Values Of K1 Research Articles

Development of a kinetic model of magnetite leaching

The object of the research is the process of magnetite leaching with nitric acid solutions, and the subject of the research is the mathematical justification of the kinetic model and the calculation of kinetic parameters. The article considers the case of leaching in the kinetic region, while magnetite is considered as a polydispersity material of spherical shape. It is proposed to use the distribution function of the number of particles N by their radius r in the form N=a∙rb, where a and b are constants. This distribution was used to derive the equation for the rate of the process W, taking into account the change in the surface of the particles depending on the degree of leaching α: W=dα/dτ=K*∙(1–α)m∙((С0(γ–α)/γ))n, where K* is the rate constant; m and n are the order of solid material and nitric acid, respectively; C0 and γ are the initial concentration of nitric acid and its stoichiometric excess. The order m is defined as m=(b+2)/(b+3), at b→∞ the order m→1. When b=0, m=2/3 is the case of the equation for a shrinking sphere. An algorithm for calculating kinetic parameters in the Excel is proposed. Experimental dependences of the degree of transformation α on time τ are approximated by a third-order equation; by differentiating the obtained equation, the values of the velocity Wexp=dα/dτ at individual points are calculated. After the logarithm of the above equation, there is the expression (γ=1): ln(Wexp)=ln(K*)+m∙ln(1–α)+n∙ln(С0(1–α)). With the help of the «LINEST» function in Excel, for a temperature of 373 K, the values of the order of m=0.93 and n=1.29 and the rate constant K*=0.08 were obtained. Calculation of kinetic parameters for different temperatures takes into account the dependence of the rate constant on temperature: ln(Wexp)=lnk0–E/R∙1/T+m∙ln(1–α)+n∙ln(C0(1–α)). As a result of the calculations, the values n=0.83; m=1.2; E/R=–10402; lnk0=25.09 were obtained. The value of the multiplier k0=exp(lnk0)=7.88∙1010, the activation energy E=–8.31∙E/R=86440 J/mol, the total reaction order n+m=2.03 was calculated. The obtained kinetic parameters were used to determine the calculated values of the rate W. The average relative error between the experimental and calculated values of the leaching rates is 10 %. The proposed method of processing experimental data using a mathematical leaching model can be used for any leaching process.

Measurement and correlation of diffusion coefficients of vitamin K3 in a fluid mixture of carbon dioxide and decane at 313–343 K and 10–30 MPa

The diffusion coefficients D1m of vitamin K3 in a dense fluid mixture of carbon dioxide and decane were measured by the Taylor dispersion method at temperatures from (313.2–343.2) K and pressures from (10−30) MPa, over the entire range of decane composition. The D1m values of vitamin K3 increased with increasing temperature and decreasing pressure under isocratic conditions. In addition, the measured D1m values were found to be correlated with the hydrodynamic (HD) equation based on the Stokes–Einstein equation, with an average relative deviation of 4.9% for 110 conditions over a wide range of fluid viscosities ranging from that of supercritical carbon dioxide to that of compressed liquid decane, apparently irrespective of the decane composition and solvent species.

Effect of adsorption of pyocyanin on the electron transfer rate at the interface of a glassy carbon electrode

Redox mediators (RM) are an alternative to improve the performance of microbial electrochemical systems (MES) as they help significantly to develop the indirect electron transfer. However, their use is limited when the redox processes between the RM and the electrode surface are not thoroughly understood. The adsorption, the intermolecular interactions with the electrode, and the effects on charge transfer kinetics are important issues in MES such as microbial sensors, microbial electrosynthesis or microbial fuel cells, but are rarely analyzed. Pyocyanin, considered an RM, may present these features due to its chemical structure. Today, the electrochemical studies indicate that pyocyanin can presents adsorption processes on glassy carbon electrodes. However, the effects of adsorption on electron transfer rate and changes as a function of pyocyanin concentration have not yet been studied. Therefore, this work presents an electrochemical study of pyocyanin to determine the effect of concentration and adsorption on the electron transfer rate at a glassy carbon electrode. Analysis of the electrochemical profiles obtained by cyclic voltamperometry (CV) indicates that there is an effect of concentration (C*) on the heterogeneous electron transfer rate constant (k0) since the criterion ΔEp varies as a function of C*. In addition, the peak proportionality parameter Ipa/Ipc and the voltamperometric function Ip/v½ help deduct the adsorption to the electrode. Experimental data obtained by chronocoulometry (CC) and CV, indicate that k0 = 5.7 × 1011 m/s and Rct = 3.40 × 10−16 Ω under the C* = 0.14 mM condition, while k0 = 1.10 × 103 m/s and Rct = 1.60 × 10−7 Ω under the C* = 0.49 mM condition. The differences in k0 and Rct values at different values of C* are due to an accumulation of pyocyanin on the electrode surface in the inner Helmholtz plane (IHP), preventing the electron transfer of bulk-dissolved pyocyanin molecules present in the outer Helmholtz plane (OHP) region. The varying values of α, indicate that a part of the energy of the redox reaction could be employed for the adsorption processes. As for the interactions at the electrode, the values of the Laviron parameter (ν'gθT) indicate that attraction interactions between the pyocyanin molecules and the electrode dominate, since the values of ν'gθT are higher than 0. The results of this study will provide a comprehensive understanding of the redox cycle of pyocyanin. The information will be useful for the future development of electrochemical-microbial systems since that the interactions mediator-electrode may be an operational variable to facilitate their practical applications in environmental, sensing and electrosynthesis areas.

