Position Of Attachment Research Articles

Effectiveness of the attachment position in molar intrusion with clear aligners: a finite element study

ObjectiveTo evaluate the biomechanical effects of different attachments’ position for maxillary molar intrusion with clear aligner treatment by finite element analysis.MethodsCone-beam computed tomography images of a patient with supra-eruption of the maxillary second molars were selected to construct three-dimensional models of the maxilla, periodontal ligaments, dentition, and clear aligner. The models were divided into four groups depending on the attachment location on the first molar: (1) no attachment (NA), (2) buccal attachment (BA), (3) palatal attachment (PA), and (4) bucco-palatal attachment (BPA). After applying an intrusion of 0.2 mm on the second molar, displacements and stress distributions of the teeth, aligner, and periodontal ligament were analyzed with the finite element software.ResultsAll groups displayed equivalent movement patterns of aligners. The NA and BA groups showed buccal tipping of the second molar, while the PA group showed palatal tipping. The BPA group had the highest intruding value and the lowest buccal/palatal tipping value. All groups showed mesial tipping of the second molar. Stress distribution in the periodontal ligament strongly correlated with the attachment position. The BPA group showed the best stress distribution.ConclusionCombined BA and PA could effectively prevent buccal and palatal tipping and showed the best efficiency in intruding the second molar. The second molar showed an unavoidable tendency to tip mesially, regardless of the attachment position.

A modal analysis of implant-supported overdentures installed on differently positioned sets of dental implants

This study evaluated the three vibration characteristics, namely, natural frequency, damping ratio, and natural mode, together with maximum displacement of a two-implant-supported overdenture (IOD) at different locator attachment positions using experimental modal analysis (EMA). Edentulous mandibular models with a gingival thickness of 1 mm or 3 mm were prepared, into which dental implants were placed using a fully guided surgical template designed with simulation software, the locator abutments were fastened, and the IODs were then fabricated. The implant positions were bilaterally marked at the lateral incisor, first premolar, and first molar regions. EMA was performed by hammering the test structures to measure the impulse response and obtain the vibration characteristics (n = 5). The Kruskal–Wallis test was performed for natural frequency and maximum displacement, and the Games-Howell test for damping ratio. The significance level was set at α = 0.05. The study indicated that the gingival thickness had a significant effect on the vibration characteristics. Moreover, the natural frequency and damping ratio results showed that the vibration subsided faster when the attachment was placed on the molar implants in the thick gingival model. Furthermore, according to the effect of lateral force on IODs, the difference in maximum displacement between the anterior and posterior regions of the IOD was smaller when the attachments were designed on the pair of lateral incisors. Thus, within the limits of this experiment, our results suggested that two anterior implant-supported IODs are preferable treatment designs in terms of vibration engineering, especially when the gingiva is thick; the molar attachment design could be considered for thin gingival conditions. The differences in gingival thickness and abutment position affected the vibration characteristics of the IOD. Further in vivo studies would be necessary to validate the implant positions and their IOD designs for the mandibular edentulous shapes and the occlusal relationship.

Structures of the (Imidazole)nH+ ... Ar (n=1,2,3) complexes determined from IR spectroscopy and quantum chemical calculations

Here, we present new cryogenic infrared spectra of the (Imidazole)_{n}mathrm{H}^{+} (n=1,2,3) ions. The data was obtained using helium tagging infrared predissociation spectroscopy. The new results were compared with the data obtained by Gerardi et al. (Chem. Phys. Lett. 501:172–178, 2011) using the same technique but with argon as a tag. Comparison of the two experiments, assisted by theoretical calculations, allowed us to evaluate the preferable attachment positions of argon to the (Imidazole)_{n}mathrm{H}^{+} frame. Argon attaches to nitrogen-bonded hydrogen in the case of the (Imidazole)H^+ ion, while in (Imidazole)_{2}mathrm{H}^{+} and (Imidazole)_{3}mathrm{H}^{+} the preferred docking sites for the argon are in the center of the complex. This conclusion is supported by analyzing the spectral features attributed to the N–H stretching vibrations. Symmetry adapted perturbation theory (SAPT) analysis of the non-covalent forces between argon and the (Imidazole)_{n}mathrm{H}^{+} (n=1,2,3) frame revealed that this switch of docking preference with increasing complex size is caused by an interplay between induction and dispersion interactions.

