Authors:Sruthi Thiraviam Saravanan, Jaysiva Ganesamurthi, Shen-Ming Chen, Tse-Wei Chen, Chun-Jung Chen, Keseven Lakshmanan, Partheeban Chinnamuthu, Xiaoheng Liu, Ramachandran Balaji First page: 536 Abstract: Increasingly sophisticated techniques for falsifying and forging legal documents demand non-destructive and accurate analysis methods. Researchers have extensively investigated ink discrimination through an interdisciplinary analysis involving Raman spectroscopy and chemometrics, which is now regarded as a leading forensic document analysis approach. In this study, a groundbreaking method was developed to identify the specific origin of blue-ink pens used in written documents. By employing Raman spectroscopy in conjunction with principal component analysis (PCA), we successfully differentiated between 45 different blue-ink pens used on various documents. The Raman spectroscopy analysis provided a visual examination of each blue ink’s unique Raman signature, and PCA was then applied to the processed spectral data. Moreover, we successfully distinguished highly similar ink types in documents through the combined use of Raman spectroscopy, Pearson’s correlation analysis, and a statistical approach (PCA). Citation: J PubDate: 2023-09-26 DOI: 10.3390/j6040035 Issue No:Vol. 6, No. 4 (2023)
Authors:Ritusnata Mishra, Chandra Shekhar Prasad Ojha First page: 544 Abstract: The friction factor is a widely used parameter in characterizing flow resistance in pipes and open channels. Recently, the application of machine learning and artificial intelligence (AI) has found several applications in water resource engineering. With this in view, the application of artificial intelligence techniques on Moody’s diagram for predicting the friction factor in pipe flow for both transition and turbulent flow regions has been considered in the present study. Various AI methods, like Random Forest (RF), Random Tree (RT), Support Vector Machine (SVM), M5 tree (M5), M5Rules, and REPTree models, are applied to predict the friction factor. While performing the statistical analysis (root-mean-square error (RMSE), mean absolute error (MAE), squared correlation coefficient (R2), and Nash–Sutcliffe efficiency (NSE)), it was revealed that the predictions made by the Random Forest model were the most reliable when compared to other AI tools. The main objective of this study was to highlight the limitations of artificial intelligence (AI) techniques when attempting to effectively capture the characteristics and patterns of the friction curve in certain regions of turbulent flow. To further substantiate this behavior, the conventional algebraic equation was used as a benchmark to test how well the current AI tools work. The friction factor estimates using the algebraic equation were found to be even more accurate than the Random Forest model, within a relative error of ≤±1%, in those regions where the AI models failed to capture the nature and variation in the friction factor. Citation: J PubDate: 2023-10-07 DOI: 10.3390/j6040036 Issue No:Vol. 6, No. 4 (2023)
Authors:Opeyemi A. Oyewo, Seshibe S. Makgato First page: 564 Abstract: The biogenic synthesis of copper oxide nanoparticles was explored using the Myriophyllum spicatum plant through a process involving co-precipitation and was utilized as an effective photocatalyst for the reduction of Cr(VI) and Pb(II) ions in an aqueous solution. The plant-mediated CuO nanoparticles were characterized using microscopic techniques (TEM and SEM), FT-IR, and XRD analyses. The amount of the reduced metal ions was determined by UV–visible and Atomic Absorption (AA) spectrophotometers. The analyses of the functional group present in the leaf extract revealed the type of bioactive molecules that were involved in the formation of copper oxide nanoparticles. The nanoparticles were used in the photo-enhanced reduction of hexavalent Cr and divalent Pb ions, and the impact of solution pH, initial metal concentrations, and photocatalyst dosage was investigated to establish the optimal performance of the CuO nanoparticles. Results revealed a direct association between the reduction of metal ions and catalyst dosage in both cases. A maximum percentage reduction of 89.2% and 79.1% was achieved for Cr(VI) and Pb(II), respectively, using 3 g of the CuO nanoparticles. This confirms that the CuO nanoparticles exhibited higher efficiency for Cr(VI) reduction as compared to Pb(II) reduction and indicates that CuO nanoparticles are a promising photocatalyst that is capable of reducing these metal ions into less toxic products. Citation: J PubDate: 2023-10-31 DOI: 10.3390/j6040037 Issue No:Vol. 6, No. 4 (2023)
Authors:Sarwan Ali, Murray Patterson First page: 579 Abstract: Data visualization plays a crucial role in gaining insights from high-dimensional datasets. ISOMAP is a popular algorithm that maps high-dimensional data into a lower-dimensional space while preserving the underlying geometric structure. However, ISOMAP can be computationally expensive, especially for large datasets, due to the computation of the pairwise distances between data points. The motivation behind this study is to improve efficiency by leveraging an approximate method, which is based on random kitchen sinks (RKS). This approach provides a faster way to compute the kernel matrix. Using RKS significantly reduces the computational complexity of ISOMAP while still obtaining a meaningful low-dimensional representation of the data. We compare the performance of the approximate ISOMAP approach using RKS with the traditional t-SNE algorithm. The comparison involves computing the distance matrix using the original high-dimensional data and the low-dimensional data computed from both t-SNE and ISOMAP. The quality of the low-dimensional embeddings is measured using several metrics, including mean squared error (MSE), mean absolute error (MAE), and explained variance score (EVS). Additionally, the runtime of each algorithm is recorded to assess its computational efficiency. The comparison is conducted on a set of protein sequences, used in many bioinformatics tasks. We use three different embedding methods based on k-mers, minimizers, and position weight matrix (PWM) to capture various aspects of the underlying structure and the relationships between the protein sequences. By comparing different embeddings and by evaluating the effectiveness of the approximate ISOMAP approach using RKS and comparing it against t-SNE, we provide insights on the efficacy of our proposed approach. Our goal is to retain the quality of the low-dimensional embeddings while improving the computational performance. Citation: J PubDate: 2023-10-31 DOI: 10.3390/j6040038 Issue No:Vol. 6, No. 4 (2023)
