bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-Melanogenic Mechanism of Tetrahydrocurcumin and Enhancing Its Topical Delivery Efficacy Using a Lecithin-Based Nanoemulsion
Authors: Tang Xudong , Dong Qiaoru , Li Jun , Li Fang , Michniak-Kohn Bozena B. , Zhao Denggao , Ho Chi-Tang , Huang Qingrong
Published: August 2021

Tetrahydrocurcumin (THC) has been well known for its superior antioxidant properties. Therefore, it is speculated that it might be effective to relieve oxidative stress-induced diseases, such as skin hyperpigmentation. In this work, an in vitro B16F10 melanoma cell model was used to study the impact of THC on the melanogenic process under stressed conditions. It was demonstrated that THC could effectively inhibit the α-MSH (melanocyte-stimulating hormone) induced melanin production in B16F10 melanoma cells and the expressions of three key enzymes involved with the biosynthetic process of melanin, tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2), were all significantly reduced. In addition, an in vitro human keratinocyte cell model was used to investigate the potential protective role of THC on H2O2-induced cytotoxicity. It was found that THC could prevent H2O2-induced oxidative stress based on the results of both the cell viability study and the intracellular ROS (reactive oxygen species) study assessed by the flow cytometry. Last, THC was formulated into a lecithin based nanoemulsion, and an in vitro Franz diffusion cell study using Strat-M® membrane concluded that the nanoemulsion could significantly enhance the membrane permeation compared to the unformatted THC suspension. This research demonstrated the anti-melanogenic benefits of THC on the melanoma and keratinocyte cell models and the topical delivery efficacy could be significantly enhanced using a lecithin based nanoemulsion.
Encapsulation of Active Pharmaceutical Ingredients in Lipid Micro/Nanoparticles for Oral Administration by Spray-Cooling
Authors: Favaro-Trindade Carmen S. , de Matos Junior Fernando E. , Okuro Paula K. , Dias-Ferreira João , Cano Amanda , Severino Patricia , Zielińska Aleksandra , Souto Eliana B.
Published: August 2021

Nanoencapsulation via spray cooling (also known as spray chilling and spray congealing) has been used with the aim to improve the functionality, solubility, and protection of drugs; as well as to reduce hygroscopicity; to modify taste and odor to enable oral administration; and many times to achieve a controlled release profile. It is a relatively simple technology, it does not require the use of low-cost solvents (mostly associated to toxicological risk), and it can be applied for lipid raw materials as excipients of oral pharmaceutical formulations. The objective of this work was to revise and discuss the advances of spray cooling technology, with a greater emphasis on the development of lipid micro/nanoparticles to the load of active pharmaceutical ingredients for oral administration.
Design of Mucoadhesive Strips for Buccal Fast Release of Tramadol
Authors: Pastório Nayla Francine Garcia , Vecchi Camila Felix , Said dos Santos Rafaela , Bruschi Marcos Luciano
Published: August 2021

Tramadol hydrochloride is a synthetic analogue of codeine and shows activity on the central nervous system as an opioid agonist and inhibitor of serotonin and norepinephrine reuptake. It has been used for controlling moderate to severe pain. Mucoadhesive fast-dissolving films can present greater drug availability and patient acceptance when compared to the systems of peroral administration. The films were prepared using the solvent casting method with ethylcellulose, polyvinylpyrrolidone and poly(vinyl alcohol). The effect of each polymer concentration was investigated using a 2³ factorial design with repetition at the central point. The formulations were subjected to physicochemical, mechanical, ex vivo mucoadhesive and in vitro drug release profile analysis. These properties were dependent on the polymeric composition (independent factors) of each system. The optimized formulations showed good macroscopic characteristics, improved resistance to bending, rigidity, rapid swelling up to 60 s, improved mechanical and mucoadhesive characteristics, and also fast dissolving and tramadol release. The optimized formulations constitute platforms and strategies to improve the therapy of tramadol with regard to availability at the site of application, considering the necessity of rapid pain relief, and show potential for in vivo evaluation.
Future Pharmacists’ Opinions on the Facilitation of Self-Care with Over-the-Counter Products and Whether This Should Remain a Core Role
Authors: Hanna Lezley-Anne , Murphy Alana , Hall Maurice , Craig Rebecca
Published: August 2021

Background: The aim was to investigate pharmacy students’ views on the role of the pharmacist in facilitating self-care with over-the-counter (OTC) medicines, particularly in light of new roles, and establish personal practice. Methods: Final year pharmacy students at Queen’s University Belfast were invited to participate. Data were collected via a pre-piloted questionnaire, distributed at a compulsory class (only non-identifiable data were requested). Descriptive statistics were performed, and non-parametric tests were employed for inferential statistical analysis (responses by gender). Results: The response rate was 87.6% (78/89); 34.6% (27/78) males and 65.4% (51/78) females. Over a third [34.6% (27/78)] reported using OTC medicines about once a month. All appreciated the importance of an evidence-based approach to optimize patient care. Most [(96.2% (75/78)] deemed OTC consultations should remain a fundamental responsibility of pharmacists and 69.2% (54/78) thought OTC consultations have the potential to be as complex as independent pharmacist prescribing. Females felt more confident recommending OTC emergency contraception than males (p = 0.002 for levonorgestrel and p = 0.011 for ulipristal acetate). Many [61.5% (48/78)] considered more medicines should not be deregulated from prescription-only status. Conclusions: Data from this single institution suggests that enabling self-medication is an important part of practice but there were confidence issues around deregulations.
Searching for Practical Wisdom in Higher Education with Logos, Pathos and Ethos. Case: Finnish Universities of Sciences
Authors: Jakubik Maria
Published: August 2021

