Bulk Density Research Articles

Effect of maltodextrin concentration and temperature process on physicochemical characteristics of instant lemon (Citrus limon l) powder minute using crystallization machine

The purpose of this study was to determine the effect of maltodextrin concentration and drying temperature on the physicochemical characteristics of instant lemon powder drinks. The research used the randomized design group with a 3x3 factorial pattern consisting of two factors with two repeats so that 18 experimental units were obtained. There is a T factor which is a concentration of maltodextrin consisting of three levels, namely t1 (10%), t2 (15%), and t3 (20%), and a K factor that is a variation of the process temperature also consisting of three levels, namely k1 (50°C), k2 (60°C), and k3 (70°C). In this study, physical responses include solubility, dissolving time, amount of yield, hygroscopicity, bulk density, and scanning electron microscopy. Chemical responses correspond to water content, antioxidant activity, pH value, and vitamin C. The results showed that maltodextrin concentration can affect solubility, dissolving time, amount of yield, hygroscopicity, bulk density, water content, pH value, and vitamin C. Variations in process temperature affect solubility, dissolving time, amount of yield, hygroscopicity, bulk density, moisture content, pH value, and vitamin C. The interaction of maltodextrin concentration and process temperature variations affects hygroscopicity but not solubility response, dissolving time, yield amount, bulk density, water content, pH value, and vitamin C.

The Effects of Forest Gaps on the Physical and Ecological Stoichiometric Characteristics of Soil in Pinus densiflora Sieb. and Robinia pseudoacacia L. Forests

Forest gaps alter the environmental conditions of forest microclimates and significantly affect the biogeochemical cycle of forest ecosystems. This study examined how forest gaps and non-gap areas affect soil’s physical properties and eco-stoichiometric characteristics. Relevant theories and methods were employed to analyze the impact of forest gaps on nutrient cycling in Pinus densiflora Sieb. (PDS) and Robinia pseudoacacia L. (RPL) forests located in the Taishan Mountains. The results revealed that (1) forest gaps significantly enhanced the soil physical properties of PDS and RPL forests compared to non-gap areas (NPs). Notably, the bulk density of the soil decreased by 53%–12%, particularly in the surface layer (0–20 cm). Additionally, its non-capillary porosity increased by 44%–65%, while the clay and silt content rose by 39%–152% and 24%–130%, respectively. Conversely, the sand content decreased significantly, by 24%–32% (p < 0.05). (2) The contents of C, N, and P in the gap soil of PDS forests showed a significant increase compared to those in non-gap soil, with increases of 56%–131% for carbon, 107%–1523% for nitrogen, and 100%–155% for phosphorus. There was a significant drop of 10%–33% and 39%–41% in their C:N and C:P ratios, respectively (p < 0.05). The contents of C and P in the gap soil of the Robinia pseudo acacia L. Forest increased significantly, by 14%–22% and 34.4%–71%, respectively. Its C:P and N:P ratios significantly increased, by 14% to 404% and 11% to 41%, respectively (p < 0.05). (3) Compared with NPs, the forest gap significantly reduced the soil electrical conductivity and increased the soil pH. Additionally, compared to the soil at the gap’s edge, the surface soil in the gap’s center had noticeably higher concentrations of C, N, and P. (4) Key variables affecting the soil pH, silt content, bulk density, and overall porosity in forest gaps include the concentrations of carbon (C), nitrogen (N), and phosphorus (P) present and their ecological stoichiometric ratios. The findings showed that forest gaps had a considerable impact on the soil’s physical characteristics and ecological stoichiometry. They also had a high potential for providing nutrients, which might aid in the establishment of plantation plants.

