Illinois Tool Works (United States)

Gallium-based liquid metals (LMs) are materials that possess some unique properties. Just like any other metal, they have high thermal conductivity and low interfacial resistance, but they are in a liquid phase at room temperature. In contrast to mercury alloys, gallium alloys are non-toxic. They don’t evaporate and they can’t be inhaled. The viscosity of those alloys is very similar to water, but they are six times as dense as water. All those properties make Gallium-based liquid metals very good candidates for thermal interface material (TIM) in electronics applications. On the other hand, the reaction and incompatibility of those alloys with some metals is one of the challenges for this type of TIM. The other challenge is that those materials are not just thermally, but also electrically conductive and that is not a desirable property for TIM. A suitable barrier that will prevent any leakage of LMs and the best way to apply the appropriate volume of LM in high-volume production (HVP) would be one of the most important things for any application. A key challenge is applying the liquid metal consistently through a traditional dispensing method due to its property and behavior which involves high surface tension. Through advanced dispensing techniques like jetting technology liquid metal can be applied reliably on a flat, uneven surface or in arrays of minuscule confined spaces or cavities. This paper highlights the dispensing quality, weight repeatability from one substrate to another, and valve hardware stability. This paper will also address the challenges faced during dispensing of liquid metal in high volume manufacturing, and how to achieve desired bondline thickness with jet dispensing for higher throughput and process reliability.

Background: Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. Ventricular arrhythmias (VAs), including ventricular tachycardia and ventricular fibrillation, are often life-threatening in setting of AMI. While advances in revascularization have improved outcomes, the burden of AMI and VA-related mortality across U.S. subpopulations remains unclear. We aimed to assess trends and demographic disparities in AMI and VA-related deaths in the United States. Methods: We analyzed national mortality data from the CDC WONDER database between 1999 and 2020. Deaths attributed to AMI and VAs were identified using ICD codes. Age-adjusted mortality rates (AAMRs) per 100,000 population and 95% confidence intervals (CIs) were calculated and stratified by sex, race/ethnicity, age group, and geographic region. Results: A total of 71,036 deaths were attributed to AMI and VAs over the study period. The AAMR declined sharply from 2.41 in 1999 to 1.08 in 2007 (APC: -9.91; 95% CI: -10.7 to -9.02). From 2007 to 2020, a gradual decline in mortality was observed (1.08 to 1.01) (APC: -0.83; 95% CI: -1.47 to -0.19). Men had consistently higher AAMR than women from 1999 (4.39 vs 1.88) to 2020 (1.84 v s0.68); moreover, since 2008, no significant decline in mortality was observed for males. Whites had the highest number of deaths (n=62,157; AAMR: 1.51 [95% CI: 1.50–1.52]), followed by Blacks or African Americans (1.43 [95% CI: 1.39–1.46]), American Indians (1.10 [95% CI: 0.98–1.22]), Hispanics (1.04 [95% CI: 1.00–1.07]), and Asian or Pacific Islanders (0.89 [95% CI: 0.85–0.94]). All races had a significant decline in mortality across years; however, Hispanics had a rise in mortality from 2011-2020 (APC: 3.06; 95% CI: 0.82 to 5.36). Mortality increased markedly with age: older adults (≥65 years) had a 49-fold higher AAMR (5.38 vs 0.11) compared to younger adults. There was also a significant state-wide difference in mortality as shown in Figure 1. Conclusion: AMI and VA-related mortality in the US from 1999–2020 remained substantial, with significant disparities by age, sex, race, and region. Older adults, males, and those residing in the South experienced the highest mortality burden. Hispanic had a increase in mortality since 2011. These findings underscore the continued need for targeted prevention, early recognition of electrical complications of AMI, improved post-AMI surveillance, and equitable access to life-saving interventions like ICDs.

