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Showing records 464 to 488 of 1263. [First] Page: 1 16 17 18 19 20 21 22 23 24 Last
Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor
Rathmalgodage Thejani Nilusha, Tuo Wang, Hongyan Wang, Dawei Yu, Junya Zhang, Yuansong Wei
July 7, 2020 (v1)
Keywords: ambient temperature, backwashing, ceramic membrane, domestic wastewater, flux recovery
The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the m... [more]
Application of Computational Intelligence in Describing the Drying Kinetics of Persimmon Fruit (Diospyros kaki) During Vacuum and Hot Air Drying Process
Alfadhl Yahya Khaled, Abraham Kabutey, Kemal Çağatay Selvi, Čestmír Mizera, Petr Hrabe, David Herák
July 7, 2020 (v1)
Keywords: artificial neural network model, computational intelligence methods, drying methods, k-nearest neighbors, persimmon fruit, support vector machine model
This study examines the potential of applying computational intelligence modelling to describe the drying kinetics of persimmon fruit slices during vacuum drying (VD) and hot-air-drying (HAD) under different drying temperatures of 50 °C, 60 °C and 70 °C and samples thicknesses of 5 mm and 8 mm. Kinetic models were developed using selected thin layer models and computational intelligence methods including multi-layer feed-forward artificial neural network (ANN), support vector machine (SVM) and k-nearest neighbors (kNN). The statistical indicators of the coefficient of determination (R2) and root mean square error (RMSE) were used to evaluate the suitability of the models. The effective moisture diffusivity and activation energy varied between 1.417 × 10−9 m2/s and 1.925 × 10−8 m2/s and 34.1560 kJ/mol to 64.2895 kJ/mol, respectively. The thin-layer models illustrated that page and logarithmic model can adequately describe the drying kinetics of persimmon sliced samples with R2 values (>... [more]
Deacidification of Palm Oil Using Betaine Monohydrate-Carboxylic Acid Deep Eutectic Solvents: Combined Extraction and Simple Solvent Recovery
Kamarza Mulia, Mohammad Nasikin, Elsa Anisa Krisanti, Ida Zahrina
July 7, 2020 (v1)
Keywords: betaine monohydrate, deacidification, deep eutectic solvent, liquid–liquid extraction, palm oil, solvent recovery
Steam stripping is commonly used to remove free fatty acids from crude palm oil. An alternative deacidification method, solvent extraction performed at a much lower temperature, would preserve the natural antioxidants in the refined palm oil. In this work, palmitic acid was extracted using betaine monohydrate-propionic acid and betaine monohydrate-acetic acid deep eutectic solvents (DESs). The effect of temperature (40 °C to 80 °C), mass ratio of palm oil to solvent (2:1 to 1:2), and palmitic acid content in the palm oil feed (2% to 8% mass) on the distribution coefficient values of palmitic acid (0.44−0.93) was investigated. For the first time, a facile recovery of DESs could be accomplished by a cooling process where up to 98% of the palmitic acid separates as solid. A solvent extraction process for palm oil deacidification, employing a DES with a distribution coefficient value much higher than unity, will provide advantages over the steam stripping process.
