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Commercial inkjet-printers from manufacturers like Epson or Brother can be used for rapid prototype printing conductive traces onto paper or flexible PET substrates by using nanoparticle based dispersions. The surface coating of the substrate influences the attainable electrical conductivity and dielectric permittivity as well as the loss tangent, which are important parameters for developing inkjet-printed microwave circuits on paper substrates. For characterizing the permittivity conventional methods are using microstrip ring or microstrip transmission line resonators that require the printing of two electrically conductive layers. In the proposed paper, a novel method is introduced to determine the relative permittivity and loss tangent via a coplanar waveguide resonator realized on a single layer. [ABSTRACT FROM AUTHOR]

This study describes a novel fabrication method of a multi-pad paper plate (MP 3 ) for transfer and optimisation of enzyme-linked immunosorbent assays (ELISA) on paper. The plate was fabricated using a combination of laser cutting and lamination for rapid and low-cost production of a multi-pad paper plate compatible with a standard 96 well microplate format. The plate was used to transfer a sandwich ELISA assay for detection of the acute phase protein bovine haptoglobin, allowing assay optimisation in the new format. The optimised protocol was also applied to detection of haptoglobin in bovine serum, demonstrating significant correlation with the traditional lab-based ELISA. [ABSTRACT FROM AUTHOR]

In 2012 the City of Flagstaff partnered with researchers at the Dept. of Civil and Environmental Engineering at Northern Arizona University to successfully develop a mix design utilizing sludge derived from the manufacturing of recycled paper pulp sludge (PPS) and fly ash as a component of a landfill cap. This research has been extended to explore the addition of polymers to the mix of waste materials in order to optimize a design that would be suitable as a component for an EPA Subtitle D-approvable landfill liner. Cinder Lake Landfill (CLL) serves several communities in Northern Arizona and is managed by the City of Flagstaff. CLL does not have a reliable source of clay needed to construct a required landfill liner, which is necessary for the upcoming 108-acre landfill expansion. However, CLL receives approximately 80 tons of recycled PPS daily from the local tissue manufacturing plant. PPS is currently used as daily cover and was tested for use as part of a landfill cap, as noted above. Incorporating polymers in alternative materials such as PPS and fly ash has the potential to meet performance criteria and be approved by state and federal regulators, and has the potential to save the City millions of dollars over conventional composite liners of geomembrane and clay. Different mixtures of PPS, fly ash and three different polymers are currently being subjected to testing for the following: Water Content, Specific Gravity, Porosity, Organic Content, Atterberg Limits (plasticity), Proctor Compaction, Consolidation, California Bearing Ratio, Shear Strength, Gas Permeability, and Liquid Permeability. The optimal mixture of PPS and fly ash will be blended with a range of polymer concentrations. The goal is to find an optimal mix of PPS, fly ash, and polymer to achieve regulatory standards related to permeability, along with other desirable properties such as strength and flexibility. The optimum mixture(s) will then be subjected to field trials, scheduled to begin in 2016, in which test cells will be created at CLL. The liner will be constructed with the optimized mixture(s), and the cells will be operated as landfills for 1-2 years. Results from lab and field testing will be submitted to federal and state regulators for consideration as an alternative liner approach. [ABSTRACT FROM AUTHOR]

In 2012 the City of Flagstaff partnered with researchers at the Dept. of Civil and Environmental Engineering at Northern Arizona University to successfully develop a mix design utilizing sludge derived from the manufacturing of recycled paper pulp sludge (PPS) and fly ash as a component of a landfill cap. This research has been extended to explore the addition of polymers to the mix of waste materials in order to optimize a design that would be suitable as a component for an EPA Subtitle D-approvable landfill liner. Cinder Lake Landfill (CLL) serves several communities in Northern Arizona and is managed by the City of Flagstaff. CLL does not have a reliable source of clay needed to construct a required landfill liner, which is necessary for the upcoming 108-acre landfill expansion. However, CLL receives approximately 80 tons of recycled PPS daily from the local tissue manufacturing plant. PPS is currently used as daily cover and was tested for use as part of a landfill cap, as noted above. Incorporating polymers in alternative materials such as PPS and fly ash has the potential to meet performance criteria and be approved by state and federal regulators, and has the potential to save the City millions of dollars over conventional composite liners of geomembrane and clay. Different mixtures of PPS, fly ash and three different polymers are currently being subjected to testing for the following: Water Content, Specific Gravity, Porosity, Organic Content, Atterberg Limits (plasticity), Proctor Compaction, Consolidation, California Bearing Ratio, Shear Strength, Gas Permeability, and Liquid Permeability. The optimal mixture of PPS and fly ash will be blended with a range of polymer concentrations. The goal is to find an optimal mix of PPS, fly ash, and polymer to achieve regulatory standards related to permeability, along with other desirable properties such as strength and flexibility. The optimum mixture(s) will then be subjected to field trials, scheduled to begin in 2016, in which test cells will be created at CLL. The liner will be constructed with the optimized mixture(s), and the cells will be operated as landfills for 1-2 years. Results from lab and field testing will be submitted to federal and state regulators for consideration as an alternative liner approach. [ABSTRACT FROM AUTHOR]

In accordance with environmental sustainability and in order to optimize the recycling process of prints from indirect electrophotography with liquid toner the results of investigating the effects of changes in printing conditions on the characteristics of recycled fibres is presented. Changing of printing machine conditions, respecting of voltage variations, comprises of the reverse rollers and intermediate cylinder. Based on the results it can be concluded that the change in the voltage of the reverse rollers more affect the recycling efficiency with respect to the voltage change of the intermediate cylinder. Brightness gain is higher when the print for recycling is made on uncoated paper compared to coated, and dependent on the voltage changes. Effective residual ink concentration decreases far more on handsheets obtained from recycled samples on uncoated paper in relation to both sides coated paper. Increasing the positive voltage of intermediate cylinder and increasing the negative charge of reverse rollers increases the 3 D gamut CIE L*a*b* color cubic units. Guidelines for the size of the voltage in order to obtain optimal print reproduction are provided. The further research will include the development in area of clean technologies, advanced materials, closed loop systems; therefore the significant terms in the area of environmental sustainability. [ABSTRACT FROM AUTHOR]

