bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-Islanding Method Development Based on Reactive Power Variation under Grid Support Environments
Authors: Yu Byunggyu
Published: September 2022

As the proportion of distributed generation (DG), including Photovoltaic (PV) generation, in the power grid system increases, there are dropouts of large-scale distributed power generation sources due to some transient conditions that negatively affect the power grid stability and power quality. Accordingly, the inverter for DG generation is in a transition period, requiring more complex control performance. Anti-islanding function requirements in particular are becoming more strict because sophisticated grid-connection requirements are demanded, such as voltage ride-through, frequency ride-through, rate of change of frequency, and other functions. Thus, highly advanced anti-islanding methods are required to detect the islanding condition quickly and accurately to stop the inverter. This paper presents the improved anti-islanding method based on reactive power variation (RPV) under grid-support environments for single-phase DG inverters. In order to verify the validity of the proposed method, PSIM simulation was conducted. The proposed method meets the requirements of IEEE Std. 1547-2018 and KS C 8564:2021 by preventing islanding within 0.007 s under the newly adopted voltage/frequency trip setting, while the conventional RPV method fails.
Robust Backstepping Control Applied to UAVs for Pest Recognition in Maize Crops
Authors: Rodríguez-Guerrero Liliam , Benítez-Morales Alejandro , Santos-Sánchez Omar-Jacobo , García-Pérez Orlando , Romero-Trejo Hugo , Ordaz-Oliver Mario-Oscar , Ordaz-Oliver Jesús-Patricio
Published: September 2022

In this paper, a robust control technique is developed to achieve the quadrotor stabilization against unmodeled matching vanishing dynamics. The synthesis of the proposed robust control is based on the Lyapunov approach and the backstepping method allowing to construct an iterative control algorithm. To compare the performance of the proposed controller, a Proportional Derivative (PD) controller is used to obtain experimental results in an outdoor environment. To compare the closed-loop system responses with both controllers, the Integral Absolute Error is computed and several tests are conducted to calculate the error standard deviation. Ultimately, employing the robust backstepping control approach in pest recognition in maize crops, which is a specific task of precision agriculture, demonstrates its effectiveness in improving the trajectory tracking of the vehicle while it captures images of the crops.
Development of Innovative CubeSat Platform for Mass Production
Authors: Areda Eyoas Ergetu , Cordova-Alarcon Jose Rodrigo , Masui Hirokazu , Cho Mengu
Published: September 2022

With the recent increase in CubeSats’ ability to undertake complex and advanced missions, they are being considered for missions such as constellations, which demand high development efficiency. From a satellite interface perspective, productivity can be maximized by implementing a flexible modular structural platform that promotes easy reconfigurability during the integration and testing phase. Thus, the structural design of a CubeSat plays a crucial role in facilitating the satellite integration process. In most cases, the mechanical interface implemented between the primary load-supporting structure and internal satellite subassemblies affects the speed and efficiency of satellite integration by adding or reducing complexity. Most CubeSat structural designs use stacking techniques to mount PCBs onto the primary structure using stacking rods/screws. As a result, the internal subsystems are interconnected. This conventional interface method is observed to increase the number of structural parts, while increasing complexity during integration. In this study, flexible 3U and 1U CubeSat platforms are developed, based on the slot concept. This innovative mounting design provides a simple method of mounting PCBs into the slots. The concept is evaluated and verified for its feasibility for mass production applications. Count and complexity analysis is carried to evaluate the proposed design against the conventional type of structural interface methods. The assessment reveals that this new concept demonstrates a significant improvement in the efficiency of the mass production process.
Guided Random Mask: Adaptively Regularizing Deep Neural Networks for Medical Image Analysis by Potential Lesions
Authors: Yu Xiaorui , Wang Shuqi , Hu Junjie
Published: September 2022

Data augmentation is a critical regularization method that contributes to numerous state-of-the-art results achieved by deep neural networks (DNNs). The visual interpretation method demonstrates that the DNNs behave like object detectors, focusing on the discriminative regions in the input image. Many studies have also discovered that the DNNs correctly identify the lesions in the input, which has been confirmed in the current work. However, for medical images containing complicated lesions, we observe the DNNs focus on the most prominent abnormalities, neglecting sub-clinical characteristics that may also help diagnosis. We speculate this bias may hamper the generalization ability of DNNs, potentially causing false predicted results. Based on this consideration, a simple yet effective data augmentation method called guided random mask (GRM) is proposed to discover the lesions with different characteristics. Visual interpretation of the inference result is used as guidance to generate random-sized masks, forcing the DNNs to learn both the prominent and subtle lesions. One notable difference between GRM and conventional data augmentation methods is the association with the training phase of DNNs. The parameters in vanilla augmentation methods are independent of the training phase, which may limit their effectiveness when the scale and appearance of region-of-interests vary. Nevertheless, the effectiveness of the proposed GRM method evolves with the training of DNNs, adaptively regularizing the DNNs to alleviate the over-fitting problem. Moreover, the GRM is a parameter-free augmentation method that can be incorporated into DNNs without modifying the architecture. The GRM is empirically verified on multiple datasets with different modalities, including optical coherence tomography, x-ray, and color fundus images. Quantitative experimental results show that the proposed GRM method achieves higher classification accuracy than the commonly used augmentation methods in multiple networks. Visualization analysis also demonstrates that the GRM can better localize lesions than the vanilla network.
SimEx: A Tool for the Rapid Evaluation of the Effects of Explosions
Authors: Sánchez-Monreal Juan , Cuadra Alberto , Huete César , Vera Marcos
Published: September 2022

