In-house Measurement Research Articles

Accuracy and precision guidelines for optimal breeding time in bitches using in-house progesterone measurement compared with chemiluminescent microparticle immunoassay.

Background and Aim:The concentration of serum progesterone is commonly used to determine the optimal mating time in bitches, and to diagnose reproductive-related abnormalities. This study aims to compare the serum progesterone results obtained by rapid fluorescence immunochromatography assay (RFICA) with those obtained by chemiluminescent microparticle immunoassay (CMIA) from the same serum samples to develop a standard guideline for optimal breeding time.Materials and Methods:Serum progesterone levels were measured in 124 bitches using RFICA and CMIA. Simple linear regression and correlation analyses were performed to analyze the data. The percentage difference between the maximum and minimum progesterone values in the same serum sample in the same assay was compared using Wilcoxon’s rank-sum test.Results:The present study showed a strong linear dependence of the results obtained by RFICA on those obtained by CMIA as R2=0.8976, with regression coefficient of 0.9474 and p<0.05, including the regression model was CMIA = (0.9483 × RFICA) − 0.761. Moreover, five critical measurement times during estrous in bitches showed statistically significant differences (p<0.05), except at the fertilizable period, which showed a non-significant difference (p>0.05).Conclusion:This study demonstrated that it is presumably acceptable to use the RFICA and CMIA methods interchangeably for quality progesterone measurements in serum samples from bitches. However, when considering the use of the RFICA method, it is advisable to carefully interpret the results and follow the interpretation guidelines. Finally, RFICA in the present study provides a reliable and convenient option for veterinarian practitioners to measure canine progesterone levels in-house.

Prevalence of SARS-CoV-2 in employees of a general hospital inNorthrhine-Westphalia, Germany

Zusammenfassung Hintergrund Wir erhoben die Prävalenz von SARS-CoV-2 in der Belegschaft eines Krankenhauses der Regel-/Schwerpunktversorgung in Nordrhein-Westfalen im Rahmen einer Querschnittsstudie. Methode Allen 1363 Mitarbeiter wurden ein nasopharyngealer Abstrich sowie eine Serologie auf SARS-CoV-2 angeboten. Zudem wurde ein Fragebogen zu Vorerkrankungen, Kontakten zu SARS-CoV-2-positiven Personen und COVID-19-typischen Symptomen vorgelegt. Ergebnisse 1212 MitarbeiterInnen nahmen teil. 19 von 1363 (1,4 %) Mitarbeitern waren PCR-positiv (3 während der Studie, 16 vorher). Bei 40 (3,3 %) bzw. 105 (8,6 %) Mitarbeitern wurde IgG bzw. IgA nachgewiesen, bei 32 (2,6 %) IgG und IgA. Damit wurden insgesamt 47 Mitarbeiter positiv für SARS-CoV-2 getestet. In dieser Gruppe waren die häufigsten Symptome Kopfschmerzen (56 %), Müdigkeit (49 %), Halsschmerzen (49 %) und Husten (46 %), Fieber wurde in 33 % berichtet. Positiv getestete Mitarbeiter gaben häufiger Kontakt zu einem COVID-19-Fall an (60,5 % vs. 37,3 %; p = 0,006). Mitarbeiter mit isoliertem IgA-Nachweis gaben seltener Symptome an. Schlussfolgerung 3,9 % der Mitarbeiter eines Krankenhauses der Regel-/Schwerpunktversorgung wurden zwischen dem 27.04. und 20.05.2020 positiv auf SARS-CoV-2 getestet. Der Anteil war geringer als erwartet; mögliche Gründe sind die geringe Durchseuchung der Bevölkerung und die umfangreichen, einheitlichen hausinternen Präventionsmaßnahmen.