Fatty Acids, Tocopherols, and Phytosterol Composition of Seed Oil and Phenolic Compounds and Antioxidant Activity of Fresh Seeds from Three Dalbergia Species Grown in Vietnam
Thi Thuy Nguyen, Lan Phuong Doan, Thu Huong Trinh Thi, Hong Ha Tran, Quoc Long Pham, Hai Ha Pham Thi, Long Giang Bach, Bertrand Matthäus, Quoc Toan Tran
July 7, 2020 (v1)
Keywords: Dalbergia species, DPPH free radical scavenging assay, fatty acid, phytosterol, tocopherol, total phenolic compound composition
This research aimed to investigate the chemical composition of seed oils extracted from three Vietnamese Dalbergia species (D. tonkinensis, D. mammosa, and D. entadoides). The fatty acid profiles and contents of tocopherols and sterols of the seed oils, and total phenolic compounds extracted from the fresh seeds were characterized using different methods. Among the examined samples, D. tonkinensis seed oils showed high contents of linoleic acid (64.7%), whereas in D. mammosa, oleic acid (51.2%) was predominant. In addition, α- and γ-tocopherol and β-sitosterol were major ingredients in the seed oils, whereas ferulic acid and rosmarinic acid are usually predominant in the seeds of these species. Regarding sterol composition, the D. entadoides seed oil figured for remarkably high content of Δ5,23-stigmastadienol (1735 mg/kg) and Δ7-stigmastenol (1298 mg/kg). In addition, extracts with methanol/water (80:20, v/v) of seeds displayed significant in vitro antioxidant activity which was deter... [more]
Controlled Drug Delivery Vehicles in Veterinary Oncology: State-of-the-Art and Future Directions
Patricia de Faria Lainetti, Fernanda Zuliani, Antonio Fernando Leis-Filho, Ricardo Henrique Fonseca Alves, Carlos Eduardo Fonseca-Alves
July 7, 2020 (v1)
Subject: Biosystems
Keywords: dogs, doxorubicin, nanoparticles, nanotechnology
Controlled drug delivery systems can be used to carry several anticancer agents, including classical chemotherapeutic agents such as doxorubicin, paclitaxel or cisplatin, and are also used for the encapsulation of tyrosine kinase inhibitors and monoclonal antibodies. Usually, the controlled systems are used to decrease drug toxicity, increase local drug concentration or target specific organs or systems. In dogs, liposomal doxorubicin is the most known controlled drug delivery vehicle in veterinary medicine. However, several antitumor drugs can be encapsulated within these systems. Since the delivery vehicles are a relatively new topic in veterinary oncology, this review aims to discuss the current knowledge regarding the controlled drug delivery vehicles and discuss the current challenges and future direction of its use in veterinary oncology.
Characterization of the Bulk Flow Properties of Industrial Powders from Shear Tests
Domenico Macri, Roberto Chirone, Hamid Salehi, Daniele Sofia, Massimiliano Materazzi, Diego Barletta, Paola Lettieri, Massimo Poletto
July 7, 2020 (v1)
Keywords: flowability, Matlab App, powder characterization, tensile strength, yield locus
Bulk flow properties from shear analysis of compacted powders can be evaluated following different approaches. Experimental values of shear stresses obtained by conventional shear cells are traditionally used to build yield loci, from which the most relevant flow properties could be found. Such flow properties play an important role in determining their performance under fluidization conditions. In this work, a useful app, named cYield, was developed by using the new Matlab’s App Developer environment. This tool enables users to calculate both linear (Coulomb) and non-linear (Warren−Spring) yield loci as the best fitting of the σ-τ experimental shear points. It also provides a wide range of statistical information related to the quality of the outcomes obtained. The different features of the tool are presented, and the crucial steps for the execution of its calculations are illustrated. Moreover, it has been applied for the yield loci analysis of four different materials traditionally... [more]
Well-Defined Conjugated Macromolecules Based on Oligo(Arylene Ethynylene)s in Sensing
Agata Krywko-Cendrowska, Dawid Szweda, Roza Szweda
July 7, 2020 (v1)
Subject: Materials
Keywords: biosensors, conjugated oligomers, oligo(arylene ethynylene)s, process monitoring, sensors, sequence-defined macromolecules, sequence-defined polymers, well-defined macromolecules
Macromolecules with well-defined structures in terms of molar mass and monomer sequence became interesting building blocks for modern materials. The precision of the macromolecular structure makes fine-tuning of the properties of resulting materials possible. Conjugated macromolecules exhibit excellent optoelectronic properties that make them exceptional candidates for sensor construction. The importance of chain length and monomer sequence is particularly important in conjugated systems. The oligomer length, monomer sequence, and structural modification often influence the energy bang gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the molecules that reflect in their properties. Moreover, the supramolecular aggregation that is often observed in oligo-conjugated systems is usually strongly affected by even minor structural changes that are used for sensor designs. This review discusses the examples of well-defined conjugat... [more]