The dynamic response of structural elements subjected to blast loading is a problem of growing interest in the field of defense and security. In this work, a novel computational tool for the rapid evaluation of the effects of explosions, hereafter referred to as SimEx, is presented and discussed. The classical correlations for the reference chemical (1 kg of TNT) and nuclear (106 kg of TNT) explosions, both spherical and hemispherical, are used together with the blast wave scaling laws and the International Standard Atmosphere (ISA) to compute the dynamic response of Single-Degree-of-Freedom (SDOF) systems subject to blast loading. The underlying simplifications in the analysis of the structural response follow the directives established by UFC 3-340-02 and the Protective Design Center Technical Reports of the US Army Corps of Engineers. This offers useful estimates with a low computational cost that enable in particular the computation of damage diagrams in the Charge Weight–Standoff distance (CW–S) space for the rapid screening of component (or building) damage levels. SimEx is a computer application based on Matlab and developed by the Fluid Mechanics Research Group at University Carlos III of Madrid (UC3M). It has been successfully used for both teaching and research purposes in the Degree in Security Engineering, taught to the future Guardia Civil officers at the Spanish University Center of the Civil Guard (CUGC). This dual use has allowed the development of the application well beyond its initial objective, testing on one hand the implemented capacities by undergraduate cadets with the end-user profile, and implementing new functionalities and utilities by Masters and PhD students. With this experience, the application has been continuously growing since its initial inception in 2014 both at a visual and a functional level, including new effects in the propagation of the blast waves, such as clearing and confinement, and incorporating new calculation assistants, such as those for the thermochemical analysis of explosive mixtures; crater formation; fragment mass distributions, ejection speeds and ballistic trajectories; and the statistical evaluation of damage to people due to overpressure, body projection, and fragment injuries.
A Novel Ground Filtering Method for Point Clouds in a Forestry Area Based on Local Minimum Value and Machine Learning
Authors: Wu Yueqiao , Sang Mengting , Wang Wei
Published: September 2022

Lidar point cloud filtering is the process of separating ground points from non-ground points and is a particularly important part of point cloud data processing. Forest filtering has always been a difficult topic in point cloud filtering research. Given that vegetation cannot be completely summarized according to the structure of ground objects, and given the diversity and complexity of the terrain in woodland areas, filtering in the forest area is a particularly difficult task. However, only few studies have tested the application of the point cloud filtering method for forest areas, the parameter setting of filtering methods is highly complex, and their terrain adaptability is weak. This paper proposes a new filtering method for forest areas that effectively combines iterative minima with machine learning, thereby greatly reducing the degree of manual participation. Through filtering tests on three types of woodlands, the filtering results were evaluated based on the filtering error definition proposed by ISPRS and were compared with the filtering results of other classical methods. Experimental results highlight the advantages of the proposed method, including its high accuracy, strong terrain universality, and limited number of parameters.
Orientation and Exposure Efficiency of a Solar Tracking Surface in Clear Sky
Authors: Klimek Kamila , Kapłan Magdalena , Halchak Volodymyr , Korobka Serhiy , Syrotyuk Serhiy , Konieczny Ryszard , Filipczak Gabriel , Dybek Barbara , Wałowski Grzegorz
Published: September 2022

With regard to the problem of current solar irradiation of the tracking surface by the tracker, this can be rationally assessed using a modeled flux with parameters close to the natural direct in accordance with the maximum transparent atmosphere. As part of the experimental research, the values of the air optical mass index in the zenith angle ranging from 0° to 90° were presented for the surface at sea level. The conducted analysis made it possible to confront the experimental research with the models of the optical air transparency mass index. In order to maximize the energy of the controlled beam of the sun’s rays, the angle of their incidence on the tracking surface by the tracker should be minimized. The modeling results show the actual hourly dependencies, which are average values of the intensity of the multi-year measurement. It was found that seasonal dependencies can be considered as theoretically possible and then used to assess the energy efficiency of the tracking surface. Theoretically, they also correspond to the maximum possible energy efficiency of continuous tracking of the Sun with a two-axis rotary tracker. A polar-rotary tracker is a device where the axis of rotation is parallel to the axis of the earth and orients the tracking surface using the simplest synchronous algorithm with a constant angular speed ω = 15 grad/h. The novelty of the article is a method presenting the combination of a normal trajectory with direction towards the sun. Due to the deviation towards the polar axis, the normal touches the horizon, not at six hours after full sun, but earlier and simultaneously. In this way, an uniaxial pole-rotating tracker provides the same irradiation regime as a biaxial one in terms of the deviation of the tracking surface from the axis of rotation, which is equal to the tilt of the sun.
Underwater Accompanying Robot Based on SSDLite Gesture Recognition
Authors: Liu Tingzhuang , Zhu Yi , Wu Kefei , Yuan Fei
Published: September 2022

