bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study of Flank Cams Manufactured by WEDM and Milling Processes
Authors: Buj-Corral Irene , Zayas-Figueras Enrique , Montaña-Faiget Àngels
Published: August 2020

Cam-follower mechanisms are usually employed in different machines, like combustion engines, sewing machines, machine tools, etc. In the present paper, the option to manufacture cams utilizing wire electrical discharge machining (WEDM) has been considered. For this, surface roughness and shape error of cam profiles manufactured by the processes of milling and wire electrical discharge machining (WEDM) are presented. The methodology used covers different stages: design, prototyping, manufacturing, and measurement of the cams. As a reference, a cam-follower mechanism from a motorcycle internal combustion engine has been used. A reverse engineering process has been performed to determine the geometrical parameters of the mechanism, which are used for the synthesis of the profile of the cam and its subsequent design. The manufacturing process of the cams has been assisted by CAD-CAM (Computer Assisted Drawing-Computer Assisted Manufacturing) software. Using fused filament fabrication (FFF), a physical prototype of the cam has been manufactured, in order to validate the goodness of the design. Finally, the roughness and shape parameters have been measured on the contour surface of the cams. The arithmetical mean roughness Ra value of the milled cam was 0.269 μm, below the requirement of 0.4 μm, and shape error was 18 μm, below 50 μm. Shape error of the WEDM cam of 48 μm meets the requirements for cams. However, the Ra value of 1.212 μm, exceeded the limit. For this reason, a finish operation is recommended in this case. Some advantages of WEDM cams over milled cams are that different conductive materials can be employed, more complex shapes can be obtained, and that, in rough operations, the amount of material to be removed in subsequent operations is considerably reduced.
Dependence of the Staphylococcal Volatilome Composition on Microbial Nutrition
Authors: Jenkins Carrie L. , Bean Heather D.
Published: August 2020

In vitro cultivation of staphylococci is fundamental to both clinical and research microbiology, but few studies, to-date, have investigated how the differences in rich media can influence the volatilome of cultivated bacteria. The objective of this study was to determine the influence of rich media composition on the chemical characteristics of the volatilomes of Staphylococcus aureus and Staphylococcus epidermidis. S. aureus (ATCC 12600) and S. epidermidis (ATCC 12228) were cultured in triplicate in four rich complex media (brain heart infusion (BHI), lysogeny broth (LB), Mueller Hinton broth (MHB), and tryptic soy broth (TSB)), and the volatile metabolites produced by each culture were analyzed using headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography—time-of-flight mass spectrometry (HS-SPME-GC×GC-TOFMS). When comparing the chemical compositions of the staph volatilomes by the presence versus absence of volatiles produced in each medium, we observed few differences. However, when the relative abundances of volatiles were included in the analyses, we observed that culturing staph in media containing free glucose (BHI and TSB) resulted in volatilomes dominated by acids and esters (67%). The low-glucose media (LB and MHB) produced ketones in greatest relative abundances, but the volatilome compositions in these two media were highly dissimilar. We conclude that the staphylococcal volatilome is strongly influenced by the nutritional composition of the growth medium, especially the availability of free glucose, which is much more evident when the relative abundances of the volatiles are analyzed, compared to the presence versus absence.
Biochemical and Molecular Characterization of a Thermostable Alkaline Metallo-Keratinase from Bacillus sp. Nnolim-K1
Authors: Nnolim Nonso E. , Mpaka Lindelwa , Okoh Anthony I. , Nwodo Uchechukwu U.
Published: August 2020

Keratinases are considerably gaining momentum in green technology because of their endowed robustness and multifaceted application potentials, such as keratinous agro-wastes valorization. Therefore, the production of novel keratinases from relatively nonpathogenic bacteria grown in agro-wastes formulated medium is cost-effective, and also imperative for the sustainability of thriving bioeconomy. In this study, we optimized keratinase production by Bacillus sp. Nnolim-K1 grown in chicken feather formulated medium. The produced keratinase (KerBNK1) was biochemically characterized and also, the keratinase-encoding gene (kerBNK1) was amplified and sequenced. The optimal physicochemical conditions for extracellular keratinase production determined were 0.8% (w/v) xylose, 1.0% (w/v) feather, and 3.0% (v/v) inoculum size, pH 5.0, temperature (25 °C) and agitation speed (150 rpm). The maximum keratinase activity of 1943.43 ± 0.0 U/mL was achieved after 120 h of fermentation. KerBNK1 was optimally active at pH and temperature of 8.0 and 60 °C, respectively; with remarkable pH and thermal stability. KerBNK1 activity was inhibited by ethylenediamine tetra-acetic acid and 1,10-phenanthroline, suggesting a metallo-keratinase. The amplified kerBNK1 showed a band size of 1104 bp and the nucleotide sequence was submitted to the GenBank with accession number MT268133. Bacillus sp. Nnolim-K1 and the keratinase displayed potentials that demand industrial and biotechnological exploitations.
Identification Mycobacterium spp. in the Natural Water of Two Austrian Rivers
Authors: Delghandi Mohammad Reza , Waldner Karoline , El-Matbouli Mansour , Menanteau-Ledouble Simon
Published: August 2020

