bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of axial and coronal acquisitions by non-contrast-enhanced renal 3D MR angiography using flow-in time-spatial labeling inversion pulse
Authors: Takahashi Junji , Ohmoto-Sekine Yuki , Yoshida Takashi , Miyazaki Mitsue
Published: December 2019

Objective

We evaluated image quality differences between axial and coronal non-contrast-enhanced renal three-dimensional (3D) magnetic resonance angiography (MRA) acquisitions, using time-spatial labeling inversion pulse (Time-SLIP) with flow-in balanced steady-state free precession (bSSFP).

Materials and methods

Axial and coronal images were acquired in 128 subjects using non-contrast-enhanced 3D-MRA with Time-SLIP flow-in bSSFP on a clinical 1.5-T MRI system. Visualization of source and maximum intensity projection (MIP) images of renal arteries were compared between the axial and coronal acquisitions using a four-point scale. For quantitative analysis, vessel-to-background contrast ratios of aorta and renal arteries were calculated.

Results

Both acquisitions yielded similarly excellent quality. In source image evaluation, coronal acquisitions showed significantly more motion degradation (p < 0.01) than did axial acquisitions. In MIP image evaluation, coronal acquisitions yielded superior image quality, less motion degradation, and better visualization of the number of renal branches than did axial acquisition. The renal artery to background signal contrast was greater in coronal than in axial acquisitions (p < 0.01).

Conclusion

Coronal acquisition provides superior contrast between the renal arteries and background and allows more persistent visualization than axial acquisitions in non-contrast-enhanced MRA using flow-in bSSFP with Time-SLIP. First-line screening of renal non-contrast-enhanced MRA should involve coronal acquisition.
Microfibrillated lignocellulose (MFLC) and nanopaper films from unbleached kraft softwood pulp
Authors: Oliaei Erfan , Lindén Pär A. , Wu Qiong , Berthold Fredrik , Berglund Lars , Lindström Tom
Published: December 2019

Microfibrillated cellulose (MFC) is an important industrial nanocellulose product and material component. New MFC grades can widen the materials property range and improve product tailoring. Microfibrillated lignocellulose (MFLC) is investigated, with the hypothesis that there is an optimum in lignin content of unbleached wood pulp fibre with respect to nanofibril yield. A series of kraft fibres with falling Kappa numbers (lower lignin content) was prepared. Fibres were beaten and fibrillated into MFLC by high-pressure microfluidization. Nano-sized fractions of fibrils were separated using centrifugation. Lignin content and carbohydrate analysis, total charge, FE-SEM, TEM microscopy and suspension rheology characterization were carried out. Fibres with Kappa number 65 (11% lignin) combined high lignin content with ease of fibrillation. This confirms an optimum in nanofibril yield as a function of lignin content, and mechanisms are discussed. MFLC from these fibres contained a 40–60 wt% fraction of nano-sized fibrils with widths in the range of 2.5–70 nm. Despite the large size distribution, data for modulus and tensile strength of MFLC films with 11% lignin were as high as 14 GPa and 240 MPa. MFLC films showed improved water contact angle of 84–88°, compared to neat MFC films (< 50°). All MFLC films showed substantial optical transmittance, and the fraction of haze scattering strongly correlated with defect content in the form of coarse fibrils.

Graphic abstract
Sevoflurane Induces Learning and Memory Impairment in Young Mice Through a Reduction in Neuronal Glucose Transporter 3
Authors: Zhu Jinpiao , Zhang Zongze , Jia Junke , Wang Lirong , Yang Qiuyue , Wang Yanlin , Chen Chang
Published: December 2019

Sevoflurane, which is widely used in paediatric anaesthesia, induces neural apoptosis in the developing brain and cognitive impairment in young mammals. Glucose hypometabolism is the key pathophysiological modulator of cognitive dysfunction. However, the effects and mechanism of sevoflurane on cerebral glucose metabolism after its use as an anaesthetic and its complete elimination are still unknown. We therefore investigated the influence of sevoflurane on neuronal glucose transporter isoform 3 (GLUT3) expression, glucose metabolism and apoptosis in vivo and in vitro and on neurocognitive function in young mice 24 h after the third exposure to sevoflurane. Postnatal day 14 (P14) mice and neural cells were exposed to 3% sevoflurane 2 h daily for three days. We found that sevoflurane anaesthesia decreased GLUT3 gene and protein expression in the hippocampus and temporal lobe, consistent with a decrease in glucose metabolism in the hippocampus and temporal lobe observed by [18F] fluorodeoxyglucose positron emission tomography (18F-FDG PET). Moreover, sevoflurane anaesthesia increased the number of TUNEL-positive cells and the levels of Bax, cleaved caspase 3 and cleaved PARP and reduced Bcl-2 levels in the hippocampus and temporal lobe. Young mice exposed to sevoflurane multiple times also showed learning and memory impairment. In addition, sevoflurane inhibited GLUT3 expression in primary hippocampal neurons and PC12 cells. GLUT3 overexpression in cultured neurons ameliorated the sevoflurane-induced decrease in glucose utilization and increase in the apoptosis rate. These data indicate that GLUT3 deficiency may contribute to sevoflurane-induced learning and memory deficits in young mice.
Correlation Between Subjective Happiness and Pleasant Activities at Workplace in Nursing Staff for Older Individuals in Japan
Authors: Takeda Shinya , Nakayama Shigeki , Uddin Md. Sahab , Hiramoto Atsumi , Inoue Masahiko
Published: December 2019

