bluuebunny/crossref_metadata_2025 huggingface dataset:
Manipulation of gas-liquid-liquid systems in continuous flow microreactors for efficient reaction processes
Authors: Liu Yanyan , Chen Guangwen , Yue Jun
Published: February 2020

Gas-liquid-liquid flow in microreactors holds great potential towards process intensification of operation in multiphase systems, particularly by a precise control over the three-phase contact patterns and the associated mass transfer enhancement. This work reviews the manipulation of gas-liquid-liquid three-phase flow in microreactors for carrying out efficient reaction processes, including gas-liquid-liquid reactions with catalysts residing in either liquid phase, coupling of a gas-liquid reaction with the liquid-liquid extraction, inert gas assisted liquid-liquid reactions and particle synthesis under three-phase flow. Microreactors are shown to be able to provide well-defined flow patterns and enhanced gas-liquid/liquid-liquid mass transfer rates towards the optimized system performance. The interplay between hydrodynamics and mass transfer, as well as its influence on the overall microreactor system performance is discussed. Meanwhile, future perspectives regarding the scale-up of gas-liquid-liquid microreactors in order to meet the industrial needs and their potential applications especially in biobased chemicals and fuels synthesis are further addressed.
Filling the Void: The Effect of Stream Bank Soil Pipes on Transient Hyporheic Exchange During a Peak Flow Event
Authors: Lotts William Seth , Hester Erich T.
Published: February 2020

The hyporheic zone is the ecotone between stream and river channel flow and groundwater that can process nutrients and improve water quality. Transient hyporheic zones occur in the riparian zone (bank storage or “lung model” exchange) during channel stage fluctuations. Recent studies show that soil pipes are widespread in stream banks and beneath floodplains, creating highly preferential flow between channel and riparian groundwater such that the traditional Darcy model of flow does not apply. We used MODFLOW with the conduit flow package to model a series of stream bank soil pipes and examined soil pipe density (number per m), length, diameter, height above baseflow water surface, connectivity, and matrix hydraulic conductivity on transient particle flow paths and total hyporheic exchange volume (i.e., bank storage) over the course of a peak flow (e.g., storm) event. We found that adding five soil pipes per meter more than doubled hyporheic volume. Soil pipe length was the most important control; adding one 1.5‐m‐long soil pipe caused a 73.4% increase in hyporheic volume. The effect of increasing soil pipe diameter on hyporheic volume leveled off at ~1 cm, as flow limitation switched from pipe flow to pipe‐matrix exchange. To validate our approach, we used the model to successfully reproduce trends from field studies. Our results highlight the need to consider soil pipes when modeling, monitoring, or managing bank storage, floodplain connectivity, or hyporheic exchange.
Increased circulating levels of Factor H-Related Protein 4 are strongly associated with age-related macular degeneration
Authors: Cipriani Valentina , Lorés-Motta Laura , He Fan , Fathalla Dina , Tilakaratna Viranga , McHarg Selina , Bayatti Nadhim , Acar İlhan E. , Hoyng Carel B. , Fauser Sascha , Moore Anthony T. , Yates John R. W. , de Jong Eiko K. , Morgan B. Paul , den Hollander Anneke I. , Bishop Paul N. , Clark Simon J.
Published: February 2020

Age-related macular degeneration (AMD) is a leading cause of blindness. Genetic variants at the chromosome 1q31.3 encompassing the complement factor H (CFH, FH) and CFH related genes (CFHR1-5) are major determinants of AMD susceptibility, but their molecular consequences remain unclear. Here we demonstrate that FHR-4 plays a prominent role in AMD pathogenesis. We show that systemic FHR-4 levels are elevated in AMD (P-value = 7.1 × 10−6), whereas no difference is seen for FH. Furthermore, FHR-4 accumulates in the choriocapillaris, Bruch’s membrane and drusen, and can compete with FH/FHL-1 for C3b binding, preventing FI-mediated C3b cleavage. Critically, the protective allele of the strongest AMD-associated CFH locus variant rs10922109 has the highest association with reduced FHR-4 levels (P-value = 2.2 × 10−56), independently of the AMD-protective CFHR1–3 deletion, and even in those individuals that carry the high-risk allele of rs1061170 (Y402H). Our findings identify FHR-4 as a key molecular player contributing to complement dysregulation in AMD.
Plant diversity effects on forage quality, yield and revenues of semi-natural grasslands
Authors: Schaub Sergei , Finger Robert , Leiber Florian , Probst Stefan , Kreuzer Michael , Weigelt Alexandra , Buchmann Nina , Scherer-Lorenzen Michael
Published: February 2020

In agricultural settings, plant diversity is often associated with low biomass yield and forage quality, while biodiversity experiments typically find the opposite. We address this controversy by assessing, over 1 year, plant diversity effects on biomass yield, forage quality (i.e. nutritive values), quality-adjusted yield (biomass yield × forage quality), and revenues across different management intensities (extensive to intensive) on subplots of a large-scale grassland biodiversity experiment. Plant diversity substantially increased quality-adjusted yield and revenues. These findings hold for a wide range of management intensities, i.e., fertilization levels and cutting frequencies, in semi-natural grasslands. Plant diversity was an important production factor independent of management intensity, as it enhanced quality-adjusted yield and revenues similarly to increasing fertilization and cutting frequency. Consequently, maintaining and reestablishing plant diversity could be a way to sustainably manage temperate grasslands.
De novo strategy with engineering anti-Kasha/Kasha fluorophores enables reliable ratiometric quantification of biomolecules
Authors: Shi Limin , Yan Chenxu , Guo Zhiqian , Chi Weijie , Wei Jingle , Liu Weimin , Liu Xiaogang , Tian He , Zhu Wei-Hong
Published: February 2020

