Notable Deformation Research Articles

Mechanics of re-entrant anti-trichiral honeycombs with nature-inspired gradient distributions

This study focuses on the nature-inspired gradient-based approach to re-designing re-entrant anti-trichiral (REAT) honeycombs through extensive experimental quasi-static compression. Novel perspectives on REAT honeycomb are offered through the introduction of gradient distributions on two critical geometrical parameters, the cylindrical diameter (chiral) and height of the unit cell, rather than the traditional thickness-based gradient approach. Chiral-based gradient approach demonstrated clear advantages in elastic stiffness, specific energy absorption (SEA) and densification strain over uniform REAT structures of constant geometrical parameters. These advantages are exhibited in their extended and constantly increasing quasi-plateau stage, consistent specific energy absorption (SEA) especially during early stages of compression, and most importantly, the ability to maintain a relatively constant energy absorption efficiency that is 25% more than that of the Base uniform REAT structure. Height gradient-based REAT structures, on the other hand, were able to leverage on associations between the negative Poisson's ratio (NPR) effect and height of unit cell to demonstrate notable deformation patterns across various portions of the structure. The present work reveals the performance enhancements through alternative gradient-based approaches over thickness-based gradient approaches and highlighted the differences in NPR between layers as the main driver of compressive collapse apart from the commonly concluded difference in relative density.

Identifying the Groundwater Sources of Huangtupo Landslide in the Three Gorges Reservoir Area of China

Groundwater plays a crucial role in triggering and reactivating deep-seated landslides. However, classical hydrogeological investigations have limitations in their applicability to deep-seated landslides due to anisotropic and heterogeneous media. The Huangtupo landslide in the Three Gorges Reservoir area has garnered significant attention due to its high hazard potential. Of particular interest is the NO.1 Riverside Sliding Mass (HTP-1), which has shown notable deformation and has become the primary focus of landslide research. The study aims to investigate the sources of water in the HTP-1 landslide through hydrochemical analysis. This was achieved by monitoring the major ion content in the groundwater within the landslide for one year. Furthermore, stable isotope investigations were conducted on the groundwater in and around the landslide area, and an analysis of the mineral composition of the landslide soil was also performed. The results indicate that the groundwater in the landslide area (LGW) is a mixture of karst groundwater (KGW) from the adjacent upslope and local precipitation (LP). The karst groundwater is a major contributor to the recharge of the landslide groundwater system, causing a high component of groundwater that can easily exceed the critical level that causes landside failure during heavy rainfall events. Furthermore, prior to the relocation of residents from the Huangtupo landslide, the landslide groundwater was also impacted by human sewage, which not only affected the chemical composition of groundwater, but also had potential implications for slope stability. These findings provide a more scientific basis for the design and implementation of interception and drainage measures for the Huangtupo landslide and other large-scale landslides with similar geological conditions in the Three Gorges Reservoir area.

A conceptual model for the shakedown response of soft clay to high-cycle, low-amplitude undrained loading

Soft soils beneath transportation infrastructures suffer dynamic traffic loads with high-frequency and high-cycle characteristics, which mainly present shakedown development of deformation yet probably induce notable deformation at the stable state. However, conventional constitutive models are still not available for the long-term behavior description of soft soils under high-cycle traffic loading. Herein, a conceptual model for high-cycle, low-amplitude undrained loading was proposed incorporating a shrinking yield surface and an expanding boundary surface, which individually indicated the weakening behavior caused by an increase in excess pore water pressure and the hardening effect due to contractive plastic deformation. Given the shakedown responses of soft soils, a mapping ratio and a one-time calculation approach were employed. Thus, the effect of loading frequency on the response of soft soil can be considered, and the calculation efficiency was greatly improved. Then, the evaluation of model parameters and parametric analyses on the loading frequency, shrinking yield surface, expanding boundary surface and mapping ratio were carried out to examine the performance of the proposed model. To further validate the proposed model, undrained cyclic triaxial tests on reconstituted Ningbo clay were conducted, and high-cycle undrained triaxial tests on Kaolin clay and Ariake clay were referenced. The predicted developments of accumulated plastic deviatoric strain and excess pore water pressure with the number of load cycles reached acceptable consistencies with the experimental results. Moreover, the effects of confining and deviatoric stresses were investigated. Not only rational developments of excess pore water pressure and plastic deviatoric strain but also nearly identical results under the same cyclic stress ratio (CSR) were obtained, which adequately confirmed the feasibility and reliability of the proposed model. Although this model was developed based on isotropically consolidated soils and contained varied parameters for different CSRs, it provides a framework contributing to rigorous model development for high-cycle conditions.

