Force and Microstructure Variation of SLM Prepared AlMgSc Samples during Three-Point Bending

Lightweight parts manufactured by metal selective laser melting (SLM) are widely applied in machinery industries because of their high specific strength, good energy absorption effect, and complex shape that are difficult to form by mechanical machining. These samples often serve in three-dimensional stress states. However, previous publications mainly focused on the unidirectional tensile/compressive properties of the samples. In this paper, AlMgSc samples with different geometric parameters were prepared by the SLM process, and the variation of force and microstructure during three-point bending were systematically investigated. The results demonstrate that the deformation resistance of these samples has good continuity without mutation in bending, even for brittle materials; the bending force-displacement curves exhibit representative variation stages during the entire bending process; the equivalent bending strength deduced from free bending formula is not applicable when compactability is less than 67%. The variations of grain orientation and size of the three representative bending layers also show regularity.

Transverse energy confinement and resonance suppression in SAW resonators using low-cut lithium tantalate

This paper discusses the applicability of double busbar design to surface acoustic wave (SAW) devices employing low-cut lithium tantalate (LT) with multi-layered structure. This design offers good energy confinement, scattering loss suppression and transverse mode suppression for a wide frequency range. In addition, the effectiveness of manipulating the slowness curve shape for transverse mode suppression is demonstrated. First, three different lateral edge designs are applied to the layered SAW configuration on low-cut LT, and their performances are compared using the periodic 3-dimensional finite-element method powered by the hierarchical cascading technique. Then, the discussion is extended to influence of the SAW slowness shape to the transverse mode suppression.

Intelligent Electromagnetic Sensors for Non-Invasive Trojan Detection

Rapid growth of sensors and the Internet of Things is transforming society, the economy and the quality of life. Many devices at the extreme edge collect and transmit sensitive information wirelessly for remote computing. The device behavior can be monitored through side-channel emissions, including power consumption and electromagnetic (EM) emissions. This study presents a holistic self-testing approach incorporating nanoscale EM sensing devices and an energy-efficient learning module to detect security threats and malicious attacks directly at the front-end sensors. The built-in threat detection approach using the intelligent EM sensors distributed on the power lines is developed to detect abnormal data activities without degrading the performance while achieving good energy efficiency. The minimal usage of energy and space can allow the energy-constrained wireless devices to have an on-chip detection system to predict malicious attacks rapidly in the front line.

Conclusions and Policy Implications

The work presented in this volume is a compilation of research highlights that represent numerous studies carried out by researchers within the Energy Governance Work Package (WP4) of the Swiss Competence Center for Energy Research, Society and Transition (SCCER CREST). As our Introduction has illustrated in detail, these researchers worked together under common scientific interests in providing recommendations to overcome governance challenges in the course of the energy transition in Switzerland. Despite the variety of disciplines involved in this group, the conscious decision not to over-precise the shared notion of governance has successfully guided this challenging but fruitful four-year collaboration. These findings should help identify basic designs and structural principles of good energy governance, i.e., governance that is more effective, efficient, and transparent. The conclusion chapter summarizes these guiding principles and further challenges that emerged from our research in the context of Swiss energy governance.

Silicon Drift Detectors’ Spectroscopic Response during the SIDDHARTA-2 Kaonic Helium Run at the DAΦNE Collider

A large-area silicon drift detectors (SDDs) system has been developed by the SIDDHARTA-2 collaboration for high precision light kaonic atom X-ray spectroscopy at the DAΦNE collider of Istituto Nazionale di Fisica Nucleare—Laboratori Nazionali di Frascati. The SDDs’ geometry and electric field configuration, combined with their read-out electronics, make these devices suitable for performing high precision light kaonic atom spectroscopy measurements in the background of the DAΦNE collider. This work presents the spectroscopic response of the SDDs system during the first exotic atoms run of SIDDHARTA-2 with kaonic helium, a preliminary to the kaonic deuterium data taking campaign. The SIDDHARTA-2 spectroscopic system has good energy resolution and a 2 μs timing window which rejects the asynchronous events, scaling the background by a factor of 10−5. The results obtained for the first exotic atoms run of SIDDHARTA-2 prove this system to be ready to perform the challenging kaonic deuterium measurement.

