bluuebunny/crossref_metadata_2025 huggingface dataset:
O-Glycan-Altered Extracellular Vesicles: A Specific Serum Marker Elevated in Pancreatic Cancer
Authors: Yokose Takahiro , Kabe Yasuaki , Matsuda Atsushi , Kitago Minoru , Matsuda Sachiko , Hirai Miwa , Nakagawa Tomomi , Masugi Yohei , Hishiki Takako , Nakamura Yuki , Shinoda Masahiro , Yagi Hiroshi , Abe Yuta , Oshima Go , Hori Shutaro , Nakano Yutaka , Honda Kazufumi , Kashiro Ayumi , Morizane Chigusa , Nara Satoshi , Kikuchi Shojiro , Shibahara Takahiko , Itonaga Makoto , Ono Masayuki , Minegishi Naoko , Koshiba Seizo , Yamamoto Masayuki , Kuno Atsushi , Handa Hiroshi , Sakamoto Michiie , Suematsu Makoto , Kitagawa Yuko
Published: August 2020

Pancreatic cancer (PC) is among the most lethal malignancies due to an often delayed and difficult initial diagnosis. Therefore, the development of a novel, early stage, diagnostic PC marker in liquid biopsies is of great significance. In this study, we analyzed the differential glycomic profiling of extracellular vesicles (EVs) derived from serum (two cohorts including 117 PC patients and 98 normal controls) using lectin microarray. The glyco-candidates of PC-specific EVs were quantified using a high-sensitive exosome-counting system, ExoCounter. An absolute quantification system for altered glycan-containing EVs elevated in PC serum was established. EVs recognized by O-glycan-binding lectins ABA or ACA were identified as candidate markers by lectin microarray. Quantitative analyses using ExoCounter revealed that the ABA- or ACA-positive EVs were significantly increased in the culture of PC cell lines or in the serum of PC patients including carbohydrate antigen 19-9 negative patients with high area under curve values. The elevated numbers of EVs in PC serum returned to normal levels after pancreatectomy. Histological examination confirmed that the tumors stained with ABA/ACA. These specific EVs with O-glycans recognized by ABA/ACA are elevated in PC sera and can act as potential biomarkers in a liquid biopsy for PC patients screening.
Synthesis and Characterization of p-n Junction Ternary Mixed Oxides for Photocatalytic Coprocessing of CO2 and H2O
Authors: Marcolongo Davide M. S. , Nocito Francesco , Ditaranto Nicoletta , Aresta Michele , Dibenedetto Angela
Published: August 2020

In the present paper, we report the synthesis and characterization of both binary (Cu2O, Fe2O3, and In2O3) and ternary (Cu2O-Fe2O3 and Cu2O-In2O3) transition metal mixed-oxides that may find application as photocatalysts for solar driven CO2 conversion into energy rich species. Two different preparation techniques (High Energy Milling (HEM) and Co-Precipitation (CP)) are compared and materials properties are studied by means of a variety of characterization and analytical techniques UV-Visible Diffuse Reflectance Spectroscopy (UV-VIS DRS), X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Energy Dispersive X-Ray spectrometry (EDX). Appropriate data elaboration methods are used to extract materials bandgap for Cu2O@Fe2O3 and Cu2O@In2O3 prepared by HEM and CP, and foresee whether the newly prepared semiconductor mixed oxides pairs are useful for application in CO2-H2O coprocessing. The experimental results show that the synthetic technique influences the photoactivity of the materials that can correctly be foreseen on the basis of bandgap experimentally derived. Of the mixed oxides prepared and described in this work, only Cu2O@In2O3 shows positive results in CO2-H2O photo-co-processing. Preliminary results show that the composition and synthetic methodologies of mixed-oxides, the reactor geometry, the way of dispersing the photocatalyst sample, play a key role in the light driven reaction of CO2–H2O. This work is a rare case of full characterization of photo-materials, using UV-Visible DRS, XPS, XRD, TEM, EDX for the surface and bulk analytical characterization. Surface composition may not be the same of the bulk composition and plays a key role in photocatalysts behavior. We show that a full material knowledge is necessary for the correct forecast of their photocatalytic behavior, inferred from experimentally determined bandgaps.
Corrosion Behavior of a Ni–Cr–Mo Alloy Coating Fabricated by Laser Cladding in a Simulated Sulfuric Acid Dew Point Corrosion Environment
Authors: Zheng Chao , Liu Zongde , Chen Shanshan , Liu Congcong
Published: August 2020

For this study, aimed at proposing a potential direction to prevent sulfuric acid dew point corrosion, a Ni–Cr–Mo alloy Hastelloy C22 coating was fabricated by coaxial laser cladding technology. The phase composition, microstructure, and corrosion behavior in a simulated sulfuric acid dew point corrosion environment were investigated and compared with a Hastelloy C22 alloy, a titanium alloy TC4, and 09CrCuSb steel (ND). The results showed that the phase composition of the C22 coating is essentially similar to that of the C22 alloy, consisting of a γ-Ni solid solution and Ni6Mo6C1.06. The finer microstructure of the C22 coating mainly contains eutectic and dentrite, presenting a typical solidification feature of laser cladding. The corrosion resistance of the C22 coating is very close to that of the C22 alloy, and outclasses that of TC4 and ND. The corrosion behavior of the C22 coating is intergranular corrosion resulting from the segregation of molybdenum, chromium containing corrosion products, and smaller anode micro-batteries.
Tribological Behaviour of Ti or Ti Alloy vs. Zirconia in Presence of Artificial Saliva
Authors: Alemanno Fabio , Peretti Veronica , Tortora Angela , Spriano Silvia
Published: August 2020

