Targeted keratin repair: A plant-based approach to hair strength and surface restoration.

One of IACMI’s stated goals is the recycling of composites into useful products. To achieve this, the institute plans to demonstrate recycling technologies at a sufficient scale to justify the investment risk for private industry commercialization. Success will mean the reduction of regulatory disposal risks, encouraging additional investment and will allow for the opening of new composite markets. This is a particular concern as failure to achieve this could mean the loss of US global competitiveness in the composites marketplace as US manufacturers become unable to meet increasing regulatory burdens surrounding composite waste disposal nor are able to compete with emerging, inexpensive recycled composites from Europe and Asia. IACMI is uniquely positioned to conquer this fundamental risk for industry by demonstrating economical recycling technologies which reduce environmental impact while creating circularity in manufacturing and producing new recycled composite intermediates and products. The core IACMI team has come to view the recycling problem along three dimensions, with the first leg of identifying of composite waste types and characterizing that waste to determine appropriate methods of recycling. Along the second leg is the science behind the materials used in advanced composites and how different recycling methods alter these materials innate mechanical performance. Along the third leg is the building of relationships with key industrial partners to procure composite waste streams and build new markets for recycled composite products. In making carbon fiber economics circular, this project was explicitly concerned with developing the materials and process to manufacture a reclaimed carbon fiber (rCF) - polyamide (PA) composite automotive body panel with a painted Class A surface comparable to the incumbent steel technology. Additional project targets included cycle time for molding the part, mechanical performance and thickness tolerances. The approach to meet these targets and showcase technical feasibility was a combination of material formulation, composite layup, processing conditions and paint application. The composite preform consisted of a comingled non-woven mat of reclaimed carbon fiber and polyamide fiber. Through compression molding, the polyamide fiber melts, forming the composite panel. To meet the cycle time target and achieve a high-quality surface finish, a rapid heating and cooling tool from RocTool was designed and built for the project. This tool was installed at Oak Ridge National Laboratory’s Manufacturing Demonstration Facility. However, due to startup challenges and troubleshooting, much of the development work for the project occurred at RocTool’s development facility in Charlotte, NC. The key technical challenge was to mitigate differences in thermal expansion between the carbon fiber and polyamide resin. The temperature changes that the molded part experiences during forming and paint curing causes the surface topology to change. Some of this surface topology can be smoothed by the paint system, but to approach the Class A designation, the polyamide resin, composite stack, and molding protocol must all be optimized to produce a smooth part directly from the tool, then the paint system can further improve the surface finish. Class A was defined based on steel benchmark panels and measured shortwave and longwave values from a BYK Wavescan® tool. The target values for this study to achieve Class A were below 20 and 10 for the shortwave and longwave values, respectively. A rCF/PA composite was demonstrated to meet these benchmark values, and a pathway has also been identified to provide further improvement in surface quality and processability in the future. The mechanical performance of the composite panels was characterized and compared with benchmark panels where cycle time and surface quality were not the target. Molded parts using the RocTool compression molding tool exhibited slightly lower mechanical performance but still exceeded the target values. Furthermore, these parts also were produced within the targeted cycle time and had a high-quality surface finish. Additional characterization showed that these parts could be produced at a repeatable thickness within the allowable tolerance and it was identified that any significant variation in the molded parts came from variability in the incoming material. The feasibility of creating a carbon fiber composite with an automotive Class A surface, suitable for high volume manufacturing, was established in this project. Areas for further optimization have been identified and would be tested in future work. A future study would focus on developing this technology further from a demonstration plaque tool to a real application to be defined with an automotive OEM.

Additive manufacturing parts often need post-treatment due to inherent shortcomings, such as poor surface quality or mechanical performance. Ball burnishing, a plastic deformation technique, can reduce these drawbacks. In this research, a specific tool was designed, and statistical models were used to determine optimal process parameters. Flexural and fatigue tests were conducted to assess the effects of ball burnishing on surface and dimensional quality, hardness, and mechanical behavior. The study shows that ball burnishing can benefit cast filament parts made of three materials and provides generalizations for its application. This research represents a novel contribution to using ball burnishing and highlights its advantages.

