bluuebunny/crossref_metadata_2025 huggingface dataset:
The Increased Likelihood in the 21st Century for a Tropical Cyclone to Rapidly Intensify When Crossing a Warm Ocean Feature—A Simple Model’s Prediction
Authors: Oey Leo
Published: October 2021

A warm ocean feature (WOF) is a blob of the ocean’s surface where the sea-surface temperature (SST) is anomalously warmer than its adjacent ambient SST. Examples are warm coastal seas in summer, western boundary currents, and warm eddies. Several studies have suggested that a WOF may cause a crossing tropical cyclone (TC) to undergo rapid intensification (RI). However, testing the “WOF-induced RI” hypothesis is difficult due to many other contributing factors that can cause RI. The author develops a simple analytical model with ocean feedback to estimate TC rapid intensity change across a WOF. It shows that WOF-induced RI is unlikely in the present climate when the ambient SST is ≲29.5 °C and the WOF anomaly is ≲+1 °C. This conclusion agrees well with the result of a recent numerical ensemble experiment. However, the simple model also indicates that RI is very sensitive to the WOF anomaly, much more so than the ambient SST. Thus, as coastal seas and western boundary currents are warming more rapidly than the adjacent open oceans, the model suggests a potentially increased likelihood in the 21st century of WOF-induced RIs across coastal seas and western boundary currents. Particularly vulnerable are China’s and Japan’s coasts, where WOF-induced RI events may become more common.
Synthesis, In Silico Study, and Anti-Cancer Activity of Thiosemicarbazone Derivatives
Authors: Sibuh Belay Zeleke , Gupta Piyush Kumar , Taneja Pankaj , Khanna Sonia , Sarkar Paratpar , Pachisia Sanya , Khan Abrar Ali , Jha Niraj Kumar , Dua Kamal , Singh Sachin Kumar , Pandey Sadanand , Slama Petr , Kesari Kavindra Kumar , Roychoudhury Shubhadeep
Published: October 2021

Thiosemicarbazones are known for their biological and pharmacological activities. In this study, we have synthesized and characterized 3-Methoxybenzaldehyde thiosemicarbazone (3-MBTSc) and 4-Nitrobenzaldehyde thiosemicarbazone (4-NBTSc) using IR, 1HNMR and 13C NMR. The compound’s in vitro anticancer activities against different cell lines were evaluated. Molecular docking, Insilco ADMET, and drug-likeness prediction were also done. The test compounds showed a comparative IC50 and growth inhibition with the standard drug Doxorubicin. The IC50 ranges from 2.82 µg/mL to 14.25 µg/mL in 3-MBTSc and 2.80 µg/mL to 7.59 µg/mL in 4-NBTSc treated cells. The MTT assay result revealed, 3-MBTSc inhibits 50.42 and 50.31 percent of cell growth in B16-F0 and EAC cell lines, respectively. The gene expression showed that tumor suppressor genes such as PTEN and BRCA1 are significantly upregulated in 7.42 and 5.33 folds, and oncogenes, PKC, and RAS are downregulated −7.96 and −7.64 folds, respectively in treated cells. The molecular docking performed on the four targeted proteins (PARP, VEGFR-1, TGF-β1, and BRAFV600E) indicated that both 4-NBTSc and 3-MBTSc potentially bind to TGF-β1 with the best binding energy of −42.34 Kcal/mol and −32.13 Kcal/mol, respectively. In addition, the test compound possesses desirable ADMET and drug-likeness properties. Overall, both 3-MBTSc and 4-NBTSc have the potential to be multitargeting drug candidates for further study. Moreover, 3-MBTSc showed better activity than 4-NBTSc.
Association of Galectin 9 Expression with Immune Cell Infiltration, Programmed Cell Death Ligand-1 Expression, and Patient’s Clinical Outcome in Triple-Negative Breast Cancer
Authors: Ju Mi-Ha , Byun Kyung-Do , Park Eun-Hwa , Lee Jin-Hwa , Han Song-Hee
Published: October 2021

Galectin-9 (Gal-9) is an immune checkpoint protein that facilitates T cell exhaustion and modulates the tumor-associated microenvironment, and could be a potential target for immune checkpoint inhibition. This study was conducted to assess Gal-9 expression in triple-negative breast cancer (TNBC) and evaluate its association with programmed cell death ligand 1 (PD-L1) expression and immune cell infiltration in tumors and the clinical outcome of patients. Overall, 109 patients with TNBC were included. Gal-9 expression was assessed its relationships with tumor clinicopathologic characteristics, tumor-infiltrating lymphocyte (TIL) levels, PD-L1+ immune cells, and tumor cells by tissue microarray and immunohistochemistry. Low Gal-9 expression was statistically correlated with higher tumor stage (p = 0.031) and presence of lymphovascular invasion (p = 0.008). High Gal-9 expression was associated with a high level of stromal TILs (sTIL; p = 0.011) and positive PD-L1 expression on tumor cells (p = 0.004). In survival analyses, low Gal-9 expression was associated with significantly poor OS (p = 0.013) in patients with TNBC with PD-L1 negativity in tumor cells. Our findings suggest that increased Gal-9 expression is associated with changes in the antitumor microenvironment, such as increased immune cell infiltration and antimetastatic changes. This study emphasizes the predictive value and promising clinical applications of Gal-9 in TNBC.
Clinically Translatable Approaches of Inhibiting TGF-β to Target Cancer Stem Cells in TNBC
Authors: Sulaiman Andrew , McGarry Sarah , Chilumula Sai Charan , Kandunuri Rohith , Vinod Vishak
Published: October 2021