The purpose of this study was to investigate the correlations between nursing staff’s mental health, number of years worked, night shifts performed, and pleasant activities at the workplace. One hundred forty-three subjects who had no missing data were analyzed. Questions consisted of basic attributes, subjective happiness scale (SHS), and pleasant activities conducted at the workplace. Denouements of SHS indicated a significant trend for the main effect, with more pleasant activities in the high SHS group than the low SHS group. The interaction was significant, with fewer pleasant activities in participants in the low SHS group who worked the night shift compared with those who worked the night shift regardless of work experience. The outcomes of this study suggest that it is essential to expand the repertoire of pleasant activities at the workplace to increase the subjective happiness of nursing staff for older individuals.
Serum-free media for the growth of primary bovine myoblasts
Authors: Kolkmann A. M. , Post M. J. , Rutjens M. A. M. , van Essen A. L. M. , Moutsatsou P.
Published: December 2019

The demand for meat is expected to exceed production capacity by livestock in the coming decennia. Therefore, cultured beef might be a viable alternative to traditional livestock-derived beef. One of the problems however is the sustainability of cultured beef through the use of fetal bovine serum. We aimed to identify a serum-free medium or a serum-replacement that is as effective as the current method used for culturing bovine myoblasts. Cells were harvested from a female Blanc Bleu Belge cow and myoblasts were subsequently isolated. Cells were cultured in either Advanced DMEM containing 20% FBS and 10% HS or one of the chemically-defined, serum-free media for 6 days. MTS was used as a measure of cell proliferation at day 1, 4 or 6 and microscopic pictures were taken to assess cell morphology. FBM™, TesR™ and Essential 8™ are commercially available xeno-free media developed for human PSCs and fibroblasts, with the highest potential to sustain bovine myoblast proliferation. Of the supplements tested, XenoFree™ and a custom-prepared growth factor mix failed to stimulate cell proliferation. LipoGro™ stimulated cell proliferation in some cases but also changed the phenotype of myoblasts to an adipocyte-like phenotype. We conclude that serum-free media stimulate exponential cell expansion, albeit not to the extent of the current growth medium containing up to 30% serum. Further research is needed to investigate whether prolonged cell culture or an adaptation period could further increase cell proliferation.
On the relation between reactive synthesis and supervisory control of non-terminating processes
Authors: Schmuck Anne-Kathrin , Moor Thomas , Majumdar Rupak
Published: December 2019

Reactive synthesis and supervisory control theory both provide a design methodology for the automatic and algorithmic design of digital systems from declarative specifications. The reactive synthesis approach originates in computer science, and seeks to synthesise a system that interacts with its environment over time and that, doing so, satisfies a prescribed specification. Here, the distinguishing feature when compared to other synthesis problems in computer science is that the interaction is temporal in that it explicitly refers to a sequence of computation cycles. Supervisory control originates in control theory and seeks to synthesise a controller that – in closed-loop configuration with a plant – enforces a prescribed specification over time. The distinguishing feature compared to other branches of control is that all dynamics are driven by discrete events as opposed to continuous signals. While both methods apparently are closely related, the technical details differ significantly. We provide a formal comparison which allows us to identify conditions under which one can solve one synthesis problem using methods from the other one; we also discuss how the resulting solutions compare. To facilitate this comparison, we give a unified introduction to reactive synthesis and supervisory control and derive formal problem statements and a characterisation of their solutions in terms of ω-languages. Recent contributions to the two fields address different aspects of the respective problem, and we expect the formal relationship identified in this paper to be useful in that it allows the application of algorithmic techniques from one field in the other.
A research of analysing the effectiveness of speaking-pen on English learning in consideration of individual differences using a linear mixed-effect model
Authors: Tsubak Michiko , Maeda Yoshihiro
Published: December 2019

The Ministry of Education, Culture, Sports, Science and Technology in Japan (2011) started the ‘Foreign Language Activities’ in fifth grade based on the new Courses of Study in April of 2011. The ministry has considered beginning this course in third grade and the ‘English Course’ in 5th grade in order to improve students’ reading, writing, listening, and speaking skills. The ministry also developed supplemental teaching instruments, such as the CALL system. The purpose of this study is to model and analyse the effectiveness of a speaking-pen on English learning among elementary school children in consideration of individual differences using a Liner Mixed-Effect Model. The authors constructed models representing students’ overall abilities in four English skills, and analysed the effectiveness of the tools such as a speaking-pen and an audio CD on English learning in consideration of students’ backgrounds including their English learning experiences and individual differences.
Empathy, honour, and the apprenticeship of violence: rudiments of a psychohistorical critique of the individualistic science of evil
Authors: Bullot Nicolas J.
Published: December 2019

