Smith Models Research Articles

GENETIC AND ENVIRONMENTAL COMPONENTS IN THE PATHOGENESIS OF DYSMETABOLIC NEPHROPATHY WITH OXALATE-CALCIUM CRYSTALLURIA

Introduction. In recent years, the prevalence of dysmetabolic nephropathies (DN) in children has been increasing, constituting a significant portion of the overall structure of kidney diseases in this age group. Aim. To elucidate the role of genetic and epigenetic components in the pathogenesis of dysmetabolic nephropathy with oxalate-calcium crystalluria in children using the methods of G. Edwards and D. Falconer. Materials and methods. A genealogical history was collected for 108 children aged 6 to 18 years with dysmetabolic nephropathy and 65 healthy children from the Ivano-Frankivsk region. Data were collected on 1076 relatives of affected children of I-II-III degrees of relatedness and 676 relatives of healthy children. Calculation of the contribution of genetic and environmental factors to the occurrence of multifactorial diseases in children was carried out using the model proposed by G. Edwards and G. Smith, and the heritability coefficient for susceptibility to these diseases was calculated using D. Falconer's model. Results and discussion. In the pathogenesis of dysmetabolic nephropathy in children, the genetic component plays a significant role, being 2-3 times greater than in the general population. The heritability coefficient for susceptibility to dysmetabolic nephropathy is very high: for first-degree relatives of affected children – 24%, for second-degree relatives – 20.9%, and for third-degree relatives, it does not differ from the population average – 3.6%. Conclusions. 1. If a family has a child with dysmetabolic nephropathy or a relative with metabolic pathology, the risk of dysmetabolic nephropathy in the second child is higher according to the G. Edward's and G. Smith's models is very high – 36.76% and 48.81%. 2. For relatives of sick children of the first degree of consanguinity, the inheritance rate of predisposition to dysmetabolic nephropathy is very high – 24% and 22%, respectively, in the observation groups and does not depend on the variant of the course of dysmetabolic nephropathy, nor on who is sick – parents or siblings. 3. The risk of having dysmetabolic nephropathy for relatives of the second degree of consanguinity of children with dysmetabolic nephropathy is also quite high – 20.9%. For relatives of the third degree – 3.6%.

Evaluation of fatigue life prediction models and investigation of fracture mechanisms of mild steel

Fatigue is one of the dilemmas of coiled tubing (CT) in oil and gas engineering. This study investigated the fatigue behavior of CT employing mild steel, which is commonly utilized in the CT110. Two fatigue life prediction methods based on cyclic strain-life principles, the Manson–Coffin and Landgraf models, as well as the Smith and Ellyin models based on energy-life principles, were evaluated. The Ellyin model demonstrated superior accuracy in predicting the low-cycle fatigue life of CT110, displaying dispersion within the 1.5 scatter band. This research integrated mechanical property analysis and microscopic deformation assessments for CT110. Fatigue mechanics studies show cyclic softening behavior in the CT110 of mild steel. The results of the microscopic analysis show that the fatigue fracture of CT110 has typical fatigue striations and equiaxial dimples as a plastic fracture. Combined with TEM and EBSD analysis, fatigue deformation increases grain deformation and dislocation density. In addition, the increase in dislocation density results from the combination of cycles and strain amplitude. The results of in situ EBSD further support this view. At 8% strain amplitude, the dislocation density increases to 0.196B when the cycle increases from 0 number to 10 number. Furthermore, the ferrite grain slip becomes accessible, but the 〈111〉 // Z0 direction is still the main texture. These are fundamental reasons for the cyclic softening of the CT110 mild steel, supported by a decrease in stress amplitude.

