Records Added in May 2021
Records added in May 2021
Change year: 2018 | 2019 | 2020 | 2021 | 2022 | 2023
Change month: January | February | March | April | May | June | July | August | September | October | November | December
Showing records 51 to 75 of 160. [First] Page: 1 2 3 4 5 6 7 Last
Microwave-Assisted Pyrolysis of Pine Wood Sawdust Mixed with Activated Carbon for Bio-Oil and Bio-Char Production
Anissa Khelfa, Filipe Augusto Rodrigues, Mohamed Koubaa, Eugène Vorobiev
May 26, 2021 (v1)
Keywords: activated carbon, Biomass, microwave absorber, pine wood sawdust, pyrolysis
Pyrolysis of pine wood sawdust was carried out using microwave-heating technology in the presence of activated carbon (AC). Experimental conditions were of 20 min processing time, 10 wt.% of AC, and a microwave power varying from 100 to 800 W. The results obtained showed that the microwave absorber allowed increasing the bio-oil yield up to 2 folds by reducing the charcoal fraction. The maximum temperature reached was 505 °C at 800 W. The higher heating values (HHV) of the solid residues ranged from 17.6 to 30.3 MJ/kg. The highest HHV was obtained for the sample heated at 800 W with 10 wt.% of AC, which was 33% higher than the non-charged sample heated at the same power. Furthermore, the addition of AC allowed showing the probable catalytic effect of the AC in the charged sample pyrolysis bio-oils.
Study on the Nonlinear Dynamics of the Continuous Stirred Tank Reactors
Liangcheng Suo, Jiamin Ren, Zemeng Zhao, Chi Zhai
May 26, 2021 (v1)
Keywords: bifurcation analysis, output multiplicity, Process Intensification, torus dynamics
Chemical processes often exhibit nonlinear dynamics and tend to generate complex state trajectories, which present challenging operational problems due to complexities such as output multiplicity, oscillation, and even chaos. For this reason, a complete knowledge of the static and dynamic nature of these behaviors is required to understand, to operate, to control, and to optimize continuous stirred tank reactors (CSTRs). Through nonlinear analysis, the possibility of output multiplicity, self-sustained oscillation, and torus dynamics are studied in this paper. Specifically, output multiplicity is investigated in a case-by-case basis, and related operation and control strategies are discussed. Bifurcation analysis to identify different dynamic behaviors of a CSTR is also implemented, where operational parameters are identified to obtain self-oscillatory dynamics and possible unsteady-state operation strategy through designing the CSTR as self-sustained periodic. Finally, a discussion on... [more]
Study on Production, Domestic and Ecological Benefits of Reservoir Water Supply Based on Emergy Analysis
Xinjian Guan, Pengkun Jiang, Yu Meng, Haidong Qin, Hong Lv
May 26, 2021 (v1)
Keywords: emergy theory, RWSBEM, water supply benefit, water transformity, WRV
As an important water conservancy project, it is necessary to evaluate its water supply benefit. Based on the emergy analysis theory, a reservoir water supply benefits evaluation model (RWSBEM) was established. Firstly, the emergy transformity of natural and engineering water body was calculated. Secondly, the water resource values (WRV) of different water users (industrial, agricultural, domestic, ecological) were calculated. Finally, combined with the water supply situation of the reservoir, the various water supply benefits of the reservoir were calculated. Taking Hekoucun reservoir as an example, its ecological water supply benefit is the largest and agriculture is the smallest, followed by industry and life. The results showed that the trend of WRV was domestic > industry > ecology > agriculture, which reflected the contribution and utility of water resources in different industries. Under the condition of current water resources, the planned water supply benefits of the reservoir... [more]
Structure Property Investigation of Glass-Carbon Prepreg Waste-Polymer Hybrid Composites Degradation in Water Condition
Norlin Nosbi, Haslan Fadli Ahmad Marzuki, Muhammad Razlan Zakaria, Wan Fahmin Faiz Wan Ali, Fatima Javed, Muhammad Ibrar
May 26, 2021 (v1)
Subject: Materials
Keywords: carbon prepreg waste, degradation, hybrid composites, water absorption
The limited shelf life of carbon prepreg waste (CPW) from component manufacturing restricts its use as a composite reinforcement fibre on its own. However, CPW can be recycled with glass fibre (GF) reinforcement to develop a unique remediate material. Therefore, this study fabricated (1) a glass fibre-carbon prepreg waste reinforced polymer hybrid composite (GF-CPW-PP), (2) a polypropylene composite (PP), (3) a carbon prepreg waste reinforced composite (CPW-PP), and (4) a glass fibre reinforced composite (GF-PP) and reported their degradation and residual tension properties after immersion in water. The polymer hybrid composites were fabricated via extrusion technique with minimum reinforce glass-carbon prepreg waste content of 10 wt%. The immersion test was conducted at room temperature using distilled water. Moisture content and diffusion coefficient (DC) were determined based on water adsorption values recorded at 24-h intervals over a one-week period. The results indicated that GF-... [more]
