bluuebunny/crossref_metadata_2025 huggingface dataset:
Summer Dystrophic Criticalities of Non-Tidal Lagoons: The Case Study of a Mediterranean Lagoon
Authors: Lenzi Mauro , Cianchi Fabio
Published: September 2022

Eutrophication determines algal blooms and the subsequent accumulation of organic matter in sediments, which, in turn, results in the dominance of anaerobic respiratory processes that release toxic gases. Dystrophy is a final dissipative moment that reduces the organic load in the sediment. A case of dystrophy occurring in the Burano lagoon (Tuscany, Italy) in 2021 is reported. The study examined the weather, physico-chemistry of the water, submerged vegetation and sediment labile organic matter. In spring, dissolved oxygen (DO) and pH showed high values, in an abundance of submerged vegetation, while low values had ammonium, nitrate and orthophosphate. In mid-August, as warm and moist sea breezes prevailed, hydrogen sulfide releases were produced, preceded by a sharp rise in ammonium and orthophosphate concentrations, which remained high until November. During dystrophy, DO varied between anoxia and oversaturation, the latter in Cyanobacteria blooms. Dystrophic waters evolved gradually due to microphytes blooms, which changed from Cyanobacteria, in August, to the Dinophyta Alexandrium tamarense, in September, and Bacillariophyta, in November. Sediment labile organic matter varied between 3% and 7%. Ruppia spiralis meadows suffered the total detachment of fronds and stems during the dystrophy and proved to be areas of accumulation of organic detritus, themselves sources of dystrophic phenomena.
Coronary Artery Bypass Graft Surgery Brings Better Benefits to Heart Failure Hospitalization for Patients with Severe Coronary Artery Disease and Reduced Ejection Fraction
Authors: Chen Yu-Wen , Lee Wei-Chieh , Fang Hsiu-Yu , Sun Cheuk-Kwan , Sheu Jiunn-Jye
Published: September 2022

Objectives: We compared the outcomes between percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) for revascularization in patients with reduced ejection fraction (EF) and severe coronary artery disease (CAD). Methods: Between February 2006 and February 2020, a total of 797 patients received coronary angiograms due to left ventricular EF ≤ 40% at our hospital. After excluding diagnoses of dilated cardiomyopathy, valvular heart disease, prior CABG, acute ST-segment myocardial infarction, and CAD with low Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score (≤22), 181 patients with severe coronary artery disease (CAD) with SYNTAX score >22 underwent CABG or PCI for revascularization. Vascular characteristics as well as echocardiographic data were compared between CABG (n = 58) and PCI (n = 123) groups. Results: A younger age (62 ± 9.0 vs. 66 ± 12.1; p = 0.016), higher new EuroSCORE II (8.6 ± 7.3 vs. 3.2 ± 2.0; p < 0.001), and higher SYNTAX score (40.5 ± 9.8 vs. 35.4 ± 8.3; p < 0.001) were noted in the CABG group compared to those in the PCI group. The CABG group had a significantly higher cardiovascular mortality rate at 1-year (19.6% vs. 5.0%, p = 0.005) and 3-year (25.0% vs. 11.4%, p = 0.027) follow-ups but a lower incidence of heart failure (HF) hospitalization at 1-year (11.1% vs. 28.2%, p = 0.023) and 3-year (3.6% vs. 42.5%, p = 0.001) follow-ups compared to those of the PCI group. Conclusions: Compared with PCI, revascularization with CABG was related to a lower incidence of HF hospitalization but a worse survival outcome in patients with severe CAD and reduced EF. CABG-associated reduction in HF hospitalization was more notable when SYNTAX score ≥33.
Encrusted Uretero-Pyelitis Caused by Corynebacterium urealyticum: Case Report and Literature Review
Authors: Rusmir Andrei Valentin , Paunescu Ionut Andrei , Martis Sandra , Latcu Silviu , Novacescu Dorin , Bardan Claudia Ramona , Bob Flaviu , Licker Monica , Botoca Mircea , Cumpanas Alin , Bardan Razvan
Published: September 2022

We report the case of a 70-year-old female patient with solitary functioning left kidney and encrusted uretero-pyelitis caused by Corynebacterium urealyticum, which was treated by antibiotic therapy and oral acidification with L-methionine. We review the literature for similarly reported cases.
Domain-Specific Cognitive Prosthesis for Face Memory and Recognition
Authors: Tani Jowy , Yang Yao-Hua , Chen Chao-Min , Siow Co Yih , Chang Tsui-San , Yang Kai , Yao Jack , Hu Chaur-Jong , Sung Jia-Ying
Published: September 2022

