Tip Distance Research Articles

Heart Shape to Fracture Distance: Characterizing Hydraulic Fracture Propagation before Hits

Summary Estimating the distance from the hydraulic fracture tip to the monitor well can be useful for fracture characterization, well spacing optimization, and preventing parent-child well interference. A heart-shaped signal is referred to as the extensional precursor of a fracture hit recorded by crosswell strain measurements and can serve as a vital tool for such estimation. This study incorporates the 3D displacement discontinuity method (DDM) to understand the impact of fracture geometry and monitor well offset on the heart-shaped signal’s characteristics. Results from numerical simulation and analytical solutions reveal a strong linear correlation between the spatial extent of the heart-shaped signal and the fracture tip distance. This relationship was further developed to predict tip distance using field data from the Hydraulic Fracture Test Site 2 (HFTS2). A reasonable approximation result from field data further validates the methodology. In addition, it is worth noting that the estimation accuracy depends on the ratio between fracture dimension and tip distance. The findings of this study offer a novel approach for real-time monitoring and characterizing hydraulic fracture propagation, which can be further used for well spacing optimization in unconventional and enhanced geothermal system reservoir development, as well as caprock integrity monitoring for carbon sequestration projects.

The red giant branch tip in the SDSS, PS1, JWST, NGRST, and Euclid photometric systems

We used synthetic photometry from Gaia DR3 BP and RP spectra for a large selected sample of stars in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) to derive the magnitude of the red giant branch (RGB) tip for these two galaxies in several passbands across a range of widely used optical photometric systems, including those of space missions that have not yet started their operations. The RGB tip is estimated by fitting a well motivated model to the RGB luminosity function (LF) within a fully Bayesian framework, allowing for a proper representation of the uncertainties of all the involved parameters and their correlations. By adopting the best available distance and interstellar extinction estimates, we provide a calibration of the RGB tip as a standard candle for the following passbands: Johnson-Kron-Cousins I (mainly used for validation purposes), Hubble Space Telescope F814W, Sloan Digital Sky Survey i and z, PanSTARRS 1 y, James Webb Space Telescope F090W, Nancy Grace Roman Space Telescope Z087, and Euclid IE, with an accuracy within a few per cent, depending on the case. We used theoretical models to explore the trend of the absolute magnitude of the tip as a function of colour in the different passbands (beyond the range spanned by the LMC and SMC), as well as its dependency on age. These calibrations can be very helpful to obtain state-of-the-art RGB tip distance estimates to stellar systems in a very large range of distances directly from data in the natural photometric system of these surveys and/or missions, without recurring to photometric transformations. We have made the photometric catalogues publicly available for calibrations in additional passbands or for different approaches in the estimate of the tip, as well as for stellar populations and stellar astrophysics studies that may take advantage of large and homogeneous datasets of stars with magnitudes in 22 different passbands.

Posture Estimation Model Combined With Machine Learning Estimates the Radial Abduction Angle of the Thumb With High Accuracy.

The thumb function is complex, and accurate evaluation through images or videos is difficult. Pose estimation, a technology that uses artificial intelligence (AI) to estimate skeletal detection of the body, is gaining popularity.In this study, we combined the pose estimation library MediaPipe-Hands and five machine learning (ML) models to predict the radial abduction angle of the thumb.Radial abduction movements of 20 hands from 10 healthy volunteers were captured on video and processed into 5,000 images. Angle measurements by goniometer were used as true values to evaluate the angle reliability of the MediaPipe-Hands and the angle reliability of the MediaPipe-Hands combined with ML. The correlation coefficient (CC) between the angle measured by goniometry and the angle calculated by MediaPipe-Hands was 0.84. In contrast, applying ML to MediaPipe-Hands resulted in models with improved accuracy, and all models showed high CCs (0.94-099) with angle measurements taken by goniometry. The ML model also predicted the abduction angles when the camera was taken from three different angles. In visualizing the features that the AI deemed important, the ML model predicted the abduction angle by focusing on the tip distance between the thumb and index finger along with the angle of the metacarpophalangeal joint between the thumb and middle finger. These results enable angle estimation even without frontal imaging with a camera, and expansion of this system may lead to real-time functional assessment in telemedicine and rehabilitation without the need for physical contact.

