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In this paper, the low-field nuclear magnetic resonance technology CPMG (Carr-Purcell-Meiboom-Gill) echo method was used to determine the cross-linking degree and cross-linking density of crospovidone (PVPP) from different manufacturers. Based on the seven physical properties of PVPP, a fingerprint spectrum (radar chart) of twenty secondary quality indicators were obtained, and three compressibility evaluation indicators, index of the parameter (IP), index of parametric profile (IPP), index of good compression (IGC) were calculated by the fingerprint spectrum. It was found that the cross-linking degree and compressibility index IP of PVPP showed a strong correlation (r = 0.816) by the correlation analysis, indicating that the cross-linking degree is one of the key quality attributes for evaluating the compressibility of PVPP.
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RESUMO Este artigo versa sobre a análise da compressibilidade dos resíduos sólidos urbanos (RSUs) do antigo vazadouro da Marambaia, localizado no município de Nova Iguaçu, Rio de Janeiro, que operou como um lixão durante o período de 1987 a 2003, quando foi encerrado e remediado. O estudo foi levado a cabo por meio de dados de monitoramento de recalque superficial, obtidos por meio de marcos superficiais de 2008 a 2015. As medidas de recalques foram analisadas à luz dos seguintes modelos de compressibilidade: Sowers, Meruelo, Ling et al. e Oweis. Os resultados do monitoramento apresentaram valores de recalques entre 79 e 204 mm, representando deformações na faixa de 0,16 a 0,41% em relação à altura inicial do maciço. Os modelos Sowers, Meruelo e Ling et al apresentaram valores de recalques relativamente próximos, evidenciando que, embora diferentes conceitualmente, podem ser usados para prever recalques em longo prazo com boa aproximação. O modelo de Oweis é o mais elaborado dos modelos analisados e o que apresentou valores mais elevados de recalques.
ABSTRACT This paper deals with the analysis of the compressibility of the old Marambaia dumping grounds' MSW, located at Nova Iguaçu City (Rio de Janeiro) that was used as a waste dump from 1987 until 2003, when it was closed and remediated. The study was carried out based on superficial settlement monitoring data of reference points between 2008 and 2015. These data were analyzed considering the following compressibility models: Sowers, Meruelo, Ling et al. and Oweis. The results of the monitoring showed settlement values between 79 and 204 mm representing deformations in the range of 0.16 to 0.41% with regards to the of the landfill's initial height. The models of Sowers, Merueloand Ling et al. render settlement values that are relatively close; revealing that, although being different in conception, both can be used to predict long-term settlements with a good approximation. The model of Oweis is the most elaborated of all models analyzed and predicted the greatest values for settlement.
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Objective: To investigate the influence of different drying methods on physical fingerprint and total flavonoids content of Mori Ramulus extract.Method: The Mori Ramulus extract was dried by freeze drying,vacuum drying,ambient pressure drying,respectively.The content of total flavonoids in samples with different drying methods were determined and compared with each other.Physical fingerprint of Mori Ramulus extract was established by radar map and the physical fingerprint of samples with different drying methods were compared with each other.In the meantime,compressible parameters were employed to analyze the compressibility characteristics of Mori Ramulus extract treated by different drying methods.Result: Similarity of control physical fingerprint of Mori Ramulus extract treated by different drying methods was 77.8%-87.3%,relative standard deviation(RSD) of average value of the first level indexes and the compressible parameters was 0-16.6%.Except for homogeneity and stability,the remaining RSDs were less than 10%.Effects of different drying methods on homogeneity and stability of Mori Ramulus extract were greater than that of other factors.Conclusion: Different drying methods have certain effects on physical fingerprint of Mori Ramulus extract,but they have little influence on total flavonoids content in Mori Ramulus extract.