Research seeking to explain the perpetration of violence and atrocities by humans against other humans offers both social and individualistic explanations, which differ namely in the roles attributed to empathy. Prominent social models suggest that some manifestations of inter-human violence are caused by parochial attitudes (attitudes characterized by interests centred on one's own community) and obedience reinforced by within-group empathy. Individualistic explanations of violence, by contrast, posit that stable intra-individual characteristics of the brain and personality of some individuals lead them to commit violence and atrocities. An individualistic explanation argues that the chief cause of violence is the perpetrator’'s lack of empathy with the victim. To offer the rudiments of a critique of the individualistic approach, I critically examine a model stating that violence is caused by empathy erosion (Baron-Cohen 2011). Specifically, the discussion of the empathy-erosion model is applied to the case of honour-based violence (HBV), a type of violence known for its communal character. Building from prior enquiries into violence and social cognition, I argue that an empathy-erosion explanation of HBV is defective because it does not consider important cultural and historical enablers of violence. Finally, as an alternative to individualism, I propose a psychohistorical approach to HBV in the migration context. This alternative combines psychological and philosophical enquiry with historical and ethnographical analysis. The psychohistorical approach hypothesises that distinct processes of cultural learning of honour codes both scaffold HBV and modulate the perpetrators’ emotions and empathy.
Design and analysis of a class of redundant collaborative manipulators with 2D large rotational angles
Authors: Jin Xiaodong , Fang Yuefa , Zhang Dan , Luo Xueling
Published: December 2019

The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to construct 2D rotational degrees of freedom (DOFs), a platform with 2D revolute joints is proposed first. Based on the constraint screw theory, the feasible limbs that can be connected in the platform are synthesized. In order to provide constant rotational axis for the platform, a class of redundant limbs are designed. A class of redundant 2R1T parallel spindle heads is obtained by connecting the redundant limbs with the platform and the redundant characteristics are verified by the modified Grübler-Kutzbach criterion. The corresponding 5-axis collaborative manipulators are presented by constructing a 2-DOF series translational bottom moving platform. The inverse kinematics and the orientation workspace as well as the decoupling characteristics of this type of 2R1T parallel spindle heads are analyzed. The results show that these manipulators have large 2D rotational angles than the traditional A3/Z3 heads and can be potentially used in the application of multi-axis machine tools and the 3D printers.
Electronic Nose and Its Applications: A Survey
Authors: Karakaya Diclehan , Ulucan Oguzhan , Turkan Mehmet
Published: December 2019

In the last two decades, improvements in materials, sensors and machine learning technologies have led to a rapid extension of electronic nose (EN) related research topics with diverse applications. The food and beverage industry, agriculture and forestry, medicine and health-care, indoor and outdoor monitoring, military and civilian security systems are the leading fields which take great advantage from the rapidity, stability, portability and compactness of ENs. Although the EN technology provides numerous benefits, further enhancements in both hardware and software components are necessary for utilizing ENs in practice. This paper provides an extensive survey of the EN technology and its wide range of application fields, through a comprehensive analysis of algorithms proposed in the literature, while exploiting related domains with possible future suggestions for this research topic.
Ethnobotany of Hawaiian figure sculpture
Authors: Rudall Paula J. , Cartwright Caroline R.
Published: December 2019

Anecdotal theories about traditional uses of Polynesian woods in relation to social and religious practices were tested using comparative wood identification. The woods used to make 135 figure carvings from the Hawaiian archipelago were identified and compared with 23 figure carvings from elsewhere in Polynesia (especially Tahiti and the Marquesas). Prior to this study, the majority of Hawaiian images were believed to have been made from wood ofMetrosideros polymorpha, the commonest forest tree on the archipelago. The results confirm thatMetrosideroswas relatively popular in Hawaii (13% of Hawaiian carvings, compared with 4% in central and south-eastern Polynesia). However, more unexpectedly, over 18 different genera were utilized for figure carvings in Hawaii. The genusCordiaaccounted for 20% of Hawaiian figure carvings identified here, compared with 26% elsewhere in Polynesia, andThespesiafor 4%, compared with 30% in Marquesas. Use of some woods, such as species ofAcacia, was not previously recorded for this purpose, including the first record ofArtocarpuswood for large Hawaiian temple images. Many species—especially those that were less popular for ritual figure carving—were also used for various other purposes, including food, canoe building and medicines. This study demonstrates that the early Polynesian settlers brought with them traditions of using certain trees, but also took advantage of elements of the extensive indigenous flora.
Inferences on the regression coefficients in panel data models: parametric bootstrap approach
Authors: Esmaeli-Ayan A. , Malekzadeh A. , Hormozinejad F.
Published: December 2019

This article presents a parametric bootstrap approach to inference on the regression coefficients in panel data models. We aim to propose a method that is easily applicable for implement hypothesis testing and construct confidence interval of the regression coefficients vector of balanced and unbalanced panel data models. We show the results of our simulation study to compare of our parametric bootstrap approach with other approaches and approximated methods based on a Monte Carlo simulation study.
Effects of calcium on the evolution of nitrogen during pyrolysis of a typical low rank coal
Authors: Lin Xiongchao , Yang Sasha , Chen Xujun , Zheng Panpan , Wang Yonggang , Zhang Shu
Published: December 2019

