Suitable Processing Conditions Research Articles

Three-dimensional processing map based on BP-ANN and interface microstructure of Fe/Al laminated sheet

To improve the coordinated deformability and working stability of pure iron/aluminum (Fe/Al) laminates, pack isothermal compression experiments were conducted at deformation temperatures and strain rates ranging from 623 to 823 K and 0.01 to 10 s−1, respectively. The back-propagation neural network (BP-ANN) model was developed to predict the flow behavior of these laminates. Three-dimensional (3D) processing maps were established to optimize processing parameters by considering the deformation temperature, strain, and strain rate variables. The results indicated that the BP-ANN model is quite accurate, with a correlation coefficient (R) of 0.9979 and a mean absolute error (MAE) of 1.4681%. A peak energy dissipation efficiency of 73% was obtained in the optimized parameter range of 723–823 K and 1-10 s−1. The excellent deformation coordination between iron and aluminum layers occurred at 723 K/10 s−1. A Fe/Al interdiffusion layer of about 1 μm was formed at the interface, and the iron and aluminum layers present fine recrystallized (DRX) grains along the interface. In the rolling experiment guided by the most suitable process conditions in the hot processing map, the Fe/Al bonding was good at 723 K, and the reduction rate was 55%.

Comparison of Physicochemical Properties and Hydroxymethyfurfural Content of Tualang Honey Treated Using Conventional Heating and Ultrasound Technique

Conventional heating is a common treatment applied to honey to preserve its quality and facilitate packaging. The treatment will reduce the viscosity and moisture level of honey, destroy yeasts, liquefy crystals, and delay crystallisation. However, conventional heating may increase the hydroxymethyfurfural (HMF) content in honey which is a potential carcinogen to human and lead to quality deterioration. Alternatively, the use of ultrasound to treat honey can minimize the heat exposure. This study was conducted to determine the suitable process conditions to be applied to Tualang honey and to compare the quality of Tualang honey treated using two different techniques. The quality of honey was determined from physicochemical analysis (turbidity, colour, pH, water activity, and moisture content), and HMF analysis using White method. Tualang honey samples were treated at different conditions; 50-90oC for 1-60 min using conventional heating and 50-90% amplitude for 10-30 min using ultrasound technique. The best condition for each treatment was determined at 70oC for 15 min using conventional heating and 70% amplitude for 10 min using ultrasound treatment. This study also points out that the use of ultrasound treatment slowed down the HMF formation compared to conventional heating. It can be concluded that Tualang honey treated with ultrasound can be used by honey producers to retain the quality of honey.

Critical dimension prediction of metal oxide nanoparticle photoresists for electron beam lithography using a recurrent neural network.

The critical dimension (CD) of lithographic patterns is the most significant indicator for evaluating the imaging performance of photoresists, and its value is seriously affected by process conditions. However, the lithographic imaging system is highly nonlinear, and extensive exposure experiments are needed to obtain the desired CD. This consumes lots of time, manpower, and cost in screening for optimal process conditions. Here, we report a combined electron beam lithography (EBL) experiment and recurrent neural network (RNN) study on the CDs of metal oxide nanoparticle photoresists, and establish a CD RNN model. Leveraging the RNN model, a process condition filter is developed to screen suitable process conditions. The experimental results demonstrate that the prediction accuracy of the CD model exceeds 93%, and the photoresist patterns under the screened process conditions can satisfy the requirements of a preset CD. This work opens up a novel perspective for accurate EBL process modeling, and provides guidance for EBL experiments.