In our complex and highly connected world, educating for life—that is, educating students with knowledge, skills, and competences infused with practical wisdom (PW) and ethical and moral values—is essential. The paper seeks to answer the question: how could university education facilitate the progress to a wiser and better world? The methodology involves case study research (CSR) based on both secondary and primary data. The missions, visions, and values of fourteen public Finnish universities are analyzed for PW. The findings demonstrate that universities, by becoming more open, unbounded, and enacting organizations, and by enhancing collaboration with businesses, could foster the cultivation of PW in higher education (HE). The novelty of this paper is the creative communication of the case study, where kairos, logos, pathos, and ethos are used to explore a new reality for HE. The article contributes to the contemporary discourses in the literature on the future of HE. Educators in HE need to transform from knowledge workers to wise leaders, wisdom workers, creators, empathizers, pattern recognizers, and meaning makers. The context of the case study research makes it difficult to generalize. Therefore, international, comparative research is used to complement the findings. The eight-stage change process applied to universities and HE could help in solving the urgent problems of society and facilitating progress to a wiser and better world.
Waterproof Galvanometer Scanner-Based Handheld Photoacoustic Microscopy Probe for Wide-Field Vasculature Imaging In Vivo
Authors: Seong Daewoon , Han Sangyeob , Lee Jaeyul , Lee Euimin , Kim Yoonseok , Lee Junsoo , Jeon Mansik , Kim Jeehyun
Published: August 2021

Photoacoustic imaging (PAI) is a hybrid non-invasive imaging technique used to merge high optical contrast and high acoustic resolution in deep tissue. PAI has been extensively developed by utilizing its advantages that include deep imaging depth, high resolution, and label-free imaging. As a representative implementation of PAI, photoacoustic microscopy (PAM) has been used in preclinical and clinical studies for its micron-scale spatial resolution capability with high optical absorption contrast. Several handheld and portable PAM systems have been developed that improve its applicability to several fields, making it versatile. In this study, we developed a laboratory-customized, two-axis, waterproof, galvanometer scanner-based handheld PAM (WP-GVS-HH-PAM), which provides an extended field of view (14.5 × 9 mm2) for wide-range imaging. The fully waterproof handheld probe enables free movement for imaging regardless of sample shape, and volume rate and scanning region are adjustable per experimental conditions. Results of WP-GVS-HH-PAM-based phantom and in vivo imaging of mouse tissues (ear, iris, and brain) confirm the feasibility and applicability of our system as an imaging modality for various biomedical applications.
Influence of 3D-Printed TPU Properties for the Design of Elastic Products
Authors: Rodríguez-Parada Lucía , de la Rosa Sergio , Mayuet Pedro F.
Published: August 2021

The design of products with elastic properties is a paradigm for design engineers because the properties of the material define the correct functionality of the product. Fused filament fabrication (FFF) allows for the printing of products in thermoplastic polyurethanes (TPU). Therefore, it offers the ability to design elastic products with the freedom of forms that this technology allows and also with greater variation of elastic properties than with a conventional process. The internal structures and the variation in thickness that can be used facilitate the design of products with different elastic realities, producing variations in the elasticity of the product with the same material. This work studies the influence of the variation of internal density as a function of basic geometries in order to quantify the difference in elasticity produced on a product when it is designed. Likewise, a case study was carried out with the creation of a fully elastic computer keyboard printed in 3D. The specimens were subjected to compression to characterize the behavior of the structures. The tests showed that the elasticity varies depending on the orientation and geometry, with the highest compressive strength observed in the vertical orientation with 80% lightening. In addition, the internal lightening increases the elasticity progressively but not uniformly with respect to the solid geometry, and also the flat faces favour the reduction in elasticity. This study classifies the behavior of TPU with the aim of being applied to the design and manufacture of products with specific properties. In this work, a totally flexible and functional keyboard was designed, obtaining elasticity values that validate the study carried out.
Effect of Fibre Orientation on Novel Continuous 3D-Printed Fibre-Reinforced Composites
Authors: Papa Ilaria , Silvestri Alessia Teresa , Ricciardi Maria Rosaria , Lopresto Valentina , Squillace Antonino
Published: August 2021

