The present article concerns with thermohydraulic performance, flow friction and entropy generation analysis in a heated tube contained with louvered winglet tape (LWT). The experiment was conducted in a uniform heat-fluxed test tube for turbulent fluid flow, Reynolds number (Re) ranging from 4760 to 29,260. The purpose of the LWT insert is to produce streamwise vortices assisting to induce impinging-jets onto the tube wall and to decline the pressure loss through the louver mounted on the winglet aside from providing rapid mixing of fluid flow. In the present experiment, the louvered winglets were mounted periodically on a double-sided straight tape with six different louver angles (θ = 0 ˗ 90°) and three winglet pitch ratios (PR = 1 ˗ 2) at a single relative winglet height (BR = 0.25) and a fixed attack angle (α) of 30°. There were two-types of LWT arrangements: inline and staggered louvered-winglet tapes (I-LWT and S-LWT). To examine the optimum thermohydraulic performance, an influence of θ at each PR on the rate of heat transfer and friction loss inside the tube was explored. The measured results disclosed that the Nusselt number (Nu) and friction factor (f) from using both types of LWTs rise considerably with the reduction of PR and θ. The entropy generation (S˙gen') was declined with the decrease in Re, PR and θ where the minimum S˙gen' was obtained for the I-LWT tube at PR = 1, θ = 0° and lowest Re. The peak thermal enhancement factors (TEF) of the S-LWT and the I-LWT were, respectively, around 2.22 and 2.18 at similar PR = 1, θ = 45°. The Nu, f and TEF correlations for using LWT insert were also reported.
Chukrasia tabularis A.Juss. is a canopy tree widely distributed in Asia and commonly used for construction-grade timber. While the residues resulting from the timber exploration constitute the major source of waste, other parts of the plant remain underutilized. Therefore, aiming the valorisation of a major residue resulting from C. tabularis wood industry, the leaves were here investigated on their potential content in bioactive constituents, but also on their capacity to modulate mediators and enzymes engaged in metabolic disorders, particularly those involved on the development and progression of diabetes. HPLC–DAD–ESI/MSⁿ and UPLC-ESI-QTOF-MS² characterization of a methanol extract obtained from the leaves, allowed the identification of 25 phenolic constituents, quercetin-3-O-rhamnoside being identified as the main bioactive. The leaf extract and the major flavonoid (quercetin-3-O-rhamnoside) were investigated on their impact towards a series of targets involved in the physiopathology of diabetes. The extract displayed significant scavenging properties against nitric oxide and superoxide radicals, inhibiting also lipid peroxidation and aldose reductase activity. While no noteworthy effects were noted on pancreatic lipase and α-amylase activity, the extract strongly inhibited α-glucosidase (IC50 = 21.14 µg/mL) and proved to be ca. 5 times more effective than the benchmark drug, acarbose. Moreover, the leaf extract significantly inhibited also 5-lipoxygenase (5-LOX) (IC50 = 13.12 µg/mL). Kinetic studies on α-glucosidase and 5-LOX activity disclosed a mixed type inhibition. Furthermore, C. tabularis extract reduced LPS-induced overproduction of NO, L-citrulline and IL-6 in activated RAW 264.7 macrophages. When individually assayed, quercetin-3-O-rhamnoside significantly contributed to the antiradical properties and inhibitory effects of the extract upon the enzymatic targets, but other phenolic bioactives appear also to underlie the recorded anti-inflammatory effects. Taken together, our results demonstrate that the leaves of C. tabularis are rich in phenolic constituents with a great potential to improve metabolic disorders. The evidenced bioactivity of this industrial product might feed R&D programs for the development of new drugs that might simultaneously improve glycaemic, oxidative and inflammatory benchmarks in diabetic patients.
CO2-assisted propane dehydrogenation has been developed in propylene production technology to deal with thermodynamic equilibrium limitations. However, the rational design of catalysts is a crucial challenge in achieving high catalytic performances. Herein, we report the successful fabrication of highly dispersed PtZn alloy on hierarchical zeolites for CO2-assisted propane dehydrogenation through the reverse water–gas shift reaction (RWGS). Compared with monometallic Pt, the synergistic effect of PtZn plays a crucial role in both direct propane dehydrogenation and RWGS, resulting in an outstanding catalytic performance with a high turnover frequency (TOF) of 1.82 × 10⁴h⁻¹. From the catalytic point of view, Pt-Zn alloy surfaces facilitate the equilibrium shift in propane conversion by consuming produced H2 through RWGS with weakening CO-metal surface interaction revealed by operando studies and DFT calculations. These findings illustrate the conceptual design of alloy catalysts and allow insights into the mechanistic details of CO2-assisted alkane dehydrogenation.
