Specimen Depths Research Articles

Automatic defect detection and three-dimensional reconstruction from pulsed thermography images based on a bidirectional long-short term memory network

Machine learning techniques have become increasingly applied to non-destructive testing based on pulsed thermography. However, existing methods need to extract characteristic data manually. The present work addresses this issue by applying a bidirectional long-short term memory (Bi-LSTM) network to identify defects, predict defect depths, and reconstruct defective materials in three dimensions automatically based on raw cooling data sequences. The network is trained and tested based on data collected for stainless-steel specimens with multiple flat-bottom holes introduced at various specimen depths. A dual-task method and a single-task method were proposed based on Bi-LSTM network. A classification model and a regression model are constructed in the dual-task method for identifying defects and predicting defect depths. Only the regression network is implemented in a single-task method to more quickly obtain the same results based on a depth threshold. Both methods are demonstrated to achieve satisfactory accuracy in the 3D reconstruction of the defects in the testing specimen. In addition, higher pulse energy and faster acquisition frequency can promote the prediction accuracy. Then the results of Bi-LSTM were compared with the results of 1D CNN and MLP. To verify the generalization of the proposed method, CFRP specimen is employed for 3D reconstruction, which also performed with good results.

Modeling the flexural strength of steel fibre reinforced concrete

<abstract> <p>Industrial applications of fibre-reinforced concrete (FRC) in structures require extensive experimental and analytical investigations of the FRC material properties. For design purposes and applications involving the flexural loading of the member, it is essential to have a predictive model for the flexural strength of the FRC material. In the present paper, a fracture mechanics approach based on Bridged Crack Model (BCM) is used to predict the flexural strength of steel fibre-reinforced concrete (SFRC) beams. The model assumes a quadratic tension-softening relationship (σ-δ) governing the bridging action of the steel fibres and a linear profile of the propagating crack. The proposed tension-softening relationship is considered valid for a wide range of fibre-reinforced concrete materials based on the knowledge of either the material micromechanical parameters (such as fibre volume fraction, fibre/matrix bond strength, fibre length, and fibre tensile strength) or an actual experimentally-measured σ-δ relationship. The flexural strength model thus obtained allows the prediction of the flexural strength of SFRC and study the variation of the latter as a function of the micromechanical parameters. An experimental program involving the flexural testing of 13 SFRC prism series was carried out to verify the prediction of the proposed model. The SFRC mixes incorporated two types of steel fibres (straight-end and hooked-end), four different concrete compressive strengths (40, 50, 60, and 70 MPa), three different fibre volume fractions (1, 1.5, and 2%), and three specimen depths (100, 150, and 200 mm). The experimental results were compared to the predictions of the proposed flexural strength model, and a reasonable agreement between the two has been observed. The model provided a useful physical explanation for the observed variation of flexural strength as a function of the test variables investigated in this study.</p> </abstract>

Is Endocervical Glandular Involvement Related to The Depth of Cone Biopsy?

Introduction. This study aimed to determine whether endocervical glandular involvement by squamous intraepithelial lesion would differ with respect to the depth of the excised specimen and analyze the related factors that may define endocervical glandular involvement among cases treated with cone biopsy. Methods. Between April 2016 and December 2018, women who underwent colposcopy and excisional procedures in the department of gynecologic oncology were retrospectively investigated. Patients with multiple specimens, or whose specimen depths were not measured, and a negative/unknown HPV status were excluded from the study. Also, patients with no dysplasia or microinvasive/invasive cancer in the final pathology report and those who had not undergone endocervical curettage during colposcopy were excluded. HPV genotypes, degree of dysplasia, surgical margin status, and specimen depth were documented from medical records. Further, the association of these factors with endocervical glandular involvement was evaluated. Results: A total of 321 patients who fulfilled the criteria were included in the study, with a mean age of 41.9 years. In total, 101 patients (31.5%) had endocervical glandular involvement. The mean excised specimen depth was 17.04 mm; 17.9 and 16.7 mm for the positive and negative glandular involvement groups, respectively (p = .13). The mean ages were 42.7 and 41.6 years for these groups, respectively (p = .32). There was no association between the HPV genotypes and glandular involvement. Conclusions: Endocervical glandular involvement is not associated with the depth of the excised specimen. A deeper cone biopsy may not necessarily enable a more effective treatment of the disease.