Underwater robots are often used in marine exploration and development to assist divers in underwater tasks. However, the underwater robots on the market have some problems, such as only a single function of object detection or tracking, the use of traditional algorithms with low accuracy and robustness, and the lack of effective interaction with divers. To this end, we designed a type of gesture recognition based on interaction, using person tracking as an auxiliary means for an underwater accompanying robot (UAR). We train and test the SSDLite detection algorithm using the self-labeled underwater datasets, and combine the kernelized correlation filters (KCF) tracking algorithm with the “Active Control” target tracking rule to continuously track the underwater human body. Our experiments show that the use of underwater datasets and target tracking can effectively improve gesture recognition accuracy by 40–105%. In the outfield experiment, the performance of the algorithm was good. It achieved target tracking and gesture recognition at 29.4 FPS on Jetson Xavier NX, and the UAR made corresponding actions according to the diver gesture command.
Ameliorative Effects of Annona muricata Leaf Ethanol Extract on Renal Morphology of Alloxan-Induced Mice
Authors: Handayani Supri Irianti , Sari Mutiara Intan Permata , Sardjana Meilania Saraswati , Kusmardi Kusmardi , Nurbaya Siti , Rosmalena Rosmalena , Sinaga Ernawati , Prasasty Vivitri Dewi
Published: September 2022

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by hyperglycemia, which affects multiple tissues including kidneys. Soursop leaves (Annona muricata) are known to have antidiabetic potential, but their molecular and cellular effects are poorly characterized. We identified the bioactive compounds in soursop leaf ethanol extract (SLEE). The SLEE substances demonstrated the total alkaloid and total flavonoid contents. Twelve bioactive compounds profiles were identified in SLEE classified as alkaloid, flavonol glycoside, and monoterpenoid lactone derivatives. The SLEE treatments in mice were performed by dividing Swiss Webster mice into five groups, including negative and positive controls and three experimental groups provided with SLEE (doses 150, 300, and 600 mg/kg BW) for 14 days. The mice in the experimental groups were treated with alloxan to induce diabetes. The renal samples were stained for H&E for morphological changes. However, 600 mg/kg of SLEE showed a significant effect (p < 0.05) on the height of the Bowman’s space and prevented the tubularization of the left kidney’s glomerulus (p < 0.05). Altogether, we report no significant difference in the glomerular diameter, the thickness of the proximal convoluted tubules, the height of the Bowman’s space, and the glomerular tubularization after 14 days of treatment with SLEE.
Methodology for Predicting the Structural Response of RPC-Filled Steel Tubular Columns under Blast Loading
Authors: Jiang Zhizhong , Rong Qin , Hou Xiaomeng , Zhao Zhonghui , Yang Enyuan
Published: September 2022

Reactive powder concrete-filled steel tube (RPC-FST) is a critical supporting component of large-span, high-rise, and heavy-load structures. The collapse of RPC-FST may occur under explosive load. Therefore, investigation of the dynamic response is essential for understanding the mechanisms of collapse. In this article, the numerical simulation of reactive powder concrete (RPC) adopted the modified Holmquist–Johnson–Cook (HJC) model and the modified Karagozian and Case (K&C) model. The dynamic response of RPC-FST columns under explosive load is analyzed based on arbitrary Lagrange–Euler (ALE) method. The proposed model is verified by experimental results. Results show that the modified HJC model and modified K&C model can be applied to simulate the dynamic response of RPC-FST columns under explosive load. As compared with the modified HJC model, the modified K&C model has more accurate results. This phenomenon mainly accounts for the lack of ultimate strain of RPC (EFMIN). To analyze the reliability sensitivity of RPC-FST, an efficient probability analysis method is proposed based on the Kriging model and Monte Carlo simulation (MCS). The proposed method considers five nonlinear factors, including weight and distance of TNT, height and section diameter of RPC-FST, and steel tube thickness. Finally, the sensitivity of each factor is evaluated. Results show that TNT weight greatly influences the reliability of the RPC-FST, followed by TNT distance, RPC-FST height, RPC-FST section diameter, and steel tube thickness. In addition, the RPC-FST dynamic response analysis method based on the Kriging model and MCS can improve the calculation efficiency by more than 200 times compared with the ALE method.
Energy Generation and Attenuation of Blast-Induced Seismic Waves under In Situ Stress Conditions
Authors: Yang Jianhua , Sun Jinshan , Jia Yongsheng , Yao Yingkang
Published: September 2022

During blasting in deep mining and excavation, the rock masses usually suffer from high in situ stress. The initial seismic energy generated in deep rock blasting and its attenuation with distance is first theoretically analyzed in this study. Numerical modeling of the multiple-hole blasting in a circular tunnel excavation under varied in situ stress conditions is then conducted to investigate the influences of in situ stress levels and anisotropy on the blasting seismic energy generation and attenuation. The case study of the deep rock blasting in the China Jinping Underground Laboratory (CJPL) is finally presented to demonstrate the seismic energy attenuation laws under varied in situ stress levels. The results show that with the increase in the in situ stress level, the explosive energy consumed in the rock fracture is reduced, and more explosive energy is converted into seismic energy. The increasing in situ stress causes the seismic Q of the rock mass medium to first increase and then decrease, and consequently, the seismic energy attenuation rate first decreases and then increases. Compared to the condition without in situ stress, the blasting seismic energy decays more slowly with distance under in situ stress. Then the seismic waves generated in deep rock blasting are more likely to reach and exceed the peak particle velocity (PPV) limits stipulated in the blasting vibration standards. Under non-hydrostatic in situ stress, the generation and attenuation of the blasting seismic energy are anisotropic. The highest seismic energy density is generated in the rock mass in the minimum principal stress orientation. Its attenuation is dependent upon the in situ stress aligning the wave propagation orientation.
Drug Discovery Strategies for Inherited Retinal Degenerations
Authors: Das Arupratan , Imanishi Yoshikazu
Published: September 2022

