Variations In Dimensions Research Articles

Silicon photonic modulators with a 2 × 1 Fabry–Perot cavity

Abstract Silicon photonics modulators based on a 2 × 1 Fabry–Perot (FP) cavity, which is circulator-free, are proposed and demonstrated by introducing two asymmetric multimode-waveguide grating (AMWG) reflectors and a short straight modulation section with interleaved PN junctions. In particular, the straight modulation section in the FP cavity is broadened to be far beyond the single-mode regime, alleviating the inherent sensitivity to the variations of waveguide dimensions and thus reducing stochastic resonance-wavelength variations. The Q factor of the FP cavity is manipulated by optimally manipulating the reflection of the AMWGs, and the modulation bandwidth is enhanced to be over 40 GHz by utilizing the optical peaking enhancement effect, which happens when operating at the wavelength slightly detuning to its resonance wavelength. Eye diagrams for high-speed modulation with 50 Gbps are also demonstrated in experiments. Finally, wafer-level measurement is conducted by characterizing the silicon photonic modulators based on the 2 × 1 FP cavity and a conventional microring fabricated on the same chip, experimentally revealing an average improvement of 43 % in minimizing the random resonance-wavelength variation, which is attributed to the implementation of broadening the straight modulation section in the FP cavity.

Gender-based Morphometric Analysis of the Human Orbital Aperture Profile using 3D Reconstruction Computed Tomography: A Cross-sectional Retrospective Study

Introduction: Sex estimation is a crucial aspect of forensic medicine and requires primary consideration when examining skeletal remains. Among the various anatomical features, the orbital region holds significant importance due to its distinct morphological variations. These variations provide valuable insights for sex determination, making orbital anatomy an indispensable tool in forensic investigations and analysis. Aim: To measure and compare orbital apertures between males and females using 3D Computed Tomography (CT) in a sample from the Saudi population. Materials and Methods: A cross-sectional retrospective study was conducted from January to June 2024 in the Radiology Department of Tower Hospital, Arar, Kingdom of Saudi Arabia, following the acquisition of ethical approval from the Local Bioethics Committee at Northern Border University. A total of 100 CT scans were randomly selected from the available dataset. The study encompassed CT scans of subjects from both genders, aged 18 years and above. However, CT scans of patients who had sustained head trauma or orbital injuries were excluded from the study. The data retrieved were analysed using Statistical Package for the Social Sciences (SPSS) version 23.0. All continuous data were tested for normality and expressed as Mean±Standard deviation (SD). The significant differences in orbital measurements between males and females were assessed using the Independent t-test. A p-value of <0.05 was considered statistically significant. Results: A total of 100 participants were included in the study, with the majority being females (52%). The mean age of male and female subjects was 40.5±13.19 years and 39.13±13.10 years, respectively. A statistically significant difference was found in right orbital width (p-value=0.011), left orbital area (p-value=0.04), and Interzygomatic Distance (IZD), with these measurements being higher in males compared to females (p-value=0.009). Conclusion: The study revealed that males have greater orbital width, orbital area and IZD compared to females. These genderspecific variations in orbital and facial dimensions may play a crucial role in gender determination within forensic medicine.

Eurypterid setae and cuticle fragments from the Ora Formation (Upper Devonian) of Iraq

Eurypterid setae and fragments of cuticle are encountered in palynological samples from different areas in Gondwana. In the literature published in the past seven decades, eurypterid remains are recorded as a part of Paleozoic palynological assemblages without giving significance to their biostratigraphic potential. This is because of the absence of a taxonomical classification that allows tracking the occurrence of similar specimens from different samples and regions. In the present study, a rich assemblage of eurypterids is found in the Devonian Ora Formation in Akkas-3 well in Iraq. The assemblage includes isolated setae and cuticular sheets that still have attached setae. The detached setae show great variation in dimensions including the seta length, base width and length/width ratios. This is in addition to other important morphological characteristics such as segmentation and flexible ends. The cuticular sheets in contrast hold many setae that are identical in shape and size. The observation of cuticular sheets that hold many identical setae is an indication that individual eurypterids produce certain classes of similar setae. This is the basis that can be used to establish taxonomy for the setae after accumulation of more extensive studies. The taxonomy will facilitate the tracking of the setae throughout successive sampling interval and biostratigraphic classification. At least 23 types of setae are documented throughout the studied samples in Ora Formation with some stratigraphical variations documented for five of them. The results of this study established the basis for taxonomic nomenclature for eurypterid remains that may be of benefit to biostratigraphic studies in the Paleozoic in Gondwana. The main morphological characteristics of the eurypterid cuticles and setae recorded in the present study are compared to those from other parts of Gondwana. The morphological differences and similarities are documented. The samples are also rich in spores and other terrigenous organic matter with the complete absence of marine palynomorphs. This indicates the deposition in a fresh water environment.