A Review on Individual and Combination Technologies of UV-C Radiation and Ultrasound in Postharvest Handling of Fruits and Vegetables
Okon Johnson Esua, Nyuk Ling Chin, Yus Aniza Yusof, Rashidah Sukor
May 26, 2021 (v1)
Keywords: cavitation, decontamination, deterioration, dosage, hurdle technology, microorganisms, nonthermal
Ultraviolet-C radiation and ultrasound technology are widely accepted and continuously being appraised as alternatives to conventional thermal techniques for decontamination of fruits and vegetables. However, studies in these areas have presented challenges related to quality, safety, limited capability, and cost of energy. This review paper presents an up-to-date summary of applications of ultraviolet-C radiation and ultrasound technology for postharvest handling of fruits and vegetables from relevant literature. The limitations associated with applications of ultraviolet-C radiation and ultrasound technology individually has prompted their combination alongside other antimicrobial strategies for enhanced bactericidal effect. The combination of ultraviolet-C radiation and ultrasound technology as a hurdle approach also provides enhanced efficiency, cost effectiveness, and reduced processing time without compromising quality. The review includes further scope of industrial-led collabor... [more]
Charcoal as an Alternative Reductant in Ferroalloy Production: A Review
Gerrit Ralf Surup, Anna Trubetskaya, Merete Tangstad
May 26, 2021 (v1)
Keywords: bio-based reductant, charcoal, ferroalloy industry, kiln, pyrolysis
This paper provides a fundamental and critical review of biomass application as renewable reductant in integrated ferroalloy reduction process. The basis for the review is based on the current process and product quality requirement that bio-based reductants must fulfill. The characteristics of different feedstocks and suitable pre-treatment and post-treatment technologies for their upgrading are evaluated. The existing literature concerning biomass application in ferroalloy industries is reviewed to fill out the research gaps related to charcoal properties provided by current production technologies and the integration of renewable reductants in the existing industrial infrastructure. This review also provides insights and recommendations to the unresolved challenges related to the charcoal process economics. Several possibilities to integrate the production of bio-based reductants with bio-refineries to lower the cost and increase the total efficiency are given. A comparison of chall... [more]
Recent Advances in Reducing Food Losses in the Supply Chain of Fresh Agricultural Produce
Daniel I. Onwude, Guangnan Chen, Nnanna Eke-emezie, Abraham Kabutey, Alfadhl Yahya Khaled, Barbara Sturm
May 25, 2021 (v1)
Keywords: agricultural production, crop storage and processing, food distribution, food quality, food security, Industry 4.0, refrigeration, smart digital technology
Fruits and vegetables are highly nutritious agricultural produce with tremendous human health benefits. They are also highly perishable and as such are easily susceptible to spoilage, leading to a reduction in quality attributes and induced food loss. Cold chain technologies have over the years been employed to reduce the quality loss of fruits and vegetables from farm to fork. However, a high amount of losses (≈50%) still occur during the packaging, pre-cooling, transportation, and storage of these fresh agricultural produce. This study highlights the current state-of-the-art of various advanced tools employed to reducing the quality loss of fruits and vegetables during the packaging, storage, and transportation cold chain operations, including the application of imaging technology, spectroscopy, multi-sensors, electronic nose, radio frequency identification, printed sensors, acoustic impulse response, and mathematical models. It is shown that computer vision, hyperspectral imaging, m... [more]
Modeling and Optimization for Konjac Vacuum Drying Based on Response Surface Methodology (RSM) and Artificial Neural Network (ANN)
Zhiheng Zeng, Ming Chen, Xiaoming Wang, Weibin Wu, Zefeng Zheng, Zhibiao Hu, Baoqi Ma
May 25, 2021 (v1)
Keywords: drying, glucomannan, konjac, Optimization, vacuum
