True Density Research Articles

Evaluation of Physical, Anti-nutritional and Optimisation of Milling Characteristics of Quinoa Grains for Sustainable Food Security

Quinoa is a popular pseudo-cereal belonging from Andean region of South America. Post-harvest processing of quinoa plays important role in product development, further processing storage and shelf life extension of grains. The aim of present study was evaluation of physical properties, anti-nutritional factors of quinoa and quinoa grain were milled in order to investigate milling yield, milling loss, broken quinoa and head quinoa as the effect of milling in pearling. Post-harvest processing of quinoa was done in the form of pearling after dehulling process and obtained intermediate products. Pearling process of quinoa was done for a constant period of 5 minutes and different milling proportions were evaluated under different runs of the machine. In this study, thousand seed weight of quinoa grain observed about 2.50 to 2.58g in different runs. True density of quinoa ranged between 990 kg/cm3 (Max.) to 983 kg/cm3 (Min.) whereas bulk density of quinoa was stated between 680 to 691 Kg/cm3. Porosity of quinoa showed between 0.302 to 0.308. Saponin content in quinoa samples varied between 3.02 and 3.05% whereas phytin was found about 0.81 to 0.93%. Obtained results also showed L and b value increased after processing while a value decreased. Results obtained from processing showed that husk percentage found maximum as 19.01% whereas highest broken quinoa proportion was 23.63%. It was also observed that highest milling yield or recovery percentage was 63.58% while maximum milling loss recorded as 40.63%. Furthermore, the influence of pearling on the milling characteristics of quinoa were investigated. The milling fractions can be used to obtain new bread products with improved nutritional profiles.

Effect of magnesium stearate solid lipid nanoparticles as a lubricant on the properties of tablets by direct compression

This study discusses the lubricant properties of magnesium stearate solid lipid nanoparticles (MgSt-SLN) and their effect on the tabletability, mechanical properties, disintegration, and acetaminophen-model dissolution time of microcrystalline cellulose (MCC) tablets prepared by direct compression. The behavior of MgSt-SLN was compared to reference material (RM) to identify advantages and drawbacks. The nanoprecipitation/ion exchange method was employed to prepare the MgSt-SLN. Particle size, zeta potential, specific surface area, morphology, and true density were measured to characterize the nanosystem. The MgSt-SLN particle sizes obtained were 240 ± 5 nm with a specific surface area of 12.2 m2/g. The MCC tablets with MgSt-SLN presented a reduction greater than 20 % in their ejection force, good tabletability, higher tensile strength, lower disintegration delay, and marked differences in acetaminophen dissolution when compared to the RM. The reduced particle size of the magnesium stearate seems to offer a promising technological advantage as an efficient lubricant process that does not affect the properties of tablets.

Flowability of plant based food powders: Almond, chestnut, chickpea, coconut, hazelnut and rice

This study presents bulk material characterization, especially powder flowability, of eight food powders from six different plants (almond, chestnut, chickpea, coconut, hazelnut and rice). The characterization of the bulk powders includes the particle size distributions, true densities, bulk and tapped densities, as well as the powder porosity and moisture content. The flowability is determined by means of Hausner ratio, Carr's index, flow function by an annular shear cell and dynamic angle of repose. The flowability characteristics are discussed in regard to the bulk powder properties and evaluated for their applicability as some methods could give misleading results for the flowability.

Iterative Gradient Correction (IGC) Method for True Height Analysis of Ionograms

AbstractInversion of precise true height electron density profile from the measured virtual heights by the Ionosonde is a quite challenging and ill‐posed problem. In this paper, we present a new method to compute the true height profiles from ionograms that relies on computing the propagation path of radio waves with time. This method does not use predefined polynomial functions to fit the vertical electron density distribution; hence, it is free from fitting errors. Instead, this method implements iterative corrections in the electron density gradient between the successive points and progressively reconstructs the true height profile. This Iterative Gradient Correction (IGC) method assures minimizing the error to below a tolerance limit at all sampled points on the ionogram. The true height profiles derived from this method exhibit better accuracy than those derived from the widely used POLynomial ANalysis, particularly, at cusp and F2‐peak regions. Further, the IGC method gives the best results at higher sampling resolutions of ionograms and is less sensitive to scaling errors.

