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1.
Polymers (Basel) ; 16(15)2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39125242

RESUMEN

The limited recyclability of fibre-reinforced thermoset composites has fostered the development of alternative thermoplastic-based composites and their manufacturing processes. The most common thermoplastic-based composites are often costly due to their availability in the form of prepreg materials and to the high pressure and temperatures required for their manufacturing. Yet, the manufacturing of economic and recyclable composites, made of semi-preg composite materials using traditional composite manufacturing technologies, has only been proved at a laboratory scale through the manufacturing of flat plates. This work reports the manufacturing of a real structural part, a wing spar section with complex geometry, made of commingled polyamide 12 (PA12) fibres and carbon fibres (CFs) semi-preg and by oven vacuum bagging (OVB). The composite layup was studied using finite element analysis, and processing simulation assisted in the determination of the PA12/CF preform for OVB. Processing of two forms of semi-preg materials was first evaluated and optimised. The material selection for part manufacturing was mainly defined by the materials' processability. The spar section was manufactured in two OVB stages and was then mechanically tested. The mechanical test showed a linear strain response of the prototype up to the maximum load and validated the optimised layup configuration of the composite structure.

2.
Heliyon ; 10(14): e34672, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39130449

RESUMEN

The influence of pre-treatments and different dehydrating temperatures on the drying dynamics, energy consumption, and quality attribute of yam chips was studied. Dehydration was executed employing a convectional oven dryer under four temperatures (50, 60, 70, and 80 °C) and 2.0 m/s air velocity. Yam chips were subjected to pre-treatment conditions of blanching (for 1, 2, 3, 4, and 5 min), citric acid (1 and 5 %), and ascorbic acid (1 and 5 %) solutions whereas, untreated yam chips samples served as the control. Dehydrated yam chips were further assessed for textural and colour properties. The drying rate was found to be faster at a higher temperature of 80 °C compared to lower temperatures of 50, 60, and 70 °C. The asymptotic model was established to be the suitable descriptive model for predicting moisture profile in the pre-treated yam chips based on highest R2 values (0.995-0.999), lowest χ2 values (4.422-18.498), and the root mean square error (RMSE) values (2.103-4.30). Pre-treatment and drying temperature had a significant (p < 0.05) impact on the hardness and colour of dehydrated yam chips. Blanching at 4 min yielded yam chips with most preferred texture (hardness: 81.3 N) and lightness (L*) in colour values (71.07 %) after drying compared to other pre-treated samples. The effective moisture diffusivity values of the pre-treated samples were in the range of 5.17294 × 10-9m2/s to 1.10143 × 10-8m2/s for 5 % citric acid samples at 50 °C and all pre-treated samples at 80 °C respectively. The general findings of the study indicated a least energy usage of 43.68 kWh as a cost-effective method of drying. Also, 4 min blanching, 5 % citric acid, and 1 % ascorbic acid at 80 °C were found to be the optimum conditions for pre-treating yam chips based on lower energy level consumption rates and improved sensory properties thus attributing to the quality of the dried yam chips.

3.
Materials (Basel) ; 17(16)2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39203189

RESUMEN

Low carbon and high performance have become key trends in the development of construction materials. Understanding the mechanism by which curing conditions affect the mechanical properties of high-ductility geopolymer concrete (HDGC) is of significant importance. This study investigated three sealing curing temperatures (room temperature, 45 °C, and 60 °C) and four curing durations (1 day, 3 days, 5 days, and 7 days), while considering two final curing ages (7 days and 28 days) to explore their effects on the axial tensile and compressive properties of HDGC. The results showed that both 45 °C and 60 °C could improve the brittle failure of HDGC under axial compressive loading. However, curing at 60 °C and for durations longer than 1 day in an oven would catalyze the formation of eight-faced zeolite crystals within the slag-fly ash geopolymer matrix, and it could weaken the matrix's pore structure and subsequently affect the material's later strength development. Nevertheless, oven heat curing enhanced the bridging effect between the fibers and the matrix, partially compensating for the reduction in the initial tensile strength of HDGC. This follows the pseudo-strain-hardening material's saturation cracking criterion to enhance the strain-hardening behavior of HDGC and improve its tensile energy absorption capacity. A curing condition of 45 °C for 5 days is recommended to maximize the ductility of HDGC. This study provides important theoretical support for the design and promotion of green, low-carbon, high-ductility composite materials.