The paper presents the results of studies of the generation of methanol in the accelerated aging of paper insulation in transformer oil under the influence of an elevated temperature. All investigated materials (cable paper, transformer oil) are of Russian origin. A description is given for the used models of paper insulation samples, specially designed test cells and a circulating bath. The results of a comparison of studies conducted by authors and other researchers from countries are analyzed. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the study is to model and to simulate the thermal and electrical efficiencies of the cogeneration plant of a paper mill. The final purpose is the benefits optimization by adjusting production to the amount of energy to be sold. It is necessary to know it because the sale price goes down when the actual production of electrical energy does not match the scheduled power. [Copyright &y& Elsevier]

In this work, we investigate the influence of ZnO nanoparticles on the performance of paper-based humidity sensors. The sensors were developed on standard, commercial printing paper with laser-patterned gold interdigitated electrodes (IDE) and ZnO nanoparticles spin-coated by various sol-gels. Blank devices were used as reference sensors in an effort to elucidate the role of ZnO and the dependence of the device performance on the concentration of the sol-gels and the number of spin-coated layers. Resistive measurements were conducted at room temperature to evaluate the devices’ response on known relative humidity levels. Relatively fast rise and response times were observed even at room temperature, while all devices tested did not require refreshing procedures. The deposition of ZnO was found to affect the sensor response, resulting in reduced sensor signal, due to the blocking of water diffusion in the porous paper material. [ABSTRACT FROM AUTHOR]

A piezoelectric based touch sensitive device has been successfully fabricated by screen printing silver (Ag) and polyvinylidene fluoride (PVDF) inks as conductive and piezoelectric materials, respectively, on paper substrate. X-ray diffraction (XRD) analysis was performed to verify the formation of β-phase crystals in the PVDF layer during the curing process. Voltages, as high as 0.22 V, were observed for human finger touch tests and a sensitivity of 0.3 V/N was obtained when varying forces ranging from 0.2 N to 1.4 N, in steps of 0.2 N, were applied on the printed device. The piezoelectric-voltage analysis demonstrated that the printed device can be used for both touch and force sensing applications. [ABSTRACT FROM AUTHOR]

In this work, the fabrication of Rochelle salt based piezoelectric structures is illustrated. Structures composed of paper and Rochelle salt are easily manufactured using simple processes. Both manufacturing and the material itself are environmental friendly. Additionally Rochelle salt is biocompatible. In the paradigm of a cleaner piezoelectric technology, the fabrication of active sensing or actuating devices is developed. Thus processing method, material and piezoelectric properties have been studied: (1) pure crystals are used as acoustic actuator, (2) properties of paper impregnated with Rochelle salt are detailed, (3) charge generation is demonstrated on the impregnated material. Actuating and sensing devices are reported in order to highlight the potential of this green piezoelectric material. [ABSTRACT FROM AUTHOR]

In this work, the fabrication of Rochelle salt based piezoelectric structures is illustrated. Structures composed of paper and Rochelle salt are easily manufactured using simple processes. Both manufacturing and the material itself are environmental friendly. Additionally Rochelle salt is biocompatible. In the paradigm of a cleaner piezoelectric technology, the fabrication of active sensing or actuating devices is developed. Thus processing method, material and piezoelectric properties have been studied: (1) pure crystals are used as acoustic actuator, (2) properties of paper impregnated with Rochelle salt are detailed, (3) charge generation is demonstrated on the impregnated material. Actuating and sensing devices are reported in order to highlight the potential of this green piezoelectric material. [ABSTRACT FROM AUTHOR]

The fabrication of a mechanically flexible piezoresistive load sensor is reported. Inkjet printing offers an inexpensive non-contact fabrication method for microelectronics. Herein we report the first direct fabrication of inkjet-printed graphene arrays, and apply them to electromechanical detection of force. The graphene ink was printed on a cantilever shape paper substrate. The results illustrated a linear resistance change with the applied forces. The force range, force resolution, and sensitivity were found to be 25 mN, 10 μN, and 1.2 mV/mN, respectively. In addition, graphite ink was also used as the sensing component in order to make a comparison between the piezoresistive effect of graphene and graphite ink. The results show that using graphene ink instead of graphite increases the force range and gauge factor of the sensor, which are two important designing factors. This sensor is inexpensive, simple to fabricate, lightweight, and disposable. [ABSTRACT FROM AUTHOR]

Abstract: This paper is focuses modeling of the last part of the paper machine – the drying section. Paper is dried by letting it pass through a series of steam heated group of cylinders and the evaporation is thus performed by the latent heat of vaporization of the steam. The moisture in the paper is controlled by adjusting the set point of the steam presure controllers to the cylinders. There exist several incentives to focus on the performance of the moisture control. The time to perform a grade change is often limited by the moisture and shorter grade change time is directly correlated to economic profit. The plant model is identified periodically and the changes in its dynamic characteristics are observed. Periodic identification gives a great advantage over the conventional controller tuning methods, which uses the plant model at the nominal operating conditions. A variety of model structures are available to assist in modelling a system. Model for the drying process of Paper industry is established based on gathering 1000 groups of 2500 real-time sample data. Based on the collection of data, that was adapted to both the conventional and intelligent modelling process. Finally the suitable model is tuned with the suitable controller for optimal control of the drying process. [Copyright &y& Elsevier]

Remaining Life of the oil-immersed transformer is decided due to deterioration of the winding insulation paper (WIP). The DGA method is conventionally used to estimate the WIP deterioration status condition. This paper presented the four status conditions assessment of paper deterioration for oil-immersed transformer using fuzzy-logic (FL). In this paper the correlation between accumulated values of carbon dioxide (CO2) and carbon monoxide (CO) with insulation resistance in oil-filled power transformers is studied using FL. The authors have estimated the insulation paper deterioration condition using proposed method for 20 transformers or more. As a result, appropriate maintenance scenario can be planned. [ABSTRACT FROM AUTHOR]

