Volume Geometry Research Articles

Shrub aboveground biomass estimation considering bulk volume geometry: general and specific models for 14 species in the Mediterranean central Chile

Shrub aboveground biomass estimation considering bulk volume geometry: general and specific models for 14 species in the Mediterranean central Chile

Effect of eutectic microstructure on load transfer and creep resistance in Al-Ce alloys

This study investigates the compressive creep response of hypo- and near-eutectic Al-Ce alloys via finite-element modeling (FEM), by considering the composite response of a weak, fast-creeping Al matrix containing slow-creeping Al11Ce3 eutectic reinforcement. In the as-cast microstructure of an eutectic Al-12.5 wt%Ce alloy, the Al11Ce3 eutectic phase is lamellar, regardless of the various cross-sectional geometries (Chinese-script, fish-bone, and comb-like). FEM models based on these various lamellar microstructures investigate the effect of Al11Ce3 reinforcement volume fraction, orientation, and geometry on load transfer performance between matrix and reinforcement during creep deformation. FEM predicts that, when the lamellar Al11Ce3 phase is continuous along the loading direction (where load transfer is most effective), the creep resistance of the alloy is barely affected by cross-sectional geometry of the Al11Ce3 reinforcement or by the solid-solution strengthening of the Al matrix, at constant Al11Ce3 volume fraction. However, alloy creep resistance and load transfer between phases are significantly reduced when applying load parallel to aligned, discontinuous lamellae, and they can be improved by matrix solid-solution strengthening. Furthermore, Al11Ce3 short plates (as created in Al-12.5Ce by coarsening of lamellae upon over-aging at 590 °C/24 h) provide the least creep resistance and load transfer. Lastly, multi-colony FEM models are created by combining colonies with various lamellar orientations to approximate the creep performance of polycrystalline hypo- and near-eutectic alloys which, when compared to experimental data for hypoeutectic Al-7Ce and for near-eutectic Al-(10–13)Ce, provide better predictions than single-colony FEM models or analytical solutions.

Technical evaluation of supercritical fluid impregnation scaling-up of olive leaf extract: From lab to pilot scale

Supercritical fluid technology is an advanced field that offers remarkable versatility and it applies to a broad range of processes. However, the scaling-up of the supercritical fluid impregnation process is still scarcely explored. This research investigates the technical analysis of the supercritical fluid impregnation scaling-up of olive (Olea europaea L.) leaf extract into polypropylene (PP) films. The impregnation scale was increased up to 20-fold while maintaining constant ratios among the extract volume, film area, CO2 amount, and vessel geometry. The study compares homogeneity, total extract loading, and ABTS antioxidant activity of impregnated films at both scales. Homogeneity was assessed using CIELAB coordinates and desorption electrospray ionization mass spectroscopy (DESI-MS) imaging. Films impregnated at 250 bar and 55 °C for 1 h in 100 ml and 500 ml vessels were uniform in colour, whereas those from the larger vessel were less homogeneous. To evaluate the effect of time on impregnation at the largest scale, impregnation was conducted for 1, 6, 24, and 48 h. Homogeneity and ABTS antioxidant activity improved over time, and DESI-MS images showed a gradual decrease in oleuropein signal intensity over time. After 6 h, PP films achieved a total extract loading of 14.02 mg g−1 of polymer, 23 % ABTS antioxidant activity, with a global diffusion coefficient of the extract compounds in PP films of 3.42 × 10−13 m2 s−1. While this study offers valuable insights into scaling up the supercritical fluid impregnation of olive leaf extract into PP films, several limitations remain. Future research is required for a more comprehensive understanding and practical application of the process.