4.
Chemosphere ; 364: 143158, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39181461

RESUMEN

Soil microplastic contamination is emerging as a significant environmental concern affecting soil properties and biota, including soil aggregation. This study aimed to determine the influence of soil microplastics on soil aggregation, their impact through effects on soil microorganisms, and their effects on water and mechanical stability of soil aggregates. Soil incubation experiments were conducted using sterilized and non-sterilized soils with 15-µm polyethylene and polylactic microplastics over one month. Sterilized soils showed more water-stable aggregates, particularly in the 0.25-0.5 mm fraction (+49%), with both polyethylene and polylactic MPs significantly increasing this fraction (+34% and +35%, respectively). However, no significant effects of soil sterilization and MP addition were found on mechanical stability. The addition of MPs tended to decrease aggregate surface roughness but not significantly (-17~21%). The study provides insights into the complex interactions between microplastics and soil aggregation, suggesting that MP effects may not necessarily be related to their toxicity on soil microbes but could involve various physical interactions.

5.
J Hazard Mater ; 477: 135052, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39067287

RESUMEN

The acid and redox sites of the MnCo catalysts are simultaneously fine-tuned by the addition of V. A dual-function catalyst, designated as V0.5Mn5Co5, has been constructed for the synergistic removal of NOx and volatile organic compounds under coke-oven flue gas conditions, which exhibits > 95 % NOx conversion and > 80 % N2 selectivity at 180-300 °C. Meanwhile, it removes 70 % of ethylene at 240 °C. Besides it has excellent sulfur and water resistance. The characterization results indicate that this acid-redox dual sites modulation strategy appropriately weakens the oxidation capacity of the catalysts while increasing the surface acidity of the catalysts. The catalyst mainly performs SCR reaction through the E-R mechanism, and N2O is generated through the transition dehydrogenation of NH3 and NSCR reaction. Ethylene is first adsorbed on the catalyst surface then oxidized to form carbonate species, and finally decomposed to CO2. Ethylene oxidation follows the MvK mechanism. There is a competitive adsorption between NH3 and C2H4, and a mutual inhibition between the SCR reaction and the ethylene oxidation reaction. V0.5Mn5Co5 exhibits excellent synergistic removal of NOx and VOCs in coke oven flue gas compared with commercial VWTi catalysts, which indicates great promise for industrial application.

6.
J Environ Manage ; 367: 121752, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39067341

RESUMEN

Sustainable management of the Amazon rainforest is fundamental for supporting life on earth because of its crucial role in sequestering carbon. One of the species grown in the forest is açaí (Euterpe oleracea), which is an important food and income source for its inhabitant. The acai seed, resulting from the processing of the fruit, is a solid organic residue, which has been an agent of undesirable environmental impacts such as natural landscape modifications, clogging sewers and water courses, eutrophication of surface waters. In this research, we evaluated the use of wood chips as a source of energy in a rustic oven to produce acai biochar so that family farmers carry out sustainable management of the residue and use biochar to improve soil quality and produce seedlings of native plants to regenerate degraded forests. The experiment was conducted in Pará, Brazil, Amazon region, using a randomized complete block design. A factorial treatment structure was implemented consisting of four biochar particle sizes (3, 5, 7, and 12 mm), 4 application rates (4, 8, 16, and 32 t ha-1), and a biochar-free control, with 5 replications. The results showed that the methodology for biochar production was easy to apply and low cost, allowing its use by family farmers. The combination of biochar rate and particle size affected soil properties and the development of black pepper seedlings in different ways. The soil properties affected were water retention capacity, moisture, fluorescein diacetate hydrolysis and arylsulphatase activity. The growth parameters of the affected black pepper seedlings were height and root system development.