The objective of this study was to use dynamic contact angle (DCA) analysis and inverse gas chromatography (IGC) to probe the surface-chemical changes in wood pulp fibers during recycling. A simplified wet-dry-rewet cycle was performed on hardwood bleached kraft fibers to represent the recycling process. The DCA measurements revealed that the overall effect of recycling was an increase in the non-polar (dispersive) component and a corresponding decrease in the polar component of the surface free energy, hence resulting in a total surface free energy that remained essentially unaltered. The DCA experiment also showed that virgin fibers lost both their electronaccepting (γS +) and their electron-donating (γS -) characteristics when converted to paper. Upon rehydration, the fibers recovered some surface acidity (γS +) but surface basicity (γS -) continued to decrease. The changes in polar surface free energy correlate well with the changes in hydroxyl number determined independently using the acetylation method. IGC could not detect changes in the dispersive component of the surface free energy induced by recycling. The acid-base (KA and KB) changes in the IGC measurements were also indistinguishable between virgin fibers and recycled fibers. This research concludes that DCA analysis is preferable to IGC in better reflecting the surface changes in fiber recycling, and γS-can at least be treated as an empirical parameter to complement the hydroxyl availability data in distinguishing among virgin, paper, and recycled fibers.

Ensuring the durability and safety of modern infrastructure critically depends on the quality and strength of concrete. The Ultrasonic Pulse Velocity (UPV) method is a widely used non-destructive testing technique for evaluating concrete properties; however, factors such as aggregate size distribution, compaction methods, and surface quality can significantly influence UPV results and their correlation with compressive strength. This study investigates the effects of different aggregate sizes and an innovative vibration-assisted compaction method-developed using piezoelectric (PZT) transducers-on the mechanical, ultrasonic, and surface properties of concrete. Four distinct aggregate size distributions were employed to produce sixteen concrete specimens with constant mix proportions. Unlike conventional low-frequency, high-power vibration practices, a high-frequency (40 kHz), low-power (120 W) vibration protocol was applied through PZT elements placed within the molds to enhance compaction and reduce entrapped air. Experimental results indicated that the heaviest specimen (7.13 kg) was the medium-aggregate sample compacted using tamping and rodding methods. The highest UPV value (4143 m/s) was obtained from the coarse-aggregate specimen subjected to three minutes of vibration. In contrast, the best compressive strength performance (22.73 MPa) was observed in the medium-aggregate specimen without any vibration treatment. The findings revealed that both aggregate size and advanced vibration techniques have significant effects on the mechanical properties, ultrasonic response, and surface quality of concrete. In addition, a proof-of-concept portable surface-finishing prototype consisting of a steel plate instrumented with multiple PZT transducers was developed, and preliminary trials qualitatively suggested improved surface leveling when applied in contact with the concrete surface. Surface roughness was quantified via image processing (Light Map 150 and Specular Map 150). The rough-area fraction decreased from ~29.8% in the untreated specimen to ~4.3% after ultrasonic application, indicating a marked improvement in surface leveling and overall surface quality. The results indicate that the applied PZT vibration protocol did not improve compressive strength; in several cases, particularly under prolonged excitation, a reduction in strength was observed. In contrast, a significant improvement in surface quality was achieved, with the rough-area fraction decreasing from approximately 29.8% to 4.3%. However, due to the limited number of specimens, the findings should be interpreted as preliminary. Overall, the method appears more promising as a surface enhancement technique rather than a direct alternative to conventional compaction methods.

The Horizon2020 Virus-X project was established in 2015 to explore the virosphere of selected extreme biotopes and discover novel viral proteins. To evaluate the potential biotechnical value of these proteins, the analysis of protein structures and functions is a central challenge in this program. The stability of protein sample is essential to provide meaningful assay results and increase the crystallizability of the targets. The thermal shift assay (TSA), a fluorescence-based technique, is established as a popular method for optimizing the conditions for protein stability in high-throughput. In TSAs, the employed fluorophores are extrinsic, environmentally-sensitive dyes. An alternative, similar technique is nano differential scanning fluorimetry (nanoDSF), which relies on protein native fluorescence. We present here a novel osmolyte screen, a 96-condition screen of organic additives designed to guide crystallization trials through preliminary TSA experiments. Together with previously-developed pH and salt screens, the set of three screens provides a comprehensive analysis of protein stability in a wide range of buffer systems and additives. The utility of the screens is demonstrated in the TSA and nanoDSF analysis of lysozyme and Protein X, a target protein of the Virus-X project.