Morphometry of the Tibial Footprint of the Anterior Cruciate Ligament in Punjabi Population

Background: The anterior cruciate ligament (ACL) is responsible for knee joint stability during all possible movements. The purpose of our present study was to estimate normal values of the position and dimensions of the tibial attachment of ACL for its successful reconstruction. Methodology: A sagittal magnetic resonance imaging (MRI) sample of the knee joint of 120 patients (58 men and 62 women) of 18–50 years of age was reviewed. Results: Anterior end of the tibial footprint was located at a mean of 14.92 mm ± 3.42 mm from the anterior end of the tibial plateau. The posterior end of the tibial footprint was located with a mean of 28.76 mm (±7.02) from the anterior end of the tibial plateau. The mean tibial footprint sagittal length was 14.56 mm ± 0.66 mm. The mean anterior cruciate sagittal center was located at 42.62% ±2.99% of the anteroposterior length of the tibial plateau. The present study will provide the baseline morphometric data for the position and size of the tibial footprint of the ACL on MRI in Punjab. Mean roof angle in the present study was 35.16° (±3.49°). Mean ACL-inclination angle was 50.13°(±4.56°). Mean ACL-Bluemensaat angle in the present study was 4.23°(±2.87°). Conclusion: Present study can help surgeons to ascertain the positioning of the tibial tunnel in routine ACL reconstruction as well as revised ACL reconstruction surgeries.

Studies of Acceleration of the Human Body during Overturning and Falling from a Height Protected by a Self-Locking Device.

The use of individual fall protection equipment is one of the most commonly applied methods of protecting workers whose worksites are located above the floor level. The safety of the user in such a situation depends on both the proper selection and correct use of such equipment. Additionally, aspects such as minimizing the free-fall distance before the fall arrest, as well as quick notification of an accident and efficient rescue operation, are important factors influencing safety. This paper presents a new testing method for fall arrest equipment using a test stand consisting of the Hybrid III 50th Pedestrian ATD anthropomorphic manikin and measuring set with three-axis acceleration transducers. The proposed method and test stand were developed for the design and testing of new fall protection devices equipped with electronic detection and alarm systems, for which it is necessary to determine acceleration limits in order to determine the alarm threshold. The proposed method is based on the measurement of accelerations that occur during tipping and falling from the height of an anthropomorphic manikin secured by a self-locking device. Two places of attachment of the measuring set with a three-axis acceleration sensor were analyzed at the waist belt of the manikin (abdomen and back). Moreover, the self-locking device lanyard was attached to the two points of the safety harnesses (the front and back point). The aim of the research was to check whether the acceleration values depend on the places of attachment of the measuring and anchored system, as well as to determine their maximum values. Acceleration values corresponding to fall arrest and tipping were analyzed. Limits of acceleration have been established in order to determine the threshold of alarm triggering. The non-parametric Mann–Whitney U test was used to check whether the location of the three-axis acceleration transducer and the position of the self-locking device lanyard attachment affect the value of the recorded acceleration. For results of acceleration measurements when testing the behavior of the manikin during fall arrest, no statistically significant differences were found. For results of acceleration measurements when testing the tipping behavior of the manikin, statistically significant differences occurred. This means that during fall arrest, the location of the three-axis acceleration transducer and the position of the self-locking device lanyard attachment do not matter. This work is a continuation of previous research on accelerations characterizing human body positions occurring during normal physical activities (ADL—activities of daily living).

Anchoring geometry is a significant factor in determining the direction of kinesin-14 motility on microtubules

Kinesin-14 microtubule-based motors have an N-terminal tail attaching the catalytic core to its load and usually move towards microtubule minus ends, whilst most other kinesins have a C-terminal tail and move towards plus ends. Loss of conserved sequences external to the motor domain causes kinesin-14 to switch to plus-end motility, showing that an N-terminal attachment is compatible with plus-end motility. However, there has been no systematic study on the role of attachment position in minus-end motility. We therefore examined the motility of monomeric kinesin-14s differing only in their attachment point. We find that a C-terminal attachment point causes kinesin-14s to become plus-end-directed, with microtubule corkscrewing rotation direction and pitch in motility assays similar to that of kinesin-1, suggesting that both C-kinesin kinesins-14 and N-kinesin kinesin-1 share a highly conserved catalytic core function with an intrinsic plus-end bias. Thus, an N-terminal attachment is one of the requirements for minus-end motility in kinesin-14.

