Profile Analysis Method Research Articles

The Thickness and Volume of Young Basalts Within Mare Imbrium

AbstractBasaltic volcanism is one of the most important geologic processes of the Moon. Research on the thickness and volume of late‐stage basalts of Mare Imbrium helps better understand the source of lunar volcanism and eruption styles. Based on whether apparent flow fronts exist or not, the late‐stage basalts within Mare Imbrium were divided into two groups, namely, Upper Eratosthenian basalts (UEm) and Lower Eratosthenian basalts (LEm). Employing the topographic profile analysis method for UEm and the crater excavation technique for LEm, we studied the thickness and distribution of Eratosthenian basalts in Mare Imbrium. For the UEm units, their thicknesses were estimated to be ~16–34 (±2) m with several layers of individual lava (~8–13 m) inside. The estimated thickness of LEm units was ~14–45(±1) m, with a trend of reducing thickness from north to south. The measured thickness of late‐stage basalts around the Chang'E‐3 landing site (~37 ± 1 m) was quite close to the results acquired by the lunar penetrating radar carried on board the Yutu Rover (~35 m). The total volume of the late‐stage basalts in Mare Imbrium was calculated to be ~8,671 (±320) km3, which is 4 times lower than that of Schaber's estimation (~4 × 104 km3). Our results indicate that the actual volume is much lower than previous estimates of the final stage of the late basaltic eruption of Mare Imbrium. Together, the area flux and transport distance of the lava flows gradually decreased with time. These results suggest that late‐stage volcanic evolution of the Moon might be revised.

DEVELOPMENT OF TECHNOLOGY OF SEMI-FINISHED DESSERT PRODUCTS BASED ON DAIRY AND FRUIT-BERRY RAW MATERIALS USING THE PRINCIPLES OF COLLOID STABILIZATION OF MILK

There was realized the analysis of priority directions in the production technology of combined products, based on milk and fruit-berry raw materials. It was determined, that the common use of these components is rather limited from the point of view of providing colloid stability of the system without its stratification that is conditioned by the low рН values and influence of high temperatures at pasteurization of products. There was offered the method of milk stabilization at low рН values by decreasing the ionic calcium content to 40 % of its initial content. It was proved, that the process of milk decalcification by using sodium alginate allows to increase its acid tolerance and thermal tolerance that becomes a precondition for creating dessert semi-products, based on milk and fruit-berry raw materials. Using methods of the system analysis, there was elaborated the model of the technological system of dessert semi-products, which presents a final product as an integral technological system A, detailed to subsystems D1,…Dn, В, С, according to the developed technological process. There was established an interconnection between separate subsystems and its elements, studied ways of its functioning at macro- (interaction with the external environment) and micro-levels (study of internal characteristics). There was realized the organoleptic evaluation of the quality of products by the descriptive (qualitative) method and by the method of profile analysis (quantitative one). At that the notion of each organoleptic parameter (consistence, taste, smell and so on) is presented as a totality of components (descriptors), evaluated in the determined order by quality and intensity. The characteristic of organoleptic parameters by scales of intensity of separate signs is presented as profile diagrams. There were determined ways of using semi-products in the composition of dessert products. There was developed the principal technological scheme of their production. There was proved the effectiveness of introducing new products in institutions of restaurant economy and food industry.

High-throughput analysis of amino acids in plant materials by single quadrupole mass spectrometry

BackgroundThe amino acid profile of plants is an important parameter in assessments of their growth potential, resource-use efficiency and/or quality as food and feed. Screening studies may involve large number of samples but the classical amino acid analysis is limited by the fact that it is very time consuming with typical chromatographic run times of 70 min or more.ResultsWe have here developed a high-throughput method for analysis of amino acid profiles in plant materials. The method combines classical protein hydrolysis and derivatization with fast separation by UHPLC and detection by a single quadrupole (QDa) mass spectrometer. The chromatographic run time is reduced to 10 min and the precision, accuracy and sensitivity of the method are in line with other recent methods utilizing advanced and more expensive mass spectrometers. The sensitivity of the method is at least a factor 10 better than that of methods relying on detection by fluorescence or UV. It is possible to downscale sample size to 20 mg without compromising reproducibility, which makes the method ideal for analysis of very small sample amounts.ConclusionThe developed method allows high-throughput analysis of amino acid profiles in plant materials. The analysis is robust and accurate as well as compatible with both free amino acids and protein hydrolysates. The QDa detector offers high sensitivity and accuracy, while at the same time being relatively simple to operate and cheap to purchase, thus significantly reducing the overall analytical costs compared to methods based on more advanced mass spectrometers.

