Significant Changes In Texture Research Articles

Graphene-Wine Waste Derived Carbon Composites for Advanced Supercapacitors

In this work, we investigate the potential of a novel carbon composite as an electrode for high-voltage electrochemical double-layer capacitors. The carbon composite was prepared following a sustainable synthetic approach that first involved the pyrolysis and then the activation of a precursor formed by winery wastes and graphene oxide. The composite prepared in this way shows a very high specific surface area (2467 m2·g−1) and an optimum pore size distribution for their use in supercapacitor electrodes. Graphene-biowaste-derived carbon composites are tested as active electrode materials in two different non-aqueous electrolytes, the ammonium salt-based conventional organic electrolyte and one imidazolium-based ionic liquid (1 M Et4NBF4/ACN and EMINTFSI). It was found that the presence of graphene oxide led to significant morphological and textural changes, which result in high-energy and power densities of ~27 W·h·kg−1 at 13,026 W·kg−1. Moreover, the devices assembled retain above 70% of the initial capacitance after 6000 cycles in the case of the organic electrolyte.

Static Recrystallization Behavior and Texture Evolution during Annealing in a Cold Rolling Beta Titanium Alloy Sheet

In this study, the cold rolling microstructure and static recrystallization mechanism of the high strength titanium alloy Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe were systematically investigated. Results show that the cold rolling microstructure is mainly composed of the elongated deformed β grains containing micro-shear bands. After annealing at 815 °C for 2 min, the fine SRXed grains are observed, mainly concentrated in the micro-shear band, the grain boundary and the interior of the deformed grain. The sub-grain structure obtained by static recovery inside the deformed grain produces continuous SRX during the annealing treatment. Meanwhile, geometric and discontinued SRXed grains are also observed in the large deformed β grain and at the trigeminal grain boundaries, respectively. Many ultra-fine grains appear inside the micro-shear band, exhibiting a phenomenon of the micro-shear band assisting SRX. With the increase in the annealing holding time, the elongated β grains are significantly refined and the degree of recrystallization is continuously improved. In addition, the recrystallization behavior also results in a significant change in the fiber texture. With the extension of the annealing holding time, the rolling texture type evolves gradually, with the {111} <112> γ-fiber texture to weak α-fiber, γ-fiber, and Goss-fiber.

Clinical performance of nano-hydroxyapatite-modified glass ionomer cements in class V cavities: split mouth, randomized controlled trial

BackgroundTo evaluate the effect of modifying conventional glass ionomer (CGIC) and resin-modified glass ionomer (RMGIC) with nano-hydroxyapatite (Nano-HA) on their clinical performance as restorations for class V cavities.MethodsThe wet-chemical precipitation method was utilized to prepare the nano-hydroxyapatite particles. Nano-HA was then characterized using Scanning Electron Microscopy, Elemental Dispersive X-ray and thermal gravimetric analysis. Five wt% of the nano-hydroxyapatite (Nano-HA) was then incorporated into the powder portion of the CGIC and RMGIC. Sixty Class V cavities were prepared in thirty patients with at least two cervical caries lesions. Prepared cavities were restored using the tested materials. Modified United States Public Health Service (USPHS) criteria were used to evaluate the restorations at base line, after three, six and nine months.ResultsRegarding the investigated modified USPHS criteria, the tested restorative materials showed no statistically significant difference throughout the study period. While color match, surface texture and marginal integrity criteria showed a statistically significant change in nano-HA-GIC. Surface texture and marginal integrity showed a significant change with CGIC. A significant change in surface texture was only found with nano-HA-RMGIC.ConclusionsThe investigated restorative materials showed an equivalent clinical performance at the nine months follow-up.

4D microstructural evolution in a heavily deformed ferritic alloy: A new perspective in recrystallisation studies

We present a multiscale study on the recovery and recrystallisation of a heavily deformed (85% reduction in size) Fe–Si–Sn alloy using a combination of dark field X-ray microscopy (DFXM), synchrotron X-ray diffraction (SXRD) and electron backscatter diffraction (EBSD). By utilizing DFXM, we focus on a grain within the high stored energy (HSE) regions, and track it through consecutive isothermal annealing steps. The intra-granular structure of the as-deformed grain reveals deformation bands separated by ≈3–5∘ misorientation. During the early stages of annealing, cells with 2–5∘ misorientation form while new nuclei appear. The recrystallized grains nucleate near prior grain boundaries, having a typical internal angular spread of <0.05∘. The SXRD results suggest no significant macroscopic texture change after annealing for 1400s at 610∘C in the HSE regions. All results indicate that higher misorientation zones such as grain boundaries or junction points of deformation bands are preferential nucleation regions.

