bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing Antioxidant Activity and Phytochemical Properties of Peppermint (Mentha piperita L.) by Integrative Application of Biofertilizer and Stress-Modulating Nanoparticles under Drought Stress Conditions
Authors: Ostadi Ali , Javanmard Abdollah , Amani Machiani Mostafa , Kakaei Karim
Published: December 2022

Drought stress (DS) negatively affects plant growth, productivity, and quality in semi-arid and arid regions. Nowadays, application of biofertilizers and stress-modulating nanoparticles (NPs) improves plant performance under stressful conditions. The study evaluated the impacts of arbuscular mycorrhizal fungi (Myco-Root) and TiO2 NPs on the nutrient uptake, dry yield, essential oil (EO) productivity, and EO quality of peppermint (Mentha piperita L.) under different irrigation regimes. The treatments included three irrigation regimes containing irrigation after 20% (I20, well-watered), 40% (I40, mild DS), and 60% (I60, severe DS) maximum allowable depletion (MAD) percentage of the soil’s available water as well as four fertilizer sources contain no fertilization (control), Myco-Root biofertilizer, TiO2 NPs, and an integrative application of Myco-Root + TiO2 NPs. The results demonstrated that the highest (195.72 g m−2) and the lowest dry yield (78.76 g m−2) of peppermint was obtained in well-watered conditions with integrative application of Myco-Root + TiO2 NPs and severe drought stress (I60) without fertilization, respectively. The dry yield of peppermint was reduced by 27.7 and 53.4% in mild (I40) and severe drought stress (I60), respectively. The maximum EO content (1.49%) and EO yield (2.30 g m−2) was recorded in mild drought stress (I40) treated with Myco-Root + TiO2 NPs. Based on the GC-MS and GC-FID analysis, 29 constituents were identified in peppermint EO, with the major constituents being menthol (38.99–52%), menthone (12.72–20.13%), 1,8-cineole (6.55–7.84%), and neo-menthol (3.14–4.52%), respectively. The maximum content of menthol, 1,8-cineole, and neo-menthol was obtained under mild drought stress (I40) fertilized with Myco-Root + TiO2 NPs. The results indicate that the integrative application of Myco-Root + TiO2 NPs could be used as an alternative method of using chemical fertilizers in sustainable agricultural systems for improving the EO quantity and quality of peppermint grown under drought stress conditions.
Recent Trends in the Design, Synthesis and Biomedical Applications of Covalent Organic Frameworks
Authors: Kaur Gagandeep , Kumar Dinesh , Sundarrajan Subramanian , Ramakrishna Seeram , Kumar Pawan
Published: December 2022

The most recent and advanced class of crystalline and permeable compounds are covalent organic frameworks (COFs). Due to their exceptional qualities, such as their porous structure, high surface area, strong chemical and thermal stabilities, low density, good water stability, luminescent nature, and so on, COFs have seen remarkable growth over the past ten years. COFs have been successfully researched for a number of applications based on these characteristics. The current state of COFs has been reported in this study, with particular attention paid to their design, topology, synthesis, and a variety of biological applications, including drug delivery systems, photodynamic and photothermal therapy, biosensing, bioimaging, etc. Moreover, several miscellaneous applications, such as catalysis, gas storage and separation, photocatalysis, sensors, solar cells, supercapacitors, and 3D printers, have also been explored. It is significant that we have examined current research on COFs with a focus on the biological applications, which are infrequently covered in the literature. Descriptions of the difficulties and prospective outcomes have also been given.
Synthesis and Characterization of Cellulose Diacetate-Graft-Polylactide via Solvent-Free Melt Ring-Opening Graft Copolymerization
Authors: Zhao Shiyou , Li Jin , Wu Lifeng , Hua Ming , Jiang Changmei , Pan Ying , Yao Lirong , Xu Sijun , Ge Jianlong , Pan Gangwei
Published: December 2022

Cellulose diacetate (CDA) and L-lactide (L-LA) were used to prepare CDA−g−PLLA with a low glass transition temperature under different process conditions. Given the high glass transition temperature (Tg) of CDA, the thermal processing performance of CDA is poor, which greatly limits its application fields. To decrease the Tg of CDA, graft copolymerization was used in this research. A CDA−g−PLLA graft copolymer was synthesized by grafting CDA with L-LA under different reaction conditions using stannous octanoate as the catalyst and variations in the grafting rate under different reaction conditions were compared. The chemical structure and crystal structure of the CDA−g−PLLA were investigated, and thermal properties were also studied. The results showed that the grafting rate was the highest at the L-LA/CDA mass ratio of 4:1 under a reaction temperature of 150 °C for 90 min, and no poly-L-lactide (PLLA) homopolymer was found among the CDA−g−PLLA graft copolymers after purification. The Tg of CDA−g−PLLA was 54.2 °C, and the initial temperature of weightlessness of CDA−g−PLLA was 218.7 °C. The regularity of the original CDA molecular chains was destroyed after grafting PLLA molecular chains. In this research, we investigated the optimal grafting conditions for CDA−g−PLLA and the CDA−g−PLLA had a low Tg, which improves the thermal processing performance of CDA and broadens its application prospects in the industry.
Designing of Hollow Core Grapefruit Fiber Using Cyclo Olefin Polymer for the Detection of Fuel Adulteration in Terahertz Region
Authors: Hossain Sakawat , Mollah Md. Aslam , Hosain Md. Kamal , Islam Md. Shofiqul , Alkhateeb Abdulhameed Fouad
Published: December 2022

