Volumetric Distribution Research Articles

English

The objective of this work was to evaluate the distribution of forest volume identified through interpolation maps from data obtained from the forest. We sampled 36 plots with 1-ha area. Special maps were used by means of interpolation adjusted by the Spline method. The results indicate that after 20 years of traditional exploration, no significant oscillations were identified for volumes. However, the area explored showed a significant recovery in the total volume in this period. In addition, it showed the appearance of new species that contributed to the increase of biodiversity. This influenced the growth rates of the trees, the establishment of natural regeneration, the growth of seedlings and sticks. These will replace the losses occurring during the exploration and the increase in carbon sequestration. It should be emphasized that this method proved to be efficient in determining points of greater volumetric distribution and consequent forest recovery. Key words: Geotechnologies, spatial distribution, forest volumetric.

Fatigue life estimation of explosive cladded transition joints with the use of the spectral method for the case of a random sea state

The problem with fatigue lifetime estimation of explosive cladded transition joints under random loading conditions has been described. The paper presents the fatigue test results performed for the random state of tension-compression under a generated spectrum according to the Pierson-Moskowitz model. The obtained spectrum has a non-Gaussian characteristic. The tested material consists out of a transition joint clad with four layers of aluminium alloy A5083, A1050, Titanium Grade 1 and steel Grade D. The material has been tested for the existence of residual stresses after the welding process with the hole drilling method. The welding process has been also simulated with ANSYS and the residual stresses have been generated for the Goldak volumetric distribution. The obtained values of residual stresses comprise to the values of real tests performed for the hole drilling method. The information about the residual stress values have been taken into account in the process of fatigue lifetime estimation in the form of non-zero mean stresses compensation inside the clad. The fatigue life has been calculated with the use of the frequency domain method. The Goodman mean stress compensation model has been used in the process of residual stress compensation. The non-gaussianity has been compensated with the use of the Bracessi formula. The obtained fatigue life assessment results have been compared with stand test results. The calculated results are within the scatter area of 3, but individual scatter values have been calculated for calculated series.

Environmental product declaration of timber products: The impact of allocation method to the impact categories

Nowadays, several novel standards guide the environmental assessment work in the field of construction products. In this study, allocation methods presented in EN 15804 standard are demonstrated in a comparable manner for sawmilling products. Cradle to gate assessment was done for three European sawmills, where different allocation methods were used in manufacturing phase. Firstly, were used physical allocation (volume based) and economic allocation (value based). Secondly, manufacturing process steps were divided (subdivision) and physical and economic allocation were used for these. In the third option, used as a reference, all environmental impacts of the manufacturing stage were allocated to the main product. This study focuses on indicators for describing environmental impacts and use of primary energy.Results indicate that allocation influences how impacts are distributed to the sawmilling products. As supposed, sawn timber as main product is getting biggest impact in all cases, because of the biggest quantity in production. Physical allocation is looking volumetric distribution of the products, where economic allocation is also considering value of the products. Additional, subdivision will give more holistic approach based on different production steps together with physical or economic quantities. Based on the results, the subdivision with economic allocation or the economic allocation gives more realistic impacts to low value by-products. Subdivision with economic allocation is the most holistic option, because impacts are allocated by processes, volumes and values.Despite of all standardization work, many different assessment methods can and are still used for the environmental assessment of the building products. That has led to a situation where different datasets are not comparable with each other and this causes confusion in users of the environmental datasets. Therefore, transparent datasets are needed to avoid misunderstandings and the reporting system could be developed to be more uniform.

Experimental Determinations on Mechanical Properties for Polyester-Glass Fiber Composite Materials

The mechanical characteristics of a fiber reinforced material depend on a number of parameters related to the structure and characteristics of the component materials, the volumetric distribution, orientation, geometry and adhesion of the fibers to the matrix. The modification of these characteristics over time is due to the varied mechanical demands (repeated or lasting), the thermal and humidity demands, the chemical agents and the influence of aging. The paper presents some observations resulting from experimental tests on polyester-glass composite materials developed in the Materiaux Composites laboratory.