Effect of Sod Production on Physical, Chemical, and Biological Properties of Soils in North and South China

Lawns play a vital role in urban development, but the impact of sod production on soil properties has always been controversial. In this study, we examined the physical, chemical, and biological properties of sod production bases across different regions and years [including northern China (2.5, 3, 5, 6, 8, 10, 12 years), referred to as N-2.5, N-3, etc., and southern China (3, 10, 11, 14, 17 years), referred to as S-3, S-10, etc.], with tall fescue and Kentucky bluegrass planted in the north and bermudagrass or creeping bentgrass planted in the south. Sod production was found to increase soil bulk density while reducing porosity and field capacity, but these effects did not consistently intensify with longer production periods. Except for available phosphorus and available potassium, other soil nutrients (total carbon, total nitrogen, organic matter, alkali-hydrolyzable nitrogen, etc.) were either unaffected or increased at certain time points (S-11, S-14). Prolonged sod production (S-10, S-17) also boosted microbial content. In northern regions, organic matter and total nitrogen were the key factors influencing microbial community structure, whereas in southern regions, alkali-hydrolyzable nitrogen, electrical conductivity, available potassium, and organic matter were most influential. We also found that crop rotation, sand mulching, and deep plowing could enhance soil nutrient content and microbial activity in sod production.

Recovery of mining and agri-food wastes in fired materials: a case study of the Moroccan industry.

The linear economy follows the "take-make-dispose" model and generates huge amounts of waste without consideration for recycling or reuse. This model which deals with raw materials puts pressure on natural resources and creates a serious environmental impact. In a circular economy, the "reduce-reuse-recycle" model is applied to recycle waste into resources and reduce the impact on the environment and society. This work aims to highlight the significance of implementing a circular economy approach in the construction sector by merging two different production lines, notably mining activity and agri-food industry. The investigation presents sustainable management of coal mine waste (CMW) and olive pomace (OP) in the production of eco-friendly fired materials and introduces an innovative approach for manufacturing lightweight fired bricks. Microstructural, physical, mechanical, and thermal properties were determined to evaluate the technological quality of fired materials at 900°C. As a pore-forming agent, adding 10 wt% OP yielded specimens with a bulk density of 1552kg/m3, water absorption of 19.80%, apparent porosity of 29.61%, loss on ignition of 26.98%, and compressive strength of 7.08MPa, satisfying standards for clay masonry units. Simultaneously, it enhances the thermal insulation by reducing thermal conductivity by 18% compared to the control sample with CMW. In this regard, the transition to a greener construction sector necessitates the immediate implementation of a circular economy approach to developing eco-friendly building materials by recovering large amounts of industrial waste, limiting the overuse of natural resources (e.g., clays), and improving the engineering properties of the final product.

Effect of 67-years of manuring, fertilization and amendments on fractions of soil organic carbon, nutrient dynamics and yield sustainability in an acidic Alfisol

Amending a problem soil in addition to nutrient input is crucial for maintaining a healthy and productive soil in the long run. The study aimed at evaluating the long-term impact of manuring and fertilization with or without liming on different soil attributes and crop yield in an acidic Alfisol. Surface soil samples (0–15 cm) were collected from selected 7 treatments, viz. Control; N; FYM; ½(N+FYM)+PX/2+KY/2; NPK; NPK+L; and P(A-X)K(B-Y)+FYM+L of the Permanent Manurial Trial (PMT) of Birsa Agricultural University, Ranchi, after the harvesting of rainy (kharif) maize (Zea mays L.) at the 67th crop cycle (2023 and 2024) and assessed for various fractions of soil organic carbon (SOC), available nutrients and yield attributes. The experiment was laid out in a randomized block design (RBD) and replicated thrice. The treatments which received manures either alone or in combination with chemical fertilizers recorded significantly higher amount of all the fractions of SOC, available nitrogen and lower bulk density as compare to the unfertilized plot or treatment with inorganic alone. The study also revealed that, addition of lime helped maintaining an optimum pH level, enhanced microbial activities and nutrient availability in the soil leading to a higher crop yield. Therefore, integrated use of manures and fertilizers in addition to lime for a prolonged period would have significant positive impact on soil health and sustaining its productivity.