Nontuberculous mycobacteria constitute a subgroup among the Mycobacterium genus, a genus of Gram-positive bacteria that includes numerous pathogenic bacteria. In the present study, Mycobacterium spp. were detected in natural water samples from two Austrian rivers (Kamp and Wulka) using three different primers and PCR procedures for the identification of the 16S rRNA and hsp65 genes. Water samples were collected from the Kamp (45 samples) and Wulka (25 samples) in the summer and winter of 2018 and 2019. Molecular evidence showed a high prevalence of Mycobacterium sp. in these rivers with prevalence rates estimated at approximately 94.3% across all rivers. The present study represents the first survey into the prevalence of Mycobacterium sp. in natural water in Austria. Because nontuberculous mycobacteria have known pathogenic potential, including zoonotic, these findings may have implications for health management and public health.
Impact of Diagenesis on the Reservoir Properties of the Cretaceous Sandstones in the Southern Bredasdorp Basin, Offshore South Africa
Authors: Baiyegunhi Temitope Love , Liu Kuiwu , Gwavava Oswald , Baiyegunhi Christopher
Published: August 2020

The Cretaceous sandstone in the Bredasdorp Basin is an essential potential hydrocarbon reservoir. In spite of its importance as a reservoir, the impact of diagenesis on the reservoir quality of the sandstones is almost unknown. This study is undertaken to investigate the impact of digenesis on reservoir quality as it pertains to oil and gas production in the basin. The diagenetic characterization of the reservoir is based on XRF, XRD SEM + EDX, and petrographic studies of 106 thin sections of sandstones from exploration wells E-AH1, E-AJ1, E-BA1, E-BB1 and E-D3 in the basin. The main diagenetic processes that have affected the reservoir quality of the sandstones are cementation by authigenic clay, carbonate and silica, growth of authigenic glauconite, dissolution of minerals and load compaction. Based on the framework grain–cement relationships, precipitation of the early calcite cement was either accompanied or followed up by the development of partial pore-lining and pore-filling clay cements, particularly illite. This clay acts as pore choking cement, which reduces porosity and permeability of the reservoir rocks. The scattered plots of porosity and permeability versus cement + clays show good inverse correlations, suggesting that the reservoir quality is mainly controlled by cementation and authigenic clays.
Geochronological and Geochemical Study of Zircon from Tourmaline-Muscovite Granites of the Archaean Kolmozero–Voronya Greenstone Belt: Insights into Sources of the Rare-Metal Pegmatites
Authors: Kudryashov Nikolay M. , Udoratina Oksana V. , Coble Matthew A. , Steshenko Ekaterina N.
Published: August 2020

In order to determine the U-Pb crystallization age of zircon from the tourmaline-muscovite granites of the Kolmozero–Voronya greenstone belt located in the northeastern Fennoscandian Shield (Kola Peninsula), an isotope-geochronological study of the zircon grains was performed using a SHRIMP-RG microprobe. The belt is represented by the Archaean volcano-sedimentary rocks (2.9–2.8 Ga). Deposits of rare-metal pegmatites (Li and Cs with associated Nb, Ta, and Be) occur within the belt and on its margins. The age of the pegmatites within the belt was estimated at 2.7–2.6 Ga. Until now, there has been no generally accepted view on the genetic relation of the pegmatites with granite. Various authors have suggested that the pegmatites could potentially be associated with many type of granitoids within the region, i.e., plagiogranites, tonalites, amphibole-biotite granodiorites, microcline granites, alkaline granites, or muscovite-tourmaline granites. Zircon crystals from the muscovite-tourmaline granites are heterogeneous; they have less altered cores and strongly altered rims. The zircon cores are slightly enriched in U at a value of 173–1030 ppm, Th/U = 0.1–0.4. The zircons’ rims are heavily enriched in U at a value of 700–3300 ppm, Th/U = 0.03–0.08, indicating metasomatic processes. Zircon characteristics show that it crystallized from a melt enriched in a fluid phase. Fluid activity lasted after zircon crystallization as reflected in the irregular composition of the mineral and its rare earth element (REE) patterns that are typical of a metasomatic zircon. The computed zircon crystallization temperature in the tourmaline-muscovite granites is in the range of 650–850 °C. The discordant age calculated for five analyzed points of the zircon crystal cores is 2802 ± 13 Ma. The discordant age for four analyzed points of the zircon crystal rims is found to be 2728 ± 14 Ma. On the basis of the obtained isotope-geochronological data, we conclude that the tourmaline-muscovite granites located in the immediate vicinity of rare-metal pegmatite veins are the most probable source of matter for the pegmatites.
Molecular Dynamics Simulation of Cetyl Phosphate Adsorption in Flotation of Magnesite and Pertinent Chemical Aspects
Authors: Tang Yuan , Yao Jin , Yin Wanzhong , Kelebek Sadan
Published: August 2020