Prediction of effective thermal conductivity of porous lattice structures and validation with additively manufactured metal foams

This paper focuses on the development of simple and accurate correlations to predict the effective thermal conductivity (ETC) of lattice structures, viz. Cube, face diagonal (FD)-Cube, Tetrakaidecahedron (TKD), and Octet topologies, which have wide range of applications in the development of advanced heat exchangers and can be additively manufactured in metal. The topology of those structures is preserved through a lattice Boltzmann-based computational model for thermal transport. In particular, a novel decoupled interface treatment was also proposed to effectively model the conjugate heat transfer between different materials or phases of very large transport property ratios. The accuracy and applicability of the ETC prediction were validated with in-house measurements conducted on the additively manufactured TKD and Octet samples and comparison with published experimental and computational results in the literature. The present results show that (1) at high porosities ε ≥ 0.9, the ETC results of those lattice structures are close to each other and they are consistent with previous experimental measurements and theoretical/computational predictions for traditional metal foams, (2) while at relatively lower porosities (ε < 0.9), the structural effect on the ETC becomes more obvious, and the popular correlations in the literature would underpredict the ETC of those structures. With keff predictions on wide range of porosities and solid and fluid phase thermal conductivities, we have identified a normalized ETC, keff/ks, which was found to be insensitive to ks/kf, and therefore considered suitable for the analytical correlation development over the entire range of porosity 0 ≤ ε ≤ 1. The presented correlations are valuable for ETC evaluation when designing new metal foams with different materials and topologies.

Development and evaluation of a quality control system based on transdermal electrical resistance for skin barrier function in vitro.

In vitro skin permeation experiments are highly relevant for pharmaceutical, cosmetic, agricultural developments, and regulatory evaluation. A key requirement is the skin barrier integrity, that is accompanied by an intact stratum corneum (SC) which implements high skin quality. A variety of integrity tests are currently available, for example, measurement of transepidermal water loss, monitoring the permeation of tritiated water and the measurement of transdermal electrical resistance (TER). We aimed for a non-destructive examination of barrier integrity as quality control system, based on TER. Therefore, the in-house developed instrument SkinTER measures electrical resistance on excised human skin samples in a non-invasive and easy-to-use pattern. In this proof of concept study, we compared three human in vitro skin models with focus on their TER and permeation properties. The skin integrity was impaired to mimic conditions of skin during age, lifestyle (eg, shaving) or diseases (eg, obesity, psoriasis, and atopic dermatitis). The OECD permeation marker caffeine was correlated to the corresponding TER value. A correlation between both was obtained by having a Pearson coefficient of -0.830. Hereby, a minimum TER value for intact skin samples of ~1.77kΩ*cm2 was suggested. Intact samples are significantly different (α=≤0.05) to their impaired counterparts in flux and TER values. The new SkinTER instrument gives a quick and non-invasive feedback on skin quality before a permeation experiment.

The reliability of radiation dose display of a computed tomography scanner

BackgroundInternationally, the typical allowed difference between the measured radiation dose and dose reported by a computed tomography (CT) scanner is ±20 %. The objective is to describe a method in order to analyse this difference in a CT scanner in the Emergency Department of Kanta-Häme Central Hospital, and to calculate a correction factor for more comparable radiation dose values in further studies. MethodsTen intra-day radiation dose measurements were performed with undisturbed setting. Measurement reports on differences between measured and displayed dose were gathered from the vendor maintenance and supervising authority over a 12-year period. Additionally, two in-house measurements were made. A total of 18 datapoints were collected, with some differences in measurement settings. Data were also analysed against imaging parameters, ambient air pressure and time to identify trends or associations in the variation of the discrepancy. ResultsMeasured doses were generally lower than displayed doses. Differences between displayed and measured doses varied between −3.46 and −0.10 %, with a mean of −1.26 % in the intra-day measurements, and between +4.65 and −17.3 %, with a mean of −7.53 % in the long-term data. There were no trends nor connections in the variations. ConclusionSince the acceptable difference between the radiation dose display and the measured dose is relevant, the average difference for every CT scanner should be determined before radiation dose studies, especially when comparing multiple scanners.