Enhancement of exciton transport in porphyrin aggregate nanostructures by controlling the hierarchical self-assembly

Exciton transport in meso-tetra(4-sulfonatophenyl) porphyrin (TPPS) J-aggregates was directly imaged using the emission profile analysis method with confocal fluorescence microscopy. By controlling the structural hierarchy of TPPS aggregates, we could comparatively study the exciton transport properties in single nanotubes and bundled structures. Using the one-dimensional diffusion model, the exciton diffusion coefficients of TPPS nanotubes and bundles were estimated as 95 and 393 nm2 ps-1, respectively, showing a dramatic enhancement of exciton transport in bundled structures. To reveal the underlying mechanism of enhanced exciton transport in bundle compared to that in single strands, the spatially resolved measurements of exciton transport images were correlated with the spectral information at each local sites. We have confirmed that nanotube and its bundled form possess different energetic landscapes and exciton migration dynamics. Agglomeration into bundles led to an increase in system-environment coupling and denser distribution of energy states, facilitating longer migration length and accelerated transport. Detailed analysis in this study provides important insights into the structure-dependent exciton transport properties of self-assembled J-aggregate nanostructures.

Feature of Interest‐Based Direct Volume Rendering Using Contextual Saliency‐Driven Ray Profile Analysis

AbstractDirect volume rendering (DVR) visualization helps interpretation because it allows users to focus attention on the subset of volumetric data that is of most interest to them. The ideal visualization of the features of interest (FOIs) in a volume, however, is still a major challenge. The clear depiction of FOIs depends on accurate identification of the FOIs and appropriate specification of the optical parameters via transfer function (TF) design and it is typically a repetitive trial‐and‐error process. We address this challenge by introducing a new method that uses contextual saliency information to group the voxels along a viewing ray into distinct FOIs where ‘contextual saliency’ is a biologically inspired attribute that aids the identification of features that the human visual system considers important. The saliency information is also used to automatically define the optical parameters that emphasize the visual depiction of the FOIs in DVR. We demonstrate the capabilities of our method by its application to a variety of volumetric data sets and highlight its advantages by comparison to current state‐of‐the‐art ray profile analysis methods.

Influence of mineral substances on the synthesis of volatile organic compounds by Pleurotus ostreatus in the process of solid phase cultivation

Mineral substances play an important role in ensuring high-grade growth and high organoleptic quality of the fruit bodies of basidiomycetes. In the process of solid-phase cultivation of the mushroom Pleurotus ostreatus (Jacq.: Fr.) Kumm. the lignocellulosic substrates were enriched with mineral additives of calcium, iron and selenium. Their influence on the synthesis of volatile aroma compounds was investigated by the methods of sensory profile analysis and ultraviolet spectroscopy. Mineral additives in the form of CaCl2, FeSO2•7H2O and Na2SeO3 salts were added to the substrate (sunflower husk, barley straw) before sterilization in concentrations that correspond to the physiological needs of the mushrooms. When carrying out a sensory profile analysis of dried fruit bodies, the following attributes of the flavor were determined: mushroom, woody, sweet, herbaceous, fish, meat, floral, earthy, acidic, putrescent. The conducted profile analysis showed an unequal dependence of the effect of mineral additives for each of the P. ostreatus strains. For IBK-549 and IBK-1535, an increase in the intensity of mushroom notes of aroma was observed with the addition of calcium and selenium to the husks, and for IBK-551, this was observed with the addition of iron and selenium to both substrates. The volatile aroma compounds were extracted with hexane at boiling point for 30 minutes. Absorption spectra were recorded in the wavelength range 200–330 nm. The examined extracts had light absorption maxima at 200–210 and 260–300 nm, which is typical for solutions of unsaturated compounds that have non-conjugated double bonds, saturated and unsaturated aldehydes and ketones. Additions of iron to the substrates increased the intensity of light absorption in comparison with the control. Additions of selenium selectively influenced different strains, and calcium ions did not significantly affect the change in the intensity of light absorption, and therefore the synthesis of volatile compounds by mushrooms. The level of synthesis of aroma-forming substances was higher when cultivating fungi on sunflower husks than on barley straw. This was confirmed both by the obtained aroma profiles and by the recorded absorption spectra of all examined strains. The study showed the possibility of influencing the organoleptic qualities of P. ostreatus fruiting bodies during solid-phase cultivation by supplementing the composition of lignocellulosic substrates with various mineral additives.