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that disproportionally accounts for the majority of breast cancer-related deaths due to the lack of specific targets for effective treatments. In this review, we highlight the complexity of the transforming growth factor-beta family (TGF-β) pathway and discuss how the dysregulation of the TGF-β pathway promotes oncogenic attributes in TNBC, which negatively affects patient prognosis. Moreover, we discuss recent findings highlighting TGF-β inhibition as a potent method to target mesenchymal (CD44+/CD24−) and epithelial (ALDHhigh) cancer stem cell (CSC) populations. CSCs are associated with tumorigenesis, metastasis, relapse, resistance, and diminished patient prognosis; however, due to differential signal pathway enrichment and plasticity, these populations remain difficult to target and persist as a major barrier barring successful therapy. This review highlights the importance of TGF-β as a driver of chemoresistance, radioresistance and reduced patient prognosis in breast cancer and highlights novel treatment strategies which modulate TGF-β, impede cancer progression and reduce the rate of resistance generation via targeting the CSC populations in TNBC and thus reducing tumorigenicity. Potential TGF-β inhibitors targeting based on clinical trials are summarized for further investigation, which may lead to the development of novel therapies to improve TNBC patient prognosis.
mRNA Analysis of Frameshift Mutations with Stop Codon in the Last Exon: The Case of Hemoglobins Campania [α1 cod95 (−C)] and Sciacca [α1 cod109 (−C)]
Authors: Cardiero Giovanna , Musollino Gennaro , Prezioso Romeo , Lacerra Giuseppina
Published: October 2021

An insertion or deletion of a nucleotide (nt) in the penultimate or the last exon can result in a frameshift and premature termination codon (PTC), giving rise to an unstable protein variant, showing a dominant phenotype. We described two α-globin mutants created by the deletion of a nucleotide in the penultimate or the last exon of the α1-globin gene: the Hb Campania or α1 cod95 (−C), causing a frameshift resulting in a PTC at codon 102, and the Hb Sciacca or α1 cod109 (−C), causing a frameshift and formation of a PTC at codon 133. The carriers showed α-thalassemia alterations (mild microcytosis with normal Hb A2) and lacked hemoglobin variants. The 3D model indicated the α-chain variants’ instability, due to the severe structural alterations with impairment of the chaperone alpha-hemoglobin stabilizing protein (AHSP) interaction. The qualitative and semiquantitative analyses of the α1mRNA from the reticulocytes of carriers highlighted a reduction in the variant cDNAs that constituted 34% (Hb Campania) and 15% (Hb Sciacca) of the total α1-globin cDNA, respectively. We developed a workflow for the in silico analysis of mechanisms triggering no-go decay, and its results suggested that the reduction in the variant mRNA was likely due to no-go decay caused by the presence of a rare triplet, and, in the case of Hb Sciacca, also by the mRNA’s secondary structure variation. It would be interesting to correlate the phenotype with the quantity of other frameshift mRNA variants, but very few data concerning α- and β-globin variants are available.
Predicting Overall Survival Time in Glioblastoma Patients Using Gradient Boosting Machines Algorithm and Recursive Feature Elimination Technique
Authors: Karami Golestan , Giuseppe Orlando Marco , Delli Pizzi Andrea , Caulo Massimo , Del Gratta Cosimo
Published: October 2021

Despite advances in tumor treatment, the inconsistent response is a major challenge among glioblastoma multiform (GBM) that lead to different survival time. Our aim was to integrate multimodal MRI with non-supervised and supervised machine learning methods to predict GBM patients’ survival time. To this end, we identified different compartments of the tumor and extracted their features. Next, we applied Random Forest-Recursive Feature Elimination (RF-RFE) to identify the most relevant features to feed into a GBoost machine. This study included 29 GBM patients with known survival time. RF-RFE GBoost model was evaluated to assess the survival prediction performance using optimal features. Furthermore, overall survival (OS) was analyzed using univariate and multivariate Cox regression analyses, to evaluate the effect of ROIs and their features on survival. The results showed that a RF-RFE Gboost machine was able to predict survival time with 75% accuracy. The results also revealed that the rCBV in the low perfusion area was significantly different between groups and had the greatest effect size in terms of the rate of change of the response variable (survival time). In conclusion, not only integration of multi-modality MRI but also feature selection method can enhance the classifier performance.
Dexamethasone Alters Tracheal Aspirate T-Cell Cytokine Production in Ventilated Preterm Infants
Authors: Yazdi Siamak M. , Patel Ekta U. , Richardson Colby D. , Hardy K. Thomas , Baatz John E. , Mulligan Jennifer K. , Ryan Rita M.
Published: October 2021

