a mathematical model of the stress-strain state of a tubular conveyor belt filled with bulk load. In this case, the belt is considered as a thin elastic inextensible cylindrical shell, and the bulk load in the belt is in the limit state. A system of differential equilibrium equations for a tubular belt with a bulk load with respect to forces and bending moments in a belt was obtained, which, when simplified, was reduced to a fourth-order differential equation for belt deflections. Based on this mathematical model, analytical dependencies of the deflections of the tubular conveyor belt on the parameters of the conveyor, the radius and properties of the belt, as well as the properties of the bulk load are obtained and analyzed. As a result, the maximum allowable distance between the roller supports of the tubular conveyor is determined. It was found that the allowable distance between the roller bearings is directly proportional to the tension of the belt and inversely proportional to the square of the radius of the belt and the bulk weight of the load. The research results can be used in the design of tubular belt conveyors transporting bulk load.
Improving the criteria for choosing the strategies in management by geotechnical systems
Authors: Lapshyn Yevhen , Molchanov Robert , Blyuss Borys , Osadcha Nataliia
Published: July 2019

The conclusion has been made about the necessity to choose the optimal strategies for management by geotechnical systems, based on the analysis of geological faults, which are the main indicator of the mining and geological conditions that characterize the mineral deposits, as well as on the parameters for the infrastructure development of the underground space. The methodological peculiarity of solving the problems set is the use of game theory with modified criteria of Wald, maximax and Savage, since the manifestation of specific geological faults is probabilistic in nature. When choosing the optimal strategy, the average linear deviations of gains or risks are taken into account.
Optimizing service life of conveyor belts while transporting bulk load
Authors: Monastyrskyi Vitalii , Monastyrskyi Serhii , Mostovyi Borys
Published: July 2019

The paper considers problems concerning optimization of service life of a conveyor belt in terms of its bulk material loading. Statement of the problem of belt life optimization is in the determining minimum of difference between squared velocity of a conveyor belt and projection of horizontal component of the load velocity when it contacts a belt onto the belt motion plane. The problem was solved numerically taking into consideration the objective function, varied parameters, and their limitation. Cases of direct-flow loading and loading with the help of special devices with straight and curved trough profiles have been analyzed. Regularities of changes in the belt service life due to significant factors in terms of direct-flow loading and loading with special device have been obtained to perform comparative analysis of different variants in terms of similar value of the objective function. The variants with maximum belt life and minimum objective function have been selected. For short conveyors, in terms of direct-flow loading, belt life decreases by 1.5–2.0 times comparing to the use of a loading device, and in terms of long conveyors, it decreases by 5–6 times, if value of the objective function is 0.5–1.0 m2/s2.
Regularities of stress state of unsupported working occurring in a layered massif
Authors: Tiutkin Oleksii , Petrosian Nataliia , Radkevych Anatolii , Alkhdour Ahmad
Published: July 2019

The paper defines the regularities of stress state of unsupported working occurring in a layered massif. The relevance of the performed research is substantiated by the importance of determining the stresses of the contour of unsupported working when the elastic modulus of the matrix and the layer is varied. Since the application of analytic methods for this case is complex, we used a numerical finite element method, implemented in the SCAD. We developed a finite-element model of the above working, where the elastic moduli of the matrix and the layer varied greatly, while its position was unchanged (the layer laying in the middle of the working). The results of the numerical analysis allowed us to build the regularities of three stress components. In order to normalize cases of elastic modulus variation, a dimensionless χ -parameter is introduced which characterizes the relation between the elastic modulus of the matrix and the layer. The obtained regularities of the stress state of the χ-parameter have a functional character and allow to determine the stresses on the contour of the unsupportedworking, depending on the relation between the elastic moduli of the matrix and the layer for all possible spectrum of these parameters.
Method and equipment for the safe development of preparatory workings in the gas-bearing coal seams
Authors: Trokhymets Mykola , Maltseva Vira , Vialushkin Yehor , Antonchik Volodymyr , Moskalova Tetiana , Polushyna Maryna
Published: July 2019