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Objective: To study the influence of microcrystalline cellulose (MCC) on the direct pressure properties of powder extracted from Shufeng Jiedu formula (SFJDE), and discuss the correlation between the basic physical properties and its functional properties of the powder before compression. Methods: SFJDE and MCC was mixed in different proportions, the physical properties of the mixed powder and the compression parameters under different pressures were determined. The basic physical properties and functional parameters of the powder were processed and analyzed by linear regression and partial least squares (PLS). Results: The addition of MCC in SFJDE showed a good linear relationship with the moisture content (MC), bulk density (ρb), and porosity ratio (ε) of the powder (r2 ≥ 0.991 9), and showed a good positive correlation with Hausner ratio (HR) and Carr’s index (CI) of the powder flow index (r2 ≥ 0.834 2). The parameters of powder compressibility compaction ratio (CR) and yield pressure (Py) gradually decreased, Unit effective work (Esp) and paramter a gradually increased; The powder compaction parameter kA was gradually increased, and kB was gradually decreased. The basic physical properties of MC, ρb, tap density (ρt), true density (ρtrue), and particle size (D0.5) of the powder had the obvious impact on these parameters by PLS analysis, while size distribution (span), HR, CI had little effect on it. However, span, HR, and CI had the obvious influence on the parameters ab and f, which characterized powder breakage and rearrangement. Conclusion: The increase of MCC reduces the fluidity of SFJDE, improves the compressibility and compactibility of the powder, therefore, we should pay attention to the influence of fluidity and pressure sensitivity during the process of use.
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ABSTRACT: This study aimed to verify the influence of moisture content on the values of maximum compressive strength, proportional deformity modulus, elastic coefficients d, e, and f beyond the tangent values, and maximum grain drying of crambe (Crambe abyssinica Hochst) under compression in natural resting position. Crambe grains with moisture contents ranging from 0.1547 to 0.0482 decimal db were dried at 40°C and uniaxially compressed between two parallel plates in the natural rest position. The gravimetric method was used to monitor reduction in moisture content during drying (weight loss). It was concluded that the compression force required to deform the crambe grains decreases as the moisture content increases. The proportional deformity modulus increases as the deformation decreases, yielding values between (0.09-0.27)×102MPa. Sigmoidal model described by Taylor series adequately represents the compression resistance of crambe grains in the natural rest position with moisture content lower than 0.0813db.
RESUMO: Neste trabalho objetivou-se verificar a influência do teor de água nos valores da força máxima de compressão, módulo proporcional de deformidade, coeficientes elásticos d, e, f, além dos valores da tangente e secante máximas nos grãos de crambe (Crambe abyssinica Hochst), submetidos à compressão na posição natural de repouso. Os grãos de crambe, utilizados com teores de água entre 0,1547 e 0,0482 (decimal b.s.), foram secos nas temperaturas de 40°C e comprimidos uniaxialmente entre duas placas paralelas, na posição natural de repouso, cuja redução do teor de água ao longo da secagem foi acompanhada pelo método gravimétrico (perda de massa). A força de compressão necessária para deformar os grãos de crambe diminui com o aumento do teor de água. O módulo proporcional de deformidade aumenta com a redução da deformação, obtendo-se valores entre 0,09 e 0,27 (x 102MPa), em que o modelo sigmoidal, descrito por meio da série de Taylor, representa adequadamente a resistência dos grãos de crambe à compressão na posição natural de repouso, para os teores de água menores que 0,0813 (b.s.)
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Objective: To study the prescription and preparation technology of Huanghuai Tablets and evaluate the physical quality of intermediate particles based on quality by design. Methods: Using Huanghuai (Scutellaria baicalensis and Sophora japonica) extract as the main component, the single factor experiments were used to screen adjuvant, and the forming rate, quality difference, hardness, friability, and disintegration time of tablets were used as indicators to optimize the optimal preparation processing of Huanghuai Tablets by wet granulation process. Physical indicators of granules were characterized by using micromeritics evaluation method. The physical fingerprint of granules were constructed by nine indexes including relative homogeneity index, interparticle porosity, Carr index, bulk density, tapped density, loss on drying, hygroscopicity, Hausner ratio, and angle of repose. The granules physical fingerprint is of great importance to evaluate the quality consistency of different batches of Huanghuai granules and analyze the compressibility of the granules. Results: The optimum formula was Huanghuai granule 0.25 g, 7% croscarmellose sodium, and 2% talc powder. The optimum conditions were as follows: granulated with 16 mesh sieve, dried at 60 ℃ for 1 h, and unified with 18 mesh screen. The similarity of the physical fingerprint of five batches of Huanghuai granules was higher than 0.983, the parameters of five batches of particle parameters were all greater than 0.4, and the parameter profile index was 4.82-5.70, and the good pressure index was from 4.44 to 5.25. Conclusion: The prescription and preparation technology of Huanghuai Tablets and the physical quality of intermediate particles were scientific and reasonable, which can provide ideas and methods for the research and development of Chinese materia medica formula.
