Search

Effect of dielectric barrier discharge (DBD) cold plasma on decontamination of strawberry and its quality characteristics was considered. Weight loss, color change, and firmness of the samples were investigated under low‐temperature storage condition. Plasma levels of 7% and 14% duty cycle were examined at exposure times of 5, 10, and 20 min. Destruction of microorganisms on treated samples surface was clearly observed by scanning electron microscopy images. Treatment duration of 20 min reduced total aerobic mesophilic bacteria and yeasts/molds 1.46 and 2.75 log CFU/g, respectively. Texture and color of the treated samples showed no significant difference compared to the control and their quality attributes indicated their superiority over the untreated one. The treated samples with 14% duty cycle DBD plasma for 20 min were even marketable at the end of the storage period. The cold plasma generated by DBD could, therefore, be utilized to prolong fruits shelf life. Practical applications: Cold plasma cleaning is a novel dry and nonthermal technology without the use of chemicals. The present study would be practically advantageous as it explains decontamination of strawberry as a part of many people's diet all over the world via dielectric barrier discharge (DBD) plasma. The plasma‐treated samples for 20 min were marketable after 12 days of storage. Hence, the nonthermal DBD plasma treatment is an effective way to prolong the shelf life of strawberry. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a metabolic syndrome characterized by elevated blood glucose. The α-glucosidase enzyme is responsible for the hydrolysis of carbohydrates. This in silico study aimed to evaluate the inhibitory effects of the isolated compounds from Allium sativum L. on α-glucosidase. At first, sulfur and phenolic compounds of A. sativum L. were obtained from PubChem database, and α-glucosidase enzyme structure was obtained from Protein Data Bank. Toxicity class of compounds and the Lipinski parameter were predicted by Toxtree and Protox II and the Swiss ADME tools, respectively. Finally, the molecular interaction analysis between α-glucosidase and compounds from A. sativum L. was performed by AutoDock 4.2.6. Molecular interactions were investigated using Discovery Studio Visulizer and Ligplot 2.1 program. All of the selected sulfur and phenolic compounds from A. sativum L. followed the Lipinski's rules, had an acceptable binding energy, and lacked toxicity; therefore, they were appropriate candidates for α-glucosidase inhibition. Among these compounds, methionol and caffeic acid showed the lowest binding energy, and the highest inhibitory effect on α-glucosidase enzyme with − 3.9 and − 4.8 kcal/mol, respectively. These compounds also indicated the lower binding energy than the standard inhibitor (miglitol). Among the sulfur and phenolic compounds in A. sativum L., methionol and caffeic acid were predicted to be the powerful inhibitors, due to having more hydrogen binds and hydrophobic interactions with the active site of α-glucosidase. [ABSTRACT FROM AUTHOR]

Structural health monitoring of mechanical systems is essential to avoid their catastrophic failure. In this article, an effective deep neural network is developed for extracting the damage-sensitive features from frequency data of vibration signals to damage detection of mechanical systems in the presence of the uncertainties such as modeling errors, measurement errors, and environmental noises. For this purpose, the finite element method is used to analyze a mechanical system (finite element model). Then, vibration experiments are carried out on the laboratory-scale model. Vibration signals of real intact system are used to updating the finite element model and minimizing the disparities between the natural frequencies of the finite element model and real system. Some parts of the signals that are not related to the nature of the system are removed using the complete ensemble empirical mode decomposition technique. Frequency domain decomposition method is used to extract frequency data. The proposed deep neural network is trained using frequency data of the finite element model and real intact state and then is tested using frequency data of the real system. The proposed network is designed in two stages, namely, the pre-training classification based on deep auto-encoder and Softmax layer (first stage), and the re-training classification based on backpropagation algorithm for fine tuning of the network (second stage). The proposed method is validated using a lab-scale offshore jacket structure. The results show that the proposed method can learn features from the frequency data and achieve higher accuracy than other comparative methods. [ABSTRACT FROM AUTHOR]