Biodrying technology is commonly used in Thailand to produce refuse-derived fuel (RDF), however, this technology remains ineffective on high-moisture waste. Air supply is key to ensuring homogenous temperature development within the waste matrix during biodrying, increasing RDF quality. This study investigated negative aeration during local municipal solid waste biodrying to meet RDF standards in reduced time. Lysimeter experiments were performed on pre-shredded waste (300 kg/m3) using different aeration patterns. The temperature, vent gas oxygen level, weight loss, and leachate volume during the biodrying process were monitored. In addition, the treated waste’s temperature, moisture, and heating values were evaluated to determine the biodrying process efficiency. The results indicate that shorter heating phases can be achieved during continuous aeration. No significant temperature variation was observed in the waste layers, with a low standard deviation of 1.96% during constant air supply, indicating homogeneous temperature development during the biodrying process. The vent gas contained 15–20% oxygen and non-detectable methane, evidencing sufficient air supply. The total heat development was independent of aeration pattern; therefore, biodrying was unaffected by excess air supply at a 95% confidence level. The highest weight loss and moisture content reduction were 25% and 66%, respectively. The optimal aeration was continuous mode with non-excessive aeration, increasing the lower heating value from 2,884.0 to 4,938.0 kCal/kg, and reducing the moisture content from 48.5% to 22.2%. RDF quality can be improved 1.7 times to meet Thailand’s standards within a short biodrying period of 7 days using homogeneous temperature distribution operated under continuous aeration
In this work, a systematic investigation of external magnetic field affecting metal phase transformation of Fe-Cu/MCM-41 catalysts both during activation and reaction, and their performances by means of CO2 conversion and C2 + C3 hydrocarbons selectivity were for the first time examined in-situ using time-resolved X-ray absorption spectroscopy (TRXAS) and an online quadrupole mass spectrometer. The in-situ XANES result confirmed that FeO and Fe3O4 are major active forms of the catalyst. With magnetic flux intensities of 28.91–58.59 mT, iron oxide phases, specifically Fe3O4 and FeO, within the catalysts were stabilized and maintained. The CO2 conversion was increased for 1.03 – 1.09 times, while the concentrations of C2 + C3 hydrocarbons were considerably improved by 24.03 – 35.37 times compared to those without magnetic field. The reaction steps of CO2 hydrogenation were theoretically confirmed on the isolated catalysts using M06-L with the 6-31G(d,p) + LANL2DZ mixed basis set based on the results from LCF analysis. Fe4, Fe4O4, and Fe2Cu2 clusters were used to represent the active species of pristine Fe and iron oxide (FeO) and bimetallic Fe-Cu catalyst, respectively. It was found that CO2 hydrogenation could take place via the bimolecular route in which adsorbed CO2 on the Fe center was hydrogenated by dissociative adsorption of H2 on the Cu center—promoting chain growth probability of CO2 to form C2 + C3 hydrocarbons due to the active iron oxides (Fe3O4 and FeO) were maintained by magnetic field during the reaction.
The heat transfer and flow resistance were investigated experimentally in a rectangular duct based on compound techniques of heat transfer enhancement using 25 kHz ultrasound and Al2O3-water nanofluid. The experiment was conducted at flow rates of 0.5–2.0 l/min under constant heat flux and laminar flow conditions. Two ultrasonic transducers were mounted on the top wall of the test section to release the waves from single or double transducers in a downward direction, perpendicular to the mainstream flow. Water and Al2O3(nanoparticle volume fraction (φ) = 0.8–6.1%) nanofluid were utilized as different test fluids. The results showed that the surface temperature increased with the volume fraction of Al2O3, and rapidly reduced after applying the ultrasonic waves. At the same flow rate, the peak augmentation of the local Nusselt number using ultrasound from a single transducer was 1.31 in Al2O3(φ = 6.1%), which increased to 1.58 using double transducers in Al2O3(φ = 1.5%). The flow resistance was increased by adding the Al2O3 nanoparticles, with increased resistance with an increased volume fraction. The friction loss increased up to 3 times for φ = 6.1% compared to the base fluid of water, while it slightly increased approximately 1–2% using ultrasound. These results indicated that using these techniques, the thermal performance tended to increase with a decreased Reynolds number and volume fraction. Finally, predictive formulas for the Nusselt number and friction factor were developed for using single or double ultrasonic transducers in water or Al2O3(φ = 0.8–6.1%) nanofluids under a laminar flow regime.
