## 3 Metadata Design
### Metadata Generation Process and Validation
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Category** & **Element** & **Remarks** \\ \hline \multirow{5}{*}{Common} & Sample ID & Unique identifier for the sample \\  & Sample Name & Designated name of the sample \\  & Sample Preparation Date & Date the sample was prepared \\  & Responsible Person & Name and affiliation of the person responsible for the sample \\  & Remarks & Additional notes or observations \\ \hline \multirow{5}{*}{For Catalysts} & Catalyst Structure & Structural details of the catalyst \\  & Catalyst Loading & Weight percentage (wt\%) \\  & Elemental Composition & Composition of elements in the catalyst \\  & Crystal Structure and Homogeneity & Information on crystallinity and uniformity \\  & Catalyst Particle Size & Average particle size (nm) \\  & Support Material and Surface Treatment & Type of support material and any applied surface treatments \\  & Loading Method & Method used to load the catalyst onto the support \\  & Synthesis Conditions & Raw materials and synthesis details \\  & Additives and Surface Treatments & Details of additives, surface modifications, and their quantities \\  & Post-Treatment Processes & Information on processes such as heat or acid treatments \\  & Aging Conditions & Presence and details of any aging treatment \\ \hline \multirow{5}{*}{For Electrolyte} & Chemical Structure & Molecular structure of the material \\  & Membrane Structure & Morphology of the membrane \\  & Membrane Thickness & Measured in micrometers (turn) \\  & Ion Exchange Capacity & Equivalent weight (EW) \\  & Membrane Resistance & Electrical resistance (\(\Omega\)-cm\({}^{2}\)) \\  & Gas Permeability & Permeability in cm\({}^{3}\)/(cm\({}^{2}\)-s-kPa) \\  & Glass Transition/Softening Temperature & Temperature (\({}^{\circ}\)C) \\  & Water Content and Volume Expansion & Hydration levels and volumetric changes (\%) \\  & Durability & Durability metrics under specified conditions \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Metadata elements categorized by sample type, focusing on those submitted for analysis. This table identifies required metadata fields common to all samples as well as those specific to catalysts and electrolyte membranes. Comprehensive metadata ensures accurate documentation of sample characteristics and experimental context. Figure 16: Overview of metadata, processed data, and analysis data generation workflow. This figure illustrates the sequential steps from raw data acquisition to metadata annotation, data processing, and subsequent analysis, ensuring data traceability, reproducibility, and integration within the research framework. Although the automation of metadata generation is ongoing, certain cases still require manual intervention. Future advancements in automation will aim to achieve a fully streamlined process. To ensure ongoing reliability, all the metadata were validated against a JSON schema [42] generated from an Excel-based definition file, as shown in Figure 17. Tools such as Visual Studio Code (latest version available during the study period) [43] provide real-time feedback during metadata entry, ensuring compliance with established standards. By integrating robust metadata workflows, FC-BENTEN provides a precise and efficient framework for experimental data management, addressing the current challenges while adapting to the evolving demands of synchrotron-based research. Its metadata system ensures data accessibility, interpretability, and ability to repurpose, even as methodologies become more complex and cross-disciplinary collaborations expand. Figure 17: Metadata schema defined in an Excel file. Each category (data_info, facility, sample, measurement, instrument, dataset, analysis, entry) is represented as a separate sheet, detailing mandatory/optional status, data types, descriptions, and usage examples. A corresponding JSON schema is automatically generated from the Excel metadata to enable streamlined validation.