Mechanical Homogenization Research Articles

Techno-Economic Analysis of the Multiple-Pass Ultrasonication with Mechanical Homogenization (MPUMH) Processing of Processed Carrot Discards to Puree.

A sustainable valorization process for puree processing from processed carrot discards (PDCs) was proposed by using multiple-pass ultrasonication with mechanical homogenization (MPUMH), optimized at 9 min ultrasonication followed by mechanical homogenization for 1 min, subjected to three passes. Techno-economic analysis of the puree processing plant was studied for two process models using SuperPro Designer for a plant with a capacity of 17.4 MT/day, operational for 26 weeks, with a 20-year lifetime. The two scenarios were (i) base case (PDCs processed without peels and crowns) and (ii) case 2 (PDCs and carrots (50:50, w/w) processed with peels and crowns). Both scenarios were economically feasible with an internal rate of return (IRR) and return on investment (ROI) at 24.71% and 31.04% (base case) and 86.11% and 119.87% (case 2), respectively. Case 2 had a higher total capital investment (Can$13.7 million) but a lower annual operating cost (Can$8.9 million), resulting in greater revenue generation (Can$29.7 million), thus offering a higher ROI. Sensitivity analysis related to the number of passes on puree quality and price is suggested to lower the capital investment. For the base case, a lower ROI was due to the high labor cost incurred for manual peeling of PDCs, indicating the critical need for developing a commercial peeler equipped to cut labor costs and increase profitability. The study casts insights into the techno-economic performance of a sustainable process for the valorization of PDCs.

Effect of maleic anhydride compatibilizer addition on mechanical properties of polylactic acid (PLA)/cellulose acetate (CA) composites film

Environmental problems caused by the use of undegradable conventional plastics are still the major issue. According to the Badan Pusat Statistik (BPS) in 2021, plastic waste in Indonesia accumulated as much as 66 million tons per year and is expected to raise gradually. PLA and CA, derived from renewable resources, are biodegradable, thermoplastic, resistant to pressure, and are often used as raw materials for the manufacture of composite plastics. PLA is hydrophobic and CA is hydrophilic, so a compatibilizer is needed as a substance that can improve the mechanical properties, compatibility, and homogeneity of the resulting composite film. This research aims to obtain the ratio of PLA/CA and the concentration of maleic anhydride (MA) compatibilizer to produce PLA/CA composites film with good mechanical strength and according to packaging material standards. The method in this research is solvent casting by synthesizing composite films through sample preparation, modification of CA with MA, grafting of PLA/CA and MA, synthesis of composite films of PLA/CA and MA, as well as several characteristic tests. The results showed that the obtained films were identified as having PLA, CA, and MA, had a relatively smooth surface and were degraded at a temperature treatment of 543 o C. The best film was obtained from mass variations of PLA/CA and MA (6:4:1.5 gram) with a tensile strength of 7.38 MPa, and elongation at break reached 18.11% and met the packaging standard values by Japanese Industrial Standard (JIS).

A novel method for creation of complex microstructure cells through artificial molecular dynamics simulations

Composites have a spectrum of mechanical behavior resulting from uncertainty and variation in the microstructure shape and position. With microstructural simulation of fiber architectures, complex numerical algorithms are needed to enforce boundary constraints such as fiber-to-fiber overlap or periodic boundary conditions. Variations are not typically modeled because randomization of unique aggregate shapes can be challenging and current methods for doing so do not achieve high fiber volume fraction (FVF) when packing; however, this can cause inaccurate predictions in simulations. To address this challenge, a novel approach is developed using Molecular Dynamics (MD), achieving high FVFs up to 85% with rapid speed, easy user implementation, and a potential for capturing non-uniform fiber geometry. Two types of packing are presented to demonstrate the scope of possibilities with this approach: a post randomization molecular dynamics (PRMD) method for uniform fibers, and a mixed aggregate randomization using varying radii circles. Comparisons between periodic hexagonal, randomized, and variable radii packing fiber microstructures are performed to determine the significance of randomization and non-uniform aggregate shape for mechanical property homogenization and damage prediction in a unidirectional laminate. It was found that homogenization between the three microstructures do not vary from randomization; however, using the molecular dynamics approach randomizing fiber position and aggregate shape resulted in significant differences in predicting the transverse damage initiation, reducing the error by approximately 25% from the periodic method.

