bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Gelling Agent and Rheology Modifier in Cosmetics: Caesalpinia spinosa Gum
Authors: Rigano Luigi , Deola Miriam , Zaccariotto Francesca , Colleoni Thomas , Lionetti Nicola
Published: June 2019

Caesalpinia spinosa gum is a vegetal polysaccharide obtained by grinding the endosperm of Caesalpinia spinosa seeds. It is commonly used as a rheology modifier in food industry. Its rheological behavior, compatibility with common cosmetic ingredients, and application as a thickener in different types of cosmetic formulations were investigated in this article. At low concentrations (0.1–0.2%) the behavior is Newtonian; at higher percentages (0.5–2.0%) it is pseudoplastic without thixotropy. The gum was tested in combination with salts, chelating agents, humectants, thickeners, pigments, nano UV filters, surfactants, conditioners, and ethanol, as well as in acidic/alkaline conditions. The wide compatibility and the interesting sensory profile, even in association with other thickeners, make the Caesalpinia spinosa gum a very promising ingredient for the thickening of various cosmetic products.
Spin Transition in the Cu(hfac)2 Complex with (4-Ethylpyridin-3-yl)-Substituted Nitronyl Nitroxide Caused by the “Asymmetric” Structural Rearrangement of Exchange Clusters in the Heterospin Molecule
Authors: Artiukhova Natalia , Romanenko Galina , Letyagin Gleb , Bogomyakov Artem , Veber Sergey , Minakova Olga , Petrova Marina , Morozov Vitaliy , Ovcharenko Victor
Published: June 2019

Methods for the synthesis of binuclear [Cu(hfac)2LEt]2 and tetranuclear [[Cu(hfac)2]4(LEt)2] heterospin compounds based on copper hexafluoroacetylacetonate [Cu(hfac)2] and 2-(4-ethylpyridin-3-yl)-4,5-bis(spirocyclopentyl)-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (LEt), were developed. The crystals of the complexes are elastic and do not crash during repeated cooling–heating cycles. It was found that a singlet–triplet conversion occurred in all of the {Cu(II)–O•–N<} exchange clusters in the molecules of the binuclear [Cu(hfac)2LEt]2 which led to spin coupling with cooling. The transition occurred in a wide temperature range with a maximum gradient ΔχT at ≈180 K. The structural transformation of the crystals takes place at T < 200 K and is accompanied by the lowering of symmetry from monoclinic to triclinic, twinning, and a considerable shortening of the Cu–ONO distance (2.19 and 1.97 Å at 295 and 50 K, respectively). For the tetranuclear [[Cu(hfac)2]4(LEt)2], two structural transitions were recorded (at ≈154 K and ≈118 K), which led to a considerable change in the spatial position of the Et substituent in the nitronyl nitroxyl fragment. The low-temperature process was accompanied by a spin transition recorded as a hysteresis loop on the χT(T) curve during the repeated cooling–heating cycles (T½↑ = 122 K, T½↓ = 115 K). This transition is unusual because it causes spin coupling in half of all of the {>N–•O–Cu2+} terminal exchange clusters, leading to spin compensation for only two paramagnetic centers of the six centers in the molecule.
Design of PI Fuzzy Logic Gain Scheduling Load Frequency Control in Two-Area Power Systems
Authors: Hussein Tawfiq , Shamekh Awad
Published: June 2019

In this paper the use of the proportional integral (PI) algorithm incorporated with the fuzzy logic technique has been proposed as advanced gain scheduling load frequency control (GLFC) in two-area power systems. The proposed controller comprises two-level control systems, such that it consists of a pure integral compensator which is connected in parallel with a PI controller. However, and based on load demand, the PI parameters are updated online by means of fuzzy logic rules. With this control technique it becomes possible to eliminate steady state errors as well as to maintain good transient responses. The task of keeping a stable and overall satisfactory mode of operation in interconnected electric power systems is the main goal of any control strategy. This should be guaranteed over a wide range of operating conditions and particularly in sudden and drastic load changes. Therefore, the suggested approach has been examined following abnormal changes in loading conditions to clarify its reliability. The report also investigates the performance of the pure integral (I) controller and GLFC in individual configurations to highlight the advantages of the offered algorithm over the standard ones. The criterion of integral square error (ISE) has been exploited in the performance assessment for the designed controllers. Several simulation scenarios have been conducted, using the MATLAB–Simulink package, to illustrate the proficiency of the developed technique.
An Overview of Different Interdental Cleaning Aids and Their Effectiveness
Authors: Ng Ethan , Lim Lum Peng
Published: June 2019

