Physical Properties Of Medium Research Articles

Mechanical and Physical Properties Ofmedium Density Fiberboard Produce from Renewable Biomass of Agricultural Fiber

<p class='IJASEITAbtract'><span lang='EN-GB'>T</span>he development of Medium density fiberboard (MDF) made from renewable biomass of pineapple (Ananas comosus) leaf fiber and their suitability as a construction material has been investigated. Two different types of board with a target density of 0.8 gr/cm3 were manufactured. The board was prepared in three layers of about 1:1:1 weight ratio in unidirectional and cross-oriented board using low molecular weight (LM) PF resin type PL-3725 and high molecular weight (HM) PF resin type PL-2818 for impregnation and adhesive purposes. For comparison, boards with the same structure were prepared using high molecular weight PF resin only. The mechanical properties of the boards have been examined as well as their physical properties. The results shows that generally, mechanical properties, Modulus Of Elasticity (MOE), value was improved with mix PF resin as well as Modulus Of Rupture (MOR). Pineaplle leaf fiber resulted in significantly higher MOR, consistent with our observation during the test. This information is useful when a high MOR is required in application. Other mechanical properties such as internal bonding (IB) and screw-holding capacities (SH) improved as those of MOE and MOR. Fiber from agricultural residues such as pineapple leaf are longer than wood fiber. This might explain why screw-holding capacities increased since the failure in those tests is mainly due to tear force. Diffrences in the physical properties between the board types were caused by the presence of the low molecular weight PF resin for the impregnation of the fibers. As using of mix PF resin, thickness swelling (TS) properties improved as well. No significant difference was found for both mechanical and physical properties. The effect of the PF resin for impregnation was noted; however, fiber orientation had no effect on both physical and mechanical properties of the specimens.

ГЕОДИНАМІКА

The paper presents the techniques for processing of seismic prospecting data – for inversion of time seismic sections to depth ones. This makes it possible to extrapolate defined by wells’ geophysical investigations one-dimensional models of medium’s physical properties into the borehole environment. Correcting of the model taking into account the thermodynamic state of the medium and calculation of various physical properties of medium within the classical and non-classical theories of deformation as well as calculation of synthetic seismograms is provided. Thus, the differences between the classical and non-classical theories for values μ and λ are correspondingly 4.7 % and -1.4 %, which is substantial. 2D model of the medium is composed by extrapolating of one-dimensional model accounting the location of acoustic borders. At passing to close to the real (3D) model the changes of values of formation velocities of longitudinal and transverse waves and densities of thin layers in depth and profile takes into account as well as the changes of geostatic pressure on layers along the profile. At thus the substantial refinement of time which define the depth of the seismic horizons is reached. Time difference reaches 0.17 s, which is equivalent to the difference in depths up to 330 m or more and it is important for specifying of structural models, especially concerning the hydrocarbon traps prospecting.

Effects of UV curable urethane acrylate resins treatments on the physical properties of medium‐ and small‐diameter softwoods

AbstractThis study analyzed the effects of ultraviolet curable urethane acrylate resin (UV resin) treatments on surface homogeneity, dimensional stability, and change in colors of medium‐ and small‐ diameter softwoods produced in Taiwan. The UV resins were formulated with urethane acrylate oligomer/methyl methacrylate (MMA) monomer by the weight ratio of 50/50, 60/40, 70/30, 80/20, and 90/10, and 3% of photoinitiator (benzil dimethyl ketal) by the total weight of UV resins was added, respectively. Four kinds of softwoods, including Taiwanina, China fir, Taiwan incense cedar and Japanese fir with a diameter of 10–15 cm were obtained from Hui‐Sun Forest Station, Taiwan. Results show that the oligomer derived from 2‐hydroxyethyl methacrylate (2‐HEMA) and polymeric toluene diisocyanate (PTDI) by the molar ratio of NCO/OH = 1.0 could be readily synthesized and the prepared UV resin were also easily applied to the woods at room temperature and normal pressure. The surface hardness and moisture excluding efficiency (MEE) of woods were markedly enhanced and correlated with the increased in oligomer content of the UV resins as well as the homogeneity of softwood surfaces were also improved. According to the antiswelling efficiency (ASE), the increased in dimensional stability of woods were achieved; especially for the lower specific gravity China fir had the greatest improved efficiency of 60.68% at oligomer/MMA ratio of 80/20. In addition, a massive, colorful, and warm feeling in sense of sight on UV resin‐treated wood, which would appeal to most people, was also obtained. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

