True Density Values Research Articles

Assessment of Physical Properties of Black Gram and Green Gram Seeds in Relation to the Design of Seed Metering Mechanisms

In 2023, a comprehensive study was carried out at the Department of Agricultural Engineering, IARI, New Delhi, India, focusing on the investigation of vital physical properties encompassing size, sphericity, test weight, bulk density, true density, coefficient of static friction, and angle of repose for black gram and green gram seeds. Black gram seeds were characterized by mean dimensions of 4.90 mm (length), 3.74 mm (breadth), 3.57 mm (thickness), and a geometric mean diameter of 4.02 mm. In contrast, green gram seeds exhibited corresponding values of 5.08 mm, 4.06 mm, 3.99 mm, and 4.45 mm. Sphericity percentages were quantified as 82% for black gram and 86% for green gram. Mean bulk density measurements of 0.86 g/cc (black gram) and 0.87 g/cc (green gram) were accompanied by true density values of 1.36 g/cc and 1.38 g/cc, respectively. The mean angle of repose measurements were recorded as 24.06° (black gram) and 23.94° (green gram). The mean coefficient of static friction exhibited variability across different materials: 0.50 (aluminum), 0.45 (mild steel), 0.47 (galvanized iron), and 0.60 (plywood) for black gram seeds; while for green gram seeds, corresponding values were 0.48, 0.43, 0.45, and 0.57. Additionally, the mean thousand-grain weight was found to be 41.82 g for black gram and 46.18 g for green gram.

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.

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.

Study of mass transfer and hygroscopic properties of Australian mass-timber panels and species in hot and humid conditions- moisture sorption and desorption

ABSTRACT Wood is a commonly used building material with numerous advantages over other construction products. However, in engineered wood products such as cross-laminated-timber and laminated veneer lumber moisture absorption can lead to decay, swelling, deformation, and glue line failures, diminishing their properties. Understanding moisture intrusion processes in these materials can aid manufacturers, engineers, and architects in developing effective moisture management strategies during and after construction. The porosity of CLT 3P sections was 56.5%, higher than CLT 2P sections at 36.8%. True density varied among species, with radiata pine, southern pine, and shining gum measuring 1358, 1411, and 1031 kg/m3, respectively. True density values for CLT 3P, CLT 2P, and LVL were 1202, 837, and 1406 kg/m3, respectively. The species and sample type significantly influenced porosity and density values, crucial for future moisture modelling and predicting moisture gain/loss during wetting and drying processes. Moisture sorption and desorption properties were examined for Australian timber species, CLT, and LVL at different temperatures. LVL samples exhibited higher moisture content and dimensional changes, possibly due to improved moisture transfer facilitated by lathe checks. CLT samples demonstrated greater anisotropic behaviours than those of LVL samples. The product type and sample type had significant effects on equilibrium moisture content values.

An approach for predicting the true density of powders based on in-die compression data

Helium pycnometry, a commonly used technique for measuring the true density of powders, is sensitive to the release of volatiles during measurement. This can lead to over-estimated true density, and as such, an accurate method for determining the true density of powders containing volatile components is needed. Here, a method based on in-die compression data obtained with a compaction simulator was assessed. Specifically, the stress transmission coefficient (STC), measured using an instrumented die, was used to predict the in-die Heckel mean yield pressure (Py). A true density was derived by repeatedly performing a Heckel analysis using iteratively estimated true density values until the predicted Py value from the measured STC value is obtained from in-die density - pressure data. This novel method was validated using a set of water-free powders. Using crystalline hydrates, we further showed that the calculated true densities were closer to values calculated from crystal structure than those from helium pycnometry. Hence, this method may be used for determining the true density of powders from their STC values.