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Objective To study the influence of different drying technology on the micromeritic properties of Salvia miltiorrhiza extract powder. Methods Taking S. miltiorrhiza extract as model drug, three kinds of extract powders were obtained by vacuum drying, vacuum microwave drying, and spray drying. The properties of powder were evaluated comprehensively with 13 physical indicators, including particle size, span, width, bulk density, tap density, Hausner ratio, angle of repose, compressibility, viscosity, specific surface area, pore volume, moisture content and hygroscopicity. Furthermore, the physical properties of the powder were summarized as homogeneity, stackability, fluidity, compressibility and stability of five aspects, then established the corresponding physical fingerprint spectrum. The powder properties were evaluated by the physical property values. The similarity of the three powders was compared by similarity evaluation method. And the indexes of parameter, parametric profile, and good compression were constructed to analyze the compressibility of the powder. Results The powders obtained by the three kinds of drying methods have poor fluidity and stability. The vacuum drying and vacuum microwave drying powders have good stackability, and the spray-dried powders have excellent homogeneity and compressibility. From the similarity, it can be seen that the similarity of powdery property of spray drying and vacuum drying extract is 79%, and 81.3% with vacuum microwave drying. Conclusion The physical fingerprint of TCM can be used to evaluate the influence of different drying methods on the powder science properties of Chinese medicine extract powder and the influence of physical properties on the formability of the preparation, which provides a new evaluation method for the Chinese medicine extract powder.
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Objective:To study the application of powder comprehensive properties characterization of cefuroxime axetil in batch changes .Methods:The stability and change of the powder before the batch change of cefuroxime axetil were measured by an FT 4 mul-tifunctional powder flow tester .The flow rate, compression rate, shear property, air inflation and air permeability were measured .The corresponding powder index was established .After the batch change , the above indices were detected to assess whether meeting the re-quirements.Results:The volume index of three batches of products after the batch change was within the optimal range .Conclusion:The batch changes of cefuroxime axetil have no effect on the smooth progress of cefuroxime axetil production , which provides a new rap-id verification method for preparation manufacturers .
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Objective: To optimize the technology and evaluate the influence of micronization on Olibanum physic-chemical characteristics and dissolution. Methods: The single factor test was employed to investigate the effect of the size and freezing time of common powder particle, the ratio of excipients, and grinding time on the yield of ultramicro powder; Additionally a comparative research between ultramicro powder and common powder was designed, including micromeritic properties (angle of repose, bulk density, tap density, and squeezing degree), effective components concentration [volatile oil, octyl acetate and 3-acetyl-11-keto-β-boswellic acid (AKBA)], and cumulative dissolution rate. Results: The optimal technology of ultramicro powder was as follows: the medicinal material was ground into fine powder, followed by 4 h freezing at -20℃ and 15 min superfine grinding with excipient and fine powder in ratio of 1:5; As the degree of smashing enhanced, the angle of repose of powders increased, bulk density and tap density decreased, and compressibility had a tendency of increase as flowability declined; The concentration of octyl acetate had an increased tendency and then decreased. While the concentration of octyl acetate in ultrafine powder prepared by optimal technology was the highest, the cumulative dissolution rate of AKBA in the ultramicro powder was higher than that in common powder. Conclusion: The application of optimal superfine pulverizing technique to Olibanum is feasible, and appropriate degree of micronization is helpful for the extraction and dissolution of effective components in Olibanum.