Functional Behaviour of Cold-Worked and Straight-Annealed NiTi Elements Processed with Ultrashort Laser Cutting

Among functional materials, quasiequiatomic NiTi alloys are one of the most promising and diffused for some sectors, from the biomedical to aerospace ones. Their peculiar performance, namely, shape memory effect and pseudoelasticity, is induced via a thermomechanical treatment called shape setting or with the heat treatment of annealing. This heat treatment is carried out in cold-worked conditions. The present work studies the effect of the material conditions of straight annealing and cold working on the functional performance of diamond-shaped NiTi microdevices realised through ultrashort laser cutting. In detail, experiments were carried out aimed at studying the effect of laser power, scanning speed, and number of passes on the kerf width with the focus on defining the most suitable process condition on both straight-annealed and cold-worked sheets of 100 µm in thickness. After the process parameters had been defined, the transformation temperatures and superelastic behaviour were analysed though differential scanning calorimetry and force–displacement testing. The femtosecond cutting of straight-annealed NiTi did not change the characteristic temperatures of the base material, while the same process induced a soft martensitic transformation with respect to the cold-worked material due to a heat accumulation effect.

Cracking of F-T refined wax for producing linear α-olefin

The steam cracking of Fischer-Tropsch refined wax from the coal-to-oil process for producing linear α-olefin (LAO) was carried out on a fixed bed reactor. The effects of feedstock composition, cracking temperature, contact time, water-to-wax ratio and cyclic process on the feed conversion and products distribution were investigated and optimized. The factors such as cracking temperature and contact time have significant influence on conversion and LAO yield, and cyclic process can further improve the LAO yield. However, excess high cracking temperature and longer contact time result in the second reactions, which are unfavorable for the LAO production. Under the suitable process conditions 53% of LAO yield are obtained.

Design of laser-induced graphene electrodes for water splitting

Efficient energy storage from intermittent renewables can rely on the conversion of temporary energy excess by alkaline electrolysis, yielding oxygen and green hydrogen, which can be stored and used on demand. Electrodes made of laser-induced graphene (LIG) materials offer many advantages over the traditional graphene processing routes, due to inherent simplicity and low cost-benefit. Despite poorly studied, LIG electrodes are promising for water splitting when properly doped/modified with metals. However, proper design and processing optimization should be considered. The present study is devoted to the laser processing effects on the LIG electrode performance towards water splitting in alkaline media. Promising guidelines were obtained for hydrogen production, showing high electrochemical activity, while the microstructural degradation can be minimised by selecting suitable laser processing conditions, such as 3.6 W of laser power, 100 mm/s of laser scan rate, 36 mJ/mm of energy density and 2 laser scans.

High-Speed Alumina Stereolithography

The additive manufacturing of ceramics offers a reliable and repeatable method for fabricating parts with complex geometries. To compete with conventional ceramic forming methods, the time and cost associated with material and process optimization for ceramic stereolithography should be improved. Computational analysis methods can be utilized to reduce the number of experimental steps required for material and process optimization. This work used the discrete element method and ray tracing analyses to predict suitable material parameters and processing conditions for ceramic stereolithography. The discrete element method was used to create alumina particle dispersion models to predict suitable paste compositions, and ray tracing was used to predict suitable laser power and scan speed to achieve a sufficient curing depth for stereolithography processing. The predicted conditions of paste composition and processing parameters were comparable to experimental values, reducing the number of experimental iterations required for process optimization. Furthermore, suitable processing parameters for high-speed fabrication by stereolithography was predicted, achieving a processing speed much faster than previously reported ceramic stereolithography. The reduction in process optimization timeline, and the increase in fabrication speed, could increase the appeal of ceramic stereolithography to industry.

Drivers of coffee liking: Effect of physicochemical characteristics and aromatic profile on consumers' acceptability of mono-origin and mono-variety coffees.

Few studies have investigated at the same time how physicochemical, volatile, and sensory characteristics affect coffee liking. The aim of this study is to evaluate the influence of geographical origin and variety on physicochemical parameters and volatile compounds composition of mono-origin and mono-variety coffees. Check-all-that-apply (CATA) method was used with the aim of identifying the drivers of coffee liking. Moisture content, bulk density, solubility index, color parameters, and phenols and caffeine content were useful parameters for discriminating Robusta from Arabica variety, but not samples from different origins. The hierarchical cluster and principal component analyses performed on the headspace compositions showed a quite sharp ability to group the samples based on their variety. Based on CATA results, roasted attribute, related to the presence of pyrazines, was considered a positive driver of coffee liking unlike grassy and acidic attributes (associated to the presence of acids and aldehydes, respectively). Findings from this study can be a useful tool for coffee manufacturers for a winning market strategy, helping them in the choice of the most suitable raw materials and process conditions in order to produce a well-balanced beverage by enhancing all the possible positive drivers of acceptability and reducing the negative ones.