Authors:Friday Fosta Fred Masumbu, John Finias Kamanula, Anthony Mwakikunga, Bonface Mwamatope, David Tembo First page: 592 Abstract: This study evaluated the phytochemical composition and antioxidant activity of Piliostigma thonningii (Schumach.) Milne-Redh, Psorospermum febrifugum Spach, Inula glomerata Oliv. and Hiern, Zanthoxylum chalybeum Engl. and Monotes africanus A.DC., claimed to treat cancer by Malawian traditional herbal practitioners. Ground and dried plant extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC), total alkaloid content (TAC), ferric reducing antioxidant power (FRAP) and 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) using standard assays. The TPC, TFC, and TAC ranged from 539 ± 2.70 to 4602 ± 32 mg GAE/g DW, 6.18 ± 0.03 to 64.04 ± 0.16 mg QE/g DW and 19.25 ± 0.07 to 76.05 ± 0.36 mg CE/g DW, respectively, and the variations were significant, p < 0.05. FRAP values ranged from 82.15 ± 0.7 to 687.28 ± 0.71 mg TEAC/g DW and decreased in the following order: P. thoningii (Schumach.) Milne-Redh > P. febrifugum Spach > M. africanus A.DC > Z. chalybeum Engl > I. glomerata Oliv. and Hiern. The scavenging activity (SA50) of the extracts ranged from 0.09 ± 0.01 to 1.57 ± 0.01 μg/mL of extract with P. thonningii (Schumach.) Milne-Redh showing the lowest value. Based on the levels of phenolic compounds and their antioxidant activity, the plants in this study could be considered for use as medicinal agents and sources of natural bioactive compounds and antioxidants. Citation: J PubDate: 2023-11-20 DOI: 10.3390/j6040039 Issue No:Vol. 6, No. 4 (2023)
Authors:Yi Zhao, Yongmeng Wu, Mingjing Zhao, Zerui Xiang, Jinyi Zhi, Bochu Xu First page: 361 Abstract: High-speed health trains have the advantages of large rescue volume, strong continuous operation capability, and medical treatment on the way. It is the best transport platform for large-scale medical transfer tasks. To solve the problem of space limitations and the vehicle formation of high-speed health trains, a new method of space layout design and evaluation of high-speed health trains based on improved systematic layout planning (SLP) was proposed. First, SLP was improved, and the relationship between functional carriages was reasonably marshaled using the improved SLP. Then, according to the space constraints of high-speed trains and the requirements of the man–machine environment, the space layout of the vehicles was designed, and 3ds MAX software was used to visualize the designed layout structure. Finally, the static and dynamic simulation effects and adaptability of the design scheme were evaluated using the digital virtual simulation software JACK. The design scheme can meet the requirements of human–computer interaction efficiency. Compared with previous studies, the results of this study reflect the superiority and rationality of the design in functional configuration, space utilization, medical treatment, and injury-carrying capacity. The results of this study can provide theoretical support for the formation of high-speed health trains, and provide a reference for the research and development of such trains. It has certain practical application value. Citation: J PubDate: 2023-06-29 DOI: 10.3390/j6030025 Issue No:Vol. 6, No. 3 (2023)
Authors:Alexey Y. Bykovsky, Nikolay A. Vasiliev First page: 384 Abstract: Unmanned network robotics is a new multidisciplinary field that involves many fields of computer networks, multi-agent systems, control theory, 5G and 6G Internet, computer security, and wireless quantum communications. Efficient conjugation of such technologies needs to design new data verification schemes for robotic agents using the advantages of quantum key distribution lines. For such schemes the joint use of known fuzzy logic parametrical -gates and discrete multiple-valued logic models simplifies the application of quantum quasi-random keys. Namely, the separate regulating parameter in -gates is the most convenient tool to use quantum keys in comparatively simple classical control and verification procedures that do not involve quantum logic gates. Citation: J PubDate: 2023-07-02 DOI: 10.3390/j6030026 Issue No:Vol. 6, No. 3 (2023)
Authors:Rasit Onur Topaloglu First page: 411 Abstract: Having access to a unique quantum circuit that one wants to protect against use by others is a very likely scenario in industrial computing. However, currently, users rely on classical computer security schemes, which have known shortcomings. In this paper, we introduce a novel protection scheme along with a survey of other known methods to protect quantum information. In particular, we review physically unclonable functions (PUFs), obfuscation, and introduce quantum logic locking (QLL). The latter technique provisions end users to protect their circuit from an adversary through the use of a secret key. Citation: J PubDate: 2023-07-12 DOI: 10.3390/j6030027 Issue No:Vol. 6, No. 3 (2023)
Authors:Sergio Vélez, Raquel Martínez-Peña, David Castrillo First page: 421 Abstract: Vegetation indices (VIs) have long been a crucial tool for monitoring plant growth and health, assessing the impact of environmental factors on vegetation, and supporting decision-making processes in agriculture and forestry. Traditionally, these mathematical formulations, leveraging the spectral response of plants to sunlight, have been instrumental in assessing vegetation health. However, emerging research suggests some unconventional applications that extend the scope of VIs. This article surveys the traditional and novel uses of VIs in various fields, including other applications such as climate change studies, disaster management, or microorganism assessment. It underscores the value of VIs, such as the normalized difference vegetation index (NDVI), or the enhanced vegetation index (EVI), in tracking climate-related shifts, mitigating the impact of disasters, assessing microbial terroir, organic production, and even aiding the wine industry. Nonetheless, despite their promise, the practical application of VIs also presents interpretational and technical challenges that need to be addressed. Hence, while the vast potential of VIs is underscored in this article, it also calls for continued technological advancements and research efforts to fully harness their benefits, ultimately aiding in the sustainable management of our environment. The objective of this review is not only to reflect on the current situation, but also to explore innovative and unconventional applications of vegetation indices. This involves anticipating the potential of this dynamic and rapidly advancing scientific tool, rather than solely following mainstream approaches. Citation: J PubDate: 2023-07-25 DOI: 10.3390/j6030028 Issue No:Vol. 6, No. 3 (2023)