Inherited retinal degeneration is a group of blinding disorders afflicting more than 1 in 4000 worldwide. These disorders frequently cause the death of photoreceptor cells or retinal ganglion cells. In a subset of these disorders, photoreceptor cell death is a secondary consequence of retinal pigment epithelial cell dysfunction or degeneration. This manuscript reviews current efforts in identifying targets and developing small molecule-based therapies for these devastating neuronal degenerations, for which no cures exist. Photoreceptors and retinal ganglion cells are metabolically demanding owing to their unique structures and functional properties. Modulations of metabolic pathways, which are disrupted in most inherited retinal degenerations, serve as promising therapeutic strategies. In monogenic disorders, great insights were previously obtained regarding targets associated with the defective pathways, including phototransduction, visual cycle, and mitophagy. In addition to these target-based drug discoveries, we will discuss how phenotypic screening can be harnessed to discover beneficial molecules without prior knowledge of their mechanisms of action. Because of major anatomical and biological differences, it has frequently been challenging to model human inherited retinal degeneration conditions using small animals such as rodents. Recent advances in stem cell-based techniques are opening new avenues to obtain pure populations of human retinal ganglion cells and retinal organoids with photoreceptor cells. We will discuss concurrent ideas of utilizing stem-cell-based disease models for drug discovery and preclinical development.
The Divergent and Conserved Expression Profile of Turtle Nanog Gene Comparing with Fish and Mammals
Authors: Chen Kaili , Xu Jianfei , Ban Wenzhuo , Tian Jiaming , Tan Zhiming , Tang Zhoukai , Lei Luo , Li Wei , Zhu Xinping , Xu Hongyan
Published: September 2022

Nanog is a homeodomain-containing transcription factor, and it plays a vital role in maintaining the pluripotency of embryonic stem cells. Nanog’s function has been well studied in many species. However, there is lack of reporting on the Nanog gene in reptile. Here, we identified a 1032 bp cDNA sequence of a Nanog gene in Pelidiscus sinensis, known as PsNanog. PsNanog has a highly conserved HD domain and shares a high identity with that of Chelonia mydas and the lowest identity with Oryzias latipes. Similarly, PsNanog presented a tight cluster with C. mydas Nanog, but was far from those of teleosts. Additionally, we cloned a length of 1870 bp PsNanog promoter. Dual luciferase assay showed that the DNA fragment of −1560 to +1 exhibited a high promoter activity. The RT-PCR and RT-qPCR results showed that PsNanog was predominantly expressed in ovary, and then in testis. The in situ hybridization and immunohistochemical analysis showed that PsNanog was expressed in the early primary oocytes and the cytoplasm of the cortical region of stage VIII oocytes in ovary, and distributed in most stages of germ cells in testis. Collectively, the results imply that PsNanog probably has the conserved function in regulating germ cell development across phyla and is also a pluripotent cell gene and expressed in germ cells, which is similar to that in teleosts and mammals.
Araufuranone: A New Phytotoxic Tetrasubstituted Dihydrofuro[3,2-b]furan-2(5H)-One Isolated from Ascochyta araujiae
Authors: Masi Marco , Boari Angela , Sautua Francisco , Carmona Marcelo , Vurro Maurizio , Evidente Antonio
Published: September 2022

Araujia hortorum is a perennial vining plant species native to South America. It was introduced into many countries for ornamental and medicinal purposes as well as for its edible fruits, but it has become highly invasive, generating severe environmental problems. Biological control using bioherbicides and natural compounds is an interesting control option. The pathogenic fungus Ascochyta araujiae, isolated from infected leaves of A. hortorum, could be considered as a potential biocontrol agent. Its ability to produce bioactive metabolites was studied. The organic extract of the fungal culture filtrates showed interesting phytotoxic activities consisting of clearly visible necrotic symptoms (0.5–1 cm in diameter) in the punctured leaves. Thus, it was purified; this afforded three main metabolites. These were chemically and biologically characterised: one proved to be a new pentasubstituted dihydrofuro[3,2-b]furan-2(5H)-one, named araufuranone (1). The others were the already known fungal metabolites neovasinin and 2,4-dihydroxy-6-hydoxymethylbenzaldehyde (2 and 3). The structure of araufuranone was determined using spectroscopic methods (essentially 1D and 2D 1H and 13C NMR and HR ESIMS spectra); its relative configuration was assigned by a NOESY spectrum. To the best of our knowledge, araufuranone is the first example of a naturally occurring compound showing that carbon skeleton. Assayed by a puncture, araufuranone proved to be weakly active on the leaves of Diplotaxis sp. and Sonchus sp.; the other two metabolites were even less toxic. Tested on cress, compounds 2 and 3 were able to partially inhibit rootlet elongation whereas araufuranone was almost inactive.
Identification of Novel Ribonucleotide Reductase Inhibitors for Therapeutic Application in Bile Tract Cancer: An Advanced Pharmacoinformatics Study
Authors: Islam Md Ataul , Barshetty Mayuri Makarand , Srinivasan Sridhar , Dudekula Dawood Babu , Rallabandi V. P. Subramanyam , Mohammed Sameer , Natarajan Sathishkumar , Park Junhyung
Published: September 2022