Utilization of Steel-Making Dust in Drilling Fluids Formulations
Musaab I. Magzoub, Mohamed H. Ibrahim, Mustafa S. Nasser, Muftah H. El-Naas, Mahmood Amani
July 7, 2020 (v1)
Subject: Other
Keywords: bentonite, recycling, solid waste management, steelmaking, sustainable materials
Steelmaking is an energy-intensive process that generates considerable amounts of by-products and wastes, which often pose major environmental and economic challenges to the steel-making industry. One of these by-products is steel dust that is produced during the separation of impurities in the smelting and refining of metals in steel-making furnaces. In this study, electric arc furnace (EAF) dust has been evaluated as a potential, low-cost additive to increase the viscosity and weight of drilling muds. Currently, the cost of drilling operations typically accounts for 50 to 80% of the exploration costs and about 30 to 80% of the subsequent field development costs. Utilization of steelmaking waste in drilling fluids formulations is aimed to produce new and optimized water-based drilling formulations, which is expected to reduce the amount of bentonite and other viscosifier additives used in the drilling formulations. The results showed that in a typical water-based drilling fluid of 8.6... [more]
Implementation Criteria for Intelligent Systems in Motor Production Line Process Management
Yao-Chin Lin, Ching-Chuan Yeh, Wei-Hung Chen, Kai-Yen Hsu
July 7, 2020 (v1)
Keywords: intelligent systems, motor production lines, process management
In this study, the factors that affect the implementation of intelligent systems in motor production lines are analyzed. A motor production line located in Vietnam is used as the research object. The research methods include secondary data collection, field study, and interviews. This study demonstrates the following: firstly, the implementation of intelligent systems in motor production lines is heading toward Industry 4.0. Secondly, it is proposed that three functional systems—robot arm, image recognition, and big data analysis—can be introduced in the motor production line. This study analyzes the process involved in coil and motor production lines and attempts to combine intelligent system functions. It is expected that in the future, manpower will be reduced, production line productivity will increase, and intelligent production lines will be proposed. The factors that affect the introduction of intelligent systems in motor production lines are improved, and the importance of inte... [more]
Intelligent Setting Method of Reagent Dosage Based on Time Series Froth Image in Zinc Flotation Process
Zhaohui Tang, Liyong Tang, Guoyong Zhang, Yongfang Xie, Jinping Liu
July 7, 2020 (v1)
Keywords: cumulative distribution function, flotation process, reagent dosage, time series froth image
It is well known that the change of the reagent dosage during the flotation process will cause the froth image to change continuously with time. Therefore, an intelligent setting method based on the time series froth image in the zinc flotation process is proposed. Firstly, the sigmoid kernel function is used to estimate the cumulative distribution function of bubble size, and the cumulative distribution function shape is characterized by sigmoid kernel function parameters. Since the reagent will affect the froth image over a period of time, the time series of bubble size cumulative distribution function is processed by the ELMo model and the dynamic feature vectors are output. Finally, XGBoost is used to establish the nonlinear relationship modeling between reagent dosage and dynamic feature vectors. Industrial experiments have proved the effectiveness of the proposed method.
Comprehensive Screening of Drug Encapsulation and Co-Encapsulation into Niosomes Produced Using a Microfluidic Device
Sameer Joshi, Roderica White, Rajnish Sahu, Vida A. Dennis, Shree R. Singh
July 7, 2020 (v1)
Subject: Biosystems
Keywords: cholesterol, encapsulation, microfluidics, niosomes, non-ionic surfactants
Microfluidics is a very facile and fast method of particulate production. Besides, it enables the manufacturing of size tuned particulate systems. Niosomes due to structural similarities have importance as alternative drug delivery systems to liposomes. Niosomes can be encapsulated or co-encapsulated with hydrophilic and lipophilic drugs. The research presented here includes the optimization of method parameters for niosome production as well as evaluation of the efficiency of microfluidics to encapsulate and co-encapsulate the drugs. For this purpose, metformin (MET) and garcinol (GC) were the model drugs. Two different non-ionic surfactants (NIS), namely Tween-20 and Span-60 with significant difference in hydrophilic-lipophilic balance (HLB) value, were chosen to analyze their efficiency to form niosomes and encapsulate one or more drugs.