THERMAL AND VISCOSITY PROPERTIES OF MEDIUM‐ AND LONG‐CHAIN TRIACYLGLYCEROL BLENDS

ABSTRACT The physical properties of medium‐ and long‐chain triacylglycerol (MLCT) blends were characterized in this study. Blending MLCT oil with either palm olein or soybean oil changed the distribution of fatty acid groups, the crystallization and melting behavior of oil samples, and oil cloudiness. The crystallization and melting curves of both palm olein‐ and soybean‐based MLCT blends showed that the peaks shift to different transition temperatures depending on the percent of MLCT oil added. Viscosity analysis revealed that the oil viscosity was dependent on the temperature and triacylglycerol composition of the oil samples. Blending MLCT oil with either 50% palm olein or 50% soybean oil could assist in preventing crystal growth for the first 8 h of storage at 5 and 0C, respectively. PRACTICAL APPLICATIONSIn this study, the physical properties of medium‐ and long‐chain triacylglycerols (MLCTs) and MLCT‐blended oils were determined. Under an appropriate dietary regime, consumption of MLCT has been shown to reduce body weight and blood hypertriglyceridemic. Knowledge about the viscosity of MLCT and MLCT‐blended oils is important for process design and the transportation of fats and oils products. Moreover, this study attempted to produce clear MLCT‐blended oil as there is an important consideration for oil sold in plastic containers or glass bottles to be crystal clear. The findings from this study provide useful information for the application of MLCT‐blended oils in various food products such as frying oil.

Estimating water and ice content on planetary soils using neutron measurements: a neural network approach

A model-based neural network methodology to estimate water and ice content in planetary soils using neutron fluxes detected by in situ and/or airborne deployment of neutron detectors is proposed and shown to be effective. Focusing of epithermal and thermal energy regimes, the neutron fluxes are computed [Panfili, P.; Luciani, A.; Furfaro, R.; Ganapol, B.D.; Mostacci, D. Radiat. Eff. Defects Solids 2009, 164 (5-6), 340–344.] as functions of the medium physical properties and used to train neural networks in the inverse mode. For homogeneous soil, the model-based neural network shows satisfactory performances in retrieving the percentage of water. For soil modelled as layered, neural networks designed to retrieve both the depth and thickness of an ice layer beneath the soil surface provide good results only in a limited range of configurations. However, it has been found that training the two networks to independently retrieve the two parameter results more accurately. It has also been found that multiple measurements help improve the accuracy of the inversion for this configuration.

Effects of Fresh and Composted Organic Wastes on Media Physical Properties and Growth of Three Ornamental Species

Effects of Fresh and Composted Organic Wastes on Media Physical Properties and Growth of Three Ornamental Species

Coupled Processes of Fluid Flow, Solute Transport, and Geochemical Reactions in Reactive Barriers

A complex pattern of coupling between fluid flow and mass transport develops when heterogeneous reactions occur. For instance, dissolution and precipitation reactions can change a porous medium's physical properties, such as pore geometry and thus permeability. These changes influence fluid flow, which in turn impacts the composition of dissolved constituents and the solid phases, and the rate and direction of advective transport. Two-dimensional modeling studies using TOUGHREACT were conducted to investigate the coupling between flow and transport developed as a consequence of differences in density, dissolution precipitation, and medium heterogeneity. The model includes equilibrium reactions for aqueous species, kinetic reactions between the solid phases and aqueous constituents, and full coupling of porosity and permeability changes resulting from precipitation and dissolution reactions in porous media. In addition, a new permeability relationship is implemented in TOUGHREACT to examine the effects of geochemical reactions and density difference on plume migration in porous media. Generally, the evolutions in the concentrations of the aqueous phase are intimately related to the reaction-front dynamics. Plugging of the medium contributed to significant transients in patterns of flow and mass transport.