Automated low-temperature resistivity measurement setup: Design and fabrication

In this paper we present, the design and working of the automated low-temperature four-probe DC electrical resistivity measurement setup developed in-house. This setup measures the resistance/resistivity in the temperature range 300 K to 80 K. The overall arrangement comprises a low-temperature four-probe sample holder, Lakeshore 335 Temperature controller, Keithley Delta mode 6221 AC/DC source, 2182A Nano-voltmeter, and a vacuum system. For the measurement of sample temperature Pt-100 sensor is employed. The IEEE-488.2 card and GPIB cables link the mentioned instruments to the computer. The licenced Lab-VIEW 2018 software is employed to build the control programme. The established setup can measure the resistance of both bulk and thin-film samples, making it versatile. A test measurement on well-characterized ceramic Pr0.67Sr0.33MnO3 perovskite oxide synthesized using a solid-state route has been carried out in the newly installed setup. The data acquired from the installed setup and beforehand resistance measurement carried out in-house low-temperature resistance measurement setup at UGC-DAE-Consortium for scientific research, Indore conceded a precision for both temperature and resistance.

Understanding processing parameter effects for carbon fibre reinforced thermoplastic composites manufactured by laser-assisted automated fibre placement (AFP)

In this study, experimental investigations were performed to gain insights into the processing parameter effects of laser-assisted automated fibre placement (AFP) on the mechanical properties of carbon fibre (CF)/polyphenylene sulphide (PPS) composites from the perspective of void content and crystallinity. First, thermal characterisation was carried out to obtain the processing window for the PPS/CF composites. The temperature histories at the nip point during an AFP process were measured using an in-house temperature measurement system and the desired ranges of laser power and placement rate were determined based on the measured temperatures. The placement rate was ranging from 6 to 60 m/min, and the range of the used laser power was 1–6 kW. Then, the effects of tool temperature ranging from 30 to 120 °C on the interlaminar shear strength and compression strength of the CF/PPS composites were examined. It was found that the interlaminar void content dominated the mechanical properties of the composite rather than the crystallinity. Finally, the composites produced by the AFP were further treated by an autoclave. It was shown that the interlaminar shear strength of the composites was significantly improved after the autoclave post-consolidation treatment due to the reduction in void content and the improvement of crystallinity. The interlaminar shear strength of the composites after the autoclave treatment was found to be independent of the placement rate, indicating elimination of the AFP thermal history due to sufficient heating and compaction time in the autoclave.

Dynamics of Rising Bubbles in a Quiescent Slag Bath with Varying Thermo-Physical Properties

The motion of bubbles in a liquid slag bath with temperature gradients is investigated by means of 3D fluid dynamic computations. The goal of the work is to describe the dynamics of the rising bubbles, taking into account the temperature dependency of the thermo-physical properties of the slag. Attention is paid to the modeling approach used for the slag properties and how this affects the simulation of the bubble motion. In particular, the usage of constant values is compared to the usage of temperature-dependent data, taken from models available in the literature and from in-house experimental measurements. Although the present study focuses on temperature gradients, the consideration of varying thermo-physical properties is greatly relevant for the fluid dynamic modeling of reactive slag baths, since the same effect is given by heterogeneous species and solid fraction distributions. CFD is applied to evaluate the bubble dynamics in terms of the rising path, terminal bubble shape, and velocity, the gas–liquid interface area, and the appearance of break-up phenomena. It is shown that the presence of a thermal gradient strongly acts on the gas–liquid interaction when the temperature-dependent properties are considered. Furthermore, the use of literature models and experimental data produces different results, demonstrating the importance of correctly modeling the slag’s thermo-physical properties.

