bluuebunny/crossref_metadata_2025 huggingface dataset:
Tel-Cu-NPs Catalyst: Synthesis of Naphtho[2,3-g]phthalazine Derivatives as Potential Inhibiters of Tyrosinase Enzymes and Their Investigation in Kinetic, Molecular Docking, and Cytotoxicity Studies
Authors: Selvaraj Keerthana , Daoud Ali , Alarifi Saud , Idhayadhulla Akbar
Published: December 2020

Novel one-pot synthesis naphtho[2,3-g]phthalazine (1a–1k) of Mannich base derivatives can be achieved via grindstone chemistry using a Tel-Cu-NPs (telmisartan-copper nanoparticles) catalyst. This method offers efficient mild reaction conditions and high yields. Tyrosinase inhibitory activity was evaluated for all synthesized compounds, along with analysis of kinetic behavior and molecular docking studies. The synthesized compound, 1c was (IC50 = 11.5 µM) more active than kojic acid (IC50 = 78.0 µM). Lineweaver Burk plots were used to analyze the kinetic behavior of the most active compound 1c, it was reversible and competitive behavior. Compound 1c and kojic acid occurred in the presence of 2-hydroxyketone, which has the same inhibitory mechanism. The molecular docking of compound 1c and the control kojic acid were docked against 2Y9X protein via the Schrodinger Suite. The compound 1c showed a respectable dock score (−5.6 kcal/mol) compared to kojic acid with a dock score of (−5.2 kcal/mol) in the 2Y9X protein. Cytotoxicity activity was also evaluated by using HepG2 (liver), MCF-7 (breast), and HeLa (cervical) cancer cell lines, and high activity for 1c (GI50 = 0.01, 0.03, and 0.04 µM, respectively) against all cell lines was found compared to standard and other compounds. Therefore, this study succeeded in testing a few promising molecules as potential antityrosinase agents.
Adipic Acid Route: Oxidation of Cyclohexene vs. Cyclohexane
Authors: Ribeiro Ana P. C. , Spada Elisa , Bertani Roberta , Martins Luísa M. D. R. S.
Published: December 2020

A cleaner alternative to the current inefficient oxidation of cyclohexane to adipic acid is presented. Direct oxidation of neat cyclohexene by aq. hydrogen peroxide to adipic acid is selectively achieved in good yield (46%), in the presence of the recyclable C-homoscorpionate iron(II) complex [FeCl2{κ3-HC(pz)3}] (pz = pyrazol-1-yl) and microwave irradiation, by a nitrous oxide-free protocol.
Rapid Ammonia Carriers for SCR Systems Using MOFs [M2(adc)2(dabco)] (M = Co, Ni, Cu, Zn)
Authors: Cao Zhejian , Landström Kritika Narang , Akhtar Farid
Published: December 2020

Ammonia is one of the most common reductants for the automotive selective catalytic reduction (SCR) system owing to its high NO2 reduction (deNOx) efficiency. However, ammonia carriers for the SCR system have sluggishly evolved to achieve rapid ammonia dosing. In this study, the MOFs [M2(adc)2(dabco)] (M = Co, Ni, Cu, Zn) were synthesized and characterized as ammonia carriers. Among the four obtained MOFs, Ni2(adc)2(dabco) possessed the highest surface area, 772 m2/g, highest ammonia uptake capacity, 12.1 mmol/g, and stable cyclic adsorption-desorption performance. All the obtained MOFs demonstrated physisorption of ammonia and rapid kinetics of ammonia adsorption and desorption. Compared with halide ammonia carrier MgCl2, the obtained MOFs showed four times faster adsorption kinetics to reach 90% of the ammonia uptake capacity. For the ammonia desorption, the Ni2(adc)2(dabco) provided 6 mmol/g ammonia dosing when temperature reached 125 °C in the first 10 min, which was six times of the ammonia dosing from Mg(NH3)6Cl2. The results offer a solution to shorten the buffering time for ammonia dosing in the SCR system.
DBU Catalyzed Phospho-Aldol-Brook Rearrangement for Rapid Preparation of α-Phosphates Amide in Solvent-Free Conditions
Authors: Chen Shunhong , Guo Shengxin , He Feng , Zhang Yingxia , Wu Zengxue , Wu Jian
Published: December 2020

The 1,8-diazabicyclo [5.4.0] undec-7-ene DBU-catalyzed Phospho-Aldol-Brook Rearrangement reaction of α-ketoamide and dialkyl phosphites was developed under solvent-free at room temperature. The novel α-Phosphate Amide derivatives could be obtained with good yield (86–96%), which also exhibited good tolerance of various dialkyl phosphites and α-ketoamide, including isatins. In addition, the reaction was conducted in both gram-scale and mol-scale, and the title compounds could also be obtained in excellent yield (more than 91%) within 5 min.
A Facile Method for Preparing a Superhydrophobic Block with Rapid Reparability
Authors: Zhu Jiyuan , Liao Kaijin
Published: December 2020