This study aims to investigate the effects of calcium on the migration of nitrogen in coal (coal-N) to N-containing gas species, particularly, NH3 and HCN (volatile-N) in volatiles, as well as the chemical transformation of the N in char during coal pyrolysis under different temperatures. The pyrolysis experiments of Shengli brown coal and its derived coal samples loaded with different contents of calcium were conducted under 600–800 °C in a novel fluidized bed reactor. The experimental results showed that during coal pyrolysis, the generation of NH3 is mainly derived from secondary reactions among volatiles, tar and char with the catalytic effect of mineral matter, especially calcium in coal. Increasing pyrolysis temperature from 600 to 800 °C could enhance the release of N in coal to volatiles. Meanwhile, the increased pyrolysis temperature could also inhibit the generation of NH3 while facilitating the formation of HCN. The release of HCN is more sensitive to pyrolysis temperatures. Specifically, under higher pyrolysis temperatures, more N-containing structures in coal would become thermally unstable and crack into HCN; On the other hand, higher pyrolysis temperature could also enhance the decomposition of N in coal to N-containing species in tar or N2, thus reducing the release of HCN and NH3. Nitrogen in tar could either undergo secondary decomposition reactions, generating NH3, HCN, N2 and other N-containing species in gas phase, or experience condensation polymerization by forming macromolecular structure and be retained in char at high pyrolysis temperatures. Calcium could significantly restrain the release of N from coal, thus reducing the yields of NH3 and HCN. During coal pyrolysis, calcium catalytically enhances the fracture and combination of chemical bonds, generating abundant free radicals. These free radicals could continuously attack N-containing structures and consequently release the N-containing gaseous products, such as NH3, HCN, N2 etc., resulting in the decrease of N in char. Calcium also plays important roles in nitrogen transformation in char during coal pyrolysis by catalytically intensifying the transformation of N in char from pyridinic nitrogen (N-6) and pyrrolic nitrogen (N-5) to quaternary type nitrogen (N-Q) during coal pyrolysis.
A practical application of game theory to optimize selection of hardware Trojan detection strategies
Authors: Graf Jonathan , Batchelor Whitney , Harper Scott , Marlow Ryan , Carlisle Edward , Athanas Peter
Published: December 2019

A wide variety of Hardware Trojan countermeasures have been developed, but less work has been done to determine which are optimal for any given design. To address this, we consider not only metrics related to the performance of the countermeasure, but also the likely action of an adversary given their goals. Trojans are inserted by an adversary to accomplish an end, so these goals must be considered and quantified in order to predict these actions. The model presented here builds upon a security economic approach that models the adversary and defender motives and goals in the context of empirically derived countermeasure efficacy metrics. The approach supports formation of a two-player strategic game to determine optimal strategy selection for both adversary and defender. A game may be played in a variety of contexts, including consideration of the entire design lifecycle or only a step in product development. As a demonstration of the practicality of this approach, we present an experiment that derives efficacy metrics from a set of countermeasures (defender strategies) when tested against a taxonomy of Trojans (adversary strategies). We further present a software framework, GameRunner, that automates not only the solution to the game but also mathematical and graphical exploration of “what if” scenarios in the context of the game. GameRunner can also issue “prescriptions,” a set of commands that allows the defender to automate the application of the optimal defender strategy to their circuit of concern. Finally, we include a discussion of ongoing work to include additional software tools, a more advanced experimental framework, and the application of irrationality models to account for players who make subrational decisions.
Noise in nanopore sensors: Sources, models, reduction, and benchmarking
Authors: Liang Shengfa , Xiang Feibin , Tang Zifan , Nouri Reza , He Xiaodong , Dong Ming , Guan Weihua
Published: December 2019

Label-free nanopore sensors have emerged as a new generation technology of DNA sequencing and have been widely used for single molecule analysis. Since the first α-hemolysin biological nanopore, various types of nanopores made of different materials have been under extensive development. Noise represents a common challenge among all types of nanopore sensors. The nanopore noise can be decomposed into four components in the frequency domain (1/f noise, white noise, dielectric noise, and amplifier noise). In this work, we reviewed and summarized the physical models, origins, and reduction methods for each of these noise components. For the first time, we quantitatively benchmarked the root mean square (RMS) noise levels for different types of nanopores, demonstrating a clear material-dependent RMS noise. We anticipate this review article will enhance the understanding of nanopore sensor noises and provide an informative tutorial for developing future nanopore sensors with a high signal-to-noise ratio.
Understanding Catchment‐Scale Forest Root Water Uptake Strategies Across the Continental United States Through Inverse Ecohydrological Modeling
Authors: Knighton James , Singh Kanishka , Evaristo Jaivime
Published: December 2019

