bluuebunny/crossref_metadata_2025 huggingface dataset:
Excitation of Multi-Beam Interference and Whispering-Gallery Mode in Silica Taper-Assisted Polymer Microspheres for Refractometric Sensing
Authors: Fan Huibo , Zhou Dawei , Fan Li , Wu Yuanyan , Tao Hao , Gong Junbin
Published: April 2021

We propose and numerically analyze a fiber-optic sensor based on a silica taper-assisted multiple polymer microspheres to realize high-sensitivity refractometric sensing due to the excitation of multi-beam interference and whispering-gallery modes (WGMs) in each microsphere. Up to 5 UV-cured adhesive microspheres are dripped in sequence on the 2 µm-diameter silica taper with the certain distances in between. Scattering and reflection of light in each microsphere enhance the multi-beam interference because of the emergence of high-order modes. Moreover, WGMs with certain resonant wavelengths are excited in the microspheres, further enhancing the transmission spectrum with high contrast and quality factor. Furthermore, irregular transmission spectrum corresponds to the large wavelength tuning range. Propagating light between the microspheres could be strongly affected by the environmental factor with the large transmission spectrum shift, therefore realizing the refractometric sensing with high sensitivity of 846 nm/RIU based on the taper-assisted 2-spheres sensor. Furthermore, another two microspheres are placed on both sides of 2-spheres sensor to form 4-spheres-loop sensor, re-collecting those large-angle scattering light with the enhancement of multi-beam interference and WGMs. Therefore, the sensitivity of 4-shperes-loop sensor is further improved to the maximum of 1296.3 nm/RIU.
Digital Image Processing and Development of Machine Learning Models for the Discrimination of Corneal Pathology: An Experimental Model
Authors: Bustamante-Arias Andres , Cheddad Abbas , Jimenez-Perez Julio Cesar , Rodriguez-Garcia Alejandro
Published: April 2021

Machine learning (ML) has an impressive capacity to learn and analyze a large volume of data. This study aimed to train different algorithms to discriminate between healthy and pathologic corneal images by evaluating digitally processed spectral-domain optical coherence tomography (SD-OCT) corneal images. A set of 22 SD-OCT images belonging to a random set of corneal pathologies was compared to 71 healthy corneas (control group). A binary classification method was applied where three approaches of ML were explored. Once all images were analyzed, representative areas from every digital image were also extracted, processed and analyzed for a statistical feature comparison between healthy and pathologic corneas. The best performance was obtained from transfer learning—support vector machine (TL-SVM) (AUC = 0.94, SPE 88%, SEN 100%) and transfer learning—random forest (TL- RF) method (AUC = 0.92, SPE 84%, SEN 100%), followed by convolutional neural network (CNN) (AUC = 0.84, SPE 77%, SEN 91%) and random forest (AUC = 0.77, SPE 60%, SEN 95%). The highest diagnostic accuracy in classifying corneal images was achieved with the TL-SVM and the TL-RF models. In image classification, CNN was a strong predictor. This pilot experimental study developed a systematic mechanized system to discern pathologic from healthy corneas using a small sample.
Analysis of Graviresponse and Biological Effects of Vertical and Horizontal Clinorotation in Arabidopsis thaliana Root Tip
Authors: Villacampa Alicia , Sora Ludovico , Herranz Raúl , Medina Francisco-Javier , Ciska Malgorzata
Published: April 2021

Clinorotation was the first method designed to simulate microgravity on ground and it remains the most common and accessible simulation procedure. However, different experimental settings, namely angular velocity, sample orientation, and distance to the rotation center produce different responses in seedlings. Here, we compare A. thaliana root responses to the two most commonly used velocities, as examples of slow and fast clinorotation, and to vertical and horizontal clinorotation. We investigate their impact on the three stages of gravitropism: statolith sedimentation, asymmetrical auxin distribution, and differential elongation. We also investigate the statocyte ultrastructure by electron microscopy. Horizontal slow clinorotation induces changes in the statocyte ultrastructure related to a stress response and internalization of the PIN-FORMED 2 (PIN2) auxin transporter in the lower endodermis, probably due to enhanced mechano-stimulation. Additionally, fast clinorotation, as predicted, is only suitable within a very limited radius from the clinorotation center and triggers directional root growth according to the direction of the centrifugal force. Our study provides a full morphological picture of the stages of graviresponse in the root tip, and it is a valuable contribution to the field of microgravity simulation by clarifying the limitations of 2D-clinostats and proposing a proper use.
Uncovering the Neglected Floral Secretory Structures of Rhamnaceae and Their Functional and Systematic Significance
Authors: Ribeiro Carimi , Marinho Cristina , Teixeira Simone
Published: April 2021