Fabrication, characterization and simulated gastrointestinal digestion of sea buckthorn pulp oil microcapsule: effect of wall material and interfacial bilayer stabilization.

Sea buckthorn (Hippophae rhamnoides L.) pulp oil is rich in functional components; however, low water solubility and stability limit its applications. This study fabricated sea buckthorn pulp oil microcapsules using whey protein isolate (WPI), soy protein isolate (SPI), sodium caseinate (NaCN), gum arabic (GA), starch sodium octenylsuccinate (OSAS) and SPI mixed with chitosan (CHI). The influences of these wall materials on physicochemical properties, release behavior and digestibility were explored. Protein-based wall materials (WPI, NaCN, SPI) demonstrated lower bulk densities due to their porous structures and larger particle sizes, while GA and OSAS produced denser microcapsules. Encapsulation efficiency was the highest for protein-based microcapsules (79.41-89.12%) and the lowest for GA and OSAS. The surface oil percentage of protein-based microcapsules (1.41-4.40%) was lower than that of the other microcapsules. Protein-based microcapsules showed concave and cracked surfaces, while GA and OSAS microcapsules were spherical and smooth. CHI improved reconstitution performance, leading to faster dissolution. During simulated gastrointestinal digestion, protein-based microcapsules released more free fatty acids (FFAs) in the intestinal phase, while CHI-modified SPI microcapsules showed a delayed release pattern due to thicker walls. Protein-based wall materials were more effective for sea buckthorn pulp oil microencapsulation, providing higher encapsulation efficiency, better flow properties and releasing more FFAs. The addition of CHI led to the layer-by-layer self-assembly of the microcapsule wall and resulted in sustained release during in vitro intestinal digestion. These findings suggested the potential of protein-based microcapsules for targeted delivery and improved applications of bioactive oils in the food industry. © 2024 Society of Chemical Industry. Published by John Wiley & Sons Ltd.

Performance Evaluation of Groundnut Digger in Chhattisgarh, India

Groundnut (Arachis hypogaea L.), is a significant oilseed crop. It is grown in Chhattisgarh during rabi and kharif seasons, with traditional manual harvesting being labor-intensive and costly. To enhance efficiency, a study evaluated a tractor-operated groundnut digger in Chhattisgarh, focusing on factors such as crop size, shape, depth, spacing, and soil parameters like bulk density, true density, and moisture content. Performance metrics included exposed pod loss, buried pod loss, damaged pod loss, total pod loss, field efficiency, and digging efficiency. In this study found that at a 30° rake angle and 3.5 km h-1 speed, the maximum buried pod loss was 7.37%, exposed pod loss was 9.89%, and total pod loss was 23.79%. Conversely, the digger achieved a high digging efficiency of 96.92% with a 25° rake angle and 2 km h-1 speed. The operational cost was 972.57 Rs h-1, with a breakeven point of 100.42 hours per year and a payback period of 0.91 years. Compared to manual harvesting, which costs 37.5 Rs h-1, the tractor-operated digger significantly reduces time and costs, offering substantial improvements in harvesting efficiency.

Statistical modelling of a tractor tractive performance during ploughing operation on a tropical Alfisol