Facile nanofibrillation of strong bamboo holocellulose via mild acid-assisted DES treatment

A facile and sustainable strategy for preparing bamboo holocellulose nanofibrils (HCNFs) via zinc acetate/ choline chloride deep eutectic solvents treatment assisted with mild acetic acid (HAc) was developed in the present work. The treatment was performed under fast microwave irradiation and followed by mechanical homogenization , resulting in HCNFs with considerable amounts of xylan hemicellulose (15 %−19 %) remained. Less HAc consumption was achieved, which is beneficial for fabricating nanofibrils with higher aspect ratios (>800). More xylan contents and higher degrees of acetylation on cellulose were investigated, resulting in greater charge repulsion and steric hindrance between HCNFs and favoring the fibrils dissociation. Moreover, the HCNFs maintained high crystallinity of 70 %− 80 % and good thermal stability, confirming the intact hydrogen bonding linkages between cellulose and xylan hemicellulose. Transparent films prepared from the HCNFs suspensions by vacuum drying approach displayed better mechanical strength (>40 MPa) and well-mimicked the complex of polysaccharides interactions in plant cell walls. • Bamboo HCNFs were prepared by ZnAc/ChCl DES with mild HAc and microwave assistance. • Acetylation and charge repulsion favored the holocellulose nanofibrillated. • Higher DES ratios fabricated HCNFs with greater aspect ratios and xylan content. • HCNFs films present high transparency and improved mechanical strength.

One-pot preparation of superhydrophobic polydimethylsiloxane-coated cotton via water/oil/water emulsion approach for enhanced resistance to chemical and bacterial adhesion

The current work reports a green and straightforward preparation of superhydrophobic cotton coated with polydimethylsiloxane (PMDS) via the water/oil/water (W/O/W) emulsion approach. The W/O/W emulsion containing Polyvinyl alcohol (PVOH)-water as the internal phase, PDMS as the dispersed phase, and water as the continuous phase is prepared in less than 5 min through a simple mechanical homogenization using PVOH as an emulsifying agent. The PDMS coating was prepared via the dip-coating of cotton fabric in the emulsion, followed by the heat treatment. The use of emulsion allows a uniform formation of PDMS coating on the fabric surface while minimizing the used coating amount. The prepared cotton sample has an excellent superhydrophobicity with a water contact angle (WCA) of up to 169°. The prepared cotton effectively resisted the adhesion of and penetration of acidic and moderate-basic solutions. It also exhibited enhanced resistance against bacterial adhesion, whereby the number of bacteria adhering to the sample surface is reduced by many folds compared to untreated cotton. The PVOH concentration and the emulsion shelf time significantly impact the superhydrophobicity of the prepared sample.

A new strategy for metal additive manufacturing using an economical water-atomized iron powder for laser powder bed fusion

We develop a pre-alloyed water-atomized (WA) iron powder for laser powder bed fusion (LPBF)-based 3D printers; such a powder has never been used for 3D printing. The powder features low levels of nano-sized Cu-Ni-Mo; these alloying elements are placed into the concavities of the iron powder. When these powders were used for LPBF printing, the processing window for the volumetric energy density ranged from 93 to 130 J/mm3. However, careful control of laser power (150 – 225 W) and scan speed (500 – 900 mm/s) was essential. In terms of production, a maximum relative density of 99.67% was achieved upon application of an energy density of 108 J/mm3 (175 W, 700 mm/s). An average hardness of 217.1 ± 4.7 HV was obtained, exhibiting stable standard deviations and confirming excellent mechanical homogeneity. Energy-dispersive X-ray spectroscopy mapping revealed excellent chemical homogeneity; this translated to good mechanical homogeneity because of the uniform mixing of the nano-sized alloying elements. The printed tensile bars were stable and of a relatively high aspect ratio. Tensile strength measurements revealed that samples prepared using the partially pre-alloyed iron powder were better than those fabricated from simple raw WA iron powder; the former samples exhibited an ultimate tensile strength (UTS) of 460.91 MPa with elongation of 6.98% and the latter a UTS of 197.15 MPa with elongation of 0.45%. Therefore, the pre-alloyed WA iron powder developed in this study can successfully be used in LPBF and presents a more cost-effective alternative to traditional gas atomized iron powders.

