Physical Modeling of the Impeller Construction Impact on the Aluminum Refining Process

Obtaining high-quality aluminum is associated with the use of an effective method of refining, which is argon-purging, in which gas bubbles are introduced into the liquid metal by means of rotary impellers. Various rotary impellers are used in the industry; however, if a newly designed impeller is constructed, it should be tested prior to industrial use. For this purpose, physical modeling is used, which enables the investigation of the phenomena occurring during refining and the selection of optimal processing parameters without costly research carried out in the industry. The newly designed rotary impeller was tested on the physical model of a URO-200 batch reactor. The flow rate of refining gas was: 10, 15 and 20 dm3·min−1, whereas rotary impeller speed was 300, 400 and 500 rpm. The research consists of a visualization test showing the schemes of the gas bubbles’ dispersion level in the liquid metal and experiments for removing oxygen from water, which is an analogue of removing hydrogen from aluminum.

Lipases as Effective Green Biocatalysts for Phytosterol Esters’ Production: A Review

Lipases are versatile enzymes widely used in the pharmaceutical, cosmetic, and food industries. They are green biocatalysts with a high potential for industrial use compared to traditional chemical methods. In recent years, lipases have been used to synthesize a wide variety of molecules of industrial interest, and extraordinary results have been reported. In this sense, this review describes the important role of lipases in the synthesis of phytosterol esters, which have attracted the scientific community’s attention due to their beneficial effects on health. A systematic search for articles and patents published in the last 20 years with the terms “phytosterol AND esters AND lipase” was carried out using the Scopus, Web of Science, Scielo, and Google Scholar databases, and the results showed that Candida rugosa lipases are the most relevant biocatalysts for the production of phytosterol esters, being used in more than 50% of the studies. The optimal temperature and time for the enzymatic synthesis of phytosterol esters mainly ranged from 30 to 101 °C and from 1 to 72 h. The esterification yield was greater than 90% for most analyzed studies. Therefore, this manuscript presents the new technological approaches and the gaps that need to be filled by future studies so that the enzymatic synthesis of phytosterol esters is widely developed.

Chemical Profiling and Constituent Diversity in Nutmeg Genotypes (Myristica fragrans Houtt.)

Background: Nutmeg is a perennial tree spices which is yielding twin spices; present days research thrust is to identify high yielding mother trees. But yield and quality both are equally important due to its wide spread medicinal as well as industrial usage. Methods: The core collection of nutmeg genotypes form different locations of Kerala evaluated for biochemical composition. Seventeen morphologically distinct types of nutmeg were analysed through GC/MS method. The change in volatiles after storage (at 4°C) was also assessed after one year. Result: The range of variation was observed for kernel oil, mace oil, kernel oleoresin, mace oleoresin and fixed oil of kernel. Myristicin, elemecin and sabinene were principal volatile compounds. The identification of distinct nutmeg chemotypes for specific volatile compounds which could be used in commercial cultivation/pharmaceutical application/industrial use. Present study highlights the high and low hallucinogen (myristicine, elemicine and safrole) genotypes along with high sabinene types.

Development of a Range of Modified Multifunctional Residual Current Systems and Their Industrial Implementation

The developments of the AltSTU have been reviewed in the area of creating a new technology for preventing technogenic hazards based on the residual current devices. The residual current devices are intended for protecting people from electric shock in case of contact with conductive parts of the electric appliances and shall facilitate reduction of fire risks caused by a prolonged flow of leakage currents and fault currents resulting from them. The results of creating different modifications of protective trip circuits and their industrial use are provided.

Joining Techniques Like Welding in Lightweight Material Structures

In order to take more stringent measures in fuel economy and achieve the determined performance targets, the automotive industry needs to reduce the weight of the vehicles it produces. For this reason, all automobile manufacturers have determined their own strategies. Some manufacturers use lighter aluminum, magnesium, and composite components in their cars. In this study, the joining techniques of lightweight materials such as welding and the processes of their industrial use have been examined. There is currently no single technology that can combine all metallic panels in a car body structure. However, it is known that various joining technologies are used together. With the potential to combine certain combinations of steel and aluminum, manufacturers and scientists continue to work to identify technologies with the highest potential for lightweight joining and put them into use in high-volume automobile production. Therefore, it is important to examine the weldability of light materials such as magnesium, titanium, and aluminum.

Life–Cycle Oriented Risk Assessment Using a Monte Carlo Simulation

State of the art mechatronic systems are complex assemblies of various parts and sub-systems. In such an interconnected system, even relatively cheap parts can have a major impact on the overall performance due to unexpected failure. Hence, lifecycle management has major implications on the successful modification of existing products. Potential savings due to changes in production and procurement must be compared to the implied risk of products failing in the field due to these changes. This work documents a generic approach for risk assessment based on the distribution of the expected savings and incident costs over the whole lifecycle. To do so, a stochastic model is introduced to quantify the expected savings and costs given a non-risk-free product modification. Using a Monte Carlo simulation, the effects of uncertainty are incorporated into the risk management. The model and simulation are deployed within an industrial use case. The application demonstrates both the appropriateness of the tool and its useability.