Comparative Study of Physico-Chemical Properties of Babool (Acacia nilotica) and Karaya (Sterculia urens Roxb.) Gums

Study of the physico-chemical properties of natural gums is a prerequisite to understanding the nutritional, culinary and commercial value and their utilization. The main objective of the present piece of work was to determine some important physico-chemical properties of babool (Acacia nilotica) and karaya (Sterculia urens Roxb.) gum. The physico-chemical properties of babool and karaya gums were determined by using standard methods and the data obtained was analyzed for comparison of both the gums. The investigation revealed that there were significant differences in the percentage of swelling index, water holding capacity, solubility, moisture content, porosity, ash content, pH and protein. Although there were no significant differences obtained in the values of true density, bulk density, angle of repose, refractive index, coefficient of friction, and fat between the two test samples. The protein and nitrogen content of babool gum were superior to those of karaya gum. Water holding and oil holding capacity were superior in karaya gum to babool gum. The viscosity of babool gum was decreased with the decrease in shear rate, whereas the viscosity of karaya gum increased with the decrease in shear rate. Data generated from the study confirms that there are a number of similarities in some properties and differences in other properties of both the test gum exudates.

Densified biochar capsules as an alternative to conventional seedings

The application of biochar in soil provides various benefits that can vary in intensity as the pyrolysis temperature increases. However, its low density makes this material easily transportable and prone to being removed from the system. The objective of this study was to investigate the pyrolysis temperatures and compression pressure of densified biochar carrier capsules on the physiological quality of Schizolobium parahyba var. amazonicum seeds. Produced at three final pyrolysis temperatures (300, 600, and 900 °C), the biochar was characterized through bulk and true density analyses, immediate composition, pH, electrical conductivity, cation exchange capacity, water-soluble carbon, characterization of organic structures by FTIR, and PAH analysis. Subsequently, the biochar was compacted by briquetting at two compression pressures (50 and 200 psi) with one seed per capsule, and germination, emergence, and quality of generated seedlings were evaluated. After verifying residue normality and variance homogeneity, analysis of variance was conducted following a completely randomized design in a 3 × 2 factorial arrangement, with four replications per treatment and two additional control treatments. Upon identifying significant differences, regression model adjustments were performed. Cluster-based multivariate analysis was used to identify similarities among the studied treatments, both for capsules and controls. Pyrolysis temperature and compression pressure influenced seed germination, emergence, and initial seedling growth. Lower pressure favored shoot development, while higher pressure favored root development and generated seedlings of higher quality. The benefits of biochar to soil, combined with the implementation of seeds, make the production of densified biochar capsules an alternative to conventional seedings, potentially reducing high energy and financial costs and enabling the recovery of degraded areas, even in difficult-to-access regions.

Assessment of the Effects of Commercial or Locally Engineered Biochars Produced from Different Biomass Sources and Differing in Their Physical and Chemical Properties on Rumen Fermentation and Methane Production In Vitro.