Magnesite ores are important resources in the production of value-added magnesium materials. Generally, low selectivity of conventional collectors and the requirement of a large amount of depressant has been a motivation for researchers to identify alternate collectors. In this work, the role of potassium cetyl phosphate (PCP) as a new collector in magnesite flotation is investigated using molecular dynamics (MD) simulations and chemical equilibria, electrokinetics and wettability. The results indicate that PCP exhibits a strong collecting ability for magnesite particles even with low concentrations. The presence of PCP leads to significant alterations in the electric double layer and contact angle behavior of magnesite, which results in rapid adsorption of PCP on magnesite surface. The results from chemical computations show that the monoanionic forms of PCP are the dominant species in the weakly acidic pH range, where monohydroxy magnesium species and the ion concentration of magnesite in suspension can be controlled by adjusting pH. The adsorption models indicate that the stable adsorption of PCP on magnesite surfaces occurs spontaneously, supporting the potentiality for selective magnesite flotation in its separation from other carbonate minerals.
Fe/Ni Bimetallic Organic Framework Deposited on TiO2 Nanotube Array for Enhancing Higher and Stable Photoelectrochemical Activity of Oxygen Evaluation Reaction
Authors: You Sheng-Mu , El Rouby Waleed M. A. , Thamilselvan Annadurai , Tsai Cheng-Kuo , Darmanto Win , Doong Ruey-An , Millet Pierre
Published: August 2020

Photoelectrochemical (PEC) water splitting is a promising strategy to improve the efficiency of oxygen evolution reactions (OERs). However, the efficient adsorption of visible light as well as long-term stability of light-harvesting electrocatalysis is the crucial issue in PEC cells. Metal–organic framework (MOF)-derived bimetallic electrocatalysis with its superior performance has wide application prospects in OER and PEC applications. Herein, we have fabricated a nickel and iron bimetallic organic framework (FeNi-MOF) deposited on top of anodized TiO2 nanotube arrays (TNTA) for PEC and OER applications. The FeNi-MOF/TNTA was incorporated through the electrochemical deposition of Ni2+ and Fe3+ onto the surface of TNTA and then connected with organic ligands by the hydrothermal transformation. Therefore, FeNi-MOF/TNTA demonstrates abundant photoelectrocatalytic active sites that can enhance the photocurrent up to 1.91 mA/cm2 under 100 mW/cm2 and a negligible loss in activity after 180 min of photoreaction. The FeNi-MOF-doped photoanode shows predominant photoelectrochemical performance due to the boosted excellent light-harvesting ability, rapid photoresponse, and stimulated interfacial energy of charge separation under the UV-visible light irradiation conditions. The results of this study give deep insight into MOF-derived bimetallic nanomaterial synthesis for photoelectrochemical OER and provide guidance on future electrocatalysis design.
Seasonal Antimicrobial Activity of the Airway: Post-Hoc Analysis of a Randomized Placebo-Controlled Double-Blind Trial
Authors: Vargas Buonfiglio Luis G. , Vanegas Calderon Oriana G. , Cano Marlene , Simmering Jacob E. , Polgreen Philip M. , Zabner Joseph , Gerke Alicia K. , Comellas Alejandro P.
Published: August 2020

Background: It is widely unknown why respiratory infections follow a seasonal pattern. Variations in ultraviolet B (UVB) light during seasons affects cutaneous synthesis of vitamin D3. Serum vitamin D concentration influences the expression of airway surface liquid (ASL) antimicrobial peptides such as LL-37. Objective: We sought to determine the effect of seasons on serum vitamin D levels and ASL antimicrobial activity. Methods: Forty participants, 18–60 years old, were randomized 1:1 to receive 90 days of 1000 IU vitamin D3 or placebo. We collected ASL via bronchoscopy and measured serum 25(OH) vitamin D from participants before and after intervention across seasons. We measured ASL antimicrobial activity by challenging samples with bioluminescent Staphylococcus aureus and measured relative light units (RLUs) after four minutes. We also investigated the role of LL-37 using a monoclonal neutralizing antibody. Results: We found that participants, prior to any intervention, during summer–fall (n = 20) compared to winter–spring (n = 20) had (1) decreased live bacteria after challenge (5542 ± 175.2 vs. 6585 ± 279 RLU, p = 0.003) and (2) higher serum vitamin D (88.25 ± 24.25 vs. 67.5 ± 45.25 nmol/L, p = 0.026). Supplementation with vitamin D3 increased vitamin D levels and restored ASL antimicrobial activity only during the winter–spring. The increased ASL antimicrobial activity seen during the summer–fall was abrogated by adding the LL-37 neutralizing antibody. Conclusion: ASL kills bacteria more effectively during the summer–fall compared to the winter–spring. Supplementation of vitamin D during winter–spring restores ASL antimicrobial activity by increasing the expression of antimicrobial peptides including LL-37.
Development and Validation of the Short Healthy Eating Index Survey with a College Population to Assess Dietary Quality and Intake
Authors: Colby Sarah , Zhou Wenjun , Allison Chelsea , Mathews Anne E. , Olfert Melissa D. , Morrell Jesse Stabile , Byrd-Bredbenner Carol , Greene Geoffrey , Brown Onikia , Kattelmann Kendra , Shelnutt Karla
Published: August 2020

