Finish Layer Research Articles

Precious walls built in indoor environments inspected numerically and experimentally within long-wave infrared (LWIR) and radio regions

A thermographic non-destructive inspection conducted during the winter season on precious walls confined to an indoor environment (Baiocco room, L’Aquila, Italy) is illustrated herein. The use of a heat conveyor ad hoc selected has produced a particular benefit in terms of defect detection after the application of advanced algorithms because the thermal stimulus coming from an air heater hit the finishing layer under a laminar flow regime. Thermocouples registered both the heat-up and cool-down phases to confirm the numerical simulations conducted via Comsol Multiphysics® software. The results obtained by applying the principal component thermography (PCT) technique to raw data registered in the time domain were a priori studied through thermographic simulations. Defects were modelled on the basis of results already shown in a previous work centred on the Baiocco room, too. A comparison between the results obtained from PCT and the innovative sparse principal component thermography (SPCT) technique was also added to the discussion. The SPCT results show their benefits above all when they are supplemented with ground-penetrating radar results. The experimental analyses were conducted on a multi-layer wall called thereafter rectangular portal, in which the instant thermal conductance was experimentally measured. Subsurface cracks were detected using a long heating-up phase. This procedure is preferred by the Monuments and Fine Arts Department with respect to the use of flash lamps. Indeed, short energy pulses should be avoided on finishing layers having low emissivity values because producing spurious reflections affecting the thermographic results. A discussion on this point is also provided. On the basis of the data analysis, it is possible to say that the thermal waves should arrive at the interface between the masonry and its top layer in order to obtain a clear thermal map of the defects present at different depths. As shown, this goal can be realized through a smart solution based on: (a) the inverse knowledge of the aedicula via thermal analyses, (b) the best mesh to be selected for the numerical model, and (c) the optimal type of thermal stress to be delivered to the object under inspection.

Experimental investigation on surface characteristics in Electrical Discharge Surface Grinding (EDSG) of 6061Al/Al2O3p 10% composite

ABSTRACTThis article reports the results of an experimental study conducted to understand the mechanism of material removal in electrical discharge surface grinding (EDSG) process while machining 6061Al/Al2O3p 10% composite by composite tool electrode. Electrical discharge surface grinding (EDSG) is one of the variants of hybrid machining processes that involve combined operation of conventional grinding and spark erosion machining. In the study the effect of electrical and grinding parameters such as peak current, polarity, pulse-on time, pulse-off time, speed, abrasive particle size (APS) and abrasive particle concentration (APC) has been investigated. Surface characteristics like surface finish, surface topography and recast layer have been studied through scanning electron microscope (SEM) and electrodispersive X-ray spectroscopy (EDS). The experimental results indicate that the effects of peak current, tool polarity, speed and APS are more pronounced as compared to other machining parameters. The outcome of the study further confirms considerable improvement in surface finish at negative tool polarity as compared to the positive polarity of the tool electrode. The results of surface roughness in EDSG have also been compared with EDM. The microstructural and morphological analysis of machined surfaces during EDSG confirmed the effective removal of particulates from the composite workpiece without rupturing the base matrix. The depth of recast layer and heat affected zone is found to be more in case of positive tool polarity as compared to negative tool polarity.

Development of a Durable Vapor Phase Deposited Superhydrophobic Coating for Steam Cycle Power Generation Condenser Tubes

Condenser performance benefits afforded by dropwise condensation have long been unattainable in steam cycle power plant condensers due to the unavailability of durable and long-lasting hydrophobic surface treatments. However, recent work in superhydrophobic coating technology shows promise that durable coatings, appropriate for use on condenser tubes in steam cycle power generation systems, may soon become a reality. This work presents a nanoscale, vapor phase deposited superhydrophobic coating with improved durability comprised of several layers of rough alumina nanoparticles and catalyzed silica with a finishing layer of perfluorinated silane. This coating was applied to solid, hemicylindrical test surfaces fabricated from several common condenser tube materials used in power generation system condensers: Titanium, Admiralty brass, Cupronickel, and Sea Cure stainless steel as well as 304 stainless steel stock. The development evolution of the coating and its effect on condensation behavior on the above materials are presented. Results show that the performance enhancement, measured in rate of heat transfer spikes corresponding to condensate roll-off events, was best for the titanium surface, which produced 64% more events than the next most active material when coated using the most durable surface treatment tested in this work.