Tolerance allocation of mechanical assemblies including thermal deformation: A machine learning – based method

Tolerance allocation is one of the prominent tools to achieve the optimal manufacturing cost and the best performance for mechanical assemblies. Variations in dimensions and geometry shape due to different working temperatures for various components within an assembly can make initially assigned tolerances ineffective. Therefore, it is necessary to consider the component’s deformation caused by thermal gradients during the tolerance design. In this paper, a new method is presented for optimal tolerance allocation of mechanical assemblies under thermal deformation. First, the system’s temperature working conditions and tolerance design goals are specified, followed by the finite element simulation of the assembly at the desired working temperature. Then, the assembly equation is determined according to the complexity of the problem by using analytical methods and some machine learning (ML) algorithms such as XGBoost. The optimal tolerance design is formulated into a constrained multi-objective optimization problem. Then, to obtain the Pareto front of optimal tolerances, the multi-objective optimization is solved by the NSGA-II algorithm. Finally, to illustrate the capability of the proposed method, two case studies are considered, and obtained results from the presented method and conventional approaches are compared.

Towards efficient models for hydraulic conductivity in conifer wood. Part 1: estimation of sizes and numbers of bordered pits

Abstract Functional traits like hydraulic conductivity and vulnerability to cavitation are increasingly important due to climate change. In conifers, water is transported through lumina of tracheids connected via bordered pits, which severely limit xylem conductivity by causing large pressure drops related to their number, dimensions and structure. According to literature, numbers and dimensions of pits correlate positively with tracheid and lumen dimensions. This reflects variations from earlywood to latewood and between rings formed under different grow conditions, contributing to major conductivity variations. The wider aim of the work is to estimate such conductivity variations in trunkwood from measurement data on radial and axial variations of tracheid dimensions. This requires several integrated models, including models estimating numbers and dimensions of pits. The article presents such models developed on data from 27 Norway spruce trees representing different sites, clones and growth rates. Measured and estimated variations of tracheid, lumen and pit properties within and between rings are illustrated, indicating on average about one third smaller and fewer pits in latewood than in earlywood tracheids, and variations in numbers and areas of pits per unit volume of xylem which may be interesting also in fields like wood drying and impregnation.

Comfort of smartwatch wearing: A comparative study of different hand types

<p>This study aims to explore the relationship between wrist size and the comfort and fit of smartwatch wearability. Measurements of hand dimensions, including wrist width, palm length, finger length, and finger width, were taken from 41 participants. Based on the analysis results, participants were grouped by wrist width, and individuals from different groups were asked to subjectively rate the comfort, strap fit, and ease of operation of the smartwatch. The results revealed that wrist width significantly impacts wearing comfort, while other hand features (such as finger width) play a crucial role in the operational experience. Users with wider wrists rated strap fit and wearing pressure more favorably, whereas those with narrower wrists demonstrated superior touchscreen operation performance. Additionally, the significant effects of design factors such as strap material, dial size, and smartwatch weight on wearing experience were also validated. These findings provide valuable insights for smartwatch design, highlighting the necessity of considering variations in hand dimensions to enhance the overall user experience.</p>

PITX2 expression and Neanderthal introgression in HS3ST3A1 contribute to variation in tooth dimensions in modern humans.