Abutment is the transmucosal component in a dental implant system and its eventual appearance has a major impact on aesthetics: use of zirconia abutments can be greatly advantageous in avoiding this problem. Both in the case of one and two-piece zirconia abutments, a critical issue is severe wear between the zirconia and titanium components. High friction at this interface can induce loosening of the abutment connection, production of titanium wear debris, and finally, peri-implant gingivitis, gingival discoloration, or marginal bone adsorption can occur. As in vivo wear measurements are highly complex and time-consuming, wear analysis is usually performed in simulators in the presence of artificial saliva. Different commercial products and recipes for artificial saliva are available and the effects of the different mixtures on the tribological behaviour is not widely explored. The specific purpose of this research was to compare two types of artificial saliva as a lubricant in titanium–zirconia contact by using the ball on disc test as a standard tribological test for materials characterisation. Moreover, a new methodology is suggested by using electrokinetic zeta potential titration and contact angle measurements to investigate the chemical stability at the titanium–lubricant interface. This investigation is of relevance both in the case of using zirconia abutments and artificial saliva against chronic dry mouth. Results suggest that an artificial saliva containing organic corrosion inhibitors is able to be firmly mechanically and chemically adsorb on the surface of the Ti c.p. or Ti6Al4V alloy and form a protective film with high wettability. This type of artificial saliva can significantly reduce the friction coefficient and wear of both the titanium and zirconia surfaces. The use of this type of artificial saliva in standard wear tests has to be carefully considered because the wear resistance of the materials can be overestimated while it can be useful in some specific clinical applications. When saliva is free from organic corrosion inhibitors, wear occurs with a galling mechanism. The occurrence of a super-hydrophilic saliva film that is not firmly adsorbed on the surface is not efficient in order to reduce wear. The results give both suggestions about the experimental conditions for lab testing and in vivo performance of components of dental implants when artificial saliva is used.
Characterization of Fibrous Mordenite: A First Step for the Evaluation of Its Potential Toxicity
Authors: Di Giuseppe Dario
Published: August 2020

In nature, a huge number of unregulated minerals fibers share the same characteristics as asbestos and therefore have potential adverse health effects. However, in addition to asbestos minerals, only fluoro-edenite and erionite are currently classified as toxic/pathogenic agents by the International Agency for Research on Cancer (IARC). Mordenite is one of the most abundant zeolites in nature and commonly occurs with a fibrous crystalline habit. The goal of this paper is to highlight how fibrous mordenite shares several common features with the well-known carcinogenic fibrous erionite. In particular, this study has shown that the morphology, biodurability, and surface characteristics of mordenite fibers are similar to those of erionite and asbestos. These properties make fibrous mordenite potentially toxic and exposure to its fibers can be associated with deadly diseases such as those associated with regulated mineral fibers. Since the presence of fibrous mordenite concerns widespread geological formations, this mineral fiber should be considered dangerous for health and the precautionary approach should be applied when this material is handled. Future in vitro and in vivo tests are necessary to provide further experimental confirmation of the outcome of this work.
Taxonomic and Functional Diversity and Composition of Bats in a Regenerating Neotropical Dry Forest
Authors: Martínez-Ferreira Sergio Ramón , Alvarez-Añorve Mariana Yolotl , Bravo-Monzón Angel E. , Montiel-González Cristina , Flores-Puerto Jose Israel , Morales-Díaz Sharon Patricia , Chiappa-Carrara Xavier , Oyama Ken , Avila-Cabadilla Luis Daniel
Published: August 2020

This study evaluated the response of bat communities, from a taxonomic and functional perspective, to variation in the vegetation and landscape attributes produced by anthropogenic activities. We characterized the following: (1) the community of phyllostomid and mormoopid bats associated with the initial successional stages of a tropical dry forest, (2) the response of these communities to the variation in the attributes of the vegetation and the landscape, and (3) how the seasonality modulates such response. This allowed us to identify potential mechanisms underlying the response of bat communities to human disturbance. Our results showed that the species negatively affected by the anthropoghenic disturbance are those with greater body mass, larger nose-leaves, or a lower wing aspect ratio and relative wing loading, which perform low-speed flights and have high maneuverability and, potentially, a high directionality in their emissions. We also detected a greater sensitivity of bats to changes in the landscape attributes regarding the riparian than the dry forest, and that the effect of anthropic transformation on bats was intensified during the dry season. Then, the continued loss of the original vegetation can lead to a loss of certain groups of bat species in neotropical landscapes, reducing the resilience of the system.
Are the Neglected Tipuloidea Crane Flies (Diptera) an Important Component for Subterranean Environments?
Authors: Lunghi Enrico , Ficetola Gentile Francesco , Zhao Yahui , Manenti Raoul
Published: August 2020

