Experience of Chikungunya in a Chikungunya Clinic at Tertiary Medical College Hospital in Bangladesh.

A large outbreak of Chikungunya occurred in Bangladesh in 2017. It caused a serious impact on sufferers of the disease. Study aimed to assess the real scenario unfolding as case reporting to Directorate General of Health is less in Bangladesh by physicians. For this observational study a Chikungunya Clinic was set at Dhaka Medical College, Dhaka, Bangladesh and physicians were attached to the clinic who got training on Chikungunya by directorate General of Health from 9th July 2017 to 10th September 2017. A pre-tested questionnaire was supplied to all the physicians working at the clinic. Appropriate training was provided before data collection. Total 301 patients were enrolled. Most striking features were fever (99.3%), arthralgia (99.3%), rash 70.4%, Itching 64.8%, oral ulcer 23.9%, loose motion 18.6% and bleeding 8%.%. Most affected joints were MCP 76.9%, knee 74.9%, wrist 69.2%, Inter phalangeal joints of hand were 67.2%. Chikungunya was not very familiar with the physicians of Bangladesh. This was first time large scale experience by physicians of Bangladesh. Severity and chronicity of arthritis, rash, bleeding caused serious morbidity.

Optimization of a continuous hybrid impeller mixer via computational fluid dynamics.

This paper presents the preliminary steps required for conducting experiments to obtain the optimal operating conditions of a hybrid impeller mixer and to determine the residence time distribution (RTD) using computational fluid dynamics (CFD). In this paper, impeller speed and clearance parameters are examined. The hybrid impeller mixer consists of a single Rushton turbine mounted above a single pitched blade turbine (PBT). Four impeller speeds, 50, 100, 150, and 200 rpm, and four impeller clearances, 25, 50, 75, and 100 mm, were the operation variables used in this study. CFD was utilized to initially screen the parameter ranges to reduce the number of actual experiments needed. Afterward, the residence time distribution (RTD) was determined using the respective parameters. Finally, the Fluent-predicted RTD and the experimentally measured RTD were compared. The CFD investigations revealed that an impeller speed of 50 rpm and an impeller clearance of 25 mm were not viable for experimental investigations and were thus eliminated from further analyses. The determination of RTD using a k-ε turbulence model was performed using CFD techniques. The multiple reference frame (MRF) was implemented and a steady state was initially achieved followed by a transient condition for RTD determination.

Optimization of integrated impeller mixer via radiotracer experiments.

Radiotracer experiments are carried out in order to determine the mean residence time (MRT) as well as percentage of dead zone, V dead (%), in an integrated mixer consisting of Rushton and pitched blade turbine (PBT). Conventionally, optimization was performed by varying one parameter and others were held constant (OFAT) which lead to enormous number of experiments. Thus, in this study, a 4-factor 3-level Taguchi L9 orthogonal array was introduced to obtain an accurate optimization of mixing efficiency with minimal number of experiments. This paper describes the optimal conditions of four process parameters, namely, impeller speed, impeller clearance, type of impeller, and sampling time, in obtaining MRT and V dead (%) using radiotracer experiments. The optimum conditions for the experiments were 100 rpm impeller speed, 50 mm impeller clearance, Type A mixer, and 900 s sampling time to reach optimization.