Trees influence the partitioning of water between catchment water yield and evapotranspiration through mediation of soil water via root water uptake (RWU). Recent research has estimated the depth of RWU for a variety of tree species at plot scales with measurements of stable isotopes in water and sap flux. Though informative, there are some challenges bridging the gap between plot‐ and catchment‐scale water fluxes. We estimated catchment‐scale tree RWU behavior for 139 forested catchments across the continental United States from continuous streamflow records with inverse ecohydrological modeling. Our catchment‐scale RWU estimates agreed well with existing plot‐scale research. Monoculture catchments dense with trees reliant on shallow soil water exhibited reduced transpiration losses compared to deep‐rooted and mixed‐species forests within the Budkyo framework. This research highlights the importance of representing plant characteristics that define RWU control of transpiration in land surface and earth systems models.
Tropical Variability Simulated in ICON‐A With a Spectral Cumulus Parameterization
Authors: Baba Yuya , Giorgetta Marco A.
Published: December 2019

We implemented a spectral cumulus parameterization based on a cloud‐resolving model (SC scheme) in the icosahedral nonhydrostatic atmospheric model (ICON‐A). We compared the resulting simulated climatology and tropical variability with results from the standard version of ICON‐A using a variant of the Tiedtke‐Nordeng scheme (TK scheme) using observational and reanalysis data. The climatological errors of the SC scheme were similar to those of the TK scheme, but several biases, such as properties of meridional winds and precipitation pattern in the western Pacific, were much improved. For tropical variability, we found that the SC scheme improved the interannual response of the precipitation in the western Pacific and was able to simulate Madden‐Julian oscillation (MJO) features much better than the TK scheme. We investigated the reason for the better simulation of the MJO using composite analysis and column process analysis for moisture. Our results suggest that the entrainment parameterization of the SC scheme is necessary to reproduce the MJO; however, spectral representation and improved convective closure are also found to contribute for better MJO simulation. These parameterizations improved moisture supply from low‐level clouds and cloud mass flux which were needed to sustain the MJO.
An Energy Consistent Discretization of the Nonhydrostatic Equations in Primitive Variables
Authors: Taylor Mark A. , Guba Oksana , Steyer Andrew , Ullrich Paul A. , Hall David M. , Eldred Christopher
Published: December 2019

We derive a formulation of the nonhydrostatic equations in spherical geometry with a Lorenz staggered vertical discretization. The combination conserves a discrete energy in exact time integration when coupled with a mimetic horizontal discretization. The formulation is a version of Dubos and Tort (2014, https://doi.org/10.1175/MWR-D-14-00069.1) rewritten in terms of primitive variables. It is valid for terrain following mass or height coordinates and for both Eulerian or vertically Lagrangian discretizations. The discretization relies on an extension to Simmons and Burridge (1981, https://doi.org/10.1175/1520-0493(1981)109<0758:AEAAMC>2.0.CO;2) vertical differencing, which we show obeys a discrete derivative product rule. This product rule allows us to simplify the treatment of the vertical transport terms. Energy conservation is obtained via a term‐by‐term balance in the kinetic, internal, and potential energy budgets, ensuring an energy‐consistent discretization up to time truncation error with no spurious sources of energy. We demonstrate convergence with respect to time truncation error in a spectral element code with a horizontal explicit vertically implicit implicit‐explicit time stepping algorithm.
A self-delivery DNA nanoprobe for reliable microRNA imaging in live cells by aggregation induced red-shift-emission
Authors: Chen Zhe , Lu Jingxiong , Xiao Fan , Huang Yishun , Zhang Xuanjun , Tian Leilei
Published: December 2019

A Y-shape and pyrene-modified DNA self-assembly is developed to sensitively and specifically detect microRNA through a pyrene excimer–monomer switch.
Lattice and thermodynamic characteristics of N-stearoyl-allo-threonine monolayers
Authors: Brezesinski G. , Rudert R. , Vollhardt D.
Published: December 2019

The effect of the second chiral center of the enantiomeric and racemic forms of N-stearoyl-allo-threonine monolayers are studied on thermodynamic basis and molecular scale and compared with the corresponding threonines.
Structural responses of kiwifruit allergen Act d 2 to thermal and electric field stresses based on molecular dynamics simulations and experiments
Authors: Wang Jin , Vanga Sai Kranthi , Raghavan Vijaya
Published: December 2019

Kiwifruit is considered to be the most common plant-based food causing allergic reactions, after peanuts, soybeans, and wheat.
Mechanistic insights of the reduction of gold salts in the Turkevich protocol
Authors: Gao Yunhu , Torrente-Murciano Laura
Published: December 2019

The Turkevich protocol consists of two consecutive reduction steps (Au3+ → Au+ → Au0) rather than a reduction followed by the disproportionation reaction as conventionally believed. The second reduction is the rate-limiting step.
A combined experimental and computational study of NHC-promoted desulfonylation of tosylated aldimines
Authors: Sun Fang , Yin Tingrui , Wang Yang , Feng Anni , Yang Liuqing , Wu Wenchao , Yu Chenxia , Li Tuanjie , Wei Donghui , Yao Changsheng
Published: December 2019

