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It is well-known that fatigue failures in VHCF originate from defects present within the risk-volume. Moreover, experimental results have shown that the larger the specimen size and the risk-volume, the shorter is the VHCF life. This is known assize-effectand is generally due to the statistical increment of the defect size with the material volume. In the paper, size-effect in VHCF is critically revised. The experimental results obtained by testing specimens with different sizes are analyzed and the methodologies proposed to model size-effect are discussed, with the aim of guiding the future research on size-effect in VHCF.

Among the methods and parameters used for analyzing the productivity of machining procedures, this paper deals with an analysis based on the efficiency (material volume removed in unit time) of material removal. The paper focuses on how this specific indicator, the material removal rate (MRR), changes when different machining procedures and production sub-phases are considered. Ефективність видалення матеріалу при різанні виражається обсягом матеріалу, що видаляється або площею поверхні, обробленої в одиницю часу. Час визначається як тривалість роботи ріжучого інструменту. Це значення розглядається як теоретичне, оскільки цей параметр ефективності заснований тільки на теоретичному часі видалення матеріалу з оброблюваної деталі. Це нереально у виробничому процесі, тому що виробництво не може бути реалізоване без урахування додаткових часових параметрів. Одним з можливих методів аналізу є вивчення ефективності видалення матеріалу, при якому аналізується обсяг, видалений в одиницю часу (MRR). У цій статті досліджуються зміни MRR на різних етапах виробництва, при використанні двох різних типів інструментів, застосовуваних у різних видах обробки, які мають різні геометричні параметри і при обробці різних розмірів партій деталей. При обробці певних деталей були введені деякі параметри, що виражають ефективність видалення матеріалу. Також було показано, як змінюються ці параметри, якщо в розрахунках враховуються більш реалістичні компоненти терміну обробки. Вибраний параметр ефективності, який може бути застосований до будь-якої фази процесу, є спеціальним індикатором, який включає в себе ефективність видалення припуску і витрати часу, необхідні за технологічними умовами. Оскільки виробничий процес включає в себе численні етапи (і, отже, різні часові компоненти), першим етапом аналізу ефективності має бути рішення про те, для якої фази процесу або для якої процедури повинна застосовуватися практична цінність MRR, і чи потрібно нам проаналізувати ефективність або застосувати її для порівняльного аналізу. Відхилення аналізованих параметрів від теоретичного значення продемонстровані для різних геометрій інструментів. Результати довели, що недостатньо проаналізувати теоретичні значення MRR, тому що це може призвести до викривленого висновку.

Heterogeneous catalysis for olefin polymerization is one of the most relevant industrial processes in terms of worldwide diffusion, material volume, and economic turnover. At the base of this process, two main families of multicomponent catalysts, the Ziegler-Natta and the Phillips ones, which have been developed independently since the 1950s and nowadays serve different sectors of the market. This review aims at unifying the picture of these catalysts, pointing out the often-neglected relevance of the ligands around the active sites, including not only the additives explicitly included in the general composition, but also some compounds that are generated in situ during the catalytic process by side reactions, and even the support material itself. All these components have a direct influence on the properties of the catalytic sites and, in turn, on the overall activity and on the properties of the produced polymers. A multi-technique spectroscopic investigation has the potential to shed light on the fleeting, but decisive interactions among all the components and their effect on the catalytic active sites, contributing to create a proper three-dimensional (nano-sized) environment and acting in a concerted way during the olefin polymerization. A few spectroscopic results obtained in our lab are reported, in order to show in parallel how the same principles of coordination chemistry can be effectively applied to both Ziegler-Natta and Phillips catalysts.

A topology optimization formulation is developed to find the stiffest structure with desirable material distribution subjected to seismic loads. Finite element models of the structures are generated and the optimality criteria method is modified using a simple penalty approach and introducing fictitious strain energy to simultaneously consider both material volume and displacement constraints. Different types of shear walls with/without opening are investigated. Additionally, the effects of shear wall-frame interaction for single and coupled shear walls are studied. Gravity and seismic loads are applied to the shear walls so that the definitions provide a practical approach for locating the critical parts of these structures. The results suggest new viewpoints for architectural and structural engineering for placement of openings.