To reveal quality change rules and establish the predicting model of konjac vacuum drying, a response surface methodology was adopted to optimize and analyze the vacuum drying process, while an artificial neural network (ANN) was applied to model the drying process and compare with the response surface methodology (RSM) model. The different material thickness (MT) of konjac samples (2, 4 and 6mm) were dehydrated at temperatures (DT) of 50, 60 and 70 °C with vacuum degrees (DV) of 0.04, 0.05 and 0.06 MPa, followed by Box−Behnken design. Dehydrated samples were analyzed for drying time (t), konjac glucomannan content (KGM) and whiteness index (WI). The results showed that the DT and MT should be, respectively, under 60 °C and 4 mm for quality and efficiency purposes. Optimal conditions were found to be: DT of 60.34 °C; DV of 0.06 MPa and MT of 2 mm, and the corresponding responses t, KGM and WI were 5 h, 61.96% and 82, respectively. Moreover, a 3-10-3 ANN model was established to compare... [more]
DOA Estimation in Non-Uniform Noise Based on Subspace Maximum Likelihood Using MPSO
Jui-Chung Hung
May 25, 2021 (v1)
Keywords: direction of arrival estimation, memetic algorithms, non-uniform noise, Particle Swarm Optimization, subspace maximum-likelihood
In general, the performance of a direction of arrival (DOA) estimator may decay under a non-uniform noise and low signal-to-noise ratio (SNR) environment. In this paper, a memetic particle swarm optimization (MPSO) algorithm combined with a noise variance estimator is proposed, in order to address this issue. The MPSO incorporates re-estimation of the noise variance and iterated local search algorithms into the particle swarm optimization (PSO) algorithm, resulting in higher efficiency and a reduction in non-uniform noise effects under a low SNR. The MPSO procedure is as follows: PSO is initially utilized to evaluate the signal DOA using a subspace maximum-likelihood (SML) method. Next, the best position of the swarm to estimate the noise variance is determined and the iterated local search algorithm to reduce the non-uniform noise effect is built. The proposed method uses the SML criterion to rebuild the noise variance for the iterated local search algorithm, in order to reduce non-un... [more]
A New Control Performance Evaluation Based on LQG Benchmark for the Heating Furnace Temperature Control System
Haisheng Li, Rongxuan Li, Feng Wu
May 25, 2021 (v1)
Keywords: control performance assessment, FO-PFC control, fractional order system, linear quadratic Gaussian (LQG) benchmark
Temperature control systems are a series of processes with large time-delay and non-linear characteristics. Research shows that using fractional-order modeling and corresponding control strategies can better control these processes. At the same time, the existing studies for control performance assessment are almost committed to the integer order control systems, and the methods used in few literatures on performance assessment of fractional order systems are also one-sided. This paper applies the linear quadratic Gaussian (LQG) evaluation benchmark to the performance evaluation of fractional-order control systems for the first time, starting with the LQG evaluation benchmark considering the input and output performance. The LQG benchmark can be obtained by the analytical algorithm, which simplifies the complexity of LQG solution. Finally, taking the application of the fractional predictive function control (FO-PFC) controller in the experiment of industrial heating furnace temperature... [more]
Eulerian−Eulerian Modeling of Multiphase Flow in Horizontal Annuli: Current Limitations and Challenges
Amina Shynybayeva, Luis R. Rojas-Solórzano
May 25, 2021 (v1)
Keywords: annuli, flow pattern, liquid hold up, multiphase flow, numerical modeling, pressure drop
Multiphase flows are present in many natural phenomena, processing technologies, and industries. In the petroleum industry, the multiphase flow is highly relevant, and special attention is paid to the development of predictive tools that determine flow conditions to guarantee safe and economic hydrocarbon extraction and transportation. Hydrodynamic aspects such as pressure drop and holdup are of primary relevance for the field engineer in daily operations like pumping power calculation and equipment selection and control. Multiphase flow associated with oil production is usually a mixture of liquids and gas. The hydrodynamic behavior has been studied in different pipeline configurations (i.e., vertical ascending/descending and horizontal/inclined pipelines). However, the available information about flow patterns as well as the general conditions present in horizontal annuli is incomplete, even if they are of fundamental relevance in today’s horizontal drilling, production, and well int... [more]
Comparative Performances of Microalgal-Bacterial Co-Cultivation to Bioremediate Synthetic and Municipal Wastewaters Whilst Producing Biodiesel Sustainably
Wai Hong Leong, Kunlanan Kiatkittipong, Worapon Kiatkittipong, Yoke Wang Cheng, Man Kee Lam, Rashid Shamsuddin, Mardawani Mohamad, Jun Wei Lim
May 25, 2021 (v1)
Subject: Biosystems
Keywords: biodiesel, Biomass, lipid, microalgal-bacterial cultures, wastewater treatment