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The aim of this work is the assessment of the eventual enhancing effects of Carbopol 971P NF on the performance of Benecel K4M as a controlled release agent and its impact on other technological properties such as compactibility and powder flowability. The effect of Carbopol 971P NF and Benecel K4M in the performance of metronidazole tablets with controlled release was assessed using dissolution and compactibility profiles and the flowability of powders. Benecel K4M produces release profiles with an average exponent n=0.711 while Carbopol 971P NF displays average values of n=1.19. The values for tablets containing equal parts of Carbopol 971P NF and Benecel K4M was an average of n=0.947. Metronidazole tablets containing the Benecel K4M/Carbopol 971P NF blend shows a compactibility 2-3 times higher than tablets containing only Benecel K4M. Metronidazole/Benecel K4M blends flow sufficiently at all studied polymer proportions (≤ 30%) while admixtures of metronidazole/Benecel K4M with Carbopol 971P NF flow sufficiently only at polymer proportions ≤ 17%. Carbopol 971P NF enhances the overall performance of Benecel K4M in the same way as Noveon AA1 does, it reduces better the drug release and improves the compactibility, although decreases the flowability.
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The objective of this study was the evaluation of different types of lactose on the powders flow properties and dissolution of tablets of formulations with captopril and amoxicillin. Data of powders flow rate, compressibility index and dissolution profiles of tablets are presented. The powders flow rate showed higher sensitivity to small changes in their properties, compared to compressibility index. SuperTabs 21AN and 24AN flow at least 20 times faster than Lactopress and lactose NF. Lubrication increases the flow rate, maintaining the observed comparative differences. Dilution of lactoses with 50% captopril or amoxicillin reduces drastically the powder flow, producing also an equalizing effect. The greater flowability of SuperTabs, compared to other types of lactose, practically disappears. Dissolution of lubricated and unlubricated lactose tablets show a much faster dissolution of SuperTab 21AN tablets followed by Lactopress, lactose NF and SuperTab 24AN tablets. Dilution of lactoses with 50% captopril displays a quite smaller dissolution rate with a comparative similar behavior as observed before while dilution with amoxicillin show an equalizing effect of drug dissolution with minor differences between lactoses. The effect of lactose excipients on dissolution is attributed in a greater extent to mechanical properties of their tablets than to differences in solubility and dissolution.
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This work aimed the assessment of the effect of different proportions of Noveon AA1 on performance of HPMC as a controlled release agent for direct compression tablets. The functionality of polymer blends was determined using dissolution profiles, compactibility profiles and the powders compressibility index. Ten percent HPMC allows a metronidazole release after 3 h of 85%, an exponent n=0.48 and a release constant K=6.9. The increasing polymer substitution by Noveon AA1 decreases drug dissolution up to 36%, increases the exponent to 1.0 and decreases the release constant to 0.2%. The metronidazole/HPMC blend shows a slower increasing and a lower potential of tablets compactibility (20 N) while its increasing substitution by Noveon AA1 attains faster increasing and higher potential compactibilities (39 N). The metronidazole/HPMC (90:10) blend shows a low compressibility index (14%) that increases up to 33.2% with increasing Noveon AA1 proportions. Noveon AA1 proportions ≤ 5% display good/passable powder flowabilities. Noveon AA1 enhances the overall controlled release performance of HPMC, inducing zero order release patterns without lag or burst effects and reducing drug release more efficiently. Noveon AA1 also improves the compactibility of metronidazole/HPMC blends, however, decreases their flowability; flowability is acceptable only at lesser polymer proportions.
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Objective: To study the effect of microcrystalline cellulose (MCC) on compressibility and moldability of Galla chinensis extract (GCE). Methods: Four types of MCC were chosen and mixed with GCE respectively in different proportions. The powder was tabletted by Korsch XP-1 Intelligent Induction Tablet Machine, and the compressibility and moldability were evaluated using plasticity constant, elastic recovery, compression ratio, yield pressure, tensile strength, and their change rules as indexes. Results: The compressibility and moldability of GCE were poor. CeolusKG802 was the best at improving elastic recovery and compression ratio among the four kinds of MCC. AvicelDG improved the plasticity constant and tensile strength most when the adding amount was low, and CeolusKG802 improved them most when the adding amount was high. To yield pressure, CeolusKG802 exhibited greater reduction than the other MCC when added in a low amount. As for a high amount, the result was opposite. Conclusion: MCC has good compressibility and moldability in the compression process; Different types of MCC have different advantages. The change law of compression parameters is obtained by investigating the compression of mixed powders of MCC with different proportions on GCE.