In this research, the effect of polyethylene glycol (PEG) molecular weight on permeability and selectivity of polysulfone/polyethylene glycol (PSF/PEG) composite membrane is investigated. Polyethylene glycol with molecular weights of 4000, 6000, and 10,000 is applied. It is shown from the results that PEG applied in composite membranes with molecular weight of 1000 had the best diffusivity in comparison with the other composite membranes containing PEG with lower molecular weights. In addition, it is perceived that the permeability of CO2 from PSF/PEG10000 composite membranes has increased with enhancing weight percent. CO2 permeability into PSF/PEG composite membranes containing 20 wt% PEG10000 is calculated 7.64 barrer (1 barrer = 10−10 cm3 (STP) cm/cm2 s cmHg). The ideal selectivity for CO2/N2 gas pair in PSF pure membrane and composite membranes containing 10 wt% and 20 wt% PEG10000 are calculated 26.57, 30.61, and 32.12, respectively. Finally, the morphology and membrane structure of the membrane were evaluated with infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile strength test. [ABSTRACT FROM AUTHOR]

Considerable advancement in spatiotemporal resolution of remote sensing and ground-based measurements has enabled refinement of parameters used in land surface models for simulating surface water fluxes. However, land surface modeling capabilities are still inadequate for accurate representation of subsurface properties and processes, which continue to limit the accuracy of land surface model simulation. Our objective in this study was to examine the performance of the variously parameterized Noah land surface model with multiphysics option (Noah-MP) in simulating evapotranspiration (ET) and soil moisture dynamics in stony soils using verification from eddy covariance ET and in situ soil moisture data during the growing season of year 2015, obtained from the Lower Sheep subcatchment within the Reynolds Creek Experimental Watershed in southwestern Idaho. We evaluated the performance of Noah-MP considering four different scenarios with 1) a one-layer soil profile with Noah-MP default soil hydraulic parameters and three more fivelayer soil profiles using 2) Noah-MP default soil hydraulic parameters; 3) soil hydraulic parameters derived from a pedotransfer function using field observations; and 4) hydraulic parameters from scenario 3, which also accounted for stone content in each layer. Each modeling experiment was forced with the same set of initial conditions, atmospheric input, and vegetation parameters. Our results indicate that enhanced representation of soil profile properties and stone content information noticeably improve the Noah-MP land surface model simulation of soil moisture content and evapotranspiration. [ABSTRACT FROM AUTHOR]

The increasing need for more efficient separation processes has motivated the development of polymer membranes that can provide fast and selective transport. In this work, cadmium‐based metal–organic framework (MOF) nanoparticles and a polyurethane–urea (PUU) elastomer were synthesized. New mixed‐matrix membranes (MMMs) were then fabricated from the nanoparticles and the PUU. SEM images verified that embedding the nanoparticles changes the morphology of the PUU and the nanoparticles disperse well in the PUU due to satisfactory compatibility of the polymer and nanoparticles. Fourier transform infrared spectroscopy and X‐ray diffraction analysis confirmed the dispersion of the nanoparticles in the soft segment of the PUU. With increased temperature, gas permeabilities of the MMMs improved but their sieving ability deteriorated. An MMM incorporating 2.5 wt % of the MOF showed a CO2 permeability of ~140 barrer and a CO2/N2 selectivity of ~30, which are 89 and 38% higher than those of the pristine membrane. Gas permeation tests showed that the higher CO2/N2 selectivity of the MMMs was due to improved solubility selectivity and the higher CO2 permeability was a result of improved CO2 diffusivity and solubility coefficients. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48704. [ABSTRACT FROM AUTHOR]