Impact of Using Hermetic Packaging and Preservative on Physical Properties of Rice Bran During Storage

Rice bran is one of the feed ingredients used in various types of animal rations in Indonesia. In addition to containing anti-nutrients, rice bran has also a low storability. This research was conducted to study the impact of using hermetic packaging and a preservative containing calcium propionate (ProsidTM MI 208) application on the physical properties of rice bran during storage. The factorial completely randomized design (CRD), 3 x 4 with 4 replications was applied. The first factor was storage time 0 (W0), 30 (W30), and 60 (W60) days; the second factor was burlap sack + 0 ppm calcium propionate (P1), burlap sack + 160 ppm calcium propionate (P2), hermetic sack + 0 ppm calcium propionate (P3), and hermetic sack + 160 ppm calcium propionate (P4). The variables measured were moisture content (MC), bulk density (BD), tapped density (TD) dan true density (TDS). The obtained data were analyzed using if there was a significant difference, followed by Duncan's multiple range test. The results showed that storage time significantly (P<0.05) increased the MC and decreased the BD, TD, and TDS values. The increasing MC and the decreasing BD, TD, and TDS values of the rice bran during storage were higher (P<0.05) in the burlap sakcs than in the hermetic sacks packaging both with and without the addition of calcium propionate. The combination of using hermetic sacks with the application of calcium propionate could further increase to maintain of the physical properties of rice bran from the damage. The use of a hermetic sack and the application of calcium propionate could maintain the quality of rice bran and increase the resistance of rice bran to damage during 60 days of storage.

Some physical, chemical, and germination properties of Peganum harmala L. seeds

AbstractIn this study, the aim was to determine some physical and chemical properties of the seeds of Peganum harmala, known as rue or harmel, and to determine the effects of some implementations to break the seed dormancy. The mean length, width, thickness, and surface area values for the P. harmala seeds were 4.78 mm, 1.81 mm, 1.53 mm, and 14.14 mm2, respectively. Linked to the dimensions, the arithmetic mean diameter, geometric mean diameter, and sphericity values were calculated as 2.71 mm, 2.34 mm, and 0.50. The bulk density and true density values were measured as 0.5379 and 1.015 g cm−3, respectively, and the porosity value calculated linked to these values was 46.98%. The static friction angles on two different surfaces of galvanized metal and polyvinyl chloride (PVC) were measured as 15.67° and 17.67°, and the static friction coefficient values linked to these angles were 0.28 for galvanized metal and 0.32 for PVC. Terminal velocity experiments determined the velocity for P. harmala seeds was 5.03 ms−1. According to analysis results for the chemical structure of P. harmala, dry matter ratio was 89.7%, crude ash ratio was 11.0%, crude protein was 10.3%, crude fiber was 42.0%, and crude oil ratio was 10.8%. In seed dormancy studies, the effects of sulfuric acid, precooling, soaking in water, and mechanical scarification (sanding) applications were determined. Accordingly, the most effective method for germination of P. harmala seeds was sanding with 84.0% germination rate. This was followed by soaking in water (78.0%) and 5 min H2SO4 (75.0%) applications.Practical ApplicationsTurkey is a country with a current account deficit in the seed import–export balance. Therefore, the efficient use of seeds in each step of farming and postharvest operations is essential to reduce the seed waste. Determining the engineering properties of seeds will help to provide more efficient systems. The physical properties of seeds are important to design, develop, and adjustment of planters, storage structures, transporting systems, and postharvest systems. Chemical properties are essential to determine the optimum storage conditions and postharvest chemical processes for optimum utilization of seeds as foods or as raw materials for medicinal and industrial purposes. Seed dormancy‐breaking features will be useful to determine optimum presowing conditions and breeding conditions of the seeds.

Traffic density estimation using vehicle sensor data

The objective of this study is to analyze the possibility of using vehicle sensors to estimate traffic density in future traffic environments. For the analysis, the simulation experiments used in this study consist of three steps to estimate traffic density based on vehicle sensor data. The first step is to develop software module that can generate error of distance measurement in a similar way to the real road driving. In the second step, this study conducted traffic simulation experiments by combining the true distance value measured in the simulation with the error value calculated by the error generating module of the first step. Finally, we conducted evaluation procedure by comparing the estimation results of traffic density to the true density value. According to the experiment results, the use of front and rear radar showed best performance in that this case maintained low MAPE (Mean Absolute Percentage Error) results even at low probe vehicle ratio as compared to other cases. In case of camera sensor, it can be important alternative at the standpoint of potential future applications, especially under limited traffic environments of high ratio of sensor-equipped vehicle and congested traffic conditions such as LOS (Level of Service) D or E.