Superhydrophobic surfaces are fragile and are prone to failure in harsh outdoor environments. The preparation of robust superhydrophobic surfaces with stable performance and excellent properties can extend their application. In this paper, we report a simple and cost-effective method to prepare a superhydrophobic block using superhydrophobic zinc oxide powder and die pressing. The prepared sample has a contact angle of 163° and a sliding angle of 7°. Tests show that the superhydrophobic block can resist the impact of water flow, maintain its superhydrophobicity after friction or knife scraping, and quickly repair the destroyed surface by sandpaper abrasion. The sample exhibited excellent self-cleaning effect, robust mechanical property, and rapid repairability. This preparation method is also environmental-friendly and easy to operate. It will have a wide application prospect in many important fields.
Preparation of TiO2 Nanoparticle Aggregates and Capsules by the ‘Two-Emulsion Method’
Authors: Politova-Brinkova Nadya I. , Tsibranska-Gyoreva Sonya R. , Tcholakova Slavka S. , Denkov Nikolai D. , Danner Thomas
Published: December 2020

TiO2-based materials are of great practical interest in several technological areas. Both the size and the morphology of the TiO2 particles are of critical importance for their applications. The current study explores the effect of several factors on the outcome of the TiO2 particle synthesis via the so-called ‘two-emulsion method’. In this technique, two water-in-oil emulsions—each of them containing different reactant in the dispersed water drops—are mixed under well controlled conditions. Upon such mixing, partial coalescence of the water drops from the two emulsions leads to mixing of the drop content, with chemical reaction occurring within the drops, and to synthesis of Ti(OH)4 particles. Afterwards, the latter are transformed by emulsion heating into TiO2 particles and aggregates of predominantly anatase structure. Our results show that—depending on the precursor and surfactant concentrations, oil viscosity, emulsification time, and mixing speed—the obtained nanoparticles could aggregate either on the drop surface, forming capsules with a very smooth surface, or inside the water droplets, thus leading to hierarchically structured aggregates of micrometer size. The spherical smooth capsules are constructed of very small monodisperse TiO2 nanoparticles with size below 5 nm. The hierarchical bulk aggregates, on the other hand, are formed from bigger primary particles of sub-micrometer size. The obtained results show that one can obtain various TiO2 structures by controlling the conditions during the emulsion preparation and mixing
Evaluation of Parameters for Estimating the Postmortem Interval of Skeletal Remains Using Bovine Femurs: A Pilot Study
Authors: Nagai Midori , Sakurada Koichi , Imaizumi Kazuhiko , Ogawa Yoshinori , Uo Motohiro , Funakoshi Takeshi , Uemura Koichi
Published: December 2020

The postmortem interval (PMI) of victims is a key parameter in criminal investigations. However, effective methods for estimating the PMI of skeletal remains have not been established because it is determined by various factors, including environmental conditions. To identify effective parameters for estimating the PMI of skeletal remains, we investigated the change in bone focusing on the amount of DNA, element concentrations, and bone density that occurred in the bone samples of bovine femurs, each maintained under one of five simulated environmental conditions (seawater, freshwater, underground, outdoors, and indoors) for 1 year. The amount of extracted mitochondrial DNA (mtDNA; 404 bp fragment) decreased over time, and significant DNA degradation (p < 0.01), as estimated by a comparison with amplification results for a shorter fragment (128 bp), was detected between 1 month and 3 months. Eleven of 30 elements were detected in samples by inductively coupled plasma optical emission spectrometry, and Na and Ba showed significant quantitative differences in terms of environmental conditions and time (p < 0.01). This preliminary study suggests that the level of DNA degradation determined by real-time polymerase chain reaction and element concentrations determined by inductively coupled plasma optical emission may be useful indices for estimating the PMI of victims under a wide range of environmental conditions. However, this study is a limited experimental research and not applicable to forensic cases as it is. Further studies of human bone with longer observation periods are required to verify these findings and to establish effective methods for PMI estimation.
Entropy Profiling: A Reduced—Parametric Measure of Kolmogorov—Sinai Entropy from Short-Term HRV Signal
Authors: Karmakar Chandan , Udhayakumar Radhagayathri , Palaniswami Marimuthu
Published: December 2020

Entropy profiling is a recently introduced approach that reduces parametric dependence in traditional Kolmogorov-Sinai (KS) entropy measurement algorithms. The choice of the threshold parameter r of vector distances in traditional entropy computations is crucial in deciding the accuracy of signal irregularity information retrieved by these methods. In addition to making parametric choices completely data-driven, entropy profiling generates a complete profile of entropy information as against a single entropy estimate (seen in traditional algorithms). The benefits of using “profiling” instead of “estimation” are: (a) precursory methods such as approximate and sample entropy that have had the limitation of handling short-term signals (less than 1000 samples) are now made capable of the same; (b) the entropy measure can capture complexity information from short and long-term signals without multi-scaling; and (c) this new approach facilitates enhanced information retrieval from short-term HRV signals. The novel concept of entropy profiling has greatly equipped traditional algorithms to overcome existing limitations and broaden applicability in the field of short-term signal analysis. In this work, we present a review of KS-entropy methods and their limitations in the context of short-term heart rate variability analysis and elucidate the benefits of using entropy profiling as an alternative for the same.
Laminar Flame Characteristics of Premixed Methanol–Water–Air Mixture
Authors: Zhu Zhennan , Liang Kun , Chen Xinwen , Meng Zhongwei , He Wenbin , Song Hao
Published: December 2020