PRODUCTION OF GLYCOSAMINOGLYCAN (GAG) FROM CHICKEN STERNUM BY ENZYMATIC HYDROLYSIS AND OPTIMIZATION OF PROCESS PARAMETERS

Bu çalışmada tavuk sternumundan enzimatik hidrolizasyon yöntemiyle sülfatlanmış glikozaminoglikan (GAG) ekstraksiyonu gerçekleştirilmiş ve optimum enzimatik hidrolizasyon işlem koşulu belirlenmiştir. İşlem koşullarının optimizasyonu için Yanıt Yüzey Yöntemi kullanılmıştır. Enzim miktarı, pH değeri, ekstraksiyon sıcaklığı ve süresi olarak seçilen dört parametrenin GAG verimi üzerindeki etkilerini açıklamak için Merkezi Kompozit Tasarımıyla oluşturulan deneme deseni uygulanmıştır. En yüksek GAG verimine en kısa ekstraksiyon süresi ve en az enzim miktarı ile ulaşmak hedeflenmiştir. Ekstraksiyon işlemi için en uygun işlem koşulları %0.6 enzim miktarı, 6.99 pH değeri, 62.96°C ekstraksiyon sıcaklığı ve 10.79 saat ekstraksiyon süresi olarak bulunmuştur. Bu koşullarda, ekstraksiyon verim değerinin %26.07 olması öngörülmüş ve deneysel olarak da doğrulanması sağlanmıştır.

Preliminary Study Of Nitrate Production By Plasma Discharge As Potential Fertilizer Material

Nitrogen-based fertilizer production mainly involves the Haber-Bosch process, which synthesizes Ammonia via a chemical reaction of N2 from the air and H2 under high temperature and pressure conditions in the presence of a catalyst. However, the environmental concern for greenhouse gas emissions and high energy consumption triggers other Nitrogen fixation method development. The non-thermal plasma oxidation of N2 into Nitrate is a promising method since it has lower energy consumption and a more suitable process condition with a better environmental profile. This study tested the designed plasma discharge reactor tube to produce nitrate from air N2 with varying voltage, time, and airflow rate operating conditions. Nitrate concentration was analyzed using a UV-Vis spectrophotometer. The results show that nitrate concentration changes linearly with the applied voltage in a constant airflow rate and length of treatment time. The highest performance of the plasma discharge reactor was achieved on a 6 kV applied voltage with a flow rate of 0.2 L/min and a treatment time of 40 minutes where the obtained nitrate concentration was 7.7 ppm, which indicated the potential plasma discharged nitrate production for green fertilizer application. Further study shall be carried out to enhance the performance.

Stochastic ice nucleation governs the freezing process of biopharmaceuticals in vials

Biopharmaceuticals commonly require freezing to ensure the stability of the active pharmaceutical ingredients (APIs). At commercial scale, freezing is typically carried out over the course of days in pallets comprising tens of thousands of vials. The selected process conditions have to ensure both complete freezing in all vials and a satisfactory manufacturing throughput. Current process design, however, is mainly experimental, since no mechanistic understanding of pallet freezing and its underlying phenomena has been achieved so far. Within this work, we derive a mechanistic modeling framework and compare the model predictions with engineering run data from the Janssen COVID-19 vaccine. The model qualitatively reproduced all observed trends and reveals that stochastic ice nucleation governs both process duration and batch heterogeneity. Knowledge on the ice nucleation kinetics of the formulation to be frozen thus is required to identify suitable freezing process conditions. The findings of this work pave the way towards a more rational design of pallet freezing, from which a plethora of frozen drug products may benefit. For this reason, we provide open source access to the model in the form of a python package (Deck et al., 2021).