Fluorescence-based technologies have revolutionized in vivo monitoring of biomolecules. However, significant technical hurdles in both probe chemistry and complex cellular environments have limited the accuracy of quantifying these biomolecules. Herein, we report a generalizable engineering strategy for dual-emission anti-Kasha-active fluorophores, which combine an integrated fluorescein with chromene (IFC) building block with donor-π-acceptor structural modification. These fluorophores exhibit an invariant near-infrared Kasha emission from the S1 state, while their anti-Kasha emission from the S2 state at around 520 nm can be finely regulated via a spirolactone open/closed switch. We introduce bio-recognition moieties to IFC structures, and demonstrate ratiometric quantification of cysteine and glutathione in living cells and animals, using the ratio (S2/S1) with the S1 emission as a reliable internal reference signal. This de novo strategy of tuning anti-Kasha-active properties expands the in vivo ratiometric quantification toolbox for highly accurate analysis in both basic life science research and clinical applications.
Effects of Optical Turbulence and Density Gradients on Particle Image Velocimetry
Authors: Matt Silvia , Nootz Gero , Hellman Samuel , Hou Weilin
Published: February 2020

Particle image velocimetry (PIV) is a well-established tool to collect high-resolution velocity and turbulence data in the laboratory, in both air and water. Laboratory experiments are often performed under conditions of constant temperature or salinity or in flows with only small gradients of these properties. At larger temperature or salinity variations, the changes in the index of refraction of water or air due to turbulent microstructure can lead to so-called optical turbulence. We observed a marked influence of optical turbulence on particle imaging in PIV. The effect of index of refraction variations on PIV has been described in air for high Mach number flows, but in such cases the distortion is directional. No such effect has previously been reported for conditions of isotropic optical turbulence in water. We investigated the effect of optical turbulence on PIV imaging in a large Rayleigh-Bénard tank for various path lengths and turbulence strengths. The results show that optical turbulence can significantly affect PIV measurements. Depending on the strength of the optical turbulence and path length, the impact can be mitigated in post-processing, which may reduce noise and recover the mean velocity signal, but leads to the loss of the high-frequency turbulence signal.
Assessing diagnostic value of microRNAs from peripheral blood mononuclear cells and extracellular vesicles in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Authors: Almenar-Pérez Eloy , Sarría Leonor , Nathanson Lubov , Oltra Elisa
Published: February 2020

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating multisystemic disease of unknown etiology, affecting thousands of individuals worldwide. Its diagnosis still relies on ruling out medical problems leading to unexplained fatigue due to a complete lack of disease-specific biomarkers. Our group and others have explored the potential value of microRNA profiles (miRNomes) as diagnostic tools for this disease. However, heterogeneity of participants, low numbers, the variety of samples assayed, and other pre-analytical variables, have hampered the identification of  disease-associated miRNomes. In this study, our team has evaluated, for the first time, ME/CFS miRNomes in peripheral blood mononuclear cells (PBMCs) and extracellular vesicles (EVs) from severely ill patients recruited at the monographic UK ME biobank to assess, using standard operating procedures (SOPs), blood fractions with optimal diagnostic power for a rapid translation of a miR-based diagnostic method into the clinic. Our results show that routine creatine kinase (CK) blood values, plasma EVs physical characteristics (including counts, size and zeta-potential), and a limited number of differentially expressed PBMC and EV miRNAs appear significantly associated with severe ME/CFS (p < 0.05). Gene enrichment analysis points to epigenetic and neuroimmune dysregulated pathways, in agreement with previous reports. Population validation by a cost-effective approach limited to these few potentially discriminating variables is granted.
Epidemiological study on dengue in southern Brazil under the perspective of climate and poverty
Authors: Bavia Lorena , Melanda Francine Nesello , de Arruda Thais Bonato , Mosimann Ana Luiza Pamplona , Silveira Guilherme Ferreira , Aoki Mateus Nóbrega , Kuczera Diogo , Sarzi Maria Lo , Junior Wilson Liuti Costa , Conchon-Costa Ivete , Pavanelli Wander Rogério , Duarte dos Santos Claudia Nunes , Barreto Rafael Carvalho , Bordignon Juliano
Published: February 2020

Social and epidemiological aspects of dengue were evaluated in an important metropolitan area in southern Brazil, from August 2012 to September 2014. Demographic, clinical, serological data were collected from patients with acute dengue symptoms treated at public health system units (HSUs). A systematic approach to analyze the spatial and temporal distribution of cases was developed, considering the temporal cross-correlation between dengue and weather, and the spatial correlation between dengue and income over the city’s census tracts. From the 878 patients with suggestive symptoms, 249 were diagnosed as positive dengue infection (28%). Considering the most statistically significant census tracts, a negative correlation was found between mean income and dengue (r = −0.65;p = 0.02; 95% CI: −0.03 to −0.91). The occurrence of dengue followed a seasonal distribution, and it was found to be three and four months delayed in relation to precipitation and temperature, respectively. Unexpectedly, the occurrence of symptomatic patients without dengue infection followed the same seasonal distribution, however its spatial distribution did not correlate with income. Through this methodology, we have found evidence that suggests a relation between dengue and poverty, which enriches the debate in the literature and sheds light on an extremely relevant socioeconomic and public health issue.
COMT-Polymorphisms Modulated Functional Profile of the Fusiform Face Area Contributes to Face-Specific Recognition Ability
Authors: Wu Chao , Zhen Zonglei , Huang Lijie , Huang Taicheng , Liu Jia
Published: February 2020