Towards a manufacturing signature for unstiffened flow formed thin-walled shell structures

Thin-walled shell structures such as those used for space launch vehicles are highly sensitive to various kinds of imperfections. This imperfection sensitivity makes it challenging to predict the load carrying capacity of these structures. A correlation between the manufacturing process and the load carrying capacity, called manufacturing signature, would facilitate the design of these structures. Therefore, in this paper, a step towards a manufacturing signature of flow formed unstiffened isotropic shell structures is made. For this purpose, the investigated shell structures and their manufacturing process are introduced in detail in this work. Afterwards, the geometric and thickness imperfections of these shell structures are measured using an in-house developed measurement system. The measurement results are evaluated in detail and the buckling loads of the measured shell structures are calculated numerically. The results show that all six shell structures have similar knock down factors (ρi≈0.74), which indicates a correlation between the manufacturing process and the load carrying capacity. Subsequently, experimental buckling tests are carried out for three shell structures. The discrepancies between the numerically calculated and the experimentally measured buckling loads are tracked back to load imperfections. Finally, the impact of load imperfections is studied briefly.

Recurrence analysis and time extrapolation of a confined turbulent jet using modal decomposition

We investigated the long-term dynamics of a turbulent, submerged jet at Re = 16 400 to develop a strategy for data-assisted, fast calculations of passive species transport. We obtained our data from high-fidelity large eddy simulations LES, which we validated against in-house particle image velocimetry measurements. The flow was split into coherent and incoherent fields using the method of proper orthogonal decomposition (POD). Depending on the number of POD modes to construct coherent velocity fields, different patterns in the recurrence plot of the system were found. For low mode numbers, line segments parallel to the main diagonal were present, which indicated that close states evolved similarly for a finite duration. Strong turbulent fluctuations in the original velocity fields, on the other hand, hid any large-scale recurrences and caused a structureless recurrence statistics. Using an iterated method of analogs, we time-extrapolated a short time series of coherent, distinctly recurring velocity fields of 50 s to 250 s and performed a study of species transport. We found that coherent dynamics alone could not reproduce LES results due to the lack of turbulent, small-scale fluctuations, but already a small set of incoherent flow fields sufficed to cure this shortcoming considerably. Surprisingly, time extrapolation of the original database without decomposition and without any obvious recurrences led to the best results in very close agreement with LES but with high demands regarding memory. Our data-assisted simulations outperformed LES on the same computational mesh by a speed-up factor of 15.

Generalised probe method to measure the liquid complex permittivity

A generalised probe method is proposed for fast and accurate complex permittivity measurements. The method is based on the simulated reflection coefficients using the finite difference frequency domain method. A database is set up, which consists of the simulated complex reflection coefficients of the unknown material under test. A fast searching algorithm is performed to match the measured reflection coefficients to the reference values in the database, thus the complex permittivity of the liquid can be obtained. An in-house measurement system is developed. The unique feature of this system is that it can be applied to an arbitrarily-shaped probe. Liquid samples are measured and the results are compared with that published in the literature. Good agreements are obtained. These results could be useful for liquid microwave component designs and applications.

In-house texture measurement using a compact neutron source.

In order to improve the instrumental accessibility of neutron diffraction techniques, many emerging compact neutron sources and in-house neutron diffractometers are being developed, even though the precision level of neutron diffraction experiments performed on such instruments was thought to be incomparable with that of large-scale neutron facilities. As a challenging project, the RIKEN accelerator-driven compact neutron source (RANS) was employed here to establish the technical environment for texture measurements, and the recalculated pole figures and orientation distribution functions of an interstitial-free steel sheet obtained from RANS were compared with the results from another two neutron diffractometers well established for texture measurement. These quantitative comparisons revealed that the precise neutron diffraction texture measurement at RANS has been realized successfully, and the fine region division of the neutron detector panel is invaluable for improving the stereographic resolution of texture measurements. Moreover, through selectively using the parts of the obtained neutron diffraction patterns that exhibit good statistics, the Rietveld texture analysis improves the reliability of the texture measurement to a certain extent. These technical research results may accelerate the development of other easily accessible techniques for evaluation of engineering materials using compact neutron sources, and also help to improve the data-collection efficiency for various time-resolved scattering experiments at large-scale neutron facilities.

