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Lignin-glyoxal-formaldehyde resin towards formaldehyde-reduced wood adhesives
No full textPhenolic adhesives are widely used in the wood panel industry due to their excellent mechanical properties and durability. However, concerns related to their high carbon footprint and formaldehyde emissions have driven research toward bio-based alternatives. This study investigates the synthesis and characterization of lignin-glyoxal-formaldehyde (LGF) adhesives as a sustainable alternative to conventional phenol-formaldehyde (PF) adhesives. Pressurized hot water extracted softwood lignin, a type of hydrolysis lignin (HL), and softwood kraft lignin (KL) were fractionated using sequential solvent extraction using the solvents isopropanol, ethanol, and methanol to improve the reactivity of lignin. LGF resins were synthesized using an alkaline catalyst with a lignin-to-aldehydes (glyoxal and formaldehyde) molar ratio of 1:2, while varying the glyoxal/formaldehyde ratios (100/0, 50/50, 0/100 mol/mol). The ethanol soluble (EtOH-s) fraction of HL and the isopropanol (iPrOH-s) fraction of KL exhibited the highest reactivity, with molar mass of approximately 5000 and 3300 g/mol, respectively. LGF adhesives showed low formaldehyde emissions (<0.5 mg/L), complying with the E0 standard for interior plywood applications. The highest dry bonding strength was achieved with the 0/100 mol/mol glyoxal/formaldehyde formulation of HL-EtOH-s, reaching 0.38 MPa, while the 50/50 mol/mol glyoxal/formaldehyde formulation of KL-iPrOH-s reached 0.48 MPa. Incorporating phenol into the resin formulation at a lignin/phenol ratio of 50/50 wt/wt, along with a 50/50 mol/mol glyoxal/formaldehyde mixture, significantly increased the bonding strength of HL-EtOH-s from 0.22 MPa to 0.68 MPa. Notably, the wet bonding strength increased from 0 to 0.5 MPa after undergoing a 28-hour boiling-drying-boiling pre-treatment. These findings highlight the potential of lignin-glyoxal formulations for producing formaldehyde-reduced bio-based adhesives suitable for both interior and exterior-grade plywood applications
Designing for Decision-Making: A Study of Digital Nudges in Finland’s Vero and Kela Platforms
No full textThe digitalization of public services presents both opportunities and challenges, particularly in user interaction and decision-making. As governments transition to online service delivery, ensuring usability, efficiency, and accessibility is essential. Digital nudging, subtle interface modifications that guide users toward desired actions without restricting choice, plays a key role in service design. This thesis examines digital nudging in two Finnish governmental platforms, Vero and Kela, analyzing how interface cues influence task completion and accuracy. Considering the role of behavioral economics and Human-Computer Interaction (HCI) in digital service development, this study explores the implementation and impact of digital nudges.
Using Hansen and Jespersen’s nudge taxonomy, we analyze transparent and non-transparent nudging strategies embedded in these platforms. Transparent nudges, such as progress indicators and error-prevention mechanisms, assist users while maintaining their sense of control. Non-transparent nudges, including default selections and pre-filled forms, reduce cognitive effort but raise ethical concerns regarding user autonomy and informed consent.
The empirical analysis highlights distinct approaches to digital nudging. Both platforms employ Type 1 and Type 2 nudges with varying levels of transparency to optimize task completion and user experience. Vero emphasizes error prevention, default settings, and structured navigation to ensure compliance in tax-related tasks. In contrast, Kela uses social proof, simplified decision pathways, and reminders to encourage benefit application completion. This contrast underscores the context-dependent nature of digital nudging, emphasizing the importance of a user-centered approach aligned with the goals of each public service platform.
While these nudging strategies contribute to a more seamless user experience, they also introduce ethical considerations. The extent to which users recognize they are being nudged and their ability to override default choices are critical factors in assessing fairness. Although non-transparent nudges can simplify decision-making, they must be designed carefully to maintain trust and prevent potential manipulation.
This study provides practical insights for policymakers, service designers, and UX professionals seeking to optimize digital public services. While nudging can enhance usability and efficiency, its design should prioritize transparency, user autonomy, and long-term engagement. Future research should explore the longitudinal effects of nudging, examining how repeated exposure influences user behavior over time. Additionally, cross-cultural comparisons could offer further insights into how different populations respond to digital nudging strategies in public services