The present study proposes a cognitive prosthesis device for face memory impairment as a proof-of-concept for the domain-specific cognitive prosthesis. Healthy subjects (n = 6) and a patient with poor face memory were enrolled. An acquaintance face recognition test with and without the use of cognitive prosthesis for face memory impairment, face recognition tests, quality of life, neuropsychological assessments, and machine learning performance of the cognitive prosthesis were followed-up throughout four weeks of real-world device use by the patient. The healthy subjects had an accuracy of 92.38 ± 4.41% and reaction time of 1.27 ± 0.12 s in the initial attempt of the acquaintance face recognition test, which changed to 80.48 ± 6.23% (p = 0.06) and 2.11 ± 0.20 s (p < 0.01) with prosthesis use. The patient had an accuracy of 74.29% and a reaction time of 6.65 s, which improved to 94.29% and 3.28 s with prosthesis use. After four weeks, the patient’s unassisted accuracy and reaction time improved to 100% and 1.23 s. Functional MRI study revealed activation of the left superior temporal lobe during face recognition task without prosthesis use and activation of the right precentral motor area with prosthesis use. The prosthesis could improve the patient’s performance by bypassing the brain area inefficient for facial recognition and employing the area more efficiently for the cognitive task.
Developing a Simple Score for Diagnosis of Acute Cholecystitis at the Emergency Department
Authors: Faikhongngoen Saowaluck , Chenthanakij Boriboon , Wittayachamnankul Borwon , Phinyo Phichayut , Wongtanasarasin Wachira
Published: September 2022

We aim to develop a diagnostic score for acute cholecystitis that integrates symptoms, physical examinations, and laboratory data to help clinicians for timely detection and early treatment of this disease. We retrospectively collected data from our database from 2010 to 2020. Patients with acute abdominal pain who underwent an ultrasound or computed tomography (CT) scan at the emergency department (ED) were included. Cases were identified by pathological, CT, or ultrasound reports. Non-cases were those who did not fulfill any of these criteria. Multivariable regression analysis was conducted to identify predictors of acute cholecystitis. The model included 244 patients suspected of acute cholecystitis. Eighty-six patients (35.2%) were acute cholecystitis confirmed cases. Five final predictors remained within the reduced logistic model: age < 60, nausea and/or vomiting, right upper quadrant pain, positive Murphy’s sign, and AST ≥ two times upper limit of normal. A practical score diagnostic performance was AuROC 0.74 (95% CI, 0.67–0.81). Patients were categorized with a high probability of acute cholecystitis at score points of 9–12 with a positive likelihood ratio of 3.79 (95% CI, 1.68–8.94). ED Chole Score from these five predictors may aid in diagnosing acute cholecystitis at ED. Patients with an ED Chole Score >8 should be further investigated.
Lung Ultrasound Monitoring of Legionella Ventilator-Associated Pneumonia in an Extremely Low-Birth-Weight Infant
Authors: Liu Jing , Qiu Ru-Xin
Published: September 2022

Ventilator-associated pneumonia (VAP) is a common complication of different severe lung diseases that need to be treated with mechanical ventilation in newborn infants. However, VAP due to Legionella pneumophila infection is rarely reported in the literature, especially in extremely low-birth-weight (ELBW) infants. Lung ultrasound (LUS) has been used in the diagnosis of neonatal pneumonia, but there is no literature on the ultrasound characteristics of Legionella-VAP in ELBW infants. This paper introduced the typical LUS findings of Legionella-VAP in ELBW infants, which mainly includes severe and large-area lung consolidation and atelectasis in the bilateral lungs; whether there is blood supply in the consolidated area has an important reference value for predicting the prognosis. In addition, the treatment and management experience were also introduced together, thereby helping us to deepen the understanding of the disease and avoid missed diagnoses.
Diagnosis and Pattern Identification of Intrathoracic Malignant Melanoma Metastasis: A Retrospective Single Center Analysis
Authors: Fontana Matteo , Rossi Laura , Ghinassi Federica , Piro Roberto , Scelfo Chiara , Taddei Sofia , Casalini Eleonora , Ruggiero Patrizia , Pollorsi Chiara , Beghe’ Bianca , Longo Caterina , Facciolongo Nicola
Published: September 2022

The lung is a frequent site of secondary malignancies. Melanoma is a malignant tumor originating from melanocytes, that accounts for the majority of death related to skin cancers. In advanced stages, it can also present with intrathoracic metastasis, particularly in the lungs, but infrequent intrathoracic manifestations are possible. A retrospective analysis of the cases referred to the pulmonary endoscopy unit of the hospital of Reggio Emilia in the last 10 years (since December 2012) was carried out, discovering 17 cases of melanoma metastasis with thoracic localizations, either with or without a diagnosis of primary melanoma. Four repetitive patterns of clinical-radiological presentation have been identified and described through the same number of paradigmatic clinical cases: nodal involvement (35%), lung mass(es) (41%), diffuse pulmonary involvement (12%), and pleural involvement (12%). These different presentations imply the use of different diagnostic techniques, with an overall high diagnostic yield (87.5%). Finally, a brief analysis of survival based on the pattern of presentation has been performed, finding no statistically significant differences between the four groups at metastasis diagnosis (p-value = 0.06, median survival of respectively 54, 8, 9, and 26 months from metastasis diagnosis), while there is a significant difference considering patients with lung involvement versus nodal/pleural involvement (p = 0.01).
Usefulness of Practitioner-Led Pancreatic Cancer Screening
Authors: Matsumoto Kazuya , Kushiyama Yoshinori , Izumi Akio , Ohnishi Koji , Miura Masahiko , Ohuchi Yasufumi , Hori Ikuko , Nakamura Tomonori , Hori Kotaro , Koshino Kenji , Kobayashi Junko , Yoshino Nagisa , Hoshino Ushio , Okumura Takekiyo , Tanimura Takashi , Tanaka Shinsuke , Tanaka Shino , Nabika Tadashi , Nozu Tatsuaki , Wakatsuki Yutaka , Katayama Syunsuke , Yoshioka Shizue , Ito Kenichi , Uchida Akiko , Yuhara Noriji , Noma Hisashi , Isomoto Hajime
Published: September 2022