Applications of Electrolyzed Water as a Sanitizer in the Food and Animal-By Products Industry
Juan C. Ramírez Orejel, José A. Cano-Buendía
July 2, 2020 (v1)
Keywords: electrolyzed water, foodborne pathogens, sanitization
Food demand is increasing every year and, usually animal-derived products are generated far from consumer-places. New technologies are being developed to preserve quality characteristics during processing and transportation. One of them is electrolyzed water (EW) that helps to avoid or decrease the development of foodborne pathogens, or losses by related bacteria. Initially, EW was used in ready-to-eat foods such as spinach, lettuce, strawberries, among others; however, its application in other products is under study. Every product has unique characteristics that require an optimized application of EW. Different sanitizers have been developed; unfortunately, they could have undesirable effects like deterioration of quality or alterations in sensory properties. Therefore, EW is gaining popularity in the food industry due to its characteristics: easy application and storage, no corrosion of work surfaces, absence of mucosal membrane irritation in workers handling food, and it is conside... [more]
Production of Ethanol from Hemicellulosic Sugars of Exhausted Olive Pomace by Escherichia coli
Juan Carlos López-Linares, Irene Gómez-Cruz, Encarnación Ruiz, Inmaculada Romero, Eulogio Castro
July 2, 2020 (v1)
Keywords: acid hydrolysate, biorefinery, detoxification, Fermentation, lignocellulosic residue
Exhausted olive pomace (EOP) is the main residue generated in olive oil industries, after the extraction of the residual oil from olive pomace with hexane. This work studies the ethanol production from hemicellulosic sugars of EOP. The fermentability of the sugar solution, resulting from the acid pretreatment of EOP, was evaluated using Escherichia coli SL100, although a detoxification step was required before fermentation. Overliming and activated charcoal detoxification were tested to minimize the presence of inhibitory compounds in the hydrolysate and to achieve a fermentable medium. E. coli assimilated all sugars in both detoxified hydrolysates and achieved ethanol yields of about 90% of the theoretical one. However, the fermentation time was much shorter when the hydrolysate had been detoxified with activated charcoal (20 h versus 120 h).
Catalytic Aquathermolysis of Boca de Jaruco Heavy Oil with Nickel-Based Oil-Soluble Catalyst
Alexey V. Vakhin, Firdavs A. Aliev, Irek I. Mukhamatdinov, Sergey A. Sitnov, Andrey V. Sharifullin, Sergey I. Kudryashov, Igor S. Afanasiev, Oleg V. Petrashov, Danis K. Nurgaliev
July 2, 2020 (v1)
Keywords: aquathermolysis, catalyst, heavy oil, in situ upgrading, nickel, SARA-analysis
This paper investigates aquathermolysis of heavy oil in carbonate reservoir rocks from Boca de Jaruco, which is developed by the cyclic steam stimulation method. The nickel-based catalyst precursor was introduced in order to intensify the conversion processes of heavy oil components. The active form of such catalysts—nickel sulfides—are achieved after steam treatment of crude oil at reservoir conditions. The experiments were carried out on a rock sample extracted from the depth of 1900 m. Changes in composition and structure of heavy oil after the conversion were identified using SARA-analysis, Gas Chromatography-Mass Spectroscopy of saturated fractions, FTIR spectroscopy of saturated fractions, and MALDI of resins. It is revealed that catalyst particles provide a reduction in the content of resins and asphaltenes due to the destruction of carbon-heteroatom bonds. Moreover, the destruction of C=Carom. bonds and interactions with aromatic rings are heightened. In contrast, the results o... [more]
Polyphenol Content and Biological Activities of Ruta graveolens L. and Artemisia abrotanum L. in Northern Saudi Arabia
Hosam O. Elansary, Agnieszka Szopa, Paweł Kubica, Halina Ekiert, Diaa O. El-Ansary, Fahed A. Al-Mana, Eman A. Mahmoud
July 2, 2020 (v1)
Keywords: antibacterial, antifungal, antioxidant, antiproliferative, Artemisia abrotanum, cytotoxicity, flavonoids, leaf extract, phenolic acids, Ruta graveolens
Natural populations of Ruta graveolens L. and Artemisia abrotanum L. in northern Saudi Arabia may be a rich source of natural polyphenols with potential biological activities. Therefore, tentative high-performance liquid chromatography−diode array detection was used to analyze the polyphenol contents of leaf extracts. R. graveolens mainly contained the phenolic acids chlorogenic acid and p-coumaric acid and the flavonoids rutoside and quercetin, whereas those of A. abrotanum mainly contained the phenolic acids isochlorogenic acid and rosmarinic acid and the flavonoid quercetin. Leaf extracts of both species showed antioxidant activities due to the presence of quercetin, chlorogenic acid, and p-coumaric acid as well as antiproliferative and cytotoxic activities against cancer cells, which may be attributed to necrotic cell accumulation during the early and late apoptotic periods. Both species also exhibited antibacterial activity, although the activity was higher in R. graveolens due to... [more]
Controlling the Skin Barrier Quality through the Application of Polymeric Films Containing Microspheres with Encapsulated Plant Extract
Justyna Kozlowska, Bartosz Tylkowski, Natalia Stachowiak, Weronika Prus-Walendziak
July 2, 2020 (v1)
Subject: Biosystems