Microstructure Development of Cu/SiO₂ Hybrid Bond Interconnects After Reliability Tests

The focus of this study is a detailed characterization of hybrid Cu/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> wafer-to-wafer bonding interconnects after reliability testing. Hybrid bonding (or direct bond interconnect) is a technology of choice for fine pitch bonding without microbumps. The main challenge of the hybrid bonding technology is the preparation of a clean Cu/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> surface with controlled Cu dishing. The Cu/Cu interface after hybrid bonding and after reliability testing was investigated by electron backscatter diffraction (EBSD) in this study. The Cu interconnects (diameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4 ~\mu \text{m}$ </tex-math></inline-formula> and pitch <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$18 ~\mu \text{m}$ </tex-math></inline-formula> ) enclosed by SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> were formed by wafer-to-wafer bonding. The small diced stacks were used for subsequent reliability tests. Three types of tests were carried out: temperature shock test (TST) at −40 °C/125 °C up to 1000 cycles, isothermal storage at 150 °C, 300 °C, and 400 °C, and multiple bonding cycles. The results include a comprehensive estimation of the changes in grain diameter, grain boundaries, and texture of the interconnects. All samples showed good reliability and stayed intact after all tests. Grain refinement was observed after TST, storage at 150 °C, and multiple bonding cycles compared to the state after bonding. Grain growth was found for the storage at 300 °C/400 °C (up to 6 h). No significant changes in texture was found after the reliability tests. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\langle 111\rangle $ </tex-math></inline-formula> direction with its characteristic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\langle 115\rangle $ </tex-math></inline-formula> twin orientation is the dominating orientations perpendicular to the bonding interface. The migration of 60° twin boundaries has been observed after reliability testing. The results indicate a rotation toward nearby high-angle grain boundaries (HAGBs, 60°–45°).

Effect of incorporation of nano-hydroxyapatite particles on the clinical performance of conventional and resin-modified glass ionomer cement in class V cavities: split-mouth, randomized controlled trial

BackgroundThe aim of this study was to compare the clinical performance of Nano-hydroxyapatite-modified conventional glass ionomer cement (NHA-GIC) and Nano-hydroxyapatite-modified resin-modified glass ionomer cement (NHA-RMGIC) with conventional glass ionomer (CGIC) and resin-modified glass ionomer (RMGIC) in the treatment of caries class V cavities. Sixty patients with at least two cervical caries lesions participated in this study. A total of 120 class V cavities were prepared and then restored using different restorative materials. Restorations were clinically evaluated according to modified United States Public Health Service criteria at baseline and after 3, 6 and 9 months.ResultsThere was no statistically significant difference in the clinical performance of the different restorative materials at any of the follow-up periods. However, throughout the study period there was a statistically significant change in the color match, surface texture and marginal integrity in NHA-GIC. A statistically significant change in the surface texture and marginal integrity was found in GIC. On the other hand, there was only a statistically significant change in surface texture in NHA-RMGIC.ConclusionsAll tested restorative materials, control (CGIC and RMGIC) as well as experimental (NHA-GIC and NHA-RMGIC), exhibited comparable clinical performance after 9 months follow-up.

Gastrophysical and chemical characterization of structural changes in cooked squid mantle.

Squid (Loligo forbesii and Loligo vulgaris) mantles were cooked by sous vide cooking using different temperatures (46°C, 55°C, 77°C) and times (30 s, 2min, 15min, 1 h, 5h, 24h), including samples of raw tissue. Macroscopic textural properties were characterized by texture analysis (TA) conducted with Meullenet-Owens razor shear blade and compared to analysis results from differential scanning calorimetry. The collagen content of raw tissues of squid was quantified as amount of total hydroxyproline using ultra-high-performance liquid chromatography. Structural changes were monitored by Raman spectroscopy and small-angle X-ray scattering and visualized by second harmonic generation microscopy. Collagen in the squid tissue was found to be highest in arms (4.3% of total protein), then fins (3.0%), and lowest in the mantle (1.5%), the content of the mantle being very low compared to that of other species of squid. Collagen was found to be the major protein responsible for cooking loss, whereas both collagen and actin were found to be key to mechanical textural changes. A significant decreased amount of cooking loss was obtained using a lower cooking temperature of 55°C compared to 77°C, without yielding significant textural changes in most TA parameters, except for TA hardness which was significantly less reduced. An optimized sous vide cooking time and temperature around 55-77°C and 0.5-5h deserves further investigation, preferably coupled to sensory consumer evaluation. PRACTICAL APPLICATION: The study provides knowledge about structural changes during sous vide cooking of squid mantle. The results may be translated into gastronomic use, promoting the use of an underutilized resource of delicious and nutritious protein (Loligo vulgaris and Loligo forbesii).

