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1
Trippe, Sascha. "The “graviton picture”: a Bohr model for gravitation on galactic scales?" Canadian Journal of Physics 93, no. 2 (February 2015): 213–16. http://dx.doi.org/10.1139/cjp-2014-0158.
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Modified Newtonian dynamics (MOND) provides a successful description of stellar and galactic dynamics on almost all astronomical scales. A key feature of MOND is the transition function from Newtonian to modified dynamics, which corresponds to the empirical mass discrepancy–acceleration (MDA) relation. However, the functional form of the MDA relation does not follow from theory in a straightforward manner; in general, empirical MDA relations are inserted ad hoc into analyses of stellar dynamics. I revisit the possibility of gravity being mediated by massive virtual particles, gravitons. Under certain reasonable assumptions, the resulting “graviton picture” implies a MDA relation that is equivalent to the — empirical — “simple μ” function of MOND, which is in very good agreement with observations. I conclude that the “graviton picture” offers a simple description of gravitation on galactic scales, potentially playing a role for gravitation analogous to the role played by Bohr’s model for atomic physics.
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Alimohammadi, M., and H. Hassanabadi. "The X(3) model for the modified Davidson potential in a variational approach." International Journal of Modern Physics E 26, no. 09 (September 2017): 1750054. http://dx.doi.org/10.1142/s0218301317500549.
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In this work, we investigate the [Formula: see text]-rigid version of Bohr–Hamiltonian for the modified Davidson potential. Since the corresponding wave equation cannot be solved analytically, we apply the variational method. The related wave function, energy spectra and transition rates are determined. In order to evaluate our results, we fit the formula for the energy spectra to the available experimental data for some nuclei and compare the obtained standard error with the corresponding one in other similar work. Moreover, we study the collective behavior of these nuclei through the evolution of two quantities [Formula: see text] and [Formula: see text] in terms of number of valence nucleons.
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Freitas, Savana Dos Anjos, and Agostinho Serrano. "Use of different external mediating mechanisms of the Bohr atom model: Evidence of Meaningful Learning through verbal-gestural analysis in elementary school students." Acta Scientiae 21, no. 4 (September 4, 2019): 133–48. http://dx.doi.org/10.17648/acta.scientiae.v21iss4id5253.
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The present article sought to investigate if the use of different external mediation mechanisms to teach the Bohr Atom model in elementary education with the didactic methodology of the Potentially Significant Teaching Units (PSTU) can result in Meaningful learning. Therefore, we naturally use the theoretical contribution of the Ausubelian Meaningful Learning Theory, in particular by discussing elements that indicate evidence of meaningful learning. This theory was adopted with the purpose of understanding and analyzing whether or not there is evidence of meaningful learning with elementary level students after about a year of using the didactic methodology. The didactic methodology used was the application of didactic sequences inspired by the PSTU model, modified to be applied in Elementary School. We also use different external mediation mechanisms that independently reproduce the Bohr atom model, such as model building (psychophysical mediation), teacher explanation on a blackboard (social mediation), use of textbooks (cultural mediation) and computer simulations (hypercultural mediation). Data analysis was carried out through two semi-structured interviews according to the Report Aloud protocol followed by the depictive gestural analysis, performed with an interval of almost one year, both interviews were carried out after the application of the didactic methodology, in order to assess the retention of the learning residue. We argue that the students' verbal-gestural production indicates that there was meaningful learning of the Bohr Atom model, especially related to social and hypercultural mediations.
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Soheibi, Nahid, Majid Hamzavi, Mahdi Eshghi, and Sameer M. Ikhdair. "Calculations of the decay transitions of the modified Pöschl–Teller potential model via Bohr Hamiltonian technique." International Journal of Modern Physics E 26, no. 11 (November 2017): 1750073. http://dx.doi.org/10.1142/s0218301317500732.
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We calculate the eigenvalues and their corresponding eigenfunctions of the Bohr’s collective Hamiltonian with the help of the modified Pöschl–Teller (MPT) potential model within [Formula: see text]-unstable structure. Our numerical results for the ground state (g.s.) [Formula: see text] and [Formula: see text] band heads, together with the electric quadrupole [Formula: see text] transition rates, are displayed and compared with the available experimental data.
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Abou-Salem, L. I., K. E. Abdelmageed, I. A. Elmashad, and R. Al Allam. "Testing the core-cluster model calculations for some heavy deformed nuclei." International Journal of Modern Physics E 28, no. 07 (July 2019): 1950049. http://dx.doi.org/10.1142/s0218301319500496.
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In this work, the spectra of some even–even isotopes are studied by selecting core-cluster decomposition of the parent nucleus. The considered nuclei lie in the rare-earth and the transition metal regions. The Schrödinger equation can be solved using Bohr–Sommerfeld relation and the modified Woods–Saxon beside Coulomb potentials to reproduce the spectra of these isotopes with mass number [Formula: see text]. The theoretical calculations of the excitation energies of the ground state rotational band are compared to the experimental data. The cluster model calculations show a good agreement with the experimental data for the transitional and rotational nuclei more than the vibrational nuclei. Some negative parity bands of the chosen nuclei are studied. The core-cluster charge products are correlated with the transition probability [Formula: see text].
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PIIPER, JOHANNES, PETER SCHEID, STEVEN F. PERRY, and GEORGE M. HUGHES. "Effective and Morphometric Oxygen-Diffusing Capacity of the Gills of the Elasmobranch Scyliorhinus Stellaris." Journal of Experimental Biology 123, no. 1 (July 1, 1986): 27–41. http://dx.doi.org/10.1242/jeb.123.1.27.
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Calculations of the effective O2 conductance (diffusing capacity or transfer factor, Dcff) of fish gills, obtained from experimental data on gill O2 exchange, were compared with the predicted CVexchange properties of gill models based on morphometric measurements of the elasmobranch, Scyliorhinus stellaris. Deff was calculated from O2 uptake and POO2 in gill water and blood, using a modified Bohr integration technique. In the morphometric gill model, O2 conductance was considered for both the water-blood tissue barrier (Dm) and the interlamellar water (Dw). Dm was calculated from the total secondary lamellar surface area, the harmonic mean water-blood barrier thickness, and an assumed Krogh 02-diffusionconstant for gill tissue. Dw was estimated from the dimensions of the interlamellar spaces, the mean respiratory water flow velocity, and the diffusion coefficient of O2 in water. The ratio Dm/Dw was 1.84 in quiescently resting, 1.68 in resting alert, and 1.47 in swimming fish, showing that diffusion across interlamellar water was somewhat more important than that across the water-blood barrier in limiting the diffusive O2 transfer between water and blood. The total morphometric diffusing capacity, Dmorph estimated by the combined membrane-and-water diffusing capacity, Dm+w, which is defined as 1/Dm+w= 1/Dm+1/Dw, was similar to Deff, the ratio Dm+w/Deff being 1.64 for quiescently resting, 1.02 for resting alert, and 0.92 for swimming fish. The good agreement between the effective and morphometric D estimates validates the approach, and leaves, at least for the alert and swimming fish, little space for functional inhomogeneities, which are expected to reduce Deff as compared to Dm+w.
