bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensor Fusion for Simultaneous Estimation of In-Plane Permeability and Porosity of Fiber Reinforcement in Resin Transfer Molding
Authors: Qi Wei , Chiu Tzu-Heng , Kao Yi-Kai , Yao Yuan , Chen Yu-Ho , Yang Hsun , Wang Chen-Chieh , Hsu Chia-Hsiang , Chang Rong-Yeu
Published: June 2022

To meet the expectation of the industry, resin transfer molding (RTM) has become one of the most promising polymer processing methods to manufacture fiber-reinforced plastics (FRPs) with light weight, high strength, and multifunctional features. The permeability and porosity of fiber reinforcements are two of the primary properties that control the flow of resin in fibers and are critical to numerical simulations of RTM. In the past, various permeability measurement methods have been developed in the literature. However, limitations still exist. Furthermore, porosity is often measured independently of permeability. As a result, the two measurements do not necessarily relate to the same entity, which may increase the time and labor costs associated with experiments and affect result interpretation. In this work, a measurement system was developed by fusing the signals from capacitive sensing and flow visualization, based on which a novel algorithm was developed. Without complicated sensor design or expensive instrumentation, both in-plane permeability and porosity can be simultaneously estimated. The feasibility of the proposed method was illustrated by experiments and verified with numerical simulations.
Numerical Analysis of Micro-Residual Stresses in a Carbon/Epoxy Polymer Matrix Composite during Curing Process
Authors: Gonçalves Paulo Teixeira , Arteiro Albertino , Rocha Nuno , Pina Luis
Published: June 2022

The manufacturing process in thermoset-based carbon fiber-reinforced polymers (CFRPs) usually requires a curing stage where the material is transformed from a gel state to a monolithic solid state. During the curing process, micro-residual stresses are developed in the material due to the different chemical–thermal–mechanical properties of the fiber and of the polymer, reducing the mechanical performance of the composite material compared to the nominal performance. In this study, computational micromechanics is used to analyze the micro-residual stresses development and to predict its influence on the mechanical performance of a pre-impregnated unidirectional CFRP made of T700-fibers and an aeronautical grade epoxy. The numerical model of a representative volume element (RVE) was developed in the commercial software Abaqus® and user-subroutines are used to simulate the thermo-curing process coupled with the mechanical constitutive model. Experimental characterization of the bulk resin properties and curing behavior was made to setup the models. The higher micro-residual stresses occur at the thinner fiber gaps, acting as triggers to failure propagation during mechanical loading. These micro-residual stresses achieve peak values above the yield stress of the resin 55 MPa, but without achieving damage. These micro-residual stresses reduce the transverse strength by at least 10%, while the elastic properties remain almost unaffected. The numerical results of the effective properties show a good agreement with the macro-scale experimentally measured properties at coupon level, including transverse tensile, longitudinal shear and transverse shear moduli and strengths, and minor in-plane and transverse Poisson’s ratios. A sensitivity analysis was performed on the thermal expansion coefficient, chemical shrinkage, resin elastic modulus and cure temperature. All these parameters change the micro-residual stress levels and reduce the strength properties.
A New Approach Utilizing Aza-Michael Addition for Hydrolysis-Resistance Non-Ionic Waterborne Polyester
Authors: Fu Hao , Gong Linbo , Gong Shuling
Published: June 2022

This work first synthesized a series of linear polyesters by step-growth polycondensation, then an amino-terminated hydrophilic polyether was grafted to the polyester as side-chains through aza-Michael addition to prepare a self-dispersible, non-ionic waterborne comb-like polyester (NWCPE). In contrast to traditional functionalization methods that usually require harsh reaction conditions and complex catalysts, the aza-Michael addition proceeds efficiently at room temperature without a catalyst. In this facile and mild way, the NWCPE samples with number-average molecular weight (Mn) of about 8000 g mol−1 were obtained. All dispersions showed excellent storage stability, reflected by no delamination observed after 6 months of storage. The NWCPE dispersion displayed better hydrolysis resistance than an ionic waterborne polyester, as was indicated by a more slight change in pH value and Mn after a period of storage. In addition, the film obtained after the NWCPE dispersion was cross-linked with the curing agent, it exhibited good water resistance, adhesion, and mechanical properties.
Degradation of Hydrogels Based on Potassium and Sodium Polyacrylate by Ionic Interaction and Its Influence on Water
Authors: Pinzon-Moreno Diego David , Maurate-Fernandez Isabel Rosali , Flores-Valdeon Yury , Neciosup-Puican Antony Alexander , Carranza-Oropeza María Verónica
Published: June 2022