Dental morphology varies greatly throughout evolution, including in the human lineage, but little is known about the biology of this variation. Here, we use multiomics analyses to examine the genetics of variation in tooth crown dimensions. In a human cohort with mixed continental ancestry, we detected genome-wide significant associations at 18 genome regions. One region includes EDAR, a gene known to impact dental features in East Asians. Furthermore, we find that EDAR variants increase the mesiodistal diameter of all teeth, following an anterior-posterior gradient of decreasing strength. Among the 17 novel-associated regions, we replicate 7/13 in an independent human cohort and find that 4/12 orthologous regions affect molar size in mice. Two association signals point to compelling candidate genes. One is ∼61 kb from PITX2, a major determinant of tooth development. Another overlaps HS3ST3A1, a paralogous neighbor of HS3ST3B1, a tooth enamel knot factor. We document the expression of Pitx2 and Hs3st3a1 in enamel knot and dental epithelial cells of developing mouse incisors. Furthermore, associated SNPs in PITX2 and HS3ST3A1 overlap enhancers active in these cells, suggesting a role for these SNPs in gene regulation during dental development. In addition, we document that Pitx2 and Hs3st3a1/Hs3st3b1 knockout mice show alterations in dental morphology. Finally, we find that associated SNPs in HS3ST3A1 are in a DNA tract introgressed from Neanderthals, consistent with an involvement of HS3ST3A1 in tooth size variation during human evolution.

Morphometric Study of the Larynx: A Cadaveric Study in Sri Lanka

Introduction: Morphometric data of the larynx are important for the diagnosis and treatment of laryngeal disorders, as they provide crucial information for various medical procedures and for surgeries. These measurements are fundamental in the development of biomechanical models of larynx. Objectives: To describe the detailed morphometry of adult human larynx and its variations. Methods: The study was performed on 11 larynges, from 6 male and 5 female cadavers older than 40 years, with no history of laryngeal pathology, neck trauma, or neck surgery. Specific external and internal measurements of the larynx were recorded using a digital vernier caliper with an accuracy of 0.1 mm. Data were analysed using Statistical Package for Social Sciences (SPSS) version 26.0. Results: The mean values of external and internal dimensions of the larynx were higher in males than of females, except for the length from the lower border of thyroid cartilage to the upper border of cricoid cartilage (L6) and the length of the sinus. The difference was statistically significant only for the length from floor of thyroid notch to lower border of cricoid cartilage (L3), width of thyroid cartilage (L7), length from floor of thyroid notch to projection of anterior commissure (L8) and length of infraglottic cavity. Although, bilateral asymmetry was present in majority of specimens, there was no statistically significant difference between measurements on left and right sides of bilateral structures (vestibular, vocal, and aryepiglottic folds). Conclusion: There was a wide individual variation in both external and internal dimensions of the larynx, with males having generally higher values compared to females. This knowledge can be integrated on laryngeal morphometry into clinical and surgical practices, as well as into the design of advanced biomechanical models to achieve better patient care and innovative treatment solutions.

The Effect of Differences in Fiber Sizes on the Cutting Force During the Drilling Process of Natural Fiber-Reinforced Polymer Composites

This experiment aimed to analyze the impact of different fiber sizes on cutting forces during the drilling of Natural Fiber-Reinforced Polymer Composites (NFRPC) while also evaluating surface quality attributes, including delamination, fiber pullout, and overhanging fibers, influenced by variations in coconut fiber dimensions within the NFRPC material. The manufacturing process for composite panels utilized various methods, including hand layup for 200 mm long coconut fibers and composite casting for shorter fibers (2, 4, and 6 mm) mixed with polymer-epoxy. The results indicate that panels made from NFRPC with continuous fiber lengths of 200 mm exhibit higher cutting force values (253,650 N) compared to epoxy panels without fibers (235,288 N), suggesting that a significant force is required to sever the continuous fibers within the NFRPC. Conversely, the incorporation of short coconut fibers measuring 2, 4, and 6 mm reduces the cutting forces on the composite panels. However, excessive surface roughness in the final hole quality can be detrimental, primarily due to issues of delamination and fiber pull-out.