Abstract Tractor is the most prominent off-road agricultural machinery that is significant to the global food security. The tractive modelling of tyre–soil interaction and agricultural implement dynamics is a complex phenomenon that require holistic approach. Terramechanics techniques such as empirical, semi-empirical, analytical, and numerical methods such as finite element models and discrete element models have gained traction in tractive performance studies. Some of these approaches are premised on large arrays of variables for modelling tractive performance based on the soil–tyre and tools interactions. In this study, soft computing in R software domain was used to model the tractor tractive performance during ploughing operations on a tropical Alfisol. The research farm at the National Centre for Agricultural Mechanization was used for the field experiment. The experimental design was a nested-factorial under a Randomized Complete Block Design having three replications. The input factors were tractor power size, T, (60, 65, and 70 hp); tyre inflation pressure, P, (83, 124, and 165 kPa); implement configuration, I, (2 and 3 bottoms disc plough); and operational speed, S, (6.31, 7.90, 9.47, 11.05, and 12.63 km/h). Standard procedures were followed to obtain the measured parameters in the field, which were statistically analysed. Correlation analysis and analysis of variance of the measured parameters at 5% significance level were established. Multiple linear regression was used to develop the model, validated using the 10-fold cross-validation method. The results revealed that the evaluated variables have a range of 1.56–7.79 kN, 5.15–27.20%, 9.10–32.00 cm, 4.50–13.94%, 1.31–1.67 g/cm3, 95.89–207.78 kPa, and 98.67–295.56 for draught, wheel slip, depth of cut, moisture content, bulk density, cone index (CI), and shear stress, respectively. A positive correlation exists between the towing force (TF) and the measured variables except for the shear stress and CI. The final developed model has seven variables for predicting TF with a 6.5% error and an average of 0.4735 cross validation root mean square error. The model quality of fit achieved an R Adj 2 = 0.8754 {R}_{\text{Adj}}^{2}=0.8754 which satisfactorily described the response variable. The study provides insights into tractive dynamic systems modelling of machine, tractive medium (soil), and agricultural tools anchored on soft computing approach. Its adoption will assist in quality ploughing operation integrating the variables established in the model.

Application of preoperative advanced diffusion magnetic resonance imaging in evaluating the postoperative recurrence of lower grade gliomas

BackgroundRecurrence of lower grade glioma (LrGG) appeared to be unavoidable despite considerable research performed in last decades. Thus, we evaluated the postoperative recurrence within two years after the surgery in patients with LrGG by preoperative advanced diffusion magnetic resonance imaging (dMRI).Materials and methods48 patients with lower-grade gliomas (23 recurrence, 25 nonrecurrence) were recruited into this study. Different models of dMRI were reconstructed, including apparent fiber density (AFD), white matter tract integrity (WMTI), diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), Bingham NODDI and standard model imaging (SMI). Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) was used to construct a multiparametric prediction model for the diagnosis of postoperative recurrence.ResultsThe parameters derived from each dMRI model, including AFD, axon water fraction (AWF), mean diffusivity (MD), mean kurtosis (MK), fractional anisotropy (FA), intracellular volume fraction (ICVF), extra-axonal perpendicular diffusivity (De⊥), extra-axonal parallel diffusivity (De∥) and free water fraction (fw), showed significant differences between nonrecurrence group and recurrence group. The extra-axonal perpendicular diffusivity (De⊥) had the highest area under curve (AUC = 0.885), which was significantly higher than others. The variable importance for the projection (VIP) value of De⊥ was also the highest. The AUC value of the multiparametric prediction model merging AFD, WMTI, DTI, DKI, NODDI, Bingham NODDI and SMI was up to 0.96.ConclusionPreoperative advanced dMRI showed great efficacy in evaluating postoperative recurrence of LrGG and De⊥ of SMI might be a valuable marker.

A frequency-dependent model for bone remodeling using a micromorphic porous medium subjected to harmonic mechanical loading

AbstractIn this paper, the bone tissue was modeled as a linear viscoelastic material saturated with interstitial fluid. We considered a specific case of harmonic loading and related the mechanical stimuli to the loading frequency. In this way, we could include the inertial effect in the model while not having to deal with the perturbation during each loading period. Two types of mechanical signals were considered: strain energy and dissipation energy. A parametric study revealed the dependency of the two signals on loading frequency and material property. The evolution of the apparent mass density supported the parametric study’s findings. Under the three different frequency loadings, the strain energy-stimulated samples experienced identical remodeling scenarios. The samples stimulated with dissipation energy, on the other hand, exhibited a strong frequency dependence. An additional study was performed to investigate the effect of long-term variations in the loading frequency on the remodeling process. This demonstrated the model’s capabilities in designing and evaluating load regimes for rehabilitation following a bone injury or bone reconstruction.

