Vacuum Step Research Articles

Dehydration of goethite during vacuum step-heating and implications for he retentivity characterization

Uncertainty exists over what environmental conditions and mineralogical/chemical properties are required to ensure retention of helium such that (UTh)/He dates record the time of goethite crystallization. We undertook vacuum step heating experiments to determine He diffusion parameters for extrapolation to Earth surface conditions on 10 goethite specimens in which we had created a uniform distribution of 3He. Arrhenius plots of apparent diffusion coefficients on all samples follow the same pattern. At temperatures <200 °C the data define arrays consistent with progressive degassing of increasingly large crystallites. However, above 200 °C the computed diffusivities increase dramatically until about 80% of the helium is extracted, after which they suddenly decline. The sudden increase in diffusivity at 200 °C coincides with the onset of dehydration of the goethite structure, a process which continues throughout the remainder of the step heat. There is a strong correlation between evolved water and 3He amounts. These observations likely reflect previously reported processes of formation, growth, and coalescence of pores as the phase transition to hematite proceeds. While significantly higher dehydration temperatures of ∼270 °C are observed using techniques such as thermogravimetric analysis in air, the long step durations, and vacuum conditions of our experiments destabilize goethite. Orders of magnitude differences in the computed diffusivities among our samples may reflect crystallite-size-distribution control on dehydration kinetics, and the qualitative size distributions we infer from the step heats are consistent with SEM observations of crystallite lengths. Vacuum step-heating experiments in which goethite is decomposing cannot be used to determine He diffusion behavior in nature, but the inferred crystallite size distribution provides some useful indirect evidence. A strong relationship exists between metrics of the crystallite size distribution from step heating results and the degree of He retention in nature inferred from the 4He/3He method. This observation provides evidence supporting the validity of the 4He/3He technique for estimating retention, and further suggests that the dominant control on He retention in nature is the crystallite size distribution. Experiments under hydrothermal conditions in which goethite remains stable may be an alternative approach to address the question of He diffusion behavior in nature.

Safety assessment of the process Lietpak, based on the EREMA MPR technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process Lietpak (EU register number RECYC319), which uses the EREMA MPR technology. The input material is hot caustic washed and dried poly(ethylene terephthalate) (PET) flakes originating from collected post-consumer PET containers, including no more than 5% PET from non-food consumer applications. The flakes are heated ■■■■■ under vacuum (step 2). Having examined the challenge test provided, the Panel concluded that this step 2, for which the challenge test was provided, is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of this step are temperature, pressure and residence time. It was demonstrated that this recycling process is able to ensure a level of migration of potential unknown contaminants into food below the conservatively modelled migration of 0.15 μg/kg food, derived from the exposure scenario for toddlers, when such recycled PET is used at up to 100%. Therefore, the Panel concluded that the recycled PET obtained from this process is not considered to be of safety concern when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, except drinking water, for long-term storage at room temperature or below, with or without hot fill. Articles made of this recycled PET are not intended to be used in microwave or conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process ENVICCO, based on EREMA basic and Polymetrix SSP leaN technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panelon Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process ENVICCO (EU register number RECYC301), which uses the EREMA basic and Polymetrix SSP leaN technology. The input consists of hot caustic washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post-consumer PET containers, with no more than 5% PET from non-food consumer applications. The flakes are pre-decontaminated in the EREMA reactor at high temperature under vacuum (step 2) before being extruded, pelletised and crystallised (step 3). The crystallised pellets are then preheated (step 4) and submitted to solid-state polycondensation (SSP) (step 5) at ■■■■■ temperature and under nitrogen flow. Having examined the challenge tests provided, the Panelconcluded that step 2 as well as steps 4 and 5 are critical for determining the decontamination efficiency of the process. The operating parameters to control the performance of these critical steps are temperature, pressure and residence time for step 2 and temperature, residence time and gas velocity for steps 4 and 5. It was demonstrated that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panelconcluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long-term storage at room temperature or below, with or without hotfill. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process RE-PETKunststoffrecycling, based on Gneuss 4 technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process RE-PETKunststoffrecycling (EU register number RECYC286), which uses the Gneuss 4 technology. The input consists of washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post-consumer PET containers, with no more than 5% PET from non-food consumer applications. The flakes are melted in an extruder (step 2) and decontaminated during a melt-state polycondensation step under ■■■■■ and vacuum (step 3) and finally pelletised. Having examined the challenge test provided, the Panel concluded that the melt-state polycondensation (step 3) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of the critical step are the pressure, the temperature, the residence time and the characteristics of the reactor. It was demonstrated by the challenge test that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long-term storage at room temperature or below, with or without hotfill. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process ISKO, based on Gneuss 4 technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process ISKO (EU register number RECYC287), which uses the Gneuss 4 technology. The input consists of washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post-consumer PET containers, with no more than 5% PET from non-food consumer applications. The flakes are melted in an extruder (step 2), decontaminated during a melt-state polycondensation step ■■■■■ and vacuum (step 3) and finally pelletised. Having examined the challenge test provided, the Panel concluded that the melt-state polycondensation (step 3) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of the critical step are the pressure, the temperature, the residence time and the characteristics of the reactor. It was demonstrated by the challenge test that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long-term storage at room temperature or below, with or without hotfill. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process Renovapet, based on the VACUNITE (EREMA basic and Polymetrix SSP V-leaN) technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process Renovapet (EU register number RECYC271), which uses the VACUNITE (EREMA basic and Polymetrix SSP V-leaN) technology. The input consists of hot caustic washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post-consumer PET containers, including no more than 5% PET from non-food consumer applications. The flakes are pre-decontaminated in a first ■■■■■ reactor at high temperature under vacuum (step 2), then extruded and pelletised. The pellets are crystallised, ■■■■■ and then submitted to solid-state polycondensation (SSP) in a continuous reactor at ■■■■■ under ■■■■■ and ■■■■■ (step 4). Having examined the challenge test provided, the Panel concluded that step 2 (■■■■■ reactor) and step 4 (■■■■■ and SSP) are critical for determining the decontamination efficiency of the process. The operating parameters to control the performance are temperature, pressure and residence time for steps 2 and 4 as well as gas velocity for step 4. It was demonstrated that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long-term storage at room temperature, with or without hotfill. Articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Process analysis of temperature swing adsorption and temperature vacuum swing adsorption in VOCs recovery from activated carbon