A new species of the Amolops monticola group (Anura, Ranidae) from southern Yunnan, China

A new species of the Amolops monticola group is described from Yunnan Huanglianshan National Nature Reserve, southern Yunnan, China. Morphologically, the new species is characterized by a moderate body size (snout–vent length 38.3–40.8 mm in adult males and 62.3–63.1 mm in adult females), head being longer than wide, nostril to snout tip distance being slightly smaller than eye to nostril distance, the presence of pineal body, distinct tympanum, vomerine teeth being invisible in males and weak but visible in females, distinct dorsolateral folds, the absence of outer metatarsal tubercle, the presence of vocal sac and nuptial pad in adult males, dorsal surface of head and body being green with no or a few black dots, and the presence of a few large flat white tubercles on the posterior inferior flank. Genetically, the uncorrected genetic distance between the new species and other species of the A. monticola group ranged from 3.0% to 7.6% in 16S ribosomal RNA and from 7.2% to 17.1% in NADH dehydrogenase subunit 2 gene sequences. Currently, the new species is known only from its type locality in Lvchun County, Honghe Prefecture, Yunnan Province, China.

C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery

ObjectiveTo describe the feasibility, safety and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with the high-riding vertebral artery (HRVA). MethodsDuring the period January 2020 to September 2022, fifteen patients underwent posterior occipitocervical fixation in our department. All patients had unilateral HRVA on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 13 females aged 47 ± 11.9 years (range: 17–64 years). After the correction of the vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. A routine three-dimensional reconstructed CT examination was executed to confirm the trajectory of C2 pedicle screws post-operation, and a CT angiography examination was performed when necessary. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including anterior atlantodental interval (ADI), the distance of odontoid tip above Chamberlain line, and clivus-canal angle (CCA), were collected and compared by paired t-test. ResultsAll 15 patients had atlas assimilation, among which 12 patients had C2–C3 fusion (Klippel-Feil syndrome). Mobilization of the HRVA was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were reached in all 15 patients. All the patients achieved bone fusion 6 months after surgery. No looseness and shift of internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative JOA score and the main radiological measurements were remarkably improved and statistically significant. ConclusionsC2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

Learning Curves of Harvester Operators in a Simulator Environment

Simulator training helps provide safe and cost-effective training for operators of modern forestry machines that require high motor skills, constant concentration, and proper planning. The aim of the study was to analyze the learning curves of the trainees in order to determine the period during which most development takes place. In this study, 11 trainees were trained on a John Deere harvester simulator for approximately 15 h each. In each case, a clear learning curve could be identified, despite high inter- and intra-person variability. Effective time showed a steady decrease during training, with a group minimum at the end of training (1.25 min). Crane tip distance per tree dropped rapidly in the first 3–4 h, followed by a more gradual decrease to reach a minimum of 23.8 m. Crane control showed a significant increase from an initial 0.63 to a maximum of 0.8 by the 9th hour of training. A number of crane functions used simultaneously increased more rapidly to almost a maximum value (1.8) already in the 5th hour. The individual curves for each trainee were highly variable, showing a wide range of values and shapes. In conclusion, most personal development occurs during the first phase of simulator training, which typically takes approximately 9–10 h. It is important to consider significant inter-personal variability and tailor the duration of simulator training to individual needs.