The fracture resistance of restored mandibular molars using different cavity designs: An in vitro comparative evaluation

Background: The stress distribution of a restored tooth is different from that of an intact sound tooth. The fracture resistance of a restored tooth depends on cavity design, remaining tooth structure, and material used. Aim: This in vitro study evaluated and compared the fracture resistance of mandibular molars restored using composite resin. Materials and Methods: Forty freshly extracted, intact mandibular molars were used, with their roots embedded in acrylic resin for stability. Cavities were prepared using a No. 2 round bur and straight fissure diamond, then divided into four groups with specific variations in cavity dimensions. Samples were tested using a universal testing machine, applying vertical load along the long axis at the central fossa to record fracture load. Statistical Analysis: One-way analysis of variance and Tukey’s post hoc analysis were used for statistical analysis. Results: Fracture resistance of the groups, listed in descending order, was: Lingual wall 1.5 mm (2417 ± 160 N) > Buccal wall 1.5 mm (2122 ± 75.9 N) > Lingual wall 1 mm (1966 ± 75.7 N) > Buccal wall 1 mm (1335 ± 216 N). Conclusion: The lingual wall 1.5 mm exhibited the highest fracture resistance, while the buccal wall with 1 mm thickness showed the least resistance.

Documenting weld pool behavior differences in variable-gap laser self-melting and wire-filling welding of titanium alloys

In large-scale welding processes involving complex geometries, variations in gap dimensions and the transition of filler wire form distinctive molten pool flow behaviors, significantly affecting weld formation and quality. This paper investigates the differences in the laser self-melting and wire-filling welding pool behavior of titanium alloy with variable gaps through both simulation and experimentation. An innovative three-dimensional transient heat-flow coupling model is developed to simulate laser welding with variable gap structures, incorporating the dynamics of the welding wire-filling process. The different laser welding modes and the filling process under the variable gap structure were numerically simulated. The results indicate that the maximum flow rate of the laser self-melting pool remains stable in proximity to the keyhole, reaching a maximum of approximately 2.491 m/s, with molten metal entering through the area surrounding the keyhole. As the gap size gradually increases to 0.2 mm during the laser self-fusion welding stage, keyhole instability becomes more pronounced. In transitioning from laser self-fusion to wire-filling welding, the welding wire behavior can be divided into three stages. The molten metal at the end of the welding wire is transferred to the liquid melt pool through a liquid metal bridge. The flow rate of this bridge initially rises before gradually decreasing, reaching a maximum flow rate of 1.606 m/s. Notably, the welding wire lags approximately 0.6 mm behind the laser's focal point, with the narrowest width of the liquid bridge measuring about 0.89 mm. Based on the simulation results and considering the melting transition time of the welding wire, the initiation time for the welding wire has been further adjusted to the first 10 ms when the gap threshold reaches 0.2 mm. Experimental verification confirms the successful laser welding of a 2 mm variable gap structure thin plate. This study elucidates the melt pool flow, keyhole fluctuations, and metal transition behaviors during the laser welding process, contributing to a deeper understanding of the complex heat and mass transfer dynamics inherent in variable gap structure laser self-melting and wire-filling welding. Ultimately, these insights aim to enhance the application of laser welding in adaptive welding for large structural components.

New Applications of Knudsen Effusion Mass Spectrometry (KEMS) for Gas Evolution Analysis in Lithium-Ion Batteries