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Karunanithy, C., K. Muthukumarappan, and A. Donepudi. "Moisture Sorption Characteristics of Corn Stover and Big Bluestem." Journal of Renewable Energy 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/939504.
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Moisture content is an important feedstock quality in converting it into energy through biochemical or thermochemical platforms. Knowledge of moisture sorption relationship is useful in drying and storage to preserve the quality of feedstocks. Moisture sorption isotherms for potential feedstocks such as corn stover and big bluestem are missing. EMC values of corn stover and big bluestem were determined using static gravimetric technique with saturated salt solutions (ERH 0.12–0.89) at different temperatures (20, 30, and 40°C). Depending upon the ERH values, EMC values were ranged from 8.0 to 19.6 and 8.8 to 19.2% db for corn stover and big bluestem, respectively, and they followed typical type II isotherm found in food materials. Nonlinear regression was used to fit five commonly used three-parameter isotherm models (i.e., modified Oswin model, modified Halsey model, modified Chung-Pfost model, modified Henderson model, and the modified Guggenheim-Anderson-de Boer (GAB) model) to the experimental data. Modified Halsey emerged as the best model with highF-statistic andR2values with lowEmandEsand fairly random scattered residual plot for corn stover and big bluestem. These models can be used to predict the equilibrium moisture content of these feedstocks starting from harvesting, drying, preprocessing, transportation, storage, and conversion.
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Jiang, Xiuping, Xiuping Jiang, Huanhuan Li, Hosahalli S. Ramaswamy, Songming Zhu, Yong Yu, Huanhuan Li, Hosahalli S. Ramaswamy, Songming Zhu, and Yong Yu. "Moisture Sorption Isotherms and Isosteric Heats of Sorption of High-Pressure Treated Paulownia Wood under Different Storage Conditions." Transactions of the ASABE 62, no. 1 (2019): 105–14. http://dx.doi.org/10.13031/trans.12899.
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Abstract. Understanding of moisture sorption isotherms (MSI) is critical for predicting the stability of wood during handling, transport, and storage. The aim of this study was to evaluate the adsorption and desorption isotherm characteristics of high-pressure (HP) treated paulownia wood and to identify the best-fitting model to describe its sorption behavior. The equilibrium moisture contents (EMCs) of HP-treated paulownia wood were obtained using a static gravimetric method under different storage conditions: three temperatures (20°C, 30°C, and 40°C) and five water activity (aw) levels (0.32 to 0.95). Results showed that HP parameters did not significantly affect the MSI trend of treated groups. Eight modified models (modified Chung-Pfost, modified Henderson, modified Oswin, modified Halsey, Chen-Clayton, Guggenheim-Anderson-de Boer (GAB), simply modified GAB, and Peleg) were fitted to the experimental data. The Chen-Clayton model (temperature-dependent) produced randomized residuals and the best prediction performance for both adsorption and desorption among all models. Net isosteric heat of adsorption and desorption decreased from 7.55 to 4.84 kJ mol-1 and from 18.1 to 12.2 kJ mol-1, respectively, with an increase in EMC from 7.5% to 10%. The isosteric temperature (Tß) was 352 K for adsorption and 335 K for desorption, between which all the adsorption and desorption reactions proceeded at the same rate. All thermodynamic functions were adequately characterized by a power law model. Keywords: Equilibrium moisture content, High-pressure treatment, Modeling, Moisture sorption isotherm, Paulownia wood, Temperature, Thermodynamic analysis.
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Cho, Min Gyoung, Gwanyong Jung, and Hong-Gye Sung. "Performance Parameter Analysis of a Hall Effect Thruster With Modified Bohm Parameter Model." International Journal of Aeronautical and Space Sciences 21, no. 4 (April 2, 2020): 1028–36. http://dx.doi.org/10.1007/s42405-020-00263-w.
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Ocieczek, Aneta, Magdalena Skotnicka, and Kinga Baranowska. "Sorptive properties of modified maize starch as indicators of their quality." International Agrophysics 31, no. 3 (July 1, 2017): 383–92. http://dx.doi.org/10.1515/intag-2016-0061.
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AbstractThe physical and adsorptive properties of three products of modified maize starch in terms of the susceptibility of starch granules to surface processes as affected by their physicochemical diversity was compared in this study, using five mathematical models. It was assumed that modification of native starch is an important factor affecting its adsorptive properties. The products under study differed significantly in terms of the distribution of the size and shape parameters of their granules. The Guggenheim, Anderson and de Boer equation, characterised by relatively low sums of square deviations and low and similar errors of their different parameters, was the most useful in the description of empirically determined isotherms of adsorption. Parameters of the Guggenheim, Anderson and de Boer equation were used to estimate the parameters of the product surface microstructure. Modification of native maize starch differentiated the size of the monolayer, specific surface of sorption, and characteristics of capillaries.
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Shringi, Smriti, Donal O’Toole, Emily Cole, Katherine N. Baker, Stephen N. White, Gaetano Donofrio, Hong Li, and Cristina W. Cunha. "OvHV-2 Glycoprotein B Delivered by a Recombinant BoHV-4 Is Immunogenic and Induces Partial Protection against Sheep-Associated Malignant Catarrhal Fever in a Rabbit Model." Vaccines 9, no. 2 (January 26, 2021): 90. http://dx.doi.org/10.3390/vaccines9020090.
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An efficacious vaccine for sheep-associated malignant catarrhal fever (SA-MCF) is important for the livestock industry. Research towards SA-MCF vaccine development is hindered by the absence of culture systems to propagate the causative agent, ovine herpesvirus-2 (OvHV-2), which means its genome cannot be experimentally modified to generate an attenuated vaccine strain. Alternative approaches for vaccine development are needed to deliver OvHV-2 antigens. Bovine herpesvirus 4 (BoHV-4) has been evaluated as a vaccine vector for several viral antigens with promising results. In this study, we genetically engineered BoHV-4 to express OvHV-2 glycoprotein B (gB) and evaluated its efficacy as an SA-MCF vaccine using a rabbit model. The construction of a viable recombinant virus (BoHV-4-AΔTK-OvHV-2-gB) and confirmation of OvHV-2 gB expression were performed in vitro. The immunization of rabbits with BoHV-4-AΔTK-OvHV-2-gB elicited strong humoral responses to OvHV-2 gB, including neutralizing antibodies. Following intra-nasal challenge with a lethal dose of OvHV-2, 42.9% of the OvHV-2 gB vaccinated rabbits were protected against SA-MCF, while all rabbits in the mock-vaccinated group succumbed to SA-MCF. Overall, OvHV-2 gB delivered by the recombinant BoHV-4 was immunogenic and partly protective against SA-MCF in rabbits. These are promising results towards an SA-MCF vaccine; however, improvements are needed to increase protection rates.