Keywords: Calendula officinalis flower extract, encapsulation, microspheres, polymer films, skin barrier, sodium alginate, starch, transepidermal water loss
Human skin has protective functions and it is a barrier that protects the interior of the body from harmful environmental factors and pathogen penetration. An important role of the skin is also to prevent the loss of water from the body and if the skin barrier is damaged, the amount of water emitted from the internal environment is increased. Therefore, it is crucial to recovery and maintenance of epidermal barrier integrity. The aim of the current work was to encapsulate Calendula officinalis flower extract in gelatin microspheres and then incorporation microspheres into thin polymeric films made from sodium alginate or mixture of sodium alginate and starch. Such materials may find applications in the cosmetic field for example in the preparation of masks for skin, according to the Calendula officinalis flower extract wide influence on skin condition. Thus, the release profile of this extract from the materials was tested under conditions corresponding to the skin (pH 5.4, 37 °C). The... [more]
Numerical Modeling of Transport Phenomena in the Horizontal Single Belt Casting (HSBC) Process for the Production of AA6111 Aluminum Alloy Strip
Usman Niaz, Mihaiela Minea Isac, Roderick I. L. Guthrie
July 2, 2020 (v1)
Keywords: computational fluid dynamics (CFD), double impingement feeding system, horizontal single belt casting process (HSBC)
In this research study, numerical modelling and experimental casting of AA6111 strips, 250 mm wide, 6 mm thick, was conducted. The velocity of the molten AA6111 alloy at the nozzle slot outlet was raised to 2 m/s, whilst the belt speed was kept at 0.3 m/s. The numerical model demonstrates considerable turbulence/fluctuations in the flow of the molten AA6111 alloy in the HSBC process, rendering its free surface highly non-uniform and uneven. These discontinuites in the flow resulted from the sudden impact of molten metal onto the inclined refractory plane, and then onto the slowly moving belt. However, it has been determined that these surface variations are rapidly damped, and as such are not detrimental to final strip surface quality. Any surface perturbations remaining can be eliminated via hot plastic deformation. The experimental findings are in accordance with the model predictions. Furthermore, at high metal heads inside the delivery launder, the molten metal was observed to be f... [more]
A General Stroke-Based Model for the Straightening Process of D-Type Shaft
Hong Lu, Yue Zang, Xinbao Zhang, Yongquan Zhang, Le Li
July 2, 2020 (v1)
Keywords: D-type shaft, prediction of straightening parameters, straightening process, stroke-based straightening model, three-dimensional bending deformation
D-type shaft is widely used in precision machinery products such as motors and intelligent robots. The straightness of the D-type shaft is an important factor influencing its machining accuracy and dynamic performance, which is normally improved by the three-point pressure straightening process. This paper proposes a general stroke-based model to predict the relevant parameters for the straightening process of D-type shaft, considering the bending deformations in three dimensions. The distribution of stress and strain inside the D-type shaft during the straightening process in arbitrary position of the cross section and the bending moment are analyzed by using linear hardening material model. The relationship between deflection and the internal stress on the loading position is explored, and a straightening stroke model of D-type shaft is obtained. The correctness of the stroke-based straightening model has been validated by finite element method (FEM) simulation analysis and bending e... [more]
Valorization of OFMSW Digestate-Derived Syngas toward Methanol, Hydrogen, or Electricity: Process Simulation and Carbon Footprint Calculation
Aristide Giuliano, Enrico Catizzone, Cesare Freda, Giacinto Cornacchia
July 2, 2020 (v1)
Keywords: bio-hydrogen, bio-methanol, digestate, gasification, low carbon processes, process simulation
This paper explores a possible waste-based economy transition strategy. Digestate from the organic fraction of municipal solid waste (OFMSW) is considered, as well as a low-added value product to be properly valorized. In this regard, air gasification may be used to produce syngas. In this work, the production of methanol, hydrogen, or electricity from digestate-derived syngas was assessed by ChemCAD process simulation software. The process scheme of methanol production comprises the following parts: water gas shift (WGS) with carbon capture and storage units (CCS), methanol synthesis, and methanol purification. In the case of hydrogen production, after WGS-CCS, hydrogen was purified from residual nitrogen by pressure swing absorption (PSA). Finally, for electricity production, the digestate-derived syngas was used as fuel in an internal combustion engine. The main objective of this work is to compare the proposed scenarios in terms of CO2 emission intensity and the effect of CO2 stora... [more]
Plant-Based Tacca leontopetaloides Biopolymer Flocculant (TBPF) Produced High Removal of Turbidity, TSS, and Color for Leachate Treatment
Nurul Shuhada Mohd Makhtar, Juferi Idris, Mohibah Musa, Yoshito Andou, Ku Halim Ku Hamid, Siti Wahidah Puasa
July 2, 2020 (v1)
Keywords: flocculant properties, leachate, Tacca leontopetaloides biopolymer flocculant (TBPF), Tacca leontopetaloides sp.