Three‐Dimensional Mapping of Mt. Ruapehu Volcano, New Zealand, From Aeromagnetic Data Inversion and Hyperspectral Imaging

AbstractCombining 3‐D inversion of high‐resolution aeromagnetic data with airborne hyperspectral imaging creates a new method to map buried structure and hydrothermal alteration, applied to Mt. Ruapehu volcano, New Zealand. Hyperspectral imaging is sensitive to surface mineralogy including alteration minerals, while magnetic vector inversion reveals the volumetric distribution of magnetic susceptibility from which we interpret buried geology. Probability assessment from multiple model regularizations provides an important model uncertainty estimate. At Ruapehu, hyperspectral imaging highlights two main regions of surface alteration: the Pinnacle Ridge and the southeast flanks. The magnetic model of Pinnacle Ridge shows that alteration seen at surface continues to depth, but strongly magnetic, unaltered dikes form the core of the ridge. On the southeast flanks, the magnetic model also shows alteration imaged on the surface continues to depth; however, a previously unknown, magnetized sill intrudes part of the flank. Several smaller demagnetized regions are modeled, unlike at neighboring Mt. Tongariro where the hydrothermal system created a large demagnetized core. We propose that these differences relate to spatially focused (Ruapehu) vs distributed (Tongariro) eruption vents, the degree of faulting of the edifice and its glaciation history. Lava‐ice interaction produces fine‐grained lavas with measured magnetic susceptibilities similar to some moderately altered lavas, illustrating that care must be taken in the interpretation of magnetic data in the absence of geological information. The combination of hyperspectral imaging and aeromagnetic data inversion distinguishes shallow surface weathering from deeper‐seated hydrothermally altered rock masses, with implications for the magnitude and probability of collapse events.

Bulk intrinsic heterogeneity of metallic glasses probed by Meissner effect

Structural heterogeneity has been proposed as a key intrinsic feature and mechanism underline unique properties and dynamic behavior of metallic glasses; however, it is still challenging in precisely describing and effectively characterizing the atomic-scale heterogeneity in metallic glasses. In this work, we employed the Meissner effect of superconductivity in magnetic susceptibility measurements as a sensitive bulk probe and successfully revealed the three-dimensional structural heterogeneity and its two-way evolution tuned by structural aging or rejuvenation in a La-based metallic glass. Compared with the resistivity measurements which only signal the most superconductive loop in inhomogeneous materials, the diamagnetic susceptibility signal of the Meissner effect maps the volumetric distribution of all superconductive regions and the corresponding structural heterogeneity in metallic glasses with high sensitivity. The experimental results reported in this article can be well interpreted based on a structural model of tunable “soft liquid-like” regions with soft vibration modes mixed with “hard solid-like” regions, validating the heterogeneity models of metallic glasses with new experimental data and approach.

3D free fall rock size sensor

The energy efficiency of the grinding process is less than 1%, and it consumes about 40% of the energy in a typical open-pit mine operation (CIPEC, 2005). One of the causes of this low energy efficiency is the high variability of the run-of-mine ore hardness and size distribution, which must be measured accurately in order to develop process control strategies that will minimise their impact on mill efficiency. On-line rock hardness sensors are still unavailable and 2D rock size sensors show important limitations under uncontrolled outside lighting conditions. A rock hardness sensor based on primary crusher data analysis has provided interesting results but it requires a more accurate size measurement of the run-of-mine ore, which is a key information for evaluating the reduction ratio and compute the rock hardness index accordingly.Recently, laser 3D profiler has been identified as an interesting technology for measuring rock size distribution over a conveyor belt and they are now commercially available. This paper discusses the extension of this application to the measurement of ore size distribution as it is dumped into the primary crusher. The objectives are (1) to provide an accurate evaluation of the reduction ratio at the primary crushing stage and to allow the development of a rock hardness sensor, (2) to quantify the quality of the blast before any crushing size reduction, and (3) to address the measurement error of the fines associated with the conveyor belt system.A first prototype of the 3D rock sizing technology was evaluated in a rock quarry environment. The prototype was then improved based on the findings. The most important upgrade is a free fall rock- speed evaluation technique, which is based on the spectral analysis of a line-scan image of the rock flow. Despite some accuracy enhancement over existing 2D technologies, the 3D free fall rock-sizing sensor is still, in its industrial arrangement, limited to the measurement of a surface based rock size distribution. This limitation is due to the intrinsic depth sampling error of the 3D sensor, which sees only the front layer of the rock flow and, as a result, overestimates the percentage of coarser rocks. A full volumetric 3D free fall rock-sizing sensor was built in parallel at laboratory scale to overcome this limitation: it measures the entire volume of each piece of rock as they fall in a monolayer flow between two facing laser scanners. The resulting volumetric rock size distribution was found to be coherent to the size distribution measured by sieving, unbiased and, therefore, more accurate than any surface based rock size distribution. The volumetric 3D free fall rock-sizing sensor is proposed for upgrading commercial 2D imaging technologies, which are now used as an alternative to rock sieving in laboratory. A few industrial application scenarios, including its potential integration into an ore-sorting process, are also being investigated.