The 5-year survival rate for pancreatic cancer has improved (10%) but remains worse than that for other cancers. Early pancreatic cancer diagnosis is challenging, and delayed diagnosis can delay treatment, which impairs survival. Practitioners do not promptly refer cases to a general hospital, causing delayed discovery. Herein, we aimed to examine the usefulness of the Pancreatic Cancer Project in Matsue, whose objective is to detect pancreatic cancer in patients presenting at any medical institution in Matsue City. Clinical data were extracted from medical records, and abdominal ultrasonography and tumor marker blood level assessments were performed (n = 234; median age, 71 [range, 41–94] years; 51% male). Cases with abnormal abdominal ultrasonography or blood test findings were referred for specialist imaging and followed up. The pancreatic cancer detection rate was 6.0% (n = 14); all cases were referred to a general hospital by practitioners within 1 month. Patients had stage IA (n = 1), IIA (n = 6), IIB (n = 2), III (n = 1), and IV (n = 4) disease. Overall, pancreatic cancer could be detected at an earlier stage (I–II), but referral to a general hospital by visiting practitioners should be prompt. The Pancreatic Cancer Project in Matsue may help improve the detection and prognosis of pancreatic cancer.
SARS-CoV-2 Infection during Pregnancy and Histological Alterations in the Placenta
Authors: Pacu Irina , Roșu George-Alexandru , Zampieri Giorgia , Rîcu Anca , Matei Alexandra , Davițoiu Ana-Maria , Vlădescu Teodora , Ionescu Crîngu Antoniu
Published: September 2022

(1) Background: Despite the high number of cases of COVID-19 during pregnancy, SARS-CoV-2 congenital infection is rare. The role of the placenta as a barrier preventing the transmission of SARS-CoV-2 from the mother to the fetus is still being studied. This study aimed to evaluate the impact of SARS-CoV-2 infection on placental tissue. (2) Methods: This was a transversal monocentric observational study. In the study, we included pregnant women with COVID-19 who delivered at “Sfântul Pantelimon” Clinical Emergency Hospital between 1 April 2020 and 30 March 2022. Histological analyses, both macroscopic and microscopic, were performed for placentas that came from these cases. (3) Results: To date, a characteristic placental lesion has not been clearly demonstrated, but most findings include features of maternal and fetal vascular malperfusion, which probably reflect the reduction in placental blood flow due to low oxygen level from the hypoxic respiratory disease and underlying hypercoagulable state induced by the COVID-19 infection. (4) Conclusions: The histopathological aspects found in placentas that came from COVID-19-positive pregnant women are common for many other diseases, but when they are found together, they are highly suggestive for viral infectious involvement of the placenta.
Autonomous Surveying of Plantation Forests Using Multi-Rotor UAVs
Authors: Lin Tzu-Jui , Stol Karl A.
Published: September 2022

Modern plantation forest procedures still rely heavily on manual data acquisition in the inventory process, limiting the quantity and quality of the collected data. This limitation in collection performance is often due to the difficulty of traversing the plantation forest environment on foot. This work presents an autonomous system for exploring plantation forest environments using multi-rotor UAVs. The proposed method consists of three parts: waypoint selection, trajectory generation, and trajectory following. Waypoint selection is accomplished by estimating the rows’ locations within the environment and selecting points between adjacent rows. Trajectory generation is completed using a non-linear optimization-based constant speed planner and the following is accomplished using a model predictive control approach. The proposed method is tested extensively in simulation against various procedurally generated forest environments, with results suggesting that it is robust against variations within the scene. Finally, flight testing is performed in a local plantation forest, demonstrating the successful application of our proposed method within a complex, uncontrolled environment.
A Framework for Soil Salinity Monitoring in Coastal Wetland Reclamation Areas Based on Combined Unmanned Aerial Vehicle (UAV) Data and Satellite Data
Authors: Xie Lijian , Feng Xiuli , Zhang Chi , Dong Yuyi , Huang Junjie , Cheng Junkai
Published: September 2022

Soil salinization is one of the most important causes of land degradation and desertification, often threatening land management and sustainable agricultural development. Due to the low resolution of satellites, fine mapping of soil salinity cannot be completed, while high-resolution images from UAVs can only achieve accurate mapping of soil salinity in a small area. Therefore, how to realize fine mapping of salinity on a large scale based on UAV and satellite data is an urgent problem to be solved. Therefore, in this paper, the most relevant spectral variables for soil salinity were firstly determined using Pearson correlation analysis, and then the optimal inversion model was established based on the screened variables. Secondly, the feasibility of correcting satellite data based on UAV data was determined using Pearson correlation analysis and spectral variation trends, and the correction of satellite data was completed using least squares-based polynomial curve fitting for both UAV data and satellite data. Finally, the reflectance received from the vegetated area did not directly reflect the surface reflectance condition, so we used the support vector machine classification method to divide the study area into two categories: bare land and vegetated area, and built a model based on the classification results to realize the advantages of complementing the accurate spectral information of UAV and large-scale satellite spectral data in the study areas. By comparing the modeling inversion results using only satellite data with the inversion results based on optimized satellite data, our method framework could effectively improve the accuracy of soil salinity inversion in large satellite areas by 6–19%. Our method can meet the needs of large-scale accurate mapping, and can provide the necessary means and reference for soil condition monitoring.
Active Disturbance Rejection Control for the Robust Flight of a Passively Tilted Hexarotor
Authors: Orozco Soto Santos Miguel , Cacace Jonathan , Ruggiero Fabio , Lippiello Vincenzo
Published: September 2022

