Hold Time Research Articles

Effect of TiO2 and CaO Addition on the Crystallization and Flexural Strength of Novel Leucite Glass-Ceramics.

The aim of this study was to investigate the effects of TiO2/CaO addition on the crystallization and flexural strength of leucite glass-ceramics (GC). Synthesis of translucent and high strength GCs is important for the development of aesthetic and durable dental restorations. To achieve this, experimental aluminosilicate glasses (1-3 mol% TiO2 and CaO (B1, B2, B3)) were melted in a furnace to produce glasses. Glasses were ball milled, screened and heat treated via crystallization heat treatments, and characterized using XRD, differential scanning calorimetry, dilatometry, SEM and biaxial flexural strength (BFS). Increasing nucleation hold time (1-3 h) led to a reduction in crystallite number for B2 and B3 GC, and significant differences in leucite crystal size at differing nucleation holds within and across test groups (p < 0.05). A high area fraction of leucite crystals (55.1-60.8%) was found in the GC, with no matrix microcracking. Changes in the crystal morphology were found with higher TiO2/CaO addition. Mean BFS of the GC were 211.2-234.8 MPa, with significantly higher Weibull modulus (m = 18.9) for B3 GC. Novel glass compositions enriched with TiO2/CaO led to crystallization of leucite GC of high aspect ratio, with high BFS and reliability. The study's findings suggest a potential high performance translucent leucite GC for use in the construction of dental restorations.

Application of Anti-Solvent Crystallization for High-Purity Potash Production from K-Feldspar Leaching Solution

Potassium-containing feldspars provide a high potential for producing potash, a product with widespread use in agriculture. The present work assesses applying the anti-solvent crystallization method for the purification and recovery of high-purity muriate of potash (KCl) from feldspar leaching solutions. Initially, screening experiments were carried out on a synthetic leaching solution with the aim of analyzing the crystallization behavior of key components. Screening experiments were performed using five anti-solvents, namely methanol, ethanol, acetone, 2-propanol, and ethylene glycol. Acetone and 2-propanol were viable options for crystallization of potassium chloride. Then, the effects of anti-solvent ratio (O/A), time, and anti-solvent addition rate on potassium-chloride crystallization were further investigated using acetone and 2-propanol. A recovery of 83% of potassium was achieved when using acetone at the O/A of 5 with the addition rate of 10 mL/min, at room temperature with a hold time of 180 min. The optimum conditions for 2-propanol were determined to be similar, except for using a 5 mL/min addition rate for 79% recovery. The final muriate of potash products had a purity of over 99.9% using either of the anti-solvent. However, differences in morphology and crystal size of products were observed. Acetone-formed potash crystals were aggregates of cubic crystals with an average size of 3 microns, while 2-propanol-formed potash crystals were 20 microns in size as cubic particles with a hollow core. Despite having almost the same performance in potassium recovery, acetone was found to be a more feasible anti-solvent for potash recovery due to simpler downstream solvent recovery.

Hyperdoping: doping TiO2 beyond thermodynamic limits using Flash sintering

For the first time, it has been demonstrated that TiO2 optical properties can be improved by doping Fe using flash sintering. Hyperdoped TiO2 (doped with 10 at% Fe) fabricated using flash sintering, exhibited remarkable improvements in optical characteristics. Hyperdoping (exceeding the equilibrium solubility limit), induces charge trap centers or inhibits charge recombination in semiconductors. By employing XPS and UV-Vis spectroscopy, surface species alterations including oxygen vacancies, Ti4+, Ti3+, and optical characteristics were investigated. With varying holding periods, flash sintering unveiled substantial enhancements in optical absorbance and absorption regions by generating Ti3+ and oxygen vacancies. Notably, a 10-second hold time during flash sintering displayed the highest redshift among the investigated samples, indicating superior optical improvement. Oxygen vacancies and Ti3+ increased with decreased holding time during flash, suggesting the influence of flash sintering parameters on forming a metastable phase, signifying the pivotal role of flash sintering's time parameter in modulating material properties.