Effects of urea on the aqueous solvation structure and dynamics of cis/trans-N-methylformamide: An insight from molecular dynamics simulation study

We have performed classical molecular dynamics simulation of aqueous cis/trans-N-methylformamide (NMF) systems in the presence of urea at 298 K by considering the Smith and Duffy models of urea with varying concentrations, ranging from 0 to 13.26 m. It is found that irrespective of urea models, the donating ability of the hydrogen atom of NMF to the oxygen of urea is higher than the oxygen of water, while it is comparatively higher in Duffy model. The overall urea–water interaction is significant for the Smith model, whereas the Duffy model favors the urea–urea interactions. The center of mass radial distribution functions [gCM(r)] of cis/trans-NMF suggest water is preferred in the near vicinity over urea in the solvation shell of these two conformers. A shoulder around 3.50 Å in gCM(r) of trans-NMF and water is mainly due to the hydrogen bonding contribution from the water molecules. The translational and rotational dynamics of cis/trans-NMF are slower with the addition of urea, but the slowing down is significant in trans-NMF. A similar behavior is also observed for water and urea. The higher dipole orientational relaxation time of urea for the Duffy model indicates its aggregation behavior. The hydrogen bond lifetime of Otrans…Hwat is higher compared to Ocis…Hwat for both the urea models. It is also observed that a significant increase in water–water hydrogen bond lifetime with varying concentrations of the Smith model of urea. It is also found that the stability of all these hydrogen bonds comparatively higher in Smith model.

Potential effect of citrate nanocellulose on barrier, sorption, thermal and mechanical properties of chitosan/Arabic gum packaging film

Currently, the necessity to diminish environmental pollution caused by petroleum-based packaging plastics has encouraged interest in creating renewable and biodegradable packaging polymers. The objective of this study is the development of a green nanocomposite constructed from citrate cellulose nanospheres (CNC) that have been embedded in (CH/AG) Chitosan/Arabic gum (CNC@CH/AG) to meet the mechanical requirements. Citrate CNC was prepared using a citric acid/HCl acid mixture and it is investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Zeta potential, and degree of substitution. CNC@CH/AG film was investigated by FTIR, XRD, scanning electron microscope (SEM), wettability, mechanical, barrier, water vapor sorption, and thermal characteristics. CNC@CH/AG film displayed declining in water vapor permeability. The lowest water vapor permeability (WVP) value was 0.044 ± 23 × 10−3 g. mm. kPa−1. h−1. m−2 compared with control (CH/AG) was 0.129 ± 81 × 10−3 up to 3 mg CNC. For sorption properties, the CNC@CH/AG nanocomposite films are consistent with the GAB model, Smith, Henderson, and Peleg models. In comparison to CH/AG, the addition of CNC enhances all of the nanocomposites' tensile strength and Young's modulus by nearly two and three times, respectively, with a decrease in elongation percentage. The addition of CNC renders CNC@CH/AG nanocomposite films more thermally stable and the total activation energy of CNC@CH/AG nanocomposite film (−94.97 J/mol) is more than three times that CH/AG film (−34.04 J/mole).

Nonlinear modeling of carbon dynamics in soil treated with tannery sludge

In 2020, the Brazilian commercial cattle herd was the largest in the world, representing 14.3% of the worldwide herd, with201.7 million heads. Although this activity yields significant profits, contributing to the economic and social development ofBrazil, it has been the target of concerns, mainly due to the large production of waste/effluents associated to bovine leatherprocessing. In this scenario, mineralization is important because nutrients essential for plant growth are released duringthe process of organic waste decomposition, and the dynamics of carbon release can be described by nonlinear regressionmodels. Thus, this study aimed to model the mineralization of organic carbon in the soil for 6, 12, 24, and 36 megagramsdoses per hectare (Mg ha−1) of tannery sludge using the Stanford & Smith, Cabrera, and Juma nonlinear models. Very clayeysoil samples were used: eutroferric red nitosol (NVef). Mineralized carbon was measured in 21 observations over time untilthe 105th day of incubation. Parameters were estimated using the least squares method. Adjustments were compared usingthe corrected Akaike information criterion (AICc) and the adjusted coefficient of determination (R2aj) as selection criteria. The Cabrera model had the best adjustments for doses 6, 12, and 24 Mg ha−1 and Juma for dose 36 Mg ha−1, based on the selection criteria used. Although the Stanford & Smith model is the most widely used in the literature to model soil carbon dynamics, its use was not the most appropriate for any of the doses evaluated in this study. The higher the dose of tannerysludge, the greater the amount of potentially mineralizable carbon.