This paper presents a robust control strategy for controlling the flight of an unmanned aerial vehicle (UAV) with a passively (fixed) tilted hexarotor. The proposed controller is based on a robust extended-state observer to estimate and reject internal dynamics and external disturbances at runtime. Both the stability and convergence of the observer are proved using Lyapunov-based perturbation theory and an ultimate bound approach. Such a controller is implemented within a highly realistic simulation environment that includes physics motors, showing an almost identical behavior to that of a real UAV. The controller was tested for flying under normal conditions and in the presence of different types of disturbances, showing successful results. Furthermore, the proposed control system was compared with another robust control approach, and it presented a better performance regarding the attenuation of the error signals.
Evaluation of Geometric Attractor Structure and Recurrence Analysis in Professional Dancers
Authors: Błażkiewicz Michalina
Published: September 2022

Background: Human motor systems contain nonlinear features. The purpose of this study was to evaluate the geometric structure of attractors and analyze recurrence in two different pirouettes (jazz and classic) performed by 15 professional dancers. Methods: The kinematics of the body’s center of mass (CoM) and knee of the supporting leg (LKNE) during the pirouette were measured using the Vicon system. A time series of selected points were resampled, normalized, and randomly reordered. Then, every second time series was flipped to be combined with other time series and make a long time series out of the repetitions of a single task. The attractors were reconstructed, and the convex hull volumes (CHV) were counted for the CoM and LKNE for each pirouette in each direction. Recurrence quantification analysis (RQA) was used to extract additional information. Results: The CHVs calculated for the LKNE were significantly lower for the jazz pirouette. All RQA measures had the highest values for LKNE along the mediolateral axis for the jazz pirouette. This result underscores the high determinism, high motion recurrence, and complexity of this maneuver. Conclusions: The findings offer new insight into the evaluation of the approximation of homogeneity in motion control. A high determinism indicates a highly stable and predictive motion trajectory.
Comparative Study of the Thermal and Hydraulic Performance of Supercritical CO2 and Water in Microchannels Based on Entropy Generation
Authors: Tu Yi , Zeng Yu
Published: September 2022

The excellent thermophysical properties of supercritical CO2 (sCO2) close to the pseudocritical point make it possible to replace water as the coolant of microchannels in application of a high heat flux radiator. The computational fluid dynamics (CFD) method verified by experimental data is used to make a comparison of the thermal hydraulic behavior in CO2-cooled and of water-cooled microchannels. The operation conditions of the CO2-based cooling cases cover the pseudocritical point (with the inlet temperature range of 306~320 K and the working pressure of 8 MPa), and the water-based cooling case has an inlet temperature of 308 K at the working pressure of 0.1 MPa. The channel types include the straight and zigzag microchannels with 90°, 120°, and 150° bending angles, respectively. The analysis result shows that, only when the state of CO2 is close to the pseudocritical point, the sCO2-cooled microchannel is of a higher average heat convection coefficient and a lower average temperature of the heated surface compared to the water-cooled microchannel. The entropy generation rate of the sCO2-cooled microchannel can reach 0.58~0.69 times that of the entropy generation rate for the water-cooled microchannel. Adopting the zigzag structure can enhance the heat transfer, but it does not improve the comprehensive performance represented by the entropy generation rate in the sCO2-cooled microchannel.
An Evaluation of the Treatment of Full-Thickness Wounds Using Adipose Micro-Fragments within a Liquid Dermal Scaffold
Authors: Sheikh-Oleslami Sara , Hassanpour Ida , Amiri Nafise , Jalili Reza , Kilani Ruhangiz Taghi , Ghahary Aziz
Published: September 2022

In full-thickness wounds, inflammation, lack of matrix deposition, and paucity of progenitor cells delay healing. As commercially available solid (sheet) scaffolds are unable to conform to wounds of varying shapes and sizes, we previously generated a nutritious, injectable, liquid skin substitute that can conform to wound topography. In combination with adipose micro-fragments as a viable source of progenitor cells, a composite, in situ forming skin substitute was tested for the treatment of silicon ring splinted full-thickness wounds in rats. The in vitro survivability and migratory capacity of adipocytes derived from rat micro-fragmented fat cultured in our scaffold was examined with a Live/Dead assay, showing viability and migration after 7 and 14 days. In vivo, the efficacy of our scaffold alone (LDS) or with adipose micro-fragments (LDS+A) was compared to a standard dressing protocol (NT). LDS and LDS+A showed ameliorated wound healing, including complete epithelialization and less immune cell infiltration, compared to the NT control. Our findings demonstrate that a 3D liquid skin scaffold is a rich environment for adipocyte viability and migration, and that the addition of adipose micro-fragments to this scaffold can be used as a rich source of cells for treating full-thickness wounds.
Misuse of Deferred Taxes in Portugal
Authors: Moniz Alexandre , Couto Gualter , Pimentel Pedro
Published: September 2022