In recent years, interest in using biochar as feed additives to mitigate enteric methane (CH4) emissions from ruminants has increased. It has been suggested that the mitigating potential of biochar is influenced by its physical (e.g., porosity-related) and chemical (e.g., redox-potential-related) properties. Thus, the aim of this in vitro study was to evaluate the effects of commercial or locally engineered biochars, produced from different biomass sources and differing in their physical and chemical characteristics, on rumen fermentation and CH4 production. For this purpose, a 24 h batch culture of ruminal fluid incubations was conducted in a complete randomized block design (repeated three times) that included a negative control (no additive), a positive control (monensin, 10 mg/mL), and four commercial and three locally engineered biochars, each evaluated at 1%, 2%, or 5% of the substrate's (i.e., the total mixed ration) dry matter. The evaluated biochars greatly differ in their chemical (i.e., moisture, ash, pH, redox potential, volatiles, carbon, fixed carbon, hydrogen, and sulfur) and physical (i.e., fine particles < 250 µm, bulk density, true density, porosity, electrical conductivity, specific surface area, and absorbed CO2) properties. Despite these differences and compared with the negative control, none of the biochars evaluated (regardless of the inclusion rate) influenced gas and CH4 production, volatile fatty acid characteristics (total concentration and profile), or ammonia-nitrogen (NH3-N) concentrations. As expected, monensin (i.e., the positive control) decreased (p < 0.05) CH4 production mainly because of a decreased (p < 0.05) acetate-to-propionate ratio. The results of this study reveal that despite the large differences in the physical and chemical properties of the biochars evaluated, their inclusion at different rates in vitro failed to modify rumen fermentation and decrease CH4 production. Based on these in vitro findings, it was concluded that biochar does not represent a viable strategy for mitigating enteric CH4 emissions.

Investigation of Physical and Frictional Properties of Mustard Seed Varieties to Design inclined Plate Metering Mechanism

The physical and frictional properties were studied for three distinct mustard seed varieties: RLC-1, GSC-7, and PBR-91, with the primary objective of designing an efficient inclined plate seed metering mechanism for agricultural seeders. Mustard, a globally significant oilseed crop, plays a vital role in both agriculture and industry. Our comprehensive analysis encompassed various properties, including seed dimensions, test weight (1000 seed), moisture content, geometric mean diameters, surface area, bulk density, true density, sphericity, angle of repose, and coefficients of friction on plywood and GI sheet surfaces.&#x0D; The results revealed significant variations among the mustard seed varieties. For instance, RLC-1 seeds exhibited lengths of 4.029 ± 0.37 mm, widths of 2.210 ± 0.31 mm, and thicknesses of 0.851 ± 0.19 mm, whereas GSC-7 displayed lengths of 4.110 ± 0.42 mm, widths of 2.300 ± 0.35 mm, and thicknesses of 0.910 ± 0.24 mm. Additionally, GI sheet surfaces exhibited a lower coefficient of friction compared to plywood.&#x0D; This comprehensive dataset informs the design of tailored seed metering mechanisms, optimizing seed handling, minimizing damage and losses, and reducing blockage during seeding operations, thereby enhancing overall efficiency in mustard crop cultivation and seeding technology.

Preparation of mullite whisker foam ceramics and exploration of its application in adsorption

In order to improve the surface loading capacity, the adsorption capacity and thermal insulation properties of ceramic foams, mullite ceramic foams (MCFs) with different mullite whisker content by impregnating NH4F solution with high specific surface area and high surface roughness prepared. The filtration effect of different MCFs on Fe2O3 turbid liquid was tested and compared by a specific experimental device, and MCFs with 100 % mullite whisker content showed 250 % adsorption capacity compared to MCFs without mullite whiskers. The phase composition and microstructure of MCFs were characterized by XRD and SEM. The bulk density, true density, total porosity, thermal conductivity and compressive strength of different MCFs were compared. In this study, MCFs with 100 % mullite whisker content had the highest compressive strength of 26.15 MPa and the lowest thermal conductivity of 0.17–0.23 W/(m·K) (200–800 °C).

Physico-chemical Characteristics and the Effects of Processing Methods on the Nutritional and Anti-nutritional Quality of Soybean (Glycine max (L.) Merrill)

