Irvine, Joshua Lelemia

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Now showing 1 - 9 of 9
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    Understanding bioswale as a small water and wastewater treatment plant: A theoretical review
    (Desalination and Water Treatment, 2018-12) Irvine, Joshua Lelemia ; Kim, Albert S.
    Stormwater threats can be mitigated with the application of sustainable and renewable technologies such as low-impact development (LID) and best management practice (BMP). This paper aims to fill the present gap in practical applications and engineering science regarding modeling bioswales, a type of LID/BMP devices. Included is a new theoretical framework that treats bioswales as combined physico-chemical processes. A discussion of a coherent analogy between the bioswale and a conventional water and wastewater treatment plant (WWWTP) is presented without including biological processes. Finally, we provide new perspectives regarding computational fluid dynamics (CFD) for widespread use as a promising tool to optimize LID/BMP design for stormwater management.
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    Sewer chamber design under critical conditions using computational fluid dynamics (CFD)
    (Desalination and Water Treatment, 2018-03) Tsuchida, Tyler ; Irvine, Joshua Lelemia ; Siufung Tanga ; Lumb, Leighton ; Kima, Albert S. ; Nishikawab, Jamie
    Transient sewage flow patterns inside a utility chamber are studied using open source computational fluid dynamics software, OpenFOAM. The solver used is based on Reynolds-averaged Navier–Stokes equations with κ – ∈ turbulence model. We found that there are two distinct flow regimes based on the inflow rate. For a low inflow rate, the sewage level does not exceed the outlet pipe, and a steady state is reached within a minute. For a high inflow rate, the tantalizing phenomenon is observed such that the sewage level periodically moves up and down passing the top of the outlet pipe. In this case, a steady state is intrinsically absent, and the sewage level continuously fluctuates for a long time. A chamber overflow occurs with a small outlet diameter and a fast inflow rate. Using Scotch algorithm parallel computation of an OpenFOAM solver, interFoam, has been efficiently conducted within a reasonable amount of time.
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    Native Hawaiians in Engineering: A Path the Professoriate
    (American Society for Engineering Education, 2018-06) Nguyen, Thanh Truc Thi ; Francis, Oceana Puananilei ; Miller, Scott F. ; Kuehu, Donna Sweetie ; McLean, Mitchell Kapena ; Irvine, Joshua Lelemia ; Izawa, Nicholas R.
    In this paper and presentation, a research team of engineers and educators from the University of Hawai‘i at Mānoa will present early findings from a three-phase, mixed-methods study where they sought to understand the gaps in progression of Native Hawaiian students to an academic career in engineering. The study is grounded in Tinto’s integration framework and Bean’s student attrition models, in which authors look at persistence in higher education. Tinto and Bean both suggested that students are more likely to persist in college if they are connected to both the academic as well as social life. Where both Tinto and Bean were primarily studying undergraduates, this study further explores the engineering graduate students' persistence, motivation, and the idea of connection to the Hawaiian culture. Furthermore, the study seeks to extends Bean’s work regarding higher education faculty where he suggested that intrinsic factors such as being true to self and valuing of students were essential characteristics for new faculty. One of the most underrepresented ethnic groups in engineering may be Native Hawaiians (NH). According to the 2011 US Census, the combined working population of NHs, Pacific Islanders, and ‘Other Race’ (grouped by U.S. Census due to small sample size) represents 4.6% of the total U.S. workforce but only 1.4% of science, technology, engineering, and mathematics (STEM) occupations. This makes NHs and Pacific Islanders the most underrepresented ethnic groups in the nation in STEM employment. Additionally, the U.S. Census national data indicates that only 700 single-race NHs or other Pacific Islanders received doctoral degree in science, engineering, and health fields in 2008. First, selected data are shared from a 43-item undergraduate survey administered to engineering students asking about background and preparation to pursue engineering as a major (N=168). Barriers, support systems, financial aid, and self-perception of success between NH students (n=17) and non-NH students (n=151) differences and similarities will be discussed. Second, major themes that emerged from structured interviews with 6 of 8 NH engineering graduate students are presented, including a sense of belonging to their chosen major, past performance in academics, and family support, important factors for degree completion in underrepresented groups such as Hawaiians, Filipinos, African-American and Blacks Hispanics, and women in science, technology, engineering, and mathematics (STEM) fields. Third, a short description of a six-workshop series called A‘o in Engineering and research and teaching opportunities designed to support interested senior and graduate engineering students (N=20) will follow. The authors end with a proposed education model to increase NH career interest in the engineering professoriate.