In Vitro Evaluation of Flexural Strength of Different Skin Staples

Abstract Objective The aim of the study was to assess the flexural deformation strength of various brands of skin staples postfiring, and to compare the distance and alignment of the staple tips. Study Design In this experimental in vitro study, nine types of commercially available skin staples were tested. Following firing, six staples of each type were mounted on a material testing machine. Mechanical properties of staples were evaluated under uniaxial loading test, which translated to the bending of the staple for determination of flexural deformation strength. Staples were evaluated for tip alignment and distance between pointed tips. Results Maximum force to flexural deformation was greater for Precise (29.633 ± 7.8421 N), than Proximate (16.200 ± 1.1541 N; p = 0.000), Henry Schein (23.383 ± 5.2282 N; p = 0.011), Weck Visistat (24.329 ± 1.0372 N; p = 0.025), Appose (18.133 ± 1.2675 N; p = 0.000), Manipler (14.067 ± 3.7393 N; p = 0.000), and Leukoclip (22.288 ± 1.6915 N; p = 0.002) but was not different from Gima (27.483 ± 6.5637 N; p = 0.370) and Advan (27.283 ± 2.8708 N; p = 0.327) Precise, Appose, and Advan fired staples had their pointed tips met, whereas Manipler, Leukoclip, Gima, Henry Schein, Proximate, and Weck Visistat showed a gap between pointed tips. Proximate staples also showed malalignment between their pointed tips. Conclusion The flexural deformation strength of skin staples manufactured by Precise, Gima, and Advan was between 29 and 27 N and thus significantly superior to the other six staple types tested.

An open computational toolbox to analyze multi- and single-unit sympathetic nerve activity in microneurography.

Microelectrode recordings from human peripheral and cranial nerves provide a means to study both afferent and efferent axonal signals at different levels of detail, from multi- to single-unit activity. Their analysis can lead to advancements both in diagnostic and in the understanding of the genesis of neural disorders. However, most of the existing computational toolboxes for the analysis of microneurographic recordings are limited in scope or not open-source. Additionally, conventional burst-based metrics are not suited to analyze pathological conditions and are highly sensitive to distance of the microelectrode tip from the active axons. To address these challenges, we developed an open-source toolbox that offers advanced analysis capabilities for studying neuronal reflexes and physiological responses to peripheral nerve activity. Our toolbox leverages the observation of temporal sequences of action potentials within inherently cyclic signals, introducing innovative methods and indices to enhance analysis accuracy. Importantly, we have designed our computational toolbox to be accessible to novices in biomedical signal processing. This may include researchers and professionals in healthcare domains, such as clinical medicine, life sciences, and related fields. By prioritizing user-friendliness, our software application serves as a valuable resource for the scientific community, allowing to extract advanced metrics of neural activity in short time and evaluate their impact on other physiological variables in a consistent and standardized manner, with the final aim to widen the use of microneurography among researchers and clinicians.

Distance Measurement of Contra-Rotating Rotor Blades with Ultrasonic Transducers.

Coaxial rotor helicopters have great potential in civilian and commercial uses, with many advantages, but challenges remain in the accurate measurement of rotor blades' distance to prevent blade collision. In this paper, a blade tip distance measurement method based on ultrasonic measurement window and phase triggering is proposed, and the triggering time of the transmitter is studied. Due to the complexity of the measured signal, bandpass filtering and a time-of-flight (TOF) estimation based on the power density of the received signal are utilised. The method is tested on an experimental test platform with a pair of 200 kHz ultrasonic transducers. The experimental results show that the maximum ranging error is less than 1.0% for the blade tip distance in a range of 100-1000 mm. Compared with the amplitude threshold method, the proposed TOF estimation method works well on the received signal with a low SNR and improves the ranging accuracy by about 5 mm when the blade tip distance is larger than 500 mm. This study provides a good reference for the accurate measurement of rotor blade tip distance, and gives a solution for ranging high-speed rotating objects.

An MRI study demonstrating consistent anatomic relation of central longitudinal artery and associated periosteal vessels with the medial femoral epicondyle and adductor tubercle-A visual landmark method for femoral tunnel placement in medial patellofemoral ligament reconstruction.