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Chaudhary, Sandhya, Nilesh Nimje, Nishchhal Yadav, and S. Ghosh. "Drift Modified Longitudinal Electrokinetic Mode in Colloids Laden Semiconductor Quantum Plasmas." Physics Research International 2014 (September 15, 2014): 1–5. http://dx.doi.org/10.1155/2014/634763.
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Dispersion and absorption characteristics of electrokinetic wave in unmagnetised extrinsic semiconductor with streaming carriers are analytically investigated. By using quantum hydrodynamic model, a linear dispersion relation is derived for longitudinal electrokinetic wave in colloids laden semiconductor plasma under slow electrokinetic mode regime. Results indicate that quantum effect through Bohm potential significantly modifies the dispersion and absorption characteristics of electrokinetic wave spectrum. The outcome is hoped to add substantially to the present knowledge of wave spectrum of longitudinal electrokinetic wave in colloids laden quantum semiconductor plasma subjected to a dc electric field along the direction of wave propagation.
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Marolleau, A., F. Salaün, D. Dupont, H. Gidik, and S. Ducept. "Study and modeling of fabric hydric behavior to improve wearer comfort." Textile Research Journal 89, no. 17 (December 10, 2018): 3632–52. http://dx.doi.org/10.1177/0040517518817030.
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In this study, the sorption and desorption isotherms from the dynamic vapor sorption test are modeled by using six different models, that is, the (i) BET (Brunauer–Emmett–Teller), (ii) modified BET, (iii) GAB (Guggenheim–Anderson–Boer), (iv) PEK (parallel exponential kinetics), (v) HH (Hailwood–Horrobin), and (vi) Nelson and Young models. The application principle of each model is explained and a comparison is done between these models, based on the understanding of sorption mechanisms on or into the textile substrates. They mainly depend on the chemical nature of the fibers used to manufacture the samples. Thus, the presence of various sorption/desorption sites on the surface and/or in the inner core of hydrophilic materials promotes the formation of more hydrogen bonds with water vapor molecules than for hydrophobic materials. Among these previous used models, the PEK, HH, and Nelson and Young models were studied to analyze the water molecule diffusion into the structures, while the GAB and BET models were selected to gain information on the water uptaken as the monolayer and energies of interactions between fibers and water molecules. By understanding the hydric behavior of fabrics during sorption/desorption processes, the fiber blends can be modified for improving the wearer comfort.
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Stass, V. L. "An Analytical Model of Animal Growth." European Scientific Journal, ESJ 13, no. 27 (September 30, 2017): 1. http://dx.doi.org/10.19044/esj.2017.v13n27p1.
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The purpose of this study was to explain some aspects of ontogenetic growth in pigs by analysing the relationships between variables that are significant to the development of animals. The novelty of the study is a new modelling approach to the growth problem, with the attention that has been paid to both a new set of variables, and an analytical discrete-continuous hybrid model, innovative for the field. This is a first species-specific hybrid model for animal growth formulated in discrete-time difference equation technique. The efficiency of the model is not only due to the modelling technique but also due to a set of relevant variables, especially a feed conversion coefficient, which provides a link between macro and micro physiological scales. The model is based on functional relationships between relevant variables acquired from experimental data analyses, and field observations. The concept explains some aspects of growth in pigs from 30 kg to 600 kg, which is considered the maximum individual weight for a boar, and further growth up to a species maximum weight. The model predicts that boar can reach their maximum individual weight of 600 kg when 6,40 years old and are required to consume 62,51 kg of feed to put on the last kilogram. The phenotypes that can attain their maximum individual weight go through bifurcation of the growth trajectory, a transform in the growth mode. After bifurcation, the smallest number of the phenotypes go on the growth trajectory that leads to a set of species maximum weights of over 1205 kg, and the greatest number of phenotypes continue to live until aged 24,90 years, provided their maximum weights do not change. The study includes growth rate equations, identifies species maximum weight phenotypes, and produces insight into pig longevity. The results suggest that species maximum weight growth trajectories are phenotype-dependant. A modified discrete-time difference equation technique combined with standard continuum methods is an appropriate formalism to model ontogenetic growth in animals.
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Kumar, Punit, and Nafees Ahmad. "Surface plasma wave in spin-polarized semiconductor quantum plasma." Laser and Particle Beams 38, no. 2 (May 27, 2020): 159–64. http://dx.doi.org/10.1017/s026303462000018x.
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AbstractThe possibilities of surface plasma wave (SPW) on a metal-vacuum interface in semiconductor quantum plasma by considering the effects of Coulomb exchange (CE) interaction and the spin-polarization has been explored. The dispersion for the SPW has been setup using the modified quantum hydrodynamic (QHD) model taking into account the Fermi pressure, the quantum Bohm force, the CE, and the electron spin. The optical gain of SPW has been evaluated. It is found that CE effects and spin-polarization increases the wave frequency and enhances the gain during the stimulated emission.
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SHUKLA, P. K., L. STENFLO, and R. BINGHAM. "Instability of plasma waves caused by incoherent photons in dense plasmas." Journal of Plasma Physics 76, no. 6 (August 17, 2010): 845–51. http://dx.doi.org/10.1017/s0022377810000437.
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AbstractWe consider the nonlinear instability of modified Langmuir and ion–sound waves caused by partially coherent photons in dense quantum plasmas. In our model, the dynamics of the photons is governed by a wave kinetic equation. The evolution equations for the Langmuir and ion–sound waves are deduced from the quantum hydrodynamic equations accounting for the incoherent photon pressure, the quantum statistical electron pressure, and the quantum Bohm force acting on the degenerate electrons. The governing equations are Fourier analyzed to obtain nonlinear dispersion relations. The latter are analyzed to predict instability of the modified Langmuir and ion–sound waves in the presence of partially coherent photons. Possible applications of our investigation to the next generation of intense laser–solid dense plasma experiments and compact dense astrophysical bodies are mentioned.
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Shome, Pinki, Biswajit Sahu, and Swarup Poria. "Nonlinear dynamics of ion-acoustic waves in quantum plasmas with exchange-correlation effects." Zeitschrift für Naturforschung A 75, no. 8 (August 27, 2020): 677–85. http://dx.doi.org/10.1515/zna-2020-0008.