ANALISIS BIAYA OPERASIONAL KENDARAAN BERDASARKAN KECEPATAN RATA-RATA PERJALANAN DI JALAN MAJAPAHIT KOTA MATARAM

The city of Mataram, the center of trade, offices, and education, experienced an increase in population and vehicles. The 2023 data recorded 441.147 thousand residents and 385,579 motor vehicles. The increase in traffic volume on road Majapahit has an impact on traffic performance and vehicle operating costs. The study entitled " Analysis Of Vehicle Operational Costs Based On Average Travel Speed On Jalan Majapahit Mataram City" was conducted to further understand the condition of road section performance and the Operating Cost of Vehicles passing through the road. The MKJI method is a calculation standard used to analyze the performance of road sections, assess capacity and service levels, based on traffic volume and road geometry. while to calculate BOK (Vehicle Operating Costs) used an equation method developed by the PCI 1989 method to measure vehicle costs, including fixed costs and non-fixed costs, which are influenced by the average speed of travel. The results of the study on the Majapahit road section show the service level of the Majapahit road section in category C. For the calculation of the free flow speed, namely 52.68 km / h (east) and 49.10 km / h (west). The speed of the eastbound peak clock is 48 km/h and the westward is 42 km/h. While the calculation results of BOK Group I (Eastward) Free Flow Speed Rp1.049,- / km, Peak Hour Speed Rp1.082,- /km. Group I (West) Free Flow Speed Rp1.072,- /km, Peak Hour Speed Rp1.163,- /km. Group IIA (Eastward) Peak Hour Speed Rp2.921,- /km, Peak Hour Speed Rp3.007,- /km. Group IIA (Westward) Free Flow Speed Rp2.980,- /km, Peak hour speed Rp3.235,- /km

ASSESSMENT OF TRAFFIC CONGESTION AND ITS IMPACT ON ROAD CAPACITY IN URBAN AREAS UNDER MIXED TRAFFIC CONDITIONS USING MULTIPLE REGRESSION ANALYSIS - A CASE STUDY IN ADDIS ABABA CITY

Traffic congestion is a complex phenomenon, which is connected to a number of vehicle movements on the road. The major reasons behind this problem are due to various continuous activities in the urban areas such as education, employment, recreation, business, political, social and cultural. These activities in addition to floating and migration increase congestion on city roads. This will affect the traffic stream characteristics and reduces the road capacity and level of service. The present study is aimed to evaluate and analyze the traffic congestion and its effect on road capacity and level of service at Mebrat haile mid-block location in Addis Ababa city. To achieve the objective, the Mebrat haile mid-block was divided into four segments appropriately and the traffic volume and speed studies were conducted at each segment, for a period of 10 hours in a day at every 15 minutes consecutive interval. The necessary traffic data including road geometry at each segment was recorded. The congestion levels at each segment were then measured by estimating the reduced speed between each segment. The volume to capacity ratio (v/c ratio) was then estimated and found to be exceeding 1 in most of the hours of the day, resulting poor level of service F. Various Multiple Regression Models were developed correlating the reduced speed with traffic volume, composition and road geometry. The results from the analysis indicates that the traffic congestion on the urban roads, have an impact on urban characteristics.

New multi-function building plate for improving metal laser powder bed fusion by enhancing the alignment accuracy of in-process monitoring data, computed tomography measurements, and building volume geometry

AbstractLaser-based powder bed fusion of metals (PBF-LB/M) is an additive manufacturing process enabling the fabrication of parts with highly complex and customizable geometries, enhanced strength-to-weight properties, and minimized material waste. Despite its unique capabilities, PBF-LB/M needs research and innovation efforts to enhance process dynamics and product quality, as well as to broaden its adoption in high-value industrial sectors, such as aerospace and biomedical. In this context, in-process monitoring solutions and post-process part quality evaluations are fundamental to improving the process towards sustainable, first-time-right, and zero-defect production. This paper describes a novel building plate concept for metal laser powder fusion, whose characteristics were specifically designed to enable and improve the performances of in-process monitoring and high-resolution X-ray computed tomography (CT) measurements. In particular, the plate features markers for perspective correction in off-axis optical monitoring and dismountable inserts with machined geometrical elements to be used for the precise alignment between high-resolution CT reconstructions, in-process gathered data, and building volume geometry. The plate capabilities were demonstrated through examples related to in-process monitoring and post-process X-ray CT measurements.