Investigation of the non-uniform distribution of current density in commercial-size proton exchange membrane fuel cells

It is necessary to obtain the current density distribution in order to understand local reactions inside the proton exchange membrane (PEM) fuel cells. Enlarging the active area to commercial-size makes it difficult to maintain uniform assembly pressure, gas supply and heat dissipation inside the fuel cell stack. Existing studies for laboratory-level fuel cells cannot effectively guide the development of large-area fuel cells. In this study, current density distribution inside a 250 cm2 and 3 kW level fuel cell stack is measured and analyzed using the printed circuit board (PCB) technology. A four-layer PCB sensor plate covering 144 current collecting segments and shunt resistors for current measurement is well-designed. The in-house developed measurement system is proved with good function, and the accuracy of current density measurement is within 2%. Results show that the flow field configuration and stack assembly condition greatly affects the uniformity of local current densities. Higher current passes through the area with larger contact pressure, and the current density is low in the poor contact area. The local current density has larger deviations for higher output current, but the normalized current is more uniform. Effects of operating conditions including stoichiometric ratio and flow direction are investigated.

Deep Convolutional Neural Network Assisted Reinforcement Learning Based Mobile Network Power Saving

This paper addresses the power saving problem in mobile networks. Base station (BS) power and network traffic volume (NTV) models are first established. The BS power is modeled based on in-house equipment measurement by sampling different BS load configurations. The NTV model is built based on traffic data in the literature. Then, a threshold-based adaptive power saving method is discussed, serving as the benchmark. Next, a BS power control framework is created using Q-learning. The action-state function of the Q-learning is approximated via a deep convolutional neural network (DCNN). The DCNN-Q agent is designed to control the loads of cells in order to adapt to NTV variations and reduce power consumption. The DCNN-Q power saving framework is trained and simulated in a heterogeneous network including macrocells and microcells. It can be concluded that with the proposed DCNN-Q method, the power saving outperforms the threshold-based method.

Oncotype DX Breast Cancer recurrence score resists inter-assay reproducibility with RT2-Profiler Multiplex RT-PCR

The Oncotype Dx assay is frequently used to test if breast cancer patients can be spared from chemotherapy without negative effects for their future clinical course. However, due to conflicting data on the assay utility, in the recent past its reimbursement situation in Germany was revised; due to continued requests by clinicians for predictive values, our group decided to implement an Oncotype Dx like alternative assay with the objective of obtaining quality and cost optimization. Customized RT2-Profiler assays covering the 21 gene panel of the Oncotype Dx assay were applied to a pilot cohort of breast cancer patients with known Oncotype Dx Recurrence Score (RS). The Ct values obtained with RT2-Profiler-assays were used to calculate the unscaled Recurrence Score (RSu) values and the thereon based RS according to the Oncotype DX assay rules if available. Despite consistent assay performance it was impossible to establish correlations between RT2-Profiler recurrence scores with the respective Oncotype DX values not to mention exact matches. By following the Oncotype DX assay and its interpretation as close as possible we faced several obstructions such as lack of information on RNA amount used, missing units in the single gene expression report, missing references cited in the original study that should explain the determination of the recurrence score formula, and vague information on the normalization of the gene expression impeding the reproduction of Oncotype Dx results in other laboratories. Unfortunately, the Oncotype Dx assay cannot be confirmed by the customized RT2-profiler assay, not least because of the fact that the individual gene measurements are not provided in the medical report, although these are mandatory for the RS calculation. In fact, the “single gene report” only contains unscaled scores of the ER, PR, and Her2 genes without any internationally accepted unit used to describe a transcript quantity. Therefore a direct comparison with the in-house measurement to evaluate its performance is impossible. With regard to our findings and the fact that the Oncotype RS represents a likelihood of the risk of relapse it thus remains impossible to assess the clinical necessity of this assay.

