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The effects of climate change are becoming increasingly clear, and the urgency of solving the energy and resource crisis has been recognized by politicians and society. One of the most important solutions is sustainable energy technologies. The problem with the state of the art, however, is that production is energy-intensive and non-recyclable waste remains after the useful life. For monocrystalline photovoltaics, for example, there are recycling processes for glass and aluminum, but these must rather be described as downcycling. The semiconductor material is not recycled at all. Another promising technology for sustainable energy generation is dye-sensitized solar cells (DSSCs). Although efficiency and long-term stability still need to be improved, the technology has high potential to complement the state of the art. DSSCs have comparatively low production costs and can be manufactured without toxic components. In this work, we present the world' s first experiment to test the recycling potential of non-toxic glass-based DSSCs in a melting test. The glass constituents were analyzed by optical emission spectrometry with inductively coupled plasma (ICP-OES), and the surface was examined by scanning electron microscopy energy dispersive X-ray (SEM-EDX). The glass was melted in a furnace and compared to a standard glass recycling process. The results show that the described DSSCs are suitable for glass recycling and thus can potentially circulate in a circular economy without a downcycling process. However, material properties such as chemical resistance, transparency or viscosity are not investigated in this work and need further research.

Melting models for flood fed single screw extruders, like the Tadmor model, describe the melting of pure thermoplastic polymers. However, the melting behavior of heterogenous polymer systems is of great interest for recycling issues, for example. In this work, the melting of polymer mixtures and that of pure bulk polymers by the drag induced melt removal principle is examined both theoretically and experimentally. The applied model experiments represent the melting of the solid bed at the barrel in single screw extruders. As polymer pellet mixtures, polypropylene-homopolymer mixed with polypropylene-block-copolymer, high density polyethylene, polyamide 6, and polymethylmethacrylate were studied using different mixing ratios. The melting rate and the shear stress in the melt film were evaluated dependent on the mixing ratio. The results show that when processing unfavorable material combinations, both shear stress and melting rate can be far below that of pure materials, which was also confirmed by screw extrusion and screw pull-out experiments. Furthermore, approaches predicting the achievable melting rate and the achievable shear stress of polymer mixtures based on the corresponding values of the pure materials are presented.

We conducted isotopic model calculations and high-pressure melting experiments in order to estimate the major element composition of the “missing reservoir”, which is a supposed component that should compensate the difference in ¹⁴²Nd/¹⁴⁴Nd ratio between the bulk silicate Earth and carbonaceous chondrite, from which the Earth is assumed to have formed. Our estimation demonstrated that the missing reservoir should have picritic to komatiitic composition, and that it was likely to have been lost from the Earth's surface by a giant impact event at the last stage of the Earth formation.

We conducted isotopic model calculations and high-pressure melting experiments in order to estimate the major element composition of the “missing reservoir”, which is a supposed component that should compensate the difference in ¹⁴²Nd/¹⁴⁴Nd ratio between the bulk silicate Earth and carbonaceous chondrite, from which the Earth is assumed to have formed. Our estimation demonstrated that the missing reservoir should have picritic to komatiitic composition, and that it was likely to have been lost from the Earth's surface by a giant impact event at the last stage of the Earth formation.

In order to understand the transition in sea ice, snow transformation, and temperature variations, we carried out tank experiments in a cold room. In the melting experiment of bare ice, the transition of the condition of the ice surface was observed through visual observations and reflectance measurements. The first change was manifested in the surface becoming wet and acquiring a rough texture. Subsequently, a porous layer was formed under the ice surface. Since this layer scattered the incident light, it appeared as a bright surface. The reflectance of this surface was high as compared with that measured during the initial stages of melting. However, this thin scattering layer disappeared as the melting progressed. As a result, the reflectance was reduced to its value during the initial stage of melting. In the melting experiments on snow covered sea ice, the structure of snow-ice became porous and mechanically weak before the thickness reduction commenced. The temperature gradients of bare ice and snow covered ice were small during the melting process compared to those during the growth period.

We carried out high pressure melting experiments on a mixture of mineral separates of quartz, plagioclase (antiperthite) and a rare amount of orthopyroxene at 1000-1150℃ and 1.0 Gpa under dry conditions. The starting material was obtained from an ultrahigh-temperature (UHT) garnet-orthopyroxene-bearing quartzo-feldspathic gneiss in the Mt. Riiser-Larsen of the Napier Complex, East Antarctica. This UHT gneiss is considered to be equilibrated at metamorphic conditions >1070℃. The mineral assemblages in the run products at 1000℃ and 1100℃ are the same as those of the starting material. K_2O content in K-feldspar lamellae of antiperthite decreases with temperature. Granitic glass (

In order to estimate the depth of emplacement of the granitic dikes intruded into the granulites of the Sør Rondane Mountains, phase relations of the retrograde granulites adjacent to the dikes and the host granulites were experimentally determined in a temperature range of 600 to 900°C, under water pressures of 0.1-0.33 Gpa and oxygen fugacities of the FMQ and NNO buffers. The preliminary experimental results indicate that biotite from retrograde granulite is stable at pressures lower than 0.3 Gpa. The stability field of biotite in the gneisses suggests that the depth of emplacement of the granitic dikes from the northern central part of the mountains is similar to that of syenites from the southern central part of the mountains (T. OBA and K. SHIRAISHI; Proc. NIPR Symp. Antarct. Geosci., 8, 96, 1995)

Melting experiments at high-pressure and temperature were conducted at pressures from 16 to 25 GPa using chondritic starting material but with slightly enhanced Na- and K-contents while keeping the chondritic Na/K ratio constant. The experiments revealed that majorite garnet contains enhanced concentrations of Na (3.75-4.71 wt.% Na2O) and moderately enhanced concentrations of K (0.3-0.46 wt.% K2O) from 16 to 20 GPa and it is therefore the Na- and K-bearing phase at this pressure range. The Na2O/K2O ratio (8-15) in garnet is close to the initial chondritic ratio (7) of the starting material, which might indicate that at these pressures only little Na/K fractionation takes place. At pressures above 21 GPa, the high-pressure phases enriched in Na include majorite garnet (3.08-6.22 wt.% Na2O), magnesiowustite (1.83-3.3 wt.% Na2O), and (Mg,Fe)SiO3-perovskite (0.43-1.25 wt.% Na2O). These phases contain only small amounts of K ( 21 GPa should have taken place in the early accretional period in the primitive chondritic mantle of the Earth.