PT X had an accident of slope failure that caused fatalities and injuries experienced by labor mining, and also some heavy mining equipments buried by material s that causing companies g ot financial loss. therefore important to analyze the slope stability of surface mining operation, and predicting total volume of slope failure to anticipate the impact of fatalities/ injuries and financial risks. This research aim is to analyze slope stability before failure conditions, predicting volume of slope failure, and determine position of critical zone using limit equilibrium “Simpilfied Bishop” method 3-dimensional, then doing validation with calculation of actual volume by comparing results of topography maps before and after failure using the cut and fill method. From the result of research, the slope on unstability conditions, actual and predicted volume of slope failure is 8,629 m 3 and 10,559 m 3 , so percent of calculation error is 18.3% .

Multiresolution topology optimization (MTO) methods involve decoupling of the design and analysis discretizations, such that a high‐resolution design can be obtained at relatively low analysis costs. Recent studies have shown that the MTO method can be approximately 3 and 30 times faster than the traditional topology optimization method for 2D and 3D problems, respectively. To further exploit the potential of decoupling analysis and design, we propose a dp‐adaptive MTO method, which involves locally increasing/decreasing the polynomial degree of the shape functions (p) and the design resolution (d). The adaptive refinement/coarsening is performed using a composite refinement indicator which includes criteria based on analysis error, presence of intermediate densities as well as the occurrence of design artefacts referred to as QR‐patterns. While standard MTO must rely on filtering to suppress QR‐patterns, the proposed adaptive method ensures efficiently that these artefacts are suppressed in the final design, without sacrificing the design resolution. The applicability of the dp‐adaptive MTO method is demonstrated on several 2D mechanical design problems. For all the cases, significant speed‐ups in computational time are obtained. In particular for design problems involving low material volume fractions, speed‐ups of up to a factor of 10 can be obtained over the conventional MTO method.

The article deals with the experimental investigation of the influence of material volume of a lattice structure on bending stress. FDM (Fused Deposition modelling) technique and ABS (Acrylonitrile Butadiene Styrene) material were selected for the samples production. Three types of samples with the same simple lattice structure and the same size of a basic cell 5 mm, but differ in a material volume ratio, were analysed experimentally. Minimally six pieces of the samples of each volume ratio were produced and tested using the ZWICK 1456 testing machine at an ambient temperature of 22 °C and at a relative humidity of 60 % according to the standard EN ISO 604. The stress-strain diagrams have been plotted and the values of maximum stresses have been tabled. The measured data were statistically processed, and average values of bending stresses were calculated. Based on the results the behaviour of the structure has been mathematically described, while the results showed that the dependency has an exponential trend.

The article deals with the experimental investigation of the influence of material volume of a lattice structure on bending stress. FDM (Fused Deposition modelling) technique and ABS (Acrylonitrile Butadiene Styrene) material were selected for the samples production. Three types of samples with the same simple lattice structure and the same size of a basic cell 5 mm, but differ in a material volume ratio, were analysed experimentally. Minimally six pieces of the samples of each volume ratio were produced and tested using the ZWICK 1456 testing machine at an ambient temperature of 22 °C and at a relative humidity of 60 % according to the standard EN ISO 604. The stress-strain diagrams have been plotted and the values of maximum stresses have been tabled. The measured data were statistically processed, and average values of bending stresses were calculated. Based on the results the behaviour of the structure has been mathematically described, while the results showed that the dependency has an exponential trend.