Among the several additive manufacturing techniques, fused filament fabrication (FFF) is a 3D printing technique that is fast, handy, and low cost, used to produce complex-shaped parts easily and quickly. FFF adds material layer by layer, saving energy, costs, raw material costs, and waste. Nevertheless, the mechanical properties of the thermoplastic materials involved are low compared to traditional engineering materials. This paper deals with the manufacturing of composite material laminates obtained by the Markforged continuous filament fabrication (CFF) technique, using an innovative matrix infilled by carbon nanofibre (Onyx), a high-strength thermoplastic material with an excellent surface finish and high resistance to chemical agents. Three macro-categories of samples were manufactured using Onyx and continuous carbon fibre to evaluate the effect of the fibre on mechanical features of the novel composites and their influence on surface finishes. SEM (Scanning Electron Microscopy) analysis and acquisition of roughness profile by a confocal lens were conducted. Tensile and compression tests, thermogravimetric analysis and calorimetric analysis using a DSC (differential scanning calorimeter) were carried out on all specimen types to evaluate the influence of the process parameters and layup configurations on the quality and mechanical behaviour of the 3D-printed samples.
Recent Advances in Polymer-Inorganic Mixed Matrix Membranes for CO2 Separation
Authors: Li Sipei , Liu Yang , Wong Dana A. , Yang John
Published: August 2021

Since the second industrial revolution, the use of fossil fuels has been powering the advance of human society. However, the surge in carbon dioxide (CO2) emissions has raised unsettling concerns about global warming and its consequences. Membrane separation technologies have emerged as one of the major carbon reduction approaches because they are less energy-intensive and more environmentally friendly compared to other separation techniques. Compared to pure polymeric membranes, mixed matrix membranes (MMMs) that encompass both a polymeric matrix and molecular sieving fillers have received tremendous attention, as they have the potential to combine the advantages of both polymers and molecular sieves, while cancelling out each other’s drawbacks. In this review, we will discuss recent advances in the development of MMMs for CO2 separation. We will discuss general mechanisms of CO2 separation in an MMM, and then compare the performances of MMMs that are based on zeolite, MOF, metal oxide nanoparticles and nanocarbons, with an emphasis on the materials’ preparation methods and their chemistries. As the field is advancing fast, we will particularly focus on examples from the last 5 years, in order to provide the most up-to-date overview in this area.
Combining Sandblasting, Alkaline Etching, and Collagen Immobilization to Promote Cell Growth on Biomedical Titanium Implants
Authors: Liu Chia-Fei , Chang Kai-Chun , Sun Ying-Sui , Nguyen Diem Thuy , Huang Her-Hsiung
Published: August 2021

Our objective in this study was to promote the growth of bone cells on biomedical titanium (Ti) implant surfaces via surface modification involving sandblasting, alkaline etching, and type I collagen immobilization using the natural cross-linker genipin. The resulting surface was characterized in terms topography, roughness, wettability, and functional groups, respectively using field emission scanning electron microscopy, 3D profilometry, and attenuated total reflection-Fourier transform infrared spectroscopy. We then evaluated the adhesion, proliferation, initial differentiation, and mineralization of human bone marrow mesenchymal stem cells (hMSCs). Results show that sandblasting treatment greatly enhanced surface roughness to promote cell adhesion and proliferation and that the immobilization of type I collagen using genipin enhanced initial cell differentiation as well as mineralization in the extracellular matrix of hMSCs. Interestingly, the nano/submicro-scale pore network and/or hydrophilic features on sandblasted rough Ti surfaces were insufficient to promote cell growth. However, the combination of all proposed surface treatments produced ideal surface characteristics suited to Ti implant applications.
Dielectric, Thermal and Water Absorption Properties of Some EPDM/Flax Fiber Composites
Authors: Airinei Anton , Asandulesa Mihai , Stelescu Maria Daniela , Tudorachi Niţǎ , Fifere Nicusor , Bele Adrian , Musteata Valentina
Published: August 2021

This paper deals with the dielectric and sorption properties of some flax fiber-reinforced ethylene-propylene-diene monomer (EPDM) composites containing different fiber loadings as well as their behavior after exposure to different doses of electron beam irradiation. Three relaxation processes were evinced, a weak relaxation β at sub-Tg temperatures and two α-type relaxations above the Tg. The EPDM/flax composites exhibited higher values of dielectric constant, dielectric loss and conductivity as compared to a pristine EPDM sample. Using thermogravimetric analysis (TG) coupled with Fourier transform infrared spectroscopy (FTIR) and mass spectrometry (MS) (TG/FTIR/MS system), the degradation products can be identified. The water uptake increased as the flax fiber level increased in composites. The water uptake tests of irradiated composites showed that the highest water content was obtained for a flax fiber level of 20 phr.
Carbon Capture Utilization for Biopolymer Foam Manufacture: Thermal, Mechanical and Acoustic Performance of PCL/PHBV CO2 Foams
Authors: Oluwabunmi Kayode E. , Zhao Weihuan , D’Souza Nandika Anne
Published: August 2021