A grapefruit-shape hollow-core liquid infiltrated photonic crystal fiber (LI-PCF) is proposed and evaluated to identify the percentage of kerosene in adulterated petrol. The proposed hollow-fiber sensor is designed with Cyclo Olefin Polymer (Zeonex) and likely to be filled with different samples of petrol which is adulated by the kerosene up to 100%. Considering the electromagnetic radiation in THz band, the sensing properties are thoroughly investigated by adopting finite element method (FEM) based COMSOL Multiphysics software. However, the proposed sensor offers a very high relative sensitivity (RS) of 97.27% and confinement loss (CL) less than 10−10 dB/m, and total loss under 0.07 dB/cm, at 2 THz operating frequency. Besides that, the sensor also possesses a low effective material loss (EML), high numerical aperture (NA), and large Marcuse spot size (MSS). The sensor structure is fabrication feasible through existing fabrication methodologies consequently making this petrol adulteration sensor a propitious aspirant for real-life applications of petrol adulteration measurements in commercial and industrial sensing.
Stability of Silica Nanofluids at High Salinity and High Temperature
Authors: Hutin Anthony , Lima Nicolle , Lopez Felicle , Carvalho Marcio
Published: December 2022

Nanoparticles have shown great potential in many sectors of the oil and gas industry, including enhanced oil recovery (EOR). They can be used to improve water flooding by altering the wettability of the porous medium, reducing the interfacial tension, blocking pores, or preventing asphaltene precipitation. Ensuring the stability of nanofluids injected into reservoirs is essential and a great challenge. However, high temperature favors particle collisions and high salinity (ionic strength) decreases electrostatic repulsion between particles. Therefore, nanofluids are extremely unstable at reservoir conditions. In this paper, we investigated the effects of electrolytes (brine and seawater) and temperature (up to 80 °C) on the stability of silica nanofluids. The nanofluids are characterized by dynamic light scattering (size), turbidity (stability), and zeta potential (electrostatic repulsions). One solution to increase the stability is to compensate for the loss of repulsive forces due to salts in the solution through increased electrostatic and/or steric repulsions by changing the pH of the base fluid. At high ionic strength (42 g/L NaCl and seawater), the stability of 0.1 and 0.5 wt% silica nanofluids at basic pH is about one day, regardless of temperature. In contrast, at pH 1.5, the nanofluids have a stability of at least three weeks at 80 °C. The results obtained with base fluids containing divalent cations confirmed their more destabilizing effect. This study confirmed that it is possible to stabilize silica nanofluids beyond one month at reservoir conditions just by lowering the pH near the isoelectric point.
Increase by Substitution of Galvanized Steel for Aluminum Mirrors in the UV Solar Radiation in Canal with Fins and Side Panels That Disinfect Wastewater
Authors: Cisterna-Osorio Pedro , Galvez-Gonzalez María , Moraga-Chaura Miguel , Quijada-Vera Sergio
Published: December 2022

The need arises to seek new depuration technological responses aimed at the reuse of wastewater, which requires the development and promotion of economically and environmentally sustainable technologies. In this paper, it studies an improvement to a disinfection system sustainable, low-cost, patented in 2019, and based on solar energy. The water passes through a canal of reflective material in the continuous regime, and in the batch regime, the water remains in the canal. The panels are located parallel to the lateral faces of the canal. The fraction of the radiation reflected outside the canal reaches the reflective side panels that return the radiation to the canal. These panels concentrate the radiation in the canal through reflection. The disinfectant canal with fins and side panels uses ultraviolet radiation to eliminate the bacterial load carried by treated wastewater. For this reason, the present work analyzes the incidence in the area of influence of the disinfectant canal. When reflective aluminum mirrors were installed on the sloping walls of the canal, global radiation increased by 4%, when they were used on the side panels, it increased 3%, and when the aluminum mirrors were used on the canal walls and side panels, it increased 8%. The important thing about this work is that it opens windows for improving the system through materiality so the new challenge is the search for the optimal material considering the impact on global radiation and consequently on the bacteriological elimination.
Subcritical Water Extraction as an Effective Technique for the Isolation of Phenolic Compounds of Achillea Species
Authors: Radovanović Katarina , Gavarić Neda , Švarc-Gajić Jaroslava , Brezo-Borjan Tanja , Zlatković Bojan , Lončar Biljana , Aćimović Milica
Published: December 2022