Design and Performance Evaluation of Self-propelled Intra-Canopy Boom Spraying System

A self-propelled intra-canopy boom spraying system was designed for spraying chemicals in small height row crops. The performance of the spraying system was evaluated both under laboratory and field conditions to assess the efficacy and minimize the loss of spray liquid. Flat fan and hollow cone nozzles were tested to determine the boom volumetric distribution, swath and spray angle at different combinations of pressure and height. The flat fan nozzle gave better volumetric distribution at 2.5 kgf.cm-2, while the hollow cone nozzle gave at 2.0 kgf.cm-2 pressure corresponding to 300 mm nozzle height. The spraying system was tested on soybean crop at forwarding speeds of 1.5, 2.0 and 2.5 km.h-1. With an increase in forwarding speed, the mean percentage of coverage decreased significantly (30.30 - 15.37 % for top and 20.01- 4.12 % for bottom part of the leaves), and the mean droplet density varied significantly (277.35 - 243.40 no.cm-2 for top and 262.87 - 78.44 no.cm-2 for the bottom part of the leaves) at 5 % level of significance. A good percentage of leaf area coverage (30.30 % and 20.01 % for top and bottom of the plant) was obtained at low forward speed (1.5 km.h-1) while compromising more spray volume and less field capacity as compared to higher forward travel speeds. The effect of forwarding travel speed, position of tags and nozzle types were significant (p<0.05) for mean droplet size, number median diameter, percentage coverage of leaf area and droplet density. The field capacity of the spraying system ranged between 0.22 and 0.36 ha.h-1 with an increase in forward travel speed from 1.50 km.h-1 to 2.50 km.h-1 at an average swath of 1.8 m.

Design and Performance Evaluation of Self-propelled Intra-Canopy Boom Spraying System

A self-propelled intra-canopy boom spraying system was designed for spraying chemicals in small height row crops. The performance of the spraying system was evaluated both under laboratory and field conditions to assess the efficacy and minimize the loss of spray liquid. Flat fan and hollow cone nozzles were tested to determine the boom volumetric distribution, swath and spray angle at different combinations of pressure and height. The flat fan nozzle gave better volumetric distribution at 2.5 kgf.cm-2, while the hollow cone nozzle gave at 2.0 kgf.cm-2 pressure corresponding to 300 mm nozzle height. The spraying system was tested on soybean crop at forwarding speeds of 1.5, 2.0 and 2.5 km.h-1. With an increase in forwarding speed, the mean percentage of coverage decreased significantly (30.30 - 15.37 % for top and 20.01- 4.12 % for bottom part of the leaves), and the mean droplet density varied significantly (277.35 - 243.40 no.cm-2 for top and 262.87 - 78.44 no.cm-2 for the bottom part of the leaves) at 5 % level of significance. A good percentage of leaf area coverage (30.30 % and 20.01 % for top and bottom of the plant) was obtained at low forward speed (1.5 km.h-1) while compromising more spray volume and less field capacity as compared to higher forward travel speeds. The effect of forwarding travel speed, position of tags and nozzle types were significant (p<0.05) for mean droplet size, number median diameter, percentage coverage of leaf area and droplet density. The field capacity of the spraying system ranged between 0.22 and 0.36 ha.h-1 with an increase in forward travel speed from 1.50 km.h-1 to 2.50 km.h-1 at an average swath of 1.8 m.