Modal Analysis of a Lithium-Ion Battery for Electric Vehicles

The battery pack in electric vehicles is subjected to road-induced vibration and this vibration is one of the potential causes of battery pack failure, especially once the road-induced frequency is close to the natural frequency of the battery when resonance occurs in the cells. If resonance occurs, it may cause notable structural damage and deformation of cells in the battery pack. In this study, the natural frequencies and mode shapes of a commercial pouch lithium-ion battery (LIB) are investigated experimentally using a laser scanning vibrometer, and the effects of the battery supporting methods in the battery pack are presented. For this purpose, a test setup to hold the LIB on the shaker is designed. A numerical analysis using COMSOL Multiphysics software is performed to confirm that the natural frequency of the designed test setup is much higher than that of the battery cell. The experimental results show that the first natural frequency in the two-side supported and three-side supported battery is about 310 Hz and 470 Hz, respectively. Although these frequencies are more than the road-induced vibration frequencies, it is recommended that the pouch LIBs are supported from three sides in battery packs. The voltage of the LIB is also monitored during all experiments. It is observed that the battery voltage is not affected by applying mechanical vibration to the battery.

Coalbed Methane Industry Development Framework and Its Limiting Factors in China

The current average daily gas production of single coalbed methane (CBM) wells in China is less than 1,300 m3. The low production rate of CBM wells dramatically limits the sustainable development of the CBM industry in China. To promote CBM industry development, three universal geological factors, i.e., gas sources, channels, and driving force of the low production wells are analyzed, considering the various and complicated geological conditions of CBM reservoirs in China. Additionally, we find that the growth in proven CBM reserves should be greatly promoted as the CBM proven rate is only less than 3% by the end of 2020. The widespread CBM extraction mode based on depressurization via dewatering generates very limited effects in coal seams with notable deformation, high in situ stress, or little water. Therefore, a specific design of CBM development modes is proposed, according to the applicable geological conditions of different CBM development modes. It covers depressurization via dewatering, depressurization via stress release, and coal and CBM comining. Moreover, the regional governments play a key role in the development of the regional CBM industry, and favorable policies should be formulated to promote the multipoint development conditions across China. This study is concluded to provide a recommended development framework involving sustainable CBM production in China and its development processes.

InSAR Constrained Downdip and Updip Afterslip Following the 2015 Nepal Earthquake: New Insights into Moment Budget of the Main Himalayan Thrust

We use ALOS-2 and Sentinel-1 data spanning 2015–2020 to obtain the post-seismic deformation of the 2015 Mw 7.8 Nepal earthquake. ALOS-2 observations reveal that the post-seismic deformation was mainly distributed in four areas. A large-scale uplift deformation occurred in the northern subsidence area of the co-seismic deformation field, with a maximum uplift of ~80 mm within 4.5 yr after the mainshock. While in the southern coseismic uplift area, the direction of the post-seismic deformation is generally opposite to the co-seismic deformation. Additionally, two notable deformation areas are located in the region around 29° N, and near the MFT, respectively. Sentinel-1 observations reveal post-seismic uplift deformation on the north side of the co-seismic deformation field with an average rate of ~20 mm/yr in line-of-stght. The kinematic afterslip constrained by InSAR data shows that the frictional slip is distributed in both updip and downdip areas. The maximum cumulative afterslip is 0.35 m in downdip areas, and 0.2 m in the updip areas, constrained by the ALOS measurements. The stress-driven afterslip model shows that the afterslip is distributed in the downdip area with a maximum slip of 0.3 m during the first year after the earthquake. Within the 4.5 yr after the mainshock, the estimated moment released by afterslip is ~1.5174 × 1020 Nm,about 21.2% of that released by the main earthquake.

