Biomechanical Study Using the Finite Element Method of Internal Fixation in Pauwels Type III Vertical Femoral Neck Fractures

Background: Several factors are known to influence osseous union of femoral neck fractures. Numerous clinical studies have reported different results, hence with different recommendations regarding treatment of Pauwels III fractures: femoral neck fractures with a more vertically oriented fracture line. The current study aimed to analyze biomechanically whether this fracture poses a higher risk of nonunion. Objectives: To analyze the influence of one designated factor, authors believe that a computerized fracture model, using a finite element Finite Element Method (FEM), may be essential to negate the influence of other factors. The current study aimed to investigate a single factor, i.e. orientation of the fracture line toward a horizontal line, represented by Pauwels classification. It was hypothesized that a model with a vertically oriented fracture line maintaining parity of all other related factors has a higher stress at the fracture site, which would delay fracture healing. This result can be applicable to other types of pinning. Patients and Methods: The finite element models were constructed from computed tomography data of the femur. Three fracture models, treated with pinning, were constructed based on Pauwels classification: Type I, 30° between the fracture line and a horizontal line; Type II, 50°; and Type III, 70°. All other factors were matched between the models. The Von Mises stress and principal stress distribution were examined along with the fracture line in each model. Results: The peak Von Mises stresses at the medial femoral neck of the fracture site were 35, 50 and 130 MPa in Pauwels type I, II, and III fractures, respectively. Additionally, the peak Von Mises stresses along with the fracture site at the lateral femoral neck were 140, 16, and 8 MPa in Pauwels type I, II, and III fractures, respectively. The principal stress on the medial femoral neck in Pauwels type III fracture was identified as a traction stress, whereas the principal stress on the lateral femoral neck in Pauwels type I fracture was a compression stress. Conclusions: The most relevant finding was that hook pinning in Pauwels type III fracture may result in delayed union or nonunion due to significantly increased stress of a traction force at the fracture site that works to displace the fracture. However, in a Pauwels type I fracture, increased compression stress contributes to stabilize it. Surgeons are recommended not to treat Pauwels type III femoral neck fractures by pinning

Impacts of seasonal transitions of enso on atmospheric river activity over east Asia

Atmospheric rivers (ARs), which are narrow water vapor transport bands over the mid-latitudes, often have great socio-economic impacts over East Asia. Although summertime AR activity over East Asia is strongly induced by preceding-winter El Niño development, the extent to which seasonal transitions of El Niño–Southern Oscillation (ENSO) from winter to summer affect the AR activity remains unclear. Here, we examine the relationship between the seasonal transitions of ENSO and the summertime AR activity over East Asia using an atmospheric reanalysis and high-resolution atmospheric general circulation model (AGCM) ensemble simulations. A rapid transition from preceding-winter El Niño to summertime La Niña results in more AR occurrence over northern East Asia via the northward expansion of an anomalous low-level anticyclone over the western North Pacific compared with sustained or decayed El Niño cases. The northward expansion of the anticyclone is consistent with a steady response of the atmosphere to the anomalous condensation heating over the Maritime Continent and equatorial Pacific. Meridional positions of the extratropical AR occurrence and circulation anomalies are different between the reanalysis and AGCM simulations, which is possibly contributed by a limited sample size and/or AGCM biases and suggests that the seasonal prediction of AR-related natural disaster risk over East Asia on a regional scale remains a challenge

Atmospheric rivers over the Northwestern Pacific: Climatology and interannual variability

Atmospheric rivers (ARs), conduits of intense water vapor transport in the midlatitudes, are critically important for water resources and heavy rainfall events over the west coast of North America, Europe, and Africa. ARs are also frequently observed over the northwestern Pacific (NWP) during boreal summer but have not been studied comprehensively. Here the climatology, seasonal variation, interannual variability, and predictability of NWP ARs (NWPARs) are examined by using a large ensemble, high-resolution atmospheric general circulation model (AGCM) simulation and a global atmospheric reanalysis. The AGCM captures general characteristics of climatology and variability compared to the reanalysis, suggesting a strong sea surface temperature (SST) effect on NWPARs. The summertime NWPAR occurrences are tightly related to El Niño-Southern Oscillation (ENSO) in the preceding winter through Indo-western Pacific Ocean capacitor (IPOC) effects. An enhanced East Asian summer monsoon and a low-level anticyclonic anomaly over the tropical western North Pacific in the post-El Niño summer reinforce low-level water vapor transport from the tropics with increased occurrence of NWPARs. The strong coupling with ENSO and IPOC indicates a high predictability of anomalous summertime NWPAR activity

