650 research outputs found
On quantifying fault patterns of the mesh interconnect networks
One of the key issues in the design of Multiprocessors System-on-Chip (MP-SoCs), multicomputers, and peerto- peer networks is the development of an efficient communication network to provide high throughput and low latency and its ability to survive beyond the failure of individual components. Generally, the faulty components may be coalesced into fault regions, which are classified into convex and concave shapes. In this paper, we propose a mathematical solution for counting the number of common fault patterns in a 2-D mesh interconnect network including both convex (|-shape, | |-shape, ý-shape) and concave (L-shape, Ushape, T-shape, +-shape, H-shape) regions. The results presented in this paper which have been validated through simulation experiments can play a key role when studying, particularly, the performance analysis of fault-tolerant routing algorithms and measure of a network fault-tolerance expressed as the probability of a disconnection
Combination of modified Yld2000-2d and Yld2000-2d in anisotropic pressure dependent sheet metals
Altered localisation of the copper efflux transporters ATP7A and ATP7B associated with cisplatin resistance in human ovarian carcinoma cells
Metals in Catalysis, Biomimetics & Inorganic Material
Estimation of the nutritive value of grape pomace for ruminant using gas production technique
The aim of this study was to determine the chemical composition and estimation of nutritive value of white grape pomace (WGP) using in vitro gas production technique. Fermentation of WGP samples were carried out with rumen fluids obtained from three mature cannulated steers. The samples were collected from a factory in Urmia, Iran. The amount of gas production for WGP at 2, 4, 6, 8, 12, 24, 48, 72 and 96 h were measured. The results showed that the crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and non-fibrous carbohydrate (NFC) contents were 17.27, 59.5, 52.5 and 13.5%, respectively. Gas production at 24 h and potential gas production (a + b) were 30.92 and 79.89 ml, respectively. The organic matter digestibility (OMD), metabolizable energy (ME) and short chain fatty acid (SCFA) contents were 50.50%, 7.4 MJ kg-1 DM and 0.69 mmol, respectively. The net energy for lactation (NEL) content was 3.31 MJ kg-1 DM. According to the results of this study, it seems that WGP could be used as a valuable food industrial by-product in ruminant nutrition.Key words: Nutritive value, gas production, grape pomace, short chain fatty acid, metabolizable energy
Investigating Physical and Mechanical Properties of Bionanocomposite Film Based on Flaxseed Mucilage and Cellulose Nanocrystal
Introduction
Manufacturers are trying to replace plastic materials in the food packaging industry with biodegradable and edible films. Biodegradable edible films and coatings are mainly made from carbohydrates, lipids and proteins and their mixtures. In recent decades, various carbohydrates from plant sources have been investigated and introduced as new compounds for the preparation of these films. Flaxseed gum is a white to cream-colored powder that dissolves in water and produces a gel, and is a desirable compound for forming films and coatings. Recently, through the integration of reinforcements or fillers with at least one nanometer dimension in the substrate of one or more natural biopolymers, the physicochemical, mechanical, optical, thermal and barrier properties of pure biofilms have been improved. The use of cellulose nanoparticles in biofilms as a reinforcing agent for polymer materials leads to the creation of composite films with better quality characteristics and leads to the creation of functionalization activities in film production. Therefore, the aim of this research was to produce and characterize edible and biodegradable film based on the combination of flaxseed gum and cellulose nanocrystals.
Materials and Methods
Cellulose nanocrystals (Degree of crystallinity: 42% and average particle size: 58 nm) were extracted from cotton linters. Glycerol and other chemicals used for this research were obtained from Merck, Germany. Flaxseeds were purchased from the local market of Shiraz (Iran). Bionanocomposite films were prepared from different ratios (0:100, 30:70, 50:50, 70:30 and 100:0) of flaxseed mucilage (2% w/v) and cellulose nanocrystal (6% w/v) solutions. The prepared solutions were poured on a petri dish with a diameter of 15 cm and dried in an oven at 80°C for 4 hours. Their physical, color and mechanical properties were investigated and the best ratio was selected for the preparation of bionanocomposite film. The produced films were subjected to different analysis to determine thickness, solubility, water absorption capacity, permeability to water vapor, tensile strength, elongation at break point, and colorimetry. The microstructure of the produced film was studied using a scanning electron microscopy (SEM).The average data were analyzed by analysis of variance in a completely randomized design using SPSS 22.0 software. Differences between treatments were expressed in Duncan's multiple range test at the 95% probability level (p<0.05) and the corresponding graphs were drawn with Excel 2013.