The potentiality of a microalgal-bacterial culture system was explored in bioremediating wastewater while generating biomass for biodiesel production. A pre-determined optimal activated sludge and microalgal ratio was adopted and cultivation performance was evaluated in both synthetic and municipal wastewater media for nitrogen removal along with biomass and lipid generation for biodiesel production. The microalgal-bacterial consortium grown in the municipal wastewater medium produced higher biomass and lipid yields than those in the synthetic wastewater medium. The presence of trace elements in the municipal wastewater medium, e.g., iron and copper, contributed to the upsurge of biomass, thereby leading to higher lipid productivity. Both the microbial cultures in the synthetic and municipal wastewater media demonstrated similar total nitrogen removal efficiencies above 97%. However, the nitrification and assimilation rates were relatively higher for the microbial culture in the munici... [more]
Microfluidic Nano-Scale qPCR Enables Ultra-Sensitive and Quantitative Detection of SARS-CoV-2
Xin Xie, Tamara Gjorgjieva, Zaynoun Attieh, Mame Massar Dieng, Marc Arnoux, Mostafa Khair, Yasmine Moussa, Fatima Al Jallaf, Nabil Rahiman, Christopher A. Jackson, Lobna El Messery, Khristine Pamplona, Zyrone Victoria, Mohammed Zafar, Raghib Ali, Fabio Piano, Kristin C. Gunsalus, Youssef Idaghdour
May 25, 2021 (v1)
Subject: Biosystems
Keywords: COVID-19, detection, microfluidics, nano-qPCR, SARS-CoV-2, ultra-sensitive, viral load, viral RNA
A major challenge in controlling the COVID-19 pandemic is the high false-negative rate of the commonly used RT-PCR methods for SARS-CoV-2 detection in clinical samples. Accurate detection is particularly challenging in samples with low viral loads that are below the limit of detection (LoD) of standard one- or two-step RT-PCR methods. In this study, we implemented a three-step approach for SARS-CoV-2 detection and quantification that employs reverse transcription, targeted cDNA preamplification, and nano-scale qPCR based on a commercially available microfluidic chip. Using SARS-CoV-2 synthetic RNA and plasmid controls, we demonstrate that the addition of a preamplification step enhances the LoD of this microfluidic RT-qPCR by 1000-fold, enabling detection below 1 copy/µL. We applied this method to analyze 182 clinical NP swab samples previously diagnosed using a standard RT-qPCR protocol (91 positive, 91 negative) and demonstrate reproducible and quantitative detection of SARS-CoV-2 ov... [more]
Regulation of Metabolic Processes by Hydrogen Peroxide Generated by NADPH Oxidases
María Magdalena Vilchis-Landeros, Deyamira Matuz-Mares, Héctor Vázquez-Meza
May 25, 2021 (v1)
Subject: Biosystems
Keywords: hydrogen peroxide, NADPH oxidases, signaling, superoxide anion
Hydrogen peroxide (H2O2) is an important oxidizing molecule that regulates the metabolisms of aerobic organisms. Redox signaling comprises physiological oxidative stress (eustress), while excessive oxidative stress causes damage to molecules. The main enzymatic generators of H2O2 are nicotinamide adenine dinucleotide phosphate oxidases or NADPH oxidases (NOXs) and mitochondrial respiratory chains, as well as various oxidases. The NOX family is constituted of seven enzyme isoforms that produce a superoxide anion (O2−), which can be converted to H2O2 by superoxide dismutase or spontaneously. H2O2 passes through the membranes by some aquaporins (AQPs), known as peroxyporins. It diffuses through cells and tissues to initiate cellular effects, such as proliferation, the recruitment of immune cells, and cell shape changes. Therefore, it has been proposed that H2O2 has the same importance as Ca2+ or adenosine triphosphate (ATP) to act as modulators in signaling and the metabolism. The present... [more]
Double-Loop Control Structure for Rotary Drum Granulation Loop
Ludmila Vesjolaja, Bjørn Glemmestad, Bernt Lie
May 25, 2021 (v1)
Keywords: automatic control, dynamic simulation, granulation, oscillatory behaviour, PID controller, population balance
The operation of granulation plants on an industrial scale is challenging. Periodic instability associated with the operation of the granulation loop causes the particle size distribution of the particles flowing out from the granulator to oscillate, thus making it difficult to maintain the desired product quality. To address this problem, two control strategies are proposed in this paper, including a novel approach, where product-sized particles are recycled back to maintain a stable granulation loop process. A dynamic model of the process that is based on a population balance equation is used to represent the process dynamics. Both of the control strategies utilize a double-loop control structure that is suitable for highly oscillatory systems. The simulation results show that both control strategies, including the novel approach, are able to remove the oscillating behaviour and stabilize the granulation plant loop.