Building carbon intensity is related to material choice, but more importantly, material volume. The building structural frame itself is responsible for 20–30% of whole-life carbon over 50 years. This figure will double once we build net-zero operational carbon buildings. Carbon savings in the use of materials are therefore he key to reducing the environmental impact of buildings. Recent studies have shown that up to 40% of material in building structural frames could be successfully removed without affecting design code compliance. This unnecessary overdesign of buildings is in part due to a lack of structural optimisation, and acceptance by designers of conservative serviceability assumptions that represent the “low hanging fruit” of reducing embodied carbon in buildings. This paper examines steel frames buildings to determine the carbon savings that can be achieved for cross-section optimisation, as this is the most accessible form of optimisation, without changing the floor system and beam layout. For this purpose the Lightest Beam Method (LBM) was developed that studied non-composite universal beams (UB) members in buildings. Choosing the lightest section with the Eurocodes we can achieve 26.5% of steel savings by mass, with a half of beams governed by serviceability limit states (SLS). If deflection is calculated using variable loads, the proportion of beams governed by the SLS drops to 31.1% giving additional 2.2% mass savings. The highest steel savings of 34.5% can be achieved for lower natural frequency assumptions (3 Hz) and using the average rather than the characteristic steel yield strength. In this case the proportion of beams by mass governed by SLS drops to 19.7%. Based on available case studies it was found that 1/3 of steel in the frames could have been saved which represents 36% of initial embodied carbon or 5% of whole-life carbon for the building over 60 years.

The paper summarizes measurements and the Monte Carlo simulations performed to adapt the high purity germanium (HPGe) detectors of the system to the particular tasks of the decommissioning site. The work carried out for the installation and adaptation in CIEMAT of the prototype ‘SuperMum’, developed in the framework of the European MetroDecom II project for segregation and declassification of materials is described. The activities related to the validation of the prototype for the specific needs of a real Waste Management Unit are presented. Monte Carlo models of the SuperMum have been developed at CIEMAT and CMI using different codes and adapted to the geometries used (big-bag containers with the material volume of up to 0.5 m3). Uncertainty budget reporting tailored for the possible deviations between Monte Carlo assumptions and real waste have been analyzed. Data for several filling levels and activity distributions have been measured with reference sources and a good agreement has been obtained with calculated values.

This study compared the efficacy of XP-Endo Finisher R and R1-Clearsonic insert in removing filling material remnants from oval canals. Twelve pairs of contralateral premolars were treated and subsequently retreated with Reciproc 50. A supplementary procedure with XP-Endo Finisher R or R1-Clearsonic was performed. Micro-computed tomography was used to quantify the filling material volume in the full canal and apical segment lengths. Intragroup analyses revealed significant reduction of filling material after both procedures, not only in the full canal but also in the apical segment (P 0.05). The amount of filling material removed with XP-Endo Finisher R and R1-Clearsonic was 47.9% and 52.2% in the apical segment (P 0.05), and 82.1% and 64.6% in the full canal (P 0.05). None of the instruments was effective in completely removing the filling material from the apical canal, but better results were obtained with XP-Endo Finisher R in the total canal length.

We show that, using thermo -elastic processing, metallic -glass foils can be shaped, without being embrittled, into linear and annular wave springs. These springs exhibit an undulatory behaviour, unique to metallic -glass foils, in which under compression the number of arcs in the spring increases, increasing the load -bearing capacity and the spring constant. We evaluate the performance limits of the metallic -glass wave springs, and consider how the undulatory behaviour can be exploited. The metallic -glass springs can operate over the same load -ranges as commercially available crystalline wave springs, but have material volumes (and therefore weights) that are one to two orders of magnitude less. Their energy storage per unit material volume is as high as 2600 kJ m – 3 . We suggest that the undulatory behaviour is important in rendering the springs fail -safe in case of overload. We discuss the range of applicability of thermo -elastic processing, the likely working limit of metallic -glass wave springs, and the potential for application of metallic -glass springs in MEMS devices.