Abstract: We study the evolution of deformation on a quasi 2D paper sample during fatigue and creep experiments. Paper is a fibrous material, sensitive to various parameters (humidity, temperature, history effect). As for many materials, the lifetime varies a lot. Basquin''s law claims that the number of cycles at break in fracture tests has a power-law dependence on the external load amplitude; Monkman-Grant relationship predicts that lifetime is proportional to the minimum strain rate during creep. The main question is therefore: is it possible to predict the time-dependent rupture? We perform creep and cyclic tests on paper samples. The main tools of investigation are acoustic emission (AE) -based analysis and digital image correlation (DIC). Via the AE, one can follow the damage evolution in samples, like microcrack formation that releases elastic energy. The DIC instead works well as a tool to measure at great accuracy both global and local deformation fields. From these, local strain rates can be derived, which then can be used to understand the microscopic dynamics that lie behind a certain rheology or sample response. The issue is to predict the break by looking at the sample-to-sample variation and by comparing experiments. [Copyright &y& Elsevier]

Abstract: We study the evolution of deformation on a quasi 2D paper sample during fatigue and creep experiments. Paper is a fibrous material, sensitive to various parameters (humidity, temperature, history effect). As for many materials, the lifetime varies a lot. Basquin''s law claims that the number of cycles at break in fracture tests has a power-law dependence on the external load amplitude; Monkman-Grant relationship predicts that lifetime is proportional to the minimum strain rate during creep. The main question is therefore: is it possible to predict the time-dependent rupture? We perform creep and cyclic tests on paper samples. The main tools of investigation are acoustic emission (AE) -based analysis and digital image correlation (DIC). Via the AE, one can follow the damage evolution in samples, like microcrack formation that releases elastic energy. The DIC instead works well as a tool to measure at great accuracy both global and local deformation fields. From these, local strain rates can be derived, which then can be used to understand the microscopic dynamics that lie behind a certain rheology or sample response. The issue is to predict the break by looking at the sample-to-sample variation and by comparing experiments. [Copyright &y& Elsevier]

Ever increasing user demands and development of modern communication technologies have led to the evolution of communication networks from 1st Generation (1G) network to 4G heterogeneous networks. Further, 4G with heterogeneous network environment will provide features such as, “Always Best Connected”, “Anytime Anywhere” and seamless communication. Due to diverse characteristics of heterogeneous networks such as bandwidth, latency, cost, coverage and Quality of Service (QoS) etc., there are several open and unsolved issues namely mobility management, network administration, security etc. Hence, Designing proficient mobility management to seamlessly integrate heterogeneous wireless networks with all-IP is the most challenging issue in 4G networks. Mobile IPv6 (MIPv6) developed by Internet Engineering Task Force (IETF) has mobility management for the packet-switched devices of homogeneous wireless networks. Further, mobility management of homogeneous networks depends on network related parameter i.e., Received Signal Strength (RSS). However the mobility management of heterogeneous networks, not only depends on network related parameters, but also on terminal-velocity, battery power, location information, user-user profile & preferences and service-service capabilities & QoS etc. Designing mobility management with all-IP, while, considering issues such as context of networks, terminal, user and services is the main concern of industry and researchers in the current era. [ABSTRACT FROM AUTHOR]

Abstract: Australia produces both black and brown coal and is the world''s fourth largest producer of black coal, after China, USA and India. Australian underground coal mines operate under controlled safety codes. The establishment of the mine safety management system, including the 1994 outburst management plan, contributed to a significant improvement in mine safety leading to non-fatality in outburst related incidences since 1994. The management of outburst risk, as a part of the overall safety and health management system is described. Also discussed are the introduction of outburst threshold limit values and the desorption rate index which forms the basis for determining safe mining conditions along with the “Authority to Mine” process The measures taken and lessons learned from safe mining of Australia''s outburst prone mines represent an opportunity for improved mining safety in other countries, such as China.. The role of the Australian Coal Association Research Program, which supports research in critical areas such as outburst risk control and management, is also discussed. [Copyright &y& Elsevier]

This paper documents the motivation and methodology developed to evaluate the cost effectiveness and potential improvements for the transportation and storage of food aid commodities. Additionally, preliminary fieldwork conducted to map out the domestic portions of the supply chain is also presented. We hypothesize that modern bag technologies, such as hermetic bags, offer the potential to cost effectively improve the quality of food aid commodities as a substitute to current fumigation processes. A range of packaging (current and new), shipping modes, commodities, and foreign ports will be evaluated in the traditional supply chain with the use of a factorial design. Furthermore, the down-stream supply chain portions such as storage will be simulated by placement in prepositioning warehouses in foreign ports for up to three months. The use of a factorial design with sliding levels is a crucial method utilized to accommodate the various factors involved in the complex supply chain of food aid. Domestic fieldwork has provided valuable insights into the viability of implementing modern bagging technologies in the existing supply chain. [ABSTRACT FROM AUTHOR]

Multi-layered composites are frequently used in many applications as constructional materials. Such materials represent a difficult inspection task for some traditional techniques of non-destructive testing (NDT). Typical defects of composite materials are delaminations, lack of adhesion and crumpling, just to name a few. IR thermography and ultrasonics are typically considered as candidate techniques to detect different types of defects. In order to assess the potential usefulness of both methods, a composite laminate with a polytetrafluoroethylene disk inserted between two layers to simulate a delamination is investigated. Experimental evidences resulting from the two technologies are discussed. [ABSTRACT FROM AUTHOR]

