3D Plate Research Articles

Direct numerical simulation of a transitional, cryogenic cavitating mixing layer of liquefied natural gas behind a flat splitter plate using a homogenous equilibrium mixture cavitation model

A major challenge in the design of liquefied natural gas (LNG) pumps is concerned with the accurate prediction of flow behaviour at off-design conditions where destructive phase change from liquid to vapor - named cavitation - at cryogenic conditions may emerge undesirably and downgrade the machine performance. As a first step of our research towards addressing this challenge, the present study employs a homogenous equilibrium mixture (HEM) –based cryogenic cavitation solver to run direct numerical simulation (DNS) of a fundamental case study of transitional cavitating mixing layer of LNG behind a 3D planar flat plate, which resembles actual conditions of flow behind the vanes of industrial LNG sub-merged pumps. Assessment of the preliminary findings shows that the mixing layer is mainly driven by different modes of the well-known Kelvin-Helmholtz (K–H) instabilities, which develop coherent vortex structures that tend to shed off periodically across the mixing layer. The cavity structures are formed via transient interactions of the shedding vortices, and in the meantime of their pairing processes. The shedding of cavities, which mostly appear as “horse-shoe” and “croissant”-shaped vapor structures, maintains by the unsteady sheet cavity formed on the splitter upper wall and the latent heat exchange mechanisms, beside the dominant K–H instabilities. The presence of three-dimensionality is found to enhance instability of the mixing layer by increasing the frequency of phase change successions.

Prolonged Maintenance of Ex Vivo Functional Vk*MYC Multiple Myeloma Cells Allows for in Vitro Manipulation and Subsequent In Vivo Analysis

Human multiple myeloma (MM) cell lines are easy to culture but only partially reflect the heterogeneity of primary MM samples as most cell lines are derived from primary human plasma-cell leukemia samples and have often lost their dependence on the marrow microenvironment. In contrast, maintaining primary human MM samples ex vivo and in vivo is very challenging. To bridge this gap, the immunocompetent Vk*MYC transgenic MM model was developed. It has high biological fidelity to the human disease characteristics and features easy in vivo engraftment and serial transplantation. However, Vk*MYC cells are considered notoriously difficult to grow and manipulate in vitro, limiting their usage for functional studies. Aim To overcome these limitations, we aimed to develop a robust culture system which promotes survival and function of primary Vk*MYC MM cells in culture as a research tool for in vitro manipulation and subsequent in vivo transplantation. Method Splenocytes from tVk*MYC (Vk12598 clone) engrafted mice were routinely maintained ex vivo and conditioned media collected for M-spike quantification. Analysis of cultures by flow cytometry allowed for Vk*MYC population quantification over time. Our novel plating method includes the following components to support Vk*MYC cell survival: 3D plating as hanging drops, low (6.5%) oxygen culture, high density cultures and a cytokine cocktail. Results The culture method described here routinely results in maintenance or slight enrichment of Vk*MYC (CD138+B220-) splenocyte fraction. Monoclonal immunoglobulin (M spike) accumulation in conditioned culture media was assessed after 7 days culture as a clinically relevant, functional output marker. Culture media displayed the same immunoglobulin isotype as parent Vk*MYC (Vk12598 clone). Figure 1 shows previously frozen donor Vk*MYC splenocytes (day 0) assessed by flow cytometry and either injected directly, or maintained 7 days ex vivo, prior to IV injection into naive C57BL/6 recipient mice. Culture-recipient mice developed Vk*MYC MM disease with the same serum M-spike isotype band, similar engraftment ratio, similar time to evidence of biochemical disease and similar overall survival time as mice transplanted with freshly defrosted Vk*MYC splenocytes. To exemplify in vitro manipulation, Vk*MYC splenocytes were cultured as described and treated with Cy3-labelled liposomal nanoparticles (LNP), a non-toxic way to deliver treatment loads e.g. siRNAs, then maintained in culture for up to 7 days after treatment. Flow analysis showed >95% of viable CD138+ cells were Cy3 positive as a marker of LNP uptake. In addition, Vk*MYC splenocytes were transduced with GFP-encoding lentivirus, then maintained in culture for up to 7 days. Flow analysis showed viable, CD138+B220- cells expressing GFP as a marker of lentiviral transduction, highlighting the potential of this culture method to allow manipulation of Vk*MYC cells in vitro. Discussion This innovative culture method allows for survival and enrichment, but not expansion of Vk*MYC splenocytes in culture. Our seven-day culture protocol allows in vitro manipulation with liposomal nanoparticles as well as viral vectors and subsequent in vivo investigations. Figure 1. Experimental setup. A) (Day 0) donor tVk*MYC spleen was defrosted and assessed for MM burden by flow (CD138+ B220-). Splenocytes were maintained for 7 days ex vivo in 3D hanging drop cultures. At day 7, conditioned media was assessed by modified SPEP method for evidence of biochemical disease, and cultured cells assessed by flow or injected into naive C57BL/6 recipient mice. B) After 4 weeks, evidence of biochemical disease (M-spike) was confirmed by SPEP and mouse spleen Vk*MYC burden assessed by flow cytometry. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Modeling of the Lamb wave asymmetric modes with an improved two-dimensional thin plate theory