Hydrogels are a very useful type of polymeric material in several economic sectors, acquiring great importance due to their potential applications; however, this type of material, similarly to all polymers, is susceptible to degradation, which must be studied to improve its use. In this sense, the present work shows the degradation phenomena of commercial hydrogels based on potassium and sodium polyacrylate caused by the intrinsic content of different types of potable waters and aqueous solutions. In this way, a methodology for the analysis of this type of phenomenon is presented, facilitating the understanding of this type of degradation phenomenon. In this context, the hydrogels were characterized through swelling and FTIR to verify their performance and their structural changes. Likewise, the waters and wastewaters used for the swelling process were characterized by turbidity, pH, hardness, metals, total dissolved solids, electrical conductivity, DLS, Z-potential, and UV-vis to determine the changes generated in the types of waters caused by polymeric degradation and which are the most relevant variables in the degradation of the studied materials. The results obtained suggest a polymeric degradation reducing the swelling capacity and the useful life of the hydrogel; in addition, significant physicochemical changes such as the emergence of polymeric nanoparticles are observed in some types of analyzed waters.
Grafted Pullulan Derivatives for Reducing the Content of Some Pesticides from Simulated Wastewater
Authors: Ghimici Luminita , Constantin Marieta , Nafureanu Maria-Magdalena
Published: June 2022

The goal of the current article was to obtain data regarding the application of a series of grafted pullulan derivatives, as flocculating agents, for removal of some pesticide formulations from model wastewater. The pullulan derivatives are cationic polyelectrolytes, with various content and length of grafted poly[(3-acrylamidopropyl)-trimethylammonium chloride] chains onto the pullulan (P-g-pAPTAC)]. The commercial pesticides are either fungicide (Bordeaux Mixture) (BM) or insecticides (Decis (Dc)—active ingredient Deltamethrin, Confidor Oil (CO)—active ingredient Imidacloprid, Confidor Energy (CE)—active ingredients Deltamethrin and Imidacloprid and Novadim Progress (NP)—active ingredient Dimethoate). The removal efficiency has been assessed by UV-Vis spectroscopy measurements as a function of some parameters, namely polymer dose, grafted chains content and length, pesticides concentration. The P-g-pAPTAC samples showed good removal efficacy at doseop, more than 94% for BM, between 84 and 90% for DC, CO and CE and around 93% for NP. The maximum percentage removal decreased with the pesticides (DC, CO, CE, NP) concentration declining; no effect of BM concentration in suspension on its removal efficiency process has been noted. Differences indicated by zeta potential and particle size distribution measurements regarding the pesticides removal mechanisms by pullulan derivatives (charge neutralization, bridging, etc.) are discussed.
Forms of Non/Religiosity in Slovakia after 1989
Authors: Tížik Miroslav
Published: June 2022

This study analyses in detail the dynamics of the development of different types of worldviews (religious and particularly non-religious) in Slovakia. It is based on the results of four censuses along with the European Values Study (EVS) conducted in Slovakia in 1991, 1999, 2008, and 2017. The basic analytical tool is the typological method based on data from the EVS. The results show that in Slovakia, among the large number of possible theoretical types of worldviews, only five are empirically present in an analysable quantity, two of which concern people without religious affiliation. The results show that in this latter group, which has remained around 25% over the long term in Slovakia, the majority are rather indifferent to religion and only about one-fifth of them (4.5% of the total population in 2017) are people who can be considered atheists.
Ionospheric Behavior during the 10 June 2021 Annular Solar Eclipse and Its Impact on GNSS Precise Point Positioning
Authors: Valdés-Abreu Juan Carlos , Díaz Marcos A. , Bravo Manuel , Báez Juan Carlos , Stable-Sánchez Yohadne
Published: June 2022

The main effects of the 10 June 2021 annular solar eclipse on GNSS position estimation accuracy are presented. The analysis is based on TEC measurements made by 2337 GNSS stations around the world. TEC perturbations were obtained by comparing results 2 days prior to and after the day of the event. For the analysis, global TEC maps were created using ordinary Kriging interpolation. From TEC changes, the apparent position variation was obtained using the post-processing kinematic precise point positioning with ambiguity resolution (PPP-AR) mode. We validated the TEC measurements by contrasting them with data from the Swarm-A satellite and four digiosondes in Central/South America. The TEC maps show a noticeable TEC depletion (<−60%) under the moon’s shadow. Important variations of TEC were also observed in both crests of the Equatorial Ionization Anomaly (EIA) region over the Caribbean and South America. The effects on GNSS precision were perceived not only close to the area of the eclipse but also as far as the west coast of South America (Chile) and North America (California). The number of stations with positioning errors of over 10 cm almost doubled during the event in these regions. The effects were sustained longer (∼10 h) than usually assumed.
Seaweed Habitats on the Shore: Characterization through Hyperspectral UAV Imagery and Field Sampling
Authors: Diruit Wendy , Le Bris Anthony , Bajjouk Touria , Richier Sophie , Helias Mathieu , Burel Thomas , Lennon Marc , Guyot Alexandre , Ar Gall Erwan
Published: June 2022