In this work we demonstrate that the phase shift detection technique can be applied to reveal, with very high sensitivity and resolution, concentrations of chemical/biological substances optically detectable by measuring power variations of a light source. The system is based on the synchronous demodulation technique and employs a Si photodiode (PD) operating in photovoltaic regime biased through a small modulating sinusoidal waveform. The phase shift variations are measured between this biasing voltage and that one generated by the Si PD illuminated by the light, that interacts with the chemical/biological sample under analysis, providing the phase shift change. Experimental results demonstrate that is possible to achieve phase detection sensitivity, with respect to light power variations, up to 3100°/μW as a function of the Si PD settable operating conditions. By using a commercial lock-in amplifier with a 0.01° phase resolution, a light power variation resolution of about 3pW has been achieved. As a case-example, variations of the molar concentration of a methylene blue solution are detected by performing optical absorption standard measurements. Despite the phase resolution limitation of the used lock-in amplifier, the comparison between the data obtained through the proposed technique and those ones achieved by conventional amplitude measurements demonstrates a high improvement of the detection sensitivity. As a consequence, the measurement of molar concentration variations with a resolution of 80pM is achieved resulting 33 times higher than that one obtained with the amplitude detection. [ABSTRACT FROM AUTHOR]

The formation of wrinkling in deep drawing processes generally occurs in the two area of flange and cup wall. In this paper, a geometric method based on FEM simulation has been developed to investigate the wrinkling in the wall area of conical cups. Wrinkling wave variation was considered as the criterion of wrinkle defect. The forming process in this study is hydrodynamic deep drawing assisted by radial pressure with inward flowing liquid. The effects of radial pressure and cavity pressure on wrinkle phenomenon have been investigated. To verify the results of the simulation, experiments were performed on the steel sheets. Good agreement between the simulation and experimental results shows the reliability of this method in the wrinkling study. Results showed that radial pressure and cavity pressure have significant impacts on creation or prevention of wrinkling in the side wall. [ABSTRACT FROM AUTHOR]

In the era of mass manufacturing, MRR (material removal rate) is of primary concern even in manufacturing using contemporary CNC (computer numerical controlled) machines. In this paper Taguchi method has been employed with L25 (5^3) Orthogonal Array for three parameters namely Speed, Feed and Depth of cut. For each of these parameters five different levels have been identified and used to perform the turning parameters for maximization of material removal rate on an EMCO Concept Turn 105 CNC lathe. The material selected for machining was SAE 1020 with carbide cutting tool. The MRR is observed as the objective to develop the combination of optimum cutting parameters. This paper proposes an optimization approach using orthogonal array for the maximized MRR and the result from this study confirms the same. This study also produced a predictive equation for determining MRR with a given set of parameters in CNC turning. Thus, with the proposed optimal parameters it is possible to increase the efficiency of machining process and decrease production cost in an automated manufacturing environment. [ABSTRACT FROM AUTHOR]

As large amount of dye has been discharged as wastewater and infiltrated into our water system, it is now affecting the aquatic life due to its carcinogenic nature. Although heterogenous photocatalytic process is found effective in mineralizing these organic pollutants into less harmful one through light irradiation, the most often explored TiO 2 is active only under UV light, thus limits its real application such photocatalyst in environmental remediation. A new class materials with hydrotalcite like structure, layered double hydroxides (LDH) has been recently explored for their superior photocatalytic degradation property as their anionic intercalating layer boosts their absorption capabilities, thus yielding high active surface area for photo-degradation to proceed. Despite their band gap tunability, chemical versatility and high reproducibility in large quantities, they suffer from poor control over particles size and morphology. Here in this paper, three different Nickel-Cobalt LDH morphologies are uniformly produced by utilizing a facile and economical synthesis method and by adjusting the precursor, ammonium fluoride. It is shown that NH 4 F can act as a structural-mediating agent that transforms 1D to 2D structure as well as a crystal forming agent that boosts the photocatalyst’s crystallinity, which would essentially enhance its photocatalytic methyl orange degradation for almost 2-fold than those of poor crystallinity. In short, this paper demonstrates a facile control of morphology and crystallinity of LDH for better photocatalysis under visible light irradiation. [ABSTRACT FROM AUTHOR]

The paper discusses available analytical approaches for analyzing radar absorbing performance of composite materials. Most published reports on the microwave properties of magnetic composites refer to radar absorbers as possible applications. The conventional approach is based on measurements of the effective permittivity and permeability of a composite with certain concentrations of inclusions; calculations of reflection coefficient of the composite layer backed by a metal substrate for the normal incidence of electromagnetic wave; and selection of the layer thickness that produces deep minimum of the frequency dependence of the reflectivity. The obtained reflectivity minimum, typically of −30, −40 dB, or even −60 dB deep is conventionally considered as a proof for “a good absorbing ability” of the inclusions comprising the composite. In the paper, simple analytical approximations based on the series expansions of the reflection coefficient are suggested for the reflection coefficient of radar absorbers. It is shown that the problem of radar absorbing performance is not reduced to obtaining good absorbing ability, but is a problem of matching of parameters of the absorbing material. Therefore, the depth of reflection minimum is not a suitable measure for the characterization of radar absorbers. To describe the quality of an absorber, other quality criteria are needed. [ABSTRACT FROM AUTHOR]

In this paper, a new discrete element method (DEM) containing particle flow code (PFC) is presented as an efficient-to-implement alternative to the existing finite element method (FEM) for simulating internal forces and deformations of a hot-rolled H-section steel beam subject to static loading. Unlike FEM, which is efficient to solve continuous problems, the PFC method can solve discontinuous problems, such as collapse procedure of structures, and the collapse procedure of the structure can be monitored at different times in a more time-saving way. First of all, a linear constitutive model in FEM was built to compare with the linear parallel bond model built in PFC, a hot-rolled H-section steel beam considering geometrically non-linearity subject to static loading was simulated and the simulation results were compared with theoretical solution and FEM results. Both internal forces and deformations before yielding were compared and good agreements were achieved. Secondly, with the object-oriented programming technique and the redeveloped interface of PFC, a user-defined parallel bond model was developed to consider material nonlinearity and compared with the bilinear constitutive model built in FEM. Both internal forces and deformations before and after yielding were compared and good agreements were observed. Thus, the DEM model adopted in this paper can be efficiently used to simulate the behavior of the H-section steel beam. In the future, the developed parallel bond model can be used to simulate the performance of H-section steel beam subject to vertical impact loading and three-dimensional steel framed structure subject to horizontal collision. [ABSTRACT FROM AUTHOR]