Postnatal corticosteroids improve respiratory status and facilitate respiratory support weaning in preterm infants with bronchopulmonary dysplasia (BPD). Older literature describes characteristic cytokine profiles in tracheal aspirates (TA) of BPD patients which are altered with corticosteroids. Corticosteroids also influence peripheral blood T-cell presence. However, little is known regarding TA T-cell phenotype and cytokine production before or after exogenous corticosteroids. We hypothesized that postnatal dexamethasone alters the TA T-cell cytokine profiles of preterm infants. TA samples were collected from 14 infants born from 23 0/7 to 28 6/7 weeks who were mechanically ventilated for at least 14 days. Samples were collected up to 72 h before a ten-day dexamethasone course and again 1 to 3 calendar days after dexamethasone initiation. The primary outcome was change in T cell populations present in TA and their intracellular cytokine profile after dexamethasone treatment, ascertained via flow cytometry. Following dexamethasone treatment, there were significant decreases in respiratory severity score (RSS), percent CD4+IL-6+ cells, CD8+IL-6+ cells, CXCR3+IL-6+ cells, and CXCR3+IL-2+ cells and total intracellular IFN-γ in TA. RSS significantly correlated with TA percent CD4+IL-6+ cells. To our knowledge, this is the first study demonstrating that dexamethasone reduced T-cell IL-6 and this reduction was associated with improved RSS in pre-term infants with evolving BPD.
Delivery Room Care for Premature Infants Born after Less than 25 Weeks’ Gestation—A Narrative Review
Authors: Schwaberger Bernhard , Urlesberger Berndt , Schmölzer Georg M.
Published: October 2021

Premature infants born after less than 25 weeks’ gestation are particularly vulnerable at birth and stabilization in the delivery room (DR) is challenging. After birth, infants born after <25 weeks’ gestation develop respiratory and hemodynamic instability due to their immature physiology and anatomy. Successful stabilization at birth has the potential to reduce morbidities and mortalities, while suboptimal DR care could increase long-term sequelae. This article reviews current neonatal resuscitation guidelines and addresses challenges during DR stabilization in extremely premature infants born after <25 weeks’ gestation at the threshold of viability.
Psychosocial and Functional Predictors of Mental Disorder among Prostate Cancer Survivors: Informing Survivorship Care Programs with Evidence-Based Knowledge
Authors: Massoeurs Lia , Ilie Gabriela , Lawen Tarek , MacDonald Cody , Bradley Cassidy , Vo Jasmine , Rutledge Robert
Published: October 2021

Recent research has revealed that prostate cancer (PCa) survivors are facing a silent epidemic of mental disorder. These findings are not surprising when the side effects of highly effective current treatment modalities are considered. Here, we assess the association between urinary function and quality of life indicators to mental disorder among survivors of PCa. This is a cross sectional examination of an analytical sample of 362 men with a history of PCa residing in the Maritimes who took a survey assessing social, physical and health-related quality of life indicators between 2017 and 2021. Mental disorder was assessed using Kessler’s Psychological Distress Scale (K-10). Predictor variables included emotional, functional, social/family and spiritual well-being, measured by Functional Assessment of Cancer Therapy-Prostate (FACT-P), and urinary function was measured by International Prostate Symptom Score (IPSS). Multivariate logistic regression analysis evaluated the contribution of predictors while controlling for age, income, survivorship time (months) since diagnosis, relationship status and treatment modality. Mental disorder was identified among 15.8% of PCa survivors in this sample. High emotional (aOR = 0.81, 95% CI: 0.69–0.96) and spiritual well-being (aOR = 0.88, 95% CI: 0.81–0.96) were protective factors against mental disorder. Men who screened positive for moderate to severe urinary tract symptoms had three times higher odds (aOR = 3.02, 95% CI: 1.10, 8.32) of screening positive for mental disorder. Men who were on active surveillance or radical prostatectomy with or without added treatment had higher (aOR = 5.87, 95% CI: 1.32–26.13 or aOR = 4.21, 95% CI: 1.07–16.51, respectively) odds of screening positive for mental disorder compared to men who received radiation treatment with or without hormonal therapy for their PCa diagnosis. Unmet emotional and spiritual needs, increased urinary problems and some forms of treatment (e.g., active surveillance or surgery) were associated with mental disorder among PCa survivors. The development of survivorship care programs and support systems that focus on the long-term effects of PCa treatments and the consequences of unmet psychosocial needs of patients during the survivorship journey are critically needed.
Combined Exoscopic and Endoscopic Technique for Craniofacial Resection
Authors: Iwami Kenichiro , Watanabe Tadashi , Osuka Koji , Ogawa Tetsuya , Miyachi Shigeru , Fujimoto Yasushi
Published: October 2021