Intertidal macroalgal habitats are major components of temperate coastal ecosystems. Their distribution was studied using field sampling and hyperspectral remote mapping on a rocky shore of Porspoder (western Brittany, France). Covers of both dominating macroalgae and the sessile fauna were characterized in situ at low tide in 24 sampling spots, according to four bathymetric levels. A zone of ca. 17,000 m2 was characterized using a drone equipped with a hyperspectral camera. Macroalgae were identified by image processing using two classification methods to assess the representativeness of spectral classes. Finally, a comparison of the remote imaging data to the field sampling data was conducted. Seven seaweed classes were distinguished by hyperspectral pictures, including five different species of Fucales. The maximum likelihood (MLC) and spectral angle mapper (SAM) were both trained using image-derived spectra. MLC was more accurate to classify the main dominating species (Overall Accuracy (OA) 95.1%) than SAM (OA 87.9%) at a site scale. However, at sampling points scale, the results depend on the bathymetric level. This study evidenced the efficiency and accuracy of hyperspectral remote sensing to evaluate the distribution of dominating intertidal seaweed species and the potential for a combined field/remote approach to assess the ecological state of macroalgal communities.
New Reprocessing towards Life-Time Quality-Consistent Suomi NPP OMPS Nadir Sensor Data Records (SDR): Calibration Improvements and Impact Assessments on Long-Term Quality Stability of OMPS SDR Data Sets
Authors: Yan Banghua , Pan Chunhui , Beck Trevor , Jin Xin , Wang Likun , Liang Ding , Flynn Lawrence , Chen Junye , Huang Jingfeng , Buckner Steven , Zou Cheng-Zhi , Sun Ninghai , Lin Lin , Young Alisa , Zhou Lihang , Hao Wei
Published: June 2022

The Nadir Mapper (NM) and Nadir Profiler (NP) within the Ozone Mapping and Profiler Suites (OMPS) are ultraviolet spectrometers to measure Earth radiance and Solar irradiance spectra from 300–380 nm and 250–310 nm, respectively. The OMPS NM and NP instruments flying on the Suomi-NPP (SNPP) satellite have provided over ten years of operational Sensor Data Records (SDRs) data sets to support a variety of OMPS Environmental Data Record (EDR) applications. However, the discrepancies of quality remain in the operational OMPS SDR data prior to 28 June 2021 due to changes in calibration algorithms associated with the calibration coefficient look-up tables (LUTs) during this period. In this study, we present results for the newly (v2) reprocessed SNPP OMPS NM and NP SDR data prior to 30 June 2021, which uses consistent calibration tables with improved accuracy. Compared with a previous (v1) reprocessing, this new reprocessing includes the improvements associated with the following updated tables or error correction: an updated stray light correction table for the NM, an off-nadir geolocation error correction for the NM, an artificial offset error correction in the NM dark processing code, and biweekly solar wavelength LUTs for the NP. This study further analyzes the impact of each improvement on the quality of the OMPS SDR data by taking advantage of the existing OMPS SDR calibration/validation studies. Finally, this study compares the v2 reprocessed OMPS data sets with the operational and the v1 reprocessed data sets. The results demonstrate that the new reprocessing significantly improves the accuracy and consistency of the life-time SNPP OMPS NM and NP SDR data sets. It also advances the uniformity of the data over the dichroic range from 300 to 310 nm between the NM and NP. The normalized radiance differences at the same wavelength between the NM and NP observations are reduced from 0.001 order (v1 reprocessing) or 0.01 order (operational processing) to 0.001 order or smaller. The v2 reprocessed data are archived in the NOAA CLASS data center with the same format as the operational data.
Automatic Deployment of Convolutional Neural Networks on FPGA for Spaceborne Remote Sensing Application
Authors: Yan Tianwei , Zhang Ning , Li Jie , Liu Wenchao , Chen He
Published: June 2022

In recent years, convolutional neural network (CNN)-based algorithms have been widely used in remote sensing image processing and show tremendous performance in a variety of application fields. However, large amounts of data and intensive computations make the deployment of CNN-based algorithms a challenging problem, especially for the spaceborne scenario where resources and power consumption are limited. To tackle this problem, this paper proposes an automatic CNN deployment solution on resource-limited field-programmable gate arrays (FPGAs) for spaceborne remote sensing applications. Firstly, a series of hardware-oriented optimization methods are proposed to reduce the complexity of the CNNs. Secondly, a hardware accelerator is designed. In this accelerator, a reconfigurable processing engine array with efficient convolutional computation architecture is used to accelerate CNN-based algorithms. Thirdly, to bridge the optimized CNNs and hardware accelerator, a compilation toolchain is introduced into the deployment solution. Through the automatic conversion from CNN models to hardware instructions, various networks can be deployed on hardware in real-time. Finally, we deployed an improved VGG16 network and an improved YOLOv2 network on Xilinx AC701 to evaluate the effectiveness of the proposed deployment solution. The experiments show that with only 3.407 W power consumption and 94 DSP consumption, our solution achieves 23.06 giga operations per second (GOPS) throughput in the improved VGG16 and 22.17 GOPS throughput in the improved YOLOv2. Compared to the related works, the DSP efficiency of our solution is improved by 1.3–2.7×.
Evaluation of Field Applicability of High-Speed 3D Digital Image Correlation for Shock Vibration Measurement in Underground Mining
Authors: Seo Seunghwan , Ko Younghun , Chung Moonkyung
Published: June 2022