Ti, F Codoped Sodium Manganate of Layered P2-Na 0.7 MnO 2.05 Cathode for High Capacity and Long-Life Sodium-Ion Battery

Ti, F Codoped Sodium Manganate of Layered P2-Na _0.7 MnO _2.05 Cathode for High Capacity and Long-Life Sodium-Ion Battery

Homogeneous-heterogeneous reactions in MHD mixed convection fluid flow between concentric cylinders with heat generation and heat absorption

In this article homogeneous-heterogeneous (HH) reactions within MHD mixed convection flow on viscous fluid having the characteristic of heat generation/absorption between infinitely long concentric cylinders have been examined. Momentum and energy equations in dimensionless form have been converted into Bessel's differential equations for heat generation/absorption cases respectively, these equations are solved analytically. Furthermore, Runge-Kutta (R–K) technique has been applied for the nonlinear ODE of the concentration profile. Velocity, temperature and concentration profiles have been elaborated graphically by utilizing the impact of physical parameters Kn,H,Gr/Re,M,K1,K2andSc. The mixed convection parameter upsurges the velocity on the heated (inner) cylinder, and it decreases on the cold (outer) cylinder. Temperature declines through Rd when heat is generated, and it rises when heat is absorbed on the heated (inner) cylinder and a reverse impact is found on the cold (outer) cylinder. The concentration profile falls away for escalating values of Schmidt number Sc and homogeneous reaction parameter K1.

Exploring Lateral Movement Coefficient's Influence on Ground Movement Patterns in Shallow Urban Tunnels

In its natural state, the ground experiences geostatic stresses, which tunnel excavation disrupts, inducing both elastic and plastic deformations in the areas surrounding the tunnel. Consequently, displacements occur in the vicinity of the tunnel and at the Earth's surface. These displacements have the potential to inflict damage on existing structures and pose environmental hazards. To mitigatethese adverse consequences, accurate prediction of these changes is imperative. Several factors influence these movements, with the lateral earth pressure coefficient (K0) being a pivotal parameter. This paper delves into the repercussions of varying K0 values on surface movements, encompassing both longitudinal and Lateral directions, within shallow urban tunnelsis investigated using two excavation methods, NATM and TBM. The study leverages numerical simulations facilitated by the PLAXIS 3D TUNNEL software, with the results meticulously presented separately. The primary objective of this research is to furnish valuable insights into the intricacies of tunneling-induced ground movements, offering pragmatic implications for the field of tunnel engineering practices and the broader realm of urban infrastructure development.

Determination of Stability Constant of Flurosubstituted Chlconemines for its Medicinal Efficiency

The good activity of drug is depending upon its stability constant i.e. proton ligand stability constant and metal ligand stability constant. If the stability constant is fairly very good then it should use as a good and effective medicine .In content to this in present work the proton ligand stability constant and metal ligand stability constant of fluro substituted chalconeimines L5 = 2-Hydroxy naphthalene 4-dimethyl aniline 4- fluro chalconeimine [FN] are studied with highly reactive transition metal like (Cu (II), Co(II),Cr(II) and Fe(III)). The 70% dioxane water solvent system used in the present investigation. The presence of –OH group confirmed by using of 0.1 M ionic strength. The transition metal (Cu (II),Co (II),Cr(II)and Fe(III)) used and the ligand form 1:1 and 1:2 complex with all values of log k1 and log k2 positive.