• The adsorption process of TSA and TVSA for VOCs in waste gas was studied, and the parameters of process purification and recovery of VOCs were discussed. • The dynamic adsorption experiment was completed,The adsorption isotherm of benzene on activated carbon was determined. • A mathematical model was established to simulate the process of TSA and TVSA. • The initial range of the optimal hot-cold purge ratio is determined. • The influence of vacuum step on adsorption and desorption step is discussed. • Under the condition of low grade heat source, TVSA will be an environmental protection process. In order to better guide the design of industrial process for purification and recovery of VOCs, Temperature swing adsorption (TSA) and Temperature vacuum swing adsorption (TVSA) process for VOCs purification and recovery were studied systematically with activated carbon adsorbent. The adsorption and desorption behaviors of benzene on activated carbon in above two processes were investigated systematically. Effects of operating parameters on process performances were further analyzed, including as regeneration temperature, purging feed ratio and hot-cold purging ratio. The results showed that the increase of hot-cold purging ratio (HP/CP) could obtain the same regeneration effect as the increase of desorption temperature. Increasing the feed purge ratio without increasing the hot-cold purging ratio is not conducive to bed regeneration, because a large number of cold purge gases cannot utilize the residual heat of temperature wave, thus reducing the desorption effect of the cooling step on the bed. In addition, the vacuum step can enhance the regeneration ability of hot nitrogen to the bed at the same regeneration temperature, making the bed regeneration of TVSA process more thorough. Temperature in the middle and lower part of the bed in TVSA process was higher and the regeneration was more thorough. In conclusion, TVSA has more obvious advantages than TSA in terms of energy consumption, hot or cold purge volume and bed regeneration.