When combined with high-speed photography technology, the digital image correlation (DIC) method provides an excellent photographic image processing capability that can be used to convert the evolving full-field surface properties of structures to sets of two-dimensional (2D) or three-dimensional (3D) coordinate values. In this study, the applicability of the DIC method and high-speed cameras in underground mining was investigated by measuring the displacement and vibration of rock pillars caused by blasting. This technique is used extensively in engineering and is increasingly being applied to new fields. As a result of comparing the DIC results for blast vibration with the measured values of the contact sensor through field tests, the maximum displacement and vibration speed were found to be 86% and 93% accurate, respectively. In addition, the obtained values appeared similar to those predicted through numerical analysis. Field test results indicate that both methods yielded similar results. Therefore, it is concluded that it is feasible to use the DIC and high-speed camera to measure ground displacements and vibrations from blasting in underground mining. In addition, the system conditions required for blast vibration measurement were considered by comparing the accuracy with the existing measurement methods.
Can Satellite-Based Thermal Anomalies Be Indicative of Heatwaves? An Investigation for MODIS Land Surface Temperatures in the Mediterranean Region
Authors: Agathangelidis Ilias , Cartalis Constantinos , Polydoros Anastasios , Mavrakou Thaleia , Philippopoulos Kostas
Published: June 2022

In recent years, an exceptional number of record-shattering temperature extremes have been observed, resulting in significant societal and environmental impacts. The Mediterranean region is particularly thermally vulnerable, frequently suffering from intense and severe heatwaves. Using daily temperature observations from 58 weather stations (NOAA Global Historical Climatology Network daily database) in the Mediterranean area, past heatwave episodes were initially detected. A daily LST time series was developed using Land Surface Temperature (LST) products from Moderate Resolution Imaging Spectroradiometer (MODIS) (Terra & Aqua satellites) for a 19-year period (2002–2020) at the station locations. LST anomalies were identified using percentile-based indices. It was found that remotely sensed-based LST presents the potential for understanding and monitoring heatwave events, as surface thermal anomalies were generally indicative of heatwaves. Approximately 42% (39%) of heatwave days during daytime (nighttime) coincided with LST anomalies; conversely, 51% of daytime LST anomalies overlapped with the exact days of a heatwave (38% at night). Importantly, the degree of association was significantly higher for extremely hot days (up to an 80% match) and long-lasting heatwaves (up to an 85% match). Rising trends in frequency and duration were observed for both heatwaves and LST anomalies. The results advance the understanding of surface-atmosphere coupling during extreme temperature days and reflect the suitability of thermal remote sensing in heatwave preparedness strategies.
Noncontact and High-Precision Sensing System for Piano Keys Identified Fingerprints of Virtuosity
Authors: Oku Takanori , Furuya Shinichi
Published: June 2022

Dexterous tool use is typically characterized by fast and precise motions performed by multiple fingers. One representative task is piano playing, which involves fast performance of a sequence of complex motions with high spatiotemporal precision. However, for several decades, a lack of contactless sensing technologies that are capable of precision measurement of piano key motions has been a bottleneck for unveiling how such an outstanding skill is cultivated. Here, we developed a novel sensing system that can record the vertical position of all piano keys with a time resolution of 1 ms and a spatial resolution of 0.01 mm in a noncontact manner. Using this system, we recorded the piano key motions while 49 pianists played a complex sequence of tones that required both individuated and coordinated finger movements to be performed as fast and accurately as possible. Penalized regression using various feature variables of the key motions identified distinct characteristics of the key-depressing and key-releasing motions in relation to the speed and accuracy of the performance. For the maximum rate of the keystrokes, individual differences across the pianists were associated with the peak key descending velocity, the key depression duration, and key-lift timing. For the timing error of the keystrokes, the interindividual differences were associated with the peak ascending velocity of the key and the inter-strike variability of both the peak key descending velocity and the key depression duration. These results highlight the importance of dexterous control of the vertical motions of the keys for fast and accurate piano performance.
A Self-Regulating Power-Control Scheme Using Reinforcement Learning for D2D Communication Networks
Authors: Ban Tae-Won
Published: June 2022

We investigate a power control problem for overlay device-to-device (D2D) communication networks relying on a deep deterministic policy gradient (DDPG), which is a model-free off-policy algorithm for learning continuous actions such as transmitting power levels. We propose a DDPG-based self-regulating power control scheme whereby each D2D transmitter can autonomously determine its transmission power level with only local channel gains that can be measured from the sounding symbols transmitted by D2D receivers. The performance of the proposed scheme is analyzed in terms of average sum-rate and energy efficiency and compared to several conventional schemes. Our numerical results show that the proposed scheme increases the average sum-rate compared to the conventional schemes, even with severe interference caused by increasing the number of D2D pairs or high transmission power, and the proposed scheme has the highest energy efficiency.
A Comparison of a Novel Stretchable Smart Patch for Measuring Runner’s Step Rates with Existing Measuring Technologies
Authors: Verdel Nina , Drobnič Miha , Maslik Jan , Björnander Rahimi Klara , Tantillo Giorgio , Gumiero Alessandro , Hjort Klas , Holmberg Hans-Christer , Supej Matej
Published: June 2022