Previous studies have shown that the heterotrimeric G protein, Gsalpha (Gsα), is ensconced predominantly in lipid rafts in acutely depressed subjects with major depressive disorder (MDD) in contrast to healthy controls, and that effective antidepressant treatment (ADT) facilitates translocation of Gsα from lipid rafts. The measurement of Gsα via prostaglandin E1 stimulation of adenylyl cyclase (PGE1 stimulation) has been proposed as a peripheral biomarker for assessing clinical status in MDD. We examined the Gsα biomarker in a new study. PGE1 stimulation was used to assess the coupling of Gsα with platelet adenylyl cyclase in depressed subjects in active treatment and healthy controls. The Quick Inventory of Depressive Symptomatology (QIDS-C16) measured thresholds of symptom severity at two study visits spaced 2 weeks apart. QIDS-C16 scores and PGE1 stimulated responses were stable between the two study visits. The QIDS-C16 was inversely correlated with PGE1 stimulated responses at each visit (rs = -0.33, rs = -0.60, respectively). MDD subjects with mild-moderate depressive symptoms (defined by QIDS-C16 ≥ 6) had significantly lower PGE1 stimulated responses than asymptomatic MDD subjects (QIDS-C16 < 6) or healthy controls (p = 0.001 and 0.002 respectively). MDD subjects with moderate depressive symptoms (QIDS-C16 ≥ 10) had the lowest PGE1 responses of all subjects (Fisher's exact = 0.012). These results support our earlier findings that a simple, high-throughput-capable platelet assay may be a useful biomarker to assess the clinical status of depressed subjects. Larger studies are needed to evaluate the utility of this biomarker for diagnosis and treatment response.

Background: Inspiratory synchronized vibrating mesh nebulizer (iVMN) has been reported to improve aerosol delivery during mechanical ventilation in adult models. A prototype VMN generating smaller aerosol particles than conventional VMN was developed. We aimed to compare the delivery efficiency of small and standard aerosol particles with an iVMN prototype and conventional controller during neonatal and pediatric mechanical ventilation. Methods: A critical care ventilator with heated ventilator circuit (pediatric and neonatal) was connected to an endotracheal tube (ETT) attached to a collecting filter and passive test lung. Set parameters for pediatric was volume control (VC), VT 100 mL, frequency 25 breaths/min, Ti 0.8 s, PEEP 5 cm H2O, bias flow 3.5 L/min, I:E 1:2 and ETT 4.0 mm ID. Set parameters for neonate was VC, VT 24 mL, frequency 30 breaths/min, Ti 0.67 s, PEEP 5 cm H2O, bias flow 2 L/min, I:E 1:2 and ETT 3.5 mm ID. 1mL of albuterol (2.5 mg/mL) was administered with prototype small particle and conventional VMN, in iVMN and continuous mode, placed at inlet of humidifier, inspiratory limb at Y-piece, and between the Y-piece and ETT (n = 5). Albuterol was eluted from the collection filter and assayed with UV spectrophotometry (276 nm). Results: Percent of albuterol dose inhaled (mean ± standard deviation) are shown in Table 1, 2. Compared to continuous VMN, iVMN generated higher inhaled dose in both neonatal and pediatric mechanical ventilation, regardless of nebulizer placement and particle sizes (all P <.05). During neonatal mechanical ventilation, inhaled dose was higher with VMN placed between ETT and Y-piece than at the inlet of humidifier, regardless of aerosol generating modes and particle sizes (all P <.05). During pediatric mechanical ventilation, the inhaled dose was highest with continuous VMN placed at the inlet of humidifier. When iVMN was used, the inhaled dose was highest with small-particle VMN placed between ETT and Y-piece and no significant differences in conventional VMN placements. Small-particle VMN outperformed conventional VMN only when nebulizer was placed between ETT and Y-piece. Conclusions: During neonatal mechanical ventilation, aerosol delivery was higher with nebulizer placed between ETT and Y-piece than inlet of humidifier, regardless of the aerosol generating modes and particle sizes. During pediatric ventilation, highest aerosol delivery was achieved with continuous VMN placed at the inlet of humidifier and small particle iVMN placed between ETT and Y-piece.

X-ray measurements of diesel sprays from two of the Engine Combustion Network (ECN) Spray B injectors are described. Measurements in these three-hole nozzles complement both visible light measurements of these sprays and previous x-ray measurements of the axial single-hole ECN Spray A injectors. Both axial and lateral motions of the injector needle valve were measured with x-ray phase contrast imaging. Additionally, the liquid mass distribution in room temperature sprays at elevated ambient pressure was determined with x-ray radiography. Measurements of both needle valve motion and spray distribution were performed at both the standard Spray A/B conditions and with selected variations of injection pressure, ambient density, and injection timing. The needle valve motion for the Spray B injectors is quite similar to that of the Spray A injectors, though little lateral motion is seen in either Spray B injector. Compared to the sprays from the Spray A injectors, the sprays from Spray B penetrate more slowly in the near-nozzle region, demonstrate a broader, more uniform distribution in the transverse direction, and are significantly more variable with respect to time. These differences demonstrate the importance of studies with multi-hole nozzles to provide insight into applied diesel combustion.