Biochemical and Structural Characterization of a Novel Bacterial Tannase From Lachnospiraceae bacterium in Ruminant Gastrointestinal Tract

Tannases are a family of esterases that catalyze the hydrolysis of ester and depside bonds present in hydrolyzable tannins to release gallic acid. Here, a novel tannase from Lachnospiraceae bacterium (TanALb) was characterized. The recombinant TanALb exhibited maximal activity at pH 7.0 and 50°C, and it maintained more than 70% relative activity from 30°C to 55°C. The activity of TanALb was enhanced by Mg2+ and Ca2+, and was dramatically reduced by Cu2+ and Mn2+. TanALb is capable of degrading esters of phenolic acids with long-chain alcohols, such as lauryl gallate as well as tannic acid. The Km value and catalytic efficiency (kcat /Km) of TanALb toward five substrates showed that tannic acid (TA) was the favorite substrate. Homology modeling and structural analysis indicated that TanALb contains an insertion loop (residues 341–450). Based on the moleculer docking and molecular dynamics (MD) simulation, this loop was observed as a flap-like lid to interact with bulk substrates such as tannic acid. TanALb is a novel bacterial tannase, and the characteristics of this enzyme make it potentially interesting for industrial use.

Comparison of the Accelerated and Spontaneous Deactivation of the HDS Catalyst

Owing to the increased use of secondary materials for diesel production, refineries must confront bad quality parameters. Therefore, catalysts with certain capabilities (to remove heteroatoms and improve quality parameters at low hydrogen consumption) and their lifetimes are required. An important parameter that influences the quality of the products and the economy of the unit is the activity of the catalyst. Prior to industrial use, the catalyst is typically tested in a pilot unit. This is necessary to obtain a considerable amount of data on the lifetime of the catalyst in the shortest feasible time. Here, deactivation steps were used to test the catalyst. Two experiments were performed to evaluate the effect of two types of accelerated deactivations on the catalyst activity and product properties. The first type of deactivation proceeded for 6 h and comprised a tripling of the amount of incoming feedstock, and the second type proceeded for 18 h without an increase in the amount of feedstock. For both cases, the pressure and hydrogen flow were minimised. Both types of accelerated deactivations had similar effects on the quality of the final products and catalyst. The only difference was in the duration of catalyst recovery after deactivation. The results were compared with those of a test in which the spontaneous deactivation of the catalyst was studied.

Purification, Identification And Characterization of Nag2 N-Acetylglucosaminidase From Trichoderma Virens Strain Mango

Background: N -acetylglucosaminidase (NAGase) could liberate N -acetylglucosamine (GlcNAc) from GlcNAc-containing oligosaccharides. Trichoderma spp. is an important source of chitinase, particularly NAGase for industrial use. nag1 and nag2 genes encoding NAGase , are found in the genome in Trichoderma spp. The deduced Nag1 and Nag2 shares ~55% homology in Trichoderma virens. Most studies were focus on Nag1 and nag1 previously. Results: The native NAGase (TvmNAG2) was purified to homogeneity with molecular mass of ~68 kDa on SDS-PAGE analysis, and identified as Nag2 by MALDI/MS analysis from an isolate T. virens strain mango. RT-PCR analyses revealed that only nag2 gene was expressed in liquid culture of T. virens , while both of nag1 and nag2 were expressed in T. virens cultured on the plates. TvmNAG2 was thermally stable up to 60 o C for 2 h, and the optimal pH and temperature were 5.0 and 60-65 o C, respectively, using p -nitrophenyl- N -acetyl- β -D-glucosaminide ( p NP-NAG) as substrate. Using colloidal chitin as substrate, the end product catalyzed by TvmNAG2 was GlcNAc, based on HPLC and TLC analyses. The optimal temperature for TvmNAG2 to produce GlcNAc was 40 o C. TvmNAG2 possesses antifungal activity, inhibiting the mycelium growth of Sclerotium rolfsii . And it was resistant to the proteolysis by papain and trypsin. Conclusions: The native Nag2, TvmNAG2 was purified and identified from T. virens strain mango, as well as enzymatic properties. To our knowledge, it is the first report with the properties of native Trichoderma Nag2.

A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones

A simple and efficient method for α-brominating lactones that affords α-bromolactones under mild conditions using tetraalkylammonium hydroxide (R4N+OH−) as a base was developed. Lactones are ring-opened with Br2 and a substoichiometric amount of PBr3, leading to good yields of the corresponding α-bromocarboxylic acids. Subsequent intramolecular cyclization over 1 h using a two-phase system (H2O/CHCl3) containing R4N+OH− afforded α-bromo lactones in good yields. This method can be applied at the 10 mmol scale using simple operations. α-Bromo-δ-valerolactone, which is extremely reactive and difficult to isolate, could be isolated and stored in a freezer for about one week using the developed method. Optimizing the solvent for environmentally friendly large-scale syntheses revealed that methyl ethyl ketone (MEK) was as effective. In addition, in situ-generated α-bromo-δ-valerolactone was directly converted into a sulfur-substituted functional lactone without difficulty by reacting it with a sulfur nucleophile in one pot without isolation. This new bromination system is expected to facilitate the industrial use of α-bromolactones as important intermediates.