scholarly journals What about Phenol Formaldehyde (PF) Foam in Modern-Contemporary Art? Insights into the Unaged and Naturally Aged Material by a Multi-Analytical Approach

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1964
Author(s):  
Valentina Pintus ◽  
Anna Piccolo ◽  
Wilfried Vetter ◽  
Ligia Maria Moretto ◽  
Katja Sterflinger ◽  
...  
Keyword(s):  
Contemporary Art ◽  
Analytical Approach ◽  
Phenol Formaldehyde ◽  
Oxidation Reactions ◽  
Ph Measurements ◽  
Cell Structures ◽  
Closed Cell ◽  
Red Color ◽  
Aged State ◽  
Extreme Sensitivity

The ageing behavior of phenol formaldehyde (PF) foam, a material increasingly used in modern-contemporary art, was investigated by a multi-analytical approach. PF foams with open- and closed-cell structures were selected and analyzed in their unaged and naturally indoor-aged state by employing optical microscopy (OM) and fiber optical reflectance spectroscopy (FORS) for assessing their morphology and color alteration. Micro-Fourier transform infrared spectroscopy (μ-FTIR) was used for determining chemical changes and oxidation processes, and the acidity was monitored by pH measurements. The results clearly showed the extreme sensitivity of both open- and closed-cell PF foams to conditions typically found in indoor museums. OM indicated that the cells of the foams are prone to disrupt, and a tendency towards a red color shift was observed with FORS. μ-FTIR revealed the formation of quinone groups resulting from oxidation reactions. Finally, a slight decrease in the acidity was found by pH measurements.

Open-Cell Foam Metal Production and Characterization by Aluminum Solid Mold Investment Casting

2019 ◽  
Author(s):  
Kerem Altug Guler
Keyword(s):  
Investment Casting ◽  
Replication Process ◽  
Open Cell ◽  
Metal Fabrication ◽  
Cell Structures ◽  
Closed Cell ◽  
Small Complex ◽  
Open Cell Foam ◽  
Foam Metal ◽  
Cell Foam

Foam metals can be categorized in two basic classes: open-cell and closed-cell structures, which both have different numerous unique properties. Up to the present, several production processes have been developed for each class. Investment casting is known as a replication process for open-cell foam metal fabrication. Solid mold, which can be evaluated as a subtechnique of the investment casting, is specialized especially for small complex shapes with ultrathin sections. This work is a presentation of aluminum open-cell foam production with solid mold investment casting using two different kinds of patterns. The first one is “burnable,” in which liquid metal directly fills the shape of pattern and the second is “leachable,” in which metal takes the form of intergranular network shape of porous salt preforms.

scholarly journals Energy Absorption of Different Cell Structures for Closed-Cell Foam-Filled Tubes Subject to Uniaxial Compression

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1579 ◽  
Author(s):  
Yang Yu ◽  
Zhuokun Cao ◽  
Ganfeng Tu ◽  
Yongliang Mu
Keyword(s):  
Energy Absorption ◽  
Absorption Efficiency ◽  
Foam Core ◽  
Aluminum Foams ◽  
Static Compression ◽  
Cell Structures ◽  
Closed Cell ◽  
Energy Absorption Efficiency ◽  
Foam Filled ◽  
Quasi Static Compression

The energy absorption of different cell structures for closed-cell aluminum foam-filled Al tubes are investigated through quasi-static compression testing. Aluminum foams are fabricated under different pressures, obtaining aluminum foams with different cell sizes. It is found that the deformation of the foam core is close to the overall deformation, and the deformation band is seriously expanded when the cell size is fined, which leads to the increase of interaction. Results confirm that the foam-filled tubes absorb more energy due to the increase of interaction between the foam core and tube wall when the foaming pressure increases. The energy absorption efficiency of foam-filled tubes can reach a maximum value of 90% when the foam core is fabricated under 0.30 MPa, which demonstrates that aluminum foams fabricated under increased pressure give a new way for the applications of foam-filled tubes in the automotive industry.

scholarly journals Characterization and Preparation of Furanic-Glyoxal Foams

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 692 ◽  
Author(s):  
Xuedong Xi ◽  
Antonio Pizzi ◽  
Hong Lei ◽  
Guanben Du ◽  
Xiaojian Zhou ◽  
...  
Keyword(s):  
Ignition Temperature ◽  
Furfuryl Alcohol ◽  
Room Temperature ◽  
Laser Desorption ◽  
Open Cell ◽  
Molar Ratios ◽  
Cell Structures ◽  
Closed Cell ◽  
Combustion Properties ◽  
Compression Resistance