Financial transparency is essential for stakeholders to make decisions, ensuring a correct amount of tax is paid to the state. Many companies have opted for the recognition of deferred tax assets to present a different result, but there is scant literature. This study investigates the impact of recognizing deferred tax assets and their contribution to earnings manipulation, together with the effect of the 2008 global financial crisis. Using data from 29 companies listed on the stock exchange and headquartered in Portugal between 2007 and 2012, formalize correlation tests and a linear regression model were used, concluding that more indebted companies tend to recognize more deferred tax assets, paying less tax to the state and that for the sample size and study period, it was not possible to conclude the impact of the 2008 financial crisis.
E-Learning Courses Evaluation on the Basis of Trainees’ Feedback on Open Questions Text Analysis
Authors: Tsimaras Dimitrios O. , Mystakidis Stylianos , Christopoulos Athanasios , Zoulias Emmanouil , Hatzilygeroudis Ioannis
Published: September 2022

Life-long learning is a necessity associated with the requirements of the fourth industrial revolution. Although distance online education played a major role in the evolution of the modern education system, this share grew dramatically because of the COVID-19 pandemic outbreak and the social distancing measures that were imposed. However, the quick and extensive adoption of online learning tools also highlighted the multidimensional weaknesses of online education and the needs that arise when considering such practices. To this end, the ease of collecting digital data, as well as the overall evolution of data analytics, enables researchers, and by extension educators, to systematically evaluate the pros and cons of such systems. For instance, advanced data mining methods can be used to find potential areas of concern or to confirm elements of excellence. In this work, we used text analysis methods on data that have emerged from participants’ feedback in online lifelong learning programmes for professional development. We analysed 1890 Greek text-based answers of participants to open evaluation questions using standard text analysis processes. We finally produced 7-gram tokens from the words in the texts, from which we constructed meaningful sentences and characterized them as positive or negative. We introduced a new metric, called acceptance grade, to quantitatively evaluate them as far as their positive or negative content for the online courses is concerned. We finally based our evaluation on the top 10 sentences of each category (positive, negative). Validation of the results via two external experts and data triangulation showed an accuracy of 80%.
Planning Underground Power Distribution Networks to Minimize Negative Visual Impact in Resilient Smart Cities
Authors: Pabón Francisco , Inga Esteban , Campaña Miguel
Published: September 2022

This paper presents the application of heuristic methods in conjunction with graph theory in the optimal routing and sizing of underground distribution networks in georeferenced (GIS) scenarios, which are modeled and simulated in the advanced engineering tool CYMDIST. The tool allows the deployment of underground networks to facilitate the design, planning, and implementation of networks, taking into consideration distribution company regulations, thus allowing overview and future planning in the growth of distribution systems. Further, this method is modeled in real georeferenced scenarios, where the coverage of the electric service to all users connected to the network is guaranteed according to population density and energy demand while minimizing the number of distribution transformers used. The applied method considers the location of transformer chambers, the capacity and coverage of the distribution transformers, and the voltage drops over the line section, which should not exceed 5% of the nominal value as described in the ANSI C84.1 standard. Consequently, to verify the efficiency of the applied method, the limitations and restrictions of the mathematical model are considered, as well as the characteristics of the georeferenced system and a comparison with different research studies that address the subject presented here. In addition, supply coverage is guaranteed to be 100%.
A Framework for the Classification and Evaluation of Game Mechanics for Virtual Reality Games
Authors: Vlahovic Sara , Suznjevic Mirko , Skorin-Kapov Lea
Published: September 2022

In broad terms, UX design is concerned with minimizing the workload neccessary for the user to interact with the system. In gaming, however, the system is supposed to provide a level of challenge to keep the player entertained, along with offering specific tools and mechanisms of interaction that are not commonly found across other use-cases. When talking about virtual reality (VR), numerous sources have discussed the optimization of interaction techniques, but there is a gap in research on the subject of gaming-specific VR interaction design, which we aimed to address in this paper. Focusing on the diversity of VR gaming, we introduced the term “interaction mechanics” and provided a taxonomy of interaction mechanics based on several criteria. Based on this taxonomy, we highlighted multiple target-related, task-related, and tool-related parameters that may influence the quality of interaction mechanics. Lastly, we presented the INTERACT framework, which was created to serve as a conceptual foundation for creating applications to be used as tools for user research, and used it to design an application aimed at facilitating the evaluation of interaction mechanics quality.
A Novel Airspace Planning Algorithm for Cooperative Target Localization
Authors: Mao Yi , Zhu Yongwen , Tang Zhili , Chen Zhijie
Published: September 2022