This thesis describes a body of work to investigate a mechanical dry powder coating approach aiming to modify the surface properties of fine pharmaceutical powders. Powders were coated with magnesium stearate (MgSt) in order to improve their bulk powder properties such as flowability, fluidization and aerosolization. The flow characteristics of a cohesive milled lactose monohydrate powder (Pharmatose® 450M, VMD around 20 μm) were substantially improved by processing with 1% w/w magnesium stearate using a commercially available mechanofusion system. A substantially greater improvement was demonstrated for those powders coated with 1% magnesium stearate compared to those coated with 1% fumed silica. This was attributed to the different qualities of the resulting coating of the different additive materials. The improvement of the flow of powder by mechanofusion was found to be influenced strongly by particle size distribution. Modification of the surface chemical and physical properties of such fine lactose powder (Pharmatose® 450M) via mechanical dry coating was characterized. The particle surface morphology was altered from angular to more rounded forms including an apparent modified texture after the coating process, indicating the combined effects of surface coating, morphological modification and plastic deformation. The chemical component distributions measured by time-of-flight secondary ion mass spectrometry (ToF-SIMS) demonstrated a high level coverage of near continuous coating. X-ray photoelectron spectroscopy (XPS) results supported such modification in surface chemical properties quantitatively and suggested a mean coating depth of the order of a few nano-meters. The surface energy profiles measured using inverse gas chromatography (IGC) at finite dilution indicated substantial reductions in dispersive energy for the majority of the lactose surfaces after mechanofusion, although a higher dispersive energy was demonstrated at infinite dilution. The improvement in flow behaviours for this cohesive lactose powder was strongly dependent on the surface coating quality. In this study, the changes in surface chemical properties after coating generally were shown to have a more substantial impact than the changes in surface physical properties on powder flow and cohesion characteristics. The study examined the influence of surface coating model fine lactose powders on their fluidization and de-agglomeration behaviours as well as the relationship of such powder bulk properties to the aerosol performance from an inhaler device. Improvements in powder bulk behaviour by surface modification can result in a substantially improved emitted dose as well as improved de-agglomeration performance from dry powder inhalers (DPIs). The aerosol performance of three drug powders from carrier-free DPI formulations was significantly improved after mechanofusion as measured by twin stage impinger (TSI) and laser diffraction (Spraytec). Such improvements in the aerosol performance were attributed to the reduction in agglomerate strength caused by decreasing powder intrinsic cohesion after surface modification. Intensive mechanical dry coating processing was demonstrated to be an attractive simple one-step approach to modify particle surface properties, to control powder cohesion and to obtain improved and more consistent powder bulk characteristics of fine cohesive pharmaceutical powders.

Emerging trends in extrusion-based additive manufacturing (AM) focus on improving the mechanical performance of pristine polymers with high strength reinforcing materials. Prominent reviews have indicated a heavy dependence on PLA polymer for fused deposition Modeling (FDM) based studies. To promote biodegradability, the effect of natural fibres as reinforcement has been widely researched in the literature. However, it is noted that discontinuous natural fibre reinforcement yields negative or negligible improvement in the strength and modulus of FDM-based biocomposites. Hence, an attempt to hybridise FDM with a conventional composite manufacturing method was made in this study by cladding natural fibre reinforcement over FDM-based polymer. Tensile and flexural test coupons were additively manufactured by FDM and reinforced with a skin of bi-directional woven basalt fibre through compression moulding. A 90% improvement in tensile strength and a similar significant increase in flexural strength was observed. Further, an average increment of 46.38% and 237.24% in tensile and flexural modulus, respectively, was achieved through this manufacturing technique. In conclusion, a drastic improvement in mechanical performance can be obtained through the hybridisation of manufacturing methods and needs further investigation towards the compatibility of adhesive materials with FDM polymers.