Effect of sulfur dioxide on adsorption capacity of zeolite sorbents for carbon dioxide

The article discusses a rather serious problem limit-ing the use of adsorption for the CO2 capture from flue gas, in the presence of sulfur dioxide. An apparatus with a vertical batch adsorber was constructed to study adsorption under elevated pressure in a wide range of temperatures and evaluation of CO2 breakthrough curves with an infrared analyzer. The article summarizes the results of experiments conducted with zeolite clinoptilolite, which represented natural materials, and molecular sieve 13X as a representative of synthetic sorbents. Adsorption capacities achieved during cyclically repeated tests with a model gaseous mixture free of SO2 and a mixture of the same composition but enriched with a low volume fraction of SO2 (0.3 %) were compared. Adsorption took place at a temperature of 20 °C and at two overpressures (200 and 500 kPa) of the gas with a 13 % volume fraction of CO2. Each sub-experiment consisted of five adsorption and desorption cycles, where desorption was based on depressurization followed by temperature increase to 120 °C under nitrogen atmosphere. There were no changes in capacities when tested with the gaseous mixture without SO2. Relative to the weight of the sample, the 13X sample at an overpressure of 500 kPa had a capacity of 11.3 % and clinoptilolite 3.8 %. Tests in the presence of SO2 led to a permanent reduction of the equilibrium capacities for both samples and at both pressures. At the overpressure of 500 kPa, the capacity decreased to 7.4 % for the 13X and to 2.5 % for the clinoptilolite. A more intensive desorption involving a thermal and vacuum step did not lead to any improvement for the 13X sample. In contrast, the effect for clinoptilolite was very positive. Its capacity in the fifth cycle reached 3.4 % close to the state without SO2 exposition. In the case when SO2 in the gas was accompanied with 40 % relative humidity, vacuum desorption did not lead to positive results in any case. After five cycles, the capacity of 13X dropped to 3.2 % and clinoptilolite to 1.4 %. When moisture, SO2 and the presence of O2 (volume fraction of 6 %) in the model mixture were further combined, the capacity of 13X decreased to 1.4 % and clinoptilolite to 0.4 % after five cycles. Tests with SO2 (dry gas) caused a decrease in the specific surface area from 512 to 211 m2.g‒1 for the 13X sample. On the other hand, for clinoptilolite it decreased from only 29 to 28 m2.g‒1 under the same conditions. Ac-cording to XRF, it was not possible to remove sorbed SO2 from the 13X sample even by evacuation followed by heating up to 200 °C. Using the XRD method, it was found that SO2 remains in the matrix, although it does not undergo transition to the crystalline phase. The study verified that synthetic molecular sieve 13X, unlike natural clinoptilolite, is not applicable for CO2 adsorption from SO2 containing flue gas.

Triple Radial Junction Hydrogenated Amorphous Silicon Solar Cells with &gt;2 V Open‐Circuit Voltage

Amorphous Silicon Solar Cells In article number 2200248, Pere Roca i Cabarrocas and co-workers demonstrated triple junction amorphous silicon solar cells grown around silicon nanowires, providing the elevated voltage (>2V) and enhanced effective surface area necessary for applications such as water splitting. The semi-randomly dispersed nanowires are grown in the same vacuum step as the solar cells and without lithography, making this technology a good candidate for low-cost applications.

Vacuum pressure swing adsorption for producing fuel cell grade hydrogen from IGCC

In this work, a vacuum pressure swing adsorption (VPSA) process was developed for the fuel cell grade hydrogen purification from H2-rich syngas of an integrated gasification combined cycle (IGCC) plants, where activated carbon, 5 A zeolite, and Cu(I)AC were used as adsorbents. Two kinds of cycle configurations were proposed and evaluated to achieve a higher process performance based on ten bed VPSA process. Meanwhile, the effects of key operating parameters on the performance of the VPSA process with different cycle configurations were investigated. The results demonstrated that the impact of argon content in the feed gas on the process performance was significant, and the hydrogen purity in the light product stream would decrease from 99.9902% to 99.9119% when the argon content in feed gas varied from 1000 ppm to 10,000 ppm. Moreover, the cycle configuration 2 of VPSA process with a receive purge step achieves much better process performances compared with the cycle configuration 1 of VPSA process just with a blowdown step and vacuum step. Although the energy consumption of cycle configuration 2 is approximately 2–3 times that of cycle configuration 1, it's close to 90% hydrogen recovery and high productivity make it more competitive.