Microstructure refinement in biodegradable Zn-Cu-Ca alloy for enhanced mechanical properties, degradation homogeneity, and strength retention in simulated physiological condition

• The first application of ultrasonic treatment (UST) for microstructure refinement in biodegradable Zn alloy. • UST processing eliminated the cracked and segregated CaZn 13 phase in Zn-Cu-Ca alloy after hot rolling. • The UST-processed Zn-Cu-Ca alloy indicated improved mechanical properties. • The corrosion of UST-Zn-Cu-Ca alloy is more uniform than the non-UST counterpart under the similar corrosion rate. • The uniform degradation mechanism favour the strength retention of UST-Zn-Cu-Ca alloy in vitro . Zn-1.0Cu-0.5Ca (TA15) alloy has shown promising characteristics of enhanced mechanical properties and biodegradability for absorbable cardiovascular stents, endovascular devices, and wound closure devices applications. In this study, the TA15 alloy for bioabsorbable biomedical applications is investigated. In the conventionally cast TA15 (TA15-C) alloy, CaZn 13 phase are present as a large dendritic network with an average size of 73.25 ± 112.84 μm. Hot rolling of the TA15-C alloy has broken the long and dendritic network of the CaZn13 phases, however, the refined phases are observed as segregations and the distribution is non-uniform. These segregated CaZn 13 suffered heavy localised corrosion which lead to poor mechanical properties in the as-fabricated condition and after biodegradation. Ultrasonic treatment (UST) during casting is identified as an effective technique for the refinement and redistribution of CaZn 13 particles in TA15 alloy, which successfully reduce the size of the CaZn 13 phase to 10.91 ± 4.65 μm in the as-solidified condition. After hot rolling, the UST processed TA15 (TA15-UST) shows improved mechanical properties due to grain refinement and the reduction in microstructural defects, i.e. the broken CaZn 13 phase. Results of 8-week immersion corrosion tests showed that both alloys possess very similar corrosion rate. However, TA15-UST has markedly improved corrosion homogeneity compared to TA15-N which favours the retention of mechanical properties even after prolonged exposure to physiological fluids.

Extraction and Isolation of Cellulose from Cladodes of Cactus Opuntia Ficus-Indica

Cellulose is the most abundant material in the earth, it is considered a renewable polymer of the cell walls of wood and plant cells, their interest and their use in different field is the purpose of extracting it namely: cellulose native (cotton), the transformation of cellulose into sheets (paper and filter paper), cupric cellulose, zinc cellulose (industrial applications), the functionalization of cellulosic materials in the field of printed electronics, textile, treatment, medicine, and agribusiness. The objective of this study, is the extraction of cellulose at several stages and recovery of a waste based on old cactus rackets, type Opuntia ficus -indica smooth. The cellulose extracted showed good isolation, dispersion and purification of nanofibrils by the removal of oils, mucilage, pectins, hemicellulose and coloring substances. The substitution of ethanol by acetone in the extraction protocol used [1], gave suspensions of purified cell walls is well individualized, on the other hand the cellulose extracted from the beet pulp, chuck pulp prickly pear fruit peel requires a mechanical homogenizer.

Hybrid Microwave Solid-Phase Synthesis of Wollastonite Based on Natural Renewable Raw Materials

A method was tested to perform the solid-phase synthesis of ceramic wollastonite under hybrid microwave heating using such natural renewable raw materials as sea shells as a source of CaCO3 with the addition of commercial SiO2 powder. The XRD, SEM, TGA, and EDS methods were used to explore the effect of the mechanical homogenization time and the conditions for the chemical interaction of raw materials, provided that the required phase composition is reached. It was studied how temperature (800–1150°C) and time (15–60 min) of sintering affect the composition and structure of the ceramic wollastonite samples, including those in the presence of the strengthening additive sodium tetraborate. The formation of an apatite (Ca10(PO4)6(OH)2) layer on the surface of the obtained samples under conditions of their contact with artificial human blood plasma was assessed to confirm the biocompatible properties of these materials. The proposed method of synthesis is promising for obtaining a chemically pure valuable biomaterial in the form of synthetic wollastonite with the possibility of rational use of biogenic raw materials.