The present investigation was carried out to determine the physico-chemical characteristics and effects of processing methods on the nutritional and anti-nutritional quality of soybeans. Soybean seeds were analysed using physico-chemical approaches, in order to obtain a detailed profile on these qualities. The effects of processing methods on the nutritional and anti-nutritional quality of soybean had an impact on the nutritional and anti-nutritional values. Soybeans were subjected to different processing methods which were sorted, washed, dried, and milled into flour (Sample A- Control), soaked in water (1:3) for 12h, mechanically dried at 60 ± 2 oC for 10 h and milled into flour (Sample B), soaked in water (1:3) for 12h, sprouted 72 h, mechanically-dried at 60 ± 2 oC for 10 h, roasted for 3 min and milled into flour (Sample C), boiled for 30 min in an open lid, mechanically-dried at 60 ± 2 oC for 10 h, roasted for 3 min and milled into flour (Sample D). The study revealed that raw soybean seeds had 90.43 ±3.93 g seed weight, 6.31 ± 0.41 mm length, 5.50 ± 0.29 mm breadth,4.58 ± 0.35 mm height, 0.88 ± 0.04 mm sphericity, 753.01 ± 6.62 kg/ m3 bulk density, 1181.03 ± 11.72 kg/ m3 true density, 36.33 ± 0.79 % porosity, 0.13 ± 0.005 g/seed hydration capacity, 1.25 ± 0.07 hydration index, 0.12 ± 0.01 mL swelling capacity, 1.62 ± 0.05 swelling index. The colour was recorded to be (L* 59.52, a* 8.97, b* 34.01), Chroma (c*) 35.17, and hue angle (ho) 9.84. After processing, moisture content increased (10.61 - 12.43 %), crude protein (42.97– 47.87 %), crude fibre (9.44 - 11.57 %), ascorbic acid (5.38 - 11.65 mg/ 100 g), and ash content (4.84-5.99 %) while total carbohydrates and total energy decreased significantly (17.70 - 15.92 %) and (439.69 - 397.82 %), respectively. Similarly, the phytic acid content decreased from 8.12 to 5.19 mg/100 g while the tannin decreased from 25.34 to 18.57 % and the protease inhibitor decreased from 7.12 to 5.01 %. The overall results of the current study revealed that the processing methods of soybeans had an impact on the nutritional and anti-nutritional values. Further, the study showed that processing methods can significantly improve the nutritional qualities of soybeans while substantially reducing their anti-nutritional properties, thereby boosting the nutrients' bioavailability.

Engineering and bio‐chemical properties of asparagus roots (Asparagus racemosus L.)

AbstractThe post‐harvesting procedures, such as grading, washing, transporting, and packaging can be made better with understanding of the attributes of agricultural commodities. The paper aims to estimate the asparagus roots' thermal, physical, and biochemical characteristics. The asparagus was found to vary in the range of 6.26–13.60 cm long. The width and thickness of the root were almost the same and ranged from .69 to 1.10 cm. The bulk density, true density, and porosity ranged from .561 to .771 g/cm3, 1.418 to 2.124 g cm3, and 60.437 to 63.689%, respectively. The water activity of the roots was observed to be in the range of .797–.828. The color characteristics of asparagus roots were found to be L* = 45.46, a* = 6.94, and b* = 23.23. The obtained values of the following thermal variables were: thermal diffusivity = 8.176 × 10−8 m2/s, thermal conductivity = .493 W/m °C, specific heat = 3.424 kJ/kg °C, and latent heat = 23442.74 J/kg. The total phenolic and tannin content in the roots were observed to be 24.41 ± .09 mg of gallic acid equivalent (GAE)/g and 1.73 ± .06 mg of tannic acid equivalent (TAE)/g, respectively. The flavonoid content in the roots was 10.33 ± .04 mg of quercetin equivalent (QE)/g. The root samples were found to be a high capacity to scavenge free radicals and also contain phytochemical components that may prove valuable in future research to combat oxidative stress. The findings of this study will also be advantageous in developing handling and processing equipment for the industrial production of asparagus root products.Practical applicationsAsparagus is a medicinal plant which is now widely used in food processing to produce the fortified‐functional food products because of its high nutritional and medicinal properties. The grading, sorting, conveying, pulping, processing, and handling equipment for various horticultural goods, including asparagus, are designed using machine designing parameters, which are vital and essential parameters. The size and shape of all agricultural commodities varies. The slight modifications to size and form could reduce the effectiveness of numerous procedures and their associated machinery. Therefore, the knowledge about these engineering and biochemical properties of asparagus will inspire researchers to create and upgrade machinery used for grading, sorting, conveying, pulping, and processing.

