bluuebunny/crossref_metadata_2025 huggingface dataset:
Active Pharmaceutical Ingredients Transportation and Release from Aerogel Particles Processes Modeling
Authors: Lebedev Igor , Uvarova Anastasia , Mochalova Maria , Menshutina Natalia
Published: August 2022

In this work, active pharmaceutical ingredients release from aerogel particles and active pharmaceutical ingredients transportation processes were investigated. Experimental studies were carried out on the release of various types of active pharmaceutical ingredients from various types of aerogel particles. Release curves were obtained. A hybrid model using the lattice Boltzmann method and a cellular automata approach to simulate the release of active pharmaceutical ingredients from aerogel particles and active pharmaceutical ingredients transport processes is proposed. The proposed model can be used in new drug development, which allows partially replacing full-scale experiments with computational ones, therefore reducing the experimental studies cost.
To Be or Not to Be a (4,4) Net: Reactions of 4′-{4-(N,N-Diethylaminophenyl)}- and 4′-{4-(N,N-Diphenylaminophenyl)}-3,2′:6′,3″- and 4,2′:6′,4″-Terpyridines with Cobalt(II) Thiocyanate
Authors: Rocco Dalila , Nikoletić Anamarija , Prescimone Alessandro , Constable Edwin C. , Housecroft Catherine E.
Published: August 2022

The ligands 4′-{4-(N,N-diethylaminophenyl)}-3,2′:6′,3″-terpyridine (1) and 4′{4-(N,N-diphenylaminophenyl)}-3,2′:6′,3″-terpyridine (2) were prepared and characterized, including the single crystal structure of 2. Along with their 4,2′:6′,4″-terpyridine isomers, 3 and 4, ligands 1 and 2 were reacted with Co(NCS)2 under conditions of crystal growth by layering, using solvent mixtures of MeOH and CHCl3. The single crystal structures of [Co(NCS)2(1)]n·0.8nCHCl3, [Co(NCS)2(2)2(MeOH)2]·3CHCl3, [Co(NCS)2(3)]n·2nCHCl3, and [Co(NCS)2(4)]n were determined. The complexes with 1, 3, and 4 assemble into 2D (4,4) nets with the Co(II) centres as 4-connecting nodes, whereas [Co(NCS)2(2)2(MeOH)2] is a discrete molecular species, illustrating that MeOH can act as a non-innocent solvent. The effects on the structure of changing from the 3,2′:6′,3″-terpyridine (3,2′:6′,3″-tpy) to a 4,2′:6′,4″-tpy metal-binding unit, and of introducing R2N functionalities with different steric demands, are discussed. PXRD of bulk samples of all four products confirmed the single-crystal structures as representative of the bulk materials.
Al-Si@Al(OH)3 Nanosheets Composite for Enhanced Efficient Strategy to Synthesize Al-Si@Al2O3 Core-Shell Structure
Authors: Lin Yuhui , Chen Panyu , Wang Ying , Li Chengdong
Published: August 2022

Owing to the combined advantages of Al-Si alloy and Al2O3, Al-Si@Al2O3 is widely utilized as a heat storage material, catalyst carrier, and water adsorption host. Hence, the preparation of Al-Si@Al2O3 and corresponding precursors is of utmost significance. Herein, an Al-Si@Al(OH)3 precursor is investigated, and Al(OH)3 nanosheets are in situ formed on the surface of Al1-xSix, where x = 0,10, 0,20, and 0,30 in the presence of water. The influence of the Si content, diameter of Al-Si particles, and heating parameters on the morphology and thickness of the Al(OH)3 nanosheets is systematically explored using X-ray diffraction, electron microscopy, Fourier transform infrared spectroscopy, and N2 adsorption/desorption isotherms. The growth mechanism of Al(OH)3 nanosheets is revealed, and a pathway to obtain Al-Si@Al2O3 nanosheets with the desired structure and thickness is demonstrated.
Investigation of Glycine Polymorphic Transformation by In Situ ATR-FTIR and FT-Raman Spectroscopy
Authors: Li Zunhua , Zhang Bowen
Published: August 2022

The solution-mediated phase transformation of α-form to γ-form glycine, including dissolution of metastable α-form, nucleation, and growth of stable γ-form during polymorphic transformation, was investigated using in situ attenuated total-reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and Fourier transform Raman spectroscopy (FT-Raman). The mechanistic influence of operating parameters such as agitation speed, crystallization temperature, α-form seed concentration, and NaCl concentration on polymorphic phase transformation was examined. When the agitation speed, crystallization temperature, and NaCl concentration were increased, the polymorphic transformation process was improved due to the promotion of nucleation and growth of stable γ-form, in addition to the promotion of dissolution of metastable α-form. Moreover, the time to induce γ-form nucleation and complete conversion of α-form to γ-form was also reduced with increasing α-form seed concentration.
Towards Precision Oncology: Enhancing Cancer Screening, Diagnosis and Theragnosis Using Artificial Intelligence
Authors: Tran William T.
Published: August 2022

Highly complex and multi-dimensional medical data containing clinical, radiologic, pathologic, and sociodemographic information have the potential to advance precision oncology [...]
An Approach to the Diversity of Achelata and Brachyura (Crustacea, Decapoda) from the Southern Mexican Caribbean
Authors: Jarquín-González Jani , Valdez-Moreno Martha , Rosas-Luis Rigoberto
Published: August 2022