The two most common techniques to determine femoral tunnel placement during medial patellofemoral ligament (MPFL) reconstruction are radiographic and by palpation. Their intra/interobserver reliability is widely debated. Both techniques rely on identifying bony landmarks such as the medial epicondyle (ME) and adductor tubercle (AT) during surgery. During MPFL reconstructive surgery, the central longitudinal vessels (CLVs) are seen consistently. The aim of this study was to investigate the anatomic relationship of CLV to ME and AT and to determine if CLV might be used as a landmark during MPFL reconstruction. A retrospective review of MRI scans in skeletally mature patients was undertake. There were two groups, a PFI group that consisted of patients with a diagnosis of patellofemoral instabiliy (PFI) and a non-PFI group that underwent MRI scan for an alternative diagnosis. MRIs were measured for the CLV-ME-AT anatomy and relationship. Following exclusions, 50 patients were identified in each group. The CLV passed anterior to the AT and ME in all patients. ME morphology did not differ greatly between the groups except in the tubercle height, where there was statistically significant but not a clinically important difference (larger in the non-PFI group, 2.95 vs. 2.52 mm, p = 0.002). The CLV to ME tip distance was consistent between the groups (PFI group 3.8 mm and non-PFI group 3.9 mm). The CLV-ME-AT relationship remained consistent irrespective of patients' presenting pathology. The CLV consistently courses anterior to ME and AT. The CLV could be used as a vascular landmark assisting femoral tunnel placement during MPFL reconstruction.

First report of the damaging pest Meloidogyne enterolobii parasitizing mulberry (Morus alba L.) in Vietnam.

Mulberry (Morus alba L.) is highly important crop in Vietnam, playing a key role in the country's economy through sericulture, food supply, pharmaceuticals, and beverage industries (Nguyen et al., 2018; Rohela et al., 2020). Recently, many mulberry-growing areas in Lam Dong, Vietnam have reported severe symptoms associated with nematode infection, including yellowing leaves, stunted growth, and severe root galling, leading to a significant decline in mulberry productivity. From April to December 2022, twenty soil and root samples from mulberry-growing areas in Lam Dong (Da Teh: 11°28'48.11"N; 107°28'23.74"E elevation: 133m; Lam Ha 11°48'25.13"N; 108°14'7.13"E elevation: 848m) were collected to uncover the presence of Meloidogyne enterolobii parasitizing mulberry in Vietnam. One nematode population was randomly selected for characterizing in this study among analyzed nematode populations. Females were extracted from heavily galled roots (Fig. S1) from a single mulberry tree in Lam Dong, Vietnam, using a needle and forceps (Subbotin et al., 2021). The perineal patterns of adult females (n = 10) have an oval shape, with clearly visible phasmids, along with a prominently high and squared dorsal arch. The striae are smooth and coarse, while the perivulval region remains devoid of striae. The lateral lines appear indistinct, and the tail tip is easily observable. Morphometric measurements were as follows: body length = 585 ± 78 (464-724) µm, body width = 367 ± 75 (271-529) µm, neck length = 221.5 ± 30.7 (167-269.6) µm, stylet length = 13.1 ± 1.2 (11.4-15.1) µm, vulva-slit length 16.3±2.3 (10.4-18) µm, vulva-anus distance = 16.8±3.0 (11.4-18) µm, anus-tail tip distance = 10.3±2.1 (6.9-14.2) µm, interphasmidial distance = 15.9 ± 3.7 (10.3-23.4) µm. The morphology of this nematode population is highly in agreement with the original description of M. enterolobii (Yang & Eisenback, 1983). This population was also identified using the D2-D3 of 28S rRNA and 18S rRNA (Powers et al., 2017; Subbotin et al., 2006) regions. The D2-D3 of 28S rRNA sequences from this study (accession numbers: OR889633) exhibited 99.5-99.8% similarity to the sequences of M. enterolobii from GenBank (accession numbers: OR214950 and ON496981). While the 18S rRNA sequences (accession numbers: OR896547) showed 99.2-99.3% similarity to the sequences of M. enterolobii from GenBank (accession numbers: MZ955995, MZ531901, and MW488150). To carry out Koch's postulates, 2000 J2s from collected M. enterolobii egg masses (initial population) were inoculated on two-month-old plantlets of mulberry (n = 6), planted on 2L pots within a screenhouse, non-inoculated plantlets (n=6) served as negative controls. After 90 days post-inoculation, nematode reproduction factors (RF = final density (nematodes were extracted from the whole root system and corresponding soil samples (Subbotin et al., 2021)) / initial population) and root damage symptoms were evaluated. The inoculated plantlets exhibited consistent yellowing leaves, stunting, and root galling symptoms (Fig. S1), mirroring observations from the field, with an average RF of 11.5. Control plants displayed no symptoms. Root-knot nematodes extracted from the roots were identified as M. enterolobii through molecular analyses of D2-D3 of 28S and 18S rRNA regions (GenBank accession numbers: OR889634 (D2-D3 of 28S) and OR896548 (18S)), thereby confirming that mulberry acts as a host for M. enterolobii. Currently, this nematode has been reported to be associated with two different host plants, including guava (Trinh et al., 2022) and pomelo (Le et al., 2023). Our discovery marks the first documented case of Meloidogyne enterolobii parasitizing mulberry in Vietnam. While the impact on mulberry productivity remains to be really important for sericulture food supply, pharmaceuticals, and beverage industries; the aggressive nature of M. enterolobii, as observed in the field and confirmed by the screenhouse tests, raises concerns about potential economic losses in mulberry production. Therefore, further investigations are needed to assess the extent of M. enterolobii infestation in mulberry orchards and to develop effective control measures to safeguard the sustainability of mulberry cultivation in Vietnam.