Authors:Alexander G. Aleksandrov First page: 437 Abstract: In this paper, we studied the Picard–Fuchs systems and equations which appear in the theory of Gauss–Manin systems and connections associated with deformations of isolated singularities. Among other things, we describe some interesting properties of such systems and relationships between them. Then we show how to calculate the fundamental solutions to the Gauss–Manin system for Aμ-singularities and to the corresponding generalized Legendre equations in terms of the multidimensional Horn’s hypergeometric functions. In conclusion, some important questions concerning basic properties of the local and global Picard–Fuchs systems of Pfaffian type, involving integrability conditions and commuting relations, are discussed in some detail. Citation: J PubDate: 2023-08-04 DOI: 10.3390/j6030029 Issue No:Vol. 6, No. 3 (2023)
Authors:Koichi Takahashi First page: 460 Abstract: This paper is aimed at eliciting consistency conditions for the existence of unsteady incompressible axisymmetric swirling viscous Beltrami vortices and explicitly constructing solutions that obey the conditions as well as the Navier–Stokes equations. By Beltrami flow, it is meant that vorticity, i.e., the curl of velocity, is proportional to velocity at any local point in space and time. The consistency conditions are derived for the proportionality coefficient, the velocity field and external force. The coefficient, whose dimension is of [length−1], is either constant or nonconstant. In the former case, the well-known exact nondivergent three-dimensional unsteady vortex solutions are obtained by solving the evolution equations for the stream function directly. In the latter case, the consistency conditions are given by nonlinear equations of the stream function, one of which corresponds to the Bragg–Hawthorne equation for steady inviscid flow. Solutions of a novel type are found by numerically solving the nonlinear constraint equation at a fixed time. Time dependence is recovered by taking advantage of the linearity of the evolution equation of the stream function. The proportionality coefficient is found to depend on space and time. A phenomenon of partial restoration of the broken scaling invariance is observed at short distances. Citation: J PubDate: 2023-08-05 DOI: 10.3390/j6030030 Issue No:Vol. 6, No. 3 (2023)
Authors:Rajvi N. Thakkar, Ivelina P. Kioutchoukova, Ian Griffin, Devon T. Foster, Pratiksha Sharma, Eduardo Molina Valero, Brandon Lucke-Wold First page: 477 Abstract: The glymphatic system is a newly discovered waste-clearing system that is analogous to the lymphatic system in our central nervous system. Furthermore, disruption in the glymphatic system has also been associated with many neurodegenerative disorders (e.g., Alzheimer’s disease), traumatic brain injury, and subarachnoid hemorrhage. Thus, understanding the function and structure of this system can play a key role in researching the progression and prognoses of these diseases. In this review article, we discuss the current ways to map the glymphatic system and address the advances being made in preclinical mapping. As mentioned, the concept of the glymphatic system is relatively new, and thus, more research needs to be conducted in order to therapeutically intervene via this system. Citation: J PubDate: 2023-08-08 DOI: 10.3390/j6030031 Issue No:Vol. 6, No. 3 (2023)
Authors:María Jesica Montero-Martínez, María del Refugio Castañeda-Chávez, Fabiola Lango-Reynoso, Gabycarmen Navarrete-Rodríguez, Leonardo Martínez-Cárdenas First page: 492 Abstract: The management of effluents and their treatment is a fundamental issue in water management, the removal of different types of contaminants is another relevant issue for public health and the environment. Bacteria are one of the main types of contaminants in untreated water discharged to receiving bodies. The objective of this research was to evaluate the removal efficiency of pathogenic bacteria in a horizontal feeding subsurface artificial wetland that treats wastewater originated from the Boca de Río Technological Institute, Veracruz, Mexico. A hybrid system composed of seven cells with three types of substrates and ornamental type vegetation was designed; the indicators evaluated were the concentration of total and fecal coliforms and the efficiency of bacterial removal in the stages of the system. The artificial wetland system demonstrated a significant reduction (p < 0.05) between the different cells of the system. The values of pathogenic bacteria removal obtained in the wetland were higher than 99% in the cells of the system and times. In conclusion, it was identified that the interaction of the components of this system and its operation under the climatic seasons of the site influenced the removal efficiency of pathogenic bacteria, allowing optimal removal efficiency. Citation: J PubDate: 2023-08-28 DOI: 10.3390/j6030032 Issue No:Vol. 6, No. 3 (2023)
Authors:Mikiko Watanabe, Alessandro Laviano, Angela Balena, Angelo Vitaterna, Emiliano Angeloni, Raffaella Toscano, Giuseppe Natoli, Carla Lubrano, Lucio Gnessi First page: 508 Abstract: With the prevalence of obesity soaring and the absence of an effective and safe treatment that is low-cost and always feasible, food supplements have gained attention for their potential benefits in the absence of significant safety concerns. Cinnamomum cassia (CC) and Withania somnifera (WS) are plant-based supplements reported to be effective in improving metabolic health and body composition, the first mainly acting on insulin resistance and the second on energy expenditure and leptin resistance, as shown in preclinical and some clinical studies. Their combination, which is possibly synergistic given their different mechanisms of action, has never been studied. This was a double-blind placebo-controlled study. Patients with overweight or obesity were prescribed a mildly hypocaloric diet with 300 mg CC plus 150 mg WS tid for 4 weeks in a crossover design; anthropometric parameters and safety outcomes were collected. Forty patients were enrolled, and the combination CC + WS induced significant weight loss compared with placebo (−2.66% vs. −1.28%, respectively; p = 0.0002). No significant adverse events were recorded. Our study demonstrates for the first time that the tested combination is an inexpensive yet effective strategy to enhance weight loss in patients receiving a mildly hypocaloric diet. Further studies are warranted to investigate the mechanisms underlying the weight loss effect of CC/WS in human subjects, as well as to explore potential additional metabolic effects obtained with this treatment. Citation: J PubDate: 2023-09-02 DOI: 10.3390/j6030033 Issue No:Vol. 6, No. 3 (2023)