Improvement of Pacific White Shrimp (Litopenaeus vannamei) Drying Characteristics and Quality Attributes by a Combination of Salting Pretreatment and Microwave

This study investigated the effects of salting pretreatment and microwave (MW) power on drying characteristics, water distribution and quality attributes of Pacific white shrimp (Litopenaeus vannamei). With increasing salt concentration (0–8%, w/v) and MW power (300–900 W), the drying time of shrimp was shortened by 15.15–28.57%, compared with the untreated samples. Regarding the quality of dried shrimp, increasing the salt concentration and MW power increased the hardness (from 13,073.6 to 24,556.5 g), while the springiness, color parameters and astaxanthin content showed an initial decrease but a later increase trend. Low field nuclear magnetic resonance (LF-NMR) demonstrated that the T2 curve of the pretreated samples moved toward the negative x-axis and the immobilized water content decreased with increasing salt concentration. E-nose showed that volatile components were different and could be obviously distinguished at different salt concentrations and MW powers. Raman spectroscopy illustrated that the protein secondary structure of dried shrimp was altered by salting pretreatment and drying conditions, and the lowest conversion degree of α-helix to β-sheet of dried shrimp was obtained at the salt concentration of 4% (w/v) and MW power of 500 W. By comprehensively considering the drying time and quality attributes, the combination of 4% (w/v) salt and 500 W MW power was concluded as the best drying conditions for shrimp using a microwave. The results could provide an innovative combination of salt pretreatment and MW drying with suitable processing conditions for producing high-quality dried shrimp.

Methodology and experimental validation of analytical melt pool models for laser powder bed fusion

Laser Powder Bed Fusion (LPBF) is a frequently used Additive Manufacturing (AM) technique for producing metal parts with complex shapes. One of the crucial factors in obtaining an optimal part is understanding the behaviour of the melt pool, a pool of liquid metal molten by a laser. Its size and shape are the result of a wide range of (processing) parameters, making it labour intensive and costly to identify an optimal processing range. To accelerate the identification of suitable processing conditions, this work presents a novel methodology that combines (semi-) analytical expressions of the melt pool width w and the aspect ratio R=d/w to compute the depth d over a large processing range. This range includes both conduction (R<1) and keyhole (R>1) mode melting regimes. The novelty of the presented approach is the prediction of absolute melt pool dimensions for both the conduction and keyhole regime. Furthermore, this methodology is extensively validated for three common LPBF materials: Titanium Ti-6Al-4V, Stainless Steel 316L and Inconel 718. The average errors obtained between model and experimental data of the melt pool width & depth in a relevant processing range (0,8<R<3) are 10,92% & 11,37%, 12,58% & 10,99% and 15,27% & 12,81% for the three materials respectively. With these results, this work shows that the proposed methodology performs well in predicting melt pool dimensions for a large processing range, both in terms of speed and accuracy.

Injection molding and characterization of microtextures on polycarbonate using laser textured inserts

ABSTRACT The purpose of this paper is to demonstrate the easy manufacturing and quick characterization of several microtextured functional surfaces on two transparent thermoplastics of general interest for several industrial sectors. Microtextured polymeric surfaces with special optical, tribological and easy-cleaning properties were manufactured via isothermal injection-molding using laser-microtextured steel mold inserts. For that purpose, conventional injection molding of two chosen amorphous transparent polymers (polycarbonate, PC, and polymethyl methacrylate, PMMA) utilizing laser-microtextured steel inserts was carried out, and a detailed morphological and functional characterization of the injected specimens was conducted later on. We also report on the suitable process conditions for the injection molding of these specimens using design of experiment (DOE) techniques. The analysis of the degree of replication (DR%) on the injected samples shows that mold temperature and injection speed are the most relevant parameters to obtain a successful replication and confirm the viability of conventional injection molding as a processing technique to obtain microtextured functional surfaces in amorphous transparent thermoplastics. The success of the procedure is further checked by the confirmation of the obtained surface functionalities by various standard and self-developed methods.