This research aimed to enhance the dissolution rate of mefenamic acid (MEF) by preparing a novel cocrystal containing MEF, paracetamol (PAR) and nicotinamide (NIC) via the Gas Anti-Solvent (GAS) process. Box−Behnken design of experiments was implemented to evaluate impacts of various process variables on the dissolution rate of MEF and find optimal conditions for the production ternary system cocrystal with the highest dissolution rate of MEF. The results showed that the fastest dissolution time (t63.2) of 4.19 min was obtained when using the precipitation temperature of 25 °C, NIC−PAR−MEF molar ratio of 4.78:4.78:1 and % MEF saturation of 89.74 %. The obtained cocrystals from GAS at the optimal conditions exhibited an improved dissolution rate 16.40 times higher than that of unprocessed MEF. In order to obtain a product containing a ratio of MEF to PAR that is in line with commercially available drugs (MEF to PAR mass ratios are in the range of 0.4–1.54) and exhibiting a high dissolution rate of MEF, further experiments were conducted using different ratios of PAR to NIC. It was found that the GAS products prepared at 25 °C with the use of % saturation of MEF at 89.74 % and NIC−PAR−MEF molar ratio of 12:2.39:1 (OPT1) had t63.2 value of 2.88 min and MEF to PAR mass ratio of 0.65. When using the NIC−PAR−MEF molar ratio of 9.56:1:1 (OPT2), the product had t63.2 value of 3.30 min and MEF to PAR mass ratio of 1.52.
Key message An organomercurial phenylmercury activates AtPCS1, an enzyme known for detoxification of inorganic metal(loid) ions in Arabidopsis and the induced metal-chelating peptides phytochelatins are essential for detoxification of phenylmercury. Abstract Small thiol-rich peptides phytochelatins (PCs) and their synthases (PCSs) are crucial for plants to mitigate the stress derived from various metal(loid) ions in their inorganic form including inorganic mercury [Hg(II)]. However, the possible roles of the PC/PCS system in organic mercury detoxification in plants remain elusive. We found that an organomercury phenylmercury (PheHg) induced PC synthesis in Arabidopsis thaliana plants as Hg(II), whereas methylmercury did not. The analyses of AtPCS1 mutant plants and in vitro assays using the AtPCS1-recombinant protein demonstrated that AtPCS1, the major PCS in A. thaliana, was responsible for the PheHg-responsive PC synthesis. AtPCS1 mutants cad1-3 and cad1-6, and the double mutant of PC-metal(loid) complex transporters AtABCC1 and AtABCC2 showed enhanced sensitivity to PheHg as well as to Hg(II). The hypersensitivity of cad1-3 to PheHg stress was complemented by the own-promoter-driven expression of AtPCS1-GFP. The confocal microscopy of the complementation lines showed that the AtPCS1-GFP was preferentially expressed in epidermal cells of the mature and elongation zones, and the outer-most layer of the lateral root cap cells in the meristematic zone. Moreover, in vitro PC-metal binding assay demonstrated that binding affinity between PC and PheHg was comparable to Hg(II). However, plant ionomic profiles, as well as root morphology under PheHg and Hg(II) stress, were divergent. These results suggest that PheHg phytotoxicity is different from Hg(II), but AtPCS1-mediated PC synthesis, complex formation, and vacuolar sequestration by AtABCC1 and AtABCC2 are similarly functional for both PheHg and Hg(II) detoxification in root surficial cell types.