Methanol is hygroscopic in a gaseous state and is a promising alternative fuel for internal combustion engines. It is understood that adding water can improve the antiknock performance for spark ignition engines, but this will also affect the flame speed and stability. In this work, laminar flame characteristics of methanol/water/air mixtures were experimentally investigated at a temperature range of 380–450 K, a pressure range of 1–4 bar, and water fractions (vaporous water molar fraction in the water–methanol fuel gas) of 0–40%. The results show that laminar burning velocity increases with temperature but decreases with pressure. The burning velocity decreases linearly with water fraction at a stoichiometric ratio. For rich mixtures and high pressures, the laminar flames tend to be more sensitive to stretch and, thus, more prone to being unstable. Increasing the water fraction can slightly increase the Markstein length. Increasing the initial pressure enhances the general flame instability, while increasing the initial temperature suppresses the general flame instability. Increasing the water fraction can lead to a decreasing thermal expansion ratio and an elevated flame thickness, both of which can lead to a suppression of hydrodynamic instability. An increase in the water fraction decreases the Lewis number, resulting in preferential diffusion instability. There is no direct relationship between the onset of cellularity and general flame instability.
The Potential of Depleted Oil Reservoirs for High-Temperature Storage Systems
Authors: Stricker Kai , Grimmer Jens C. , Egert Robert , Bremer Judith , Korzani Maziar Gholami , Schill Eva , Kohl Thomas
Published: December 2020

HT-ATES (high-temperature aquifer thermal energy storage) systems are a future option to shift large amounts of high-temperature excess heat from summer to winter using the deep underground. Among others, water-bearing reservoirs in former hydrocarbon formations show favorable storage conditions for HT-ATES locations. This study characterizes these reservoirs in the Upper Rhine Graben (URG) and quantifies their heat storage potential numerically. Assuming a doublet system with seasonal injection and production cycles, injection at 140 °C in a typical 70 °C reservoir leads to an annual storage capacity of up to 12 GWh and significant recovery efficiencies increasing up to 82% after ten years of operation. Our numerical modeling-based sensitivity analysis of operational conditions identifies the specific underground conditions as well as drilling configuration (horizontal/vertical) as the most influencing parameters. With about 90% of the investigated reservoirs in the URG transferable into HT-ATES, our analyses reveal a large storage potential of these well-explored oil fields. In summary, it points to a total storage capacity in depleted oil reservoirs of approximately 10 TWh a−1, which is a considerable portion of the thermal energy needs in this area.
Technical and Economic Analysis of Battery Storage for Residential Solar Photovoltaic Systems in the Brazilian Regulatory Context
Authors: Deotti Lucas , Guedes Wanessa , Dias Bruno , Soares Tiago
Published: December 2020

This paper presents a comprehensive study of the technical and economic benefits that a typical residential prosumer may experience when investing in a solar photovoltaic (PV) system with a battery energy storage system (BESS). To this end, a home energy management system has been designed to simulate the prosumer’s daily operation, considering a novel method for calculating battery degradation while minimizing its operating costs. In order to contribute to the regulatory review process of the distributed generation underway in Brazil, a set of PV+BESS configurations has been assessed under the current and future regulatory scenarios proposed for discussion by the Brazilian regulatory agency. Although the results demonstrate that the prosumer’s self-consumption rate may increase up to 14% with the BESS coupling in the PV system, the investment proved to be economically unattractive in the current regulatory scenario and practically unfeasible in any of the proposed future scenarios. To make PV+BESS systems economically feasible, some business models are proposed and discussed, and for example, provide subsidies for policymakers, financial agents, and battery manufacturers. A sensitivity analysis for each business model showing its economic feasibility spectrum is provided to assist the different sector players, especially the consumers, in their decision-making process.
Validation of the Stolwijk and Tanabe Human Thermoregulation Models for Predicting Local Skin Temperatures of Older People under Thermal Transient Conditions
Authors: Tang Yin , Yu Hang , Wang Zi , Luo Maohui , Li Chaoen
Published: December 2020

Human thermoregulation models can predict human thermal responses to evaluate thermal comfort and help create a healthy environment, while their applicability to older people has not been sufficiently validated. This study aimed to evaluate the performance of the Stolwijk model and the Tanabe model for predicting older people’s mean and local skin temperatures under thermal transient conditions. Eighteen healthy older people were recruited and exposed to transient environments including neutral (26 °C), low-temperature (23 and 21 °C), and high-temperature (29 and 32 °C) conditions. The local skin temperatures of the subjects were measured and compared to predictions of the Stolwijk model and the Tanabe model. The results revealed that the Stolwijk model and the Tanabe model could accurately predict the mean skin temperature of older people under neutral and high-temperature conditions, while their predictive accuracy declined under low-temperature conditions. Increased deviations were observed in the predictions of local skin temperatures for all conditions. This work attempted to provide an understanding of older people’s thermal response characteristics under transient conditions and to inspire the improvement of thermoregulation models for older people.
Editorial to the Special Issue: Impacts of Compound Hydrological Hazards or Extremes
Authors: Beevers Lindsay , White Christopher J. , Pregnolato Maria
Published: December 2020

Hydrological hazards, or ‘hydro-hazards’, are defined as “extreme events associated with the occurrence, movement and distribution of water, such as floods and droughts” (Visser-Quinn et al [...]
Socioeconomic Disparities in All-Cause and Cause-Specific Mortality Rates among Municipalities in Japan, 1999–2019
Authors: Okui Tasuku
Published: December 2020