Although the use of 5-axis machining is widely used in finishing operations of complex shapes, it is less considered for roughing. However, such a strategy could optimize the entire production process through greater accessibility and shorter tool length requirements. In this paper, a CAM methodology is proposed to generate roughing paths with automatic tilting of the tool axis. This methodology is based on two guide curves extracted from the volume of material to remove at each axis level. Machining experiments carried out on a 5-axis high speed milling machine show the benefits of the proposed method compared to classical strategies.

Repairing large bone defects caused by severe trauma or tumor resection remains one of the major challenges in orthopedics and maxillofacial surgery. A promising therapeutic approach is the use of osteoinductive materials, i.e. materials able to drive mesenchymal stem cells into the osteogenic lineage. Even though the mechanism of this so-called intrinsic osteoinduction or material-induced heterotopic ossification has been studied for decades, the process behind it remains unknown, thus preventing any design of highly potent osteoinductive materials. We propose and demonstrate for the first time that intrinsic osteoinduction is the result of calcium and/or phosphate depletion, thus explaining why not only the material (surface) composition but also the material volume and architecture (e.g. porosity, pore size) play a decisive role in this process.

The research on the size-effects in Very-High-Cycle Fatigue (VHCF) has recently drawn the attention of several scholars. The fatigue cracks in VHCF originate from the largest defect present within the loaded material volume (risk-volume) and the larger the risk-volume, the larger the probability of critical defects affecting the VHCF response (size-effect). Many models have been proposed in the literature to deal with size-effects in VHCF. However, the proposed models cannot be validated on full-scale components, since VHCF tests are typically carried out with ultrasonic fatigue testing machines. The authors have proposed a specimen geometry, the so-called Gaussian specimens, to enlarge as much as possible the risk-volume in ultrasonic VHCF tests. In this study, fully reversed tension&ndash, compression ultrasonic VHCF tests up to 109 cycles were carried out on AISI H13 steel Gaussian specimens with a risk-volume of 5000 mm3, two times larger than the largest tested in the literature. The stress distribution and the absence of bending loads were verified with strain gages, proving that VHCF tests on risk-volumes of 5000 mm3 can be reliably carried out. Ultrasonic VHCF tests were also carried out on small hourglass specimens, confirming that larger risk-volumes allow for a more reliable design against VHCF failures.

AIM To compare the effects of three instrumentation systems, and a supplementary approach with a finishing instrument, on filling material removal during retreatment of mandibular molar canals. METHODS Sixty mesial canals from mandibular molars (Vertucci's type IV anatomy) were instrumented, filled and subjected to retreatment. After initial removal of the root canal filling material using the D-RaCe system, the canals were randomly distributed into three groups (n = 20) according to the instrument system used for preparation: the Self-Adjusting File (SAF), TRUShape or XP-endo Shaper. The filling material volume in the apical 5 mm of the canals was assessed by means of micro-computed tomography (micro-CT) before and after retreatment. All specimens with residual filling material were subjected to a supplementary approach with the XP-endo Finisher R instrument and another micro-CT scan was taken. Data on the volumes of filling material and incidence of total removal were compared between groups by the general linear model for paired data and the Fisher's exact test. The effects of the refinement step were evaluated by the Wilcoxon Signed Ranks test. RESULTS The amount of removed material was 92.4%, 96.9% and 96.9% for the SAF, TRUShape and XP-endo Shaper, respectively. There were no significant differences between them (P > 0.05). Canals were completely cleaned of filling material in 70% of the specimens for XP-endo Shaper, 55% for SAF and 30% for TRUShape; the difference between XP-endo Shaper and TRUShape was significant (P = 0.03). The supplementary step with the XP-endo Finisher R instrument was associated with additional filling material removal of 38% (P