Horizontal Curve Safety Performance Evaluation Based on Naturalistic Vehicle Lane Position Data

Performance-based design is a renewed approach for project decision-making to specifically address the purpose and needs of projects by providing design flexibility. Resources to evaluate roadway design based on safety performance are an important need for transportation practitioners. In this study, naturalistic driving study (NDS) data were used to estimate the safety effect of elements that influence driving behavior on rural undivided two-lane horizontal curves. Available data included 3,292 horizontal curves and 150,233 traversals, which required a significant data processing effort to conduct data cleaning and quality assessment. From the safety surrogates evaluated and methods implemented, lane position provided the most consistent and statistically significant results. Centerline and edge line encroachment events were modeled with the negative binomial using traffic volume and curve geometry as the predictor components. Encroachment estimates were associated with observed crashes from state data to convert encroachments to crashes. Predictor variables such as curve radius showed a decreasing trend in predicted crashes as curve radius increased. Similarly, as shoulder or lane width increased, predicted crashes decreased. Crash estimates derived from safety surrogates were used to develop an analytical tool aimed at practitioners for curve design considerations. Data input includes curve radius, shoulder width, lane width, curve length, traffic volume, expected service life, and construction cost. The economic assessment provides a quantitative measure for practitioners to evaluate alternative curve designs by assessing the tradeoffs between safety and costs of implementation.

Modified plastic damage model for steel fiber reinforced concrete

AbstractSteel fiber reinforced concrete (SFRC) structures have been widely adopted and attracted great research attention due to their excellent performance in resisting tension and flexure bending. However, the existing analytical and numerical analyses of SFRC structures rely mainly on the experimental data of material tests, thereby being suitable for a case‐by‐case basis. This is due to the lack of a general and reliable constitutive material model for SFRC, which analytically considers the fiber‐dependent parameters such as fiber geometry, fiber stiffness, and interface properties of fibers and concrete matrix. This study presents an approach to modify the concrete plastic damage model to represent the SFRC material constitutive relations for simulating the structural behavior of SFRC. In this approach, the general procedure to integrate the bridging effect of fibers through the pull‐out mechanism into the constitutive relation of SFRC was proposed. The comparison between the numerical and experimental results was conducted to verify the reliability of the proposed model. The results demonstrated the proposed model could well represent the material performance of SFRC and the numerical simulations could capture reasonably the effect of the volume fraction, geometry, and properties of fibers on the structural response of SFRC.

Enhancing Traffic Flow and Safety at LMU Nurtanio Road Crossings - Abdul Rahman Saleh Intersection in Bandung

Bandung is the largest metropolitan city in West Java Province and serves as its provincial capital. One of the locations where vehicle queues or traffic congestion occurs is at the level crossings between the highway and railway tracks, including the direct crossing (JPL) at Andir on LMU Nurtanio Street - Abdul Rahman Saleh Street. The purpose of this research is to assess the performance of the existing road section, simulate it using the PTV VISSIM program, and find alternative solutions to the identified problems. In this study, primary data was obtained through direct field measurements, including vehicle volume, queue length, and road geometry data. Additionally, secondary data on the number of trains passing through the crossing was obtained from PT Kereta Indonesian Fire. The PTV VISSIM program used in this analysis is a student-licensed program, which implies limitations and simplifications in the analysis. The performance calculation of the road section yielded a degree of saturation (Ds) value of 0.73 for LMU Nurtanio Street and 0.77 for Abdul Rahman Saleh Street. According to the road service levels set by the government, both roads fall below service level C. The PTV VISSIM modeling results indicated a queue length of 66.59 m for LMU Nurtanio Street and 105.18 m for Abdul Rahman Saleh Street. Bandung study uses PTV VISSIM to assess LMU Nurtanio - Abdul Rahman Saleh Streets, revealing congestion issues. Queue lengths highlight improvement needs.

Mathematical formulae for neutron self-shielding properties of media in an isotropic neutron field

In the current study, an ab initio derivation of the neutron self-shielding factor to solve the complex neutron transport problem of the decrease of the neutron flux as it penetrates into a material placed in an isotropic neutron field having equal flux in all directions. The theory of steady-state neutron transport was employed, starting from Stuart’s formula, to derive simple analytical formulae based on the integral cross-section parameters. The formulae could be adopted by the user according to various variables, such as the neutron flux distribution and geometry of the simulation at hand. The concluded formulae of the self-shielding factors comprise an inverted sigmoid function normalized with a weight representing the ratio between the macroscopic total and scattering cross-sections of the medium. The general convex volume geometries are reduced to a set of chord lengths, while the neutron interaction probabilities within the volume are parameterized to the epithermal and thermal neutron energies. The arguments of the inverted-sigmoid function were derived from a simplified version of neutron transport formulation. The derived analytic formulae agreed greatly with the experimental observations for different elements and geometries.