Posterior intra-articular distraction technique to treat pediatric atlantoaxial instability.

Surgical treatment for atlantoaxial instability in pediatric patients is challenging. We report our experience with posterior intra-articular distraction technique in treating this disorder. This is a retrospective descriptive study which included 15 patients of atlantoaxial instability whose age was less than 16years at the time of clinical presentation. All patients underwent anterior soft tissue released through a posterior-only approach, followed by intra-facet cage implantation, cantilever correction, and instrumentation. Clinical results were measured using the Japanese Orthopedic Association (JOA) scale and radiographic measurements including the atlantodental interval (ADI), posterior atlantodental interval (pADI), the distance of odontoid tip above Chamberlain's line, clivuscanal angle (CCA), and triangular area (TA) of craniovertebral junction. The follow-up period ranged from 18 to 72months, with an average of 41.2 ± 15.2months. The JOA score increased from 13.6 ± 2.3 to 16.6 ± 0.8. ADI decreased from 4.31 ± 2.37 to 1.85 ± 1.09mm, and TA decreased from 261.96 ± 107.99 to 197.12 ± 72.37 mm2. pADI increased from 12.89 ± 3.52 to 18.25 ± 3.89mm, and CCA improved from 132.19 ± 16.34 to 144.35 ± 13.91°. All changes in measurements showed statistically significant. There were no evidence of surgery-related complications or iatrogenic secondary cervical deformity during follow-up. Radiological evaluation showed satisfactory corrections and bony fusions of C1-2 facet joint in all cases. Posterior intra-articular distraction followed by cage implantation and cantilever correction can be one of the safe and effective ways to solve atlantoaxial instability in pediatric patients.