This study employed the principles of electrothermal process using ohmic heating (OH) to extract phenolic compounds from rambutan peel. Deionized water and ethanol at different concentrations (50% and 70%) were used as electrical-transmission medium at different holding times (15, 30 and 60 min). The result showed significant difference (p ≤ 0.05) between the water and ethanol-based extracts in terms of yield, total phenolic, flavonoid contents and antioxidant activities. The main compounds such as gallic acid, corilagin, geraniin and ellagic acid were identified in the peel. Bread fortified with the extract showed better phenolic content and antioxidant activities, with 15 µg/mL fortification level having excellent texture properties. Interestingly, fortified breads showed excellent antifungal activity, thereby extended the shelf life of the bread crumb. The efficient ohmic heating extraction technique and proper formulation of rambutan peel extract in food, could serves as vital approach for high-quality products development with longer shelf life.
Soil salinity is a major global concern for sustainable crop production, and proper screening of crop genotypes against salt stress should be a major consideration before recommending a genotype for field cultivation. Germination, growth, yield, physiological, and biochemical responses of 11 hybrid baby corn genotypes (Kasetsart 3, PAC 271, PAC 321, PAC 571, SG 17 Super, CP B468, CP B905, WS 111, WS 9103, Chang Daeng 18, and HY 074656) to five levels of NaCl-induced salinity (0.7 [control], 3, 6, 9, and 12 dS m–1) were evaluated in a germination trial in petri dishes followed by a polyhouse study to assess genotypic variation of baby corn genotypes in salinity tolerance. Data on various germination traits, growth, yield, physiological, and biochemical parameters were collected. Increasing salinity level above 6 dS m–1 was equally detrimental for germination and growth of all tested genotypes. Germination response of Chang Daeng 18 genotype to salt stress was the poorest (22.2% germination rate and 7.7% mean daily germination). Growth, yield, physiological, and sodium (Na⁺) accumulation data revealed that SG 17 Super genotype was the most susceptible to salt stress, whereas PAC 571 was the most tolerant. SG 17 Super had 28% lower shoot dry matter, 54% lower cob yield, 25% less membrane stability index, and 158% more Na⁺ accumulation compared with PAC 571. All other genotypes were between slightly salt-tolerant to moderately salt-tolerant category, which was also verified by the Hierarchical cluster analysis. Physiological and biochemical parameters, such as free proline, membrane electrolyte leakage, and membrane stability index, as well as ion accumulation parameter, such as Na⁺, were the most representative of salt stress. Salinity reduced leaf greenness (SPAD value), while net photosynthetic rate, stomatal conductance, and transpiration rate were not affected. Na⁺ exclusion and higher K⁺/Na⁺ ratio in leaves of baby corn genotypes correlated well with their higher salinity tolerance, and greater K⁺/Na⁺ discrimination was shown by salt-tolerant genotypes. The relative susceptibility of baby corn genotypes to salinity should be taken into consideration for plant breeding programs. The selected salt-tolerant baby corn genotypes have potentials for cultivation in salt-affected soils for better productivity.
Using microalgae for biological fixation of CO2 is an attractive option for limiting the amount of CO2 emissions from power plants. In this experiment, Spirulina maxima was successfully grown utilizing direct flue gas emitted from the Ratchaburi Electricity Generating Company Limited, Thailand. The aims of this study were to determine the optimal conditions for large-scale culturing of this alga for maximum biomass as well as CO2 abatement. The results showed that the carbon source of NaHCO3 can be reduced from standard Zarrouk medium of 16.8 down to 8 g/L, producing fresh and dry weight biomass yields of 206 and 21.57 kg, respectively, within 30 days of cultivation. The optimal initial pH was 9.0, thereby reducing the lag phase of algal growth and producing the best fresh weight yield. The natural light intensity (with CO2) prevented stressed and weakened the algal cells, resulting in extending the algal life and producing the highest yields of fresh and dry weight. The morphology of algal cells was examined following culturing at pH 9 and pH10.5. The algal cells produced at pH 9 had a helical shape of the trichome, a separate septum and thylakoids, and the vacuoles were distributed throughout the cell, while algal cells cultured in medium with an initial pH of 10.5 mostly had the straight form, with the septum and thylakoids being unclear. The maximum CO2 level used was 2.5 times base level of the CO2 (141.75 g CO2/h) produced the highest biomass of fresh and dry weights. The optimal culture for CO2 gas was the continuous culture system and using CO2 efficiently, which encouraged algal growth and produced higher biomass yields than those from the batch culture system. There was no significant difference in nutritional value terms for the protein and pigments contents between the algal biomass products in assay with and without CO2 Furthermore, there was no metal contamination in algal biomass. The results indicate that the use of waste CO2 from a power plant can be successfully used for large-scale Spirulina production.