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AbstractNonlinear properties of ion-acoustic waves (IAWs) are studied in electron-ion (EI) degenerate plasma with the electron exchange-correlation effects by using the quantum hydrodynamic (QHD) model. To investigate arbitrary amplitude IAWs, we have reduced the model equations into a system of ordinary differential equations using a traveling wave transformation. Computational investigations have been performed to examine the combined effect of Bohm potential and exchange-correlation potential significantly modifies the dynamics of IAWs by employing the concept of dynamical systems. The equilibrium points of the model are determined and its stability natures are analyzed. The phase portrait and Poincaré return map of the dynamical system are displayed numerically. Quasiperiodic as well as chaotic dynamics of the system are confirmed through the Poincaré return map diagrams.
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Masthan, S. Khaja, K. S. Rama Rao, P. S. Sai Prasad, and P. Kanta Rao. "Derivation of the Expanded Form of the BJH Equation and its Application to the Pore Structure Analysis of Mesoporous Adsorbents." Adsorption Science & Technology 9, no. 4 (December 1992): 212–30. http://dx.doi.org/10.1177/026361749200900401.
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The BJH equation, [Formula: see text], used for pore structure analyses via its application to the N2 desorption isotherms at 78 K of porous materials, has been modified by substituting the value of ci and expanding the last term. The quantity vn is the volume of the pores involved in the nth desorption step and is given in terms of the volume of N2, (ΔV)n, exuded from the porous material, the constants Rn and ci which depend on the average pore size and average thickness of the physically adsorbed multilayer, Δtn being the decrease in thickness of the multilayer as a result of the nth desorption step and Ai the surface area of the set of pores involved in the ith desorption step. A derivation of the modified equation is presented. It has been applied to the N2 desorption data of bone char used by Barrett, Joyner and Halenda (BJH). The effect of the multilayer thickness (t) values given by Pierce and de Boer on the pore size distribution of bone char has been studied. The pore size distribution data are compared with those obtained by the original BJH and Pierce methods. The pore system conforms very well with the idealised open-ended cylindrical pore model. The expanded BJH equation has also been applied to the desorption isotherms of fresh and sintered silica-alumina cracking catalysts over the entire range of silica/alumina ratios. The multilayer thickness (t) values given by de Boer have been used in the calculations. The pore systems of the catalysts, vacuum-dried at 400°C, are observed to conform to the cylindrical pore model as revealed by the excellent agreement between the cumulative surface areas obtained in P.S.D. calculations and the BET surface areas. The pore systems of the catalysts, sintered at different temperatures in a dry oxygen stream, deviate considerably from the cylindrical pore model. Enlargement of the pores and their nonconformity with the ideal pore model are attributed to modifications of the pore structures brought about by the phenomenon known as ‘self-steaming’ with the water vapour released from the catalysts.
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Petrounkina, A., R. Petzoldt, KF Weitze, D. Waberski, and E. Topfer-Petersen. "Cell Subpopulation-related Volumetric Parameters: a Complementary Tool of the Modified Hypo-osmotic Swelling Test on Model of Boar Spermatozoa." Reproduction in Domestic Animals 35, no. 5 (October 2000): 201–6. http://dx.doi.org/10.1046/j.1439-0531.2000.00210.x.
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Azzollini, D., A. Derossi, and C. Severini. "Understanding the drying kinetic and hygroscopic behaviour of larvae of yellow mealworm (Tenebrio molitor) and the effects on their quality." Journal of Insects as Food and Feed 2, no. 4 (October 24, 2016): 233–43. http://dx.doi.org/10.3920/jiff2016.0001.
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The use of insects for preparing high nutritional value foods is emerging. The dehydration kinetic of yellow mealworms larvae and its hygroscopic behaviour were described also analysing the changes in quality attributes. Blanching was performed before air drying at 50, 60 and 70 °C while sorption isotherms were studied after air drying and freeze-drying. The Page model described the dehydration kinetic at 50, 60 and 70 °C with a coefficient of determination of 0.993. Moisture diffusion coefficients between 4.85×10-11 and 1.62×10-10 m2/s were estimated and their temperature dependence was described by the Arrhenius equation, estimating an Ea of 52.1 kJ/mol. The Guggenheim-Anderson-de Boer model well fitted experimental data, showing isotherms of type II and estimating a monolayer value of 0.05 g H2O/g dry matter. Blanching significantly modified the adsorption isotherms, increased the moisture of fresh larvae without affecting their proximate composition. Rehydration after lyophilisation produced higher colour degradation probably due to the increase of enzymatic activity.
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Tsai, Pei-Hsuan, and Chin-Tsai Lin. "How Should National Museums Create Competitive Advantage Following Changes in the Global Economic Environment?" Sustainability 10, no. 10 (October 17, 2018): 3749. http://dx.doi.org/10.3390/su10103749.
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Management strategies play an important role in enhancing the competitive advantage and sustainable development of national museums. The purpose of this study is to focus on evaluating the management strategies of national museums to reduce the gaps in visitor satisfaction that are caused by the interdependence and feedback problems of the so-called BOCR dimensions (namely, benefits, opportunity, costs, and risks) and 24 criteria. This study creates a hybrid competitive advantage multiple-criteria decision-making model for national museums by integrating the decision-making trial and evaluation laboratory-based analytic network process and modified VIKOR (VlšeKriterijumska Optimizacija I Kompromisno Resenje) techniques to solve the problems. We consider five different types of national museums to illustrate how the proposed new evaluation model enhances the competitive advantage of national museums. Our results provide national museum curators with the knowledge and understanding to create promotional and marketing strategies that reduce the gaps in dimensions and criteria to satisfy visitors’ needs and to enhance their competitive advantage.
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Druart, Xavier, Jean-Luc Gatti, Sylvie Huet, Jean-Louis Dacheux, and Patrice Humblot. "Hypotonic resistance of boar spermatozoa: sperm subpopulations and relationship with epididymal maturation and fertility." REPRODUCTION 137, no. 2 (February 2009): 205–13. http://dx.doi.org/10.1530/rep-08-0225.
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Hypotonic resistance of boar spermatozoa was investigated by measuring the ratio of live/dead spermatozoa (SYBR-14/propidium iodide) by flow cytometry after hypotonic stress. The survival rate of ejaculated spermatozoa incubated in hypotonic solutions ranging from 3 to 330 mmol/kg followed a sigmoid curve that fitted a simple logistic model. The critical osmolality value (Osmcrit) at which 50% of spermatozoa died was determined with this model. Hypotonic resistance of spermatozoa increased with temperature between 15 and 39 °C and decreased after hydrogen superoxide treatment, but was not modified during 8 days of preservation in Beltsville thawing solution. Hypotonic resistance markedly decreased during epididymal maturation and after ejaculation as Osmcritat 15 °C was 54.7±3.2, 68.5±10.6, 116.7±2.1 and 194.3±3.7 mmol/kg for the caput, corpus, cauda and ejaculated spermatozoa respectively. Hypo-osmotic stress of 100 mmol/kg revealed a sperm subpopulation exhibiting increased hypotonic resistance compared with the whole ejaculate (Osmcrit=67.8±2.1 mmol/kg). Consistent differences were observed between lean and standard breeds (Pietrain versus Large White) and between boars within the same breed. According to data collected by artificial insemination centers during a large-scale field trial, hypotonic resistance of ejaculates was found to be positively correlated within vivofertility.