Authors:Rizos N. Krikkis First page: 517 Abstract: In the present study, a numerical bifurcation analysis of a PTC thermistor problem is carried out, considering a realistic heat dissipation mechanism due to conduction, nonlinear temperature-dependent natural convection, and radiation. The electric conductivity is modeled as a strongly nonlinear and smooth function of the temperature between two limiting values, based on measurements. The temperature field has been resolved for both cases were either the current or the voltage (nonlocal problem) is the controlling parameter. With the aid of an efficient continuation algorithm, multiple steady-state solutions that do not depend on the external circuit have been identified as a result of the inherent nonlinearities. The analysis reveals that the conduction–convection parameter and the type of the imposed boundary conditions have a profound effect on the solution structure and the temperature profiles. For the case of current control, depending on the boundary conditions, a complex and interesting multiplicity pattern appears either as a series of nested cusp points or as enclosed branches emanating from pitchfork bifurcation points. The stability analysis reveals that when the device edges are insulated, only the uniform solutions are stable, namely, one “cold” and one “hot”. A key feature of the “hot” state is that the corresponding temperature is proportional to the input power and its magnitude could be one or even two orders of magnitude higher than the “cold” one. Therefore, the change over from the “cold” to the “hot” state induces a thermal shock and could perhaps be the reason for the mechanical failure (delamination fracture) of PTC thermistors. Citation: J PubDate: 2023-09-04 DOI: 10.3390/j6030034 Issue No:Vol. 6, No. 3 (2023)
Authors:Raj Deep, Takuma Akazawa, Toshiyuki Yoshida, Yasuhisa Fujita First page: 207 Abstract: The fabrication of ZnO nanoparticles (NPs) was monitored and studied in situ by controlling the plasma parameters of the direct current (DC) arc plasma system, such as the current density and chamber pressure. The optical emission signature of nitrogen was spectroscopically studied using optical emission spectroscopy (OES) techniques, and it showed a dependency on the nitrogen concentration in the ZnO nanoparticles in relation to the output of the ZnO NPs-based homojunction light-emitting diodes (LEDs). The synthesized NPs had a good crystalline quality and hexagonal wurtzite structure, and they were characterized by X-ray diffraction (XRD) techniques and scanning electron microscope (SEM). The photoluminescence properties of the ZnO NPs and the optical and electrical parameters of the LEDs were also analyzed and correlated. The results indicate that the nitrogen dopants act as acceptors in the ZnO NPs and are favored in low plasma temperatures during fabrication. We anticipate that the results can provide an effective way to realize reliable nitrogen-doped p-type ZnO and tremendously encourage the development of low-dimensional ZnO homojunction LEDs. Citation: J PubDate: 2023-04-07 DOI: 10.3390/j6020016 Issue No:Vol. 6, No. 2 (2023)
Authors:Matthew T.J. Halma, Jessica Rose, Theresa Lawrie First page: 220 Abstract: Pharmacovigilance databases are showing evidence of injury in the context of the modified COVID-19 mRNA products. According to recent publications, adverse event reports linked to the mRNA COVID-19 injections largely point to the spike protein as an aetiological agent of adverse events, but we propose that the platform itself may be culpable. To assess the safety of current and future mRNA vaccines, further analysis is needed on the risks due to the platform itself, and not specifically the expressed antigen. If harm can be exclusively and conclusively attributed to the spike protein, then it is possible that future mRNA vaccines expressing other antigens will be safe. If harms are attributable to the platform itself, then regardless of the toxicity, or lack thereof, of the antigen to be expressed, the platform may be inherently unsafe, pending modification. In this work, we examine previous studies of RNA-based delivery by a lipid nanoparticle (LNP) and break down the possible aetiological elements of harm. Citation: J PubDate: 2023-04-17 DOI: 10.3390/j6020017 Issue No:Vol. 6, No. 2 (2023)
Authors:Sarwan Ali, Babatunde Bello, Murray Patterson First page: 236 Abstract: The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, has generated a renewed interest in the larger family of Coronaviridae, which causes a variety of different respiratory infections in a variety of different hosts. Understanding the mechanisms behind the ability of a family of viruses to spill over into different hosts is an ongoing study. In this work, we studied the relationship between specific amino acid sites and the solvent accessibility of the surface (or spike) protein of different Coronaviridae. Since host specificity hinges on the portion(s) of the protein that interfaces with the host cell membrane, there could be a relationship between information gain in specific amino acid sites and solvent accessibility. We found a connection between sites with high information gain and solvent accessibility within several major subgenera of Coronaviridae. Such a connection could be used to study other lesser-known families of viruses, which is desirable because information gain is much easier to compute when the number of sequences is large, as we show. Finally, we produced a visualization of the sequences within each major subgenus and discussed several regions of interest, as well as focused on some pairs of Coronaviridae hosts of interest. Citation: J PubDate: 2023-04-22 DOI: 10.3390/j6020018 Issue No:Vol. 6, No. 2 (2023)
Authors:Pavel Anatolyevich Nikolaychuk First page: 248 Abstract: The spectrophotometric methods of determination of the active pharmaceutical ingredients meloxicam and nimesulide were reviewed and a simple UV-spectrophotometric method for the determination of these active pharmaceutical ingredients in industrial equipment cleaning validation samples was proposed. The methods were based on extraction of the residual quantities of meloxicam and nimesulide from the manufacturing equipment surface by the concentrated sodium carbonate solution and the subsequent UV-spectrophotometric determination of the basic forms of the drugs at the wavelength of 362 nm for meloxicam and at 397 nm for nimesulide. The calibration graphs were linear in the range from 5 to 25 mg/L of both nimesulide and meloxicam, the molar attenuation coefficients were 6100 m2/mol for nimesulide and 9100 m2/mol for meloxicam, the limit of detection was 0.8 mg/L for nimesulide and 1.9 mg/L for meloxicam and the limit of quantification was 2.5 mg/L for nimesulide and 5.8 mg/L for meloxicam. The methods were selective with respect to the common excipients, showed a good accuracy (the relative uncertainty did not exceed 7%) and precision (the relative standard deviation did not exceed 4%), did not require lengthy sample preparation or sophisticated laboratory equipment and were suitable for the routine analysis of cleaning validation samples. Citation: J PubDate: 2023-04-22 DOI: 10.3390/j6020019 Issue No:Vol. 6, No. 2 (2023)