Decapods include species of economic importance, such as Achelata (lobsters) and Brachyura (true crabs), since they have aesthetic, commercial, gastronomic, and biomedical value. These groups exhibit a great variety of shapes, larval stages, habits, and sizes, making them difficult to recognize. In the Southern Mexican Caribbean (SMC), no taxonomic list or analysis of the biological diversity for the Achelata and Brachyura has been performed. Herein, the biological diversity of these groups was analyzed by reviewing the literature and collecting specimens in the SMC to obtain morphological, ecological, and molecular data. These results showed a total of 29 families, 67 genera, and 98 species recorded, of which, one is considered as a potentially new species, six are new records for the SMC, 12 expanded their distribution range, and 14 species names were updated. In addition, the BOLD system assigned 21 BINs supported with morphological identification. This work contributes positively to the knowledge of the marine and coastal decapods from the SCM as it represents the first effort to recognize their current biological diversity. This information will be used to develop adequate strategies for the conservation and management of marine and coastal natural resources of the SMC.
Discovering the Diversity of Arbuscular Mycorrhizal Fungi Associated with Two Cultivation Practices of Theobroma cacao
Authors: Pacheco Flores de Valgaz Angela , Naranjo-Morán Jaime , Reyes Román Guillermo , Oviedo-Anchundia Javier , Ratti Torres Maria , Barcos-Arias Milton
Published: August 2022

In recent years, new data on the diversity of genera and species in the phylum Glomeromycota continue to be added and rearranged. Arbuscular mycorrhizal fungi are key to plant nutrition and agriculture. Studies report different short- and long-term cultivation practices that influence the abundance and diversity of Glomeromycota. To the best of our knowledge, there are no known studies of the fungal communities in the fine aroma cocoa cultivars. In this context, our work aims to discover the diversity of arbuscular mycorrhizae associated with two cocoa cultivation practices (conservative and semi-conservative) through the isolation of spores using microscopy and metabarcoding of the internal transcribed spacer region (ITS). Morphological analysis showed that the density of Glomeromycota spores exhibited significant differences between production systems. Although the metabarcoding analysis showed that diversity indices showed a higher increase in the roots than in the cocoa soil, independently of the cultivation practice. An abundance of 348 and 114 taxa were observed, corresponding to the conservative and semi-conservative practices, respectively. Seven genera were observed for the first time in cocoa crop agroforestry systems, including P. scintillans, R. diaphanus, R. fasciculatus, R. custos, D. disticha, M. perpusilla, and D. bernensis.
Genetic Variation in Gaultheria nummularioides (Ericaceae: Gaultherieae) from the Sky Islands of the Himalaya-Hengduan Mountains
Authors: Zhang Jing , Cheng Xiaojuan , Fritsch Peter W. , Li Yirong , Yang Shuda , Lu Lu
Published: August 2022

Species diversity is high in the Himalaya-Hengduan Mountains, particularly at the edges characterized by deep ravines and “sky islands”. Studies focused on sky-island species are sparse and the patterns observed in response to both geographic and climatic factors are inconsistent. Here phylogeographic and phylogenetic analyses of Gaultheria nummularioides, a species originating in the late Pliocene with its main distribution in the Himalaya-Hengduan Mountains, were conducted to reveal the pattern of genetic dynamics in response to physical geography, glacial fluctuations, and monsoons. We found that in this species genetic variation is higher among populations than within populations, with a significant phylogeographic boundary between the central Himalaya and the eastern Himalaya and the Hengduan Mountains. We also found a high incidence of private alleles, possibly associated with strong habitat isolation. The phylogeographic pattern recovered is consistent with populations in glacial refugia that have experienced expansion after glaciation. The divergence times of most haplotypes coincide with the time of the weakening of the Asian monsoon in these regions. Models of geographic range size showed a significant decrease from the Last Interglacial through the Last Glacial Maximum to the Current, and a predicted increase from the Current to the year 2070. Our study provides insights for understanding speciation among sky islands in this region.
The Accuracy of Cytology, Colposcopy and Pathology in Evaluating Precancerous Cervical Lesions
Authors: Pleş Liana , Radosa Julia-Carolina , Sima Romina-Marina , Chicea Radu , Olaru Octavian-Gabriel , Poenaru Mircea-Octavian
Published: August 2022

Introduction: Cervical cancer (CC) is the third most common cancer in the world, and Romania has the highest incidence of cervical cancer in Europe. The aim of this study was to evaluate the correlation between cytology, colposcopy, and pathology for the early detection of premalignant cervical lesions in a group of Romanian patients. Methods: This observational type 2 cohort study included 128 women from our unit, “Bucur” Maternity, who were referred for cervical cancer screening. Age, clinical diagnosis, cytology results, colposcopy impression, and biopsy results were considered. Colposcopy was performed by two experienced examiners. The pathological examination was performed by an experienced pathologist. Results: The cytology found high-grade squamous intraepithelial lesions in 60.9% of patients, low-grade squamous intraepithelial lesions in 28.1%, atypical squamous cells for which a high-grade lesion could not be excluded in 9.4%, and atypical squamous cells of undetermined significance, known as repeated LSIL, in 1.6%. The first evaluator identified low-grade lesions in 56.3%, high-grade lesions in 40.6%, and invasion in 3.1% of patients. The second evaluator identified low-grade lesions in 59.4%, high-grade lesions in 32.0%, and invasion in 8.6% of patients. The pathological exam identified low-grade lesions in 64.1%, high-grade lesions in 25%, and carcinoma in 14% of patients. The colposcopic accuracy was greater than the cytologic accuracy. Conclusions: Colposcopy remains an essential tool for the identification of cervical premalignant cancer cells. Standardization of the protocol provided an insignificant interobserver variability and can serve as support for further postgraduate teaching.
Temporal Changes in Subcutaneous Fibrosis in Patients with Lower Extremity Lymphedema Following Surgery for Gynecologic Cancer: A Computed Tomography-Based Quantitative Analysis
Authors: Lee Soyoung , Lee Dong Gyu , Kim Kyoung Tae
Published: August 2022