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Rohvein, C., E. Santalla, and M. C. Gely. "Note: Estimation of Sorption Isotherm and the Heat of Sorption of Quinoa (Chenopodium quinoaWilld.) Seeds." Food Science and Technology International 10, no. 6 (December 2004): 409–13. http://dx.doi.org/10.1177/1082013204049513.
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A modified Guggenheim-Anderson-de Boer (GAB) equation of four parameters was obtained to adjust the experimental sorption data for washed quinoa seeds. From the original GAB equation, only the monolayer moisture resulted in a dependence-temperature parameter showing a negative exponential trend with the absolute temperature. The results of the statistical adjustment showed that the new four parameters GAB equation adequately represented the experimental data in the range of 20 to 30°C with a corrected correlation coefficient of 0.999. The sorption heat of washed quinoa seeds was estimated by combining the GAB model with the Clapeyron equation and it resulted approximately 32% higher than the sorption heat of pure water in the temperature ranges between 20 and 60°C for temperature and 0.003 and 0.30 for moisture content. Using Othmer method the ratio of latent heats varied from 1.18 to 1.0474 in the range of moisture content studied.
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LOEBEL, Dietrich, Andrea SCALONI, Sara PAOLINI, Carlo FINI, Lino FERRARA, Heinz BREER, and Paolo PELOSI. "Cloning, post-translational modifications, heterologous expression and ligand-binding of boar salivary lipocalin." Biochemical Journal 350, no. 2 (August 23, 2000): 369–79. http://dx.doi.org/10.1042/bj3500369.
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Boar submaxillary glands produce the sex-specific salivary lipocalin (SAL), which binds steroidal sex pheromones as endogenous ligands. The cDNA encoding SAL was cloned and sequenced. From a single individual, two protein isoforms, differing in three amino acid residues, were purified and structurally characterized by a combined Edman degradation/MS approach. These experiments ascertained that the mature polypeptide is composed of 168 amino acid residues, that one of the three putative glycosylation sites is post-translationally modified and the structure of the bound glycosidic moieties. Two of the cysteine residues are paired together in a disulphide bridge, whereas the remaining two occur as free thiols. SAL bears sequence similarity to other lipocalins; on this basis, a three-dimensional model of the protein has been built. A SAL isoform was expressed in Escherichiacoli in good yields. Protein chemistry and CD experiments verified that the recombinant product shows the same redox state at the cysteine residues and that the same conformation is observed as in the natural protein, thus suggesting similar folding. Binding experiments on natural and recombinant SAL were performed with the fluorescent probe 1-aminoanthracene, which was efficiently displaced by the steroidal sex pheromone, as well as by several odorants.
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López-Cortés, C., G. Osorio-Revilla, T. Gallardo-Velázquez, and S. Arellano-Cárdenas. "Adsorption of vapor-phase VOCs (benzene and toluene) on modified clays and its relation with surface properties." Canadian Journal of Chemistry 86, no. 4 (April 1, 2008): 305–11. http://dx.doi.org/10.1139/v08-017.
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A mexican bentonite was used to prepare three modified clays: an organoclay (OC–CPC) by intercalating cetylpyridinium chloride (CPC), an aluminum-pillared clay (Al-PILC), and an inorganic–organic clay (IOC–CPC) prepared from Al-PILC intercalating CPC. The infrared and thermogravimetric analyses enabled us to differentiate between the structures obtained. Interlayer distance was assessed through X-ray diffraction; the OC–CPC was the clay that showed the highest value (12.4 Å). The natural clay’s specific area was 43.5 m2/g, increasing to 157.2 m2/g for Al-PILC. The OC–CPC and IOC–CPC specific areas were 13.27 m2/g and 14.5 m2/g, respectively. Al-PILC was a microporous material; whereas natural clays, OC–CPC and IOC–CPC were non-porous materials. Toluene and benzene adsorption on OC–CPC was higher than in IOC–CPC and Al-PILC. Natural clay showed no adsorption capacity for these compounds. Comparison of the GC retention times for non polar and low-polarity compounds (octyne and benzene) in columns packed with OC–CPC and a commercial non polar column (squalene) showed that the OC–CPC possessed a higher organophilic (non polar) nature than squalene. This explains the higher benzene and toluene adsorption capacity of the OC–CPC compared with the other modified clays. The toluene and benzene adsorption isotherm for OC–CPC was well-described by the GAB (Guggenheim–Anderson–De Boer) model for the whole range of relative pressure used in this work (0–0.9) describing multilayer adsorption and capillary condensation.Key words: organoclay, inorgano–organo clay, vapor phase VOC’s adsorption, clay surface properties.
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Paliathanasis, Andronikos. "Quantum Potentiality in Inhomogeneous Cosmology." Universe 7, no. 3 (February 28, 2021): 52. http://dx.doi.org/10.3390/universe7030052.
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For the Szekeres system which describes inhomogeneous and anisotropic spacetimes we make use of a point-like Lagrangian, which describes the evolution of the physical variables of the Szekeres model, in order to perform a canonical quantization and to study the quantum potentiality of the Szekeres system in the content of de Broglie–Bohm theory. We revise previous results on the subject and we find that for a specific family of trajectories with initial conditions which satisfy a constraint equation, there exists additional conservation laws for the classical Szekeres system which are used to define differential operators and to solve the Wheeler–DeWitt equation. From the new conservation laws we construct a wave function which provides a nonzero quantum potential term that modifies the Szekeres system. The quantum potential corresponds to new terms in the dynamical system such that new asymptotic solutions with a nonzero energy momentum tensor of an anisotropic fluid exist. Therefore, the silent property of the Szekeres spacetimes is violated by quantum correction terms, which results in the quantum potential adding pressure to the solution.
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Böyükata, M., C. E. Alonso, J. M. Arias, L. Fortunato, and A. Vitturi. "Review of Shape Phase Transition Studies for Bose-Fermi Systems: The Effect of the Odd-Particle on the Bosonic Core." Symmetry 13, no. 2 (January 28, 2021): 215. http://dx.doi.org/10.3390/sym13020215.