Reduction of pipe wall erosion by creating a vortex flow in anthracite powder pneumatic transport for power plants

From the total electricity generated in South Africa, about 85% is coal based. Coal powder is a solid fuel used in injectors for electricity production. The coal powder is extremely abrasive therefore it is important to maintain a minimum admissible flow speed. As the most severe pipe wall erosion takes place in bends, the most significant factor influencing wall erosion is the solid particle velocity. The aim of this research was to reduce the wall erosion through flow velocity control. Computational fluid dynamics (CFD) simulations, showed that for the same velocity, the erosion is dependent on flow direction change and the ratio between the radius of the bend and pipe diameter. The reduction of flow velocity was achieved by subtracting a spiral volume, from the inner volume of a horizontal pipe, just before an upward or downward bend. The modified volume geometry generated a vortex flow in the bend, achieving a more even distribution of maximum erosion points over the bend surface. The wall erosion, expressed in mm–wall thickness loss/hour, in the modified volume decreased by about 28,8 % while the installation life expectancy increased significantly. Furthermore the bend radius was proved to influence the erosion magnitude and location.

Applicability of Electron-Beam and Hybrid Plasmas for Polyethylene Terephthalate Processing to Obtain Hydrophilic and Biocompatible Surfaces.

The applicability of beam-plasma chemical reactors generating cold hybrid plasma for the production of noncytotoxic polymeric surfaces with high hydrophilicity and good biocompatibility with human fibroblast culture and human red blood cells was studied. Oxygen hybrid plasma was excited by the joint action of a continuous scanning electron beam and a capacity-coupled RF-gas discharge. Experiments showed that hybrid plasma treatment caused polar oxygen-containing functional group formation in the surface layer of poly (ethylene terephthalate) films. No thermal or radiative damage in tested polymer samples was found. The plasma-modified polymers turned out to be noncytotoxic and revealed good biocompatibility with human fibroblasts BJ-5ta as well as lower hemolytic activity than untreated poly (ethylene terephthalate). Experiments also demonstrated that no phenomena caused by the electrostatic charging of polymers occur in hybrid plasma because the electron beam component of hybrid plasma eliminates the item charge when it is treated. The electron beam can effectively control the reaction volume geometry as well as the fluxes of active plasma particles falling on the item surface. This provides new approaches to the production of abruptly structured patterns or smooth gradients of functionalities on a plane and 3D polymeric items of complicated geometry.

Exploring the Utility of Auto-machine Learning in Predicting Traffic Accident Severity in Jordan

The World Health Organization (WHO) estimates that approximately 1.35 million annual fatalities are caused by road traffic accidents, representing a significant global challenge. This study focuses on creating a machine-learning model to forecast traffic accident severity in Jordan. The objective of this study is to help reduce fatalities and economic losses caused by accidents, which can achieve using various machinelearning classifiers, like Decision Trees, Random Forests, Light Gradient Boosting Machines, Extra Trees, Bagging Classifiers, and Gradient Boosting. These models were assessed before and after down-sampling to deal with imbalance in accuracy, balanced accuracy, recall, precision, and F1-score metrics with and without hyper parameter tuning. The study emphasized the importance of advanced analytics in improving road safety measures and reducing accident severity. The researchers analyzed a dataset of 115,148 accidents. Factors considered included traffic volume, environmental conditions, and road geometry features. The data was segmented into urban and rural categories for customized modeling. Down-sampling improved the models' ability to detect injuries and deaths in both urban and rural areas. Hyper parameter tuning offered an additional improvement in balanced recall and F1-score, particularly after down-sampling. In urban areas, the LGBM and Gradient Boosting classifiers showed the most significant gains in recall for minority classes, while in rural areas the Random Forest, Bagging, and Extra Trees classifiers maintained a better balance between precision and recall. All classifiers achieved high accuracy (above 0.97) in both urban and rural areas, so that these models can accurately forecast the severity of accidents, including property damage, fatalities, and injuries. The authors have also recommended incorporating variables of temporal patterns, driver behavior, demographic data, and geographic location into the models of accident prediction to make them more efficient and stronger. Keywords: Accident severity prediction, Auto-machine learning, Accident classifiers, Python, Jordan.