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    Integrating an anaerobic Bio-nest and an aerobic EMMC process as pretreatment of dairy wastewater for reuse: a pilot plant study
    (Springer Link, 2009-04-02) Kongsil, Piyalerg ; Irvine, Joshua Lelemia ; Yang, P. Y.
    A large dairy farm located on the island of Oahu, Hawaii was the site for an investigation for the potential integration of the existing facultative lagoon system with a cost effective pretreatment unit process. Based on the results from a laboratory study, a pilot plant was installed with two anaerobic bioreactors (10 m 3 each) and one aerobic reactor (3.8 m 3 ). Two layers of media ‘‘Bio-nest,’’ providing a void volume of 98%, were placed into each anaerobic bioreactor with 19% space-based on the bioreactor water volume. For better performance and reduction of shock-load, the equalization/settling tank was employed prior to the first anaerobic Bio-nest reactor. The intermediate holding tank settled effluent suspended solids from the Bio-nest reactor and adjusted the loading rate in order to improve the performance of the aerobic EMMC (entrapped mixed microbial cell) bioreactors. Based on the start-up operation of the Bio-nest system at an organic loading rate of about 1.5 g TCOD/l/day, the production rate of biogas from the first and second Bio-nest reactors was 0.64 and 0.15 l/l/day, respectively. This indicates that the anaerobic degradation of organics occurs mainly in the first Bio-nest reactor due to the low loading rate. The removal efficiency from the Bio-nest system shows TCOD removal of about 70%. The EMMC process provided further treatment to achieve a removal efficiency of TCOD at about 50% and a TN of about 35%. The cost for these pretreatments in order to be integrated with the existing lagoon system is US $1.1 per 1,000 gallons (3.8 m3 ) for dairy wastewater and $91 for each ton of TCOD removal. This integration system provides a sustainable improvement of environment and agricultural production.
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    EMMC technology for treatment/reuse of dilute dairy wastewater
    (Springer-Verlag, 2009-05-01) Lin, Rhoda Luo-Ting ; Irvine, Joshua Lelemia ; Kao, J. C. M. ; Yang, P. Y.
    A rural dairy farm located on the island of Oahu, Hawaii needed to upgrade current lagoon treatment system for further reuse as floor flushing and crop irrigation. This is a comprehensive bench scale and pilot plant study to evaluate the potential biological treatment and reuse systems. Systems evaluated include: (1) pre-existing lagoon system, (2) integrated anaerobic BIO-NEST/aerobic EMMC (entrapped mixed microbial cell) system, (3) aerobic EMMC reactor only system. Based upon a comprehensive economic evaluation and sensitivity analysis, the EMMConly system achieved the best effluent quality for simultaneous removal of carbon and nitrogen. The pilot study of the EMMC-only reactor achieved an overall of 78% TCOD, 63% SCOD, 65% TN, and 96% soluble NH3-N removal efficiencies (HRT 12 h, continuous aeration). Implementing this system would cost about $0.25 a cow/ day to remove a ton of organic TCOD ($88.10/cow/year). The information presented provides a model for animal producers to consider in evaluating alternatives to upgrade existing waste management facilities.
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    Hydraulic design perspectives of bioswale vegetation layers: a meta-research theory
    (Desalination Publications, 2019-03) Irvine, Joshua Lelemia ; Kim, Albert S.
