bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Evolution and Diversification of Proteins Involved in miRNA Maturation Pathway
Authors: Moturu Taraka Ramji , Sinha Sansrity , Salava Hymavathi , Thula Sravankumar , Nodzyński Tomasz , Vařeková Radka Svobodová , Friml Jiří , Simon Sibu
Published: March 2020

Small RNAs (smRNA, 19–25 nucleotides long), which are transcribed by RNA polymerase II, regulate the expression of genes involved in a multitude of processes in eukaryotes. miRNA biogenesis and the proteins involved in the biogenesis pathway differ across plant and animal lineages. The major proteins constituting the biogenesis pathway, namely, the Dicers (DCL/DCR) and Argonautes (AGOs), have been extensively studied. However, the accessory proteins (DAWDLE (DDL), SERRATE (SE), and TOUGH (TGH)) of the pathway that differs across the two lineages remain largely uncharacterized. We present the first detailed report on the molecular evolution and divergence of these proteins across eukaryotes. Although DDL is present in eukaryotes and prokaryotes, SE and TGH appear to be specific to eukaryotes. The addition/deletion of specific domains and/or domain-specific sequence divergence in the three proteins points to the observed functional divergence of these proteins across the two lineages, which correlates with the differences in miRNA length across the two lineages. Our data enhance the current understanding of the structure–function relationship of these proteins and reveals previous unexplored crucial residues in the three proteins that can be used as a basis for further functional characterization. The data presented here on the number of miRNAs in crown eukaryotic lineages are consistent with the notion of the expansion of the number of miRNA-coding genes in animal and plant lineages correlating with organismal complexity. Whether this difference in functionally correlates with the diversification (or presence/absence) of the three proteins studied here or the miRNA signaling in the plant and animal lineages is unclear. Based on our results of the three proteins studied here and previously available data concerning the evolution of miRNA genes in the plant and animal lineages, we believe that miRNAs probably evolved once in the ancestor to crown eukaryotes and have diversified independently in the eukaryotes.
The Histone Marks Signature in Exonic and Intronic Regions Is Relevant in Early Response of Tomato Genes to Botrytis cinerea and in miRNA Regulation
Authors: Crespo-Salvador Óscar , Sánchez-Giménez Lorena , López-Galiano Mª , Fernández-Crespo Emma , Scalschi Loredana , García-Robles Inmaculada , Rausell Carolina , Real M , González-Bosch Carmen
Published: March 2020

Research into the relationship between epigenetic regulation and resistance to biotic stresses provides alternatives for plant protection and crop improvement. To unravel the mechanisms underlying tomato responses to Botrytis cinerea, we performed a chromatin immunoprecipitation (ChIP) analysis showing the increase in H3K9ac mark along the early induced genes SlyDES, SlyDOX1, and SlyLoxD encoding oxylipin-pathway enzymes, and SlyWRKY75 coding for a transcriptional regulator of hormonal signaling. This histone mark showed a more distinct distribution than the previously studied H3K4me3. The RNAPol-ChIP analysis reflected the actual gene transcription associated with increased histone modifications. A different pattern of marks in the oxylipin-related genes against P. syringae supported a pathogen-specific profile, while no significant differences occurred in SlyWRKY75. The epigenetic regulation of SlyWRKY75 by the intron-binding miR1127-3p was supported by the presence of SlyWRKY75 pre-mRNA in control plants. Interestingly, mRNA was found to be accumulated in response to B. cinerea and P. syringae, while reduction in miRNA only occurred against B. cinerea. The intronic region presented a similar pattern of marks than the rest of the gene in both pathosystems, except for H3K4me3 in the miRNA binding site upon B. cinerea. We located the gene encoding Sly-miR1127-3p, which presented reduced H3K4me3 on its promoter against B. cinerea.
Flexibility in the Energy Balancing Network of Photosynthesis Enables Safe Operation under Changing Environmental Conditions
Authors: Walker Berkley J. , Kramer David M. , Fisher Nicholas , Fu Xinyu
Published: March 2020

Given their ability to harness chemical energy from the sun and generate the organic compounds necessary for life, photosynthetic organisms have the unique capacity to act simultaneously as their own power and manufacturing plant. This dual capacity presents many unique challenges, chiefly that energy supply must be perfectly balanced with energy demand to prevent photodamage and allow for optimal growth. From this perspective, we discuss the energy balancing network using recent studies and a quantitative framework for calculating metabolic ATP and NAD(P)H demand using measured leaf gas exchange and assumptions of metabolic demand. We focus on exploring how the energy balancing network itself is structured to allow safe and flexible energy supply. We discuss when the energy balancing network appears to operate optimally and when it favors high capacity instead. We also present the hypothesis that the energy balancing network itself can adapt over longer time scales to a given metabolic demand and how metabolism itself may participate in this energy balancing.
Genotypic Variation in Resistance Gene-Mediated Calcium Signaling and Hormonal Signaling Involved in Effector-Triggered Immunity or Disease Susceptibility in the Xanthomonas campestris pv. Campestris–Brassica napus Pathosystem
Authors: Mamun Md. Al , Islam Md. Tabibul , Lee Bok-Rye , La Van Hien , Bae Dong-Won , Kim Tae-Hwan
Published: March 2020