NHC-catalyzed mild desulfonylation of tosylated aldimines provides efficient access to aryl nitriles with broad substrate scope. DFT calculations demonstrate that the reaction undergoes multiple stepwise processes.
Unconventionally fabricating defect-rich NiO nanoparticles within ultrathin metal–organic framework nanosheets to enable high-output oxygen evolution
Authors: Hu Qi , Huang Xiaowan , Wang Ziyu , Li Guomin , Han Zhen , Yang Hengpan , Ren Xiangzhong , Zhang Qianling , Liu Jianhong , He Chuanxin
Published: December 2019

A controllable calcination route was developed for the crafting ultrafine NiO nanoparticles within ultrathin Ni-based metal–organic frameworks (Ni-MOFs), which are highly efficient for oxygen evolution reaction.
Thermal and compositional driven relaxor ferroelectric behaviours of lead-free Bi0.5Na0.5TiO3–SrTiO3 ceramics
Authors: He Hongying , Lu Xin , Li Minchan , Wang Yumei , Li Zhenrong , Lu Zhouguang , Lu Li
Published: December 2019

The dielectric, piezoelectric and ferroelectric properties of (1 − x)(Bi0.5Na0.5)TiO3–xSrTiO3 ceramics are systematically studied to investigate their relaxor ferroelectric behaviours driven by thermal and compositional changes.
Improved strategy for human action recognition; experiencing a cascaded design
Authors: Khan Muhammad Attique , Akram Tallha , Sharif Muhammad , Muhammad Nazeer , Javed Muhammad Younus , Naqvi Syed Rameez
Published: December 2019

Human motion analysis has received a lot of attention in the computer vision community during the last few years. This research domain is supported by a wide spectrum of applications including video surveillance, patient monitoring systems, and pedestrian detection, to name a few. In this study, an improved cascaded design for human motion analysis is presented; it consolidates four phases: (i) acquisition and preprocessing, (ii) frame segmentation, (iii) features extraction and dimensionality reduction, and (iv) classification. The implemented architecture takes advantage of CIE‐Lab and National Television System Committee colour spaces, and also performs contrast stretching using the proposed red–green–blue* colour space enhancement technique. A parallel design utilising attention‐based motion estimation and segmentation module is also proposed in order to avoid the detection of false moving regions. In addition to these contributions, the proposed feature selection technique called entropy controlled principal components with weights minimisation, further improves the classification accuracy. The authors claims are supported with a comparison between six state‐of‐the‐art classifiers tested on five standard benchmark data sets including Weizmann, KTH, UIUC, Muhavi, and WVU, where the results reveal an improved correct classification rate of 96.55, 99.50, 99.40, 100, and 100%, respectively.
Two‐stage traffic sign detection and recognition based on SVM and convolutional neural networks
Authors: Hechri Ahmed , Mtibaa Abdellatif
Published: December 2019

Nowadays, traffic sign recognition is the most important task of advanced driver assistance systems since it improves the safety and comfort of drivers. However, it remains a challenging task due to the complexity of road traffic scenes. In this study, a novel two‐stage approach for real‐time traffic sign detection and recognition in a real traffic situation was proposed. The first stage aims to detect and classify the detected traffic signs into circular and triangular shape using HOG features and linear support vector machines (SVMs). The main objective of the second stage is to recognise the traffic signs using a convolutional neural network into their subclasses. The performance of the whole process is tested on German traffic sign detection benchmark (GTSDB) and German traffic sign recognition benchmark (GTSRB) datasets. Experimental results show that the obtained detection and recognition rate is comparable with those reported in the literature with much less complexity. Furthermore, the average processing time demonstrates its suitability for real‐time processing applications.
Intuitive control technique for grid connected partially shaded solar PV‐based distributed generating system
Authors: Kumar Nishant , Saxena Vardan , Singh Bhim , Panigrahi Bijaya Ketan
Published: December 2019

In this study, an intuitive control technique based on ‘fifth‐order generalised‐integrator (FOGI)’ is proposed for grid‐connected solar photovoltaic (PV) energy conversions system (SECS). In the grid‐tied SECS, a single‐phase single‐stage topology is considered. Moreover, on solar PV array, partially shaded condition is considered, where for global maximum power point tracking, the human psychology optimisation is utilised. The prime intention of the control technique is, feed all the generated solar power at the unity power factor into the grid, which is successfully achieved by the FOGI‐based control method. During the evaluation of the performance of control based on FOGI, different adverse conditions related to the grid and dynamic change of solar insolation are considered, where the proposed control technique's performance illustrates the fulfilment of the motive of the work.
Inertia emulation control technique based frequency control of grid‐connected single‐phase rooftop photovoltaic system with battery and supercapacitor
Authors: Sarojini Ratnam Kamala , Palanisamy K. , Sanjeevikumar P. , Nielsen Jens Bo‐Holm
Published: December 2019