Biopolymer foams manufactured using CO2 enables a novel intersection for economic, environmental, and ecological impact but limited CO2 solubility remains a challenge. PHBV has low solubility in CO2 while PCL has high CO2 solubility. In this paper, PCL is used to blend into PBHV. Both unfoamed and foamed blends are examined. Foaming the binary blends at two depressurization stages with subcritical CO2 as the blowing agent, produced open-cell and closed-cell foams with varying cellular architecture at different PHBV concentrations. Differential Scanning Calorimetry results showed that PHBV had some solubility in PCL and foams developed a PCL rich, PHBV rich and mixed phase. Scanning Electron Microscopy and pcynometry established cell size and density which reflected benefits of PCL presence. Acoustic performance showed limited benefits from foaming but mechanical performance of foams showed a significant impact from PHBV presence in PCL. Thermal performance reflected that foams were affected by the blend thermal conductivity, but the impact was significantly higher in the foams than in the unfoamed blends. The results provide a pathway to multifunctional performance in foams of high performance biopolymers such as PBHV through harnessing the CO2 miscibility of PCL.
Effect of Rot-, Fire-, and Water-Retardant Treatments on Jute Fiber and Their Associated Thermoplastic Composites: A Study by FTIR
Authors: Shahinur Sweety , Hasan Mahbub , Ahsan Qumrul , Sultana Nayer , Ahmed Zakaria , Haider Julfikar
Published: August 2021

Natural renewable materials can play a big role in reducing the consumption of synthetic materials for environmental sustainability. Natural fiber-reinforced composites have attracted significant research and commercial importance due to their versatile characteristics and multi-dimensional applications. As the natural materials are easily rotten, flammable, and moisture absorbent, they require additional chemical modification for use in sustainable product development. In the present research, jute fibers were treated with rot-, fire-, and water-retardant chemicals and their corresponding polymer composites were fabricated using a compression molding technique. To identify the effects of the chemical treatments on the jute fiber and their polymeric composites, a Fourier transformed infrared radiation (FTIR) study was conducted and the results were analyzed. The presence of various chemicals in the post-treated fibers and the associated composites were identified through the FTIR analysis. The varying weight percentage of the chemicals used for treating the fibers affected the physio-mechanical properties of the fiber as well as their composites. From the FTIR analysis, it was concluded that crystallinity increased with the chemical concentration of the treatment which could be contributed to the improvement in their mechanical performance. This study provides valuable information for both academia and industry on the effect of various chemical treatments of the jute fiber for improved product development.
Ziziphus joazeiro Stem Bark Extract as a Green Corrosion Inhibitor for Mild Steel in Acid Medium
Authors: Mauro Aparecida Cristina , Ribeiro Bernardo Dias , Garrett Rafael , Borges Ricardo Moreira , da Silva Talis Uelisson , de Paula Machado Sérgio , de Araujo Joyce Rodrigues , de Oliveira Massafra Sanair , de Oliveira Junior Francisco Odencio Rodrigues , D’Elia Eliane
Published: August 2021

The aqueous extract of Joazeiro stem bark (EJSB) and its high molecular weight fraction (HMWF) were examined as potential corrosion inhibitors of mild steel in 1 mol L−1 hydrochloric acid media, using weight-loss measurements, potentiodynamic polarization curves and an electrochemical impedance spectroscopy (EIS).Varying the concentration of the inhibitors from 100 to 800 mg L−1, the results show an increase in anticorrosive efficiency from 85.4 to 89.8 and 89.8 to 93.0% for EJSB and its HMWF, respectively, using the data of the gravimetric essay, and from 84.5 to 94.5 and 89.9 to 94.7% for EJSB and its HMWF, respectively, from the impedance data. The composition of the crude extract was chemically characterized by liquid chromatography-high resolution mass spectrometry. Additionally, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used, respectively, to morphologically and chemically characterize the surface. Considering that the saponin molecules, the main constituent from juá, are responsible for its inhibitory action, quantum chemical calculations showed that the C67, C69 and O144 atoms likely have an important role in the process of electron-donation of saponin to metal, due to the higher values of ƒk+ and %HOMO observed on these atoms.
Experimental Study of a Loop Heat Pipe with Direct Pouring Porous Wick for Cooling Electronics
Authors: Cai Bing , Deng Weizhong , Wu Tong , Wang Tingting , Ma Zhengyuan , Liu Wei , Ma Lei , Liu Zhichun
Published: August 2021

A pouring silicate wick was manufactured to explore the influence of process and physical properties on the production and performance of loop heat pipes (LHP). This paper theoretically analyzed the advantages of pouring porous wick and introduced the technology of pouring silicate directly on evaporator. Based on this, the heat transfer performance of copper-methanol LHP system with pouring porous wick was tested under different positions. The results showed that with the input of multiple heat sources, the LHP could start up and maintain a stable temperature from 40 W to 160 W. When the vapor grooves were located above the compensation chamber, it was difficult to start up positively. By adding gravity assistance, the system could obtain more stable liquid supply and vapor flow, so as to realize start up. In the variable heat load test, the LHP showed good adaptability to the change of heat load. The thermal resistance of the system decreased with the increase of heat load. The thermal resistance of the evaporator almost unchanged and was always lower than 0.05 °C/W, which indicated that the pouring porous wick in the evaporator had good heat load matching.
Pitch Angle Modulation of the Horizontal and Vertical Axes Wind Turbine Using Fuzzy Logic Control
Authors: El-Fahham Ibrahim , Abdelshahid George , Mokhiamar Ossama
Published: August 2021