With the development of modern electromagnetic stealth technology and ARM, traditional active radar detection cannot accomplish its detection mission, limited by its ability. Relying on such superior advantages such as imperceptibility, anti-electromagnetic interference and electromagnetic stealth, passive transducers are playing an indispensable and significant role in situation awareness. While, in addition to different passive transducer localization modes and solutions of target’s location, the reasonable planning and optimal layout of passive transducers’ location are other major factors affecting the precision of localization. Planning an optimal airspace for passive transducers is the key problem to improve the monitoring efficiency. This paper proposes the optimal layout algorithm for the cooperative platform in the space based on the geometrical relationship of cooperative localization. For example, the principle of direction location in traditional methods is simple: only two passive sensors can work, but the location accuracy of long-distance targets is low. At the same time, TDOA (Time Difference Of Arrival) location has high accuracy and good stability, but it needs at least three passive sensors to work together, which requires the most resources. In this paper, a platform optimization layout algorithm based on direction and TDOA hybrid positioning is proposed. Compared with direction positioning, it improves the long-distance positioning accuracy, reduces the number of sensors required for TDOA positioning, and reduces the resource occupancy rate. However, the TDOA positioning data mixed with direction positioning data inevitably leads to the decline of overall accuracy. In order to solve these difficulties, the weighted least square method is used to optimize the accuracy. The simulation shows that, within the designated target airspace, the optimal action airspace can be generated automatically based on the platforms’ cooperation mode. If there is no resource limitation, the airspace planning based on TDOA positioning has the highest accuracy for the target. However, in practical application, considering the resource limitation, the hybrid positioning of direction and TDOA can also meet the requirements of high accuracy and high stability. The average error is reduced by more than 45% compared with direction positioning, and the airspace occupancy is reduced by more than 30% compared with TDOA positioning. The goal of minimizing the scope of platform airspace planning is realized.
Inverted Microstrip Gap Waveguide Coplanar EBG Filter for Antenna Applications
Authors: Inclán-Sánchez Luis
Published: September 2022

The possibility of making compact stopband filters using coplanar-coupled EBG resonators in inverted microstrip gap waveguide technology is studied in this work. To do this, the filtering characteristics of different configurations of mushroom-type elements are shown in which the short-circuit element is placed on the edge of the resonator’s patch. The behavior of the structure as well as its main advantages such as: low losses, self-packaging, low level of complexity, flexibility and easy design are illustrated in the paper. To evaluate the possibility of integrating these structures in gap waveguide planar antennas feeding networks, a 5-cell EBG filter was designed and built at the X band. The proposed filter reached a maximum rejection level of −35.4 dB, had a stopband centered at 9 GHz and a relative fractional bandwidth below −20 dB of 10.6%. The new compact filter presented a flat passband in which it was well matched and had low insertion losses that, including the connectors, were close to 1.5 dB in most of the band. These results are enough to improve low-complexity future antenna designs with filter functionalities in this technology.
Dynamic Modeling and Investigation of a Tunable Vortex Bladeless Wind Turbine
Authors: Bahadur Issam
Published: September 2022

This paper investigates the dynamics of an electromagnetic vortex bladeless wind turbine (VBWT) with a tunable mechanism. The tunable mechanism comprises a progressive-rate spring that is attached to an oscillating magnet inside an electromagnetic coil. The spring stiffness is progressively adjusted as the wind speed changes to tune the turbine fundamental frequency to match the shedding frequency of the vortex-induced vibration (VIV) due to the wind flow crossing over the oscillating mast. Coupled nonlinear equations of motion of the tunable turbine are developed using the lumped-mass representation and Lagrange formulation. Numerical results show that the tunable turbine performs effectively beyond a threshold wind speed. An analytical expression of the threshold speed is derived based on the mechanical fundamental frequency of the turbine. The analytical results are in reasonable agreement with the numerical evaluations. At a given wind speed past the threshold, the tunable turbine has an optimum spring stiffness at which the output power is maximum. Numerical studies also show that the output power of the 2 m long tunable turbine is tens of times larger in comparison to a conventional bladeless turbine. For example, at a wind speed of 4.22 m/s, the output rms power of the tunable turbine is around 1105 mW versus 17 mW of the conventional VBWT. The power can be further maximized at an optimum external load. This research work demonstrated the feasibility and merits of the proposed tunable mechanism to enhance the overall performance of the bladeless wind turbine.
Carbon Dioxide Assisted Conversion of Hydrolysis Lignin Catalyzed by Nickel Compounds
Authors: Medvedev Artem A. , Beldova Daria A. , Kalmykov Konstantin B. , Kravtsov Alexey V. , Tedeeva Marina A. , Kustov Leonid M. , Dunaev Sergey F. , Kustov Alexander L.
Published: September 2022

In this work, hydrolysis lignin with nickel compounds deposited on the surface was prepared. The resulting material was introduced into the process of carbon dioxide assisted conversion and the catalytic activity of the deposited nickel compounds in this reaction was evaluated. Use of the obtained catalytic system increases CO2 conversion by more than 30% in the temperature range 450–800 °C. After the conversion process, the material was subjected to a study using a variety of physico-chemical analysis methods (TEM, SEM-EDX, and X-ray phase analysis). Physico-chemical methods of analysis of a sample calcined at 300 °C to decompose nickel nitrate revealed NiO nanoparticles with an average particle size of 16.9 nm.
Analysis on the Effect of Obstruction on Sprinkler Skipping in Air Conditioner Room Fire
Authors: Kim Ji Tae , Nam Jun Suk , Kim Ryang Hoon , Kim Seung Yeon , Ryou Hong Sun
Published: September 2022

