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Records Added in February 2023
Records added in February 2023
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Showing records 8201 to 8225 of 12650. [First] Page: 325 326 327 328 329 330 331 332 333 Last
N−Doped Porous Carbon Microspheres Derived from Yeast as Lithium Sulfide Hosts for Advanced Lithium-Ion Batteries
Sheng Liang, Jie Chen, Xuehua He, Lingli Liu, Ningning Zhou, Lei Hu, Lili Wang, Dewei Liang, Tingting Yu, Changan Tian, Chu Liang
February 23, 2023 (v1)
Keywords: lithium sulfide, lithium-ion battery, nitrogen doping, porous carbon microsphere
Lithium sulfide (Li2S) is considered to be the best potential substitution for sulfur-based cathodes due to its high theoretical specific capacity (1166 mAh g−1) and good compatibility with lithium metal-free anodes. However, the electrical insulation nature of Li2S and severe shuttling of lithium polysulfides lead to poor rate capability and cycling stability. Confining Li2S into polar conductive porous carbon is regarded as a promising strategy to solve these problems. In this work, N-doped porous carbon microspheres (NPCMs) derived from yeasts are designed and synthesized as a host to confine Li2S. Nano Li2S is successfully entered into the NPCMs’ pores to form N-doped porous carbon microspheres−Li2S composite (NPCMs−Li2S) by a typical liquid infiltration−evaporation method. NPCMs−Li2S not only delivers a high initial discharge capacity of 1077 mAh g−1 at 0.2 A g−1, but also displays good rate capability of 198 mAh g−1 at 5.0 A g−1 and long-term lifespan over 500 cycles. The improve... [more]
Layered Double Hydroxides as a Drug Delivery Vehicle for S-Allyl-Mercapto-Cysteine (SAMC)
Ivan Vito Ferrari, Riccardo Narducci, Giuseppe Prestopino, Ferdinando Costantino, Alessio Mattoccia, Lina Di Giamberardino, Morena Nocchetti, Maria Luisa Di Vona, Annalisa Paolone, Marzia Bini, Riccardo Pezzilli, Ilaria Borromeo, Simone Beninati, Pier Gianni Medaglia
February 23, 2023 (v1)
Subject: Biosystems
Keywords: antitumor garlic derivative molecules, cancer, drug delivery, hepatoma, intercalation compounds, S-allyl-mercapto-cysteine (SAMC), ZnAl-LDH
The intercalations of anionic molecules and drugs in layered double hydroxides (LDHs) have been intensively investigated in recent years. Due to their properties, such as versatility in chemical composition, good biocompatibility, high density and protection of loaded drugs, LDHs seem very promising nanosized systems for drug delivery. In this work, we report the intercalation of S-allyl-mercapto-cysteine (SAMC), which is a component of garlic that is well-known for its anti-tumor properties, inside ZnAl-LDH (hereafter LDH) nanostructured crystals. In order to investigate the efficacy of the intercalation and drug delivery of SAMC, the intercalated compounds were characterized using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The increase in the interlayer distance of LDH from 8.9 Å, typical of the nitrate phase, to 13.9 Å indicated the intercalation of SAMC, which was also confirmed using FT-IR spectra. Indeed... [more]
Silica-Supported Styrene-Co-Divinylbenzene Pickering Emulsion Polymerization: Tuning Surface Charge and Hydrophobicity by pH and Co-Aid Adsorption
Benoit Fouconnier, M. Ali Aboudzadeh, Francisco López-Serrano
February 23, 2023 (v1)
Subject: Materials
Keywords: hybrid monoliths, microspheres, Pickering emulsion polymerization, silica nanoparticles
In this work, polymerizations of styrene (St) in the presence of divinylbenzene (DVB) as a crosslinking agent and sodium 4-vinylbenzenesulfonate (VBS) have been performed in Pickering emulsions, using silica nanoparticles (SNps) as stabilizing agents and ammonium persulfate as a hydrophilic initiator. In oil-in-water Pickering emulsions with alkaline continuous phase (pH = 9) at 1, 2, and 3 wt% DVB (relative to St), polydisperse spheroid copolymer submicronic nanoparticles were obtained. Comparatively, polymerizations performed in Pickering emulsions with acidic continuous phase (pH = 5) allowed preparing St-co-DVB microspheres with core−shell structures at 1 wt% DVB and St-co-DVB hybrid monoliths with bi-continuous morphologies at 2 and 3 wt% DVB. It is noteworthy that this work reports Pickering emulsion polymerization as a new strategy for preparing hybrid percolated scaffolds with bi-continuous porosity. The proposed mechanisms originated by pH, DVB, and VBS and the drastic impact... [more]