The genus Achillea has significant medical potential due to the presence of highly bioactive compounds in its chemical composition. To take advantage of plants’ biomedical potential, it is of great importance to use a proper extraction process. This study aimed to determine and compare the preliminary chemical composition of five different Achillea species extracted with two conventional (infusion and maceration) and two non-conventional (ultrasound-assisted extraction (UAE) and Subcritical water extraction (SWE)) techniques. The extracts were prepared using the previously described procedures for infusion, maceration, UAE and SWE extraction. For all extracts, the extraction yield (dry extract (DE)) was determined. The analyzed extracts were preliminarily chemically characterized spectrophotometrically in terms of total phenolic content (TPC) and total flavonoid content (TFC). The obtained results showed that non-conventional techniques delivered higher values of TPC and TFC than conventional. There is a statistically significant increase in DE and TPC content when applying SWE for all observed Achillea species. The highest DE value, 48.80 ± 1.76%, was observed for A. asplenifolia. The highest TPC values were observed after applying SWE: 93.63 ± 1.01 mg GAE/g DE for A. millefolium, and 90.12 ± 0.87 mg GAE/g DE for A. crithmifolia. The results for TFC revealed a statistically significant difference in values, with A. nobilis subsp. nelreichii as the sample with the highest content of TFC (11.11 ± 0.22 mg QE/g DE) when using UAE. Consequently, it could be concluded that SWE is a superior non-conventional extraction technique, and A. nobilis subsp. nerleichii presents as the most promising plant.
An Integrated Method of Bayesian Optimization and D-Optimal Design for Chemical Experiment Optimization
Authors: Huang Xinye , Zhang Shuyuan , Li Haoran , Qiu Tong
Published: December 2022

The smart chemical laboratory has recently emerged as a promising trend for future chemical research, where experiment optimization is of vital importance. The traditional Bayesian optimization (BO) algorithm focuses on exploring the dependent variable space while overlooking the independent variable space. Consequently, the BO algorithm suffers from becoming stuck at local optima, which severely deteriorates the optimization performance, especially with bad-quality initial points. Herein, we propose a novel stochastic framework of Bayesian optimization with D-optimal design (BODO) by integrating BO with D-optimal design. BODO can balance the exploitation in the dependent variable space and the exploration in the independent variable space. We highlight the excellent performance of BODO even with poor initial points on the benchmark alpine2 function. Meanwhile, BODO demonstrates a better average objective function value than BO on the benchmark Summit SnAr chemical process, showing its advantage in chemical experiment optimization and potential application in future chemical experiments.
Rapid Identification of Insecticide- and Herbicide-Tolerant Genetically Modified Maize Using Mid-Infrared Spectroscopy
Authors: Liu Xiaodan , Yu Yonghui , Bai Xiulin , Li Xiaolong , Zhang Jun , Wang Dun
Published: December 2022

Genetically modified (GM) technology is of great significance for increasing crop production, protecting biodiversity, and reducing environmental pollution. However, with the frequent occurrence of safety events regarding GM foods, more and more disputes have arisen over the potential safety of transgenic technology. It is particularly necessary to find a fast and accurate method for transgenic product identification. In this research, mid-infrared spectroscopy, coupled with chemometric methods, was applied to discriminate GM maize from its non-GM parent. A total of 120 GM maize and 120 non-GM maize samples were prepared, and the spectral information in the range of 400–4000 cm−1 was collected. After acquiring the spectra, wavelet transform (WT) was used to preprocess the data, and k-means was carried out to split all samples into calibration and prediction sets in the ratio of 2:1. Principal component analysis (PCA) was then conducted to qualitatively distinguish the two types of samples, and an apparent cluster was observed. Since the full spectrum covered a large amount of data and redundant information, we adopted the successive projections algorithm (SPA) to select optimal wavelengths for further analysis. Chemometrics, including partial least squares-discriminant analysis (PLS-DA), the k-nearest neighbor algorithm (KNN), and the extreme learning machine (ELM), were performed to establish classification models based on full spectra and optimal wavelengths. The overall results indicated that ELM models based on full spectra and optimal spectra showed better accuracy and reliability, with a 100% recognition rate in the calibration set and a 98.75% recognition rate in the prediction set. It has been confirmed that mid-infrared spectroscopy, combined with chemometric methods, can be a novel approach to identify transgenic maize.
Thin-Film Carbon Nitride (C2N)-Based Solar Cell Optimization Considering Zn1−xMgxO as a Buffer Layer
Authors: Ahmad Waqas , Farooq Waqas , Khan Adnan Daud , Jan Shayan Tariq , Jasiński Michał , Leonowicz Zbigniew , Gono Radomir , Petrov Jan
Published: December 2022

Carbon nitride (C2N), a two-dimensional material, is rapidly gaining popularity in the photovoltaic (PV) research community owing to its excellent properties, such as high thermal and chemical stability, non-toxic composition, and low fabrication cost over other thin-film solar cells. This study uses a detailed numerical investigation to explore the influence of C2N-based solar cells with zinc magnesium oxide (Zn1−xMgxO) as a buffer layer. The SCAPS-1D simulator is utilized to examine the performance of four Mg-doped buffer layers (x = 0.0625, 0.125, 0.1875, and 0.25) coupled with the C2N-based absorber layer. The influence of the absorber and buffer layers’ band alignment, quantum efficiency, thickness, doping density, defect density, and operating temperature are analyzed to improve the cell performance. Based on the simulations, increasing the buffer layer Mg concentration above x = 0.1875 reduces the device performance. Furthermore, it is found that increasing the absorber layer thickness is desirable for good device efficiency, whereas a doping density above 1015 cm−3 can degrade the cell performance. After optimization of the buffer layer thickness and doping density at 40 nm and 1018 cm−3, the cell displayed its maximum performance. Among the four structures, C2N/Zn0.8125Mg0.1875O demonstrated the highest PCE of 19.01% with a significant improvement in open circuit voltage (Voc), short circuit density (Jsc), and fill factor (FF). The recorded results are in good agreement with the standard theoretical studies.
Belief in Karma: The Belief-Inducing Power of a Collection of Ideas and Practices with a Long History
Authors: Lehtonen Tommi
Published: December 2022