Previous studies have shown that face-specific recognition ability (FRA) is heritable; however, the neural basis of this heritability is unclear. Candidate gene studies have suggested that the catechol-O-methyltransferase (COMT) rs4680 polymorphism is related to face perception. Here, using a partial least squares (PLS) method, we examined the multivariate association between 12 genotypes of 4 COMT polymorphisms (rs6269-rs4633-rs4818-rs4680) and multimodal MRI phenotypes in the human fusiform face area (FFA), which selectively responds to face stimuli, in 338 Han Chinese adults (mean age 20.45 years; 135 males). The MRI phenotypes included gray matter volume (GMV), resting-state fractional amplitude of low-frequency fluctuations (fALFF), and face-selective blood-oxygen-level-dependent (BOLD) responses (FS). We found that the first COMT-variant component (PLS1) was positively associated with the FS but negatively associated with the fALFF in the FFA. Moreover, participants with the COMT heterozygous-HEA-haplotype showed higher PLS1 FFA-MRI scores, which were positively associated with the FRA in an old/new face recognition task, than those with the COMT homozygous HEA haplotype and HEA non-carriers, suggesting that individuals with an appropriate (intermediate) level of dopamine activity in the FFA might have better FRA. In summary, our study provides empirical evidence for the genetic and neural basis for the heritability of face recognition and informs the formation of neural module functional specificity.
Improvement in predicting drug sensitivity changes associated with protein mutations using a molecular dynamics based alchemical mutation method
Authors: Ono Fumie , Chiba Shuntaro , Isaka Yuta , Matsumoto Shigeyuki , Ma Biao , Katayama Ryohei , Araki Mitsugu , Okuno Yasushi
Published: February 2020

While molecular-targeted drugs have demonstrated strong therapeutic efficacy against diverse diseases such as cancer and infection, the appearance of drug resistance associated with genetic variations in individual patients or pathogens has severely limited their clinical efficacy. Therefore, precision medicine approaches based on the personal genomic background provide promising strategies to enhance the effectiveness of molecular-targeted therapies. However, identifying drug resistance mutations in individuals by combining DNA sequencing and in vitro analyses is generally time consuming and costly. In contrast, in silico computation of protein-drug binding free energies allows for the rapid prediction of drug sensitivity changes associated with specific genetic mutations. Although conventional alchemical free energy computation methods have been used to quantify mutation-induced drug sensitivity changes in some protein targets, these methods are often adversely affected by free energy convergence. In this paper, we demonstrate significant improvements in prediction performance and free energy convergence by employing an alchemical mutation protocol, MutationFEP, which directly estimates binding free energy differences associated with protein mutations in three types of a protein and drug system. The superior performance of MutationFEP appears to be attributable to its more-moderate perturbation scheme. Therefore, this study provides a deeper level of insight into computer-assisted precision medicine.
Blind testing of shoreline evolution models
Authors: Montaño Jennifer , Coco Giovanni , Antolínez Jose A. A. , Beuzen Tomas , Bryan Karin R. , Cagigal Laura , Castelle Bruno , Davidson Mark A. , Goldstein Evan B. , Ibaceta Raimundo , Idier Déborah , Ludka Bonnie C. , Masoud-Ansari Sina , Méndez Fernando J. , Murray A. Brad , Plant Nathaniel G. , Ratliff Katherine M. , Robinet Arthur , Rueda Ana , Sénéchal Nadia , Simmons Joshua A. , Splinter Kristen D. , Stephens Scott , Townend Ian , Vitousek Sean , Vos Kilian
Published: February 2020

Beaches around the world continuously adjust to daily and seasonal changes in wave and tide conditions, which are themselves changing over longer time-scales. Different approaches to predict multi-year shoreline evolution have been implemented; however, robust and reliable predictions of shoreline evolution are still problematic even in short-term scenarios (shorter than decadal). Here we show results of a modelling competition, where 19 numerical models (a mix of established shoreline models and machine learning techniques) were tested using data collected for Tairua beach, New Zealand with 18 years of daily averaged alongshore shoreline position and beach rotation (orientation) data obtained from a camera system. In general, traditional shoreline models and machine learning techniques were able to reproduce shoreline changes during the calibration period (1999–2014) for normal conditions but some of the model struggled to predict extreme and fast oscillations. During the forecast period (unseen data, 2014–2017), both approaches showed a decrease in models’ capability to predict the shoreline position. This was more evident for some of the machine learning algorithms. A model ensemble performed better than individual models and enables assessment of uncertainties in model architecture. Research-coordinated approaches (e.g., modelling competitions) can fuel advances in predictive capabilities and provide a forum for the discussion about the advantages/disadvantages of available models.
Stereochemistry of two pheromonal components of the bumblebee wax moth, Aphomia sociella
Authors: Wallin Erika A. , Kalinová Blanka , Kindl Jiří , Hedenström Erik , Valterová Irena
Published: February 2020