Computational Study of the Adsorption of Phosphates as Wastewater Pollutant Molecules on Faujasites
Luis Fernando Capa-Cobos, Ximena Jaramillo-Fierro, Silvia González
February 23, 2023 (v1)
Subject: Environment
Keywords: Adsorption, DFT, faujasite, phosphate, wastewater treatment
The adsorption of sodium dihydrogen phosphate (NaH2PO4) onto X- and Y-type faujasite zeolites was computationally studied using the Density Functional Theory (DFT) method. The structures were modeled using the Materials Studio software. The Si/Al ratios for the X- and Y-type zeolite models were 1.2 and 2.5, respectively. The central pore of the zeolite provided a more favorable coordination for adsorbing NaH2PO4. Full molecular optimization and adsorption energy calculations were performed using the VASP code. The adsorption was more effective on zeolite Y, with an adsorption energy of 161 kJ/mol, compared to the zeolite X system, with an adsorption energy of 31.64 kJ/mol. This calculated value for X-type faujasite was found in the interval of the adsorption energy of H2PO4− on hydrated Fe oxide (94.4 kJ/mol) and modified polyether sulfone (22.5 kJ/mol), and the calculated adsorption energy of the molecule on Y-type faujasite coincides with the reported value for this adsorbate on Mg/C... [more]
Experimental Evaluation of Axial Reaction Turbine Stage Bucket Losses
Marek Klimko, Richard Lenhard, Pavel Žitek, Katarína Kaduchová
February 23, 2023 (v1)
Keywords: axial turbine stage, bucket losses, wake traversing
The article describes the measurement methods and data evaluation from a single-stage axial turbine with high reaction (50%). Four operating modes of the turbine were selected, in which the wake traversing behind nozzle and bucket with five-hole pneumatic probes took place. The article further focuses on the evaluation of bucket losses for all four measured operating modes, including the analysis of measurement uncertainties.
Renewable Hydrogen Production from Butanol Steam Reforming over Nickel Catalysts Promoted by Lanthanides
João Paulo da S. Q. Menezes, Gabriel M. Guimarães, Mônica A. P. da Silva, Mariana M. V. M. Souza
February 23, 2023 (v1)
Subject: Environment
Keywords: Butanol, coke, Hydrogen, lanthanides, reforming
Hydrogen is mainly produced by steam reforming of natural gas, a nonrenewable resource. Alternative and renewable routes for hydrogen production play an important role in reducing dependence on oil and minimizing the emission of greenhouse gases. In this work, butanol, a model compound of bio-oil, was employed for hydrogen production by steam reforming. The reaction was evaluated for 30 h in a tubular quartz reactor at 500 °C, atmospheric pressure, GHSV of 500,000 h−1, and an aqueous solution feed of 10% v/v butanol. For this reaction, catalysts with 20 wt.% NiO were prepared by wet impregnation using three supports: γ-alumina and alumina modified with 10 wt.% of cerium and lanthanum oxides. Both promoters increased the reduction degree of the catalysts and decreased catalyst acidity, which is closely related to coke formation and deactivation. Ni/La2O3−Al2O3 presented a higher nickel dispersion (14.6%) which, combined with other properties, led to a higher stability, higher mean hydro... [more]
Identifying the Most Potent Dual-Targeting Compound(s) against 3CLprotease and NSP15exonuclease of SARS-CoV-2 from Nigella sativa: Virtual Screening via Physicochemical Properties, Docking and Dynamic Simulation Analysis
Syed Mohd Danish Rizvi, Talib Hussain, Afrasim Moin, Sheshagiri R. Dixit, Subhankar P. Mandal, Mohd Adnan, Qazi Mohammad Sajid Jamal, Dinesh C. Sharma, Abulrahman Sattam Alanazi, Rahamat Unissa
February 23, 2023 (v1)
Keywords: dithymoquinone, dynamic simulation, physicochemical properties, SARS-CoV-2, virtual screening