This article provides an analysis of the concept of karma and related concepts, such as rebirth, merit, and transfer of merit, along with a historical survey focusing on classical texts. The attractiveness of the belief in karma lies in two main reasons. The first is the moral ideal of getting one’s just deserts on the basis of one’s actions and omissions. The second reason involves the idea of rebirth. The belief in both karma and rebirth can bring consolation with the hope of life hereafter, where one’s destiny is determined not by chance, but by the moral quality of one’s actions in this or previous lives. The belief in karma also incorporates diverging elements, such as transfer of merit. The practice of transfer of merit serves to improve an individual’s moral and religious status through rituals or other suitable means, while the doctrine of karma itself strongly speaks to the strict fulfilment of retributive justice. Both motives—fulfilling justice according to the law of karma and improving one’s moral status through transfer of merit—are psychologically powerful and attractive, although their mutual compatibility is debatable.
Accessing the Time-Series Two-Dimensional Displacements around a Reservoir Using Multi-Orbit SAR Datasets: A Case Study of Xiluodu Hydropower Station
Authors: Chen Qi , Zhang Heng , Xu Bing , Liu Zhe , Mao Wenxiang
Published: December 2022

The construction of large-scale hydropower stations could solve the problem of China’s power and energy shortages. However, the construction of hydropower stations requires reservoir water storage. Artificially raising the water level by several tens of meters or even hundreds of meters will undoubtedly change the hydrogeological conditions of an area, which will lead to surface deformation near the reservoir. In this paper, we first used SBAS-InSAR technology to monitor the surface deformation near the Xiluodu reservoir area for various data and analyzed the surface deformation of the Xiluodu reservoir area from 2014 to 2019. By using the 12 ALOS2 ascending data, the 100 Sentinel-1 ascending data, and the 97 Sentinel-1 descending data, the horizontal and vertical deformations of the Xiluodu reservoir area were obtained. We found that the Xiluodu reservoir area is mainly deformed along the vertical shore, with a maximum deformation rate of 250 mm/a, accompanied by vertical deformation, and the maximum deformation rate is 60 mm/a. Furthermore, by analyzing the relationship between the horizontal deformation sequence, the vertical deformation sequence, and the impoundment, we found the following: (1) Since the commencement of Xiluodu water storage, the vertical shore direction displacement has continued to increase, indicating that the deformation caused by the water storage is not due to the elastic displacement caused by the load, but by irreversible shaping displacement. According to its development trend, we speculate that the vertical shore direction displacement will continue to increase until it eventually stabilizes; (2) Vertical displacement increases rapidly in the initial stage of water storage; after two water-storage cycles, absolute settlement begins to slow down in the vertical direction, but its deformation still changes with the change in the storage period.
Sleep Quality Evaluation Based on Single-Lead Wearable Cardiac Cycle Acquisition Device
Authors: Li Yang , Li Jianqing , Yan Chang , Dong Kejun , Kang Zhiyu , Zhang Hongxing , Liu Chengyu
Published: December 2022

In clinical conditions, polysomnography (PSG) is regarded as the “golden standard” for detecting sleep disease and offering a reference of objective sleep quality. For healthy adults, scores from sleep questionnaires are more reliable than other methods in obtaining knowledge of subjective sleep quality. In practice, the need to simplify PSG to obtain subjective sleep quality by recording a few channels of physiological signals such as single-lead electrocardiogram (ECG) or photoplethysmography (PPG) signal is still very urgent. This study provided a two-step method to differentiate sleep quality into “good sleep” and “poor sleep” based on the single-lead wearable cardiac cycle data, with the comparison of the subjective sleep questionnaire score. First, heart rate variability (HRV) features and ECG-derived respiration features were extracted to construct a sleep staging model (wakefulness (W), rapid eye movement (REM), light sleep (N1&N2) and deep sleep (N3)) using the multi-classifier fusion method. Then, features extracted from the sleep staging results were used to construct a sleep quality evaluation model, i.e., classifying the sleep quality as good and poor. The accuracy of the sleep staging model, tested on the international public database, was 0.661 and 0.659 in Cardiology Challenge 2018 training database and Sleep Heart Health Study Visit 1 database, respectively. The accuracy of the sleep quality evaluation model was 0.786 for our recording subjects, with an average F1-score of 0.771. The proposed sleep staging model and sleep quality evaluation model only requires one channel of wearable cardiac cycle signal. It is very easy to transplant to portable devices, which facilitates daily sleep health monitoring.
Neutron and Gamma-Ray Detection System Coupled to a Multirotor for Screening of Shipping Container Cargo
Authors: Marques Luís , Félix Luís , Cruz Gonçalo , Coelho Vasco , Caetano João , Vale Alberto , Cruz Carlos , Alves Luís , Vaz Pedro
Published: December 2022