13-93B3 Bioactive glasses containing Ce3+, Ga3+ and V5+: dose rate and gamma radiation characteristic for medical purposes

In this study, dose rates and radiation attenuation features of a group of fabricated bioactive glasses were investigated. The borate-based 13-93B3 bioactive glass powders (B3) containing cerium (III), gallium (III) or vanadium (IV) were prepared by melting a homogenized mixture of reagent-grade CaCO3, Na2CO3, MgCO3, K2CO3, H3BO3, CaHPO4.2H2O, Ga2O3, V2O5 or Ce(CH3CO2)3, and disc-shaped scaffolds were prepared by die pressing. Bioactive glasses were modelled by using MCNPX (version 2.7.0) general-purpose Monte Carlo code. A gamma-ray transmission set-up was utilized for determination of mass attenuation coefficients. The obtained coefficients were used for determination of other essential attenuation properties. Finally, exposure (EBF) and energy absorption (EABF) build-up factors were determined. Although the chemical structure of the additive material in bioactive glasses is identical, it can be inferred that the chemical structure of the additive is closely linked to the radiation attenuation characteristics of the bioactive glasses. Results also revealed that, although the bulk densities of the disc-shaped bioactive glass samples were lower than the measured true density values of the melt-derived glass powders due to porosity concerns, they exhibited radiation shielding effect. Findings of the study may be useful in understanding the radiation shielding characteristics of the bioactive glass scaffolds fabricated by powder processing. It can be concluded that outcomes of recent investigation can be useful during the evaluation of potential interactions between the bioactive glasses and medical radiation in the body.

REM: performance on a high-density fallow deer (Dama dama) population

We present an application of the random encounter model (REM) to estimate population density of a closed population of fallow deer (Dama dama). REM promises to be a powerful tool for providing density estimates for species which are not individually recognisable, but it still requires thorough testing to assess its limits and performance. In our study area, effective fencing prevents animals from migrating in or out of the area thus assuring a closed population; still the application of REM presented several challenges, including a very high density (more than 600 ind/km2) and a constant fission/fusion of groups of the study species. We applied both stratified and unstratified analysis approach, and we estimated density over a range of daily range values. The REM approach underestimates the true density value of about 31% and 28% the CV of the estimates was 0.39 and 0.52, for stratified and unstratified approach, respectively. Still it provides evidence in support of REM as a method for providing density estimates of free-ranging unmarked individuals with a fission–fusion social structure.

Effect of embedding eggshells to form calcium feldspar as flux in porcelain via slip casting process for bio-dental and medical applications

ABSTRACTBio-dental and medical porcelain products embedded with eggshell as a calcium flux were prepared by slip casting and fired at 600°C, 700°C, 800°C, and 900°C for 1 h, 3 h, and 5 h. The main composition of eggshell was calcium carbonate at 96.35 wt%, it is an inorganic material used to enhance mechanical, thermal, and physical properties of porcelain in the glassy phase formation during sintering. The obtained porcelain products, with embedded eggshell powder and fired at the low temperatures at 600°C, 700°C, 800°C, and 900°C for 1 h, 3 h, and 5 h, possessed relatively low thermal expansion coefficients, good true density values with high densification, high compressive strength, and high hardness. Scanning electron micrographs, X-ray diffraction patterns, Vickers micro-hardness, thermal expansion coefficient and physical properties (bulk density, true density, densification and shrinkage) were utilised to investigate and identify the microstructure, phase composition, hardness, thermal properties and characteristics of the porcelain products. The obtained soft porcelain products are potential in dental and medical applications such as artificial bone, teeth and joint, and medical glove formation.

Assessing mineral composition and morpho-physiological properties of de-hulled einkorn wheat during storage at different moisture levels

In this study were investigated the effects of different moisture levels (4.8, 9.5, 13, 16.7 and 20%, w.b.) during the storage at 10 °C for three months on some mineral compositions and morpho-physiological properties as dimensional (length, width, thickness, arithmetic mean diameter, geometric mean diameter, surface area and volume, sphericity), gravimetric (thousand grain weight, bulk and true densities) and the seed (colour measurement and electrical conductivity) of de-hulled einkorn wheat seeds. Mineral composition of wheat seeds changed with increasing moisture level. In particular, decreases in mineral composition were observed above 16.7% moisture level. Dimensional properties showed increases depending on increased moisture level. It was found that thousand grain weight and true density values increased with increase in moisture level. However, bulk density values were found to decrease with increase in moisture level. The seed colour properties as L*, a*, b*, Chroma, hue angle and Browning index did not change statistically at the end of three months storage with increase at moisture level. The results showed that mineral compositions and functional properties of seeds at moisture level of 9.5% is more suitable than other moisture levels. As a result, high moisture levels during storage can cause degradation of seed quality.