Background: The outbreak of the coronavirus (SARS-CoV-2) has drastically affected the human population and caused enormous economic deprivation. It belongs to the β-coronavirus family and causes various problems such as acute respiratory distress syndrome and has resulted in a global pandemic. Though various medications have been under trial for combating COVID-19, specific medicine for treating COVID-19 is unavailable. Thus, the current situation urgently requires effective treatment modalities. Nigella sativa, a natural herb with reported antiviral activity and various pharmacological properties, has been selected in the present study to identify a therapeutic possibility for treating COVID-19. Methods: The present work aimed to virtually screen the bioactive compounds of N. sativa based on the physicochemical properties and docking approach against two SARS-CoV-2 enzymes responsible for crucial functions: 3CLpro (Main protease) and NSP15 (Nonstructural protein 15 or exonuclease). Ho... [more]
Chrono::GPU: An Open-Source Simulation Package for Granular Dynamics Using the Discrete Element Method
Luning Fang, Ruochun Zhang, Colin Vanden Heuvel, Radu Serban, Dan Negrut
February 23, 2023 (v1)
Subject: Materials
Keywords: Discrete Element Method, GPU computing, granular material, physics-based simulation
We report on an open-source, publicly available C++ software module called Chrono::GPU, which uses the Discrete Element Method (DEM) to simulate large granular systems on Graphics Processing Unit (GPU) cards. The solver supports the integration of granular material with geometries defined by triangle meshes, as well as co-simulation with the multi-physics simulation engine Chrono. Chrono::GPU adopts a smooth contact formulation and implements various common contact force models, such as the Hertzian model for normal force and the Mindlin friction force model, which takes into account the history of tangential displacement, rolling frictional torques, and cohesion. We report on the code structure and highlight its use of mixed data types for reducing the memory footprint and increasing simulation speed. We discuss several validation tests (wave propagation, rotating drum, direct shear test, crater test) that compare the simulation results against experimental data or results reported in... [more]
Dynamic Measurement of Relative Complex Permittivity of Microwave Plasma at Atmospheric Pressure
Ge Wang, Hui Pan, Shimiao Lai, Yongjie Zhou, Li Wu, Huacheng Zhu, Yang Yang
February 23, 2023 (v1)
Keywords: BP neural network, complex permittivity, microwave plasma
Complex permittivity is one of the most important parameters to characterize the interaction between microwave and medium, especially for microwave-excited plasma. It is convenient to study plasma’s dielectric properties and microwave propagation characteristics by measuring its complex permittivity. A dynamic measurement method of equivalent relative complex permittivity of microwave-excited plasma at atmospheric pressure is proposed in this paper. Firstly, a cavity based on WR-430 at a frequency of 2.45 GHz was specially designed in COMSOL. Then, the samples with different real parts of complex permittivity and loss tangent were simulated in the designed cavity to obtain their corresponding S parameters, and they were used to train the BP neural network until the error was lower than 0.001. A two-port network was built to excite the plasma. The input power, reflected power, and transmitted power could be measured by the transmission reflection method. Finally, the measured power valu... [more]
A Review on the Role of Amorphous Aluminum Compounds in Catalysis: Avenues of Investigation and Potential Application in Petrochemistry and Oil Refining
Aliya N. Mukhamed’yarova, Bulat I. Gareev, Danis K. Nurgaliev, Firdavs A. Aliev, Alexey V. Vakhin
February 23, 2023 (v1)
Subject: Materials
Keywords: amorphous alumina, amorphous aluminum gel, amorphous aluminum hydroxide, asphaltenes, heavy oil
Aluminum oxides and hydroxides are widely applied because of the great variety of their modifications. In particular, aluminum oxides and hydroxides are used in petrochemistry and oil refining. However, amorphous aluminum compounds have not been sufficiently studied due to the complexity of their synthesis and the problems encountered during their study. The study of amorphous aluminum compounds is hindered by the ambiguity of terminology. In this work, the structures of amorphous aluminum compounds prepared by different methods and the properties that determine their applications have been highlighted in detail. Amorphous aluminum compounds play both positive and negative roles in petrochemistry; however, in petroleum refining, amorphous compounds (without promoters and transition metal salts) demonstrate a promising catalytic performance in oil upgrading.
