Optimization Of Physical Parameters Research Articles

Electronmicroscopic examination of myometrium scar after use of monoand bipolar cauters

Uterine fibroids, which, according to various estimates, are found in 50% of cases, is the most common benign disease of the female genital area. A radical method of treating this disease is surgical removal. In radical operations are actively used bi- and monopolar cauters, both for cutting and for coagulation. After such an exposure necrotic scars are often formed, leading to gross deformations of the tissue and, as a consequence, to the impossibility of a normal onset and course of pregnancy. The question of studying postoperative myometrium scars at the ultrastructural level, with the aim of possible optimization of physical parameters for the most gentle operation, is highly important, since allows to estimate changes in tissues at the level of cellular and subcellular structures. At the moment, this experience is absent in our country. The electron microscopic investigation of a myometrium subjected to an electric current is considered in the article.

Optimization of the GBMV2 implicit solvent force field for accurate simulation of protein conformational equilibria.

Accurate treatment of solvent environment is critical for reliable simulations of protein conformational equilibria. Implicit treatment of solvation, such as using the generalized Born (GB) class of models arguably provides an optimal balance between computational efficiency and physical accuracy. Yet, GB models are frequently plagued by a tendency to generate overly compact structures. The physical origins of this drawback are relatively well understood, and the key to a balanced implicit solvent protein force field is careful optimization of physical parameters to achieve a sufficient level of cancellation of errors. The latter has been hampered by the difficulty of generating converged conformational ensembles of non-trivial model proteins using the popular replica exchange sampling technique. Here, we leverage improved sampling efficiency of a newly developed multi-scale enhanced sampling technique to re-optimize the generalized-Born with molecular volume (GBMV2) implicit solvent model with the CHARMM36 protein force field. Recursive optimization of key GBMV2 parameters (such as input radii) and protein torsion profiles (via the CMAP torsion cross terms) has led to a more balanced GBMV2 protein force field that recapitulates the structures and stabilities of both helical and β-hairpin model peptides. Importantly, this force field appears to be free of the over-compaction bias, and can generate structural ensembles of several intrinsically disordered proteins of various lengths that seem highly consistent with available experimental data. © 2017 Wiley Periodicals, Inc.

Improving reducibility of iron ore pellets by optimization of physical parameters

Reducibility of iron bearing material is an important property which represents its suitability of reduction in iron making furnaces. It has direct influence on improving productivity and lowering energy consumption in iron making process. The reducibility of iron ore pellets of a specific chemistry can be improved by the optimization of physical parameters such as induration temperature, improving size distribution of fines, improving apparent porosity etc. In this study, the reference pellet is prepared in a typical plant condition and the properties of the reference pellet are considered as base value to improve reducibility index (RI) maintaining other properties at the acceptable limit without altering pellet chemistry. Optimization of induration temperature at the 1250-1275?C shows around 74 % RI, which is 5 points more than the base value of 69.5 %. Furthermore, on optimizing additives size, such as limestone fines and anthracite coal fines at -350 mesh and induration temperature of 1250-1275?C, RI is improved to 77 %, i.e., 8 points improvement is achieved with respect to the base value.

Analysis on the shift strategy of hydro-mechanical infinitely variable transmission based on the orthogonal test

This article focuses on the shift strategy of hydro-mechanical infinitely variable transmission. A computer simulation is carried out to investigate the shift strategy, and the simulation results are verified by the test data. There are four typical working conditions in the continuous shift process, among which the shift process from F2(N) to F3(P) plays a decisive role in shift quality. The shift strategy based on the physical parameters from F2(N) to F3(P) is lower engine rotating speed, smaller load torque, lower main circuit pressure, and larger speed valve flow rate. The shift strategy based on the shift time from F2(N) to F3(P) is to switch the third group of clutches first, then disengage the first group of clutches, and engage the second group of clutches at last. The results show that the shift quality of hydro-mechanical infinitely variable transmission can be improved greatly by the optimization of physical parameters and shift time.