Experimental and Finite Element Analysis of External ALC Panel Steel Frames with New Semi-Rigid Connector

In this paper, a new ALC panel connector was proposed. It has a good engineering economy and high fault tolerance. A quasistatic loading experiment was carried out to verify the feasibility of the external ALC panel steel frame under seismic loading. The test phenomena, hysteretic curve, skeleton curve, stiffness degradation, and energy dissipation of two sets of full-scale specimens were analyzed and discussed. Moreover, the simulation of pendulous Z-panel connectors with different thicknesses was carried out using ABAQUS software. The comparison reveals that the semi-rigid connection has a full hysteresis curve, good energy dissipation capacity, and a 15% increase in peak load capacity. Finally, similar results for different thicknesses in the use of pendulous Z-panel connectors reveal that using the 6 mm connector may be the most economical solution for engineering.

Research on seismic performance of prefabricated concrete-filled steel tubular frame joints

PurposeConcrete-filled steel tube structures are widely used for their high bearing capacity, good plasticity, good fire resistance and optimal seismic performance. In order to give full play to the advantages of concrete-filled steel tube, this paper proposes a prefabricated concrete-filled steel tube frame joint.Design/methodology/approachThe concrete-filled steel tube column and beam are connected by high-strength bolted end-plate, and the steel bars in the concrete beam are welded vertically with the end-plates through the enlarged pier head. In addition, the finite element software ABAQUS is used numerically to study the seismic performance of the structure.FindingsThe ductility coefficient of the joint is in 1.72–6.82, and greater than 2.26 as a whole. The equivalent viscous damping coefficient of the joint is 0.13–3.03, indicating that the structure has good energy dissipation capacity.Originality/valueThe structure is convenient for construction and overcomes the shortcomings of the previous on-site welding and on-site concrete pouring. The high-strength bolted end-plate connection can effectively transfer the load, and each component can give play to its material characteristics.

Simple Nomographs for Assessing Lighting in Urban Environments

<p>Incorporating different technologies and lighting techniques in the illumination of structures has allowed us to portray fantastic night time vistas of our cities. However, the success of the selected technique or technology is frequently assessed based on what the lighting does to the overall environment. At present, it is a common practice for the client or architect to require an illuminated night view of the building. These views are often used as part of the marketing strategy to promote building facilities. Alternatively, on a large scale, they can help promote buildings as city icons. The illumination of building facades requires an appropriate selection of one or more floodlighting techniques and light sources to achieve the desired lighting effect. This selection, often driven by lighting standards and design considerations, will heavily influence the way in which that the overall lit environment will be portrayed at the end of the lighting project. Currently, tables and floodlighting techniques exist to select the recommended quantity of light and the most suitable luminaire arrangement to illuminate a façade. There is however, no direct indication of how the surrounding area will be affected when the recommended light levels are achieved on the façade. Despite the increased importance of the floodlighting technique, the design of a good illuminated façade does not have a tradition on which to base parameters for the lighting design. This is often individually approached based on the knowledge, understanding, experience and proficiency of the lighting designer. Considering the diversity of buildings in urban environments, the selection of uncoordinated design parameters could have a significant impact on the area where the building is located. This could affect the occupant comfort and good energy management. In light of the considerations presented above, it is only with a methodological approach that the lighting designer will be able to provide predictable and consistent results in any number of different situations. This presents an opportunity to develop a methodology to identify whether a façade is over-lit or if the proposed lighting solution is adequate for the area where it is situated. The proposed methodology will provide a tool to estimate the potential lighting results while considering the effect on the overall environment where the building is located. When a façade is illuminated, the degree of the light experienced at street level is very much dependent upon the reflected light from the primary lit surface. This allows for a relationship based on light levels received at the surrounding street and the average illuminance level achieved on the façade. Considering that lighting parameters such as lamp lumen output, the reflective qualities of the surface and the luminaire position are intrinsically connected to light reflections, a mathematical expression is formulated to link the relationship mentioned above with lighting design parameters through a set of nomographs. This method provides a good foundation to systematically approach lighting designs with a comprehensive procedure to link the practical lighting considerations with the lighting requirements that will provide occupant comfort and good energy management. This method will help designers to compare different lighting alternatives by analysing the lighting impact of different lit facade options at the very early stage of the lighting design process.</p>