Lymphedema causes inflammation, which provokes fibrosis within the epifascial tissue. Temporal change in fibrosis according to severity of the lymphedema has not been widely investigated. We aimed to study the quantitative changes in epifascial fibrosis during lymphedema treatment using computed tomography (CT). Forty-five patients (mean age: 57.75 ± 11.12 years) who developed lymphedema following gynecologic surgery were included in this retrospective study. Two weeks of complete decongestive therapy and continued self-bandaging or compression garments were prescribed under regular follow-up monitoring. Lower-extremity epifascial fibrosis was quantitatively analyzed on the initial and follow-up CT scans. Circumference, skin fibrosis, subcutaneous tissue, and fibrosis ratio were calculated in the axial scan. Based on the change in lymphedema severity, we divided subjects into ‘improved’ and ‘aggravated’ groups. The affected lower extremities showed higher circumference, more skin fibrosis and subcutaneous tissue, and higher fibrosis ratio than the unaffected sides on initial CT scan. At follow-up, compared to the aggravated group, the improved group showed significant decreases in fibrosis of skin and subcutaneous tissue and fibrosis ratio. Subcutaneous fibrosis was reversible with volume resolution of lymphedema. Therapeutic approaches should be established on the basis of the reversible nature of fibrotic changes in patients with lower extremity lymphedema.
FAPI PET versus FDG PET, CT or MRI for Staging Pancreatic-, Gastric- and Cholangiocarcinoma: Systematic Review and Head-to-Head Comparisons of Diagnostic Performances
Authors: Veldhuijzen van Zanten Sophie E. M. , Pieterman Kay J. , Wijnhoven Bas P. L. , Pruis Ilanah J. , Groot Koerkamp Bas , van Driel Lydi M. J. W. , Verburg Frederik A. , Thomeer Maarten G. J.
Published: August 2022

Introduction: There is a pressing demand for the development of cancer-specific diagnostic imaging tools, particularly for staging of pancreatic-, gastric- or cholangiocarcinoma, as current diagnostic imaging techniques, including CT, MRI and PET using FDG, are not fully adequate. The novel PET-tracer “FAPI” has the potential to visualize even small tumour deposits employing the tumour-specific expression of fibroblast-activating protein (FAP) in malignant cells. Methods: We performed a systematic review to select studies investigating the use of FAPI PET for staging pancreatic-, gastric- and cholangiocarcinoma (PROSPERO CRD42022329512). Patient-wise and lesion-wise comparisons were performed for primary tumour (T), lymph nodes (N), organ metastases (M) and peritoneal carcinomatosis (PC). Maximum standardized uptake values (SUVmax) and tumour-to-background ratios (TBR) were compared between PET using FAPI versus FDG (if reported). Results: Ten articles met the inclusion criteria. In all studies, FAPI PET showed superiority over FDG-PET/CT/MRI for the detection of T, N, M and PC, both in the patient-wise and in lesion-wise comparisons (when performed). Additionally, higher SUVmax and TBRmax values were reported for use of FAPI compared to FDG. Conclusions: The positive results of this review warrant prospective clinical studies to investigate the accuracy and clinical value of FAPI PET for diagnosing and staging patients with pancreatic-, gastric- and cholangiocarcinoma.
Proposal for a New Diagnostic Histopathological Approach in the Evaluation of Ki-67 in GEP-NETs
Authors: Faviana Pinuccia , Boldrini Laura , Gentile Carlo , Erba Paola Anna , Sammarco Enrico , Bartoli Francesco , Esposito Enrica , Galli Luca , Lippolis Piero Vincenzo , Bardi Massimo
Published: August 2022

Introduction: Studies have shown that the Ki-67 index is a valuable biomarker for the diagnosis, and classification of gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs). We re-evaluated the expression of Ki-67 based on the intensity of the stain, basing our hypothesis on the fact that the Ki-67 protein is continuously degraded. Background: The aim was to evaluate whether a new scoring method would be more effective in classifying NETs by reducing staining heterogeneity. Methods: Patients with GEP-NET (n = 87) were analyzed. The classification difference between the two methods was determined. Results: The classification changed significantly when the Ki-67 semiquantal index was used. The percentage of G1 patients increased from 18.4% to 60.9%, while the G2 patients decreased from 66.7% to 29.9% and the G3 patients also decreased from 14.9% to 9.2%. Moreover, it was found that the traditional Ki-67 was not significantly related to the overall survival (OS), whereas the semiquantal Ki-67 was significantly related to the OS. Conclusions: The new quantification was a better predictor of OS and of tumor classification. Therefore, it could be used both as a marker of proliferation and as a tool to map tumor dynamics that can influence the diagnosis and guide the choice of therapy.
Functional Evaluation of Major Salivary Glands Using Viscosity PLUS and 2D Shear-Wave PLUS Elastography Techniques in Healthy Subjects—A Pilot Study
Authors: Muntean Delia Doris , Lenghel Manuela Lavinia , Petea-Balea Diana-Raluca , Ciurea Anca Ileana , Solomon Carolina , Dudea Sorin Marian
Published: August 2022