Recently, additive manufacturing (AM) has gained much traction due to its processing advantages over traditional manufacturing methods. However, there are limited studies which focus on process optimization for surface quality of AM materials, which can dictate mechanical, thermal, and tribological performance. For example, in heat-transfer applications, increased surface quality is advantageous for reducing wear rates of vibrating tubes as well as increasing the heat-transfer rates of contacting systems. Although many post-processing and in situ manufacturing techniques are used in conjunction with AM techniques to improve surface quality, these processes are costly and time-consuming compared to optimized processing techniques. With improved as-built surface quality, particles tend to be better fused, which allows for greater wear resistance from contacting tube surfaces. Additionally, improved surface quality can reduce the entropy and exergy generated from flowing fluids, in turn increasing the thermodynamic efficiency of heat-transferring devices. This review aims to summarize the process-optimizing methods used in AM for metal-based heat exchangers and the importance of as-built surface quality to its performance and long-term energy conservation. The future directions and current challenges of this field will also be covered, with suggestions on how research in this topic can be improved.

Simultaneous improvement in surface quality and hardness of laser shock peened Zr-based metallic glass by laser polishing

Surface quality remains a critical factor limiting the widespread adoption of incremental sheet forming (ISF). This study proposes a novel acetal wheel-type rotating tool and systematically investigates the influence of tool structure and material on surface quality through experimental and numerical analyses. The results demonstrate that the acetal tool significantly improves surface quality by 32-40% compared to conventional metal ball tools, primarily due to enhanced sheet-tool contact area that effectively suppresses the formation of surface waviness topography. Furthermore, the wheel-type tool reduces contact stress by over 37.5% while improving surface quality by 21.1% relative to traditional metal ball tools. Notably, the acetal rotating wheel achieves a 32.0% surface quality enhancement while eliminating tool wear, highlighting its industrial applicability. These findings provide both a mechanistic understanding and a practical tooling solution, highlighting significant potential for improving surface quality in ISF industrial applications.

To enhance the forming quality of wood-plastic composite (WPC) models manufactured by fused filament fabrication (FFF) 3D printing, particularly in terms of surface quality and mechanical properties, this study analysed the 3D printing process parameters (layer height, extrusion ratio, and printing speed) for WPC filaments. Through surface roughness and tensile property tests, the optimal combination of process parameters for achieving the best forming quality was determined. Based on the optimized parameters, FFF technology and WPC filament were applied to practice 3D printing of wooden crafts. Experimental results showed that as the layer height decreases, extrusion ratio increases, and printing speed decreases, both the arithmetic average roughness (Ra) and average maximum height (Rz) of the WPC models decreased, leading to a significant improvement in surface quality. Concurrently, the mechanical properties of the WPC models were enhanced due to the increase in ultimate strength and elongation at break. Under the process conditions of 0.1 mm layer height, 110% extrusion ratio, and 20 mm/s printing speed, the printed wooden bowl and spoon exhibited excellent surface quality and favorable mechanical properties, providing a valuable reference for the application of 3D printing in the rapid fabrication of wooden crafts.

Advanced processing technology for improving the surface quality of SRIM components

The fly morphogen Hedgehog (Hh) and its mammalian orthologs, Sonic, Indian, and Desert hedgehog, are secreted signaling molecules that mediate tissue patterning during embryogenesis and function in tissue homeostasis and regeneration in the adult. The function of all Hh family members is regulated at the levels of morphogen multimerization on the surface of producing cells, multimer release, multimer diffusion to target cells, and signal reception. These mechanisms are all known to depend on interactions of positively charged Hh amino acids (the Cardin-Weintraub (CW) motif) with negatively charged heparan sulfate (HS) glycosaminoglycan chains. However, a precise mechanistic understanding of these interactions is still lacking. In this work, we characterized ionic HS interactions of multimeric Sonic hedgehog (called ShhNp) as well as mutant forms lacking one or more CW residues. We found that deletion of all five CW residues as well as site-directed mutagenesis of CW residues Lys(33), Arg(35), and Lys(39) (mouse nomenclature) abolished HS binding. In contrast, CW residues Arg(34) and Lys(38) did not contribute to HS binding. Analysis and validation of Shh crystal lattice contacts provided an explanation for this finding. We demonstrate that CW residues Arg(34) and Lys(38) make contact with an acidic groove on the adjacent molecule in the multimer, suggesting a new function of these residues in ShhNp multimerization rather than HS binding. Therefore, the recombinant monomeric morphogen (called ShhN) differs in CW-dependent HS binding and biological activity from physiologically relevant ShhNp multimers, providing new explanations for functional differences observed between ShhN and ShhNp.

On the effect upon the surface finish and mechanical performance of ball burnishing process on fused filament fabricated parts

Investigation of surface properties of physico-chemically modified natural fibres using inverse gas chromatography