The aim of this research work is to modulate the pitch angle of both types of wind turbines based on fuzzy logic control (FLC), as changes in the pitch angle have various functions in horizontal and vertical axis wind turbines. For HAWT, pitch angle control is applied to shield the electrical components of the turbine when the wind speed exceeds the rated speed without shutting down the turbine. FLC is used to control the angular velocity using two inputs and one output with three membership functions for both inputs and output. In VAWT, pitch angle control is applied to boost the performance of the turbine and its self-starting torque. FLC utilizes two inputs and one output with five membership functions for both inputs and output. For both turbine types, FLC produces a control signal that drives the actuator to achieve the desired pitch angle. The dynamics of HAWT and VAWT are simulated by the MATLAB/Simulink to demonstrate the influence of pitch controls on their dynamics. For HAWT, the FLC control has successfully maintained the angular speed of the rotor. The values of tip speed ratio and coefficient of performance are reduced in order to maintain the rotor angular velocity at its rated value. On the other hand, the results showed that the torque produced by the VAWT individual blade has improved with the pitch angle control. In addition, using FLC to control the pitch angle gives enhanced output and higher Cp at low tip speed ratios. Gain schedule PI controller is also used in both HAWT and VAWT for comparative study.
Phytosynthesis of Copper Nanoparticles Using Extracts of Spices and Their Antibacterial Properties
Authors: Vijayakumar Gayathri , Kesavan Hindhuja , Kannan Anisha , Arulanandam Dhanalakshmi , Kim Jeong Hee , Kim Kwang Jin , Song Hak Jin , Kim Hyung Joo , Rangarajulu Senthil Kumaran
Published: August 2021

To prevent microbial growth, chemical solvents are typically utilized. However, chemical solvents are hazardous to human health with low antimicrobial effects. Metallic-element (such as copper, silver, and gold) nanoparticles have many applications in biotechnology and biomedicine. Copper nanoparticles (CuNPs) are efficient owing to their antimicrobial, anti-inflammatory, and anti-proliferative properties. The objective of this study was to perform biogenic synthesis of copper nanoparticles using three different spices (star anise, seed of Illicium verum; nutmeg, seed of Myristica fragrans; and mace, membrane covering the seed of Myristica fragrans) and determine their antibacterial properties. CuNPs of spices were prepared by dissolving copper sulfate in the respective plant extract. They were then characterized by UV-Vis spectroscopy, FTIR, GC-MS, EDAX, and SEM analysis. Results of UV-Vis spectroscopy showed the maximum absorbance peak at 350 nm. SEM analysis showed that the sizes of these CuNPs were in the range of 150–200 nm. EDAX analysis confirmed the presence of copper and oxygen and revealed that copper existed in an oxidized form. FTIR spectroscopy showed the presence of different functional groups in these synthesized nanoparticles. GC-MS analysis revealed compounds such as Anethole D-limonene, heptadecanoic acid, 16-methyl-, methyl ester, myristene, methyl eugenol, and methyl stearate, indicating the presence of functional groups. The antibacterial activities of the three extracts from spices were analyzed using growth zone inhibition and TLC-bioautography methods. The results showed that star anise spice extract had the highest antibacterial activity. These results indicate that such CuNPs phyto-formulated with spice extracts having antibacterial properties could be used as potential therapeutics for microbial diseases.
Anti-Cancer Effect of Panax Ginseng and Its Metabolites: From Traditional Medicine to Modern Drug Discovery
Authors: Kim Sejin , Kim Nayeon , Jeong JaYeon , Lee Soojin , Kim Woojin , Ko Seong-Gyu , Kim Bonglee
Published: August 2021

Cancer incidence and mortality rate are growing worldwide. The effectiveness of cancer therapy depends on the degree of cancer development. Anticancer prevention, screening tests, detection of precancerous conditions or cancers at an early stage of development help to prevent the development of cancer, and in the event of cancer development, they provide the best chance for a full recovery. However, in most cases of advanced cancer, there is no method that can fully cure this disease. Recently, natural products have gained more attention in cancer therapy. Panax ginseng (PG), one of the most popular natural products, is reported to have a wide range of pharmacological activities in cancer. Therefore, the anti-cancer effects and mechanisms of PG and its metabolites (compound K, Ginsenoside Rh1, Rh2, Rh3 and F1) in five major cancers (lung cancer, breast cancer, colon cancer, prostate cancer and stomach cancer) are reviewed in this study. It is confirmed that PG and its metabolites regulated apoptosis, epithelial mesenchymal transition (EMT), angiogenesis, cell cycle arrest and multidrug resistance (MDR) in vitro and in vivo cancer models. In particular, ginsenoside Rh2 showed anticancer effects in all five major cancers. This review could improve the understanding of anticancer mechanisms of PG and its metabolites against major five cancers. Further clinical studies are needed for development anti-cancer drugs using PG and its metabolites.
Analysis of the Performance of a Solar Thermoelectric Generator for Variable Leg Geometry with Nanofluid Cooling
Authors: Ramos-Castañeda Cristian Francisco , Olivares-Robles Miguel Angel , Méndez-Méndez Juan Vicente
Published: August 2021