Simulation of char-pellet combustion and sodium release inside porous char using lattice Boltzmann method

Char-pellet combustion is studied with the lattice Boltzmann method (LBM) including sodium release and the ash inhibition effect on oxygen diffusion in the porous char. The sodium release and the shrinking of the char pellet are simulated by accounting for the reactions occurring both in the solid and gas phases. The combustion of a single char pellet is considered first, and the results are compared against measurements. The simulation of the pellet mass, pellet temperature and sodium release agreed well with in-house optical measurements. The validated lattice Boltzmann approach is then extended to investigate the combustion of porous char and sodium release inside the porous medium. The pore-structure evolution and the flow path variation are simulated as combustion proceeds. The simulations reproduce the expected different behaviors between the combustion products (CO and CO2) and the released volatile, here the sodium vapor. The combustion products are mostly generated at the flame front and then transported by the flow and molecular diffusion inside the complex porous char structure. However, the volatile sodium vapor forms in the entire porous char and tends to accumulate in regions where the flow motion stays weak, as in internal flow microchannels, or blocked, as in closed pores. These results confirm the potential of the LBM formalism to tackle char-pellet combustion accounting for the topology of the porous medium.

Bidirectional energy filtering for electronic and phonon transport in Al2O3/ZnO superlattice films with anisotropy

Directional anisotropy transport in particular in nanostructured superlattice films could be crucial to understanding their thermoelectric properties, including figure-of-merit (ZT). However, few experimental studies have considered anisotropic properties in superlattice films. Therefore, this study investigated electronic and phonon transport anisotropy for atomic layer deposition Al2O3 (AO)/ZnO superlattice films on SiO2/Si substrates at 77–500 K using the four-point-probe 3-ω method and in-house Seebeck measurement system as a first step toward understanding corresponding superlattice film properties. In-plane and out-of-plane ZT values for AO/ZnO superlattice films were determined as 0.00017–0.19 and 0.00035–0.44, respectively, at 77–500 K. Higher ZT for both directions can be explained by synergistic combination of enhanced phonon scattering and bidirectional energy filtering in phonon and electronic transport compared to undoped ZnO films over the temperature range. We also found that out-of-plane thermal conductivity suppression was mostly attributable to increased ZT anisotropy in the out-of-plane direction rather than enhanced AO/ZnO superlattice film Seebeck and power factors.

Enhanced Cross-Plane Thermoelectric Figure of Merit Observed in an Al2O3/ZnO Superlattice Film by Hole Carrier Blocking and Phonon Scattering

We experimentally investigate the cross-plane figure of merit (ZT) for an Al2O3/ZnO (AO/ZnO) superlattice film by measuring cross-plane electrical and thermal conductivity and Seebeck coefficient using the 3-ω method and an in-house Seebeck coefficient measurement system recently developed for 300–500 K and examine how ZT factors depend on the AO layer inside the AO/ZnO superlattice film using measured thermoelectric properties. The AO/ZnO superlattice film exhibited maximum power factor of ∼276.2 μW/m K2 with low thermal conductivity (∼0.31 W/m K), producing ZT ≥ 0.45 at 500 K, which is approximately 2,650% improvement compared with an undoped ZnO film (∼0.017). The enhanced ZT performance of the AO/ZnO superlattice film can be explained by enhanced phonon scattering at the interface and minority carrier blocking at the interfacial barrier due to the AO layer, suggesting that the interfacial AO layer is important to enhance ZT in oxide-based films. These results open new applications for micro- or nanoscale thin film-based thermoelectric devices.

A poly(vinylidene fluoride) film printing system using solution droplet casting

The aim of this study is development of an improved PVDF film printing system. First, solution-cast PVDF films of three types are prepared by dropping and drying PVDF/acetone solution, PVDF/dimethylformamide (DMF) solution, and PVDF/hexamethylphosphoric triamide (HMPA) solution droplets on a glass plate. Second, after constructing an in-house Raman spectroscopy measurement system, the crystalline structure of solution-cast PVDF films is measured using the system. Measurement results demonstrate that the measurement system can be used to distinguish between α-phase, β-phase, and γ-phase in the PVDF sample. Third, after a piezoelectric polymer dual head printer system (P–p dual head printer system) equipped with a syringe pump head and an inkjet head is developed, a circle type PVDF film is printed on a glass plate using the P–p dual head printer system. The printed PVDFs show that the P–p dual head printer system can print fine 2D moulding.