A Study on the Effects of Hob Temperature on the Rock-Breaking Characteristics of Sandstone Strata

To explore the effect of hob temperature on the rock-breaking characteristics of full-section tunnel boring machines (TBMs) in sandstone strata, high-temperature furnace heating experiments of sandstone and physical and mechanical experiments at room temperature and high temperatures were conducted to obtain the mechanical properties of sandstone at different temperatures. The mechanical properties at different temperatures were calibrated using PFC3D to obtain micro-mechanical and thermodynamic parameters and establish a rock-breaking model. The orthogonal experiments were used to establish the simulation experiments of rock breaking under different temperatures, confining pressure conditions, knife tip distances, and penetration degrees. The results show that the hob tip force is gradually increasing with an increase in the confining pressure. When below 600 °C, there is little temperature transfer from particle to particle as the temperature increases. At this time, with the two sides of the rock slag flaking, the hob knife tip force is the first to reduce. After 600 °C, with the expansion of the rock extrusion hob, the temperature rises on both sides; at this time, the hob tip force also increased. The hob tip force is minimal at a tip distance of 70 mm and an S/P of 14. As the surrounding pressure increases, the rock-breaking efficiency of the hobber decreases. The highest rock-breaking efficiency is achieved at 25 °C and 600 °C. The rock-breaking efficiency is highest when the knife tip distance is designed to be 70 mm, and when the S/P is 14. The three-dimensional constitutive analysis of rock-breaking particles showed that the increment caused by the hob temperature is mainly distributed in the normal force direction in the surrounding rock without any confining pressure, and the increment caused by the hob temperature exposed to the confining pressure occurs in all directions.

Evaluation of maxillary transverse dimensions in individuals with a unilaterally impacted canine.

The aim of this study was to investigate the maxillary width within individuals with a unilaterally impacted maxillary canine and to determine any association between the impacted canine location and some canine-related variables. A cross-sectional analytical study using a split-mouth design included 22 CBCTs of individuals with unilaterally impacted maxillary canines (a total of 44 sides). The maxillary width was measured and compared in both impacted and non-impacted sides at various levels: basal, alveolar, and dental. The following canine-related variables were analyzed and compared with impaction location: impacted canine angulation, cusp tip distance from the occlusal plane, type of impaction (vertical or horizontal), presence of root resorption, deciduous teeth, or adjacent teeth transposition. Significance was considered at P < 0.05. There was a significant reduction in maxillary width on the impacted side at the following levels: maxillary first premolar alveolar crest in both coronal and axial sections, dental width measured from the central fossa of maxillary first molar to the midline, and width measured from the canine cusp tip to the midline. Moreover, the distance from the palatally impacted canine cusp tip to the occlusal plane was statistically significantly lower (7.6 ± 1.5 mm) compared to buccal (10.8 ± 3.3 mm) and mid-alveolus (12.0 ± 3.9 mm) impaction, (P values = 0.02). There was a significant association between canine impaction and reduction in the maxillary width at least on the dental level. The palatally impacted canine cusp tip was significantly closer to the occlusal plane compared to the buccal and mid-alveolar impaction.

Squeezed Protons and Infrared Plasmonic Resonance Energy Transfer.

Unusual nuclear quantum effects may emerge near noble metal nanostructures such as squeezed vibrational states in molecular junctions and plasmonic resonance energy transfer in the infrared domain. Herein, nuclear quantum effects near heavy metals are studied by nuclear-electronic orbital density functional theory (NEO-DFT) with an effective core potential. For a quantum proton sandwiched between a pair of gold tips modeled by two Au6 clusters, NEO-DFT calculations suggest that the quantum proton density can be squeezed as the tip distance decreases. For an HF molecule placed near a one-dimensional Au nanowire composed of up to 34 Au atoms, real-time NEO time-dependent density functional theory (RT-NEO-TDDFT) shows that the infrared plasmonic motion within the Au nanowire may resonantly transfer electronic energy to the HF proton vibrational stretch mode. Overall, these calculations illustrate the advantages of the NEO approach for probing nuclear quantum effects, such as squeezed proton vibrational states and infrared plasmonic resonance energy transfer.