In another paper at this workshop, the development of Eco-Friendly Ductile Cementitious Composite (EDCC) and its response to uniaxial tensile is described. Here, its performance when used as a strengthening coat on unreinforced masonry is described. This paper elaborates on the results of shake table tests on full-scale masonry wall specimens, each about 2m wide by 3m high, retrofitted using sprayed EDCCs. Six full-scale unreinforced non-grouted masonry wall specimens were assembled and then retrofitted using Sprayable EDCC. The walls are tested at the Earthquake Engineering Research Facility (EERF) at UBC on the Linear Shake Table (LST) under different ground motions with varying intensities. The wall specimens were fully instrumented and data were collected using 34 different channels including 10 accelerometers, 8 channels of displacement sensors, 8 strain gauges and time synchronized video recording using eight HD cameras. Test indicated that even a single-sided retrofit with appropriate EDCC can significantly enhance the overall ductility of the system and change the fundamental behaviour of the wall from a typical “Rocking Mechanism” to a “Beam” type behaviour, with significant rotations at the hinge supports of the base. The added flexibility to the system resulted in a substantial increase in energy dissipation, and thereby increasing the overall drift limits before collapsing, causing the wall to withstand extensive levels of shaking under different types and intensities of earthquake generated ground motions. [ABSTRACT FROM AUTHOR]

The paper presents the main theoretical backgrounds and application of FE program ATENA to simulation of severe accident in nuclear structures. The software was developed by Cervenka Consulting, Prague, Czech Republic with the aim to offer a tool for numerical simulation of concrete structures subjected to actions in service, ultimate as well as extreme limit states due to mechanical as well as physical effects. Nonlinear behavior of concrete is modeled by theories of damage and plastic flow [1]. Paper outlines the basic features of the used material model. It demonstrates the model accuracy on results from recent blind prediction competitions [2]. In the last section, it shows examples of simulations of severe accidents scenarios in nuclear power plants structures [4]. [ABSTRACT FROM AUTHOR]

In recent years, high strength steel has gradually attracted the attention of the construction industry, due to its high yield strength, tensile strength, good performance of resistance to brittle failure and high reliability of structures. Common finite element ABAQUS software is employed in this paper to simulate the lateral torsional buckling of Q460 welded beams. Finite element analysis models considering initial geometric imperfections were conducted. Besides, parametric studies were carried out to evaluate the effect of key parameters on the global stability behavior of Q460 beams as well. And the results obtained from finite element analysis simulations were compared with the design buckling curves from Chinese steel structure design codes (GB50017-2003, GB50017-201X) and AS4100. Finally, new design buckling curves are presented in this paper in order to evaluate the global stability behavior of Q460 steel beams. [ABSTRACT FROM AUTHOR]

Fire has a significant influence on concrete structures and members. A concrete column, compared to other structural members, has most often to cope with vertical forces and bending moments from slabs and beams. Therefore, it is important to investigate the fire resistance of concrete columns. In fact, simplified methods are often adopted to evaluate the capacity of concrete columns. In the fib Model Code 2010, a curvature approximation is introduced. However, this method has not been validated to be used in case of fire. Hence, a parametric study is performed in this paper to investigate the application of this method. As a first step of this paper, a curvature approximation formula used at ambient temperature is introduced. As this formula is based on the curvature and in order to verify the application, a numerical tool that can obtain the bending moment and curvature relationships is presented and validated. Further, an ISO 834 standard fire is adopted. Finally, parameters like dimensions, the reinforcement ratio and the slenderness ratio are investigated. Comparing the effect of dimensions, the reinforcement ratio as well as the slenderness ratio, it is concluded that only the slenderness ratio has a significant influence on the column capacity with the proposed formula. The difference between the deflections obtained with the simplified method and the numerical values increase in function of the slenderness ratio (in case of the same axial load). However, this method is proven to be easy-to-use and safe for the prediction of the fire resistance of concrete columns. [ABSTRACT FROM AUTHOR]

Reliable deformation measurement is required for proper quantification of fire performance of concrete structures. Predictive capability of models for many critical properties, including Young’s moduli, stress-strain relationships and load-induced thermal strains, is first and foremost dependent on such reliable deformation capturing. This paper first presents a state-of-the-art review of existing methods for capturing deformation of concrete structures at elevated temperatures. Key merits, limitations and challenges associated with each measuring technique are discussed. It is shown that existing testing facilities and measuring instruments generally do not allow reliable direct measurement of deformation and strain of high-temperature concrete. As a result, the deformation has typically been captured either indirectly or outside the heated zones, inevitably introducing additional uncertainty and errors that are difficult to be adequately quantified. On the basis of that review, the paper details a new test set-up for reliable non-contact full-field deformation capturing of concrete structures at high temperatures using 3D Digital Image Correlation technique. Key features of the new setup that enable to successfully address major challenges of thermal boundary condition, thermal stability of speckle pattern, contrast of image and hot air movement are presented; together with evidences giving confidence to the reliability of such set-up. With its combined advantages of reliable full-field deformation capturing and thermal boundary conditions on test specimens, the new set-up allows to generate required reliable data on performance of concrete at elevated temperatures, thereby facilitating the development of effective rational fire design and analysis of concrete structures. [ABSTRACT FROM AUTHOR]