Impact of the Anthryl Linking Mode on the Photophysics and Excited-State Dynamics of Re(I) Complexes [ReCl(CO)3(4'-An-terpy-κ2N)

Rhenium(I) complexes with 2,2′:6′,2″-terpyridines (terpy) substituted with 9-anthryl (1) and 2-anthryl (2) were synthesized, and the impact of the anthryl linking mode on the ground- and excited-state properties of resulting complexes [ReCl(CO)3(4′-An-terpy-κ2N)] (An—anthryl) was investigated using a combination of steady-state and time-resolved optical techniques accompanied by theoretical calculations. Different attachment positions of anthracene modify the overlap between the molecular orbitals and thus the electronic coupling of the anthracene and {ReCl(CO)3(terpy-κ2N)} chromophores. Following the femtosecond transient absorption, the lowest triplet excited state of both complexes was found to be localized on the anthracene chromophore. The striking difference between 1 and 2 concerns the triplet-state formation dynamics. A more planar geometry of 2-anthryl-terpy (2), and thus better electronic communication between the anthracene and {ReCl(CO)3(terpy-κ2N)} chromophores, facilitates the formation of the 3An triplet state. In steady-state photoluminescence spectra, the population ratio of 3MLCT and 3An was found to be dependent not only on the anthryl linking mode but also on solvent polarity and excitation wavelengths. In dimethyl sulfoxide (DMSO), compounds 1 and 2 excited with λexc > 410 nm show both 3MLCT and 3An emissions, which are rarely observed. Additionally, the abilities of the designed complexes for 1O2 generation and light emission under the external voltage were preliminary examined.

Indirect bonding: an in-vitro comparison of a Polyjet printed versus a conventional silicone transfer tray.

To investigate and compare transfer accuracy between a Polyjet printed indirect bonding (IDB) tray (SureSmile, Dentsply Sirona, Richardson, TX, USA) and a conventional two-layered silicone tray. Plaster models of 24 patients were digitized with an intraoral scanner, and brackets and tubes were positioned virtually on the provider's homepage. IDB trays were designed over the planned attachments and Polyjet 3D-printed. For the conventional tray, brackets and tubes were bonded in their ideal positions manually before fabricating a two-layered silicone tray. For both trays, attachments were transferred indirectly to corresponding models. A second scan was performed of each bonded model to capture actual attachment positions, which were then compared to initial bracket positions using Geomagic Control (3D Systems Inc., Rock Hill, SC, USA). Linear and angular deviations were evaluated for each attachment within a clinically acceptable range of ≤0.2 mm and 1°. A descriptive statistical analysis and a mixed model were executed. Both trays showed highest accuracy in the orobuccal direction (99.5% for the 3D-printed tray and 100% for the conventional tray). For the 3D-printed tray, most frequent deviations were found for torque (15.4%) and, for the silicone tray, for rotation (1.9%). A significant difference was observed for angular measurements (P = .004) between the trays. Transfer accuracy of Polyjet printed IDB tray is not as high as transfer accuracy of the conventional silicone tray, though both trays show good results and are suitable for clinical application.

A Wearable Multi-Joint Wrist Contour Measuring Device for Hand Shape Recognition

Recently, various types of hand shape recognition systems have been developed for human–machine interfaces. However, most wearable recognition systems cannot robustly handle the variations in attachment positions of the devices. Thus, we propose a hand shape recognition system using a wearable multi-joint wrist contour measuring device to realize robust and effective recognition of hand shape, regardless of attachment position variations. In particular, this device can measure the wrist contour and band flexion data to recognize hand shape. The wrist contour data are measured using photo-reflectors mounted inside the device, and the band flexion data are measured using photo-interrupters installed at the device joints. Additionally, the attachment position information is extracted from the wrist contour or band flexion data using dimensional compression or attachment position recognition to achieve robustness against the position variations. Subsequently, the extracted information is incorporated into the hand shape recognizer. The results of the recognition experiment demonstrate that the attachment position information extracted from the band flexion data using dimensional compression could effectively realize robust hand shape recognition, considering variations in the device attachment position.

Investigation of fragmentation behaviors of steroidal drugs with Li+, Na+, K+ adducts by tandem mass spectrometry aided with computational analysis

In this study, we have investigated the fragmentation of the widely used steroidal pharmaceutical drugs (n = 14), complexed by a singly charged proton or alkali metal ion (Li + , Na + , K + ) using Ion trap and quadrupole time-of-flight mass spectrometers. Spectra were collected by LC-MS/MS analysis using system automated collision energy i.e., of 25–60 eV. Theoretical calculations were also calculated using DFT software. The metal complexes showed different fragmentation pathways not commonly observed for protonated compounds. There was a distinct difference observed in the relative intensities of some common fragments for free vs. metallated drugs. Some major fragments from protonated and lithium adducts showed close resemblance, while sodium and potassium adducts showed different fragments. Theoretical calculations showed a distinct difference in the position of attachment of proton and metals. This adducts ion fragmentation information will be helpful for the identification of these compounds in complex samples.