Optimisation of plaque control is essential for the success of non-surgical and surgical periodontal therapy. This cannot be achieved with brushing alone; hence, there is a need for adjunctive interdental cleaning aids. The aim of this paper is to provide an overview of different interdental cleaning aids and review the literature for consensus on their effectiveness. A literature search of articles in English, up to December 2018, was conducted in Pubmed. High-quality flossing is difficult to achieve, and ineffective routine use of floss may not confer significant benefits over brushing alone. Interdental brushes are more effective than brushing as a monotherapy. They are at least as good if not superior to floss in reducing plaque and gingivitis. Although they are effective for patients regardless of their periodontal status (healthy or active), they are especially indicated in periodontal patients where widened embrasures are common. Added benefits include ease of use, patient acceptance, and recontouring of interdental tissues. Rubberpiks do not demonstrate inferiority to conventional interdental brushes. Wooden interdental aids appear to offer no significant advantage over brushing with respect to plaque removal; they may, however, reduce gingival bleeding. Oral irrigators are a promising tool for reducing gingival inflammation, despite minimal changes to plaque levels. For cleaning around dental implants, oral irrigators and interdental brushes are preferred over floss.
Effect of Dietary Fiber on the Composition of the Murine Dental Microbiome
Authors: Sedghi Lea , Byron Craig , Jennings Ryan , Chlipala George E. , Green Stefan J. , Silo-Suh Laura
Published: June 2019

The oral cavity houses a diverse consortium of microorganisms, heavily influenced by host diet, that can mediate dental health and disease. While the impact of dietary carbohydrates to the dental microbiome has been well-documented, the effect of fiber as a mechanical influence on the dental microbiome is unexplored. We performed 16S rRNA gene analysis to investigate the response of the dental microbiome to the presence of increased fiber in terms of microbial taxonomic abundance and diversity. Dental microbial community structure was significantly different in mice fed a diet supplemented with increased fiber and/or sugar. Fiber significantly affected measures of beta diversity at the phylum and genus levels, and a strong interactive effect on alpha diversity was observed between sugar and fiber at the phylum level. The addition of fiber also induced significant variation in relative taxonomic abundance. This study demonstrates that fiber can promote significant variations in the mouse dental microbiome.
Anorexia, Oral Health and Antioxidant Salivary System: A Clinical Study on Adult Female Subjects
Authors: Mascitti Marco , Coccia Erminia , Vignini Arianna , Aquilanti Luca , Santarelli Andrea , Salvolini Eleonora , Sabbatinelli Jacopo , Mazzanti Laura , Procaccini Maurizio , Rappelli Giorgio
Published: June 2019

The aim of this study was to compare the oral health status and salivary antioxidant system between patients diagnosed with anorexia nervosa (AN) and healthy controls. A total of 25 female AN patients and 25 matched healthy controls were enrolled. Clinical parameters and saliva samples were collected for each patient. Two questionnaires to investigate oral health and hygiene were administered. Superoxide Dismutase (SOD) activity and High Reactive Oxygen Species (hROS) were evaluated. Salivary concentration of SOD was significantly higher in subjects with AN compared with control group (1.010 ± 0.462 vs. 0.579 ± 0.296 U/mL; p = 0.0003). No significant differences between groups were identified for hROS (233.72 ± 88.27 vs. 199.49 ± 74.72; p = 0.15). Data from questionnaires indicated that, although most of the patients recognized the oral hygiene importance in maintaining a good oral health, more than half of them had poor oral hygiene. Altered biochemical composition of saliva in patients with AN could be interpreted as an effective defence mechanism against oxidative stress. Moreover, despite the discrepancy between clinical findings and perception of the oral health in AN population arose, the quality of life of these patients appears not to be significantly affected by their dental condition.
Spectrophotometric Determination of the Aggregation Activity of Platelets in Platelet-Rich Plasma for Better Quality Control
Authors: Tsujino Tetsuhiro , Isobe Kazushige , Kawabata Hideo , Aizawa Hachidai , Yamaguchi Sadahiro , Kitamura Yutaka , Masuki Hideo , Watanabe Taisuke , Okudera Hajime , Nakata Koh , Kawase Tomoyuki
Published: June 2019

Although platelet-rich plasma (PRP) is now widely used in regenerative medicine and dentistry, contradictory clinical outcomes have often been obtained. To minimize such differences and to obtain high quality evidence from clinical studies, the PRP preparation protocol needs to be standardized. In addition, emphasis must be placed on quality control. Following our previous spectrophotometric method of platelet counting, in this study, another simple and convenient spectrophotometric method to determine platelet aggregation activity has been developed. Citrated blood samples were collected from healthy donors and used. After centrifugation twice, platelets were suspended in phosphate buffered saline (PBS) and adenosine diphosphate (ADP)-induced aggregation was determined using a spectrophotometer at 615 nm. For validation, platelets pretreated with aspirin, an antiplatelet agent, or hydrogen peroxide (H2O2), an oxidative stress-inducing agent, were also analyzed. Optimal platelet concentration, assay buffer solution, and representative time point for determination of aggregation were found to be 50–100 × 104/μL, PBS, and 3 min after stimulation, respectively. Suppressed or injured platelets showed a significantly lower aggregation response to ADP. Therefore, it suggests that this spectrophotometric method may be useful in quick chair-side evaluation of individual PRP quality.
Analytical Solutions of Fractional-Order Diffusion Equations by Natural Transform Decomposition Method
Authors: Shah Rasool , Khan Hassan , Mustafa Saima , Kumam Poom , Arif Muhammad
Published: June 2019