Defect characterization, diagnosis and repair of wood flooring based on a field survey

A statistical characterization of defects in 35 buildings and 98 wood floorings (softwood and hardwood floors, and laminated and engineered wood floors), their diagnostic methods and repair solutions is presented. An expert system for inspecting wood flooring, comprising the classification of defects, their most probable causes, diagnostic methods and repair techniques, was used. Results include age, affected area, severity and frequency of defects and their main causes, as well as appropriate diagnostic methods, preventive and curative repair solutions most prescribed and the most significant correlations. Scratches were detected in more than five sixths of the sample, highly associated with exterior mechanical actions, and with an inadequate finishing layer. Wearing of the finishing layer was detected in a quarter of the inspected floorings. Accordingly, the application of a suitable finishing layer and, alternatively, its replacement are the most prescribed repair techniques.

Evaluation of conventional standards of nickel electroplating process for surface finish layer of AISI 316L stainless steel using copper rod bars as cathode

Nickel electroplating process at UD Barito Electroplating is a modern methodology installed in an open complex environment and at controlled temperature with trust consideration of specimen composition. The evaluation of process at UD Barito has been undertaken by considering Stainless steel AISI 316L as specimen through a conventional nickel electroplating process. This paper presents the proper scientifically tool to be used at UD Barito in order to meet the time required and the surface layer quality of the electroplated product. The use of ultrasonic to replace air compressor assembly does not cause any harm to the surface finish smoothness and the quality of plated specimen given that the process is conventional. Concerning the process of 10 min compared up to 15 min of the process at UD Barito; showed the facility of ultrasonic assisted the electroplating process. This process is also a useful method in maintenance activities for surface cleaning and for product surface-layer quality enhancement through the coating process. From the data analyzed, the specimen has a hydrogen embrittlement rate range between 20 to 65% of Rockwell scale HRC52.

Energy saving concept development for the MORE-CONNECT pilot energy renovation of apartment blocks in Denmark

The European Horizon2020 project MORE-CONNECT on prefabricated deep energy renovation of residential dwellings also covers pilot demonstration projects, which are to be carried out in six of the participating countries. For each country a unique, climate specific concept development analysis is carried out. The concept development follows the MORE-CONNECT methodology and thus aims towards a Zero Energy Building (ZEB) level or if cost limitations require nearly Zero Energy Building (nZEB). For the Danish situation, this means that the energy requirement for heating purpose is to be brought down from around 100 kWh/m² to below 20 kWh/m². As the pilot project has not yet been identified, concept development calculations has been conducted for a generic building. The technologies to be considered for this energy renovation are: Insulation of the façade, insulation of the roof, low-energy windows, heat-recovery ventilation, solar domestic hot water and a PV-system. Within the MORE-CONNECT two technologies are under development in Denmark. The first is a new PV-roof solution in which the PV-cells are fully integrated in the roofing elements. This PV-roof can be fitted into any roof surface shape. It can also be constructed as a PVT-roof connected to a heat pump for heating purposes. The second technology under development is 3-D finishing of a new layer of façade insulation by an industry robot. When an insulation layer has been placed on any given façade a finishing layer of plaster can be added and finished with any desired patterns or painting.The paper presents the present stage of the concept development work and is a continuation of the first concept development analysis presented at the SBE conference in Tallinn in 2016.

Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete

Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience.

Assessment of the Temperature of Waterproofing Membrane When A Recycled Crushed Glass Finish Layer Is Used On Flat Roofs to Protect From Sun Radiance

The aim of this research was to determine the impact of the use of a recycled crushed glass finish coat on flat roofs to reduce the transmission of heat from sun radiance to indoor spaces in the buildings. This research forms part of previous studies carried out by LiTa on the application of cool roof products to reduce the energy required for air-conditioning inside buildings.Many flat roofs are finished with crushed stone aggregates of natural or artificial origin. The use of recycled crushed glass as a cool roof is potentially a double opportunity to reduce the environmental footprint: it is a recycled material and it may reduce air-conditioning demand. In order to evaluate the real efficiency of recycled crushed glass, this research compared the results with other technical alternatives that are generally applied in real conditions.

Ambient Characterization of Synthetic Fibers by Laser Ablation Electrospray Ionization Mass Spectrometry.