Young’s Modulus and Loss Factor Estimation of Sandwich Beam with Three Optimization Methods by FEM

physical properties identification of sandwich beams by measured flexural resonance frequencies. The physical parameters are the Young‟s modulus and the loss factor. They are estimated for each one of materials that constitute the structure of the sandwich beam which is made with the association of Hot-rolled steel, Polyurethane Rigid Foam and High Impact Polystyrene. This kind of the sandwich beam are widely used for the assembly of household refrigerators and food freezers. The solutions are obtained with parametric optimization of physical parameters of the materials that forming the sandwich beam with three methods: Genetic Algorithms (GA), Differential Evolution (DE), and Particle Swarm Optimization (PSO). Furthermore, this work intend verify the quality of the solutions obtained with parametric optimization. The parameters are estimated using measured and numeric frequency response functions (FRFs). The mathematical model to verify numeric FRF is obtained using the Finite Element Method and the two-dimensional elasticity theory coupled to three optimization methods. The results of the optimizations show that it is possible to determine effectively the physical parameters of a sandwich beam with this methodology.

Utilization of agro-industrial wastes for the production of lipase from Stenotrophomonas maltophilia isolated from Arctic and optimization of physical parameters

Abstract In the present work production of lipase by Arctic sediment isolate Stenotrophomonas maltophilia was investigated , and focus was on the lipase production using agro industrial waste. Optimization of physical parameters which enhance the lipase production in agricultural waste such as groundnut cake, rice bran, wheat bran, neem cake, and coconut cake was achieved and significance was validated by ANOVA. The crude lipase was concentrated by precipitation with acetone and further purification was carried out by ion exchange chromatography followed by SDS-PAGE. When screened for extracellular lipase production, 54 isolates showed positive results and significant activity was expressed by sediment isolate KS 46 which was phylogenetically identified to be S. maltophilia . The groundnut cake supported maximum enzyme production (74.117 U/ml) followed by coconut cake (61.911 U/ml), neem cake (58.737 U/ml), wheat bran (49.614 U/ml) and rice bran (28.165 U/ml). Characterization of the enzyme revealed the optimum temperature to be 28 °C and optimum pH to be 6 for groundnut cake, neem cake and coconut cake while pH 7 for rice bran and wheat bran. Maximum lipase production was attained at 60% moisture for all substrates except for neem cake (70%). The enzyme was purified to 2.9 fold and molecular weight was found to be 49.1 KDa. The results suggest that agro wastes such as groundnut cake has the potential to be used as alternative cost effective substrate for lipase production and optimum conditions vary for the same enzyme when different substrates are utilized.

Optimization of Physical Parameters for Cereals-Pulses Combination Based Extrudates Using Sequential Response Surface Methodology

Plant proteins in the form of flour, grits etc. are not in the palatable form as such due to lack of meat like texture, flavour and appearance. Thus the present need exists to prepare a palatable inexpensive vegetable based high protein foods. The extrusion cooking process converts the protein in its amorphous defatted flour form to fibrous structures. An extruded snack from Bengal gram brokens-sorghum blends was prepared by using Wenger X-5 extruder. The properties of the extrudates were studied at three different moisture levels (15, 20 and 25% w.b.) and three levels of barrel temperature (80, 90 and 100°C) with 5 levels of blending ratio of Bengal gram brokens-sorghum blends (10, 15, 20, 25 and 30%). All the physical parameters were optimized to have the best quality extrudates by RSM. The best quality extruded snack was obtained at 80°C barrel temperature, 15% moisture content of feed and 10% blending ratio followed by 15% moisture content of feed and 10% blending ratio at 100°C barrel temperature. Texture analysis of the optimized extrudate was also done for crispiness test and hardness test to have an idea of the resistance that the snack may offer on first bite to the consumer. The maximum value of crispness and minimum hardness was obtained at 15% moisture content, 100°C temperature. DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10607 J. Food Sci. Technol. Nepal, Vol. 7 (61-63), 2012