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Introducción: la deficiencia de minerales en la población está asociada a enfermedades metabólicas, hormonales e inmunológicas. Usualmente, los minerales son suplementados en el organismo en forma de sales inorgánicas, las cuales pueden causar molestias gástricas y baja absorción en dependencia del tipo de sal empleado. Estudios previos muestran una adecuada absorción y ausencia de efectos gástricos cuando los minerales están asociados a ligandos orgánicos como enzimas, proteínas y particularmente aminoácidos. Objetivo: determinar mediante un estudio de preformulación la viabilidad de utilizar asparaginatos de cobre, magnesio, manganeso y zinc en suplementos nutricionales. Métodos: se realizó la síntesis y la verificación de formación de los complejos por espectroscopia infrarroja por transformada de Fourier y difracción de rayos X de polvos. Se evaluó la solubilidad, la constante de disociación, la eficiencia de la disolución y las propiedades físicas del estado sólido (morfología, distribución y tamaño de partícula, índice de Haussner, porosidad y compresibilidad) de los complejos. Se determinó la compatibilidad de los complejos con excipientes. Resultados: en los espectros infrarrojos se observó la participación del grupo carboxilo de la asparagina en la formación del enlace de coordinación de los complejos. En los difractogramas de rayos X se mostró la ausencia de los materiales de partida y la cristalinidad en los complejos. La solubilidad, la constante de disociación y la eficiencia de la disolución de los complejos, establecieron su carácter anfótero. Conclusiones: los resultados en las propiedades físicas del estado sólido, la humedad y la compatibilidad con excipientes, establecen que las formulaciones de los aparaginatos de cobre, magnesio, manganeso y zinc tienen propiedades reológicas adecuadas para propósitos farmacéuticos.
Introduction: the mineral deficiency in the human population has been associated with metabolic, hormonal and immunological disorders. These minerals are generally supplemented with inorganic salts in the body, but they might cause gastric distress and low absorption problems depending on the type of salt used. Previous studies demonstrated adequate absorption and absence of gastric effects when minerals were associated with organic ligands such as enzymes, proteins and particularly amino acids. Objective: to determine the viability of copper, magnesium, manganese and zinc asparaginates as nutritional supplements in a preformulation study. Methods: the synthesis and verification of the formation of complexes were carried out by Fourier transformed infrared spectroscopy and X-ray diffraction of powders. The solubility, the dissociation constant, the dissolution efficiency and the physical solid state properties (morphology, particle distribution and size, Haussner´s index, porosity and compressibility) of these complexes were evaluated. The compatibility of the complex with excipients was determined. Results: the involvement of the asparagine carboxyl group in the formation of the coordination bond of the complex was observed in the infrared spectra. the absence of starting materials and the crystallinity in the complexes were evidenced in the X-ray diffraction of powders. The solubility, the dissociation constant and the dissolution efficiency of the complexes established their amphoteric character. Conclusions: the results achieved in the physical solid state properties, the level of moisture and the compatibility with the formulation excipients indicate that copper, magnesium, manganese and zinc asparaginates have suitable rheological properties for pharmaceutical purposes.
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OBJECTIVE: To study correlation between physical properties and compressibility and compactablility of Microcrystalline cellulose. METHODS: After determining the physical properties such as particle size distribution, moisture capacity, angle of repose, bulk density, tapped density, the powder was tableted by the Korsch XP1 at the same filling height, and data derived from heckle model, plasticity constant, cumulative elastic recovery, tensile strength and it's changes with time were evaluated. RESULTS: The physical properties of microcrystalline cellulose had great effect on its compactablility as well as cumulative elastic recovery out of die, but not on compressibility. And pressure applied correlated closely with changes of tensile strength in storage, which was intensified by the influence of water in powder on the particle size. CONCLUSION: Microcrystalline cellulose shows excellent compressibility, however, particle size reduction is able to decrease the compactability. Since the water in powder can increase particle size by changing internal structure of particles and plays a prerequisite role in lubrication and adherence, the variation of water content may weaken the compatability of microcrystalline cellulose and worsen the mechanical strength stability of tablets in storage.