Asunto(s)
Carbón Orgánico , Plantones , Semillas , Suelo , Suelo/química , Plantones/crecimiento & desarrollo , Semillas/crecimiento & desarrollo , Brasil , Piper nigrum
7.
Food Res Int ; 191: 114716, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39059964

RESUMEN

Dehydration is an effective method for the long-term storage and aroma retention of gonggan (Citrus sinensis Osb. 'Deqing Gonggan'), which is a Chinese variety of citrus, with unique and characteristic floral, fruity, and citrus flavors. However, the aroma profiles of gonggans prepared using oven- and freeze-drying, the most widely-used drying methods, remain unclear. In this study, a total of 911 volatile organic compounds (VOCs) were detected in dried gonggan. These were primarily composed of alcohols (7.69%), aldehydes (7.03%), esters (15.38%), ketones (7.58%), and terpenoids (23.19%). A total of 67 odorants contributed significantly to the overall aroma of dried gonggans, with the major odor qualities being detected as green, citrus, fruity, floral, and sweet. These were mainly attributed to the presence of aldehydes, esters, and terpenoids. Freeze-drying was more effective in maintaining the unique citrus and mandarin-like aromas attributed to compounds such as limonene, citrial, ß-myrcene, ß-pinene, and γ-terpinene. Moreover, (E,E)-2,4-decadienal had the highest relative odor activity value (rOAV) in freeze-dried gonggans, followed by (E)-2-nonenal, furaneol, (E, E)-2, 4-nonadienal, and E-2-undecenal. Oven-drying promoted the accumulation of terpenes such as octatriene, trans-ß-ocimene, cyclohexanone, copaene, and ɑ-irone, imparting a soft aroma of flowers, fruits, and sweet. Increasing the temperature led to an increase in existing VOCs or the generation of new VOCs through phenylpropanoid, terpenoid, and fatty acid metabolism. The findings of this study offer insights into an optimized procedure for producing high-quality dried gonggans. These insights can be valuable for the fruit-drying industry, particularly for enhancing the quality of dried fruits.


Asunto(s)
Liofilización , Odorantes , Terpenos , Compuestos Orgánicos Volátiles , Compuestos Orgánicos Volátiles/análisis , Odorantes/análisis , Terpenos/análisis , Frutas/química , Citrus sinensis/química , Desecación/métodos , Aldehídos/análisis , Cromatografía de Gases y Espectrometría de Masas , Cetonas/análisis , Monoterpenos Bicíclicos/análisis , Ésteres/análisis , Alcadienos/análisis , Ciclohexenos/análisis , Manipulación de Alimentos/métodos , Monoterpenos Acíclicos , Monoterpenos Ciclohexánicos , Alquenos , Sesquiterpenos
8.
Materials (Basel) ; 17(12)2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38930158

RESUMEN

The present work reports an effective method for the removal of inorganic and organic pollutants using membranes based on different carbonaceous materials. The membranes were prepared based on cellulose acetate (18 wt. %), polyvinylpyrrolidone as a pore-generating agent (2 wt. %) and activated carbon (1 wt. %). Activated carbons were developed from residues after extraction of the mushroom Inonotus obliguus using microwave radiation. It has been demonstrated that the addition of activated carbon to the membranes resulted in alterations to their physical properties, including porosity, equilibrium water content and permeability. Furthermore, the chemical properties of the membranes were also affected, with changes observed in the content of the surface oxygen group. The addition of carbon material had a positive effect on the removal of copper ions from their aqueous solutions by the cellulose-carbon composites obtained. Moreover, the membranes proved to be more effective in the removal of copper ions than iron ones and phenol. The membranes were found to show higher effectiveness in copper removal from a solution of the initial concentration of 800 mg/L. The most efficient in copper ions removal was the membrane containing urea-enriched activated carbon.