Optimization of Multiple W1/O/W2 Emulsions Processing for Suitable Stability and Encapsulation Efficiency.

Double emulsions are a type of multiple emulsions, which can be defined as a multicompartmentalized system where the droplets are dispersed into the continuous phase containing other emulsions. Although double food-grade emulsions have been manufactured, there is a lack of scientific background related to the influence of different processing conditions. This work analyses the influence of processing variables in (W1/O/W2) double emulsions: passes through the valve homogenizer, pressure applied, lipophilic emulsifier concentration, the ratio between the continuous phase (W2) and the primary emulsion (W1/O), and the incorporation of xanthan gum (XG) as a stabilizer. The results obtained show that these emulsions can be obtained after selecting suitable processing conditions, making them easily scalable in industrial processes. In terms of droplet size distribution, the input of higher energy to the system (20 MPa) during emulsification processing led to emulsions with smaller droplet sizes (D3,2). However, more monodispersed emulsions were achieved when the lowest pressure (5 MPa) was used. As for the number of passes, the optimal (emulsions more monodispersed and smaller droplet sizes) was found around 2–3 passes, regardless of the valve homogenizer pressure. However, emulsions processed at 20 MPa involved lower encapsulation efficiency (EE) than emulsions processed at 5 MPa (87.3 ± 2.3 vs. 96.1 ± 1.8, respectively). The addition of XG led to more structured emulsions, and consequently, their kinetic stability increased. The results obtained indicated that a correct formulation of these W1/O/W2 double emulsions allowed the optimal encapsulation of both hydrophilic and lipophilic bioactive compounds. Thus, the development of food matrices, in the form of multiple emulsions, would allow the encapsulation of bioactive compounds, which would result in the development of novelty food products.

Scale-up and mass transfer of the adsorption/desorption process of anthocyanins in amorphous silica

The purification and recovery of anthocyanins are important to maintain the stability of the purified solution, ensuring that the health-beneficial properties of this substance are not altered. This work aimed to obtain and compare solutions of commercial and natural grape and red cabbage anthocyanins, suitable process conditions, as well as purification and recovery through detailed analysis called two-stage, estimation of phenomenological parameters of mass transfer and scale-up using Bugram Protect® as amorphous silica. The adsorbent was characterized as amorphous and with a high silicon dioxide composition. The pH 3.0 potentiated the stability of flavylium cation in solution. The Freudlich isotherm represented the equilibrium data. The phenomenological parameters KE and Ds and the limiting step of mass transfer were estimated. Scale-up indicated dosages of adsorbents to meet the process specifications. This work presented additional results in phenomenological aspects and industrial scale in the recovery and purification of anthocyanins.

Biocatalytic System Made of 3D Chitin, Silica Nanopowder and Horseradish Peroxidase for the Removal of 17α-Ethinylestradiol: Determination of Process Efficiency and Degradation Mechanism.

The occurrence of 17α-ethinylestradiol (EE2) in the environment and its removal have drawn special attention from the scientific community in recent years, due to its hazardous effects on human and wildlife around the world. Therefore, the aim of this study was to produce an efficient enzymatic system for the removal of EE2 from aqueous solutions. For the first time, commercial silica nanopowder and 3D fibrous chitinous scaffolds from Aplysina fistularis marine sponge were used as supports for horseradish peroxidase (HRP) immobilization. The effect of several process parameters onto the removal mechanism of EE2 by enzymatic conversion and adsorption of EE2 were investigated here, including system type, pH, temperature and concentrations of H2O2 and EE2. It was possible to fully remove EE2 from aqueous solutions using system SiO2(HRP)–chitin(HRP) over a wide investigated pH range (5–9) and temperature ranges (4–45 °C). Moreover, the most suitable process conditions have been determined at pH 7, temperature 25 °C and H2O2 and EE2 concentrations equaling 2 mM and 1 mg/L, respectively. As determined, it was possible to reuse the nanoSiO2(HRP)–chitin(HRP) system to obtain even 55% EE2 degradation efficiency after five consecutive catalytic cycles.