In the context of the ongoing worldwide efforts directed to achieving environmental sustainability by mitigating environmental challenges and reversing the depletion of the environmental resources, the work presented in this paper has the purpose to identify the most effective solution for ensuring access to good quality drinking water for the localities in the southern part of Constanta County, Romania. At present, the communities in the analyzed area are using drinking water abstracted from ground water sources which have registered continuous quality degradation over the last 30 years, while the water losses in the water supply systems are high. As the existing water treatment facilities are unable to remove the pollutants found in the raw water (ammonia, nitrates, Iron and Manganese), within a complex regional project which aims at the same time for reduction of water losses and reaching drinking water quality compliance, a comprehensive analysis was prepared, in order to identify the most efficient solution for supplying the localities at the border of the Black Sea with sufficient and appropriate quality water. This paper shows the systematic approach used for conducting the options analysis in which there have been considered different applicable solutions ranging from decommissioning the existing sources and construction of a regional water supply local treatment, to keeping the existing sources and construction of new appropriate treatment facilities or blending water from multiple sources. The conducted analysis has revealed that the most feasible option for long term sustainability of water supply is the construction of a regional water supply system supplied by a very good quality wellfield with additional flow input from an existing water treatment plant having spare capacity available. [ABSTRACT FROM AUTHOR]

Bucharest City is the capital of Romania and also the biggest city. Situated in an alluvial plane, the geological settings are represented by a series of overlaying Quaternary strata of aquifers and aquitards. Some of these aquifers are used for water supply (the deeper aquifers) and the shallow and medium ones are characterized by an intense interaction with the urban infrastructure. The paper presents the drivers and also the architecture of the urban groundwater monitoring systems developed in the last years in order to observe the urban impact upon the first two aquifers layers. The anatomy of the system is correlated with the urban infrastructure. Also the paper presents the future monitoring system that will be develop within a European JPI project. [ABSTRACT FROM AUTHOR]

The article present the potential of using the BIM technology in the process of bills of quantities preparation for construction works. The article show the role of information collected in the model. The information entered into model and collected in the model during the design phase has a big impact on Bill of Quantities. The more detailed the information in the BIM model and as a result the more detailed description of the works in the BoQ make a cost calculation more accurate. As an example the paper presents the process of feeding information to the model based on selected construction works design software. Then, the paper presents the process of entering information on construction works and elements and the impact of entered information on bill of quantities on examples of earthworks, foundations and wall construction. [ABSTRACT FROM AUTHOR]

In metal forming processes, friction between tool and workpiece is an important parameter influencing the material flow, surface quality and tool life. Theoretical models of friction in metal forming are based on analysis of the real contact area in tool-workpiece interfaces. Several research groups have studied and modelled the asperity flattening of workpiece material against tool surface in dry contact or in contact interfaces with only thin layers of lubrication with the aim to improve understanding of friction in metal forming. This paper aims at giving a review of the most important contributions during the last 80 years covering experimental techniques, upper bound solutions, slip-line analyses and numerical simulations. Each of the contributions shed light on the importance of the real contact area and the influencing parameters including the material properties, surface conditions, normal pressure, sliding length and speed, temperature changes, friction on the flattened plateaus and deformation of the underlying material. The review illustrates the development in the understanding of asperity flattening and the methods of analysis. Finally, the present paper discusses the necessary future work in order to advance further in modelling of real contact area in relation to implementation of frictional conditions existing finite element codes for simulation of metal forming processes. [ABSTRACT FROM AUTHOR]

Cutting blades for harvesting applications are used in a variety of agricultural machines. These parts are in contact with highly abrasive lawn clippings and often wear out within hours which results in high expensive re-sharpening maintenance. This paper relates to locally graded steel materials as semi-finished products for self-sharpening cutting blades. As these materials comprise a layered structure consisting of a hard, wear resistant layer and a relatively softer layer which is lesser wear resistant. As the cutting blade is subjected to wear conditions, the less wear resistant layer wears faster than the relatively more wear resistant harder layer. As a result, the more wear resistant layer is always exposed at the tip of the blade and determines its geometry. As the hard layer’s thickness is almost the same within the part, the cutting edge remains unchanged and provides constant performance in service. This paper displays suitable designs for such cutting blades, test setups for its characterization and capable manufacturing techniques for making locally graded steel materials as semi-finished products. [ABSTRACT FROM AUTHOR]

Large continuous casting billet always contain void defects which may adversely affect the mechanical properties and safe performance of final products. The void must be completely eliminated during hot forging process. In this paper, different types of void defects in large billet are showed and analyzed. It is found that the voids have different geometry, orientations and positions. Using finite element (FE) software DEFORM 3D, a FE model was developed to investigate the void closure in large continuous casting billet during multi-pass stretching process. The wide die heavy blow forging (WHF) method which has been proved to be an effective method to eliminate void defects was adapted during the stretching process. Then, the stretching processes of various sizes of billets which contained different kinds of void defects were simulated. The closure processes of different kinds of void defects were obtained. The critical forging ratio for large billets from Φ500mm to Φ1000mm was obtained as 2.40. In addition, the void closure evaluation index is analyzed, and the critical value for the closure of all voids is 0.87. The work in this paper is verified by actual production, which illustrates that the simulation results and the proposed criterion in this research are reliable. [ABSTRACT FROM AUTHOR]

This paper is devoted to the development of technological process of production of magnesium alloy tubes by laser dieless drawing process. The purpose of the paper is the development and verification of the FEM code for simulation of LDD process and the study of main regularities of this process for magnesium alloy tubes. The problems of forecasting the geometric dimensions of the tube and the possibility of the crack of the material were considered.. The developed FEM code takes into account the three-dimensional deformation of the material, thermal processes, laser heating, the mechanical properties of the material and process parameters. Calibration of the model included the definition of the absorption coefficient, which determines the efficiency of laser heating. For this purpose the experimental analysis of the temperature distribution during the process was made. In laboratory conditions the experiment of laser dieless drawing of tube from AZ31 alloy was performed with the initial outside diameter of 5 mm and a wall thickness of 1 mm. In the experiment the tube surface was covered with a graphite paint to increase the absorption coefficient. The value of absorption coefficient was determined by the inverse analysis and was equal to 0.12. The calculated results were used for producing tube in laboratory. As a result, a good correspondence of geometrical dimensions of the final tube with the calculated values was achieved. [ABSTRACT FROM AUTHOR]