Safety assessment of the process Wellman Neufchâteau Recyclage (WNR), based on the NGR technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process Wellman Neufchâteau Recyclage (WNR) (EU register number RECYC233), which uses the NGR technology. The input is washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post‐consumer PET containers, with no more than 5% PET from non‐food consumer applications. The flakes are dried (step 2), melted in an extruder (step 3) and decontaminated during a melt‐state polycondensation step under high temperature and vacuum (step 4). In step 5, the melt material is granulated. Having examined the challenge test provided, the Panel concluded that the melt‐state polycondensation (step 4) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of the critical steps are the pressure, the temperature, the residence time (depending on the mass and throughput of the melt) and the characteristics of the reactor. It was demonstrated that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long‐term storage at room temperature, with or without hotfill. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process 3R, based on NGR technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process 3R (EU register number RECYC237), which uses the NGR technology. The input is washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post‐consumer PET containers, with no more than 5% PET from non‐food consumer applications. The flakes are dried (step 2), melted in an extruder (step 3) and decontaminated during a melt‐state polycondensation step under high temperature and vacuum (step 4). In step 5, the melt material is granulated. Having examined the challenge test provided, the Panel concluded that the melt‐state polycondensation (step 4) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of the critical steps are the pressure, the temperature, the residence time (depending on the mass and throughput of the melt) and the characteristics of the reactor. It was demonstrated that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long‐term storage at room temperature. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process Indorama Ventures Recycling Verdun (IVRV), based on the NGR technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process Indorama Ventures Recycling Verdun (IVRV) (EU register number RECYC240), which uses the NGR technology. The input is washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post‐consumer PET containers, with no more than 5% PET from non‐food consumer applications. The flakes are dried (step 2), melted in an extruder (step 3) and decontaminated during a melt‐state polycondensation step under high temperature and vacuum (step 4). In step 5, the melt material is granulated. Having examined the challenge test provided, the Panel concluded that the melt‐state polycondensation (step 4) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of the critical steps are the pressure, the temperature, the residence time (depending on the mass and throughput of the melt) and the characteristics of the reactor. It was demonstrated that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long‐term storage at room temperature, with or without hotfill. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Safety assessment of the process rPET InWaste, based on the NGR technology, used to recycle post-consumer PET into food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process rPET InWaste (EU register number RECYC231), which uses the NGR technology. The input is washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post‐consumer PET containers, with no more than 5% PET from non‐food consumer applications. The flakes are dried (step 2), melted in an extruder (step 3) and decontaminated during a melt‐state polycondensation step under high temperature and vacuum (step 4). In step 5, the melt material is granulated. Having examined the challenge test provided, the Panel concluded that the melt‐state polycondensation (step 4) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of the critical steps are the pressure, the temperature, the residence time (depending on the mass and throughput of the melt) and the characteristics of the reactor. It was demonstrated that this recycling process is able to ensure that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.1 μg/kg food. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long‐term storage at room temperature, with or without hotfill. The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

Experimental Study on the Treatment of Sludge Discharged from an In Situ Soil Washing Plant by Vacuum Preloading

Soil in situ remediation, such as washing, always produces much sludge that has the characteristics of a high fine particle proportion, high moisture content, and high metal content. Problems such as high transportation costs, large land area, and the influence on landfill capacity often occur in the process of reclamation or landfill disposal. To solve the above problems, the vacuum preloading method was used to treat the sludge. The effect of this method on reducing the water content and volume of the sludge was investigated. Initial vacuum preloading (IVP) and step vacuum preloading (SVP) laboratory experiments were carried out on the sludge from the washing waste at a heavy metal soil remediation site in Shanghai. The drainage rate and settlement rate of the sludge during the experiment were recorded, and the moisture content and unconfined compressive strength (UCS) of the sludge samples after the experiment were tested and analyzed. Finally, the mechanism of uneven water content and shear strength of sludge treated by IVP and SVP were analyzed based on the grain size distribution. The results showed that the moisture content of the sludge near the prefabricated vertical drains (PVDs) decreased to 48.55%, and its volume decreased to 41.6% of the initial volume. The UCS of the sludge near the PVDs under SVP was 20.32% higher than that under IVP. The sludge treated by the vacuum preloading method can be disposed of in a landfill or other resource utilization.