Structure of Pigment Metabolic Pathways and Their Contributions to White Tepal Color Formation of Chinese Narcissus tazetta var. chinensis cv Jinzhanyintai.

Chinese narcissus (Narcissus tazetta var. chinensis) is one of the ten traditional flowers in China and a famous bulb flower in the world flower market. However, only white color tepals are formed in mature flowers of the cultivated varieties, which constrains their applicable occasions. Unfortunately, for lack of genome information of narcissus species, the explanation of tepal color formation of Chinese narcissus is still not clear. Concerning no genome information, the application of transcriptome profile to dissect biological phenomena in plants was reported to be effective. As known, pigments are metabolites of related metabolic pathways, which dominantly decide flower color. In this study, transcriptome profile and pigment metabolite analysis methods were used in the most widely cultivated Chinese narcissus “Jinzhanyintai” to discover the structure of pigment metabolic pathways and their contributions to white tepal color formation during flower development and pigmentation processes. By using comparative KEGG pathway enrichment analysis, three pathways related to flavonoid, carotenoid and chlorophyll pigment metabolism showed significant variations. The structure of flavonoids metabolic pathway was depicted, but, due to the lack of F3ʹ5ʹH gene; the decreased expression of C4H, CHS and ANS genes; and the high expression of FLS gene, the effect of this pathway to synthesize functional anthocyanins in tepals was weak. Similarly, the expression of DXS, MCT and PSY genes in carotenoids synthesis sub-pathway was decreased, while CCD1/CCD4 genes in carotenoids degradation sub-pathway was increased; therefore, the effect of carotenoids metabolic pathway to synthesize adequate color pigments in tepals is restricted. Interestingly, genes in chlorophyll synthesis sub-pathway displayed uniform down-regulated expression, while genes in heme formation and chlorophyll breakdown sub-pathways displayed up-regulated expression, which also indicates negative regulation of chlorophyll formation. Further, content change trends of various color metabolites detected by HPLC in tepals are consistent with the additive gene expression patterns in each pathway. Therefore, all three pathways exhibit negative control of color pigments synthesis in tepals, finally resulting in the formation of white tepals. Interestingly, the content of chlorophyll was more than 10-fold higher than flavonoids and carotenoids metabolites, which indicates that chlorophyll metabolic pathway may play the major role in deciding tepal color formation of Chinese narcissus.

XPS study of multilayer multicomponent films

In the paper, we propose an XPS-based quantitative method for depth profile analysis of chemical and phase composition of multi-component and multi-layer samples. The method includes: (1) new method for background subtraction accounting for depth non-uniformity of electron energy losses; (2) new method for photoelectron line decomposition into elementary peaks, which accounts for physical nature of the decomposition parameters; (3) joint solving of both background subtraction and photoelectron line decomposition problems; (4) criterion for assessing of line decomposition accuracy; (5) simple formula for layer thickness extraction for multi-element and multi-layer sample. We apply the developed method for analysis of multilayer niobium oxide and sub-oxide films before and in course of ion milling.

Impact of carbon quantum dots on dynamic properties of BSA and BSA/DPPC adsorption layers

The effects of carbon quantum dots (CQDs) on the dynamic properties of bovine serum albumin (BSA) were investigated using pendant drop profile analysis method. Moreover, the effects of CQDs on the competitive adsorption of BSA and dipalmitoyl phosphatidylcholine (DPPC) were examined. CQDs reduce the fluorescence intensity of BSA and cause a red shift in fluorescence emission. The quenching constant at pH 4.3 is almost twice as large as that of the value obtained at pH 6.0. A small amount of CQDs does not influence the dynamic surface adsorption properties of BSA molecules. As the CQD concentration increases, a gradual increase in adsorption rate of BSA molecules is observed. Moreover, the addition of CQDs results in a significant transition of kinetic dependencies of surface elasticity of BSA solution when the CQD concentration exceeds a critical value. The appearance of the maximum surface elasticity value is probably attributed to the formation of tails and loops. When the dynamic surface properties are dominated by BSA molecules, the effects of CQDs on the surface properties of BSA/DPPC mixture are similar to those of BSA alone. However, when the surface film mainly consists of DPPC, CQDs can obviously change the interfacial properties of DPPC monolayer.