STUDY OF WAVE TRANSFORMATION AT COASTLINE CHANGE IN MENDALOK, SUNGAI KUNYIT SUB-DISTRICT, MEMPAWAH REGENCY, WEST KALIMANTAN

As one of the coastal areas, Mendalok, Sungai Kunyit sub-District, Mempawah Regency faces problems caused by coastline changes such as administrative area changes and damage to the mangrove forest ecosystem in the region. The objective of this study is to determine the process of wave conversion leading to coastline changes and to determine the potential for coastline changes from 2021 to 2031. Coastline change modelling analysis is performed with the CEDAS-NEMOS application. The results showed that the wave movement pattern was dominated by the southwest and west with a significant wave height averaging 1.36 meters and the waves were broken with a wave angle of 208.09o. The result of the coastline change modelling shows that coastline changes are more dominant in the study area when experiencing abrasion with calibration values of K1 0.5 and K2 0.25. Predicting the coastline changes that will occur from 2021 to 2031 shows that the coast with the greatest abrasion value of 31.83 meters and some accretion is more dominant with the greatest accretion value of 11.21 meters.

STUDY OF WAVE TRANSFORMATION AT COASTLINE CHANGE IN MENDALOK, SUNGAI KUNYIT SUB-DISTRICT, MEMPAWAH REGENCY, WEST KALIMANTAN

As one of the coastal areas, Mendalok, Sungai Kunyit sub-District, Mempawah Regency faces problems caused by coastline changes such as administrative area changes and damage to the mangrove forest ecosystem in the region. The objective of this study is to determine the process of wave conversion leading to coastline changes and to determine the potential for coastline changes from 2021 to 2031. Coastline change modelling analysis is performed with the CEDAS-NEMOS application. The results showed that the wave movement pattern was dominated by the southwest and west with a significant wave height averaging 1.36 meters and the waves were broken with a wave angle of 208.09o. The result of the coastline change modelling shows that coastline changes are more dominant in the study area when experiencing abrasion with calibration values of K1 0.5 and K2 0.25. Predicting the coastline changes that will occur from 2021 to 2031 shows that the coast with the greatest abrasion value of 31.83 meters and some accretion is more dominant with the greatest accretion value of 11.21 meters.

Study on K0 consolidation triaxial test of remolded saturated loess

Experimental study on K0 consolidation test of remolded saturated loess is carried out by GDS static triaxial apparatus. The deformation characteristics of specimens, under different loading rates, are discussed and the test results are compared and analyzed. The results show that the changing trend of the curve modeling the relation between the axial stress and the axial strain of the sample is consistent even with the change in loading rates. Thus, under this same context, the larger the loading rate is, the greater the axial strain will be, when the axial stress reaches the same value. Moreover, under different loading rates, the trend of the relationship curve between the lateral pressure coefficient K0 and the axial strain of the soil sample is basically consistent. The stability value of the lateral pressure coefficient K0 of the sample varies with the loading rate, but only within a fixed range.

The Performance of Modified Progressive Mean Control Chart with different constant value.

Any manufacturing process cannot produce exactly identical items. In all kinds of processes, a certain amount of variability is present, which causes such kind of variations in the products. A modified progressive mean (MPM) control chart has recently been proposed plotting the statistic which uses the present data as well as the past data. We used the modified progressive mean (MPM) control chart with a different value of constant K0. The results showed an improved performance of the proposed chart for smaller, moderated and larger shifts in terms of power.

Efficient AcFc-[FeIII (acac)3 ] Redox Couple for Non-aqueous Redox Flow Battery at Low Temperature.

The temperature dependency of the electrochemical analysis of acetyl ferrocene (AcFc) and iron(III) acetylacetonate ([Fe(acac)3 ]) has been investigated for non-aqueous redox flow batteries (NARFBs). AcFc and [Fe(acac)3 ] were utilized as catholyte and anolyte species, respectively, in an electrochemical cell with a cell voltage of 1.41 V and Coulombic efficiencies >99% for up to 50 total cycles at room temperature (RT, 25 °C). Experiments with a rotating ring disk electrode (RRDE) indicate that the diffusion coefficient reduces with decreasing temperature from 25 °C to 0 °C, yet the overall storage capacity was higher than that of an aqueous redox flow battery (ARFBs). The electrochemical kinetic rate constant (k0 ) of AcFc was found to be greater than that of [Fe(acac)3 ]. However, the value of k0 was not affected by the variable temperature. 1 H NMR investigations reveal that temperature change during battery trials did not occur in any structural modification. The obtained result demonstrates the suitability of this battery at low temperatures.