МЕЛАТОНІН ПОКРАЩУЄ ГІСТОФІЗІОЛОГІЮ СЕЛЕЗІНКИ ЩУРІВ З ІНДУКОВАНИМ ОЖИРІННЯМ: ХРОНОТЕРАПЕВТИЧНИЙ ПІДХІД

One of the most commoncharacteristics of obesity is the development of a systemic low-grade proinflammatory state in the entire body, including the immune organs. Spleen enlargement during diet-induced obesity contributes to the development of chronic inflammation. Melatonin due to immunomodulatory, antioxidant, and systemic metabolic rolesis proposed to be an effective candidate for anti-obesity therapy. As immune systems demonstrate pronounced circadian rhythmicity and immune cells have different types of melatonin receptors, a chronotherapeutic approach might be used to choose the most effective regimes of melatonin administration for the correction of obesity-provoked damage to the spleen. Thus, the main goal of our research was the analysis of the rats' spleen histophysiology during the development of high-calorie diet-inducedobesity (HCD) after administering melatonin daily at different times (morning or evening). Melatonin was administered by gavage for 7 weeks in the dose of 30 mg/kg 1 h before lights-off (HCD ZT11, M ZT11, evening), or 1 h after lights-on (HCD ZT01, M ZT01, morning). For assessment of the morpho-functional state of the spleen,the histopathological evaluation of red and white pulp in different zones of lymphoid follicles was implemented. It was observed that obesity development wasaccompaniedbyhyperemia and vessel dilatation in the red pulp; while in the white pulp notable deformation of germinal centers and destroyed borders between zones of lymphoid follicles were noticed.The HCD group demonstrated a decrease inthe relative amount of the white pulp, the crosssectional area of germinal centers, and the cross-sectional area of the marginal zone; whilethe increased relative amount of red pulp and marginal zone/germinal centers ratiowere detected compared with control. Melatonin administration to obese rats increases the relative amount of the white pulp (HCD ZT11 group), the cross-sectional area of germinal centers (HCD ZT01 and HCD ZT11 groups), and the cross-sectional area of the marginal zone (HCD ZT11 group), and decreasesmarginal zone/germinal centers ratio (HCD ZT01 group) in comparison with the HCD group.Also,it was demonstrated that a choice between the morning or evening regimes of the melatonin treatment did not affect the histophysiology of the spleen in rats receivingthe standard diet (M ZT01 and M ZT11 groups). These results indicate that melatonin can be considered to be a powerful potential therapeutic agent for the amelioration of obesity-induced changes in the spleen.

Volumetric magnetic resonance imaging analysis of multilevel upper airway surgery effects on pharyngeal structure.

The Sleep Apnea Multilevel Surgery (SAMS) trial found that modified uvulopalatopharyngoplasty with tonsillectomy (if tonsils present) combined with radiofrequency tongue ablation reduced obstructive sleep apnea (OSA) severity and daytime sleepiness in moderate-severe OSA. This study aimed to investigate mechanisms of effect on apnea-hypopnea index (AHI) reduction by assessing changes in upper airway volumes (airway space, soft palate, tongue, and intra-tongue fat). This is a case series analysis of 43 participants of 51 randomized to the surgical arm of the SAMS trial who underwent repeat magnetic resonance imaging (MRI). Upper airway volume, length, and cross-sectional area, soft palate and tongue volumes, and tongue fat were measured. Relationships between changes in anatomical structures and AHI were assessed. The participant sample was predominantly male (79%); mean ± SD age 42.7 ± 13.3 years, body mass index 30.8 ± 4.1 kg/m2, and AHI 47.0 ± 22.3 events/hour. There were no, or minor, overall volumetric changes in the airway, soft palate, total tongue, or tongue fat volume. Post-surgery there was an increase in the minimum cross-sectional area by 0.1 cm2 (95% confidence interval 0.04-0.2 cm2) in the pharyngeal airway, but not statistically significant on corrected analysis. There was no association between anatomical changes and AHI improvement. This contemporary multilevel upper airway surgery has been shown to be an effective OSA treatment. The current anatomical investigation suggests there are not significant post-operative volumetric changes associated with OSA improvement 6-month post-surgery. This suggests that effect on OSA improvement is achieved without notable deformation of airway volume. Reduced need for neuromuscular compensation during wake following anatomical improvement via surgery could explain the lack of measurable volume change. Further research to understand the mechanisms of action of multilevel surgery is required. This manuscript presents a planned image analysis of participants randomized to the surgical arm or the clinical trial multilevel airway surgery in patients with moderate-severe obstructive sleep apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=266019&isReview=true%20Australian%20New%20Zealand%20Clinical%20Trials%20Registry%20ACTRN12514000338662, prospectively registered on March 31, 2014.

