No abstract

Product platform design and development is an arduous process that involves multiple stakeholders both inside and outside of a company. However, owing to its benefits, product platform has been widely implemented in the industry. Although numerous methodologies for product platform option generation, selection, and optimization have been proposed and demonstrated through various case studies, only a few researchers have explored and demonstrated a product platform design process that considered various value chain impacts. Herein, a value chain and stakeholderdriven product platform design process is introduced. The process is demonstrated through a case study, where different water purifier product platform options were generated and evaluated for their effects on value chain, such as organization structure, production line configuration, economic effect, and preferences of different stakeholders. K E Y W O R D SProduct Platform, Quality Function Deployment, Value Chain Analysis, Water Purifier 1 wileyonlinelibrary.com/journal/sys Systems Engineering. 2020;23:312-326.

Some indoor bio-aerosols trigger allergic reactions, including hypersensitivity pneumonitis, allergic rhinitis, and various types of asthma. Moreover, human influenza virus is one of the bio-aerosols that causes significant morbidity and mortality every year worldwide. Although vaccination is the most effective way to address the risk of airborne infection, they are not always feasible, available and practiced. An air cleaning device is effective and efficient in removing indoor bio-aerosols and thereby controlling or eliminating these airborne biological contaminants. An antimicrobial filter is developed and its antimicrobial activities against influenza viruses are measured. An extract from Gingko Biloba L. and Sumac (Rhus Javanica L.) possesses antifungal, antibacterial, and antiviral activities thus this class of natural products is used as an antimicrobial agent in this study. An antimicrobial air filters were prepared by coating the natural agent on polypropylene filter media. The antimicrobial rates of the filter against new influenza (H1N1) virus and A/PuertoRico/8/34 (A/PR/8) virus were greater than 99.9999%. The antimicrobial filters were effective in controlling the bio-aerosols by inhibiting bacterial and viral survival on the filter, thereby preventing secondary contamination of filter from breeding of bio-aerosols. An air cleaning device equipped with the antimicrobial air filter was tested for the inhibition effect on viruses and no virus was detected at the outlet of the purifier. Although the antimicrobial filters are developed and tested only for the inactivation of virus in this study, the filter could be also effective in removing other types of bio-aerosols, such as bacteria, fungi, and allergens. The antimicrobial filter appears to be promising application in air cleaning and biological protection fields.

We validated the use of the mass balance model to determine the effectiveness of portable air purifiers in removing ultrafine (<0.10 μm) and submicrometer particles (0.10-0.53 μm) in an apartment. We evaluated two identical portable air purifiers, equipped with high efficiency particulate air filters, for their performance under three different air flow settings and three target air exchange rates: 0.60, 0.90, and 1.20 h(-1). We subsequently used a mixed effects model to estimate the slope between the measured and modeled effectiveness by particle size. Our study showed that effectiveness was highly particle size-dependent. For example, at the lowest target air exchange rate, it ranged from 0.33 to 0.56, 0.51 to 0.75, and 0.60 to 0.81 for the three air purifier flow settings, respectively. Our findings suggested that filtration was the dominant removal mechanism for submicrometer particles, whereas deposition could play a more important role in ultrafine particle removal. We found reasonable agreement between measured and modeled effectiveness with size-resolved slopes ranging from 1.11 ± 0.06 to 1.25 ± 0.07 (mean ± SE), except for particles <35 nm. Our study design can be applied to investigate the performances of other portable air purifiers as well as the influences of various parameters on effectiveness in different residential settings.