Gamalama Volcanic Soil Potency as a Low-cost adsorbent for Mercury Removal

The increase in metal mining in the North Maluku region poses a threat of mercury pollution. In order to overcome this problem, a study was conducted on the utilization of Gamalama volcanic soil as a low-cost adsorbent for mercury removal. Gamalama is one of five active volcanoes in North Maluku, Indonesia, that have erupted hundreds of times and produced millions of tons of volcanic soil. Before being used as a mercury adsorbent, Gamalama volcanic soil was first activated using 2M HCl. The effect of activation was studied using FTIR and XRD spectroscopy. The activation treatment has an effect on decreasing the diffraction intensity of albite as a result of dealumination. Mercury adsorption was carried out by adding 20 grams of activated volcanic soil to 50 mL Hg2+ 5 ppm. The mixture was stirred with time variations of 10, 30, 60, 90 and 120 minutes. The highest percentage of mercury removal was 41.6% at a contact time of 120 minutes with an adsorbent mass of 40 mg. The adsorption process followed the pseudo-second-order kinetic model with the values of K2 and qe being 0.0451 and 3.212 respectively.

Impact of end-group modifications and planarity on BDP-based non-fullerene acceptors for high-performance organic solar cells by using DFT approach.

With the aim to enhance the photovoltaic properties of organic solar cells (OSCs), seven new non-fullerene acceptors (K1-K7) have been designed by end-group modifications of benzo[2,1-b:3,4-b']bis(4H-dithieno[3,2-b:2',3'-d]pyrrole) (BDP)-based small molecule "MH" (which is taken as our reference R) using computational techniques. To investigate their various optoelectronic parameters, DFT studies were applied using the B3LYP functional at 6-31G (d, p) basis set. The measurement of molecular planarity parameter (MPP) and span of deviation from plane (SDP) confirmed the planar geometries of these structures resulting in enhanced conjugation. Frontier molecular orbital (FMO) and density of states (DOS) analyses confirmed shorter band gaps of K1-K7 as compared to R, which promotes charge transfer in them. Optical properties demonstrated that these compounds have absorption range from 692 to 711nm, quite better than the 684nm of reference R. Molecular electrostatic potential (MEP) and Mulliken' charge distribution analysis also revealed the presence of epic charge separation in these structures. K1-K7 showed enhanced LHE values as compared to R putting emphasis on their better abilities to produce charge carrier by absorption of light. Reorganization energies showed that all newly designed compound could have better rate of charge carrier mobility (except K4) than R. Calculations of open-circuit voltage (Voc) and fill factor (FF) revealed its highest values for K3 and K4. Among newly designed molecules, K3 showed betterment in all its investigated parameters, making it a strong candidate to get enhanced power conversion efficiencies of OSCs.

Do microplastics affect sulfamethoxazole sorption in soil? Experiments on polymers, ionic strength and fulvic acid

Microplastics (MPs) and sulfamethoxazole (SMX) are emerging contaminants that are ubiquitous in the soil environment. In this study, we investigated MPs polymer type and soil environmental factor effects on SMX adsorption behavior in the soil system. Our results showed that MPs dosage affected the soil particles' SMX adsorption rate and capacity (Qe). Adding 1 % polystyrene (PS) increased the SMX adsorption rate significantly. The value of K1, which represented the adsorption rate, increased from 0.569 h−1 to 1.019 h−1. However, the addition of MPs reduced the soil's SMX equilibrium adsorption capacity slightly. Moreover, increasing salinity strength enhanced SMX adsorption capacity by MPs significantly. However, increasing calcium ions concentration decreased SMX adsorption in the MPs amended soil due to multivalent cationic bridging and competitive adsorption mechanisms. In addition, we observed that fulvic acid addition inhibited SMX adsorption. This study suggests that the addition of MPs reduced the adsorption of SMX in the soil slightly due to dilution effect. Meanwhile, changes in environmental factors also affected the adsorption behavior of SMX in soil amended with MPs.