Differences in all-cause and cause-specific mortality rates depending on municipal socioeconomic status (SES) in Japan have not been revealed over the last 20 years. This study exposes the difference in 1999 and 2019 using the Vital Statistics. All of the municipalities were grouped into five quintiles based on their SES, and standardized mortality ratio (SMR) of each municipal quintile compared with all of Japan was calculated for all-cause mortality and representative cause of deaths. As a result, although SMR for all-cause mortality for women tended to be lower in low SES quintiles in 1999, the reverse phenomenon was observed in 2019. Additionally, although SMR for all-cause of mortality for men was the lowest in the highest SES quintiles already in 1999, the difference in the SMR for all-cause mortality rates between the lowest and highest SES quintiles increased in 2019. The improvement of the SMR in the highest SES quintile and the deterioration in the lowest was also observed in representative types of cancer, heart disease, stroke, pneumonia, liver disease, and renal failure for men and women. Therefore, this study indicates a disparity in mortality depending on municipal SES enlarged in the last 20 years.
Interactive Visual Analysis of Mass Spectrometry Imaging Data Using Linear and Non-Linear Embeddings
Authors: Jawad Muhammad , Soltwisch Jens , Dreisewerd Klaus , Linsen Lars
Published: December 2020

Mass spectrometry imaging (MSI) is an imaging technique used in analytical chemistry to study the molecular distribution of various compounds at a micro-scale level. For each pixel, MSI stores a mass spectrum obtained by measuring signal intensities of thousands of mass-to-charge ratios (m/z-ratios), each linked to an individual molecular ion species. Traditional analysis tools focus on few individual m/z-ratios, which neglects most of the data. Recently, clustering methods of the spectral information have emerged, but faithful detection of all relevant image regions is not always possible. We propose an interactive visual analysis approach that considers all available information in coordinated views of image and spectral space visualizations, where the spectral space is treated as a multi-dimensional space. We use non-linear embeddings of the spectral information to interactively define clusters and respective image regions. Of particular interest is, then, which of the molecular ion species cause the formation of the clusters. We propose to use linear embeddings of the clustered data, as they allow for relating the projected views to the given dimensions. We document the effectiveness of our approach in analyzing matrix-assisted laser desorption/ionization (MALDI-2) imaging data with ground truth obtained from histological images.
International Strategic Management: A Conceptual Model with Top Managers’ Emotional Intelligence, Cultural Intelligence, and Networking
Authors: Cabral Ângelo Miguel R. , Carvalho Fernando Manuel P. O. , Ferreira José António Vasconcelos
Published: December 2020

The conceptual approach in this article follows and analyzes the holistic model of Kuivalainen, Sundqvist, Saarenketo, and McNaughton in 2012, making it analytically fitting to the SMEs’ international strategic groups concerning their international scale and scope. That model, according to our conceptual proposal, needs a methodological readjustment to an effective conformity towards the cross-sectional research. Accordingly, we presented two main considerations. First, we put together a conceptual model, fitted towards the field of top managers’ psychological characteristics as major antecedent of the firms’ international strategy. Second, the proposed conceptual model is methodologically oriented for cross-sectional studies. In relation to the antecedents, we took top managers’ emotional intelligence and cultural intelligence as distinctive capabilities of the firms’ international strategy and as major antecedents of top managers’ networking behaviors. Regarding firms’ international performance as the major conceptual model outcome, a multidimensional approach is taken with financial, strategic, and overall performance. These elements of the international firms are regarded as of major importance within the international firms’ enterprise architecture. Methodologically, we performed a bibliographic review on the fundamental concepts that we present in the model. Concerning the results, we provided a research model that raised a whole set of new leads for research with some proposals for future investigations.
Identification of Metabolic Biomarkers in Relation to Methotrexate Response in Early Rheumatoid Arthritis
Authors: Gosselt Helen R. , Muller Ittai B. , Jansen Gerrit , van Weeghel Michel , Vaz Frédéric M. , Hazes Johanna M. W. , Heil Sandra G. , de Jonge Robert
Published: December 2020

This study aimed to identify baseline metabolic biomarkers for response to methotrexate (MTX) therapy in rheumatoid arthritis (RA) using an untargeted method. In total, 82 baseline plasma samples (41 insufficient responders and 41 sufficient responders to MTX) were selected from the Treatment in the Rotterdam Early Arthritis Cohort (tREACH, trial number: ISRCTN26791028) based on patients’ EULAR response at 3 months. Metabolites were assessed using high-performance liquid chromatography-quadrupole time of flight mass spectrometry. Differences in metabolite concentrations between insufficient and sufficient responders were assessed using partial least square regression discriminant analysis (PLS-DA) and Welch’s t-test. The predictive performance of the most significant findings was assessed in a receiver operating characteristic plot with area under the curve (AUC), sensitivity and specificity. Finally, overrepresentation analysis was performed to assess if the best discriminating metabolites were enriched in specific metabolic events. Baseline concentrations of homocystine, taurine, adenosine triphosphate, guanosine diphosphate and uric acid were significantly lower in plasma of insufficient responders versus sufficient responders, while glycolytic intermediates 1,3-/2,3-diphosphoglyceric acid, glycerol-3-phosphate and phosphoenolpyruvate were significantly higher in insufficient responders. Homocystine, glycerol-3-phosphate and 1,3-/2,3-diphosphoglyceric acid were independent predictors and together showed a high AUC of 0.81 (95% CI: 0.72–0.91) for the prediction of insufficient response, with corresponding sensitivity of 0.78 and specificity of 0.76. The Warburg effect, glycolysis and amino acid metabolism were identified as underlying metabolic events playing a role in clinical response to MTX in early RA. New metabolites and potential underlying metabolic events correlating with MTX response in early RA were identified, which warrant validation in external cohorts.
Decomposing the Effect of Domestic and Foreign Economic Policy Uncertainty Shocks on Real and Financial Sectors: Evidence from BRIC Countries
Authors: Kumar Ameet , Kalhoro Muhammad Ramzan , Kumar Rakesh , Ghumro Niaz Hussain , Dakhan Sarfraz Ahmed , Kumar Vikesh
Published: December 2020