    Optimized bioswale-design requires a fundamental understanding of mass and momentum transfer through a bioswale vegetation layer (BVL) on top of the porous soil zone. Conventional theories of canopy flows are applicable to structuring BVL in a planning phase. Plants in the BVL can be modeled as an embedded collection of cylindrical rods characterized by using (mean) diameter and height. The number density and spatial periodicity of the plants determine the structural and hydraulic characteristics of the BVL. The current paper stands as what we are calling meta-research or “research of research” consisting of an in-depth literature review followed by our own theoretical development and its application. A design equation for an emergent BVL is developed, which suggests the minimum length-to-width ratio of a bioswale as a function of runoff hydraulic characteristics. We calculate a proper bioswale length near which the viscous force fully supersedes the inertial force along the BVL. Moreover, a supplementary graphical method is developed within this study as a simple tool with which to design bioswale dimensions.
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    Coupled transport phenomena of a bioswale process during storm runoff events: a CFD study using OpenFOAM
    (Desalination Publications, 2019-02) Irvine, Joshua Lelemia ; Kim, Albert S.
    Coupled transport phenomena within a bioswale are studied using the open-source computational fluid dynamics (CFD) software OpenFOAM. We investigated the unsteady behavior of momentum and mass transfer in a double-layered bioswale. To study the diffusive transport of a model pollutant, we developed a new solver, that we named interPhaseDiffusionFoam ( interPhaseDiffusionFoam), which better mimics transport phenomena of non-volatile species at a phase boundary. We observed that heterogeneous infiltration patterns are strongly dependent upon stormwater runoff velocity, reverse air flow, and the presence of the drain pipe. The performance estimation and optimal design of a bioswale were thoroughly examined using 2D CFD simulations for a holistic understanding of coupled mass and momentum transport phenomena.
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    From Akamai Intern to PDP Instructor: The Coupled Impact on Becoming a STEM Professional
    (UC Santa Cruz: Institute for Scientist & Engineer Educators, 2022-09-03) Chu, Devin ; Barnes, Austin ; Sueoka, Stacey ; Irvine, Joshua Lelemia
    The Akamai Internship in Hawai‘i and the Professional Development Program (PDP) address key issues of sustaining a diverse, equitable, and inclusive STEM workforce in industry and academia. Established in 2002, the Akamai program builds capacity to overcome the brain-drain workforce problem that Hawaiʻi faces by connecting local undergraduate students with internship opportunities in the STEM industries on the islands of Maui and Hawaiʻi. The PDP provides opportunities for graduate students, early-career scientists and industry leaders to learn effective andragogical practices for teaching science and engineering to the next generation at the undergraduate level. A unique, grounding aspect of the Akamai program across all cohorts is a week-long course preparing interns to work with their local industry partners and build an inclusive community. The course is co-led by Akamai program staff and PDP alumni in collaboration with PDP design teams who run complementary inquiry learning activities. Since the first cohort of 2003, 451 interns and around 100 design team members have participated in Akamai. Of the 451 interns who participated in the Akamai program, at least 8 participants have become PDP design team members. The purpose of this panel discussion is to feature four of those alumni that participated in both Akamai and PDP programs. The panelists will share the factors that influenced them to become a PDP instructor as well as highlight the impacts that both programs had in shaping their respective life and career pathways.
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    The Unseen Impact of Inclusive Professional Development and Pedagogic Training on Underestimated Minority Graduate Students
    (UC Santa Cruz: Institute for Scientist & Engineer Educators, 2022-09-05) Lui, Lauren M. ; Roth, Danica L. ; Roybal-Jungemann, Gabriel ; Irvine, Joshua Lelemia
    Ostensibly, the main goal of the ISEE Professional Development Program (PDP) is to teach scientists and engineers how to be intentional, inclusive educators by experiencing and designing inquiry-based learning activities. However, the PDP program has many indirect, positive effects on its participants as well, including building community and a sense of STEM identity, fluency to understand and discuss diversity, equity, and inclusion topics, and recognizing the importance of psychological safety in learning, academia, and industry. We present four narratives from past participants with underestimated minority identities, who discuss how the PDP program had a positive impact on their growth as scientists and engineers. In each case, the PDP provided critical tools, knowledge or support that enabled their success as graduate students and into their respective career and life journeys.