Usually, biospeleological studies focus on cave-specialist taxa showing strong adaptation to the subterranean environment, as their unusual morphological and ecological features represent intriguing case studies. On the other hand, species occurring in subterranean environments but without marked adaptations have been generally overlooked, probably because they are thought to be accidental and not very important for the ecosystem. Particularly exemplificative is the case of Tipuloidea crane flies (Diptera), which although abundant, are rarely considered in biospeleological studies. Here, by analyzing the crane fly occupancy, we observed that individuals occur within the shallowest areas of subterranean environments throughout the year, with a peak of presence during hot season. Crane flies occupy dark and warm areas close to the connection with surface and with smoother walls. Furthermore, we observed that the presence of crane flies is positively related to the abundance and the richness of cave predators, highlighting their importance for the sustainment of the local community. With this study we aim to stimulate future researches on these important, but still neglected cave species.
Management of Non-Tubal Ectopic Pregnancies: A Single Center Experience
Authors: Stabile Guglielmo , Zinicola Giulia , Romano Federico , Buonomo Francesca , Mangino Francesco Paolo , Ricci Giuseppe
Published: August 2020

Non-tubal ectopic pregnancies (NT-EPs) are rare but potentially life-threatening conditions. The incidence ranges are between 5–8.3% of all ectopic pregnancies. For this retrospective observational study, 16 patients with NT-EP and treated from January 2014 to May 2020 were recruited. Demographic details, symptoms, Beta human chorionic gonadotrophin (β-hCG) levels, ultrasound findings, management and treatment outcomes were presented. In hemodynamically stable patients, diagnosis was made using ultrasounds and β-hCG levels. Laparoscopy was essential to identify and remove the ectopic pregnancy in clinical unstable patients. A radical laparoscopic approach was chosen in one case of cervical pregnancy diagnosed late in the first trimester. Medical treatment and minimally invasive procedure, alone or combined, resulted in effective strategies in asymptomatic women with an early diagnosis of NT-EP. We report cases of cervical pregnancies successfully treated by hysteroscopy alone or combined with medical treatment, the first case of scar pregnancy treated by mini-reseptoscope and curettage and the fifth case of interstitial pregnancy treated with Methotrexate and Mifepristone. In this manuscript we report a single center experience in the management of NT-EPs with the aim of outlining the importance of the early diagnosis for a minimally invasive treatment in order to reduce maternal morbidity and mortality and preserve future fertility.
The Correlation Between Abnormal Uterine Artery Flow in the First Trimester and Genetic Thrombophilic Alteration: A Prospective Case-Controlled Pilot Study
Authors: Vedmedovska Natalija , Bokucava Diana , Kivite-Urtane Anda , Rovite Vita , Zake-Nikitina Liene , Klovins Janis , Fodina Violeta , Donders Gilbert G. G.
Published: August 2020

Introduction. Evaluation of the first trimester uterine artery flow can predict the development of obstetrical complications. A genotype, making women prone to microthrombi. constitutes the main known susceptibility factor for anomalous development of placenta. Our aim was to study whether polymorphisms of 10 genes leading to blood clotting abnormalities are related to abnormal uterine artery blood flow in the first trimester, and may predict placenta-related diseases. Material and methods. In primary analyses we included 19 singleton pregnancies with abnormal blood flow in the uterine arteries during the first trimester of gestation, and 24 matched control with normal flow patterns. All patients were genotyped for sequence variations in F5, F2, F11, MTHFR, SERPINE-1, CYP4V2, SELE, GP6, angiotensinogen (AGT) and fibrinogen gamma (FGG) genes and followed up until delivery. Results. There were no differences between groups regarding selected sequence variations in any of these genes. The co-occurrence of several polymorphisms in the same patient was also not related to the blood flow patterns in the uterine arteries. Conclusions. Although we found certain trends of genetic polymorphisms being related to preeclampsia and fetal growth, we failed to find an association between clotting gene polymorphisms, single or in combination, with the abnormal uterine flow in the first trimester.
Impact of H19 Polymorphisms on Prostate Cancer Clinicopathologic Characteristics
Authors: Hu Ju-Chuan , Lin Chia-Yen , Wang Shian-Shiang , Chiu Kun-Yuan , Li Jian-Ri , Chen Chuan-Shu , Hung Sheng-Chun , Yang Cheng-Kuang , Ou Yen-Chuan , Cheng Chen-Li , Yang Shun-Fa
Published: August 2020

Active surveillance is the preferred strategy for very low risk, low risk, and some favorable intermediate risk of prostate cancer. However, the current risk stratifications with initial prostate-specific antigen (iPSA) levels and Gleason scores at biopsy can underestimate the true oncologic threat. More precise predictors are required to avoid the overtreatment of prostate cancer. H19 single-nucleotide polymorphisms (SNPs) have been found to play crucial roles in numerous malignancies, but not yet in prostate cancer. This study assessed the clinicopathologic effects of H19 SNPs on prostate cancer to identify potential active surveillance candidates. A total of 579 patients with prostate cancer who underwent robot-assisted radical prostatectomy between 2012 and 2017 were recruited. The patients were grouped by iPSA levels, and five H19 SNPs were evaluated. Our results show that patients with an iPSA level of ≤7 ng/mL had increased an likelihood of having Gleason score and group grade upgrades after radical prostatectomy compared with patients with an iPSA level of >7 ng/mL. Moreover, patients with loci polymorphisms in either rs3024270 or rs3741219 had a significantly higher risk of perineural invasion (rs3024270: Odds ratio (OR) 2.76, 95% confidence interval (CI) 1.30–5.87, p = 0.01; rs3741219: OR 2.30, 95% CI 1.17–4.54, p = 0.018). In conclusion, our results suggested that H19 SNPs play a role in the perineural invasion of prostate cancer.
Detection of Recurrent Cervical Cancer and Prediction of Its Patient Survival with Serum Squamous-Cell Carcinoma-Antigen and 2-[18F] Fluoro-2-Deoxy-d-Glucose-Positron Emission Tomography/Computed Tomography
Authors: Peng Nan-Jing , Hu Chin , Chiu Yu-Li , Yu Chang-Ching , Li Chia-Jung , Sheu Jim Jinn-Chyuan , Chiang An-Jen
Published: August 2020