Cellulose Nanocrystals Mimicking Micron-Sized Fibers to Assess the Deposition of Latex Particles on Cotton

We report the interactions of cationic latex particles synthesized by RAFT/MADIX-mediated emulsion polymerization with anionic cellulose nanocrystals (CNCs) and cotton fabrics. Latexes in the size range 200-300 nm with poly(butyl acrylate) or poly(2-ethylhexyl acrylate) hydropho-bic cores and hydrophilic shell are synthesized. We show that the latex/CNC interaction is me-diated by electrostatics, the interaction being the strongest with the most charged particles. The adsorption process is efficient and does not require any functionalization step for either cellulose or latex. A major result is the observation by cryogenic transmission electron micros-copy of latexes coated with entangled arrays of CNCs, and for the softer particles a notable deformation of their structure into faceted polyhedra. By labeling the latexes with hydrophobic carbocyanine dyes, their deposition on woven cotton fabrics is studied in situ and quantified by fluorescence microscopy. As with the CNCs, the highest deposition on cotton in the wet and dried states is achieved with the most charged latexes. This demonstrates that CNCs can serve as models to adjust the interactions of latex particles with cotton, and thus optimize manufac-turing processes for the development of advanced textiles.

Laboratory Measurement of Excavation Disturbance Effect Due to Trenchless Construction Using Distributed Fiber Optics Strain Sensing

Abstract Excavation disturbance induced by trenchless construction may lead to underground movement and deformation, which can be a potential hazard to the safety of overlying pavement structure. However, the development of a fiber optic–distributed sensing approach in recent years has provide an effective way for continuous measurement of soil strain. In this study, the mechanism of the excavation disturbance effect that is due to trenchless construction was investigated based on laboratory experiments. The sensing fibers were embedded within the overburden layer above the excavation surface to measure the distributed soil strain using Brillouin optical time-domain analysis. The relationships between ground settlements and soil strains were analyzed. The partition theory of excavation disturbance zone was verified based on test results. The influence of excavation on mechanical responses of overlying model pavement, including bending deformation and soil pressure, was measured and discussed. Laboratory test results indicated that soil strains were nearly symmetrically distributed around the excavation area, which was compressive close to the centerline and then became tensile on both sides of the excavation area. The width of the excavation disturbance zone derived from the soil strain measurements was found close to the calculation results based on the partition theory. Because of the uneven distribution of the support force that was caused by foundation settlement, the model pavement showed notable bending deformation after excavation. Therefore, the combined effects of traffic loading and excavation disturbance should be considered in the safety evaluation of trenchless construction.

Deformation Behavior of Al/Cu Clad Composite During Twist Channel Angular Pressing.