Rhamnaceae flowers are notably recognized by their fleshy nectary. Other types of floral secretory structures have been scarcely reported for this family. Thus, the objective of the present study was to update the occurrence of these structures in the family and to contribute to the knowledge of their morphology and systematic significance. To this end, we carried out an extensive bibliographic search on the secretory structures of the family and obtained data for 257 taxa. Additionally, we presented here novel data (surface, anatomy, and ultrastructure) for six species belonging to the main clades within Rhamnaceae. The family has a wide diversity of types of mucilage-secreting structures: epidermis, hypodermis, idioblasts, cavities, and ducts. Mucilage and phenolic idioblasts are widely distributed among the floral organs. Colleters are present in all sampled species, and these are the first reports of their occurrence in floral organs of Rhamnaceae. The information obtained about the structure, secreted content, and occurrence of the secretory structures of Rhamnaceae helped us to understand the assertive folk use of its species. The absence of mucilage and the presence of resin or mucilage cavities and ducts in some taxa may have intrafamily systematic significance.
Identification and Isolation of an Intermediate Metabolite with Dual Antioxidant and Anti-Proliferative Activity Present in the Fungus Antrodia cinnamomea Cultured on an Alternative Medium with Cinnamomum kanehirai Leaf Extract
Authors: Zeng Wen-Wen , Chen Tsan-Chi , Liu Cheng-Huan , Wang Sheng-Yang , Shaw Jei-Fu , Chen Yu-Ting
Published: April 2021

The fungus Antrodia cinnamomea has been used as a folk medicine for various diseases, especially cancer. When A. cinnamomea is cultured on the original host, an endangered woody plant Cinnamomum kanehirai Hayata, the fungus produces more active ingredients, but its growth is slow. Here, C. kanehirai leaf ethanol extract (KLEE) was used as a substitute for C. kanehirai wood to culture A. cinnamomea on solid medium to shorten the culture period and produce active metabolites en masse. The antioxidant activities of methanol extracts from A. cinnamomea cultured on KLEE (MEAC-KLEE) were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, reducing power, and ferrous ion-chelating effect, and the effective concentration (EC50) values were 0.27, 0.74, and 0.37 mg mL−1, respectively. MEAC-KLEE exhibited specific anti-proliferative activity against a non-small-cell lung cancer cell line (A549) by Annexin V assay. A secondary metabolite (2,4-dimethoxy-6-methylbenzene-1,3-diol, DMMB) present in the extract (MEAC-KLEE) was purified by high-performance liquid chromatography (HPLC) and identified by nuclear magnetic resonance (NMR) spectra. DMMB exhibited moderate antioxidant activity against DPPH radicals and reducing power, with EC50 values of 12.97 and 25.59 μg mL−1, respectively, and also induced apoptosis in A549 cells. Our results provide valuable insight into the development of DMMB for nutraceutical biotechnology.
Gas Exchange, Water Use Efficiency, and Biomass Partitioning among Geographic Sources of Acer saccharum Subsp. saccharum and Subsp. nigrum Seedlings in Response to Water Stress
Authors: Hauer Richard J. , Wei Hongxu , Koeser Andrew K. , Dawson Jeffrey O.
Published: April 2021

Responses to water stress were measured for sugar maple (Acer saccharum subsp. saccharum Marshall) sources from Oklahoma (Caddo sugar maple), Missouri, Tennessee, Ontario, and a black maple (Acer saccharum subsp. nigrum F. Michx.) source from Iowa. Seedling sources were selected for differences in temperature and precipitation of their geographic origins. Seedlings were preconditioned through moist (watered daily) or dry (watered every 4–7 days) cycles and then exposed to prolonged water stress. As water stress increased, dry preconditioned 17-week-old sugar maple seedlings from Oklahoma, Missouri, and Tennessee, sources from warmer, and/or drier climates with greater restrained photosynthesis, stomatal conductance, and water use efficiency than those from cooler and moister climates. Under imposed water stress, the Ontario and Iowa sourced seedlings increased their root to shoot ratios and decreased their specific leaf area, mechanisms for drought avoidance. However, no corresponding changes in these values occurred for Oklahoma, Missouri, and Tennessee sources and for the variable of leaf wilting across all sources. Results from this study suggest greater tolerance of water stress in the Oklahoma, Missouri, and Tennessee ecotypes from the western and southern range of sugar maple resulted primarily with water use efficiency (WUE) rather than other water stress coping mechanisms. Findings from this study provide evidence to support selection of sugar maples sources for forestation.
Tribulus terrestris Efficacy and Safety Concerns in Diabetes and Erectile Dysfunction, Assessed in an Experimental Model
Authors: Ștefănescu Ruxandra , Farczadi Lenard , Huțanu Adina , Ősz Bianca E. , Mărușteri Marius , Negroiu Ancuța , Vari Camil E.
Published: April 2021

The present project aims to evaluate Tribulus terrestris (TT) extracts by addressing various possible mechanisms of action in order to see whether the use of TT supplements in diabetes and diabetes complications is justified. Diabetic rats were divided into three groups: diabetic control group, TT extract with low protodioscin content group (TT-LPC) and TT extract with high protodioscin content group (TT-HPC). After twelve weeks of treatment, fasting blood glucose, insulin, LH, FSH and testosterone levels were measured. Both TT preparations reduced elevated blood glucose level. Insulin and luteinizing hormone levels were not significantly different compared with the control group; however, the FSH and testosterone levels were significantly higher in the TT-HPC group compared with the diabetic control group. The testosterone level is correlated in part with the protodioscin concentration in extracts and is probably mediated through an FSH-linked pathway.
An Overview of Key Factors Affecting Genomic Selection for Wheat Quality Traits
Authors: Plavšin Ivana , Gunjača Jerko , Šatović Zlatko , Šarčević Hrvoje , Ivić Marko , Dvojković Krešimir , Novoselović Dario
Published: April 2021