Authors:Amal Al-Ghorayeb, Walid Al-Shaar, Adel Elkordi, Ghaleb Faour, Mohamad Al-Shaar, Youssef Attalah First page: 267 Abstract: Urbanization has led to the degradation of green areas and natural resources, which are critical for preserving biodiversity and natural benefits. Sustainable urban development (SUD) practices aim to balance urbanization with preserving and protecting green land and natural resources to achieve greater sustainability. This study evaluated land suitability for SUD in the Nabatiyeh area of Lebanon using a multi-criteria decision analysis technique, the analytical hierarchy process, combined with a geographic information system. The elevations and slopes were the most important criteria, followed by the distances from urban agglomeration and industrial areas, accessibility, and land cover types, with corresponding weights of 34% and 36%, 12%, 9%, 6%, and 3%, respectively. The study created a suitability map for future SUD. This identification assists urban planners and policymakers in making informed decisions regarding the development of urban areas. The study’s findings highlight the efficiency of combining multi-criteria decision analysis with geospatial techniques for urban planning and environmental management in promoting sustainable development and protecting the environment. Future research could explore the possibility of integrating administrative reforms to promote SUD, including improving governance, enhancing the efficiency of governmental agencies responsible for urban development, building scientific capacities, and increasing officials’ accountability. Citation: J PubDate: 2023-05-15 DOI: 10.3390/j6020020 Issue No:Vol. 6, No. 2 (2023)
Authors:Alexander K. Saraev, Nikita Yu. Bobrov, Arseny A. Shlykov First page: 286 Abstract: In the controlled source radiomagnetotelluric (CSRMT) sounding method, a horizontal magnetic dipole, HMD (vertical loop) or a horizontal electric dipole, and HED (grounded line) are used as sources. When working with HMD, the source is usually tuned to resonance to increase the current in the loop. However, the disadvantage of this approach is the narrow frequency range realized in the CSRMT method (1–12 kHz) and the short operating distance from the source (600–800 m). The need to tune the source to resonance at each selected frequency reduces the efficiency of the survey. In the case of using HED for sounding, measurements are performed in a wider frequency range of 1 to 1000 kHz, and along with the signal of the base frequency, its subharmonics are measured. In this case, emitted signal measurements are possible at a distance of up to 3–4 km from the source. At the same time, the disadvantage of using HED is that it requires grounding, the arrangement of which requires additional time when working on frozen ground or dry stony soil. We consider the possibilities of generation and registration of signals of subharmonics of base frequencies when applying the CSRMT method with loop sources—HMD and VMD (horizontal loop). A matching unit (MU) based on a step-up transformer was developed, which increases the output voltage of the CSRMT transmitter. In a field test with base frequencies of 20, 40, and 80 kHz, the signal amplitudes increased by a factor of two to four for subharmonics at frequencies of 60–200 kHz and by up to 10–13 times for subharmonics at frequencies of 200–500 kHz due to transformation of signal spectrum provided by MU. The possibility of using odd subharmonics of base frequencies for inversion has been demonstrated in the results of field experiments with different sources (HED, HMD, and VMD). This expands the frequency range of the method when working with loop sources and increases the survey’s effectiveness. The use of loop sources in the CSRMT method is especially advantageous for winter work in Arctic regions. Citation: J PubDate: 2023-05-17 DOI: 10.3390/j6020021 Issue No:Vol. 6, No. 2 (2023)
Authors:Rizos N. Krikkis First page: 302 Abstract: The multiple steady states of Ag/Bi2212-composite high-Tc superconducting leads modeling current delivery to a superconducting magnet have been numerically calculated. The model is based on longitudinal conduction combined with convective heat dissipation from a helium gas stream along the conductor. Because of the nonlinearities introduced by the voltage–current relationship and the temperature-dependent material properties, up to three solutions have been identified within the range of parameters considered. Linear stability analysis reveals that two of them are stable, i.e., the superconducting and the normal branches, while the remaining one is unstable. The limit points separating the stable from the unstable steady states form the blow-up threshold, beyond which any further increase in the operating current results in a thermal runway. Interesting findings are that for low filling ratios no bounded solution exists when the length of the lead exceeds the lower limit point, while very high maximum temperatures may be encountered along the normal solution branch. The effect of various parameters such as the conduction–convection parameter, the applied current, and the reduction in coolant flow (LOFA) on the bifurcation structure and their stabilization effect on the blow-up threshold are also evaluated. Apart from the steady and unsteady operating modes, the multiplicity analysis is also used to identify the range of the design and operating variables where safe operation, with a sufficient margin from the onset of instabilities, may beestablished, thus facilitating the protection of the leads and the device connected to it. Citation: J PubDate: 2023-05-31 DOI: 10.3390/j6020022 Issue No:Vol. 6, No. 2 (2023)
Authors:Michael L. Carty, Stephane Bilodeau First page: 318 Abstract: In this review, the authors conducted benchmarks for three thermodynamic models to analyze PSA-based medical oxygen concentrator (MOC) systems to allow for optimization and operational flexibility. PSA oxygen generator plants are good medical-grade oxygen sources, a crucial tool in healthcare from the primary to the tertiary level. However, they must be designed accordingly and properly operated, considering key design goals such as improving adsorbent productivity, improving oxygen recovery, and innovating to reduce unit size and weight. The importance of mapping the performance of various design and operating requirements or designs themselves on outlet product specifications and production effectiveness is outlined. Emphasizing optimal PSA design and operation, the authors suggest considering simulation-based optimization frameworks or high-fidelity modeling for the optimal layout and operation conditions of adsorption-based MOC systems. Notwithstanding, a simplified first-principles-based model with additional assumptions and simplifications generates a large volume of scenarios faster. Therefore, it represents a good approach for a feasibility study dealing with many options and designs or even the real-time monitoring of PSA operating conditions. All this paved the way for efficient translation into machine learning models and even deep learning networks that might be better suited to simulate the complex PSA process. The conclusion outlines that PSA-based plants can be flexible and effective units using any of the three models when properly optimized. Citation: J PubDate: 2023-06-02 DOI: 10.3390/j6020023 Issue No:Vol. 6, No. 2 (2023)