To characterize cultivar variation in resistance gene (R-gene)-mediated calcium signaling and hormonal regulation in effector-triggered immunity (ETI) and disease susceptibility, Xanthomonas campestris pv. campestris (Xcc) was inoculated in two Brassica napus cultivars (cvs. Capitol and Mosa). At 14 days post inoculation (DPI) with Xcc, there was a necrotic lesion in cv. Mosa along with the significant accumulation of H2O2 and malondialdehyde (MDA), whereas no visual symptom was observed in cv. Capitol. The cultivar variations in the R-gene expressions were found in response to Xcc. ZAR1 is a coiled-coil-nucleotide binding site-leucine-rich repeat (CC-NB-LRR)-type R-gene that is significantly induced in cv. Capitol, whereas toll/interleukin-1 receptor-nucleotide binding site-leucine-rich repeat (TIR-NB-LRR)-type R-gene, TAO1, is significantly upregulated in cv. Mosa Xcc-inoculated plants. The defense-related gene’s non-race-specific disease resistance 1 (NDR1) and mitogen-activated protein kinase 6 (MAPK6) were enhanced, whereas calcium-dependent protein kinase (CDPK5) and calcium-sensing protein 60g (CBP60g) were depressed in cv. Capitol Xcc inoculated plants, and opposite results were found in cv. Mosa. The calcium-sensing receptor (CAS), calmodulin (CaM), expression was induced in both the cultivars. However, the CAS induction rate was much higher in cv. Mosa than in cv. Capitol in response to Xcc. The phytohormone salicylic acid (SA) and jasmonic acid (JA) levels were significantly higher in cv. Capitol along with the enhanced SA receptors (NPR3 and NPR4) and JA synthesis and signaling-related gene expression (LOX2, PDF1.2), whereas the JA level was significantly lower in cv. Mosa Xcc inoculated plants. The SA synthesis and signaling-related genes (ICS1, NPR1) and SA were present at higher levels in cv. Mosa; additionally, the SA level present was much higher in the susceptible cultivar (cv. Mosa) than in the resistant cultivar (cv. Capitol) in response to Xcc. These results indicate that ZAR1 mediated the coordinated action of SA and JA synthesis and signaling to confirm ETI, whereas TAO1 enhanced the synthesis of SA through CAS and CBP60g to antagonize JA synthesis and signaling to cause disease susceptibility in the Brassica napus–Xcc pathosystem.
High-Level Expression, Purification and Initial Characterization of Recombinant Arabidopsis Histidine Kinase AHK1
Authors: Hofmann Alexander , Müller Sophia , Drechsler Thomas , Berleth Mareike , Caesar Katharina , Rohr Leander , Harter Klaus , Groth Georg
Published: March 2020

Plants employ a number of phosphorylation cascades in response to a wide range of environmental stimuli. Previous studies in Arabidopsis and yeast indicate that histidine kinase AHK1 is a positive regulator of drought and osmotic stress responses. Based on these studies AHK1 was proposed a plant osmosensor, although the molecular basis of plant osmosensing still remains unknown. To understand the molecular role and signaling mechanism of AHK1 in osmotic stress, we have expressed and purified full-length AHK1 from Arabidopsis in a bacterial host to allow for studies on the isolated transmembrane receptor. Purification of the recombinant protein solubilized from the host membranes was achieved in a single step by metal-affinity chromatography. Analysis of the purified AHK1 by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting show a single band indicating that the preparation is highly pure and devoid of contaminants or degradation products. In addition, gel filtration experiments indicate that the preparation is homogenous and monodisperse. Finally, CD-spectroscopy, phosphorylation activity, dimerization studies, and protein–protein interaction with plant phosphorylation targeting AHP2 demonstrate that the purified protein is functionally folded and acts as phospho-His or phospho-Asp phosphatase. Hence, the expression and purification of recombinant AHK1 reported here provide a basis for further detailed functional and structural studies of the receptor, which might help to understand plant osmosensing and osmosignaling on the molecular level.
Horizontal Gene Transfer and Endophytes: An Implication for the Acquisition of Novel Traits
Authors: Tiwari Pragya , Bae Hanhong
Published: March 2020

Horizontal gene transfer (HGT), an important evolutionary mechanism observed in prokaryotes, is the transmission of genetic material across phylogenetically distant species. In recent years, the availability of complete genomes has facilitated the comprehensive analysis of HGT and highlighted its emerging role in the adaptation and evolution of eukaryotes. Endophytes represent an ecologically favored association, which highlights its beneficial attributes to the environment, in agriculture and in healthcare. The HGT phenomenon in endophytes, which features an important biological mechanism for their evolutionary adaptation within the host plant and simultaneously confers “novel traits” to the associated microbes, is not yet completely understood. With a focus on the emerging implications of HGT events in the evolution of biological species, the present review discusses the occurrence of HGT in endophytes and its socio-economic importance in the current perspective. To our knowledge, this review is the first report that provides a comprehensive insight into the impact of HGT in the adaptation and evolution of endophytes.
Comparative Study of Growth, Cadmium Accumulation and Tolerance of Three Chickpea (Cicer arietinum L.) Cultivars
Authors: Ullah Shakir , Khan Jafar , Hayat Khizar , Abdelfattah Elateeq Ahmed , Salam Uzma , Yu Bofan , Ma Yuehua , Wang Hongzheng , Tang Zhong-Hua
Published: March 2020

