Material flow during the extrusion of simple and complex cross-sections using FEM

This paper deals with the extrusion of rod and shape sections and uses a 3D finite element model analysis (FEM) to predict the effect of die geometry on maximum extrusion load. A description of material flow in the container is considered in more detail for rod and shape sections in order to fully comprehend the transient conditions occurring during the process cycle. A comparison with experiments is made to assess the relative importance of some extrusion parameters in the extrusion process and to ensure that the numerical discretisation yields a realistic simulation of the process. The usefulness and the limitation of FEM are discussed when modelling complex shapes. Results are presented for velocity contours and shear stress distribution during the extrusion process. It is shown that for most of the shapes investigated, the material making up the extrudate cross-sections originates from differing regions of virgin material within the billet. The outside surface of the extrudate originates from the material moving along the dead metal zone (DMZ) and the core of the extrudate from the central deformation zone. The FE program appears to predict all the major characteristics of the flow observed macroscopically

Material flow during the extrusion of simple and complex cross-sections using FEM

This paper deals with the extrusion of rod and shape sections and uses a 3D finite element model analysis (FEM) to predict the effect of die geometry on maximum extrusion load. A description of material flow in the container is considered in more detail for rod and shape sections in order to fully comprehend the transient conditions occurring during the process cycle. A comparison with experiments is made to assess the relative importance of some extrusion parameters in the extrusion process and to ensure that the numerical discretisation yields a realistic simulation of the process. The usefulness and the limitation of FEM are discussed when modelling complex shapes. Results are presented for velocity contours and shear stress distribution during the extrusion process. It is shown that for most of the shapes investigated, the material making up the extrudate cross-sections originates from differing regions of virgin material within the billet. The outside surface of the extrudate originates from the material moving along the dead metal zone (DMZ) and the core of the extrudate from the central deformation zone. The FE program appears to predict all the major characteristics of the flow observed macroscopically

Culture of micro-organisms on cellophone membrane

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Properties of an alkali-thermo stable xylanase from Geobacillus thermodenitrificans A333 and applicability in xylooligosaccharides generation

An extracellular thermo-alkali-stable and cellulase-free xylanase from Geobacillus thermodenitrificans A333 was purified to homogeneity by ion exchange and size exclusion chromatography. Its molecular mass was 44 kDa as estimated in native and denaturing conditions by gel filtration and SDS-PAGE analysis, respectively. The xylanase (GtXyn) exhibited maximum activity at 70 °C and pH 7.5. It was stable over broad ranges of temperature and pH retaining 88 % of activity at 60 °C and up to 97 % in the pH range 7.5–10.0 after 24 h. Moreover, the enzyme was active up to 3.0 M sodium chloride concentration, exhibiting at that value 70 % residual activity after 1 h. The presence of other metal ions did not affect the activity with the sole exceptions of K+ that showed a stimulating effect, and Fe2+, Co2+ and Hg2+, which inhibited the enzyme. The xylanase was activated by non-ionic surfactants and was stable in organic solvents remaining fully active over 24 h of incubation in 40 % ethanol at 25 °C. Furthermore, the enzyme was resistant to most of the neutral and alkaline proteases tested. The enzyme was active only on xylan, showing no marked preference towards xylans from different origins. The hydrolysis of beechwood xylan and agriculture-based biomass materials yielded xylooligosaccharides with a polymerization degree ranging from 2 to 6 units and xylobiose and xylotriose as main products. These properties indicate G. thermodenitrificans A333 xylanase as a promising candidate for several biotechnological applications, such as xylooligosaccharides preparation

Optimizing banana powder production: A quadratic approachusing Box-Behnken Design for hot-air oven drying parameters

Optimization of parameters in food product processing is essential for achieving high-quality output and efficient production. While the use of fresh green bananas is limited, drying them into powder expands their applications significantly. This study focuses on optimizing the production of banana powder, which has numerous applications in the food industry. Key parameters such as steaming time, citric acid concentration, and drying time need to be optimized using Box-Behnken design of response surface methodology (RSM), as they directly impact the quality of the banana powder. The moisture content of the sample was measured using the gravimetric method, while water activity was assessed with a digital water activity meter. Amylose content was determined using a calorimeter, while starch content of the sample was measured using the anthrone method and color characteristics were evaluated with a spectrophotometer. The quadratic model was found to be the best fit for most of the responses (R² = 0.96–1), and the linear model was fit for starch content (R² = 0.73). Results obtained using Box-Behnken Design of response surface methodology reveals that steaming time of 10 minutes, citric acid concentration of 0.5% and a drying time of 7 hours are ideal conditions for enhance powder making. Under the optimized condition, the values of yield, moisture content, water activity, amylose, starch content and L* was predicted to be 19.99%, 5.73%, 0.40 aw, 23.43 g/100g, 86.72 g/100g and 50.82 of banana powder respectively, aligning with the experimental values using the desirability function

Investigations on the absorption spectrum of TiO2 nanofluid

Nanofluids are tailored nano- colloidal suspensions of nanoparticles in a suitable base fluid. This present work investigates the absorption spectrum in TiO2-water nanofluids to identify the potential application of nanofluids in Direct Absorption Solar Collectors (DASC). Nanoparticles of Titanium dioxide (TiO2) are prepared by sol gel and characterized by X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). TiO2-water nanofluids with weight fraction of 0.1% are prepared by a two-step process with sonication. The prepared nanofluids are investigated for their stability by a gravity sedimentation method and for their optical property by UV-Vis spectroscopy. Stability of nanofluid is essential for the applications of nanofluid in DASC. TiO2 nanoparticles with a crystallite size of 43nm are obtained .The SEM image reveals the agglomerated state of TiO2 nanoparticles and the stability of TiO2 nanofluid is reported as 9-10days. UV results indicate the decrease in absorption from 440-500nm, complete absorption from 500-700nm and increase in absorption from 700-900nm.TiO2 nanofluids are recommended as potential candidates for DASC in UV and IR regions