Authors:Pedro Pérez Medina, María Guadalupe Galindo Mendoza, Gregorio Álvarez Fuentes, Leonardo David Tenorio Martínez, Valter Armando Barrera López First page: 342 Abstract: The sugarcane industry has a high environmental impact. In countries such as Mexico, cultivation and harvesting practices consume and pollute many ecological resources. However, quantifying these impacts is difficult due to their diverse nature and different units of measurement. In this study, an approach with two focuses was taken to assess the environmental costs of the sugarcane industry in San Luis Potosí, México. The first focus is human health costs related to air pollution (black carbon) and the second one is a lifecycle assessment applied to the production phase. In the first case, four scenarios, with different concentrations and populations, were projected. Costs of 516.8 thousand USD were estimated for a scenario in which black carbon concentrations exceeded the WHO reference by one unit for the total population. In the second case, costs of 642 million USD were estimated for the impairment of seven ecosystem-based services. These estimates may vary due to the source and specificity of the information provided, but nevertheless are considered an appropriate approximation of the cost of environmental damage. It is recommended that first-hand information be collected and systematized to improve the certainty of the estimates and that changes to sugarcane agrifood systems be considered to reduce environmental costs. Citation: J PubDate: 2023-06-03 DOI: 10.3390/j6020024 Issue No:Vol. 6, No. 2 (2023)
Authors: Gupta, Jayaraman, Sidhu, Malviya, Chatterjee, Chhikara, Singh, Chanda First page: 32 Abstract: Foot-related problems are prevalent across the globe, and this issue is aggravated by the presence of diabetes mellitus. Diabetic-foot-related issues include extreme foot pain, plantar corns, and diabetic foot ulcers. To assess these conditions, accurate characterization of plantar pressure is required. In this work, an in-shoe, low-cost, and multi-material pressure measuring insole, based on a piezoresistive material, was developed. The device has a high number of sensors, and was tested on 25 healthy volunteers and 25 patients with different degrees of diabetes. The working range of the device was observed to be 5 kPa to 900 kPa, with an average hysteresis error of 3.25%. Plantar pressure was found to increase from healthy to diabetic volunteers, in terms of both standing and walking. In the case of the diabetic group, the-high pressure contact area was found to strongly and positively correlate (R2 = 0.78) with the peak plantar pressure. During the heel strike phase, the diabetic volunteers showed high plantar pressure on the medial heel region. In regard to the toe-off phase, the central forefoot was found to be a prevalent site for high plantar pressure across the diabetic volunteers. The developed device is expected not only to assist in the prediction of diabetic ulceration or re-ulceration, but also to provide strategies and suggestions for foot pressure alleviation and pain mitigation. Citation: J PubDate: 2023-01-05 DOI: 10.3390/j6010003 Issue No:Vol. 6, No. 1 (2023)
Authors:Sergey Goncharov, Andrey Nechesov First page: 48 Abstract: A lot of libraries for neural networks are written for Turing-complete programming languages such as Python, C++, PHP, and Java. However, at the moment, there are no suitable libraries implemented for a p-complete logical programming language L. This paper investigates the issues of polynomial-computable representation neural networks for this language, where the basic elements are hereditarily finite list elements, and programs are defined using special terms and formulas of mathematical logic. Such a representation has been shown to exist for multilayer feedforward fully connected neural networks with sigmoidal activation functions. To prove this fact, special p-iterative terms are constructed that simulate the operation of a neural network. This result plays an important role in the application of the p-complete logical programming language L to artificial intelligence algorithms. Citation: J PubDate: 2023-01-06 DOI: 10.3390/j6010004 Issue No:Vol. 6, No. 1 (2023)
Authors:Alexander Robitzsch First page: 58 Abstract: The two-parameter logistic (2PL) item response model is likely the most frequently applied item response model for analyzing dichotomous data. Linking errors quantify the variability in means or standard deviations due to the choice of items. Previous research presented analytical work for linking errors in the one-parameter logistic model. In this article, we present linking errors for the 2PL model using the general theory of M-estimation. Linking errors are derived in the case of log-mean-mean linking for linking two groups. The performance of the newly proposed formulas is evaluated in a simulation study. Furthermore, the linking error estimation in the 2PL model is also treated in more complex settings, such as chain linking, trend estimation, fixed item parameter calibration, and concurrent calibration. Citation: J PubDate: 2023-01-11 DOI: 10.3390/j6010005 Issue No:Vol. 6, No. 1 (2023)
Authors:Reza Maleki, Libing Fu, Ricardo Sobhie Diaz, Francisco Eduardo Gontijo Guimarães, Otávio Cabral-Marques, Gustavo Cabral-Miranda, Mohammad Sadraeian First page: 85 Abstract: Pulchellin is a plant biotoxin categorized as a type 2 ribosome-inactivating protein (RIPs) which potentially kills cells at very low concentrations. Biotoxins serve as targeting immunotoxins (IT), consisting of antibodies conjugated to toxins. ITs have two independent protein components, a human antibody and a toxin with a bacterial or plant source; therefore, they pose unique setbacks in immunogenicity. To overcome this issue, the engineering of epitopes is one of the beneficial methods to elicit an immunological response. Here, we predicted the tertiary structure of the pulchellin A-chain (PAC) using five common powerful servers and adopted the best model after refining. Then, predicted structure using four distinct computational approaches identified conformational B-cell epitopes. This approach identified some amino acids as a potential for lowering immunogenicity by point mutation. All mutations were then applied to generate a model of pulchellin containing all mutations (so-called PAM). Mutants’ immunogenicity was assessed and compared to the wild type as well as other mutant characteristics, including stability and compactness, were computationally examined in addition to immunogenicity. The findings revealed a reduction in immunogenicity in all mutants and significantly in N146V and R149A. Furthermore, all mutants demonstrated remarkable stability and validity in Molecular Dynamic (MD) simulations. During docking and simulations, the most homologous toxin to pulchellin, Abrin-A was applied as a control. In addition, the toxin candidate containing all mutations (PAM) disclosed a high level of stability, making it a potential model for experimental deployment. In conclusion, by eliminating B-cell epitopes, our computational approach provides a potential less immunogenic IT based on PAC. Citation: J PubDate: 2023-01-16 DOI: 10.3390/j6010006 Issue No:Vol. 6, No. 1 (2023)