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O tráfego de máquinas agrícolas é considerado uma das principais fontes da compactação do solo. Uma prática utilizada para minimizar os efeitos da compactação é a escarificação, porém a haste escarificadora pode causar compactação subsuperficial. O objetivo deste trabalho foi avaliar a influência do tráfego de máquinas na compressibilidade de um Argissolo Vermelho-Amarelo distrófico arênico, de textura franco arenosa e avaliar o comportamento mecânico desse solo abaixo da linha de atuação da haste escarificadora. Os tratamentos investigados foram: semeadura direta há 13 anos, semeadura direta há 13 anos com tráfego adicional (intensidade de tráfego de 24,67Mg km ha-1), cultivo mínimo recém implantado e cultivo mínimo recém implantado com tráfego adicional. Para a determinação da densidade do solo, de índice de vazios, da pressão de preconsolidação e do coeficiente de compressão, foram coletadas amostras nas camadas de 0,0-0,10m, 0,10-0,20m, 0,20-0,30m e 0,30-0,40m. O tratamento semeadura direta há 13 anos apresentou a menor capacidade de suporte e maior suscetibilidade à compactação. A intensidade de tráfego de 24,67Mg km ha-1 aumentou a densidade do solo e reduziu o índice de vazios até 0,20m. A escarificação não afetou a pressão de preconsolidação e o coeficiente de compressão do solo na camada abaixo da linha de atuação da ponteira do escarificador.
Farm machinery wheeling is considered a major source of soil compaction. The use of chisel plow can minimize such effects, but the chisel can cause subsurface compaction. The aim of this study was to evaluate the effect of traffic and is present below the compaction layer thought compressive parameters of soil. The treatments investigated were: no-tillage, no-tillage with additional traffic (traffic intensity of 24.67Mg km ha-1), no-tillage chiseling recent implanted, no-tillage with additional traffic and chiseling recent implanted. For the density, void ratio, preconsolidation pressure and coefficient of compressibility determination in the layers 0.0-0.10m, 0.10-0.20m, 0.20-0.30m and 0.30 to 0.40m samples were collected. The treatment no-tillage showed the lowest load support capacity and greater susceptibility to compaction. The traffic intensity of 24.67Mg km ha-1 increased bulk density and decreased void ratio until 0.30m depth. The chisel plow did not affect the preconsolidation pressure and coefficient of compressibility of soil layer below the line of action of the chisel tip.
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Acoustical and volumetric properties have been measured for substituted heterocyclic compounds drugs and compounds in acetone-water mixture at 303K. The measurement have been perform to evaluate acoustical parameters such as adiabatic compressibility (bs ), Partial molal volume (fv), intermolecular free length (Lf), apparent molal compressibility (fk), specific acoustic impedance (Z), relative association (RA), salvation number (Sn).
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Objetivou-se, neste trabalho, quantificar o efeito da vinhaça no comportamento compressivo e nos atributos mecânicos, como consistência, umidade ótima de compactação e densidade máxima, de um Latossolo Vermelho-Amarelo (LVA); avaliar o efeito da vinhaça e do estado de compactação no salpicamento de partículas, da região de Lavras, MG. A vinhaça foi proveniente de um alambique de cachaça artesanal. Foram coletadas amostras deformadas e indeformadas nas profundidades de 0 a 3 cm e 60 a 63 cm. As amostras deformadas destinaram-se à caracterização do solo, determinação dos limites de consistência e realização do ensaio de Proctor Normal, após a incubação do material com vinhaça. As amostras indeformadas foram saturadas com vinhaça ou água destilada (controle), por 48 horas e destinaram-se aos ensaios de compressibilidade e resistência ao salpicamento, usando-se um minisimulador de chuvas. A vinhaça alterou os limites de consistência das camadas estudadas. Para a camada de 0-3 cm a vinhaça reduziu a faixa friável e para a camada 60-63 cm aumentou. Para ambas as camadas, a vinhaça aumentou a Dmáx e reduziu a Uótima. As camadas 0-3 cm e 60-63 cm, independentemente do tratamento com vinhaça, apresentaram a mesma capacidade suporte de carga. O estado de compactação das amostras influenciou a erosão por salpicamento. O aumento da pressão aplicada sobre as amostras resultou no aumento da quantidade de material salpicado. Na camada 60-63 cm, o tratamento com vinhaça reduziu a quantidade de material salpicado com o aumento da pressão aplicada, notadamente com as amostras na capacidade de campo.