Selection for wheat (Triticum aestivum L.) grain quality is often costly and time-consuming since it requires extensive phenotyping in the last phases of development of new lines and cultivars. The development of high-throughput genotyping in the last decade enabled reliable and rapid predictions of breeding values based only on marker information. Genomic selection (GS) is a method that enables the prediction of breeding values of individuals by simultaneously incorporating all available marker information into a model. The success of GS depends on the obtained prediction accuracy, which is influenced by various molecular, genetic, and phenotypic factors, as well as the factors of the selected statistical model. The objectives of this article are to review research on GS for wheat quality done so far and to highlight the key factors affecting prediction accuracy, in order to suggest the most applicable approach in GS for wheat quality traits.
Seed Priming with Sorghum Water Extract Improves the Performance of Camelina (Camelina sativa (L.) Crantz.) under Salt Stress
Authors: Huang Ping , He Lili , Abbas Adeel , Hussain Sadam , Hussain Saddam , Du Daolin , Hafeez Muhammad Bilal , Balooch Sidra , Zahra Noreen , Ren Xiaolong , Rafiq Muhammad , Saqib Muhammad
Published: April 2021

Seed priming with sorghum water extract (SWE) enhances crop tolerance to salinity stress; however, the application of SWE under salinity for camelina crop has not been documented so far. This study evaluated the potential role of seed priming with SWE in improving salt stress tolerance in camelina. Primed (with 5% SWE and distilled water-hydropriming) and nonprimed seeds were sown under control (no salt) and salt stress (10 dS m−1) conditions. Salinity reduced camelina’s emergence and growth, while seed priming with SWE improved growth under control and stress conditions. Under salt stress, seed priming with SWE enhanced emergence percentage (96.98%), increased root length (82%), shoot length (32%), root dry weight (75%), shoot dry weight (33%), α-amylase activity (66.43%), chlorophyll content (60–92%), antioxidant enzymes activity (38–171%) and shoot K+ ion (60%) compared with nontreated plants. Similarly, under stress conditions, hydrogen peroxide, malondialdehyde (MDA) content, and shoot Na+ ion were reduced by 60, 31, and 40% by seed priming with SWE, respectively, over the nonprimed seeds. Therefore, seed priming with SWE may be used to enhance the tolerance against salt stress in camelina.
Dependence of the Concentration of Bioactive Compounds in Origanum vulgare on Chemical Properties of the Soil
Authors: Klimienė Asta , Klimas Ramutis , Shutava Hanna , Razmuvienė Liuda
Published: April 2021

The aim of this study was to determine the dependence of the total phenolic, flavonoid, and extractive content in extracts of Origanum vulgare L. on the soil pH, humus, total nitrogen (Ntotal), and plant-available/mobile phosphorus (P2O5), as well as potassium (K2O), total calcium (Ca), magnesium (Mg), and sodium (Na) concentrations. Experimental fields were formed in four locations in Lithuania. Soil and perennial O. vulgare samples were taken at three sites of each experimental field. A total of 12 samples of soil and 12 samples of the tested plant were collected and analyzed. The concentrations of bioactive compounds in plants are significantly (p < 0.05–0.01) affected by some chemical properties of the soil: the total phenolic content was reliably correlated with the soil pH, Ntotal, Ca, Mg, and P2O5; the flavonoid content was correlated with the soil P2O5, K2O, Mg, and Na; and the extractive content was correlated with the soil humus, Ntotal, and Na. The obtained results are useful for the development of the commercial cultivation of O. vulgare.
Nanoimpact in Plants: Lessons from the Transcriptome
Authors: García-Sánchez Susana , Gala Michal , Žoldák Gabriel
Published: April 2021

Transcriptomics studies are available to evaluate the potential toxicity of nanomaterials in plants, and many highlight their effect on stress-responsive genes. However, a comparative analysis of overall expression changes suggests a low impact on the transcriptome. Environmental challenges like pathogens, saline, or drought stress induce stronger transcriptional responses than nanoparticles. Clearly, plants did not have the chance to evolve specific gene regulation in response to novel nanomaterials; but they use common regulatory circuits with other stress responses. A shared effect with abiotic stress is the inhibition of genes for root development and pathogen response. Other works are reviewed here, which also converge on these results.
Genetic Diversity and Population Structure of Potato Germplasm in RDA-Genebank: Utilization for Breeding and Conservation
Authors: Lee Kyung-Jun , Sebastin Raveendar , Cho Gyu-Taek , Yoon Munsup , Lee Gi-An , Hyun Do-Yoon
Published: April 2021

Potato (Solanum tuberosum L.) is an important staple food and economic crop in many countries. It is of critical importance to understand the genetic diversity and population structure for effective collection, conservation, and utilization of potato germplasm. Thus, the objective of the present study was to investigate the genetic diversity and population structure of potato germplasm conserved in the National Agrobiodiversity Center (NAC) of South Korea to provide basic data for future preservation and breeding of potato genetic resources. A total of 24 simple sequence repeat (SSR) markers were used to assess the genetic diversity and population structure of 482 potato accessions. A total of 257 alleles were detected, with an average of 10.71 alleles per locus. Analysis of molecular variance showed that 97% of allelic diversity was attributed to individual accessions within the population, while only 3% was distributed among populations. Results of genetic structure analysis based on STRUCTURE and discriminant analysis of principal components revealed that 482 potato accessions could be divided into two main subpopulations. Accessions of subpopulation 1 mainly belonged to cultivars and breeding lines. Accessions of subpopulations 2 basically corresponded to wild relatives of potatoes. Results of this study provide useful information for potato improvement and conservation programs, although further studies are needed for a more accurate evaluation of genetic diversity and phenotypic traits of potatoes.
Interaction of Diphenhydramine Hydrochloride with Cationic and Anionic Surfactants: Mixed Micellization and Binding Studies
Authors: Azum Naved , Rub Malik Abdul , Alfaifi Sulaiman Yahya , Asiri Abdullah M.
Published: April 2021