Because diet quality (DQ) is associated with risk of chronic disease and is a common construct assessed in health-related research, validated tools to assess DQ are needed that have low respondent and researcher burden. Thus, content experts develop the Short Healthy Eating Index (sHEI) tool and an associated scoring system. The sHEI scoring system was then refined using a classification and regression tree (CRT) algorithm methodology with an iterative feedback process with expert review and input. The sHEI scoring system was then validated using a concurrent criterion validation process that included the sHEI DQ scores (calculated from responses from 50 participants) being compared to the participants’ Healthy Eating Index scores derived from 24 h recalls. The total HEI score from the CRT algorithm highly correlated with the 24 h recall HEI score (0.79). For individual food group items, the correlation between the CRT algorithm scoring and the 24 h recall data scoring ranged from 0.44 for refined grains to 0.64 for whole fruits. The sHEI appears to be a valid tool for estimating overall dietary quality and individual items (with correlations > 0.49) for fruits, vegetables, dairy, added sugar, sugar from sugar-sweetened beverages, and calcium.
Culturally Optimised Nutritionally Adequate Food Baskets for Dietary Guidelines for Minimum Wage Estonian Families
Authors: Lauk Janne , Nurk Eha , Robertson Aileen , Parlesak Alexandr
Published: August 2020

Although low socioeconomic groups have the highest risk of noncommunicable diseases in Estonia, national dietary guidelines and nutrition recommendations do not consider affordability. This study aims to help develop nutritionally adequate, health-promoting, and culturally acceptable dietary guidelines at an affordable price. Three food baskets (FBs) were optimised using linear programming to meet recommended nutrient intakes (RNIs), or Estonian dietary guidelines, or both. In total, 6255 prices of 422 foods were collected. The Estonian National Dietary Survey (ENDS) provided a proxy for cultural acceptability. Food baskets for a family of four, earning minimum wage, contain between 73 and 96 foods and cost between 10.66 and 10.92 EUR per day. The nutritionally adequate FB that does not follow Estonian dietary guidelines deviates the least (26% on average) from ENDS but contains twice the sugar, sweets, and savoury snacks recommended. The health-promoting FB (40% deviation) contains a limited amount of sugar, sweets, and savoury snacks. However, values for vitamin D, iodine, iron, and folate are low compared with RNIs, as is calcium for women of reproductive age. When both the RNIs and dietary guidelines are enforced, the average deviation (73%) and cost (10.92 EUR) are highest. The composition of these FBs can help guide the development of dietary guidelines for low income families in Estonia.
Therapeutic Use of the Ketogenic Diet in Refractory Epilepsy: What We Know and What Still Needs to Be Learned
Authors: Zarnowska Iwona Maria
Published: August 2020

Ketogenic diet (KD) has been used to treat epilepsy for 100 years. It is a high-fat, low-carbohydrate, and sufficient-protein-for-growth diet that mimics the metabolic changes occurring during starvation. Except for classic KD, its modified counterparts, including modified Atkins diet and low-glycemic-index treatment, have gained grounds to increase palatability and adherence. Strong evidence exists that the KD offers protection against seizures in difficult-to-treat epilepsy and possesses long-lasting anti-epileptic activity, improving long-term disease outcome. The KD can also provide symptomatic and disease-modifying activity in a wide range of neurodegenerative diseases. In an era of highly available new anti-seizure medications (ASMs), the challenge of refractory epilepsy has still not been solved. This metabolic therapy is increasingly considered due to unique mechanisms and turns out to be a powerful tool in the hands of a skillful team. Despite decades of extensive research to explain the mechanism of its efficacy, the precise mechanism of action is to date still largely unknown. The key feature of this successful diet is the fact that energy is derived largely from fat but not from carbohydrates. Consequently, fundamental change occurs regarding the method of energy production that causes alterations in numerous biochemical pathways, thus restoring energetic and metabolic homeostasis of the brain. There are barriers during the use of this special and individualized therapy in many clinical settings worldwide. The aim of this review is to revisit the current state of the art of therapeutic application of KD in refractory epilepsy.
Atypical Non-H2S-Producing Monophasic Salmonella Typhimurium ST3478 Strains from Chicken Meat at Processing Stage Are Adapted to Diverse Stresses
Authors: Mourão Joana , Rebelo Andreia , Ribeiro Sofia , Peixe Luísa , Novais Carla , Antunes Patrícia
Published: August 2020

Poultry products are still an important cause of Salmonella infections worldwide, with an increasingly reported expansion of less-frequent serotypes or atypical strains that are frequently multidrug-resistant. Nevertheless, the ability of Salmonella to survive antimicrobials promoted in the context of antibiotic reducing/replacing and farming rethinking (e.g., organic acids and copper in feed/biocides) has been scarcely explored. We investigated Salmonella occurrence (conventional and molecular assays) among chicken meat at the processing stage (n = 53 batches/29 farms) and characterized their tolerance to diverse stress factors (antibiotics, copper, acid pH, and peracetic acid). Whole-genome sequencing was used to assess adaptive features and to perform comparative analysis. We found a low Salmonella occurrence (4%) and identified S. Enteritidis/ST11 plus atypical non-H2S-producing S. 1,4,[5],12:i:-/ST3478. The ST3478 presented the ability to grow under diverse stresses (antibiotics, copper, and acid-pH). Comparative genomics among ST3478 isolates showed similar antibiotic/metal resistance gene repertoires and identical nonsense phsA thiosulfate reductase mutations (related to H2S-negative phenotype), besides their close phylogenetic relationship by cgMLST and SNPs. This study alerts for the ongoing national and international spread of an emerging monophasic Salmonella Typhimurium clonal lineage with an enlarged ability to survive to antimicrobials/biocides commonly used in poultry production, being unnoticed by conventional Salmonella detection approaches due to an atypical non-H2S-producing phenotype.
Brucella abortus-Stimulated Platelets Activate Brain Microvascular Endothelial Cells Increasing Cell Transmigration through the Erk1/2 Pathway
Authors: Rodríguez Ana María , Trotta Aldana , Melnyczajko Agustina P. , Miraglia M. Cruz , Kim Kwang Sik , Delpino M. Victoria , Barrionuevo Paula , Giambartolomei Guillermo Hernán
Published: August 2020