Understanding the Formation of a Solid-Polymer Interphase between Argyrodite-Type Li6PS5Cl and Polymer-Based PEO:LiTFSI

Lithium-ion batteries (LIBs) play a crucial role in today’s consumer goods and transportation market due to their superior ability to store energy. While the energy and power density has been strongly increased since its commercialization in 1991, LIBs will soon reach a limit, which cannot be overcome with conventional liquid electrolyte based systems [1]. However, solid-state batteries (SSB) based on solid electrolytes (SE) offer the possibility to further enhance the energy and power density [2]. Sulfide-based SEs show superior conductivities of several mS/cm at room temperature. Their ductile nature allows for cold pressing and results in good electrode contacting and hence lower interfacial resistance compared to oxide-based SEs [3]. However, sulfide-based SEs are not stable against lithium and the formation of an interphase has been shown in theory and experiment. The degradation of argyrodite-type Li6PS5X (X = Cl, Br, I) in contact with lithium has been investigated by Wenzel et al. using in-situ XPS. They reported Li3P, Li2S and LiX as decomposition products, which is in accordance to a thermodynamic analysis based on first-principle calculations carried out by Zhu et al. [4,5]. A promising approach to prevent the lithium/Li6PS5X interface from decomposition is the introduction of an interlayer. While many examples about sputtering thin interlayers onto the SE or lithium have been reported, only few reports can be found about thin polymer interlayers. However, the latter could be more attractive for commercial applications as they can be applied by less expensive techniques than sputtering. By the introduction of a polymer interlayer between lithium and Li6PS5X, an extra electrolyte/electrolyte interface in addition to the lithium/electrolyte interface is formed. While the lithium/electrolyte interface has already been intensively studied for several electrolytes, only little is known about the electrolyte/electrolyte interface especially in case of the polymer/solid electrolyte interfaces. In previous studies, the specific resistances for the La0.55Li0.35TiO3\\PEO20:LiCF3SO3 (2200 Ωcm2, 80°C) [6], the Ohara\\PEO16:LiCF3SO3 (32 Ωcm2, 80°C) [7], the Ohara\\PEO10:LiTFSI (47 Ωcm2, 40°C) [7], and the Li7La3Zr2O12/PEO20:LiClO4 (9000 Ωcm2, 70°C) [8] interfaces have been reported. However, these studies use oxide-based SEs while to the best of our knowledge no comprehensive study on the interface between polymer electrolyte and sulfide-based SE exists. In the present study, we electrochemically and analytically investigate the interface between argyrodite-type Li6PS5Cl and poly(ethylene oxide): lithium bis(trifluoromethanesulfonyl)imide (PEO:LiTFSI). The PEO:LiTFSI electrolyte is prepared solvent-free in order to exclude any solvent-related decomposition reactions at the Li6PS5Cl/PEO:LiTFSI interface. In the first part, the Li6PS5Cl/PEO:LiTFSI interface is studied via electrochemical impedance spectroscopy (EIS). Two separated processes, which occur at different characteristic frequencies, are identified using an in-house developed four-point measurement setup (Figure 1a). The development of the cell impedance is monitored over 10 days at 80°C and reveals the rise of a medium-frequency process over time. In order to study the interface analytically, the polymer is removed and X-ray Photoelectron Spectroscopy (XPS) measurements are carried out after different ageing times. A clear evolution of decomposition products at the Li6PS5Cl/PEO:LiTFSI interface is observed (Figure 1b). These observations are confirmed via Time-of-Flight secondary ion mass spectrometry (ToF-SIMS). Possible decomposition pathways are discussed.