In the present article, fractional-order diffusion equations are solved using the Natural transform decomposition method. The series form solutions are obtained for fractional-order diffusion equations using the proposed method. Some numerical examples are presented to understand the procedure of the Natural transform decomposition method. The Natural transform decomposition method has shown the least volume of calculations and a high rate of convergence compared to other analytical techniques, the proposed method can also be easily applied to other non-linear problems. Therefore, the Natural transform decomposition method is considered to be one of the best analytical technique, to solve fractional-order linear and non-linear partial deferential equations, particularly fractional-order diffusion equation.
The Thermodynamics of Network Coding, and an Algorithmic Refinement of the Principle of Maximum Entropy
Authors: Zenil Hector , Kiani Narsis A. , Tegnér Jesper
Published: June 2019

The principle of maximum entropy (Maxent) is often used to obtain prior probability distributions as a method to obtain a Gibbs measure under some restriction giving the probability that a system will be in a certain state compared to the rest of the elements in the distribution. Because classical entropy-based Maxent collapses cases confounding all distinct degrees of randomness and pseudo-randomness, here we take into consideration the generative mechanism of the systems considered in the ensemble to separate objects that may comply with the principle under some restriction and whose entropy is maximal but may be generated recursively from those that are actually algorithmically random offering a refinement to classical Maxent. We take advantage of a causal algorithmic calculus to derive a thermodynamic-like result based on how difficult it is to reprogram a computer code. Using the distinction between computable and algorithmic randomness, we quantify the cost in information loss associated with reprogramming. To illustrate this, we apply the algorithmic refinement to Maxent on graphs and introduce a Maximal Algorithmic Randomness Preferential Attachment (MARPA) Algorithm, a generalisation over previous approaches. We discuss practical implications of evaluation of network randomness. Our analysis provides insight in that the reprogrammability asymmetry appears to originate from a non-monotonic relationship to algorithmic probability. Our analysis motivates further analysis of the origin and consequences of the aforementioned asymmetries, reprogrammability, and computation.
Single Event Transients in CMOS Ring Oscillators
Authors: Prinzie Jeffrey , De Smedt Valentijn
Published: June 2019

In this paper, a time-variant analysis is made on Single-Event Transients (SETs) in integrated CMOS ring oscillators. The Impulse Sensitive Function (ISF) of the oscillator is used to analyze the impact of the relative moment when a particle hits the circuit. The analysis is based on simulations and verified experimentally with a Two-Photon Absorption (TPA) laser setup. The experiments are done using a 65 nm CMOS test chip.
Risk-Based Decision Methods for Vehicular Networks
Authors: Shaikh Riaz Ahmed , Thayananthan Vijey
Published: June 2019

Vehicular networks play a key role in building intelligent transport systems for smart cities. For the purpose of achieving traffic efficiency, road safety, and traveler comfort, vehicles communicate and collaborate with each other as well as with the fixed infrastructure. In practice, not all vehicles are trustworthy. A faulty or malicious vehicle may forward or share inaccurate or bogus information, which may cause adverse things, such as, road accidents and traffic congestion. Therefore, it is very important to evaluate risk before a vehicle takes any decision. Various risk-based decision systems have already been proposed in the literature. The fuzzy risk-based decision model of vehicular networks is one of them. In this paper, we have proposed various extensions in the fuzzy risk-based decision model to achieve higher robustness, reliability, and completeness. We have presented the theoretical and simulation-based analysis and evaluation of the proposed scheme in a comprehensive manner. In addition, we have analytically cross verified the theoretical and simulation-based results. Qualitative comparison of the proposed scheme has also been presented in this work.
Utilizing Asphalt Heat Energy in Finnish Climate Conditions
Authors: Mäkiranta Anne , Hiltunen Erkki
Published: June 2019

Geothermal energy is a form of renewable energy, which offers carbon-free solutions for heating and cooling spaces. This study evaluates the use of renewable asphalt heat energy in frozen ground conditions. Asphalt heat energy can be harnessed using a low-energy network, heat collection pipes and heat pumps. This study measured temperatures under the asphalt layer during a three-year period between 2014 and 2017. Measurements were made using a distributed temperature sensing method based on light scattering. Temperatures taken at four different depths under the asphalt (0.5 m, 1.0 m, 3.0 m and 10 m) are presented here. These temperatures are compared with that detected at the depth at which the temperature remains constant all year round. The temperature difference curve between 0.5 m depth and the constant soil temperature depth indicates that from April to October the soil at 0.5 m depth is warming and the temperature difference is positive, even as much as 18 °C. Instead, at the 3.0 m depth, the difference curve is smoother and it varies only from −5 to +5 °C. It is positive from June to November. The surface layer (0 m–1.0 m) is suitable for harvesting heat that can be stored in a deeper (1.5 m–3.0 m) purpose-built storage or in a bedrock heat battery. The calculated heat capacities indicate that asphalt energy, because of high temperatures, is a noteworthy renewable energy source.
Reduction of Heat Losses in a Pre-Insulated Network Located in Central Poland by Lowering the Operating Temperature of the Water and the Use of Egg-shaped Thermal Insulation: A Case Study
Authors: Krawczyk Dorota Anna , Teleszewski Tomasz Janusz
Published: June 2019

