Mean spherical approximation for the Lennard-Jones-like two Yukawa model: Comparison against Monte Carlo data

Monte Carlo simulation studies are performed for the Lennard-Jones like two Yukawa (LJ2Y) potential to show how properties of this model fluid depend on the replacement of the soft repulsion by the hard-core repulsion. Different distances for the positioning of hard core have been explored. We have found, that for temperatures that are slightly lower and slightly higher of the critical point temperature for the Lennard-Jones fluid, placing the hard core at distances that are shorter than zero-potential energy is well justified by thermodynamic properties that are practically the same as in original LJ2Y model without hard core. However, going to extreme conditions with the high temperature one should be careful since presence of the hard core provokes changes in the properties of the system. The later is extremely important when the mean spherical approximation (MSA) theory is applied to treat the Lennard-Jones-like fluid.Comment: 11 pages, 13 figure

Merkel cell carcinoma of skin-current controversies and recommendations

The review covers the current recommendations for Merkel cell carcinoma (MCC), with detailed discussion of many controversies. The 2010 AJCC staging system is more in-line with other skin malignancies although more complicated to use. The changes in staging system over time make comparison of studies difficult. A wide excision with margins of 2.5–3 cm is generally recommended. Even for primary </= 1 cm, there is a significant risk of nodal and distant metastases and hence sentinel node biopsy should be done if possible; otherwise adjuvant radiotherapy to the primary and nodal region should be given. Difficulties of setting up trials owing to the rarity of the disease and the mean age of the patient population result in infrequent reports of adjuvant or concurrent chemotherapy in the literature. The benefit, if any, is not great from published studies so far. However, there may be a subgroup of patients with high-risk features, e.g. node-positive and excellent performance status, for whom adjuvant or concurrent chemotherapy may be considered. Since local recurrence and metastases generally occur within 2 years of the initial diagnosis, patients should be followed more frequently in the first 2 years. However delayed recurrence can still occur in a small proportion of patients and long-term follow-up by a specialist is recommended provided that the general condition of the patient allows it. In summary, physician judgment in individual cases of MCC is advisable, to balance the risk of recurrence versus the complications of treatment

Spall behaviour of the low alloyed high strength steel

Des theories basées sur l'energie de rupture d' ecaillage sont examinées. L'influence de la structure est etudiée. La transition fracture est examinée.The spall behaviour of low alloyed high strength steel was studied. Nine different microstructures of this steel were prepared. The experimentally found dependence of spall strength, σc, on the strain rate, ε., exhibited features suggesting a transition in the spall fracture mode. The results were interpreted in terms of an energy-based theory of spall

Microstructural changes caused by penetration of shaped charge jet into steel targets

On étudie l'effect de l'impact des jets métalliques sur le comportement. Des travaux ont été en trepris sur le comportement d'un acier (0.37C, 0.80Mn, 1.04Cr, 1.38Ni, 0.24Mo) et l'impact des jets métalliques. La microstructure est examinée par microscopie électronique à balayge.The interaction of the shaped charge jet with low alloyed high strength steels subjected to different heat treatment along with low alloyed bainitic and cast austenitic steel has been studied. The structure affected by jet penetration was evaluated by means of light and scanning electron microscopy and X-ray microanalysis. The microstructural features and their changes are described (perforation surface layer, cracking, adiabatic shear bands etc.

ADIABATIC SHEARING IN CAST AUSTENITIC STEEL UNDER BALLISTIC ATTACK

Des cibles constituées par des empilements de disques d'aciers austénitiques 18/8 ont été soumises à des jets de charges creuses avec revêtement en cuivre. Les modifications de structures induites dans le matériau cible ont été étudiées par microscopie optique. MET et MEB. Le processus de déformation est principalement la combinaison de maclage et de glissement de dislocations. Les bandes de cisaillement adiabatique ont un cœur sans limites de grains et de macles bien définies entouré par une zone à forte déformation. La densité de dislocations et de macles dans cette zone décroit progressivement en fonction de la distance au cœur. Les taches des diffractions associées à la ferrite ont été rarement observées au cœur des bandes de cisaillement. La taille des grains à l'origine des taches observées est inférieure à 0.05 µmDiscs from 18/8 austenitic steel were stacked to form targets. The targets were loaded by shaped charge with copper liner. Optical, scanning and transmission electron microscopy were used to evaluate structure changes in target material. Deformation process is mainly the combination of twinning and dislocation slip. Adiabatic shear bands have a core where no sharp grain or twin boundaries were resolved, surrounded by high strained region. Dislocation and twin density in this region gradually decreasing with the distance from the core. Rarely diffraction spots corresponding to the ferrite were observed in the core of adiabatic shear bands. DF images show that the size of grains giving rise to spots are less than 0,05 µm

Further characterization of antigen-dependent migration inhibition factor in mice.

Antigen-dependent MIF was produced in inbred mice. Lymph node cells from mice sensitized to tubercle bacilli were incubated with small quantities of antigen. The supernatant contained antigen-dependent MIF and its activity when tested on mouse and rabbit spleen was minimal unless PPD was added to the supernatant. The production of the antigen-dependent MIF was T cell-dependent, as shown by the use of anti-theta serum. Its molecular weight was in the range of 50--100,000 and it was concluded that the factor is different from conventional antibodies or antigen-antibody complexes

Determination of different metals in wastewater using new microsensors based on diamond doped with boron (BDD)

International audienc

Determination of different metals in wastewater using new microsensors based on diamond doped with boron (BDD)

International audienc