Consolidation Methods Research Articles

Reducing the Seismic Vulnerability for RC Buildings by Using Steel Bracing Elements

Abstract This article aims to highlight, through a comparative study, the efficiency of steel bracing systems used to reduce seismic vulnerabilities in existing buildings with reinforced concrete structures (reinforced concrete frames and reinforced concrete dual structures, general building structures including those used in transport infrastructure). In order to simplify the calculations, the analysis was reduced to the study of the behavior of resistance lines corresponding to four-, nine- and fifteen-level buildings with the same plane distribution. In order to obtain features similar to those of existing building elements, structures were initially loaded with seismic forces corresponding to code P13-63. The next step was to apply to previously dimensioned structures the seismic loads according to P100-3: 2008 in relation to P100-1: 2013, thus obtaining the deficiencies of the existing structures against the requirements of these norms. Correction of these strength and stiffness deficiencies was attempted by introducing X-shaped centric brace systems. The bracing systems used as consolidation methods are of three types: direct bracings stuck in the reinforced concrete frames and bracings of the indirect type, made of internal and external bracing steel frames. Structural calculations were made in the linear elastic field using the ETABS program.

Energy and Migration Cost-Aware Dynamic Virtual Machine Consolidation in Heterogeneous Cloud Datacenters

Energy efficiency has become one of the major concerns for today's cloud datacenters. Dynamic virtual machine (VM) consolidation is a promising approach for improving the resource utilization and energy efficiency of datacenters. However, the live migration technology that VM consolidation relies on is costly in itself, and this migration cost is usually heterogeneous as well as the datacenter. This paper investigates the following bi-objective optimization problem: how to pay limited migration costs to save as much energy as possible via dynamic VM consolidation in a heterogeneous cloud datacenter. To capture these two conflicting objectives, a consolidation score function is designed for an overall evaluation on the basis of a migration cost estimation method and an upper bound estimation method for maximal saved power. To optimize the consolidation score, a greedy heuristic and a swap operation are introduced, and an improved grouping genetic algorithm (IGGA) based on them is proposed. Lastly, empirical studies are performed, and the evaluation results show that IGGA outperforms existing VM consolidation methods.

Advanced methods for consolidation of powder materials by impulse electromagnetic fields

Advanced technologies for the production of new materials and, in particular, nanostructured materials, using powder technologies require fundamentally new approaches for the formation and preservation of a given structural-phase state. Precision control of the state of materials in the process of consolidating powders of nanomaterials can be carried out using pulsed electromagnetic fields. The aim of the project is to study the effect of high-voltage and low-voltage pulsed electromagnetic fields in the technologies of powder consolidation. The experimental devices of spark-plasma sintering, flash-sintering, high-voltage consolidation and magnetic-pulse compaction are used in our laboratory for the production of advanced materials from metal powders, ceramic and composite powders. We can produce boron carbide, silicon carbide, uranium nitride, tungsten carbide - cobalt - diamond composites, tungsten heavy alloys, and others by electromagnetic methods of powder consolidation. Experimental results to consolidation metal powders, ceramic and composites powders by electromagnetic methods presage fruitful results.

Improving marine soils by different consolidation methods for stability of harbour structures

Marine geotechnics is one of the most difficult specialties and is part of coastal engineering. The geotechnician is interested in soils as these are the main element of the context in which the stability of a structure will be designed. The methods of improvement of vibroflotation (VF), dynamic compaction (DC) and the pre-loading took a scale in Algeria these last years, they are applied at the port of DjenDjen in Jijel province, object of our study, in the framework of its extension and its development, in order to improve the support soil which will receive the foundations of the protections structures and the container terminal in caissons. The main objective is to establish numerical studies of the stability of the protection structure realized on the improved soil which was itself taken into consideration in the modelling, while respecting also the real phasing of construction of this structure. However, soil improvement was checked before and after treatment to verify its influence on the stability of the harbour structures.