Sprinkler skipping is an important issue in fire spread. In general, two sprinklers are installed in air conditioner rooms at the ceiling and 30 cm below to avoid spray failure by energy recovery ventilator in the ceiling. However, there is a problem in that sprinkler skipping occurs in the air conditioner room. In this study, the sprinkler skipping phenomenon was analyzed through numerical analysis and the applicability of the open type of sprinkler operation method was reviewed. As a result, when the upper sprinkler works, sprinkler skipping occurred in all cases. The lower sprinkler shall not rise above the operating temperature of 68.3 °C with a maximum temperature of 65 °C. In particular, the spray failure caused by the energy recovery ventilator reduces the sprinkler head temperature by more than 8 °C by concentrating the spray droplets. As an open type, simultaneous operation of two sprinklers is capable of obtaining an appropriate fire extinguishing effect by covering the fire source with the spray of the lower sprinkler. The research results are expected to help in fire protection in buildings such as modern apartments with air-conditioned rooms.
Recovery of Residual Carbon from Ti-Extraction Blast Furnace Slag by Flotation with Simultaneous Dechlorination
Authors: You Hao , Sun Hongjuan , Peng Tongjiang , Qin Yating , Tang Song
Published: September 2022

Ti-extraction blast furnace slag (EBFS) is a secondary slag produced by titanium extraction of titanium-bearing blast furnace slag (TBBFS), which is challenging to be used directly because of its residual carbon and chlorine. This study was performed to recover the residual carbon and remove chlorine from EBFS by froth flotation. The finely ground EBFS (FEBFS) contained graphitized carbon and khamrabaevite and had a 10.19% loss on ignition (LOI) and 5.52% Cl. The graphitized carbon was mainly recovered by flotation rather than khamrabaevite. Graphitized carbon appeared as flakes embedded in or stacked on the surface of the concentrate grains. The irregular-shaped particles were amorphous aluminosilicate glasses, whose presence adversely affected the quality and performance of the flotation concentrate. The Cl contents of the flotation concentrate and tailings obtained under the optimized flotation conditions were significantly reduced to 1.17% and 0.4%, respectively. The dechlorination efficiency reached 71.56%. Meanwhile, the LOI of flotation tailing was reduced to 1.32% and the carbon recovery was 84.79%. Froth flotation could recover residual carbon and remove chlorine from EBFS simultaneously, a novel way to deal with EBFS as a resource and harmless process.
Design and Implementation of Real-Time Kitchen Monitoring and Automation System Based on Internet of Things
Authors: Hassan Ch Anwar Ul , Iqbal Jawaid , Khan Muhammad Sufyan , Hussain Saddam , Akhunzada Adnan , Ali Mudabbir , Gani Abdullah , Uddin Mueen , Ullah Syed Sajid
Published: September 2022

Automation can now be found in nearly every industry. However, home automation has yet to reach Pakistan. This paper presents an Internet of Things smart kitchen project that includes automation and monitoring. In this project, a system was developed that automatically detects the kitchen temperature. It also monitors the humidity level in the kitchen. This system includes built-in gas detection sensors that detect any gas leaks in the kitchen and notify the user if the gas pressure in the kitchen exceeds a certain level. This system also allows the user to remotely control appliances such as freezers, ovens, and air conditioners using a mobile phone. The user can control gas levels using their phone with this system. In this paper, the ESP32, DHT11 Sensor, 5 V Relay X 8, and MQ-135 gas sensors create a smart kitchen by controlling the temperature, managing humidity, and detecting gas leakage. The system was built on an Arduino board that is connected to the Internet. The hardware was integrated and programmed using an Arduino, and a user Android application was developed. The project’s goal is to allow any Android smartphone to remotely control devices. This method is commonly used in homes, businesses, and grocery stores. Users will be able to control all of their instruments from anywhere, including switches, fans, and lights. Furthermore, simulation was performed using Matlab2016b on multiple houses. In the simulation, not only was the kitchen considered, but also two, four, and six houses. Each house has two bedrooms, one living room, one guest room, two bathrooms, and one kitchen. The results revealed that using this system will have a scientifically significant impact on electricity consumption and cost. In the case of the houses, the cost was USD 33.32, 32.64, 22.32, and 19.54 for unscheduled, two, four, and six houses, respectively. Thus, it was observed that the cost and power are directly proportional to each other. The results reveal that the proposed solution efficiently reduces the cost as compared to that of unscheduled houses.
Faulty Operation of Coils’ and Humidifier Valves in a Typical Air-Handling Unit: Experimental Impact Assessment of Indoor Comfort and Patterns of Operating Parameters under Mediterranean Climatic Conditions
Authors: Rosato Antonio , Guarino Francesco , El Youssef Mohammad , Capozzoli Alfonso , Masullo Massimiliano , Maffei Luigi
Published: September 2022

Data-driven Automated Fault Detection and Diagnosis (AFDD) are recognized as one of the most promising options to improve the efficiency of Air-Handling Units (AHUs). In this study, the field operation of a typical single-duct dual-fan constant air volume AHU is investigated through a series of experiments carried out under Mediterranean (southern Italy) climatic conditions considering both fault-free and faulty scenarios. The AHU performances are analyzed while artificially introducing the following five different typical faults: (1) post-heating coil valve stuck at 100% (always open); (2) post-heating coil valve stuck at 0% (always closed); (3) cooling coil valve stuck at 100% (always open); (4) cooling coil valve stuck at 0% (always closed); (5) humidifier valve stuck at 0% (always closed). The measured faulty data are compared against the corresponding fault-free performance measured under the same boundary conditions with the aim of assessing the faults’ impact on both thermal/hygrometric indoor conditions, as well as patterns of 16 different key operating parameters. The results of this study can help building operators and facility engineers in identifying faults’ symptoms in typical AHUs and facilitate the related development of new AFDD tools.
Heterogeneous Effect of “Eco-Friendly” Dwellings on Transaction Prices in Real Estate Market in Portugal
Authors: Koengkan Matheus , Fuinhas José Alberto
Published: September 2022