Moisture sorption isotherms and thermodynamic properties of tiger nuts: An oil-rich tuber

The moisture adsorption isotherms of tiger nuts were determined by a gravimetric static method at 15, 25, 35 °C within the water activity varying from 0.113 to 0.979. Ten mathematical models were selected to fit the adsorption data using non-linear regression technique. Thermodynamic properties such as isosteric heat, sorption entropy and Gibbs free energy were evaluated. The results indicated that equilibrium moisture content of tiger nuts tended to increase with increasing water activity and decreasing temperature. The isotherm curves of tiger nuts exhibited a Type Ⅱ sigmoidal shape. Peleg model was the most suitable for describing the experimental sorption behavior, followed by the Smith and GAB models. The adsorption surface area and monolayer moisture content of tiger nuts obtained from GAB model were 166.37–149.74 m2/g solid and 4.71–4.24 H2O/100 g solid, respectively, which decreased with increasing temperature. Moreover, the isosteric heat of adsorption decreased exponentially with the increase of equilibrium moisture content, while the Gibbs free energy was opposite. Adsorption entropy was negative in value and it decreased sharply and then rose slowly as the moisture content increased, having a minimum value (6.43 J/mol K) at a moisture content of 11 g/100 g d.b.

Adsorption Isotherms and Thermodynamic Properties of Dried Tomato Slices

Moisture adsorption isotherms and thermodynamic properties of dried tomato slices obtained from four tomato varieties were investigated. Freshly harvested tomatoes were pretreated with potassium metabisulphite solution (0.2%, weight/volume) before drying in a cabinet dryer at 60± 2° C. Moisture adsorption behavior of the dried tomato slices was determined using the static gravimetric method at 25, 30 and 40o C. The data fitted to GAB, M.BET, DLP, Smith and Oswin sorption models. The isosteric heat of sorption was also determined. Moisture adsorption isotherm of dried tomato slices from UC82B, Roma, Eva-F1 and Kerewa varieties exhibited a sigmoid isotherm curve typical of type II BET classification. Increase in temperature resulted into a decrease in the equilibrium moisture content. The GAB, DLP and modified BET model adequately modeled the isotherms of dried tomato slices. The relationship between isosteric heat of sorption and the equilibrium moisture of dried tomato slices were accurately described by exponential model.

Data-driven Update of Smith Predictor and Models by Using Initial Control Signals

Data-driven Update of Smith Predictor and Models by Using Initial Control Signals

Moisture sorption isotherms and estimation of isosteric heat of sorption of donkey milk powder

The moisture sorption isotherms of donkey milk powder were studied at 20, 25 and 30°C for 0.22 to 0.93 aw through gravimetric method. GAB, Peleg, Smith and Oswin mathematical models were fitted to experimental data. Equilibrium moisture content of the sample increased from 0.0499 to 0.3255, 0.0447 to 0.2904, 0.0426 to 0.2618 kg.kg−1 solid at 20, 25 and 30°C with increasing aw from 0.22 to 0.93. Isotherm curves showed type II behavior. Monolayer moisture content decreased from 0.0373 to 0.0301 g.100 g−1 solids at 20 to 30°C. The net isosteric heat of sorption decreased from 98.55 to 0.74 kJ.mol−1 with increased moisture content from 2 to 20% (d.b.). The adsorption isotherm curves suggest that the sample requires more attention when handled in RH higher than 24, 33 and 42% at 20, 25 and 30°C. Novelty impact statement Donkey milk powder was stable below 42% RH at 30°C. The best-fitting Oswin model equation provides a solid foundation for future research on drying and storage of donkey milk powder. Isosteric heat of sorption of donkey milk powder decreases with increase in moisture content.

Non-Drude-Type Response of Photocarriers in Fe-Doped β-Ga2O3 Crystal

Beta gallium oxide, β-Ga2O3, is one of the promising ultrawide bandgap semiconductors with a monoclinic (C2/m) β-phase structure showing strong anisotropic properties. To improve the performance of these devices, more optical characterization is required. Here, the anisotropic carrier dynamics in optically excited (010) oriented Fe-doped β-Ga2O3 was studied by terahertz time-domain spectroscopy. An 800 nm continuous-wave light source was employed to excite carriers from Fe acceptors to the conduction band and to probe an anisotropic interaction with the THz field. The complex THz conductivities fitted with the Drude and Drude–Smith models revealed that the optically excited carriers behave as nearly free carriers along the a-axis, whereas those along the c-axis show a non-Drude type response. The estimated mobility for the c-axis agrees with the reported values, whereas the results suggest much higher mobility along the a-axis.