Hierarchical model to predict common carp and bigmouth buffalo abundance from electrofishing data

Catch per unit effort (CPUE) is used as an index of fish abundance under the premise that changes in CPUE result from changes in true density. However, catchability may also vary based on environmental conditions that affect observed CPUE. We developed a hierarchical model for estimating common carp ( Cyprinus carpio) and bigmouth buffalo ( Ictiobus cyprinellus) relative abundance with electrofishing survey data from six shallow lakes in northwest Iowa, USA, between 2018 and 2020. Common carp catchability was negatively associated with lake perimeter but unrelated to lake surface area, water depth, Secchi depth, temperature, and month of sampling. Bigmouth buffalo catchability was negatively associated with Secchi depth and water temperature and unrelated to other environmental variables. Hierarchical model posterior distributions of bigmouth buffalo density were less precise than Schnabel estimates, whereas common carp posterior distribution abundance estimates were more precise than Schnabel estimates. Our results indicate that hierarchical models can be a viable substitute for labor-intensive capture–mark–recapture methods to estimate unknown latent variables like relative abundance, and could be applied to other species, sampling gears, and management frameworks.

IMPACT OF HEAT TREATMENT METHOD AND MILLET POD TYPE ON REAL DENSITY AND POZZOLANIC ACTIVITY INDEX BY ASH RESISTANCE

Artificial pozzolans derived from agricultural by-products are generally obtained by heat treatment. The thermal treatment method used and the type of waste influence the quality of the final product. The aim of this study was to measure the actual density and pozzolanic activity index of millet pod ash produced in three different ways. Ash A is produced by direct calcination of the husks from which the millet seeds are removed (without the stalk). Ash B is obtained by burning and then calcining the millet husks. Ash C is produced by direct calcination of the millet straw (husks + stalks). The actual density was determined in accordance with standard NF EN 1097-6. The pozzolanic activity index by resistance was measured on the basis of the recommendations of American standard ASTM-C618. For the ashes A, B and C produced, we respectively obtained true densities of 2.256 g/cm3 2.150 g/cm3 and 2.033 g/cm3. The pozzolanic activity indices per strength obtained were 0.42, 0.23 and 0.70 respectively. These results showed that the ash produced from direct calcination of raw millet waste (straw) had the best reactivity and the lowest density. It is therefore well suited to the production of low-density cementitious matrix composites.

The effect of n-heptane soluble content on the composition and structure of coal tar pitch and the preparation of needle coke

To explore the effect of n-heptane soluble (HS) content in refined coal tar pitch (RCTP) on the preparation of needle coke (NC), a series of RCTP with different HS content were prepared by the solvent method. The RCTPs were reacted at 490 °C and 0.2 MPa for 6 h to obtain green cokes (GCs), and the GCs were calcined at 1400 °C to obtain NCs. The properties of RCTPs were studied by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance spectrum (1H NMR), and thermogravimetric (TG) analyses. The appearance and polarized microstructure of the GCs, and the Scanning electron microscope (SEM) image, X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, linear expansion coefficient, and true density of the NCs were obtained and analyzed. The results show that with the decrease of HS content, the aromaticity of RCTPs increases, and the amount and length of branched chains decrease. Mesophase structures in GCs formed by these RCTPs have different types and orientations, which leads to obvious quality differences in NCs. The NC prepared from RCTP with HS content of 15.9% (RCTP-4) has the lowest linear expansion coefficient of 0.991 × 10−6 /°C, the highest true density of 2.1195 g/cm3, better fiber structure and carbon microcrystalline structure. Therefore, the HS content should be controlled not less than 15.9%, and the TI content should not be higher than 12.6% when RCTP was prepared by solvent method.