For the modeling of Lamb wave propagation, the accuracy of some two-dimensional (2D) plate theories like the first order shear deformation theory (FSDT) may decline at a high frequency, since their displacement fields cannot match those complicated Lamb wave structures. To address this issue, this paper proposes an improved 2D thin plate theory which has a more accurate high frequency modeling ability of Lamb wave than the FSDT. This is done by designing the displacement field according to the high frequency Lamb wave structure. Since the shear stress curves of the Lamb wave are complicated and would vary with the frequency, the initial displacement field takes a combination of polynomial and trigonometric forms, which has two coefficients that need to be determined by fitting the shear stress curve at a certain frequency. Then, a strategy is applied to determine the eventual displacement field by searching the high frequency range for the optimum coefficients that enable a best modeling accuracy. The relative error of its modeling result of A0 mode can be controlled within 0.03 % below 800 kHz·2 mm, and keeps the highest error of 1.43 % up to 2500 kHz·2 mm. To verify its high frequency modeling performance, a finite element method program is finally built. Results show that both the wavefields of A0 and A1 can be accurately simulated with the improved two-dimensional thin plate theory.

A uniformly-valid asymptotic plate theory of growth with numerical implementation

In this paper, we aim to develop a simplified and uniformly-valid finite-strain plate theory of growth. First, starting from a consistent finite-strain plate theory of growth proposed in our previous work, we specify the magnitudes of growth functions in five different cases and conduct systematic asymptotic analyses, from which the original plate theory can be reduced to some classical plate and membrane theories. Based on the asymptotic analyses, it is found that some terms in the original plate equations (which contain the high-order stress tensor S(2)) always have higher asymptotic orders. By dropping these terms, the plate equations can be simplified significantly. Then, a reduced finite-strain plate theory of growth is established, which is valid in a wide range of growth and mechanical loading conditions. The associated weak form of this uniformly-valid plate theory has also been derived for numerical implementation. To demonstrate the efficiency of this plate theory, it is implemented into a finite element software and applied to study four typical examples. To verify the accuracy of the 2D plate models, the corresponding 3D volume models have also been constructed for these examples. Through some comparisons, it is found that the numerical results obtained from the 2D and 3D models can fit each other quite well. Furthermore, the numerical calculations based on the plate models show obvious advantages in the aspects of computational efficiency, convergence rate and stability. In our opinion, the uniformly-valid asymptotic plate theory of growth proposed in the current work is adequate for studying the complex growth behaviors of thin hyperelastic plates.

Unanticipated fake-and-cut maneuvers do not increase knee abduction moments in sport-specific tasks: Implication for ACL injury prevention and risk screening.