PURPOSE: Assessment of ventilatory constraint has become essential in the assessment of exercise performance. However, minimal data exists regarding a systematic evaluation of these constraints in an elite athletic population. The study was performed to provide new normative data and preliminary analysis of how these variables correlate. METHODS: Twenty four individuals were analyzed as part of a human performance evaluation. 16 individuals competed in Div 1 soccer (16F, age 18-22 yrs) and 8 in AAA hockey (8M, age 13-14 yrs). A graded maximal exercise test was performed (Bike: Lode Excalibur) with breath by breath gas analysis (Med Graphics). Expiratory flow limitation (EFL%), VE/MVV, ventilatory reserve capacity (VRC%), shift in EELV (IC/VC%), shift in EILV (VT/IC%), and inspiratory reserve (IR) were recorded. Spearman coefficients were determined between ventilatory constraint and exercise variables. Unpaired Student t tests were performed for comparison within constraint variables. Values are expressed as mean±SD with significance set at p<0.05. RESULTS: All constraint variables were obtained except IR (incomplete data). EFL% (37.8+26.5), VRC% (90.2+1.7), IC/VC% (65.1+8.9), VE/MVV% (100.4+8.5) and VT/IC% (83.5+7.7) did not vary by sport. EFL% correlated to VRC% (r=0.57, p<0.05) and weakly correlated to IC/VC% (r=0.35, p=0.09) but not VE/MVV% or VT/IC%. No relationship existed between the remaining variables. VO2 (ml/kg lean body mass) was higher for VE/MVV >100% than <100% (64.2+6.1 vs 59.9+3.4, p<0.05). Peak work capacity (PWC)/LBM, % of predicted, was similarly affected (142.5+10.5 vs 153.6 + 10.2, p<0.05). For IC/VC%, higher PWC (297.7+47.3 vs 265.8+22.3 Watts, p<0.05) and VO2 (3.32+0.51 vs 2.98+0.29 liters, p<0.05) were seen in the low IC/VC group (<65%) compared to the high group (>65%). EFL% and VT/IC% did not correlate with PWC or VO2. CONCLUSIONS: Ventilatory constraint analysis yielded normative data. EFL was associated with ventilatory reserve. However, unlike previous data in cystic fibrosis, VE/MVV was not correlated to ventilatory constraint. While a shift in EELV (IC/VC%) may be considered abnormal in underlying respiratory diseases, the ratio in this study was associated with increased exercise performance reflecting different underlying compensatory breathing mechanics.

The work presented here aims to develop and transition angled-beam shear-wave inspection techniques for crack localization at fastener sites in multi-layer aircraft structures. This requires moving beyond detection to achieve reliable crack location and size, thereby providing invaluable information for maintenance actions and service-life management. The technique presented is based on imaging cracks in “True” B-scans (depth view projected in the sheets along the beam path). The crack traces that contribute to localization in the True B-scans depend on small, diffracted signals from the crack edges and tips that are visible in simulations and experimental data acquired with sufficient gain. The most recent work shows that cracks rotated toward and away from the central ultrasonic beam also yield crack traces in True B-scans that allow localization in simulations, even for large obtuse angles where experimental and simulation results show very small or no indications in the C-scans. Similarly, for two sheets joined by sealant, simulations show that cracks in the second sheet can be located in True B-scans for all locations studied: cracks that intersect the front or back wall of the second sheet, as well as relatively small mid-bore cracks. These results are consistent with previous model verification and sensitivity studies that demonstrate crack localization in True B-scans for a single sheet and cracks perpendicular to the ultrasonic beam.

Process Compensated Resonant Testing (PCRT) is a full-body nondestructive testing (NDT) method that measures the resonance frequencies of a part and correlates them to the part’s material and/or damage state. PCRT testing is used in the automotive, aerospace, and power generation industries via automated PASS/FAIL inspections to distinguish parts with nominal process variation from those with the defect(s) of interest. Traditional PCRT tests are created through the statistical analysis of populations of “good” and “bad” parts. However, gathering a statistically significant number of parts can be costly and time-consuming, and the availability of defective parts may be limited. This work uses virtual databases of good and bad parts to create two targeted PCRT inspections for single crystal (SX) nickel-based superalloy turbine blades. Using finite element (FE) models, populations were modeled to include variations in geometric dimensions, material properties, crystallographic orientation, and creep damage. Model results were verified by comparing the frequency variation in the modeled populations with the measured frequency variations of several physical blade populations. Additionally, creep modeling results were verified through the experimental evaluation of coupon geometries. A virtual database of resonance spectra was created from the model data. The virtual database was used to create PCRT inspections to detect crystallographic defects and creep strain. Quantification of creep strain values using the PCRT inspection results was also demonstrated.