Full textAbstract:
The quantum phase transition studies we have done during the last few years for odd-even systems are reviewed. The focus is on the quantum shape phase transition in Bose-Fermi systems. They are studied within the Interacting Boson-Fermion Model (IBFM). The geometry is included in this model by using the intrinsic frame formalism based on the concept of coherent states. First, the critical point symmetries E(5/4) and E(5/12) are summarized. E(5/4) describes the case of a single j=3/2 particle coupled to a bosonic core that undergoes a transition from spherical to γ-unstable. E(5/12) is an extension of E(5/4) that describes the multi-j case (j=1/2,3/2,5/2) along the same transitional path. Both, E(5/4) and E(5/12), are formulated in a geometrical context using the Bohr Hamiltonian. Similar situations can be studied within the IBFM considering the transitional path from UBF(5) to OBF(6). Such studies are also presented. No critical points have been proposed for other paths in odd-even systems as, for instance, the transition from spherical to axially deformed shapes. However, the study of such shape phase transition can be done easily within the IBFM considering the path from UBF(5) (spherical) to SUBF(3) (axial deformed). Thus, in a second part, this study is presented for the multi-j case. Energy levels and potential energy surfaces obtained within the intrinsic frame formalism of the IBFM Hamiltonian are discussed. Finally, our recent works within the IBFM for a single-j fermion coupled to a bosonic core that performs different shape phase transitional paths are reviewed. All significant paths in the model space are studied: from spherical to γ-unstable shape, from spherical to axially deformed (prolate and oblate) shapes, and from prolate to oblate shape passing through the γ-unstable shape. The aim of these applications is to understand the effect of the coupled fermion on the core when moving along a given transitional path and how the coupled fermion modifies the bosonic core around the critical points.
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Machaty, Z., C. Wang, and K. Lee. "176 CYTOCHALASIN PREVENTS SPERM HEAD INCORPORATION INTO FERTILIZED PIG OOCYTES." Reproduction, Fertility and Development 24, no. 1 (2012): 200. http://dx.doi.org/10.1071/rdv24n1ab176.
Full textAbstract:
At fertilization, an acrosome-reacted sperm fuses to the plasma membrane of the oocyte. It is then internalized into the ooplasm and its head forms the male pronucleus that moves toward the female pronucleus. Experiments using cytochalasin, an inhibitor of actin polymerization, suggest that filamentous actin is necessary for spermatozoa incorporation deep into the oocyte cytoplasm. However, the exact role of actin in the process is not entirely clear and the consequences of inhibiting actin polymerization on embryo development are not known. In the present study, we investigated the effect of cytochalasin B on fertilization and subsequent embryo development in the porcine model. In vitro-matured oocytes were rinsed in fertilization medium, a modified Tris-buffered medium supplemented with 0.1% BSA and 1 mM caffeine. Groups of 30 oocytes were placed into 50-μL droplets of the medium covered with mineral oil. Fresh semen was collected from both a wild-type boar and a transgenic boar heterozygous for the green fluorescent protein (GFP), washed 3 times in Dulbecco's PBS and added at a final concentration of 5 × 105 cells mL–1 to each droplet containing the oocytes. The gametes were co-incubated for 5 h at 39°C under 5% CO2 in air. In the treatment group, 10 μg mL–1 of cytochalasin B was supplemented into the fertilization droplets; control groups received an equivalent amount of dimethyl sulfoxide, the solvent used to dissolve the inhibitor. After gamete co-incubation, potential zygotes were transferred to PZM-3 medium for culture. In experiment 1, mature oocytes were fertilized with the wild-type boar sperm. Embryos at the 6- or 8-cell stage were then collected, the blastomeres were separated and DNA from each blastomere was isolated for PCR analysis to monitor the presence of the male-specific SRY gene. In experiment 2, the GFP transgenic sperm was used for fertilization. Fertilized oocytes were cultured for 7 days and the resultant embryos were examined for GFP expression using an epifluorescence microscope. The developmental stages of the embryos were also determined by staining their nuclei with Hoechst 33342. We found that after cytochalasin B treatment, only 19.1% (21/110) of the blastomeres were positive for the SRY gene, whereas in the control group, SRY was detected in 54.5% (61/112) of the cases. In addition, in the cytochalasin B-treated group, 1.9% (7/376) of the embryos expressed GFP, as indicated by green fluorescence; this percentage was 35.4% (146/412) in the control embryos. The frequency of 2-cell and blastocyst-stage embryos was similar between the control and cytochalasin B-treated groups (84.1 vs 81.0%; and 11.6 vs 12.5%, respectively). The results indicate that the presence of cytochalasin B during fertilization effectively blocks the incorporation of the male nucleus into the newly formed zygote without affecting the developmental potential of the pre-implantation embryo.
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Kalam, Tamanna, Tejesvini A. Puttaveeraswamy, Rajeev K. Srivastava, Jean-Philippe Puyravaud, and Priya Davidar. "Spatial aggregation and specificity of incidents with wildlife make tea plantations in southern India potential buffers with protected areas." Journal of Threatened Taxa 12, no. 11 (August 25, 2020): 16478–93. http://dx.doi.org/10.11609/jott.5590.12.11.16478-16493.
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Abstract: Many wildlife species survive in human-modified landscapes and understanding the opinions of those who share space with wildlife will aid conservation efforts. Using a questionnaire, we assessed the presence of 12 mammal species in 78 tea plantations in the Nilgiris, southern India. We obtained data on (i) plantation size, location, and elevation, (ii) species presence over a year, (iii) type and number of wildlife incidents caused, (iv) financial cost of wildlife damage, and (v) support for wildlife conservation. We used a generalized linear model to assess whether the distance to protected areas, elevation, and plantation size influenced species presence and the effect of these variables and wildlife incidents on support for conservation. Among all species reported, Bonnet Macaque, Wild Boar, and Porcupine were the most widespread, and the former two and the Gaur reportedly caused >50% of damages. Crop damage was the most frequent (74%, n = 244), whereas livestock predation, attacks on people, and infrastructure damage constituted <10% of incidents reported. The cost of wildlife damage was negligible for 72 estates and significant for six. The number of species increased with proximity to protected areas, with increasing elevation and plantation area. Plantation management (62%) supported wildlife conservation, and support increased with decreasing plantation size, increasing distance to protected areas, and with a higher number of species reported, but decreased with increasing incidents of wildlife damage. Mitigating impacts of a few widely distributed species that cause disproportionate damage and compensating those that incur disproportionately high costs could increase support for conservation. Education and awareness programs for the plantation community can further help increase support and participation in wildlife conservation activities. Plantations can thus serve as supplementary habitats for wildlife in regions where hard boundaries between protected areas and human settlements prevail.
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Bergmann, A., U. Taylor, and D. Rath. "10 SPERM BINDING TO PORCINE UTERINE EPITHELIAL CELLS MIGHT BE LECTIN MEDIATED." Reproduction, Fertility and Development 25, no. 1 (2013): 152. http://dx.doi.org/10.1071/rdv25n1ab10.