Non-contact anterior cruciate ligament injuries typically occur during cutting maneuvers and are associated with high peak knee abduction moments (KAM) within early stance. To screen athletes for injury risk or quantify the efficacy of prevention programs, it may be necessary to design tasks that mimic game situations. Thus, this study compared KAMs and ranking consistency of female handball players in three sport-specific fake-and-cut tasks of increasing complexity. The biomechanics of female handball players (n = 51, mean ± SD: 66.9 ± 7.8 kg, 1.74 ± 0.06 m, 19.2 ± 3.4 years) were recorded with a 3D motion capture system and force plates during three standardized fake-and-cut tasks. Task 1 was designed as a simple pre-planned cut, task 2 included catching a ball before a pre-planned cut in front of a static defender, and task 3 was designed as an unanticipated cut with three dynamic defenders involved. Inverse dynamics were used to calculate peak KAM within the first 100 ms of stance. KAM was decomposed into the frontal plane knee joint moment arm and resultant ground reaction force. RANOVAs (α ≤ 0.05) were used to reveal differences in the KAM magnitudes, moment arm, and resultant ground reaction force for the three tasks. Spearman's rank correlations were calculated to test the ranking consistency of the athletes' KAMs. There was a significant task main effect on KAM (p = 0.02; = 0.13). The KAM in the two complex tasks was significantly higher (task 2: 1.73 Nm/kg; task 3: 1.64 Nm/kg) than the KAM in the simplest task (task 1: 1.52 Nm/kg). The ranking of the peak KAM was consistent regardless of the task complexity. Comparing tasks 1 and 2, an increase in KAM resulted from an increased frontal plane moment arm. Comparing tasks 1 and 3, higher KAM in task 3 resulted from an interplay between both moment arm and the resultant ground reaction force. In contrast to previous studies, unanticipated cutting maneuvers did not produce the highest KAMs. These findings indicate that the players have developed an automated sport-specific cutting technique that is utilized in both pre-planned and unanticipated fake-and-cut tasks.

The analysis and validation of natural frequencies and mode shapes of 3D plates in the framework of the generalized thermoelastic theory

This article considers thermal effects that induce thermoelastic damping and, which, consequently, because of the absorbed thermal energy, cause thermal stresses. The problem is stated in the framework of the generalized thermoelastic theory. The natural frequency and mode shape analyzes of 3D plates are presented under uniform and nonuniform heating. From the modeling point of view, this results in the quadratic eigenvalue problem where complex frequencies and modes are obtained. Moreover, the quality factor related to the thermoelastic damping is also calculated in terms of the imaginary and the real parts of the frequencies for both the uniform and nonuniform thermal distributions. The variation of natural frequencies with temperature is investigated and compared with the experimental results for the plates with free boundary conditions. The first two mode shapes are also examined for all clamped edges for the uniform and nonuniform cases. Complex frequencies and complex modes are observed due to the thermal effects. For the uniform case, the real part of the modes decreases and the complex part increases, while the mode’s norm remains the same as in the classical modes as temperature increases. For the nonuniform case, the mode shape analysis is performed under the assumption that the elasticity modulus, thermal expansion, and specific heat parameters are functions of temperature. The peak point of the out-of-plane displacement is shown to be shifted toward the warm zone. The obtained outcomes may help design thermal structures and allow for future extensions.

Evaluation of the efficacy of Three-dimensional mini plates versus conventional mini plates used in the management of anterior mandibular fractures

The management of mandibular fractures has evolved from closed reduction to open reduction. Champy’s miniplates have become highly popular and is a time-tested method of treatment of mandibular fractures. However, advances like 3D miniplate with claimed advantages like requires less armamentarium, providing better occlusal stabilityEvaluative study conducted in 24 patients & randomly divided in 2 groups, use of 3D miniplate vs conventional miniplates in anterior mandibular fractures, age group 15-90, post-operative evaluation at day 1, 7 & 3 month, fracture stability, mobility of fracture fragment, complications & bite force. The level of significance was fixed at 5% and p ≤ 0.05 was considered statistically significant. 3D mini plating system (p value:- .001)have lesser operating time when compared to 2D conventional miniplating system, also 3D miniplate system have better intraoperative and lesser complications, significantly better bite force results (p value .002*(s)) with 3D miniplate compared to 2D conventional miniplating system.3D miniplate a novel form of plating system with better intraoperative and post operative results, better stability compared to conventional miniplating system.