The bumblebee wax moth, Aphomia sociella, is a parasite of bumblebees. In this species, males produce sexual pheromone to attract females, while females produce an aphrodisiac pheromone that initiates male courtship. Both pheromones contain 6,10,14-trimethylpentadecan-2-one (TMPD-one) and the corresponding alcohol, 6,10,14-trimethylpentadecan-2-ol (TMPD-ol) in sex specific quantities. Male sex pheromone consists of 7 components with TMPD-one as a minor one and traces of TMPD-ol. In female aphrodisiac pheromone, TMPD-ol is the major component, while TMPD-one is present in traces. Here we report on the absolute configuration of TMPD-one in male sex pheromone and TMPD-ol in female aphrodisiac pheromone of A. sociella. The configuration was determined from GC/MS of prepared (S)-acetoxypropionyl esters of TMPD-ol. TMPD-one was first reduced to the alcohol that was then derivatized with (S)-acetoxypropionyl chloride. The GC/MS data of obtained diastereoisomers were compared with synthetic standards. The absolute configuration of TMPD-one in the male pheromone was (6R,10R). The configuration of TMPD-ol in the female pheromone was (2R,6R,10R). Electrophysiological experiments showed that TMPD-one and TMPD-ol are perceived by both sexes. The synthetic standards of naturally produced stereoisomers elicited higher responses than mixtures of all stereoisomers.
Survey of mitochondrial sequences integrated into the bovine nuclear genome
Authors: Grau Erwin Tramontin , Charles Mathieu , Féménia Maureen , Rebours Emmanuelle , Vaiman Anne , Rocha Dominique
Published: February 2020

Nuclear copies of the mitochondrial DNA (NUMTs) have already been described in several species. In this context, we identified and analysed 166 bovine NUMT regions with a total length of 430 kbp, representing about 0.02% of the cattle nuclear genome. Copies of all mitochondrial regions were detected in the nuclear genome, with distinct degrees of sequence similarity to the mitogenome. Some NUMT regions include large mitogenome segments and show high similarity to the organelle genome sequence. NUMT regions are frequently modified by insertion of repetitive sequences and by sequence rearrangements. We confirmed the existence of 29 NUMT regions by PCR amplification using DNA from the cow (Dominette) which was used to generate the bovine genome reference sequence, ruling out the possibility that these NUMTs could be artifacts of the genome assembly. As there are NUMT regions with high similarity to the mitogenome, special care is needed when designing primers for mitochondrial DNA amplification. Our results can therefore be used to avoid co-amplification of bovine nuclear sequences similar to mitochondrial DNA.
Active site manipulation in MoS2 cluster electrocatalysts by transition metal doping
Authors: Humphrey Jo J. L. , Kronberg Rasmus , Cai Rongsheng , Laasonen Kari , Palmer Richard E. , Wain Andrew J.
Published: February 2020

Combining precision cluster synthesis with atomistic modelling uncovers fundamental differences in the influence of transition metal dopants on the electrocatalytic activity of MoS2 towards the hydrogen evolution reaction.
Flat bands and gaps in twisted double bilayer graphene
Authors: Culchac F. J. , Del Grande R. R. , Capaz Rodrigo B. , Chico Leonor , Morell E. Suárez
Published: February 2020

We explain the behavior of the bandgap for twisted double bilayer graphene for different angles and discuss the two mechanisms involved. We propose corrections to the tight binding and continuum models.
A coumarin-containing Schiff base fluorescent probe with AIE effect for the copper(ii) ion
Authors: Wang Ying , Hao Xiaohui , Liang Lixun , Gao Luyao , Ren Xumin , Wu Yonggang , Zhao Hongchi
Published: February 2020

A novel coumarin-derived Schiff base fluorescent “turn-off” chemosensor with AIE effect showed selectivity towards Cu2+. The recognition mechanism is presented.
Compartmentalized cross-linked enzymatic nano-aggregates (c-CLEnA) for efficient in-flow biocatalysis
Authors: De Martino M. Teresa , Tonin Fabio , Yewdall N. Amy , Abdelghani Mona , Williams David S. , Hanefeld Ulf , Rutjes Floris P. J. T. , Abdelmohsen Loai K. E. A. , van Hest Jan C. M.
Published: February 2020

c-CLEnA are obtained via cross-linking enzymes in the nanocavity of supramolecular stomatocytes. Such c-CLEnA can be recycled while retaining its activity – an excellent nanoreactors platform for in-flow bio-catalysis.
Bi0.5Sb1.5Te3-based films for flexible thermoelectric devices
Authors: Shang Hongjing , Dun Chaochao , Deng Yuan , Li Taiguang , Gao Zhaoshun , Xiao Liye , Gu Hongwei , Singh David J. , Ren Zhifeng , Ding Fazhu
Published: February 2020

A flexible TE generator exhibits a high power density of 897.8 μW cm−2 at a relatively small ΔT of 40 K.
Ultrathin fluorinated self-cleaning membranes via coordination-driven metal-bridging assembly for water purification
Authors: Yu Qianqian , You Xinda , Wu Hong , Su Yanlei , Zhang Runnan , Liu Yanan , Yang Chao , Shen Jianliang , Yuan Jinqiu , Jiang Zhongyi
Published: February 2020

