Gold Nanoparticles-based Colorimetric Sensor for Cysteine Detection

AbstractA simple, sensitive and selective colorimetric method for the detection of cysteine was demonstrated with unmodified gold nanoparticles (AuNPs) as probes. In this approach, the synthesized AuNPs solution was stabilized by the citrate anions as their repulsion protected the AuNPs from aggregation. Cysteine was added to AuNPs solution and was incubated to react for 3min. The resulting mixture color changes dramatically from red-purple-blue because cysteine induced the nanoparticle aggregation. These processes were studied and characterized by UV–vis spectroscopy, zeta potential and dynamic light scattering. Several parameters including AuNPs size, reaction time and media pH that governed the analytical performance of the method have been studied in detail and optimized. Under the optimized experimental conditions, cysteine could be selectively detected in a concentration range from 0.1 to 0.6ppm with a limit of detection as 0.01ppm at a signal-to-noise ratio of 3. The sensitivity was calculated as 1.474 Abs/ppm. Some common interferents such as Na+, Cu2+, Cl− and urea showed no interference in the determination of cysteine by using AuNPs

Material Flow Behaviour on Fine Blanking Process for Sheet Metal Extrusion

Sheet metal extrusion in fine-blanking process (SME-FB) can create a different of sheet metal thickness. These research studies explain the characteristic of material-flow behavior on SME-FB. That is, The causes of surface crack and end-rod shrinkage which are the general problems in the SME-FB. In this study, the medium steel S45C (JIS) was used as a material extruded vary in tool radii; i.e., 0.0, 0.1, 0.2 and 0.3 mm. Therefore, the material-flow behavior on the SME-FB process was investigated the formation of the defection with respect to the several die radii by using the Finite Element Method (FEM). From the results, it indicated that applying the small die radius caused the material flow difficult resulting in the decreasing of smooth surface. In contrast, in the case of large die radius, the material can flow easy is resulting in the increasing of smooth surface. Moreover, the FEM simulation results of a larger die radius will cause the residual stress at work piece

Study of Microstructure and Mechanical Properties Effects on Workpiece Quality in Sheet Metal Extrusion Process

Sheet metal extrusion is a metal forming process in which the movement of a punch penetrates a sheet metal surface and it flows through a die orifice; the extruded parts can be deflected to have an extrusion cavity and protrusion on the opposite side. Therefore, this process results in a narrow region of highly localized plastic deformation due to the formation and microstructure effect on the work piece. This research investigated the characteristics of the material-flow behavior during the formation and its effect on the microstructure of the extruded sheet metal using the finite element method (FEM). The actual parts and FEM simulation model were developed using a blank material made from AISI-1045 steel with a thickness of 5 mm; the material’s behavior was determined subject to the punch penetration depths of 20%, 40%, 60%, and 80% of the sheet thickness. The results indicated the formation and microstructure effects on the sheet metal extrusion parts and defects. Namely, when increasing penetration, narrowing the die orifice the material flows through, the material was formed by extruding, and defects were visibility, and the microstructure of the material’s grains’ size was flat and very fine. Extrusion defects were not found in the control material flow. The region of highly localized plastic deformation affected the material gain and mechanical properties. The FEM simulation results agreed with the experimental results. Moreover, FEM could be investigated as a tool to decrease the cost and time in trial and error procedures

Effect of cassava pulp treated with Lactobacillus casei TH14, urea, and molasses on gas kinetics, rumen fermentation, and degradability using the in vitro gas technique

This study focused on examining the gas dynamics, rumen fermentation, and digestibility of ensiled cassava pulp (CSVP) using Lactobacillus casei TH14, urea, and molasses in the context of a laboratory experiment. All data in this study were analyzed using treatments arranged in 2 × 2 × 2 factorial arrangements using a completely randomized design. The L. casei TH14 additive (L) was factor A. Factor B was the molasses additive (M), while factor C was urea (U). There was no interaction effect of L, U, and M on gas production, volatile fatty acid (VFA) content, pH value, or ammonia-nitrogen level (P<0.05). The interaction of L, U, and M influenced in vitro dry matter digestibility (IVDMD) at 12 h (P < 0.05), and the CSVP fermented with the additions of L, U, and M together (LUM) was higher than the additions of CON, M, U, UM, and L on IVDMD (P < 0.05). However, the IVDMD values of adding LUM were higher in the control group (CON), M, U, UM, and L additive groups (P < 0.05). There was an interaction effect of L, U, and M on the protozoal count at 8 h (P<0.05), which had a lower protozoal count in the control group. In addition, acetic acid and butyric acid concentrations at 4 h and 8 h (P<0.05) were increased during the fermentation of CSVP using L and M combinations. Furthermore, the combination of U and M enhanced (P<0.05) average acetic acid, propionic acid, and pH at 4 h and 8 h while reducing (P<0.05) the gas generation from the insoluble portion (b). It was suggested that utilizing L. casei TH14 together with urea and molasses can enhance nutrient contents and improve the in vitro dry matter digestibility of CSVP, although it has no effect on ruminal fermentation or gas production