Aim: To evaluate the usefulness of serum squamous-cell carcinoma antigen (SCC-Ag) and 2-[18F]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) for the detection of recurrent squamous-cell carcinoma (SqCC) of the uterine cervix, and its prediction of patient survival. Methods: FDG-PET/CT was performed for patients with serum SCC-Ag levels elevated to ≥1.5 ng/mL (Group 1) and those with suspicious recurrences without any increase in serum SCC-Ag levels (Group 2). The results were analyzed on the basis of histological data, disease progression and/or clinical follow-up. Recurrence was defined as evidence of recurrent lesions within 6 months of FDG-PET/CT. The outcome was determined using medical records. Results: In total, 88 consecutive patients with cervical SqCC cancer with suspected recurrence (62 in Group 1 and 26 in Group 2) were enrolled. Recurrences were observed in 55 patients (77.4% (48/62) in Group 1 vs. 26.9% (7/26) in Group 2, p < 0.001). The overall sensitivity, specificity and accuracy of serum SCC-Ag were 87.3%, 57.6% and 76.1%, respectively, and those of FDG-PET/CT were 98.2%, 90.9% and 95.5%, respectively; the corresponding values were 97.9%, 92.9% and 96.8% for Group 1 and 100%, 89.5% and 92.3% for Group 2. Surgical resection was performed for 16 patients. At the end of the study, 40.3% (25/62) of Group 1 patients and 88.5% (23/26) of Group 2 patients were alive (p < 0.001). The survival of patients who underwent surgical resection for recurrent tumors was higher than that of patients who did not undergo resection (62.5% (10/16) vs. 17.9% (7/39), p = 0.001). Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) derived from FDG-PET/CT showed significantly different in-patient survival. Conclusions: Serum SCC-Ag could predict tumor recurrence and the survival of patients with SqCC cervical cancer. As such, the surgical resection of limited recurrent disease, as determined using FDG-PET/CT, might improve the survival of patients with cervical cancer. MTV and TLG may serve as a prognostic biomarker of survival in patients with recurrent cervical cancer.
Omics Derived Biomarkers and Novel Drug Targets for Improved Intervention in Advanced Prostate Cancer
Authors: Frantzi Maria , Hupe Marie C. , Merseburger Axel S. , Schanstra Joost P. , Mischak Harald , Latosinska Agnieszka
Published: August 2020

Prostate cancer (PCa) is one of the most frequently diagnosed malignancies, and the fifth leading cause of cancer related mortality in men. For advanced PCa, radical prostatectomy, radiotherapy, and/or long-term androgen deprivation therapy are the recommended treatment options. However, subsequent progression to metastatic disease after initial therapy results in low 5-year survival rates (29%). Omics technologies enable the acquisition of high-resolution large datasets that can provide insights into molecular mechanisms underlying PCa pathology. For the purpose of this article, a systematic literature search was conducted through the Web of Science Database to critically evaluate recent omics-driven studies that were performed towards: (a) Biomarker development and (b) characterization of novel molecular-based therapeutic targets. The results indicate that multiple omics-based biomarkers with prognostic and predictive value have been validated in the context of PCa, with several of those being also available for commercial use. At the same time, omics-driven potential drug targets have been investigated in pre-clinical settings and even in clinical trials, holding the promise for improved clinical management of advanced PCa, as part of personalized medicine pipelines.
Human Stress and StO2: Database, Features, and Classification of Emotional and Physical Stress
Authors: Liu Xinyu , Shan Yuhao , Peng Min , Chen Huanyu , Chen Tong
Published: August 2020

Emotional and physical stress can cause various health problems. In this paper, we used tissue blood oxygen saturation (StO2), a newly proposed physiological signal, to classify the human stress. We firstly constructed a public StO2 database including 42 volunteers subjected to two types of stress. During the physical stress experiment, we observed that the facial StO2 right after the stress can be either increased or decreased comparing to the baseline. We investigated the StO2 feature combinations for the classification and found that the average StO2 values from left cheek, chin, and the middle of the eyebrow can provide the highest classification rate of 95.56%. Comparison with other stress classification method shows that StO2 based method can provide best classification performance with lowest feature dimension. These results suggest that facial StO2 can be used as a promising features to identify stress states, including emotional and physical stress.
A Comprehensive Three-Dimensional Analysis of a Large-Scale Multi-Fuel CFB Boiler Burning Coal and Syngas. Part 1. The CFD Model of a Large-Scale Multi-Fuel CFB Combustion
Authors: Krzywanski Jaroslaw , Sztekler Karol , Szubel Mateusz , Siwek Tomasz , Nowak Wojciech , Mika Łukasz
Published: August 2020