Coordination-driven metal-bridging assembly between polyphosphate ligands and perfluorosulfonate polymeric ligands generates an ultrathin fluorine-based membrane with superior permeance and self-cleaning properties.
Voltage-controlled skyrmion-based nanodevices for neuromorphic computing using a synthetic antiferromagnet
Authors: Yu Ziyang , Shen Maokang , Zeng Zhongming , Liang Shiheng , Liu Yong , Chen Ming , Zhang Zhenhua , Lu Zhihong , You Long , Yang Xiaofei , Zhang Yue , Xiong Rui
Published: February 2020

Skyrmion size in an synthetic antiferromagnet is significantly altered via voltage control of RKKY coupling, which exhibits potential for a neuromorphic computing with ultralow dissipation.
Occurrence of Microplastic in surface water of Jatiluhur Reservoir
Authors: Ramadan Attar Hikmahtiar , Sembiring Emenda
Published: February 2020

Microplastic is generally defined as synthetic polymers which size less than 5 mm. Based on the latest research, microplastics pollutions have many impacts on the environment and human. Jatiluhur, as one of the biggest freshwater reservoir in Indonesia, has potential to be polluted by microplastics because the water source of this reservoir streamed from Citarum watershed. Citarum River is one of the most polluted river in Indonesia. To find the occurrence of microplastics and to facilitate future policies in order to overcome microplastic pollution which occurs in Jatiluhur Reservoir, a study of microplastic abundance is conducted. Primary data is obtained by using the volume reduced sampling method. Manta trawl is pulled beside a boat for 5 -15 minutes for each sample and flow meter installed onto the mouth of manta trawl to determine the towing distance in surface water. Microplastic abundance in surface water presented in the form of microplastics amounts per unit surface area. Furthermore, microplastic characteristics analyzed with visual analysis, particle density analysis, and polymer analysis using FTIR. Based on seven sampling locations, microplastics have found in Jatiluhur Reservoir ranging from 0.71×104 – 4.59×105 particles/km2. The most type of microplastic found is fragmented polyethylene.
Comparing domain wall synapse with other non volatile memory devices for on-chip learning in analog hardware neural network
Authors: Kaushik Divya , Singh Utkarsh , Sahu Upasana , Sreedevi Indu , Bhowmik Debanjan
Published: February 2020

Resistive Random Access Memory (RRAM) and Phase Change Memory (PCM) devices have been popularly used as synapses in crossbar array based analog Neural Network (NN) circuit to achieve more energy and time efficient data classification compared to conventional computers. Here we demonstrate the advantages of recently proposed spin orbit torque driven Domain Wall (DW) device as synapse compared to the RRAM and PCM devices with respect to on-chip learning (training in hardware) in such NN. Synaptic characteristic of DW synapse, obtained by us from micromagnetic modeling, turns out to be much more linear and symmetric (between positive and negative update) than that of RRAM and PCM synapse. This makes design of peripheral analog circuits for on-chip learning much easier in DW synapse based NN compared to that for RRAM and PCM synapses. We next incorporate the DW synapse as a Verilog-A model in the crossbar array based NN circuit we design on SPICE circuit simulator. Successful on-chip learning is demonstrated through SPICE simulations on the popular Fisher’s Iris dataset. Time and energy required for learning turn out to be orders of magnitude lower for DW synapse based NN circuit compared to that for RRAM and PCM synapse based NN circuits.
Change of plasma propagation state due to force balance with collision
Authors: Yambe Kiyoyuki , Kondo Shoma
Published: February 2020

The main findings of this study are that the plasma propagation state changes with the force equilibrium relationship between the driving force due to the electromagnetic field and neutral gas flow. The plasma propagation transitions from a continuous state to a discontinuous state when plasma emission light intensity changes. The plasma emission light intensity changes suddenly as the applied voltage frequency varies. The frequency at which plasma emission light changes is inversely proportional to the dynamic pressure with the flow velocity of neutral gas. The plasma with strong light emission at high frequency propagates continuously, while that with weak light emission at low frequency propagates discontinuously. Because the plasma current with strong light emission is larger than that with weak light emission, the plasma charge quantity—the amount of plasma generated—increases. Consequently, when the plasma quantity is enough to exist continuously as a group, the plasma group propagates in space with time variations like a stationary wave. However, when the plasma quantity is inadequate to exist continuously, the plasma group propagates through the space discontinuously like a bullet state.
Intelligent Transportation System: Traffic Load Monitoring and Remote Sensing Structural Health Monitoring of Critical Bridges in Metro Manila using Multi Modal Analysis
Authors: Montes K M , Embalzado K A , Sayno A J , Tani L C , Marquez I , Uy F A A
Published: February 2020