Investigating the Impact of Co-processed Excipients on the Formulation of Bromhexine Hydrochloride Orally Disintegrating Tablets (ODTs)

PurposeOrodispersible tablets (orally disintegrating tablets, ODTs) have been used in pharmacotherapy for over 20 years since they overcome the problems with swallowing solid dosage forms. The successful formula manufactured by direct compression shall ensure acceptable mechanical strength and short disintegration time. Our research aimed to develop ODTs containing bromhexine hydrochloride suitable for registration in accordance with EMA requirements.MethodsWe examined the performance of five multifunctional co-processed excipients, i.e., F-Melt® C, F-Melt® M, Ludiflash®, Pharmaburst® 500 and Prosolv® ODT G2 as well as self-prepared physical blend of directly compressible excipients. We tested powder flow, true density, compaction characteristics and tableting speed sensitivity.ResultsThe manufacturability studies confirmed that all the co-processed excipients are very effective as the ODT formula constituents. We noticed superior properties of both F-Melt’s®, expressed by good mechanical strength of tablets and short disintegration time. Ludiflash® showed excellent performance due to low works of plastic deformation, elastic recovery and ejection. However, the tablets released less than 30% of the drug. Also, the self-prepared blend of excipients was found sufficient for ODT application and successfully transferred to production scale. Outcome of the scale-up trial revealed that the tablets complied with compendial requirements for orodispersible tablets.ConclusionsWe proved that the active ingredient cannot be absorbed in oral cavity and its dissolution profiles in media representing upper part of gastrointestinal tract are similar to marketed immediate release drug product. In our opinion, the developed formula is suitable for registration within the well-established use procedure without necessity of bioequivalence testing.

Moisture dependent postharvest physical and textural characteristics of brown sesame seed (var. TMV-4)

Physical and textural characteristics are important in design and manufacturing of harvest and post harvest machines. Some postharvest physical and textural characteristics of brown sesame seed (var. TMV-4) were determined as a function of moisture content in the range of 4.3 per cent to 20 per cent (d.b). The axial dimensions, geometric mean diameter, surface area, volume, sphericity and aspect ratio were found to be increasing linearly for all studied moisture levels. Furthermore, the thousand seed mass, true density, porosity and the angle of repose also increased linearly whereas, bulk density decreased linearly with the increase of moisture content under study. The results showed that the static coefficient of friction on four different surfaces of plywood, mild steel, galvanized iron and glass also increased linearly for all level of moisture. The initial cracking force, average rupture force and average rupture energy decreased linearly with increased moisture content of 4.3 to 20 per cent (d.b.).

Comparison of structural properties and removal behavior of composites containing chitosan and hexagonal boron nitride in different compositions

ABSTRACT This study aims to prepare different possible composites using hBN and chitosan in varying ratios and compare them with each other. Composites c/hBN:100/0, c/hBN:75/25 and c/hBN:50/50 were prepared in varying mass ratios. Depending on the changing mass composition, the characterization results are presented in comparison with each other. The surface structures were observed by SEM analysis. FTIR analysis was used for functional group determination. Surface and pore identification was carried out by BET analysis. Crystalline formations were revealed by XRD analysis. True density values were determined by pycnometric analysis. Also, the RB 49 dye removal behavior of the composites was examined and compared with each other. c/hBN:100/0 and c/hBN:75/25 showed the highest removals at pH 4 and as 86.53 and 90.2%, respectively, while c/hBN:50/50 showed it at pH 3 and as 86.59%. The highest adsorption capacities were determined as 105.28, 160.71 and 159.01 mg/g for c/hBN:100/0, c/hBN:75/25 and c/hBN:50/50, respectively at 0.3 g/L dosage. The pseudo-second-order kinetic model and intraparticle diffusion model fitted well with the processes over time. The Freundlich isotherm model was found to be compatible with the processes. The positive ΔH and ΔS values and negative ΔG values of each process were presented.