Experimental Investigation of the Flexural Behavior of Steel Fiber Reinforced Concrete

This research study is conducted to investigate the flexural behaviour of steel fiber reinforced concrete (SFRC) prisms incorporating different types and volume fractions of steel fibers, various grades of concrete, and different specimen depths, all tested under displacement control mode using four-point loading configuration. Two types of steel fibers (hooked end and straight) were incorporated into the concrete mixes at two different dosages (1% and 2%). Concrete mixes with compressive strengths of 40, 50, and 70 MPa were used to cast the samples. Specimen depth was also among the test variables, where prisms of depth 100, 150 and 200 mm were tested to study the size effect on the flexural behaviour of SFRC. Test results indicated that for the straight-end steel fibers, the increase in the fiber volume fraction from 1 to 2% had a noticeable effect on both flexural strength (or Modulus of Rupture, MOR) and associated prism mid-span deflection. However, for the hooked end steel fibers, there was only a limited increase in the same measured values due to reduced workability of the SFRC fresh mix. The test results also have shown that the increase in the concrete compressive strength had only a modest effect on the average MOR value, but a noticeable effect on average mid-span deflection at peak load. The latter was attributed to the relatively long length and the hooked end geometry of the steel fibers. Finally, test results revealed that specimen depth had an impact on the measured flexural strength, where increase in specimen depth was associated with reduced MOR values, a phenomenon that is commonly referred to in the literature as size effect.

Comparative Effect of Self- or Dual-Curing on Polymerization Kinetics and Mechanical Properties in a Novel, Dental-Resin-Based Composite with Alkaline Filler. Running Title: Resin-Composites with Alkaline Fillers.

Dental bulk-fill restorations with resin-composites (RBC) are increasing in popularity, but doubts concerning insufficient curing in depth still disconcert clinicians. An alternative might be offered by modern dual-cured RBCs, which additionally provide bioactive properties. This study assessed the impact of additional light-curing on polymerization kinetics, the degree of conversion (DC) and mechanical properties of a novel, dual-cured RBC with alkaline fillers. Since the bioactivity of a material often implies a release of compounds, the mechanical stability in simulated clinical environments was also evaluated. Polymerization kinetics and DC were assessed at 2- and 4-mm specimen depths in real-time up to one hour (n = 6). Incident and transmitted irradiance and radiant exposure were recorded at 2- and 4-mm depths. Micro-mechanical profiles (n = 6) were assessed in 100-µm steps along 6-mm deep specimens at 24 h post-polymerization. Flexural strength and modulus (n = 10) were determined up to three months of immersion in neutral (6.8) and acidic (4) pH conditions. DC variation in time was best described by a sigmoidal function (R2 > 0.98), revealing a retarded (3.4 ± 0.4 min) initiation in C=C double bond conversion in self-cured versus dual-cured specimens. The setting reaction kinetic was identical at 2- and 4-mm depths for the self-cure mode. For the dual-cure mode, polymerization initiated at 2-mm depth instantly with light-irradiation, while being retarded (0.8 min) at 4-mm depth. The material behaves similarly, irrespective of curing mode or depth, later than 11 min after mixing. Flexural strength and modulus was comparable to regular RBCs and maintained up to three months in both neutral and acidic conditions. Additional light-curing initially accelerates the polymerization kinetic and might help shorten the restauration procedure by hardening the material on demand, however with no effect on the final properties.

Characterization of a low-grade copper-sulphide ore to assess its suitability for in situ recovery

CSIRO Minerals is developing new technologies and approaches for the in situ recovery (ISR) of valuable metals. ISR provides opportunities to process small and/or deep deposits and could create additional revenue for conventional uneconomic mines. Unlike for conventional processing, no standard methodology exists for characterizing sample suitability for ISR. The authors are developing a workflow to understand sample and deposit amenability to ISR processing. A South Australian low-grade iron-oxide-copper-gold sulphide ore was studied. A total of 37 drill cores samples were obtained from the ore sample for detailed mineralogical and leaching characterization. A range of characterization techniques including chemical analysis, X-ray fluorescence mapping, quantitative evaluation of minerals by scanning electron microscopy, computed tomography scanning, and bulk- and micro-X-ray diffraction analyses were applied to understand the ore mineralogy. Leaching tests at 50 °C were performed on selected samples to understanding their leaching behaviour. Mineralogical characterization found that copper was present mostly as discrete secondary copper sulphides distributed in various areas and at various specimen depths, which, in theory should be readily available for leaching, provided sufficient solution access exists. Leaching results showed steady copper recovery under the conditions tested. This study provides insight into understanding the suitability of an ore for ISR processing.

Detecting the Water-soluble Chloride Distribution of Cement Paste in a High-precision Way.