Effects of Process Variables on Physico-Mechanical Properties of Abura (Mitrogyna ciliata) Sawdust Briquettes

Efficient utilization of biomass requires conversion into forms that can be optimally applied in energy generation. Briquetting involves the compaction of biomass into solid blocks that are more efficient than raw biomass, and provides ease of transport and handling. These are improved when the briquettes possess a high density, shatter index, and compressive strength. Due to differences in nature and composition, it is imperative to define optimum conditions for the production of quality and durable briquettes for individual biomasses that are compacted into briquettes. This study investigated the effects of process variables on the strength, durability, and density of biomass briquettes produced using Abura sawdust. The lateral compressive strength and drop shatter index were investigated whilst varying the temperature (100–150 °C), pressure (9–15 MPa), and hold time (15–30 min). The compressive strength ranged between 2.06 and 5.15 MPa, whilst the shatter index was between 50 and 600. Briquette density was between 518.8 and 822.9 kg/m3. The pressure was significant to the determination of the compressive strength (p &lt; 0.1) and the shatter index (p &lt; 0.05). The pressure, temperature, and hold time are significant to the briquette density. Physical and mechanical characteristics of the binderless Abura sawdust briquettes can be improved by optimizing the densification variables during the briquetting process when moderate pressures are used for compaction.

Robust and fast backbone tracking via phase-locked loops

Phase-locked loops are commonly used for shaker-based backbone tracking of nonlinear structures. The state of the art is to tune the control parameters by trial and error. In the present work, an approach is proposed to make backbone tracking much more robust and faster. A simple PI controller is proposed, and closed-form expressions for the gains are provided that lead to an optimal settling of the phase transient. The required input parameters are obtained from a conventional shaker-based linear modal test, and an open-loop sine test at a single frequency and level. For phase detection, an adaptive filter based on the LMS algorithm is used, which is shown to be superior to the synchronous demodulation commonly used. Once the phase has locked, one can directly take the next step along the backbone, eliminating the hold times. The latter are currently used for recording the steady state, and to estimate Fourier coefficients in the post-process, which becomes unnecessary since the adaptive filter yields a highly accurate estimation at runtime. The excellent performance of the proposed approach is demonstrated for a doubly clamped beam undergoing bending–stretching coupling leading to a 20 percent shift of the lowest modal frequency. Even for fixed control parameters, designed for the linear regime, only about 100 periods are needed per backbone point, also in the nonlinear regime. This is much faster than what has been reported in the literature so far.

Real-World Evidence From a Digital Health Treatment Program for Female Urinary Incontinence: Observational Study of Outcomes Following User-Centered Product Design.

Urinary incontinence (UI) affects millions of women with substantial health and quality-of-life impacts. Supervised pelvic floor muscle training (PFMT) is the recommended first-line treatment. However, multiple individual and institutional barriers impede women's access to skilled care. Evidence suggests that digital health solutions are acceptable and may be effective in delivering first-line incontinence treatment, although these technologies have not yet been leveraged at scale. The primary objective is to describe the effectiveness and safety of a prescribed digital health treatment program to guide PFMT for UI treatment among real-world users. The secondary objectives are to evaluate patient engagement following an updated user platform and identify the factors predictive of success. This retrospective cohort study of women who initiated device use between January 1, 2022, and June 30, 2023, included users aged ≥18 years old with a diagnosis of stress, urgency, or mixed incontinence or a score of >33.3 points on the Urogenital Distress Inventory Short Form (UDI-6). Users are prescribed a 2.5-minute, twice-daily, training program guided by an intravaginal, motion-based device that pairs with a smartphone app. Data collected by the device or app include patient-reported demographics and outcomes, adherence to the twice-daily regimen, and pelvic floor muscle performance parameters, including angle change and hold time. Symptom improvement was assessed by the UDI-6 score change from baseline to the most recent score using paired 2-tailed t tests. Factors associated with meeting the UDI-6 minimum clinically important difference were evaluated by regression analysis. Of 1419 users, 947 met inclusion criteria and provided data for analysis. The mean baseline UDI-6 score was 46.8 (SD 19.3), and the mean UDI-6 score change was 11.3 (SD 19.9; P<.001). Improvement was reported by 74% (697/947) and was similar across age, BMI, and incontinence subtype. Mean adherence was 89% (mean 12.5, SD 2.1 of 14 possible weekly uses) over 12 weeks. Those who used the device ≥10 times per week were more likely to achieve symptom improvement. In multivariate logistic regression analysis, baseline incontinence symptom severity and maximum angle change during pelvic floor muscle contraction were significantly associated with meeting the UDI-6 minimum clinically important difference. Age, BMI, and UI subtype were not associated. This study provides real-world evidence to support the effectiveness and safety of a prescribed digital health treatment program for female UI. A digital PFMT program completed with visual guidance from a motion-based device yields significant results when executed ≥10 times per week over a period of 12 weeks. The program demonstrates high user engagement, with 92.9% (880/947) of users adhering to the prescribed training regimen. First-line incontinence treatment, when implemented using this digital program, leads to statistically and clinically substantial symptom improvements across age and BMI categories and incontinence subtypes.