This paper presents possible variants of reducing the heat loss in an existing heating network made from single pre-insulated pipes located in central Europe. In order to achieve this aim, simulations were carried out for five different variants related to the modification of the network operation temperature, replacement of a single network with a double pre-insulated one, and changes in the cross-section geometry of the thermal insulation of the double heating network from circular to egg-shaped. The proposed egg-shaped thermal insulation was obtained by modifying the shape of the Cassini oval, in that the supply pipe has a greater insulation thickness compared to the return pipe. The larger insulation field in the supply pipe contributed to reducing the heat flux density around the supply line and, as a result, to significantly reducing heat loss. The egg-shaped thermal insulation described in the publication in a mathematical formula can be used in practice. This work compares the heat losses for the presented variants and determines the ecological effect. Heat losses were determined using the boundary element method (BEM), using a proprietary computer program written as part of the VIPSKILLS 2016-1-PL01-KA203-026152 project Erasmus+.
Numerical Analysis of Effects of Arms with Different Cross-Sections on Straight-Bladed Vertical Axis Wind Turbine
Authors: Hara Yutaka , Horita Naoki , Yoshida Shigeo , Akimoto Hiromichi , Sumi Takahiro
Published: June 2019

Most vertical axis wind turbines (VAWTs) need arms connecting the blades with the rotational axis. The arms increase the power loss of VAWTs; however, the distribution between the pressure and friction influences and their degrees of influence have not yet been investigated in detail in past research. We applied computational fluid dynamics (CFD) targeting a small-sized straight-bladed VAWT to elucidate the effects of arms on turbine performance. In the analysis, three kinds of arms with different cross-sections (NACA 0018 airfoil, 18% rectangular, circular) with the same height were added to an armless rotor. The tangential forces and resistance torques caused by the added arms were recalculated by dividing the pressure and friction influences based on the surface pressure and friction distributions obtained by the CFD on an arm or a blade. The pressure-based tangential force of an arm, regardless of the cross-section, had a tendency to increase near the connection part between the arm and a blade. Though the value was small, the friction on the rectangular arm generated a driving force, whereas the friction on the other arms generated resistance forces. The pressure-based tangential force of a blade increased for a wide region around the connection part. The friction-based tangential force of a blade dropped around the connection part of every arm-equipped rotor. The arm resistance torque added to a VAWT by the existence of arms was larger than the added blade resistance torque in the cases of rectangular and circular arm rotors. Conversely, in the case of the airfoil arm rotor, the resistance torque added to blades became larger than that of arms.
Recent Advances in Layer-by-Layer Assembled Conducting Polymer Based Composites for Supercapacitors
Authors: Kulandaivalu Shalini , Sulaiman Yusran
Published: June 2019

Development of well-designed electrodes is the key to achieve high performance supercapacitors. Therefore, as one of the effective methods, a layer-by-layer (LBL) approach is often fruitfully employed for the fabrication of electrode material. Benefiting from a tunable parameter of the LBL approach, this approach has paved a way to design a highly ordered nanostructured electrode material with excellent performance. Conducting polymers (CPs) are the frontrunners in supercapacitors and notably, the LBL assembly of CPs is attracting extensive attention. Therefore, this critical review covers a comprehensive discussion on the research progress of CP-based composites with special importance on the LBL approach predominately for supercapacitors. Following a brief discussion on supercapacitors and CPs, the most up-to-date techniques used in LBL are highlighted.
Fuzzy-Enhanced Modeling of Lignocellulosic Biomass Enzymatic Saccharification
Authors: Furlong Vitor B. , Corrêa Luciano J. , Giordano Roberto C. , Ribeiro Marcelo P. A.
Published: June 2019

The enzymatic hydrolysis of lignocellulosic biomass incorporates many physico-chemical phenomena, in a heterogeneous and complex media. In order to make the modeling task feasible, many simplifications must be assumed. Hence, different simplified models, such as Michaelis-Menten and Langmuir-based ones, have been used to describe batch processes. However, these simple models have difficulties in predicting fed-batch operations with different feeding policies. To overcome this problem and avoid an increase in the complexity of the model by incorporating other phenomenological terms, a Takagi-Sugeno Fuzzy approach has been proposed, which manages a consortium of different simple models for this process. Pretreated sugar cane bagasse was used as biomass in this case study. The fuzzy rule combines two Michaelis-Menten-based models, each responsible for describing the reaction path for a distinct range of solids concentrations in the reactor. The fuzzy model improved fitting and increased prediction in a validation data set.
Decentralized Optimal Control of a Microgrid with Solar PV, BESS and Thermostatically Controlled Loads
Authors: Zhuo Wenhao , Savkin Andrey V. , Meng Ke
Published: June 2019