Effect of baking powder as a substitute of pork lard on the texture of Mexican tamales

In order to encourage the efforts of nutritionists and public policies to reduce the caloric value of traditional food, and to increase the knowledge about Mexican and Latin American traditional cuisines, the aim of this study was to evaluate the effect of fat reduction and its replacement with a leavening agent on the texture properties of Mexican tamales. Through a full factorial 22 experimental design, the combined effect of pork lard and baking powder on tamales texture properties was evaluated. The levels of each factor were 0.0 and 27.3 g of pork lard and 0.0 and 0.68 g of baking powder per 100 g of tamales dough including a central experimental unit (13.65 g of pork lard and 0.34 g baking powder per 100 g of tamales dough). The decrease in pork lard causes a significant increase in tamales chewiness. However, baking powder prevents the chewiness increase caused by the decrease in tamales fat content slightly affecting their adhesiveness. At the highest level of pork lard, baking powder does not cause significant changes in tamales texture but in the absence of fat, the leavening agent causes a desirable texture, similar to the traditional texture of these food products. Fat globules, identified by light microscopy, surround the starch granules and may be the cause of the increase in tamales adhesiveness.

Quality and Shelf Life of White Shrimp (Litopenaeus vannamei) Processed with High-Pressure Carbon Dioxide (HPCD) at Subcritical and Supercritical States

Phase changes of carbon dioxide (supercritical or subcritical) depend on its proximity to a pressure of 7.35 MPa and temperature of 31.1°C. Carbon dioxide becomes supercritical and subcritical when it is above and slightly below its critical point, respectively. This study aims to determine the effect of high-pressure CO2 treatments at a pressure of 900 psi, 950 psi (subcritical), and 1100 psi (supercritical) and at holding times of 5, 10, and 15 min on the quality parameters of white shrimp (Litopenaeus vannamei) and to determine the shelf life of white shrimp processed with the best treatment. The results showed that the interaction between pressure and holding time had a significantp&lt;0.05effect on cholesterol, protein, moisture content, andb∗value, but pressure had a significant effect on carotene content. The best treatment was a supercritical CO2 treatment at 1100 psi for 10 min, which was determined based on a significant reduction in the number of microorganisms and no significant changes in color, texture, and fat content were observed compared with control. The best treatment was applied to process shrimps, which were then stored at 4°C to evaluate the effectiveness of scCO2 treatment on the shelf life. No significant changes were found in PV and lipid in treated and scCO2-treated shrimps during storage, but the treatment significantly affected pH, TVBN, and microbial counts. Among the samples, there was no hedonic difference in all sensory attributes. Supercritical CO2 treatment at 1100 psi for 10 min can be an alternative method for preservation of shrimps.

Influence of tributaries on downstream bed sediment grain sizes under flysch conditions

Tributaries are one of the most important factors contributing to variability in the downstream evolution of bed sediment grain size. The primary aim of this work is to evaluate the response of the bed sediment texture in the recipient channel induced by ten tributaries of the Cerna Ostravice stream and find reach-scale and catchment-scale parameters that would be able to predict this response. The research was based on collecting information on the grain size distributions at sites adjacent to confluence zones. A significant change in sediment texture occurred in the vicinity of five confluences. Considering the other factors contributing to grain size variability (e.g., local channel geometry, lithology, and lateral sediment sources), it was assumed that only four of them were associated with a sufficient bedload influx to alter the sediment calibre below the junction. Moreover, a significant morphological effect in the form of a large confluence bar was observed in one case. These tributaries had several common features: (i) they had a larger relative catchment area than that of nonsignificant tributaries; (ii) they were characterized by different bed grain sizes, with some exceptions; and (iii) they had a higher unit stream power close to the confluence in relation to that of the mainstream. These characteristics were represented by the proposed relative parameters, including the relative unit stream power and bed material texture, which allowed the best classification of significant and nonsignificant tributaries. In their simplified form, the parameters described the transport capacity and grain size distribution, which were generally considered to be primary factors responsible for a redefinition of the sediment texture in the recipient channel. However, it should be noted that these results are subject to some degree of uncertainty due to the relatively small sample size of only 10 tributaries.