Biliary tract cancer (BTC) is constituted by a heterogeneous group of malignant tumors that may develop in the biliary tract, and it is the second most common liver cancer. Human ribonucleotide reductase M1 (hRRM1) has already been proven to be a potential BTC target. In the current study, a de novo design approach was used to generate novel and effective chemical therapeutics for BTC. A set of comprehensive pharmacoinformatics approaches was implemented and, finally, seventeen potential molecules were found to be effective for the modulation of hRRM1 activity. Molecular docking, negative image-based ShaEP scoring, absolute binding free energy, in silico pharmacokinetics, and toxicity assessments corroborated the potentiality of the selected molecules. Almost all molecules showed higher affinity in comparison to gemcitabine and naphthyl salicylic acyl hydrazone (NSAH). On binding interaction analysis, a number of critical amino acids was found to hold the molecules at the active site cavity. The molecular dynamics (MD) simulation study also indicated the stability between protein and ligands. High negative MM-GBSA (molecular mechanics generalized Born and surface area) binding free energy indicated the potentiality of the molecules. Therefore, the proposed molecules might have the potential to be effective therapeutics for the management of BTC.
Urinary Angiotensinogen and Progression of Chronic Kidney Disease: Results from KNOW-CKD Study
Authors: Suh Sang Heon , Oh Tae Ryom , Choi Hong Sang , Yang Eun Mi , Kim Chang Seong , Bae Eun Hui , Ma Seong Kwon , Oh Kook-Hwan , Jung Ji Yong , Hyun Young Youl , Kim Soo Wan
Published: September 2022

The prognostic value of urinary angiotensinogen (UAGT) in patients with chronic kidney disease (CKD) has not been completely evaluated, although the association of UAGT with renal outcomes has been suggested in specific subsets of CKD. In the present study, to investigate the association of UAGT with renal outcomes in patients with non-dialysis CKD irrespective of the primary cause, a total of 1688 subjects from the Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) were prospectively analyzed. The subjects were divided into the quintile by UAGT to urine creatinine ratio (UAGT/Cr) level. The primary outcomes of interest were composite renal event, which included decline in kidney function and onset of end-stage renal disease during follow-up periods. The median follow-up duration was 6.257 years. Cox regression model analysis unveiled that the risk of composite renal event was significantly higher in the fifth quintile (adjusted hazard ratio 1.528, 95% confidence interval 1.156 to 2.021) compared to that of the first quartile. The association between high UAGT/Cr level and adverse renal outcome remained consistent in sensitivity analyses, including the analysis of the cause-specific hazard model. Subgroup analyses revealed that the association of UAGT level with renal outcomes is modified by certain clinical contexts, such as BMI and albuminuria. In conclusion, high UAGT level is associated with adverse renal outcomes in patients with non-dialysis CKD. Further studies are warranted to elaborate and expand the predictive role of UAGT as a biomarker for renal outcomes in CKD.
Forgiveness as a Mediator between Psychological Suzhi and Prosocial Behavior in Chinese Adolescents
Authors: Chen Xu , Zhao Hongxia , Zhang Dajun
Published: September 2022

Prosocial behavior contributes to the well-being of individuals as well as the harmonious development of society. This research aimed to reveal the mechanisms underlying the relationship between the psychological suzhi and prosocial behavior of Chinese adolescents with the consideration of time. A total of 477 adolescents (228 boys, 49.1%; Mage = 14.04 and SD = 1.77) from southwest China completed three questionnaires during waves 1 and 2. Results showed that psychological suzhi and forgiveness were positively correlated with prosocial behavior in both waves 1 and 2; psychological suzhi significantly predicted both current and three months later prosocial behavior and forgiveness played a mediating role in both immediate and lasting effects of psychological suzhi on prosocial behavior. Psychological suzhi and forgiveness are vital predictors of adolescents’ prosocial behaviors in China. Interventions based on psychological suzhi and forgiveness are essential to promote the development of pro-social behaviors.
Machine Learning Algorithm for Shear Strength Prediction of Short Links for Steel Buildings
Authors: Almasabha Ghassan , Alshboul Odey , Shehadeh Ali , Almuflih Ali Saeed
Published: September 2022