THE STUDY ON GLUE-APPLYING METHODS AND HOT-PRESSING TECHNOLOGY OF PARALLEL STRAND LUMBER

Parallel strand lumber (PSL) was manufactured from the veneer strand cut from the poplar broken veneers of the plywood enterprises, by analyzing the influence of the size of veneer strands, the glue concentration and glue-applying time on the glue-absorbing amount of veneer strands, the influence of three different glue-applying was, hot-pressing time and temperature on the physical and mechanical properties of PSL was reviewed and the hot-pressing technology was optimized. The experiment results showed that the size of the veneer strands have not notableinfluence on the gluing-absorbing amount, and mainly affect the homogeneity and appearance quality of the product. The glue concentration is one main factor to affect theglue-absorbing amount of veneer strands and PF resin of 30% concentration was chosen. The glue-applying way is the main factor to affect the mechanical property of PSL. Thehot-pressing time and temperature have significant influence on physical and mechanical properties of PSL. Comprehensively considering, the physical and mechanical properties and homogeneity of products are better using the veneer strands with 100 mm length, theglue-spraying way and hot-pressing technology with the time 35 min and thetemperature of 150°C.

Combination of Micelle Collapse and CuNi Surface Dissolution for Electrodeposition of Magnetic Freestanding Chitosan Film.

Magnetic chitosan hydrogel has aroused immense attention in recent years due to their biomedical significance and magnetic responsiveness. Here, A new electrodeposition method is reported for the fabrication of a novel CuNi-based magnetic chitosan freestanding film (MCFF) in an acidic chitosan plating bath containing SDS-modified CuNi NPs. Contrary to chitosan’s anodic and cathodic deposition, which typically involves electrochemical oxidation, the synthetic process is triggered by coordination of chitosan with Cu and Ni ions in situ generated by the controlled surface dissolution of the suspended NPs with the acidic plating bath. The NPs provide not only the ions required for chitosan growth but also become entrapped during electrodeposition, thereby endowing the composite with magnetic properties. The obtained MCFF offers a wide range of features, including good mechanical strength, magnetic properties, homogeneity, and morphological transparency. Besides the fundamental interest of the synthesis itself, sufficient mechanical strength ensures that the hydrogel can be used by either peeling it off of the electrode or by directly building a complex hydrogel electrode. Its fast and easy magnetic steering, separation and recovery, large surface area, lack of secondary pollution, and strong chelating capability could lead to it finding applications as an electrochemical detector or adsorbent.

In Situ Preparation of High‐Quality Flexible Manganese‐Halide Scintillator Films for X‐Ray Imaging

AbstractEnvironmentally friendly metal halides have emerged as emitters in lighting and X‐ray imaging applications. However, the conventional scintillator fabrication process involves high‐temperature sintering or powder grinding, resulting in large bulk crystals or agglomerates, which hamper flexible device integration and processability. Here, large‐area flexible scintillation screen films containing (C24H20P)2MnBr4 nanocrystals are prepared in situ, which prevents the generation of agglomerated powders or large bulk crystals, and the preparation duration and cost are reduced. The film exhibits good mechanical stability and homogeneity, and the photoluminescence quantum yield is over 85%. Moreover, the film presents excellent scintillation performance with detection limit as low as 0.608 μGyair s−1 and 14.5 lp mm−1 X‐ray imaging resolution. This excellent performance and simple preparation method are expected to favor industrial mass production.