Harnessing the Potential of Symbiotic Endophytic Fungi and Plant Growth-Promoting Rhizobacteria to Enhance Soil Quality in Saline Soils
Zahra Rouydel, Mohsen Barin, Mir Hassan Rasouli-Sadaghiani, Maryam Khezri, Ramesh Raju Vetukuri, Sandeep Kushwaha
February 23, 2023 (v1)
Subject: Biosystems
Keywords: biological indices, endophytic, micro-organisms, salinity, wheat
Soil salinity is one of the most important abiotic stresses limiting crop growth and production worldwide. Some microorganisms can improve the plants’ tolerance to salinity. For this purpose, a greenhouse experiment was performed to understand the influence of various microorganisms on soil biological indices and wheat growth under different saline conditions. The factors varied in the experiment were the microbial treatment (rhizobacteria, mycorrhizal fungi, endophytic fungus, and control) and salinity stress (0.5, 8, and 14 dS m−1). Rhizobacteria were isolated from saline soils, but the fungi were prepared from a microbial bank. Overall, ten isolates were purified, and three with promising growth-promoting properties were identified using phenotypic and molecular methods. The selected isolates belonged to the genera Pseudomonas (P. aeruginosa Ur83 and P. fluorescens Ur67) and Stenotrophomonas (S. maltophilia Ur52). Soil quality indices were found to decrease with increasing salinity,... [more]
Demulsification Treatment of Spent Metalworking Fluids by Metal Cations: The Synergistic Effect and Efficiency Evaluation
Yanqing Zhang, Lingxue Wu, Xiaochen Zhang, Baoxin Ge, Yuanfeng Qi
February 23, 2023 (v1)
Subject: Environment
Keywords: demulsification, efficiency evaluation, hazardous waste minimization, spent metalworking fluids, synergistic effect
In this paper, various metal ions were utilized for the demulsification of spent metalworking fluids discharged from an automobile parts workshop. Five types of metal ions, i.e., Fe3+, Al3+, Fe2+, Ca2+ and Mg2+, combined with coagulant were systematically evaluated, and the synergistic effect as well as the optimum operating conditions were studied. The results indicated that the Ca2+ as well Mg2+ possessed hardly efficiency for the demulsification, on the contrary, Fe2+ reduced the yield of the by-product sludge and lowered the SV30 ratio, and Al3+ boosted the CODCr removal. Furthermore, Fe3+ and Al3+ had a significant synergistic effect to achieve a better transmittance and a higher CODCr/SV30 ratio which revealed that more CODCr was removed, as well as less by-product sludge was generated. For a better demulsification of spent metalworking fluids, the optimum operating conditions were gathered as follows: the dosage of metal ions was 0.08 mol/L with Al3+:Fe3+ ratio was 1.5:1, the re... [more]
Parameter Identification of a Quasi-3D PEM Fuel Cell Model by Numerical Optimization
Maximilian Haslinger, Christoph Steindl, Thomas Lauer
February 23, 2023 (v1)
Keywords: differential-evolution algorithm, fuel cell, isotherm, Nelder–Mead simplex algorithm, numerical optimization, polymer electrolyte membrane, quasi-3D model, single-phase
Polymer electrolyte membrane fuel cells (PEMFCs) supplied with green hydrogen from renewable sources are a promising technology for carbon dioxide-free energy conversion. Many mathematical models to describe and understand the internal processes have been developed to design more powerful and efficient PEMFCs. Parameterizing such models is challenging, but indispensable to predict the species transport and electrochemical conversion accurately. Many material parameters are unknown, or the measurement methods required to determine their values are expensive, time-consuming, and destructive. This work shows the parameterization of a quasi-3D PEMFC model using measurements from a stack test stand and numerical optimization algorithms. Differential evolution and the Nelder−Mead simplex algorithm were used to optimize eight material parameters of the membrane, cathode catalyst layer (CCL), and gas diffusion layer (GDL). Measurements with different operating temperatures and gas inlet pressu... [more]