Biological soft tissues are characterized by viscoelastic properties. The propagation of shear waves within tissues is influenced by both elasticity, which is linked to the shear wave speed, and viscosity, which is linked to the shear wave dispersion. This study aimed to functionally assess the parotid glands (PG) and submandibular glands (SMG) in a group of 40 healthy subjects using the novel Viscosity PLUS (Vi.PLUS) and 2D Shear-Wave Elastography PLUS (2D-SWE.PLUS) techniques. The viscosity and stiffness of PG and SMG were measured before and after gustatory stimulation with a sialagogue agent (commercially available lemon juice) using the new SuperSonic MACH 30 ultrasound system equipped with a curvilinear C6-1X transducer. PG presented a mean basal viscosity and elasticity of 2.10 ± 0.19 Pa.s and 11.32 ± 1.91 kPa, respectively, which significantly increased poststimulation to 2.39 ± 0.17 Pa.s (p < 0.001) and 12.58 ± 1.92 kPa (p < 0.001), respectively. SMG did not present statistically increased values of viscosity and elasticity following stimulation (2.31 ± 015 Pa.s vs. 2.37 ± 0.18 Pa.s, p = 0.086, and 10.40 ± 1.64 kPa vs. 10.90 ± 1.98 kPa, p = 0.074, respectively). Vi.PLUS measurements presented a good positive correlation with 2D-SWE.PLUS values for PG and SMG, before and after stimulation. Gender and BMI were not confounding factors for these two parameters. Vi.PLUS represents an innovative non-invasive imaging technique that, together with 2D-SWE.PLUS proves to be useful in functionally assessing the major salivary glands in healthy subjects.
In Vivo Study of Local and Systemic Responses to Clinical Use of Mg–1Ca Bioresorbable Orthopedic Implants
Authors: Adam Răzvan , Antoniac Iulian , Negoiță Silviu , Moldovan Cosmin , Rusu Elena , Orban Carmen , Tudorache Sorin , Hârșovescu Tudor
Published: August 2022

(1) Background: Resorbable Mg-based implants represent a new direction in orthopedic surgery but have some drawbacks, such as their rapid biodegradation and increased rate of corrosion. Some in vitro studies hypothesized that tissue necrosis, incision dehiscence, risk of gas embolization in vital organs, interference with coagulation processes, and trophocyte viability impairment can occur. (2) Methods: We conducted an in vivo study on ten rabbit cases, in two groups; group one, consisting of six cases, received cylindrical implants of Mg–1Ca alloy in tibial intramedullary bone tissue. Group two, consisting of four cases, received Mg–1Ca parallelepiped implants, in the thigh muscular tissue. We recorded and compared weight (preoperatively and at 2, 4, and 6 weeks postoperatively), complete blood count, serum electrolytes, liver and kidney functional markers, and coagulation parameters, prior to and at 6 weeks after surgery. Local evolution was assessed radiologically and with tissue biopsies with complete pathology analysis. (3) Results: All biological markers and clinical evolution were favorable, showing good integration of the implants with none of the local or systemic signs of degradation. (4) Conclusions: Our study shows that the clinical use of Mg–1Ca bioresorbable alloys can be safe as none of the cited local or systemic complications have been identified.
A Well-Balanced Unified Gas-Kinetic Scheme for Multicomponent Flows under External Force Field
Authors: Xiao Tianbai
Published: August 2022

The study of the evolution of the atmosphere requires careful consideration of multicomponent gaseous flows under gravity. The gas dynamics under an external force field is usually associated with an intrinsic multiscale nature due to large particle density variation along the direction of force. A wonderfully diverse set of behaviors of fluids can be observed in different flow regimes. This poses a great challenge for numerical algorithms to accurately and efficiently capture the scale-dependent flow physics. In this paper, a well-balanced unified gas-kinetic scheme (UGKS) for a gas mixture is developed, which can be used for the study of cross-scale multicomponent flows under an external force field. The well-balanced scheme here indicates the capability of a numerical method to evolve a gravitational system under any initial condition to the hydrostatic equilibrium and to keep such a solution. Such a property is crucial for an accurate description of multicomponent gas evolution under an external force field, especially for long-term evolving systems such as galaxy formation. Based on the Boltzmann model equation for gas mixtures, the UGKS leverages the space–time integral solution to construct numerical flux functions and, thus, provides a self-conditioned mechanism to recover typical flow dynamics in various flow regimes. We prove the well-balanced property of the current scheme formally through theoretical analysis and numerical validations. New physical phenomena, including the decoupled transport of different gas components in the transition regime, are presented and studied.
Monte Carlo Simulation of Stochastic Differential Equation to Study Information Geometry
Authors: Thiruthummal Abhiram Anand , Kim Eun-jin
Published: August 2022