Anti-impact performance of bionic tortoiseshell-like composites

Biological stiff-soft phase composite structures, such as tortoise shells and conch shells, have excellent anti-impact performance to withstand various types of high-stress events encountered in nature. A remarkable 3D interdigitating zigzag architecture in the tortoise shell, named occlusal suture structure, makes the tortoise shell simultaneously possess high mechanical strength and toughness, which is also an ideal stiff-soft phase composite prototype to mimic. In this study, four types of bionic anti-impact composite plates that feature the hard-soft phase architecture of tortoiseshell (Bio-T), mollusk shell (Bio-M), beetle exoskeleton (Bio-B) and nacre (Bio-N) and a homogeneous structure plate (HSP) are designed, to systematically examine and compare their roles in impact energy dissipation. Through an integrated approach combining additive manufacturing and drop tower testing, the peak force, residual velocity, and energy absorption of these bionic composite plates are studied and compared. Experimental results indicate that the Bio-T composite plate has the best impact resistance, compared with the other three bionic composites. Furthermore, the influence of the ply angle and the dimension of suture structure on the impact resistance of the Bio-T composite plate is identified. The [0°/30°/0°] arrangement is able to resist higher loads before failure. The 3D Bio-T composite plate provides a significant enhancement of anti-impact performance than the 2D Bio-T composite plate. Finally, the crack propagation mode in the suture structure of the Bio-T composite plates is examined, enhancing our understanding of the underlying mechanisms during impact. Such findings may prove useful for the design of future protective apparatus for soldiers and aircrafts, with improved anti-impact performance.

Flexible Solid Supercapacitors of Novel Nanostructured Electrodes Outperform Most Supercapacitors.

Sustainable and scalable fabrication of electrode materials with high energy and power densities is paramount for the development of future electrochemical energy storage devices. The electrode material of a supercapacitor should have high electrical conductivity, good thermal and chemical stability, and a high surface area per unit volume (or per unit mass). Researchers have made great efforts to use two-dimensional (2D) nanomaterials, but the separated 2D plates are re-stacked during processing for electrode fabrication, impeding the transport of ions and reducing the number of active sites. We developed a novel process for manufacturing thin and flexible electrodes using a 2D material (MXene,Ti3AlC2) and a conducting polymer (poly(3,4-ethylenedioxythiophene), PEDOT). Because the PEDOT layer is electrochemically synthesized, it does not contain the activator poly(styrene sulfonate). The electrospray deposition technique solves the restacking problem and facilitates the infilling of the gel electrolyte by forming a highly porous open structure across the entire electrode. In the PEDOT/MXene multilayered electrode, the double-layer capacitance increased substantially because of a dramatic increase in the number of accessible sites through the MXene layer. Although applied to solid supercapacitors, these new supercapacitors outperform most aqueous electrolyte supercapacitors as well as other solid supercapacitors.

A reduced-order, rotation-based model for thin hard-magnetic plates

We develop a reduced-order model for thin plates made of hard magnetorheological elastomers (hard-MREs), which are composed of hard-magnetic particles embedded in a polymeric matrix. First, we propose a new magnetic potential, as an alternative to an existing torque-based 3D continuum theory of hard-MREs, obtained by reformulating the remnant magnetization of a deformed hard-MRE body. Specifically, the magnetizations in the initial and current configurations are related by the rotation tensor decomposed from the deformation gradient, independently of stretching deformation, motivated by recently reported observations in microscopic homogenization simulations. Then, we derive a 2D plate model through the dimensional reduction of our proposed rotation-based 3D theory. For comparison, we also provide a second plate model derived from the existing 3D theory. Finally, we perform precision experiments to thoroughly evaluate the proposed 3D and 2D models on hard-magnetic plates under various magnetic and mechanical loading conditions. We demonstrate that our rotation-based modification of the magnetic potential is crucial in correctly capturing the behavior of plates subjected to an applied field aligned with the magnetization, and undergoing in-plane stretching. In all the tested cases, our rotation-based 3D and 2D models yield predictions in excellent quantitative agreement with the experiments and can thus serve as predictive tools for the rational design of hard-magnetic plate structures.