Bridge load limit monitoring is a major problem in the Philippines. Since this was not implemented strictly, the structural integrity of the bridges was affected hence it resulted to frequent maintenance, retrofitting of strucutral members and collapse. The integrity of the bridge continously decreases through time once the maximum load limit was experienced by the structure. Therefore, this study aims to emphasize the importance of traffic load monitoring in conducting structural health assessment of bridges aside from earthquake and mass loads. The 7.7% increase in the flexure stress of the bridge deck indicates that truck loading has a significant effect on the bridge. In addition for this, variation on the truck volume for peak hours and non peak hours will correlate to the reading of the smart sensor attached on the bridge for structural health monitoring.
The Influence of Powdered Crumb Rubber on the Mechanical Properties and Thermal Performance of Lightweight Foamed Concrete
Authors: Heng Lim Zhi , Wei Lee Foo , Hung Mo Kim , Zee Kwong Kok , Kun Yew Ming
Published: February 2020

The introduction of powdered crumb rubber into the lightweight foamed concrete influenced various mechanical and physical behaviour of the concrete. The objective of this study is to investigate the influence of 15 %, 30 % and 45 % crumb rubber, in replacement of sand on the mechanical properties and thermal performance of lightweight foamed concrete. Compressive strength, flexural strength and thermal conductivity tests were conducted to evaluate the performance of crumb rubber lightweight foamed concrete. Laboratory results indicated that the strength properties of crumb rubber lightweight foamed concrete were weaker than those of conventional lightweight foamed concrete with a similar density. The compressive strength and flexural strength were reduced from 14.02 MPa to 10.66 MPa and 4.92 MPa to 3.06 MPa respectively, as the crumb rubber proportion was increased from 0 % to 45 %. However, it is worth mentioning that the optimum incorporation of 45 % crumb rubber in lightweight foamed concrete enhanced the thermal insulating performance by lowering the heat conductivity of the concrete from 1.1863 W.K−1m− to 0.9733 W.K−1m−1.
Encapsulate Materials Effect on ZnxCd1-xS White Light Quantum Dots-Based White Light-Emitting Diodes
Authors: Huang Y. X. , Chung S. R.
Published: February 2020

In this study, colloidal ternary ZnxCd1-xS white light quantum dots (WQDs) were prepared, which have the characteristics of broad emission window. We used epoxy, styrene ethylene butylene styrene block copolymer (SEBS), and silicone as encapsulate materials to pack the device. The results show that the Zn0.5 and Zn0.8 have band edge and surface state emission. The quantum yield (QY) and particle size of Zn0.5 and Zn0.8 WQDs is 19, 32 % and 4.5±0.5 and 3.1±0.5 nm, respectively. The white light-emitting diodes (WLEDs) were obtained by mixing WQDs with different resins, and pumping by UV chip. The luminous efficacy is 6.7 and 8.5 lm/W for Zn0.5 and Zn0.8-based WLED by using epoxy resin as encapsulate material. Moreover, the long period test can maintain 201 and 184 h for Zn0.5 and Zn0.8-based WLED, respectively. The results of this study present that the device encapsulated by epoxy resin can improve the luminous efficacy and stability of device. This outstanding finding may contribute to the future development of solid-state lighting (SSL).
Inorganic InP/ZnS Quantum Dots: Optical Properties and Fabrication in Display Application
Authors: Chumchujan Chaikit , Chung Shu-Ru
Published: February 2020

Inorganic InP/ZnS quantum dots (QDs) is one kind of optoelectronic materials owing to the high quantum yield (QY) and non-toxicity. In this study, green light InP/ZnS QDs with high QY were synthesized by one-pot injection method and mixed with red light CsPbBrI2 QDs as converting material. Those converting material blend with epoxy glue, and pumping by InGaN blue chip to form white light-emitting diode (WLED). The results show that the CIE of WLED provides at (0.31, 0.33) with NTSC of 90 %.
Effect of Electric Arc Furnace Dust Treatment on the Properties of Fresh and Hardened Mortar
Authors: Syahyadi R , Fauzi A , Majuar E , Rizal F , Reza M , Fajri dan
Published: February 2020

Electric arc-furnace dust (EAFD) is generated in considerable amounts by the electric arc steelmaking process. Use of EAFD in concrete improved many properties of concrete. Yet, the prolonged setting time even at low dosages of EAFD was a serious limitation. This phenomenon was attributed to the presence of transition metal in the material of EAFD. Therefore, it was necessary to stabilize the transition metal in an insoluble crystalline matrix. The calcination with high-temperature was done to fix the transition metal in a complex matrix with the cementitious properties. This material was called Engineered Dust (ED). The use of ED with different replacement levels of 0, 5, 10, 15 and 20% at w/b ratio of 0.5 was carried out. The results showed that the use of ED solved the prolonged setting time which the replacement up to 20% had a normal setting time of 5 to 6 hours. Furthermore, the material of ED was used up to 15% replacement level with the replacement of 20% ED that gave the lowest electric charge values in the RCPT.
Mechanical Splices for Seismic Retrofitting of Concrete Structures
Authors: Huaco G , Jirsa J
Published: February 2020

As an alternative to lap splicing, mechanical splices can be used for retrofit purposes. They are generally most economical than traditional lap splices when available spacing or length makes laps difficult to utilize. Mechanical splices are frequently used in new construction. However, their use is limited and not practical for use in retrofitted structures. However, if the bars to be joined do not need to be threaded in order to be connected with a special mechanical splice, such mechanical splices can be useful. It is presented a proposal of using two types of mechanical splices for retrofit purposes. Cycle Tension and cycle tension-compression tests are presented and discussed. It was found that mechanical splices are suitable and have acceptable response under seismic loads.
On-line Monitoring by Acoustic Emission of Butt Joint Structure on the Composite Fuselage Frame
Authors: Qi X F , Yang Y , Kang W P , Wang Q , Zhao G
Published: February 2020