Constructing microgrids with renewable energy systems could be one feasible solution to increase the penetration of renewable energy. With proper control of the battery energy storage system (BESS) and thermostatically controlled loads (TCLs) in such microgrids, the variable and intermittent energy can be smoothed and utilized without the interference of the main power grid. In this paper, a decentralized control strategy for a microgrid consisting of a distributed generator (DG), a battery energy storage system, a solar photovoltaic (PV) system and thermostatically controlled loads is proposed. The control objective is to maintain the desired temperature in local buildings at a minimum cost. Decentralized control algorithm involving variable structure controller and dynamic programming is used to determine suitable control inputs of the distributed generator and the battery energy storage system. The model predictive control approach is utilized for long-term operation with predicted data on solar power and outdoor temperature updated at each control step.
An Intelligent Battery Energy Storage-Based Controller for Power Quality Improvement in Microgrids
Authors: Alshehri Jaber , Khalid Muhammad , Alzahrani Ahmed
Published: June 2019

Modern power systems rely on renewable energy sources and distributed generation systems more than ever before; the combination of those two along with advanced energy storage systems contributed widely to the development of microgrids (MGs). One of the significant technical challenges in MG applications is to improve the power quality of the system subjected to unknown disturbances. Hence innovative control strategies are vital to cope with the problem. In this paper, an innovative online intelligent energy storage-based controller is proposed to improve the power quality of a MG system; in particular, voltage and frequency regulation at steady state conditions are targeted. The MG system under consideration in this paper consists of two distributed generators, a diesel synchronous generator, and a photovoltaic power system integrated with a battery energy storage system. The proposed control approach is based on hybrid differential evolution optimization (DEO) and artificial neural networks (ANNs). The controller parameters have been optimized under several operating conditions. The obtained input and output patterns are consequently used to train the ANNs in order to perform an online tuning for the controller parameters. Finally, the proposed DEO-ANN methodology has been evaluated under random disturbances, and its performance is compared with a benchmark controller.
An Integrated Assessment of the Environmental and Economic Impact of Offshore Oil Platform Electrification
Authors: Riboldi Luca , Völler Steve , Korpås Magnus , Nord Lars O.
Published: June 2019

Electrification of offshore oil and gas installations on the Norwegian continental shelf is one of several options to decrease the CO2 emitted from these installations. However, there is an ongoing debate regarding how the increased electricity consumption will influence the CO2 emissions in the power market, both in the short-run and in the long-run. This paper aims to address the issue and investigate the feasibility of the electrification of a large offshore area in the North Sea in comparison to standard concepts to supply energy offshore. A novel integrated model was developed for the purpose that includes and combines a process model of the offshore power generation units and a model of the European power system. The integration of the two models allows to simultaneously simulate the behavior of the offshore energy conversion systems and the effect of electrification on the onshore power system. The outcomes of the analysis show that the environmental performance of electrification is strongly affected by the selected approach to quantify the CO2 emissions associated with power from shore. Taking standard methods to supply offshore energy as basis for comparison, the marginal effect of electrification would result in increased CO2 emissions (+40%), while the average effect would entail large reductions in CO2 emissions (−48% to −90%), the extent of which depends on the geographical scope selected. An analysis on the economics of electrification indicates that its economic viability would be challenging and would not be favoured by a strong European commitment towards environmental policies since the expected increase of power price will outbalance the gains for the reduced emission costs.
Integrating Two-Stage Phase Change Material Thermal Storage for Cascaded Waste Heat Recovery of Diesel-Engine-Powered Distributed Generation Systems: A Case Study
Authors: Li Dacheng , Ding Yulong , Wang Peilun , Wang Shuhao , Yao Hua , Wang Jihong , Huang Yun
Published: June 2019

Thermal energy storage using the latent heat of phase change materials (PCMs) is a promising technique to solve the time mismatch between the availability and usage of flue gas heat in distributed generation systems (DGSs). A diesel-engine-powered DGS integrated with two-stage tube-type PCM modules for exhaust gas heat recovery was developed and studied. Energy and exergy analysis for the PCM storage unit was carried out to verify the effectiveness of the PCM modules for heat recovery and to highlight the merits of the cascaded configuration through a practical engineering case. Furthermore, the performance of the DGS was evaluated to study the contribution of PCM storage to improving system efficiency. The results showed that 56.4% energy and 48.3% exergy of the input flue gas were stored by the two-stage storage unit. Additional integration of the low-temperature PCM module to the high-temperature module improved the average storage efficiency from 33.6% to 62.3% for energy and 33.1% to 50.8% for exergy. By utilizing the stored energy for heating water, the thermal efficiency of the diesel engine was increased from the original 35.8% to 41.9%, while the exergy efficiency was improved from 29.5% to 29.7%.
Estimation of Static Young’s Modulus for Sandstone Formation Using Artificial Neural Networks
Authors: Mahmoud Ahmed Abdulhamid , Elkatatny Salaheldin , Ali Abdulwahab , Moussa Tamer
Published: June 2019