The research and development of modern metallic materials goes hand in hand with increasing their lifetime via optimized deformation processing. The presented work deals with preparation of an Al/Cu clad composite with implemented reinforcing Cu wires by the method of twist channel angular pressing (TCAP). Single and double pass extrusion of the clad composite was simulated numerically and carried out experimentally. This work is unique as no such study has been presented so far. Detailed monitoring of the deformation behavior during both the passes was enabled by superimposed grids and sensors. Both the sets of results revealed that already the single pass imparted significant effective strain (higher than e.g., conventional equal channel angular pressing (ECAP)), especially to the Al matrix, and resulted in notable deformation strengthening of both the Al and Cu composite components, which was confirmed by the increased punch load and decreased plastic flow velocity (second pass compared to first pass). Processing via the second pass also resulted in homogenization of the imposed strain and residual stress across the composite cross-section. However, the investigated parameters featured slight variations in dependence on the monitored location across the cross-section.

Rare Knee Injury In A Hurdler

HISTORY: 18-year-old female with history of asthma presented to the ED with injury to knee. About 20 minutes prior to arrival she tripped over a hurdle and landed awkwardly. Immediately felt pain to the left knee and left hip and had an obvious left knee deformity. The high school trainer was able to palpate distal pulses. EMS was called and patient was placed in an air splint and transferred to the ED. PHYSICAL EXAM: In the ED Patient had stable vital signs. She had notable deformity to the left knee, left lower limb notably shorter than right and externally rotated with dimpling at the medial knee. Unable to flex at the left knee joint. Tenderness at the left knee joint, no erythema, no swelling. Able to wiggle toes, dorsiflex and plantarflex. L3-S1 Sensation intact. Dorsalis pedis and posterior tibialis pulses 1+ on the left, weaker than the right. Brisk cap refill. DIFFERENTIAL DIAGNOSES: 1. Anterior Knee Dislocation with multiple ligamentous damage with vascular compromise. 2. Anterior Knee Dislocation with multiple ligamentous damage without vascular compromise. 3. Anterior Knee Dislocation with minimal ligamentous injury. 4. Hip Fracture/dislocation TESTS AND RESULTS: 1. XR KNEE LT 2V IMPRESSION: Complete dislocation at the left knee joint. Distal femur displaced posteriorly with respect to proximal tibia. No fractures noted. No radiopaque foreign body. 2. XR PELVIS 1V IMPRESSION: Normal Xray, no fracture, dislocations or deformities noted. 3. XR KNEE LT 2V Post Reduction IMPRESSION: Relocation of previously seen dislocation. Normal alignment noted. No fractures. FINAL WORKING DIAGNOSIS: Anterior Knee Dislocation with multiple ligamentous damage and vascular compromise. TREATMENT AND OUTCOME: 1. Pt underwent a closed reduction in the ED with sedation by ortho and ED physicians. 2. Distal pulses improved and patient was placed in an immobilizer. 3. Vascular surgery was consulted, and a CTA of the lower extremity was done which showed no vascular injury. 4. Pt had external fixation procedure with fluoroscopy for knee stabilization. 5. Pt was followed up with outpatient Ortho. External fixation was removed 2-3 months after the surgery. 6. Pt was placed in an immobilizer and was started with physical therapy. Further management pending orthopedic evaluation and patient progression.

Anharmonicity Extends Carrier Lifetimes in Lead Halide Perovskites at Elevated Temperatures.

Lead halide perovskites constitute a very promising class of materials for a broad range of solar and optoelectronic applications. Perovskites exhibit many unusual properties, and recent experiments demonstrate an unusual temperature dependence of charge carrier lifetimes. Focusing on the all-inorganic CsPbBr3, and using a combination of ab initio nonadiabatic molecular dynamics and time-domain density functional theory, we demonstrate that the unconventional behavior arises because of a highly anharmonic nature of atomic motions in perovskites. As temperature increases, perovskite structure undergoes a notable deformation, reflected in tilting of octahedral units, and experiences large-scale anharmonic movements away from the equilibrium geometry. As a result, the electronic energy gap increases, and phonon-induced loss of coherence within the electronic subsystem accelerates. These two factors slow down nonradiative electron-hole recombination, which constitutes the main limitation on efficiencies of perovskite solar, optical, and electronic devices. The increase of charge carrier lifetimes with temperature is particularly beneficial in applications, because materials heat up, for instance, from sunlight during solar energy harvesting. The behavior of the all-inorganic halide perovskite investigated here is different from that of hybrid organic-inorganic perovskites, which exhibit additional disorder associated with reorientations of the asymmetric organic cations. The reported simulations generate an in-depth understanding of the unusual properties of inorganic perovskites, relevant for photocatalytic, photovoltaic, electronic, and optical applications.