The focus of the present work is to evaluate the interactions of an anti-allergic drug (diphenhydramine hydrochloride, DPH) with anionic (sodium dodecyl sulfate, SDS) and cationic (cetylpyridinium chloride, CPC) surfactants in the aqueous medium. The mixed micellization behavior and surface properties of drug-surfactant mixtures have been examined by surface tension measurements. Various theoretical approaches were applied to explore the synergistic or non-ideal behavior of the current mixed systems. Furthermore, the binding studies of drug with surfactants have been elaborated by UV–visible spectroscopy. Benesi–Hildebrand (B-H) theory was used to compute stoichiometric ratio, binding constant, and free energy change for the drug-surfactant mixtures. The outputs are deliberated taking into consideration the use of surfactants as capable drug delivery agents for DPH and hence advance bioavailability.
Applicability of the Cox-Merz Rule to High-Density Polyethylene Materials with Various Molecular Masses
Authors: Rathner Raffael , Roland Wolfgang , Albrecht Hanny , Ruemer Franz , Miethlinger Jürgen
Published: April 2021

The Cox-Merz rule is an empirical relationship that is commonly used in science and industry to determine shear viscosity on the basis of an oscillatory rheometry test. However, it does not apply to all polymer melts. Rheological data are of major importance in the design and dimensioning of polymer-processing equipment. In this work, we investigated whether the Cox-Merz rule is suitable for determining the shear-rate-dependent viscosity of several commercially available high-density polyethylene (HDPE) pipe grades with various molecular masses. We compared the results of parallel-plate oscillatory shear rheometry using the Cox-Merz empirical relation with those of high-pressure capillary and extrusion rheometry. To assess the validity of these techniques, we used the shear viscosities obtained by these methods to numerically simulate the pressure drop of a pipe head and compared the results to experimental measurements. We found that, for the HDPE grades tested, the viscosity data based on capillary pressure flow of the high molecular weight HDPE describes the pressure drop inside the pipe head significantly better than do data based on parallel-plate rheometry applying the Cox-Merz rule. For the lower molecular weight HDPE, both measurement techniques are in good accordance. Hence, we conclude that, while the Cox-Merz relationship is applicable to lower-molecular HDPE grades, it does not apply to certain HDPE grades with high molecular weight.
Multiresponsive Cellulose Nanocrystal Cross-Linked Copolymer Hydrogels for the Controlled Release of Dyes and Drugs
Authors: Jiang Yuchen , Li Guihua , Yang Chenyu , Kong Fangong , Yuan Zaiwu
Published: April 2021

Multiresponsive hydrogels have attracted tremendous interest due to their promising applications in tissue engineering, wearable devices, and flexible electronics. In this work, we report a multiresponsive upper critical solution temperature (UCST) composite hydrogel based on poly (acrylic acid-co-acrylamide), PAAc-co-PAAm, sequentially cross-linked by acid-hydrolysis cellulose nanocrystals (CNCs). Scanning electron microscopy (SEM) observations demonstrated that the hydrogels are formed by densely cross-linked porous structures. The PAAc/PAAm/CNC hybrid hydrogels exhibit swelling and shrinking properties that can be induced by multiple stimuli, including temperature, pH, and salt concentration. The driving force of the volume transition is the formation and dissociation of hydrogen bonds in the hydrogels. A certain content of CNCs can greatly enhance the shrinkage capability and mechanical strength of the hybrid hydrogels, but an excess addition may impair the contractility of the hydrogel. Furthermore, the hydrogels can be used as a matrix to adsorb dyes, such as methylene blue (MB), for water purification. MB may be partly discharged from hydrogels by saline solutions, especially by those with high ionic strength. Notably, through temperature-controlled hydrogel swelling and shrinking, doxorubicin hydrochloride (DOX-HCl) can be controllably adsorbed and released from the prepared hydrogels.
Polyelectrolyte Multilayers on Soft Colloidal Nanosurfaces: A New Life for the Layer-By-Layer Method
Authors: Mateos-Maroto Ana , Abelenda-Núñez Irene , Ortega Francisco , Rubio Ramón G. , Guzmán Eduardo
Published: April 2021

The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials with controlled structure and functionality through the alternate deposition onto a template of two mutual interacting molecules, e.g., polyelectrolytes bearing opposite charge. The current development of this methodology has allowed the fabrication of a broad range of systems by assembling different types of molecules onto substrates with different chemical nature, size, or shape, resulting in numerous applications for LbL systems. In particular, the use of soft colloidal nanosurfaces, including nanogels, vesicles, liposomes, micelles, and emulsion droplets as a template for the assembly of LbL materials has undergone a significant growth in recent years due to their potential impact on the design of platforms for the encapsulation and controlled release of active molecules. This review proposes an analysis of some of the current trends on the fabrication of LbL materials using soft colloidal nanosurfaces, including liposomes, emulsion droplets, or even cells, as templates. Furthermore, some fundamental aspects related to deposition methodologies commonly used for fabricating LbL materials on colloidal templates together with the most fundamental physicochemical aspects involved in the assembly of LbL materials will also be discussed.
Improving Cooling Performance of Injection Molding Tool with Conformal Cooling Channel by Adding Hybrid Fillers
Authors: Kuo Chil-Chyuan , Chen Wei-Hua
Published: April 2021