Trace metals (TM) contamination is a severe problem in the environment and produced an adverse effect on the productivity of crops. Cadmium (Cd) is a TM ranked seven among the top 20 pollutants due to its high toxicity and solubility in water, taken up by the plants and affects their growth and metabolism. In this study, we evaluated the growth, Cd accumulation and tolerance capacities of three chickpea (Cicer arietinum L.) cultivars (NC234 (NC2), ICCV89310 (IC8) and ICCV89323-B (IC8-B)), subjected to two Cd concentrations (25 and 50 µM) in hydroponic culture. The toxicity of Cd reduced the plant height and fresh and dry biomass in all cultivars. The maximum reduction was observed at 50 µM of Cd. Compared with IC8-B, cultivars IC8 and NC2 exhibited better performance with high growth, biomass, root to shoot (R/S) ratio and water content under high Cd stress. To measure the accumulation of Cd in root and shoot, an inductively coupled plasma optical emission spectrometer (ICP-OES) was used. IC8 and NC2 had comparatively high Cd tolerance and accumulation ability (> 100 µg g−1 dry weight), with IC8 being more tolerant and accumulated higher Cd in shoot than NC2, while cultivar IC8-B was sensitive. Root accumulated more Cd than shoot in a dose-dependent manner. The bioconcentration factors (BCF) and bioaccumulation coefficients (BAC) were far higher than one (> 1) and increased with an increase in Cd concentrations, while the translocation factor (TF) was less than one (< 1), suggesting that all the three cultivars were unable to transfer Cd from the root to the shoot efficiently. Our results indicated that IC8 and NC2 proved to be resistant, while IC8-B showed sensitivity when exposed to high Cd stress (50 µM).
New Insights into Evolution of Plant Heat Shock Factors (Hsfs) and Expression Analysis of Tea Genes in Response to Abiotic Stresses
Authors: Xu Ping , Guo Qinwei , Pang Xin , Zhang Peng , Kong Dejuan , Liu Jia
Published: March 2020

Heat shock transcription factor (Hsf) is one of key regulators in plant abotic stress response. Although the Hsf gene family has been identified from several plant species, original and evolution relationship have been fragmented. In addition, tea, an important crop, genome sequences have been completed and function of the Hsf family genes in response to abiotic stresses was not illuminated. In this study, a total of 4208 Hsf proteins were identified within 163 plant species from green algae (Gonium pectorale) to angiosperm (monocots and dicots), which were distributed unevenly into each of plant species tested. The result indicated that Hsf originated during the early evolutionary history of chlorophytae algae and genome-wide genetic varies had occurred during the course of evolution in plant species. Phylogenetic classification of Hsf genes from the representative nine plant species into ten subfamilies, each of which contained members from different plant species, imply that gene duplication had occurred during the course of evolution. In addition, based on RNA-seq data, the member of the Hsfs showed different expression levels in the different organs and at the different developmental stages in tea. Expression patterns also showed clear differences among Camellia species, indicating that regulation of Hsf genes expression varied between organs in a species-specific manner. Furthermore, expression of most Hsfs in response to drought, cold and salt stresses, imply a possible positive regulatory role under abiotic stresses. Expression profiles of nineteen Hsf genes in response to heat stress were also analyzed by quantitative real-time RT-PCR. Several stress-responsive Hsf genes were highly regulated by heat stress treatment. In conclusion, these results lay a solid foundation for us to elucidate the evolutionary origin of plant Hsfs and Hsf functions in tea response to abiotic stresses in the future.
Investigation of the Thermal Conductivity of Resin-Based Lightweight Composites Filled with Hollow Glass Microspheres
Authors: Xing Zhipeng , Ke Hongjun , Wang Xiaodong , Zheng Ting , Qiao Yingjie , Chen Kaixuan , Zhang Xiaohong , Zhang Lili , Bai Chengying , Li Zhuoran
Published: March 2020

The design and development of thermal insulation materials is very important for the treatment of offshore oil pipelines. Understanding thermal energy transport in thermal insulation materials and predicting their thermal conductivities have important theoretical and practical value for the design of thermal insulation materials. In this work, lightweight and thermally insulated (LWTI) composites with the desired mechanical strength for offshore oil pipelines applications were prepared using epoxy resin (EP) as the matrix and hollow glass microspheres (HGMs) as the filler. The morphology, density, and mechanical properties of HGM/EP LWTI composites were studied first. The flexural strength and the flexural modulus of HGM/EP LWTI composites could still be as high as 22.34 ± 2.75 Mpa and 1.34 ± 0.03 GPa, respectively, while the density was only 0.591 g/cm3. The relationship between the effective thermal conductivity of HGM/EP LWTI composites and material parameters (sizes and contents together) has been studied systematically. A three-phase prediction model was built using the self-consistent approximation method to predict the effective thermal conductivity of HGM/EP LWTI composites, and the resin matrix, the wall thickness, the HGM particle size, and other parameters (such as air) were fully considered during the derivation of this three-phase thermal conductivity model. Finally, the insulation mechanism of HGM/EP LWTI composites was systematically analyzed. The thermal conductivities of HGM/EP LWTI composites with different diameters and HGM contents calculated by the three-phase prediction model agreed well with the experimental test results, with a minimum error of only 0.69%. Thus, this three-phase thermal conductivity model can be used to theoretically simulate the thermal conductivity of epoxy resin-based LWTI composites and can be the theoretical basis for the design and prediction of the thermal conductivity of other similar hollow spheres filled materials.
Destruction of Polyelectrolyte Microcapsules Formed on CaCO3 Microparticles and the Release of a Protein Included by the Adsorption Method
Authors: Musin Egor V. , Kim Aleksandr L. , Tikhonenko Sergey A.
Published: March 2020