In order to detect special nuclear materials and other radioactive materials in Security and Defense scenarios, normally, a combination of neutron and gamma-ray detection systems is used. In particular, to avoid illicit traffic of special nuclear materials and radioactive sources/materials, radiation portal monitors are placed at seaports to inspect shipping-container cargo. Despite their large volume (high efficiency), these detection systems are expensive, and therefore only a fraction of these containers are inspected. In this work, a novel mobile radiation detection system is presented, based on an EJ-200 plastic scintillator for the detection of gamma rays and beta particles, and a neutron detector EJ-426HD plastic scintillator (with 6Li) embedded in a compact and modular moderator. The use of silicon photomultipliers in both detectors presented advantages such as lightweight, compactness, and low power consumption. The developed detection system was integrated in a highly maneuverable multirotor. Monte Carlo simulations were validated by laboratory measurements and field tests were performed using real gamma-ray and neutron sources. The detection and localization within one meter was achieved using a maximum likelihood estimation algorithm for 137Cs sources (4 MBq), as well as the detection of 241Am–beryllium (1.45 GBq) source placed inside the shipping container.
Direction-of-Arrival Estimation Based on Frequency Difference–Wavenumber Analysis for Sparse Vertical Array Configuration
Authors: Kim Donghyeon , Byun Gihoon , Kim Jeasoo
Published: December 2022

Frequency–wavenumber (f–k) analysis can estimate the direction of arrival (DOA) of broadband signals received on a vertical array. When the vertical array configuration is sparse, it results in an aliasing error due to spatial sampling; thus, several striation patterns can emerge in the f–k domain. This paper extends the f–k analysis to a sparse receiver-array, wherein a multitude of sidelobes prevent resolving the DOA estimates due to spatial aliasing. The frequency difference-wavenumber (Δf–k) analysis is developed by adopting the concept of frequency difference, and demonstrated its performance of DOA estimation to a sparse receiver array. Experimental results verify the robustness of the proposed Δf–k analysis in the estimation of the DOA of cracking sounds generated by the snapping shrimps, which were recorded by a sparse vertical array configuration during the shallow water experiment.
A Rapid Self-Alignment Strategy for a Launch Vehicle on an Offshore Launching Platform
Authors: Mu Rongjun , Zhang Tengfei , Li Shoupeng
Published: December 2022

To reduce the impact of offshore launching platform motion and swaying on the self-alignment accuracy of a launch vehicle, a rapid self-alignment strategy, which involves an optimal combination of anti-swaying coarse alignment (ASCA), backtracking navigation, and reverse Kalman filtering is proposed. During the entire alignment process, the data provided by the strapdown inertial navigation system (SINS) are stored and then applied to forward and backtrack self-alignment. This work elaborates the basic principles of coarse alignment and then analyzes the influence of ASCA time on alignment accuracy. An error model was built for the reverse fine alignment system. The coarse alignment was carried out based on the above work, then the state of the alignment system was retraced using the reverse inertial navigation solution and reverse Kalman filtering with the proposed strategy. A cycle-index control function was designed to approximate strict backtracking navigation. Finally, the attitude error was compensated for after the completion of the first and the last forward navigation. To demonstrate the effectiveness of the proposed strategy, numerical simulations were carried out in a scenario of launch vehicle motion and swaying. The proposed strategy can maximize the utilization of SINS data and hence improve the alignment accuracy and further reduce the alignment time. The results show that the fully autonomous alignment technology of the SINS can replace the complex optical aiming system and realize the determination of the initial attitude of a launch vehicle before launch.
Towards Single Camera Human 3D-Kinematics
Authors: Bittner Marian , Yang Wei-Tse , Zhang Xucong , Seth Ajay , van Gemert Jan , van der Helm Frans C. T.
Published: December 2022

Markerless estimation of 3D Kinematics has the great potential to clinically diagnose and monitor movement disorders without referrals to expensive motion capture labs; however, current approaches are limited by performing multiple de-coupled steps to estimate the kinematics of a person from videos. Most current techniques work in a multi-step approach by first detecting the pose of the body and then fitting a musculoskeletal model to the data for accurate kinematic estimation. Errors in training data of the pose detection algorithms, model scaling, as well the requirement of multiple cameras limit the use of these techniques in a clinical setting. Our goal is to pave the way toward fast, easily applicable and accurate 3D kinematic estimation. To this end, we propose a novel approach for direct 3D human kinematic estimation D3KE from videos using deep neural networks. Our experiments demonstrate that the proposed end-to-end training is robust and outperforms 2D and 3D markerless motion capture based kinematic estimation pipelines in terms of joint angles error by a large margin (35% from 5.44 to 3.54 degrees). We show that D3KE is superior to the multi-step approach and can run at video framerate speeds. This technology shows the potential for clinical analysis from mobile devices in the future.
Gold Nanoparticles/Nanographene-Based 3D Sensors Integrated in Mini-Platforms for Thiamine Detection
Authors: Gheorghe Damaris-Cristina , van Staden Jacobus (Koos) Frederick , Stefan-van Staden Raluca-Ioana , Sfirloaga Paula
Published: December 2022