Central nervous system invasion by bacteria of the genus Brucella results in an inflammatory disorder called neurobrucellosis. A common feature associated with this pathology is blood–brain barrier (BBB) activation. However, the underlying mechanisms involved with such BBB activation remain unknown. The aim of this work was to investigate the role of Brucella abortus-stimulated platelets on human brain microvascular endothelial cell (HBMEC) activation. Platelets enhanced HBMEC activation in response to B. abortus infection. Furthermore, supernatants from B. abortus-stimulated platelets also activated brain endothelial cells, inducing increased secretion of IL-6, IL-8, CCL-2 as well as ICAM-1 and CD40 upregulation on HBMEC compared with supernatants from unstimulated platelets. Outer membrane protein 19, a B. abortus lipoprotein, recapitulated B. abortus-mediated activation of HBMECs by platelets. In addition, supernatants from B. abortus-activated platelets promoted transendothelial migration of neutrophils and monocytes. Finally, using a pharmacological inhibitor, we demonstrated that the Erk1/2 pathway is involved in the endothelial activation induced by B. abortus-stimulated platelets and also in transendothelial migration of neutrophils. These results describe a mechanism whereby B. abortus-stimulated platelets induce endothelial cell activation, promoting neutrophils and monocytes to traverse the BBB probably contributing to the inflammatory pathology of neurobrucellosis.
An African Canine Trypanosomosis Case Import: Is There a Possibility of Creating a Secondary Focus of Trypanosoma congolense Infection in France?
Authors: Calvet Florence , Medkour Hacène , Mediannikov Oleg , Girardet Caroline , Jacob Antoine , Boni Mickaël , Davoust Bernard
Published: August 2020

African animal trypanosomosis are parasitic diseases caused by several protozoa of the genus Trypanosoma, transmitted by hematophagous insects, essentially tsetse flies, but also, less frequently by Tabanidae and Stomoxidae. They are geolocated in a part of the continent and affect livestock animals and carnivores; dogs are especially sensitive to them. They do not seem to present a zoonotic risk. Despite the chemical prevention with trypanocides for French military working dogs on mission in Côte d’Ivoire, a fatal case induced by Trypanosoma congolense in France after returning from Abidjan raises the question of an imported secondary focus. The clinical case was developed and the causative agent was confirmed by microscopy and PCR methods. The three necessary pillars to create a secondary potential focus are present: the parasite introduction in a new territory, the presence and the propagation vectors, and their proximity with sensitive species.
Monoolein Assisted Oil-Based Transdermal Delivery of Powder Vaccine
Authors: Kitaoka Momoko , Oka Atsushi , Goto Masahiro
Published: August 2020

An increasing number of protein vaccines have been researched for cancer, inflammation, and allergy therapies. Most of the protein therapeutics are administered through injection because orally-administered proteins are metabolized by the digestive system. Although transdermal administration has received increasing attention, the natural barrier formed by the skin is an obstacle. Monoolein is a common skin penetration enhancer that facilitates topical and transdermal drug delivery. Conventionally, it has been used in an aqueous vehicle, often with polyhydric alcohols. In the current study, monoolein was dissolved in an oil vehicle, isopropyl myristate, to facilitate the skin permeation of powder proteins. The skin permeabilities of the proteins were examined in-vivo and ex-vivo. Monoolein concentration-dependently enhanced the skin permeation of proteins. The protein permeability correlated with the zeta potential of the macromolecules. Dehydration of the stratum corneum (SC), lipid extraction from the SC, and disordering of ceramides caused by monoolein were demonstrated through Fourier transform infrared spectroscopic analysis and small-angle X-ray scattering analysis. An antigen model protein, ovalbumin from egg white, was delivered to immune cells in living mice, and induced antigen-specific IgG antibodies. The patch system showed the potential for transdermal vaccine delivery.
Dynamic Scattering Approach for Solving the Radar Cross-Section of the Warship under Complex Motion Conditions
Authors: Zhou Zeyang , Huang Jun
Published: August 2020

To obtain the electromagnetic scattering characteristics of the warship under complex motion conditions, a dynamic scattering approach (DSA) based on physical optics and physical theory of diffraction is presented. The observation angles, turret rotation, hull attitude changes and sea wave models are carefully studied and discussed. The research results show that the pitching and rolling angles have a large effect on the radar cross-section (RCS) of the warship. Turret movement has a greater impact on its own RCS but less impact on the warship. The RCS of the warship varies greatly at various azimuths and elevations. Different sea surface models have a greater impact on the lateral RCS of the warship. The DSA is effective and efficient to study the dynamic RCS of the warship under complex motion conditions.
A Novel Data-Aided Frame Synchronization Method Based on Hough Transform for Optical Communications
Authors: Yin Huiwen , Li Sida , Huang Zhiping , Chen Jie
Published: August 2020