Synthetic foams have become an essential industrial product for a great variety of applications. Furfuryl alcohol, as a biomass chemical, was reacted with glyoxal at room temperature to prepare furanic-glyoxal rigid foams, and p-toluenesulfonic acid was used as a catalyst to initiate the reaction. Foams with different molar ratios (furfuryl alcohol/glyoxal) were prepared in this work, and uniform cells foams have been obtained. Their compression resistance, 24-h water absorption, density, and other basic properties were tested. Scanning electron microscopy (SEM) was used to observe the cellular morphology of the foams prepared, thermogravimetric analysis (TGA) helped to understand their thermal and combustion properties, and FTIR and Matrix Assisted Laser Desorption Ionisation Time of Flight (MALDI ToF) mass spectroscopy to explain the structure of the resulting foams to clarify the reactions occurring during foaming. The results show that the compression resistance of furanic-glyoxal foams declined as the furfuryl alcohol/glyoxal ratio decreases also. SEM observations revealed that foams with open-cell were obtained when furfuryl alcohol was added in greater amounts, and more closed cell structures were formed as the proportion of glyoxal increased. TGA results showed that the initial ignition temperature of furanic-glyoxal foams is ~200 °C higher than that of wood, and the smaller comprehensive combustion index S (about 0.15 × 10−7 (%2 K−3 min−2)) indicates that the foam burns slowly and has poor flammability, that is, it is not easy to burn.

Compressive properties of two-layered aluminum foams with closed-cell and open-cell structures

2020 ◽  
Vol 24 ◽  
pp. 101249
Author(s):  
Yoshihiko Hangai ◽  
Mizuki Ando ◽  
Masataka Ohashi ◽  
Kenji Amagai ◽  
Ryosuke Suzuki ◽  
...  
Keyword(s):  
Compressive Properties ◽  
Aluminum Foams ◽  
Open Cell ◽  
Cell Structures ◽  
Closed Cell

Study on Evaluation Methods for Biodegradability and Biotoxicity of Industrial Effluents

2012 ◽  
Vol 518-523 ◽  
pp. 516-519 ◽  
Author(s):  
De Gang Xu ◽  
Ju Feng Li ◽  
Yu Zhong Li
Keyword(s):  
Oxygen Uptake ◽  
Dehydrogenase Activity ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
Phenol Formaldehyde ◽  
Industrial Effluents ◽  
Assessment Method ◽  
Sewage Plant ◽  
Extreme Sensitivity ◽  
Specific Oxygen Uptake Rate

The industrial effluents produced in petrochemical production contain kinds of pollutants and fluctuate wildly, also lead sewage plant to be impacted frequently. It is significant to develop a method that warms the effluents quality early, efficiently and accurately. As a result, it can make the biochemical devices run and manage smoothly. Based on the extreme sensitivity of Oxygen Uptake Rate (OUR) and Dehydrogenase Activity (DHA) to the abnormal effluents and toxicants, this study proposed a comprehensive assessment method of biodegradability and biotoxicity with Specific Oxygen Uptake Rate (SOUR) and Specific Dehydrogenase Activity (SDHA). And it also discussed the biodegradability and biotoxicity of the industrial effluents with different pH and toxicant by detecting OUR, SOUR and DHA. The results showed that, these three indexes were extremely sensitive and accurate to the effluents quality change. And the maximum concentrations of phenol, formaldehyde and carbinol that the microorganisms can allow in the industrial effluents were 350mg/L, 70mg/L and 170 mg/L. When the sewage plant was functioning normally, SOUR and SDHA fluctuations were 3.0~7.0 and 1.0~4.0 respectively. Therefore, they have important application value and prospect to early warming in the effluents quality.