This study determined a practical method to reduce environmental pollution by wastewater from fish ponds. Water quality in three hybrid red tilapia ponds (0.24 ha) was examined before and during harvest at five water depths of 10, 20, 50, 100, and 150 cm, as well as at the water surface and pond bottom. All water samples were analyzed for BOD, TN, TP, TAN, TS, TSS, and SS, with results compared with the Thailand control standard for freshwater aquaculture effluent. All quality parameters of the seven water samples showed statistical significance (p<0.05) that increased with water depth. Degradation was highest in the bottom 50 cm of the fish pond. Limiting drainage to a depth of 50 cm was achieved by tilting the drainage pipe, and the resulting effluent met all water quality parameter standards. At a water depth of 50 cm, the remaining water was drained using a water pump, and all water quality parameters failed to meet the required standards. When this water was allowed to settle for 24 h, BOD, TN, TP, TAN, and TSS reduced to 21.06%, 2.42%, 11.68%, 5.47%, and 43.36% of full pond values, respectively. Results suggested sedimentation as a practical technique requiring a smaller pond area to reduce environmental pollution.
Corrosion-induced bond degradation leads to changes in deformation characteristics, cracking patterns, and loss in tension stiffening in structural members. Since the induced damage is dependent upon multiple inter-related parameters, prediction of post-corrosion deformation behavior requires sophisticated numerical simulations. This study integrates corrosion expansion and bond degradation models into a discrete analysis framework, 3D RBSM (Rigid Body Spring Model), to simulate post-corrosion loss of tension stiffening. Uniaxial tensile loading is applied to reinforced concrete models with different degrees of corrosion to obtain plots of load versus average strain and surface cracking patterns. Simulated surface cracking patterns due to corrosion and uniaxial loading in uncorroded and corroded models are similar to experimental results. As the degree of corrosion increases, the number of transverse cracks on the concrete surface decrease and the load at first cracking also decreases. Further, internal stress and bond stress investigation directly illustrate the decrease in stress transfer from reinforcing bar to concrete due to corrosion.
Recently, our group reported the synthesis and fabrication of composite hydrogels of chitosan (CS) and star-shaped polycaprolactone (stPCL). The co-crosslink of modified stPCL with carboxyl at the end chain (stPCL-COOH) provided good mechanical properties and stability to the composite hydrogels. This research presents the bioactivities of composite hydrogels showing a potential candidate to develop biomaterials such as wound dressing and bone tissue engineering. The bioactivities were the antibacterial activity, cell viability, skin irritation, decomposability, and ability to attach ions for apatite nucleation. The results showed that all the composite hydrogels were completely decomposed within 2 days. The composite hydrogels had better antibacterial activity and higher efficiency to Gram-negative (Escherichia coli) than to Gram-positive (Staphylococcus epidermidis) bacteria. The composite hydrogels were studied for cell viability based on MTT assay and skin irritation on rabbit skin. The results indicated high cell survival more than 80% and no skin irritation. In addition, the results showed that calcium and phosphorous were preferentially attached to the composite hydrogel surface to grow apatite crystal (Ca/P ratio 1.86) compared to attaching to the chitosan hydrogel (Ca/P ratio 1.48) in 21 days of testing.