Silicone rubber mold (SRM) is capable of reducing the cost and time in a new product development phase and has many applications for the pilot runs. Unfortunately, the SRM after injection molding has a poor cooling efficiency due to its low thermal conductivity. To improve the cooling efficiency, the thermal conductivity of the SRM was improved by adding fillers into the SRM. An optimal recipe for fabricating a high cooling efficiency low-pressure injection mold with conformal cooling channel fabricated by fused deposition modeling technology was proposed and implemented. This study proposes a recipe combining 52.6 wt.% aluminum powder, 5.3 wt.% graphite powder, and 42.1 wt.% liquid silicon rubber can be used to make SRM with excellent cooling efficiency. The price–performance ratio of this SRM made by the proposed recipe is around 55. The thermal conductivity of the SRM made by the proposed recipe can be increased by up to 77.6% compared with convention SRM. In addition, the actual cooling time of the injection molded product can be shortened up to 69.1% compared with the conventional SRM. The actual cooling time obtained by the experiment is in good agreement with the simulation results with the relative error rate about 20%.
Flexible Methyl Cellulose/Polyaniline/Silver Composite Films with Enhanced Linear and Nonlinear Optical Properties
Authors: Atta Ali , Abdelhamied Mostufa M. , Abdelreheem Ahmed M. , Berber Mohamed R.
Published: April 2021

In order to potentiate implementations in optical energy applications, flexible polymer composite films comprising methyl cellulose (MC), polyaniline (PANI) and silver nanoparticles (AgNPs) were successfully fabricated through a cast preparation method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating a successful incorporation of AgNPs into the MC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNPs into the MC/PANI blend. The optical parameters such as band gap (Eg), absorption edge (Ed), number of carbon cluster (N) and Urbach energy (Eu) of pure MC polymer, MC/PANI blend and MC/PANI/Ag films were determined using the UV optical absorbance. The effects of AgNPs and PANI on MC polymer linear optical (LO) and nonlinear optical (NLO) parameters including reflection extinction coefficient, refractive index, dielectric constant, nonlinear refractive index, and nonlinear susceptibility are studied. The results showed a decrease in the band gap of MC/PANI/AgNPs compared to the pure MC film. Meanwhile, the estimated carbon cluster number enhanced with the incorporation of the AgNPs. The inclusion of AgNPs and PANI has enhanced the optical properties of the MC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications.
Recovery of Carbon Fibre from Waste Prepreg via Microwave Pyrolysis
Authors: Hao Siqi , He Lizhe , Liu Jiaqi , Liu Yuhao , Rudd Chris , Liu Xiaoling
Published: April 2021

Management of waste from carbon fibre composites has become a significant societal issue as the application of composite grows across many industries. In this study, carbon fibres (CF) were successfully recovered from cured carbon fibre/epoxy (CF/EP) prepreg under microwave pyrolysis at 450, 550 and 650 °C followed by oxidation of any residual char. The recovered fibres were investigated for their tensile properties, surface morphologies and the elements/functional groups presented on the surface. The chemical compositions of gaseous and oil pyrolysis products were also analysed. The microwave pyrolysis effectively pyrolyzed the epoxy (EP) resin. Char residue remained on the fibre surface and the amount of char reduced as the pyrolysis temperature increased. Compared to virgin fibres, the recovered fibre suffered from a strength reduction by less than 20%, and this reduction could be mitigated by reducing the pyrolysis temperature. The surface of recovered fibre remained clean and smooth, while the profile of elements and functional groups at the surface were similar to those of virgin fibres. The main gaseous products were CO, H2, CO2 and CH4, whilst the liquid product stream included phenolic and aromatic compounds.
Self-Reinforced Nylon 6 Composite for Smart Vibration Damping
Authors: Salahuddin Bidita , Mutlu Rahim , Baigh Tajwar A. , Alghamdi Mohammed N. , Aziz Shazed
Published: April 2021

Passive vibration control using polymer composites has been extensively investigated by the engineering community. In this paper, a new kind of vibration dampening polymer composite was developed where oriented nylon 6 fibres were used as the reinforcement, and 3D printed unoriented nylon 6 was used as the matrix material. The shape of the reinforcing fibres was modified to a coiled structure which transformed the fibres into a smart thermoresponsive actuator. This novel self-reinforced composite was of high mechanical robustness and its efficacy was demonstrated as an active dampening system for oscillatory vibration of a heated vibrating system. The blocking force generated within the reinforcing coiled actuator was responsible for dissipating vibration energy and increase the magnitude of the damping factor compared to samples made of non-reinforced nylon 6. Further study shows that the appropriate annealing of coiled actuators provides an enhanced dampening capability to the composite structure. The extent of crystallinity of the reinforcing actuators is found to directly influence the vibration dampening capacity.
Bacterial Biopolymer: Its Role in Pathogenesis to Effective Biomaterials
Authors: Ghosh Sreejita , Lahiri Dibyajit , Nag Moupriya , Dey Ankita , Sarkar Tanmay , Pathak Sushil Kumar , Atan Edinur Hisham , Pati Siddhartha , Ray Rina Rani
Published: April 2021