Effect of Hold Time on Electrical Properties of Lithium Zinc Borate Glass Ceramics for Energy Storage Applications

Effect of Hold Time on Electrical Properties of Lithium Zinc Borate Glass Ceramics for Energy Storage Applications

Cyclic deformation behaviors and damage mechanisms in P92 steel under creep-fatigue loading: Effects of hold condition and oxidation

P92 steel has gained plenty of attention as a top contender for steam generator components and main steam tubes due to the growing need to increase the energy conversion efficiency. However, a major contributor to the premature failure of these components remains the interaction of creep and fatigue damage caused by typical dwell fatigue loading conditions. In this study, creep-fatigue tests of P92 steel were conducted under strain-controlled cyclic loading including hold durations up to 3600 s at 873 K in air. Special attention was given to the influence of hold conditions and oxidation on cyclic deformation and damage mechanisms. The results revealed that introducing hold time substantially decreased the failure life, with compressive hold causing more severe damage than tensile hold. Additionally, oxidation became severer with longer hold time, resulting in increased surface roughness, crack initiation sites and density of secondary cracks. Fatigue dominated the failure in the case of the short-term tensile hold, and the interaction of creep, fatigue and oxidation dominated the failure in long-term tensile hold tests. In contrast, the failure in compressive hold case was dominated by fatigue and severe oxidation. Furthermore, a three-dimensional oxidation-creep-fatigue damage interaction diagram was proposed for quantitative assessments in practice.

Determining the Reactivity of Selected Biomass Types Considering Their Application in Pyrometallurgical Processes of Metal Production.

In this paper, results of research on the reactivities of selected biomass types considering their application in pyrometallurgical processes of metal production are presented. Walnut shells, sunflower husk pellets and spent coffee grounds were selected as biomass materials. Their use as potential reducers in the process of metallurgical slag decopperisation is an innovative approach to this subject. The thermogravimetric findings show that all three tested biomass types are classified as highly reactive. The time to reach maximum reactivity ranges from 1.5 to 3 min and, the lowest value is recorded for the sample of spent coffee grounds. The sample hold time of two hours enables copper content reduction to approx. 1 wt% for practically all the reducers tested. A longer duration of liquid slag contact with the reducer results in a decreased copper content in the slag to a value below 1 wt%. Copper concentrations of 0.5 wt% and lower are observed with a hold time of 4 h. The preliminary results indicate that there is great potential for the use of this type of material in non-ferrous metallurgy, which may translate into replacing fossil raw materials and thus introducing the principles of a sustainable process in this case of metal production.

Assessing Potential Bias in PFAS Concentrations in Groundwater and Surface Water Samples

AbstractPer‐ and polyfluoroalkyl substances (PFAS) encompass a large group of recalcitrant anthropogenic compounds that have been used in a variety of consumer and industrial products and processes over many decades. Drinking water standards were recently finalized for two PFAS at low nanogram per liter concentrations. Due to the widespread use of PFAS and low health‐based thresholds, a literature review and laboratory and field studies were conducted to assess several potential sources of bias in PFAS concentrations. Fluoropolymers are commonly present in equipment, products, and materials used during field sampling, potentially leading to false positive results. Laboratory results confirmed the presence of PFAS in multiple commonly used field materials. However, best practices can be used to limit pathways for cross contamination. Laboratory‐specified hold times and sample storage temperatures are scientifically founded and adequately prevent bias due to PFAS sorption to sampling containers or partial degradation of some PFAS to form others. PFAS are also known to accumulate at the air‐water interface and other interfaces. Results from laboratory and field studies indicate that PFAS enrichment in foam and in the surface microlayer does occur. However, the effect of this phenomenon is within the range of analytical and spatial sampling variability and therefore a change in sampling procedures is not needed. Findings were distilled into science‐based and practical recommendations to minimize bias during PFAS sampling without incurring unnecessary cost and effort.

A phase-field fracture model for creep-fatigue behavior

A phase-field fracture model for creep-fatigue behavior is proposed. The fatigue and creep behavior are simulated by modifying the free energy functional through a total degradation function that diminishes fracture toughness with the accumulation of the relevant history variable. Specifically, strain energy density and creep strain serve as the chosen fatigue and creep history variables, respectively. To model the creep-fatigue interaction, we propose several total degradation function formulations comprising fatigue and creep degradation functions. Numerical experiments demonstrate the capability of our model to reproduce the strain-lifetime relationship and crack growth behavior under creep-fatigue loading conditions with varying hold times. Moreover, we simulated examples of plates with holes, demonstrating the capability of our model for complex crack paths.

