Study About Some Mechanical Properties for Composites Reinforced with Corn Cob Powder

In this paper we have created some composites reinforced with corn cob powder and the matrix was made by a combination between Resoltech 1050 resin with its Resoltech 1058 hardener. For the composites manufacturing, we have used the manual casting technique. For the new manufactured composites, we have determined the mechanical properties from the tensile test according to ASTM D3039: Young modulus, breaking strength and elongation at break. We have also molded samples for the compression test according to ASTM D695-15 and we have determined the breaking strength. The tensile and compression tests were made on universal testing machines. In the end, we have determined also the dynamic mechanical properties for the studied material by clamping the samples at one edge and leaving the samples unconstrained at the other edge. At the unconstrained edge we have placed a Bruel&Kjaer accelerometer which recorded the samples free vibrations. From the free vibrations recording and Euler-Bernoulli theory, we have determined the next dynamic mechanical properties: damping factor per unit mass and length, eigenfrequency, dynamic modulus of elasticity, loss factor and dynamic rigidity. From the experimental results, we have obtained increased breaking strength values for the proposed material at compression compared to the tensile test. Compared to similar materials studied in the engineering literature, we have obtained increased compression breaking strength.

Graphene coated cotton nonwoven for electroconductive and UV protection applications

The functional properties and applications of graphene coated textiles depend on the magnitude of graphene add-on which in turn is influenced by the type of substrate and the dipping conditions. In the present study, optimized GO (graphene oxide) dipping conditions are identified for the preparation of cost-effective and scalable rGO (reduced graphene oxide) coated cotton nonwoven for electroconductive and UV (ultraviolet) blocking applications. To understand the influence of GO dipping variables on rGO add-on and electrical resistivity of cotton, batch adsorption studies are carried out in loose fibre form to eliminate the structural influence of yarn or fabric. Batch adsorption studies suggest that GO concentration, pH of GO solution and sodium dithionite (reductant) concentration are the most influencing dipping variables and these dipping variables are optimized for cotton nonwoven fabric using Box–Behnken response surface design to achieve minimum surface resistivity. The rGO coated cotton nonwoven fabric shows excellent UV blocking properties (UV protection factor = 89.38) at the optimized GO dipping conditions. Physical properties of cotton nonwoven fabric such as GSM, thickness, stiffness, breaking strength and elongation are analysed at different dipping cycles. After the rGO coating, bending rigidity, bending modulus and breaking elongation of the cotton nonwoven fabric decrease, whereas the breaking strength increases. rGO coated cotton fabric exhibits excellent stability towards multiple washing and rubbing. The graphene coated cotton is characterised by FT-IR, XRD, Raman, TGA, FESEM and LEICA image analyser.

Biogenic synthesis of nano-sulfur using Punica granatum fruit peel extract with enhanced antimicrobial activities for accelerating wound healing

Microbial wound infections leading to secondary complications in wound healing has resulted in high demand for therapeutic drugs with improved efficacy. Despite achieving enhanced bio-activity and higher bioavailability compared to its bulk form, nano-sulfur (SNP) has been explored to a very limited extent for wound healing applications. In this work, we prepare biogenic SNP (SNP-B) via simple biogenic technique using pomegranate (Punica granatum) peel extract and demonstrate its antimicrobial and wound healing activity. The SNP-B was characterized using powder x-ray diffractometer, FESEM, transmission electron microscopy and Raman spectroscopy. Different wound models (excision, incision, dead space and burn) were used to assess the wound healing potential of SNP-B. The 2% (w/w) SNP-B treated group exhibited enhanced wound contraction rate (excision wound, 99.62 ± 0.59%; burn wound, 99.46 ± 0.59%), breaking strength (393.2 ± 10.87 g cm−2), and granulation tissue weight (166.8 ± 9.45 mg) compared to the control group (excision wound, 84.24 ± 2.78%; burn wound, 90.58 ± 3.2%; breaking strength, 241.3 ± 16.11 g cm−2; granulation tissue weight, 91.17 ± 7.28 mg). The efficacy of 2% (w/w) SNP-B was comparable to that of standard (5% w/w povidone-iodine ointment) in all the wound models analyzed. The SNP-B showed enhanced antibacterial activity with a MIC value of 90, 80, 80, and 60 μg ml−1 for Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureus, respectively. The results obtained prove the potential of SNP-B as a multifunctional therapeutic agent for topical applications.