Direct analysis of synthetic fibers under ambient conditions is highly desired to identify the polymer, the finishes applied and irregularities that may compromise its performance and value. In this paper, laser ablation electrospray ionization ion mobility time-of-flight mass spectrometry (LAESI-IMS-TOF-MS) was used for the analysis of synthetic polymers and fibers. The key to this analysis was the absorption of laser light by aliphatic and aromatic nitrogen functionalities in the polymers. Analysis of polyamide (PA) 6, 46, 66, and 12 pellets and PA 6, 66, polyaramid and M5 fibers yielded characteristic fragment ions without any sample pretreatment, enabling their unambiguous identification. Synthetic fibers are, in addition, commonly covered with a surface layer for improved adhesion and processing. The same setup, but operated in a transient infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mode, allowed the detailed characterization of the fiber finish layer and the underlying polymer. Differences in finish layer distribution may cause variations in local properties of synthetic fibers. Here we also show the feasibility of mass spectrometry imaging (MSI) of the distribution of a finish layer on the synthetic fiber and the successful detection of local surface defects.

A short note on the archaeometric study of two sculptures in the Gabinetto Segreto of Naples National Archeological Museum: the ‘Pan and the She-Goat’ group and the ‘Bikini Venus’

Presented here are the results of an archeological and archaeometric study of two famous marble sculptures displayed in the Gabinetto Segreto of the National Archeological Museum of Naples: the “Pan and She-Goat” group from the Villa of the Papyri at Herculaneum and the statue of the “Bikini Venus” leaning on a statuette of Priapus from the House of Julia Felix in Pompeii. This study offers some art historical observations about the sculptures and the first minero-petrographic (polarizing microscopy on thin section and x-ray diffraction on powders) and isotopic (C and O stable isotope ratio) investigation of their marble types. The results indicate that the “Pan and She-Goat” group employed the statuary white Carrara variety, while the Parian lychnites was used for the “Bikini Venus”. Analyses proved also that the red finishing layer present on the latter statue is composed by sandyx.

On the Modeling, Characterization, and Analysis of the Current Distribution in PCB Transmission Lines With Surface Finishes

Due to manufacturing requirements, surface finishes have become a necessity in printed circuit board design. These finishes have significant effects on the RF performance of the transmission lines. In this paper, a filament modeling approach is used to model skin, proximity, and surface roughness effects in transmission lines with surface finishes up to 70 GHz. The approach shows a high accuracy compared with measurements. The model also gives an insight into how the current distributes itself by showing the frequency dependent proportion of the current that flows in each surface finish layer. In the case of NiP–Au or Ni–Au surface finishes, current migrates increasingly into gold at high frequencies and reaches a maximum in the Ni or NiP at around 3.5 GHz, and then declines. The distribution of the current in different materials can also be explained as the decay of an electromagnetic wave at the surface of the conductor. This approach shows that the evanescent wave in the cross section of the conductor can be analyzed as analog to a transmission–reflection problem, what we will call the surface finish effect. This effect brings into question the accuracy of the traditional skin-depth value, $\delta $ , and the models that depend on it, such as most surface roughness correction factors, for structures where different metals are layered in thicknesses that are not much larger than $\delta $ .

An adaption of the Archard equation for electrical contacts with thin coatings

For the wear resistance of sliding contacts geometry, contact force and coating system are strong factors of influence. In this paper a mathematical description of the available wear volume of frequently used hemispherical and U-type geometries is given. Smooth surface layers are worn abrasively and adhesively. In the first stage the flat geometry becomes ploughed, in the second stage adhesive wear dominates. The hardness of the surface depends on the substrate, underlayer and finish layer. A wear model based on a flat distribution of the Archard work density with consideration of the abrasive wear and the depth depending hardness for hemispherical and U-type geometries is derived. With theoretical and experimental methods an optimization of the Archard equation is discussed.

Silicon-on-Insulator Photodiode on Micro-Hotplate Platform With Improved Responsivity and High-Temperature Application

This paper reports on the performance of a silicon-on-insulator photodiode suspended on a dielectric membrane. The micro-hotplate platform consists of a micro-heater and a thin-film lateral P+/P−/N+ (PIN) photodiode. Without optimizing the multilayer stack on top of the PIN diode, experimental responsivities of the suspended photodiodes at room temperature (RT) are 0.02–0.06/W within the visible and near the IR light range, under a reverse bias of −2 V. Up to $2.5\times $ , responsivity improvement has been achieved with regard to the diodes on the substrate thanks to reflection from the gold finish layer of the device package acting as a bottom mirror. Optimizing the layer stack above the diode, the responsivity of the on-membrane device can be theoretically improved up to 0.09–0.11 A/W within 450–520-nm wavelength range. Measured from RT up to 200 °C, the photodiodes on membrane continuously show an improved optical response under high-power LED illumination. Assisted by the micro-heater as heat source, the suspended photodiode can work stably up to 200 °C with in situ temperature sensing and control, which makes it highly suitable and attractive for high-temperature application. Full 2-D ATLAS device simulations have been comprehensively performed to investigate the optical and electrical characteristics. Very good agreement has been achieved between the numerical simulations and the experimental data.