A novel approach to design sustainable fiber reinforced materials from renewable sources: mathematical modeling for the evaluation of the effect of fiber content on biocomposite properties

The paper reports a sustainable, fast and efficient methodology to treat natural hemp fibers (HF) using a mechanochemical approach. Mechanical milling was used to carry out an alkaline attack on HFs for 30 min at ambient temperature. Composites HF/pectins were prepared by varying the fiber weight fraction (3%; 7.5%; 10%; 20% w/w by weight). The improvement in thermal degradation, mechanical and barrier properties to water vapor was correlated with the fiber volume fraction and mainly due to the improved fiber-matrix adhesion. The fibers–matrix interaction was then evaluated by analyzing and modeling the mechanical properties using several mathematical models: a modified Nielsen and Pukànszky and Smith models. Sorption isotherms to water vapor were analyzed through a modified Guggenheim, Anderson, de Boer (GAB) model where a new parameter, α, was introduced to consider the heterogeneity of the system. Finally, a modified Burgemman model was used to fit the experimental data and support the improvement in water diffusion with fiber loading.

Max-stable processes with geometric Gaussian model on ocean wave height data

In Spatial extreme value (SEV) is a method used to model an extreme event in several locations where there are dependencies between these locations. This method is a development of the Extreme Value Theory which is used in univariate cases. One of the approaches used in SEV is the max-stable process. Several models used in the max-stable process are the Smith, Schlater, Brown Resnick and Gaussian Geometric models. In general, these models have a Generalized Extreme Value (GEV) distribution. This study uses rainfall data in Central Java, then the extreme data is selected by the Maxima block method. The basic principle of maxima block is that extreme data is selected from the maximum data in each predefined block. The next step is modeling the extreme data with a geometric-Gaussian model. This method is a development of the Smith and Schlater models. The model obtained is then used to predict extreme rainfall using the return level. The result is that the maximum extreme rainfall in the next two periods is Pekalongan Station 1.16, Rembang station 0.8 and Semarang station 1.29 with an RMSE of 1.9.

Revisiting the application of classical formulas to estimate Bali cattle’s body weight based on body measurement variables

Predicting cattle’s body weight is a common practice considering various reasons. This paper revisits four classical formulas commonly found in papers published by Indonesian researchers in predicting cattle’s body weight based on their body measurements namely Schoorl, Winter, Smith and Lambourne models. Data on body weight (BW) and body measurements (Chest Girth=CG and Body Length=BL) of 118 male and 106 female Bali cattle (2-3 yo) were collected from Bali cattle Breeding Center. The estimates from the prediction formulas were compared to the actual body weight. We run 10-folds cross validation procedure to obtain the predictive ability parameters. The mean BW, CG and BL for male cattle were 199.19±51.51 Kg; 144.55±13.43 cm and 107.86±9.30 cm; whereas for females were 161.34±34.35 Kg; 134.25±10.26 cm and 101.48±3.60 cm respectively. All four formulas have the accuracy between 84.90 to maximum of 89.68% in both male and female cattle groups. RMSE were considerably high in both male group (17.64 – 45.31) and female group (11.52 – 26.61). Although the correlations between actual and predicted BW are high, further study need to be done to determine whether the utilization of these predicted values as a response variable will introduce enough bias to affect the results of a research.

Max-stable processes with geometric Gaussian model on ocean wave height data

In Spatial extreme value (SEV) is a method used to model an extreme event in several locations where there are dependencies between these locations. This method is a development of the Extreme Value Theory which is used in univariate cases. One of the approaches used in SEV is the max-stable process. Several models used in the max-stable process are the Smith, Schlater, Brown Resnick and Gaussian Geometric models. In general, these models have a Generalized Extreme Value (GEV) distribution. This study uses rainfall data in Central Java, then the extreme data is selected by the Maxima block method. The basic principle of maxima block is that extreme data is selected from the maximum data in each predefined block. The next step is modeling the extreme data with a geometric-Gaussian model. This method is a development of the Smith and Schlater models. The model obtained is then used to predict extreme rainfall using the return level. The result is that the maximum extreme rainfall in the next two periods is Pekalongan Station 1.16, Rembang station 0.8 and Semarang station 1.29 with an RMSE of 1.9.