The objective of this study was to quantify the effect of plonk on compressive behavior and mechanical attributes such as consistency, optimum moisture for compaction and maximum density of a Red-Yellow Latosol (Oxisol) to evaluate the effect of plonk and compaction state in splashed particles, from Lavras (MG) region. The plonk was obtained from an artisanal sugarcane brandy alembic. Undisturbed and disturbed soil samples were collected at 0 to 3 cm and 60 to 63 cm depths. Disturbed soil samples were used for soil characterization, determination of consistence limits and Normal Proctor essay after material incubation with plonk. Undisturbed soil samples were saturated with plonk or distilled water (control) during 48 hours for testing the compressibility and resistance to splash by using simulated rainfall. The plonk altered the consistence limits of studied layers. For the 0-3 cm layer, the plonk reduced the friable range, and for the 60-63 cm layer the effect was in the opposite direction. For both layers, the plonk increased Dmax and decreased Uoptimum. Regardless of the plonk treatment, both layers presented the same load support capacity. The compaction degree of samples influenced the splash erosion. The increase of the applied pressure over the samples resulted in increase of splash material quantity. At the 60-63 cm layer, the plonk treatment reduced the splash material quantity by increasing the applied pressure, mainly when the samples were at field capacity.
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The ultrasonic velocity, density and viscosity were measured in aqueous mixtures of zinc sulphate (Heptahydrate) and zinc nitrate (Hexahydrate) at 308 K. Acoustic parameters, such as specific acoustic impedance, free length, isotropic compressibility, molar compressibility, molar sound velocity, free volume, available volume, relaxation time, excess parameters and the deviation from the experimental values has been evaluated. The value of ultrasonic velocity decreases and comes to a minimum and then increases as the mole fraction of zinc nitrate increases in the mixed salt solution. The excess adiabatic compressibility of zinc sulphate and zinc nitrate mixed solution with water was positive at all concentrations, while it is negative at a mole fraction of 0.7945. Variation of these parameters with concentration indicates the non-linear behavior. This non-linear variation of velocity with increase in concentration indicates the complex formation between the constituents of mixture. The results were interpreted as per the intermolecular interactions.
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OBJECTIVE: This study was designed to evaluate the compressibility of heel pads in patients with diabetes mellitus. METHOD: The subject were twenty control subjects and 20 patients with diabetes mellitus diagnosed at least 5 years previously, over the age of 40. The thickness of heel pads was measured by ultrasonography without pressure and with pressure of 1 kg, 2 kg and 3 kg at the line connecting the second toe and the mid-heel point. The ratio of the thickness of the heel pad with pressure of 1 kg, 2 kg, 3 kg and without pressure, R1 (ratio of the thickness of heel pad with 1 kg and without pressure), R2 (2 kg) and R3 (3 kg), was compared between controls and diabetics. RESULTS: There was no significant difference of heel pad thickness between controls and diabetics without pressure in sole. The diabetics had greater ratio, less compressibility than controls (p<0.05). The ratio of the control group was R1; 0.67+/- 0.07, R2; 0.53+/-0.07 and R3; 0.45+/-0.07, whereas that ratio of the diabetic group was R1; 0.80+/-0.09, R2; 0.68+/-0.09 and R3; 0.58+/-0.09. CONCLUSION: The evaluation of compressibility of heel pad of the patients with diabetes mellitus compared with the control group will help to make a treatment of heel pain or discomfort.