Heat losses in ATES systems: The impact of processes, storage geometry and temperature

The technical and economic success of an Aquifer Thermal Energy Storage (ATES) system depends strongly on its thermal recovery efficiency, i.e. the ratio of the amount of energy that is recovered to the energy that was injected. Typically, conduction most strongly determines the thermal recovery efficiency of ATES systems at low storage temperatures (<25 °C), while the impact of buoyancy-driven flow can lead to high additional heat losses at high storage temperatures (>50 °C). To date, however, it is unclear how the relative contribution of these processes and mechanical dispersion to heat losses across a broad temperature range is affected by their interaction for the wide range of storage conditions that can be encountered in practice. Since such process-based insights are important to predict ATES performance and support the design phase, numerical thermo-hydraulic ATES simulations were conducted for a wide range of realistic operational storage conditions ([15–90 °C], [50,000–1,000,000 m3/year]) and hydrogeological conditions (aquifer thickness, horizontal hydraulic conductivity, anisotropy). The simulated heat loss fractions of all scenarios were evaluated with respect to analytical solutions to assess the contribution of the individual heat loss processes. Results show that the wide range of heat losses (10–80 % in the 5th year) is the result of varying contributions of conduction, dispersion and buoyancy-driven flow, which are largely determined by the geometry of the storage volume (ratio of screen length / thermal radius, L/Rth) and the potential for buoyancy-driven flow (q0) as affected by the storage temperature and hydraulic conductivity of the aquifer. For ATES systems where conduction dominates the heat losses, a L/Rth ratio of 2 minimizes the thermal area over volume ratio (A/V) and resulting heat losses for a given storage volume. In contrast however, the impact of dispersion decreases with L/Rth and particularly for ATES systems with a high potential for buoyancy-driven flow (q0 > 0.05 m/d), increasingly smaller L/Rth ratios (<1) strongly reduce the heat losses due to tilting. Overall, the results of this study support the assessment of thermal recovery efficiencies for particular aquifer and storage conditions, thereby aiding the optimization of initial ATES designs.

Hardware accelerated ray-tracing in ocean acoustics

Due to the expense and complexity of real-world data collection, machine learning applications in ocean acoustics demand ever-faster and more realistic models for training. In this talk, I discuss some recent GPU technologies which support hardware accelerated ray tracing and how they can be exploited to boost the throughput of certain types of calculations. Firstly, I describe RTX-Prop, which is a large-scale range-dependent Gaussian beam model which benefits from hardware-acceleration of bounding volume hierarchy searches and geometry intersection calculations. Designed to ingest oceanographic forecasts from the Royal Australian Navy’s Bluelink system, RTX-Prop has been developed as an embedded model to support tactical decisions by autonomous underwater vehicles. In the second application, I discuss hardware acceleration in the context of high-frequency sonar simulation. By synthesising fine-scale environmental detail, we have previously shown that simulated imagery can be almost indestinguishable from real data. Simulated sidescan and SAS imagery from our S4 model has recently become the basis of a machine-learning pipeline for training detectors and classifiers for naval mine countermeasures. [Work supported by the Trusted Autonomous Systems Defence Coorperative Research Centre.]

Predicting the electrical conductivity of short carbon fiber/graphene nanoplatelet/polymer composites

The current work examines the effect of graphene nanoplatelet (GNP) additives upon the electrical conductivity of short carbon fiber (SCF)-reinforced polymer multifunctional composites. GNPs and SCFs are randomly dispersed into the representative volume element of the composite. A multi-step physics-based approach is developed to determine the effective electrical conductivity of SCF/GNP/polymer composites. Outcomes of the current work are compared with the available experimental data and other numerical results to verify its accuracy. Changes in the volume fraction and geometry of multi-scale reinforcements, interphase characteristics, barrier height, nanofiller tunneling distance and fiber material property are considered to reflect the influence of microstructures on the electrical conducing behavior of SCF/GNP/polymer multifunctional composites. It is found that the electrical conductivity of the multifunctional composite enhances by the increase of volume fraction and aspect ratio of GNP as well as the reduction of its thickness. Moreover, the multifunctional composite shows a higher electrical conductivity with the increase of fiber aspect ratio. The electrical conductivity of the SCF/GNP-reinforced composite depends on the interphase such that its value increases by the increase of interphase thickness. The developed method can be adopted to provide useful guidelines for the design and optimization of multifunctional composites filled by hybrid reinforcements.