We determined the feasibility of the combined exoscopic-endoscopic technique (CEE) as an alternative to the microscope in craniofacial resection (CFR). This retrospective study was conducted at a single institution and included eight consecutive patients with head and neck tumors who underwent CFR between September 2019 and July 2021. During the transcranial approach, microsurgery was performed using an exoscope in the same manner as in traditional microscopic surgery, and an endoscope was used at the blind spot of the exoscope. The exoscope provided images of sufficient quality to perform microsurgery, while the sphenoid sinus lumen was the blind spot of the exoscope during anterior (n = 3) and anterolateral CFR (n = 2), and the medial aspect of the temporal bone was the blind spot of the exoscope during temporal bone resection (n = 2). These blind spots were visualized by the endoscope to facilitate accurate transection of the skull base. The advantages of the exoscope and endoscope include compact size, ergonomics, surgical field accessibility, and equal visual experience for neurosurgeons and head and neck surgeons, which enabled simultaneous transcranial and transfacial surgical procedures. All the surgeries were successful without any relevant complications. CEE is effective in transcranial skull base surgery, especially CFR involving simultaneous surgical procedures.
The Rethinking Clinical Trials (REaCT) Program. A Canadian-Led Pragmatic Trials Program: Strategies for Integrating Knowledge Users into Trial Design
Authors: Saunders Deanna , Liu Michelle , Vandermeer Lisa , Alzahrani Mashari Jemaan , Hutton Brian , Clemons Mark
Published: October 2021

We reviewed patient and health care provider (HCP) surveys performed through the REaCT program. The REaCT team has performed 15 patient surveys (2298 respondents) and 13 HCP surveys (1033 respondents) that have addressed a broad range of topics in breast cancer management. Over time, the proportion of surveys distributed by paper/regular mail has fallen, with electronic distribution now the norm. For the patient surveys, the median duration of the surveys was 3 months (IQR 2.5–7 months) and the median response rate was 84% (IQR 80–91.7%). For the HCP surveys, the median survey duration was 3 months (IQR 1.75–4 months), and the median response rate, where available, was 28% (IQR 21.2–49%). The survey data have so far led to: 10 systematic reviews, 6 peer-reviewed grant applications and 19 clinical trials. Knowledge users should be an essential component of clinical research. The REaCT program has integrated surveys as a standard step of their trials process. The COVID-19 pandemic and reduced face-to-face interactions with patients in the clinic as well as the continued importance of social media highlight the need for alternative means of distributing and responding to surveys.
Parameter Analysis of Multiscale Two-Dimensional Fuzzy and Dispersion Entropy Measures Using Machine Learning Classification
Authors: Furlong Ryan , Hilal Mirvana , O’Brien Vincent , Humeau-Heurtier Anne
Published: October 2021

Two-dimensional fuzzy entropy, dispersion entropy, and their multiscale extensions (MFuzzyEn2D and MDispEn2D, respectively) have shown promising results for image classifications. However, these results rely on the selection of key parameters that may largely influence the entropy values obtained. Yet, the optimal choice for these parameters has not been studied thoroughly. We propose a study on the impact of these parameters in image classification. For this purpose, the entropy-based algorithms are applied to a variety of images from different datasets, each containing multiple image classes. Several parameter combinations are used to obtain the entropy values. These entropy values are then applied to a range of machine learning classifiers and the algorithm parameters are analyzed based on the classification results. By using specific parameters, we show that both MFuzzyEn2D and MDispEn2D approach state-of-the-art in terms of image classification for multiple image types. They lead to an average maximum accuracy of more than 95% for all the datasets tested. Moreover, MFuzzyEn2D results in a better classification performance than that extracted by MDispEn2D as a majority. Furthermore, the choice of classifier does not have a significant impact on the classification of the extracted features by both entropy algorithms. The results open new perspectives for these entropy-based measures in textural analysis.
Liquid Propane Injection in Flash-Boiling Conditions
Authors: Kapusta Łukasz Jan , Bachanek Jakub , Jiang Changzhao , Piaszyk Jakub , Xu Hongming , Wyszyński Mirosław Lech
Published: October 2021

This study aimed to investigate the influence of flash-boiling conditions on liquid propane sprays formed by a multi-hole injector at various injection pressures. The focus was on spray structures, which were analysed qualitatively and quantitatively by means of spray-tip penetration and global spray angle. The effect of flash boiling was evaluated in terms of trends observed for subcooled conditions. Propane was injected by a commercial gasoline direct injector into a constant volume vessel filled with nitrogen at pressures from 0.1 MPa up to 6 MPa. The temperature of the injected liquid was kept constant. The evolution of the spray penetration was observed by a high-speed camera with a Schlieren set-up. The obtained results provided information on the spray evolution in both regimes, above and below the saturation pressure of the propane. Based on the experimental results, an attempt to calibrate a simulation model has been made. The main advantage of the study is that the effects of injection pressure on the formation of propane sprays were investigated for both subcooled and flash-boiling conditions. Moreover, the impact of the changing viscosity and surface tension was limited, as the temperature of the injected liquid was kept at the same level. The results showed that despite very different spray behaviours in the subcooled and flash-boiling regimes, leading to different spray structures and a spray collapse for strong flash boiling, the influence of injection pressure on propane sprays in terms of spray-tip penetration and spray angle is very similar for both conditions, subcooled and flash boiling. As for the numerical model, there were no single model settings to simulate the flashing sprays properly. Moreover, the spray collapse was not represented very well, making the simulation set-up more suitable for less superheated sprays.
Application Properties of ZnO and AZO Thin Films Obtained by the ALD Method
Authors: Swatowska Barbara , Powroźnik Wiesław , Czternastek Halina , Lewińska Gabriela , Stapiński Tomasz , Pietruszka Rafał , Witkowski Bartłomiej S. , Godlewski Marek
Published: October 2021