With the increasing penetration of renewable energy sources in the power system, the power electronic inverters are widely used to interface with the grid, which will reduce the inertia of the power system. This study proposes ancillary inertial service from single‐phase rooftop solar photovoltaic (PV) based inverter to the grid. The inertia emulation control technique transforms the behaviour of inverter like a synchronous generator under power imbalances. A hybrid energy storage system consisting of battery and supercapacitor (SC) has been connected at the DC bus to take care of the variability in PV output power and load fluctuations. The SC absorbs/injects the fast‐varying power and provides the inertial response to arrest the frequency deviation and battery charges/discharges to bring back the frequency to the nominal value. Real‐time simulation is carried out to test the system behaviour for different operating conditions using OPAL‐RT 5700.
Time-resolved interference microscopy for studying nonideal plasma formed by high-power femtosecond laser pulses
Authors: Sitnikov D S
Published: December 2019

Measurement results of characteristic size of plasma density inhomogeneity on the surface of bulk iron target formed under action of femtosecond laser pulses with intensity of 1016 W/cm2 are presented. Investigations are performed using time-resolved interference microscopy technique. Femtosecond laser pulses with high time contrast of 107 generated by chromium:forsterite laser system are applied. Efficacy of the chosen technique is demonstrated; the size of plasma inhomogeneity is shown to be less than 30 nm.
Application of hyperspectral imaging for analysis of embryonic development of lower vertebrates
Authors: Burlakov A B , Shirokov S V , Khokhlov D D , Kuzmin V I , Gadzaov A F
Published: December 2019

The task of analyzing the characteristics of the embryonic development of lower vertebrates using non-invasive optical methods is considered. We propose to apply hyperspectral imaging for segmentation of embryo zones with different physical and chemical properties. This approach allows one to obtain information on the spatial distribution of optical spectral properties of the observed object. An experimental setup based on a microscope coupled with a spectral imaging add-on module utilizing a tunable acousto-optic filter has been created to implement this approach. Hyperspectral data arrays are formed as a series of spectral narrowband images obtained by successive tuning of the acousto-optic filter within the working spectral range. A series of experiments was conducted in which the development of embryos of the Misgurnus fossilis loach during their transition from the 32nd to the 33rd developmental stage was observed using the described experimental setup. Characteristic spatial regions corresponding to certain parts of the loach embryo were identified. The time dependences characterizing the change in the spectral properties of the selected regions were obtained. It is shown that joint processing of a series of spectral images obtained in different spectral bands within the working spectral range of an acousto-optical spectral imaging module allows one to effectively identify differences in the kinetics of the optical transmission spectral density for various regions of the axial mesoderm.
Numerical simulation of supersonic flow around a cone in a three-dimensional formulation in the software package OpenFOAM
Authors: Kuvshinnikov A E
Published: December 2019

Three solvers of the OpenFOAM package are chosen to numerically solve the problem of supersonic flow around a cone. The cone half-angle and the angle of attack varied. The obtained results are compared with the well-known numerical solution of this problem. It has been established that the rhoCentralFoam solver provides minimal error for the pressure field and pisoCentralFoam solver for velocity field.
Experimental observation of turbulent exchange between heterogeneous vortex ring and surrounding medium by the shadowgraph method
Authors: Nikulin V V , Panenko R A
Published: December 2019

A shadow visualization of turbulent exchange between vortex ring containing fluid less dense than that out of it and surrounding medium is performed. A characteristic distance and time of this process are determined and the dependence of time on both vortex velocity and the related Reynolds number is obtained. Using characteristic time, the turbulent diffusion coefficient in the vortex atmosphere is estimated.
Investigation of temperature field of weakly ionized gas jet by the background oriented schlieren method
Authors: Korotkikh I I , Malakhov Yu I , Kuchmenko A V
Published: December 2019

The paper shows the possibility of using the background oriented schlieren technique to study the temperature field of a weakly ionized plasma jet created as a result of a spark discharge in argon at atmospheric pressure. The design of the spark source, the experimental setup, the experimental method and the processing of experimental data are presented. The temperature field of weakly ionized plasma jet and the temperature distribution around it were obtained.
Researches of two-phase stream by methods of registration of fluorescence of drops of liquid and Shadowgraph
Authors: Chelebyan O G , Vasilyev A Y , Sviridenkov A A , Loginova A A
Published: December 2019

In this paper, the fluorescent method is used in conjunction with the shadowgraph method to obtain the concentration distributions and droplet sizes in the spray. A beam of light from a pulsed laser, passing through a longitudinal or cross-section of a jet of atomized fuel, tinted with a fluorescent additive, oxyquinoline, partially scatters on droplets (Mi-scattering), while blue light with a wavelength λ = 488 nm excites fluorescence in the green range of the wavelength spectrum. A color image of the cross section of the fuel spray by a laser beam is recorded during scanning by a digital camera, the optical axis of which is directed at a right angle to the axis of the laser beam. Thus, at each point of the image of the spray cross section, fluorescence intensities are recorded, proportional to the volume concentration of the droplets and vertically polarized by the component scattered on the light drops with respect to the scattering plane (measurement). The ratio of fluorescence intensity to Mie scattering intensity is proportional to the diameter of the fuel droplets averaged over the Sauter.
Optical study of the concentration and particle size distribution of octadecylamine in water
Authors: Skornyakova N M , Anikeev A V , Parshin V A
Published: December 2019