Automatic processing and analysis of the structural properties of bone tissue

The volumetric distribution of bone tissue can be analysed in terms of orthotropic medium. In this case, it is important to define the orthotropic directions. Nowadays, computed tomography methods allow getting such information. The method for automation such analysis is presented. Firstly, the threshold of binarization should be calculated. Then the sample should be meshed and each element should be binarized. After that fabric tensor, eigenvalues, eigenvectors and fractional anisotropy can be calculated for each element. Statistical methods were used to analyse the field of the obtained data. Described methods were used on a bone sample. It was shown that for a sample the fabric tensor is constant and the fractional anisotropy is close to zero. That’s means that the medium in the sample was isotropic.

Identification of process-induced residual stresses in 3D woven carbon/epoxy composites by combination of FEA and blind hole drilling

Process-induced residual stresses in 3D woven carbon-epoxy composites are studied by blind hole drilling experiments interpreted with finite element (FE) modeling. It is assumed that residual stresses are primarily caused by the difference in thermal expansion coefficients of the constituents which are modelled as temperature-dependent linear elastic solids. The impact of residual stresses is quantified by drilling blind holes in the composite panels and mapping the resulting in-plane surface displacements by electronic speckle pattern interferometry. Mesoscale finite element models are used to correlate these surface displacements with the volumetric distribution of the residual stresses in the composite. This is done by determining the effective temperature drop ΔTeff that results in the same predictions for the surface displacements as experimentally measured. The effective temperature drop approach allows to use linear elastic models while approximately accounting for various nonlinear effects occurring in the material during processing. The models are also used to establish the sensitivity of the predicted results to the exact location of a hole and its depth.

Geometric sensitivity of beacon placement using airborne mobile anchors

Locating fixed sensing devices with a mobile anchor is attractive for covering larger deployment areas. However, the performance sensitivity to the geometric arrangement of anchor beacon positions remains unexplored. Therefore, localization using new RSSI-based localization algorithm, which uses a volumetric probability distribution function is proposed to find the most likely position of a node by information fusion from several mobile beacon radio packets to reduce error over deterministic approaches. This paper presents the guidelines of beacon selection that leads to design the most suitable trajectory, as a trade-off between the energy costs of travelling and transmitting the beacons versus the localization accuracy.

Platelet Activation State Intermixing in a Venous Puncture Model Indicates Novel Patterns of Thrombus Formation

No relevant conflicts of interest to declare.

EXTH-41. A NANOPARTICLE-BASED CANCER-SELECTIVE GENE TRANSFER STRATEGY FOR LOCALIZED THERAPY OF MALIGNANT HIGH GRADE GLIOMAS

Abstract Treatment for malignant high grade gliomas entails surgery, followed by chemotherapy and/or radiation. Despite the intensive care, there is a ~90% recurrence rate. This is attributed to suboptimal efficacy of treatments in tackling widespread cancer cells. We have previously developed nanoparticles that provide widespread therapeutic distribution both in healthy and tumor tissues, but are incapable of differentiating between them. This limitation applies to the current standard-of-care and state-of-the-art gene therapies. Here, we evaluate the efficacy of DNA nanoparticles carrying promoters that drive transgene expression specifically in tumor cells to achieve widespread yet cancer-selective gene transfer in high grade gliomas. To identify tumor-specific promoters, we used ELISA to confirm elevated expression of proteins previously reported to be upregulated in tumor tissue. We observed that expression of survivin in cancer cells was significantly greater than that of other cancer-rich proteins, exhibiting two orders of magnitude greater levels in rodent and human cancer cells compared to their respective healthy cells. Furthermore, the CMV promoter mediated similarly high expression in healthy cells, whereas the level achieved by the survivin promoter was significantly lower, if not negligible, suggesting its tumor specificity. Likewise, CMV-driven plasmids delivered into the brain by the nanoparticles mediated virtually identical volumetric distribution of transgene expression in both normal and tumor tissues in vivo. In contrast, nanoparticles carrying survivin-driven plasmids provided widespread transgene expression only in an orthotopically established tumor, but not healthy brain tissue. Additionally, we demonstrate therapeutic efficacy in an established brain tumor model using the DNA nanoparticles carrying survivin promoter-driven plasmids expressing a therapeutic protein. We identified survivin promoter as a lead TSP and confirmed its ability to mediate highly efficient and widespread but cancer-selective transgene expression with the aid of our nanoparticles uniquely designed to penetrate in healthy and tumor tissues.