The Effect of Carrier Quantity and Drying Method on the Physical Properties of Apple Juice Powders

The study aimed at the evaluation of the physical properties of apple juice powders mixed with different concentration of maltodextrin obtained by freeze-, vacuum and spray drying methods. Due to the chemical composition of apple juice there was a possibility to obtain apple juice powders by freeze-, spray and vacuum drying, excluding vacuum drying at 40 °C when 15% and 20% of maltodextrin were added. The moisture content of powders was more dependent on the drying method than on the quantity of maltodextrin added. The spray drying process in the context of an increase in maltodextrin quantity resulted in a decrease in the water activity of apple powders, whereas low temperature processes increased its values. Lower values of true density were observed after spray drying in comparison to freeze- and vacuum drying processes. The application of selected drying methods resulted in the formation of different particles’ size of apple powders influencing the bulk density of the products. The highest values of bulk density were indicated for powders obtained by vacuum drying due to the bigger size of the particles (crystalized structure). The porosity of apple juice powders was strictly related to the bulk density. Colour parameters of powders were more influenced by drying techniques than the quantity of maltodextrin (15% up to 35%) added.

Indian wheat (Triticum aestivum L.) cultivars: physical characteristics, micronutrients and heavy metal content

Six (C-306, PBW-373, WH-147, WH-1025, PBW-343 and PBW-502) Indian wheat cultivars were evaluated for their physical, milling and colour characteristics. The micronutrients and heavy metals were detected using an atomic absorption spectrophotometer. The physical parameters of grains revealed that WH-1025 had the smallest whereas WH-147 had the biggest grain size. Cultivar’s C-306 and WH-147 showed significantly (P≤0.05) higher (58.828 and 58.805%, respectively) grain sphericity, so grains from these cultivars were more spherical in shape compared to other cultivars under study. The grains of studied cultivars were mealy and intermediate vitreous as reflected from their bulk and true density values. Cultivar WH-147 was the heaviest (4.313 g/100 grains) and also showed more volume (3.9 ml/100 grains) as compared to others, which reflected its importance for higher flour yield. Grains from cultivar WH-147 also showed the highest hunter L* and b* values, whereas grains from C-306 had the lowest hunter L*, a* a...

Coffee Husks Characterization for the Fast Pyrolysis Process

The lignocellulosic biomass is a renewable alternative for fossil fuels. The extensive cultivation of coffee grounds in Brazil generates a large amount of residues, as coffee husks. The work aimed at performing the coffee husks characterization, investigating the viability for fast pyrolysis application. Coffee husks were dried, grinded in a knives mill and sieved using a mechanical sieving; different vibration frequencies and times were used to evaluate the effect of these variables in the size distribution. The true density was inferred for three distinct size ranges of the coffee husks, using a helium pycnometer. Proximate and ultimate analyses were performed. The analytical pyrolysis was realized at 550°C, using a micro pyrolyzer (CDS 5200), vapors was identified by a gas chromatograph and a mass spectrometer (GC-MS QP 2010 plus, Shimadzu). The influence of the particles irregular shape was evidenced in the results of size distribution. The values of true density were around 1.5 g/cm3. The smaller the particle size, the higher the true density of the sample. Coffee husks can be used to generate high added value compounds: 1,3 pentadiene, limonene and n-hexadecanoic acid. Considering the use of coffee husks bio-oil as a fuel, results indicated that the bio-oil will present high calorific value, important acidity and smaller increases in viscosity and molecular weight if compared to the bio-oil of other lignocellulosic materials.