Information Geometry is a useful tool to study and compare the solutions of a Stochastic Differential Equations (SDEs) for non-equilibrium systems. As an alternative method to solving the Fokker–Planck equation, we propose a new method to calculate time-dependent probability density functions (PDFs) and to study Information Geometry using Monte Carlo (MC) simulation of SDEs. Specifically, we develop a new MC SDE method to overcome the challenges in calculating a time-dependent PDF and information geometric diagnostics and to speed up simulations by utilizing GPU computing. Using MC SDE simulations, we reproduce Information Geometric scaling relations found from the Fokker–Planck method for the case of a stochastic process with linear and cubic damping terms. We showcase the advantage of MC SDE simulation over FPE solvers by calculating unequal time joint PDFs. For the linear process with a linear damping force, joint PDF is found to be a Gaussian. In contrast, for the cubic process with a cubic damping force, joint PDF exhibits a bimodal structure, even in a stationary state. This suggests a finite memory time induced by a nonlinear force. Furthermore, several power-law scalings in the characteristics of bimodal PDFs are identified and investigated.
Makassar Strait Area Development in Indonesia Based on the Marine Economy Sector
Authors: Gani Irwan , Auliansyah Auliansyah , Gaffar Emmilya Umma Aziza , Muliati Muliati , Aprianti Yesi , Rachmadi Revy Fadly Robby , Agustina Nadia Indri
Published: August 2022

The new capital city of Indonesia, Nusantara, having moved from Jakarta on Java Island to Kalimantan, is now officially located in the interregional area of the Makassar Strait. This area is expected to develop as the engine of the Indonesian economy, while various economic infrastructures are still very limited. The Makassar Strait area covers East Kalimantan, South Kalimantan, South Sulawesi, West Sulawesi and Central Sulawesi. These provinces have significant marine resource commodities and make a relatively significant economic contribution to the Indonesian economy as a whole. Using the data of the 2016 Inter-Regional Input-Output (IRIO) table which was updated in January 2021, this study aims to analyze the main sectors and inter-provincial linkages between each sector in the region. The results show that each province has a different main sector of economic development, which leads to differenct strategies based on their quadrants. Furthermore, the goal of provincial development as the new engine of the Indonesian economy is based on the assumption that the marine sector is on an industrial scale.
Geo-Location Method for Images of Damaged Roads
Authors: Zhang Wenbo , Qu Jue , Wang Wei , Hu Jun , Li Jie
Published: August 2022

Due to the large difference between normal conditions and damaged road images, geo-location in damaged areas often fails due to occlusion or damage to buildings and iconic signage in the image. In order to study the influence of post-war building and landmark damage conditions on the geolocation results of localization algorithms, and to improve the geolocation effect of such algorithms under damaged conditions, this paper used informative reference images and key point selection. Aiming at the negative effects of occlusion and landmark building damage in the retrieval process, a retrieval method called reliability- and repeatability-based deep learning feature points is proposed. In order to verify the effectiveness of the above algorithm, this paper constructed a data set consisting of urban, rural and technological parks and other road segments as a training set to generate a database. It consists of 11,896 reference images. Considering the cost of damaged landmarks, an artificially generated method is used to construct images of damaged landmarks with different damage ratios as a test set. Experiments show that the database optimization method can effectively compress the storage capacity of the feature index and can also speed up the positioning speed without affecting the accuracy rate. The proposed image retrieval method optimizes feature points and feature indices to make them reliable against damaged terrain and images. The improved algorithm improved the accuracy of geo-location for damaged roads, and the method based on deep learning has a higher effect on the geo-location of damaged roads than the traditional algorithm. Furthermore, we fully demonstrated the effectiveness of our proposed method by constructing a multi-segment road image dataset.
Fusion Schemes Based on IRS-Enhanced Cooperative Spectrum Sensing for Cognitive Radio Networks
Authors: Peng Guangqian , Wu Wei
Published: August 2022

The detection performance of cooperative spectrum sensing (CSS) is poor when there are obstacles blocking. Therefore, fusion schemes based on intelligent reflecting surface (IRS)-enhanced CSS are investigated. Existing fusion schemes can be divided into the soft combination and the hard combination. In the soft combination, each secondary user (SU) uploads the decision statistic to a fusion center (FC). Comparatively, during the hard combination, each SU reports the local 0/1 decision result to FC instead of decision statistic. In this paper, the equal gain combination (EGC) and the selection combination (SC) schemes are studied for the soft combination. The weighted hard combination (WHC) scheme is studied for the hard combination, and an optimal set combination (OSC) scheme is proposed based on signal-to-noise ratio (SNR). By using the definition of the non-centrality chi-square distribution and the moment-matching method, the closed-form expressions for the average probability of detection of all the schemes are derived. Simulation results reveal that the detection performance of IRS-enhanced CSS obviously outperforms the decode and forward (DF) relay case and the no IRS case. In addition, our proposed OSC are superior to the K-rank in terms of the detection performance.
Hybrid Precoding Based on a Switching Network in Millimeter Wave MIMO Systems
Authors: Yi Hongbin , Wei Xizhang , Tang Yanqun
Published: August 2022