Compartmentalized Metabolic Engineering for Artemisinin Biosynthesis and Effective Malaria Treatment by Oral Delivery of Plant Cells

Artemisinin is highly effective against drug-resistant malarial parasites, which affects nearly half of the global population and kills \u3e500 000 people each year. The primary cost of artemisinin is the very expensive process used to extract and purify the drug from Artemisia annua. Elimination of this apparently unnecessary step will make this potent antimalarial drug affordable to the global population living in endemic regions. Here we reported the oral delivery of a non-protein drug artemisinin biosynthesized (~0.8 mg/g dry weight) at clinically meaningful levels in tobacco by engineering two metabolic pathways targeted to three different cellular compartments (chloroplast, nucleus, and mitochondria). The doubly transgenic lines showed a three-fold enhancement of isopentenyl pyrophosphate, and targeting AACPR, DBR2, and CYP71AV1 to chloroplasts resulted in higher expression and an efficient photo-oxidation of dihydroartemisinic acid to artemisinin. Partially purified extracts from the leaves of transgenic tobacco plants inhibited in vitro growth progression of Plasmodium falciparum-infected red blood cells. Oral feeding of whole intact plant cells bioencapsulating the artemisinin reduced the parasitemia levels in challenged mice in comparison with commercial drug. Such novel synergistic approaches should facilitate low-cost production and delivery of artemisinin and other drugs through metabolic engineering of edible plants

A technical perspective on integrating artificial intelligence to solid-state welding

The implementation of artificial intelligence (AI) techniques in industrial applications, especially solid-state welding (SSW), has transformed modeling, optimization, forecasting, and controlling sophisticated systems. SSW is a better method for joining due to the least melting of material thus maintaining Nugget region integrity. This study investigates thoroughly how AI-based predictions have impacted SSW by looking at methods like Artificial Neural Networks (ANN), Fuzzy Logic (FL), Machine Learning (ML), Meta-Heuristic Algorithms, and Hybrid Methods (HM) as applied to Friction Stir Welding (FSW), Ultrasonic Welding (UW), and Diffusion Bonding (DB). Studies on Diffusion Bonding reveal that ANN and Generic Algorithms can predict outcomes with an accuracy range of 85 – 99%, while Response Surface Methodology such as Optimization Strategy can achieve up to 95 percent confidence levels in improving bonding strength and optimizing process parameters. Using ANNs for FSW gives an average percentage error of about 95%, but using metaheuristics refined it at an incrementally improved accuracy rate of about 2%. In UW, ANN, Hybrid ANN, and ML models predict output parameters with accuracy levels ranging from 85 to 96%. Integrating AI techniques with optimization algorithms, for instance, GA and Particle Swarm Optimization (PSO) significantly improves accuracy, enhancing parameter prediction and optimizing UW processes. ANN’s high accuracy of nearly 95% compared to other techniques like FL and ML in predicting welding parameters. HM exhibits superior precision, showcasing their potential to enhance weld quality, minimize trial welds, and reduce costs and time. Various emerging hybrid methods offer better prediction accuracy

From Plants to Therapies: Exploring the Pharmacology of Coumestrol for Neurological Conditions.

Neurological disorders are possibly the most prevalent and have been identified to occur among individuals with autism beyond chance. These disorders encompass a diverse range of consequences with neurological causes and have been regarded as a major threat to public mental health. There is no tried-and-true approach for completely protecting the nervous system. Therefore, plant-derived compounds have developed significantly nowadays. Coumestrol (CML) is a potent isoflavone phytoestrogen with a protective effect against neurological dysfunction and has been discovered to be structurally and functionally similar to estrogen. In recent years, more research has been undertaken on phytoestrogens. This research demonstrates the biological complexity of phytoestrogens, which consist of multiple chemical families and function in various ways. This review aimed to explore recent findings on the most significant pharmacological advantages of CML by emphasising neurological benefits. Numerous CML extraction strategies and their pharmacological effects on various neurological disorders, including PD, AD, HD, anxiety, and cognitive impairments, were also documented

Crush characteristics and energy absorption of thin-walled tubes with through-hole crush initiators

An experimental investigation was conducted to compare the crush characteristics and energy absorption capacity of circular and square tubes with located through-hole crush initiator. Circular through-holes were fabricated at three different configurations based on location into steel tubes which had a length of 200 mm. Furthermore, two different side configurations along the tube were considered for introducing the crush initiators. The results found that adding crush initiator onto the tubes effectively reduced the initial peak force of a thin-walled circular and square tubes under axial quasi-static loading. The peak crush force was reduced within a range 3-10% and 5-16% for circular and square tubes, respectively when compared with corresponding tubes without crush initiator. Moreover, the energy absorption capacity of the tubes was independent with the incorporation of through-hole crush initiators. However, the energy absorption of circular and square tubes slightly decreases when compared with the tubes fabricated four sided crush initiation and tubes without crush initiator. Overall, the effect of location and number of crush initiation significantly influenced the initial peak forces while maintain the energy absorbed