The thin layers of ZnO and ZnO: Al (Al doped zinc oxide—AZO) were deposited by the atomic deposition layer (ALD) method on silicon and glass substrates. The structures were deposited using diethylzinc (DEZ) and deionized water as zinc and oxygen precursors. A precursor of trimethylaluminum (TMA) was used to introduce the aluminum dopant. The present study of ALD-deposited ZnO and AZO films was motivated by their applications in photovoltaics. We attempted to expose several properties of such films. Structural, optical (including ellipsometric measurements) and electrical investigations were performed. We discussed the relations between samples doped with different Al fractions and their properties.
Adaptive Neuro-Fuzzy Inference System-Based Maximum Power Tracking Controller for Variable Speed WECS
Authors: Chhipa Abrar Ahmed , Kumar Vinod , Joshi Raghuveer Raj , Chakrabarti Prasun , Jasinski Michal , Burgio Alessandro , Leonowicz Zbigniew , Jasinska Elzbieta , Soni Rajkumar , Chakrabarti Tulika
Published: October 2021

This paper proposes an adaptive neuro-fuzzy inference system (ANFIS) maximum power point tracking (MPPT) controller for grid-connected doubly fed induction generator (DFIG)-based wind energy conversion systems (WECS). It aims at extracting maximum power from the wind by tracking the maximum power peak regardless of wind speed. The proposed MPPT controller implements an ANFIS approach with a backpropagation algorithm. The rotor speed acts as an input to the controller and torque reference as the controller’s output, which further inputs the rotor side converter’s speed control loop to control the rotor’s actual speed by adjusting the duty ratio for the rotor side converter. The grid partition method generates input membership functions by uniformly partitioning the input variable ranges and creating a single-output Sugeno fuzzy system. The neural network trained the fuzzy input membership according to the inputs and alter the initial membership functions. The simulation results have been validated on a 2 MW wind turbine using the MATLAB/Simulink environment. The controller’s performance is tested under various wind speed circumstances and compared with the performance of a conventional proportional–integral MPPT controller. The simulation study shows that WECS can operate at its optimum power for the proposed controller’s wide range of input wind speed.
Changes in Electricity Production from Renewable Energy Sources in the European Union Countries in 2005–2019
Authors: Matuszewska-Janica Aleksandra , Żebrowska-Suchodolska Dorota , Ala-Karvia Urszula , Hozer-Koćmiel Marta
Published: October 2021

The policy related to the use of renewable sources is a key element of the energy policy executed in the European Union (EU). One of the targets set for 2050 is to increase the share of electricity in energy consumption to 50%, and 80% of electricity is to be generated from low-carbon sources. In recent years, the EU economies have significantly modified their electricity production, which raises the question of the scale of these changes. The aim of the presented analysis is to assess changes in the use of renewable sources for electricity production in the EU countries in 2005–2019. Gini coefficient and k-mean are applied in the analysis. The conducted research shows that EU countries, in line with the energy policy assumptions, have both increased the share of renewable sources in energy production, especially in electricity production, as well as increased the diversity of used renewable sources. The results also indicate a vast diversity in terms of the use of such sources for the production of renewable electricity in the EU. This indicates that the energy transition is being implemented by EU countries with individual country-level approaches. Nonetheless, a variety of the EU’s both support and restrictive measures are of considerable importance for the ongoing energy transition.
Control-Oriented Modeling for Nonlinear MIMO Turbofan Engine Based on Equilibrium Manifold Expansion Model
Authors: Lv Chengkun , Wang Ziao , Dai Lei , Liu Hao , Chang Juntao , Yu Daren
Published: October 2021

This paper investigates the control-oriented modeling for turbofan engines. The nonlinear equilibrium manifold expansion (EME) model of the multiple input multiple output (MIMO) turbofan engine is established, which can simulate the variation of high-pressure rotor speed, low-pressure rotor speed and pressure ratio of compressor with fuel flow and throat area of the nozzle. Firstly, the definitions and properties of the equilibrium manifold method are presented. Secondly, the steady-state and dynamic two-step identification method of the MIMO EME model is given, and the effects of scheduling variables and input noise on model accuracy are discussed. By selecting specific path, a small amount of dynamic data is used to identify a complete EME model. Thirdly, modeling and simulation at dynamic off-design conditions show that the EME model has model accuracy close to the nonlinear component-level (NCL) model, but the model structure is simpler and the calculation is faster than that. Finally, the linearization results are obtained based on the properties of the EME model, and the stability of the model is proved through the analysis of the eigenvalues, which all have negative real parts. The EME model constructed in this paper can meet the requirements of real-time simulation and control system design.
A Novel Hybrid Life Cycle Assessment Approach to Air Emissions and Human Health Impacts of Liquefied Natural Gas Supply Chain
Authors: Al-Yafei Hussein , Kucukvar Murat , AlNouss Ahmed , Aseel Saleh , Onat Nuri C.
Published: October 2021