Simple Nomographs for Assessing Lighting in Urban Environments

<p>Incorporating different technologies and lighting techniques in the illumination of structures has allowed us to portray fantastic night time vistas of our cities. However, the success of the selected technique or technology is frequently assessed based on what the lighting does to the overall environment. At present, it is a common practice for the client or architect to require an illuminated night view of the building. These views are often used as part of the marketing strategy to promote building facilities. Alternatively, on a large scale, they can help promote buildings as city icons. The illumination of building facades requires an appropriate selection of one or more floodlighting techniques and light sources to achieve the desired lighting effect. This selection, often driven by lighting standards and design considerations, will heavily influence the way in which that the overall lit environment will be portrayed at the end of the lighting project. Currently, tables and floodlighting techniques exist to select the recommended quantity of light and the most suitable luminaire arrangement to illuminate a façade. There is however, no direct indication of how the surrounding area will be affected when the recommended light levels are achieved on the façade. Despite the increased importance of the floodlighting technique, the design of a good illuminated façade does not have a tradition on which to base parameters for the lighting design. This is often individually approached based on the knowledge, understanding, experience and proficiency of the lighting designer. Considering the diversity of buildings in urban environments, the selection of uncoordinated design parameters could have a significant impact on the area where the building is located. This could affect the occupant comfort and good energy management. In light of the considerations presented above, it is only with a methodological approach that the lighting designer will be able to provide predictable and consistent results in any number of different situations. This presents an opportunity to develop a methodology to identify whether a façade is over-lit or if the proposed lighting solution is adequate for the area where it is situated. The proposed methodology will provide a tool to estimate the potential lighting results while considering the effect on the overall environment where the building is located. When a façade is illuminated, the degree of the light experienced at street level is very much dependent upon the reflected light from the primary lit surface. This allows for a relationship based on light levels received at the surrounding street and the average illuminance level achieved on the façade. Considering that lighting parameters such as lamp lumen output, the reflective qualities of the surface and the luminaire position are intrinsically connected to light reflections, a mathematical expression is formulated to link the relationship mentioned above with lighting design parameters through a set of nomographs. This method provides a good foundation to systematically approach lighting designs with a comprehensive procedure to link the practical lighting considerations with the lighting requirements that will provide occupant comfort and good energy management. This method will help designers to compare different lighting alternatives by analysing the lighting impact of different lit facade options at the very early stage of the lighting design process.</p>

Experimental testing of the effectiveness of novel hydrocyclones for separation of impurities in biofuels

This paper investigates the potential sources of renewable energy, in particular biofuels. Biofuels tend to contain multiple harmful impurities that need to be separated if the biofuel is to have good energy performance, and the systems that run on it to produce electricity or heat are to operate more reliably. The paper discusses use of hydrocyclones as the most productive and reliable biofuel purification method. It dwells upon the factors that negatively affect separation of mixtures in a hydrocyclone, which are attributable to the complex hydrodynamics of the flow in such a unit. In order to eliminate these factors, the authors hereof have developed two hydrocyclone designs. An experimental test bench was designed and made to test these designs. Parts of the units were 3D printed from an environmentally friendly material. For testing, we used a biodiesel made from waste cooking oil with an impurity content of 23%. Experiments showed a maximum separation rate of 94.2%. The proposed solutions did improve the effectiveness of biodiesel mixture separation. These designs can be effectively used to separate non-homogeneous mixtures.