The rapid growth of using the short links in steel buildings due to their high shear strength and rotational capacity attracts the attention of structural engineers to investigate the performance of short links. However, insignificant attention has been oriented to efficiently developing a comprehensive model to forecast the shear strength of short links, which is expected to enhance the steel structures’ constructability. As machine learning algorithms was successfully used in various fields of structural engineering, the current study fills the gap in estimating the shear strength of short links using sophisticated machine learning algorithms. The deriving factors such as web and flange slenderness ratios, the flange-to-web area ratio, the forces in web and flange, and the link length ratio were investigated in this study, which is imperative to formulate an integrated prediction model. Consequently, the aim of this study utilizes advanced machine learning (ML) models (i.e., Extreme Gradient Boosting (XGBOOST), Light Gradient Boosting Machine (LightGBM), and Artificial Neural Network (ANN) to produce accurate forecasting for the shear strength. In this study, publicly available datasets were used for the training, testing, and validation. Different evaluation metrics were employed to evaluate the prediction’s performance of the used models, such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and Coefficient of Determination (R2). The prediction result displays that the XGBOOST and LightGBM provided better, and more reliable results compared to ANN and the AISC code. The XGBOOST and LightGBM models yielded higher values of R2, lower (RMSE), (MAE), and (MAPE) values and have shown to perform more accurate. Therefore, the overall outcomes showed that the LightGBM outperformed the XGBOOST model. Moreover, the overstrength ratio predicted by the LightGBM showed an excellent performance compared to the Gene Expression and Finite Element-based models. The developed models are vital for practitioners to predict the shear strength accurately, which pave the road towards wider application for automation in the steel buildings.
Mechanical and Thermal Properties of Composite Precast Concrete Sandwich Panels: A Review
Authors: Tawil Herman , Tan Chee Ghuan , Sulong Nor Hafizah Ramli , Nazri Fadzli Mohamed , Sherif Muhammad M. , El-Shafie Ahmed
Published: September 2022

Precast concrete sandwich panels (PCSPs) are utilized for the external cladding of structures (i.e., residential, and commercial) due to their high thermal efficiency and adequate composite action that resist applied loads. PCSPs are composed of an insulating layer with high thermal resistance that is mechanically connected to the concrete. In the recent decades, PCSPs have been a viable alternative for the fast deployment of structures due to the low fabrication and maintenance cost. Furthermore, the construction of light and thin concrete wythes that can transfer and resist shear loads has been achieved with the utilization of high-performance cementitious composites. As a result, engineers prefer PCSPs for building construction. PCSP design and use have been examined to guarantee that a building is energy efficient, has structural integrity, is sustainable, is comfortable, and is safe. Hence, this paper reviews the expanding knowledge regarding the current development of the mechanical and thermal properties of the PCSPs components; subsequently, future potential research directions are suggested.
Research on the Material and Spatial Psychological Perception of the Side Interface of an Underground Street Based on Virtual Reality
Authors: Sun Liang , Ding Shanmin , Ren Yanbing , Li Ming , Wang Bo
Published: September 2022

In the context of the rapid development of the construction of urban underground spaces in China, people’s demands for the quality of these spaces have become increasingly prominent. As an important part of underground spaces, the different materials used in underground street interfaces give rise to different spatial experiences, which are important for creating a comfortable underground space atmosphere. However, current research on the perception of underground street spaces lacks an exploration of the influence of materials, and most research on materials focuses on the interface design of above-ground commercial streets. In this study, material characteristics were extracted as independent variables, 17 scenes were orthogonalized, and the efficient simulation characteristics of VR were used to build a scene model for the experiment. Participants’ evaluations of the scenes were measured during the experiment, and conclusions were drawn through scene ranking and one-way ANOVA. The results showed that the use of white, high-finish materials with non-directional textures and low bumpiness for the side interface was more in line with the participants’ preferences. This study provides new ideas for the design of high-quality underground commercial streets.
Development and Investigation of Photoactive WO3 Nanowire-Based Hybrid Membranes
Authors: Shehab Mohammed Ahmed , Sharma Nikita , Karacs Gábor , Nánai Lilla , Kocserha István , Hernadi Klara , Németh Zoltán
Published: September 2022

Novel hybrid structures have attracted attention in several instances of scientific research and different technological applications in this decade due to their novel characteristics and wide range of applicability. Hybrid membranes with multiple components (three or more) are also increasingly used in water purification applications, and their ease of handling and reusability make them a promising candidate for the degradation of organic pollutants by photocatalysis. In this study, the preparation and characterization of tungsten trioxide nanowire (WO3 NW)-based hybrid membrane structures are reported. Furthermore, the adsorption properties and photocatalytic efficiency of the as-prepared membranes against methylene blue (MB) organic dye under UV irradiation is also presented. Characterization techniques, such as scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray powder diffraction (XRD) are performed to study the morphology and surface of the as-prepared hybrid membranes. The removal efficiency of the hybrid membranes against MB is 77% in a 120 min decomposition reaction. The enhanced value can be attributed to the hybrid structure of the membrane that enhances not only the adsorption capability, but also the photocatalytic performance. Based on the results obtained, it is hoped that hybrid membrane technology could be a promising candidate for future photocatalysis-based water treatment applications.
CO Oxidation over Alumina-Supported Copper Catalysts
Authors: Ma Guoyan , Wang Le , Wang Xiaorong , Li Lu , Ma Hongfei
Published: September 2022