9.
Materials (Basel) ; 17(12)2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38930201

RESUMEN

3D-printable composites have become an attractive option used for the design and manufacture of electrochemical sensors. However, to ensure proper charge-transfer kinetics at the electrode/electrolyte interface, activation is often required, with this step consisting of polymer removal to reveal the conductive nanofiller. In this work, we present a novel effective method for the activation of composites consisting of poly(lactic acid) filled with carbon black (CB-PLA) using microwave radiation. A microwave synthesizer used in chemical laboratories (CEM, Matthews, NC, USA) was used for this purpose, establishing that the appropriate activation time for CB-PLA electrodes is 15 min at 70 °C with a microwave power of 100 W. However, the usefulness of an 80 W kitchen microwave oven is also presented for the first time and discussed as a more sustainable approach to CB-PLA electrode activation. It has been established that 10 min in a kitchen microwave oven is adequate to activate the electrode. The electrochemical properties of the microwave-activated electrodes were determined by electrochemical techniques, and their topography was characterized using scanning electron microscopy (SEM), Raman spectroscopy, and contact-angle measurements. This study confirms that during microwave activation, PLAs decompose to uncover the conductive carbon-black filler. We deliver a proof-of-concept of the utility of kitchen microwave-oven activation of a 3D-printed, free-standing electrochemical cell (FSEC) in paracetamol electroanalysis in aqueous electrolyte solution. We established satisfactory limits of linearity for paracetamol detection using voltammetry, ranging from 1.9 µM to 1 mM, with a detection limit (LOD) of 1.31 µM.

11.
Toxics ; 12(6)2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38922096

RESUMEN

The air fryer utilizes heated air rather than hot oil to achieve frying, eliminating the need for cooking oil, rendering it a healthier cooking method than traditional frying and baking. However, there is limited evidence supporting that the air fryer could effectively reduce the level of food-derived carcinogen. In this study, we compared the concentration of Benzo[a]pyrene (BaP), a typical carcinogen, in beef patties cooked using an air fryer and an oven, under different cooking conditions, including temperatures (140 °C, 160 °C, 180 °C, and 200 °C), times (9, 14, and 19 min), and oil added or not. The adjusted linear regression analysis revealed that the BaP concentration in beef cooked in the air fryer was 22.667 (95% CI: 15.984, 29.349) ng/kg lower than that in beef cooked in the oven. Regarding the air fryer, the BaP concentration in beef cooked without oil brushing was below the detection limit, and it was significantly lower than in beef cooked with oil brushing (p < 0.001). Therefore, cooking beef in the air fryer can effectively reduce BaP concentration, particularly due to the advantage of oil-free cooking, suggesting that the air fryer represents a superior option for individuals preparing meat at high temperatures.

12.
J Food Prot ; 87(7): 100298, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38734415

RESUMEN

Validation of baking processes for the inactivation of Salmonella is complicated by the combined effects of product heating and drying. The goal of this study was to quantitatively evaluate a previously disseminated approach to validating baking processes utilizing a predictive model developed using only isothermal and single-moisture inactivation data for the initially formulated dough. A simple cracker dough was formulated using flour inoculated with a five-strain cocktail of Salmonella. Side-by-side isothermal and baking experiments were performed to estimate Salmonella inactivation kinetics and to quantify survivors in a dynamic environment, respectively. Isothermal, single-moisture inactivation experiments were performed with cracker dough (water activity, aw = 0.956 ± 0.002; moisture content = 0.50 ± 0.01 dry basis) at three temperatures (56, 60, or 63°C) with ≥6 time intervals. Baking experiments were performed in a convection oven at 177°C with samples pulled every 30 s up to 360 s, with an endpoint product aw (25°C) of 0.45. The Salmonella isothermal, single-moisture inactivation kinetics in cracker dough resulted in D60°C and z-values of 4.6 min and 4.9°C, respectively; this model was then integrated over the dynamic product temperature profiles from the baking experiments. In the baking experiments, an average of 5-log reductions of Salmonella was achieved by 150 s of treatment; however, >100-log reductions were predicted by the dough-based models at that time point. This fail-dangerous overestimation of Salmonella lethality in crackers explicitly demonstrated that single-level moisture-based prediction models are inappropriate for describing inactivation in a process with both dynamic temperature and moisture, and that model-based validations must incorporate moisture/aw. Furthermore, end-users should exercise caution when utilizing unvalidated models to validate preventive control processes.