The degradation of polyelectrolyte microcapsules formed on protein-free CaCO3 particles consisting of polyallylamine (PAH) and polystyrene sulfonate (PSS) and the resulting yield of protein in the presence of various salts of different concentrations, as well as at two pH values, was studied by fluorescence spectroscopy; the protein was incorporated into prepared microcapsules by adsorption. It was found that a high concentration of sodium chloride (2 M) leads to considerable dissociation of PAH, which is apparently due to the loosening of polyelectrolytes under the action of ionic strength. At the same time, 0.2 M sodium chloride and ammonium sulfate of the same ionic strength (0.1 M) exert less influence on the amount of dissociated polymer. In the case of ammonium sulfate (0.1 M), the effect is due to the competitive binding of sulfate anions to the amino groups of the polyelectrolyte. However, unlike microcapsules formed on CaCO3 particles containing protein, the dissociation of polyelectrolyte from microcapsules formed on protein-free particles increased with increasing temperature. Apparently, a similar effect is associated with the absence of a distinct shell, which was observed on microcapsules formed on protein-containing CaCO3 particles. The high level of the presence of Fluorescein isothiocyanate (FITC)-labeled Bovine Serum Albumin (BSA) in the supernatant is explained by the large amount of electrostatically bound protein and the absence of a shell that prevents the release of the protein from the microcapsules. In 2 M NaCl, during the observation period, the amount of the released protein did not exceed 70% of the total protein content in the capsules, in control samples, this value does not exceed 8%, which indicates the predominantly electrostatic nature of protein retention in capsules formed on protein-free CaCO3 particles. The increase in protein yield and peeling of PAH with increasing pH is explained by the proximity of pH 7 to the point of charge exchange of the amino group of polyelectrolyte, as a result of the dissociation of the microcapsule.
Influence of Fabric Weave on Thermal Radiation Resistance and Water Vapor Permeability
Authors: Kiš Ana , Brnada Snježana , Kovačević Stana
Published: March 2020

In this work, aramid fibers were used to develop new, high-performance fabrics for high-temperature protective clothing. The research was based on the impact of the weave structure on fabric resistance to radiant heat. The goals of the research were primarily related to the development of new fabric structures created by the weave structure, which gives better protection of the body against high temperatures in relation to the standard weave structures that are used today. According to the results obtained it can be concluded that the fabric weave significantly affects the fabric structure, which consequently determines the effectiveness of protection against high temperatures. The justification for the use of multi-weft and strucks weave structure, which provides greater thermal protection and satisfactory breathability than commonly used weave structures, was ascertained.
Studies of Cellulose and Starch Utilization and the Regulatory Mechanisms of Related Enzymes in Fungi
Authors: Wang Bao-Teng , Hu Shuang , Yu Xing-Ye , Jin Long , Zhu Yun-Jia , Jin Feng-Jie
Published: March 2020

Polysaccharides are biopolymers made up of a large number of monosaccharides joined together by glycosidic bonds. Polysaccharides are widely distributed in nature: Some, such as peptidoglycan and cellulose, are the components that make up the cell walls of bacteria and plants, and some, such as starch and glycogen, are used as carbohydrate storage in plants and animals. Fungi exist in a variety of natural environments and can exploit a wide range of carbon sources. They play a crucial role in the global carbon cycle because of their ability to break down plant biomass, which is composed primarily of cell wall polysaccharides, including cellulose, hemicellulose, and pectin. Fungi produce a variety of enzymes that in combination degrade cell wall polysaccharides into different monosaccharides. Starch, the main component of grain, is also a polysaccharide that can be broken down into monosaccharides by fungi. These monosaccharides can be used for energy or as precursors for the biosynthesis of biomolecules through a series of enzymatic reactions. Industrial fermentation by microbes has been widely used to produce traditional foods, beverages, and biofuels from starch and to a lesser extent plant biomass. This review focuses on the degradation and utilization of plant homopolysaccharides, cellulose and starch; summarizes the activities of the enzymes involved and the regulation of the induction of the enzymes in well-studied filamentous fungi.
Polystyrene Chain Growth Initiated from Dialkylzinc for Synthesis of Polyolefin-Polystyrene Block Copolymers
Authors: Kim Tae Jin , Baek Jun Won , Moon Seung Hyun , Lee Hyun Ju , Park Kyung Lee , Bae Sung Moon , Lee Jong Chul , Lee Pyung Cheon , Lee Bun Yeoul
Published: March 2020