In optical communication systems, frame synchronization is essential for subsequent operations, such as error correction and payload extraction. Various methods, so far, have been proposed in the published literature, but the performance is unsatisfactory under high bit error rate (BER) conditions. We present, in this work, a novel data-aided frame synchronization technique for optical packet transmission systems, in which the transmitter sends a sequence of packets with a specific synchronization word periodically inserted, and the receiver blindly recognizes the synchronization word to attain frame synchronization. The proposed algorithm detects the synchronization word based on Hough transform (HT), a classic method for line detection in digital image processing. The core principle of the algorithm is to exploit the periodicity of the frame synchronization word, which appears as black-and-white spaced stripes on a binary image when the frames are all aligned. Simulations are conducted over a 56Gbps optical QPSK transmission system, and the results show that our algorithm is still effective in attaining frame synchronization at a BER of 0.3. A comparison is also made between our algorithm and existed autocorrelation (AC)-based algorithm. The results demonstrate that our algorithm has a better error resilience performance. When the BER is higher than 0.03, our algorithm outperforms an AC-based algorithm significantly.
Insights into the Role of Streptomyces hydrogenans as the Plant Growth Promoter, Photosynthetic Pigment Enhancer and Biocontrol Agent against Meloidogyne incognita in Solanum lycopersicum Seedlings
Authors: Sharma Nandni , Khanna Kanika , Manhas Rajesh Kumari , Bhardwaj Renu , Ohri Puja , Alkahtani Jawaher , Alwahibi Mona S. , Ahmad Parvaiz
Published: August 2020

Root-knot nematodes (RKN), Meloidogyne sp. hinders functioning of crops and causes global losses in terms of productivity and yield. Meloidogyne sp. are microscopic, obligatory endoparasites with ubiquitous distribution in different parts of the world. Taking into consideration these aspects, the present study was conducted to explore nematicidal activity of the Streptomyces hydrogenans strain DH-16 against M. incognita to regulate its pathogenicity in plants. In-vitro experimentation revealed that pretreated seeds with solvent and culture supernatant lowered root galls in infested plants and promoted growth of Solanum lycopersicum seedlings, revealed through the morphological analysis. Additionally, antioxidative defense responses were induced with microbes. However, oxidative stress markers were considerably reduced after microbial inoculations. Apart from this, secondary metabolites were assessed and modulated in RKN infested plants on microbial supplementations. Confocal studies evaluated glutathione accumulation within root apices and its enhancement was directly proportional to defense responses. Therefore, the current study concluded the role of S. hydrogenans in stimulating antioxidant potential against RKN along with growth promoting aids. Thus, the outcome of the current study endorses that metabolites produced by S. hydrogenans can be used as safe biocontrol agents against M. incognita and also as plant growth promoting agents.
Plasma Treatment of Polypropylene-Based Wood–Plastic Composites (WPC): Influences of Working Gas
Authors: Sauerbier Philipp , Köhler Robert , Renner Gerrit , Militz Holger
Published: August 2020

In this study, a polypropylene (PP)-based wood–plastic composite with maleic anhydride-grafted polypropylene (MAPP) as a coupling agent and a wood content of 60% was extruded and specimens were injection molded. The samples were plasma treated utilizing a dielectric barrier discharge (DBD) setup with three different working gases: Ar/O2 (90%/10%), Ar/N2 (90%/10%), and synthetic air. This process aims to improve the coating and gluing properties of the otherwise challenging apolar surface of PP based wood–plastic composites (WPC). Chemical analysis with X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) showed the formation of oxygen-based functional groups on the surface, independently from the working gas used for the treatment. Laser scanning microscopy (LSM) examined the surface roughness and revealed that the two argon-containing working gases roughened the surface more than synthetic air. However, the contact angle for water was reduced significantly after treatment, revealing measurement artifacts for water and diiodomethane due to the severe changes in surface morphology. The adhesion of acrylic dispersion coating was significantly increased, resulting in a pull-off strength of approximately 4 N/mm2, and cross-cut tests assigned the best adhesion class (0), on a scale from 0 to 5, after plasma treatment with any working gas.
The Study of Plasticized Amorphous Biopolymer Blend Electrolytes Based on Polyvinyl Alcohol (PVA): Chitosan with High Ion Conductivity for Energy Storage Electrical Double-Layer Capacitors (EDLC) Device Application
Authors: Aziz Shujahadeen B. , M. Hadi Jihad , Dannoun Elham M. A. , Abdulwahid Rebar T. , R. Saeed Salah , Shahab Marf Ayub , Karim Wrya O. , Kadir Mohd F.Z.
Published: August 2020