VSG Sequence Impedance Modeling and Stability Analysis of Dead-Beat Control

Virtual Synchronous Generator uses dead-beat predictive control in the voltage and current loop to improve the dynamic response speed of the system, but the presence of zero-order hold and computation time can lead to system instability. To address this issue, this paper adopts an improved dead-beat predictive control strategy for VSG. This is achieved by linear interpolation to forward predict voltage-current reference values to reduce the impact of delay, while introducing error compensation coefficients to enhance the stability of the voltage-current inner loop of VSG. The selection of error compensation coefficients is based on closed-loop impulse response functions. A harmonic linearization method is used to construct a complete sequence impedance model of VSG, and it's stability is analyzed. The results indicate that VSG's negative sequence impedance exhibits instability in the low-frequency range. To address this, a method of introducing a virtual resistor into VSG is proposed to improve stability. By constructing a sequence impedance model of VSG that includes virtual resistance, the variations in system stability under different virtual resistances and grid impedances are analyzed. The effectiveness of the proposed method is verified by building a VSG model.

Thermal Fatigue Failure of Micro-Solder Joints in Electronic Packaging Devices: A Review

In electronic packaging products in the service process, the solder joints experience thermal fatigue due to temperature cycles, which have a significant influence on the performance of electronic products and the reliability of solder joints. In this paper, the thermal fatigue failure mechanism of solder joints in microelectronic packages, the microstructure changes of the thermal fatigue process, the influence factors on the joint fatigue life, and the simulation analysis and forecasting of thermal fatigue life are reviewed. The results show that the solder joints are heterogeneously coarsened, and this leads to fatigue cracks occurring under the elevated high-temperature phase of alternating temperature cycles. However, the thickness of the solder and the hold time in the high-temperature phase do not significantly influence the thermal fatigue. The coarsened region and the IMC layer thicken with the number of cycles, and the cracks initiate and propagate along the interface between the intermetallic compound (IMC) layer and coarsened region, eventually leading to solder joint failure. For lead-containing and lead-free solders, the lead-containing solder shows a faster fatigue crack growth rate and propagates by transgranular mode. Temperature and frequency affect the thermal fatigue life of solder joints to different degrees, and the fatigue lifetime of solder joints can be predicted through a variety of methods and simulated crack trajectories, but also through the use of a unified constitutive model and finite element analysis for prediction.

An integrated experimental and analytical approach on mechanical characterization of advanced powder metallurgy aluminium metal matrix composites reinforced with different particulates

Over the last few decades, ‘Discontinuously Reinforced Particulate Composites (DRPCs)’ are a popular class of composite materials with considerable challenge in processing, characterization and machinability because of their increased strength-weight ratio, stiffness, specific strength and oxidization when compared to various metals and their alloys. This paper discusses experimental and numerical investigation on mechanical characteristics of aluminum metal matrix reinforced with various reinforcement particulates such as silicon carbide, aluminium oxide, and zirconium oxide, compaction pressure (kN) and hold time (s) based on Design of Experiments (DOE) and Finite Element Analysis. Initially this paper discusses the process optimization of Aluminum Matrix reinforced with different particulates experimentally to identify the favourable processing conditions by varying reinforcement materials, compaction pressure (kN) and hold time (s) based on TDOE (Taguchi’s Design of Experiments). Further, this paper concentrates to determine ‘maximum principal stress, equivalent elastic strain and equivalent (von-mises) stress’ based on Finite Element Analysis (ANSYS Workbench-2023R1). The results of the experimentation showed that the highest hardness values were achieved with ZrO2 reinforcement material. Increasing the compaction pressure from 8 to 12 kN resulted in a slight decrease in surface roughness and porosity. Higher compaction pressures have assumed to facilitate better particle distribution and improved interfacial bonding, leading to smoother surfaces and lower void content. The simulation results showed that the maximum principal stress achieved were (2235.8 MPa) SiC, (3444.4 MPa) Al2O3, and (3582.5 MPa) ZrO2. The equivalent elastic strain achieved was (0.2488) SiC, (0.2421) Al2O3 and (0.262) ZrO2. The equivalent (Von Mises) stress achieved was (28751 MPa) for SiC, (24880 MPa) for ZrO2 and (26972 MPa) for Al2O3. This experimentation and simulation demonstrated that the PM process can be used to fabricate DRAMMC with different reinforcement particulates. The understanding gained experimentally and analytically from this research can be applied for future processing of Aluminum Matrix Reinforced with different particulates.