Bacteria are considered as the major cell factories, which can effectively convert nitrogen and carbon sources to a wide variety of extracellular and intracellular biopolymers like polyamides, polysaccharides, polyphosphates, polyesters, proteinaceous compounds, and extracellular DNA. Bacterial biopolymers find applications in pathogenicity, and their diverse materialistic and chemical properties make them suitable to be used in medicinal industries. When these biopolymer compounds are obtained from pathogenic bacteria, they serve as important virulence factors, but when they are produced by non-pathogenic bacteria, they act as food components or biomaterials. There have been interdisciplinary studies going on to focus on the molecular mechanism of synthesis of bacterial biopolymers and identification of new targets for antimicrobial drugs, utilizing synthetic biology for designing and production of innovative biomaterials. This review sheds light on the mechanism of synthesis of bacterial biopolymers and its necessary modifications to be used as cell based micro-factories for the production of tailor-made biomaterials for high-end applications and their role in pathogenesis.
Evaluation of the Technical Viability of Distributed Mechanical Recycling of PLA 3D Printing Wastes
Authors: Beltrán Freddys R. , Arrieta Marina P. , Moreno Eduardo , Gaspar Gerald , Muneta Luisa M. , Carrasco-Gallego Ruth , Yáñez Susana , Hidalgo-Carvajal David , de la Orden María U. , Martínez Urreaga Joaquín
Published: April 2021

3D printing PLA wastes were recovered from a well-known reference grade and from different sources. The recovered wastes were subjected to an energic washing step and then reprocessed into films by melt-extrusion, followed by compression molding to simulate the industrial processing conditions. The obtained materials were characterized and the optical, structural, thermal and crystallization behavior are reported. The mechanical recycling process leads to an increase of the crystallinity and a decrease of the intrinsic viscosity of the formulations, particularly in the sample based on blends of different 3D-PLA wastes. Moreover, the obtained films were disintegrated under composting conditions in less than one month and it was observed that recycled materials degrade somewhat faster than the starting 3D-PLA filament, as a consequence of the presence of shorter polymer chains. Finally, to increase the molecular weight of the recycled materials, the 3D-PLA wastes were submitted to a solid-state polymerization process at 110, 120, and 130 °C, observing that the recycled 3D-wastes materials based on a well-known reference grade experiences an improvement of the intrinsic viscosity, while that coming from different sources showed no significant changes. Thus, the results show that 3D printing PLA products provides an ideal environment for the implementation of distributed recycling program, in which wastes coming from well-known PLA grades can successfully be processed in films with good overall performance.
Adsorption/Desorption Characteristics and Simultaneous Enrichment of Orientin, Isoorientin, Vitexin and Isovitexin from Hydrolyzed Oil Palm Leaf Extract Using Macroporous Resins
Authors: Che Zain Mohamad Shazeli , Lee Soo Yee , Teo Chian Ying , Shaari Khozirah
Published: April 2021

Oil palm leaves (OPL) containing flavonoid C-glycosides are abundantly generated as oil palm byproducts. The performances of three macroporous resins with different physical and chemical properties for the enrichment of isoorientin, orientin, vitexin, and isovitexin from acid-hydrolyzed OPL (OPLAH) extract were screened. The XAD7HP resin exhibited the best sorption capacities for the targeted flavonoid C-glycosides and was thus selected for further evaluation. Static adsorption using the XAD7HP resin under optimal conditions (extract adjusted to pH 5, shaken at 298 K for 24 h) gave adsorption kinetics that fit well with a pseudo-second-order kinetic model. The adsorption of isoorientin and orientin was well described by Langmuir isotherms, while vitexin and isovitexin fit well with the Freundlich isotherms. Dynamic sorption trials using the column-packed XAD7HP resin produced 55–60-fold enrichment of isovitexin and between 11 and 25-fold enrichment of isoorientin, vitexin, and orientin using aqueous ethanol. The total flavonoid C-glycoside-enriched fractions (enriched OPLAH) with isoorientin (247.28–284.18 µg/mg), orientin (104.88–136.19 µg/mg), vitexin (1197.61–1726.11 µg/mg), and isovitexin (13.03–14.61 µg/mg) showed excellent antioxidant free radical scavenging activities compared with their crude extracts, with IC50 values of 6.90–70.63 µg/mL and 44.58–200.00 µg/mL, respectively. Hence, this rapid and efficient procedure for the preliminary enrichment of flavonoid C-glycosides by using macroporous resin may have practical value in OPL biomass waste utilization programs to produce high value-added products, particularly in the nutraceuticals, cosmeceuticals, pharmaceuticals, and fine chemicals industries.
Special Issue on “Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes”
Authors: Gao Zhiwei , Chen Michael Z. Q. , Zhang Dapeng
Published: April 2021

Complex industrial automation systems and processes, such as chemical processes, manufacturing systems, wireless network systems, power and energy systems, smart grids and so forth, have greatly contributed to our daily life [...]
Development of Robust and Physically Interpretable Soft Sensor for Industrial Distillation Column Using Transfer Learning with Small Datasets
Authors: Hsiao Yu-Da , Kang Jia-Lin , Wong David Shan-Hill
Published: April 2021