Optimization of ultrasonication-assisted extraction conditions using RSM-I-Optimal experimental design to recover vitamin D2 and K1 from selected green leafy vegetable samples

This study employed the response surface methodology to optimize the extraction conditions for recovering vitamins D2 and K1 from green leafy vegetables using ultrasonication-assisted extraction. The vitamin content was determined using an Accucore C18 column and a UPLC-Q-ToF/MS method. An RSM-I-Optimal design was used for designing the experiment to find the best combination of solvent level (mL), sonication time (min), sonication frequency (kHz), and temperature (°C). The experimental data from a 25-sample set were fitted to a second-order polynomial equation using multiple regression analysis. The extraction models had R2 values of 0.895 and 0.896, respectively, and the probability values (p < 0.0001) indicated that the regression model was highly significant. The optimal extraction conditions were: solvent level of 65 mL, sonication time of 45 min, sonication frequency of 70 kHz, and temperature of 45 °C. Under these conditions, the predicted recovery (%) values for vitamins D2 and K1 were 90.7% and 90.4%, respectively. This study has the potential to use the reported extraction method for routine quantification of vitamins D2 and K1 in the laboratory using UPLC-Q-ToF/MS.

Larger Intrinsic Rate Constants of Alpha-amylase is Possible if Intrinsic Forward Rate Constant is ≠ Diffusion limited Rate of Encounter

Background: Previous research has shown that the intrinsic reverse (backward) and forward rate constants are larger than the effective or apparent rate constants for the formation and dissociation of an enzyme-substrate complex (ES). It is speculated that such intrinsic rate constants could be larger if an appropriate mathematical equation was adopted for their computation. &#x0D; Methods: Theoretical, experimental (Bernfeld method), and computational methods.&#x0D; Objectives: 1) To rederive the equations for calculating the intrinsic rate constants for forward (k1) and reverse (i.e., backward) (k2) reactions; 2) to calculate the intrinsic rate constants; and 3) to show that the probability (1/g) (or req(r)) that an enzyme is at a distance from the substrate is a variable. &#x0D; Results and Discussion: The equations for the determination of k2 and k1 were rederived. Unlike previous findings, the intrinsic (reverse) first order rate, k2 and forward second order rate, k1 were larger than their apparent counterparts, but they were, however, very similar in magnitude. The intrinsic rate constants were much larger than previously reported values when the enzyme (E) total concentration [ET] was much less than substrate’s total concentration [ST]. The k1 and apparent forward second order rate (kf) values where [ET] is much less than [ST] were &gt; where [ET] is less than [ST]. Therefore, the magnitude of the second order rate constant is a function of [ET]. The values of k1 and k2 where [ET] is much less than [ST] and vice-versa were respectively, 7.41 exp. (+6) L/mol. min and 81.34 exp. (+4) /min, and 15.76 exp. (+6) L/mol. min and 58.08 exp.(+4) /min. It was discovered that the probability (1/g) (or req(r))) that an enzyme is at a distance from the substrate with the possibility of mutual attraction is not constant. &#x0D; Conclusion: If the intrinsic forward rate constant (k1) is not equal to diffusion limited rate (kD) of encounter, the k1 and k2 values could be larger than values where k1 is equal to kD. The probability (1/g) (or req(r)) that an enzyme is at a distance from the substrate with the possibility of mutual attraction has been discovered to be a variable constant dependent on the concentration of the reaction mixture components and the enzyme's affinity for the substrate, and vice versa. Future research may attempt to derive an equation for the determination of an intrinsic catalytic rate constant for the formation of a product.

Analysis of Mixed Convection on Two-Phase Nanofluid Flow Past a Vertical Plate in Brinkman-Extended Darcy Porous Medium with Nield Conditions

The rapid advancement in technology in recent years has shown that nanofluids are very vital to further development in science and technology. Moreover, many industrial specifications cannot be met by allowing natural convection only, hence the need to incorporate forced convection and natural convection into a single flow regime. The research aims to quantify the mixed convective two-phase flow past a vertical permeable surface in a Brinkman-Extended Darcy porous medium (BEDPM) induced by nanofluid, with heat and mass transfer. In addition, the Nield condition is also incorporated. The model of the problem was initially constructed in the vital form of leading governing equations (LGEs). These LGEs are specifically called partial differential equations (PDEs) (because of two or more independent variables) which were later converted into a set of the single independent variable of ordinary differential equations (ODEs) by implementing the similarity transformations. The set of single independent ODEs was numerically solved via the boundary value problem of fourth-order (bvp4c) technique. The bvp4c is one of the most frequently recommended built-in MATLAB subroutines based on the three-stage Labatto formula. The impact of several physically embedded influential parameters on the fluid flow, along with mass and thermal properties of the nanofluid in a Brinkman-Extended Darcy porous medium for the cases of buoyancy assisting flow (BAF) and buoyancy opposing flow (BOF), were investigated and argued. The numerical outcomes clarify that the porosity parameter reduces the velocity, whereas the concentration and the temperature enhance in the case of the buoyancy assisting and buoyancy opposing flows. In addition, the wall drag force elevates for the larger value of the dimensionless permeability parameter K1 and the buoyancy ratio parameter N, while it declines for the modified porosity parameter ε1.