Resolving Teleseismic Earthquake Catalog and InSAR Data Discrepancies in Absolute Space to Explore Rupture Complexity Along the Ecuadorian Megathrust Fault

AbstractThe 2016 MW 7.8 Pedernales, Ecuador, megathrust earthquake produced notable crustal deformation and generated an extensive aftershock sequence that included two M6.5+ events. We combine an improved teleseismic earthquake catalog for Ecuador with analysis of coseismic interferometric synthetic aperture radar data derived from the Sentinel‐1A satellite to better delineate the spatial and temporal slip history of the megathrust fault in absolute space. The revised teleseismic catalog spans 1961‐2016 and incorporates catalog phase onset times and waveform correlation derived differential times to locate earthquakes. Using teleseismic double‐difference (DD) tomography to simultaneously solve for an updated regional 3‐D compressional velocity model and locations yields earthquakes shifted ~25 km southwest relative to rapidly available teleseismic catalogs. The DD catalog better compares in absolute space to the Ecuadorian local catalog and better models the measured deformation fields of the 2016 Pedernales mainshock and largest aftershocks. Additionally, the DD mainshock location agrees with local‐scale seismic and geodetic studies that show the 2016 event had concentrated slip on a highly coupled asperity that likely participated in the 1942 Ecuador megathrust earthquake. The two large aftershocks also ruptured on the megathrust where moderate to strong interseismic coupling is observed. The DD catalog contains moderate‐sized aftershocks that concentrate outside high slip regions, primarily in areas that produced earthquakes during the interseismic cycle, and outside areas of aseismic slip. Development of rapid relative location approaches linking new seismicity to better constrained global catalogs could aid with near real‐time hazard assessment in areas lacking local data.

A VIGA VIERENDEEL: PASSADO E PRESENTE DE UMA TIPOLOGIA INOVADORA

In the late 19th century, Belgian engineer Jules Arthur Vierendeel registered the patent for a new type of beam. This would be later on better known as the Vierendeel truss. It is characterized by the frame’s lack of diagonal members, something which would appear to contradict conditions of steadiness and balance, along with its notable deformation and difficult calculation, caused technicians in his time to be skeptical about its applicability. Nevertheless, its application surged in popularity during the 20th century, being used both in civil engineering and architecture. What are the advantages of the Vierendeel truss as compared to other types, such as diagonal trusses? In this article, the Vierendeel typology will be introduced along with its main features, its calculation as well as its implementation in civil engineering and architectural works. Keywords: Vierendeel, Pratt, statistically indeterminate structures.

Structures of the ISWI-nucleosome complex reveal a conserved mechanism of chromatin remodeling.

Chromatin remodelers are diverse enzymes, and different models have been proposed to explain how these proteins work. Here we report the 3.3 Å-resolution cryogenic electron microscopy (cryo-EM) structures of Saccharomyces cerevisiae ISWI (ISW1) in complex with the nucleosome in adenosine diphosphate (ADP)-bound and ADP-BeFx-bound states. The data show that after nucleosome binding, ISW1 is activated by substantial rearrangement of the catalytic domains, with the regulatory AutoN domain packing the first RecA-like core and the NegC domain being disordered. The high-resolution structure reveals local DNA distortion and translocation induced by ISW1 in the ADP-bound state, which is essentially identical to that induced by the Snf2 chromatin remodeler, suggesting a common mechanism of DNA translocation. The histone core remains largely unperturbed, and prevention of histone distortion by crosslinking did not inhibit the activity of yeast ISW1 or its human homolog. Together, our findings suggest a general mechanism of chromatin remodeling involving local DNA distortion without notable histone deformation.