In the development of soft sensors for industrial processes, the availability of data for data-driven modeling is usually limited, which led to overfitting and lack of interpretability when conventional deep learning models were used. In this study, the proposed soft sensor development methodology combining first-principle simulations and transfer learning was used to address these problems. Source-domain models were obtained using a large amount of data generated by dynamic simulations. They were then fine-tuned by a limited amount of real plant data to improve their prediction accuracies on the target domain and guaranteed the models with correct domain knowledge. An industrial C4 separation column operating at a refining unit was used as an example to illustrate the effectiveness of this approach. Results showed that fine-tuned networks could obtain better accuracy and improved interpretability compared to a simple feedforward network with or without regularization, especially when the amount of actual data available was small. For some secondary effects, such as interaction gain, its interpretability is mainly based on the interpretability of the corresponding source models.
Emerging Technologies for Biorefining, Food and Environmental Applications
Authors: Castro-Muñoz Roberto
Published: April 2021

Several emerging technologies, such as membrane technologies, biofermentation, oxidation processes, among others, are currently attracting interest in different areas of biotechnological and chemical engineering [...]
Experimental Study on a Closed-Cycle Humidification and Dehumidification System for Treating Wastewater Containing High Concentrations of Inorganic Salts and Organic Matter
Authors: Liu Jun , Sun Yong , Yv Sanjiang , Wang Jiaquan , Hu Kaixuan
Published: April 2021

Industrial wastewater contains high concentrations of inorganic salts and organic matter. This experiment studied a system for treating wastewater containing high concentrations of inorganic salts and organic matter. The setup consists of a closed-cycle humidification and dehumidification system and a filter press. Chemical wastewater was used as the treatment solution, and the treatment performance of the system was tested and analyzed. The system effectively reduced the chemical oxygen demand (COD), electric conductivity (EC), total nitrogen (TN), and ammonia nitrogen (NH4-N) in the wastewater and, at the same time, dehydrated sludge was obtained through a filter press. The system maintains a stable removal rate of each index (COD, EC, TN, and NH4-N) in wastewater and can remove inorganic salts and organic matter from wastewater. The system can successfully treat industrial wastewater containing high concentrations of inorganic salts and organic matter.
Advances in the Development of Sol-Gel Materials Combining Small-Angle X-ray Scattering (SAXS) and Machine Learning (ML)
Authors: Scherdel Christian , Miller Eddi , Reichenauer Gudrun , Schmitt Jan
Published: April 2021

The requirements for new materials are increasing with each new application, which, in most cases, means an enhancement in the complexity of the development process. Nanoporous sol-gel-based materials, especially aerogels, are promising candidates for thermal superinsulation, electrodes for energy conversion and storage or high-end adsorbers. Their synthesis and processing route is complex, and the relationship between the material/processing parameters and the resulting structural and physical properties is not straightforward. Using small-angle X-ray scattering (SAXS) allows for fast structural characterization of both the gel and the resulting aerogel; combining these results with the respective physical properties of the aerogels and using these data as inputs for machine learning (ML) algorithms provide an approach to predict physical properties on the basis of a structural dataset. This data-driven strategy may be a feasible approach to speed up the development process. Thus, the study aimed to provide a proof of concept of ML-based model derivation from material, process and SAXS data to predict physical properties such as the solid-phase thermal conductivity (λs) of silica aerogels from a structural dataset. Here, we used different data subsets as predictors according to different states of synthesis (wet and dry) to evaluate the model performance.
Simultaneous Removal of Trivalent Arsenic and Nitrate Using Microbial Fuel Cells
Authors: Guo Jing , Cheng Jianping , Wang Jiaquan , Hu Shuheng
Published: April 2021

A rectangular double chamber with trivalent arsenic as the electron donor of the biological anode was constructed by microbial fuel cells (MFC), and the feasibility of the MFC simultaneous degradation of trivalent arsenic and nitrate was studied. Experimental results show that the co-matrix-coupled MFC reactor oxidizes trivalent arsenic in an anode chamber and degrades nitrate in the cathode chamber. The removal rate of trivalent arsenic is about 63.35%, and the degradation rate of nitrate is about 55.95% during the complete and stable operation period. MFC can continuously output electric energy, and the maximum output voltage is 388 mV. We compared and analyzed the main functional microflora of biofilm microorganisms in an anode chamber. In the long-term arsenic-polluted environment, the activity of Acinetobacter, Pseudomonas bacteria with arsenic resistance, was improved. It is inferred that a fraction of trivalent arsenic was oxidized to pentavalent arsenic by electrode-attached microorganisms. While remaining trivalent, arsenic was taken up by the suspended bacterial biomass and converted into stable arsenide. The results of this study have theoretical reference value for the expansion of the MFC application scope.
Being True
Authors: DeLay Steven
Published: April 2021

Turning to Karl Jaspers’s 1937 lectures, later published as Philosophy of Existence, this paper examines what might be meant by the colloquial expression “spiritual but not religious”. In doing so, it is argued that while Jaspers’s critique of organized religion mostly hits the mark, critiques of religion—as represented here by Jaspers’s Existenzphilosophie—fail to undermine a form of genuine spirituality grounded in a faith in the revealed Christ.
Following the Footsteps of John Polkinghorne: In Search of Divine Action in the World
Authors: Karaba Miroslav
Published: April 2021