Global interest in LNG products and supply chains is growing, and demand continues to rise. As a clean energy source, LNG can nevertheless emit air pollutants, albeit at a lower level than transitional energy sources. An LNG plant capable of producing up to 126 MMTA was successfully developed and simulated in this study. A hybrid life cycle assessment model was developed to examine the social and human health impacts of the LNG supply chain’s environmental air emission formation. The Multiregional Input–Output (MRIO) database, the Aspen HYSYS model, and the LNG Maritime Transportation Emission Quantification Tool are the key sources of information for this extensive novel study. We began our research by grouping environmental emissions sources according to the participation of each stage in the supply chain. The MDEA Sweetening plant, LNG loading (export terminal), and LNG transportation stages were discovered to have the maximum air emissions. The midpoint air emissions data estimated each stage’s CO2-eq, NOx-eq, and PM2.5-eq emissions per unit LNG generated. According to the midpoint analysis results, the LNG loading terminal has the most considerable normalized CO2-eq and NOx-eq emission contribution across all LNG supply chain stages. Furthermore, the most incredible intensity value for normalized PM2.5-eq was recorded in the SRU and TGTU units. Following the midpoint results, the social human health impact findings were calculated using ReCiPe 2016 characterization factors to quantify the daily loss of life associated with the LNG process chain. SRU and TGTU units have the most significant social human health impact, followed by LNG loading (export terminal) with about 7409.0 and 1203.9 (DALY/million Ton LNG produced annually), respectively. Natural gas extraction and NGL recovery and fractionation units are the lowest for social human health consequences.
A Multi-Factorial Review of Repowering Wind Generation Strategies
Authors: Gil-García Isabel C. , Fernández-Guillamón Ana , García-Cascales M. Socorro , Molina-García Angel
Published: October 2021

The integration of renewables into power systems is a key transformation for mitigating climate change and reducing fossil-fuel dependence. Among the different resources, wind participation has become crucial in recent decades—both onshore and offshore wind power plants. However, assuming the useful life of the wind turbines at approximately 20 years, different solutions should be discussed to overcome the turbine’s aging problem. In the coming years, some countries within the wind sector will face the decision of partially or totally repowering or dismantling their turbines. This paper reviews different repowering strategies and contributions from a multifactorial perspective. A set of categories is defined by the authors and those multifactorial parameters are then classified according to such categories: technical, economic, environmental, social, and political. From each category, the most relevant factors to be considered for repowering decision-making purposes are identified and discussed. According to the specific literature, more than 90% of the reviewed contributions are focused on onshore wind power plant repowering actions. This percentage is in line with onshore and offshore wind generation units installed in recent decades. The reviewed studies show that Germany has a major number of contributions. Regarding offshore repowering strategies, all contributions propose a multifactorial analysis, in contrast to onshore repowering strategies where only 68% of the authors carry out a multifactorial analysis. The revised repowering methodologies and the categorization of factors can also be used by the repowering market, as a useful tool in the near future.
Numerical Simulation of Leakage and Diffusion Process of LNG Storage Tanks
Authors: Li Xue , Zhou Ning , Chen Bing , Zhang Qian , Rasouli Vamegh , Liu Xuanya , Huang Weiqiu , Kong Lingchen
Published: October 2021

To investigate the evolution process of LNG (Liquefied Natural Gas) liquid pool and gas cloud diffusion, the Realizable k-ε model and Eluerian model were used to numerically simulate the liquid phase leakage and diffusion process of LNG storage tanks. The experimental results showed that some LNG flashed and vaporized rapidly to form a combustible cloud during the continuous leakage. The diffusion of the explosive cloud was divided into heavy gas accumulation, entrainment heat transfer, and light gas drift. The vapor cloud gradually separated into two parts from the whole “fan leaf shape”. One part was a heavy gas cloud; the other part was a light gas cloud that spread with the wind in the downwind direction. The change of leakage aperture had a greater impact on the whole spill and dispersion process of the storage tank. The increasing leakage aperture would lead to 10.3 times increase in liquid pool area, 78.5% increase in downwind dispersion of methane concentration at 0.5 LFL, 22.6% increase in crosswind dispersion of methane concentration at 0.5 LFL, and 249% increase in flammable vapor cloud volume. Within the variation range of the leakage aperture, the trend of the gas cloud diffusion remained consistent, but the time for the liquid pool to keep stable and the gas cloud to enter the next diffusion stage was delayed. The low-pressure cavity area within 200 m of the leeward surface of the storage tank would accumulate heavy gas for a long time, forming a local high concentration area, which should be an area of focus for alert prediction.
Impact of Time-Use Behaviour on Residential Energy Consumption in the United Kingdom
Authors: Lőrincz Máté János , Ramírez-Mendiola José Luis , Torriti Jacopo
Published: October 2021