Polyolefins (POs) are the most abundant polymers. However, synthesis of PO-based block copolymers has only rarely been achieved. We aimed to synthesize various PO-based block copolymers by coordinative chain transfer polymerization (CCTP) followed by anionic polymerization in one-pot via conversion of the CCTP product (polyolefinyl)2Zn to polyolefinyl-Li. The addition of 2 equiv t-BuLi to (1-octyl)2Zn (a model compound of (polyolefinyl)2Zn) and selective removal or decomposition of (tBu)2Zn by evacuation or heating at 130 °C afforded 1-octyl-Li. Attempts to convert (polyolefinyl)2Zn to polyolefinyl-Li were unsuccessful. However, polystyrene (PS) chains were efficiently grown from (polyolefinyl)2Zn; the addition of styrene monomers after treatment with t-BuLi and pentamethyldiethylenetriamine (PMDTA) in the presence of residual olefin monomers afforded PO-block-PSs. Organolithium species that might be generated in the pot of t-BuLi, PMDTA, and olefin monomers, i.e., [Me2NCH2CH2N(Me)CH2CH2N(Me)CH2Li, Me2NCH2CH2N(Me)Li·(PMDTA), pentylallyl-Li⋅(PMDTA)], as well as PhLi⋅(PMDTA), were screened as initiators to grow PS chains from (1-hexyl)2Zn, as well as from (polyolefinyl)2Zn. Pentylallyl-Li⋅(PMDTA) was the best initiator. The Mn values increased substantially after the styrene polymerization with some generation of homo-PSs (27–29%). The Mn values of the extracted homo-PS suggested that PS chains were grown mainly from polyolefinyl groups in [(polyolefinyl)2(pentylallyl)Zn]−[Li⋅(PMDTA)]+ formed by pentylallyl-Li⋅(PMDTA) acting onto (polyolefinyl)2Zn.
Green Corrosion Inhibitors from Agri-Food Wastes: The Case of Punica granatum Extract and Its Constituent Ellagic Acid. A Validation Study
Authors: Magni Mirko , Postiglione Ester , Marzorati Stefania , Verotta Luisella , Trasatti Stefano P.
Published: March 2020

Giving a “new life” to wastes should be the golden rule for all production processes in the forthcoming future, aiming at making them more sustainable and environmentally friendly. In the corrosion science field, the ambitious circular economy paradigm has recently led to the employment of extracts from plants (and, in less extent, from agri-food wastes) as green inhibitors against corrosion of metals. However, in spite of the number of scientific papers published in the field, a deep revision of the scientific approach is needed both in the execution of experiments and in the critical analysis of the results. Starting from some discrepancies in published data, the corrosion inhibition effect induced by a well-characterized methanolic extract from wastes of fermented Punica granatum and by its main component (ellagic acid, EA) was validated. The corrosion behaviour of Armco® pure iron in the presence of small concentrations of ellagic acid and extract (containing ca. 10 µM and 100 µM EA) was studied by combining results from mass loss tests, at free corrosion potential, and from polarization tests, by linearly sweeping the potential applied to the metal substrate. Experiments were carried out both in acidic medium (typical for a general corrosion phenomenon) and in near-neutral chloride bearing solution (characteristic of a localized pitting corrosion phenomenon). Neat conflicts with already published data have been identified first in the solubility of the inhibitor and then in the inhibition efficiency (around 40% in a 0.05 M HCl). The very limited solubility in aqueous environment was identified as the main drawback, hindering any possible exploitation of ellagic acid and pomegranate extract as promising green corrosion inhibitors. Results point to the necessity to establish clear and rigorous good laboratory practices to follow while reporting results on such complex matrices like vegetable extracts.
Oxidative Coupling of Methane in Membrane Reactors; A Techno-Economic Assessment
Authors: Cruellas Aitor , Heezius Jelle , Spallina Vincenzo , van Sint Annaland Martin , Medrano José Antonio , Gallucci Fausto
Published: March 2020

Oxidative coupling of methane (OCM) is a process to directly convert methane into ethylene. However, its ethylene yield is limited in conventional reactors by the nature of the reaction system. In this work, the integration of different membranes to increase the overall performance of the large-scale oxidative coupling of methane process has been investigated from a techno-economic point of view. A 1D membrane reactor model has been developed, and the results show that the OCM reactor yield is significantly improved when integrating either porous or dense membranes in packed bed reactors. These higher yields have a positive impact on the economics and performance of the downstream separation, resulting in a cost of ethylene production of 595–625 €/tonC2H4 depending on the type of membranes employed, 25–30% lower than the benchmark technology based on oil as feedstock (naphtha steam cracking). Despite the use of a cryogenic separation unit, the porous membranes configuration shows generally better results than dense ones because of the much larger membrane area required in the dense membranes case. In addition, the CO2 emissions of the OCM studied processes are also much lower than the benchmark technology (total CO2 emissions are reduced by 96% in the dense membranes case and by 88% in the porous membranes case, with respect to naphtha steam cracking), where the high direct CO2 emissions have a major impact on the process. However, the scalability and the issues associated with it seem to be the main constraints to the industrial application of the process, since experimental studies of these membrane reactor technologies have been carried out just on a very small scale.
Biodrying of the Light Fraction from Anaerobic Digestion Pretreatment in Order to Increase the Total Recovery Rate
Authors: Pecorini Isabella , Bacchi Donata , Iannelli Renato
Published: March 2020