A novel wearable smart patch can monitor various aspects of physical activity, including the dynamics of running, but like any new device developed for such applications, it must first be tested for validity. Here, we compare the step rate while running in place as measured by this smart patch to the corresponding values obtained utilizing ‘‘gold standard’’ MEMS accelerometers in combination with bilateral force plates equipped with HBM load cells, as well as the values provided by a three-dimensional motion capture system and the Garmin Dynamics Running Pod. The 15 healthy, physically active volunteers (age = 23 ± 3 years; body mass = 74 ± 17 kg, height = 176 ± 10 cm) completed three consecutive 20-s bouts of running in place, starting at low, followed by medium, and finally at high intensity, all self-chosen. Our major findings are that the rates of running in place provided by all four systems were valid, with the notable exception of the fast step rate as measured by the Garmin Running Pod. The lowest mean bias and LoA for these measurements at all rates were associated consistently with the smart patch.
Spatiotemporal Eye-Tracking Feature Set for Improved Recognition of Dyslexic Reading Patterns in Children
Authors: Vajs Ivan , Ković Vanja , Papić Tamara , Savić Andrej M. , Janković Milica M.
Published: June 2022

Considering the detrimental effects of dyslexia on academic performance and its common occurrence, developing tools for dyslexia detection, monitoring, and treatment poses a task of significant priority. The research performed in this paper was focused on detecting and analyzing dyslexic tendencies in Serbian children based on eye-tracking measures. The group of 30 children (ages 7–13, 15 dyslexic and 15 non-dyslexic) read 13 different text segments on 13 different color configurations. For each text segment, the corresponding eye-tracking trail was recorded and then processed offline and represented by nine conventional features and five newly proposed features. The features were used for dyslexia recognition using several machine learning algorithms: logistic regression, support vector machine, k-nearest neighbor, and random forest. The highest accuracy of 94% was achieved using all the implemented features and leave-one-out subject cross-validation. Afterwards, the most important features for dyslexia detection (representing the complexity of fixation gaze) were used in a statistical analysis of the individual color effects on dyslexic tendencies within the dyslexic group. The statistical analysis has shown that the influence of color has high inter-subject variability. This paper is the first to introduce features that provide clear separability between a dyslexic and control group in the Serbian language (a language with a shallow orthographic system). Furthermore, the proposed features could be used for diagnosing and tracking dyslexia as biomarkers for objective quantification.
EOG-Based Human–Computer Interface: 2000–2020 Review
Authors: Belkhiria Chama , Boudir Atlal , Hurter Christophe , Peysakhovich Vsevolod
Published: June 2022

Electro-oculography (EOG)-based brain–computer interface (BCI) is a relevant technology influencing physical medicine, daily life, gaming and even the aeronautics field. EOG-based BCI systems record activity related to users’ intention, perception and motor decisions. It converts the bio-physiological signals into commands for external hardware, and it executes the operation expected by the user through the output device. EOG signal is used for identifying and classifying eye movements through active or passive interaction. Both types of interaction have the potential for controlling the output device by performing the user’s communication with the environment. In the aeronautical field, investigations of EOG-BCI systems are being explored as a relevant tool to replace the manual command and as a communicative tool dedicated to accelerating the user’s intention. This paper reviews the last two decades of EOG-based BCI studies and provides a structured design space with a large set of representative papers. Our purpose is to introduce the existing BCI systems based on EOG signals and to inspire the design of new ones. First, we highlight the basic components of EOG-based BCI studies, including EOG signal acquisition, EOG device particularity, extracted features, translation algorithms, and interaction commands. Second, we provide an overview of EOG-based BCI applications in the real and virtual environment along with the aeronautical application. We conclude with a discussion of the actual limits of EOG devices regarding existing systems. Finally, we provide suggestions to gain insight for future design inquiries.
A Narrative Review of the Potential Roles of Lipid-Based Vesicles (Vesiculosomes) in Burn Management
Authors: Abdul Rasool Bazigha K. , Al Mahri Nema , Alburaimi Nora , Abdallah Fatima , Shamma Anfal Saeed Bin
Published: June 2022

Burn injuries can have a lasting effect on people’s quality of life, as they negatively impact their physical and mental health. Then, they are likely to suffer psychological problems as a result. A serious problem is that deep burns are more challenging to treat due to their slow healing rate and susceptibility to microbial infection. Conventional topical medications used for burn treatment are sometimes ineffective because they cannot optimize their ability of transcutaneous absorption at the targeted site and accelerate healing. However, nanotechnology offers excellent prospects for developing current medical wound therapies and is capable of addressing issues such as low drug stability, water solubility, permeability, and bioavailability. The current review focuses on lipid-based vesicles (vesiculosomes) as an example of advanced delivery systems, showing their potential clinical applications in burn wound management. Vesiculosomes may help overcome impediments including the low bioavailability of active agents, offering the controlled release of drugs, increased drug stability, fewer side effects, and reduced dosing frequency, which will ultimately improve therapeutic efficacy and patient compliance. We discuss the application of various types of vesiculosomes such as liposomes, niosomes, ethosomes, cubosomes, transfersomes, and phytosomes in burn healing therapy, as these demonstrate superior skin penetration compared to conventional burn topical treatment. We also highlight their noteworthy uses in the formulation of natural products and discuss the current status as well as future perspectives of these carriers in burn management. Furthermore, the burn treatment options currently available in the market are also summarized.
Colorectal Cancer Chemoprevention by S-Allyl Cysteine–Caffeic Acid Hybrids: In Vitro Biological Activity and In Silico Studies
Authors: Herrera-Ramirez Angie , Yepes-Pérez Andres F. , Quintero-Saumeth Jorge , Moreno-Quintero Gustavo , Naranjo Tonny W. , Cardona-Galeano Wilson
Published: June 2022