Asunto(s)
Microbiología de Alimentos , Salmonella , Cinética , Recuento de Colonia Microbiana , Humanos , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Seguridad de Productos para el Consumidor , Harina , Culinaria , Temperatura , Calor , Agua
13.
Artículo en Inglés | MEDLINE | ID: mdl-38777977

RESUMEN

This research is aimed to investigate the efficacy of membrane separation technology in treating coke oven wastewater (COW). A comparative study was conducted using three types of membranes: commercial polymeric (CP) membrane, commercial ceramic (CC) membrane, and synthesized ceramic (SC) membrane. The potential of the SC membrane in COW treatment was assessed in comparison to the CC membrane, which had a molecular weight cut-off (MWCO) of 1 Kilo-Dalton. The experiments were conducted under various trans-membrane pressure (TMP) conditions ranging from 1 to 4 bar. Additionally, the effect of the CP membrane on COW treatment was examined at TMP levels ranging from 5 to 25 bar. The research findings revealed that the SC membrane exhibited promising results in terms of permeability and flux compared to the CC membrane. Also, a significant reduction was observed in various water parameters such as TSS decreased by 89.74%, chlorides by 8.24%, nitrogen by 10%, and hardness by 22%. Moreover, the study was carried out by implementing an anti-fouling mechanism to mitigate fouling effects on membrane performance.

14.
ACS Appl Mater Interfaces ; 16(19): 25280-25293, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38712718

RESUMEN

Composite laminates utilizing autoclave-grade carbon fiber-reinforced plastic (CFRP) prepreg were manufactured using a polymer nanoporous network (NPN) interlayer that generates capillary pressure in lieu of pressure from an autoclave. The polymer nanofiber NPN film is integrated into the interlaminar region and is shown to eliminate voids in a vacuum-bag-only (VBO) curing process. After a preliminary investigation of the effect of NPN thickness on the interlaminar region and performance, an 8 µm thick polymer NPN was selected for a scaled manufacturing demonstration. Combining the polymer NPN with "out-of-oven" (OoO) electrothermal heating of a carbon nanotube (CNT)-heated tool, a 0.6 × 0.6 m void-free plate is successfully manufactured. OoO cure enables an accelerated cure cycle, which reduces the cure time by 35% compared to the manufacturer-recommended cure cycle (MRCC). X-ray microcomputed tomography (µ-CT) reveals that the laminates are void-free and of identical quality to autoclave-cured specimens. An array of mechanical tests including tension, compression, open-hole compression (OHC), tension-bearing (bolt-bearing), and compression after impact, reveal that the accelerated NPN-cured composites were broadly equivalent, with some instances of improved properties, relative to the autoclave-cured parts, e.g., OHC strength increased by 5%. With reduced capital costs, energy consumption, and increased throughput, the facile polymer NPN-enabled out-of-autoclave (OoA) fabrication method is shown to be a practical and attractive alternative to conventional autoclave fabrication.

15.
Ecotoxicol Environ Saf ; 277: 116401, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38677069

RESUMEN

Exposure to fine particulate matter (PM) is associated with the neurodegenerative diseases. Coke oven emissions (COEs) in occupational environment are important sources of PM. However, its neurotoxicity is still unclear. Therefore, evaluating the toxicological effects of COE on the nervous system is necessary. In the present study, we constructed mouse models of COE exposure by tracheal instillation. Mice exposed to COE showed signs of cognitive impairment. This was accompanied by a decrease in miR-145a-5p and an increase in SIK1 expression in the hippocampus, along with synaptic structural damage. Our results demonstrated that COE-induced miR-145a-5p downregulation could increase the expression of SIK1 and phosphorylated SIK1, inhibiting the cAMP/PKA/CREB pathway by activating PDE4D, which was associated with reduced synaptic structural plasticity. Furthermore, restoring of miR-145a-5p expression based on COE exposure in HT22 cells could partially reversed the negative effects of COE exposure through the SIK1/PDE4D/cAMP axis. Collectively, our findings link epigenetic regulation with COE-induced neurotoxicity and imply that miR-145a-5p could be an early diagnostic marker for neurological diseases in patients with COE occupational exposure.