High Energy Density Cathode Composite for All-Solid-State Lithium-Sulfur Battery

Lithium-sulfur battery with an all-solid-state configuration is expected to possess high energy density (>1600 mAh/g), safety, and reliability. However, poor ionic/electronic conductivities and a large volume change of sulfur are the problems to be solved to achieve its intrinsic high-potential. Carbon replica (CR) having a three-dimensional pore arrangement within the matrix is a good candidate to design high energy density cathode composite since the high electric conductivity and sufficient pore volume (~2-3 cm3/g) to accommodate a large amount of sulfur [1]. Therefore, sulfur-carbon replica matrix (S-CR) with high sulfur loading rate (80wt.%) is possible theoretically. Also, the incorporated sulfur in the pore (~10-100 nm) could show lower volume changes and smaller resistance for ion diffusion. In the present study, an improved melting method was used to introduce sulfur into CR pores, and the particle size of the sulfur was controlled by simultaneously controlling the particle size and pore size of the CR to improve the sulfur utilization rate.Based on the reported melting method, the powdered S-CR mixture was heated at 155°C for 2h [2]. As an initial step, CRs with different pore sizes (10 and 100 nm; CR10 and CR100) were examined. Furthermore, a vacuum sealing process was conducted before heating to fill the entire mesopores of CR with sulfur. Four kinds of S-CR (S:CR=80:20wt.%) were fabricated to compare their battery performance: (i) the melting method using CR100; (ii) the melting method using CR10; (iii) the vacuum sealing method using CR10; and (iv) the vacuum sealing method using CR10 and particle classification treatment (~10 µm) were used. A lithium superionic conductor of Li10GeP2S12 (LGPS) and Li-In alloy was used as a solid electrolyte and negative electrode, respectively [3]. The S-CR-LGPS composites (S:CR:LGPS=32:8:60wt.%) were fabricated by ball milling. The obtained composites were characterized by SEM, BET, TG/DTA. Electrochemical properties of the composite electrodes were evaluated by the constant current charge-discharge measurements.Initially, we used the reported melting method to fabricate a cathode composite and elucidated the effect of CR pore size to battery performance. A higher capacity was obtained when CR10 was used because the reduction in pore size enables smaller incorporated sulfur size. Since sulfur is an insulator, reducing the size of sulfur can increase the utilization rate of sulfur to obtain a higher capacity [4]. However, when using the reported melting method, a large irreversible capacity (~80 mAh/g) was observed in the first cycle. This indicates that a part of sulfur may exist on the outer surface of the CR, which could show poor reversibility for the reaction. This is due to that the residual gas in the pores prevents the entry of liquid sulfur. Therefore, before introducing sulfur using the melting method, a vacuum step was applied to remove the gas from the pores. As a result, the initial irreversible capacity was decreased to ~10 mAh/g. Then TG, SEM, and BET analysis confirmed the successful filling of sulfur into the CR pores. Nevertheless, since the specific capacity was still smaller than the theoretical capacity of sulfur, the particle sizes of CR and LGPS were adjusted to about 10 µm by a dry classification method before composite fabrication to improve the utilization rate of sulfur. The optimized composite showed a larger capacity of over 1400 mAh/g and its coulomb efficiency was close to 100% after the second cycle. This proves that controlling the particle size of CR and LGPS can improve the utilization rate of sulfur (84%) which results in a higher capacity. The results show that the particle size classification could contribute the constructing the ion/electron pathway in the composite because of better dispersion of each particle. It can be expected that the further optimization of the weight ratio, mixing method, and other conductive additives of the composite electrodes could provide better ion and electron transport paths inside the composite, which lead to better performance. Reference s : [1] J. Power Sources, 2016, 330, 120-126.[2] Energy Technology, 2019, 0, 1900077.[3] Nat Mater, 2011, 10, 682-686.[4] Adv. Energy Mater, 2017, 7.17, 1602923. Figure 1

Progress and control in development of single layer graphene membranes

Recent approaches in graphene transfer on different substrates and nanostructured surfaces have opened up new potential applications such as: pressure sensors, separation membranes, electrochemical sensors. Graphene single layer is a promising membrane material, due to chemically inert, large specific surface area with hydrophobic property. In this work, single layer graphene have been synthesized by CVD on copper catalyst and transferred by three different wet chemical transfer methods on Si/SiO2 holes of approximatively 7 μm diameter. The novelty of this study is the introduction of a vacuum step to help remove liquids from underneath the graphene layer while maintaining the structural integrity of the membrane. Raman spectroscopy was performed to analyze the number of layers and the quality of graphene. The morphology of the graphene transferred on the holes were examined using scanning electron microscopy (SEM).