Conventional chemotherapy for colorectal cancer (CRC) gives only a small increase in patient survival, since it is often diagnosed at late stages, when the tumor has disseminated to other organs. Moreover, it is common to observe that malignant cells may acquire resistance to conventional chemotherapies through different mechanisms, including reducing drug activation or accumulation (by enhancing efflux), inducing alterations in molecular targets, and inhibiting the DNA damage response, among other strategies. Considering these facts, the discovery of new molecules with therapeutic potential has become an invaluable tool in chemoprevention. In this context, we previously evaluated two hybrids (SAC-CAFA-MET and SAC-CAFA-PENT) that exhibited selective cytotoxicity against SW480 cells, with better results than the conventional chemotherapeutic agent (5-fluorouracil; 5-FU). Here, we investigated the possible mechanisms of these molecules in greater depth, to identify whether they could be valuable therapeutic scaffolds in the search for new molecules with chemopreventive potential for the treatment of CRC. Both compounds reduced ROS formation, which could be related to antioxidant effects. Further evaluations showed that SAC-CAFA-MET induces cell death independent of caspases and the tumor-suppressor protein p53, but probably mediated by the negative regulation of the pro-apoptotic Bcl-2. In addition, the lack of activation of caspase-8 and the positive regulation of caspase-3 induced by SAC-CAFA-PENT suggest that this compound acts through an apoptotic mechanism, probably initiated by intrinsic pathways. Furthermore, the downregulation of IL-6 by SAC-CAFA-PENT suggests that it also induces a significant anti-inflammatory process. In addition, docking studies would suggest caspase-3 modulation as the primary mechanism by which SAC-CAFA-PENT elicits apoptosis in SW480human colorectal adenocarcinoma cells. Meanwhile, density functional theory (DFT) calculations suggest that both hybrids would produce effects in the modulation of ROS in SW480 cells via the hydrogen atom transfer (HAT) pathway. The present work notes that SAC-CAFA-MET and SAC-CAFA-PENT could be potential candidates for further investigations in the search for potential chemopreventive agents.
Corporate Social Responsibility and Firm Performance in GCC Countries: A Panel Smooth Transition Regression Model
Authors: Ghardallou Wafa , Alessa Noha
Published: June 2022

There is evidence for mixed effects of corporate social responsibility (CSR) on corporate financial performance. In particular, evidence is reported to be positive, negative, and insignificant. These controversies are generally explained by two opposing schools of thought, which are the social impact hypothesis and the shift of focus hypothesis. This paper attempts to contribute to the ongoing debate by investigating whether the relationship between CSR and firm financial results is nonlinear. Therefore, this research relies on a panel smooth transition regression (PSTR) model in order to calculate the value transition threshold of CSR in 70 Gulf Cooperation Council (GCC) firms from 2015 to 2020, using the CSR composite index and various CSR dimensions, which include environmental, social, and governance transition dimensions. Empirical findings indicate that investment in CSR does not help to boost corporate value until it exceeds the value transition threshold. However, when the marginal benefit exceeds the cost, CSR investment becomes a positive contributor to corporate performance. Furthermore, results indicate that the nonlinear relationship persists when using the individual CSR dimensions, i.e., governmental, social, and environmental CSR measurements. Finally, an interesting finding shows that the social CSR dimension is associated with the highest threshold level. Hence, firms should invest more in the social aspects of CSR in order to see their profitability increase.
Effect of Al2O3 Nanoparticles on Performance and Emission Characteristics of Diesel Engine Fuelled with Diesel–Neem Biodiesel Blends
Authors: Kaushik Yatendra , Verma Vijay , Saxena Kuldeep Kumar , Prakash Chander , Gupta Lovi Raj , Dixit Saurav
Published: June 2022

Indagation in the sphere of nanoparticle utilisation has provided commendatory upshots in discrete areas of application varying from medicinal use to environmental degradation alleviation. This study incorporates alumina nanoparticles as additives to diesel and biodiesel blends. The prime objective of the present study was the scrutinisation of the denouement of Al2O3 nanoparticle incorporation in diesel–biodiesel blends on a diesel engine’s performance and emission characteristics. Test fuel samples were prepared by blending different proportions of biodiesel and dispersing two concentrations of alumina nanoparticles (25 and 50 ppm) in the diesel. Dispersion was made without the use of a nanoparticle stabiliser to meet real-world feasibility. High-speed shearing was employed to blend the biodiesel and diesel, while nanoparticles were dispersed in the blends by ultrasonication. The blends so devised were tested using a single-cylinder diesel engine at fixed RPM and applied load for three compression ratios. Upshots of brake-specific fuel consumption (BSFC) and brake thermal efficiency (BTE) for fuel samples were measured with LabView-based software, whereas CO emissions and unburnt hydrocarbon (UBHC) emissions were computed using an external gas analyser attached to the exhaust vent of the engine. Investigation revealed that the inclusion of Al2O3 nanoparticles culminates in the amelioration of engine performance along with the alleviation of deleterious exhaust from engine. Furthermore, the incorporation of alumina nanoparticles assisted in the amelioration of dwindled performance attributed to biodiesel blending. More favourable results of nanoparticle inclusion were obtained at higher compression ratios compared to lower ones. Reckoning evinced that the Al2O3 nanoparticle is a lucrative introduction for fuels to boost the performance and dwindle the deleterious exhaust of diesel engines.
How Impactful Are Public Policies on Environmental Sustainability? Debating the Portuguese Case of PO SEUR 2014–2020
Authors: Medeiros Eduardo , Valente Bernardo , Gonçalves Vasco , Castro Paula
Published: June 2022