Stochastic representation of the agglomeration process: Implications on the saturation variability in a dynamic heap leach

Liquid saturation within a heap leach is a critical factor in the heap's metallurgic performance. This saturation is affected by the agglomerate quality used to build the heap. In this context, our study investigates how the spatial distribution of the agglomerate quality within the heap affects its fluid saturation. The heterogeneity of the heap's fluid saturation is quantified using the saturation nonuniformity. The differences in agglomerate quality, represented by the permeability of the media, are generated by imperfections in the agglomeration process, which are represented as a stochastic process modeled with Markov chains. The agglomerates produced by this process are stacked orderly in narrow diagonal stages to build a heap. The fluid flow within this test heap is represented as a multiphase flow in a porous media and simulated in OpenFOAM, and the results are analyzed at steady state. Our results show that the volumetric water content distribution within the simulated heap was similar to that of a real copper leaching heap. Four key factors were studied, three of them regarding the physical structure of the heap (agglomeration quality, slope of the heap and percentage of well-agglomerated ore) and a fourth operational parameter (irrigation flux). The agglomeration quality had a significant impact on the heap's saturation nonuniformity due to the diagonal layers of low permeability along the heap's angle of repose. On the other hand, heap slope variations between 32° and 38° did not have a significant impact on the average saturation nonuniformity. Also, even when the heap's percentage of well-agglomerated ore was kept constant, it had more saturation nonuniformity than a uniformly distributed heap with the same percentage of well-agglomerated ore. Finally, the saturation nonuniformity remained constant when the heap was operated with different irrigation fluxes, suggesting that it is a property inherent to the heap's physical structure and not an operation parameter. The main limitation of this study is the inability of the developed model to represent spatial changes in the capillarity characteristics of the agglomerates. A sensitivity analysis including capillarity characteristic changes revealed that its impact is as relevant as the spatial distribution, which must be further explored in the future.

Fluence-map generation for prostate intensity-modulated radiotherapy planning using a deep-neural-network

A deep-neural-network (DNN) was successfully used to predict clinically-acceptable dose distributions from organ contours for intensity-modulated radiotherapy (IMRT). To provide the next step in the DNN-based plan automation, we propose a DNN that directly generates beam fluence maps from the organ contours and volumetric dose distributions, without inverse planning. We collected 240 prostate IMRT plans and used to train a DNN using organ contours and dose distributions. After training was done, we made 45 synthetic plans (SPs) using the generated fluence-maps and compared them with clinical plans (CP) using various plan quality metrics including homogeneity and conformity indices for the target and dose constraints for organs at risk, including rectum, bladder, and bowel. The network was able to generate fluence maps with small errors. The qualities of the SPs were comparable to the corresponding CPs. The homogeneity index of the target was slightly worse in the SPs, but there was no difference in conformity index of the target, V60Gy of rectum, the V60Gy of bladder and the V45Gy of bowel. The time taken for generating fluence maps and qualities of SPs demonstrated the proposed method will improve efficiency of the treatment planning and help maintain the quality of plans.