Wastewater treatment is crucial to ensure a sustainable supply of clean water, especially for human use. Natural flocculants can overcome the disadvantages of chemical flocculants in wastewater treatment. This study proposes a new natural-based flocculant from the Tacca leontopetaloides plant for leachate treatment. The plant tuber was processed through gelatinization to produce Tacca leontopetaloides biopolymer flocculant (TBPF). The characterization of TBPF for flocculant properties was investigated, and the performance of TBPF on leachate treatment using a standard jar test procedure was examined at different pH values of leachate and TBPF dosages. The characteristics of TBPF in terms of amylose/amylopectin fraction, viscosity, and zeta potential were 26:74, 0.037−0.04 Pa·s, and −13.14 mV, respectively. The presence of −COOH and −OH structure in TBPF indicates the flocculant properties. TBPF reduced the turbidity, total suspended solids (TSS), and color from 218 NTU, 214 mg/L, 14201... [more]
Dentistry 4.0 Concept in the Design and Manufacturing of Prosthetic Dental Restorations
Leszek A. Dobrzański, Lech B. Dobrzański
July 2, 2020 (v1)
Subject: Other
Keywords: additive manufacturing technologies, CAD/CAM methods, CBCT tomography, dental implants, dental prosthesis restoration manufacturing center, Dentistry 4.0, hybrid multilayer biological-engineering composites biomaterials, implant-scaffolds, Industry 4.0, prosthetic restorations, selective laser sintering, stereolithography, stomatognathic system, surgical guide
The paper is a comprehensive but compact review of the literature on the state of illnesses of the human stomatognathic system, related consequences in the form of dental deficiencies, and the resulting need for prosthetic treatment. Types of prosthetic restorations, including implants, as well as new classes of implantable devices called implant-scaffolds with a porous part integrated with a solid core, as well as biological engineering materials with the use of living cells, have been characterized. A review of works on current trends in the technical development of dental prosthetics aiding, called Dentistry 4.0, analogous to the concept of the highest stage of Industry 4.0 of the industrial revolution, has been presented. Authors’ own augmented holistic model of Industry 4.0 has been developed and presented. The studies on the significance of cone-beam computed tomography (CBCT) in planning prosthetic treatment, as well as in the design and manufacture of prosthetic restorations, h... [more]
Pollen Bee Aqueous Extract-Based Synthesis of Silver Nanoparticles and Evaluation of Their Anti-Cancer and Anti-Bacterial Activities
Hanan M. Al-Yousef, Musarat Amina, Ali S. Alqahtani, Mohammed S. Alqahtani, Abdul Malik, Mohammad Rafe Hatshan, Mohammed Rafiq H. Siddiqui, Mujeeb Khan, Mohammed Rafi Shaik, Mohammad Shamsul Ola, Rabbani Syed
July 2, 2020 (v1)
Subject: Biosystems
Keywords: anti-bacterial, anti-cancer, bee pollen aqueous extract, eco-friendly, silver nanoparticles
Bee pollens are rich source of essential amino acids and are often considered as complete food for human beings. Herein, we exploited the potential reducing abilities of Bee pollens extract for the eco-friendly preparation of silver nanoparticles (AgNPs-G). The resulting NPs were characterized using a combination of microscopic and spectroscopic techniques. The analyses confirm the formation of spherical Ag NPs. AgNPs-G obtained from the aqueous extract of bee pollens was used to study their antibacterial properties against Gram-positive and Gram-negative microbes using the Minimum Inhibitory Concentration 50 (MIC50) method. The antibacterial properties of AgNPs-G were compared to the properties of chemically synthesized Ag NPs (AgNPs-C) using sodium borohydride as a reducing agent. The green synthesized nanoparticles (AgNPs-G) exhibited a better antibacterial activity against most of the studied strains when compared to the chemically synthesized Ag NPs (AgNPs-C). In addition, the ant... [more]
A Review on Insights for Green Production of Unconventional Protein and Energy Sources Derived from the Larval Biomass of Black Soldier Fly