Sustainable development is a key feature of national, European Union and global development strategies. The main research goal is to provide evidence on how impactful public policies on environmental sustainability in Portugal are at the regional level, in various policy areas. In this context, this paper analyses the main impacts of the Portuguese Operational Programme for Sustainability and Efficient Use of Resources (PO SEUR 2014–20). The research uses a territorial impact assessment (TIA) methodology (TARGET_TIA) to assess these impacts in five analytic dimensions (economy with low emissions, adaptation to climate change, risk prevention and management, environmental protection and resource efficiency) in the five mainland Portuguese NUTS 2. It concludes that, in overall terms, PO SEUR produced low to moderate positive impacts in all NUTS II and analysed dimensions, but it was particularly positive in measures fostering adaptation to climate change, and less impactful in measures supporting an economy with low emissions and resource efficiency in Portugal. Despite data limitations, the research provided adequate evidence that key public policies supporting environmental sustainability in Portugal are largely ineffective and inefficient in view of their policy goals and allocated funding. To turn this scenario around, the process of project selection needs to undergo significant improvements to better adjust the regional needs on environmental sustainability-related issues to the available funding. Moreover, on a policy strategic level, there needs to be support for a prosperous, modern, competitive and climate-neutral economy in Portugal via concrete actions exploring environmental capital and a green economy in urban areas.
Optimization Method for Conventional Bus Stop Placement and the Bus Line Network Based on the Voronoi Diagram
Authors: Wang Fu , Ye Manqing , Zhu Hongbin , Gu Dengjun
Published: June 2022

With the rapid development of the economy, the existing conventional bus transit system finds it difficult to meet people’s increasing travel needs. In addition, with the emergence and rapid development of urban rail transit, it is also necessary to integrate the existing conventional bus transit system with the rail transit system to realize the optimization of the whole public transport system. This study introduces the concept of the Voronoi diagram and uses it to divide the service area of bus stops. Taking the average walking time of regional passengers to the station as the main index, the convenience of passengers in the service area was evaluated, and a set of candidate station sites is established. Against the background of urban rail transit, a complete optimization model for a conventional bus station layout and line network was proposed. Finally, taking Wuhan East Lake High-tech Development Zone as an example, two optimization schemes for the public transport system were obtained. Compared with the status quo, the optimized scheme had obvious improvement effects on the repetition coefficient of bus lines, per capita transfer time, bus line network coverage and station service rate. This has been recognized by the local authorities, which proves the practicality and scientificity of the optimization method of this study.
Effect of a Novel Vibration Mixing on the Fiber Distribution and Mechanical Properties of Ultra-High Performance Concrete
Authors: Zheng Yangzezhi , Zhou Yang , Nie Fan , Luo Haoyuan , Huang Xiaoming
Published: June 2022

A novel double-axis vibration mixing technology is presented to further enhance the performance of ultra-high performance concrete (UHPC). It improves the problem of inefficient zone in concrete mixing and enhances the homogeneity of concrete through the coupling of vibration and velocity fields during mixing. The X-CT scan results demonstrate that this novel technology improves the fiber distribution coefficient from 0.512 to 0.581. Moreover, the standard deviation of fiber orientation is reduced, the proportion of invalid fibers is decreased, and the pore space distribution is more uniform. The mechanical experimental results show that the new vibration mixing technology improves the mechanical properties of UHPC, and the percentage of early strength improvement is more significant; the impact compressive strength and the toughness of UHPC are also strengthened. The vibration mixing technology is expected to achieve the reduction of raw materials dosage with the same mechanical properties to reduce the cost and carbon emission.
Effects of Combined Applications of Biogas Slurry and Biochar on Phosphorus Leaching and Fractionations in Lateritic Soil
Authors: Zhang Bangxi , Yin Rongxiu , Wei Quanquan , Qin Song , Peng Yutao , Zhang Baige
Published: June 2022