This study examines the impact of domestic and foreign shocks on the real and financial sector of BRIC countries. For this purpose, we use a structural vector autoregressive (SVAR) model over the extended period of 1997 to 2016. We conclude that domestic policy shocks have a more substantial impact on Brazilian, Indian, and Russian economy than foreign shocks, while foreign shocks have more contribution in the case of China. Interestingly, results show the negative impact of policy shocks on bank credit provided, implying its role in multiplying the impact of shocks on real variables. Surprisingly EPU of USA has a positive impact on stock markets of India and China, implying capital flight phenomenon, where investor transfer investment from risky to safer places.
Mycotoxin Identification and In Silico Toxicity Assessment Prediction in Atlantic Salmon
Authors: Tolosa Josefa , Barba Francisco J. , Pallarés Noelia , Ferrer Emilia
Published: December 2020

The present study aimed to identify mycotoxins in edible tissues of Atlantic salmon (Salmo salar) using liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). After using a non-targeted screening approach and a home-made spectral library, 233 mycotoxins were analyzed. Moreover, the occurrence of mycotoxins in fish filets was evaluated, and their potential toxicity was predicted by in silico methods. According to the obtained results, forty mycotoxins were identified in analyzed salmon samples, the predominant mycotoxins being enniatins (also rugulosin and 17 ophiobolins), commonly found in cereals and their by-products. Thus, mycotoxin carry-over can occur from feed to organs and edible tissues of cultivated fish. Moreover, the toxicity of detected mycotoxins was predicted by the in silico webserver ProTox-II, highlighting that special attention must be paid to some less reported mycotoxins due to their toxic predicted properties.
Alterins Produced by Oyster-Associated Pseudoalteromonas Are Antibacterial Cyclolipopeptides with LPS-Binding Activity
Authors: Desriac Florie , El Harras Abderrafek , Simon Matthieu , Bondon Arnaud , Brillet Benjamin , Le Chevalier Patrick , Pugnière Martine , Got Patrice , Destoumieux-Garzón Delphine , Fleury Yannick
Published: December 2020

Discovery after discovery, host-associated microbiota reveal a growing list of positive effects on host homeostasis by contributing to host nutrition, improving hosts’ immune systems and protecting hosts against pathogens. In that context, a collection of oyster associated bacteria producing antibacterial compounds have been established to evaluate their role in non-host-derived immunity. Here, we described alterins; potent anti-Gram negative compounds produced by Pseudoalteromonas hCg-6 and hCg-42 isolated from different healthy oyster hemolymph. The strains hCg-6 and hCg-42 produce a set of at least seven antibacterial compounds, ranging from 926 to 982 Da structurally characterized as cyclolipopeptides (CLPs). Alterins share the same cationic heptapeptidic cycle connected via an amido bond to different hydrophobic hydrocarbon tails. Their MICs disclosed a potent antibacterial activity directed against Gram-negative bacteria including oyster and human pathogens that may confer a beneficial defense mechanism to the host but also represents an untapped source of new antibiotics. The alterins’ mechanisms of action have been deciphered: after binding to lipopolysaccharides (LPS), alterins provoke a membrane depolarization and permeabilization leading to bacterial lysis. As hCg-6 and hCg-42 produced a set of natural derivatives, the structure/activity relationship linked to the carbon tail is clarified. We showed that the hydrocarbon tail determines the LPS-binding properties of alterins and consequently their antibacterial activities. Its length and saturation seem to play a major role in this interaction.
Removal of Different Dye Solutions: A Comparison Study Using a Polyamide NF Membrane
Authors: Hidalgo Asunción María , León Gerardo , Gómez María , Murcia María Dolores , Gómez Elisa , Macario José Antonio
Published: December 2020

The removal of organic dyes in aquatic media is, nowadays, a very pressing environmental problem. These dyes usually come from industries, such as textiles, food, and pharmaceuticals, among others, and their harm is produced by preventing the penetration of solar radiation in the aquatic medium, which leads to a great reduction in the process of photosynthesis, therefore damaging the aquatic ecosystems. The feasibility of implementing a process of nanofiltration in the purification treatment of an aqueous stream with small size dyes has been studied. Six dyes were chosen: Acid Brown-83, Allura Red, Basic Fuchsin, Crystal Violet, Methyl Orange and Sunset Yellow, with similar molecular volume (from 250 to 380 Å). The nanofiltration membrane NF99 was selected. Five of these molecules with different sizes, shapes and charges were employed in order to study the behavior of the membrane for two system characteristic parameters: permeate flux and rejection coefficient. Furthermore, a microscopy study and a behavior analysis of the membrane were carried out after using the largest molecule. Finally, the Spiegler–Kedem–Katchalsky model was applied to simulate the behavior of the membrane on the elimination of this group of dyes.
Effect of TiN Spray Coating on Cracking Susceptibility and Energy Absorption in Laser Welding of Aluminum Alloys
Authors: Nam Sangwoo , Jung In-Ho , Kim Young-Min
Published: December 2020