In this study, plasticized films of polyvinyl alcohol (PVA): chitosan (CS) based electrolyte impregnated with ammonium thiocyanate (NH4SCN) were successfully prepared using a solution-casting technique. The structural features of the electrolyte films were investigated through the X-ray diffraction (XRD) pattern. The enrichment of the amorphous phase with increasing glycerol concentration was confirmed by observing broad humps. The electrical impedance spectroscopy (EIS) portrays the improvement of ionic conductivity from 10−5 S/cm to 10−3 S/cm upon the addition of plasticizer. The electrolytes incorporated with 28 wt.% and 42 wt.% of glycerol were observed to be mainly ionic conductor as the ionic transference number measurement (TNM) was found to be 0.97 and 0.989, respectively. The linear sweep voltammetry (LSV) investigation indicates that the maximum conducting sample is stable up to 2 V. An electrolyte with the highest conductivity was used to make an energy storage electrical double-layer capacitor (EDLC) device. The cyclic voltammetry (CV) plot depicts no distinguishable peaks in the polarization curve, which means no redox reaction has occurred at the electrode/electrolyte interface. The fabricated EDLC displays the initial specific capacitance, equivalent series resistance, energy density, and power density of 35.5 F/g, 65 Ω, 4.9 Wh/kg, and 399 W/kg, respectively.
Study of the Influence of Technological Parameters on Generating Flat Part with Cylindrical Features in 3D Printing with Resin Cured by Optical Processing
Authors: Tulcan Aurel , Vasilescu Mircea Dorin , Tulcan Liliana
Published: August 2020

The objective of this paper is to determine how the supporting structure in the DLP 3D printing process has influences on the characteristics of the flat and cylindrical surfaces. The part is printed by using the Light Control Digital (LCD) 3D printer technology. A Coordinate Measuring Machine (CMM) with contact probes is used for measuring the physical characteristics of the printed part. Two types of experiment were chosen by the authors to be made. The first part takes into consideration the influence of the density of the generated supports, at the bottom of the printed body on the characteristics of the flat surface. In parallel, it is studying the impact of support density on the dimension and quality of the surface. In the second part of the experiment, the influence of the printed supports dimension on the flatness, straightness and roundness of the printed elements were examined. It can be observed that both the numerical and dimensional optimum zones of the support structure for a prismatic element could be determined, according to two experiments carried out and the processing of the resulting data. Based on standardized data of flatness, straightness and roundness, it is possible to put in accord the values determined by measurement within the limits of standardized values.
From Secular to Sacred: Bringing Work to Church
Authors: Howard Ecklund Elaine , Daniels Denise , Schneider Rachel C.
Published: August 2020

Work and faith are significant life commitments for many people. Understanding how people integrate these facets of life is important for scholars, faith leaders, and religious communities. We use data from Faith at Work: An Empirical Study, which includes a U.S. general population survey (n = 13,270) and in-depth interviews. Drawing data from a Christian sub-sample we ask: How do Christians draw on their faith community in relation to work? For those in different social locations, in what ways does talk about work come up in churches? Finally, what work-related challenges do Christians experience, and how do Christians want their churches and pastors to address them? We find that many Christians see faith as a resource for enhancing their work lives but do not often encounter discussion of work at church or talk with pastors about work, though Black congregants are nearly twice as likely as whites to hear their pastors discuss work. Further, specific groups of Christians want their pastors and churches to do more to support them in their work and/or to help them navigate faith in the workplace. They also want churches to better accommodate the needs of working people at church, so they can more fully participate.
Variability of Air Temperature, Precipitation and Outflows in the Vistula Basin (Poland)
Authors: Kubiak-Wójcicka Katarzyna
Published: August 2020

This study examines trends in temperature, precipitation and discharge rates over a 65-year observation period (1951–2015) and compares the two sub-periods 1951–1980 and 1981–2015. The research was carried out on annual and monthly values. The research area is the basin of the Vistula, the largest river in Poland. The main aim of the study was to assess how changes in air temperature and precipitation in the Vistula basin have translated into river hydrology. In the 65-year study period, a lack of statistically significant trends in outflow prevailed. Compared to the full period 1951–2015, the sub-period 1951–1980 stood out for its statistically significant increase in annual average outflows. In the years 1981–2015 a slight falling trend in outflow of the Vistula was noted, though the values were not statistically significant. This was caused by significant warming during this period (an increase in air temperature of between 0.27 and 0.45 °C per decade, depending on location) and a slight increase in precipitation. Seasonal changes in outflows were more volatile. The results indicate that the Vistula’s water resources have fallen slightly as a result of changes in air temperature and precipitation and due to the river’s significant hydrological inertia, which in turn results from the catchment being very large and physiographically diverse.
Implementation of a Nowcasting Hydrometeorological System for Studying Flash Flood Events: The Case of Mandra, Greece
Authors: Spyrou Christos , Varlas George , Pappa Aikaterini , Mentzafou Angeliki , Katsafados Petros , Papadopoulos Anastasios , Anagnostou Marios N. , Kalogiros John
Published: August 2020

Severe hydrometeorological hazards such as floods, droughts, and thunderstorms are expected to increase in the future due to climate change. Due to the significant impacts of these phenomena, it is essential to develop new and advanced early warning systems for advance preparation of the population and local authorities (civil protection, government agencies, etc.). Therefore, reliable forecasts of extreme events, with high spatial and temporal resolution and a very short time horizon are needed, due to the very fast development and localized nature of these events. In very short time-periods (up to 6 h), small-scale phenomena can be described accurately by adopting a “nowcasting” approach, providing reliable short-term forecasts and warnings. To this end, a novel nowcasting system was developed and presented in this study, combining a data assimilation system (LAPS), a large amount of observed data, including XPOL radar precipitation measurements, the Chemical Hydrological Atmospheric Ocean wave System (CHAOS), and the WRF-Hydro model. The system was evaluated on the catastrophic flash flood event that occurred in the sub-urban area of Mandra in Western Attica, Greece, on 15 November 2017. The event was one of the most catastrophic flash floods with human fatalities (24 people died) and extensive infrastructure damage. The update of the simulations with assimilated radar data improved the initial precipitation description and led to an improved simulation of the evolution of the phenomenon. Statistical evaluation and comparison with flood data from the FloodHub showed that the nowcasting system could have provided reliable early warning of the flood event 1, 2, and even to 3 h in advance, giving vital time to the local authorities to mobilize and even prevent fatalities and injuries to the local population.
The IoT as a Key in the Sensitive Balance between Development Needs and Sustainable Conservation of Cultural Resources in Italian Heritage Cities
Authors: Lerario Antonella
Published: August 2020