(Invited) Pushing Lithium-Metal Batteries to the Limit: Fast Charging, Low Temperature, and Safety

The performance of lithium metal batteries has advanced significantly, thanks to continuous improvement in the lithium metal anode. Many chemical and mechanical control strategies have been employed to combat its degradation mechanisms such as parasitic reactions, dendritic growth, and formation of isolated lithium. Electrolytes with high salt concentrations, including those with non-solvating diluents (known as localized high concentration electrolytes, or LHCE), electrolyte additives, artificial coatings, 3D plating hosts Li, and applying pressures in the 100s-1000s of kPa range have all been found to be effect in yielding dense, high efficiency Li metal deposits. Despite these advancements, reported lithium metal batteries tend to be charged at low rates, operated under ambient conditions, and lacking sufficient information on their safety characteristics. In this talk, we will review our recent progress in pushing the lithium metal batteries to extreme operating conditions in term of temperature, charging rates, and shorting behavior.To enable fast charging, we have focused on developing a nucleation agent on the surface of current collector that can induce the formation of large, uniform nucleation sites. These nanoscopic sites enable dense lithium plating at 5 mA c-2 of current density, when a planar Cu electrode will fail catastrophically. This uniform nucleation method leads to a 45 um thick Li deposit that is nearly porosity free. A lithium metal cell with a metal oxide cathode is capable of 1C charging for extended cycles.To enable low temperature operation, we have focused on the development of new electrolyte compositions that uses weakly solvating solvents. These electrolytes, represented by monodentate ethers and LHCEs made of ethers, promote the formation of contact ion pairs after solvation over solvent separated ion pairs. These electrolytes have enabled the formation of dense lithium metal deposits at as low as -60oC, while strongly solvating electrolytes will promote the formation of dendrites and cell shorting.Finally, any practical implementation of lithium metal batteries operating under these extreme conditions have to feature safety designs that mitigate the impact of internal shorting. In this regard, we have focused on separator designs that can detect and intercept lithium dendrites.

A bridging model and volume averaging approach for the dynamic analyses of 3D braided plates based on 3D shear deformation theory under low-velocity impact

In 3D braided composites, some fibers are oriented in thickness directions, increasing strength and reducing de-lamination ability. The equivalent elastic properties of the 3D braided plate are computed using a volume averaging approach. Here, the low-velocity impact of the 3D braided plate is investigated at various locations based on the 3D shear deformations theory incorporated with twelve-degree freedom per node using an eight nodded isoparametric finite element method. In this theory, transverse displacement is the function of the thickness coordinates, which is the unique advantage of this theory. The various parametric studies are performed by varying geometrical and material parameters.

Automatic lung tumor segmentation from CT images using improved 3D densely connected UNet.

Accurate lung tumor segmentation has great significance in the treatment planning of lung cancer. However, robust lung tumor segmentation becomes challenging due to the heterogeneity of tumors and the similar visual characteristics between tumors and surrounding tissues. Hence, we developed an improved 3D dense connected UNet (I-3D DenseUNet) to segment various lung tumors from CT images. The nested dense skip connection adopted in the I-3D DenseUNet aims to contribute similar feature maps between encoder and decoder sub-networks. The dense connection used in encoder-decoder blocks also encourages feature propagation and reuse. A robust data augmentation strategy was employed to alleviate over-fitting based on a 3D thin plate spline (TPS) algorithm. We evaluated our method on 938 lung tumors from three datasets consisting of 421 tumors from the Cancer Imaging Archive (TCIA), 450 malignant tumors from the Lung Image Database Consortium (LIDC), and 67 tumors from the private dataset. Experiment results showed an excellent Dice similarity coefficients (DSC) of 0.8316 for the TCIA and LIDC and 0.8167 for the private dataset. The proposed method presents a strong ability in lung tumor segmentation, and it has the potential to help radiologists in lung cancer treatment planning. Framework of the proposed lung tumor segmentation method.

Buckling instability and dynamic response of a planar gridshell under thermal load

We introduce a discrete model to predict the buckling instability and the vibration performance of an elastic gridshell which experiences a thermal load. With both thermal stress and temperature-dependent material property considered, a discrete framework for the simulation of hollow grid is developed based on a well-established Discrete Elastic Rods (DER) method and a specific mapping technique. It is found that the critical temperatures which induce a structural instability are identical for single rod system and multiple rods network, regardless of rod density. Meanwhile, its natural frequency linearly enhances with the growth of rod number. Moreover, the increase of environmental temperature will result in that the resonant peak of displacement response moves toward a lower frequency. Interestingly, we found that the natural frequency of gridshell is closer to the beam model, while its displacement response distribution shows similarity to plate theory. The free vibration frequencies of one-dimensional (1D) beam and two-dimensional (2D) plate with a simply-supported boundary condition under thermal effects are also derived analytically for cross-validation. We hope our findings could provide a fundamental insight in structural dynamics and further facilitate the designs in mechanical and aerospace engineering, e.g., deployable structures and smart metamaterials.

