Relocation Scheduling in a Two–Machine Flow Shop with Resource Recycling Operations

This paper considers a variant of the relocation problem, which is formulated from an urban renewal project. There is a set of jobs to be processed in a two-machine flow shop subject to a given initial resource level. Each job consumes some units of the resource to start its processing on machine 1 and will return some amount of the resource when it is completed on machine 2. The amount of resource released by a job is not necessarily equal to the amount of resource acquired by the job for starting the process. Subject to the resource constraint, the problem is to find a feasible schedule whose makespan is minimum. In this paper, we first prove the NP-hardness of two special cases. Two heuristic algorithms with different processing characteristics, permutation and non-permutation, are designed to construct feasible schedules. Ant colony optimization (ACO) algorithms are also proposed to produce approximate solutions. We design and conduct computational experiments to appraise the performances of the proposed algorithms.

Japan’s International Standards of Waste Recycling Treatment: Disseminating the Osaki System in Depok and Bali

This research explains the importance of approach and coordination from the Osaki Town government on waste recycling management of Osaki System to the community residents and companies, for changing their mindset on responsibilities and duties. This was done since the beginning when Osaki system was created until it becomes a sustainable system in daily life. The important key aspects on implementing the Osaki system are good cooperation and bond of trust shared among the government, community residents and companies. Osaki Town has achieved no.1 in the highest rate of waste resource recycling for 12 consecutive years in all of Japan. The system has made Osaki Town to become a SDGs system model in Japan, after receiving SDGs award from the Japanese government in December 2019. The Osaki System has succeeded to solve problems on reducing the volume of waste in landfill site. Being a sustainable waste resource recycling system and a model not only in Japan but also abroad, Osaki Town then disseminates the Osaki System in Indonesia which has the same problems, such as approach and cooperation between the government and the residents, reduce the waste volume in landfill areas by separate waste method for recycling and low cost management.

A scalable fish-school inspired self-assembled particles system for solar-powered water-solute separation

Completed separation of water and solute is pursued as the ultimate goal of water treatment, for maximized resource recycling. However, commercialized approaches such as evaporative crystallizers consume a large amount of electricity with significant carbon footprint, which calls for energy-efficient and eco-friendly strategies. Here inspired by schooling fish, we demonstrate a collective system self-assembled by the expanded polystyrene (EPS)-core/Graphene oxide (GO)-shell particles, which enables autonomous, efficient, and complete water-solute separation powered by sunlight. By taking advantage of surface tension, these tailored particles school together naturally and are bonded as a system to function collectively and coordinatively, to nucleate, grow and output salt crystals continuously and automatically out of even saturated brine, till the complete water-solute separation. Solar-vapor conversion efficiency over 90% and salt production rate as high as 0.39 kg m–2 h–1 are achieved under 1-sun illumination for this system. It reduces the carbon footprint of ∼50 kg for treating 1 ton saturated brine compared with the commercialized approaches.