On multigraded generalizations of Kirillov-Reshetikhin modules

We study the category of Z^l-graded modules with finite-dimensional graded pieces for certain Z+^l-graded Lie algebras. We also consider certain Serre subcategories with finitely many isomorphism classes of simple objects. We construct projective resolutions for the simple modules in these categories and compute the Ext groups between simple modules. We show that the projective covers of the simple modules in these Serre subcategories can be regarded as multigraded generalizations of Kirillov-Reshetikhin modules and give a recursive formula for computing their graded characters

Household mortgage demand: a study of the UK, Australia and Japan

Households combine their personal savings and mortgage debt to finance their home purchases. In developed countries, mortgage debt is the largest debt on a household’s balance sheet and in these countries, the mortgage penetration rates are high. For the stability of the mortgage market and thereby the money market in an economy, it is important to understand households' mortgage demand decisions and riskiness of these borrowers. There are differences in mortgage systems among countries, which play an important role in determining the mortgage decisions that households make. These differences arise from the availability of types of mortgage instrument (adjustable versus fixed rate mortgages), length of fixed period for a fixed rate mortgage contracts, conditions of prepayment, tax treatment, lenders’ constraints related to repayment, loan to value ratio, foreclosure and personal bankruptcy laws etc. These differences impact borrowers' choice of mortgage contract and mortgage demand. This paper analyses the mortgage demand behaviour of households in the UK, Australia and Japan. Specific questions that have been asked relate to the factors that determine household mortgage demand, housing demand and loan to value ratio. Though the homeownership is a preferred tenure and the mortgages are 'recourse' loans, housing markets in these three countries operate in different mortgage market institutional structure. Results indicate that income elasticity of mortgage demand differ despite income elasticity of housing demand being similar. Mortgage institutions that pose constraints for borrowers also determine the extent of mortgage demand. Other factors such as demography, economic conditions have also played an important role in determining mortgage and housing demand

Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage

We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe2O3) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the “pure” conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt4BF4 (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of charge–discharge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertion–expulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during charge–discharge processes

Subaru near infrared coronagraphic images of T Tauri

High angular resolution near-infrared (JHK) adaptive optics images of T Tau were obtained with the infrared camera Coronagraphic Imager with Adaptive Optics (CIAO) mounted on the 8.2m Subaru Telescope in 2002 and 2004. The images resolve a complex circumstellar structure around a multiple system. We resolved T Tau Sa and Sb as well as T Tau N and S. The estimated orbit of T Tau Sb indicates that it is probably bound to T Tau Sa. The K band flux of T Tau S decreased by ˜ 1.7 Jy in 2002 November compared with that in 2001 mainly because T Tau Sa became fainter. The arc-like ridge detected in our near-infrared images is consistent with what is seen at visible wavelengths, supporting the interpretation in previous studies that the arc is part of the cavity wall seen relatively pole-on. Halo emission is detected out to ˜2\u27\u27from T Tau N. This may be light scattered off the common envelope surrounding the T Tauri multiple system

Effects of mandrel shape on deformation behavior for hot mandrel bending of elbows

Elbows of steel pipe joints are used in the industrial plants and are mainly manufactured by the hot mandrelbending from raw material of straight steel pipe. Elbows are generally manufactured at elevatedtemperature by means of pushing, expanding and bending of pipes simultaneously, using the innertool of mandrel. Characteristics of mandrel bending strongly depend on the integrated shape anddimensions of the mandrel. We investigate the effects of shape and dimension of mandrel on deformationbehaviors for hot mandrel bending of elbows, conducting experimental test and numerical analysis. Weclarify the effects of bending radius ratio Rout/Dout, expansion ratio Dout/Din, mandrel length ratio L/Doutand other items of mandrel shape. And optimum conditions of mandrel are estimated as conclusion