Achievable accuracy of resonating nanomechanical systems for mass sensing of larger analytes in GDa range

Measurement of larger analytes such as many chemical and biological structures or viruses in gigadalton (GDa) range is a reminding fundamental task in analytical chemistry and life sciences, which can be possibly resolved with the resonating nanomechanical systems. Common approaches to mass sensing with these systems model the bound analyte as a point particle and assume the analyte does not change the vibrational mode shapes. However, for larger analytes their stiffness and size not only affect the resonant frequencies but also cause the significant changes in the vibrational mode shapes making their measurement highly challenging and still under-explored problem. Here, we develop a 3D model capable to accurately predict the resonant frequencies and vibrational mode shapes of the resonating nanomechanical systems with the bound analyte of arbitrary properties and size. Then, we examine in details the impact of analyte properties, size and its position of attachment on the resonant frequencies and vibrational mode shapes and, correspondingly, resolve a dispute over the achievable detection limits of the nanomechanical systems, especially for mass sensing of larger analytes. Furthermore, we identify three different sensing regimes, that is, the ultra-light, light and heavy, for which the effects of the analyte mass, stiffness, its size and the position of attachment on the accuracy of the determined mass can be separated. For the ultra-light regime (mass ratio < 10−3) the analyte stiffness and its size affect notably the resonant frequencies, the point mass approximation is inaccurate and the analyte can be identified by its mass and stiffness. For the light regime the point mass approximation is accurate, while for the heavy one (mass ratio > 2∙10−2) the mass effect dominates the frequency response and alters the vibrational mode shapes which, for the common approaches, yields the errors in the determined analyte mass. Finally, we also propose an easily accessible approach for the identification of larger analytes (in GDa range) that does not require the advanced computational tools or experimental setup, applicable to the majority of the clamped-clamped ends resonating nanomechanical systems.

3’ Terminal end‐labeling of structured RNA by Klenow DNA polymerase

RNA labeling is a key step in studying RNA localization, folding, and structural dynamics using fluorescence based assays. Current methods of fluorophore attachment to long (&gt;100 nucleotides) and structured RNAs are hampered by low labeling yields and limitations in attachment position. These challenges have led to an interest in developing alternative methods that would enable the site‐specific labeling of long and structured RNAs. To this end, we have developed a site‐specific, chemo‐enzymatic method of fluorophore incorporation to RNAs. This novel method uses Klenow enzyme, a DNA polymerase, to add modified nucleotides to RNAs 3’ end in a templated manner. To facilitate this modified nucleotide addition in structured RNAs, we designed helper DNA oligonucleotides to disrupt any pre‐existing RNA intramolecular structure. Using this method, we have achieved efficient 3’ terminal end‐labeling of chemically synthesized and in‐vitro transcribed RNAs of different lengths with cyanine dyes.This method will be routinely used in fluorescence‐based assays that investigate the structure‐function relationships of RNAs involved in cancer and HIV progression.

Numerical Investigation of Ultrafine Aerosol Deposition inside a Needle Charger without Applied Voltage

The deposition of ultrafine aerosols with a size range of 3–20 nm in a needle charger has been studied numerically by simulating the flow field and the particle trajectory. The calculation model explored the particle deposition in the needle charger without applied voltage for various particle diameters, flow rates, entrance radial positions and deposition axial distances. It is first quantitatively proposed that most of the particles are attached to the outer electrode wall instead of the needle electrode wall for different flow rates and particle diameters. It is found that the numerical results of the particle deposition of the needle charger are consistent with previous experimental data. Moreover, the results demonstrate that reducing the flow rate increases the particle deposition of the needle charger. The numerical models explain and quantify the particle deposition and its attachment position for the needle charger without applied voltage.

Influence of ethanol patch attachment position and storage orientation on astringency removal and storability in ‘Hiratanenashi’ persimmon (Diospyros kaki Thunb.) fruits

ISHS VII International Symposium on Persimmon Influence of ethanol patch attachment position and storage orientation on astringency removal and storability in ‘Hiratanenashi’ persimmon (Diospyros kaki Thunb.) fruits

Optimization of Class I Histone Deacetylase PROTACs Reveals that HDAC1/2 Degradation is Critical to Induce Apoptosis and Cell Arrest in Cancer Cells.