John Polkinghorne was, undoubtedly, one of the most influential authors in the dialogue between science and religion. His attitude is characterized by a focus on the concept of kenosis in response to the ontological orientation of process philosophy and theology. God’s omnipotence implies the possibility that God created the universe as an evolutionary and autonomous world, which is not predetermined but has been created for openness. According to Polkinghorne, the position of this openness may be in the uncertainty associated with the world of quantum and chaotic phenomena. God’s self-limitation of his own omnipotence can thus be understood as an effort to respect the autonomy of natural processes and human freedom. Such an image of God is compatible with the current state of scientific knowledge, which itself becomes the starting point for thinking about God and his relationship to the world. Thus, despite the problems of some parts of its concept, Polkinghorne creates a comprehensive integrative approach to the dialogue between science and religion.
An Optimal Tail Selection in Risk Measurement
Authors: Just Małgorzata , Echaust Krzysztof
Published: April 2021

The appropriate choice of a threshold level, which separates the tails of the probability distribution of a random variable from its middle part, is considered to be a very complex and challenging task. This paper provides an empirical study on various methods of the optimal tail selection in risk measurement. The results indicate which method may be useful in practice for investors and financial and regulatory institutions. Some methods that perform well in simulation studies, based on theoretical distributions, may not perform well when real data are in use. We analyze twelve methods with different parameters for forty-eight world indices using returns from the period of 2000–Q1 2020 and four sub-periods. The research objective is to compare the methods and to identify those which can be recognized as useful in risk measurement. The results suggest that only four tail selection methods, i.e., the Path Stability algorithm, the minimization of the Asymptotic Mean Squared Error approach, the automated Eyeball method with carefully selected tuning parameters and the Hall single bootstrap procedure may be useful in practical applications.
Economic and Financial Crime: Corruption, Shadow Economy, and Money Laundering: Book Review. Written by Monica Violeta Achim and Sorin Nicolae Borlea. Springer Nature: Cham, Switzerland, 2021. ISBN 978-3-030-51780-9
Authors: Schneider Friedrich
Published: April 2021

The authors Monica Violeta Achim and Sorin Nicolae Borlea structured their book entitled “Economic and Financial Crime: Corruption, shadow economy, and money laundering” in four major parts [...]
Remote Sensing of Forest Structural Changes Due to the Recent Boom of Unconventional Shale Gas Extraction Activities in Appalachian Ohio
Authors: Liu Yang
Published: April 2021

Dense unconventional shale gas extraction activities have occurred in Appalachian Ohio since 2010 and they have caused various landcover changes and forest fragmentation issues. This research investigated the most recent boom of unconventional shale gas extraction activities and their impacts on the landcover changes and forest structural changes in the Muskingum River Watershed in Appalachian Ohio. Triple-temporal high-resolution natural-color aerial images from 2006 to 2017 and a group of ancillary geographic information system (GIS) data were first used to digitize the landcover changes due to the recent boom of these unconventional shale gas extraction activities. Geographic object-based image analysis (GEOBIA) was then employed to form forest patches as image objects and to accurately quantify the forest connectivity. Lastly, the initial and updated forest image objects were used to quantify the loss of core forest as the two-dimensional (2D) forest structural changes, and initial and updated canopy height models (CHMs) derived from airborne light detection and ranging (LiDAR) point clouds were used to quantify the loss of forest volume as three-dimensional (3D) forest structural changes. The results indicate a consistent format but uneven spatiotemporal development of these unconventional shale gas extraction activities. Dense unconventional shale gas extraction activities formed two apparent hotspots. Two-thirds of the well pad facilities and half of the pipeline right-of-way (ROW) corridors were constructed during the raising phase of the boom. At the end of the boom, significant forest fragmentation already occurred in both hotspots of these active unconventional shale gas extraction activities, and the areal loss of core forest reached up to 14.60% in the densest concentrated regions of these activities. These results call for attention to the ecological studies targeted on the forest fragmentation in the Muskingum River Watershed and the broader Appalachian Ohio regions.
Multiview Deep Feature Learning Network for SAR Automatic Target Recognition
Authors: Pei Jifang , Huo Weibo , Wang Chenwei , Huang Yulin , Zhang Yin , Wu Junjie , Yang Jianyu
Published: April 2021

Multiview synthetic aperture radar (SAR) images contain much richer information for automatic target recognition (ATR) than a single-view one. It is desirable to establish a reasonable multiview ATR scheme and design effective ATR algorithm to thoroughly learn and extract that classification information, so that superior SAR ATR performance can be achieved. Hence, a general processing framework applicable for a multiview SAR ATR pattern is first given in this paper, which can provide an effective approach to ATR system design. Then, a new ATR method using a multiview deep feature learning network is designed based on the proposed multiview ATR framework. The proposed neural network is with a multiple input parallel topology and some distinct deep feature learning modules, with which significant classification features, the intra-view and inter-view features existing in the input multiview SAR images, will be learned simultaneously and thoroughly. Therefore, the proposed multiview deep feature learning network can achieve an excellent SAR ATR performance. Experimental results have shown the superiorities of the proposed multiview SAR ATR method under various operating conditions.