Aiming at the algorithm difficult optimization of the fully-connected hybrid precoding structure and the complex hardware implementation in millimeter wave multiple-input multiple-output (MIMO) systems, this paper proposes a novel hybrid precoding structure based on a switching network (SNHBP). The structure enables the dynamic grouping of the sub-arrays in three ways by switching the network, which can greatly reduce the hardware complexity, simplify the optimization algorithm, and avoid the performance degradation defect caused by a partially-connected structure. Through simulation of different antenna sizes and different numbers of RF chains, experimental results show that SNHBP can approach the performance of the full digital precoder. Under the condition of more than 2 RF chains, the difference between the unit structure and the full digital precoding is less than 0.13 dB. The spectral efficiency of the low-precision phase optimization algorithm is better than that of the partially-connected structure when the quantization bit of the phase shifter is 3. The feasibility of the three dynamic grouping schemes is verified, which is more beneficial to engineering implementation than the fully-connected structure.
Neural Network-Based Dual-Cylinder Synchronous Control of a Multi-Link Erection Mechanism
Authors: Zhu Weilin , Ge Yaowen , Deng Wenxiang , Li Lan , Liu Xiangxin , Zhang Jialin , Yao Jianyong
Published: August 2022

A dual-cylinder erection mechanism, in which two telescopic cylinders physically connect to a load, is a nonlinear system with model uncertainties and coupled dynamics. In this paper, a novel synchronous control algorithm with thrust-allocation law is proposed for eliminating the excessive internal forces caused by the unbalanced rotation and lateral moments during the erection process. With regulated internal forces, the “pull and drag” issue is attenuated and better synchronization performance is attained. For improved tracking accuracy, the inter-stage collision dynamics of the telescopic cylinder are considered for model compensation to enhance stage-changing and in-position performance. A radial basis function (RBF) neural network is utilized to estimate the model uncertainties and external disturbances, which alleviates reliance upon the accuracy of a system model for controller implementation. As a result, theoretical analysis revealed that the semi-global asymptotic stability and synchronized motion performance with decreased internal forces can be achieved via the presented synchronous controller with thrust-allocation strategy. Contrasting simulations were implemented on a multi-link erection mechanism and the results confirmed the superiority and effectiveness of the proposed synchronous control algorithm.
Short-Term Load Forecasting on Individual Consumers
Authors: Melo João Victor Jales , Lira George Rossany Soares , Costa Edson Guedes , Leite Neto Antonio F. , Oliveira Iago B.
Published: August 2022

Maintaining stability and control over the electric system requires increasing information about the consumers’ profiling due to changes in the form of electricity generation and consumption. To overcome this trouble, short-term load forecasting (STLF) on individual consumers gained importance in the last years. Nonetheless, predicting the profile of an individual consumer is a difficult task. The main challenge lies in the uncertainty related to the individual consumption profile, which increases forecasting errors. Thus, this paper aims to implement a load predictive model focused on individual consumers taking into account its randomness. For this purpose, a methodology is proposed to determine and select predictive features for individual STLF. The load forecasting of an individual consumer is simulated based on the four main machine learning techniques used in the literature. A 2.73% reduction in the forecast error is obtained after the correct selection of the predictive features. Compared to the baseline model (persistent forecasting method), the error is reduced by up to 19.8%. Among the techniques analyzed, support vector regression (SVR) showed the smallest errors (8.88% and 9.31%).
Parameter Variation Study of Two-Stroke Low-Speed Diesel Engine Using Multi-Zone Combustion Model
Authors: Jurić Zdeslav , Kutija Roko , Vidović Tino , Radica Gojmir
Published: August 2022

The latest electronically controlled marine engines have a control system that allows the operator to view all the essential parameters of the engine in real conditions during operation. The system is connected to the electronic control system (ECS) through the control network, thus controlling the engine. The operator has various management and monitoring options. The objective of this paper was to become familiar with the specific factors that affect engine operation and optimize engine operation. A model of a large marine engine was developed and calibrated with measured data. Simulations were performed, and the combustion process was analyzed. The parameter study was performed by varying the fuel injection and the gas exchange timing. Fuel consumption decreases by 6 g/kWh, and NOx emissions decrease by 0.5 g/kWh. The research conducted in this work will be used by engineers to understand the potential of new technologies to optimize combustion in real-world conditions during operation and for the future development of an expert system to continuously monitor, diagnose, and optimize engine health during operation.
Analysis and Design of Wireless Power Transfer Systems Applied to Electrical Vehicle Supercapacitor Charge Using Variable-Resistance-Based Method
Authors: Geng Yuyu , Wang Tao , Xie Shiyun , Yang Yi
Published: August 2022

Supercapacitors (SCs) are widely used as energy storage devices in many practical applications of wireless power transfer. However, the modeling and analysis of a wireless power transfer system are seldom based on SC load; thus, the effects of the charging process on the wireless power transfer system cannot be analyzed clearly. In this paper, a variable-resistance-based method is proposed for the modeling and analysis of the process of constant current charging. First, how to make an SC equivalent in variable resistance is described, and the relationship between SC and variable resistance is considered. Next, the charging process, including charging current, voltage, power and transfer efficiency, is analyzed in detail. Furthermore, the effects of transmitting side voltage and frequency offset on this system are studied, and the optimal design method for an SC-load WPT system is provided on a preliminary basis. Finally, the theoretical derivation and analysis are verified by means of simulations and experiments.
Research on Anomaly Detection of Wind Farm SCADA Wind Speed Data
Authors: Wen Wu , Liu Yubao , Sun Rongfu , Liu Yuewei
Published: August 2022