Class I histone deacetylase (HDAC) enzymes 1, 2, and 3 organize chromatin as the catalytic subunits within seven distinct multiprotein corepressor complexes and are established drug targets. We report optimization studies of benzamide-based Von Hippel–Lindau (VHL) E3-ligase proteolysis targeting chimeras (PROTACs) and for the first time describe transcriptome perturbations resulting from these degraders. By modifying the linker and VHL ligand, we identified PROTACs 7, 9, and 22 with submicromolar DC50 values for HDAC1 and/or HDAC3 in HCT116 cells. A hook effect was observed for HDAC3 that could be negated by modifying the position of attachment of the VHL ligand to the linker. The more potent HDAC1/2 degraders correlated with greater total differentially expressed genes and enhanced apoptosis in HCT116 cells. We demonstrate that HDAC1/2 degradation by PROTACs correlates with enhanced global gene expression and apoptosis, important for the development of more efficacious HDAC therapeutics with reduced side effects.

Comparison of Two 3D-Printed Indirect Bonding (IDB) Tray Design Versions and Their Influence on the Transfer Accuracy.

Objective: This study aims to investigate the transfer accuracy of two different design versions for 3D-printed indirect bonding (IDB) trays. Materials and Methods: Digital plaster models of 27 patients virtually received vestibular attachments on every tooth using OnyxCeph³™ (Image Instruments, Chemnitz, Germany). Based on these simulated bracket and tube positions, two versions of transfer trays were designed for each dental arch and patient, which differed in the mechanism of bracket retention: Variant one (V1) had arm-like structures protruding from the tray base and reaching into the horizontal and vertical bracket slots, and variant two (V2) had a pocket-shaped design enclosing the brackets from three sides. Both tray designs were 3D-printed with the same digital light processing (DLP) printer using a flexible resin-based material (IMPRIMO® LC IBT/Asiga MAX™, SCHEU-DENTAL, Iserlohn, Germany). Brackets and tubes (discovery® smart/pearl, Ortho-Cast M-Series, Dentaurum, Ispringen, Germany) were inserted into the respective retention mechanism of the trays and IDB was performed on corresponding plaster models. An intraoral scan (TRIOS® 3W, 3Shape, Copenhagen, Denmark) was performed to capture the actual attachment positions and compared to the virtually planned positions with Geomagic© Control (3D Systems Inc., Rock Hill, SC, USA) using a scripted calculation tool, which superimposed the respective tooth surfaces. The resulting attachment deviations were determined in three linear (mesiodistal, vertical and orovestibular) and three angular (torque, rotation and tip) directions and analyzed with a descriptive statistical analysis. A comparison between the two IDB tray designs was conducted using a mixed model analysis (IBM, SPSS® Statistics 27, Armonk, NY, USA). Results: Both design versions of the 3D-printed IDB trays did not differ significantly in their transfer accuracy (p > 0.05). In total, 98% (V1) and 98.5% (V2) of the linear deviations were within the clinically acceptable range of ±0.2 mm. For the angular deviations, 84.9% (V1) and 86.8% (V2) were within the range of ±1°. With V1, most deviations occurred in the mesiodistal direction (3.3%) and in rotation (18%). With V2, most deviations occurred in the vertical direction (3.8%) and in palatinal and lingual crown torque (16.3%). Conclusions: The transfer accuracies of the investigated design versions for 3D-printed IDB trays show good and comparable results albeit their different retention mechanisms for the attachments and are, therefore, both suitable for clinical practice.

RAY-POS: a LIDAR-based assistance system for intraoperative repositioning of mobile C-arms without external aids

PurposeIn current clinical practice, intraoperative repositioning of mobile C-arms is challenging due to a lack of visual cues and efficient guiding tools. This can be detrimental to the surgical workflow and lead to additional radiation burdens for both patient and personnel. To overcome this problem, we present our novel approach Lidar-based X-ray Positioning for Mobile C-arms (RAY-POS) for assisting circulating nurses during intraoperative C-arm repositioning without requiring external aids.MethodsRAY-POS consists of a localization module and a graphical user interface for guiding the user back to a previously recorded C-Arm position. We conducted a systematic comparison of simultaneous localization and mapping (SLAM) algorithms using different attachment positions of light detection and ranging (LIDAR) sensors to benchmark localization performance within the operating room (OR). For two promising combinations, we conducted further end-to-end repositioning tests within a realistic OR setup.ResultsSLAM algorithm gmapping with a LIDAR sensor mounted 40 cm above the C-arm’s horizontal unit performed best regarding localization accuracy and long-term stability. The distribution of the repositioning error yielded an effective standard deviation of 7.61 mm.ConclusionWe conclude that a proof-of-concept for LIDAR-based C-arm repositioning without external aids has been achieved. In future work, we mainly aim at extending the capabilities of our system and evaluating the usability together with clinicians.