Numerical Prediction of the Effective Thermal Conductivity of Open- and Closed-Cell Foam Structures

2010 ◽  
Vol 297-301 ◽  
pp. 1210-1217 ◽  
Author(s):  
Seyed Mohammad Hossein Hosseini ◽  
Andreas Öchsner ◽  
Thomas Fiedler
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Relative Density ◽  
Effective Thermal Conductivity ◽  
Linear Trend ◽  
Space Filling ◽  
Open Cell ◽  
Cell Structures ◽  
Closed Cell ◽  
Cell Foam

This paper investigates the thermal properties of metallic open-cell and closed-cell foam structures in space filling and non-space filling configurations. In both, i.e. open-cell and closed-cell structures, a linear trend depending on the relative density has been reported. However the closed-cell structures compared to open-cell ones have a higher thermal conductivity for the same relative density.

Engineering Three Dimensional Nanotextured Opal-Like Silica Foams

2005 ◽  
Vol 901 ◽  
Author(s):  
Florent Carn ◽  
Pascal Massé ◽  
Serge Ravaine ◽  
Rénal Backov
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Good Control ◽  
Water Volume ◽  
Porous Scaffolds ◽  
Void Space ◽  
Cell Structures ◽  
Closed Cell ◽  
Water Volume Fraction ◽  
Liquid Foam

AbstractNovel meso-/macroporous SiO2 monoliths have been reached by applying a nanotectonic pathway within a confined geometry, i.e. a non-static air-liquid foam patterning process. Final scaffolds are a very close transcription of the tailored periodic air-liquid foam template while coalesced silica particles are texturing the as-synthesized foam walls. The interconnected nanoparticles and associated void space between adjacent particles allow generating intrinsic mesopores, thereby defining hierarchically organized porous scaffolds. The good control over both the air-liquid foam’s water volume fraction and the bubble size allow a rational tuning of the macropore shape (diameter, Plateau border’s width). In contrast with previous study, closed-cell structures can be reached, while the opal like scaffold structure is maintained with thermal treatment, avoiding thus strong shrinkage associated to the sintering effect.

scholarly journals Fabrication of Two-Layered Aluminum Foam with Closed-Cell and Open-Cell Structures and Shaping of Closed-Cell Layer by Press Forming Immediately after Foaming

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 140
Author(s):  
Yoshihiko Hangai ◽  
Mizuki Ando ◽  
Masataka Ohashi ◽  
Kenji Amagai
Keyword(s):  
Aluminum Alloy ◽  
Melting Point ◽  
Aluminum Foam ◽  
Cell Layer ◽  
Open Cell ◽  
Press Forming ◽  
Cell Structures ◽  
Closed Cell ◽  
The Press

Two-layered aluminum foam consisting of both closed and open cells is expected to improve the functionality of aluminum foam, because the cells have different morphologies and characteristics. In this study, press forming of the closed-cell layer of the two-layered aluminum foam immediately after foaming was performed to shape the closed-cell layer. By measuring the temperatures of the two layers during foaming, we found that it is necessary to use aluminum alloy with a higher melting point for the open-cell layer than that for the closed-cell layer to foam the closed-cell layer. In the press forming experiments, the closed-cell layer could be shaped by press forming while the shape of the open-cell layer was maintained.

scholarly journals The Deliberative Action in the Labor Market of Iraqi Art The Concepts and the Application

Al-academy ◽  
2019 ◽  
pp. 91-102 ◽  
Keyword(s):  
Labor Market ◽  
Production Process ◽  
Contemporary Art ◽  
Analytical Approach ◽  
Social Structures ◽  
Deliberative Discourse ◽  
Applied Approach

The analysis of the orientations of Iraqi art commodification contributed to the discovery of deliberation, which was founded in the deliberative discourse in the trends towards commodification in the Iraqi art, since the important transformations in social structures and relations produced a dictionary with new vocabulary and tools that replaced the traditions and norms that have been in circulation for a century. Deliberation and commodification have become more prevalent in the mechanics and trends of the art where the pace of change is becoming increasingly frantic towards the market. The general market for art constitutes one of the most effective phenomena within contemporary art, that there has been a proliferation of sales auctions, markets and halls and became part of the production process, and there is a general agreement on the deliberative consumerism and the functional use which has reverted the course of art in different directions in its procedural form. The research has adopted the descriptive analytical approach that determines the image which the phenomenon of deliberation must take. This approach is not limited to knowing the characteristics of the phenomenon, but extends beyond that to know the variables and factors that cause its existence, diagnosis and description, and the research will has adopted the applied approach in the analysis of some of its outputs.

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