Supervisory control and data acquisition (SCADA) systems are critical for wind power grid integration and wind farm operation and maintenance. However, wind turbines are affected by regulation, severe weather factors, and mechanical failures, resulting in abnormal SCADA data that seriously affect the usage of SCADA systems. Thus, strict and effective data quality control of the SCADA data are crucial. The traditional anomaly detection methods based on either “power curve” or statistical evaluation cannot comprehensively detect abnormal data. In this study, a multi-approach based abnormal data detection method for SCADA wind speed data quality control is developed. It is mainly composed of the EEMD (Ensemble Empirical Mode Decomposition)-BiLSTM network model, wind speed correlation between adjacent wind turbines, and the deviation detection model based on dynamic power curve fitting. The proposed abnormal data detection method is tested on SCADA data from a real wind farm, and statistical analysis of the results verifies that this method can effectively detect abnormal SCADA wind data. The proposed method can be readily applied for real-time operation to support an effective use of SCADA data for wind turbine control and wind power prediction.
Influence of Temperature on the Adsorption and Diffusion of Heavy Oil in Quartz Nanopore: A Molecular Dynamics Study
Authors: Chen Dongsheng , Zheng Wei , Wang Taichao , Liu Fan , Cheng Tong , Chen Hengyuan , Miao Tingting
Published: August 2022

The desorption of heavy oil is one of the important indicators affecting the development efficiency of the remaining oil in nanopores. However, the study of the adsorption and diffusion mechanisms of heavy oil molecules in nanopores remains scarce. In this work, the influences of temperature on the adsorption and diffusion properties of the heavy oil four-fractions in quartz nanopore have been investigated via molecular dynamics simulations. Our results show that the heavy oil molecules will form a denser multilayer adsorption oil layer on the nanopore surface, and high temperature can alter the adsorption behaviors of the heavy oil four-fractions. As the temperature increases, the saturate molecules are desorbed from the nanopore surfaces, but the aromatic, resin, and asphaltene molecules maintain a tendency to aggregate towards the nanopore surface. In particular, the agglomeration behaviors of most saturate, aromatic and asphaltene molecules in nanopore can be suppressed by the confined space compared with the heavy oil molecules in oil droplet. In addition, the influence of temperature on the movement of heavy oil molecules in nanopore decreases compared with the oil molecules in a heavy oil droplet due to the confined space and adsorption effect. Interestingly, there is a competition phenomenon between the adsorption and diffusion of aromatic, resin, and asphaltene molecules in the nanopore, resulting in different adsorption behaviors with the increase in temperature. The results obtained in this paper will provide molecular-level theoretical guidance for understanding the adsorption and desorption mechanisms of heavy oil in nanopores.
Successfully Navigating the Project Lifecycle for Deployment of Centralized Biogas Projects—The Case of Solrød Biogas
Authors: Nielsen Mark Booker , Lybæk Rikke , Kjær Tyge
Published: August 2022

The aim of this study is to identify non-technological critical success factors (CSFs) that influence the different phases of the project life cycle for the deployment of centralized biogas projects; as there is a knowledge gap in this area. This was performed by applying a longitudinal process analysis approach and an analytical framework based on findings from previous studies. Data were collected through extensive document collection and analysis, combined with in-depth semi-structured interviews. The study resulted in the identification of a total of 30 non-technological critical success factors in the case of Solrød Biogas. These were subsequently linked to one of the different phases of the project lifecycle (conceptualization phase, planning phase, execution phase) or categorized as general CSFs. We hope that the findings in this study can help ensure better management of biogas projects and enhance the capabilities of governmental bodies in supporting projects in the future, so a higher rate of centralized biogas projects is successfully implemented both in Denmark and other countries
Electrification of Rural Remote Areas Using Renewable Energy Sources: Literature Review
Authors: Karamov Dmitriy N. , Ilyushin Pavel V. , Suslov Konstantin V.
Published: August 2022

The current stage of development of autonomous energy systems is characterized by a rapid increase in renewable energy sources’ installed capacity. Such growth is observed both in centralized and isolated energy systems. Renewable energy sources show high efficiency in the electrification of rural remote settlements around the world. The power of such power complexes varies from several kilowatts to tens of megawatts. When solving the problems of rural remote settlements electrification, the main issues of optimizing the composition of equipment and the structure of the energy systems play an extremely important role. Moreover, depending on the specifications of the problem being solved, criteria for evaluating efficiency are used, which are different. For example, the following are used as objective functions: minimization of the levelized cost of energy and fossil fuel consumption; maximizing the standard of people living and reliability indicators; the payback period of the project and other indicators. Various combinations of objective functions and the solution to the multi-criteria optimization problem are possible. Moreover, an important stage in the development of renewable energy in remote rural areas is the availability of new mechanisms to support an environmentally friendly generation. These mechanisms can be used in solving problems of optimizing the structure and composition of energy equipment in remote power systems. The main purpose of this article is to demonstrate the world practices of optimal design of isolated energy systems. The review includes both the main questions that arise when solving such problems, and specific problems that require a more detailed analysis of the object of study.
Gasification of Spruce Wood Chips in a 1.5 MWth Fluidised Bed Reactor
Authors: Montagnaro Fabio , Zaccariello Lucio
Published: August 2022