Effect of Nozzle Angle, Size and Pressure on Spray Distribution based on Laboratory Conditions

The objective of this study is to investigate spray parameters for different 40°– 95° even flat fan nozzle angles for banding spraying application, such as spray pattern width and spray volumetric distribution at pressures of 2 and 3bar using different nozzle sizes (0.15, 0.2, 0.3, 0.4 gpm). Spray distribution data was extracted from spray analyzer system or patternator. The results showed that nozzle angle and pressure significantly affected the spray pattern width. In addition, as the nozzle size increased, the liquid volume and the peak height under the nozzle center increased. These results suggest that the use of bigger nozzle angles improved the spray volumetric distribution.

Experimental investigation of surface temperature non-uniformity in spray cooling

The surface temperature non-uniformity is crucial in understanding the heat transfer mechanism of spray cooling. It is also a sensitive factor in the thermal management of electronic devices or in the application of transient sprays where the surface heat flux is obtained from the internal temperature measurement. In this study, the effects of heat flux, subcooling, nozzle-to-surface height, and injection pressures on the surface temperature uniformity in a spray cooling application were studied. The distribution of droplet diameter and the spray volumetric flux was found to significantly vary under the above experimental conditions. A higher spray volumetric flux and smaller droplet diameter resulted in a lower surface temperature. In general, the spray volumetric flux is the dominant parameter. The effect of droplet diameter distribution always became obvious with low spray volumetric flux. Regarding the high spray volumetric flux, there was an offset between these two parameters. The results also indicated that increasing the heat flux, nozzle-to-surface height, and subcooling, as well as decreasing the inlet pressure, all resulted in higher surface temperature uniformity owing to the variation in the droplet diameter and spray volumetric flux distributions. Finally, prediction methods for temperature non-uniformity were proposed for single-phase and two-phase regimes.

Energetics of blood flow in Fontan circulation under VAD support

The need to simulate the normal operating conditions of the human body is the key factor in every study and engineering process of bioelectronic devices designed for implantation. The Fontan procedure is an example of such aprocess aimed to support the human body function. It is a standard treatment method for patients with a functionally univentricular heart. However, it has significant drawbacks such as overload of the only functional heart ventricle that often leads to the necessity of the heart transplantation. In this study, we analyze the total cavopulmonary connection (TCPC) influence on the blood with and without connected auxiliary blood circulation pump. We investigate four different types of TCPC configurations, analyze blood pressure and different flow rate, study the turbulent kinetic energy distribution, and evaluate hydraulic and power losses for various cases. Finally, we calculate volumetric scalar shear stresses distribution and demonstrate the high potential of TCPC configuration with connected rotary pump as a tool for the load redistribution in the functional heart ventricle. This work is particularly relevant for improving existing TCPCs' quality that can extend the life of Fontan patients. Moreover, it also applies to the reduction of morbidity and mortality of the patients waiting for the heart transplantation.

China's First Demonstration of Cobalt-rich Manganese Crust Thickness Measurement in the Western Pacific with a Parametric Acoustic Probe.

Cobalt-rich manganese crusts (CRCs) are important as a potential mineral source that could occur throughout the Pacific on seamounts, ridges, and plateaus. We built a prototype parametric acoustic probe to complete the task of in-situ thickness measurements to estimate the volumetric distribution of deep-sea mineral. The prototype is designed with dual-channels for receiving the primary and secondary signal, which lays a foundation for improving the thickness extraction algorithm. Considering that the signal quality is degraded by the system interference and ambient noise, some improvements to the algorithm are proposed by including the wavelet-based envelope extraction method and the adaptive estimation strategy based on the dual-channel information. Additionally, wavelet regression is applied to reduce the measuring noise assuming that the CRCs have local thickness invariability. The algorithm is suitable for the CRCs with the structure of the multilayers at the top surface and one single layer at the bottom surface. A laboratory experiment is performed to validate the effectiveness of the algorithm. The experiments carried out on the China Ocean 51th voyage in the Western Pacific Ocean on Aug 30, 2018, are described and the data obtained by using the sit-on-bottom stationary measurement are processed to validate the design of the prototype.