Modified Dynamically-updated Weighted Opportunity Cost Based Algorithm for Unbalanced Transportation Problem

Recently, Weighted Opportunity Cost (WOC) based algorithms are developed for solving balanced Transportation Problems (TPs). The exceptionality of the WOC based approaches is to introduce supply and demand as weight factor to cost entries for the control of flow of allocations. But in the unbalanced TP, there exist a pitfall whenever balancing the TP with zero dummy transportation cost as done in existing classical approaches, so that the total cost is unaffected due to dummy transportations. A modified dynamically-updated weighted opportunity cost-based algorithm embedded on Least Cost Method (LCM) is proposed which is suitable for both balanced and unbalanced TPs. Numerical instances have been carried out to demonstrate the effectiveness and efficiency of the proposed method. It is observed that, the proposed modified dynamically-updated weighted opportunity cost-based algorithm sometimes outperforms for the LCM as well as the existing weighted opportunity cost-based algorithm in unbalanced TPs. Journal of Engineering Science 12(2), 2021, 119-131

Fluidic Platforms Incorporating Photo-Responsive Soft-Polymers Based on Spiropyran: From Green Synthesis to Precision Flow Control

In this paper, we describe how to create simple fluidic systems incorporating soft polymer actuator valves, that can provide highly precise control of flow rates in fluidic channels as an example of a 4D-materials based platform. The particular approach we describe employs photoresponsive gels that swell/contract via a light stimulus, enabling flow behavior to be controlled from outside the fluidic platform in a completely remote and non-contact manner. An improved synthesis of the spiropyran molecular photoswitch that delivers high yields (77%) using scalable green chemistry is described, along with details on how to build the valve structures in custom designed sites within the fluidic system. Fabrication of a demonstrator fluidic system incorporating up to four valves is described, along with electronics and in-house developed PID control software for achieving precise control of flow in the channels using LEDs. The resulting system demonstrates an innovative approach to microfluidics that offers scalability in terms of the number of polymer actuators along with wide variability of actuator form and function.