The paper is focused on the idea of multi-fuel combustion in a large-scale circulating fluidized bed (CFB) boiler. The article discusses the concept of simultaneous coal and syngas combustion. A comprehensive three-dimensional computational fluid dynamics (CFD) model is developed, which allows us to describe complex phenomena that occur in the combustion chamber of the CFB boiler burning coal and syngas produced from coal sludge.
On-The-Fly Syntheziser Programming with Fuzzy Rule Learning
Authors: Paz Iván , Nebot Àngela , Mugica Francisco , Romero Enrique
Published: August 2020

This manuscript explores fuzzy rule learning for sound synthesizer programming within the performative practice known as live coding. In this practice, sound synthesis algorithms are programmed in real time by means of source code. To facilitate this, one possibility is to automatically create variations out of a few synthesizer presets. However, the need for real-time feedback makes existent synthesizer programmers unfeasible to use. In addition, sometimes presets are created mid-performance and as such no benchmarks exist. Inductive rule learning has shown to be effective for creating real-time variations in such a scenario. However, logical IF-THEN rules do not cover the whole feature space. Here, we present an algorithm that extends IF-THEN rules to hyperrectangles, which are used as the cores of membership functions to create a map of the input space. To generalize the rules, the contradictions are solved by a maximum volume heuristics. The user controls the novelty-consistency balance with respect to the input data using the algorithm parameters. The algorithm was evaluated in live performances and by cross-validation using extrinsic-benchmarks and a dataset collected during user tests. The model’s accuracy achieves state-of-the-art results. This, together with the positive criticism received from live coders that tested our methodology, suggests that this is a promising approach.
PAPR Reduction in UFMC for 5G Cellular Systems
Authors: Al-Rayif Mohammed I. , Seleem Hussein E. , Ragheb Amr M. , Alshebeili Saleh A.
Published: August 2020

Universal filtered multi-carrier (UFMC) is a potential multi-carrier system for future cellular networks. UFMC provides low latency, frequency offset robustness, and reduced out-of-band (OOB) emission that results in better spectral efficiency. However, UFMC suffers from the problem of high peak-to-average power ratio (PAPR), which might impact the function of high power amplifiers causing a nonlinear distortion. We propose a comparative probabilistic PAPR reduction technique, called the decomposed selective mapping approach, to alleviate PAPR in UFMC systems. The concept of this proposal depends on decomposing the complex symbol into real and imaginary parts, and then converting each part to a number of different phase vectors prior to the inverse fast Fourier transform (IFFT) operation. The IFFT copy, which introduces the lowest PAPR, is considered for transmission. Results obtained using theoretical analysis and simulations show that the proposed approach can significantly enhance the performance of the UFMC system in terms of PAPR reduction. Besides, it maintains the OOB emission with candidate bit error rate and error vector magnitude performances.
Pyrolysis of Rapeseed Oil Press Cake and Steam Gasification of Solid Residues
Authors: Nowicki Lech , Siuta Dorota , Markowski Maciej
Published: August 2020

A deoiled rapeseed press cake (RPC) was pyrolyzed by heating at a slow heating rate to 1000 °C in a fixed bed reactor, and the produced char was then gasified to obtain data for the kinetic modeling of the process. The gasification experiments were performed in a thermogravimetric analyzer (TGA) under steam/argon mixtures at different temperatures (750, 800 and 850 °C) and steam mole fractions (0.17 and 0.45). The three most commonly used gas-solid kinetic models, the random pore model, the volumetric model and the shrinking core model were used to describe the conversion of char during steam gasification. The objective of the kinetic study was to determine the kinetic parameters and to assess the ability of the models to predict the RPC conversion during steam gasification. A TGA-MS analysis was applied to assess the composition of the product gas. The main steam gasification product of the RPC was hydrogen (approximately 60 mol % of the total product). The volumetric model was able to accurately predict the behavior of the RPC char gasification with steam at temperatures of 750–850 °C and steam concentrations less than 0.45 mole fraction. The activation energy and the reaction order with respect to steam were equal to 166 kJ/mol and 0.5, respectively, and were typical values for the gasification of biomass chars with steam
Simulation-Based Coyote Optimization Algorithm to Determine Gains of PI Controller for Enhancing the Performance of Solar PV Water-Pumping System
Authors: Arfaoui Jouda , Rezk Hegazy , Al-Dhaifallah Mujahed , Ibrahim Mohamed N. , Abdelkader Mami
Published: August 2020