Prepare and analysis for claims in construction projects using Primavera Contract Management (PCM)

Change management has a crucial importance in the project management field. Changes in the construction field can be consolidated directly or converted to a full process project claims. A lot of theories and area of concerns spotted claims consolidation methods and techniques to seek best practices to solve such problems between all construction project stakeholders. It is not easy to completely prohibit claims from arising in the construction project, but as the technology developing rapidly; it became easier to face arising claims with a fully documented project, as the good documentation is a fundamental requirement in a successful claim Lixia et al. [5].Due to project complexity increasing and project cost rising, it is essential for companies to succeed in managing their project's budget and schedule. According to Oracle, 90% of projects overrun their assigned budget, which leads to a high percentage of failed projects in the construction field.Hence, a lot of software appeared to help claimers to manage their claims in the best effective way to reduce the time consumed in the hard preparation which needs a lot of effort and resources to be completed. In another way, the new software maintains focusing on how to win the claim not how documents prepared to go through a claim.One of this software is Oracle Primavera Contract Management (PCM) which is a web-based program includes many features such as document management, cost control, field monitoring and time management. In addition to that, it decreases time schedule delays which provide visibility in the contract performance by providing a central repository for data on the turnaround time on a given process. Reporting this data provides the project managers with a useful metric of average contractor performance and work process and helps to identify which contractor needs extra attention or should be avoided in future projects.PCM enables timely payments for completed work by providing the ability to view, track and automate performance beast progress payment to subcontractors. In addition, to ensure that unnecessary delays are avoided it also reduces liability by improving turnaround time between project contributors. This paper aims to identify the method of using the PCM program and Primavera P6 to prepare the claims in a short time with less effort to produce fully documented claims. In addition to that, it illustrates how users able to make delay analysis using Primavera contract management, which linked to the PCM program. In addition to that, it illustrates the application of one of the web-based project management software toward construction company performance. Also, to emphases and analyze the advantages of implementing the Web-based project management system. Also, this paper investigates the PCM effectiveness in stringing and managing construction projects. Finally, improvement in project progress can be achieved by applying PCM to generally enhance company performance and specifically during facing claims.

ETAS: Energy and thermal‐aware dynamic virtual machine consolidation in cloud data center with proactive hotspot mitigation

SummaryData centers consume an enormous amount of energy to meet the ever‐increasing demand for cloud resources. Computing and Cooling are the two main subsystems that largely contribute to energy consumption in a data center. Dynamic Virtual Machine (VM) consolidation is a widely adopted technique to reduce the energy consumption of computing systems. However, aggressive consolidation leads to the creation of local hotspots that has adverse effects on energy consumption and reliability of the system. These issues can be addressed through efficient and thermal‐aware consolidation methods. We propose an Energy and Thermal‐Aware Scheduling (ETAS) algorithm that dynamically consolidates VMs to minimize the overall energy consumption while proactively preventing hotspots. ETAS is designed to address the trade‐off between time and the cost savings and it can be tuned based on the requirement. We perform extensive experiments by using the real‐world traces with precise power and thermal models. The experimental results and empirical studies demonstrate that ETAS outperforms other state‐of‐the‐art algorithms by reducing overall energy without any hotspot creation.

Pulsed Current Activated Sintering of Nanostructured ZrO₂ and 3YSZ and Their Mechanical Properties.

As nanostructured materials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid for the application of nanomaterials. When conventional sintering processes are used to sinter nano-sized zirconia powders, concomitant grain growth leads to the destruction of the nanostructure. This focuses attention on consolidation methods in which grain growth can be eliminated or significantly reduced. To accomplish this, rapid sintering methods have been widely used to sinter nano-sized powders. Nanopowders of ZrO₂ and 3YSZ were fabricated and rapidly consolidated using high-energy ball milling and the pulsed current activated sintering (PCAS). The sintering behavior and crystallite size ZrO₂ and 3YSZ powders were evaluated. A nanostructured dense 3YSZ compact with a relative density of up to 99% was readily obtained within one min. The hardness and fracture toughness of ZrO₂ and 3YSZ sintered from powders milled for 10 h were 450 and 1160 kg/mm², 3 and 4.4 MPa·m1/2. Not only hardness but also fracture toughness of 3YSZ are higher than those of ZrO₂.