Presbyopia correction with a new Extended Depth of Focus Intraocular Lens.

Extended depth of focus intraocular lenses (EDoF IOLs) offer an expanded number of modalities for simultaneous cataract and presbyopia treatment. The objective of the current study was to assess clinical outcomes with a new mono-EDoF intraocular lens and to analyze the effect of different parameters on postoperative results. The inclusion criteria were defined as uneventful cataract surgery, no history of concomitant ocular disease, implantation of ZOE Primus-HD lens. Parameters from IOL Master 500 were analyzed. The main outcome measures were postoperative uncorrected distance (UDVA) and intermediate (UIVA) visual acuity. The study included 39 eyes of 37 patients (15 males and 22 females) with a mean age of 73.59±7.71. Postoperatively, the UDVA improved to 0.84±0.16 (p<0.001) and UIVA was 0.86±0.14. There was no correlation between K1, K2 and IOL power with both postoperative UDVA and IDVA. Moreover, there was no statistically significant difference between UDVA and UIVA between patients with mean K value over or under 44.0D (p=0.204 and p=0.817, respectively). The results of a multinomial logistic regression analysis for the predictive value of the factors K1, K2 and IOL power demonstrated no statistical significance, except for UIVA with a significant influence of IOL power (p=0.024) in patients with less than 0.9 Snellen visual acuity. The implantation of the new mono-EDoF ZOE Primus-HD lens led to improvement in both UDVA and UIVA. Patients with keratometry values less than 44.0D could still benefit from the mono-EDoF lenses. Further studies including wavefront aberrometry are needed to study the interaction between corneal aberrations and EDoF IOLs. Abbreviations: IOL = Intraocular lens, UDVA = Uncorrected distance visual acuity, UIVA = Uncorrected intermediate visual acuity, D = Diopters, EDoF = Enhanced Depth of Focus, MF IOL = Multifocal intraocular lens, AUC = area under the curve.

327 Parameter Updates in the Davis Growth Model for Growth, Intake, and Composition of Modern Angus-Cross Cattle

Abstract The Davis Growth Model is a dynamic model used to estimate body composition and growth in beef cattle by simulating total body DNA and protein turnover. Since model development and parametrization in the 1980s, the model has been re-structured to account for previous rate of protein accretion and prior nutrition. Original parameter estimates for alpha (maintenance constant, where net energy for maintenance is alpha x shrunk body weight0.75; 0.08406) and K2 (protein synthesis rate constant; 0.0444) may not fit modern, heavier, more productive cattle. Angus-cross steers (n = 24; initial body weight 402 ± 12 kg) were fed using automated feed weight stations in group pens (8 steers/pen). Steers were fed a high energy ration twice daily, at 10% greater than the intake from the previous day. Steers were measured for hip height, body weight (BW), and ultrasonic measurements for ribeye area and back fat every 28 d until harvest (d 128). These measurements were used to calculate empty BW, empty body fat, and empty percent body fat for alpha and K2 estimates. Parameter estimates (± SD) were 0.12661 (0.01587) and 0.04919 (0.00220) for alpha and K2, respectively. Parameter estimates in the current study reflect a large increase in apparent maintenance. Maintenance requirements were moderately correlated with back fat thickness and feed conversion efficiency. Protein turnover had very strong correlations with ribeye area and feed conversion efficiency. Average feed conversion efficiency in the current study was 0.17. To evaluate parameter estimates, the model was re-run using the new values for alpha and K2. On average, the model underpredicted final empty body weight by 0.08 kg and empty body fat percent by 0.01%-units. Considering the relatively large variation among observed alpha values and the magnitude of increase compared with those previously reported, further research is required to determine an accurate alpha.