In this study, we used artificial neural networks (ANN) to estimate static Young’s modulus (Estatic) for sandstone formation from conventional well logs. ANN design parameters were optimized using the self-adaptive differential evolution optimization algorithm. The ANN model was trained to predict Estatic from conventional well logs of the bulk density, compressional time, and shear time. The ANN model was trained on 409 data points from one well. The extracted weights and biases of the optimized ANN model was used to develop an empirical relationship for Estatic estimation based on well logs. This empirical correlation was tested on 183 unseen data points from the same training well and validated using data from three different wells. The optimized ANN model estimated Estatic for the training dataset with a very low average absolute percentage error (AAPE) of 0.98%, a very high correlation coefficient (R) of 0.999 and a coefficient of determination (R2) of 0.9978. The developed ANN-based correlation estimated Estatic for the testing dataset with a very high accuracy as indicated by the low AAPE of 1.46% and a very high R and R2 of 0.998 and 0.9951, respectively. In addition, the visual comparison of the core-tested and predicted Estatic of the validation dataset confirmed the high accuracy of the developed ANN-based empirical correlation. The ANN-based correlation overperformed four of the previously developed Estatic correlations in estimating Estatic for the validation data, Estatic for the validation data was predicted with an AAPE of 3.8% by using the ANN-based correlation compared to AAPE’s of more than 36.0% for the previously developed correlations.
H2O2-Enhanced Shale Gas Recovery under Different Thermal Conditions
Authors: Yu WeiGang , Lei Jiang , Wang Tengxi , Chen Wei
Published: June 2019

The permeability of tight shale formations varies from micro-Darcy to nano-Darcy. Recently, hydrogen peroxide (H2O2) was tested as an oxidizer to remove the organic matter in the rock in order to increase shale permeability. In this study, shale particles were reacted with hydrogen peroxide solutions under different temperature and pressure conditions in order to “mimic” underground geology conditions. Then, low-temperature nitrogen adsorption and desorption experiments were conducted to measure the pore diameters and porosity of raw and treated shale samples. Moreover, scanning electron microscopy (SEM) images of the samples were analyzed to observe pore structure changes on the surface of shale samples. From the experiments, it was found that the organic matter, including extractable and solid organic matter, could react with H2O2 under high temperature and pressure conditions. The original blocked pores and pore throats were reopened after removing organic matter. With the increase of reaction temperature and pressure, the mean pore diameters of the shale samples decreased first and then increased afterwards. However, the volume and Brunauer–Emmett–Teller (BET) surface areas of the shale particles kept increasing with increasing reaction temperature and pressure. In addition to the effect of reaction temperature and pressure, the pore diameter increased significantly with the increasing reaction duration. As a result, H2O2 could be used to improve the shale permeability.
Numerical Modeling of Space–Time Characteristics of Plasma Initialization in a Secondary Arc
Authors: Li Jinsong , Yu Hua , Jiang Min , Liu Hong , Li Guanliang
Published: June 2019

A numerical model based on the finite element simulation software COMSOL was developed to investigate the secondary arc that can limit the success of single-phase auto-reclosure solutions to the single-phase-to-ground fault. Partial differential equations accounting for variation of densities of charge particles (electrons, positive and negative ions) were coupled with Poisson’s equation to consider the effects of space and surface charges on the electric field. An experiment platform was established to verify the numerical model. The brightness distribution of the experimental short-circuit arc was basically consistent with the predicted distribution of electron density, demonstrating that the simulation was effective. Furthermore, the model was used to assess the particle density distribution, electric field variation, and time dependence of ion reactions during the short-circuit discharge. Results showed that the ion concentration was higher than the initial level after the short-circuit discharge, which is an important reason for inducing the subsequent secondary arc. The intensity of the spatial electric field was obviously affected by the high-voltage electrode at the end regions, and the intermediate region was mainly affected by the particle reaction. The time correspondence between the detachment reaction and the ion source generated in the short-circuit discharge process was basically consistent, and the detachment reactions were mainly concentrated in the middle area and near the negative electrode. The research elucidates the relevant plasma process of the secondary arc and will contribute to the suppression of it.
Reduced-Order DC Terminal Dynamic Model for Multi-Port AC-DC Power Electronic Transformer
Authors: Wang Zhe , Li Yaohua , Li Zixin , Zhao Cong , Gao Fanqiang , Wang Ping
Published: June 2019

As new electric power conversion equipment, a multi-port power electronic transformer (MP-PET), including a power electronic converter, high-frequency transformer, and multiple ac or dc interconnection interfaces, has a broad application in the hybrid distribution network. However, high integration and a large number of energy storage devices has led to very a high-order model of the system. To address this issue, a reduced-order small signal model of MP-PET is established in this paper. By taking the participation factors of the system mode to the state variables, the reduced-order model is derived based on the state variables, which are highly correlated with the dc voltage dominant mode. Compared with the full-order model, the proposed reduced-order model is accurate enough and simplified, and the validity of the simplified model is verified against simulations on a 10 kV/3 MVA MP-PET. The simulation results indicate that the proposed reduced-order model coincides well with the dynamic performance of the MP-PET.
Grinding Test on Tremolite with Fibrous and Prismatic Habit
Authors: Baietto Oliviero , Diano Mariangela , Zanetti Giovanna , Marini Paola
Published: June 2019