Vermicomposting Bio Earth: A Sustainable Approach for Enhanced Nutrient Content and Heavy Metal Remediation in Soil Management

<p style="text-align:justify; margin-bottom:11px"><span style="font-size:11pt"><span style="line-height:150%"><span style="font-family:Calibri,"sans-serif""><span lang="EN-US" style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman","serif"">The present study obtained the Bio Earth sample from six locations, represented as LS-(1-6). The collected bio earth sample was blended with an adult earthworm (<i>Eisenia fetida</i>). The experimental investigation was conducted for 108 days, and earthworms showed maximum biomass and population ephemerality in Bio Earth samples (Bio Earth + cow dung). However, the pre-treated and post-treated samples were monitored through physicochemical analysis like pH, electrical conductivity (EC), bulk density (<i>ρ</i>), total organic content (TOC), total nitrogen (TN), total phosphorous (TP), total potassium (TK), C:N ratio, and heavy metals. Among the six Bio Earth samples, the most significant LS-3 reveals the reduction of operating parameters and finds the below detection limit of heavy metals. At the initial level of LS-3, samples were found to be pH-7.2, EC-1.4 ms/cm, <i>ρ</i>-0.8 g/cm<sup>3</sup>, TOC-8.6%, TN-0.6%, TP- 0.3%, TK-0.4%, C:N ratio-16.3%, heavy metals (Zn-448.8 mg/kg; Cu-132.5 mg/kg; Ni-61.4 mg/kg; Pb-91.2 mg/kg; Cr-116.3 mg/kg), whereas the post-treated vermicomposting sample results were exhibited at pH-6.8, EC-2.167 ms/cm, <i>ρ</i>-0.85 g/cm<sup>3</sup>, TOC-9.54%, TN-0.67%, TP-0.48%, TK-0.13%, C:N ratio-14.23%, heavy metals (Zn-64.13 mg/kg; Cu-5.5 mg/kg; Ni-7.26 mg/kg; Pb-101 mg/kg; Cr-51 mg/kg). The data displays that vermicomposting (using <em>E. fetida</em>) is an applicable technology for decomposing organic matter into prosperous nutrient soil enlargement.</span></span></span></span></span></span></p>

Elevational patterns of soil organic carbon and its fractions in tropical seasonal rainforests in karst peak-cluster depression region

Karst ecosystems, especially tropical karst forests, are crucial to the global carbon cycle. In mountainous and hilly areas, elevation-related changes in environment and vegetation often lead to shifts in the accumulation and decomposition of soil organic carbon (SOC). However, the elevational patterns and influencing variables of SOC and its fractions in tropical karst forest ecosystems remain largely unexplored. Here, we analyzed the elevational patterns of SOC and its fractions in the topsoil and subsoil in the tropical seasonal rainforests within typical peak-cluster depression region of Southwest China. Our results indicated that the SOC content was highest at 400 m asl, which was significantly higher than that at 200 m asl (p < 0.05). Overall, SOC content demonstrated an increasing trend with rising elevation. Additionally, SOC content was significantly higher in the topsoil compared to the subsoil (p < 0.05). The majority of SOC fractions exhibited an increase with elevation but decrease with soil depth. Notably, only water-soluble organic carbon (WSOC) displayed a decrease with elevation. Meanwhile, recalcitrant organic carbon (ROC, 54.27%), particulate organic carbon (POC, 30.19%), and easily oxidizable organic carbon (EOC, 16.95%) were the main SOC fractions. Labile organic carbon (LOC) in the karst forest soil was predominantly composed of EOC and POC. Correlation analysis unveiled significant positive correlations between SOC and certain fractions with elevation, soil total nitrogen, and exchangeable magnesium. Conversely, significant negative correlations were observed with soil bulk density (SBD), soil total phosphorus, and litter phosphorus (Litter P). Redundancy analysis indicated that elevation, SBD, and Litter P were the main environmental variables influencing shifts in SOC and its fractions. Structural equation models showed that SOC was primarily directly impacted by soil properties but indirectly impacted by elevation. ROC was mainly associated with the direct effects of soil properties and litterfall, although elevation exerted a substantial impact through indirect pathways. Moreover, LOC was predominantly influenced by the direct impact of soil properties. Therefore, this study demonstrates that SOC and its fractions are strongly influenced by elevation in karst peak-cluster depression regions and have important implications for forest management and sustainable ecosystem development in these regions.