Production of syngas from the gasification of a biomass is attracting attention with an eye to the concepts of circularity, sustainability, and recent needs, triggered by socio-political events, to increase the level of self-sufficiency of energy sources for a given community. This manuscript reports on the gasification of spruce wood chips in a demonstration fluidised bed gasifier (1.5 MWth, height of 5.40 m, internal diameter of 1.2 m), with 0.2–0.4 mm olivine inventory (1000 kg). Gasification was carried out in air, at four different values of equivalence ratio (from 27% to 36%). The bed was fluidised at about 0.6 m/s, and the bed temperature resulted in the range of about 960–1030 °C as a function of the different tests. A mass flow rate of biomass in the range of about 360–480 kg/h (as a function of the different tests) was fed to the fluidised bed gasifier. Syngas lower heating value, specific mass and energetic yield, and chemical composition, were reported along with data on the production of elutriated fines. Moreover, tar compounds were collected, quantified and chemically speciated. The effect of the equivalence ratio on the main process parameter was critically discussed, proposing useful analytical relationships for the prediction of syngas lower heating value, tar mass flow rate and chemical composition.
A Multilevel Control Approach to Exploit Local Flexibility in Districts Evaluated under Real Conditions
Authors: Carrillo Rafael E. , Peppas Antonis , Stauffer Yves , Politi Chrysa , Gorecki Tomasz , Alet Pierre-Jean
Published: August 2022

The increasing penetration of renewable energy sources creates a challenge for the stability of current power systems due to their intermittent and stochastic nature. This paper presents the field results of an efficient demand response solution for controlling and adjusting the electric demand of buildings in an energy district through the activation of their thermal mass while respecting the occupants’ thermal comfort constraints. This multilevel control approach aims to support grid flexibility during peak times by constraining the energy exchange with the grid and increasing the self-consumption of the district. The results show a great potential for increasing the self-consumption up to 37% for offices, as well as improving the indoor environment, based on real data collected from a case study in Greece.
An Auto-Extraction Framework for CEP Rules Based on the Two-Layer LSTM Attention Mechanism: A Case Study on City Air Pollution Forecasting
Authors: Liu Yuan , Yu Wangyang , Gao Cong , Chen Minsi
Published: August 2022

Energy is at the center of human society and drives the technologies and overall human well-being. Today, artificial intelligence (AI) technologies are widely used for system modeling, prediction, control, and optimization in the energy sector. The internet of things (IoT) is the core of the third wave of the information industry revolution and AI. In the energy sector, tens of billions of IoT appliances are linked to the Internet, and these appliances generate massive amounts of data every day. Extracting useful information from the massive amount of data will be a very meaningful thing. Complex event processing (CEP) is a stream-based technique that can extract beneficial information from real-time data through pre-establishing pattern rules. The formulation of pattern rules requires strong domain expertise. Therefore, at present, the pattern rules of CEP still need to be manually formulated by domain experts. However, in the face of complex, massive amounts of IoT data, manually setting rules will be a very difficult task. To address the issue, this paper proposes a CEP rule auto-extraction framework by combining deep learning methods with data mining algorithms. The framework can automatically extract pattern rules from unlabeled air pollution data. The deep learning model we presented is a two-layer LSTM (long short-term memory) with an attention mechanism. The framework has two phases: in the first phase, the anomalous data is filtered out and labeled from the IoT data through the deep learning model we proposed, and then the pattern rules are mined from the labeled data through the decision tree data mining algorithm in the second phase. We compare other deep learning models to evaluate the feasibility of the framework. In addition, in the rule extraction stage, we use a decision tree data mining algorithm, which can achieve high accuracy. Experiments have shown that the framework we proposed can effectively extract meaningful and accurate CEP rules. The research work in this paper will help support the advancement of the sector of air pollution prediction, assist in the establishment of air pollution regulatory strategies, and further contribute to the development of a green energy structure.
Combined Transcriptomic and Metabolomic Analysis Reveals the Mechanism of Flavonoid Biosynthesis in Handroanthus chrysanthus (Jacq.) S.O.Grose
Authors: Shang Xiuhua , Liu Guo , Wu Zhihua , Zhang Peijian
Published: August 2022

Handroanthus and Tabebuia are known for their ornamental and medicinal value, which are attributed to metabolites. However, the mechanisms underlying the synthesis of these metabolites are poorly understood. In this study, the expression levels of secondary metabolites and the mechanism of flavonoid biosynthesis in the bark and leaves of Handroanthus chrysantha (Jaq.) were examined using transcriptomic and metabolomic techniques. Metabolic analysis identified several differentially accumulated metabolites (DAMs), most of which were flavonoids, isoprenoids, and sterols. Additionally, 30 flavonoids were identified in the bark and leaves of H. chrysantha. Transcriptomic analysis identified 69 genes involved in flavonoid biosynthesis, among which 49 were significantly different between the bark and leaves. qRT-PCR analysis of eight genes involved in flavonoid biosynthesis showed that the expression patterns of the genes were consistent with the transcriptome sequencing data. Integrative transcriptomic and metabolomic analysis showed that 20 differentially expressed genes (DEGs) associated with flavonoid biosynthesis were strongly correlated with seven DAMs, confirming the involvement of the DEGs in flavonoid biosynthesis. These findings considerably contribute to the understanding of the biosynthesis of secondary metabolites in H. chrysantha and serve as a reference for further pharmacological studies.