The conic-paraboloid volume equation is receiving increased use with downed coarse woody material (CWM), but the consequences for taper have not been identified mathematically. Requiring that subdivision of a conic-paraboloid yields two smaller conic-paraboloids leads to an exact taper equation intermediate between those of cones and second-order paraboloids. This exact taper equation does not have an explicit inverse, however. An alternative, naive approach does have an explicit inverse, but subdivision does not yield two conic-paraboloids. The exact conic-paraboloid is closely approximated by Fermat’s paraboloid with exponent 7/5. The exact and naive conic-paraboloids match in volume; differences in taper are ≤2.2% of large-end cross-sectional area and ≤5.9% of large-end diameter, while differences in inverse taper are ≤3.7% of total length. Fermat’s paraboloid is always within 1.2% of total volume; differences in taper are ≤0.8% of large-end cross-sectional area and ≤2.0% of large-end diameter, while differences in inverse taper are ≤1.1% of total length. Such differences are negligible given the variety of CWM shapes and practical measurement challenges. Either the exact conic-paraboloid or the corresponding Fermat’s paraboloid provides appropriate equations for estimating the volume and taper of CWM that is intermediate between conical and ordinary paraboloid frusta.

The paper presents a review of experiments and calculation procedures for the resistances of ship structural components subjected to impact loadings. The purpose of the paper is to highlight the importance of large-scale collision and grounding experiments and to discuss the technical difficulties and challenges in analytical, empirical and numerical analyses. Experiments on ship structural components are benchmarks and baselines, used to propose analytical or empirical formulae for the structural energy absorptions and/or to validate numerical analyses considering the actual structural and material characteristics. In recent literature, analytical and numerical calculations provide relatively accurate prediction of the purely plastic responses of ship structures under impact loads, but universal approaches have not been found for fracture predictions. The existing formulae for failure criteria still show limitations when evaluating material fracture in various damage patterns. Recently, semi-analytical approaches have been developed to evaluate the relationship between the absorbed energy and the damaged material volume, taking into account the structural arrangements. It seems that these semi-analytical methods often show better accuracy than the numerical simulations when predicting the experimental results.

This paper contributes to broadening the knowledge regarding cutting tool wear in the finish turning operations of nickel-chromium-based superalloy Inconel 718. Three cutting tools coated with heat isolating TiAlN/AlTiN layers with different stoichiometry ratios recommended as specially designed cutting tools for aerospace industry applications are tested. The primary comparison of tool wear resistance was based on the wear curves related to the cutting time and the removed material volume. The basic study include the modeling of wear progress and examining tool wear scars based on SME images and EDX analysis. In addition, tool wear progress was recorded along with continuous measurements of cutting forces and determination of relevant amount of the specific cutting energy and the friction coefficient.

The principle of Topological Interlocking for masonry construction has gained a growing interest over the last decade due to its special structural properties. This paper presents ongoing research on the correlation between block geometry and structural performance in flat assemblies of convex interlocking blocks. It describes four research stages that analyze different geometries of interlocking blocks through numerical and physical analyses. The results highlight advantageous geometries for simple block types, discuss structural behavior of the blocks under loads, and present novel types of block arrangements that achieve higher load bearing capacity than previously known assembly types while using similar material volume.

This paper describes a parametric framework for early-stage tall timber design, which enables a comparison across a range of geometries with respect to embodied carbon of the main structural elements for two mass timber structural systems: post-beam-panel and post-and-platform. This research finds that the post-beam-panel system on average has a higher embodied carbon that increases faster as the building height increases. In both structural systems, the floors are a major contributor to the embodied carbon. The framework can inform higher resolution decisions, help designers detect broad trends and relationships in the tall timber design space, and allow designers to adapt geometries and immediately assess the impact on the embodied carbon. For each geometry, the embodied carbon of both structural systems can be compared to determine which system is more appropriate. Within each structural system, the timber elements with the largest material volume can be identified, and alternative materials can be considered. As a result, the framework permits designers to make simultaneous decisions on the structural system and the geometry from the perspective of both aesthetic and embodied carbon performance. By providing guidance and feedback on early-stage design, this paper aims to increase the recognition and application of timber as a structural material for large-scale construction.