Sabrina Hasnol, Kunlanan Kiatkittipong, Worapon Kiatkittipong, Chung Yiin Wong, Cheng Seong Khe, Man Kee Lam, Pau Loke Show, Wen Da Oh, Thiam Leng Chew, Jun Wei Lim
July 2, 2020 (v1)
Keywords: biodiesel, black soldier fly larvae, lipid, protein, substrate, transesterification
The purpose of this review is to reveal the lipid and protein contents in black soldier fly larvae (BSFL) for the sustainable production of protein and energy sources. It has been observed from studies in the literature that the larval lipid and protein contents vary with the rearing conditions as well as the downstream processing employed. The homogenous, heterogenous and microbial-treated substrates via fermentation are used to rear BSFL and are compared in this review for the simultaneous production of larval protein and biodiesel. Moreover, the best moisture content and the aeration rate of larval feeding substrates are also reported in this review to enhance the growth of BSFL. As the downstream process after harvesting starts with larval inactivation, various related methods have also been reviewed in relation to its impact on the quality/quantity of larval protein and lipids. Subsequently, the other downstream processes, namely, extraction and transesterification to biodiesel, a... [more]
Catalytic Performance of Metal Oxides Promoted Nickel Catalysts Supported on Mesoporous γ-Alumina in Dry Reforming of Methane
Anis H. Fakeeha, Abdulaziz A. Bagabas, Mahmud S. Lanre, Ahmed I. Osman, Samsudeen O. Kasim, Ahmed A. Ibrahim, Rasheed Arasheed, Abdulmajeed Alkhalifa, Ahmed Y. Elnour, Ahmed E. Abasaeed, Ahmed S. Al-Fatesh
July 2, 2020 (v1)
Keywords: Dry Reforming, Gd-promoted catalyst, mesoporous γ-alumina, metal oxide promoters, methane, Ni-based catalyst, synthesis gas
Dry reforming of CH4 was conducted over promoted Ni catalysts, supported on mesoporous gamma-alumina. The Ni catalysts were promoted by various metal oxides (CuO, ZnO, Ga2O3, or Gd2O3) and were synthesized by the incipient wetness impregnation method. The influence of the promoters on the catalyst stability, coke deposition, and H2/CO mole ratio was investigated. Stability tests were carried out for 460 min. The H2 yield was 87% over 5Ni+1Gd/Al, while the CH4 and CO2 conversions were found to decrease in the following order: 5Ni+1Gd/Al > 5Ni+1Ga/Al > 5Ni+1Zn/Al > 5Ni/Al > 5Ni+1Cu/Al. The high catalytic performance of 5Ni+1Gd/Al, 5Ni+1Ga/Al, and 5Ni+1Zn/Al was found to be closely related to their contents of NiO species, which interacted moderately and strongly with the support, whereas free NiO in 5Ni+1Cu/Al made it catalytically inactive, even than 5Ni/Al. The 5Ni+1Gd/Al catalyst showed the highest CH4 conversion of 83% with H2/CO mole ratio of ~1.0.
Fabrication of Highly Filled Composites with an Innovative Miniaturized Spouted Bed
Hannah Sophia Rothberg, Swantje Pietsch, Gerold A. Schneider, Stefan Heinrich
July 2, 2020 (v1)
Keywords: highly filled composites, mechanical properties of composites, miniaturized spouted bed, particle coating, three-point bending test
In nature bio-composites such as nacre show remarkable mechanical properties due to their complex hierarchical structure and high-volume fraction of its hard component. These composites are highly interesting for structural applications in different branches of industries for mechanical engineering and process technology. The aim of this work was to provide a scalable method for the production of highly filled composites by mimicking the structure of bio-composites. Therefore, composites from iron oxide (Fe2O3) and SBC-polymer (styrene-butadiene block copolymer) were fabricated by using a miniaturized spouted bed with an innovative fluidization gap design. Small iron oxide particles (25−45 μm) were fluidized in the spouted bed and coated with a polymer solution via a bottom spray nozzle. Afterwards the coated granules were hot-pressed and the mechanical properties of the obtained composites were tested. By this method composites with a bending strength of up to 6 MPa were fabricated. A... [more]
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