Microstructure and properties of WC-17Co cermets prepared using different processing routes

WC-17Co cermets were prepared using three different processing routes. An as-ball milled powder mixture (BMPM) and pre-solid solution treatment powder (PSTP) were used as feedstock. Sinter-hot isostatic pressing (SHIP) and high-velocity oxy-fuel (HVOF) thermal spraying were used as consolidation methods. The microstructure and properties of the WC-17Co cermets prepared using the BMPM-SHIP, PSTP-SHIP, and PSTP-HVOF routes were characterized and systematically compared. Solid-solution strengthening of the Co binder phase accounted for the higher hardness and lower fracture toughness (KIC) of the cermets produced using the PSTP-SHIP and PSTP-HVOF routes compared with those of the BMPM-SHIP-produced cermet. Moreover, the SHIP method yielded WC grains featuring an equilibrium truncated triangular prism morphology, which were faceted compared to the round-edged WC grains prepared using HVOF. Owing to the formation of a dense protective tribofilm on its surface, the cermet prepared using the BMPM-SHIP route exhibited the lowest wear rate of 0.13 × 10−7 mm3/(Nm), while the wear rates of the cermets prepared using PSTP-SHIP and PSPT-HVOF were 0.24 × 10−7 and 0.96 × 10−7 mm3/(Nm), respectively.

Multi-Objective VM Consolidation Based on Thresholds and Ant Colony System in Cloud Computing

With the large-scale deployment of cloud datacenters, high energy consumption and serious service level agreement (SLA) violations in datacenters have become an increasingly urgent problem to be addressed. Implementing an effective virtual machine (VM) consolidation methods is of great significance to reduce energy consumption and SLA violations. The VM consolidation problem is a well-known NP-hard problem. Meanwhile, efficient VM consolidation should consider multiple factors synthetically, including quality of service, energy consumption, and migration overhead, which is a multi-objective optimization problem. To solve the problem above, we propose a new multi-objective VM consolidation approach based on double thresholds and ant colony system (ACS). The proposed approach leverages double thresholds of CPU utilization to identify the host load status, VM consolidation is triggered when the host is overloaded or underloaded. During consolidation, the approach selects migration VMs and destination hosts simultaneously based on ACS, utilizing diverse selection policies according to the host load status. The extensive experiment is conducted to compare our proposed approach with the state-of-art VM consolidation approaches. The experimental results demonstrate that the proposed approach remarkably reduces energy consumption and optimizes SLA violation rates thus achieving better comprehensive performance.

Two Key Tasks of Accounting

In the article, two main tasks of accounting are considered, which were formulated by Italian professor Vincenzo Giitti at the end of the nineteenth century, namely, the task of creating a scientifically sound accounting theory, and the task of developing accounting methods that meet the needs of modern enterprises. It is noted that at the present stage of development of accounting, these tasks have not lost their relevance. Despite all the attempts made, the generally recognized scientific theory of accounting has not yet been created, and the existing methods of accounting do not correspond to the needs of organizations created in the form of large integrated structures. The conducted research has shown that presently in the economy of the Russian Federation the significant share is occupied by the organizations carrying out financial and economic activity through affi ed and dependent societies. Organizations with a branched, integrated structure that includes subsidiaries and affiliates, as well as affiliated persons, account for at least 37% of the aggregate output of Russian organizations (total revenue of organizations) and a significant share of the capitalization of Russian organizations. The author argues that the existing consolidation methods provided for by international fi reporting standards are outside the accounting methodology, which, in turn, actualizes the problem of developing consolidated accounting methodology.