Vitamins are essential for sustaining daily activities and perform crucial roles in metabolism, such as preventing vascular events and delaying the development of diabetic nephropathy. The ultrasensitive assessment of thiamine in foods is required for food quality evaluation. A mini-platform utilizing two 3D sensors based on nanographene and gold nanoparticles paste modified with protoporphyrin IX and protoporphyrin IX cobalt chloride is proposed for the detection of thiamine in blueberry syrup, multivitamin tablets, water, and a biological sample (urine). Differential pulse voltammetry was utilized for the characterization and validation of the suggested sensors. The sensor modified with protoporphyrin IX has a detection limit of 3.0 × 10−13 mol L−1 and a quantification limit of 1.0 × 10−12 mol L−1, whereas the sensor modified with protoporphyrin IX cobalt chloride has detection and quantification limits of 3.0 × 10−12 and 1.0 × 10−11 mol L−1, respectively. High recoveries (values greater than 95.00%) and low RSD (%) values (less than 5.00%) are recorded for both 3D sensors when used for the determination of thiamine in blueberry syrup, multivitamin tablets, water, and urine, demonstrating the 3D sensors’ and suggested method’s high reliability.
A Framework for Analytical Validation of Inertial-Sensor-Based Knee Kinematics Using a Six-Degrees-of-Freedom Joint Simulator
Authors: Ortigas Vásquez Ariana , Maas Allan , List Renate , Schütz Pascal , Taylor William R. , Grupp Thomas M.
Published: December 2022

The success of kinematic analysis that relies on inertial measurement units (IMUs) heavily depends on the performance of the underlying algorithms. Quantifying the level of uncertainty associated with the models and approximations implemented within these algorithms, without the complication of soft-tissue artefact, is therefore critical. To this end, this study aimed to assess the rotational errors associated with controlled movements. Here, data of six total knee arthroplasty patients from a previously published fluoroscopy study were used to simulate realistic kinematics of daily activities using IMUs mounted to a six-degrees-of-freedom joint simulator. A model-based method involving extended Kalman filtering to derive rotational kinematics from inertial measurements was tested and compared against the ground truth simulator values. The algorithm demonstrated excellent accuracy (root-mean-square error ≤0.9°, maximum absolute error ≤3.2°) in estimating three-dimensional rotational knee kinematics during level walking. Although maximum absolute errors linked to stair descent and sit-to-stand-to-sit rose to 5.2° and 10.8°, respectively, root-mean-square errors peaked at 1.9° and 7.5°. This study hereby describes an accurate framework for evaluating the suitability of the underlying kinematic models and assumptions of an IMU-based motion analysis system, facilitating the future validation of analogous tools.
The Preparation of Apigenin Nanoparticles and the Study of Their Anti-Inflammatory and Anti-Tumor Activities In Vitro
Authors: Wang Wei , Li Ying , Wang Huimei , Zhao Xiuhua
Published: December 2022

Apigenin (API) has many biological activities, but its poor solubility limits its clinical application. In this research, API nanoparticles were prepared by the liquid antisolvent precipitation (LAP) technique, which effectively improved the solubility and bioavailability of API. Through the design of a single-factor test, the effects of the type and dosage of surfactants, API concentration, the antisolvent to solvent volume ratio, the speed and time of stirring, the temperature of precipitation, and the dropping speed on the MPS (mean particle size) of API nanosuspension were carried out. The optimum technological conditions were determined as follows: 5 mg/mL of tween 80 as a surfactant, 20 mg/mL of API, an antisolvent/solvent volume ratio of 10, a 1200 r/min stirring speed for 5 min, a 45 °C precipitation temperature, and a 1 mL/min dropping speed. Under the optimum conditions, we obtained API nanosuspension with 170.5 nm MPS and then it was freeze-dried to obtain the API nanoparticles. Moreover, we characterized the API nanoparticles by SEM, FTIR, XRD, DSC, and TG. Results showed that although API nanoparticles transformed into an amorphous form, their internal chemical structure had not been changed and had a higher solubility. Finally, API nanoparticles’ anti-inflammatory activities were evaluated by observing the effect of API on nitric oxide (NO) production and IL-10 production toward RAW264.7 cells induced by lipopolysaccharide (LPS). Moreover, the anti-tumor effect of API was determined by testing cell viability and apoptosis. The results suggested that API nanoparticles exhibited much better anti-inflammatory and anti-tumor activities compared to raw API.
Gender, Class, and Ethnicity: Perspectives of White Portuguese and Black African Women on Labor Dynamics in the Cleaning Sector
Authors: Santos Maria Helena , Romão Núria , Cerqueira Carla
Published: December 2022