In this study, the impact of nanofluid use in solar-thermoelectric generators (Solar-TEG) on thermal performance is investigated through analysis and simulation methodology. For conventional cooling analysis, we use air as a coolant and graphene nanoplatelet aqueous nanofluids (GNAN) for nanofluid cooling. We make a comparison between traditional and nanofluid cooling to find the best performance. GNAN at a dispersion of 0.025, 0.05, 0.075, and 0.1-wt% are added to the cooling system. GNAN has been used in the technological development of energy conversion. It has been proposed as a material to achieve better efficiency in Solar-TEG. Five different geometries are developed to analyze the efficiency in a Solar-TEG to find the optimal design. The impact of the thermal concentration relationship, substrate area, and convective transfer coefficient on Solar-TEG performance is investigated. To simplify and speed up simulations, we use equivalent models based on FEM. We are considering the properties of temperature-dependent semiconductors. For thermoelement materials, we use lead-tellurium. Lead-tellurium is an excellent material for thermoelectric study and supports large temperature ranges (up to 750 K). The thermal concentration relationship depends on the substrate area, which affects the efficiency of Solar-TEG. The maximum efficiency between the five geometry types is 5.53%, with a substrate of 110 × 100 mm2. The efficiency and output power using 0.1% wt GNAN as the refrigerant is enhanced by 14.74% and 26.39%. GNAN cooling improves compared to conventional fluid cooling in a Solar-TEG. Different convection coefficients are used to verify this fact.
Response Surface Methodology Routed Optimization of Performance of Hydroxy Gas Enriched Diesel Fuel in Compression Ignition Engines
Authors: Usman Muhammad , Nomanbhay Saifuddin , Ong Mei Yin , Saleem Muhammad Wajid , Irshad Muneeb , Hassan Zain Ul , Riaz Fahid , Shah Muhammad Haris , Qyyum Muhammad Abdul , Lee Moonyong , Show Pau Loke
Published: August 2021

In this study, the response surface methodology (RSM) optimization technique was employed for investigating the impact of hydroxy gas (HHO) enriched diesel on performance, acoustics, smoke and exhaust gas emissions of the compression ignition (CI) engine. The engine was operated within the HHO flow rate range of 0–10 L/min and engine loads of 15%, 30%, 45%, 60% and 75%. The results disclosed that HHO concentration and engine load had a substantial influence on the response variables. Analysis of variance (ANOVA) results of developed quadratic models indicated the appropriate fit for all models. Moreover, the optimization of the user-defined historical design of an experiment identified an optimum HHO flow rate of 8 L/min and 41% engine load, with composite desirability of 0.733. The responses corresponding to optimal study factors were 25.44%, 0.315 kg/kWh, 117.73 ppm, 140.87 ppm, 99.37 dB, and 1.97% for brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), CO, HC, noise, and smoke, respectively. The absolute percentage errors (APEs) of RSM were predicted and experimental results were below 5%, which vouched for the reliable use of RSM for the prediction and optimization of acoustics and smoke and exhaust emission characteristics along with the performance of a CI engine.
On Bell’s Inequality in PT-Symmetric Quantum Systems
Authors: Bhosale Sarang S. , Rath Biswanath , Panigrahi Prasanta K.
Published: August 2021

Bell’s inequality is investigated in parity-time (PT) symmetric quantum mechanics, using a recently developed form of the inequality by Maccone, with two PT-qubits in the unbroken phase with real energy spectrum. It is shown that the inequality produces a bound that is consistent with the standard quantum mechanics even after using Hilbert space equipped with CPT inner product and therefore, the entanglement has identical structure with standard quantum mechanics. Consequently, the no-signaling principle for a two-qubit system in PT-symmetric quantum theory is preserved.
Worship for People with Cognitive Challenges in the Pandemic Era: A Korean Presbyterian Perspective
Authors: Moon Hwarang
Published: August 2021

During COVID-19, many people in the world experienced tremendous suffering. Because of its strong infection rate, people avoided gathering. In these circumstances, public worship, which is the heartbeat of the church, has declined. The decline in participation is especially true among one group of marginalized people: the people who are cognitively challenged. Traditionally, the Korean Church has not had much concern about the matter of public worship and the sacraments for those who are cognitively challenged, except for a few churches which have special departments for ministries to special populations. During the COVID-19 situation, these ministries have slowed, which means that those who benefited have had few opportunities to join worship services or participate in religious education. Going forward, there is a high possibility of another pandemic. Therefore, it is time to prepare for the future. Some churches have utilized online worship and Zoom meetings, showing that the cognitively challenged can effectively participate in online worship and religious education if family members can help them. Churches should invest in new platforms which harmonize onsite worship and online worship and expand resources to create new software for Christian education.
Preparing to Educate for a Thriving Bivocational Ministry: A Seminary Case Study
Authors: Stephens Darryl W.
Published: August 2021

How can institutions of higher learning in theological education respond to an increasing need for bivocational ministry preparation, training, and support? This article presents detailed findings from one US, mainline Protestant seminary’s effort to evaluate current and perceived needs in this area. Data from surveys of students, staff, faculty, and trustees at Lancaster Theological Seminary and learnings from a six-session student focus group are presented. Explored are questions of perception and relevance of bivocational ministry, distinct stressors of bivocational ministry, opinions about current educational programs at the seminary, and opinions about institutional changes designed to better support and prepare seminarians for bivocational ministry. These findings are indicative rather than definitive, inviting further research involving more schools and a larger set of respondents. The article concludes with a discussion of challenges and opportunities facing this seminary in its strategic effort to educate for a thriving bivocational ministry.
The Battle for Symbolic Power: Kraków as a Stage of Renegotiation of the Social Position of the Catholic Church in Poland
Authors: Motak Dominika , Krotofil Joanna , Wójciak Dorota
Published: August 2021