Closing the loop: Valorizing pyrolyzed waste tyre residue into functional carbon materials, SiO2 with exceptionally high silanol groups, and Zn salt

This study aims to identify suitable processing conditions for converting pyrolytic solid residue from off-the-road tyres (OTR) to improve carbon materials properties that can be used in multiple applications and the recovery of minerals from OTR. Pyrolysis of OTR at 800 °C and a heating rate 2 °C.min−1 gave a carbon material with the highest surface area, most defective carbon structures, and the highest micro-porosity. This operating condition was used to compare the conventional three-step carbonization approach, which involves a demineralization stage that produces high volumes of toxic wastewater, with a two-step approach that bypasses this stage. Analysis of the carbon structures showed that the quality of the carbon material from the two-step approach is similar to the three-step approach. This two-step approach resulted in a solid and a liquid phase, in which ∼ 93.4% of Zn was selectively fractionated to the liquid phase. The wastewater from the acid wash of the carbonized OTR was neutralized to recover the SiO2, of which 55.5% was reactive SiO2. The SiO2 was found to have an exceptionally high cross-linking ratio of 5.94, achievable only when SiO2 is reacted with silane groups. The study demonstrated that the engineered carbon material from OTR has a H2 uptake of 1.03 wt% at 77 K and 1.2 bar, and the sulfonated counterpart was an effective catalyst (64% conversion) for the Aldol condensation of levunilic acid to two dimer products [tetrahydro-2- methyl-5,γ-dioxo-2-furanpentanoic acid (TMDFA) and 3-(2-methyl-5-oxo- tetrahydrofuran-2-yl)-4-oxopentanoic acid (MOTOA)] that are precursors for fuels and chemicals.

Effect of Dietary Protein and Processing on Gut Microbiota-A Systematic Review.

The effect of diet on the composition of gut microbiota and the consequent impact on disease risk have been of expanding interest. The present review focuses on current insights of changes associated with dietary protein-induced gut microbial populations and examines their potential roles in the metabolism, health, and disease of animals. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol was used, and 29 highly relevant articles were obtained, which included 6 mouse studies, 7 pig studies, 15 rat studies, and 1 in vitro study. Analysis of these studies indicated that several factors, such as protein source, protein content, dietary composition (such as carbohydrate content), glycation of protein, processing factors, and protein oxidation, affect the digestibility and bioavailability of dietary proteins. These factors can influence protein fermentation, absorption, and functional properties in the gut and, consequently, impact the composition of gut microbiota and affect human health. While gut microbiota can release metabolites that can affect host physiology either positively or negatively, the selection of quality of protein and suitable food processing conditions are important to have a positive effect of dietary protein on gut microbiota and human health.

Evaluation of the interfacial adhesion between polymer and metal on polymer-metal hybrids

Up to now there is no measuring method to quantify the interfacial adhesion between metal and polymer on hybrid parts. The present paper suggests a possible solution. With regard to interfacial tightness, the investigation on both a monolithic and a hybrid test specimen with a helium vacuum leakage measurement proved to be target-oriented for evaluating interfacial adhesion. The recording of the helium leakage rate over test duration enables the determination of a tight and thus well-adhering bond between polymer and metal. The results show that the previous consideration of absolute values instead of the time course of the leakage rate is not useful for determining a gap-free and thus tight interface, since gaps in the microscale result in a correspondingly low leakage rate. The determination of the leakage rate on both specimens allows the separation between measurand falsifying permeation rate and actual interfacial leakage rate. Therefore, gap-free interfaces from different material combinations can be compared regarding their true adhesion performance. On the other hand, microscopic studies of the interfacial zone as well as mechanical testing of the interfacial strength do not provide complete information on interfacial adhesion, micrographs especially can present interpretation confusing artefacts. The new developed and presented method will enable research into compatible material combinations, effective adhesion modifications and suitable processing conditions for improving interfacial adhesion between polymer and metal.