The main objective of this work is the evaluation of the morphology change in tremolite particles before and after a grinding process. The crushing action simulates anthropic alteration of the rock, such as excavation in rocks containing tremolite during a tunneling operation. The crystallization habit of these amphibolic minerals can exert hazardous effects on humans. The investigated amphibolic minerals are four tremolite samples, from the Piedmont and Aosta Valley regions, with different crystallization habits. The habits can be described as asbestiform (fibrous) for longer and thinner fibers and non-asbestiform (prismatic) for prismatic fragments, also known as “cleavage” fragments. In order to identify the morphological variation before and after the grinding, both a phase contrast optical microscope (PCOM) and a scanning electron microscope (SEM) were used. The identification procedure for fibrous and prismatic elements is related to a dimensional parameter (length–diameter ratio) defined by the Health and Safety Executive. The results highlight how mineral comminution leads to a rise of prismatic fragments and, therefore, to a potentially safer situation for worker and inhabitants.
Oral Wine Texture Perception and Its Correlation with Instrumental Texture Features of Wine-Saliva Mixtures
Authors: Laguna Laura , Álvarez María Dolores , Simone Elena , Moreno-Arribas Maria Victoria , Bartolomé Begoña
Published: June 2019

Unlike solid food, texture descriptors in liquid food are scarce, and they are frequently reduced to the term viscosity. However, in wines, apart from viscosity, terms, such as astringency, body, unctuosity and density, help describe their texture, relating the complexity and balance among their chemical components. Yet there is uncertainty about which wine components (and their combinations) cause each texture sensation and if their instrumental assessment is possible. Therefore, the aim of the present work was to study the effect of wine texture on its main components, when interacting with saliva. This was completed by using instrumental measurements of density and viscosity, and by using two types of panels (trained and expert). For that, six different model-wine formulations were prepared by adding one or multiple wine components: ethanol, mannoproteins, glycerol, and tannins to a de-alcoholised wine. All formulations were mixed with fresh human saliva (1:1), and their density and rheological properties were measured. Although there were no statistical differences, body perception was higher for samples with glycerol and/or mannoproteins, this was also correlated with density instrumental measurements (R = 0.971, p = 0.029). The viscosity of samples with tannins was the highest due to the formation of complexes between the model-wine and salivary proteins. This also provided astringency, therefore correlating viscosity and astringency feelings (R = 0.855, p = 0.030). No correlation was found between viscosity and body perception because of the overlapping of the phenolic components. Overall, the present results reveal saliva as a key factor when studying the wine texture through instrumental measurements (density and viscosity).
High-Silica Lava Morphology at Ocean Spreading Ridges: Machine-Learning Seafloor Classification at Alarcon Rise
Authors: Maschmeyer Christina H. , White Scott M. , Dreyer Brian M. , Clague David A.
Published: June 2019

The oceanic crust consists mostly of basalt, but more evolved compositions may be far more common than previously thought. To aid in distinguishing rhyolite from basaltic lava and help guide sampling and understand spatial distribution, we constructed a classifier using neural networks and fuzzy inference to recognize rhyolite from its lava morphology in sonar data. The Alarcon Rise is ideal to study the relationship between lava flow morphology and composition, because it exhibits a full range of lava compositions in a well-mapped ocean ridge segment. This study shows that the most dramatic geomorphic threshold in submarine lava separates rhyolitic lava from lower-silica compositions. Extremely viscous rhyolite erupts as jagged lobes and lava branches in submarine environments. An automated classification of sonar data is a useful first-order tool to differentiate submarine rhyolite flows from widespread basalts, yielding insights into eruption, emplacement, and architecture of the ocean crust.
A Simple Effective Method for Three-Dimensional Modelling of Cementation, Fracturing and Dissolution of Carbonate Rocks: Illustrated through Oolitic Limestone
Authors: Buckman James , Higgins Sean
Published: June 2019

Sandstones and many carbonates (e.g., oolitic limestone and other grainstones), comprise solid particulates (grains) and pores, which have a given pore network architecture relationship, and associated porosity—permeability values. Over time, through the process of diagenesis, the pore network architecture may be extensively altered. Changes can include compaction, particle deformation, cementation, dissolution and fracturing, with the pathway followed after deposition depending on factors such as the energy level, rate of burial, degree of biological activity, local heat flow, sediment composition, Eh, pH and the presence or absence of organic materials. Any method that provides a means of modelling changes is therefore highly desirable, in particular, allowing a prediction of changes in porosity and permeability with time. The current work illustrates a simple method that uses freely available open source image analysis software to model the development of cement phases within an oolitic limestone in three-dimensions. As well as cementation, it demonstrates the modelling of fracture development and dissolution processes, and records how porosity and permeability change during such processes.
Agents of Secularisation—Ibsen and the Narrative of Secular Modernity
Authors: Schiedermair Joachim
Published: June 2019