The objective of this study was to determine the size of the investigated particles in water. The particles studied were octadecylamine inclusions which are invisible to the naked eye. To increase the accuracy of the results obtained, the study was carried out using two optical methods: direct video surveillance in a digital stereo microscope and laser diffraction method.
The choice of an image processing algorithm for increasing sensitivity of the surface plasmon resonance method
Authors: Pavlov I N , Vedyashkina A V , Yanina G M
Published: December 2019

The paper describes the principles of the surface plasmon resonance imaging method in application to investigation of heat and mass transfer processes. It is shown, that one the main obstacles to increase its sensitivity is low signal-to-noise ratio due to speckles and stray interference structures in the experimental images. An algorithm of image processing is developed to overcome this obstacle. Several ways to do it is discussed in the paper.
In-plane interferometry of terahertz surface plasmon polaritons
Authors: Nikitin A K , Khitrov O V , Gerasimov V V , Khasanov I Sh , Ryzhova T A
Published: December 2019

The paper is devoted to the development of interferometric schemes for determining the complex refractive index κ = κ′+i·κ″ κ of surface plasmon-polaritons (SPPs) of the terahertz (THz) spectral range. As the value of κ depends on the dielectric constant εm
of the metal surface guiding the SPPs it can be used for determining ϵm
in the far infrared what other optical methods fail to do due to high reflectivity of metals. We discuss two types of THz SPP interferometers in which the interference pattern is formed as a result of the interaction of SPP beams themselves rather than bulk waves produced by these beams. The first type of interferometers are static devices that enable one to investigate fast processes on the metal surface, while the second type are dynamic ones that make it possible to realize Fourier spectroscopy of the metal surface and its transition layer at THz frequencies. Devices of the both types produce interferograms enabling one to determine the real and the imaginary parts of κ. The results of experiments on the interaction of THz SPPs with flat mirrors and beam – splitting plates, the key elements of the THz SPP interferometers, are presented.
Long-focus low-cost lens deigned for biomedical hyperspectral camera
Authors: Batshev V I , Gavlina A E
Published: December 2019

In this work a design of 250 mm F/20 lens for hyperspectral imaging of biomedical micro objects is presented. The designed lens consists of only standard optical elements and does not contain any newly developed component. Its low aperture and small field of view causes that image quality is limited only by diffraction and two optical aberrations – field curvature and chromatic focal shift. That is why an achromatic doublet is utilized as a basic lens component. Its residual field curvature is corrected by a Smith lens – a single plane-concave lens located near the image plane. The components are selected from commercially available ones. A distance between components was the only optimized parameter. Such layout makes the lens cheap and easy to manufacture.
Applying PIV to study a fluid flow in the vicinity of a circular streamlined cylinder
Authors: Dobroselsky K G
Published: December 2019

The round cylinder streamlining by a turbulent water flow in a hydrodynamic pipe is investigated experimentally. Using the optical method of PIV (Particle Image Velocimetry) the averaged velocity fields near the cylinder are obtained and, on their basis, the geometric characteristics of the vortex zone of the near wake are calculated for the non-cavitation and cavitation flow regimes in the critical region of Reynolds numbers. The use of two mirrors, set at a certain angle to each other, allows obtaining a picture of the velocity fields around the entire cylinder, rather than around half of it, as it is done in most of the works. Using vector patterns of averaged velocity fields, the angles of the boundary layer separation from the cylinder surface along the reverse flow are determined in the considered flow regimes. An asymmetrical separation of the boundary layer from different sides of the streamlined cylinder was obtained. It is shown that the increase in the Reynolds number for the non-cavitation flow regimes leads to a more than two times decrease in the vortex zone behind the cylinder, and, accordingly, to a displacement of the separation angles downstream. Cavitation increases the vortex zone behind the cylinder and displaces the separation angles upstream.
Development of a cylindrical acoustic lens to control the amplitude and phase characteristics of optical radiation
Authors: Bykhanov A N
Published: December 2019

The promising method of light beam phase control based on beam transmission through the medium layer perturbed with acoustid wave generated by the lateral surface “lens”, requives the exact calculation of the acoustic field inside cylindrical cavity of the “lens”. We use the comm program Comsol for calculation and demonstrate that for the axial symmetric cylinder, which was used as a test object, the calculated distribution very close coinsides with theoretical form resulted from acoustic equations solutions.
Application of acoustic emission and laser optoacoustics at various stages of defect formation during friction stir welding
Authors: Stepanova K , Kinzhagulov I , Yakovlev Y
Published: December 2019

This paper covers basic aspects of laser ultrasound and acoustic emission non-destructive testing methods in application of monitoring friction stir welds during its deformation and fracture. Stress-strain curves for such welds were obtained and the mechanical characteristics of welded joints of aluminum-magnesium alloy were determined. Using acoustic elastic effect levels of mechanical stresses were measured. Signals of acoustic emission, stimulated by one-axis loading, were registered and analyzed. It was established that acoustic emission during deformation and fracture of samples of welded joints is associated with the course of the process of plastic flow of the material. The nature of the distribution of acoustic emission parameters in the destruction of welded joints with defects has distinctive features. In conditions of one axis quasi static loading rate event count acoustic emission is the most informative parameter.