The article describes a method and equipment for the safe development of preparatory working on a gas-bearing, outburst hazardous coal seam by a heading machine. The described method significantly prevents the gas emission during mining operations. Determination of the amount of degassing and relief wells is performed according to the given in article mathematical formulas. This ensures a significant increase in the level of safety processing the preparatory roadway on a gas-bearing, prone to outbursts coal seam by a heading machine. Due to this, the speed of conducting excavation increases and the cost of mining is reduced. The proportionality coefficients of the mathematical models were determined. Mathematical models are used to calculate the number of relief and degassing wells, which are drilled during the impulse hydraulic loosing of the nearby part of the coal seam. Also the duration of liquid injection into a coal seam is also determined. Mathematical models for calculating the number of injection, unloading and degassing boreholes can be used in development of the passports for conducting preparatory workings on a gas-bearing, prone to outburst coal seam by a heading machine with a preliminary impulse hydraulic loosing of the nearby part of a coal seam.
Modelling of mined rock thin layer disintegration taking into consideration its properties changing during compaction
Authors: Tytov Oleksandr , Haddad Jamil , Sukhariev Vitalii
Published: July 2019

The aim of the work is modelling of stressed condition of the loose mined rock thin layer between two parallel working plates of disintegrator, taking into consideration the dependences of the layer porosity and its side thrust coefficient on the main stress value with hereditary model of deformation accumulation. The equation of extreme balance of mined rock compactable thin layer is obtained for the case of its compression with partial sliding on working surfaces. It is shown, that there is no sliding in the central area of deformed zone, unlike the peripheral area. The iterative algorithm for parameters calculation of the layer stressed condition for the hypothesis of symmetric parabolic distribution of the axial normal stresses in the directions being perpendicular to the plates is developed. The distributions of the side thrust coefficient in the layer, the effective coefficient of external friction and the stresses of disintegrators working surfaces are grounded. The practical value of the research is the possibility to determine precisely the contact forces while crushing of fine-grained material taking into consideration its compactibility.
Investigation of the deformation characteristics of water-saturated coal samples with a hole for estimating the discharge of the reservoir during hydrolysis
Authors: Usov Oleh , Poliakov Yurii , Andriievska Liudmyla
Published: July 2019

The deformation characteristics of the uniaxial compression of the same sample with a central hole at different humidity are presented. The sample was saturated with water under pressure through the hole. The deformation curve has the form of a one-term power dependence. Increasing the humidity by 2 % reduces axial stresses by 3.2 times, and the modulus of elasticity - by 2.5 times with the same deformation.
Bonding energy and methane amount at the open surface of metamorphic coal
Authors: Vasilkovskyi Vsevolod , Minieiev Serhii , Kaluhina Nadiia
Published: July 2019

Objective of the studies is to measure and determine regularities of changes in adsorption and methane energy bond with the open surface of mineral carbons within metamorphism series. Donbas mineral carbons have been used as the samples. Volumetric method has been applied in the range of room temperatures and pressures of free methane phase (i.e. 0.015 to 3.5 MPa) to measure methane amount at the open surface of the mineral carbons. Depending upon changes in carbon content, adsorption behaviour is close to parabolic one: adsorption is maximal on the peripheries of metamorphic series, and minimal within its central part. For the first time, methane energy bond with the open surface of mineral carbons has been determined. In the context of the metamorphic series, bonding energy varies from 2 to 10 kJ/mol. Direct linear dependence of adsorption from pressure takes place for coal where carbon content is less than 76 %. It is the result of effect of large area of open surface of low-metamorphized coal. Inversely, nonlinear dependence is observed as for anthracite. The authors connect the fact with filling of all spaces at the open surface when gas phase pressure is 0.1 MPa.
Parameters of interaction of a hydro impulse device with a coalseam during its loosening
Authors: Vasyliev Dmytro
Published: July 2019

In the Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine (IGTM NAS of Ukraine), in order to improve the efficiency of hydro loosening in order to prevent sudden emissions of coal and gas, a method and device for impulse hydro loosening of coal seams are developed at the patent level. The device is based on the principle of periodic cavitation and is equipped with means for monitoring and controlling pressure in the filter cavity of the well – backwater pressure. Laboratory studies have established that the device provides maximum values of the range of pressure fluctuations at low values of the backwater. The backwater is formed by the hydraulic pressure necessary for the development of shear cracks. A method for calculating this pressure in order to compare its values with rational backwater values has been developed. In addition, the device has a backwater pressure control mechanism for bringing the device to a rational mode of its operation.
Some important aspects of rock mechanics and geomechanics
Authors: Voloshyn Oleksii , Riabtsev Oleh
Published: July 2019

This work considers the analysis of important aspects of rock mechanics, such as the variability of the mechanical properties of rocks under the samples testing, the continuity of the rock mass and the deformation beyond the elastic limit, which have a great influence on the accuracy and reliability when conducting geomechanical studies of the rock mass during coal mining. The main methods for solving geomechanical problems are shown.
Endoskopische Vakuumtherapie bei infizierter walled-off Pankreasnekrose
Authors: Triller Carsten
Published: July 2019