Dynamic Optimization of Chemical Processes Based on Modified Sailfish Optimizer Combined with an Equal Division Method
Yuedong Zhang, Yuanbin Mo
February 23, 2023 (v1)
Subject: Optimization
Keywords: adaptive, chemical dynamic optimization problem, chemical reactors, equal division method, modified sailfish optimizer
The optimal solution of the chemical dynamic optimization problem is the basis of automatic control operation in the chemical process, which can reduce energy consumption, increase production efficiency, and maximize economic benefit. In this paper, a modified sailfish optimizer (MSFO) combined with an equal division method is proposed for solving chemical dynamic optimization problems. Based on the basic sailfish optimizer, firstly, the tent chaotic mapping strategy is introduced to disturb the initialization of sailfish and sardine populations to avoid the loss of population diversity. Secondly, an adaptive linear reduction strategy of attack parameters is proposed to enhance the exploration and exploitation ability of sailfish. Thirdly, the updating formula of sardine position is modified, and the global optimal solution is used to attract all sardine positions, which can avoid the premature phenomenon of the algorithm. Eventually, the MSFO is applied to solve six classical optimiza... [more]
A Small-Scale Study on Removal of Heavy Metals from Contaminated Water Using Water Hyacinth
An The Huynh, Yi-Ching Chen, Bich Ngoc Thi Tran
February 23, 2023 (v1)
Subject: Environment
Keywords: arsenic, cadmium, copper, heavy metals, lead, water hyacinth, zinc
The aim of this research was to determine whether water hyacinth can be used to remove heavy metals, such as cadmium, arsenic, lead, zinc, and copper, from industrial wastewater. Investigations of the pollution removal or prevention potential of aquatic macrophytes, such as heavy metal bio-indicators in aquatic habitats, can prove to be advanced field studies. Water hyacinth is one of the aquatic plant species that has been effectively utilized for the treatment of wastewater. It is extremely effective in removing stains, suspended solids, BOD, organic matter, and heavy metals. This research focused on the use of water hyacinth to treat wastewater from heavy metals. Water hyacinths can grow in sewage, absorbing and digesting contaminants and transforming sewage effluents into comparatively clean water in the process. As a result, the plants have the potential to be used as natural water purification systems at a fraction of the cost of a standard sewage treatment facility. The experime... [more]
Variable Neighborhood Strategy Adaptive Search for Optimal Parameters of SSM-ADC 12 Aluminum Friction Stir Welding
Suppachai Chainarong, Thanatkij Srichok, Rapeepan Pitakaso, Worapot Sirirak, Surajet Khonjun, Raknoi Akararungruangku
February 23, 2023 (v1)
Subject: Optimization
Keywords: D-optimal, differential evolution algorithm, friction stir welding, SSM-ADC 12