Full textAbstract:
Evidence suggests that porcine spermatozoa bind to the endometrium lining after entering the uterus. In previous studies, it was verified that this binding is specific to porcine uterine epithelial cells (UEC). Here, we present trials aimed at identifying the engaged binding mechanism. Several interactions of spermatozoa with the female reproductive tract are known to be lectin mediated. The respective sugar ligands are species specific for the oviductal as well as zona pellucida surface membrane. Therefore, we hypothesised that sperm-endometrium interactions are mediated by lectins, too. To block possibly existing sugar moieties on the sperm surface, we pre-incubated spermatozoa with lectins selected for their strong binding to viable spermatozoa [wheat germ agglutinin WGA, succinylated WGA (sWGA), concanavalin A (ConA)] and subsequently undertook co-incubation studies using an established cell culture model from primary porcine uterine epithelial cells. All trials were carried out in modified Dulbecco’s Modified Eagle’s Medium containing 20% serum (D20) because the UEC monolayer proved to react sensitive to PBS as well as to semen extender. Pre-trials confirmed that in D20 sperm vitality remained unaffected and lectin binding efficiency did not differ compared with PBS. The sperm-rich fraction of the ejaculate from 3 German Landrace boars was collected in D20 and washed by centrifugation. The pellet was resuspended in D20 and the concentration adjusted to 100 × 106 spermatozoa mL–1. Then, the samples were incubated with 1 of the 3 lectins (10 µg mL–1) for 15 min at 37°C. As a control, 1 aliquot of the sperm suspension was incubated without lectins. After another washing step, the pellet was resuspended in D20. For co-incubation with UEC, 500 µL of lectin-incubated sperm was released onto a UEC monolayer and the binding activity observed under a phase contrast microscope. The binding density was quantified by area under view and compared to results from the control incubation with untreated sperm. Images (2 repeats/boar and lectin) were divided into fields of 61.6 µm2 and the fields with and without sperm were counted. For statistical analysis, a Tukey Test was carried out. Sperm treated with WGA and sWGA, both binding to glucosamine molecules, showed significantly reduced binding activity to the UEC (P < 0.05), whereas ConA-treated and untreated sperm bound in the dense pattern as shown in previous trials. The results indicate that the sperm-UEC binding mechanism is mediated by glucosamine moieties on the sperm surface, which interact with matching lectins placed on the UEC membrane surface. Investigations for further confirmation of the suggested binding mechanism between porcine sperm and the uterine epithelial layer are ongoing. Supported by IMV Technologies, L’Aigle, France.
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Chiarelli, Piero. "The Gravity of the Classical Klein-Gordon Field." Symmetry 11, no. 3 (March 4, 2019): 322. http://dx.doi.org/10.3390/sym11030322.
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The work shows that the evolution of the field of the free Klein–Gordon equation (KGE), in the hydrodynamic representation, can be represented by the motion of a mass density ∝ | ψ | 2 subject to the Bohm-type quantum potential, whose equation can be derived by a minimum action principle. Once the quantum hydrodynamic motion equations have been covariantly extended to the curved space-time, the gravity equation (GE), determining the geometry of the space-time, is obtained by minimizing the overall action comprehending the gravitational field. The derived Einstein-like gravity for the KGE field shows an energy-impulse tensor density (EITD) that is a function of the field with the spontaneous emergence of the “cosmological” pressure tensor density (CPTD) that in the classical limit leads to the cosmological constant (CC). The energy-impulse tensor of the theory shows analogies with the modified Brans–Dick gravity with an effective gravity constant G divided by the field squared. Even if the classical cosmological constant is set to zero, the model shows the emergence of a theory-derived quantum CPTD that, in principle, allows to have a stable quantum vacuum (out of the collapsed branched polymer phase) without postulating a non-zero classical CC. In the classical macroscopic limit, the gravity equation of the KGE field leads to the Einstein equation. Moreover, if the boson field of the photon is considered, the EITD correctly leads to its electromagnetic energy-impulse tensor density. The work shows that the cosmological constant can be considered as a second order correction to the Newtonian gravity. The outputs of the theory show that the expectation value of the CPTD is independent by the zero-point vacuum energy density and that it takes contribution only from the space where the mass is localized (and the space-time is curvilinear) while tending to zero as the space-time approaches to the flat vacuum, leading to an overall cosmological effect on the motion of the galaxies that may possibly be compatible with the astronomical observations.
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Menkov, Nikolay D., and Albena G. Durakova. "Equilibrium Moisture Content of Semi-Defatted Pumpkin Seed Flour." International Journal of Food Engineering 1, no. 3 (April 1, 2005). http://dx.doi.org/10.2202/1556-3758.1008.
Full textAbstract:
Moisture equilibrium data (adsorption and desorption) of semi-defatted (fat 10.6 % wet basis) pumpkin seed flour were determined using the static gravimetric method of saturated salt solutions at three temperatures 10 °C, 25 °C, and 40 °C. The range of water activities for each temperature was between 0.11 and 0.85. Equilibrium moisture content decreased with the increase in storage temperature at any given water activity. The experimental data were fitted to five mathematical models (modified Oswin, modified Halsey, modified Chung-Pfost, modified Henderson and Guggenheim-Anderson-de Boer). The GAB model was found to be the most suitable for describing the sorption data. The monolayer moisture content was estimated using the Brunauer-Emmett-Teller equation.
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"Some problems of modeling laser-induced filaments." Journal of V. N. Karazin Kharkiv National University, Series "Physics", no. 32 (2020). http://dx.doi.org/10.26565/2222-5617-2020-32-06.
Full textAbstract:
Experimental data of formation laser-induced filaments in various media (potassium chloride, water, air and silicon carbide) are represented. These phenomena are analyzed as processes of Nonlinear and Relaxed Optics. Problems of modeling the creation the volume laser-induced filaments are investigated. Comparative analysis of plasma, nonlinear optical, diffractive and interference phenomena (including diffractive stratification), shocking processes (including Cherenkov radiation) and physical-chemical processes (including cascade model of excitation the proper chemical bonds in the regime of saturation the excitation), methods and models are represented and discussed. The optical breakdown for various matters has various natures: from shock ionization of gas to disruption of all chemical bonds for solid in the region of interaction light and matter or from nonequilibrium radiated processes in gas and liquid to irreversible phase transformations in solid. For diffraction stratification the modified models of Rayleygh rings was used. We show that this model allow to explain the experimental data for silicon carbide more effectively as Lugovoy-Prokhorov theory of moving foci. Modified Niels and Aage Bohrs models (microscopic) and Golub model (macroscopic) of Cherenkov radiation were used for the explanation of generation continuous radiation. Diffraction stratification shows the surface conic nature of Cherenkov radiation. It was show that physical-chemical method of estimations of corresponding processes is more general as electromagnetic (Kerr media) and one allow explain basic terms of resulting chain process with united point of view. Modified I. Frank model of interference the Cherenkov radiation was used for the explanation laser-induced optical breakdown in silicon carbide. Modified Rayleygh model and methods of continuum mechanics was created and used for the estimation sizes and form of observing nanovoids of silicon carbide. In whole the represented models allow to explain the corresponding chain more fuller and really as other models because one take into account of nonlinear optical transformation of primary laser radiation.