Coupled Processes of Fluid Flow, Solute Transport, and Geochemical Reactions in Reactive Barriers

A complex pattern of coupling between fluid flow and mass transport develops when heterogeneous reactions occur. For instance, dissolution and precipitation reactions can change a porous medium's physical properties, such as pore geometry and thus permeability. These changes influence fluid flow, which in turn impacts the composition of dissolved constituents and the solid phases, and the rate and direction of advective transport. Two‐dimensional modeling studies using TOUGHREACT were conducted to investigate the coupling between flow and transport developed as a consequence of differences in density, dissolution–precipitation, and medium heterogeneity. The model includes equilibrium reactions for aqueous species, kinetic reactions between the solid phases and aqueous constituents, and full coupling of porosity and permeability changes resulting from precipitation and dissolution reactions in porous media. In addition, a new permeability relationship is implemented in TOUGHREACT to examine the effects of geochemical reactions and density difference on plume migration in porous media. Generally, the evolutions in the concentrations of the aqueous phase are intimately related to the reaction‐front dynamics. Plugging of the medium contributed to significant transients in patterns of flow and mass transport.

Dynamic Viscoelastic Effects on Sound Wave Diffraction by Spherical and Cylindrical Shells Submerged in and Filled with Viscous Compressible Fluids

An analysis for sound scattering by fluid-filled spherical and cylindrical viscoelastic shells immersed in viscous fluids is outlined. The dynamic viscoelastic properties of the scatterer and the viscosity of the surrounding and core fluids are rigorously taken into account in the solution of the acoustic scattering problem. The novel features of Havriliak-Negami model for viscoelastic material dynamic behaviour description along with the appropriate wave-harmonic field expansions and the pertinent boundary conditions are employed to develop a closed-form solution in form of infinite series. Subsequently, the associated acoustic field quantities such as the scattered far-field pressure directivity pattern, form function amplitude, transmitted intensity ratio, and acoustic force magnitude are evaluated for given sets of medium physical properties. Numerical results clearly indicate that in addition to the traditional fluid viscosity-related mechanisms, the dynamic viscoelastic properties of the shell material as well as its thickness can be of major significance in sound scattering. Limiting cases are examined and fair agreements with well-known solutions are established.

Growth of Container-grown Plants With and Without Azomite Soil Amendment

Azomite is a mined, commercially available, hydrated sodium calcium aluminosiliclate soil amendment reported to act as a source of mineral elements. To determine its effect on plant growth, Dendranthema `Connie' rooted cuttings, Malus seedlings, and Citrus seedlings were grown in containers in one of two growing media: ProMix BX or ProMix BX with Azomite (1:1, v:v). Plant height was monitored weekly and after 6 weeks of growth, fresh and dry plant weights of roots and shoots were determined. There was no difference in any of the parameters measured as a result of the addition of Azomite. Any nutritional influence of the Azomite may only be evident in different conditions, e.g., field soil, or over an extended period of time. The Azomite altered the medium's physical properties and therefore bulk density and water-holding capacity of the Azomite were determined for consideration.

Utilization of MSW for Nursery Container Stock Production

Five composted Municipal Solid Waste (MSW) (garbage) products and a composted manure were evaluated as container growing media components on eight woody and herbaceous plants. Plant growth response to the different composts and to the quality of compost used was species-specific. Media UM Manure 100 provided the greatest increase in plant height across all species during the first year. However, only one species, V. lentaga, actually ranked number one in UM Manure 100. J.h. `Blue Chip' and A. tuberosa both grew the tallest in Control I. The remaining five species grew tallest in five different media. Therefore, several amended media can provide increased plant height for specific species; however, the top three media for plant height across all species were: #1 UM Manure 100, #2 Prairieland 50, and #3 Pennington 50. Plant height was the lowest in Recomp 100 media. Pennington 50 provided the greatest increase in plant volume. Media producing the highest plant dry weights across all species were: #1 Prairieland 50, #2 Pennington 50 and #3 UM Manure 50. Plants grown in Recomp 100 had the lowest plant dry weight. Media physical properties such as media drainage and aeration were affected by amendment quality and quantity.

Vessel Volume, Gelling Agent, and Basal Salts Affect pH and Gel Strength of Autoclave Tissue Culture Media

Effects of autoclaving volume, gelling agent (Bactoagar, Gel-gro, Phytagar), and basal salts [Murashige and Skoog (MS); Woody Plant Medium (WPM); Gamborg B5 (GB)] on gel strength and pH of tissue culture media were tested. Gel strength was significantly affected by gelling agent and basal medium. MS media were generally softer than comparable WPM or GB media. As the vessel volume during autoclaving decreased, gel strength significantly decreased with Phytagar and Bactoagar gelling agents; Gel-gro had greater gel strength at the intermediate volume of medium autoclave. In all cases, autoclaving resulted in a pH decrease of 0.2 to 0.5 pH units. Lower pH values were associated with softer gels. The type of gelling agent did not greatly affect the postautoclave pH; mean values among gelling agents were within 0.05 pH units. Postautoclave pH of MS medium was lower than that of WPM or GB. This study verifies the need to observe uniform sterilization protocols to maintain consistency in the chemical and physical properties of media.