Application of Novel Processing Method (Multiple-Pass Ultrasonication with Mechanical Homogenization) for Producing Puree from Processed Carrot Discards

Application of Novel Processing Method (Multiple-Pass Ultrasonication with Mechanical Homogenization) for Producing Puree from Processed Carrot Discards

Soil Penetration Resistance Influenced by Eucalypt Straw Management under Mechanized Harvesting

This study aimed to evaluate the impacts of mechanized harvesting and soil tillage on soil penetration resistance (PR), influenced by the eucalypt straw management under sandy clay Oxisol in Southern Brazil. The study was conducted in a eucalyptus production area under Oxisol in Paraná State, Brazil. The treatments consisted of two harvesting systems: harvester + forwarder (HF) and feller + skidder (FS) both applied in areas under coppicing and stand renewal eucalypt cultivation systems. For stand renewal areas, eucalypt straw was managed on the soil surface at levels of 100, 50, and 0% before soil tillage. PR and soil moisture measurements were made in points distributed in regular grid for all treatments. This grid also was used to evaluate the geospatial behavior of PR in the stand renewal areas. During the measuring of PR, the averages (± confidence interval) of soil moisture up to 0–0.60 m depth were 0.20 ± 0.01 and 0.24 ± 0.01 in coppicing and stand renewal areas, respectively. In areas under coppicing, the PR mean ± confidence interval at 0–0.05 m layer in HF (1.28 ± 0.24 MPa) was lower than in FS treatment (2.11 ± 0.44 MPa). However, the PR values were similar between treatments in stand renewal areas, regardless of the forest straw level on the soil surface. For both harvesting systems, there was a lack of spatial dependence of PR up to 0.40 m soil depth, indicating some physical and mechanical homogenization induced by the soil tillage in the layer. Eucalypt straw contributed to mitigating effects of harvest traffic on PR level in coppicing forest systems. However, different levels of eucalypt straw managed before soil tillage did not influence PR levels in stand renewal forest systems.

Nanocellulose with unique character converted directly from plants without intensive mechanical disintegration

TEMPO oxidized nano-fibrillated cellulose (TONFC) has been used in different applications including biomedical, packing materials, paints and cosmetics because of its higher transparency, mechanical properties and better biocompatibility. However, pulping is always required to remove lignin and hemicellulose, and high-energy homogenization is required to defibrillate cellulose bundle into filament. Therefore, it is desirable to find a novel way to get TONFC with high carboxyl content without intensive mechanical disintegration. In this work, nanocellulose (TOHOLO) with higher carboxyl groups (2.2 ± 0.2 mmol/g) and smaller size (length = 400–685 nm and diameter = 5.9 nm) was prepared by a two-step strategy without intensive mechanical homogenization. In addition to the advantages in terms of diameter and carboxyl groups, TOHOLO showed better transparency and re-dispersibility as well as higher mechanical properties (122.8 MPa) compared to previous reports. Furthermore, for high carboxyl group and dispersibility, the TOHOLO can be used as a reinforcing filler to fabricate nanocomposites. The reinforced PVA fibers show a tensile strength of 484.4 MPa, which is about 170 % higher than comparison samples (PVA/TOCN-M, 291.9 MPa).

Resource efficient collagen extraction from common starfish with the aid of high shear mechanical homogenization and ultrasound

Processes currently used for collagen extraction are complicated requiring a great deal of time and chemicals. Here, high shear mechanical homogenization (HSMH) and ultrasound (US) were integrated in the pretreatment step of collagen extraction from common starfish to reduce chemical use and time consumption. Effects of the assistant technologies on yield, structural integrity and functionality of collagen were also investigated. HSMH reduced the deproteinization time from 6 h to 5 min and its required amount of alkali 4 times, compared with classic methods. HSMH + US reduced the demineralization time from 24 h to 12 h and improved its efficiency in extraction of minerals. Collagen extraction with HSMH and HSMH + US resulted in similar yield as the classic method and did not affect triple helical structural integrity, polypeptide pattern, thermal stability or fibril-formation capacity of the collagens. Altogether, HSMH and US can effectively improve resource efficiency during collagen extraction without imposing negative effect on collagen quality.