In recent years the application of information and communication technologies (ICTs) to the built heritage has been increasingly finalized to heritage promotion in order to maximize visitor flows. New urgent challenges facing built heritage loom now over its very existence and our possibilities to preserve it for future generations. Italian heritage cities represent a delicate context, where concerns related to tourist flows and resource consumption are amplified due to the concentration of sites and points of interests in urban areas, also in very small ones, while tourism remains vital for economic growth. In such contexts, balancing economic development and sustainable heritage conservation demands well-calibrated tools and approaches. The article presents an overview of the ways the Internet of Things (IoT) is currently used to solve urban issues and support heritage projects. On this basis, and considering the characters and problems typical of heritage cities, as well as the features of the Italian scenario, the most appropriate application lines of IoT for the Italian heritage cities are identified. Then, their potentialities, the mutual impacts between them and the heritage field and the key role of the IoT in supporting the delicate balance between economic development and cultural resource conservation are finally discussed.
Ostracod Fauna: Eyewitness to Fifty Years of Anthropic Impact in the Gulf of Trieste. A Potential Key to the Future Evolution of Urban Ecosystems
Authors: Salvi Gianguido , Acquavita Alessandro , Celio Massimo , Ciriaco Saul , Cirilli Stefano , Fernetti Michele , Pugliese Nevio
Published: August 2020

For the first time, the distribution and modifications of living ostracod associations present in the Gulf of Trieste (GoT) in relation to alterations caused by human activity in the last 20 years were investigated. The results were compared with the main physicochemical parameters (especially nitrogen and phosphorus) measured over the same period, which can lead to a general decrease in environmental quality. For a more in-depth analysis of the changes recorded by ostracods in the last 50 years, a period in which eutrophication and anoxia increased, we revisited the study carried out by Masoli in the GoT in 1967. The results obtained made it possible to verify how, over the last 20 years, ostracod assemblages have suffered a decrease both qualitatively and quantitatively. Most of the species recovered show characteristics of opportunism and tolerance to environmentally stressful conditions, high organic matter concentrations, and oxygen deficiency. The ostracods analyzed in 1967 showed similar results with few dominant opportunistic species. We verified how ostracods recorded in GoT, similar to Mollusks and Foraminifera, have been impaired by the possible environmental crisis linked to the recurrence of mucilage and hypoxic events documented for the GoT in the last 50 years. Finally, a comparison with the best environmental conditions found in the Marine Nature Reserve of Miramare (MPA) allowed us to emphasize the important role of protected areas to avoid loss of biodiversity due to urbanization.
The Impact of Financial Development on Carbon Emission: Evidence from China
Authors: Guo Mingyuan , Hu Yanfang
Published: August 2020

This paper studies the impact of financial development on carbon emissions in China from 1997 to 2016. First, this paper uses the entropy method to construct a synthetical index to measure the financial development. Meanwhile, a two-dimensional panel framework is introduced to group provinces in the panel analysis. The estimation results of the time series autoregressive distributed lag model show that for China as a whole, there is a weak carbon emissions reduction effect of financial development, whether it is a long-term effect or a short-term effect. The estimation results of the panel autoregressive distributed lag model also support that an increase in financial development suppresses carbon emissions. Although financial development inhibits carbon emissions both in the short run and in the long run, the absolute value of the long-term coefficient of financial development is significantly greater than that of the short-term coefficient.
Socio-Ecological Interactions and Sustainable Development—Introduction to a Special Issue
Authors: Aarts Noelle , Drenthen Martin
Published: August 2020

Understanding socio-ecological interactions requires an interdisciplinary approach that recognizes the value of both a social and an ecological perspective. However, such a recognition does not yet automatically result in an integral approach. Many studies of socio-ecological transformations start from either social science or a natural science perspective, and take results from other academic disciplines merely as a given, thus treating these disciplines as black boxes. In this editorial we argue that socio-ecology requires a new paradigm that not only seeks to transcend the separation between social sciences and ecological sciences but also develops a more intimate relationship between these different academic disciplines. We argue that studying socio-ecological interactions is not merely the sum total of social scientific and ecological research, because socio-ecological interactions are not interactions between sociological and ecological systems, but interactions that take place within the socio-ecological whole. Therefore, the study of socio-ecological interactions should start with a new ontology, in which social and ecological aspects are considered different aspects of one and the same reality. The papers in this special issue all show aspects of socio-ecological interactions, but also illustrate the challenge of studying socio-ecological interactions in a comprehensive way.