In this study, we present a new algorithm for finding the optimal friction stir welding parameters to maximize the tensile strength of a butt joint made of the semisolid material (SSM) ADC 12 aluminum. The welding parameters were rotational speed, welding speed, tool tilt, tool pin profile, and rotational direction. The method presented is a variable neighborhood strategy adaptive search (VaNSAS) approach. The process of finding the optimal friction stir welding parameters comprises five steps: (1) identifying the type and range of friction stir parameters using a literature survey; (2) performing experiments according to (1); (3) constructing a regression model using the response surface method optimizer (RSM optimizer); (4) using VaNSAS to find the optimal parameters for the model obtained from (3); and (5) confirming the results from (4) using the parameter levels obtained from (4) to perform real experiments. The computational results revealed that the tensile strength generated fr... [more]
Vis-NIR Hyperspectral Imaging for Online Quality Evaluation during Food Processing: A Case Study of Hot Air Drying of Purple-Speckled Cocoyam (Colocasia esculenta (L.) Schott)
John Ndisya, Ayub Gitau, Duncan Mbuge, Arman Arefi, Liliana Bădulescu, Elke Pawelzik, Oliver Hensel, Barbara Sturm
February 23, 2023 (v1)
Keywords: antioxidants, browning index, CIE L*a*b*, moisture content, non-invasive measurements, phenolic compounds, rehydration ratio, shrinkage, structural morphology, water activity
In this study, hyperspectral imaging (HSI) and chemometrics were implemented to develop prediction models for moisture, colour, chemical and structural attributes of purple-speckled cocoyam slices subjected to hot-air drying. Since HSI systems are costly and computationally demanding, the selection of a narrow band of wavelengths can enable the utilisation of simpler multispectral systems. In this study, 19 optimal wavelengths in the spectral range 400−1700 nm were selected using PLS-BETA and PLS-VIP feature selection methods. Prediction models for the studied quality attributes were developed from the 19 wavelengths. Excellent prediction performance (RMSEP < 2.0, r2P > 0.90, RPDP > 3.5) was obtained for MC, RR, VS and aw. Good prediction performance (RMSEP < 8.0, r2P = 0.70−0.90, RPDP > 2.0) was obtained for PC, BI, CIELAB b*, chroma, TFC, TAA and hue angle. Additionally, PPA and WI were also predicted successfully. An assessment of the agreement between predictions from the non-invas... [more]
Exhaustive Plant Profile of “Dimocarpus longan Lour” with Significant Phytomedicinal Properties: A Literature Based-Review
Priyanka Paul, Partha Biswas, Dipta Dey, Abu Saim Mohammad Saikat, Md. Aminul Islam, Md Sohel, Rajib Hossain, Abdullah Al Mamun, Md. Ataur Rahman, Md. Nazmul Hasan, Bonglee Kim
February 23, 2023 (v1)
Subject: Biosystems
Keywords: 4-O-methyl gallic acid, anti-colorectal cancer, antiproliferative, Dimocarpus longan Lour, flavonoid, immunomodulatory, neurological disorder, obesity
Background: “Dimocarpus longan Lour” is a tropical and subtropical evergreen tree species mainly found in China, India, and Thailand; this plant, found naturally in Bangladesh, even locally, is used as “kaviraj” medication for treating different diseases, such as gastrointestinal disorders, wounds, fever, snake bites, menstrual problem, chickenpox, bone fractures, neurological disorders, and reproductive health. Different parts of this plant, especially juice pulp, pericarp, seeds, leaves, and flowers, contain a diverse group of botanical phytocompounds, and nutrient components which are directly related to alleviating numerous diseases. This literature-based review provides the most up-to-date data on the ethnomedicinal usages, phytochemical profiling, and bio-pharmacological effects of D. longan Lour based on published scientific articles. Methodology: A literature-based review was conducted by collecting information from various published papers in reputable journals and cited organ... [more]
Robust Detection of Minute Faults in Uncertain Systems Using Energy Activity
Manarshhjot Singh, Anne-Lise Gehin, Belkacem Ould-Boaumama