Optimizing sound diffusion in a concert hall using scale-model measurements and simulations

To propose optimal guidelines for the diffusion design of concert halls, sound field variations in the presence or absence of reflectors (canopies and clouds) and diffusers were comprehensively examined in terms of stage and auditorium acoustics using 1:25 scale-model measurements and acoustic simulations. The sound field variations were investigated based on the just-noticeable differences. For stage acoustics, the stage support parameters STEarly and STLate were analyzed; for auditorium acoustics, the reverberation time (RT), early decay time (EDT), clarity (C80), and center time (TS) were analyzed. The canopies reduced the reverberations but increased STEarly and STLate. The clouds increased STEarly and reduced the deviation of the auditorium EDT and TS whilst increasing the initial EDT that had been reduced by the canopies. The diffusers decreased STEarly, STLate, RT, EDT, and TS regardless of the attachment position, and they increased the C80 of some auditoriums. However, diffuser attachments reduced the seat-to-seat deviations of acoustic parameters. Furthermore, attaching diffusers near to (as opposed to far from) the sound source represents the optimal design strategy for increasing the density of early reflections. This study is significant as an initial attempt to examine the effects of concert hall diffusion design in terms of both auditorium and stage acoustics, and it is significant in that it presents an appropriate method for evaluating the effects of a concert hall diffusion design that can be employed by architects and sound consultants. The findings of this study are expected to be suitable as basic data for the diffusion design of rectangular concert halls.

Effects of varying attachment positions on palatal displacement of maxillary incisors with clear aligner therapy : Athree-dimensional finite element analysis.

Clear aligner therapy (CAT) has evolved as an esthetic alternative to fixed appliance therapy. However, studies on the effects of attachments on CAT are scarce. This research was done to evaluate the effect of labial and/or palatal attachments on maxillary incisor displacement in CAT through finite element analysis (FEA). Finite element modeling was used to create four models with aligners. The following combinations were created: (1)without attachments (WO), (2)with labial attachments (WLA), (3)with palatal attachments (WPA), (4)with labial and palatal attachments (WLPA). Maximum displacement, directional displacement and stresses induced following apalatal displacement of 0.25 mm was evaluated for each of the four models. Models without attachments and those with palatal attachments showed agreater tooth movement at the incisal part of the crown (0.22 mm and 0.24 mm, respectively) than the models with labial and labiopalatal attachments (0.21 mm and 0.19 mm, respectively). The von Mises stresses were concentrated at the middle third of the roots in the model with the labial attachments (30.257 MPa), while in the other three models, stresses were concentrated at the cervical third of the roots. Maximum displacement was seen at the incisal third of the maxillary incisors in the model with palatal attachments. The model without attachment generated the highest stresses. However, labial attachments as compared to other models appear to offer some biomechanical advantage by reducing uncontrolled tipping.

A statistical analysis of thermal characteristics of 55-Ah large-format LIB pouch cell with different tab-type, tab size, and tab position

The non-uniform temperature distribution in large-format lithium-ion batteries (LIBs) can lead to thermal runaway or performance degradation. This study develops a three-dimensional electrochemical–thermal model of a 55-Ah large-format LiFePO4/graphite pouch cell and statistically analyzes the effects of width, height, and attachment positions of the nominal tab (NT), lateral tab (LT), and counter tab (CT) on the temperature distribution. The temperature difference that occurs across the cell is analyzed separately for each design factor through design of experiments (DOE) and analysis of variance (ANOVA). Accordingly, wider tabs reduce the maximum temperature and temperature difference irrespective of the tab type. Taller tabs yield higher maximum temperatures, resulting in a larger temperature difference. Attaching tabs to the edge of the cell increases the maximum temperature and temperature difference. The locations of the negative NTs and CTs do not affect the temperature difference. However, the location of the negative LT increases the minimum temperature, thereby decreasing the temperature difference. The ANOVA revealed that the p-value of the width, height, and attachment position of the positive tab is lower than 0.05 which means the factors strongly influence the temperature difference for all tab-types. Also, the attachment position of the negative tab affects only the LT-type.