Two pilot-scale tests were carried out to assess if biodrying could be an effective process for the treatment of light fraction produced by an hydromechanical pre-treatment in an anaerobic digestion plant. The trials were performed using two pilot-scale stainless steel cylindrical reactors of 750 L capacity. Two tests were performed: in Test 1, only the light fraction was used; in Test 2, the light fraction was mixed with a bulking agent composed of garden and pruning waste. In Test 2, the highest temperature (71 °C) in a short time (8 days) was reached. An average water content reduction of 78% in Test 1 and 61% in Test 2 was measured, leading to similar reductions of weight (47–48%) and volume (27–29%). A high biological stability was measured on the final light fraction samples collected from both the tests. Furthermore, the lower heating value obtained after the biodrying treatment complies with the quality specification of the European standard on refuse-derived fuels.
Numerical Simulation of Cavitation Performance in Engine Cooling Water Pump Based on a Corrected Cavitation Model
Authors: Li Wei , Li Enda , Shi Weidong , Li Weiqiang , Xu Xiwei
Published: March 2020

To analyze the internal flow of the engine cooling water pump (ECWP) under thermodynamic effect, Zwart cavitation model based on the Rayleigh-Plesset equation is corrected, and NACA0015 hydrofoil was selected to verify the corrected model. The cavitation performances of ECWP with different temperatures were numerically simulated based on a corrected cavitation model. Research results show that simulation values of pressure distribution coefficient in hydrofoil surface at 70 °C are in closest agreement with experimental values when the evaporation and condensation coefficients are 10 and 0.002, respectively. With the decrease of absolute pressure in pump inlet, bubbles firstly occurred at the blade inlet side near the suction surface and then gradually extended to the pressure surface, finally clogged the impeller passage. Compared to the inlet section, the cavitation degree is much more serious close to the trailing edge. With the temperature increases, the cavitation in ECWP occurs in advance and rapidly, and the temperature plays an important role in promoting cavitation process in ECWP. Based on the unsteady simulation of ECWP, the influence of cavitation on the performance characteristics is studied. The results provide a theoretical reference for the prediction and optimization of the cavitation performance in ECWP.
Laser-Induced Ignition and Combustion of Individual Aluminum Particles Below 10 μm by Microscopic High-Speed Cinematography
Authors: Hou Fengting , Li Shengji , Wang Yue , Huang Xuefeng
Published: March 2020

Metal aluminum has been widely used as an ingredient in propellant, gunpowder and thermite, but there is less understanding of the combustion mechanism of aluminum particles from submicron to several microns in diameter. This paper proposes to experimentally investigate the ignition and combustion characteristics of individual aluminum particles below 10 μm. A specific in situ diagnostic experimental apparatus was first designed for directly observing the ignition and combustion behaviors of individual aluminum particles, with a submicrometer spatial resolution and a temporal resolution of tens of microseconds. Direct observation through microscopic high-speed cinematography demonstrated that, when heated by a continuous laser, individual aluminum particles thermally expanded, followed by shell rupture; the molten aluminum core overflowed and evaporated, leading to ignition and combustion. Further results showed that, when the laser power densities were gradually increased (5.88, 7.56 and 8.81 × 105 W/cm2), the durations of thermal expansion, melting and evaporation were shortened. The required time for the aluminum particles to expand to 150% of their initial diameter was shortened (34 s, 0.34 s and 0.0125 s, respectively). This study will be beneficial to further extend the investigation of other individual metal particles and reveal their combustion mechanism by direct observation.
RF-ICP Thermal Plasma for Thermoplastic Waste Pyrolysis Process with High Conversion Yield and Tar Elimination
Authors: Aboughaly Mohamed , Gabbar Hossam A. , Damideh Vahid , Hassen Isaac
Published: March 2020

This paper demonstrates an RF thermal plasma pyrolysis reaction apparatus that achieves 89 wt.% reaction conversion yield with no tar content. The demonstrated experimental apparatus consists of a 1100 W RFVII Inc. (104 Church St, Newfield, NJ 08344, United States) @ 13.56 MHz RF thermal plasma generator, a Navio matching network, intelligent feedback controller, and an 8-turn copper RF-ICP torch embedded in a 12 L thermochemical reactor. The intelligent feedback controller optimizes the thermal performance based on feedback signals from three online gas analyzers: CO, CO2 and NOx. The feedback controller output signal controls the RF thermal plasma torch current that provides real-time temperature control. The proposed reaction system achieves precise temperature profiles for both pyrolysis and gasification as well as increases end-product yield and eliminates undesired products such as tar and char. The identified hydrocarbon liquid mixture is 90 wt.% gasoline and 10 wt.%. diesel. The 8-turn RF-ICP thermal plasma torch has an average heating rate of +35 °C/min and a maximum operating temperature of 2000 °C and is able to sustain stable flame for more than 30 min. The reaction operating parameters are (550–990 °C τ = 30 min for pyrolysis and (1300 °C τ = 1 sec) for the gasification process. The identified hydrocarbon liquid products are 90 wt.% of a n-butyl-benzene (C6H5C4H9) and oluene (C7H8) mixture with less than 10 wt.% decane diesel fuel (C10 H22). Comsol simulation is used to assess the RF-ICP thermal plasma torch’s thermal performance.
Development of Advanced Biodevices Using Quantum Beam Microfabrication Technology
Authors: Oyama Tomoko G. , Kimura Atsushi , Nagasawa Naotsugu , Oyama Kotaro , Taguchi Mitsumasa
Published: March 2020