February 23, 2023 (v1)
Keywords: bond graph, energy activity, Fault Detection
Fault detection is one of the key steps in Fault Detection and Isolation (FDI) and, therefore, critical for subsequent prognosis or implementation of Fault Tolerant Control (FTC). It is, therefore, advisable to utilize detection algorithms which are quick and can detect the smallest faults. Model-based detection methods satisfy both these criteria and should be preferred. However, a big limitation for model-based methods is that they require the accurate value of the component parameters, which is difficult to obtain in real situations. This limits the accuracy of model-based methods. This paper proposes a new method for fault detection using Energy Activity (EA) which can detect minute levels of fault in systems with high component uncertainty. Different forms of EA are developed for use as an FDI metric. The proposed forms are simulated using a two-tank system under various types of faults. The results are compared with each other and with the traditional model-based FDI method using... [more]
Handling Measurement Delay in Iterative Real-Time Optimization Methods
Anwesh Reddy Gottu Mukkula, Sebastian Engell
February 23, 2023 (v1)
Subject: Optimization
Keywords: active perturbation strategy, gradient estimation, guaranteed model adequacy, iterative optimization, modifier adaptation, plant-model mismatch, quadratic approximation, real-time optimization, time delay
This paper is concerned with the real-time optimization (RTO) of chemical plants, i.e., the optimization of the steady-state operating points during operation, based on inaccurate models. Specifically, modifier adaptation is employed to cope with the plant-model mismatch, which corrects the plant model and the constraint functions by bias and gradient correction terms that are computed from measured variables at the steady-states of the plant. This implies that the sampling time of the iterative RTO scheme is lower-bounded by the time to reach a new steady-state after the previously computed inputs were applied. If analytical process measurements (PAT technology) are used to obtain the steady-state responses, time delays occur due to the measurement delay of the PAT device and due to the transportation delay if the samples are transported to the instrument via pipes. This situation is quite common because the PAT devices can often only be installed at a certain distance from the measur... [more]
A Review of Gum Hydrocolloid Polyelectrolyte Complexes (PEC) for Biomedical Applications: Their Properties and Drug Delivery Studies
Jindrayani Nyoo Putro, Valentino Bervia Lunardi, Felycia Edi Soetaredjo, Maria Yuliana, Shella Permatasari Santoso, I Gede Wenten, Suryadi Ismadji
February 23, 2023 (v1)
Keywords: drug delivery, gum polysaccharides, hydrocolloid, polyelectrolyte complexes
The utilization of natural gum polysaccharides as the vehicle for drug delivery systems and other biomedical applications has increased in recent decades. Their biocompatibility, biodegradability, and price are much cheaper than other materials. It is also renewable and available in massive amounts, which are the main reasons for its use in pharmaceutical applications. Gum can be easily functionalized with other natural polymers to enhance their applications. Various aspects of the utilization of natural gums in the forms of polyelectrolyte complexes (PECs) for drug delivery systems are discussed in this review. The application of different mathematical models were used to represent the drug release mechanisms from PECs; these models include a zero-order equation, first-order equation, Higuchi, simplified Higuchi, Korsmeyer−Peppas, and Peppas−Sahlin.