The main objective of this research is to assess the impact of energy certificate ratings (EPCs) on the value per m2 of Portuguese housing sales. Data from 289 Portuguese municipalities between 2014 and 2019, analysed with a fixed effects panel and method of moments quantile regression, were used. EPCs with high energy efficiency ratings (e.g., A+, A, B, and B-) are used as a proxy for dwellings with “green” or “environmentally friendly” certificates. On the other hand, ratings with a low energy efficiency (e.g., C, D, E, and F) are used as a proxy for dwellings with “non-green” or “not environmentally friendly” certificates. The results support that EPCs associated with green housing increase the value per m2 of housing sales, and those associated with non-green housing decrease the sales value. It was also found that municipal GDP, tax/financial incentive policies for energy efficiency, and the number of completed dwellings in new constructions for family housing will increase sales value. On the other hand, credit agreements and completed reconstructions reduce sales value. Lastly, the results and outgrowths of this study will support the policymakers and governments in developing consistent policies and initiatives that promote the “green” or “eco-friendly” dwellings in Portugal or in similar economies.
A Lead-Free Piezoelectric Fiber Generator with a High Energy Conversion Constant Material
Authors: Kim Kyung-Bum , Lee Jaegeun
Published: September 2022

This paper introduces a fiber generator using PVDF with a high-performance lead-free piezoelectric ceramic as filler. The piezoelectric ceramic filler was Ba0.84Ca0.16Ti0.90Zr0.10O3 + CuO 0.25 wt% (BCTZC0.25) sintered at 1550 °C. The BCTZC0.25 has an improved high-energy conversion constant (d33 × g33). The fiber generator made of PVDF/BCTZC0.25 composite fiber showed 1.6 times better piezoelectric power generation performance compared to a pure PVDF fiber generator. The PVDF/BCTZC0.25 fiber generator produced an output voltage of 1.9 V at 4 Hz. Hence, we successfully demonstrated that a composite fiber generator that uses piezoelectric ceramics which are harmless to the human body can outperform a pure PVDF fiber generator.
Comparison of Impact on Turbine Shafts Torsional Behavior for Integration of Two Types of Wind Farm into a Series-Compensated Transmission System
Authors: Lin Chi Hsiang
Published: September 2022

Deep decarbonization is the goal of modern power systems, so it is inevitable that large-scale wind farms will be integrated into systems. This also gives rise to many problems, which have been studied in detail in the literature. However, these studies basically have two deficiencies. One is to assume that traditional generator units are fully loaded, and the other is not to compare the differences in the impact of different types of wind farm. This paper discusses these two points in detail. Taking a series-compensated transmission system as the research object, and assuming that the wind farm only replaces part of the power of the traditional generator unit in the transition period of energy conversion, the difference between the torsional vibration behaviors of the traditional unit caused by adopting different types of wind farm is discussed. The results of the study show that the impact of integration of the type 3 wind farm is dominated by the induction generator effect of doubly fed induction generator units. The penetration rate as low as 19% could cause instability. However, the paralleled metal-oxide varistor can effectively improve the stability. For the type 4 wind farm, the dominant factor turns out to be the de-rating operations of the steam turbine generator unit. The allowable penetration rate depends on the turbine damping. When the turbine damping is sufficient, the penetration rate can be as high as 87.5%. In conclusion, in order to integrate wind farms into a series compensated transmission system, one should not only focus on the compensation factor to avoid the sub-synchronous torsional vibrations, but also pay attention to the types of wind farm as well as the penetration rate. The findings can be used as the decision-making basis for the integration of wind farms during the energy transition period.
Thermal Estimation and Thermal Design for Coupling Coils of 6.6 kW Wireless Electric Vehicle Charging System
Authors: Jiang Jinhai , Lan Yu , Zhang Ziming , Zhou Xingjian , Song Kai
Published: September 2022

Wireless electric vehicle charging technology is developing in the direction of high power levels. However, more generated heat brought by higher power will accelerate the system’s aging and can even lead to damage. An excellent thermal design for the magnetic coupler can reduce each part’s maximum temperature, ensuring long-term operation reliability. Therefore, in this article, the magnetic coupler’s thermal estimation and design are studied based on a 6.6 kW wireless electric vehicle charging system. First, the calculation method of internal resistance of a litz coil, core loss, and eddy current loss of a shielding aluminum plate are studied. Considering the influence of thermal fields on material properties, each part’s power loss calculation formula is further modified to improve the accuracy. After that, heat dissipation research is carried out. The heat dissipation measures, such as filling the surface of the shielding aluminum plate with thermal conductive silicone grease, are proposed. Finally, the effectiveness of the heat dissipation measures is verified by simulation and experiments. The experiment shows that the error between the power loss value of each part calculated by simulation and measured by the experiment is less than 15%, and the maximum temperature of the magnetic coupler is controlled below 80 °C.