Influence Factors of Platinum Dissolution in Proton Exchange Membrane Fuel Cells: A Sensitivity Study

Polymer electrolyte fuel cells for heavy-duty applications require lifetimes beyond 30,000 h, which poses a durability challenge. In this study, we investigated the influence of various factors on loss of electrochemically active surface area (ECSA) in the cathode, which is a major limiting factor. We derive a parameter range from simulated drive cycles showing that the voltage ranges between 0.70 and 0.85 V and that the cells are in idle state at upper potential limit (UPL) most of the time. We evaluate the influence and interaction of UPL, lower potential limit (LPL), temperature, relative humidity, and cycle time on ECSA and performance at four different operating conditions after 10,000 potential cycles based on 25 experiments. The results indicate that UPL and the hold time at UPL have the strongest impact on degradation, while LPL has a small impact, which does not increase below the potential of full platinum reduction (0.55 V) or hold times longer than 2 s. Furthermore, the interaction of humidity with other factors becomes significant for long experiment times. In summary, the findings of this work can serve as guidelines for minimizing ECSA loss, e.g. by keeping the fuel cell in a benign operation regime via systems control.

Interlaboratory study of the operational stability of automated sorption balances

Automated sorption balances are widely used for characterizing the interaction of water vapor with hygroscopic materials. These instruments provide an efficient way to collect sorption isotherm data and kinetic data. A typical method for defining equilibrium after a step change in relative humidity (RH) is using a particular threshold value for the rate of change in mass with time. Recent studies indicate that commonly used threshold values yield substantial errors and that further measurements are needed at extended hold times as a basis to assess the accuracy of abbreviated equilibration criteria. However, the mass measurement accuracy at extended times depends on the operational stability of the instrument. Published data on the stability of automated sorption balances are rare. An interlaboratory study was undertaken to investigate equilibration criteria for automated sorption balances. This paper focuses on the mass, temperature, and RH stability and includes data from 25 laboratories throughout the world. An initial target for instrument mass stability was met on the first attempt in many cases, but several instruments were found to have unexpectedly large instabilities. The sources of these instabilities were investigated and greatly reduced. This paper highlights the importance of verifying operational mass stability of automated sorption balances, gives a method to perform stability checks, and provides guidance on identifying and correcting common sources of mass instability.

Production of native recombinant proteins using a novel split intein affinity technology

Affinity tags are frequently engineered into recombinant proteins to facilitate purification. Although this technique is powerful, removal of the tag is desired because the tag can interfere with biological activity and can potentially increase the immunogenicity of therapeutic proteins. Tag removal is complex, as it requires adding expensive protease enzymes. To overcome this limitation, split intein based affinity purification systems have been developed in which a CC-intein tag is engineered into a protein of interest for binding to a NC-intein peptide ligand fixed to a chromatographic support. Tag removal in these systems is achieved by creating an active intein-complex during protein capture, which triggers a precise self-cleavage reaction. In this work, we show applications of a new split intein system, Cytiva™ ProteinSelect™. One advantage of the new system is that the NC-intein ligand can be robustly produced and conjugated to large volumes of resin for production of gram scale proteins. SARS-CoV-2 spike protein receptor binding domain and a Bispecific T Cell Engager in this work were successfully captured on the affinity resin and scaled 10-fold. Another advantage of this system is the ability to sanitize the resin with sodium hydroxide without loosing the 10–20 g/L binding capacity. Binding studies with IL-1b and IFNAR-1 ECD showed that the resin can be regenerated and sanitized for up to 50 cycles without loosing binding capacity. Additionally, after several cycles of sanitization, binding capacity was retained for the SARS-CoV-2 spike protein receptor binding domain and a Bispecific T Cell Engager. As with other split intein systems, optimization was needed to achieve ideal expression and recovery. The N-terminal amino acid sequence of the protein of interest required engineering to enable the cleavage reaction. Additionally, ensuring the stability of the CC-intein tag was important to prevent premature cleavage or truncation. Controlling the hold time of the expression product and the prevention of protease activity prior to purification was needed. These results demonstrate the feasibility of the Cytiva™ ProteinSelect™ system to be used in academic and industrial research and development laboratories for the purification of novel proteins expressed in either bacterial or mammalian systems.