To improve the accuracy of the chloride distribution along the depth of cement paste under cyclic wet-dry conditions, a new method is proposed to obtain a high-precision chloride profile. Firstly, paste specimens are molded, cured, and exposed to cyclic wet-dry conditions. Then, powder samples at different specimen depths are grinded when the exposure age is reached. Finally, the water-soluble chloride content is detected using a silver nitrate titration method, and chloride profiles are plotted. The key to improving the accuracy of the chloride distribution along the depth is to exclude the error in the powderization, which is the most critical step for testing the distribution of chloride. Based on the above concept, the grinding method in this protocol can be used to grind powder samples automatically layer by layer from the surface inward, and it should be noted that a very thin grinding thickness (less than 0.5 mm) with a minimum error less than 0.04 mm can be obtained. The chloride profile obtained by this method better reflects the chloride distribution in specimens, which helps researchers to capture the distribution features that are often overlooked. Furthermore, this method can be applied to studies in the field of cement-based materials, which require high chloride distribution accuracy.

Impact of light transmittance mode on polymerisation kinetics in bulk-fill resin-based composites

Objectivesto determine the mode of light transmission and its impact on the polymerisation kinetic in modern bulk-fill resin-based composites (B-RBC). Materials and methodsFour low-viscosity methacrylate-based and one high-viscosity ormocer-based B-RBCs were considered. One material was available in three different shades that were all analyzed. Polymerization kinetic and light transmittance were assessed in 2 and 4mm specimen depths. Incident and transmitted irradiance and radiant exposure were measured in real-time on a laboratory-grade spectrometer. ResultsA progressive enhanced light transmittance during polymerisation was identified in all materials except for TetricEvoFlow BulkFill, which became progressively opaque in all shades. One-way ANOVA and multivariate analysis (α=0.05) were performed. The parameter material has a significant (p<0.001) effect on DC (ηP2=0.856) and light transmittance parameters (irradiance, ηP2=0.965; radiant exposure, ηP2=0.956); specimen depth influences only transmittance (ηP2=0.978; 0.980). DC variation in time was best described by an exponential sum function (R2>0.95), differentiating between the gel- and the glass-phase and revealing a faster initiation of polymerization and a slower transition into the glass-phase by lowering the filler volume. Depth retarded the transition into the glass-phase, but did not alter DC measured 300s post-irradiation. Moderate inverse correlation was identified among DC and filler volume% (−0.646) or filler weight% (−0.403), while no correlation among DC and light transmittance (p=0.141; 0.125). The maximal rate of carbon-carbon double bond conversion varied within the analyzed materials but was independent from specimen’s depths. ConclusionsLight transmission changes during polymerization do not alter polymerization kinetics in modern B-RBCs. DC 300s post-irradiation was maintained with depth, while light was attenuated, the faster the more translucent the material was. DC and quality of curing cannot be related to light transmittance in B-RBCs.

In vitro comparison of polymerisation kinetics and the micro-mechanical properties of low and high viscosity giomers and RBC materials

ObjectivesThe study aims to characterise a low and high viscosity giomer bulk fill resin restorative with established low and high viscosity resin-based composite (RBC) restoratives at simulated clinical relevant specimen depths. MethodsThe irradiance of a light curing unit (Bluephase 20i) was measured on a laboratory-grade spectrometer at distances up to 10mm from the light tip (in 1mm increments). Polymerization kinetics (real-time decrease of CC double bond and degree of cure, DC) and micro-mechanical properties (Vickers hardness/HV; Depth of cure/DOC; Indentation modulus/E) were assessed at varying specimen depths (0.1–6mm in 100μm steps for E, DOC and HV and 0.1, 2, 4 and 6mm for DC) for a 20s irradiation. ResultsOne and two-way ANOVA (α=0.05) were performed. The parameter material has a significant (p<0.001) effect on DC (ηP2=0.839), HV (ηP2=0.683), and E (ηP2=0.536), whereas the specimen depth influenced only DC (ηP2=0.584) but not HV (p=0.093) or E (p=0.133). The polymerisation kinetic could be described by an exponential sum function, distinguishing between the gel and the glass phase. The hardness drop out was lower than 20%, indicated a depth of cure of 6mm for all materials. ConclusionsThe low and high viscosity giomer bulk-fill restoratives fulfil the requirements of bulk-fill placement, since under the analysed irradiation conditions an adequate depth of cure of >4mm was identified. Variation of DC with specimen depth was low, with little variation at specimen depths of <4mm. The micro-mechanical properties of the giomer materials were higher compared with the conventional RBC materials.