An approach to first principles electronic structure calculation by symbolic-numeric computation

This article is an introduction to a new approach to first principles electronic structure calculation. The starting point is the Hartree-Fock-Roothaan equation, in which molecular integrals are approximated by polynomials by way of Taylor expansion with respect to atomic coordinates and other variables. It leads to a set of polynomial equations whose solutions are eigenstate, which is designated as algebraic molecular orbital equation. Symbolic computation, especially, Gr\"obner bases theory, enables us to rewrite the polynomial equations into more trimmed and tractable forms with identical roots, from which we can unravel the relationship between physical parameters (wave function, atomic coordinates, and others) and numerically evaluate them one by one in order. Furthermore, this method is a unified way to solve the electronic structure calculation, the optimization of physical parameters, and the inverse problem as a forward problem.

Statistical optimization of physical parameters for enhanced bacteriocin production by L. casei

Antimicrobial proteinaceous compounds such as bacteriocins produced from Lactobacillus sp. are widely known. They have potential antimicrobial activities towards closely related bacteria and several pathogens associated with food spoilage and hence can be a potential food bio-preservative agent. Bacteriocin production requires optimized process, complex media and well-controlled physical conditions including pH and temperature. A probiotic strain of L. casei LA-1 isolated from mango pickle was used in the present study. The influence of physical parameters viz. temperature (15 ∼ 45°C), pH (4.0 ∼ 7.0), incubation time (up to 48 h) and inoculum size (0.7 ∼ 2.0 O.D) on bacteriocin production was analyzed. The effect of all the parameters was first investigated using the one-factor-at-a-time method (OFAT) to see the significance of these parameters on bacteriocin production and then further optimized by response surface methodology (RSM). Following OFAT analysis, all factors were found to have a significant effect on bacteriocin production. Bacteriocin production of 2,844 AU/mL was obtained at temperature 37°C, pH 6.7 and inoculum size 1.8 O.D at an incubation time of 20 h and it was produced during the stationary phase of growth. Statistical analysis showed that three variables-pH, temperature and incubation time have significant effects on bacteriocin production. RSM proved to be a powerful tool in the optimization of bacteriocin production by L. casei LA-1 with a two-fold increase, giving a production of 4652.15 AU/mL at pH 7.19, temperature 33.3°C and incubation time of 22.2 h.

Optimization of physical parameters for batch mode Zn (II) ion removal from liquid phase: A potential biosorption study

The present investigation has been undertaken for the evaluation of biosorption capacity of zinc sequestering bacteria VMSDCM (Accession Number. HQ108109). The maximum biosorption capacity and percentage removal of Zn (II) ion from liquid phase in batch mode were 0.21 mol g−1 and 100%, respectively, obtained at optimized pH 7, 308 K, adsorbate dose 7 mol L−1, adsorbent dose 1 g L−1, and contact time 8 h. Fourier transformation infrared (FTIR) and scanning electron micrograph (SEM) analyses revealed the fact that the surface of bacterial mass was noncrystalline, amorphous, and enriched with negatively charged viz amino, carboxyl, amide, immidazolic, hydroxyl, and ketonic groups before the metal ion sorption. The bacterial surface became crystalline, smooth without protrusions after the sorption of Zn (II) ion onto surface of bacterium, and the reflectance of FTIR spectrum shifted from original location indicating the involvement of negatively charged surface groups in metal ion binding. The maximum inhibitory concentration (MIC) in the present work was 8 mol l−1 for this bacterium. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 213-222, 2013