In this study, a simulation-based coyote optimization algorithm (COA) to identify the gains of PI to ameliorate the water-pumping system performance fed from the photovoltaic system is presented. The aim is to develop a stand-alone water-pumping system powered by solar energy, i.e., without the need of electric power from the utility grid. The voltage of the DC bus was adopted as a good candidate to guarantee the extraction of the maximum power under partial shading conditions. In such a system, two proportional-integral (PI) controllers, at least, are necessary. The adjustment of (Proportional-Integral) controllers are always carried out by classical and tiresome trials and errors techniques which becomes a hard task and time-consuming. In order to overcome this problem, an optimization problem was reformulated and modeled under functional time-domain constraints, aiming at tuning these decision variables. For achieving the desired operational characteristics of the PV water-pumping system for both rotor speed and DC-link voltage, simultaneously, the proposed COA algorithm is adopted. It is carried out through resolving a multiobjective optimization problem employing the weighted-sum technique. Inspired on the Canis latrans species, the COA algorithm is successfully investigated to resolve such a problem by taking into account some constraints in terms of time-domain performance as well as producing the maximum power from the photovoltaic generation system. To assess the efficiency of the suggested COA method, the classical Ziegler–Nichols and trial–error tuning methods for the DC-link voltage and rotor speed dynamics, were compared. The main outcomes ensured the effectiveness and superiority of the COA algorithm. Compared to the other reported techniques, it is superior in terms of convergence rapidity and solution qualities.
Fault-Structure-Based Active Fault Diagnosis: A Geometric Observer Approach
Authors: Zhang Zhao , He Xiao
Published: August 2020

Fault diagnosis techniques can be classified into passive and active types. Passive approaches only utilize the original input and output signals of the system. Because of the small amplitudes, the characteristics of incipient faults are not fully represented in the data of the system, so it is difficult to detect incipient faults by passive fault diagnosis techniques. In contrast, active methods can design auxiliary signals for specific faults and inject them into the system to improve fault diagnosis performance. Therefore, active fault diagnosis techniques are utilized in this article to detect and isolate incipient faults based on the fault structure. A new framework based on observer approach for active fault diagnosis is proposed and the geometric approach based fault diagnosis observer is introduced to active fault diagnosis for the first time. Based on the dynamic equations of residuals, auxiliary signals are designed to enhance the diagnosis performance for incipient faults that have specific structures. In addition, the requirements that auxiliary signals need to meet are discussed. The proposed method can realize the seamless combination of active fault diagnosis and passive fault diagnosis. Finally, a numerical example is presented to demonstrate the effectiveness of the proposed approach, and it is indicated that the proposed method significantly improves the accuracy of the diagnosis for incipient faults.
Impact of US Shale Gas on the Vertical and Horizontal Dynamics of Ethylene Price
Authors: Kim Soohyeon , Oh Surim
Published: August 2020

The rise of shale resources in the United States is changing the petrochemical industries. Ethylene, the first building block of petrochemical products, is becoming the first target to be hit by the shale boom, and its shifting price dynamics needs to be explored. This study analyzes the transition of ethylene prices from crude oil to natural gas (vertical price dynamics) and investigates widening gaps among regional ethylene prices (horizontal price dynamics). To do this, we detect structural changes in cointegrating relationships and derive time-varying cointegration equations. In addition, for the long- and short-run dynamics, this study established and estimated an error correction model (ECM), with controlling, time-varying cointegrations. This study develops econometric studies by applying time-varying cointegration to nonenergy uses of fossil fuels. Thereby, our results discover that the feedstock structure of US ethylene is moving from crude oil to natural gas and that the comovement of US and Japanese prices is getting intensified.
Use of Carbon Additives towards Rechargeable Zinc Slurry Air Flow Batteries
Authors: Choi Nak Heon , del Olmo Diego , Milian Diego , El Kissi Nadia , Fischer Peter , Pinkwart Karsten , Tübke Jens
Published: August 2020

The performance of redox flow batteries is notably influenced by the electrolyte, especially in slurry-based flow batteries, as it serves as both an ionic conductive electrolyte and a flowing electrode. In this study, carbon additives were introduced to achieve a rechargeable zinc slurry flow battery by minimizing the zinc plating on the bipolar plate that occurs during charging. When no carbon additive was present in the zinc slurry, the discharge current density was 24 mA∙cm−2 at 0.6 V, while the use of carbon additives increased it to up to 38 mA∙cm−2. The maximum power density was also increased from 16 mW∙cm−2 to 23 mW∙cm−2. Moreover, the amount of zinc plated on the bipolar plate during charging decreased with increasing carbon content in the slurry. Rheological investigation revealed that the elastic modulus and yield stress are directly proportional to the carbon content in the slurry, which is beneficial for redox flow battery applications, but comes at the expense of an increase in viscosity (two-fold increase at 100 s−1). These results show how the use of conductive additives can enhance the energy density of slurry-based flow batteries.
Study on Reasonable Amount of Flushing Fluid and Flushing Time
Authors: Wang Jingpeng , Xiong Youming , Wu Baocheng , Lu Zongyu , Li Xiaoxiao , Zhang Zheng
Published: August 2020

Oil-based drilling fluid has many advantages, such as stable performance, strong anti-pollution ability, and strong inhibition, and it has been widely used in the world. However, at present, there is no unified evaluation standard for the effect of flushing fluid under this condition, and most of them are based on the flushing effect evaluation of water-based drilling fluid. However, there are few studies on wetting reversal phenomenon, reasonable dosage, and flushing time between oil-based drilling fluid and flushing fluid on the two-phase interface. Therefore, it is necessary to establish a comprehensive evaluation method for the effect of flushing fluid under oil-based drilling fluid, and explore the relationship between the amount of flushing fluid and flushing efficiency, so as to determine the reasonable range of flushing fluid consumption. In this paper, using the existing experimental instruments, a type A oil-based flushing fluid commonly used in oil fields was selected for the experiment, and on the basis of the high-temperature and high-pressure filtration meter, a flushing fluid evaluation device was developed. Based on the principle of equal shear rate, the flushing displacement and flushing time were determined, and then the flushing effect was evaluated. In order to comprehensively consider the influencing factors of the well wall flushing effect, five experimental factors, including different core, flushing displacement, flushing time, flushing fluid type, and surfactant concentration, were selected to formulate the flushing experiment scheme. The contrast method was used to test the cementation strength of core and cement slurry under different conditions, and the microscopic morphology of the interface was observed and analyzed to explore the reasons for the change of cementation strength between core and cement slurry due to the existence of oil-based drilling fluid. The conclusion obtained has very important practical significance to guide the field practice.
Energy and Exergy Evaluations of a Combined Heat and Power System with a High Back-Pressure Turbine under Full Operating Conditions
Authors: Zhao Shifei , Wang Weishu , Ge Zhihua
Published: August 2020