Characterization of air voids in cold in-place recycling mixtures using X-ray computed tomography

With the increasing application of cold in-place recycling (CIR) techniques, many performance studies have been done, but they rarely focus on the internal structure of CIR mixture. The objective of this study is to investigate the characteristics of air voids in CIR mixtures with the X-ray computed tomography (CT) and digital image processing (DIP) methods. The volume, size, and number of air voids in CIR specimens were statistically analyzed considering different aggregate gradations and compaction methods. The two-parameter Weibull function was used to model the air void gradation of CIR mixtures. Especially, the differences in air voids between CIR and hot mix asphalt (HMA) mixtures were fully quantified. According to the results of this study, with coarser aggregate gradation, the CIR mixture tends to have larger size and less number of air voids. Comparing with the Superpave gyratory compactor (SGC) method, the Static Load compaction produces relatively small air voids. The distributions of air void number in specimen depths for the three compaction methods are different. The scale and shape parameters in Weibull function are both sensitive to the changes in aggregate gradation and compaction method. The substantial difference of air voids between CIR and HMA mixtures is in the aspect of the air void number rather than the air void size. Overall, this study provides a solid foundation for future research in exploring the internal structure and mix design of CIR mixtures.

Direct tensile strength of lightweight concrete with different specimen depths and aggregate sizes

To examine the size effect in direct tension, 8 ready-mixed concrete batches classified into all-lightweight concrete (ALWC) and sand-lightweight concrete (SLWC) groups were prepared. In each group, the maximum aggregate size varied between 4mm and 19mm, and then the lateral depth of specimen with rectangular section ranged from 100mm to 500mm in each concrete batch. The size effect curves based on the basic formulas proposed by Bažant (1984) [1], Kim and Eo (1990) [2], and Yang and Sim (2011) [3] were also determined using a total of 28 lightweight concrete (LWC) data of current tests and 114 normal-weight concrete (NWC) data compiled from the available literature (Carpinteri and Ferro, 1994; Hu, 2011) [4,5], though specimens with lateral depth beside 100mm is very insufficient even in NWC. The present experimental observations and verifications by prediction models clearly showed that the size effect is more notable with the decrease of the unit weight of concrete and it is stronger in direct tension than in compression. The validity of Bažant’s model (Bažant, 1984) [1] is significantly dependent on the maximum aggregate size, while the models proposed by Kim and Eo (1990) [2] and Yang and Sim (2011) [3] closely predict the size effect trend observed from test data, confirming that the influence of the maximum aggregate size on the concrete tensile strength and the size effect is negligible, especially for LWC.

Dielectric analysis of depth dependent curing behavior of dental resin composites

ObjectivesThe aim of this study is to investigate depth dependent changes of polymerization process and kinetics of visible light-curing (VLC) dental composites in real-time. The measured quantity – “ion viscosity” determined by dielectric analysis (DEA) – provides the depth dependent reaction rate which is correlated to the light intensity available in the corresponding depths derived from light transmission measurements. MethodsThe ion viscosity curves of two composites (VOCO Arabesk Top and Grandio) were determined during irradiation of 40s with a light-curing unit (LCU) in specimen depths of 0.5/0.75/1.0/1.25/1.5/1.75 and 2.0mm using a dielectric cure analyzer (NETZSCH DEA 231 with Mini IDEX sensors). The thickness dependent light transmission was measured by irradiation composite specimens of various thicknesses on top of a radiometer setup. ResultsThe shape of the ion viscosity curves depends strongly on the specimen thickness above the sensor. All curves exhibit a range of linear time dependency of the ion viscosity after a certain initiation time. The determined initiation times, the slopes of the linear part of the curves, and the ion viscosities at the end of the irradiation differ significantly with depth within the specimen. The slopes of the ion viscosity curves as well as the light intensity values decrease with depth and fit to the Lambert–Beer law. The corresponding attenuation coefficients are determined for Arabesk Top OA2 to 1.39mm−1 and 1.48mm−1, respectively, and for Grandio OA2 with 1.17 and 1.39mm−1, respectively. For thicknesses exceeding 1.5mm a change in polymerization behavior is observed as the ion viscosity increases subsequent to the linear range indicating some kind of reaction acceleration. SignificanceThe two VLC composites and different specimen thicknesses discriminate significantly in their ion viscosity evolution allowing for a precise characterization of the curing process even with respect to the polymerization mechanism.