Asunto(s)
Disfunción Cognitiva , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4 , MicroARNs , Plasticidad Neuronal , Proteínas Serina-Treonina Quinasas , Animales , MicroARNs/genética , Ratones , Disfunción Cognitiva/inducido químicamente , Plasticidad Neuronal/efectos de los fármacos , Masculino , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , AMP Cíclico/metabolismo , Hipocampo/efectos de los fármacos , Ratones Endogámicos C57BL , Contaminantes Atmosféricos/toxicidad , Material Particulado/toxicidad
16.
Artículo en Inglés | MEDLINE | ID: mdl-38688175

RESUMEN

The present work aimed at the development and characterization of aroeira leaf flour (Schinus terebinthifolius Raddi), obtained by lyophilization and drying in an air circulation oven. The technological, physical, physico-chemical, morphological, functional, and microbiological aspects were analyzed. Physico-chemical analysis identified the following properties with values provided respectively for fresh leaves (FOin) and flours (FES and FLIO): low water activity (0.984, 0.370, 0.387 g/100 g), moisture (64.52, 5.37, 7.97 g /100 g), ash (2.69, 6.51, and 6.89 g/100 g), pH (0.89, 4.45, 4.48 g/100 g), lipids (0.84, 1.67, 5.23 g/100 g), protein (3.29, 8.23, 14.12 g/100 g), carbohydrates (17.02, 53.12, 33.02 g/100 g), ascorbic acid (19.70, 34.20, 36.90 mg/100 g). Sources of fiber from plant leaves and flours (11.64, 25.1, 32.89 g/100 g) showed increased levels of luminosity. For NMR, the presence of aliphatic and aromatic compounds with olefinic hydrogens and a derivative of gallic acid were detected. The most abundant minerals detected were potassium and calcium. Micrographs identified the presence of irregular, non-uniform, and sponge-like particles. The main sugars detected were: fructose, glucose, and maltose. Malic, succinic, citric, lactic, and formic acids were found. Fifteen phenolic compounds were identified in the samples, highlighting: kaempferol, catechin, and caffeic acid. The values ​​found for phenolics were (447, 716.66, 493.31 mg EAG/100 g), flavonoids (267.60, 267.60, 286.26 EC/100 g). Antioxidant activity was higher using the ABTS method rather than FRAP for analysis of FOin, FES, and FLIO. Since the flours of the aroeira leaf have an abundant matrix of nutrients with bioactive properties and antioxidant activity, they have a potential for technological and functional use when added to food.


Asunto(s)
Anacardiaceae , Harina , Hojas de la Planta , Hojas de la Planta/química , Anacardiaceae/química , Harina/análisis , Liofilización , Carbohidratos/análisis , Carbohidratos/química , Antioxidantes/análisis , Antioxidantes/química , Schinus
17.
Molecules ; 29(7)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38611810

RESUMEN

A single combi oven, known for its versatility, is an excellent choice for a variety of chicken soup preparations. However, the impact of universal steam ovens on the flavor quality of chicken soup remains unclear. This study aimed to explore the impact of different cooking methods on the aroma and taste of chicken soup. Three cooking methods with various stewing times were compared: ceramic pot (CP), electric pressure cooker (EPC), and combi oven (CO). Analyses were conducted using electron-nose, electron-tongue, gas chromatography-ion mobility spectrometry (GC-IMS), automatic amino acid analysis, and chemometric methods. A total of 14 amino acids, including significant umami contributors, were identified. The taste components of CP and CO chicken soups were relatively similar. In total, 39 volatile aroma compounds, predominantly aldehydes, ketones, and alcohols, were identified. Aldehydes were the most abundant compounds, and 23 key aroma compounds were identified. Pearson's correlation analyses revealed distinct correlations between various amino acids (e.g., glutamic acid and serine) and specific volatile compounds. The aroma compounds from the CP and CO samples showed similarities. The results of this study provide a reference for the application of one-touch cooking of chicken soup in versatile steam ovens.