Internal validation of STRmix™ for the interpretation of single source and mixed DNA profiles

The interpretation of DNA evidence can entail analysis of challenging STR typing results. Genotypes inferred from low quality or quantity specimens, or mixed DNA samples originating from multiple contributors, can result in weak or inconclusive match probabilities when a binary interpretation method and necessary thresholds (such as a stochastic threshold) are employed. Probabilistic genotyping approaches, such as fully continuous methods that incorporate empirically determined biological parameter models, enable usage of more of the profile information and reduce subjectivity in interpretation. As a result, software-based probabilistic analyses tend to produce more consistent and more informative results regarding potential contributors to DNA evidence. Studies to assess and internally validate the probabilistic genotyping software STRmix™ for casework usage at the Federal Bureau of Investigation Laboratory were conducted using lab-specific parameters and more than 300 single-source and mixed contributor profiles. Simulated forensic specimens, including constructed mixtures that included DNA from two to five donors across a broad range of template amounts and contributor proportions, were used to examine the sensitivity and specificity of the system via more than 60,000 tests comparing hundreds of known contributors and non-contributors to the specimens. Conditioned analyses, concurrent interpretation of amplification replicates, and application of an incorrect contributor number were also performed to further investigate software performance and probe the limitations of the system. In addition, the results from manual and probabilistic interpretation of both prepared and evidentiary mixtures were compared.The findings support that STRmix™ is sufficiently robust for implementation in forensic laboratories, offering numerous advantages over historical methods of DNA profile analysis and greater statistical power for the estimation of evidentiary weight, and can be used reliably in human identification testing. With few exceptions, likelihood ratio results reflected intuitively correct estimates of the weight of the genotype possibilities and known contributor genotypes. This comprehensive evaluation provides a model in accordance with SWGDAM recommendations for internal validation of a probabilistic genotyping system for DNA evidence interpretation

Methylated site display (MSD)-AFLP, a sensitive and affordable method for analysis of CpG methylation profiles

BackgroundIt has been pointed out that environmental factors or chemicals can cause diseases that are developmental in origin. To detect abnormal epigenetic alterations in DNA methylation, convenient and cost-effective methods are required for such research, in which multiple samples are processed simultaneously. We here present methylated site display (MSD), a unique technique for the preparation of DNA libraries. By combining it with amplified fragment length polymorphism (AFLP) analysis, we developed a new method, MSD-AFLP.ResultsMethylated site display libraries consist of only DNAs derived from DNA fragments that are CpG methylated at the 5′ end in the original genomic DNA sample. To test the effectiveness of this method, CpG methylation levels in liver, kidney, and hippocampal tissues of mice were compared to examine if MSD-AFLP can detect subtle differences in the levels of tissue-specific differentially methylated CpGs. As a result, many CpG sites suspected to be tissue-specific differentially methylated were detected. Nucleotide sequences adjacent to these methyl-CpG sites were identified and we determined the methylation level by methylation-sensitive restriction endonuclease (MSRE)-PCR analysis to confirm the accuracy of AFLP analysis. The differences of the methylation level among tissues were almost identical among these methods. By MSD-AFLP analysis, we detected many CpGs showing less than 5% statistically significant tissue-specific difference and less than 10% degree of variability. Additionally, MSD-AFLP analysis could be used to identify CpG methylation sites in other organisms including humans.ConclusionMSD-AFLP analysis can potentially be used to measure slight changes in CpG methylation level. Regarding the remarkable precision, sensitivity, and throughput of MSD-AFLP analysis studies, this method will be advantageous in a variety of epigenetics-based research.

Coupling slope–area analysis, integral approach and statistic tests to steady-state bedrock river profile analysis

Abstract. Slope–area analysis and the integral approach have both been widely used in stream profile analysis. The former is better at identifying changes in concavity indices but produces stream power parameters with high uncertainties relative to the integral approach. The latter is much better for calculating channel steepness. Limited work has been done to couple the advantages of the two methods and to remedy such drawbacks. Here we show the merit of the log-transformed slope–area plot to determine changes in concavities and then to identify colluvial, bedrock and alluvial channels along river profiles. Via the integral approach, we obtain bedrock channel concavity and steepness with high precision. In addition, we run bivariant linear regression statistic tests for the two methods to examine and eliminate serially correlated residuals because they may bias both the estimated value and the precision of stream power parameters. We finally suggest that the coupled process, integrating the advantages of both slope–area analysis and the integral approach, can be a more robust and capable method for bedrock river profile analysis.