Die nekrotisierende Pankreatitis ist nach wie vor eine therapeutische Herausforderung. 38 % der Fälle münden in ein frühes Organversagen, 15 % führen zum Tod. Interventionen werden in 38 % der Fälle nötig 1. Aufgrund geringerer Mortalität gegenüber der klassischen offenen chirurgischen Vorgehensweise sind endoskopische und chirurgische minimalinvasive Methoden etabliert 2. Die endoskopische Vakuumtherapie kann hier eine Ergänzungsmethode darstellen, zu der bisher nur wenige Fallbeschreibungen existieren. Ein fester Stellenwert gegenüber den Standardverfahren wie endoskopischer Nekrosektomie mit Lavage besteht derzeit noch nicht (vgl. ESGE-Guideline „Endoscopic management of acute necrotizing pancreatitis“, 2018; Abschnitt 4.2.8) 1.

Der vorliegende Fall beschreibt eine erfolgreiche endoskopische Vakuumtherapie bei infizierter walled-off Pankreasnekrose unter Verwendung einer modifizierten Drainagefolie in Ergänzung zur Standardmethode der endoskopischen Nekrosektomie.
Effects of Various Work-to-rest Ratios during High-intensity Interval Training on Athletic Performance in Adolescents
Authors: Seo Myong-Won , Lee Jung-Min , Jung Hyun Chul , Jung Sung Woo , Song Jong Kook
Published: July 2019

To examine the effect of high-intensity interval training (HIIT) with different work-to-rest ratios on athletic performance in athletes. Forty-seven male Taekwondo athletes (aged 15–18 yrs) were randomly assigned into 3 HIIT groups and a control group. Each group performed 6 and 8 bouts of HIIT: 1) 1:2 (30:60 s), 2) 1:4 (30:120 s), and 3) 1:8 (30:240 s) groups while the control group performed only Taekwondo training program. All HIIT groups completed 10 sessions over 4 weeks. Athletic performance tests including VO2max test, Wingate anaerobic test, vertical jump, and agility T-test were measured at both pre- and post-tests. Two-way repeated measures ANOVA were applied to examine the performance changes between protocols. VO2max improved significantly in all HIIT groups (p<0.01), and the post-hoc test indicated that the only 1:4 group showed significant improvement compared to the control group. The HIIT with 1:4 ratio showed the effective protocol for enhancing anaerobic capacity including relative peak and mean power compared to control (p<0.01). Ten sessions of HIIT involving the 1:4 group, lasting over a brief 4-week period revealed the effective protocol for enhancing both aerobic and anaerobic capacity. Our findings provide practical implications to develop a performance-enhancing program specialized for adolescent Taekwondo athletes.
Improvements of C–H Radio-Iodination of N-Acylsulfonamides toward Implementation in Clinics
Authors: Dubost Emmanuelle , Babin Victor , Benoist Florian , Hébert Alexandra , Pigrée Gilbert , Bouillon Jean-Philippe , Fabis Frédéric , Cailly Thomas
Published: July 2019

An improved protocol to perform C–H radio-iodination is described. These new conditions allow rapid and clean formation of radio-iodinated N-acylsulfonamides using [125I]NIS and catalytic amounts of palladium acetate and para-toluenesulfonic acid. No pre-functionalized precursors are required and the products are obtained with radiochemical conversions (RCC) of 27–84%.
Willgerodt-Type Dichloro(aryl)-λ3-Iodanes: A Structural Study
Authors: Sarie Jérôme C. , Neufeld Jessica , Daniliuc Constantin G. , Gilmour Ryan
Published: July 2019

Crystallographic structural analysis of four electronically diverse Willgerodt-type reagents is disclosed together with a solution-phase NMR analysis. These data reveal a plethora of intermolecular non-covalent interactions and confirm the expected T-shape geometry of the reagents. In all cases the I–Cl bonds are orthogonal to the plane of the aryl ring. This study provides important structural insights into this venerable class of dichlorination reagent and has implications for crystal engineering.
Outcomes in Patients with a Calipered Kinematically Aligned TKA That Already Had a Contralateral Mechanically Aligned TKA
Authors: Shelton Trevor J. , Gill Manpreet , Athwal Gurbir , Howell Stephen M. , Hull Maury L.
Published: July 2019