Numerical investigation on turbulent flame jet characteristics of a pre-chamber fueled with CH4/O2 and CH4/NH3/O2 mixture under different initial pressures

Ammonia is a very potential carbon-free alternative fuel with extremely low reactivity. The application of ammonia in internal combustion engines faces the risks of ignition failure, low burning rate, and poor combustion stability. Pre-chamber turbulent jet ignition (TJI), which can provide much more ignition energy, is a promising method to ignite ammonia fuel. However, the transient propagation process of pre-chamber jet flame has not been fully investigated yet. In this paper, the propagation characteristic of methane jet flame was numerically studied based on a constant volume combustion system. The supersonic jet flame propagation and Mach disk phenomenon were further analyzed with numerical methods. And the propagation characteristic of methane/ammonia mixed jet flame was investigated. According to the results, the formation and propagation process of methane jet flame has different characteristics at different stages. In High-speed development stage (Stage II) and Low-speed oscillation development stage (Stage III), the penetration distance of flame jet tip is almost proportional to the penetration time. However, the penetration speed of the two stages is significantly different. The change trend of the jet velocity at the outlet of orifice hole can also be divided into four stages: slow increasing, rapid increasing, gradual decreasing, and periodic oscillation. The periodic oscillation of the jet tip velocity and the jet velocity at the outlet of orifice hole is caused by the effect of forward and reverse shock waves. The calculation results of CH4/NH3/O2 mixture jet flame show that the addition of ammonia has significant effects on the flame propagation process in PC, the thermodynamic state of PC, and the propagation characteristics of jet flame. With the increase of ammonia proportion, the maximum pressure of PC gradually decreases and the pressure rise rate slows down. Meanwhile, the two-stage (the high-speed development stage and the low-speed development stage) characteristic of jet propagation process gradually disappears. And the addition of ammonia is more likely to destroy the two-stage characteristic under low initial pressure.

A Large Cohort Analysis of Epiglottic Phenotypes and Pharyngeal Residue.

To describe the phenotypic characteristics of the epiglottis at rest and their impact on vallecular residue. Videofluoroscopic studies (VFSS) were pooled from 2 Laryngology practices, and Image J was used to measure epiglottic anatomic features at rest. Studies were rated by the MBSImp and presence of vallecular residue following swallow of thin and puree boluses. A conditional inference tree analysis was performed to isolate which epiglottic parameters were risk factors for presence of vallecular reside followed by logistic regression. The majority of patients had a normal shaped epiglottis, followed by omega shape. The mean angle of the epiglottis from the hyoid was approximately 90°. Only abnormal epiglottic movement was associated with increased risk of residue for thin boluses (OR 35.09, CI 10.93-158.66, P < .001). However, in those with normal epiglottic movement, age >70 years old was associated with increased risk of residue (OR 3.98, CI 1.73-9.23, P = .001). For puree boluses, a normal or omega shaped epiglottis was associated with residue (OR 5.19, CI 2.41-11.51, P < .001), and this relationship was further modulated by increased distance of the epiglottic tip from the posterior pharyngeal wall. No other anatomic features of the resting epiglottis were associated with residue. Comorbidities potentially affecting swallow were infrequent in the cohort and were not associated with residue. Abnormal epiglottic movement is associated with aspiration, and in this study we find that abnormal epiglottic movement increases the risk of vallecular residue and that older age is a risk factor for residue. The resting properties of the epiglottis do not appear to be associated with abnormal epiglottic movement or residue.

HEAT TRANSFER ANALYSIS OF A COMBINED PIEZOELECTRIC FAN–TRANSLATIONAL AGITATOR COOLING SYSTEM

This paper investigates the heat transfer characteristics of a channel system consisting of a finned heat sink and two piezoelectric devices, the piezoelectric fan (PF) and the piezoelectric translational agitator (PTA), both experimentally and computationally. In the proposed system, the mean flow is generated by a cantilevered PF, and the flow between the fins is agitated using a PTA. A single-channel system consisting of a PTA, the PF, and two fins is analyzed numerically using ANSYS Fluent software after validating numerical predictions against experimental measurements. The effect of design variables such as frequency ratio, phase difference, PF's tip distance from PTA, and squeezing fraction is explored. A PTA increases the heat transfer from the heated surfaces without incrementally aiding in the mass-flow rate. Velocity and temperature fields are plotted to understand the physics of the system for one complete cycle of a PTA blade. The concept of total Reynolds number that incorporates the effect of both axial and transverse fluid flow is used in this study. The Nusselt number increases with an increment in the total Reynolds number. It is noted that the integration of the PF and the PTA with the finned heat sink system has enhanced the heat transfer coefficient by 76.88&amp;#37; compared to the system with PTA and by 30.92&amp;#37; as compared to the system with the PF only.