Biodevices with engineered micro- and nanostructures are strongly needed for advancements in medical technology such as regenerative medicine, drug discovery, diagnostic reagents, and drug delivery to secure high quality of life. The authors produced functional biocompatible plastics and hydrogels with physical and chemical properties and surface microscopic shapes that can be freely controlled in three dimensions during the production process using the superior properties of quantum beams. Nanostructures on a biocompatible poly(L-lactic acid) surface were fabricated using a focused ion beam. Soft hydrogels based on polysaccharides were micro-fabricated using a focused proton beam. Gelatin hydrogels were fabricated using γ-rays and electron beam, and their microstructures and stiffnesses were controlled for biological applications. HeLa cells proliferated three-dimensionally on the radiation-crosslinked gelatin hydrogels and, furthermore, their shapes can be controlled by the micro-fabricated surface of the hydrogel. Long-lasting hydrophilic concave structures were fabricated on the surface of silicone by radiation-induced crosslinking and oxidation. The demonstrated advanced biodevices have potential applications in three-dimensional cell culture, gene expression control, stem cell differentiation induction/suppression, cell aggregation into arbitrary shapes, tissue culture, and individual diagnosis in the medical field.
Generative Transfer Learning for Intelligent Fault Diagnosis of the Wind Turbine Gearbox
Authors: Guo Jianwen , Wu Jiapeng , Zhang Shaohui , Long Jianyu , Chen Weidong , Cabrera Diego , Li Chuan
Published: March 2020

Intelligent fault diagnosis algorithms based on machine learning and deep learning techniques have been widely used in industrial applications and have obtained much attention as well as achievements. In real industrial applications, working loads of machines are always changing. Hence, directly applying the traditional algorithms will cause significant degradation of performance with changing conditions. In this paper, a novel domain adaptation method, named generative transfer learning (GTL), is proposed to tackle this problem. First, raw datasets were transformed to time–frequency domain based on short-time Fourier transformation. A domain discriminator was then built to distinguish whether the data came from the source or the target domain. A target domain classification model was finally acquired by the feature extractor and the classifier. Experiments were carried out for the fault diagnosis of a wind turbine gearbox. The t-distributed stochastic neighbor embedding technique was used to visualize the output features for checking the effectiveness of the proposed algorithm in feature extraction. The results showed that the proposed GTL could improve classification rates under various working loads. Compared with other domain adaptation algorithms, the proposed method exhibited not only higher accuracy but faster convergence speed as well.
A Model-Based Design Floating-Point Accumulator. Case of Study: FPGA Implementation of a Support Vector Machine Kernel Function
Authors: Bassoli Marco , Bianchi Valentina , De Munari Ilaria
Published: March 2020

Recent research in wearable sensors have led to the development of an advanced platform capable of embedding complex algorithms such as machine learning algorithms, which are known to usually be resource-demanding. To address the need for high computational power, one solution is to design custom hardware platforms dedicated to the specific application by exploiting, for example, Field Programmable Gate Array (FPGA). Recently, model-based techniques and automatic code generation have been introduced in FPGA design. In this paper, a new model-based floating-point accumulation circuit is presented. The architecture is based on the state-of-the-art delayed buffering algorithm. This circuit was conceived to be exploited in order to compute the kernel function of a support vector machine. The implementation of the proposed model was carried out in Simulink, and simulation results showed that it had better performance in terms of speed and occupied area when compared to other solutions. To better evaluate its figure, a practical case of a polynomial kernel function was considered. Simulink and VHDL post-implementation timing simulations and measurements on FPGA confirmed the good results of the stand-alone accumulator.
Trace Elements in Soils of a Typical Industrial District in Ningxia, Northwest China: Pollution, Source, and Risk Evaluation
Authors: Zhang Songlin , Liu Yuan , Yang Yujing , Ni Xilu , Arif Muhammad , Charles Wokadala , Li Changxiao
Published: March 2020