International audience; Recently, the combination of additive and subtractive manufacturing technologies is gaining significant attention from both the industrial and academic sectors. Due to consolidated advantages of individual techniques, this combination provides the capability of producing innovative products, and opens new perspectives for developing new remanufacturing/manufacturing strategies. In this paper, an innovative strategy is proposed. The strategy aims to manufacture a new part directly from an EoL part (or existing part), using a sequence of additive and subtractive manufacturing processes. The existing part is transformed into the new part without involving the material recycling phase. This paper particularly focuses on the environmental assessment of the proposed strategy. For this purpose, a methodology based on the life cycle assessment method is developed. The environmental trade-offs between the proposed strategy and the conventional strategy are also discussed through the case study. The conventional strategy uses conventional processes (such as material recycling, casting and machining) to manufacture the new part, whereas the proposed strategy is based on combining electron beam melting (EBM) and CNC machining processes. The results show that the proposed strategy becomes more environmentally friendly when the material volume of existing part reused increases more than 60%. The proposed methodology can help designers and manufacturers to select the most suitable strategy to manufacture new parts from existing parts with minimum environmental impacts.

Few researchers have paid attention to designing structures in consideration of uncertainties in the loading locations, which may significantly influence the structural performance. In this work, cloud models are employed to depict the uncertainties in the loading locations. A robust algorithm is developed in the context of minimizing the expectation of the structural compliance, while conforming to a material volume constraint. To guarantee optimal solutions, sufficient cloud drops are used, which in turn leads to low efficiency. An innovative strategy is then implemented to enormously improve the computational efficiency. A modified soft-kill bi-directional evolutionary structural optimization method using derived sensitivity numbers is used to output the robust novel configurations. Several numerical examples are presented to demonstrate the effectiveness and efficiency of the proposed algorithm.

Moment-of-fluid (MOF) method is an extended volume-of-fluid method which incorporates material centroid in addition to material volume fraction for interface reconstruction. MOF is an exact method for linear interfaces and second-order accurate for curved interfaces. The interface reconstruction in the MOF is based on the best possible approximation of material centroid. Exact matching of the reconstructed centroid with the reference centroid produces the exact material configuration. This is however possible only for linear interfaces when the material volume and centroid are consistent. Consistent moments can be obtained by adaptive mesh refinement moment-of-fluid method (AMR–MOF) in the interfacial cells based on a refinement criterion. In the case of AMR–MOF, the centroid error is used as the refinement criterion. Since the material centroid is approximated to the reference centroid in interface reconstruction, centroid error is always higher than the prescribed tolerance. Therefore, intermedi...

When a material volume consisting of an uncured rubber matrix reinforced with two non-parallel sets of embedded reinforcement wires or cords is subjected to large deformations, pantographing may occur. In other words, the angles between reinforcement wires change. We introduce a simple phenomenological fluid model suitable for the numerical prediction of pantographing, as can be encountered in industrial processes such as the manufacturing of rubber tires or reinforced hoses. The reinforced material is described with an orthotropic continuous fluid model. Here the reinforcement wires or cords are accounted for by the orthotropy, whose direction is locally affected by the deformation undergone by the matrix, and is updated accordingly. The model is subsequently applied to the simulation of a sagging experiment, where the role of pantographing is illustrated.

This manuscript presents the findings of an experimental study aiming to develop an Ultra High Performance Fibre Reinforced Concrete (UHPFRC) best suitable for impact loading. The mechanical properties of this material and the failure mechanisms under impact loading were investigated. The UHPFRC developed in this research program is a cement–based material with increased percentage of microsilica and a combination of two types of steel fibres: 6 mm long with 0.16 mm diameter and 13 mm long with 0.16 mm diameter. It includes local calcarenite sand with grains 125–500 μm in size. Four composition mixtures were produced, three UHPFRC and one Ultra High Performance Concrete (UHPC), without steel fibres. The influence of the amount and type of steel fibres was examined. Slabs with dimensions: 200 × 200 mm and thickness of 15, 30, 50 and 70 mm were produced and were subjected to projectile impact (real shotgun used). The penetration depth and material volume loss were measured.