Carrier transport mechanism and carrier dynamics of layered molybdenum disulfide

The carrier transport mechanism of layered molybdenum disulfide (MoS2) is studied by terahertz time-domain spectroscopy. The sheet conductivity and the change of sheet conductivity of layered MoS2 under different pump excitations is studied. The carrier mobility is obtained by analyzing the optical conductivity with the Drude and Drude–Smith models. The carrier dynamics of layered MoS2 is investigated by an optical pump-terahertz probe. It was found that multilayer MoS2 exhibits a higher optical conductivity and mobility than monolayer MoS2, especially under pump excitation.

Isothermal adsorption modelling of pupuru flour

The amount of moisture adsorbed by stored food products usually varies with temperature and relative humidity at a constant pressure. This research was carried out to determine the sorption isotherm behaviour of pupuru flour in the temperature and water activity (aw) ranges of 10−50 oC and 0.10−0.93 using gravimetric method. The Guggenheim-Anderson-De Boer (GAB), Brunauer-Emmett-Teller (BET), Oswin and Smith sorption equations, formulated for the sorption characterization of starchy foods, were used to constitute the models. The results show that the sorption isotherm curve is similar to a Type II classification typical of starchy foods. Also, the sorption parameters (Mo, C and K) were generally higher for the products stored at 10 oC and 0.10 aw. The parameter K decreases with an increase in the temperature for the GAB and the Smith models, but remains inconsistent for the Oswin model. The Mo increases with an increase in the temperature for the GAB and Smith models. The GAB, Oswin and Smith models were generally adequate and valid with an MSE< 10% and a high degree of fitness (R2 and R2adj > 90%). This indicates their ability to predict the sorption isortherm characteristics of the pupuru flour within its range of the aw and the storage temperature.

Thermodynamics, kinetics, and isotherms for phenol removal from wastewater using red mud

Abstract The phenol removal through adsorption using industrial waste has been studied. The red mud generated as waste in the aluminum plants was used in this research. The surface characterizations of red mud were assessed. The batch experiment was investigated with pH (2–12), adsorption period (120–600 min), phenol content (40–200 mg/L), adsorbent dose (2–7 g/L), and temperature (30–50 °C). At the optimum operating condition, the percentage of phenol removal was 87.5%. The pseudo-second-order kinetic model (r2 = 0.98625–0.99994) fitted better than the pseudo-first-order kinetic model. The Freundlich isotherm model was best fitted (r2 = 0.99734–0.99955) among Langmuir, Dubinin–Radushkevich (D-R), and Temkin isotherms. The Langmuir monolayer adsorption capacity was 49.30966 mg/g at 30 °C. The adsorption mechanisms were supported by Reichenberg, Fick, Elovich, Furusawa, and Smith and Boyd models (r2 > 0.8). The thermodynamics suggested endothermic, random, and spontaneous adsorption above 50 °C. The scale-up design using the Langmuir isotherm, and the disposal of used adsorbent after incineration, was established in this study. The research concludes that the red mud generated from the aluminum plant can be used to remove the phenol from wastewater.