High back-pressure technology is a promising method for the waste heat recovery of exhaust steams in combined heat and power systems. In this research, a 300 MW coal-fired subcritical combined heat and power system was selected as the reference system, and modeled in EBSILON professional. Then, energy-based and exergy-based performances of the high back-pressure system and traditional combined heat and power system were compared under full operating conditions. Moreover, a novel exergy-based evaluation method, which considers the energy level of the heating supply, was proposed and applied to evaluate the two systems. Results show that: In design conditions, both the heating capacity and power output of the high back-pressure system were higher than those of the extraction condensing system, which led to 17.67% and 33.21% increments of the gross thermal efficiency and generation efficiency, respectively. Compared with the extraction condensing system, the exergy efficiencies of the high back-pressure system were 7.04–8.21% higher. According to the novel exergy-based evaluation, the exergy efficiencies for the generation of the high back-pressure system and extraction condensing system were 46.48% and 41.22%, respectively. This paper provides references for the thermodynamic performance evaluation of the combined heat and power system.
Energy Performance Evaluation for Exterior Insulation System Consisting of Truss-Form Wire-Frame Mullion Filled with Glass Wool
Authors: Song Jin-Hee , Park Cheol-Yong , Jeong Jae-Weon
Published: August 2020

Heat loss and gain through opaque envelopes of buildings are major factors that affect the overall cooling and heating loads in buildings. The government has enforced regulations to strengthen the thermal transmittance requirement level as a major means of reducing greenhouse gas emissions in the building sector. In addition, the thermal bridge is considered to be one of the major factors in heating load of buildings. In this study, truss-form wire frame was developed in order to minimize thermal bridge of steel mullion in exterior insulation system. In the case of thermal transmittance test for specimen of 0.145 W/m2 K as design value, the value of the steel pipe was 0.190 W/m2 K and the value of the truss-form wire frame was 0.150 W/m2 K, respectively. This means the other is much smaller than the one in thermal bridge. For four cases, annual energy performance analysis was calculated using Passive House Planning Package (PHPP)—ideal condition without thermal bridge, steel pipe mullion without insulation in the rear side, steel pipe mullion with insulation in the rear side, and truss-form wire-frame mullion filled with glass wool. As results, the annual heating energy demands were 15.68 kWh/m2, 25.42 kWh/m2, 16.78 kWh/m2, and 16.09 kWh/m2, respectively.
From Firm Solar Power Forecasts to Firm Solar Power Generation an Effective Path to Ultra-High Renewable Penetration a New York Case Study
Authors: Perez Richard , Perez Marc , Schlemmer James , Dise John , Hoff Thomas E. , Swierc Agata , Keelin Patrick , Pierro Marco , Cornaro Cristina
Published: August 2020

We introduce firm solar forecasts as a strategy to operate optimally overbuilt solar power plants in conjunction with optimally sized storage systems so as to make up for any power prediction errors, and hence entirely remove load balancing uncertainty emanating from grid-connected solar fleets. A central part of this strategy is the plant overbuilding that we term implicit storage. We show that strategy, while economically justifiable on its own account, is an effective entry step to achieving least-cost ultra-high solar penetration where firm power generation will be a prerequisite. We demonstrate that in the absence of an implicit storage strategy, ultra-high solar penetration would be vastly more expensive. Using the New York Independent System Operator (NYISO) as a case study, we determine current and future costs of firm forecasts for a comprehensive set of scenarios in each ISO electrical region, comparing centralized vs. decentralized production and assessing load flexibility’s impact. We simulate the growth of the strategy from firm forecast to firm power generation. We conclude that ultra-high solar penetration enabled by the present strategy, whereby solar would firmly supply the entire NYISO load, could be achieved locally at electricity production costs comparable to current NYISO wholesale market prices.
Anti-Disturbance Finite-Time Adaptive Sliding Mode Backstepping Control for PV Inverter in Master–Slave-Organized Islanded Microgrid
Authors: Yang Chengshun , Ni Shuangfei , Dai Yuchen , Huang Xiaoning , Zhang Dongdong
Published: August 2020