Evidence of turbulence in the stratosphere

Arnold (1954) has observed considerable turbulence in the stratosphere on four different occasions at Belmar, New Jersey, while tracking balloons with a telescope and a radio direction finder. The turbulence was so severe that the radiosonde separated from the balloon, though it was suspended with a cord with a nominal breaking strength of about 70 lbs. During three observations in June 1950, the instrument separated from the balloon at heights ranging from 28 to 32 km, while in the observation in October it separated at 24 km. He has estimated that a descending current of about 11 m. sec-1 could provide the necessary conditions for a free fall of the sonde of about 10 ft which could break the line.

Supplemental Effects of Phytase on Modulation of Mucosa-Associated Microbiota in the Jejunum and the Impacts on Nutrient Digestibility, Intestinal Morphology, and Bone Parameters in Broiler Chickens

This study aimed to determine supplemental effects of phytase on modulation of the mucosa-associated microbiota in the jejunum, intestinal morphology, nutrient digestibility, bone parameters, and growth performance of broiler chickens. Three hundred and sixty newly hatched broiler chickens (Ross 308) (44 ± 2 g BW) were randomly allotted in 6 treatments with 10 birds per cage based on a completely randomized design and fed for 27 d. The treatments consisted of one negative control (NC), diet formulated meeting the requirements suggested by Ross recommendations (2019), and without phytase supplementation. The other treatments consisted of a positive control diet (PC) formulated with 0.15% deficient Ca and P and split into 5 treatments with different phytase inclusion levels (0, 500, 1000, 2000, 4000 FTU/kg feed). Titanium dioxide (0.4%) was added to feeds as an indigestible marker to measure apparent ileal digestibility (AID) of nutrients. On d 27, 3 birds were randomly selected from each cage and euthanized to collect samples for analyzing the mucosa-associated microbiota in the jejunum, oxidative stress status, AID, and bone parameters. Data were analyzed using the proc Mixed of SAS 9.4. Phytase supplementation tended to have a quadratic effect (p = 0.078) on the overall ADG (maximum: 41 g/d at 2833 FTU/kg of feed). Supplementation of phytase at 2,000 FTU/kg increased (p < 0.05) the relative abundance of Lactobacillus and reduced (p < 0.05) Pelomonas. Moreover, it tended to reduce Helicobacter (p = 0.085), Pseudomonas (p = 0.090) Sphingomonas (p = 0.071). Phytase supplementation increased (p < 0.05) the villus height and the AID of CP; and tended to increase (p = 0.086) the AID of P. Phytase supplementation increased (p < 0.05) breaking strength and P content in the tibia. In conclusion, phytase supplementation showed potential benefits on the modulation of the mucosa-associated microbiota in the jejunum by tending to reduce harmful bacteria (Pelomonas, Helicobacter, and Pseudomonas) and increase beneficial bacteria (Lactobacillus). In addition, it showed positive effects increasing apparent ileal digestibility of CP and P, enhancing intestinal morphology (villus height), and improving the bone parameters (bone breaking strength, ash, and P content). Phytase supplementation at a range of 38 to 59 FTU/d or 600 to 950 FTU/kg of feed provided the most benefits related to nutrient digestibility.

The use of aluminum slag waste in the preparation of roof tiles

Aluminum slag waste generated from the smelting process of bauxite was used to prepare roof tiles samples. Clay was substituted by slag waste in percentages reaching 40% in the basic mix and the plasticity of the obtained mud was determined. This was followed by pressing the mud in steel molds and drying. The effect of waste addition on drying shrinkage was subsequently assessed. Firing of the green bodies was carried out at three temperatures (900, 1000 and 1100oC) and hour soaking at each temperature. Fired roof tile properties improved on increasing the percentage of alumina sludge and firing temperature possibly because of the presence of high amounts of fluxing oxides in aluminum slag. This caused a drop in porosity that increased the mechanical strength of tiles. The results showed that the substitution of clay by 40% waste and firing at 1100oC resulted in products conforming to ASTM C-1167 for clay type roof tiles. Cold water absorption dropped to 12%, below the maximum permissible limit of 15%, the value of Saturation Coefficient was 0.83, below the 0.86 limit and the obtained breaking strength of 3370N significantly exceeded the minimum requirement of 890N.