Analysis and Recommendations of Sand Consolidation Methods to Limit Sand Production in Gas Wells

Nowadays more and more oil and gas fields are developed in unconsolidated sandstones. Sand production is becoming more common process and complicates the work of downhole equipment and also can lead to higher production prime cost and increase the frequency of repair works. The study of features of oil and gas fields’ development in unconsolidated terrigenous reservoirs showed that in rare cases, sand production can have a positive result, but only during the operation of low-permeability reservoir presented by sandstones, and in this case sand production increases the permeability of the pay zone. Sand production in slightly cemented formation is one of the most urgent problems in many regions of Russia. Wear of equipment and its failure are due to the removal of sand and mechanical impurities. Production of the existing well reserves is also greatly reduced. Huge amounts of money are spent annually to repair wells damaged as a result of sand removal, and the average downtime of one well is about 30 days

Nanolime for the consolidation of lime mortars: A comparison of three available products

Nanolime products are one of the most promising consolidation methods for historic calcareous substrates. Whilst the popularity of nanolime has been growing, its consolidation mechanism still needs to be fully understood when applied to highly porous substrates. The aim of this paper is to compare the three available nanolime products in terms of consolidation efficacy on lime mortar specimens. It is shown that repeated applications of a low concentrated nanolime can increase the superficial cohesion and the mechanical strength of the mortar within 1 cm from the surface, while also reducing porosity, number of micro-pores and capillary water absorption coefficient. Nanorestore Plus® yielded the highest short-term consolidation effect. However, L’Aquila nanolime showed a higher durability which was attributed to a better developed crystalline structure.

A Machine Learning Approach to Shipment Consolidation

This research analyzes the current approach used by a client of DHL LLP for the transportation of shipments from suppliers to production sites. As a result of this analysis, several improvements are proposed that can be used to reduce the costs of transportation in the logistics network. Focus is put on shipment consolidation, rather than on the rerouting of shipments. In this paper, two consolidation methods are introduced. Cluster analysis groups together suppliers that are geographically close and generally ship to the same production sites, and a time-based policy that introduces a maximum waiting time for shipments before they are released. While only marginal improvements are obtained when applying these techniques indepen- dently, a combination of the two provides a powerful synergy. A trade-off between the savings and proportion of on-time shipments arises, when a maximum waiting time is introduced. The potential savings, therefore, depends on the company’s tol- erance for late shipments. While the proposed techniques work in theory, practical and organizational challenges emerge when applying them in the real world.

Fabrication and damping behavior of a novel Mg/TiNiCu composite

A novel Mg/TiNiCu composite was successfully fabricated from porous TiNiCu shape memory alloy (SMA) and pure Mg via non-pressure infiltration process with the aim of developing a new kind of high damping material with excellent mechanical properties. In order to restrain the formation of undesired Mg2Cu phase, the methods of short-time infiltration and rapid consolidation were adopted. Resultant material had homogenously distributed and 3D interconnected Mg particles in the TiNiCu matrix. Compared with porous TiNiCu SMA, in addition to the notable increase of storage modulus the damping property of Mg/TiNiCu composite was also obviously improved, which could be attributed to the superposition effect of multiple damping sources.

Author’s Journal as Type of Literary Edition

Taking into account the structural features, peculiarities of the journal context and methods of its integration, the article demonstrates a typological model of the “author’s” literary journal considered as one of the typological models of a large-volume journal (literary, universal, common journal type). The article reveals typological versions of the “author’s” journals of Russian press in the 18-19th centuries. The authors established that the general typological model united the “author’s” journals with similar typological features. The owner, the publisher and the editor acted on his/her own, as well as he/she was the only or the main author of journal texts of different genres. Besides, he/she had an opportunity to create all journal discourses directly: artistic, publicistic, literary review which lead to the extreme consolidation of the journal context on the semantic (problem and thematic), formal (compositional and stylistic), worldview levels. The article proves that in the course of evolution, differentiation of the “the author’s journal» model with the formation of its typological features has taken place. Russian journalism included the author’s journal novel, the author’s literary and artistic journal, the author’s encyclopaedic journal, the author’s monographic journal. The authors of the article demonstrate that typological versions of the author’s journal are distinguished by degree of the publisher’s and editor’s involvement into the journal management process, their structure, ratio of the main journal discourses, volume and genres of the texts published, as well as methods of journal context consolidation.