Authors:Haruhito Hiiro, Kentaro Otsuka, Shogo Hamaguchi, Iyuki Namekata, Hikaru Tanaka First page: 104 Abstract: The negative chronotropic effects of eight Vaughan Williams Class I antiarrhythmic drugs were examined in guinea pig right atrial tissue preparations. The drugs decreased the spontaneous beating rate at concentrations overlapping with their therapeutic blood levels. Cibenzoline, aprindine, flecainide, and propafenone showed stronger effects; 10 µM of each drug decreased the beating rate to about 75% of initial values. Disopyramide, mexiletine, pilsicainide, and ranolazine showed weaker effects; 10 µM of each drug decreased the beating rate to about 90% of initial values. The potency of drugs correlated with the reported IC50 values to block the L-type Ca2+ channel current rather than the Na+ and K+ channel currents. The reported IC50 values for the blockade of the hyperpolarization-activated inward current (If) and the Na+-Ca2+ exchanger current were much higher than those for the blockade of the L-type Ca2+ channel current. These results indicate that the negative chronotropic effects of Class I antiarrhythmic drugs can be largely explained by their blockade of the L-type Ca2+ channel. Citation: J PubDate: 2023-02-11 DOI: 10.3390/j6010008 Issue No:Vol. 6, No. 1 (2023)
Authors:Wilfred A. Chisamile, Mubo A. Sonibare, John F. Kamanula First page: 115 Abstract: Local communities in Mzimba District, Malawi, have limited access to healthcare services and often rely on traditional medical practice and medicinal plants (MPs) for most of their medical care. However, phytomedicines’ use has not been well documented. This study aimed to identify and document medicinal plants and the associated ethnobotanical knowledge. Ethnobotanical data were collected in seven localities (19 villages) in the T/A Mbelwa, Mzimba, from May to June 2021. Forty traditional healers, herbalists, and farmers selected purposively and by snowball sampling were interviewed through semi-structured interviews, field observations, group discussions, and guided field walks. Quantitative indices, viz. relative frequency of citation (RFC), use value (UV), relative importance (RI) values, informant consensus factors (ICFs), and fidelity levels (FLs), were used to analyze the data. Eighty MPs belonging to 43 families and 77 genera were recorded. The Leguminosae family showed the highest number of species (16), followed by Solanaceae, Rubiaceae, and Phyllanthaceae. Trees (35 species) and roots (62%) accounted for the most significant habit and part, respectively. Washing (29%) was the most common preparation method. The most cited plant was Zanthoxylum chalybeum (RFC = 0.80, UV = 0.28, RI = 1.66), followed by Cassia abbreviata (RFC = 0.68, UV = 0.35, RI = 1.50). Respiratory disorders showed the highest ICF (0.53), followed by general and unspecified disorders (0.31). Z. chalybeum, C. abbreviata, and Oldfieldia dactylophylla showed maximum FLs (100%) for treating malaria and dysentery. Phytochemical, bioassay, toxicity, and conservation studies are needed to assess medicinal plants’ safety, efficacy, and quality as steps toward discovering new promising therapeutic leads without neglecting conservation programs for their sustainable utilization. Citation: J PubDate: 2023-02-23 DOI: 10.3390/j6010009 Issue No:Vol. 6, No. 1 (2023)
Authors:Stylianos Vasileios Kontomaris, Georgios Chliveros, Anna Malamou First page: 140 Abstract: Solving nonlinear oscillations is a challenging task due to the mathematical complexity of the related differential equations. In many cases, determining the oscillation’s period requires the solution of complicated integrals using numerical methods. To avoid the complexity, there are many empirical equations in the literature that can be used instead of rigorous mathematical analysis to provide an acceptable approximation. In this paper, a recently developed method, He’s formulation, is applied to find the period in many different cases of nonlinear oscillators. The cases are those of the Duffing equation, the Helmholtz nonlinear oscillator, the simple pendulum and the case of a vertical oscillation under the influence of a nonlinear elastic force. The results of the method are accurate; thus, He’s formulation is a strong tool for solving nonlinear oscillations. Citation: J PubDate: 2023-02-28 DOI: 10.3390/j6010010 Issue No:Vol. 6, No. 1 (2023)
Authors:Jack Howard, Alexander Rodriguez, Neel Haldolaarachchige, Kalani Hettiarachchilage First page: 152 Abstract: Recent attempts at searching for new materials have revealed a large class of materials that show topological behaviors with unusual physical properties and potential applications leading to enthralling discoveries both theoretically and experimentally. We computationally predict new three-dimensional topological compounds of space group 139(I/4mmm). After conducting a full volume optimization process by allowing the rearrangement of atomic positions and lattice parameters, the first-principles calculation with a generalized gradient approximation is utilized to identify multiple Dirac-type crossings around X and P symmetric points near Fermi energy. Importantly, the band inversion at point P is recognized. Further, we investigate the compound for topological crystalline insulating behavior by conducting surface state calculation and by investigating gapping behavior by increasing lattice parameters. Additionally, we perform formation energy, elastic properties, and phonon modes calculations to verify the structural, mechanical, and dynamical stability of the compounds. Therefore, we suggest compounds for further investigation and experimental realization. Citation: J PubDate: 2023-02-28 DOI: 10.3390/j6010011 Issue No:Vol. 6, No. 1 (2023)