Plain water jet cleaning of titanium alloy after abrasive water jet milling: Surface contamination and quality analysis in the context of maintenance

Abrasive water jet (AWJ) milling process, though being an effective alternative to conventional machining for difficult-to-machine materials, induces abrasive embedment which is an issue for repair application by structural bonding. In this context, the effectiveness of cleaning Ti6Al4V specimens by Plain Water Jet (PWJ) post AWJ milling is studied. For this, Ti6Al4V specimens are milled by AWJ process with varying parameters to create several levels of surface quality and contamination. Different characterization techniques have been used to perform a multi-scale analysis of the machined surfaces and surface quality has been quantified by an innovative criterion called “crater volume” (Cv). Then the specimens are subjected to PWJ cleaning operation (using a single set of parameters chosen after preliminary study). Finally, surface texture analysis and contamination quantification is performed and compared with the AWJ milled surfaces. The results revealed that PWJ cleaning reduced the surface contamination by 65% without any significant change in Cv, surface texture and topology. However, it was found that it was impossible to dislodge deeply embedded particles. The comparison of pre and post-cleaning contamination levels also revealed that PWJ cleaning process efficiency depends on the AWJ milling parameters (mainly pressure).

Fixed-Bed Adsorption of Ciprofloxacin onto Bentonite Clay: Characterization, Mathematical Modeling, and DFT-Based Calculations

The objective of this paper was to examine the adsorption of the antibiotic ciprofloxacin (CIP) in a calcined Verde-lodo (CVL) clay-packed fixed-bed system. The characterization study of the fresh and contaminated clay indicated filling of the clay pores by the CIP (pore volume decreased from 65.4 to 31.1 cm³ g–¹) and did not evidence significant changes in the clay texture. The fixed-bed system reached a breakthrough adsorption capacity of 0.038 mmol g–¹ (12.6 mg g–¹) and a mass transfer zone of 4.29 cm. Five mathematical models were fitted to the breakthrough curves, and the dual-site diffusion displayed the best fit to the experimental data (R² > 0.98). The adsorption performance of CIP was compared to that of the antibiotic ofloxacin, reported in the literature, in which density functional theory (DFT) computations were performed to clarify the particularities of the adsorption of both compounds onto CVL clay.

Impacts of a novel live shrimp (Litopenaeus vannamei) water-free transportation strategy on flesh quality: Insights through stress response and oxidation in lipids and proteins

A novel strategy of water-free transportation (WFT) for live shrimp was recently developed. In this study, survival rate, hormone response, free radical content, oxidation in lipids and proteins, and flesh quality were evaluated after WFT. Meanwhile water transportation (WT) was employed as a reference for comparison. Results showed only 5.1% mortality after 10 h of WFT, while crustacean hyperglycemic hormone (CHH), reactive nitrogen species (RNS), free fatty acid content (FFA), peroxide value (PV), carbonyl concentration, intrinsic fluorescence intensity (IFI), and surface hydrophobicity significantly increased. Myosin heavy chain (MHC) and actin degradation were also detected after WFT. Although oxidation occurred in lipids and proteins, no significant changes in texture and water-holding capacity (WHC) were detected after WFT or WT (p > 0.05). The 10 h of WFT showed little influence on flesh quality of shrimp even though lipids and proteins oxidation occurred during the mimicked water-free transportation.

Use of high-power ultrasound combined with supercritical fluids for microbial inactivation in dry-cured ham