This paper intends to study an effect of burnishing and annealing on static recrystallization. The result is expected to be used for a new technology to control only material surface microstructure in a steel plate. In this process, the stored strain energy by burnishing and the thermal energy by annealing lead to static recrystallization and grain growth in a material, which improve the microstructure of the material. In this paper, roller burnishing is employed to introduce the shear strain into the surface of the pure iron sheet. And effects of burnishing and annealing on static recrystallization in the finished surface layer are investigated utilizing Electron Back Scattering Diffraction (EBSD) analysis technique. The generation of shear deformation was confirmed by Kernel Average Misorientation (KAM) values at the surface layer. By conducting a series of the annealing and EBSD analyses, the static recrystallization process is observed. Since enough strain energy is accumulated by the burnishing in a specimen with large shear deformation zone, the static recrystallization occurs on the burnished surface preferentially after the annealing. [ABSTRACT FROM AUTHOR]

Stamping is one of the most widely used sheet metal forming processes. Esthetics and durability of the deformed products are limited by defects in the form of strain localization, grooves or cracks. Forming limits, e. g. in form of forming limit curve (FLC), help to avoid above-mentioned defects in the sheet metal during forming. Besides the common steel sheets for deep drawing processes, e.g. DC04, components can also be made of metal with specified strength and chemical resistance properties. One of such materials is titanium sheet. In this paper, FLC for GR1 titanium sheet will be presented. It was obtained by means of a new author’s method named as ALSAD (Analysis of Laser Speckle Activity Differences). So far, applied methods of FLC determination have been mainly based on the measurement of the strain distribution in the area of the created groove, deformation gradient and deformation speed. For this reason, detection of strain localization has been dependent on the strain measurement method. The ALSAD, based on laser speckle phenomenon allows detection of defects initiation on the sample surface independently of the strain distribution measurement and it allows, for example, to relate a moment of defect initiation directly to the sample height or forces occurring in the process. In this paper strain values for strain localization, grooves and cracks for GR1 titanium sheet will be shown. Obtained results show good formability of this material, which was verified by means of 3D digital microscope. Such results allow tracing precisely the formation of the defects starting from strain localization up to the crack appearance, which would be helpful for advanced numerical simulations. [ABSTRACT FROM AUTHOR]

Sandwich materials offer high stiffness in combination with small weight. Functional integration allows for additional active and passive functionalities. The paper deals with sandwich materials with sensor and actuator functionality using integrated piezoceramics. The challenges in production are examined in the paper by experiments and numerical simulation. In order to enable the sandwich material for forming, the adhesive properties are highly significant. An appropriate process chain is developed for manufacturing a semi-finished part with integrated piezoceramics which is suitable for forming. [ABSTRACT FROM AUTHOR]

Due to the special characteristics of metal forming processes (i.e., large deformations, complex nonlinear, etc.), finite element method (FEM) often encounters the mesh distortion problem in simulating large and severe deformation metal forming processes. Once meshes become severely distorted, the whole simulation process cannot be continued unless the remeshing is used. Nevertheless, remeshing usually leads to not only the deterioration of computational precision but also the increase of time-consuming. To solve the problem, a meshless method known as natural element method (NEM) is introduced to analyze metal forming processes in the paper. The shape function of NEM is constructed by employing the natural neighbor interpolation method, and it has the high accuracy of the approximation. In addition, because the shape function possesses the Kronecker δ property like the FEM, the essential boundary conditions can be imposed directly. Therefore, the paper combines NEM with rigid/visco-plastic flow theory and applies it to simulate metal forming processes. Furthermore, a numerical analysis procedure is developed. A numerical example of metal forming processes is analyzed. The validity of the numerical simulation program is evaluated by comparing simulation results with those obtained by rigid/visco-plastic finite element method. [ABSTRACT FROM AUTHOR]

Radial-axial ring rolling is the most important production process for seamless rings. One of the most occurring process errors is the climbing of a ring in the radial rolling gap. With the conventional sensors of a radial-axial ring rolling machine, it has not yet been possible to detect a ring’s climbing in any way. For this purpose, an image processing system was installed at the radial-axial ring rolling machine of the LPS (Chair of Production Systems) which particularly records the side of a ring in the radial rolling gap. This paper proves the basic measuring capability of this intelligent image processing system in the rather difficult setting and presents different steps and experiments chosen to give reliable information on the system’s measurement accuracy. Furthermore the used algorithm to detect the climbing height of rings is presented and the degree of repeatability gets examined and evaluated. Once it is proven that the system delivers reliable results, this work uses different parameters based on the state of the art to affect the climbing of a ring. The intensity with which these parameters affect a ring’s climbing is tested in a fractional factorial design. This knowledge is used to design rolling strategies which avoid a climbing of the ring. Based on these strategies, this work introduces first experiments with static parameters during the entire rolling process. This paper shows the necessary steps and the ways these are realized to implement an image processing system to determine a ring’s climbing height. This finally serves to implement an automated system to avoid a ring’s climbing at an early stage in radial-axial ring rolling. [ABSTRACT FROM AUTHOR]