Innovative Hemp Shive-Based Bio-Composites: Part I: Modification of Potato Starch Binder by Sodium Meta-Silicate and Glycerol

The growing demand for sustainable building materials has boosted research on plant-based composite materials, including hemp shives bound with biodegradable binders. This study investigates the enhancement of potato-starch-based binders with sodium metasilicate and glycerol to produce eco-friendly bio-composites incorporating hemp shives. Potato starch, while renewable, often results in suboptimal mechanical properties and durability in its unmodified form. The addition of sodium metasilicate is known to improve the mechanical strength and thermal stability of starch-based materials, while glycerol acts as a plasticizer, potentially enhancing flexibility and workability. Bio-composites were produced with varying concentrations of sodium metasilicate (0–107% by mass of starch) and glycerol (0–133% by mass of starch), and their properties were evaluated through thermal analysis, density measurements, water absorption tests, compressive strength assessments, and thermal conductivity evaluations. The results demonstrate that sodium metasilicate significantly increases the bulk density, water resistance, and compressive strength of the bio-composites, with enhancements up to 19.3% in density and up to 2.3 times in compressive strength. Glycerol further improves flexibility and workability, though excessive amounts can reduce compressive strength. The combination of sodium metasilicate and glycerol provides optimal performance, achieving the best results with an 80% sodium metasilicate and 33% glycerol mixture by weight of starch. These modified bio-composites offer promising alternatives t2 o conventional building materials with improved mechanical properties and environmental benefits, making them suitable for sustainable construction applications.

Effect of metakaolin and lime addition on geopolymerization of construction and demolition waste.

Construction and demolition waste generates the largest amount of waste by volume, which threatens sustainable development and adversely affects the environment. These wastes contain a significant amount of aluminosilicates that have the potential to be used as building materials for value-added applications applicable to alternative construction materials. This study aims to synthesize geopolymers from brick powder using metakaolin/lime as additives and compare their physico-mechanical properties. The compressive strengths of the geopolymer products GP-1, GP-2, and GP-3 developed at 28days from brick powder and metakaolin/lime with the activator solution were found to be 8.35, 21.30, and 25.0MPa respectively, 2.55 and 2.99 times higher when metakaolin and lime were added. FTIR spectra and SEM-EDX micrographs of the reaction products showed structural changes and formation of aluminosilicate hydrate and calcium silicate hydrate gel with Al2O3/Na2O ratios of 0.75, 1.67, and 1.98 respectively. The reaction products containing SiO2/(SiO2 + Al2O3 + Fe2O3) ratios of 0.70 and 0.76 were found to be desirable. The geopolymer product GP-3 was found to have a higher bulk density and mechanical strength than those of GP-1 and GP-2. These products are found to be very hard, with potential applications in construction industries to conserve the environment.