Nanorobot Propulsion Using Helical Elastic Filaments at Low Reynolds Numbers

Swimming in micro/nano domains is a challenge and involves a departure from standard methods of propulsion, which are effective at macrodomains. Flagella based propulsion is seen extensively in nature and has been proposed as a means of propelling nanorobots. Natural flagella actively consume energy in order to generate bending moments that sustain constant or increasing amplitude along their length. However, for man-made applications fabricating passive elastic filaments to function as flagella is more feasible. Of the two methods of flagellar propulsion, namely, planar wave and helical wave, the former has been studied from a passive filament point of view, whereas the latter is largely unexplored. In the present work an elastohydrodynamic model of the filament has been created and the same is used to obtain the steady state shape of an elastic filament driven in a Stokes flow regime. A modified resistive force theory, which is very effective in predicting propulsion parameters for a given shape, is used to study the propulsive dynamics of such a filament. The effect of boundary conditions of the filament on determining its final shape and propulsive characteristics are investigated. Optimization of physical parameters is carried out for each of the boundary conditions considered. The same are compared with the planar wave model.

Adsorption of polyphenols from ginger rhizomes on an anion exchange resin Amberlite IR-400 – Study on effect of pH and temperature

Adsorption of ginger (Zingiber officinale) polyphenol on an anion exchange resin, Amberlite IR-400 was studied for purification of polyphenols from the crude extract. The work was carried out to understand how the processing parameters can be manipulated to optimize the purification of ginger phenolics for its further use in nutraceuticals and functional foods. In this work the effect of pH and temperature on ginger polyphenol adsorption on anion exchange resin was studied. Adsorption was studied by mixing 10 gm (dry weight basis) of pretreated resin (Amberlite IR-400) with dilute hydro alcoholic (50:50) ginger extract at temperature varying from 25-40°C and pH values ranging from 4.0 to 6.5. The total polyphenol content was determined by Folin-Ciocalteau method. Within the pH range studied, pH 4.5 and 5.5 gave the best results reaching 91% and 92% adsorption of total polyphenol. At 25°C highest adsorption was obtained (92%). With the increase of temperature, adsorption percentage showed a gradual decrease, with only 70% adsorption of total polyphenols at 40°C. Statistical analysis of pH and temperature variation was done to obtain their influence on the efficiency of adsorption. For pH, we found that the calculated value of F at 5% level of significance at degrees of freedom (2, 15) [Fcalculated=13.738] is much greater than the given value of F=3.68. In case of temperature as a variable, the calculated value of F at 5% level of significance at degrees of freedom (2,9) [FCalculated=28.66] is also much greater than the given value of F=4.26. The Null hypothesis at 5% level was rejected and it was concluded that the difference in adsorption percentage of total polyphenols under different pH and temperature range is significant. This result will help in designing experiments for optimization of physical parameters for purification of polyphenols from ginger.

Efficient genetic transformation of Jatropha curcas L. by microprojectile bombardment using embryo axes

An efficient and reproducible protocol was established for genetic transformation in Jatropha curcas through microprojectile bombardment. Decotyledonated embryos from mature seeds were pre-cultured for 5 days and elongated embryonic axis was subjected to bombardment for the optimization of physical parameters. The frequency of transient gus expression and survival of putative transformants were taken into consideration for the assessment of physical parameters. Statistical analysis reveal that microcarrier size, helium pressure and target distance had significant influence on transformation efficiency. Among different variables evaluated, microcarrier size 1μm, He pressure 1100 and 1350psi with a target distance of 9 and 12cm respectively were found optimum by co-relating microcarrier size, helium pressure and target distance on the frequency of gus expression and survival of putative transformants. Selection of putative transformants was done with increasing concentrations (5–7mgL−1) of hygromycin. The integration of desired gene into Jatropha genome was confirmed with PCR amplification of 0.96 and 1.28kb bands of hptII and gus gene respectively from the T0 transgenics and Southern blot analysis using PCR amplified DIG labeled hptII gene as a probe. A successful attempt of genetic transformation was made with optimized conditions using particle gene gun and establishing a stable transformation in J. curcas with 44.7% transformation efficiency. The procedure described will be very useful for the introgression of desired genes into J. curcas and the molecular analysis of gene function.