In academic and popular discourses, Poland has been consistently described as a “Catholic country”. However, the level of identification with the Catholic Church in Poland has been gradually declining in the last three decades. In this paper, we explore the recent wave of civil protests which began in October 2020 as a reaction to the new restrictions on legal access to abortion. Thousands of people took to the streets to participate in what became known as “the Women’s Strike”. The protesters not only rejected the government but also dissented from the Catholic Church and its strong influence over the Polish state. The case study presented here focuses on the events that took place in Kraków, particularly the protests around the famous “Pope’s window”. We identify the symbolic tools used by the protesters and explore the connection between “Women’s Strike”, the emergent discourses on the poor handling of the sexual abuse problems in the Catholic Church by John Paul II and his close associates, and the growing contestation of Church’s position towards LGBTQ+. We employ the notion of crisis to discuss the implications of the mass protests to the transformation of the Catholic landscape in Poland.
The Efficiency of the Polish Zloty Exchange Rate Market: The Uncovered Interest Parity and Fractal Analysis Approaches
Authors: Czech Katarzyna , Pietrych Łukasz
Published: August 2021

The study of the effectiveness of the currency market is one of the most important research problems in the field of finance. The paper aims to assess the efficiency of the Polish zloty exchange rate market. We test the market efficiency by applying two independent approaches, one based on the Uncovered Interest Parity theory, and another based on the fractal analysis of exchange rates series. The research results show that the Uncovered Interest Parity holds only on the USD/PLN market. For EUR/PLN, JPY/PLN, CHF/PLN, MXN/PLN and TRY/PLN, the Uncovered Interest Parity hypothesis is rejected and implies the existence of the forward premium anomaly and market inefficiency. The estimated Hurst coefficient provides insight into the long-range dependence of exchange rates. The MXN/PLN, TRY/PLN and EUR/PLN exchange rates exhibit anti-persistent behaviours suggesting mean-reverting characteristics. For JPY/PLN and CHF/PLN, a high value of the Hurst exponent indicates long memory in the time series. Only for USD/PLN, we achieve the Hurst exponent closest to 0.5, which implies market efficiency. The research results obtained based on the UIP hypothesis and fractal analysis are consistent. The study reveals that the market efficiency hypothesis holds only for the most tradable Polish zloty currency pair, i.e., USD/PLN.
Diurnal and Seasonal Mapping of Water Deficit Index and Evapotranspiration by an Unmanned Aerial System: A Case Study for Winter Wheat in Denmark
Authors: Antoniuk Vita , Manevski Kiril , Kørup Kirsten , Larsen Rene , Sandholt Inge , Zhang Xiying , Andersen Mathias Neumann
Published: August 2021

Precision irrigation is a promising method to mitigate the impacts of drought stress on crop production with the optimal use of water resources. However, the reliable assessment of plant water status has not been adequately demonstrated, and unmanned aerial systems (UAS) offer great potential for spatiotemporal improvements. This study utilized UAS equipped with multispectral and thermal sensors to detect and quantify drought stress in winter wheat (Triticum aestivum L.) using the Water Deficit Index (WDI). Biennial field experiments were conducted on coarse sand soil in Denmark and analyses were performed at both diurnal and seasonal timescales. The WDI was significantly correlated with leaf stomatal conductance (R2 = 0.61–0.73), and the correlation was weaker with leaf water potential (R2 = 0.39–0.56) and topsoil water status (the highest R2 of 0.68). A semi-physical model depicting the relationship between WDI and fraction of transpirable soil water (FTSW) in the root zone was derived with R2 = 0.74. Moreover, WDI estimates were improved using an energy balance model with an iterative scheme to estimate the net radiation and land surface temperature, as well as the dual crop coefficient. The diurnal variation in WDI revealed a pattern of the ratio of actual to potential evapotranspiration, being higher in the morning, decreasing at noon hours and ‘recovering’ in the afternoon. Future work should investigate the temporal upscaling of evapotranspiration, which may be used to develop methods for site-specific irrigation recommendations.
3D Point Clouds in Forest Remote Sensing
Authors: Díaz-Varela Ramón Alberto , González-Ferreiro Eduardo
Published: August 2021

Society is increasingly aware of the important role of forests and other woodlands as cultural heritage and as providers of different ecosystem services, such as biomass provision, soil protection, hydrological regulation, biodiversity conservation and carbon sequestration, among others [...]
Combining Spectral and Texture Features of UAV Images for the Remote Estimation of Rice LAI throughout the Entire Growing Season
Authors: Yang Kaili , Gong Yan , Fang Shenghui , Duan Bo , Yuan Ningge , Peng Yi , Wu Xianting , Zhu Renshan
Published: August 2021