Asunto(s)
Antifibrinolíticos , Odorantes , Animales , Pollos , Vapor , Gusto , Cromatografía de Gases y Espectrometría de Masas , Aminoácidos , Aldehídos , Culinaria
18.
Materials (Basel) ; 17(7)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38612080

RESUMEN

A heat recovery coke oven (HRCO) is one of important approaches to achieving a carbon peak and carbon neutrality in China. However, the steady operation of an HRCO is significantly influenced by the internal working conditions and the quality of lining refractories. In this work, a comprehensive study of the internal working conditions of an HRCO was carried out. The results suggest that the partition wall (PW) between the carbonization and combustion chambers is the most vulnerable area, with the corresponding traditional silica bricks inadequate for the service requirements. A reference based on a comparison of the average thermal stress and high-temperature compressive strength is offered for evaluating and selecting silica bricks for the PW. New optimized silica bricks within the reference are verified to be more applicable to the actual working conditions of an HRCO than the traditional silica bricks. As such, this work provides valuable guidance for the optimization and selection of silica bricks for the PW in an HRCO.

19.
Materials (Basel) ; 17(7)2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38612146

RESUMEN

This study investigated how different rest times affect the strength development of fly-ash-based alkali-activated mortar (AAM) over a period of 90 days. Two types of fly ash with varying calcium oxide contents of 37 and 21% were used. The rest times ranged from 2 to 36 h, and three curing methods (ambient, oven, and steam) were tested. The results showed that the rest time significantly influenced the compressive strength of the AAM. The optimal rest time was found to be between 12 and 30 h depending on the curing method and fly ash type. Beyond this range, there were only minor changes in strength. One type of fly ash (FA21) showed higher strength with longer rest times up to 30 h, while the other type (FA37) had the highest strength within a rest time range of from 12 to 24 h. Over the 90-day period, the specimens cured under ambient, oven, and steam conditions at 55 °C (131 °F) experienced increasing strength, but those steam-cured at 80 °C (176 °F) showed a decrease in strength. Analysis revealed the formation of hydration products in FA37, while FA21 showed a reduction in peaks for its main compounds. Additionally, XRD analysis revealed the formation of hydration products (CSH and CASH) in FA37, while FA21 displayed a reduction in peaks for its main compounds. EDS analysis indicated the presence of partially unreacted FA particles, highlighting the impact of curing methods on dissolving FA particles and the formation of geopolymer products (NASH and CNASH) responsible for compressive strength development.

20.
J Histochem Cytochem ; 72(4): 233-243, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38553997

RESUMEN

Xylene is the commonest clearing agent even though it is hazardous and costly. This study evaluated the clearing properties of coconut oil as an alternative cost-effective clearing agent for histological processes. Ten (10) prostate samples fixed in formalin were taken and each one was cut into 4 before randomly separating them into four groups (A, B, C and D). Tissues were subjected to ascending grades of alcohol for dehydration. Group A was cleared in xylene and Groups B, C, and D were cleared at varying times of 1hr 30mins, 3hrs, and 4hrs in coconut oil respectively before embedding, sectioning, and staining were carried out. Gross and histological features were compared. Results indicated a significant shrinkage in coconut oil-treated specimen compared with the xylene-treated specimen and only the tissues cleared in coconut oil for 4hrs were as rigid as the tissues cleared in xylene (p > 0.05). No significant difference was found in either of the sections when checked for cellular details and staining quality (p > 0.999). Coconut oil is an efficient substitute for xylene in prostate tissues with a minimum clearing time of 4hrs, as it is environmentally friendly and less expensive, but causes significant shrinkage to prostate tissue.


Asunto(s)
Formaldehído , Xilenos , Aceite de Coco , Xilenos/química , Coloración y Etiquetado , Indicadores y Reactivos
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