Secondary embryogenesis and transient expression of the β-glucuronidase gene in hypocotyls of rapeseed microspore-derived embryos

Secondary embryogenesis from rapeseed microspore-derived embryos (MDEs) was studied in three Brassica napus L. cultivars Global, PF704 and Option. The best results in terms of secondary embryogenesis percentage obtained in cultures of Global and PF704 MDEs (75.88 and 65.97 %, respectively) and PF704 produced the highest number of secondary embryos per each primary embryo (14.91 ± 2.18). After optimization of physical parameters, rapeseed hypocotyls of MDEs were bombarded with microcarriers coated with a plasmid containing GUS reporter gene. The highest levels of transient GUS expression were obtained using bombardment with gold particles of 1.6 µm, at helium pressure of 9.3 MPa, a bombardment distance of 9 cm, chamber vacuum pressure of 7.1 × 10−6 kPa and single bombardment in bombardment medium containing 0.4 M mannitol.

Optimization of Physical Parameters of Discrete Element Method for Blast Furnace and Its Application to the Analysis on Solid Motion around Raceway

Analysis of solid motion in the vicinity of raceway of the blast furnace has been carried out by discrete element method (DEM). The physical properties of particle for DEM calculation are important factors to simulate precisely the solid motion in the blast furnace. In order to represent the feature of burden such as coke in the lower part of the blast furnace, the rolling friction was cautiously determined. Through the simulation results, it was found in the result of simulation that the contact friction and the rolling friction have a great influence on the solid motion especially in the lower part of blast furnace. In the present study, the contact friction of actual coke used for blast furnace was experimentally measured. The optimum combinations of contact and rolling friction coefficients were derived from the angle of repose obtained from the DEM. On the basis of the physical parameters optimized for blast furnace, the solid motion around the raceway where the ununiformity was remarkable in blast furnace was analyzed. The influence of variation of raceway is examined to clarify the motion of coke in the lower part of blast furnace. According to the results, it was found that the height of deadman varied with changing the depth of raceway. The interval of tuyeres seriously influences on the ununiformity of solid motion in the direction of circumference. Owing to DEM based on the optimized physical parameters, three dimensional analysis of solid motion containing the ununiform region became possible.

Optimization of Ultrasound-Mediated In Vitro Reversal of Multidrug Resistance in Human Hepatocarcinoma Cell Line HepG2

Previous studies have shown that ultrasound (US) could enhance cellular uptake and cytotoxicity of chemotherapeutic agents in drug-resistant cancer cells. The goal of this study was to investigate the optimization of physical parameters of US exposure for in vitro reversal of multidrug resistance (MDR) in human hepatocarcinoma cell line (HepG2). Using a constant total energy density (3.87 J/cm 2) that could maintain cell viability at the 90% level, we exposed parent (HepG2) and MDR variant (HepG2/ADM) tumor cells to US in vitro to a variety of US frequency, exposure intensity and duty cycle. After US exposure, flow cytometry was performed to measure retention of rhodamine 123 (Rh123) in both HepG2 and HepG2/MDR cells. The results showed that US frequency and duty cycle (DC) could influence the intracellular retention of Rh123 in HepG2/ADM tumor cells; intensity and exposure duration appeared to be of little importance. At a constant total energy density of 3.87 J/cm 2, the optimal US parameters for in vitro reversal of MDR in HepG2/ADM tumor cells appear to be 0.8 MHz, 0.43W/cm 2 and 60% DC, respectively. These findings support our hypothesis that varying the physical parameters would have an effect on efficiency of US-mediated reversal of MDR in cancer cells. (E-mail: mfengwu@yahoo.com)

Optimization of Physical Parameters for Biodegradation of Caffeine by Pseudomonas sp.: A Statistical Approach

Optimization of Physical Parameters for Biodegradation of Caffeine by Pseudomonas sp.: A Statistical Approach