Shear forming is an incremental cold forming process. It transforms 2D plates into 3D structures commonly consisting of conical geometry. Roller(s) push the blank onto a cone-shaped mandrel, resulting in a decrease of the initial thickness. The shear forming process has diverse advantages, such as improved material utilisation, enhanced product characteristics, good surface finish, consistent geometric control and reduced production costs. Shear forming has potential applications in a wide range of conical geometries used within advanced aerospace structures, which are currently manufactured from bulk forgings with high associated machining costs. Research findings related to shear forming have been published over the past two decades, however, important remaining questions have still to be answered, with this paper addressing one such gap associated with the material deformation mechanism. Several studies have demonstrated the impact of key process variables on the final geometry and surface roughness, such as the feeds, roller nose radius and mandrel/roller offset. Although the material outputs are essential, as they link directly with the mechanical properties of the final components, the microstructure and texture of the material after shear forming have rarely been studied. Achieving a greater understanding in this area could reduce the reliance upon mechanical testing to validate the process and ease the exploitation route of the technology into advanced aerospace applications. Firstly, this paper presents the principle of shear forming and its related terminology. Then, a brief overview of the shear forming process including its history and origin is given. The areas of focus are a selection of the main variables encountered within this process which could impact the final properties. The generation of local stresses due to deviations from the sine law, the angle variations, and forces required during the forming operation are also considered. This is explored in the context of forming 304L stainless steel plates. This paper is written based upon experiments which observed a 52% thickness reduction using one roller. Scanning Electron Microscopy (SEM), Electron BackScatter Diffraction (EBSD) and hardness testing were utilised to characterise the shear formed material. The initial heterogeneous microstructure with relatively equiaxed grains evolved into a microstructure with elongated grains along with shear bands. A texture analysis revealed a simple shear mechanism of deformation, and theoretical and experimental shears were found to match. Identifying the mechanism of deformation was the first step to a better understanding of the effect imparted by the shear forming process on the material. Further studies will look at the impact of the key process variables on both the microstructure and texture as well as heat treatment optimisation. [ABSTRACT FROM AUTHOR]

Mechanical joining processes provide various advantages over conventional fusion welding of metallic components such as shorter cycle times, little or no heat input and reduced need for subsequent surface finishing operations. Several investigations in the past have shown that joints between tubes and sheets or plates can be manufactured by upsetting operations. Under axial compression, the tube develops a plastic instability in form of bulge. In-between two such bulges, a force and form fit to sheet material can be created. Previous work concentrated on forming fully developed bulges, i.e., at the end of the bulging process, both hinges of the bulge are in contact. This paper presents a numerical and experimental study aiming at optimizing the bulge shape to increase the bearable limit loads. Two new bulge designs are investigated, an ‘arrow bulge’ and a ‘wave bulge’. The paper details the results of FE-simulations of the bulge shapes under bending and torsion loads. Forming tools were designed and both bulge shapes were produced experimentally. The results show that the material flow under compressive plastic instability can be controlled and that the resulting bulge shapes yield improved strength in various load cases. [ABSTRACT FROM AUTHOR]

The friction spinning process is an innovative incremental forming technique that enables high degree forming operations in the field of tube and sheet metal forming. The integration of friction-sub-processes from friction welding into a metal spinning process permits the self-induced heat generation of the part. Compared with conventional spinning processes, this in-process heat treatment allows the extension of existing forming limits and also the production of more complex geometries from tubes and sheets. Additionally, the material/part properties like hardness, stress, grain structure/orientation, surface conditions etc. can be adjusted in a defined way during the forming process. This can be achieved through the use of appropriate process parameter settings in combination with the degree of deformation. The choice of feed rate, relative motion and friction coefficient gives rise to a defined temperature profile and allows the use of specific process control strategies to produce parts with different material properties in different areas. Thus, the production of a new class of individually adjustable components is enabled. For example, these parts could be designed for load optimized applications like complex hollow parts in aluminium or steel. This paper presents the results of the grain structure investigations and clarifies the influence of different process parameters in aluminium tube processing especially during flange forming operations. A flange will thus be formed from an aluminium tube and, using to further tool systems, the wall thickness of the flange can be adjusted in a defined manner. The paper addresses the influence of the significant process parameters (feed rate, rotation speed, temperature, wall thickness reduction and forming time) on the grain structure refine-ment during flange forming. In addition, the impact of the material properties (hardness, stress/strain behaviour) will be considered. [ABSTRACT FROM AUTHOR]

This paper presents a new numerical analysis method for cold pilger rolling which leads to compatible improvement of analysis accuracy and shortening calculation time. In pilger rolling, a raw tube is rolled by dozens of “shots”, which is repetitive reciprocating movement of caliber rolls. Previous studies carried out only one shot analysis for shortening calculation time. However, these studies cannot consider an accumulated plastic strain by the dozens of “shots”. The proposed method is composed of two models. In the first preliminary model, the accumulated plastic strain is evaluated based on the strain increment between the two continuous shots. The second main model is given the pre-strain calculated by the preliminary model, and analyses of shots are conducted until tool load becomes stable. This paper clarified the number of shots until stable tool load was obtained in the proposed model. In addition, the proposed model can improve analysis accuracy of the rolling load while shortening calculation time by 60 %, compared with the conventional models of dozen of shots. [ABSTRACT FROM AUTHOR]

This paper presents a generalization of the popular approach of Orowan for calculating the roll pressure in flat rolling of homogeneous strips on three-layer sheets. In contrast to the original approach, the approach for three-layer sheets requires the analysis of the velocity field for determining the shape of the bi-material interface. The present paper employs the solution for compression of a three-layer block of rigid perfectly plastic materials for finding the through thickness distribution of stress and velocity. It follows from this solution that the regime of friction at the bi-material interface (sticking or sliding) depends on the ratio of yield stresses of two materials, the ratio of the current thicknesses of two materials and the friction factor at the friction surface between the strip and rolls. On the other hand, the regime of friction at the bi-material interface controls the shape of this interface. [ABSTRACT FROM AUTHOR]

The present-day methods of numerical simulation offer a great variety of options for optimizing metal forming processes. Although it is possible to simulate complex forming processes, the results are typically available only as 2D projections on screens. Some forming processes have reached a level of complexity beyond the level of spatial sense, which makes it necessary to use physical 3D representations to develop a deeper understanding of the material flow, microstructural processes, process and design limits, or to design the required tooling. Physical 3D models can be produced in a short amount of time using 3D printing, and indexed with a wide range of colors. In this paper, the additive manufacturing of 3D color models based on simulation results are explored by means of examples from metal forming. Different 3D-printing processes are compared on the basis of quality as well as technical and economic criteria. Other examples from the fields joining by upset-bulging of tubes and microstructure simulation are also analyzed. This paper discusses the possibilities offered by the rapid progress and wide availability of 3D printers for the design and optimization of complex metal forming processes. [ABSTRACT FROM AUTHOR]