Synthesis, Properties and Application of Glucose Coated Fe3O4 Nanoparticles Prepared by Co-precipitation Method

Synthesis of glucose coated Fe3O4 magnetic nanoparticles have been successfully prepared with co-precipitation method. Raw material of natural iron-sand was obtained from Buaya River, Deliserdang, Indonesia. The milled iron-sand was dissolved in HCl (37 mole %), and stirred in 300 rpm at 70°C for 90 minutes. Glucose was added to the filtered powder with varied content of 0.01, 0.02, and 0.03 mole, and precipitated by NH3 (25 mole%). After drying process, the final product subsequently was glucose coated magnetite (Fe3O4) nanoparticles. The characterizations performed were true density measurement, FTIR, VSM, XRD, BET, and adsorbent performance by AAS. The FTIR analysis showed that M-O (bending) with M=Fe (stretching vibration) with υ = 570.92 and 401.19 cm-1. While glucose coated well on nanoparticle Fe3O4, proved by functional groups C=O (stretching), M-O (stretching) and C-H (bending) with υ = 1404.17, 570.92, and 2368.58 cm-1, respectively. Single phase of magnetite (Fe3O4) structure was determined from XRD analysis with cubic spinel structure and lattice parameter of 8.396 Å. The optimum conditions, obtained on the Fe3O4 nanoparticles with 0.01 mole of glucose addition, which has true density value of 4.57 g/cm3, magnetic saturation, Ms = 35,41 emu/g, coercivity, HcJ = 83.58 Oe, average particle size = 12.3 nm and surface area = 124.88 m2/g. This type magnetic nanoparticles of glucose-coated Fe3O4 was capable to adsorbed 93.78 % of ion Pb. Therefore, the glucose-coated Fe3O4 nanoparticle is a potential candidate to be used as heavy metal removal from wastewater.

SU‐F‐I‐41: Calibration‐Free Material Decomposition for Dual‐Energy CT

Purpose:To eliminate tedious phantom calibration or manually region of interest (ROI) selection as required in dual‐energy CT material decomposition, we establish a new projection‐domain material decomposition framework with incorporation of energy spectrum.Methods:Similar to the case of dual‐energy CT, the integral of the basis material image in our model is expressed as a linear combination of basis functions, which are the polynomials of high‐ and low‐energy raw projection data. To yield the unknown coefficients of the linear combination, the proposed algorithm minimizes the quadratic error between the high‐ and low‐energy raw projection data and the projection calculated using material images. We evaluate the algorithm with an iodine concentration numerical phantom at different dose and iodine concentration levels. The x‐ray energy spectra of the high and low energy are estimated using an indirect transmission method. The derived monochromatic images are compared with the high‐ and low‐energy CT images to demonstrate beam hardening artifacts reduction. Quantitative results were measured and compared to the true values.Results:The differences between the true density value used for simulation and that were obtained from the monochromatic images, are 1.8%, 1.3%, 2.3%, and 2.9% for the dose levels from standard dose to 1/8 dose, and are 0.4%, 0.7%, 1.5%, and 1.8% for the four iodine concentration levels from 6 mg/mL to 24 mg/mL. For all of the cases, beam hardening artifacts, especially streaks shown between dense inserts, are almost completely removed in the monochromatic images.Conclusion:The proposed algorithm provides an effective way to yield material images and artifacts‐free monochromatic images at different dose levels without the need for phantom calibration or ROI selection. Furthermore, the approach also yields accurate results when the concentration of the iodine concentrate insert is very low, suggesting the algorithm is robust with respect to the low‐contrast scenario.

Evaluation of Different Varieties of Lathyrus (<i>Lathyrus sativus</i> L.)

The physical properties of different varieties of lathyrus viz ., Ratan, Pratik, Mahateora, BIOR-231, Pusa-28, NLK-05, NLK-73, NLK-48, NLK-40 and NLK-36 were studied at moisture content of 7.90 to 19.40, 6.75 to 18.30, 9.48 to 21.02, 9.79 to 21.34, 9.52 to 21.04, 9.03 to 20.61, 9.91 to 21.49, 9.22 to 20.83, 9.42 to 21.03 and 9.10 to 20.71% (d.b.). The grain size, thousand grain weight and angle of repose, were found increased linearly and the average increase was found to be 8.07, 15.11 and 21.32%, respectively, with the corresponding increase in moisture content. The sphericity and porosity increased initially and then found decreased with further increase in moisture content. The bulk density and true density values decreased linearly and the average decrease was found to be 15.01 and 13.71%, respectively.