CO oxidation, one of the most important chemical reactions, has been commonly studied in both academia and the industry. It is one good probe reaction in the fields of surface science and heterogeneous catalysis, by which we can gain a better understanding and knowledge of the reaction mechanism. Herein, we studied the oxidation state of the Cu species to seek insight into the role of the copper species in the reaction activity. The catalysts were characterized by XRD, N2 adsorption-desorption, X-ray absorption spectroscopy, and temperature-programmed reduction. The obtained results suggested that adding of Fe into the Cu/Al2O3 catalyst can greatly shift the light-off curve of the CO conversion to a much lower temperature, which means the activity was significantly improved by the Fe promoter. From the transient and temperature-programmed reduction experiments, we conclude that oxygen vacancy plays an important role in influencing CO oxidation activity. Adding Fe into the Cu/Al2O3 catalyst can remove part of the oxygen from the Cu species and form more oxygen vacancy. These oxygen vacancy sites are the main active sites for CO oxidation reaction and follow a Mars-van Krevelen-type reaction mechanism.
Cr-Containing Rare-Earth Substituted Yttrium Iron Garnet Ferrites: Catalytic Properties in the Ethylbenzene Oxidation
Authors: do Carmo José Vitor C. , de Cássia F. Bezerra Rita , Guerra Y. , Peña-Garcia R. , Oliveira Alcineia C. , Padron-Hernandez E. , Saraiva Gilberto D. , Soares João M. , Castro Antonio Joel R. , Tehuacanaero-Cuapa Samuel , Rodríguez-Aguado Elena , Rodríguez-Castellón Enrique
Published: September 2022

A series of the Cr-containing erbium substituted yttrium iron garnet ferrites (ECYIG) was synthesized with distinct Cr amounts, herein referred to as Y3(Er0.02Fe5Cr1−x)O12, where x refers to Cr amounts from 0 to 0.05. The catalytic performance of the solids was investigated in ethylbenzene oxidation in the presence of hydrogen peroxide to assess the role of Cr and Er present in the YIG garnet lattice for fine chemistry compound production. Raman spectroscopy, HRTEM, EPR and FTIR revealed that the insertion of Er (at a fixed amount of 2%) in dodecahedral sites had a great impact on the catalytic activity of the garnets. Both Er3+ and Y3+ in the lattice simultaneously provided structural stability to the garnet structure in any harsh environment. XPS and EPR indicated that the Cr3+ ions replaced those of Fe3+ located in both octahedral and tetrahedral sites of the YIG garnets. The Cr3+ ions acted as electronic promoter to increase the oxidation rate of the Fe3+ active species responsible for activating the EB molecule. SEM-EDS demonstrated that the solids having Cr amounts lower than 4% experienced the most severe deactivation due to the Cr leaching and strong carbon species adsorption on the surface of the catalysts, which decreased their efficiency in the reaction.
Phantom Study on the Robustness of MR Radiomics Features: Comparing the Applicability of 3D Printed and Biological Phantoms
Authors: Veres Gergő , Kiss János , Vas Norman Félix , Kallos-Balogh Piroska , Máthé Nóra Beatrix , Lassen Martin Lyngby , Berényi Ervin , Balkay László
Published: September 2022

The objectives of our study were to (a) evaluate the feasibility of using 3D printed phantoms in magnetic resonance imaging (MR) in assessing the robustness and repeatability of radiomic parameters and (b) to compare the results obtained from the 3D printed phantoms to metrics obtained in biological phantoms. To this end, three different 3D phantoms were printed: a Hilbert cube (5 × 5 × 5 cm3) and two cubic quick response (QR) code phantoms (a large phantom (large QR) (5 × 5 × 4 cm3) and a small phantom (small QR) (4 × 4 × 3 cm3)). All 3D printed and biological phantoms (kiwis, tomatoes, and onions) were scanned thrice on clinical 1.5 T and 3 T MR with 1 mm and 2 mm isotropic resolution. Subsequent analyses included analyses of several radiomics indices (RI), their repeatability and reliability were calculated using the coefficient of variation (CV), the relative percentage difference (RPD), and the interclass coefficient (ICC) parameters. Additionally, the readability of QR codes obtained from the MR images was examined with several mobile phones and algorithms. The best repeatability (CV ≤ 10%) is reported for the acquisition protocols with the highest spatial resolution. In general, the repeatability and reliability of RI were better in data obtained at 1.5 T (CV = 1.9) than at 3 T (CV = 2.11). Furthermore, we report good agreements between results obtained for the 3D phantoms and biological phantoms. Finally, analyses of the read-out rate of the QR code revealed better texture analyses for images with a spatial resolution of 1 mm than 2 mm. In conclusion, 3D printing techniques offer a unique solution to create textures for analyzing the reliability of radiomic data from MR scans.
Evaluation of Subcortical Structure Volumes in Patients with Non-Specific Digestive Diseases
Authors: Skrobisz Katarzyna , Piotrowicz Grazyna , Rudnik Agata , Naumczyk Patrycja , Sabisz Agnieszka , Markiet Karolina , Szurowska Edyta
Published: September 2022