Prior studies suggest kinematically aligned (KA) total knee arthroplasty (TKA) provides some clinical benefits. There are no reports of self-reported outcome measures in patients treated with a calipered KA TKA that already had a contralateral mechanically aligned (MA) TKA. We performed a retrospective study and asked the following questions: (1) Were you satisfied with your MA TKA when you were treated with the KA TKA? (2) What are the Forgotten Joint Scores (FJS) and Oxford Knee Scores (OKS) in each of your knees? (3) Do you favor one knee? and (4) Did one knee recover faster? From January 2013 to January 2017, 2,378 consecutive primary TKAs were performed of which all were treated with calipered KA that uses serial verification checks incorporating measurements of bone resections and positions to restore the prearthritic or native joint lines accurately. A records review identified patients with a prior primary MA TKA in the contralateral limb. Excluded were those with a history of fracture, osteotomy, infection, or revision knee surgery in either limb. In September 2018, 78 patients (57 females) with a mean age of 73 years (range, 50–91 years) completed a follow-up evaluation consisting of the FJS and OKS questionnaires and three anchor questions. A total of 83% of patients were satisfied with the MA TKA and 92% were satisfied with the KA TKA. The KA TKA had a 15 point higher median FJS and a comparable OKS to that of the MA TKA. Also, 56% of patients favored the KA TKA, and 8% favored the MA TKA. Seventy four percent of patients favored the recovery of the KA TKA, and 6% favored the recovery of the MA TKA. Accordingly, a patient considering a contralateral KA TKA can expect that more often than not the KA TKA will have a higher FJS, a similar OKS, be their favorite knee, and recover faster. Present study is therapeutic and reflects level IV evidence.
In-Hospital Complications following Arthrotomy versus Arthroscopy for Septic Knee Arthritis: A Cohort-Matched Comparison
Authors: Kerbel Yehuda E. , Lieber Alexander M. , Kirchner Gregory J. , Stump Natalie N. , Prodromo John P. , Petrucelli Philip M. , Shah Mitesh P. , Brahmabhatt Shyam
Published: July 2019

There is a paucity of literature comparing the relative merits of open arthrotomy versus arthroscopy for the surgical treatment of septic knee arthritis. The primary goal of this study is to compare the risk of perioperative complications between these two surgical techniques. To this end, 560 patients treated for septic arthritis of the native knee with arthroscopy were statistically matched 1:1 with 560 patients treated with open arthrotomy. The outcome measures included major complications, minor complications, mortality, inpatient hospital charges, and length of stay (LOS). Major complications were defined as myocardial infarction, cardiac arrest, stroke, deep vein thrombosis, pulmonary embolism, pneumonia, postoperative shock, unplanned ventilation, deep surgical site infection, wound dehiscence, infected postoperative seroma, hospital acquired urinary tract infection, and retained surgical item. Minor complications included phlebitis and thrombophlebitis, postprocedural emphysema, minor surgical site infection, peripheral nerve complication, and intraoperative hemorrhage. Mortality data were extracted from the database using the Uniform Bill patient disposition. Complications were analyzed using univariate and multivariate logistic regression models, whereas mean costs and LOS were compared using the Kruskal–Wallis H-test. Major complications occurred in 3.8% of the patients in the arthroscopy cohort and 5.4% of the patients in the arthrotomy cohort (p = 0.20). Too few patients in our sample died to report based on National (Nationwide) Impatient Sample (NIS) minimum reporting standards. Rates of minor complications were similar for the arthroscopy and arthrotomy cohorts (12.5 vs. 13.9%; p = 0.48). Multivariate analysis did not reveal any greater risk of minor or major complication between the two procedures. Inpatient hospital cost was similar for arthroscopy (

 = $15,917; standard deviation [SD] = 14,424) and arthrotomy (

 = $16,020; SD = 18,665; p = 0.42). LOS was also similar for both arthrotomy (6.78 days, SD = 6.75) and arthroscopy (6.24 days, SD = 5.95; p = 0.23). Patients undergoing arthroscopic treatment of septic arthritis of the knee showed no difference in relative risk of perioperative complications, LOS, or hospital cost compared with patients who underwent open arthrotomy.
The development of ancient Chinese agricultural and water technology from 8000 BC to 1911 AD
Authors: Wu Shuanglei , Wei Yongping , Head Brian , Zhao Yan , Hanna Scott
Published: July 2019