A MODEL OF THE WOVEN FABRIC ELONGATION AND BREAKING WITH INFLUENCE OF WARP AND WEFT THREADS UNEVENNESS AND INTERACTION

The article presents the results of development of the woven fabric rectangular sample stretching and tearing computer simulation model. The model allows to set the sample size, elastic modulus and tensile breaking strength of the threads, random variations of these indicators for the warp and weft threads along their length. The modelling algorithm provides for the breakage of the warp threads, the redistribution of stress and strain between the sections of the threads and allows to get a detailed picture of the fabric sample deformation dynamics before it breaks. Examples of modelling results, the influence of the interaction degree between two systems of threads on the features of the strain distribution over the sections of the warp threads are given. The similarity of the simulation results according to the developed algorithm and the finite element method is shown, and the advantages of the proposed algorithm are noted.

Influence of Feedstock and Final Pyrolysis Temperature on Breaking Strength and Dust Production of Wood-Derived Biochars

The susceptibility to fragmentation of biochar is an important property to consider in field applications. Physical and mechanical properties of wood-derived biochars from vine shoots and holm oak were studied to evaluate the effect of biomass feedstock, final pyrolysis temperature and application conditions. Vine shoots and holm oak pruning residues were selected for biochar production. Slow pyrolysis experiments were conducted at two different final temperatures (400 and 600 °C). Physical and chemical characteristics of biomass and biochars were determined. Impact strength was evaluated through the measurement of the gravitational potential energy per unit area (J mm−2) necessary for the breakage of biochar fragments. Shear strength (N mm−2) and a combination of shear/compression strengths (N) were analyzed using a Universal Texture Analyzer. A particular mechanical treatment was carried out on biochar samples to simulate the processing bodies of a commercial manure spreader, under two gravimetric moisture contents. Holm oak-derived biochar was more resistant than vine shoot-derived biochar to the applied forces. Vine shoots-derived biochar did not show a significantly different mechanical behavior between temperatures. Holm Oak-derived biochar produced at the higher final pyrolysis temperature showed higher resistance to be broken into smaller pieces. Moistening resulted in an adequate practice to improve mechanical spreading.

Changes in Blood Metabolites, Intestinal Microbiota Composition and Gene Expression of 95 Weeks Old Laying Hens Differing in Egg Production and Egg Breaking Strength

Herein, we investigated to what extent molecular phenotypes of the systemic level (blood) and local (intestine) are associated with the performance of laying hens at 95 weeks of age. After the trial had run for 95 weeks, two performance groups were generated, i.e., egg production (PROD) and egg breaking strength (BS). A subset of 21 cages, 116 hens, was measured to indicate the metabolism and disease status. Additionally, a focus group (four cages) was made to perform molecular phenotyping in the intestine. A notifiable observation made during the post-mortem dissection was that approximately 12% of the birds at 95 weeks had developed certain aberrations and/or impairments (denoted as organ morbidity). At the systemic level, we observed five metabolites (γGT, triglycerides, HDL, glucose, and cholesterol) significantly associated to organ morbidity, and only two metabolites (urea and aspartate aminotransferase) to the performance phenotypes. At the local level, when comparing high PROD vs. low PROD, we observed differentially expressed genes involved in cell cycle processes and the extracellular matrix. When comparing high BS vs. low BS differentially, expressed genes were observed mainly involved in immune and cell cycle-related processes. This knowledge is crucial for developing novel strategies of keeping laying hens vital.

Regulation of Structure and Quality of Dried Noodles by Liquid Pre-Fermentation

Liquid pre-fermentation technology was innovatively applied to the development of dried fermented noodles. The effects of fermentation time (1, 3 and 6 h) and yeast addition (0.2, 0.5 and 1.0 g/100 g of flour) on the quality, microstructure and flavor of dried noodles were also investigated in this study. Conspicuous porous structures and greater thickness of dried noodles were found when the fermentation time was ≤ 3 h and the yeast addition was ≥ 0.5 g/100 g of flour, which contributed to the increase in the breaking strength, cooking time and water absorption. However, when the fermentation time increased to 6 h, finer microporous structures, little change related to thickness and richer flavor levels were detected. Additionally, the total titratable acidity of dried fermented noodles was increased to 3.38–4.43 mL compared with the unfermented noodles (2.15 mL). Weaker gluten network structures caused by long-time fermentation and acidic environment led to lower hardness, chewiness, tensile force and tensile distance of cooked fermented noodles.