This study focuses on cleaning services in Lisbon, Portugal, to understand the dynamics of operating in this feminine context, mostly employing women of African origin. From a qualitative and intersectional perspective, the study encompasses 17 semi-structured individual interviews with women working in these services, nine of African origin (Black) and eight of Portuguese origin (White) between 29 and 66 years of age. The thematic analysis returned five themes portraying the specificities associated with women carrying out their activities in a context of low social status, particularly for Black women. Although we verified some of the negative consequences associated with tokenism, the intersections of gender, class, and race/ethnicity generated dynamics that also contradict this phenomenon.
Strengthening Namibia’s Flood Early Warning System through a Critical Gap Analysis
Authors: Moisès Deolfa Josè , Kunguma Olivia
Published: December 2022

Floods are considered leading hydrometeorological disasters, which are increasing in frequency, intensity and complexity with the evolution of climate change. Their associated impacts have detrimental and often prolonged implications for humankind, especially communities heavily reliant on the natural environment. The development and implementation of effective flood early warning systems (FEWSs) can serve to enhance coping strategies and strengthen the adaptive capacities of target communities while simultaneously minimising flood risks. However, shortcomings related to the lack of information on the operationalisation of these systems, the technical and financial requirements, the challenges faced and the directives related to their implementation have persisted, subverting risk reduction efforts at the grassroots level. Using data from key informant interviews and focus group discussions, this study employed a systematic analysis of the official Namibian flood early warning system based on the system’s implementation in Kabbe, Namibia. The study results revealed a need for significant changes across all system components as the FEWS follows a top-down, disintegrated and response-driven approach. Roles are undefined among institutions; funding is inadequate; and community risk perceptions, coping capacities and participation are disregarded. Based on the study findings, the researchers recommend significant changes in the design and application of the system, urging practitioners to recognise FEWSs as the continuous and integrated tools that they are.
An Enhanced Model Using the Kano Model, QFDE, and TRIZ with a Component-Based Approach for Sustainable and Innovative Product Design
Authors: Tandiono Yauwseph , Rau Hsin
Published: December 2022

In order to increase their competitiveness, companies need to have five important capabilities in the product development process, namely, the ability to identify important customer and environmental requirements, convert them into technical requirements, create innovative designs, and determine the best improvement alternatives. Based on a literature survey, previous studies are still inadequate in incorporating these five important capabilities simultaneously and effectively. This study proposes an enhanced model using the Kano model, Quality Function Deployment for Environment (QFDE), and the theory of inventive problem solving (TRIZ), with a component-based approach for systematically designing sustainable and innovative products. An example of a desk lamp design improvement is used to demonstrate the proposed model. After identifying customer and environmental requirements, they are specifically characterized and transformed into a detailed design target using a combination of the Kano model and the improved QFDE method. A thorough evaluation method is developed to determine the most prominent TRIZ solutions. This enhanced model is accomplished at the component level. The results show that the proposed model is capable of incorporating the five important capabilities while reducing process complexity, which greatly assists designers in generating sustainable and innovative designs with minimal dependence on designers’ subjectivity.
Numerical Analysis of Groundwater Effects on the Stability of an Abandoned Shallow Underground Coal Mine
Authors: Zevgolis Ioannis E. , Theocharis Alexandros I. , Deliveris Alexandros V. , Koukouzas Nikolaos C.
Published: December 2022

This work systematically quantifies groundwater’s effect on the roof stability of underground openings in shallow coal mines and indirectly assesses the potential for sinkhole formation. A specific stratigraphy was analyzed where the opening instability can lead to sinkhole formation, given the geological conditions, the overburden stratigraphy, and the depth of the openings. The groundwater recharge was investigated as an individual rainfall infiltration (short-term) and as groundwater dynamics (long-term), representing the accumulation of infiltrated rainwater with time. In the latter case, two approaches were employed for the porewater pressure calculation: (a) phreatic line with hydrostatic conditions and (b) steady-state flow based on constant groundwater head on the vertical boundaries at the model’s edges. The safety analysis was based on a simplified statics model relating the stability to the bending of the roof, and numerical analysis was employed for the stress analysis. The short-term safety remained unaffected as rainfall water accumulated on the aquitard to form perched water. The long-term safety deteriorated due to the increase of the tensile stresses in the roof of the underground openings with the rise of the groundwater table. The phreatic line approach is the most conservative, resulting in lower safety than steady-state flow.
Satisfaction of Tourism Communities in World Heritage Sites Based on Residents’ Perceptions—Study Area of Mount Sanqingshan National Park, PRC
Authors: Nian Sifeng , Liu Fajian , Chen Min , Cheng Guoqing
Published: December 2022