Kivi Meyvesinin İnce Tabaka Kurutma Karakteristiklerinin ve Sorpsiyon Özelliklerinin Saptanması

Meyve ve sebzelerin hasat dönemi dışında da tüketilmesi ve pazar değerinin korunması amacıyla kullanılan yöntemlerin başında kurutma işlemi gelmektedir. Bu çalışmada, son yıllarda ülkemizde üretimi hızla artan kivi meyvesi, 3 mm kalınlıkta dilimlenerek, sıcak havalı bir kurutucuda farklı sıcaklıklarda (50-60-70˚C) ve sabit hava hızında (2.2 m/s) ince tabaka halinde kurutularak kurutma karakteristikleri saptanmıştır. Su ve ürün arasındaki fizikokimyasal ilişkiyi anlamak ve ürünün kalite stabilitesinin devamlılığı bakımından oldukça önemli olan sorpsiyon izotermleri de (desorpsiyon ve adsorpsiyon) 30, 40 ve 50 ˚C olmak üzere 3 farklı sıcaklık ve 5 farklı ortam bağıl nemi koşulunda yaş ve kurutulmuş örnekler kullanılarak belirlenmiştir. Elde edilmiş olan deneysel sorpsiyon verileri 4 farklı modele yani BET, GAB, Oswin ve Smith modellerine uydurulmuştur. Kurutma işlemlerine ilişkin deneysel sonuçlara ise Henderson ve Pabis, Page, Logaritmik, Wangh ve Singh olmak üzere 4 matematiksel kurutma modeli uygulanmıştır. Kurutma verilerinin modellenmesi sonucu elde edilmiş olan ortalama karesel hata (RMSE), khi-kare (χ 2 ) ve model etkinliği (EF) değerlerinin karşılaştırılması ile kivinin sıcak hava ile kurutulmasında en uygun matematiksel modelin Page modeli olduğu, sorpsiyon davranışları için en uygun modelin ise GAB modeli olduğu tespit edilmiştir. Efektif difüzyon katsayısı sıcaklığa bağlı olarak 2.73936 x 10 -10 (50 ˚C) ile 3.89772 x 10 -10 m 2 /s (70˚C) arasında değişmiştir.

Description of the carbon mineralization of swine manure and oat straw in the soil through nonlinear models

Agricultural management is a viable way for recycling animal residues in feedlots. Thesubstances that make up organic residues change the dynamics of the organic matter decompositionin the soil. Information on carbon mineralization curves allows seeking improvements in soil qualityand, consequently, in crop productivity. The Stanford & Smith Nonlinear Model is the most usedto describe C mineralization of organic residues in the soil. This model considers organic residuesare composed of substances that are mineralized exponentially. The Cabrera Model considers twofractions, one composed of substances that are mineralized exponentially and other composed ofmore resistant substances with constant mineralization. The objective of this work was to comparenonlinear models that describe carbon mineralization, considering residues on surface or incorporatedinto the soil. The data evaluated were from an experiment with oat straw, liquid swine manure, andswine litter bedding. The Stanford & Smith and Cabrera Models were used considering structure offirst order autoregressive errors - AR(1), when necessary. The fittings were compared using the AkaikeInformation Criterion (AIC). The Cabrera Model was more adequate to describe C mineralization infour treatments (soil + incorporated liquid swine manure; soil + oat straw on surface + liquid swinemanure on surface; soil + incorporated straw; and soil + straw on surface). The Stanford & SmithModel was better in three treatments (soil + incorporated straw + incorporated liquid swine manure;swine litter bedding on surface; and incorporated swine litter bedding). None of the models describedthe treatment soil + liquid swine manure on surface.Keywords: Decomposition. Half-life. Stanford & Smith Model. Cabrera Model.

The Effect of Projectile Nose Shape on the Critical Velocity of High-Performance Yarn

In this study, ballistic experiments were performed to determine the critical velocity of a Twaron® 2040 high-performance yarn transversely impacted by round projectiles. Four different round projectiles possessing a radius of curvature of 2 µm, 20 µm, 200 µm and 2 mm were used in this study. Load cells were mounted to the grips to measure the load history of the yarn upon impact. A high-speed camera was incorporated into the ballistic experimental setup to capture the failure process of the yarn upon impact. A scanning electron microscope was utilized to perform post-mortem failure analysis on the recovered specimens. The results showed that as the radius of curvature of the projectile increased, the critical velocity also increased. The critical velocities for all cases were bounded between those predicted from the Euler–Bernoulli beam and Smith models. Upon impact above the upper limit of the critical velocity, the axial loads revealed a demonstrative reduction. The failure surfaces changed from shear to fibrillation as the radius of curvature increased. For those specimens that failed in shear, Hertzian contact model was used to predict the critical velocity.