A review of the Material Point Method and its links to other computational methods

There is considerable interest in development of solid mechanics modelling which can cope with both material and geometric nonlinearity, particularly in areas such as computational geotechnics, for applications such as slope failure and foundation installation. One such technique is the Material Point Method (MPM), which appears to provide an efficient way to model these problems. The MPM models a problem domain using particles at which state variables are kept and tracked. The particles have no restriction on movement, unlike in the Finite Element Method (FEM) where element distortion limits the level of mesh deformation. In the MPM, calculations are carried out on a regular background grid to which state variables are mapped from the particles. It is clear, however, that the MPM is actually closely related to existing techniques, such as ALE and in this paper we review the MPM for solid mechanics and demonstrate these links

The level of aflatoxin M1 in raw and pasteurized milk produced in alborz province, Iran

Background: Aflatoxins are agroupof very toxiccompoundsproducedby a fungal speciesandare foundin food products. Aflatoxin M1 (AFM1) is a type found in dairy products and resistant to pasteurization. AFM1 can adversely affect hepatocytes in human and leading to various liver diseases. Thus, it is essential to examine raw milk for the presence of AFM1. Objectives: The current study aimed to evaluate the levels of AFM1 in raw and pasteurized milk produced in Alborz province, Iran. Materials and Methods: Ninety seven samples of rawmilk and 20 samples of pasteurized milk were collected from milk collecting centers and different supermarkets, respectively. Samples were analyzed to determine AFM1 level by immunoaffinity column chromatography, and high-performance liquid chromatography (HPLC) using a C18 column with fluorescence detector. Mobile phase was water-acetonitrile-methanol (6:2:2 V/V/V) at a flow rate of 1.0 mL/minute. Results: AFM1 was detected in all samples with various concentration levels ranging from 0.0024 to 0.231 μg/kg, the mean concentration = 0.027±0.018 μg/kg. Conclusions: According to the results of the current study, 9.27 of the rawmilk and 5 of the pasteurized milk samples had higher levels of AFM1 than the maximum recommended limit (0.05 μg/kg) by food and agriculture organization (FAO). © 2016, School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences

Distribution of Lactobacillus species in Iranian women with both human papillomavirus (HPV) infection and bacterial vaginosis (BV)

Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge for women of childbearing age. Despite many confirming surveys, which proved the relationship between BV and human papillomavirus (HPV) infection, but this remains a matter of debate. The objective of this original article is to clarify BV is associated with HPV infection in Iranian women by quantitative real-time polymerase chain reaction (qPCR) method. The vaginal swabs of seventy-five women (55 and 20 samples from patients and controls, respectively) with and without manifestation of HPV were collected during February 2018 and December 2018, and extracted DNA was assayed by real-time PCR looking for the HPV serotypes and bacterial load by using bacterial 16S rRNA gene. A total of 55 cervical, 13 (23.4) isolates were HPV-negative, and 42 (76.4) isolates were HPV-positive. In total, 83.3 of HPV-positive isolates had BV infection. The hotspot of incidence with BV is between the ages of 26�34 years. Although, we can see there are low frequency of Lactobacillus spp. in HPV 16 patients among other groups but unfortunately, we can't approve it with significant value (P-value >0.05). Lactobacillus gasseri and Lactobacillus jensenii showed higher colony count in BV women that infected with Gardnerella vaginalis than healthy women. The number of L. gasseri and L. rhamnosus are directly related to reducing the risk of HPV infection (P-value <0.05). To sum up, this study show that there was no statistically significant relationship between BV and/or HPV with Lactobacillus species. © 202

Numerical simulation of natural convection heat transfer in a trapezoidal enclosure filled with nanoparticles

In this paper, we have investigated unsteady natural convection flow and heat transfer inside a trapezoidal enclosure filled with nine different types of nanofluids having various shapes of the nanoparticle following Tiwari and Das mathematical model. The left and right walls of the enclosure are kept at different temperatures, while the top and bottom walls of the cavity are thermally insulated. The Galerkin weighted residual based finite element method has been employed to solve the governing partial differential equations after converting them into a nondimensional form. The simulation is carried out through the pde solver COMSOL Multiphysics with Matlab interface. Comparison with the previously published result is made for a special case and an excellent agreement is found. The effects of various model parameters such as the Rayleigh number, the aspect ratio, the volume fraction and the shape factor of the nanoparticles on streamlines and isotherms have been displayed graphically and discussed. The heat transfer augmentation for various combinations of pertinent parameters has also been presented in light of the average Nusselt number on the left heated wall