Acoustic emission (AE) technique is an online and dynamic non-destructive testing technology by diagnosing sounds, applicable to damage identification of all sorts of materials and structures. In order to fulfill the requirement of on-line monitoring for butt joint structure on the composite fuselage frame in static loading, Acoustic Emission (AE) is employed in this article. The experiment research is focused on examining the damage evolution process of the specimen subjected to mechanical tests by constantly monitoring the AE and strain responses. Combined with strain results, the recorded acoustic signals are analyzed using AE characteristic parameters such as AE amplitude and AE accumulative energy to identity five different damage stages and conclude the corresponding damage style during the entire test. The outcomes of this article can be available for supplementation and improvement of the current on-line non-destructive testing research for composite structures.
Exploration and Practice of Digital Factory of Complex Electronic Equipment
Authors: Changming Hu , Yaqi Cao , Zhaoyu Zhu
Published: February 2020

For the characteristics of many varieties, small batch, short delivery cycle and high quality requirements of complex electronic equipment manufacturing, combined with a new generation of information and communication technologies and the research of advanced manufacturing technology, This paper puts forward the implementation framework of digital factory of complex electronic equipment, analyzes the connotation of digital factory, explores the application of digital twin in the manufacturing stage, discusses the process of data perception, fusion and analysis of digital factory, and establishes the factory production operation control platform. This paper verifies the feasibility of complex electronic equipment digital factory floor by the example of radar assembly digital factory, and provides theoretical basis and method reference for the comprehensive application of digital factory in complex electronic equipment field in the future.
Automated Platform to the Deposition of Thin-Films and Characterization Process in Fiber Optics Sensors
Authors: Josué Rodríguez-Rodríguez Adolfo , Eduardo RodríguezRodríguez Wenceslao , Iván Luis-Morales Ricardo , Cisneros-Rojas Víctor Alan , Zamorano Báez Rocío , Isidro Acosta-Morales Jose , Antonio GarcíaGarza Luis
Published: February 2020

In the recent years the instrumentation has focused its development in devices fabricated in fiber optic applied as sensors; these devices are useful to monitorate physical, chemical and biological variables. By the previous, it is necessary its deposition of a thin- film sensible to temperature, humidity, pH, glucose, etc. There are two technics to deposit this into a fiber optic sensor: dip-coating and layer-by-layer. In both cases, is mandatory the application of a automated plataform to manipulate the fiber optic structure when it is immersed into the films to its depositon and the subsequent characterization in different liquid mediums; applying rutines stablished by times, positions and repetitions. The previous has been developed into a Robot X-Y, controlled by LabVIEW and its hardware MyRIO with an electronic arquitecture of low cost devices; also was applied the 3D impresion based on “open software” to design utensils to manipulate the devices and materials.
Study on Lumped Magnetic Circuit in Interior PM Machines for Aircraft Electric Green Taxiing Systems
Authors: Zhang Pengfei , Hu Yaohua
Published: February 2020

This paper considers the possibility of adopting a V-shaped interior permanent magnet (IPM) machine for Electric Green Taxiing (EGT) application. This rotor topology of the IPM machine has been optimized to reduce the torque ripple and iron loss. An analytical lumped magnetic circuit model was adopted to minimize the total harmonic distortion (THD) of air-gap flux density for the V-shaped IPM machine. The results of analytical lumped magnetic circuit model were compared with finite-element analysis (FEA). With the optimized rotor structure parameters, the torque ripple at the maximum torque per ampere and iron loss at the flux-weakening control were investigated.
Experimental Study on the Performance of One Micro Pulsed Plasma Thruster
Authors: Du Xinru , Wu Jianjun , Tan Sheng , Zhang Yu , Ou Yang , He Zhaofu
Published: February 2020

In the vacuum environment, the experimental platforms of discharge waveform measurement, impulse bit measurement and electromagnetic interference testing were set up for one designed micro pulsed plasma thruster (μPPT) to study the effect of the capacitance capacity, discharge voltage and electrode pads’ spacing on the discharge waveforms and impulse bit of it, as well as the electromagnetic interference. The experimental results show that the oscillation of discharge waveforms can be reduced by increasing the capacitance capacity and the distance between the two electrodes or decreasing the discharge voltage. With the increasing of the capacitance capacity, the discharge voltage and the distance between two electrodes, the impulse bit of μPPT rises. In the frequency range of 0.8∼2.6 GHz, the work of μPPT will not cause electromagnetic interference to spaceborne equipment and its signal transmission.
A Method of On-line Monitoring for Vibration Table Bearings Based on VMD
Authors: Xiaozhou Du , Qi Xin , Haiyang Gao , Zihong Zhu
Published: February 2020

Aiming at the problems that the bearing inside the sliding table of the shaker used for the dynamic test of spacecraft cannot be observed and the failure cannot be known at the initial stage, an online prediction method for bearing failure is proposed. In this paper, the acceleration sensor is selected as the monitoring medium of bearing motion state response, and the VMD (variational mode decomposition) is used as the analysis method of bearing acceleration response data to calculate the harmonic components of the bearing except the fundamental wave. Through the calculation results, the failure bearing can be intuitively interpreted.
Research on Model Correction of Turbofan Engine Based on Quantum-behaved Particle Swarm Optimization
Authors: Qian Renjun , Li Benwei , Yan Siqi , Zhao Shufan , Teng Huailiang
Published: February 2020