Technology developments have made significant impacts on both humans and the environment in which they live. However, there is limited whole-of-system understanding of ancient technology development. This paper aims to uncover the evolutionary pattern of the ancient Chinese agricultural technology system that focused on land and water mobilisations from 8000 BC to 1911 AD. Our findings show that agricultural technology in China transitioned through an extremely slow, S-shaped pathway, increasing only ten fold in over 8000 years. The technology system was initially driven by tangible tools (40% of growth), then by technological theories and practices that contributed more than 50% of growth. Its development was spatially inclined to the Yellow River then to the Yangtze River region, where over 45% of technologies were developed. This study provides an empirical baseline for comparative studies between pre-industrial and industrial technologies. Greater understanding of the mechanisms of technology development will be required to reorientate technology development for present and future generations.
Experimental study of forestry waste gasification: Pinewood chips-grass mixtures
Authors: Palencia Díaz Argemiro , Aguillón Martínez Javier Eduardo
Published: July 2019

An experimental study of forestry waste gasification using pinewood and pinewood-grass mixtures was carried out. The analyzed mixture concentrations of pinewood and grass were 90%–10%, 80%–20%, and 70%–30% (weight based). The study was performed using a laboratory-scale updraft gasifier as the reactor, and air was used as the gasifying agent. Experimental tests were carried out to investigate the influence of the equivalence ratio and the process temperature on gasification performance. The gas composition was analyzed using an infrared syngas analyzer for three levels of equivalence ratios (0.25, 0.30, and 0.34) and at temperatures between 800 °C and 1100 °C. The results showed that compared to 100% pinewood, 90% pinewood–10% grass (MX90%–10%) and 70% pinewood–30% grass (MX70%–30%), gasification of the 80% pinewood–20% grass (MX80%–20%) mixture improves carbon conversion and reduces the amount of char. In the process, a lower heating value ranging from 4.0 to 5.5 MJ/Nm3 was achieved for this mixture. Finally, a new strategy for forestry waste gasification was analyzed, and it was found that for all mixtures there were no significant changes in concentration profiles over the range of temperatures examined. The experimental results of this study will help improve the understanding of syngas production and show that gasification of forestry waste mixtures in an updraft gasifier can be an effective technology for syngas production.
Coherence and indistinguishability of highly pure single photons from non-resonantly and resonantly excited telecom C-band quantum dots
Authors: Nawrath C. , Olbrich F. , Paul M. , Portalupi S. L. , Jetter M. , Michler P.
Published: July 2019

The role of resonant pumping schemes in improving the photon coherence is investigated on InAs/InGaAs/GaAs quantum dots (QDs) emitting in the telecom C-band. The linewidths of transitions of multiple exemplary quantum dots are determined under above-band pumping and resonance fluorescence (RF) via Fourier-transform spectroscopy and resonance scans, respectively. The average linewidth is reduced from (9.74 ± 3.3) GHz in the above-band excitation to (3.50 ± 0.39) GHz under RF underlining its superior coherence properties. Furthermore, the feasibility of coherent state preparation with a fidelity of (49.2 ± 5.8)% is demonstrated, constituting a first step toward on-demand generation of coherent, single, telecom C-band photons directly emitted by QDs. Finally, two-photon excitation of the biexciton is investigated as a resonant pumping scheme. A deconvoluted single-photon purity value of gHBT(2)(0)=0.072 ± 0.104 and a postselected degree of indistinguishability of VHOM=0.894 ± 0.109 are determined for the biexciton transition. This represents another step in demonstrating the necessary quantum optical properties for prospective applications.
“Learning on a chip:” Microfluidics for formal and informal science education
Authors: Rackus Darius G. , Riedel-Kruse Ingmar H. , Pamme Nicole
Published: July 2019

Microfluidics is a technique for the handling of small volumes of liquids on the order of picoliters to nanoliters and has impact for miniaturized biomedical science and fundamental research. Because of its multi- and interdisciplinary nature (i.e., combining the fields of biology, chemistry, physics, and engineering), microfluidics offers much potential for educational applications, both at the university level as well as primary and secondary education. Microfluidics is also an ideal “tool” to enthuse and educate members of the general public about the interdisciplinary aspects of modern sciences, including concepts of science, technology, engineering, and mathematics subjects such as (bio)engineering, chemistry, and biomedical sciences. Here, we provide an overview of approaches that have been taken to make microfluidics accessible for formal and informal learning. We also point out future avenues and desired developments. At the extreme ends, we can distinguish between projects that teach how to build microfluidic devices vs projects that make various microscopic phenomena (e.g., low Reynolds number hydrodynamics, microbiology) accessible to learners and the general public. Microfluidics also enables educators to make experiments low-cost and scalable, and thereby widely accessible. Our goal for this review is to assist academic researchers working in the field of microfluidics and lab-on-a-chip technologies as well as educators with translating research from the laboratory into the lecture hall, teaching laboratory, or public sphere.