Kems4Bats, a new research group initiated under the BMBF's NanoMatFutur framework at Hochschule Mannheim, employs both established and innovative experimental methods to analyze thermal and gaseous emissions in lithium-ion batteries. Operating from a state-of-the-art laboratory equipped with advanced instrumentation, the group examines how variations in electrode materials and particle dimensions influence diffusion and gas generation. Key research focuses include studying diffusion processes, the formation of solid electrolyte interfaces, and the impacts of fast charging on battery aging. Significant achievements of Kems4Bats include the development of a new instrument based on the KEMS (Knudsen effusion mass spectrometry) method, which enables precise, real-time in-situ measurements of gas evolution in lithium-ion batteries. Moreover, this device allows for highly accurate measurements of vapor pressures, particularly for organic substances with high vapor pressures, such as electrolyte solvents. Additionally, the group has established a battery production line, enhancing the safety and effectiveness of these energy storage systems.The improvement and detailed study of lithium-ion batteries are essential for advancing energy storage technologies. Understanding how gases evolve within these batteries during their formation, operational cycles, and aging is crucial for enhancing their performance and safety. Historically, Knudsen Effusion Mass Spectrometry (KEMS) has been an effective method for measuring the temperature-dependent vapor pressures of various materials, both organic and inorganic. This technique aids in calculating important thermodynamic properties. This study expands the application of KEMS to investigate gas evolution in lithium-ion batteries, marking a significant development in battery diagnostics.A unique prototype was developed to modify the KEMS approach, allowing for accurate monitoring of gas species evolution in lithium-ion batteries. This innovation not only provides detailed insights into the types and quantities of gases produced at different stages of the battery lifecycle but also broadens the traditional boundaries of KEMS measurements. Our modified system allows for the analysis of substances with high vapor pressures, such as electrolyte components, which were previously challenging to study due to methodological limitations.The results of this research shows the complex patterns of gas formation in lithium-ion batteries, providing essential insights for improving battery design and establishing higher safety standards. This research not only advances the field of battery technology but also highlights the adaptability of KEMS as a powerful tool in materials science.

Anatomical Variations in Morphometric Measurements of the Coracoid Process in a Cross Section of the Sudanese Population: Evaluation Using Chest Computed Tomography.

Introduction The coracoid process is integral to the functionality of the scapula, serving as a crucial attachment point for several muscles involved in shoulder movement and stability. In pathologies and fractures of the coracoid process, understanding the morphometric variations is essential for devising optimal surgical strategies. Given the substantial lack of relevant data, this study aimed to analyze the morphometric variations in the dimensions of the coracoid process among the Sudanese population and evaluate the differences in the measurements in relation to gender. Methods The study was performed on 100 images of human scapulae (50 males and 50 females). The radiographs and reports were acquired from the Radiology Department at Almoalim Medical City, Khartoum, Sudan. CT scan images were uploaded to medical imaging software (PaxeraViewer version 1.0.1.9, PaxeraHealth, Newton, MA, USA). Quantitative measurements of linear parameters were calculated via this software, and data was analyzed using SPSS Statistics version 23 (IBM Corp. Released 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.). Results Our study revealed that the mean measurements of the coracoid process dimensions were as follows: the length 39 ± 2.7 mm, the tip thickness 10.8 ± 1.8 mm, the base height 13 ± 1.1 mm, and the base width 22.2 ± 1.6 mm. Gender-based comparisons showed a trend towards larger parameters in males compared to females. Significant variations in the length (p = 0.03) and base height (p = 0.002) of the coracoid process were noted. Conclusion This study demonstrated variations in coracoid process dimensions among the Sudanese population, emphasizing gender influence. Moreover, comparisons to earlier research highlighted discrepancies across different ethnicities. Further investigation with a greater number of cases from a prospective viewpoint is needed for more compound insight into this issue.

A New Paradigm in Torque Transfer: Rethinking Shaft Key Placement

In this study, an innovative approach to torque transmission mechanisms within the context of hub–shaft connections is introduced by exploring the viability of a transverse key configuration. Unlike traditional longitudinal key placements, the proposed method positions the key perpendicularly to the rotational axis, resembling a pin joint at the interface of the shaft and the hub. This research primarily aims to elucidate the maximum torque capacity of such a connection, juxtaposed against conventional methodologies. Employing a rigorous analytical framework, equations originally designed for pin connections are adapted to suit the unique geometric and loading conditions presented by the transverse key. This adaptation is essential in quantifying the resultant torque that the connection could sustain without failure. The study meticulously accounts for the variations in key dimensions and the inherent limitations posed by the method’s reliance on the end-face connection strategy. Comparative analyses underscore the manufacturing advantages of the proposed method, notably its reduced machinery requirements, by leveraging standard milling processes over more complex machining operations that are traditionally associated with keyway or keyseat creation. However, the findings also highlight the compromised torque transmission capability due to the reduced contact area, a significant consideration for designers. This research contributes to the broader discourse on mechanical connection innovations, offering a novel perspective on torque transmission solutions. It provides a foundation for future exploration into alternative key configurations, potentially revolutionizing hub–shaft connection designs in applications constrained by manufacturing capabilities or cost considerations.

