A stirred tank bioreactor (STB) integrated with an expanded bed adsorption (EBA) system containing anion-exchange resin (Diaion WA30) was developed for in situ removal of acetate to increase the production of α-interferon-2b (α-PrIFN-2b) by Escherichia coli (E. coli). Although the total acetate (9.79 g/L) secreted by E. coli in the integrated STB/EBA system was higher than that in a bioreactor ...

This study compared the environmental impact of conventional, natural and grass-fed beef production systems. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 1.0 × 10⁸ kg of hot carcass weight beef in conventional (CON), natural (NAT) and grass-fed (GFD) production systems. Production system...

This paper uses an alternative approach to reexamine a prior study on joint determination of manufacturing lot-size and shipment policy in a vendor-buyer system with rework process and an improving delivery plan. The proposed method is a straightforward approach in terms of algebraic derivations. It is different from the conventional method that needs to apply the first-order and second-order d...

Conventional approach for solving replenishment lot size problem is by using the differential calculus with the need of applying the first-order and second-order differentiations to the long-run average production-inventory cost. A recent published paper used conventional method to determine optimal lot size for an integrated production-delivery system with scrap and cost lessening distribution...

In present paper, dynamic behavior and control of a fluidized bed reactor for polyethylene production has been considered. A double active sites model for Ziegler-Natta catalysts is used for simulation of polymerization reaction. Hydrodynamic behavior of the bed is modeled using a two phase model including bubble and emulsion phases in which bubble phase has plug flow pattern with different...

Tamora Catfish Company as a Micro, Small and Medium Enterprise (UMKM) which one of the Universitas Sumatera Utara community service partners, used simple microbubble technology system to increase dissolved oxygen content in pond water order anticipate large number die fish because polluted water, impacted reducing amount oxygen. Biofloc application was observed decreasing ammonia generating nat...