The aim of this study was to analyze the application of supercritical carbon dioxide combined with high-power ultrasound (SC-CO2 + HPU) and the use of a saline solution (SS; 0.85% NaCl) on the microbial inactivation and the quality of dry-cured ham. The effect of temperature, pressure and treatment time was studied using RSM. Physicochemical analyses were carried out after the treatments and during refrigerated storage (30 days / 4 °C). The most significant inactivation of Escherichia coli (3.62 ± 0.20-log CFU/g) was obtained using the SC-CO2 + HPU + SS (25 MPa, 46-°C and 10-min), with temperature being the most important process variable. Fat content showed a significant (p < 0.05) reduction (46%) after the SC-CO2 + HPU treatment. The breakage of the muscle fibers, the disorganization in the myofibrils, as well as the enlargement of the interfibrillar spaces led to the ham softening (avg 26.5%). No significant (p > 0.05) changes in color, texture or pH were found during storage. Thus, ultrasonic-assisted SC-CO2 could be used, in combination or not with SS, to improve the shelf of dry-cured ham. Industrial relevanceSupercritical carbon dioxide (SC-CO2) inactivation technology has been shown to be highly efficient at reducing different bacteria in liquid media with minimum effect on food quality. This technology is barely applied to solid products and its use is limited by the long processing times and reduced inactivation capacity. The application of high-power ultrasound (HPU) leads to a shorter process time. This technology is useful for the inactivation of ham microbiota and inoculated E.coli. A liquid medium surrounding the treated solid can enhance microbial inactivation for the purposes of improving the effect of ultrasound cavitation, while only minimally affecting the quality of the samples (color, texture, fat and moisture contents).

Aggregation behavior of solubilized meat - Potato protein mixtures

Knowledge on the mixing behavior of meat and plant proteins is of importance for the manufacture of so-called hybrid products, a product category that is becoming of interest to food manufacturers. The aim of this study was to assess the pH-dependent miscibility and aggregation behavior in combinations of solubilized pork meat and potato tuber proteins. Analysis on their individual pH-dependent surface charge and size were followed by a visual and microscopic evaluation of their mixtures. Image analysis was used to obtain separation indices, aggregate areas, and aggregate aspect ratios and FTIR spectra were recorded to obtain insights into secondary structural elements. Net zero charge transition points differed, with a higher value for potato (pH 6.8) compared to meat proteins (pH 5.7). In mixtures, homogeneous solutions (pH 5.8 and 7.0) abruptly changed to phase-separated ones at low (pH 3) to medium (pH 5.5) pH. Here, anisotropic, clustered aggregates at high meat protein contents were exchanged for smaller, irregularly-shaped and sized microstructures at low ones and image analysis suggested a perturbing effect of potato on meat proteins to associate and form fibrous aggregates. The isoelectric point of salt-soluble meat proteins (pH ~ 5.5) was described as defining boundary value for co-solubility or interaction in between individual meat and meat and potato proteins. FTIR results confirmed alterations as a function of mixing ratio and pH. Results indicate that significant textural changes can be expected to occur in hybrid matrices, with plant proteins impeding the structural-self-association of meat proteins.

CO2 storage and conversion to CH4 by wet mechanochemical activation of olivine at room temperature

Wet mechanochemical processing of olivine under a CO2 atmosphere promotes the CO2 sequestration in the form of MgCO3 and the CO2 reduction to CH4 at room temperature. The effects of milling time and CO2 pressure on the CO2 storage and CO2 reduction were evaluated at lab-scale. Wet mechanochemical introduces progressively significant morphological, structural, microstructural, and textural changes in olivine for prolonged milling times, inducing fast carbonation reaction after 15 min of ball milling. Long milling times stimulate the CO2 conversion to CH4 and decrease the carbonation reaction rate, because both reactions occurred simultaneously. The CO2 sequestrated as MgCO3 is about 4.83 wt% and 6.81 wt% for 1.0 atm of CO2 after 120 min and 180 min of milling using different CO2 charge strategy. The amount of CO2 reduced to CH4 was 24 and 33 mmoles/kg of olivine after 120 min with 1.0 and 1.5 atm of CO2, respectively. Wet milling of olivine in CO2 atmosphere is a technique with potential for large-scale carbon mineralization.

Characterization of newly developed friction stir-arc welding method for AM60/AZ31 dissimilar Mg alloy

The dissimilar AM60/AZ31 Mg alloys joints were obtained via friction stir welding (FSW). Then, the upper and lower surfaces of the FSW joint were remelted by using tungsten inert gas (TIG) welding. The macrostructures, microstructure evolution and mechanical properties of the two kinds of joints were investigated. The results indicated that there was a TIG weld zone in both the upper and lower parts of the nugget zone (NZ) of the FSW joint after the arc heating. Further, the grain size in the NZ-middle grew to a certain extent, especially the area near the NZ-middle-center. Texture analysis showed that the texture in the NZ-middle was modified after the arc heating, especially in the TIG weld zones. However, there were no significant changes in texture and grain size near the NZ interface. The tensile results showed that the tensile strength and yield strength of the two joints were similar, but the joint elongation after arc heating was largely improved, by about 57%. The equivalent strength of the two kinds of joints was due to the similar texture and grain size near their NZ interfaces. The higher elongation was attributed to the increase of the Schmid factor values (basal slip and extension twinning) caused by the weakening of the texture, the growth of the grain size and the annihilation of the initial residual dislocation in the NZ-middle. As a result, the difficulty of deformation in the NZ-middle was reduced, which weakened the localized strain of the joint. This work could provide a new method for weakening the strain localization of FSW Mg joints.