Framework and case study for the assembly accuracy prediction of prefabricated buildings using BIM and TLS

ABSTRACT Tolerance management in the Architecture, Engineering, and Construction (AEC) sector faces challenges due to a lack of systematic scientific methods and tools. Quality issues in construction, coupled with inefficiencies, rework, and waste arising from deviation problems, hinder the sustainable development of the AEC sector. Current deviation control methods in the AEC field rely on compliance inspections and on-site rework, which are reactive and costly. In contrast, the manufacturing industry, closely linked to AEC, has developed highly automated methods for tolerance management. Although prefabricated buildings are manufactured off-site with high precision, the on-site assembly precision remains low, failing to fully leverage manufacturing industry capabilities. This research proposes a framework for predicting assembly accuracy of prefabricated buildings during the design and early construction stages. The framework, based on tolerance analysis methods from the manufacturing industry, integrates Building Information Modeling (BIM) and Terrestrial 3D Laser Scanning (TLS) technologies. This innovative approach offers a computer-aided method for conducting tolerance analysis in prefabricated buildings. A completed prefabricated building project serves as a case study, utilizing the framework to predict variations in critical dimensions, and the predictions align with measured results, demonstrating the feasibility of the proposed framework.

Semi-constant source radius and variable stress drop of repeating earthquakes: A fluid-invasion hypothesis for earthquake generation

Summary Earthquakes with very similar waveforms have been recognized as repeating earthquakes, or repeaters, which are interpreted as repeated ruptures of an isolated, frictionally locked asperity patch that are caused by stress loading due to aseismic slip in the surrounding stable regime of the fault. Ideally, the repeated ruptures of the same asperity result in the same source dimension and stress drop. However, significant variations in the stress drop have been observed during fluid-injection experiments even for a single repeater sequence. This study focuses repeater sequences in three different tectonic regimes beneath the Japanese Islands and investigates variations in the source dimension and stress drop in the same repeater sequences. The obtained results show that the variation in the source radius is mostly within 20–30% in individual repeater sequences but the stress drop is largely variable by one order of magnitude or more. We propose a fluid-invasion hypothesis to explain our observations. When pore-fluid pressures gradually invade into an asperity, the edge of the asperity tends to behave as aseismic because of the reduction of the effective normal stress to values below the critical value of effective normal stress, which makes the source radius somewhat smaller. Simultaneously, the amount of the fluid invasion into the asperity fluctuates the shear strength of the asperity, with the stress drop being smaller for higher pore-fluid pressures. The reduced source radius and stress drop expected from the fluid-invasion hypothesis can explain positive correlations between the source radius and seismic moment. We propose a conceptual model for earthquake generation by involving the triggering of aseismic slip by the enhancement of pore-fluid pressures and subsequent rupture of asperity by the stress loading due to the aseismic slip, which can be potentially applied to the genesis of repeaters and non-repeaters.

Dimensions of Child Maltreatment in Australians With a History of Out-of-Home Care.

Research suggests that the dimensions of childhood maltreatment (type, age of onset, duration, frequency and perpetrator) play an important role in determining health and wellbeing outcomes, though little information is available on these dimensions for any care experienced cohorts. This study aimed to determine if any variation in maltreatment dimensions were experienced between two subsets of the nationally representative Australian Child Maltreatment Study, both of which reported childhood maltreatment histories: care-experienced (n = 358) and non-care-experienced (n = 4922). Using a series of independent t-tests and chi-square tests, we compared the two groups on seven dimensions (number of maltreatment types, range of maltreatment items, age of onset, duration, frequency, perpetrator number, and perpetrator type) for the five child maltreatment types (physical, emotional, sexual abuse, neglect, and exposure to domestic violence). Results showed that the care-experienced group reported a higher intensity of maltreatment, being younger when maltreatment first started, experiencing greater variety of maltreatment types, for longer periods, more times and by more perpetrators than maltreated people with no care experience. We conclude that children and young people in out-of-home care experience maltreatment at a higher intensity than the rest of the population, which has implications for effective treatment.