Numerical Investigation of Injury Mechanism on the Human Knee of Long-jumpers

Long-jump is a vigorous athletic event with high speed. Due to so fast run-up and take-off velocities in horizontal and vertical directions, significantly large and varying impact loads often appear in the knee joint region so that the long-jumpers are often badly injured. Based on the physical conditions of an ordinary Chinese man long-jumper, a combination of finite element analysis (FEA) and multi-body dynamics analysis (MDA) approach was tried analyzing the real and detailed long-jump process. Research results show that the maximum resultant force does appear the second phase of the long-jump and that the most notable deformation, displacement and the maximum stresses are all located at the medial sides, especially at the lateral condyle of the articular cartilage. Our results show the feasibility and effectiveness of performing MDA as a preliminary step to FEA, and provide an insight into the injury mechanism on the Human Knee of Long-jumpers.

Mechanical Function of the Human Knee Joint Region during Triple Jump by Combined Multi-body Dynamics and Finite Element Analysis

Triple jump is a vigorous athletic event with high speed. More generally, for great contest achievements athletes must absorb extremely large and greatly varying impact loads in the knee joint region. Consequently, these loads often cause the athletes to be badly injured. Based on the physical conditions of a common Chinese man athlete, here we proposed a combination of finite element analysis (FEA) and multi-body dynamics analysis (MDA) to simulate a real human triple jump. These investigations were involved in an approach run, a hop, a bound and a jump, where the loading data in the knee joint region were obtained from an MDA and then applied to load a FE modal. Validation was implemented by comparing the calculated against the measured either in the hospital or in the literature with good qualitative agreement. Our findings showed that the maximum resultant force both occurred in the third phase of the triple jump and that the most notable deformation, displacement and the maximum stresses all appeared at the medial sides, especially at the lateral condyle of the articular cartilage. Our results demonstrate the importance of performing MDA as a preliminary step to FEA, and provide an insight into a better understanding of injury mechanisms of the jumpers.

Static fatigue analysis on the load container of a low-cost vehicle for Nigerian rural farmers

Static fatigue analysis was done on the container of a model low cost vehicle for Nigerian rural farmers to determine how well the container has been designed and its resistance to notable deformation or damage, based on the load it was subjected to. The static analysis performed involved the fixing of the container in areas where it is made to rest on the chassis. Finite element analysis of the vehicle container was conducted in two loading conditions. The result from the analysis gave a factor of safety of 4.36 for the load container at a maximum displacement of 0.131 mm and a factor of safety of 4.65 for the load container and a maximum displacement of 0.136 respectively for the two loading conditions. These maximum displacements, which can be negligible shows that the load container is well designed as the maximum stresses are above the hand calculated maximum stresses.Keywords: load container, static analysis, fatigue analysis, factor of safety, transportation, low cost vehicle

Modified Temporalis Muscle Flap for Eyelid Reanimation

The reanimation of both upper and lower paralytic eyelids requires dynamic procedures for longevity of correction. Temporalis muscle ensures the criteria for reanimation and is used widely as a result. Many modifications were described to improve the success of the classical technique. One of these modifications was reported by the senior author in 1999. Twice as much muscle mass (in thickness) to the upper eyelid than the lower was taken and passed submuscularly 5 to 6 mm away from the limbus and a thinner split was passed subcutaneously beneath the lower cilia. The aim of this study was to present the outcomes of the technique after 38 operations with 37 patients and to describe deep temporalis musculofascial-fatty flap to recover depression of temporalis muscle split donor area. Seventeen lower eyelids were evaluated as mild, 12 were as moderate, and 9 were as severe ectropion. One upper eyelid was evaluated as mild, 14 were as moderate, and 23 were as severe lagophthalmos preoperatively. Mean follow-up time was 28.8 months. Five patients had mild ectropion and 2 patients had mild lagophthalmos postoperatively at last follow-up. Two patients needed medial canthal tendon reinsertion secondary to relaxation of fixation suture at medial canthus. All patients tolerated the procedure and all complaints were resolved without creating a notable cosmetic deformity.