Ca, Mg, And Micronutrient Nutrition and Growth of Pelargonium In Pine Bark Amended With Composted Hardwood Bark

Abstract Growth and foliar nutrient analysis of Pelargonium X hortorum L. H. Bailey cv. Aurora grown in pine bark (PB) amended with 25%,50%, or 75% composted hardwood bark (HB) were studied with the bark components mixed either before or after composting. For each ratio of PB to HB, fresh PB was mixed with fresh HB before composting, or composted PB or noncomposted PB were mixed with composted HB. Media physical properties and plant growth and foliar nutrient levels were the same when media were mixed before or after composting. Plants had more shoot growth in media containing 25% or 50% HB. Media containing 25% or 50% HB had a stable pH during the study, while pH increased in other media. Plants grown in media containing 75% or more composted HB showed symptoms of Mn toxicity during the first month of growth. Except for Cu, plants grown in media containing composted HB had normal or above normal foliar tissue Ca, Mg, and micronutrient levels.

Ultrasonic Instrumentation Techniques for Thickness Measurements

The ultrasonic instruments employ the technique of pulse echo measurement and operate in a similar manner as sonar. A pulse of energy is transmitted from the probe and travels through the media to the far side where it is reflected back. The time between the transmit pulse and first echo is measured. During this travel time, due to the physical properties of media, amplitude of the echo is reduced and errors are introduced in the thickness measurements. The ultrasonic pulse also produces the thermal effect and changes the velocity of the waves. Various techniques are given to overcome these problems in case of thickness measurement using ultrasonic instruments.

Effects of Container Geometry and Media Physical Properties on Air and Water Volumes in Containers

Data derived from soil moisture retention curves of two media were combined with geometric descriptions of four containers to produce calculated values of air and water volumes for each medium-container combination. The volume air space ranged from 28% in a #1 container to 12% in a bedding plant cell (BPC). Water volume after drainage increased from 43% (#1) to 59% (BPC). The same trend occurred in these containers with the peatlite mix. These calculations were also used to mathematically model four simulated containers and to calculate the air and water contents in the resultant container-medium combinations.

AERATION OF POTTING MEDIA AND PLANT GROWTH

Providing optimum aeration for plants grown in small pots is a primary concern in the development of potting media. Aeration is defined as the percentage by volume of air-filled pores in a medium after it has been saturated with water and allowed to drain. This study describes how the physical properties of media, as well as the growth of potted plants, varied with changes in media aeration. A 1:1 (vol/vol) peat-vermiculite potting medium was adjusted to aerations of 1.0, 2.2, 5.0, 11.3, 13.3, 20.0, and 33.6%/vol by altering the particle size of the two constituents. Total pore space remained constant as aeration increased, but total moisture-holding capacity declined linearly. Water held above a matric potential of −30 cb increased slightly until aeration reached 10 to 15% and then declined. Water held below a matric potential of −30 cb decreased curvilin-early with increasing aeration. Four potted plants, begonia, coleus, impatiens and schefflera were grown in media with the seven different aerations. Although the plants varied in their sensitivity to aeration, plant growth was most limited when aeration was 5.0%/vol and below. Plants generally grew best in the aeration range of 11.3 to 20.0%/vol with a slight decrease in growth at the highest aeration of 33.6%/vol.

Exploitation of the Gaussian beam for the investigation of the refractive index changes induced in a medium by an intensive light wave

It has been shown that the experimental method consisting in the change of parameters of the Gaussian beam by the lens that the beam creates in the layer passing through it is simple and suitable for use. The experimental results obtained through this method by studying the refractive index thermal changes that took place when an He-Ne laser beam was absorbed in a layer are in good agreement with the results the theory of stationary thermal defocusation affords. Comparing the results obtained with the solutions of the organic dye brilliant green in different solvents (C2H5OH, C6H5NO2, C3H8O3) the constant dn/dϑ for glycerol has been determined. The method enables studying the physical properties of media which are connected with different mechanisms of the change of the refractive index by an intensive light beam passing through the medium.