Flow and clogging in a horizontal silo with a rotary obstacle

The external perturbation applied to a silo and the placement of an immobile obstacle before an exit are two common and effective ways to diminish clogging in the hopper/silo flow.Here,we incorporate the local perturbation into a fixed obstacle,and experimentally explore the effects of a rotary obstacle on clogging and the flowing characteristics in the horizontal silo flow driven by a conveyor belt.Even with a low spin rate,the total blocking probability that a particle constructs a stable blocking arch with its neighbors significantly drops.Correspondingly,the average flow rate of the particles through the exit abruptly rises,at least 1 order of magnitude better than that with an immobile obstacle and approaching the flow rate of continuous flow.The rotation enhances the breakage of clogging arches,which is responsible for improving the flowability in the horizontal silo.In addition,there always exists an optimal obstacle position at which the total blocking probability is minimal and the average flow rate peaks,regardless of the spin rate.Finally,clogging is relieved with the increase of the driving velocity of the conveyor belt,showing a“fast is fast”effect that is opposite to the“fast is slow”effect in other systems such as crowd evacuation and gravity-driven hoppers.

An Actuarial Approach to Reload Option Valuation for a Non-tradable Risk Assets under Jump-diffusion Process and Stochastic Interest Rate

We use an actuarial approach to estimate the valuation of the reload option for a non-tradable risk asset under the jump-diffusion processes and Hull-White interest rate. We verify the validity of the actuarial approach to the European vanilla option for non-tradable assets. The formulas of the actuarial approach to the reload option are derived from the fair premium principle and the obtained results are arbitrage. Numerical experiments are conducted to analyze the effects of different parameters on the results of valuation as well as their differences from those obtained by the no-arbitrage approach. Finally, we give the valuations of the reload options under different parameters.

Cutaneous Radiation-Associated Angiosarcoma After Cervical Cancer Treatment:A Case Report

Introduction:Cutaneous radiation-associated(cRAA)angiosarcoma is a rare malignant neoplasm derived from vascular endothelial cells,but a relatively commonly recognized complication of radiation therapy.Here,we present a patient with cRAA,who undergone radiochemotherapy for cervical cancer 11 years ago.Case presentation:A 48-year-old woman presented with a 6-month history of painless purple skin plaques and nodules on her lower abdomen and right thigh.The patient had undergone radiochemotherapy for cervical cancer 11 years ago.A skin biopsy showed a diffuse proliferation of irregular anastomosing dilated vascular structures with atypical endothelial cells.She was diagnosed as cRAA according to clinical and histological manifestations.Discussion:cRAA is a rare malignant neoplasm but it is a complication of radiation therapy.The incidence of cRAA has increased in recent years.Clinical and pathological manifestations are highly varied.Radical resection is the preferred treatment.Conclusion:Patients with suspicious violaceous lesions should undergo biopsy.Clinical suspicion and pathological examination are of the utmost importance for cRAA.