This paper reports on the effect of a TiN spray coating on aluminum to improve laser welding issues such as cracking susceptibility and laser absorption. A self-restraint hot cracking test and bead on plate test were employed to compare the laser weldability between the base material and TiN-coated material. The welds with the TiN coating can be fully penetrated without cracks at lower power than the welds without the coating. TiN-incorporated metal matrix composites were formed on the top layer irradiated with the laser. The layer increases the laser absorption to transfer energy efficiently and strengthens it to withstand higher stresses and strains. In addition, the welding mechanism of this process is such that the ceramic coating layer blocks direct interaction between the laser and the metal melting pool, so that a keyhole is not formed, and welding is performed by heat conduction through the TiN ceramic medium.
Optimization of Machine Learning in Various Situations Using ICT-Based TVOC Sensors
Authors: Cho Jae Hyuk , Lee Hayoun
Published: December 2020

A computational framework using artificial intelligence (AI) has been suggested in numerous fields, such as medicine, robotics, meteorology, and chemistry. The specificity of each AI model and the relationship between data characteristics and ground truth, allowing their guidance according to each situation, has not been given. Since TVOCs (total volatile organic compounds) cause serious harm to human health and plants, the prevention of such damages with a reduction in their occurrence frequency becomes not an optional process but an essential one in manufacturing, as well as for chemical industries and laboratories. In this study, with consideration of the characteristics of the machine learning technique and ICT (information and communications technology), TVOC sensors are explored as a function of grounded data analysis and the selection of machine learning models, determining their performance in real situations. For representative scenarios, considering features from an ICT semiconductor sensor and one targeting TVOC gas, we investigated suitable analysis methods and machine learning models such as LSTM (long short-term memory), GRU (gated recurrent unit), and RNN (recurrent neural network). Detailed factors for these machine learning models with respect to the concentration of TVOC gas in the atmosphere are compared with original sensory data to obtain their accuracy. From this work, we expect to significantly minimize risk in empirical applications, i.e., maintaining homeostasis or predicting abnormal situations to construct an opportune response.
Mineralogy and Geochemistry of Agates from Paleoproterozoic Volcanic Rocks of the Karelian Craton, Southeast Fennoscandia (Russia)
Authors: Svetova Evgeniya N. , Svetov Sergei A.
Published: December 2020

Agates of Paleoproterozoic volcanics (2100−1920 Ma) within the Onega Basin (Karelian Craton, Southeast Fennoscandia) were studied using optical and scanning electron microscopy, X-ray powder diffraction, X-ray fluorescence spectrometry XRF, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and C-O isotope analysis. Agate mineralization is widespread in the lavas gas vesicles, inter-pillow space of basalts, picrobasalts, basaltic andesites, as well as agglomerate tuffs. Agates are characterized by fine and coarse banding concentric zoning; moss, spotted, veinlet, and poor-fancy texture types were identified. Agate mineralization is represented by silicates, oxides, and hydroxides, carbonates, phosphates, sulfides, and sulfates. Among the silica minerals in agates only chalcedony, quartz and quartzine were found. The parameters of the quartz structure according to the X-ray diffraction data (well-develops reflections (212), (203), (301), large crystallite sizes (Cs 710–1050 Å) and crystallinity index (CI 7.8–10.3) give evidence of multi-stage silica minerals recrystallization due to a metamorphic (thermal) effect. The decreasing trend of trace element concentration in the banded agates from the outer zone to the core suggests a chemical purification process during crystallization. C-O isotope characteristic of agate-associated calcite reflects primary magmatic origin with the influence of hydrothermal activity and/or low-thermal meteoric fluids. Agates were formed under low PT-parameters and related to hydrothermal activity on the first stage of Svecofenian orogeny within 1780−1730 Ma. Thus, it can be believed that the temporal gap between continental flood basalts outflow and agate formation is about 190 Ma.
Silicon-Based Anode of Lithium Ion Battery Made of Nano Silicon Flakes Partially Encapsulated by Silicon Dioxide
Authors: Tzeng Yonhua , Chen Raycheng , He Jia-Lin
Published: December 2020

Ubiquitous mobile electronic devices and rapidly increasing electric vehicles demand a better lithium ion battery (LIB) with a more durable and higher specific charge storage capacity than traditional graphite-based ones. Silicon is among the most promising active media since it exhibits ten times of a specific capacity. However, alloying with lithium by silicon and dissociation of the silicon-lithium alloys induce high volume changes and result in pulverization. The loss of electrical contacts by silicon with the current collector of the anode causes rapid capacity decay. We report improved anode cycling performance made of silicon flakes partially encapsulated by silicon dioxide and coated with conductive nanocarbon films and CNTs. The silicon dioxide surface layer on a silicon flake improves the physical integrity for a silicon-based anode. The exposed silicon surface provides a fast transport of lithium ions and electrons. CNTs and nanocarbon films provide electrical connections between silicon flakes and the current collector. We report a novel way of manufacturing silicon flakes partially covered by silicon dioxide through breaking oxidized silicon flakes into smaller pieces. Additionally, we demonstrate an improved cycling life and capacity retention compared to pristine silicon flakes and silicon flakes fully encapsulated by silicon dioxide. Nanocarbon coatings provide conduction channels and further improve the anode performance.
Statistical Mechanics at Strong Coupling: A Bridge between Landsberg’s Energy Levels and Hill’s Nanothermodynamics
Authors: de Miguel Rodrigo , Rubí J. Miguel
Published: December 2020