The influence of irradiation potential on the degree of conversion and mechanical properties of two bulk-fill flowable RBC base materials

ObjectiveTo assess the depth of cure claims of two bulk-fill flowable RBC bases (SDR and x-tra base) using Fourier transform infrared (FTIR) spectroscopy, biaxial flexure strength (BFS), and Vickers hardness number (VHN) for specimen depths of 8mm (in 1mm increments). MethodsThe degree of conversion (DC) was measured by monitoring the peak height (6164cm−1) of specimens (11.0±0.1mm diameter, 1.0±0.1mm thickness) during light irradiation for 20s using a quartz tungsten halogen light curing unit at 650±26mW/cm2. DC was measured up to 120s post irradiation and repeated (n=3) for irradiation depths up to 8mm (in 1mm increments). Further series (n=20) of eight discs were prepared, stacked, light irradiated and numbered from one to eight (distance from the LCU). The specimens were stored at 37±1°C for 24h and BFS tested with the fracture fragments used to determine the VHN for each specimen. ResultsX-tra base can be irradiated to 8mm without a change in DC, something the SDR material cannot claim. However, the DC results confirm both bulk-fill flowable RBC bases have a depth of cure in excess of 4mm. One-way ANOVAs of BFS and VHN data showed significant differences between irradiation depths for x-tra base and SDR with increasing irradiation depth (4mm) resulting in significant reductions in mean BFS and VHN. SignificanceThe claims that the bulk-fill flowable RBC bases have a depth of cure in excess of 4mm can be confirmed but the differing chemistry of the resin formulations and filler characteristics contribute to significant differences in DC, BFS and VHN data between the two materials tested.

Photodegradation profiles of PVC compound and wood/PVC composites under UV weathering

This work aimed to study the effect of different ultraviolet (UV) weathering conditions (natural and accelerated) on the photodegradation of polyvinyl chloride (PVC) and wood/polyvinyl chloride (WPVC) composites by considering the structural and physical changes of PVC and WPVC samples as well as examining the photodegradation profiles at different depths from the sample surfaces. The photodegradation of PVC and WPVC composites under natural weathering condi- tions were lower than those under accelerated weathering conditions. The addition of Tinuvin P stabilizer at 2 phr was suf- ficient to stabilize PVC and WPVC composites, whereas the presence of wood appeared to accelerate the photodegradation of PVC under both natural and accelerated weathering conditions. When considering the photodegradation profiles at dif- ferent depths of the samples, it was found that the polyene and carbonyl sequences of PVC and WPVC composites were high at the sample surfaces and tended to decrease rapidly with increasing depth from the specimen surface before stabiliz- ing at a depth of 60 µm for PVC and 80 µm for WPVC composites. The differences in specimen depths for the stabilization of polyene and carbonyl sequences in PVC and WPVC samples implied that the presence of wood particles enhanced the absorption of UV radiation by the WPVC composite samples.

Time Zero Value Based on S-Wave Reflection Loss Measurement for Early Age Shrinkage Monitoring of Cementitious Specimens Subjected to Sealed and Unsealed Curing Conditions

Abstract Estimating the time at which to start monitoring early age shrinkage, especially of high performance cementitious materials, can be crucial. Despite numerous studies on early age shrinkage monitoring, there is no general agreement on the time at which early age shrinkage measurements should start (i.e., the “time zero” value [TZV]). The present paper proposes the use of the stiffening time measured via S-wave reflection loss as the TZV for early age shrinkage monitoring of high performance cementitious materials subjected to both sealed and unsealed curing conditions. The results imply that in the case of autogenous or sealed specimens, similar stiffening times occur throughout the specimen depths. In the case of unsealed specimens, however, the results show that the stiffening time might vary with depth depending on the water-to-cementitious ratio used. It is postulated that water redistribution within the specimen, as well as the formation of a “skin layer,” might significantly affect the stiffening time measured in the case of unsealed specimens used for early age drying shrinkage monitoring.

SEM investigation of interfacial dislocations in nickel‐base superalloys

A new technique for investigation of interfacial dislocations in nickel-base superalloys by scanning electron microscopy is presented. At high temperatures the pressure of interfacial dislocations against the gamma/gamma'-interface causes grooves. This 'fingerprint of the dislocation network' is visualized by deep selective etching, which removes the gamma'-phase down to the gamma/gamma'-interface. Compared with transmission electron microscopy, the proposed method has important advantages: observation of large sample areas, no superposition of dislocations lying in different specimen depths, possibility of three-dimensional view of dislocation configurations, information about the dislocation mobility, reduced time for preparation and visualization. The method can be applied for multiphase materials where the interface is grooved by interfacial dislocations.