Physical Properties of Selected Fruit Fibre and Pomace in the Context of Their Sustainable Use for Food Applications

Pomace, a waste product, generates a huge problem in the fruit and vegetable industry. Numerous studies prove that pomace and fibre are valuable sources of many nutrients. Due to their properties, their popularity is growing in many industries. Water vapour isotherms and kinetics were determined for selected fruit fibre and pomace. The activity and water content, colour, apparent and bulk density, and material structure were also investigated. In addition, the thermal stability of the tested fibres and pomace was examined. Fibre and pomace from chokeberries, apples and currants were used in the research. The determined kinetic curves proved that apple fibre absorbed more water vapour. The isotherms were found to have a shape characteristic of type III sorption isotherms. The Guggenheim–Anderson–de Boer model (GAB) described experimental data for sorption isotherms well (taking an RMS value of less than 10% as a good fit of the model to the sorption data). Thermogravimetric analysis showed good thermal stability, and all analysed fruit fibre and pomace showed similar behaviour in the three main stages of weight loss. The results suggest that the analysed waste materials can be used for different applications, including flour replacements for food products or filling materials in edible packaging films.

Use of biomass from Amazonian agro-industrial waste for the production of energy

This research aims to analyze the physical and mechanical properties of briquettes made by açaí, cupuaçu, and murumuru waste from agro-industrial activity in a region of the Brazilian Amazon. For the production of briquettes, biomass with different granulometry (48, 60, 65, and 80 mesh) was sent to hydraulic pressure at constant pressure (15t) with various pressing times (15, 20 and 30 minutes). This process occurred without the addition of binders. The obtained outcomes were evaluated for storage time, bulk density, energy density, calorific value, impact strength, water absorption, and mechanical durability. The briquettes produced with açaí and cupuaçu presented good mechanical characteristics compared to murumuru. Concerning the calorific value, the latter showed better results. There was no alteration in the physical and mechanical properties determinant for the material to present favorable energy generation and durability. The açaí briquettes demonstrated better physical and mechanical properties, while murumuru briquettes indicated the best energy properties. Thus, the use of biomass from different agro-industrial wastes from the Amazon proved to be relevant for the elaboration of briquettes, being an alternative in the production of sustainable energy and adding to the reduction of the accumulation of improper waste disposed of in the environment.

Microwave absorption properties of one-step formed CNTs/Fe3O4-carbonyl iron superflexible buckypaper by directional pressure filtration

In order to realize the integration of structure and function of microwave-absorbing materials, carbon nanotubes/magnetic nanoparticle buckypaper (CNT/MNP BP) self-supporting, ultra-flexible, ultra-thin and ultra-light composites were prepared by composing CNTs with MNPs through directional pressure filtration technology. The BP composite, with a bulk density of 0.62 g/cm3 and a thickness of 0.21 mm, can be uninterruptedly tightly wound around a 4 mm diameter glass rod many times without structural damage. The microwave-absorbing properties and magnetic properties of the CNT/MNP composites with different compositions and contents were systematically analyzed. The CNT-Fe3O4 Buckypaper with 33.3 wt% Fe3O4 content (CF33.3 %) has the best electromagnetic wave absorption capability, with a minimum reflection loss value of −52.01 dB and an effective absorption bandwidth of 4.08 GHz. The VSM test shows that the saturation magnetization strength of CF33.3 % is 38.4 emu/g. The excellent electromagnetic wave absorption performance is attributed to the polarization and conduction losses of CNTs, natural resonance, exchange resonance and eddy current losses of MNPs, and multiple scattering and reflection within the porous network structure of the composites. The CNTs and MNPs has good dispersion in the buckypaper, where CNTs construct a superflexible skeleton besides an excellent conductive network. The self-supporting superflexible CNT/MNP BP composites have a good application prospect in the field of wearable electronic devices in the future.