Anteroposterior cervical spine canal diameter: exploring ethnic variation between European and Polynesian populations.

Reduced spinal canal anteroposterior (AP) diameter and AP-transverse diameter ratio have been linked to the development of spinal cord injury and myelopathy. Previously unpublished data has suggested Maori and Pacifica individuals may have narrower cervical spine canals than their NZ European counterparts. We evaluate the existence of potential differences in dimensions of the sub-axial cervical spine canal between New Zealand European, Māori and Polynesian individuals. A computed tomography (CT) analysis of 645 intact adult sub-axial cervical vertebrae from 129 patients. A total of 645 human sub-axial (C3-C7) cervical vertebrae were analysed radiographically, using 1 mm resolution CT scans to measure AP diameter, transverse diameter and AP:transverse ratio. CT data were obtained from normal trauma scans demonstrating no acute pathology. CT data was reformatted in digital software allowing multi-planar reconstruction (MPR) to increase accuracy of measurements. Statistical analysis was performed using analysis of variance (ANOVA). A total of 245 vertebrae were from Māori individuals, 245 from NZ European and 155 from Polynesians. There were 455 male vertebrae and 215 female vertebrae. Statistically significant differences were found in AP canal diameter between all ethnic groups, at all spinal levels. The average cervical spine canal was around 2.5 mm narrower in Polynesians and around 1.5 mm narrower in Māori than NZ Europeans. No differences in Transverse canal diameter were observed, however statistically significant differences were found in the AP:transverse ratio at all spinal levels. Our study, utilizing a normal patient cohort, confirms differences in canal dimensions between ethnic groups. Ethnic variation in cervical canal dimensions as herein described, must be considered when defining and diagnosing congenital stenosis. Neglecting to account for these differences may lead to misdiagnosis of congenital stenosis in normal individuals in certain ethnic groups.

Structure Dimensions Variation of the Segmented Switched Reluctance Linear Synchronous Motor (SSRLSM) and the Effects on Its Performances

This paper proposed and discussed a SRLSM with the segmental pole. The segmented SRLSM which known as SSRLSM was designed for domestic lift application. The SSRLSM was designed to fulfill the design target requirement where the lift must be able to transport a maximum 200 kg payload. A lab-scaled prototype of the SSRLSM was developed for experimental and measurement purpose. Beforehand, the SSRLSM was designed and simulated for different structure dimension to study the effect of structure’s reduction towards its performances. The structure dimensions involved are the number of coil number and the stack length where the number of coil is reduced from 6 coils to 3 coils. The results show that the thrust produced by the 6-coils and 3-coils SSRLSM is 2400 N and 1200 N, respectively. This shows that, the thrust is reduced by 50 % as the number of coil reduced by half. At the same time, the thrust produced also reduced by approximately 50 % as the stack length, z reduced by half from 400 mm to 200 mm. This shows that, the thrust, F of the SSRLSM is directly proportional to the number of coil as well the stack length, z.

How the Spacer Influences the Stability of 2D Perovskites?

Two-dimensionallead halide perovskites (2D HPs) represent as an emerging class of materials given their tunable optoelectronic properties and long-term stability in perovskite solar cells. However, the ever-growing field of optoelectronic devices using 2D HPs requires fundamental understanding of the influence of the spacer on the physiochemical properties and stability of perovskites as well as establish which cation properties are closely related to suppress the halogen ion mobility. This study focuses on investigating the influence of organic spacers with intrinsic properties (e.g., rigidity and flexibility, special groups) and variations of material dimensions on the stability of halogen ions and inorganic frameworks in 2D HPs. It is found that the perovskite structure composed of rigidity molecules owns better stability of halogen ion and inorganic framework than that of flexible molecules. The stability of ions exhibits a negative correlation with the dimensions of perovskite. More importantly, a simple descriptor for measuring the stability of halogen ions in 2D HPs is constructed. By causal discovery algorithms with more physical and chemical significance, the Kappa shape index, number of rotatable bonds, and aromatic carbocycles in organic spacers are identified as causal and important features for the stability of halogen ions in 2D HPs.