Economic Design of Reinforced Concrete Conical Shells

This work presents economic reinforced concrete conical shells dimensions and reinforcement in order to save time and efforts of the designers who aim to design conical shells economically from 5m to 20m spans. In addition to that, this work presents the economic shell raise (hec) vs. span (D) formula that gives lowest construction cost. The considered loads are the own weight of the shell body, external finishing by glazed brick and internal finishing layer of gypsum plaster (juss). As well as the dead load, live load is considered too. A computer program is written in the Visual Basic programming language. This computer program consists of two parts. The first part is the linear analysis using the membrane theory formulas to get the forces at the crown and at the support of the shell. The second part uses Nelder and Mead's minimization method to minimize the total cost formula (objective function). Three types of constrains confine this minimization regarding to strength, buckling and accuracy of the analysis method. The minimization variables are two; shell rise (h) and shell thickness (t). The two parts of the computer program are connected together in a force and cost convergence iterative loop in order to get the dimensions and reinforcement ratios that lead to the minimum cost.

Spectroscopic investigation of Roman decorated plasters by combining FT-IR, micro-Raman and UV-Raman analyses

In this work, the complementary use of Fourier transform infrared (FT-IR) spectroscopy, conventional micro-Raman spectroscopy and UV-Raman scattering proved successful for the characterization of bulk minerals and of a variety of pigments from decorated finishing layers of plasters from a Roman archaeological site known as Villa dei Quintili, a monumental residence located in the south-eastern part of Rome (Italy).The used multi-technique approach provided insights on the pictorial technique, giving information that could be useful for proper restoration.It is worth underlining that the present study represents the first attempt of carrying out UV resonance Raman measurements for analysing cultural heritage materials.

Comparison of hermetic sealing using SAC and SnPb solder for a MEMS pressure sensor

In order to minimize the influence of packaging stress on the signal of MEMS pressure sensors, the pressure inlet can be reduced in footprint and mechanically decoupled from the mechanically moving parts. Moreover, the formation of a hermetic seal between the sensor inlet and an external inlet becomes more challenging as the footprint is reduced. Soldering is a preferred solution as a hermetic seal is achievable despite some surface roughness at the surfaces to be joined. However, the metallization on the MEMS, the solder and the metallization on the external inlet must be carefully matched to assure long term stability; the solder will react quickly with the metal layers deposited on the surfaces during the reflow process and later at a reduced rate during storage and application. The formation of intermetallic compounds (IMC) can catastrophically degrade the integrity of a joint if large amounts of voids are formed or the mechanical compliance significantly reduces as a result of the IMC formation. The metallization alternatives for the MEMS in this case were sputtered TiW/Au and NiCr/Au. The TiW and NiCr are adhesion layers whereas the Au is applied as a wetting layer which is normally fully consumed during the soldering process. A thick layer of plated Au, or a thick layer of plated Ni with a thin surface finish layer of Au, were possible metallization alternatives for the external inlet. Dewetting of solder from TiW is frequently mentioned in literature, but less conclusive work is published about soldering to NiCr/Au [1–3]. In particular, limited work has been published on long term effects of soldering to NiCr/Au surfaces using a SAC solder. In this work TiW and NiCr were compared as adhesion layers. In addition, SAC and SnPb were compared as solder, and Au and Ni/Au were compared as metallization on the external inlet. A total of 10–20 assemblies were prepared for each of 12 tested combinations. Half of the assemblies were exposed to high temperature storage (HTS) for ~300 hours at 130–150 °C. Shear testing and inspection of fracture surfaces and cross sections using light microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were performed for samples

Characterization Of Early Imperial Lacquerware From The Luozhuang Han Tomb, China