Composition of Oil after Hydrothermal Treatment of Cabonate-Siliceous and Carbonate Domanic Shale Rocks
Galina P. Kayukova, Zukhra R. Nasyrova, Anastasiya N. Mikhailova, Igor P. Kosachev, Firdavs A. Aliev, Alexey V. Vakhin
February 23, 2023 (v1)
Subject: Environment
Keywords: composition, Domanic rocks, hydrothermal processes, kerogen, mineral composition, organic matter, transformations
The hydrocarbon compositions of shale oils, generated from two different lithological−facial Domanic deposits of the Tatarstan Republic (Russia), were studied under hydrothermal impact with 30% of water addition in a 350 °С and CO2 environment. The samples were extracted from carbonate−siliceous rocks of the Semiluky−Mendym deposits of the Berezovskaya area, and carbonate deposits of the Dankovo−Lebedyan horizon of the Zelenogorskaya area of the Romashkino oil field. The distinctive features of rocks are in the composition and content of organic matter (OM), its thermal stability, as well as the structural-group composition of the shale oil products. The hydrothermal treatment of the rock samples increased the content of saturates and decreased the content of aromatics, resins and asphaltenes in the composition of crude oil. The decomposition of the polymer-like kerogen structure and destruction processes of high-molecular compounds, such as resins and asphaltenes, are accompanied with... [more]
Potential Use of Papaya Waste as a Fuel for Bioelectricity Generation
Segundo Rojas-Flores, Orlando Pérez-Delgado, Renny Nazario-Naveda, Henry Rojales-Alfaro, Santiago M. Benites, Magaly De La Cruz-Noriega, Nélida Milly Otiniano
February 23, 2023 (v1)
Subject: Biosystems
Keywords: electricity, generation, microbial fuel cells, papaya, waste
Papaya (Carica papaya) waste cause significant commercial and environmental damage, mainly due to the economic losses and foul odours they emit when decomposing. Therefore, this work provides an innovative way to generate electricity for the benefit of society and companies dedicated to the import and export of this fruit. Microbial fuel cells are a technology that allows electricity generation. These cells were produced with low-cost materials using zinc and copper electrodes; while a 150 mL polymethylmethacrylate tube was used as a substrate collection chamber (papaya waste). Maximum values of 0.736 ± 0.204 V and 5.57 ± 0.45 mA were generated, while pH values increased from 3.848 to 8.227 ± 0.35 and Brix decreased slowly from the first day. The maximum power density value was 878.38 mW/cm2 at a current density of 7.245 A/cm2 at a maximum voltage of 1072.77 mV. The bacteria were identified with an identity percentage of 99.32% for Achromobacter xylosoxidans species, 99.93% for Acineto... [more]
To Advance Industrial Green Technology via Environmental Governance—Evidence from China’s Industrial Sector
Junwei Shi, Yingjing Yu
February 23, 2023 (v1)
Subject: Environment
Keywords: environmental regulation, governance synergy, industrial green technology progress, mediating effect
Industrial green technology progress is an effective way to realize high-quality economic development in China. The different competitive incentives of local governments make a difference in the intensity of environmental regulation between regions. The intensity of environmental regulation is different in different areas of the same industry, leading to the inter-regional transfer of pollution enterprises. The regional distribution of industries is different, which determines the different industries’ needs to coordinate different regions. Only when various industries realize the coordination of regional governance can they jointly promote the progress of industrial green technology. Based on data from 33 industrial sectors in China from 2001 to 2015 and considering the institutional evolution of governance synergy, this study comprehensively investigated the influence mechanism of local government environmental regulation on the industrial green technology progress using the mediatin... [more]
Influence of Carboxylic Modification Using Polyacrylic Acid on Characteristics of Fe3O4 Nanoparticles with Cluster Structure
Jae Rok Shin, Gye Seok An, Sung-Churl Choi
February 23, 2023 (v1)
Subject: Materials
Keywords: characteristics, cluster structure, magnetite, microstructure, surface treatment
Fe3O4 nanoparticles with cluster structure are superparamagnetic particles with applicability in various high-tech fields. In this study, the influence of surface modification with polyacrylic acid (PAA), a polymeric precursor, on the characteristics of Fe3O4 nanoparticles was investigated. The particles were synthesized by the polyol method and surface modified with various amounts of PAA. The surficial, structural, optical, and magnetic properties of the PAA-modified Fe3O4 nanoparticles were analyzed, confirming that negatively charged carboxyl groups were formed on the particle surface, and the particle dispersibility was enhanced by surface modification. This arises from an increase in the electrostatic repulsive force due to the surface functional groups. Functionalization promoted dissociation of the cluster particles, which became more pronounced as the PAA content increased. The optical parameters changed with the PAA content. Analysis of the magnetic properties showed that the... [more]
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