Mineralogy, geochemistry and petrogenesis of the Khopoli mafic intrusion, Deccan Traps, India

The Khopoli intrusion, exposed at the base of the Thakurvadi Formation of the Deccan Traps in the Western Ghats, India, is composed of olivine gabbro with 50–55 % modal olivine, 20–25 % plagioclase, 10–15 % clinopyroxene, 5–10 % low-Ca pyroxene, and <5 % Fe-Ti oxides. It represents a cumulate rock from which trapped interstitial liquid was almost completely expelled. The Khopoli olivine gabbros have high MgO (23.5–26.9 wt.%), Ni (733–883 ppm) and Cr (1,432–1,048 ppm), and low concentrations of incompatible elements including the rare earth elements (REE). The compositions of the most primitive cumulus olivine and clinopyroxene indicate that the parental magma of the Khopoli intrusion was an evolved basaltic melt (Mg# 49–58). Calculated parental melt compositions in equilibrium with clinopyroxene are moderately enriched in the light REE and show many similarities with Deccan tholeiitic basalts of the Bushe, Khandala and Thakurvadi Formations. Nd-Sr isotopic compositions of Khopoli olivine gabbros (eNdt = −9.0 to −12.7; 87Sr/86Sr = 0.7088–0.7285) indicate crustal contamination. AFC modelling suggests that the Khopoli olivine gabbros were derived from a Thakurvadi or Khandala-like basaltic melt with variable degrees of crustal contamination. Unlike the commonly alkalic, pre- and post-volcanic intrusions known in the Deccan Traps, the Khopoli intrusion provides a window to the shallow subvolcanic architecture and magmatic processes associated with the main tholeiitic flood basalt sequence. Measured true density values of the Khopoli olivine gabbros are as high as 3.06 g/cm3, and such high-level olivine-rich intrusions in flood basalt provinces can also explain geophysical observations such as high gravity anomalies and high seismic velocity crustal horizons.

A Case Study on Maximizing Aqua Feed Pellet Properties Using Response Surface Methodology and Genetic Algorithm

Aims: The present case study is on maximizing the aqua feed properties using response surface methodology and genetic algorithm. Study Design: Effect of extrusion process variables like screw speed, L/D ratio, barrel temperature, and feed moisture content were analyzed to maximize the aqua feed properties like water stability, true density, and expansion ratio. Place and Duration of Study: This study was carried out in the Department of Agricultural and Food Engineering, Indian Institute of Technology, Kharagpur, India. Methodology: A variable length single screw extruder was used in the study. The process variables selected were screw speed (rpm), length-to-diameter (L/D) ratio, barrel temperature (degrees C), and feed moisture content (%). The pelletized aqua feed was analyzed for physical properties like water stability (WS), true density (TD), and expansion ratio (ER). Extrusion experimental data was collected by based on central composite design. The experimental data was further analyzed using response surface methodology (RSM) and genetic algorithm (GA) for maximizing feed properties. Results: Regression equations developed for the experimental data has adequately described the effect of process variables on the physical properties with coefficient of determination values (R2) of > 0.95. RSM analysis indicated WS, ER, and TD were maximized at L/D ratiomore » of 12-13, screw speed of 60-80 rpm, feed moisture content of 30-40%, and barrel temperature of = 80 degrees C for ER and TD and > 90 degrees C for WS. Based on GA analysis, a maxium WS of 98.10% was predicted at a screw speed of 96.71 rpm, L/D radio of 13.67, barrel temperature of 96.26 degrees C, and feed moisture content of 33.55%. Maximum ER and TD of 0.99 and 1346.9 kg/m3 was also predicted at screw speed of 60.37 and 90.24 rpm, L/D ratio of 12.18 and 13.52, barrel temperature of 68.50 and 64.88 degrees C, and medium feed moisture content of 33.61 and 38.36%. Conclusion: The present data analysis indicated that WS is mainly governed by barrel temperature and feed moisture content, which might have resulted in formation of starch-protein complexes due to denaturation of protein and gelatinization of starch. Screw speed coupled with temperature and feed moisture content controlled the ER and TD values. Higher screw speeds might have reduced the viscosity of the feed dough resulting in higher TD and lower ER values. Based on RSM and GA analysis screw speed, barrel temperature and feed moisture content were the interacting process variables influencing maximum WS followed by ER and TD.« less