Physicochemical, Hydration and Steady Shear Rheological Properties of Flours Derived From Different Crop Residues From the Honduran Agro–Food Industry

This study aimed to determine the physicochemical, hydration, and rheological characteristics of flours derived from different crop residues (taro, cassava, maize, and banana) affected by climate change in Honduras and to investigate their potential application in food processes. The physicochemical (moisture content, ash, protein, crude fat, starch, amylose content, and color), hydration (water absorption capacity (WAC), water absorption index (WAI), water solubility index (WSI), swelling power (SP), true and bulk density), pasting (pasting temperature, peak, trough, breakdown, setback, and final viscosity), and rheological properties of the flours were evaluated. Taro flour had the highest values of ash content, WAI and SP and the lowest for crude fat, amylose content, bulk density and peak, breakdown, setback viscosity and consistency index. Cassava flour had the highest breakdown viscosity and flow behavior index values and the lowest for protein content, hysteresis loop area, yield stress, and consistency index. Maize flour had the highest crude fat, protein, and amylose content, bulk density, WAC, setback viscosity, hysteresis loop area, and yield stress, and the lowest values were for ash, protein content, WSI, pasting temperature, breakdown viscosity, and flow behavior index. Banana flour had the highest starch, carbohydrate, WSI, pasting temperature, peak viscosity and consistency index, and the lowest value for protein content, WAI and SP. The study's results have determined the compositional value and functionality of the flours obtained from the agro-residues studied for their potential use in different food products. Keywords: Crop residues flour; Food security; Change climatic; physicochemical characterization; steady shear

Physical Characteristics of Local Light-Brown Waxy Sorghum with Varying Levels of Polishing

Sorghum contains a high level of tannins and is known to be anti-nutritional and give rise to an astringent flavour, so polishing is needed. This study aimed to characterize local light-brown waxy sorghum from Lamongan due to varying levels of polishing. An experimental procedure with five replications was used. The results showed that the weight of 1000 grains, seed volume, bulk density, and true density one-time polishing was 20.3109±0.3606 g, 0.016±0.000 ml, 0.755±0.015 g/ml, and 1.70±0.02 g/ml, respectively, whereas the two-time polishing was 12.6072±0.6172 g, 0.010±0.000 ml, 0.843±0,011 g/ml, and 1.67±0,02 g/ml, respectively. The sorghum seed size after one-time polishing was length 4.64±0,23 mm, width 2.98±0,17 mm, height 2.38±0,08 mm, and sphericity 69.04%, whereas after two-time polishing it was 2.90±0.12 mm, 2.89±0.09 mm, 1.84±0.11 mm, and 85.82%, respectively. More polishing resulted in a decrease in 1000 seed weight, hardness, volume, porosity, and true density of sorghum. The results also revealed that sorghum was red after one-time polishing and yellow-red after two-time polishing. Tannin content was 8971.59±42.87 mg/L and 915.88±11.64 mg/L, respectively for one-time and two-time polishing. Light-brown waxy sorghum from Lamongan should be polished two-time to be developed into flour and instant sorghum rice. Keywords: Lamongan, Light-Brown Waxy Sorghum, Polishing, Physical characteristics, Tannins

Investigation of flocculation behavior of tailings during settling-concentration: influence of true density, particle size, and mud layer height

The rapid concentration of tailings is a crucial initial step in the cemented paste backfill (CPB) process, as it ensures the stability of the backfilling slurry concentration and the continuity of the backfilling process. The structure of flocs plays a pivotal role in tailings concentration, directly contributing to such critical technical parameters as settling speed and bottom flow concentration. However, most of the current studies focus on flocculant addition rather than the tailings slurry itself. Also, there is a lack of uniform characterization of the flocculant structure in the flocculation and settling system. This study establishes a semi-quantitative assessment system for evaluating the fine structure of tailings flocs based on indicators such as the exposure state of coarse particles, floc size, and floc compactness (porosity). The findings reveal that, during the settling process, the higher true density of tailings (3.156 g/cm3) and intermediate particles (40 wt% of 38 μm–74 μm particles) attenuates the clamping effect of turbulence on settling, leading to a faster settling rate to 0.65 cm/s and 0.29 cm/s respectively. Moreover, in the thickening process, tailings located at the bottom of the mud layer expedite the precipitation of interstitial water within the floc structure through the combined influence of gravity and rake frame shear. Consequently, a denser floc structure forms, as evidenced by a higher concentration of bottom flow at a macroscopic level. This conclusion provides a theoretical basis for faster preparation of highly concentrated tailings slurry in CPB.