Architected cellular fiber-reinforced composite

Advances in 3D printing have enabled fabrication of rationally-designed cellular architectures out of fiber-reinforced composites, offering a new class of low-density high-performance materials with multifunctional properties unattainable with either of their constituent composites or the underlying cellular architectures. In this study, efficacy of the hierarchical material design approach is investigated by creating various periodic fiber-reinforced representative cells and evaluating effects of fiber volume fraction , fiber length , fiber orientation, and cell topology on their effective thermo-mechanical properties using multiscale standard mechanics homogenization with periodic boundary conditions. The incorporated approach is finally corroborated by comparing the numerical and experimental data for the Young's moduli of cellular metamaterials with tunable isotropic/anisotropic thermo-mechanical properties, 3D printed out of pure and carbon-fiber-reinforced PETG polymer.

Tissue Sampling and Homogenization with NIRL Enables Spatially Resolved Cell Layer Specific Proteomic Analysis of the Murine Intestine.

For investigating the molecular physiology and pathophysiology in organs, the most exact data should be obtained; if not, organ-specific cell lines are analyzed, or the whole organ is homogenized, followed by the analysis of its biomolecules. However, if the morphological organization of the organ can be addressed, then, in the best case, the composition of molecules in single cells of the target organ can be analyzed. Laser capture microdissection (LCM) is a technique which enables the selection of specific cells of a tissue for further analysis of their molecules. However, LCM is a time-consuming two-dimensional technique, and optimal results are only obtained if the tissue is fixed, e.g., by formalin. Especially for proteome analysis, formalin fixation reduced the number of identifiable proteins, and this is an additional drawback. Recently, it was demonstrated that sampling of fresh-frozen (non-fixed) tissue with an infrared-laser is giving higher yields with respect to the absolute protein amount and number of identifiable proteins than conventional mechanical homogenization of tissues. In this study, the applicability of the infrared laser tissue sampling for the proteome analysis of different cell layers of murine intestine was investigated, using LC–MS/MS-based differential quantitative bottom-up proteomics. By laser ablation, eight consecutive layers of colon tissue were obtained and analyzed. However, a clear distinguishability of protein profiles between ascending, descending, and transversal colon was made, and we identified the different intestinal-cell-layer proteins, which are cell-specific, as confirmed by data from the Human Protein Atlas. Thus, for the first time, sampling directly from intact fresh-frozen tissue with three-dimensional resolution is giving access to the different proteomes of different cell layers of colon tissue.

Elastic stress transfer model and homogenized constitutive equation for the multi-phase geomaterials

Multi-phase geomaterials can be classified as the particulate composites composed of finer matrix and dispersed inclusions. With the extremely nonuniform stress and strain field, prediction of the overall mechanical response from the known mechanical properties and mixed proportion of constituents is a challenging task for multi-phase geomaterials. In this paper, using a concentric composite cylinder as the equivalent representative volume element (RVE), the analytical solutions of stress transfer model are derived from the modified shear-lag analysis. Through the mechanical homogenization of internal stress/strain field, a constitutive equation has been established in the elastic regime, containing a closed-form solution (S-L method) for prediction of effective Young's modulus (EHom). By the comparison with classical models, numerical simulations and experimental results, the homogenized constitutive equation (EHom) has been validated. Meanwhile, parametric studies of proposed solutions have been conducted to discuss the effect of meso-mechanical variables (e.g., mechanical contrast and volume proportion of constituents) on the stress transfer mechanism and the overall mechanical response, providing the useful insights and explanations to previous studies.

Tween 20 Stabilized Conventional Heavy Crude Oil-In-Water Emulsions Formed by Mechanical Homogenization

This study investigated the preparation of stable conventional heavy crude oil-in-water (O/W) emulsions by mechanical homogenization with the addition of a non-ionic surfactant, Tween-20. A four-factor, five-level central composite design was carried out to investigate the effects of four independent variables, including mixing intensity (4,000–10,000 rpm), mixing duration (5–45 min), water salinity (0–40 g/L), and the concentration of emulsifier (0.1–2.1 wt%) on the emulsion stability. Emulsion stability was determined by quantification of creaming index, turbidity change rate, and average oil droplet size. The results demonstrated that the salinity of 30 g/L, mixing intensity of 8,500 rpm, mixing duration of 35 min, and emulsifier concentration of 1.6 wt% led to the formation of the most stable emulsion.