We review and show the connection between three different theories proposed for the thermodynamic treatment of systems not obeying the additivity ansatz of classical thermodynamics. In the 1950s, Landsberg proposed that when a system comes into contact with a heat bath, its energy levels are redistributed. Based on this idea, he produced an extended thermostatistical framework that accounts for unknown interactions with the environment. A decade later, Hill devised his celebrated nanothermodynamics, where he introduced the concept of subdivision potential, a new thermodynamic variable that accounts for the vanishing additivity of increasingly smaller systems. More recently, a thermostatistical framework at strong coupling has been formulated to account for the presence of the environment through a Hamiltonian of mean force. We show that this modified Hamiltonian yields a temperature-dependent energy landscape as earlier suggested by Landsberg, and it provides a thermostatistical foundation for the subdivision potential, which is the cornerstone of Hill’s nanothermodynamics.
Smart Dual-Functionalized Gold Nanoclusters for Spatio-Temporally Controlled Delivery of Combined Chemo- and Photodynamic Therapy
Authors: Tabero Andrea , Planas Oriol , Gallavardin Thibault , Nieves Ingrid , Nonell Santi , Villanueva Angeles
Published: December 2020

We report the preparation of gold nanoclusters (AuNCs) as a delivery vehicle for the clinically approved photodynamic and chemotherapeutic agents Protoporphyrin IX (PpIX) and doxorubicin (DOX), respectively, and their effect on tumor cells. DOX was attached to the gold nanoclusters through a singlet oxygen-cleavable linker and was therefore released after PpIX irradiation with red light, contributing, synergistically with singlet oxygen, to induce cell death. The doubly functionalized AuNCs proved more effective than a combination of individually functionalized AuNCs. Unlike free DOX, the photoactive nanosystem was non-toxic in the absence of light, which paves the way to introduce a spatiotemporal control of the anticancer therapy and could contribute to reducing the undesirable side effects of DOX.
Lactobacillus Bacteria in Breast Milk
Authors: Łubiech Katarzyna , Twarużek Magdalena
Published: December 2020

Breast milk is an optimal food for infants and toddlers. The composition of breast milk adapts to the needs of the developing organism, satisfying nutritional needs at an early stage of growth and development. The results of research to date have shown that breast milk is the best food for a child, containing not only nutrients but also biologically active substances that aid in the optimal, proper growth and development of infants. Among the many components of breast milk, an important element is the probiotic microflora, including bacteria of the genus Lactobacillus spp. These organisms exert a multidirectional, health-promoting effect on the body of children who consume breast milk. The number of lactic acid bacteria, including Lactobacillus, colonizing the breast milk environment and their species diversity varies and depends on many factors, both maternal and environmental. Breast milk, as a recommended food for infants, is an important source of probiotic microflora. The aim of this study was to present the current understanding of probiotic bacteria of the genus Lactobacillus present in breast milk.
Parent Perspectives on Implementing Health Behavior Recommendations for Their Infants
Authors: Nickele Katherine P. , Bolanos Liliana , Bhatti Punreet K. , Williams Karen , Mason Maryann , Ariza Adolfo J.
Published: December 2020

Little is known about the influence of parental values, preferences, and child achievement and health expectations on parent choices for their child’s rearing practices. We aimed to explore parents’ perceptions of immediate and future impact of health behavior decisions for their child and to understand factors associated with child-specific health behavior decisions. This pilot study included interviews with 25 parents of 9–24-month-old children attending well child care visits at a primary care practice. Questions assessed parental perceptions and attitudes in making health behavior changes now for their child’s future health. Themes suggest parents perceive many factors are involved, and intricately connected, in health behavior decision-making. Although almost all parents believed there is a connection between the foods they feed their child and achieving their goals, only half are willing to make a change. In addition, parents failed to consider the impact of the health practices they currently have with their children to influence the future acquisition of life skills and of healthy versus obesogenic behaviors. Our results add to the understanding of the process of health behavior change through anticipatory guidance. Study findings will be used to guide next steps towards refining our understanding of health and lifestyle change decisions made by parents.
A Low-Profile End-Fire Conformal Surface Wave Antenna with Capacitive Feed Structure
Authors: Dai Legen , Xie Yongjun , Wang Huai
Published: December 2020