An In vitro study of biomechanical comparison between titanium 4-hole 3D plates and titanium conventional 4-hole miniplates for internal fixation of mandibular angle fractures.

Fracture fixation, in the present times, is classically done using mini plates. The position and number of plates to fixate a mandibular angle fracture have been and are still extensively researched and reported in the literature. A more recent addition is 3D mini plates. To compare and evaluate the biomechanical behavior of one 2.0mm titanium 3D miniplate fixation plate (4- hole) and one 2.0mm titanium 4-hole miniplate in internal fixation of mandibular angle fractures. To measure load at break, maximum load, and displacement at maximal load for internal fixation done with 3D mini plates and conventional mini plates respectively. Five dry cadaveric mandibles were sectioned into 10 hemi-mandibles. Each cadaveric mandible was sectioned at the angle of mandible to simulate unfavorable mandibular angle fracture. The obtained hemimandible were divided into experimental groups (GROUP 1 and GROUP 2) with 5 samples in each group, plated with a linear miniplate and 3D miniplate respectively. Maximal load, Load at break, and displacement at maximum load were the only obtained parameters for comparison. Conventional miniplate showed greater mean maximum load values of 174.93N±54.45 compared to 3D mini plates which recorded a mean maximum load value of 106.96N±23.86. Load at break and displacement at maximum load were found to be both insignificant. The results in this study showed statistically no significant difference with any of the above parameters except maximal load, between the two groups evaluated. Conventional linear miniplate according to Champy's lines of osteosynthesis can be used successfully for providing satisfactory osteosynthesis with the definitive advantage of cost-effectiveness.

Embossing Lines and Dots Geometry Effect on the Key Tissue Paper Properties with Finite Element Method Analysis

Embossing is a functional and strategic process for creating high-quality multi-sensory tissue-paper products. Embossing modifies the sheet surface by generating hill and/or valley designs, changing the third-dimension z with a compressive die. This research work specifically concerns the impact study of the engraving finishing geometry on the final properties of tissue paper. This work led us to conclude that, even though the sheets individually present a higher hand-feel (HF) value for the straight finishing geometry, the highest softness was obtained in the two-ply prototype for the round finishing geometry. Moreover, this study confirmed that the HF value reduces with the increase of the bulk, being more accentuated for the micropattern. Relevant differences could not be seen in the spreading kinetics of the liquid droplets over time. Thus, the finishing geometry of the 3D plates did not impact the absorption kinetics on these samples. The finite element model allows us to understand the effect of the plate pattern and its finishing geometry on the paper, and the simulation results were in accordance with the experimental results, showing the same trend where patterns with a round finishing geometry marked the tissue-paper sheet more than patterns with a straight finishing did.

A Randomised Control Trial for Comparative Evaluation of 3-D Versus 2-D Miniplates For Internal Fixation Of Mandibular Fractures

Fracture of mandible is a common facial injury. For restoration of normal jaw structure and function, proper bony healing is important and thus, stable plate osteosynthesis has become an indispensable component of cranio-maxillofacial surgery.Aim: This study aimed to evaluate the efficacy of 3D versus 2D mini bone plates used for internal fixation of mandibular fractures.Methods and Material: A prospective randomised control trial was conducted on 20 patients with mandibular fractures in the symphysis and parasymphysis regions. In group 1, 3-D miniplates were used with a single, rectangular, 4-holed titanium plate with 4 screws and in group 2, 2-D miniplates were used with two 4-holed titanium plates fixed with 8 screws.Time taken for fixation and operators comfort was analysed using Chi square test whereas trismus and pain were analysed using Anova.Results: The difference for mean time taken for fixation was statistically highly significant (P < 0.01) between 3-D (33.1 minutes) and 2-D plate( 44.7 minutes).Fixation of 2-D plate was found more comfortable.Swelling in both the groups was generally comparable and lasted for about 1 week. Mouth opening in patients of both the groups showed a gradual recovery till 1 month after which it stabilized.Conclusion: 3-D miniplate were more economical, with less intraoperative time required and showed better performance over 2-D miniplates. However there was difficulty in their adaption and were inappropriate when fracture line was very close to mental foramen.