(1) Background: To evaluate volume of subcortical structures such as hippocampus, globus pallidus, putamen, thalamus, nucleus accumbens, amygdala, caudate in patients with non-specific digestive diseases (functional dyspepsia—FD, irritable bowel syndrome—IBS) and non-specific inflammatory bowel diseases—IBD (colitis ulcerosa and Crohn’s disease) in comparison to healthy control group (CON). (2) Material: The analysis included data obtained from 57 patients (FD-18, IBS-20, IBD-19) and 19 persons in control group. Both groups underwent examination in a 3T scanner (Achieva TX Philips Healthcare). (3) Results: Significant differences between the IBD group and Control group in volume of left thalamus and IBD group vs Control group in volume of right thalamus. (4) Conclusions: The brain-gut axis hypothesis explains connection between biological behavior, emotions and cognitive functions in patients with gastrointestinal disease. We found that there is a difference between volume of thalamus in IBD patients in comparison to both IBS and control group and it occurred to be smaller. Excess inflammation can be linked with psychological disorders like depressive symptoms, sleep difficulties and/or fatigue. Therefore, there is a need for using treatment both for depressive symptoms and IBD to reduce the causes and effects of inflammation.
Combined Disruption of the Thoracic Spine and Costal Arch Fracture: An Indicator of a Severe Chest Trauma
Authors: Schulz-Drost Stefan , Kloesel Stephan , Kühling Jan Carsten , Ekkernkamp Axel , Bakir Mustafa Sinan
Published: September 2022

Blunt high-energy chest trauma is often associated with thoracic and abdominal organ injuries. Literature for a hyperextension-distraction mechanism resulting in a costal arch fracture combined with a thoracic spine fracture is sparse. A 65-year-old male suffered a fall from a height of six meters. Initial X-ray of the chest shows left-sided high-riding diaphragm and CT scan proves anterior cartilage fracture, posterolateral serial rib fractures, traumatic intercostal pulmonary hernia, avulsion of the diaphragm, and 7th thoracic vertebral fracture. An exploratory thoracotomy was performed and the rupture of the diaphragm, creating a two-cavity injury, had been re-fixed, the pulmonary hernia was closed, and locking plate osteosyntheses of the fractured ribs including the costal arch were performed. We generally recommend surgical therapy of the thorax to restore stability in this severe injury entity. The spine was fixed dorsally using a screw-rod system. In conclusion, this thoracovertebral injury entity is associated with high overall injury severity and life-threatening thoracoabdominal injuries. Since two-cavity traumata and particularly diaphragmatic injuries are often diagnosed delayed, injuries to the costal arch can act as an indicator of severe trauma. They should be detected through clinical examination and assessment of the trauma CT in the soft tissue window.
Clinical Utility of the Contrast-Enhanced Endoscopic Ultrasound Guided Fine Needle Aspiration in the Diagnosis of Pancreatic Cyst
Authors: Olar Miruna Patricia , Bolboacă Sorana D. , Pojoga Cristina , Moșteanu Ofelia , Gheorghiu Marcel , Seicean Radu , Rusu Ioana , Sparchez Zeno , Al Hajjar Nadim , Seicean Andrada
Published: September 2022

Endoscopic ultrasound fine needle aspiration (EUS-FNA) cytology from an intracystic fluid is useful in the differentiation of pancreatic cysts, with low sensitivity, which increases when the solid component is targeted. The clinical utility of contrast-enhanced guided EUS-FNA (CH-EUS-FNA) in the solid component is not known. We aimed to assess the diagnostic value of CH-EUS-FNA in enhanced mural nodules and discrimination between different cysts using contrast-enhanced endoscopic ultrasound (CH-EUS). The prospective study recruited patients with pancreatic cysts with an unclear diagnosis. The CH-EUS was followed by CH-EUS-FNA. The final diagnosis was based on surgery or the correlation between clinical history, cross-sectional imaging, echoendoscopic morphology, cystic fluid analysis, and follow-up. Fifty-eight patients with pancreatic cysts were evaluated. The mucinous cysts had wall arterial enhancement more often than non- mucinous cysts (p < 0.0001), with 90.2% sensitivity and 70.6% specificity. The CH-EUS-FNA from cystic fluid and mural nodules identified mucinous cysts and malignancy with 82.4% and 84.2% sensitivity and 92% and 100% specificity. Twenty-one cysts had solid components, but only 13 were enhanced mural nodules on EUS assessment with conclusive cytology in all cases and malignancy in 76.9%. Contrast-enhanced endoscopic ultrasound should be completed in all PCN with solid components in order to avoid unnecessary EUS-FNA and to guide FNA for the identification of malignant cysts.
What Is the Place of Physical Education among the Teaching Priorities of Primary School Teachers? An Empirical Study on Importance, Qualification and Perceived Teachers’ Competence
Authors: Milić Mirjana , Radić Hozo Endica , Maulini Claudia , De Giorgio Andrea , Kuvačić Goran
Published: September 2022

The education of children is important because it determines the future of the world. Teachers have a great responsibility for this, which applies to every subject taught. In this regard, teachers usually specialize in a specific area and greatly influence how the subject is taught and how students gain a view of the subject. The present study aimed to investigate teachers’ attitudes about subjects in primary school, with a particular focus on physical education. The sample of participants (N = 111) included Croatian female primary school teachers with a mean age of 47.88 (±8.11 SD) years and a mean teaching experience of 21.83 (±10.24 SD) years. The variable sample consisted of a three-criteria questionnaire for the assessment of classroom subjects: (i) the importance of a subject (importance); (ii) the level of qualifications obtained during study for a subject (qualification); and (iii) the teacher’s competence for teaching (competence). Significant differences were found in the assessment of classroom subjects. The group of core academic subjects has noticeably higher assessments than the group of practical and artistic subjects. The assessment of teachers’ competence in PE teaching is the lowest of all the classroom subjects. Further research of classroom teachers’ attitudes towards the implementation of physical education is advised, with an increased number of participants and the inclusion of new measures.