The Influence of the Blade Outlet Angle on the Flow Field and Pressure Pulsation in a Centrifugal Fan
Hongchang Ding, Tao Chang, Fanyun Lin
May 25, 2021 (v1)
Keywords: aerodynamic performance, blade outlet angle, centrifugal fan, numerical simulation
This paper takes centrifugal fan as the research object and establishes five impeller models with different blade outlet angles. By means of computational fluid dynamics (CFD), the external characteristics of the centrifugal fan and the internal characteristics, including the velocity, pressure, and turbulent energy distribution, at the middle span plane of the impeller or fan were obtained and compared. In addition, the pressure fluctuations surrounding the impeller outlet were also analyzed. The results showed that the change of the blade outlet angle of the centrifugal fan had a great influence on the performance; the total pressure and efficiency of the fan were the highest when the outlet angle of the blade was increased to 29.5° under the design flow rate; and the influence of the outlet angle on the fan performance was different in off-design conditions. On the other hand, at different flow rates, the change of the internal flow field with the increase of the outlet angle was di... [more]
Tandem-Homodimer of a β-Sheet-Forming Short Peptide Inhibits Random-to-β Structural Transition of Its Original Monomer
Kin-ya Tomizaki, Tomomi Iori, Hideyasu Fukushima, Yasuhiro Nakabayashi, Yoshiki Matsumoto, Takahito Imai
May 25, 2021 (v1)
Subject: Biosystems
Keywords: amyloid β peptide, fibrillation, inhibitor, modulator, peptide, self-assembly
There is an increasing interest in designing fibrillogenesis modulators for treating amyloid β (Aβ)-peptide-associated diseases. The use of Aβ fragment peptides and their derivatives, as well as nonpeptidyl natural products, is one promising approach to prevent Aβ fibrillation. In this study, we demonstrate that tandem-homodimers (TDs) of a β-sheet-forming short peptide in which the amino acid sequence is duplicated in series and joined via an amino alkanoic acid linker of different chain lengths, preventing the random-to-β structural transition of the original monomer. Ape5-TD, containing 5-amino pentanoate, most potently prevented this transition for at least five days by generating disordered aggregates with reduced tryptic stability. The linkers in the TDs generated this inhibitory activity, probably due to their bent conformations and hydrophobicity, appropriate for accommodating and twisting the monomers, resulting in irregular arrangements of the peptides. The present study coul... [more]
Significant Effect of Sample Pretreatment on Ara h1 Extraction and Improved Sensitive SWCNT-Based Detection through Optimization
Jinyoung Lee
May 25, 2021 (v1)
Keywords: Extraction, nanobiosensor, peanut allergen, pretreatment, single-walled carbon nanotube
Single-walled carbon nanotube (SWCNT)-based nanobiosensors have received increasing attention from food researchers as a future instrument of food safety due to their high sensitivity. However, the pretreatment process of the sample applying to SWCNT-based nanobiosensor is required to be more delicate compared to other analyses. In this study, the pretreatment process of Ara h1 protein from its retained complex food matrix was optimized using various buffer compounds and the pretreated allergenic Ara h1 obtained for the optimized process was detected by SWCNT-based nanobiosensor. In the pretreatment process, the buffer extraction method with tris buffer (Tris-HNO3, pH 8.4) was developed and used to extract native peanut allergens from foods. The extraction procedure for Ara h1 from peanut butter foods was performed by varying the temperature, extraction time, and additives (NaCl and skim milk powder). The results of these tests using our SWCNT-based biosensor were analyzed to evaluate... [more]
Simulation of the Reactivation of Partially Inactivated Biocatalysts in Sequential Batch Reactors
Nadia Guajardo, Fernando A. Crespo, Rodrigo A. Schrebler
May 25, 2021 (v1)
Keywords: bioreactors, enzyme inactivation, enzyme reactivation, sequential batch bioreactor simulation