In sociology, modernisation is often identified with secularisation. How can secularisation in the texts of modernism around 1900 be analysed? Literary history books tell us that the modernist authors were lucid analysts of their time who portrayed the process of secularisation going on around them in their dramas, novels or short stories. The article tries out a different approach: By conceptualizing secularisation as a cultural narrative, the perspective on the literary material changes fundamentally. The modernist authors were involved in shaping the idea of secularisation in the first place, in propagating it and in working on its implementation. They did not react to the process of secularisation with their texts. Instead, they were involved in the creation and shaping of the interpretative category ‘secularisation’. The article exemplifies this change in approach using a pivotal text of Nordic literary modernism, Ibsen’s Rosmersholm.
Sustainable Management of Underwater Cultural Heritage: The Route from Discovery to Engagement—Open Issues in the Mediterranean
Authors: Argyropoulos Vasilike , Stratigea Anastasia
Published: June 2019

Fatal events taking place in World War (WW) I and II have left behind important historical evidence as an underwater cultural heritage (UCH) (e.g., shipwrecks, submerged aircraft, war artifacts), lying in peace at the bottom of, among others, the Mediterranean Sea. The article aims at exploring the challenges for UCH protection/preservation and sustainable exploitation with emphasis on this sea. UCH is so far dealt with in a “silo” approach by marine archaeologists or heritage professionals, who often ignore its potential for serving local sustainable development goals. The paper elaborates on the value, but also the complexity, multi- and inter-disciplinary as well as multi-actors’ nature of UCH management and sustainable exploitation, perceiving these as a “wicked” planning problem. It attempts to illuminate various important dimensions of this problem, such as its glocal (global/local) context; the conflicting and, in certain cases, inconsistent UCH legal protection framework, touching upon a variety of spatial scales; the contemporary policy frameworks favoring UCH management; etc. Exploration of these dimensions reveals open issues or gaps that need to be filled, and sets the ground for a more holistic and integrated UCH research and management approach for building up the yet largely untold, Mediterranean WW I and II UCH narrative; and shifting this area from a sea graveyard to a place of memory and cultural enrichment.
Recent Advances in Hormonal Regulation and Cross-Talk during Non-Climacteric Fruit Development and Ripening
Authors: Fuentes Lida , Figueroa Carlos R. , Valdenegro Monika
Published: June 2019

Fleshy fruits are characterized by having a developmentally and genetically controlled, highly intricate ripening process, leading to dramatic modifications in fruit size, texture, color, flavor, and aroma. Climacteric fruits such as tomato, pear, banana, and melon show a ripening-associated increase in respiration and ethylene production and these processes are well-documented. In contrast, the hormonal mechanism of fruit development and ripening in non-climacteric fruit, such as strawberry, grape, raspberry, and citrus, is not well characterized. However, recent studies have shown that non-climacteric fruit development and ripening, involves the coordinated action of different hormones, such as abscisic acid (ABA), auxin, gibberellins, ethylene, and others. In this review, we discuss and evaluate the recent research findings concerning the hormonal regulation of non-climacteric fruit development and ripening and their cross-talk by taking grape, strawberry, and raspberry as reference fruit species.
Global Properties of Latent Virus Dynamics Models with Immune Impairment and Two Routes of Infection
Authors: Raezah Aeshah A. , Elaiw Ahmed M. , Alofi Badria S.
Published: June 2019

This paper studies the global stability of viral infection models with CTL immune impairment. We incorporate both productively and latently infected cells. The models integrate two routes of transmission, cell-to-cell and virus-to-cell. In the second model, saturated virus–cell and cell–cell incidence rates are considered. The basic reproduction number is derived and two steady states are calculated. We first establish the nonnegativity and boundedness of the solutions of the system, then we investigate the global stability of the steady states. We utilize the Lyapunov method to prove the global stability of the two steady states. We support our theorems by numerical simulations.
Biodegradation of Polyethylene by Enterobacter sp. D1 from the Guts of Wax Moth Galleria mellonella
Authors: Ren Liu , Men Lina , Zhang Zhiwei , Guan Feifei , Tian Jian , Wang Bin , Wang Jihua , Zhang Yuhong , Zhang Wei
Published: June 2019

Plastic polymers are widely used in agriculture, industry, and our daily life because of their convenient and economic properties. However, pollution caused by plastic polymers, especially polyethylene (PE), affects both animal and human health when they aggregate in the environment, as they are not easily degraded under natural conditions. In this study, Enterobacter sp. D1 was isolated from the guts of wax moth (Galleria mellonella). Microbial colonies formed around a PE film after 14 days of cultivation with D1. Roughness, depressions, and cracks were detected on the surface of the PE film by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) showed the presence of carbonyl functional groups and ether groups on the PE film that was treated with D1. Liquid chromatography-tandem mass spectrometry (LC-MS) also revealed that the contents of certain alcohols, esters, and acids were increased as a result of the D1 treatment, indicating that oxidation reaction occurred on the surface of the PE film treated with D1 bacteria. These observations confirmed that D1 bacteria has an ability to degrade PE.