A high end-fire gain, low-profile surface wave antenna with capacitive feed structure is presented in this paper. The proposed dielectric-metal surface wave antenna is composed of a dielectric slab that is mounted on a metal carrier and a low-profile feed structure. The feed structure is composed of a monopole radiation pin that is loaded with a circular metal plate and a grounding pin. The profile height of the antenna is only one-tenth of the operating wavelength. With a good end-fire performance and low profile, the antenna is very suitable to be conformally mounted on the surface of flight vehicles. The proposed antenna was designed and manufactured at the center frequency of 6 GHz. Measured results demonstrated that the proposed antenna had a bandwidth of 7.33%, ranging from 5.89 to 6.33 GHz, and the antenna reached a high gain of 9.76 dBi with a length of 122.96 mm (2.45 λ) in the end-fire direction.
Verification of the Propagation Range of Respiratory Strain Using Signal Waveform Measured by FBG Sensors
Authors: Koyama Shouhei , Fujimoto Atsushi , Yasuda Yuma , Satou Yuuki
Published: December 2020

The FBG (Fiber Bragg grating) sensor is an optical fiber type strain sensor. When a person breathes, strain occurs in the lungs and diaphragm. This was verified using an FBG sensor to which part of the living body this respiratory strain propagates. When measured in the abdomen, the signal waveforms were significantly different between breathing and apnea. The respiratory cycle measured by the temperature sensor attached to the mask and the strain cycle measured by the FBG sensor almost matched. Respiratory strain was measured in the abdomen, chest, and shoulder, and the signal amplitude decreased with distance from the abdomen. In addition, the respiratory rate could be calculated from the measured strain signal. On the other hand, respiratory strain did not propagate to the elbows and wrists, which were off the trunk, and the respiratory time, based on the signal period, could not be calculated at these parts. Therefore, it was shown that respiratory strain propagated in the trunk from the abdomen to the shoulder, but not in the peripheral parts of the elbow and wrist.
Antidisturbance Control for AUV Trajectory Tracking Based on Fuzzy Adaptive Extended State Observer
Authors: Kang Song , Rong Yongfeng , Chou Wusheng
Published: December 2020

In this paper, an output-feedback fuzzy adaptive dynamic surface controller (FADSC) based on fuzzy adaptive extended state observer (FAESO) is proposed for autonomous underwater vehicle (AUV) systems in the presence of external disturbances, parameter uncertainties, measurement noises and actuator faults. The fuzzy logic system is incorporated into both the observers and controllers to improve the adaptability of the entire system. The dynamics of the AUV system is established first, considering the external disturbances and parameter uncertainties. Based on the dynamic models, the ESO, combined with a fuzzy logic system tuning the observer bandwidth, is developed to not only adaptively estimate both system states and the lumped disturbances for the controller, but also reduce the impact of measurement noises. Then, the DSC, together with fuzzy logic system tuning the time constant of the low-pass filter, is designed using estimations from the FAESO for the AUV system. The asymptotic stability of the entire system is analyzed through Lyapunov’s direct method in the time domain. Comparative simulations are implemented to verify the effectiveness and advantages of the proposed method compared with other observers and controllers considering external disturbances, parameter uncertainties and measurement noises and even the actuator faults that are not considered in the design process. The results show that the proposed method outperforms others in terms of tracking accuracy, robustness and energy consumption.
Vox Populi? Trump’s Twitter Page as Public Forum
Authors: Roca-Cuberes Carles , Young Alyssa
Published: December 2020

This article investigates Twitter replies to tweets concerning the Russia Investigation, published by the United States President, Donald J. Trump. Using a qualitative content analysis, we examine a sample of 200 tweet replies within the timeframe of the first 16 months of Trump’s presidency to explore the arguments made in favor or not in favor of Trump in the comment replies. The results show more anti-Trump than pro-Trump rhetoric in the Twitter replies; the ratio of comments displaying support for Trump or his innocence does not even reach 10%. This study concludes that Trump’s tweets do not inform his Twitter audience’s opinion on this matter, and that Trump’s repetition of catchphrases on the Russia Investigation did not have a measurable impact on his Twitter audience’s responses.
Behavioural assessment of three chicken genotypes under free-range, semi-intensive, and intensive housing systems
Authors: AHMAD Sohail , MAHMUD Athar , HUSSAİN Jibran , JAVED Khalid , USMAN Muhammad , WAQAS Muhammad , ZAİD Muhammad
Published: December 2020

The present study evaluated the effects of housing systems (free-range, semi-intensive, and intensive) on the behaviour of chickens over 10 weeks period (7-16 weeks of age. A total of 360 birds were selected and subjected to different housing systems. A Randomized Complete Block Design (RCBD) considered the following: 3 genotypes (RNN, BNN, and NN) × 2 sexes (30 cockerels and 30 pullets = 60 / genotype) × 3 housing systems (free-range, semi-intensive, and intensive) = 18 experimental units with 20 birds per unit = 360 birds. Regarding behavioural response, male birds under the intensive system were more aggressive and showed more sitting and standing behaviour followed by semi-intensive and free-range systems. Jumping, running, walking and wing flapping behaviours were higher in semi-intensive birds followed by free-range and intensive systems. Regarding females, RNN and BNN chicken revealed higher running behaviour than NN. In terms of housing systems, birds reared in the intensive system were more aggressive and showed an increased frequency of sitting and standing behaviours followed by semi-intensive and free-range systems. Birds under the free-range system spent most of their time in feeding and wing flapping followed by semi-intensive and intensive housing systems. Jumping, running, and walking was more pronounced in the semi-intensive system followed by a free-range and intensive system. It was concluded that RNN and BNN chickens expressed more natural behaviours under semi-intensive and free-range systems than NN chickens; hence, crossbred chickens could be reared under such types of environments to achieve their maximum genetic potential.