Results and Discussion
The results of the film thickness test showed that the film containing 100% mucilage has the lowest thickness and with the addition of cellulose nanocrystals, the thickness increased significantly (p<0.05). The results of the water solubility and water absorption capacity of the film samples showed that the addition of cellulose nanocrystals to the flaxseed mucilage film initially led to a significant decrease in the water solubility and water absorption capacity (p<0.05), so that the lowest level ofthese two physical parameters were obtained in the film containing the combination of 70% flaxseed mucilage and 30% cellulose nanocrystal, and then with the increase of cellulose nanocrystals, an increase in water solubility and water absorption capacity of the films was observed. Nanocrystal cellulose at low levels (30%) acted as a filler and was uniformly dispersed in the network of the film and by filling the empty pores of the biopolymer film based on flaxseed mucilage, it caused the transfer of water vapor more complicated and reduced the permeability to water vapor. However, its higher amount increased the permeability of the film to water vapor.The results showed that by adding cellulose nanocrystal to the film based on flaxseed mucilage and increasing its amount, the brightness of the films decreased and the intensity of redness, yellowness and turbidity of the films increased significantly (p<0.05). By combining flaxseed mucilage and cellulose nanocrystals in a ratio of 30:70, the best film was produced in terms of mechanical strength and stability against moisture and water vapor. The SEM image of this film showed a smooth, even surface and a uniform distribution of cellulose nanocrystals in the film network.
Conclusion
The results finally showed that the combination of flaxseed mucilage and cellulose nanocrystals in a ratio of 30:70 was able to produce a biodegradable and edible film with favorable structural and barrier properties. The characteristics of this film include; thickness (0.313mm), solubility (53.42%), water absorption capacity (44.44%), permeability to water vapor (0.350 g.m-1s-1Pa-1 × 10 -10), tensile strength (0.973 MPa), elongation at break point (30.52%) were obtained. The colorimetric indices L*, a*, b* and turbidity were determined as 79.73, 1.95, 3.48 and 1.335 mm-1 respectively.
Acknowledgement
The authors would like to express their sincere gratitude to Islamic Azad University, Sarvestan Branch
Efficient Photoelectrochemical Performance of Gamma Irradiated gC3N4 and its g-C3N4@BiVO4 Heterojunction for Solar Water Splitting
This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this recordComprehensive experimental and density functional theory simulations have been performed for the enhanced photoelectrochemical performance of gamma irradiated g-C3N4 and its heterojunction with BiVO4. The structure and morphology of g-C3N4@BiVO4 as a heterojunction were analyzed and verified from the correlation of experimental and theoretical data. It is found that gamma radiations have changed the bonding structure of g-C3N4 which ultimately reduces the optical bandgap energy. Moreover, the performance of gamma-irradiated g-C3N4 is two-fold, compared to that of non-irradiated one; increases from 3.59 to 5.86 µAcm-2 at 1.23 V versus Ag/AgCl in 0.5 M Na2SO4 electrolyte solution (pH 7). Finally, it is observed that the performance of gamma irradiated g-C3N4 in g-C3N4@BiVO4 heterojunction increased from 0.53 mA cm-2 to 1.38 mA cm-2, compared to that of the non–irradiated one. In summary, it has been concluded that gamma-irradiated g-C3N4 and its heterojunction is potentially be applied in PEC solar water splitting.National University of Malaysi
Morphological and Bactericidal Effects of Different Antibiotics on Helicobacter pylori
Background: Helicobacter pylori (H. pylori) is a spiral Gram negative bacteria that can transform to the coccoid form in adverse conditions.
Objectives: The aim of this study was to determine the in vitro morphological and bactericidal effects of metronidazole, amoxicillin and
clarithromycin on H. pylori.
Materials and Methods: The standard strain 26695 of H. pylori was cultured on Brucella agar (BA) and the minimum inhibitory
concentrations (MICs) of three antibiotics were determined by E-test method. The bacteria were exposed to antibiotics at 1/2 MIC, MIC and
2X MIC concentrations in Brucella broth (BB). Induced coccoid forms were confirmed by Gram staining and light microscopy. The viability
of cells as well as the susceptibility of viable coccoids to antibiotics were examined using the flow cytometry method.
Results: All of the three antibiotics at sub-MIC induced coccoid forms. The highest rates of coccoids (> 90%) were induced at 0.008 μg/
mL concentration (1/2 MIC) of amoxicillin, 72 hours postexposure. Metronidazole and clarithromycin with 1/2 MIC (0.5 and 0.125 µg/mL
respectively) induced lower rates of coccoid forms (60% and 40% respectively). Potent bactericidal effects on coccoids were observed with
Metronidazole at 2X MIC and clarithromycin at MIC (0.25 µg/mL) (80 - 90%). Amoxicillin with MIC and 2X MIC had no bactericidal effect on
coccoid forms.
Conclusions: Despite the good in vitro bactericidal effect of amoxicillin on spiral forms of H. pylori, this antibiotic has little effect on
induced coccoids that may develop after the inappropriate in vivo antibacterial treatment. Hence, for successful therapy, it is essential not
only to eradicate the spiral forms, but to eliminate the viable coccoids
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