With the aim to solve the problem related to the power chattering and anti-disturbance performance of a photovoltaic (PV) inverter in master–slave-organized islanded microgrid, an anti-disturbance finite-time adaptive sliding mode backstepping (DFA-SMB) controller is designed in this paper. First, the topology and the second-order dynamic model of PV inverter are established based on constant DC voltage and constant reactive power control method. Subsequently, the backstepping method is adopted to perform the control of a high-order system. Moreover, a second-order sliding mode differentiator is used to realize the function of command-filter, solving the differential expansion problem caused by the derivation of virtual controller. Besides, the terminal sliding mode control (TSMC) is introduced into the q-axis controller and d-axis inner loop controller, increasing the robustness and reducing the convergence time of the system. Adaptive control and disturbance-observer (DO) are used to perform the adaptive estimation of model parameters and the observation of lumped disturbances, respectively, enhancing the dynamic characteristics of the controller. Finally, a master–slave-organized islanded microgrid with 100 kW PV array is established in MATLAB/Simulink. The results demonstrate that the proposed control method can effectively reduce power chattering and improve the anti-disturbance ability of the PV system.
New Aspects of the Epigenetics of Pancreatic Carcinogenesis
Authors: Toruner Murat , Fernandez-Zapico Martin E. , Pin Christopher L.
Published: August 2020

Pancreatic cancer remains among the deadliest forms of cancer with a 5 year survival rate less than 10%. With increasing numbers being observed, there is an urgent need to elucidate the pathogenesis of pancreatic cancer. While both contribute to disease progression, neither genetic nor environmental factors completely explain susceptibility or pathogenesis. Defining the links between genetic and environmental events represents an opportunity to understand the pathogenesis of pancreatic cancer. Epigenetics, the study of mitotically heritable changes in genome function without a change in nucleotide sequence, is an emerging field of research in pancreatic cancer. The main epigenetic mechanisms include DNA methylation, histone modifications and RNA interference, all of which are altered by changes to the environment. Epigenetic mechanisms are being investigated to clarify the underlying pathogenesis of pancreatic cancer including an increasing number of studies examining the role as possible diagnostic and prognostic biomarkers. These mechanisms also provide targets for promising new therapeutic approaches for this devastating malignancy.
Reduction of Atmospheric Suspended Particulate Matter Concentration and Influencing Factors of Green Space in Urban Forest Park
Authors: Gao Tian , Liu Fang , Wang Yang , Mu Sen , Qiu Ling
Published: August 2020

In the process of urbanization in China, the problem of atmospheric suspended particulate matter pollution is becoming increasingly serious. It has been impossible to completely rely on pollution source control measures to solve this problem for a long time due to the diversity and complexity of pollution sources. Therefore, there is an urgent need to explore alternate solutions to significantly improve air quality through increasing the capacity of green space in cities as these locations can provide multiple ecosystem services. In this study, a three-dimensional classification system was created by utilizing Beijing’s urban forest as a study area. Considering the meteorological factors, change of month and time and the characteristics of the forest itself, the significance and difference of reducing the concentration of atmospheric suspended particulate matter by the forest with different vegetation structures were tested. The results showed that meteorological factors such as wind velocity, temperature, and relative humidity all had a very significant effect on the concentration of atmospheric suspended particulate matter in the conditions of this study. The concentration was highest in winter, followed by spring and autumn, and lowest in summer. The concentration in the morning was the lowest of the day, increasing in the noon and afternoon with time. It was the lowest in the closed single-layered mixed forest, and the highest in the open lawn green space. By comparing the forest with gradient areas of 0.5 ha and 3.0 ha, it was found that with the increase in the area, the green space did not necessarily show a better dust retention effect, and the vegetation structure type of the green space often had more important influence. There was a very significant correlation between vegetation structure and plant diversity (Shannon–Wiener Diversity Index and Simpson Diversity Index). Biodiversity could significantly support and strengthen urban forest ecological service functions that improve air quality. Increasing the plant species diversity could lead to lower particulate matter concentration. The research conclusions could provide theoretical and practical bases for how to select the combination of vegetation structure in the planning and design of urban forest oriented to improve air quality.
Staggered Conservative Scheme for 2-Dimensional Shallow Water Flows
Authors: Erwina Novry , Adytia Didit , Pudjaprasetya Sri Redjeki , Nuryaman Toni
Published: August 2020

Simulating discontinuous phenomena such as shock waves and wave breaking during wave propagation and run-up has been a challenging task for wave modeller. This requires a robust, accurate, and efficient numerical implementation. In this paper, we propose a two-dimensional numerical model for simulating wave propagation and run-up in shallow areas. We implemented numerically the 2-dimensional Shallow Water Equations (SWE) on a staggered grid by applying the momentum conserving approximation in the advection terms. The numerical model is named MCS-2d. For simulations of wet–dry phenomena and wave run-up, a method called thin layer is used, which is essentially a calculation of the momentum deactivated in dry areas, i.e., locations where the water thickness is less than the specified threshold value. Efficiency and robustness of the scheme are demonstrated by simulations of various benchmark shallow flow tests, including those with complex bathymetry and wave run-up. The accuracy of the scheme in the calculation of the moving shoreline was validated using the analytical solutions of Thacker 1981, N-wave by Carrier et al., 2003, and solitary wave in a sloping bay by Zelt 1986. Laboratory benchmarking was performed by simulation of a solitary wave run-up on a conical island, as well as a simulation of the Monai Valley case. Here, the embedded-influxing method is used to generate an appropriate wave influx for these simulations. Simulation results were compared favorably to the analytical and experimental data. Good agreement was reached with regard to wave signals and the calculation of moving shoreline. These observations suggest that the MCS method is appropriate for simulations of varying shallow water flow.