The enzymatic reactivation process enables the recovery of catalytic activity for inactive biocatalysts. However, its effect on the specific productivity of the processes has not been studied. The main objective of this work was to evaluate the specific productivity of the processes with and without reactivation using the program Spyder Python (3.7). Using fixed values for all of the parameters, the global specific productivity was 8 mM/h·gbiocat for the process without reactivation, and 4 mM/h·gbiocat for the process with reactivation. Random numbers were generated to use as different values for parameters, and the results yielded a global specific productivity of 3.79 mM/h·gbiocat for the process with reactivation and 3.68 mM/h·gbiocat for the process without reactivation. ANOVA tests showed that there were significant differences between the specific global productivities of the two processes. Reactivation has great potential for use when the biocatalyst is of high cost.
Numerical Study of Single Taylor Bubble Movement Through a Microchannel Using Different CFD Packages
Mónica F. Silva, João B. L. M. Campos, João M. Miranda, José D. P. Araújo
May 25, 2021 (v1)
Keywords: ANSYS Fluent, micro-scale, OpenFOAM, slug-flow
A Computation Fluid Dynamics (CFD) study for micro-scale gas−liquid flow was performed by using two different software packages: OpenFOAM® and ANSYS Fluent®. The numerical results were compared to assess the capability of both options to accurately predict the hydrodynamics of this kind of system. The focus was to test different methods to solve the gas−liquid interface, namely the Volume of Fluid (VOF) + Piecewise Linear Interface Calculation (PLIC) (ANSYS Fluent®) and MULES/isoAdvector (OpenFOAM®). For that, a single Taylor bubble flowing in a circular tube was studied for different co-current flow conditions (0.01 < CaB < 2.0 and 0.01 < ReB < 700), creating representative cases that exemplify the different sub-patterns already identified in micro-scale slug flow. The results show that for systems with high Capillary numbers (CaB > 0.8) each software correctly predicts the main characteristics of the flow. However, for small Capillary numbers (CaB < 0.03), spurious curren... [more]
Sustainable Rural Electrification Through Solar PV DC Microgrids—An Architecture-Based Assessment
Mashood Nasir, Saqib Iqbal, Hassan A. Khan, Juan C. Vasquez, Josep M. Guerrero
May 25, 2021 (v1)
Keywords: DC microgrids, DC power systems, loss analysis, Newton–Raphson, rural electrification, system sizing
Solar photovoltaic (PV) direct current (DC) microgrids have gained significant popularity during the last decade for low cost and sustainable rural electrification. Various system architectures have been practically deployed, however, their assessment concerning system sizing, losses, and operational efficiency is not readily available in the literature. Therefore, in this research work, a mathematical framework for the comparative analysis of various architectures of solar photovoltaic-based DC microgrids for rural applications is presented. The compared architectures mainly include (a) central generation and central storage architecture, (b) central generation and distributed storage architecture, (c) distributed generation and central storage architecture, and (d) distributed generation and distributed storage architecture. Each architecture is evaluated for losses, including distribution losses and power electronic conversion losses, for typical power delivery from source end to th... [more]
Nanoemulsion Gel Formulation Optimization for Burn Wounds: Analysis of Rheological and Sensory Properties
Małgorzata Miastkowska, Agnieszka Kulawik-Pióro, Mariola Szczurek
May 25, 2021 (v1)
Subject: Materials
Keywords: burn wound healing, nanoemulgel, rheological properties, sensory properties
Background: Despite the variety of treatment methods for wounds and scars after burns, there are still few effective preparations that can be used in a non-invasive therapy. Recent years have seen significant development of nanomedicine and nanotechnology in the treatment of infection in burn wounds. Proposal: The aim of this work was to develop a formula of a nanoemulsion gel for skin regeneration after burns, and to compare its rheological and sensory properties, as well as the effectiveness of post-burn skin regeneration with preparations available on the market. Methods: At the first stage of studies the composition and parameters of the preparation of sea buckthorn oil-based O/W (oil-in-water) nanoemulsion containing hyaluronic acid and aloe vera gel, as the active ingredients were optimized. Then, the nanoemulsion was added to the gel matrix composed of carbomer (1%) and water which resulted in receiving nanoemulgel. The physicochemical parameters of the obtained samples were cha... [more]