Redefining Diagnostic Criteria for Basilar Invagination Using Linear Craniometric Parameters.

To establish the diagnosis of basilar invagination (BI) on the basis of specific bony landmarks Klaus' index (KI), perpendicular distance between the tip of the odontoid process and palato internal occipital protuberance (PI) line. Forty-nine patients were analysed, who underwent surgery for BI, between July 2020 and June 2023. Radiological assessment was done in all the patients using reconstructed midsagittal images on computed tomography scans . Mean age was 34.82 ± 10.52 years with male preponderance (67.35%) in patients with BI. We also analysed randomly selected 120 control subjects (male: female = 59:61) with mean age 43.5 ± 14.08 years. The mean distance of tip of the odontoid process from PI line in patients with BI was 3.39 ± 3.09 mm. The mean value of KI in the patients with BI was 28.57 ± 1.68 mm. Receiver operating characteristic (ROC)curve was used for analysing the distance of the tip of the odontoid process from PI line in the patients with BI which produced area under curve( AUC) of 0.97 (confidence interval [CI] -0.931 to 0.990, p < 0.0001). Cut-off point of 7.5 mm was identified for the distance of tip of odontoid process from PI line with sensitivity of 89.8% and specificity of 97.5% having 95.27% diagnostic accuracy for BI. ROC curve analysis of value of KI for the diagnosis of BI produced AUC of 1( CI: 0.978 to 1.000, p < 0.0001). Cut-off value of 33.2 mm for KI was identified for diagnosing BI with 100% accuracy. The distance of tip of the odontoid process from PI line < 7.5 mm and value of KI < 33.2 mm, both of these parameters can diagnose BI with comparable accuracy to most widely used conventional radiological methods.

Novel multi-magnetic material transcranial magnetic stimulation coils for small animals application

Transcranial magnetic stimulation (TMS) is a non-invasive therapeutic approach with proven efficacy in treating certain psychiatric and neurological disorders. To broaden the application of TMS to a wider range of neurological disorders, the induced electric field (e-field) must be able to more focally target specific regions of the brain. Animal coil designs are promising for studying TMS effects and developing new procedures for treating various neurological and psychiatric disorders. However, investigations have mostly used coil designs intended for humans, and, as such, have failed to scale down for small animal sizes. Currently available coil systems have been limited by not adequately incorporating ideal soft magnetic materials as coil cores and not advancing the coil shapes for small animals as is necessary to achieve highly focused e-field concentration. In this study, we used multi-magnetic materials in TMS coils for the first time to our knowledge. We also considered the non-linear, hysteretic behavior of the cores in our FEM simulations of induced e-field and magnetic field in the brain models of the rat. Our study involved a comprehensive assessment of the distribution and intensity of the e-field across various coil configurations using our customized anatomically accurate rat head model. Iron-cobalt-vanadium (Permendur) alloy known for its high relative permeability, high saturation magnetization and low coercivity was used as the core material for all simulations. To enhance coil focality and concentration of the e-field, while avoiding stimulation of adjacent regions, we introduced a shape-conforming, flexible, diamagnetic pyrolytic graphite with susceptibility of -4.5×10-4 for our top performing coil. Simulation results were validated by comparing the simulated magnetic field results with experimental measurements obtained from the v-tip coil with a carbon steel AISI-1010 core at varying tip distances. This thorough study advances our knowledge of TMS coil designs and their optimization, particularly for small animal applications.