Diverse soil phosphorus (P)-leaching phenomena induced by environmental disturbance have gained increasing attention. Two kinds of typical organic materials, biochar and biogas slurry, (BS) are widely utilized to amend agricultural soil, but there is little research that gives insight into their co-effects on soil P-leaching and corresponding mechanisms. Herein, a total of six treatments (viz., control, 2% (w/w) biochar, low ratio BS with or without 2% (w/w) biochar, high ratio BS with or without 2% (w/w) biochar) were conducted to investigate the P-leaching and fraction transformation mechanisms. The column experiment results showed that compared to control, sole BS application or biochar both can slightly enhance the soil-P loss by 134.8% and 39.8%. High ratios of BS induced higher P loss than the low ratios of BS by 125.1%. In comparison with the sole BS treatment, combined BS and biochar application increase P loss but result in less soil leaching of basic cations. The incubation experiment results showed that the enhanced P-leaching in combined BS and biochar treatment is probably attributable to the enhanced soil pH, decreased DPS, soil P adsorption capacity, and transformation of moderately labile Fe–P into labile P. This research helps in understanding the abiotic process of biochar and BS in promoting soil P-leaching and soil-P management using biochar and biogas slurry.
The Influence of Yarrowia lipolytica Glycosylation on the Biochemical Properties and Oligomerization of Heterologous Invertase
Authors: Szymański Kacper , Hapeta Piotr , Moroz Paweł , Wąsik Bartosz , Robak Małgorzata , Lazar Zbigniew
Published: June 2022

Invertases are important enzymes used in the food industry. Despite many studies on the invertase-encoding SUC2 gene expression in the industrial yeast Yarrowia lipolytica, no biochemical characteristics of this enzyme expressed as heterologous protein have been provided. Here, two isoforms of extracellular invertase produced by Y. lipolytica were detected using ion-exchange chromatography. Specific activities of 226.45 and 432.66 U/mg for the first and second isoform, respectively, were determined. Basic characteristics of this enzyme were similar to the one isolated from Saccharomyces cerevisiae (optimum pH and temperature, metal ions inhibition, substrate specificity and fructooligosaccharides (FOS) biosynthesis). The apparent differences were higher KM for sucrose (67 mM) and lower molecular mass (66 kDa) resulting from lower N-glycosylation level (9.1% of mass). The N-glycan structures determined by MALDI-TOF and HPLC represented high mannose structures, though with much shorter chains than hypermannosylated glycans from S. cerevisiae. Furthermore, galactose was detected as the modifying sugar in the glycan structures of invertase expressed in Y. lipolytica. N-glycans did not affect invertase activity but were important for its oligomerization. The expressed enzyme aggregated into dimers, tetramers, hexamers, and octamers, as well as structures of higher molecular mass, which might be decamers, which have not been described so far in the literature.
Prediction of Fracture Toughness of Intermediate Layer of Asphalt Pavements Using Artificial Neural Network
Authors: Kim Dong-Hyuk , Kim Ha-Yeong , Moon Ki-Hoon , Jeong Jin-Hoon
Published: June 2022

For the sustainable management of pavements, predicting the condition of the pavement structure using a consistent and accurate method is necessary. The intermediate layer situated immediately below the surface layer has the greatest effect on the condition of the pavement structure. As a result, to accurately predict the condition of a pavement structure, the mechanistic properties of the intermediate layer are very important. Fracture toughness (FT)—a mechanistic property of the intermediate layer—is an important factor in predicting the distress that develops on the pavement surface. However, measuring FT consistently is practically impossible by coring asphalt pavement over the entire pavement section. Therefore, an artificial neural network (ANN) model—developed by using pavement surface conditions and traffic volume—can predict the FT of the intermediate layer of expressway asphalt pavements. Several ANN models have been developed by applying various optimizers, ANN structures, and preprocessing methods. The optimal model was selected by analyzing the predictive performance, error stability, and distribution of the developed models. The final selected model showed small stable errors, and the distributions of the predicted and measured FTs were similar. Furthermore, FT limits were set with outliers. Future asphalt pavement conditions can be predicted throughout the expressway network by using the proposed model without coring samples.
Toward Sustainable Gentle Awakenings and Sleep Inertia Mitigation: A Low-Cost IoT-Based Adaptable Lighting and Temperature Control Approach
Authors: Ho Tan-Jan , Huang Min-Yan , Chou Meng-Yu , Huang Bo-Han , Zhuang Ru-En
Published: June 2022

In this paper, our design aims to assist in sleep inertia reduction and avoid the startle response and irritation caused by alarm-made unpleasant wakeup stimuli. Thus, we propose an approach that employs a soft and alerting sunrise simulation, conditionally utilizes natural light, and appropriately lowers the bedroom temperature for awakening a sleeper tenderly and gradually to gain full alertness. This approach is inspired by known scientific implications confirming the effectiveness of lights and temperatures on wakefulness. In this regard, we present an economical do-it-yourself digital tech-assisted system for bedroom lighting and temperature control. The system design is based on the smartphone and Internet of Things (IoT) technology. We develop the hardware and software in the system for implementing three IoT-based control tasks. One is the tuning of artificial light brightness using the pulse width modulation technique. Another is the opening of the window curtain using stepper motor control and light detection. The other is the activation of the air-conditioning setting using an infrared remote control and temperature detection. We construct a testbed for conducting experiments. Experimental results demonstrate that the proposed system can execute task requirements satisfactorily. The proposed system is promising for achieving our goal. It embodies features of sustainability.