Utilization of Yeast Waste Fermented Citric Waste as a Protein Source to Replace Soybean Meal and Various Roughage to Concentrate Ratios on In Vitro Rumen Fermentation, Gas Kinetic, and Feed Digestion

The objective of this study was to determine the application of citric waste fermented yeast waste (CWYW) obtained from an agro-industrial by-product as a protein source to replace soybean meal (SBM) in a concentrate diet. We also determined the effect of various roughage to concentrate ratios (R:C) on the gas production kinetics, ruminal characteristics, and in vitro digestibility using an in vitro gas production technique. The experiment design was a 3 × 5 factorial design arranged in a completely randomized design (CRD), with three replicates. There were three R:C ratios (60:40, 50:50, and 40:60) and five replacing SBM with CWYW (SBM:CWYW) ratios (100:0, 75:25, 50:50, 25:75, and 0:100). The CWYW product’s crude protein (CP) content was 535 g/kg dry matter (DM). There was no interaction effect between R:C ratios and SBM:CWYW ratios for all parameters observed (p &gt; 0.05). The SBM:CWYW ratio did not affect the kinetics and the cumulative amount of gas. However, the gas potential extent and cumulative production of gas were increased with the R:C ratio of 40:60, and the values were about 74.9 and 75.0 mL/0.5 g, respectively (p &lt; 0.01). The replacement of SBM by CWYW at up to 75% did not alter in vitro dry matter digestibility (IVDMD), but 100% CWYW replacement significantly reduced (p &lt; 0.05) IVDMD at 24 h of incubation and the mean value. In addition, IVDMD at 12 h and 24 h of incubation and the mean value were significantly increased with the R:C ratio of 40:60 (p &lt; 0.01). The SBM:CWYW ratio did not change the ruminal pH and population of protozoa (p &gt; 0.05). The ruminal pH was reduced at the R:C ratio of 40:60 (p &lt; 0.01), whereas the protozoal population at 4 h was increased (p &lt; 0.05). The SBM:CWYW ratio did not impact the in vitro volatile fatty acid (VFA) profile (p &gt; 0.05). However, the total VFA, and propionate (C3) concentration were significantly increased (p &lt; 0.01) by the R:C ratio of 40:60. In conclusion, the replacement of SBM by 75% CWYW did not show any negative impact on parameters observed, and the R:C ratio of 40:60 enhanced the gas kinetics, digestibility, VFA, and C3 concentration

The recycling of tropical fruit peel waste-products applied in feed additive for ruminants: Food manufacturing industries, phytonutrient properties, mechanisms, and future applications

Tropical fruits are grown on tree varieties native to tropical regions, presenting a high concentration of phytonutrients (PTNs). Tropical fruits are often used in the extraction of juice, as well as in the preparation of jams, jellies, and canned products. The residual components, particularly fruit peels, are frequently discarded as wastes. This approach intends to reduce waste accumulation while meeting the growing public demand for PTNs, which are believed to possess antibacterial, antioxidant, methane production inhibitory, and rumen fermentation-enhancing properties. The tropical fruit wastes under consideration include banana, citrus fruit, dragon fruit, durian, jackfruit, mango, mangosteen, passion fruit, pineapple, pomegranate, and rambutan. Therefore, the objective of this review is to provide a comprehensive overview of the existing research focusing on the biological capabilities of tropical waste products derived from fruit peels, as well as their PTN profile, targeting their potential as supplements as feed additives for ruminants. The main attention of using PTNs found in tropical fruit peels is for enhancing rumen fermentation characteristics and production, while simultaneously mitigating the methane (CH4) production. Results provided by the present review showed that fruit peel waste products could buffer rumen pH levels, improve nutrient digestibility, ammonia-nitrogen (NH3–N) concentrations, blood urea nitrogen (BUN) levels, volatile fatty acids (VFAs) concentrations, and microbial populations, as well as enhancing milk production, and decrease CH4 production. These waste products could be a potential alternative plant-based PTN compound supplement to be use as a feed additive in ruminants