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Zhu, Jun, Xiaoshan Liu, and Yuee Luo. "Extraordinary and upper-hybrid waves in spin quantum magnetoplasmas with vacuum polarization effect." Journal of Plasma Physics 87, no. 4 (July 13, 2021). http://dx.doi.org/10.1017/s0022377821000738.
Full textAbstract:
The propagation of extraordinary and upper-hybrid waves in spin quantum magnetoplasmas with vacuum polarization effect is investigated. Based on the quantum magnetohydrodynamics model including Bohm potential, arbitrary relativistic degeneracy pressure and spin force, and Maxwell's equations modified by the spin current and vacuum polarization current, the dispersion relations of extraordinary and upper-hybrid waves are derived. The analytical and numerical results show that quantum effects (Bohm potential, degeneracy pressure and spin magnetization energy) and the vacuum polarization effect modify the propagation of the extraordinary wave. Under the action of a strong magnetic field, the plasma frequency is obviously increased by the vacuum polarization effect.
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Snehitha, R., Sreenivasula Reddy Boreddy, D. D. Smith, and H. V. Hema Kumar. "Equilibrium Moisture Characteristics of Egg White Powder at Higher Temperatures." Current Journal of Applied Science and Technology, October 8, 2020, 124–36. http://dx.doi.org/10.9734/cjast/2020/v39i3030980.
Full textAbstract:
The equilibrium moisture content (EMC) of food material is defined as the moisture content of the material after it has been exposed to a particular environment for an infinitely long period of time. Equilibrium moisture characteristics of Egg White Powder (EWP) was studied at higher temperatures of 50, 60, 70, 80 and 90°C in the equilibrium relative humidity (ERH) range of 10-78% (at seven levels). The standard gravimetric method was used to determine the EMC-ERH relationships of EWP by employing the various saturated inorganic salt solutions. The EMC of EWP at any particular ERH decreased with an increase in environmental temperature. The EMC of EWP ranged from 2.17 to 3.35 at lower ERH value of about 10% whereas the EMC values ranged from 12.07 to 14.80 at higher ERH value of about 78% when the environmental temperature increased from 50°C to 90°C. EMC values of EWP are different than that of the values obtained at lower temperatures, hence useful to understand the thermal processing of EWP at higher temperatures. EMC-ERH data obtained in this study was fit into seven EMC-ERH models namely Henderson, modified Henderson, modified Chung-Pfost, modified Oswin, modified Halsey, modified GAB (Guggenheim, Ander-son and de-Boer) and Chen-Clayton models and were evaluated using mean relative percent error (Pe), standard error of estimate (SEE) and residual plots. The modified Henderson equation described the EMC-ERH relationship of EWP the best, Henderson, and Chen-Clayton equations gave good fit. The heat of vaporization (hfg) of EWP at different moisture contents and temperatures was calculated from EMC-ERH data with the help of the Clausius-Clapeyron equation. The hfg values indicate that the heat of vaporization of EWP increases as the moisture content and temperature decreases and the values are higher than that of the pure water.
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PHAHOM, Traiphop. "The Study of Sorption Characteristics of Dried Crab Stick Product Using Dynamic Vapor Sorption." Walailak Journal of Science and Technology (WJST) 18, no. 13 (June 28, 2021). http://dx.doi.org/10.48048/wjst.2021.20593.
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The research delved into the sorption characteristics of dried crab stick products using dynamic vapor sorption (DVS). The obtained sorption isotherm data, including equilibrium moisture content (Me) and water activity (aw), were fitted with 6 different sorption isotherm models, such as Brunauer-Emmett-Teller (BET), Guggenheim-Anderson-Boer (GAB), Pickett-Modified BET, Adam and Shove, Blahovec-Yanniotis, and Peleg. The results showed that the Peleg model was the best-describing model with a coefficient of determination (R2), chi-square (χ2), root mean square error (RMSE), and standard error of estimate (SEE) ranging from 0.988 to 0.998, 0.719 to 4.349, 0.431 to 2.609 and 0.692 to 1.703, respectively. According to the classification of the shape of moisture sorption isotherm, the isotherm type III and II were found in this research for adsorption and desorption, respectively. The GAB and BET models were used to estimate monolayer moisture content (M0) of the sample and it was found that the M0 ranged from 3.65 to 5.36 % dry basis and 4.57 to 4.83 % dry basis for GAB and BET models, respectively. Blahovec-Yanniotis’s model was applied in this work to investigate the contribution of water and the result showed that the contribution of solution water played a major in the moisture changes of the sample during the adsorption and desorption process. Moreover, sorption isotherm data were modeled with 0 and 1st order reaction kinetics, and the results demonstrated that 0 order and 1st order models were the most appropriate model to describe moisture changes behavior of the sample at each relative humidity step for adsorption and desorption, respectively.
HIGHLIGHTS
The construction of sorption isotherms of dried crab stick product using dynamic vapor sorption
GAB and BET models were used to estimate monolayer moisture content
Peleg model was the most appropriate model to describe sorption behaviors of dried crab stick product
Blahovec-Yanniotis provided the contribution of water information of dried crab stick during adsorption and desorption processes
The application of reaction order kinetics could provide the information of moisture changing behaviors at each relative humidity step for adsorption and desorption processes
GRAPHICAL ABSTRACT
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Volinsky, A. A., J. C. Nelson, and W. W. Gerberich. "Macroscopic Modeling of Fine Line Adhesion Tests." MRS Proceedings 563 (1999). http://dx.doi.org/10.1557/proc-563-297.
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AbstractMicrowedge Indentation (MWIT) and Precracked Line Scratch (PLST) tests have been developed for adhesion measurements of microscale fine lines. In the MWIT a symmetric wedge-shaped probe is driven downward into a thin film line debonding it from the substrate. For the PLST, a precrack is introduced at one end of a thin metal line on a substrate. The line is loaded from the precrack end by an asymmetric diamond wedge until the crack propagates. When the crack reaches its critical length at a certain critical load, the film buckles.The mechanics of these tests are based on several assumptions of thin line behavior, which are not experimentally observable due to small line sizes and equipment limitations. Testing similar but larger lines allows for the direct observation of line delamination and buckling, which can be used for calculating in-situ crack lengths as well as instantaneous strain energy release rates.Both MWIT and PLST models [1–4] were experimentally verified on the macroscopic scale using polycarbonate as a line material bonded to a steel substrate with cyanoacrylate. New features such as initial crack growth as well as instantaneous crack growth at buckling were observed. Modified Kic tests were performed for strain energy release rate comparison. Adhesion values ranging from 200 to 1000 J/m2 were measured for this system, and had very strong mode mixity dependence. Connectivity to the microscale is through previous experiments by de Boer, et al using fine line W/SiO2/Si systems [ 1–4].