Metallothermic reduction of Cerium Chloride in molten Salt using Li, Na, and Ca Metal

Options for reducing purified metal chlorides to metallic form were evaluated in support of the development of a metal purification process based on the conversion of impure metal via hydriding followed by chlorination. Metallothermic reduction of CeCl3 was tested using Li, Ca, and Na as reductant metals with and without a molten salt solvent in MgO and Y2O3-coated MgO crucibles. The effects of added reductant metal form, crucible material and dimensions, and mixture hold times above Ce melting temperature were studied. Direct contact of Li and CeCl3 was ineffective due to their immiscibility. A low-density alloy was formed between Li and Ce using Li in a LiCl solvent. Na was ineffective at reducing CeCl3 to any measurable degree. The highest percent recovery (71.4 %) and consolidation of Ce was achieved when using Ca in a CaCl2-NaCl solvent with 99.8 % removal of CeCl3 from the salt. Side reaction with MgO crucibles was found to be at least partially responsible for reduced Ce recovery.

Presence of hazardous chemical elements in low-cost children's toys: A risk to their development in early childhood

ObjectivesThe objectives of the current study was to study the presence of hazardous chemical elements (Ba138, Cd111, Cr52, Pb208, As75, Co59, Cu63, Mn55, Ni60, Se82, Sr88, Zn66 and Hg202) in low-cost children's toys, and the effect of color types on chemical element concentrations. MethodsChildren's toy samples were analyzed using microwave digestion and inductively coupled plasma/mass spectrometry (ICP/MS) method. Samples were prepared into small pieces, and 500 mg of homogenized sample was used for digestion by means of digesting regents HNO3 (65 %, 5 mL) and H2O2 (35 %, 1 mL). During the digestion process, the pressure was held constant at 90 bar and the temperature, hold time, and power were varied 150–170-40° C, 10–30-5 min, 70–90-0 %, respectively. The main operating conditions of ICP/MS were: spray chamber temperature (−20 °C), RF Power (1450 W), nebulizer gas flow (0.9 L/min), auxiliary gas flow (0.8 L/min) and plasma gas flow (14.85 L/min). Samples and blanks were analyzed for 30 s and system was operated in standard mode. ResultsThe excellent method performance was achieved in terms of limit of detection (LOD, 0.001–14.89 µg/L); limit of quantification (LOQ, 0.003–45.12 µg/L); correlation coefficient (R2, 0.975–0.999) with relative standard deviation values (RSD, 0.70–4.98 %). Chemical elements were found in all the toys (0.01–742.72 ng/g) except sample S2 where only Hg202 was found (0.01 ng/g). Outcomes revealed that the Hg202 was present at a very low level (0.01 ng/g) while Zn66 was present at very high level (742.72 ng/g). Furthermore, the toys contamination was also found to be color-specific, with significant amount of chemical elements was found in black type car sample (S5, 946.98 ng/g) whereas other color type samples constitute lower amounts (0.001–210.53 ng/g). Low-cost toys designed for children's use are found to contain chemical elements that should be addressed in the course of action. As a result of exposure to high amounts of chemical elements in toys, children have a high chance of developing cancer.

A novel experimental technique to determine the tack development during automated placement of uncured thermoset carbon/epoxy tows

In-situ bond strength toughness (IBST), commonly referred to as tow tackiness, is a first order property affecting the adherence quality and defect formation (e.g., wrinkles, folds) during automated tow placement (ATP) processing of uncured thermoset polymer matrix composite (PMC) tows. Tow-tow IBST develops over characteristic millisecond timescales (tc≤50ms) due to the rapid tow placement velocity of ∼1 m/s. In this paper, an experimental technique is presented to determine millisecond timescale tow-tow mode-I IBST in terms of fracture mechanics-based traction-separation relationship. The test specimen consists of two tows bonded to rigid platens with a pre-crack between them to induce crack initiation. Experiments are performed using IM7-G/8552 carbon/epoxy prepregs for both long and short timescales at a constant debonding rate of 5 mm/s, contact pressure of 0.23 MPa, and bonding temperature of 40 °C. In addition, high-speed two-dimensional digital image correlation (2D-DIC) is used to image and measure the tow-tow interfacial deformation during debonding. The peak traction and apparent energy release rate are found to significantly decrease (about 60 %) at the short millisecond timescale contact hold times compared to longer (i.e., second) timescale.