Hybrid all-cellulose reinforcement in polypropylene matrix biocomposites for injection moulding - influence of particle geometry and volume fraction on hybrid effect

The presented study is focused on evaluation of influence of reinforcement volume fraction and geometry on the occurrence of positive hybrid effect by the hybridisation of man-made cellulose fibres (rayon viscose) with cellulose microparticle fillers applied in polypropylene matrix. Four volume fractions of reinforcement were used at 1:1 combination of short man-made cellulose fibres with cellulose microfillers of different aspect ratio. The highest volume fraction was applied for a comparison of four types of cellulose microfillers characterised by different aspect ratios. Proportional volume content of compatibiliser to volume of reinforcement and manufacturing conditions were maintained for all composites. Positive hybrid effect present in tensile and flexural performance was found to result from different factors such as: favourable combination of reinforcement owing to their similar stress–strain characteristic, decreased void fraction, slightly improved orientation of short rayon viscose fibres in hybrid and reduced relaxation of stresses during deformation.

Isogeometric bending and free vibration analyses of carbon nanotube-reinforced magneto-electric-elastic microplates using a four variable refined plate theory

The classical continuum mechanics theory is inadequate for modeling the mechanical responses of the microstructures due to its failure to account for size effects. Instead, modified strain gradient theory (MSGT) is considered as one of the most accurate theories due to its ability to adjust three length scale parameters (LSPs). Isogeometric approach (IGA) is a computational technique that is capable of accurately solving complex problems. For those reasons, the size-dependent analysis of carbon nanotube-reinforced magneto-electric-elastic microplates based on the MSGT are firstly proposed. The present approach uses the refined plate theory (RPT) with four variables, the MSGT and IGA. The magnetic and electric potentials are assumed to be a combination of a half-cosine and linear variation to satisfy Maxwell’s equations. Different types of functionally graded carbon nanotubes (CNTs) including UD, FG-X, FG-O and FG-V are reinforced in the magneto-electric-elastic matrix of the microplates. Governing equations are derived using the extended virtual work principle and then solved by IGA to determine the deflection and natural frequency of the microplates. The influence of the LSPs, CNT distributions, CNT’s volume fraction, matrix’s volume fraction, magnetic potential, electric voltage and geometry on the deflection and natural frequency of the microplates are studied and discussed.

GFANet: Group Fusion Aggregation Network for Real Time Stereo Matching

Existing 3D stereo networks with 4D volumes are computationally expensive but precise while 2D stereo networks are efficient but poor performance. In this paper, we present a novel group fusion aggregation (GFA) for 2D convolutions cost aggregation based on 4D volumes to reduce computational costs. Group-wise disparity aggregation block (GDAB) and group-wise channel fusion block (GCFB) are proposed to fuse geometry and context information of different group cost volumes in GFA, respectively. Further, we employ channel-dimension-first cost volume transformation and disparity-dimension-first cost volume transformation to convert 4D cost volumes into 3D tensors for GDAB and GCFB input in GFA. We evaluate our method on two popular public benchmark datasets. Experimental results from the KITTI official website show that our method can achieve similar accuracy with other 3D stereo networks (PSMNet, GCNet, GwcNet, etc.) at a low computing consumption. The ablation studies further demonstrate the facticity and reasonability of our proposed GFA.

Strengthening of Mg–Al–Ca alloys with C15 and C36 Laves phases

Laves phases such as CaMg2 (C14), Ca(Al,Mg)2 (C36), and CaAl2 (C15) have high melting points, high hardness at room and elevated temperatures, but are inherently brittle. Cast Mg–Al–Ca alloys having Laves phase skeleton thus have good creep properties but limited ductility. An understanding of the co-deformation behaviour of α-Mg and Laves phases is essential for further improving the mechanical performance of these alloys. Here, we study the mechanical behaviour of a Mg–4.65Al–2.82Ca alloy using micropillar compression in the α-Mg matrix, at α-Mg/C36 and α-Mg/C15 interfaces and in the C15 phase in combination with scanning electron microscopy. We show that both, C15 and C36 phases, provide considerable strengthening to the α-Mg matrix. The amount of strengthening primarily depends on the volume fraction and geometry of Laves phases in composite micropillars and correlates well with the iso-strain and iso-stress bounds predicted for α-Mg/C36 and α-Mg/C15 composites.Graphical