Physical, functional and bioactive properties of microencapsulated powders from banana pseudostem and inflorescence extracts

Application of agricultural by-products in the functional food and beverage industry is currently gaining prominence. Banana (Musa spp) is a popular tropical fruit with global production of 124.97 million tonnes. The banana production industry contributes to large amount of solid waste/ banana by-products, such as, pseudostem and inflorescence. Palayankodan (Musa × paradisiaca Mysore AAB group), Nendran (Musa × paradisiaca AAB group) and Njalipoovan (Musa × paradisiaca AB group) are three popular and common cultivars in Kerala, a state in South India. The present study was aimed to extract the potential bioactive compounds from the pseudostem and inflorescence of the above-mentioned cultivars and to standardise the process of microencapsulation using spray drying. Ultrasonication assisted extraction using ethanol as solvent was carried out. The extract and wall material parameters were standardised for microencapsulation. The encapsulated powders were analysed for encapsulation yield, retention efficiency, physical properties, phytochemical composition, antioxidant potential and anti-diabetic activity. The encapsulation yields and retention efficiencies of the encapsulated powders were found to be approximately 75 and 70.51%, respectively. Results revealed that the powders exhibited lower bulk density, good solubility and reconstitutability. Scanning electron microscopy was also conducted to reveal the particle morphology. All the powders exhibited smooth, spherical shape, with no pores. The phenolic and flavonoid contents of the encapsulated pseudostem and inflorescence extract powders ranged from 2.75 to 3.13 mg GAE/ g of powder and 34.83 to 46.67 mg QE/g of powder, respectively. The present study also reported the in vitro bioactive properties, in terms of antioxidant and anti-diabetic activities of the encapsulated powders. The HPLC analysis of the microencapsulated powders revealed the presence of gallic acid, protocatechuic acid, trans cinnamic acid, trans ferulic acid, epicatechin and syringic acid. It is clear from the study that the encapsulated powders from banana by-products have a great potential to be utilised by the functional food industry.Graphical

Characterization, modeling and prediction of foam-formed softwood fiber sound absorption

The transition towards building materials with low or negative carbon-dioxide footprint is a pressing topic in nowadays society. Materials for thermal and acoustic insulation are among those attracting a growing number of research publications. Commonly used materials in the building sector are mostly mineral wools which demand huge amounts of energy during production by melting sand or stone. Cellulose-based materials are a promising substitute for the current market leaders. These materials are able to reach negative carbon footprints due to low embodied energy and their ability to store carbon dioxide in buildings for decades. Predicting the sound absorption behavior prior to manufacturing can further improve their usability. This study delves into the prediction and characterization of wood-based pulp fiber foams and their acoustic properties. By comparing analytical models, semi-phenomenological models and experimental measurements the prediction of sound absorption based on fiber diameter and bulk density is evaluated. The findings reveal that refining a recent analytical model for natural fibers through parameter fitting to non-acoustic parameters yields improved accuracy in predicting sound absorption curves. While the accuracy declines towards higher densities, this work lays the groundwork to create environmentally sustainable sound absorbers with carefully tailored sound absorption properties.

The Usability of Metallurgical Production Waste as a Siliceous Component in Autoclaved Aerated Concrete Technology

The reconstruction of buildings is a complex process that often requires the consideration of the construction load when selecting correct building materials. Autoclaved aerated concrete (AAC)—which has a lower bulk density (compared to traditional masonry materials)—is very beneficial in such applications. A current trend in AAC development is the utilization of secondary raw materials in high-performance AAC, characterized by higher bulk density and compressive strength than regular AAC. The increase in bulk density is achieved by increasing the content of quartz sand in the mixing water. In this study, part of the siliceous component was replaced by ladle slag, foundry sand, furnace lining, and chamotte block powder. These materials are generated as by-products in metallurgy. The substitution rates were 10% and 30%. The samples were autoclaved in a laboratory autoclave for 8 h of isothermal duration at 190 °C with a saturated water vapor pressure of 1.4 MPa. The physical–mechanical parameters were determined, and the microstructure was described by XRD and SEM analyses. The results were compared with traditional AAC, with silica sand being used as the siliceous component. The measurement results show that sand substitution by the secondary raw material is possible, and it does not have a significant impact on the properties of AAC, and in a proper dosage, it can be beneficial for AAC production.