In order to solve the problem that the calculation result of mathematical model and the measured data of the whole machine deviate greatly due to the conditional simplification in the modeling process and engine component difference, an engine model correction method based on Quantum-behaved Particle Swarm Optimization(QPSO) is proposed. And the engine model calculation results are compared with the measured data of the whole machine performance. The results show that using the QPSO to modify the engine model can significantly improve the accuracy of the model. Before the correction, comparing the performance calculation result of the engine model with the measured data, the maximum error reaches 4.84%. After the correction, the accuracy of the model is greatly improved, and the maximum error is only 0.966%. The correction effect is good.
Requirements Management Applied in Airworthiness Certification in the Civil Aircraft
Authors: Wang Yi , Zhang Xinai
Published: February 2020

The civil aircraft certification is the process, which indicates whether aircraft design complies with airworthiness regulations, or not. In recent years, requirements management has been gradually implemented in civil aircraft design, showing a method, which can implement a series of stakeholder, needs or expectation including airworthiness into specific products through requirements definition, validation and verification. Requirements are hierarchical and structured, however, the lack of technical hierarchy of regulations as provisions results in a poor correlation between regulations and requirements. This paper focuses on the research about the application of requirement based engineering method in the development of civil aircraft, and exploring how to implement the regulations in the whole life cycle of the aircraft development to effectively ensure that the regulations are fully implemented into the product requirements, and fully interacted with the system development process. To a certain extent, avoid the disconnection between the airworthiness regulations and the development process, and reduce the risk that the development of civil aircraft does not meet the airworthiness regulations.
Integrated Requirements Management of Civil Aircraft
Authors: Zhang Xinyu , Zhang Xinai
Published: February 2020

Civil Aircraft is a typical complex product system, which has high integration and complex management. In the initial stage of the project, identifying market and customer needs and defining high quality requirements are the key to develop products. Meanwhile, civil aircraft needs to meet the airworthiness regulations to ensure the safety of the aircraft. From the perspective of commercial operation and airworthiness compliance, it is necessary to use requirements management method to develop civil aircraft. For civil aircraft, the requirements have the characteristics of hierarchy, variety and traceability. In this paper, an integrated requirements management method and platform are proposed based on the characteristics of civil aircraft requirements. And an application of certain type aircraft is given.
Investigation on Steady State Unbalance Response of Rotor with Elastic Ring Squeeze Film Damper
Authors: Zhao Lu , Liao Mingfu , Niu Jihui
Published: February 2020

In this paper, the method for calculating steady state response of a rotor system with elastic ring squeeze film damper(s) is studied. The finite difference method is used to calculate the oil film pressure field which excludes the influence of rotating speed and considers the action of oil orifices starting with the governing equations of oil film. The mechanical characteristic curves of ERSFD are obtained by integrating the film pressure field, based on which the steady state response of the rotor system with ERSFD(s) is calculated by the finite element method and iteration method. The calculating response is compared with the experimental data, and it is found that the calculating response is in good agreement with the actual one, with the relative error of no more than 15%, which verifies the correctness of the above algorithm, and conclusion that the elastic ring extrusion oil film damper can be regarded as a linear element when the eccentricity journal of the journal is relatively small is obtained.
Measurement and Analysis of the Key Metrics of Information System Resilience
Authors: Jinyi Wei , Ning Li , Jing Shi , Luo Xu
Published: February 2020

In view of the current situation that the resilience of information systems cannot be accurately assessed, the key metrics that affect the resilience of information systems—the overall system capability, the system’s maximum absorptive capacity, the system recovery ability and the system recovery ratio, are established. And the paper shows data calculation model of the key metrics. Finally, the information system resilience analysis method is proposed, and an aerospace simulation system is taken as an example, combined with its dual redundancy and non-redundancy mechanism to test and verify, which provides strong support for the analysis of system resilience ability.
Dynamic Optimization Design of Transverse Axis Cutting Reducer
Authors: Yin Minghu , Liu Hao , Cui Yahui , Sun Feifei , Zhang Daixiang
Published: February 2020

Focused on the gear transmission system of a certain type of transverse axis cutting reducer, this paper firstly establishes the ADAMS virtual prototype model for calculating the dynamic load coefficient of the system, and the influence of gear modulus and tooth width factor on the dynamic load coefficient of the system is determined by multiple linear regression. Then the GA-BP neural network model for calculating the dynamic load coefficient of the system is constructed based on Genetic Algorithm (GA) and BP neural network, which makes the decoupling of the system dynamics analysis and optimization design process be realized. Finally, based on the above analysis, a multi-objective optimization design with the goal of minimizing the system volume and dynamic load coefficient is carried out. The calculation results show that the gear transmission system of the transverse axis cutting reducer is optimized efficiently, and its volume is reduced by 18.8%, and the dynamic load coefficient is decreased by 11.5%. This paper starts with the system dynamics analysis, makes the GA-BP neural network model as the bridge, and finally establishes the technical method for dynamic analysis optimum design of the transverse axis cutting reducer. The analytical technique and method can provide reference for the optimization design analysis of complex gear transmission system.