Ambient Pressure XPS Studies of Liquid Solid Interfaces in Batteries

Liquid solid interfaces in batteries are not trivial to study in a realistic and detailed way. Often interfaces of cathodes or anodes in cycled batteries, are studied post mortem and at ultra-high vacuum to really determine the chemical composition in the outermost electrode/electrolyte layer. It is, therefore, a need to develop new characterisation methods which can allow for the study of dynamic reactions taking place at interfaces as a function of battery cycling. In this presentation, we will describe our attempts to develop electrochemical cells that can be used at ambient pressure (25 mbar). The cells are dependent on photoelectron spectrometers (PES) that have differential pumping systems and where the samples can be protected but still transferred without intermediate ultrahigh vacuum step of the load lock. These spectrometer exist now at synchrotron facilities but also as in house equipment. The challenge is how the electrochemical cell should be designed and how to study the liquid solid interfaces in detail and especially when the liquids are organic volatile solvents. Our first results will be presented as three examples. The first example is a comparison of the solid electrolyte interphase (SEI) on a silicon surface measured at ultrahigh vacuum with one measured at ambient pressure. Questions such as: will the chemical composition of the SEI be considerably different at ambient pressure and will the resolution of the analysis be high enough to reveal any differences in the chemical composition? The second example is a study of the surface of a droplet of a lithium-ion battery electrolyte on a metallic lithium substrate characterised at 2 mbar and 0.2 mbar, respectively, and studied with ambient pressure PES. The study was performed on the beam-line Hippie at MAXIV laboratory. Our third result is the cycling of an electrode with an electrolytes within electrochemical cell in the Hippie spectrometer. The implication of all these three studies is that a step has been taken to more realistic studies of surface reactions in a LIB context. The experimental challenges are also detailed in the presentation.

Bonding through novel solder-metallic mesh composite design

Thin metallic Cu and Ni meshes were successfully embedded within SAC305 solder joints. Defects (residues) within the joint were removed by a vacuum step in the bonding sequence. The metallic mesh inlets were metallurgically bonded by the formation of scallop-like Cu6Sn5 and faceted Ni3Sn4 intermetallic compounds (IMCs) at the Cu mesh-SAC305 solder (CMS) and Ni mesh-SAC305 solder (NMS) interfaces, respectively. After process optimization, the averaged shear strengths were found to be 44.1 (reference), 44.7 (+1%), and 51.4 MPa (+16%) for SAC305, NMS, and CMS composite joints, respectively. The solder-substrate-mesh interaction resulted in a characteristic fracture pattern, with the cracking path partly within the solder and partly at the solder-mesh interface. Finite element (FE) simulations suggested a mesh-induced stiffening effect of the solder joint by 5%. The additional reinforcement (11%) introduced by the Cu mesh inlets was attributed to a locally enhanced fracture resistance.

Improving Cull Cow Meat Quality Using Vacuum Impregnation.

Boneless strip loins from mature cows (50 to 70 months of age) were vacuum impregnated (VI) with an isotonic solution (IS) of sodium chloride. This study sought to determine the vacuum impregnation and microstructural properties of meat from cull cows. The experiments were conducted by varying the pressure, (20.3, 71.1 kPa), and time, (0.5, 2.0, 4.0 h), of impregnation. After the VI step, the meat was kept for a time, (0.0, 0.5, 2.0, 4.0 h), in the IS under atmospheric pressure. The microstructural changes, impregnation, deformation, and porosity of the meat were measured in all the treatments. Impregnation and deformation levels in terms of volume fractions of the initial sample at the end of the vacuum step and the VI processes were calculated according to the mathematical model for deformation-relaxation and hydrodynamic mechanisms. Scanning electron microscopy (SEM) was used to study the microstructure of the vacuum-impregnated meat samples. Results showed that both the vacuum and atmospheric pressures generated a positive impregnation and deformation. The highest values of impregnation (10.5%) and deformation (9.3%) were obtained at of 71.1 kPa and of 4.0 h. The sample effective porosity () exhibited a significant interaction (p < 0.01) between . The highest (14.0%) was achieved at of 20.3 kPa and of 4.0 h, whereas the most extended distension of meat fibers (98 μm) was observed at the highest levels of p1, t1, and t2. These results indicate that meat from mature cows can undergo a vacuum-wetting process successfully, with an IS of sodium chloride to improve its quality.