Tourist communities have enjoyed the benefits of tourist development in various regions and have paid the associated costs, resulting in different attitudes towards tourism development in World Heritage Sites. On this basis, this study takes the Mount Sanqingshan National Park, a World Natural Heritage site, collects 330 examples of perceptions of residents of tourism communities, relies on social exchange theory and community participation theory, uses structural equation modeling as a technical methodology, and constructs a conceptual model, including perceived benefits and costs, community satisfaction, and place attachment as mediating variables from the view of tourism’s social, economic, environmental, and heritage protection impacts. The study shows that: first, the perceptions of benefits have a significant positive influence on place attachment and community satisfaction; second, the perceived cost has a significant negative influence on place attachment, and a negative influence on community satisfaction does not hold true; third, place attachment has a full mediating effect on tourist cost perception and satisfaction, a partial mediating effect on tourist benefit perception and satisfaction, and a significant positive effect on community satisfaction. Finally, we propose the ‘SHE-ABC’ framework of WHS tourist community satisfaction based on the perspectives of heritage tourism impact perception and place attachment. The results of the study have theoretical value and practical guidance to sustainable development, tourist industry, and community management of World Heritage Sites.
Cooling and Power from Waste and Agriculture Residue as a Sustainable Strategy for Small Islands—A Case Study of Tonga
Authors: Yousefzadeh Moslem , Lenzen Manfred , Tariq Muhammad Arsalan
Published: December 2022

Identifying local energy sources and devising a circular economy could improve self-sufficiency in many Pacific Islands. On the islands with significant agriculture, the residue from the cultivation of plants has promising energy potential. The waste stream is another potential source of energy that otherwise should undergo proper treatment. Additionally, cold-storage capacity improves the preservation of crops and increases the agricultural exports of these islands. This study proposes a combined cooling and power (CCP) system driven by biomass from agriculture residue and waste streams as fuel for different districts in Tonga. The units supply a fraction of the districts’ electricity demand and provide sufficient cold-storage capacity to preserve the prospective yield of a fraction of fallow lands. The technical and economic performance of the CCP units was analysed for different fractions of electricity demand and fallow land exploitation in each district during a year of operation. The results show that the optimum combination of the CCP units supplies 38% of the total electricity demand of Tonga and prevents the annual consumption of 7.4 million litres of diesel and emission of 20 kilotonnes of CO2. In addition, it provides 3700 m2 of cold-storage area, which is sufficient for preserving the prospective yield of the exploitation of 27% of the total fallow land of Tonga. Annual export revenue of about AU$10 million is expected from such a cold-storage capacity for Tongan farmers. Furthermore, the units consume 10,000 tonnes of annual waste, significantly reducing waste management costs. This study presents an example of a comprehensive circular-economy solution for a remote island state that improves its socioeconomic and environmental condition by supplying the community’s local needs from its available and abundant resources under a viable business model. The solution presented in this study can be adapted to many island communities with significant agriculture in the economy and crucial energy and cooling needs.
Hierarchical Component Model (HCM) of Career Success and the Moderating Effect of Gender, from the Perspective of University Alumni: Multigroup Analysis and Empirical Evidence from Quevedo, Ecuador
Authors: Pico-Saltos Roberto , Sabando-Vera David , Yonfa-Medranda Marcela , Garzás Javier , Redchuk Andrés
Published: December 2022

The professional success of graduates is closely linked to the value of university performance, perhaps much more so than other indicators. This study analyses the predictive and explanatory capacity of a model on the career success of university alumni in a developing country (Ecuador), which serves as empirical evidence on the subject; we examine the moderating effect of gender on the relationships between constructs in the model. We use a Hierarchical Component Model (HCM) of Partial Least Squares Structural Equations (PLS-SEM) and a permutation-based multigroup analysis for moderation. The used database comprises 444 records from a self-administered survey of graduates of the State Technical University of Quevedo (UTEQ)—Ecuador. On the findings, the model proposed has good explanatory and predictive power for career success. Objective success has a lower incidence of professional success (22% of the variance explained) than subjective success (78% of the variance explained). In none of the latent variable correlations in the model were gender differences between men and women found to be statistically significant. Finally, we also cover the study’s theoretical and practical implications.
Flexible Working Arrangements and Social Sustainability: Study on Women Academics Post-COVID-19
Authors: Alsulami Alanoud , Mabrouk Fatma , Bousrih Jihen
Published: December 2022

One of the main challenges faced by companies, scholars, and governments nowadays is achieving economic, environmental, and social sustainability. Remote working, reduced work weeks, and other types of flexible working time arrangements (FWAs) are the new characteristics that will shape the future of work to ensure social sustainability. In changing work patterns, working styles are changed to possibly improve women employees’ mental health and life–work balance. However, recently, very few firms have succeeded in adopting these new FWA trends. The purpose of this paper is to investigate women’s preferences towards FWAs in the academic sector as a social sustainability source. We investigate the effect of the COVID-19 pandemic on female faculty members’ future job preferences. The data used in the research are collected from a survey given to female faculty members who work in a Saudi women’s university and have already experienced FWAs during the COVID-19 period. The study uses mixed methods of research, combining a choice modeling (CM) method, one sample t-test, a paired sample t-test, cluster analysis, and probit models. Our results show that flexible working arrangements improve the wellbeing of women employees, which ensures sustainable social development. The findings also show that flexibility in location plays a significant role in the decision made by female faculty members when revealing their flexibility preferences. However, flexibility in time did not play a significant role in the decisions made by respondents. This study adds to the empirical evidence in the current literature on female academic staff preferences for FWAs in Saudi Arabia, using choice modeling conjoint analysis and mixed approaches.