Particulate matter (PM) pollution and SARS-CoV-2 (COVID-19) have brought severe threats to public health. High level of PM serves as a carrier of COVID-19 which is a global pandemic. This study fabricated filter membrane for face mask using bacterial cellulose and fingerroot extract (BC–FT) via immersion technique. The surface area, pore volume and pore size of BC were analyzed by Brunauer–Emmett–Teller. The physiochemical properties of the membrane were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffractometer. The crystallinity decreased from 63.7% in pure BC to 52.4% in BC–FT filter membrane. Young’s modulus increased from 1277.02 MPa in pure BC to 2251.17 MPa in BC–FT filter membrane. The filter membrane showed excellent PM 0.1 removal efficiency of 99.83% and antimicrobial activity against Staphylococcus aureus and Escherichia coli. The fabricated membrane is excellent to prevent inhalation of PM2.5 and COVID-19 respiratory droplet. Graphic abstract
The purpose of this research was to isolate microorganisms from coffee fermentation processes and screen them for their potential to improve the flavor of Arabica coffee using a new approach that included pectin degradation ability and growth in mucilage broth. All of the studied microorganisms were isolated from 38 different samples of fresh coffee cherries, coffee mucilage and coffee pulp. A total of 262 microbial isolates were obtained and subjected to screening using pectinase screening agar medium for pectinolytic organisms. The results of the pectinase production test showed that 18 yeast isolates were found to produce pectinase that could degrade the pectin present in solid media. The sugar assimilation profiles and growth of selected strains in mucilage broth were studied. Therefore, 18 isolates from the selected yeasts were subjected to molecular identification by the use of 18S rRNA gene sequencing. The diversity of the yeast isolates was studied, and they were identified as Wickerhamomyces anomalus, Naganishia liquefaciens, Pichia kudriavzevii, Kazachstania naganishii and Kazachstania sp. Moreover, isolates SWU3YWP1-3, SWU3YSK9 and INFCY1-4 were used as a seed culture for Arabica coffee fermentation. The cupping sensory scores of the control (without yeast inoculation) and those inoculated with three isolated yeast strains that were determined by Q-Arabica Graders were 73.75, 84.75, 80.25 and 75.00, respectively. Unique flavors and aromas were detected. This is the first report of screening microorganisms from the Arabica coffee fermentation process by the combination of various properties with success in improving the quality of coffee beverage.
Main conclusions Heat shock proteins, ROS detoxifying enzymes, and ion homeostasis proteins, together with proteins in carbohydrate metabolism, cell structure, brassinosteroids, and carotenoid biosynthesis pathway were up-regulated in CSSLs under salinity stress. Abstract Rice is one of the most consumed staple foods worldwide. Salinity stress is a serious global problem affecting rice productivity. Many attempts have been made to select or produce salinity-tolerant rice varieties. Genetics and biochemical approaches were used to study the salinity-responsive pathway in rice to develop salinity tolerant strains. This study investigated the proteomic profiles of chromosome segment substitution lines (CSSLs) developed from KDML105 (Khao Dawk Mali 105, a Thai jasmine rice cultivar) under salinity stress. The CSSLs showed a clear resistant phenotype in response to 150 mM NaCl treatment compared to the salinity-sensitive line, IR29. Liquid chromatography-tandem mass spectrometry using the Ultimate 3000 Nano/Capillary LC System coupled to a Hybrid Quadrupole Q-Tof Impact II™ equipped with a nano-captive spray ion source was applied for proteomic analysis. Based on our criteria, 178 proteins were identified as differentially expressed proteins under salinity stress. Protein functions in DNA replication and transcription, and stress and defense accounted for the highest proportions in response to salinity stress, followed by protein transport and trafficking, carbohydrate metabolic process, signal transduction, and cell structure. The protein interaction network among the 75 up-regulated proteins showed connections between proteins involved in cell wall synthesis, transcription, translation, and in defense responses.
This research paper investigated the effects of the silica content and the sulfur vulcanization system on the mechanical properties of silica-filled natural rubber (NR) composite film and foam to be used in various applications. Three different sulfur vulcanization systems (conventional (CV), semi-efficient (Semi-EV), and efficient (EV)) were thoroughly studied to improve the quality of vulcanized NR and their composite with silica. The ground silica was treated with Silane 69. Scanning Electron Microscope demonstrated that the treated silica in NR was well dispersed. In addition, the treated silica resulted in better mechanical properties than for untreated silica. The optimum amount of silica in non-vulcanized rubber was 16 phr. Furthermore, the mechanical properties of vulcanized rubber from the CV system were better than those from the Semi-EV and EV systems due to the higher degree of crosslinking in the former. In addition, when the TSi/NR composite foam specimens at 8 phr had an applied load that was 4.41 times that of non-silica rubber foam.
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