Laboratory modeling of siphon drainage combined with surcharge loading consolidation for soft ground treatment

ABSTRACTConventional drainage consolidation methods cause significant energy consumption and environmental issues. In this paper, a method combining siphon drainage and surcharge loading is proposed to drain water from soft soil with vertically installed prefabricated vertical drains (PVDs) and a siphon tube. To investigate the availability and effectiveness of this method, a laboratory physical modeling test was conducted to investigate the drainage and consolidation behavior. The laboratory modeling test results of this method were compared with the calculated results of the ideal sand-drained ground consolidation method to clarify the advantages and mechanism of this method. Comparison results show that the pore pressure and settlement in the proposed method developed faster than the calculation results of ideal sand-drained consolidation theory. About 10 m thickness of unsaturated zone can be formed by siphon drainage which produce a surcharge loading effect on the soil below the flow profile. Drainage is a very slow process in soft soil, and siphon drainage can work continually. Siphon drainage combined with surcharge loading is potentially a good alternative to drain water from soft clay economically and environmentally.

Thermal Properties of Consolidated Granular Salt as a Backfill Material

Granular salt has been proposed as backfill material in drifts and shafts of a nuclear waste disposal facility where it will serve to conduct heat away from the waste to the host rock. Creep closure of excavations in rock salt will consolidate (reduce the porosity of) the granular salt. This study involved measuring the thermal conductivity and specific heat of granular salt as a function of porosity and temperature to aid in understanding how thermal properties will change during granular salt consolidation accomplished at pressures and temperatures consistent with a nuclear waste disposal facility. Thermal properties of samples from laboratory-consolidated granular salt and in situ consolidated granular salt were measured using a transient plane source method at temperatures ranging from 50 to 250 °C. Additional measurements were taken on a single crystal of halite and dilated polycrystalline rock salt. Thermal conductivity of granular salt decreased with increases in temperature and porosity. Specific heat of granular salt at lower temperatures decreased with increasing porosity. At higher temperatures, porosity dependence was not apparent. The thermal conductivity and specific heat data were fit to empirical models and compared with results presented in the literature. At comparable densities, the thermal conductivities of granular salt samples consolidated hydrostatically in this study were greater than those measured previously on samples formed by quasi-static pressing. Petrographic studies of the consolidated salt indicate that the consolidation method influenced the nature of the porosity; these observations are used to explain the variation of measured thermal conductivities between the two consolidation methods. Thermal conductivity of dilated polycrystalline salt was lower than consolidated salt at comparable porosities. The pervasive crack network along grain boundaries in dilated salt impedes heat flow and results in a lower thermal conductivity compared to hydrostatically consolidated salt.

Energy-aware and multi-resource overload probability constraint-based virtual machine dynamic consolidation method

In a data center, virtual machine consolidation has been proposed to improve the resource utilization and energy efficiency. An effective and efficient virtual machine consolidation method should achieve an appropriate balance among multiple goals, including guaranteeing service quality, reducing energy consumption and maximizing resource utilization. This problem is a multi-objective optimization problem with multiple resource constraints. To solve this problem, we propose an energy-aware dynamic virtual machine consolidation (EC-VMC) method that migrates virtual machines while satisfying constraints on the probabilities of multiple types of resources being overloaded. In our method, a series of algorithms for selecting and placing virtual machines to be migrated are utilized, with constraints on the probabilities of various resources in a physical machine being overloaded. Our algorithms integrate and cooperate similarly to artificial bee colony foraging behavior to perform an optimized search for the mapping relation between virtual machines and physical machines for consolidation. Extensive simulation is conducted to compare our EC-VMC method with previous virtual machine consolidation methods. The simulation results demonstrate that the EC-VMC method effectively overcomes the deficiencies of some existing heuristic algorithms and is highly effective in reducing VM migrations and energy consumption of data centers and in improving QoS.