Capacity envelope of plate anchors under six degree-of-freedom loads in clay

The capacity envelope of plate anchors has been established for two-dimensional case under 3 degree-of-freedom (DOF) loads, while there is limited knowledge about three-dimensional (3D) plate anchors subjected to 6 DOF loads. This paper investigates the capacities of plate anchors in 3D case through finite element modelling. A square plate anchor is first considered with 246 finite element analyses conducted under uniaxial, 2 DOF, 3 DOF and 6 DOF loads, respectively. The effect of aspect ratio on the uniaxial capacities is analysed by considering rectangular plate anchor. A 6 DOF capacity envelope is obtained by fitting a rigorous sum of squares convex polynomial equation. By analysing the correlation degree of 6 DOF loads and parameters of the polynomial equation, an easy-to-use power law equation of 6 DOF capacity envelope is developed. This simple equation is employed in a force-resultant plasticity model to predict 3D kinematics of plate anchor under 6 DOF loads. A calculation case study is then presented to demonstrate the anchor behaviour in 3D space.

(Keynote) Solution-Phase Growth of Cu Microplates: A Multi-Scale Theoretical Analysis from First Principles

We use first-principles density functional theory (DFT) to quantify the role of iodide in the solution-phase growth of Cu microplates. Our calculations show that a Cu adatom binds more strongly to hcp hollow sites than fcc hollow sites on iodine-covered Cu(111) – the basal facet of two-dimensional (2D) Cu plates. This feature promotes the formation of stacking faults during seed and plate growth which, in turn, promotes 2D growth. We also found that iodine adsorption leads to strong Cu atom binding and prohibitively slow diffusion of Cu atoms on Cu(100) – a feature that promotes Cu atom accumulation on the {100} facets of a growing 2D plate. Incorporating these DFT insights into analog experiments, in which we initiated the growth of Cu plates from small seeds consisting of magnetic spheres, we confirmed that two or more stacking faults are required for lateral plate growth, consistent with prior studies. Moreover, plates can take on a variety of shapes during growth: from triangular and truncated triangular to round and hexagonal – consistent with experiment. Using absorbing Markov chain calculations, we assessed the propensity for 2D vs. 3D kinetic growth of the plates. At experimental temperatures, we predict plates can grow to achieve lateral dimensions in the 1–5-micron range, as observed in experiments.

Versatility of various 3D non locking miniplates in treatment of mandibular fractures

Context: The optimal management of mandibular fractures continues to evolve. Fractures of mandible predispose the patients to structural, functional and aesthetic compromise if not treated. The current understanding of the biomechanics and fracture healing of the mandible has influenced the modern approach to the open reduction and internal fixation of these fractures. These help us to evaluate shortcomings of compression plates and 2D miniplates leading to development of 3D plates. Aims: To evaluate the versatility and efficacy and complication of 3 different varieties of 3D non locking plates–2x2 and 2x3 and delta plates in the treatment of mandibular fractures at different sites.Materials and Methods: A total of 86 patients of mandibular fractures were managed by open reduction and internal fixation utilizing total 114 three dimensional plates (109 non locking 3D plates (2X2,3X2) and 5 delta plates) were used for fractures of the mandible including symphysis, parasymphysis, body, angle, ramus and condyle over a period of 3 years.Results: The use of 3D plates provided semi-rigid fixation of fractured fragments with no immediate post-operative mobility. Immediate and subsequent postoperative clinical and radiographic evaluation was carried out at 15 days, 1 month, 3 months and 6 months. Post-operative complications observed were post-operative neurosensory deficit in 3 patients, occlusal discrepancy in 3 patients, wound dehiscence in 2 patient, plate exposure in 1 patient and parotid fistula in 1 patient which accounted for 8.6% of total patients. None of the patient suffered from Infection, segmental mobility, paraesthesia. Malunion, non-union. All these were treated successfully with definitive measures.Conclusion: The 3D mini-plate system is a versatile and efficient method for fixation of mandibular fractures. Delta plates are efficient method for reduction and fixation of subcondylar fracture. The only contraindication for 3D plates is their use in mental foramen region (where distance between mental foramen and inferior border is less than 1.5cm).