In order to have the best possible chance of achieving ‘decent work’ and ‘climate action’ as laid forth in the UN Sustainable Development Goals, government and policy makers must pay close attention to current time-use patterns, as well as the way these might change in the near future. Here we contribute to the existing literature on time-use behaviour through a systematic exploration of the relationship between working patterns and energy consumption from the perspective of time-use. Our starting point is the premise that different work arrangements impact the timing of energy demand not only in workplaces, but also at home. Using the data from the 2014–2015 UK time-use survey, we were able to capture patterns of time-use behaviours and to assess their relationship with daily energy consumption. We propose a systematic time-use-based approach for estimating residential energy consumption with regards to activity timing, activity location, activity coordination, and appliance type. We use this method to discover patterns in residential activities and energy consumption, as well as the causal relationship between residential energy consumption and work patterns. In this study, we unpack the heterogeneity in the work–energy relationship, particularly when comparing full-time and part-time workers. Our results suggest that full-time employees have a higher potential to reduce their energy use compared to part-time employees. We also discover a non-linear change in total energy consumption for respondents with varying levels of work time. Energy consumption reductions associated with differences in work schedules are greatest during the first few hours of the workday, but then level off. Our findings suggests that time-use data can provide useful insights for evaluating and possibly designing energy and labour-market policies.
Interlinking the Renewable Electricity and Gas Sectors: A Techno-Economic Case Study for Austria
Authors: Sejkora Christoph , Lindorfer Johannes , Kühberger Lisa , Kienberger Thomas
Published: October 2021

Achieving climate neutrality requires a massive transformation of current energy systems. Fossil energy sources must be replaced with renewable ones. Renewable energy sources with reasonable potential such as photovoltaics or wind power provide electricity. However, since chemical energy carriers are essential for various sectors and applications, the need for renewable gases comes more and more into focus. This paper determines the Austrian green hydrogen potential, produced exclusively from electricity surpluses. In combination with assumed sustainable methane production, the resulting renewable gas import demand is identified, based on two fully decarbonised scenarios for the investigated years 2030, 2040 and 2050. While in one scenario energy efficiency is maximised, in the other scenario significant behavioural changes are considered to reduce the total energy consumption. A techno-economic analysis is used to identify the economically reasonable national green hydrogen potential and to calculate the averaged levelised cost of hydrogen (LCOH2) for each scenario and considered year. Furthermore, roll-out curves for the necessary expansion of national electrolysis plants are presented. The results show that in 2050 about 43% of the national gas demand can be produced nationally and economically (34 TWh green hydrogen, 16 TWh sustainable methane). The resulting national hydrogen production costs are comparable to the expected import costs (including transport costs). The most important actions are the quick and extensive expansion of renewables and electrolysis plants both nationally and internationally.
Real-Time Load Variability Control Using Energy Storage System for Demand-Side Management in South Korea
Authors: Han Kyo Beom , Jung Jaesung , Kang Byung O
Published: October 2021

In today’s power systems, the widespread adoption of smart grid applications requires sophisticated control of load variability for effective demand-side management (DSM). Conventional Energy Storage System (ESS)-based DSM methods in South Korea are limited to real-time variability control owing to difficulties with model development using customers’ load profiles from sampling with higher temporal resolution. Herein, this study thus proposes a method of controlling the variability of customers’ load profiles for real-time DSM using customer-installed ESSs. To optimize the reserved capacity for the proposed maximum demand control within ESSs, this study also proposes a hybrid method of load generation, which synthesizes approaches based on Markov Transition Matrix (MTM) and Artificial Neuron Network (ANN) to estimate load variations every 15 min and, in turn reserve capacity in ESSs. The proposed ESS-based DSM strategy primarily reserves capacity in ESSs based on estimated variation in load, and performs real-time maximum demand control with the reserved capacity during scheduled peak shaving operations. To validate the proposed methods, this study used load profiles accumulated from industrial and general (i.e., commercial) customers under the time-of-use (TOU) rate. Simulation verified the improved performance of the proposed ESS-based DSM method for all customers, and results of Kolmogorov-Smirnov (K–S) testing indicate advances in the proposed hybrid estimation beyond the stand-alone estimation using the MTM- or ANN-based approach.
Combustion Behavior and Kinetics Analysis of Isothermal Oxidized Oils from Fengcheng Extra-Heavy Oil
Authors: Wang Liangliang , Wang Jiexiang , Pu Wanfen , Wang Tengfei
Published: October 2021

The low-temperature oxidation (LTO) of heavy oil is of great significance for the combustion front stability, which directly influences the efficiency and safety of in-situ combustion (ISC). To provide feasible heating by artificial ignition before the implementation of ISC in the Xinjiang Fengcheng (FC) oilfields, this paper investigates the oxidation behavior of FC extra-heavy oil and its isothermal oxidized oils. Firstly, FC extra-heavy oil was subjected to isothermal oxidation experiments conducted utilizing an oxidation reactor, and the physical properties of the gaseous products and oxidized oils were analyzed. The combustion behavior of the FC extra-heavy oil and oxidized oils was then studied by non-isothermal thermogravimetry and differential scanning calorimetry. Subsequently, the Friedman and Ozawa–Flynn–Wall methods were adopted to perform kinetic analysis. Oxygen consumption was always greater than the production of CO and CO2, so oxygen addition reactions were the main pathway in heavy oil LTO. H/C decreased to 8.31% from 20.94% when the oxidation temperature rose from 50 °C to 150 °C, which deepened the oxidation degree. The density and viscosity of 200 °C to 350 °C oxidized oils increased at a slower rate, which may be related to the LTO heat effect. The change law of temperature interval, peak temperature, and mass loss of the oxidized oils had a good correlation with the static oxidation temperature. Compared with other oxidized oils, the peak heat flow and enthalpy of 350 °C oxidized oil increased significantly with high-temperature combustion, and were 42.4 mW/mg and 17.77 kJ/mol, respectively. The activation energy of 350 °C oxidized oil began to decrease obviously around a conversion rate of 0.4, which indicates that it was beneficial to coke deposition with stronger activity. Finally, we came up with LTO reaction mechanisms and put forward a reasonable preheating temperature for the application of ISC in FC oilfields.
Effects of Positioning of Multi-Sensor Devices on Occupancy and Indoor Environmental Monitoring in Single-Occupant Offices
Authors: Azizi Shoaib , Rabiee Ramtin , Nair Gireesh , Olofsson Thomas
Published: October 2021