Intense industrial activities could result in massive accumulations of trace elements in the soil and risk the terrestrial ecosystems and human health. A total of 119 topsoil samples from a typical industrial area, Huinong District, Ningxia, Northwest China, were collected, and the contents of six trace elements (As, Cd, Cr, Cu, Pb, and Zn) were determined. The results indicated that the mean concentrations of Cr, Cu, Pb, and Zn were lower than the national standard values of class II, while As and Cd were 2.77 and 3.92 times the corresponding threshold values. Multivariate analyses revealed six metals can be categorized into three principal components (PC). PC1 was As, Cd, and Pb, which originated from anthropogenic inputs. PC2 consisted of Cr and Cu, which originated from the natural geological background. PC3 only included Zn and was mainly due to agricultural impacts. The spatial distribution of six metals greatly varied from local anthropic inputs. For As and Cd, the most heavily polluted area was located in the north and southwest parts of the study area, whereas most Zn was enriched in the southern part, which was mainly agricultural land. The topsoil in this area displayed a moderate environmental risk with the metal pollution order of Cd > As > Zn ≈ Cr ≈ Pb ≈ Cu. Moreover, the contents of trace elements in the industrial land and water were relatively higher than those in other land-use types, indicating a considerable risk of metal migration and accumulation to rivers and the groundwater. It is suggested that effective remediation measures for Cd and As, in particular, should be properly employed for the sustainable development of the soil and groundwater, while reducing the risk of elements to the local residents in Huinong District.
Food Origin Traceability from a Consumer’s Perspective
Authors: Walaszczyk Anna , Galińska Barbara
Published: March 2020

The awareness of food origin in the consumers’ perspective has gradually become more significant not only in reference to consumers from highly developed countries but also from emerging ones, which are already on their way from a developing to developed economy. The purpose of the paper is to answer the research question by verifying four hypotheses formulated in the research process. The research question is: "Do the variables which characterize consumers of food products in Poland, including gender, age, education and financial status, affect the aspects related to food traceability, such as identification of the producer, importance of food product features when shopping, importance of the information given on food product packaging and influence of the shopping place and frequency on tracing the food origin?" The paper presents the results, analysis, and conclusions from the study in reference to the four assumed hypotheses related to the above-mentioned research question. The study was carried out on a group of 500 consumers of food products in Poland. The study topic selection is justified by the assumed significance of tracing back a food product’s origin for a consumer who functions in a globalization-based economy; this was confirmed by the subject literature presented in the paper.
Livschitz Theorem in Suspension Flows and Markov Systems: Approach in Cohomology of Systems
Authors: Laureano Rosário D.
Published: March 2020

It is presented and proved a version of Livschitz Theorem for hyperbolic flows pragmatically oriented to the cohomological context. Previously, it is introduced the concept of cocycle and a natural notion of symmetry for cocycles. It is discussed the fundamental relationship between the existence of solutions of cohomological equations and the behavior of the cocycles along periodic orbits. The generalization of this theorem to a class of suspension flows is also discussed and proved. This generalization allows giving a different proof of the Livschitz Theorem for flows based on the construction of Markov systems for hyperbolic flows.
FCM-Based Approach for Locating Visible Video Watermarks
Authors: Embaby A. Al. , A. Wahby Shalaby Mohamed , Elsayed Khaled Mostafa
Published: March 2020

The increased usage demand for digital multimedia has induced significant challenges regarding copyright protection, which is the copy control and proof of ownership. Digital watermarking serves as a solution to these kinds of problems. Among different types of digital watermarking, visible watermarking protects the copyrights effectively, since the approach not only prevents pirates but also visually proves the copyright of the broadcasted video. A visible watermark could be in any location on the frame (corner, center, diagonal, etc.). In addition, it could either completely or partially disappear for some frames. The same video also might have multiple watermarks. In order to strengthen the techniques of adding visible watermarks, there is a need to discover the weakness of the used watermarks. Since the major step of attacking a visible watermark is to locate it accurately, in this paper, a Fuzzy C-Means (FCM)-based approach is proposed to locate visible watermarks in video. Broadcasting channels are used to utilize video logos, which can be considered as a form of visible watermark that represents a trademark or symbol to declare the intellectual property ownership. In general, a high-standard video watermark has such properties as a clear background with distinctive shape without additional texture obscuring the watermark area. In addition, the probability of the logo appearing in the four corners of the video frames is higher than in the center. Based on these common properties of the video watermark, the proposed scheme locates the visible watermark using the Fuzzy C-Means technique without any prior information. The proposed technique has two stages: the first stage is positioning, and the second is masking (extracting the watermark mask). Due to real-world limitations such as noise, shadowing, and variations in cameras, the positioning stage is developed by employing gradient and Fuzzy C-Means classifier techniques. By using the dilation and erosion operators, the masking stage is developed to extract the watermark mask. Using a set of trademark videos, the proposed algorithm is tested and evaluated. A comparative study shows that the proposed FCM-based technique is able to achieve higher accuracy at a reasonable computational cost in comparison to the most related and recent published work. The proposed technique could locate different watermarks with high symmetry in their pattern, even if they appeared mutually in the same location. Still, it will be a challenge if the symmetry is low between used watermarks in the same location.
New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra
Authors: Le T. D.
Published: March 2020

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.
Weak Local Residuals as Smoothness Indicators in Adaptive Mesh Methods for Shallow Water Flows
Authors: Mungkasi Sudi , Roberts Stephen Gwyn
Published: March 2020

This paper proposes some formulations of weak local residuals of shallow-water-type equations, namely, one-, one-and-a-half-, and two-dimensional shallow water equations. Smooth parts of numerical solutions have small absolute values of weak local residuals. Rougher parts of numerical solutions have larger absolute values of weak local residuals. This behaviour enables the weak local residuals to detect parts of numerical solutions which are smooth and rough (non-smooth). Weak local residuals that we formulate are implemented successfully as refinement or coarsening indicators for adaptive mesh finite volume methods used to solve shallow water equations.