Optimization of physical parameters for exo-biopolymer production in submerged mycelial cultures of two entomopathogenic fungi Paecilomyces japonica and Paecilomyces tenuipes

In the present study, two different optimization techniques were used to determine the suitable operating parameters for exo-biopolymer production in submerged mycelial cultures of two entomopathogenic fungi Paecilomyces japonica and Paecilomyces tenuipes. First, the rotating simplex method, a nonstatistical optimization technique, was employed to obtain the best combination of physical parameters (viz. pH, agitation intensity, aeration rate) for maximum exo-biopolymer production by P. japonica in a batch bioreactor. The optimal combination was determined to be a pH of 8.06, an aeration of 3 vvm, without any impeller agitation, producing a 17-time increase in exopolymer production (34.5 g l(-1)) when compared with that achieved in unoptimized flask cultures. Second, the uniform design method, a statistical optimization technique, was employed to determine the best operating parameters for submerged culture of P. tenuipes. The optimal combination for mycelial growth was determined to be a pH of 4.88, an aeration of 2 vvm and an agitation of 350 rpm, while a pH of 4, an aeration of 2 vvm and an agitation of 150 rpm was best for exo-biopolymer production. The exo-biopolymer production in P. japonica optimized by the rotating simplex method was strikingly improved (max. 34.5 g l(-1)), and the exo-biopolymer production in P. tenuipes optimized by the uniform design method was also significantly increased (max. 3.4 g l(-1)). The successful application of these two different optimization techniques in this study implies that these methods are worthy of applying to other fermentation systems for the production of bioactive mycelial biomass and exo-biopolymers in liquid culture of higher fungi.

Rotating simplex method of optimization of physical parameters for higher production of extracellular pectinases in bioreactor

Rotating simplex method of optimization has been successfully used to determine the optimal conditions for extracellular pectinase production by Aspergillus niger in batch bioreactor. Maximum production of 1.132 U of polymethylgalacturonase, 1.313 U of polygalacturonase and 0.0091 U of pectinlyase was obtained at pH (controlled). 3.38; agitation rate, 483 rpm and aeration rate, 2.12 vvm. These conditions were found to be more suitable for pectinase production.

Optimization of physical parameters for cell attachment and growth on macroporous microcarriers

The rates of cell attachment of the anchorage-dependent mammalian cell line Vero to the gelatin-based macroporous microcarrier Cultispher-G were determined under various conditions. An optimal rate of attachment (0.98 x 10(-2) min(-1)) occurred by an intermittent stirring regimen of 3 min stirring at 40 rpm per 33 min. This stirring regimen appeared to maximize cell-to-bead attachment and minimized cell aggregation which occurred at a broadly comparable rate.A further increase in the rate of cell-to-bead attachment occurred by preincubation of the microcarriers in serum-supplemented medium prior to cell inoculation in a serum-free medium. However, serum supplementation (>5%) was required for maximal cell growth. The pH of the medium had little effect on cell attachment over a broad range (pH 7.1-8.0). An initial cell/bead inoculum of 30 ensured an even distribution of cells on the available microcarriers with a low proportion of unoccupied beads.The rate of cell attachment to Cultispher-G was an order of magnitude lower than the determined value for the charged dextran microcarrier Cytodex-1, which was measured as 9.05 x 10(-2) min(-1). The optimal conditions for cell attachment were significantly different for the two bead types. Cell attachment to the electrostatic surface of the Cytodex-1 microcarriers was highly dependent on pH and serum supplementation. Cell aggregation during attachment to the Cytodex-1 microcarriers was minimal because of the higher rate of cell-microcarrier attachment.The porous nature of the Cultispher-G microcarriers allowed a maximum cell/bead loading of >1400, which was at least 3 times higher than equivalent loading of the cells on Cytodex-1. The Cultispher-G matrix also allowed the use of higher agitation rates (up to 100 rpm) in spinner flasks without affecting the cell growth rate or maximum cell density.