This paper focuses on the characterization of materials from fragmented pieces of an imperial lacquer plate in the Luozhuang Han tomb, which dates to the early Western Han dynasty. Various non-invasive and minimally invasive techniques were performed, including optical and electron microscopy, XRF, Raman spectromicroscopy, FT–IR, XRD and THM-Py–GC/MS. The lacquerware pieces consist of a five-layer structure, which includes (from the top): a red pigmented layer, two lacquer finish layers, a ground layer and a canvas/wood foundation layer. The red layer consists of ground cinnabar mixed with urushi. The lacquer finish layers are made of urushi mixed with perilla or tallow tree oil, without any pigment. The ground layer is a mixture of organic materials including urushi, tree oil and amorphous carbon (possibly burned ashes) and inorganic fillers such as quartz, albite and potassium feldspar. Urushi was also identified in the canvas/wood foundation layer. Though highly degraded, the canvas is probably made of hemp (bast fibres). The identification of high concentration of drying oil indicates an intentional addition of oil into the urushi to retard the rate of hardening and to increase gloss.

Innovative cool roofing membrane with integrated phase change materials: Experimental characterization of morphological, thermal and optic-energy behavior

The capability of Phase Change Materials (PCMs) to improve indoor thermal comfort conditions and reduce cooling energy demand when included in building components is widely acknowledged. In particular, the possibility to integrate PCMs in building envelopes for latent heat storage has been largely investigated in the last decades. This study deals with the development and prototyping of an innovative cool polyurethane based membrane with PCMs inclusion for roofing applications. The thermal-optical properties of such membrane are determined through laboratory analyses. Additionally, calorimetry and nanoscale morphological tests are carried out in order to verify the effectiveness of PCM inclusion into the medium and to define the thermal storage/release potential of PCMs with transition points at 25°C and 55°C. The composite membrane showed good workability properties even with high (i.e. 35%) PCM concentration. Optical properties were modified in the superficial layer by PCM inclusion, meaning that a further non-composite finishing layer of polyurethane is required to complete the field application of the new building material. Also, a promising thermal behavior and a consistent and effective increase of phase change enthalpy was registered with increasing PCM concentration within the polyurethane membrane. Therefore, the combination of cool materials and thermal storage effect produced promising results as passive technique for building thermal-energy efficiency, also highlighted by the relatively simple production process of the shape stabilized PCM inclusion.

Hygrothermal Behaviour of Three Internal Retrofit Prototype Solutions

Although the application of internal insulation to existing perimeter walls poses significant challenges in terms of building physics and loss of habitable space, it is sometimes an inevitable choice because of practical or legislative constraints. Innovative solutions are then required to deliver satisfying performances and reduce nuisance to inhabitants of residential buildings in case they are going to remain in their flats during the retrofit works.Three systems for inner thermal retrofitting purposes have been designed and produced as prototypes. Two of them are composed by silica aerogel containing fibrous material: the first one is a rigid flat laminated panel, the second one is a rollable solution with a fabric finishing layer. The third insulating system is a perlite based board with a hydrophobic layer. All the materials composing the retrofit solutions have been characterized by means of laboratory tests in order to measure their main hygrothermal properties. In fact, some parameters are fundamental for determining the hygrothermal performance of the composite systems: thermal conductivity, at dry and wet state (moisture dependant), water vapour diffusion resistance factor, hygroscopic sorption at isotherm condition and water absorption coefficient. All those measured data were necessary for optimizing the solutions, guaranteeing energy efficiency and vapour open layers to systems that are intended for installation on existing walls.

Experimental Thermal Performance Analysis of Building Components Containing Phase Change Material (PCM)

The article presents the results of experimental studies of partitions containing phase change materials. The main objective of the measurements was to determine the actual effectiveness of the used materials and their impact on energy storage capabilities through building partitions. The light partition component containing a finishing layer of organic material undergoing a phase change was the subject of research. The heat flux and temperature distribution on individual component layers were recorded while changing the temperature conditions of the surrounding air. The cycle of temperature changes has been chosen to model the probable conditions inside buildings located on Polish territory. The results made it possible to determine the actual effect of PCM applications in partitions on heat accumulation capacity increase and thermal conditions of the component. The article also addresses the issue of determining the parameters of material for which a very strong dependence of the specific heat and temperature exist. When used in construction materials, phase-variable thermal properties of the materials used must be accurately known, since the system efficiency depends on the thermal properties of materials. The article presents an attempt to determine the properties of the PCM as a function of temperature using the equipment consisting of heat meter, electronic sensors and thermocouples temperature.