The advancements in sensor and communication technologies drive the rapid developments in the applications of occupancy and indoor environmental monitoring in buildings. Currently, the installation standards for sensors are scarce and the recommendations for sensor positionings are very general. However, inadequate sensor positioning might diminish the reliability of sensor data, which could have serious impacts on the intended applications such as the performance of demand-controlled HVAC systems and their energy use. Thus, there is a need to understand how sensor positioning may affect the sensor data, specifically when using multi-sensor devices in which several sensors are being bundled together. This study is based on the data collected from 18 multi-sensor devices installed in three single-occupant offices (six sensors in each office). Each multi-sensor device included sensors to measure passive infrared (PIR) radiation, temperature, CO2, humidity, and illuminance. The results show that the positions of PIR and CO2 sensors significantly affect the reliability of occupancy detection. The typical approach of positioning the sensors on the ceiling, in the middle of offices, may lead to relatively unreliable data. In this case, the PIR sensor in that position has only 60% accuracy of presence detection. Installing the sensors under office desks could increase the accuracy of presence detection to 84%. These two sensor positions are highlighted in sensor fusion analysis as they could reach the highest accuracy compared to other pairs of PIR sensors. Moreover, sensor positioning can affect various indoor environmental parameters, especially temperature and illuminance measurements.
Reduced Scale Laboratory for Training and Research in Condition-Based Maintenance Strategies for Combustion Engine Power Plants and a Novel Method for Monitoring of Inlet and Exhaust Valves
Authors: Assuncao Frederico de Oliveira , Borges-da-Silva Luiz Eduardo , Villa-Nova Helcio Francisco , Bonaldi Erik Leandro , Oliveira Levy Ely Lacerda , Lambert-Torres Germano , Teixeira Carlos Eduardo , Sant’Ana Wilson Cesar , Lacerda Josue , da Silva Junior Jose Luiz Marques , da Silva Edenio Gomes
Published: October 2021

This paper presents the practical aspects of development of a reduced scale laboratory and a set of monitoring tools for Internal Combustion Engines used in Thermal Power Plants. The reduced scale laboratory is based on the necessity of researchers to test new sensors and monitoring strategies that, otherwise, are seldom allowed to be installed in real plants without certification. In addition, the reduced scale laboratory allows the flexibility to insert failures on purpose, in order to evaluate the performance of new sensors/strategies in a safe and controlled environment. The paper also presents the development of a set of reduced cost sensors for monitoring in-cylinder pressure, crank angle, and the position of inlet and exhaust valves (without using ultrasound sensors, which may produce noisy readings on engines operating on gas-diesel fuel mode).
Feasibility Study on Bioethanol Production by One Phase Transition Separation Based on Advanced Solid-State Fermentation
Authors: Li Hongshen , Liu Hongrui , Li Shizhong
Published: October 2021

To fulfill the consumption demand of low-cost fuel ethanol, an advanced process for feedstock fermentation and bioethanol extraction was required. This study proposed a process of combined continuous solid-state distillation and vapor permeation to extract ethanol from fermented sweet sorghum bagasse on the basis of advanced solid-state fermentation technology. Ethanol undergoes only one phase transition separation in the whole process, which drastically reduces energy consumption compared to the repeating phase transitions that occur in conventional bioethanol production. The mass balance and energy consumption of combining processes were simulated overall. A techno-economic evaluation was conducted on the flowsheet. Costs and profit of fuel ethanol produced by one phase transition separation bioethanol-producing technology were comprehensively calculated. The results of the present study show that the proposed process is an energy efficient and cost-effective alternative to conventional bioethanol production.
Reactivity Model as a Tool to Compare the Combustion Process in Aviation Turbine Engines Powered by Synthetic Fuels
Authors: Białecki Tomasz , Dzięgielewski Wojciech , Kowalski Mirosław , Kulczycki Andrzej
Published: October 2021

The paper aims to verify the thesis that the reactivity model, developed in earlier research, can be used to compare the fuels combustion processes in turbine engines, which is important for predicting the behavior of different alternative fuels in combustion process. Synthetic blending components from alcohol to jet and hydroprocessed esters and fatty acids technologies and their blends with conventional jet fuel were used in tests. The undertaken laboratory tests reveal the differences between the properties of the tested fuels. Bench tests were carried out on a test rig with a miniature turbojet engine, according to authorial methodology. For each blend, on selected points of rotational speed the carbon oxide concentration in the exhaust gases was recorded. The obtained results allowed the formulation of empirical power functions describing relations between carbon oxide concentration and fuel mass flow rate. Based on general assumptions, the reactivity model was adopted to compare the combustion processes of the different fuels in turbine engines. The directions of further research on the development of the proposed model were indicated.