Authors:Vikram Venkata Puram, Anish Sethi, Olga Epstein, Malik Ghannam, Kevin Brown, James Ashe, Brent Berry First page: 164 Abstract: Background: The Coronavirus Disease 2019 (COVID-19) is a global pandemic that has killed over 1.5 million people worldwide. A constellation of multisystem involvement with SARS-CoV-2 has been reported. COVID-19 has been shown to affect the human nervous system, however, both the extent and severity of involvement have yet to be fully elucidated. In this manuscript, we aimed to better understand the effect of COVID-19 on neuro-respiratory status by studying COVID-19 patients who presented with central apnea. Methodology: We analyzed patient characteristics, clinical outcomes, laboratory results, and imaging results of three patients with symptomatic, PCR-proven COVID-19 and episodes of central apnea. Results: Of the three patients included in this study, two patients developed new central apnea, and one patient developed an exacerbation of underlying central apnea despite COVID-19 treatments with systemic steroids and remdesivir. All occurred, on average, 15 days after the onset of COVID-19 symptoms. At 1-year follow-up, all patients experienced complete resolution of apneic breathing. Conclusions: Physicians should be vigilant for the presentation of COVID-19 with central apnea. Central apnea may be a complication in patients with severe COVID-19 infection. More research is warranted to further understand this association. Citation: J PubDate: 2023-03-03 DOI: 10.3390/j6010012 Issue No:Vol. 6, No. 1 (2023)
Authors:Christopher Onyemaechi Ezike, Chinwe Uwadiegwu, Aderonke N. Agbo First page: 172 Abstract: The acute toxicity of the detergent Nittol® 0.8, 1.0, 1.2, 1.4, 1.6, and 0.0 mg NTL/L of clean water on Heterobrunchus bidorsalis, 5.5 ± 0.3 g, 6.4 ± 0.5 cm were investigated, using semi-static bioassay, for 96 h in 50 L capacity plastic test bowls. The fingerlings of the same brood stock and age were collected from Onose Farms Limited, Ughelli, Delta State to the University Research Laboratory, Enugu Lat. 7.4 N; 8°7′5 and long 6°8′ E. 7°6′ W. The test fish were acclimatized for 14 days, and fed at 3% body weight once daily, on a 40% CP commercial diet. Feeding was suspended 24 h before and during the range finding and acute tests. The whole set-up was replicated three times, and no death was recorded during the acclimatization period and in the control. A total of 180 fingerlings were used, and 10 fingerlings were assigned to each replicate. The test set-up was monitored daily for water quality parameters, opercular ventilation, tail fin beat frequency, and mortality. Dose and time-dependent behavioural patterns exhibited by the test fish, during the exposure periods include rapid swimming, air gulping, loss of balance, and a period of convulsion before death. Significant elevation in pH and temperature, reduction of DO compared to the control (p < 0.05) in the water quality, and dose-dependent early elevation of the tail and fin movements declined towards the end of the experiment. The 96 h LC50 was determined to be 1.41 mg/L, indicating that the detergent NTL is toxic to the test fish. The haematological parameters were significantly (p < 0.05) reduced in the treated ranges of RBC 5.20 ± 0.07–8.00 ± 0.02 × 106 mm3, HB 7.53 ± 0.50–10.72 ± 0.14 g/dl, PCV 13.20 ± 0.8.50–18.00 ± 0.43 % below their elevated respective controls of 10.50 ± 0.01 × 10 6 mm3, 11.00 ± 0.01 g/dl, and 23.48 ± 0.2.6 %. The white blood cells (WBC) recorded a significant (p < 0.05) increase in ranges of 23.72 ± 0.14–51.80 ± 1.9 × 103 mm3 above the control value of 11.00 ± 0.01 × 103 mm3 Therefore, values greater than the safe amount of 0.014 mg/L should not be allowed in the receiving culture waters for Heterobrunchus bidorsalis fingerlings. Citation: J PubDate: 2023-03-11 DOI: 10.3390/j6010013 Issue No:Vol. 6, No. 1 (2023)
Authors:Christof Koplin, Eric Schwarzer-Fischer, Eveline Zschippang, Yannick Marian Löw, Martin Czekalla, Arthur Seibel, Anna Rörich, Joachim Georgii, Felix Güttler, Sinef Yarar-Schlickewei, Andreas Kailer First page: 180 Abstract: When finger joints become immobile due to an accident during sports or a widespread disease such as rheumatoid arthritis, customised finger joint implants are to be created. In an automated process chain, implants will be produced from ceramic or metallic materials. Artificial intelligence-supported software is used to calculate three-dimensional models of the finger bones from two-dimensional X-ray images. Then, the individual implant design is derived from the finger model and 3D printed. The 3D printing process and the structures used are evaluated via model tests and the final implant design via a reliability calculation in a way to ensure that this is also possible via an AI process in the future. Using additive manufacturing with silicon nitride-based ceramics, model specimens and implants are produced via the lithography-based ceramic vat photopolymerisation process with full geometry or elements of triple periodic minimal surfaces structure. The model specimens are tested experimentally, and the loads are matched with a characteristic strength assuming a Weibull distribution of defects in the volume to generate and match failure probabilities. Calculated fracture forces of the silicon nitride-based ceramic structure was validated by comparison of simulation and tests, and the calculation can be used as a quality index for training of artificial intelligence in the future. The proposed method for individualized finger implant design and manufacturing may allow for correction of potential malpositions of the fingers in the future. Citation: J PubDate: 2023-03-18 DOI: 10.3390/j6010014 Issue No:Vol. 6, No. 1 (2023)
Authors:Viet Tran, Giles Barrington, Zach Aandahl, Amelia Lawrence, Senudi Wijewardena, Brian Doyle, Louise Cooley First page: 198 Abstract: Rapid antigen testing (RAT) is a cost-effective and time-efficient method of identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and therefore a critical part of infection control strategies. There is no published evidence evaluating the use of RAT during the Omicron wave of the COVID-19 pandemic for asymptomatic patients or its performance between waves. All patients presenting to an Emergency Department over a two-week period without COVID-19 symptoms were screened for SARS-CoV-2 using both the Abbott Panbio RAT as well as the gold standard reverse transcriptase real-time polymerase chain reaction (PCR). The Abbott Panbio RAT sensitivity was 13% (95% CI 0.028, 0.336) for asymptomatic patients. The use of this test in asymptomatic patients during the Omicron wave had a statistically significant reduction in sensitivity compared with two reports of the same test in previous waves (13% vs. 86%, p < 0.0001; 13% vs. 83%, p < 0.0001). As SARS-CoV-2 continues to mutate, the sensitivity of RATs are altered and needs to be continually re-evaluated for each variant of concern if they are to be used as part of an infection control strategy. Citation: J PubDate: 2023-03-20 DOI: 10.3390/j6010015 Issue No:Vol. 6, No. 1 (2023)
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