Preparation and in vitro evaluation of melatonin-loaded HA/PVA gel formulations

Melatonin-loaded hyaluronic acid (HA) and poly(vinyl alcohol) (PVA) gels were prepared by using freeze–thaw technique and an emulsion method followed by freeze–thaw technique to produce a new synergistic system for topical application. Freeze–thaw hydrogels and emulgels were characterized by means of Fourier transform infrared spectroscopy, rheology and swelling tests. The porous structure of the hydrogels was shown by scanning electron microscopy observations and thermal properties were tested by differential scanning calorimetry measurements. Bioadhesion and in vitro release characterization of formulations were performed by texture profile analysis and dialysis bag method, respectively. The pore size of both formulations was ranging from 900 nm to 30 μm. Melatonin showed a good compatibility with the polymeric matrices as the pores were smaller for the drug-loaded systems. In vitro release studies showed that the release was improved by emulgel formulations. After 24 h, the release percentage was found to be 13.240% ± 1.094 and 15.192% ± 2.270 for hydrogel and emulgel, respectively. Emulgels had better bioadhesion properties than simple freeze–thaw samples. As a conclusion, regarding the in vitro characterization studies HA and PVA hydrogel and emulgel formulations and their lyophilized forms could be promising systems for topical application of melatonin.

INVESTIGATION OF SURFACE GRADIENT MICROSTRUCTURE OF SHOT PEENED S30432 STEEL BY X-RAY LINE PROFILE ANALYSIS METHOD

S30432 steels were processed by multistep shot peening treatment. The refined microstructures, including domain size, microstrain, domain size distribution and texture were characterized by X-ray diffraction (XRD) line profile analysis method, respectively. The results demonstrate that in the deformed layers, a gradient structure is formed after shot peening. The domain size reaches 25[Formula: see text]nm at the surface, then it decreases as the depth increases, but microstrain (0.0027) is the largest at the surface. The domain size distributions at different depths calculated by Rietveld method are consistent with domain size variation along the depth. There are no strong textures after shot peening treatment. The change of microhardness along the depth is in accordance with the gradient microstructure. It is expected that this work can offer useful information for characterizing the microstructure of shot peened materials.

The influence of sandstone caprock material on bedrock channel steepness within a tectonically passive setting: Buffalo National River Basin, Arkansas, USA

AbstractBedrock channel profile analysis typically assumes that channels evolve toward a condition of topographic steady state where channel morphology is adjusted to rock erodibility, uplift rates, and stream power. Here we use the integral method of channel profile analysis to quantify channel steepness within a large set of tributary channels that incise through layered rocks in the Buffalo National River Basin in northern Arkansas. Statistical analysis of these channels demonstrates that normalized channel steepness is not a function of local bedrock lithology but is influenced by coarse sediment supply. Specifically, normalized steepness is greatest in reaches of the basin where an interval of Pennsylvanian sandstone forms a caprock on the ridges. Block detachment of the sandstone causes large boulders to be stranded in the upper tributaries where stream power is too low to mobilize or effectively erode the boulders. Within these channels, normalized steepness is correlated with sandstone boulder size and percent boulder coverage rather than local lithology, despite strong contrasts in the mechanical strength of the lithologies incised. This analysis suggests that removal of caprock material is rate limiting within the landscape and may be responsible for the long‐term persistence of topography within this tectonically passive setting.

An evaluation of diffraction peak profile analysis (DPPA) methods to study plastically deformed metals

A range of diffraction peak profile analysis (DPPA) techniques were used to determine details of the microstructure of plastically deformed alloys. Four different alloys were deformed by uniaxial tension and compression to a range of strains. The methods we have considered include, the full-width, Williamson-Hall methods, Warren-Averbach methods, and van Berkum's alternative method. Different metals were chosen to understand the effect of the deformation microstructure and crystal structure, a nickel alloy, two stainless steel alloys and two titanium alloys.The dislocation density values found by Williamson-Hall and Warren-Averbach methods were found to be close to those expected from TEM results of similar metals. When using the Warren-Averbach methods the results suggest that systematic errors in the dislocation density are introduced by three main factors: (1) separation of instrumental broadening, (2) separation of size and strain broadening, and (3) separation of dislocation density and arrangement. Which suggests in many cases the simpler Williamson-Hall method may be preferable.The other main parameters that can be determined by DPPA are the crystal size and the dislocation arrangement. The work suggests that further investigation is needed to understand what use if any these parameters have for quantifying the deformed microstructure of plastically deformed metals.