Influence of drinks on resin composite: Evaluation of degree of cure and color change parameters

Resin composites represent a class of materials widely used in restorative dentistry due to patient demands for better aesthetics. In this study, the degree of conversion and color change parameters of commercial resin composite Charisma after immersion in commonly used drinks were investigated. Degree of conversion and color stability are important parameters of modern resin-based dental filling materials. The specimens, after curing, were immersed in distilled water, a sports drink, yogurt, a soft drink based on cola and red wine for 24 and 168 h at 37 °C. The degree of conversion, evaluated by Raman spectroscopy through the correlation of absorption bands related to C C aromatic and aliphatic stretching and C O free stretching, was 70% at all specimen depths. The ratios of these absorption bands for specimens after immersion in the drinks were of the same magnitude, indicating that no chemical reaction occurred at the surface. The influence of drinks on color change of filling resin was investigated by measuring the CIE-Lab-values. The color change parameters ( L*, a* and b*) were significantly affected when the specimens were immersed in wine or yogurt for 24 or 168 h.

Concrete fracture prediction using bilinear softening

Abstract A finite element-based cohesive zone model was developed using bilinear softening to predict the monotonic load versus crack mouth opening displacement curve of geometrically similar notched concrete specimens. The softening parameters for concrete material are based on concrete fracture tests, total fracture energy (GF), initial fracture energy (Gf), and tensile strength ( f t ′ ) , which are obtained from a three-point bending configuration. The features of the finite element model are that bulk material elements are used for the uncracked regions of the concrete, and an intrinsic-based traction-opening constitutive relationship for the cracked region. Size effect estimations were made based on the material dependent properties (Gf and f t ′ ) and the size dependent property (GF). Experiments using the three-point bending configuration were completed to verify that the model predicts the peak load and softening behavior of concrete for multiple specimen depths. The fracture parameters, based on the size effect method or the two-parameter fracture model, were found to adequately characterize the bilinear softening model.

Kossel and pseudo Kossel CCD pattern in comparison with electron backscattering diffraction diagrams

Kossel and pseudo Kossel interferences, i.e. lattice source interferences (LSI) and divergent beam X-ray interferences (DBI), as well as electron backscattering diffraction (EBSD) are complementary physical methods of investigation, by means of which material-physical parameters can be obtained from microscopic small specimen areas in a non-destructive way. The interferences are taken with a high-resolution and time-integrating CCD camera [in Proceedings of the 15th International Congress on X-Ray Optics and Microanalysis (ICXOM), August 1998, Antwerp, Belgium; J. Anal. At. Spectrom. (The Royal Society of Chemistry) 14 (1999) 409] and at once transmitted to the computer for evaluation. Thus, these techniques can be used in situ. For the methods LSI and DBI, the reflections are indexed and evaluated with the own developed simulation program KOPSKO [Cryst. Res. Technol. 34 (7) (1999) 801]. In the present case, these three methods, besides other detectors, were additionally installed by us in the CamScan CS44 scanning electron microscope for the analysis of micro regions in solids. Because of the different excitation or diffraction ranges of the techniques, information comes from different specimen depths of some nanometers to about 100 μm. On this way, the range of application for the determination of the parameters was considerably increased. By the examples of a single-crystalline ceramic specimen of BaTiO 3 as well as a Fe monocrystal one the range of application is demonstrated by the determination of the crystallographic direction with respect to the specimen surface all three methods are compared.

Measurement of Consolidation and Permeability Properties of Extruded Soy under Mechanical Pressing

A compression-permeability testing apparatus was developed to measure property functions of oilseeds relevant to mechanical pressing for oil recovery, namely time-varying coefficients of permeability, consolidation and volume change. The cell was designed to accommodate testing of different specimen depths, under various compression pressures and temperatures. Properties were measured for extruded soy for two specimen sizes (10, 20 g) compressed at three pressures (20, 40, 60 MPa) and three temperatures (22, 60, 90°C).Consolidation and permeability property functions were significantly affected by applied pressure, temperature, sample size and pressing time. Several of the key assumptions of classical consolidation theory (as developed for saturated soils) were violated for the extruded soy medium, namely, the assumption of incompressible solids phase and constant material parameters. In other words, the sample structure changed substantially during pressing. The designed testing apparatus may be used to measure time-varying material parameters for use with consolidation models that have been appropriately modified for compressible oilseeds.