Diabetes is associated with numerous complications, such as diabetic skin wounds or ulcerations. The aim of this study was to evaluate experimentally the effectiveness of applying polycaprolactone (PCL)‐gelatin scaffold, with or without rat CD93 hematopoietic stem cells (HSCs), in diabetic wound healing in a rat model. CD93 HSCs were aseptically isolated from rat bone marrow using fluorescent activated cell sorting (FACS) method and FACS‐SORTER. A total of 25 Wistar rats were divided into five groups including Group I (sham, nondiabetic, and wound covered only with sterile dressing), II (control, diabetic rat), III (CD93 HSCs alone), IV (PCL‐gelatin scaffold), and V (CD93 HSCs+PCL‐gelatin scaffold). Animals were killed on Days 7, 14, or 28 posttreatment and histological sections were blindly evaluated by two expert pathologists. Death‐associated protein kinase 1 (DAPK‐1) gene and vesicular endothelial growth factors (VEGF) protein expression were evaluated using reverse transcription‐polymerase chain reaction and western blot, respectively. The thickest and the thinnest epidermises microscopically were belonged to CD93+HSCs+scaffold and the control group, respectively. The growth rate of the epidermis and adnexal epithelia was the highest in both the cell and cell+scaffold groups. Evaluation of the protein expression level of VEGF indicated that the expression levels of this growth factor were the most on Day 7 posttreatment in sham, HSCs alone, and HSCs cell+scaffold groups. While the lowest expression levels of this growth factor was detected in the control and scaffold groups. The gene expression level of DAPK‐1 on Day 7 posttreatment was higher than that of the Day 14 posttreatment in all groups. The highest and lowest gene expression levels of DAPK‐1 belonged to control and sham groups, respectively. According to our findings, CD93 HSCs offer new prospects for the treatment of diabetic ulcers and concomitant application of these cells with PCL‐gelatin nanofiber scaffold significantly improves diabetic wound treatment. [ABSTRACT FROM AUTHOR]

In-depth knowledge about the global patterns and dynamics of land surface net water flux (NWF) is essential for quantification of depletion and recharge of groundwater resources. Net water flux cannot be directly measured, and its estimates as a residual of individual surface flux components often suffer from mass conservation errors due to accumulated systematic biases of individual fluxes. Here, for the first time, we provide direct estimates of global NWF based on near-surface satellite soil moisture retrievals from the Soil Moisture Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellites. We apply a recently developed analytical model derived via inversion of the linearized Richards' equation. The model is parsimonious, yet yields unbiased estimates of long-term cumulative NWF that is generally well correlated with the terrestrial water storage anomaly from the Gravity Recovery and Climate Experiment (GRACE) satellite. In addition, in conjunction with precipitation and evapotranspiration retrievals, the resultant NWF estimates provide a new means for retrieving global infiltration and runoff from satellite observations. However, the efficacy of the proposed approach over densely vegetated regions is questionable, due to the uncertainty of the satellite soil moisture retrievals and the lack of explicit parameterization of transpiration by deeply rooted plants in the proposed model. Future research is needed to advance this modeling paradigm to explicitly account for plant transpiration. [ABSTRACT FROM AUTHOR]

• Dynamic modeling of pigging process by improved model of PIG in pipe conveying fluid. • Theoretical and experimental study of PIG parameters effect on dynamic of pipeline. • Extraction of pipeline modal parameters through internal flow are not often possible. • Pigging process can be used as a tool to extract the modal parameters of pipeline. In this paper, the effects of PIG (Pipeline Inspection Gauge) parameters on dynamic response of a simply supported Above-Ground pipeline are investigated during pigging operation. The approach is based on finite element modeling verified by the experimental modal analysis (EMA). In the author's previous study, the governing equations of motion for system (Pipe, PIG as a moving vibrational sub-system, and conveyed fluid) were obtained using Hamilton's principle. In the present study, extracted equation are developed based on PIGs with different geometric parameters. The modal parameters of the pipeline system are calculated in the intermittent passage of PIGs along the pipe under different flow rates and their variations are extracted. Theoretical and experimental studies are performed to determine the effect various PIG parameters have on dynamic behavior of pipeline system. Changes in the system natural frequencies due to the speed and position of PIG in the pipe are also investigated. Moreover, displacement analysis for the mid-span of the considered pipe during the pigging operation is conducted using suggested theoretical model. Both numerical and experimental results show the substantial effects of PIG physical parameters, especially disc number and material, on dynamic behavior of the pipe system. [ABSTRACT FROM AUTHOR]