Graphical methods of river profile analysis to unravel drainage area change, uplift and erodibility contrasts in the Central Range of Taiwan

AbstractTo reveal river channel steepness patterns and variance in settings with significant variation in rock uplift rate, rock erodibility and moving water divides, we present a series of graphical methods to interpret channel profiles. To complement Cartesian χ plots, longitudinal profiles and mapping methods, we introduce a new method based on a radial coordinate system. We map each basin onto polar coordinates in which the radial dimension is χ and the azimuthal coordinate, ϕ, is calculated with an increment (Δϕ) scaled to the distance to neighboring channel heads. The elevation is contoured on this mapping. Average channel steepness is estimated by fitting a conical surface to the elevation. The graph simplifies the comparison of χ and elevation between channels that share a divide, and helps identify spatial changes in drainage area and patterns of erodibility.We apply this approach to derive the uplift pattern in the eastern and southern Central Range of Taiwan, where the high tectonic convergence and uplift rates combined with sub‐tropical climate and frequent typhoons results in high exhumation rate, and well‐developed, detachment‐limited river networks. Additionally, the tectonic activity leads to drainage basin reorganization. We identify examples of divide migration, discrete river capture as well as anomalous steepness that we attribute to local variability in rock erodibility.Estimated basin‐average steepness values show the highest and a near constant value from Hsinwulu basin to Liwu basin in the center of the Island. To the north and south of this region, the values gradually decrease. These estimates show good correlation with the topography of the Central Range and erosion rates derived from in situ 10Be concentrations in river‐borne quartz. We conclude that the basin steepness reflects systematic differences in rock uplift rate and erosion rate. Copyright © 2016 John Wiley & Sons, Ltd.

Wavelength dependence of the ablation characteristics of Cu (In, Ga) Se2 solar cell films and its effects on laser induced breakdown spectroscopy analysis

As a novel method for fast depth profile analysis of Cu (In, Ga) Se2 (CIGS) thin film solar cell, laser induced breakdown spectroscopy (LIBS) is introduced, and the effects of laser wavelength on depth resolution are investigated. From LIBS analysis of a commercial CIGS solar cell using an ultraviolet (λ = 266 nm) and a visible (λ = 532 nm) nanosecond Nd: YAG lasers and an intensified charge-coupled device spectrometer, it is shown that the use of a shorter wavelength laser does not guarantee an enhancement of depth resolution. Although the averaged ablation depth per pulse was smaller for the ultraviolet laser, the craters produced by the visible laser was much smoother and more uniform, demonstrating that depth resolution depends not only on laser wavelength but also strongly on the ablation mechanisms.

Current density profile characterization and analysis method for focused ion beam

The most critical challenge of circuit edit is the scaling of nano-machined features to the ever-decreasing minimum dimensions of VLSI process technologies. A key enabler for achieving small nano-machined feature sizes is a narrow focused ion beam (FIB) profile. Thus, the analysis of FIB profiles and their characteristic widths yields useful criteria of suitability for advanced circuit edit and other nano-machining applications. We present herein, the details of an analysis method of ion beam profiles based on amorphization traces produced by the beam when scanned over a [001] Si single crystal sample, with increasing doses. The amorphized region widths are measured by high resolution transmission electron microscopy. The analysis, relying on TRIM simulation, yields the transverse current density of a beam as a sum of two Gaussians and an exponential, and includes error estimates. Successful beam analyses of several modern FIB columns have been performed. We believe that this methodological approach to beam profile analysis may be used to advantage by FIB column manufacturers for characterization and development.

Rock joint topography: three-dimensional scanning and numerical analysis

Joints are the most defining features of fractured rock masses. It has been well established that joint behaviour is mainly defined by wall topography, which is difficult to measure and define. Previous works have employed both contact and non-contact scanning methods and multiple approaches to the analysis of rock surfaces, but a majority focused exclusively on individual surface characterisation without appraising wall–wall interaction. This paper presents an equipment that is easily available for laboratory scanning of rock joints. Surface topographies of eight granite rock joints (16 surfaces, made available to other researchers) are statistically analysed separately and jointly by applying a fitting algorithm to match the top and bottom surfaces that allow mapping and calculation of contact areas and void volumes during closure. Results show that traditional methods for joint profile analysis are not applicable to three-dimensional surfaces, and that often specific details of joint surfaces have opposing influence on the mechanical, dynamic or hydraulic behaviours.