Structure and Mechanical Properties of Powdered Quasicrystalline Al94Fe3Cr3 Alloy Consolidated by Quasi-Hydrostatic Compression

Background. Quasicrystalline Al-based alloys belong to the class of the state-of-the-art metal materials for the application in light engineering constructions, primarily in aviation and the motor transport industry. These materials are commonly made in the form of powders, which is due to the high productivity of powder metallurgy methods. Therefore, the powder consolidation methods are of great importance in the production of products, which is associated with certain difficulties, and consequently, they should be chosen considering not only the quasicrystals’ propensity to brittle fracture but also the metastable nature of the quasicrystalline phases. Certain possibilities in this direction are provided by the quasi-hydrostatic compression method, which can provide a non-trivial combination of strength and ductility properties of materials. Objective. The aim of the paper is to investigate the effect of high pressure under quasi-hydrostatic compression on the formation of structure, phase composition and mechanical properties of the quasicrystalline Al 94 Fe 3 Cr 3 alloy. Methods. 40 μm Al 94 Fe 3 Cr 3 alloy quasicrystalline powder was fabricated by water-atomisation technique. Consolidation of quasicrystalline powder was performed by quasi-hydrostatic compression technique in high-pressure cells at room temperature at a pressure of 2.5, 4, and 6 hPa. Structure, phase composition and mechanical characteristics of Al 94 Fe 3 Cr 3 alloy were performed by scanning electron microscopy (SEM), X-ray diffraction andmicromechanical tests. Results. Using the phase X-ray analysis and SEM, the content of the quasicrystalline icosahedral phase (i-phase) in the Al 94 Fe 3 Cr 3 alloy structure was completely preserved after its consolidation at different pressures (2.5, 4, and 6 hPa) under quasi-hydrostatic compression at room temperature. Despite the high pressure applied in the consolidation process, the morphology of quasicrystalline phase particles located in the a-Al deformed matrix solid solution remains unchanged. The mechanical properties of the alloy exceed the similar characteristics of the alloy consolidated by warm extrusion. Conclusions. Consolidation of the Al 94 Fe 3 Cr 3 alloy powder under quasi-hydrostatic compression allows for the complete conservation of metastable quasicrystalline i-phase particles in the aluminum matrix, which provides the highest values of strength properties together with sufficient ductility for application in the engineering practice.

Revisiting the structure of SiC–B4C–MedB2 systems and prospects for the development of composite ceramic materials based on them

The liquidus surface in SiC–B4C–Me d B2 quasi-ternary eutectic systems (where Me d B2 is CrB2, VB2, NbB2, TaB2, ZrB2, HfB2, and W2B5) is modeled in the approximation of the regular solution model based on the experimental data on bordering systems and individual compounds. The calculated and experimental data are compared. Regularities of the structure of phase diagrams of SiC–B4C–Me d B2 systems are analyzed. It is noted that the diboride concentration appropriately decreases in the triple eutectic with an increase in its melting point. Correlation dependences between the eutectic temperature and melting point $${t_{eut}} = f\left( {t_m^{M{e^d}{B_2}}} \right)$$ and formation enthalpy of diboride $${t_{eut}} = f\left( {\vartriangle H_f^{M{e^d}{B_2}}} \right)$$ are constructed. The character of dependences is close to previously observed similar dependences in SiC–Me d B2 and B4C–Me d B2 bordering quasi-binary systems. It is concluded based on the analysis of the structure and parameters of analyzed systems that it is promising to develop a broad series of construction and functional ceramic materials and coatings fabricated by “free” sintering and by pulsed methods of heating and consolidation based on the considered systems.