Leaf area index (LAI) estimation is very important, and not only for canopy structure analysis and yield prediction. The unmanned aerial vehicle (UAV) serves as a promising solution for LAI estimation due to its great applicability and flexibility. At present, vegetation index (VI) is still the most widely used method in LAI estimation because of its fast speed and simple calculation. However, VI only reflects the spectral information and ignores the texture information of images, so it is difficult to adapt to the unique and complex morphological changes of rice in different growth stages. In this study we put forward a novel method by combining the texture information derived from the local binary pattern and variance features (LBP and VAR) with the spectral information based on VI to improve the estimation accuracy of rice LAI throughout the entire growing season. The multitemporal images of two study areas located in Hainan and Hubei were acquired by a 12-band camera, and the main typical bands for constituting VIs such as green, red, red edge, and near-infrared were selected to analyze their changes in spectrum and texture during the entire growing season. After the mathematical combination of plot-level spectrum and texture values, new indices were constructed to estimate rice LAI. Comparing the corresponding VI, the new indices were all less sensitive to the appearance of panicles and slightly weakened the saturation issue. The coefficient of determination (R2) can be improved for all tested VIs throughout the entire growing season. The results showed that the combination of spectral and texture features exhibited a better predictive ability than VI for estimating rice LAI. This method only utilized the texture and spectral information of the UAV image itself, which is fast, easy to operate, does not need manual intervention, and can be a low-cost method for monitoring crop growth.
Ten-Year Monitoring of the Grandes Jorasses Glaciers Kinematics. Limits, Potentialities, and Possible Applications of Different Monitoring Systems
Authors: Dematteis Niccolò , Giordan Daniele , Troilo Fabrizio , Wrzesniak Aleksandra , Godone Danilo
Published: August 2021

In the Ferret Valley (NW Italy), anthropic activities coexist close to the Grandes Jorasses massif’s glaciological complex. In the past, break-off events have caused damage to people and infrastructure. These events concerned two specific sectors: the Montitaz Lobe (Planpincieux Glacier) and the Whymper Serac (Grandes Jorasses Glacier). Since 2010, permanent and discontinuous survey campaigns have been conducted to identify potential failure precursors, investigate the glacier instability processes, and explore different monitoring approaches. Most of the existing terrestrial apparatuses that measure the surface kinematics have been adopted in the Grandes Jorasses area. The monitoring sites in this specific area are characterized by severe weather, complex geometry, logistic difficulties, and rapid processes dynamics. Such exceptional conditions highlighted the limitations and potentialities of the adopted monitoring approaches, including robotic total station (RTS), GNSS receivers, digital image correlation applied to time-lapse imagery, and terrestrial radar interferometry (TRI). We examined the measurement uncertainty of each system and their monitoring performances. We discussed their principal limitations and possible use for warning purposes. In the Grandes Jorasses area, the use of a time-lapse camera appeared to be a versatile and cost-effective solution, which, however is not suitable for warning applications, as it does not guarantee data continuity. RTS and GNSS have warning potentialities, but the target installation and maintenance in remote environments remain challenging. TRI is the most effective monitoring system for early warning purposes in such harsh conditions, as it provides near-real-time measurements. However, radar equipment is very costly and requires extreme logistic effort. In this framework, we present data integration strategies to overcome the abovementioned limits and we demonstrate that these strategies are optimal solutions to obtain data continuity and robustness.
HYDROPT: An Open-Source Framework for Fast Inverse Modelling of Multi- and Hyperspectral Observations from Oceans, Coastal and Inland Waters
Authors: Holtrop Tadzio , Van Der Woerd Hendrik Jan
Published: August 2021

Biomass estimation of multiple phytoplankton groups from remote sensing reflectance spectra requires inversion models that go beyond the traditional band-ratio techniques. To achieve this objective retrieval models are needed that are rooted in radiative transfer (RT) theory and exploit the full spectral information for the inversion. HydroLight numerical solutions of the radiative transfer equation are well suited to support this inversion. We present a fast and flexible Python framework for forward and inverse modelling of multi- and hyperspectral observations, by further extending the formerly developed HydroLight Optimization (HYDROPT) algorithm. Computation time of the inversion is greatly reduced using polynomial interpolation of the radiative transfer solutions, while at the same time maintaining high accuracy. Additional features of HYDROPT are specification of sensor viewing geometries, solar zenith angle and multiple optical components with distinct inherent optical properties (IOP). Uncertainty estimates and goodness-of-fit metrics are simultaneously derived for the inversion routines. The pursuit to retrieve multiple phytoplankton groups from remotely sensed observations illustrates the need for such flexible retrieval algorithms that allow for the configuration of IOP models characteristic for the region of interest. The updated HYDROPT framework allows for more than three components to be fitted, such as multiple phytoplankton types with distinct absorption and backscatter characteristics. We showcase our model by evaluating the performance of retrievals from simulated Rrs spectra to obtain estimates of 3 phytoplankton size classes in addition to CDOM and detrital matter. Moreover, we demonstrate HYDROPTs capability for the inter-comparison of retrievals using different sensor band settings including coupling to full spectral coverage, as would be needed for NASA’s PACE mission. The HYDROPT framework is now made available as an open-source Python package.