Biotechnological Processing of Laying Hen Paw Collagen into Gelatins
Robert Gál, Pavel Mokrejš, Jana Pavlačková, Ngo Thi Hong Linh, Jiří Mlček
May 25, 2021 (v1)
Keywords: Batch Process, biotechnology, by-products, crosslinking, endoprotease, Extraction, gelatins, laying hens, paws, processing
By-products of laying hens represent a promising raw material source with a high collagen content, which is currently not adequately used. The aim of the paper is to prepare gelatins from laying hen paws. The purified collagen raw material was processed by a biotechnological process using the food endoprotease Protamex®. After cleavage of the cross-links in the collagen structure, the gelatin was extracted by a batch process with a stirrer in two extraction steps. The influence of the extraction process on the yield of gelatins and on selected qualitative parameters of gelatins was monitored by two-level factor experiments with three selected process factors. The studied factors were: enzyme dosage (0.2−0.8%), enzyme processing time (24−72 h) and gelatin extraction time (30−120 min). After the first extraction step at 75 °C, gelatin was extracted with a yield of 8.2−21.4% and a gel strength of 275−380 Bloom. In the second extraction step at 80−100 °C, it is possible to obtain another p... [more]
Effect of Harvesting Age and Size Reduction in the Performance of Anaerobic Digestion of Pennisetum Grass
Carlos Alexander Pizarro-Loaiza, Patricia Torres-Lozada, Josep Illa, Jordi Palatsi, August Bonmatí
May 25, 2021 (v1)
Keywords: anaerobic digestion, biogas, harvest age, methane yield, particle size reduction, perennial grasses, tropical climate
In the rural zones of Latin American and Caribbean developing countries, the poorest households rely on traditional fuels such as firewood to meet their daily cooking needs. Many of those countries are located near the equator, where they have a tropical climate and grass is one of the most common biomass crops. The aim of this study was to evaluate the effect of harvesting age (30, 44, and 57 days) in the performance of anaerobic digestion of King Grass (Pennisetum purpureum cv. King Grass) grown under tropical climate conditions. Three reduction methods of crop size were also compared. Results showed that 44-day harvesting age presented the greater specific methane yield (347.8 mLCH4 g−1VS) and area-specific methane yield (9773 m3CH4 ha−1 y−1). The machine chopped method (1−3 cm for stems and 1−10 cm for leaves) was the reduction method that maximized the methane production. From those results, the calculated area required for grass cultivation to provide the cooking energy to a typi... [more]
Rapid Quality Control of Woodchip Parameters Using a Hand-Held Near Infrared Spectrophotometer
Elena Leoni, Manuela Mancini, Daniele Duca, Giuseppe Toscano
May 25, 2021 (v1)
Keywords: ash content, biomass properties, bound water content, chemometrics, gross calorific value, monitoring quality biofuels, PLS, prediction quality biofuel
Near infrared spectroscopy is a non-invasive and rapid technique to support the analysis of solid biofuels such as woodchip, which is considered as a suitable alternative for energy production, according to European goals for fossil fuel reduction. Chemical and physical properties of the woodchip influence combustion performance, so the most discriminant parameters such as moisture and ash content and gross calorific value were constantly monitored. The aim of this study was the development of prediction models for these three parameters with the use of a hand-held NIR spectrometer. Laboratory analyses were carried out to evaluate the quality of several Italian samples from a power plant, and PLS regression models were developed to test prediction accuracy. Moreover, the most relevant wavelengths were investigated to discriminate chemical compounds influence. Prediction models demonstrated the capacity of handheld MicroNIR instrument to be considered a practical tool for solid biofuel... [more]
Showing records 51 to 75 of 160. [First] Page: 1 2 3 4 5 6 7 Last
Change year: 2018 | 2019 | 2020 | 2021 | 2022 | 2023
Change month: January | February | March | April | May | June | July | August | September | October | November | December