Promising bending properties of a new as-rolled medium-carbon steel achieved with furnace-cooled bainitic microstructures

The bending properties of a new thermomechanically processed medium-carbon (0.40 wt% C) low-alloy steel, intended for the slurry transportation pipeline application, have been investigated. The studied material was hot-rolled to 10 mm thick strips followed by direct quenching to two different quench-stop temperatures (QST) of 560 °C and 420 °C. The samples were subsequently cooled slowly to room temperature in a furnace, producing two different bainitic microstructures. In general, the final microstructures on the centerline consisted of different bainitic features with yield strengths of a ~700 MPa and ~1200 MPa for QST 560 °C and 420 °C, respectively. To determine the factors affecting bendability, as determined by three-point brake press bending tests, local microstructural features and texture were characterized with transmission and scanning electron-microscoy and macrohardness tests. Detailed quantitative microstructural evaluation of both subsurface and mid-thickness regions revealed that the bainitic sample produced at the higher temperature (QST 560) consisted of almost equal amounts of bainite types B1 and B2, where B1 has bainitic sheaves with a low dislocation density and intralath cementite, and B2 a very dislocation-dense morphology with mainly interlath cementite. In the QST 420 sample, the high dislocation density components B2 bainite and martensite were dominant, although martensite was only present near the strip surfaces. Different post-rolling cooling conditions did not change the general crystallographic theme but resulted in a slight increase in the texture intensity of the QST 420 sample. Neither the concave nor convex subsurface regions showed significant changes in texture after bending. The more favorable distributions of microstructural components and textural component intensities in the QST 560 sample resulted in higher elongation to fracture and work-hardening capacity, resulting a smaller minimum usable punch radius than for the stronger QST 420 sample. Fractographic examination of the cracked surfaces revealed that cracks developed by shear band formation followed by surface roughening, which promoted subsequent void and micro crack nucleation and growth.

Design and implementation of a fuzzy temperature control for a craft beer production microplant using PLC

In this study, a fuzzy-based PLC temperature control system was designed and implemented on a craft beer production plant. At present, the temperature-related controls of small-scale plants in Colombia are based on On/Off models, which are not very stable in the preparation of craft beer, which generates significant changes in flavor, scent and texture. Therefore, it is intended to incorporate into the craft beer industry, solutions that guarantee repeatability, minimize costs and potentiate production, for this, a three-stage fuzzy control model is carried out: design, implementation and start up; This is how a study of the plant´s dynamics is carried out, the response is determined from the data, a fuzzy controller is designed by using Matlab software, and a graphical interface in LabView for data capture and storage. The controller demonstrates stability in relation to the temperature variable, which provides repeatability and significant energy savings. Finally, it is concluded that the controller proved to be robust against major disturbances and stable at different temperatures, being a useful tool for efficiently controlling the variable.

Sodium carbonate treatment of fibres to improve mechanical and water absorption characteristics of short bamboo natural fibres reinforced polyester composite

ABSTRACT The effect of sodium carbonate (Na2CO3) treatment of short bamboo fibres on mechanical properties and water absorption character of polyester composite is investigated. Treatment time and Na2CO3 concentration were optimised to 6 h and 5 wt-% respectively. Microscopy of the treated fibres showed a significant change in surface texture whereas; FTIR suggested the removal of amorphous compounds from the fibres that resulted in enhanced interfacial bonding between fibres and the polyester matrix. Removal of amorphous compounds was also confirmed by TGA where material loss for untreated fibres was 15% higher than the treated fibres. Composites were prepared using 10, 20 and 30 wt-% of treated and untreated fibres. Good interfacial bonding, achieved by the fibre treatment, enhanced the strength (∼24 MPa),( decreased the impact energy (from ∼36×10−3 KJ/m2 to ∼33×10−3 KJ/m2) and improved the water absorption resistance (∼2%) in case of 20 wt-% fibres composite.