Jun Kono

Dr. Jun Kono

orcid

Research Focus & Metrics

Academic Career Length

37Years (1990-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 July 2017 in The International Journal of Life Cycle Assessment
Verified
Journal Article
Open access
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CSCorinna Salzer
Corinna Salzer
HWHolger Wallbaum
Holger Wallbaum
YOYork Ostermeyer
York Ostermeyer
JKJun Kono
Jun Kono
Purpose The environmental impact of the social building stock is relevant, particularly in emerging economies. Life cycle thinking is not yet established, however. Locally available, alternative building concepts could potentially reduce the environmental impact of the construction segment. This paper examines the environmental performance of “as-built” low-cost housing for an example of the Philippines, and the potential to reduce its environmental impact through use of three alternative building technologies: cement–bamboo frames, soil–cement blocks, and coconut board-based housing. Methods Life cycle assessment models are implemented and evaluated with software SimaPro, using the single-impact indicators global warming potential (GWP) and cumulative energy demand (CED) and the multi-impact indicator Impact2002+. According to EN 15978, the life cycle phase product and construction process (A), use stage (B), end-of-life (C) and supplementary information beyond the building life cycle (D) have been assessed. Theoretically calculated inflows from standard construction procedures used in phase A have been verified with 3 years of empirical data from implemented construction projects. For phases B, C and D, attention was given to service life, use-phase, allocation of waste products, biogenic carbon and land-use assumptions. Scenarios reflect the actual situation in the emerging economy. Processes, such as heat recovery from thermal utilization, which are not existing nor near to implementation, were excluded. Results and discussion For an assessment of the phases A–B–C–D with GWP, a 35% reduction of environmental impact for soil–cement blocks, 74% for cement–bamboo frame, and 83% for coconut board-based houses is obtained relative to a concrete reference house. In absolute terms, this relates to a reduction of 4.4, 9.3, and 10.3 t CO2 equivalents over a service life of 25 years. CED showed higher impacts for the biogenic construction methods coconut board and cement–bamboo frames of +8.0 and +4.7%, while the soil–cement technology was evaluated −7.1% compared to GWP. Sixteen of 17 midpoint categories of Impact2002+ confirmed an overall reduction potential of the alternative building methods, with the midpoint category land occupation being the exception rating the conventional practice over the alternatives. Conclusions It is concluded that the alternative construction technologies have substantial potential to reduce the environmental burden caused by the social housing sector. The service life of the alternative technologies plays a vital role for it. LCA for emerging economies needs to incorporate realistic scenarios applicable at their current state or belonging to the most probable alternatives to ensure valuable results. Recommendations for further research are provided.

13 February 2017 in The International Journal of Life Cycle Assessment
Verified
Journal Article
Open access
PDF file
JKJun Kono
Jun Kono
YOYork Ostermeyer
York Ostermeyer
HWHolger Wallbaum
Holger Wallbaum
Purpose The share of variable renewable energy sources (vRES) in the German electricity grid has increased over the past few decades. Due to the nature of the generation pattern of vRES, the increase of vRES causes the emission factor (EF) to fluctuate on an hourly basis. This fluctuation raises concerns about the accuracy of quantifying emissions with the current metric of the annual average EF as the respective EF may change depending on the time at which it is consumed. Methods The study calculated the hourly EF of Germany from 2011 to 2015 and investigated the effect of an increase of vRES on the EF. The calculated hourly EF was clustered based on three aspects of time: the period of time, the time of a day, and the day of the week. Results and discussion The study showed a higher proportion of vRES on weekend daytimes while the weekday nighttimes resulted in a lower share than the annual average. The study highlighted potential underestimation and overestimation of emissions by using annual average EF which ranged from +22% (2015 weekday nighttime of October) to −34% (2015 weekend daytime of May). Conclusions The study suggested that the application of hourly EF may be necessary to quantify the respective emission from the consumers that use electricity during the weekend daytime and weekend nighttime. For consumer use at other times, the emissions could be quantified appropriately by using the conventional annual average EF.

1 February 2016 in Key Engineering Materials
Verified
Journal Article
Closed access
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JKJun Kono
Jun Kono
YGYutaka Goto
Yutaka Goto
YOYork Ostermeyer
York Ostermeyer
RFRolf Frischknecht
Rolf Frischknecht
HWHolger Wallbaum
Holger Wallbaum
Thermal insulation material is an important component to reduce the environmental impact of buildings through the reduction of energy consumption in the operation phase. However, the material itself has embodied environmental impacts for the value it provides. Eco-efficiency is a method that quantifies relation between the environmental performance and the created value of a product system. This study investigated contributing factors of the eco-efficiency of thermal insulation materials to support decision making of material manufacturers. For the improvement of eco-efficiency, the assessment was made in two scopes: investigating the contributing factors of impact caused at production processes; and thermal performance through thermo-physical properties. For quantifying environmental impacts, cradle-to-grave life cycle assessment (LCA) of each materials were made. The life cycle impact assessment (LCIA) indicators used were ReCiPe H/A and global warming potential (GWP100a). For the assessment of production process, the inventories of the materials were assigned to six categories: heat, chemicals, electricity, transportation, raw materials and wastes. Among the assessed materials, contribution of electricity and heat within the production process was large for foam glass which had the highest potential to improve the eco-efficiency which was by factor 1.72. The analysis on relation between thermo-physical properties and eco-efficiency based on product data of the materials highlighted the importance of density as an indicator upon development and use. Althoughdensity often gains less attention,the finding suggested the effectiveness of improving the efficiency by having lower density without compensating the performance of the materials.

4 July 2018 in Sustainability
Verified
Journal Article
Open access
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JKJun Kono
Jun Kono
YOYork Ostermeyer
York Ostermeyer
HWHolger Wallbaum
Holger Wallbaum
Improving the sustainability performance of construction industry is driven by two forces: regulatory push (policy initiatives), and market pull where improving a corporate sustainability performance can be financially beneficial for enterprises. Through the investigation of the sustainability hotspots and impacts, concerning social and environmental, of the steel slag mixed concrete (green concrete) the study assessed the factors relevant for its performance and examined how to improve them. Hotspot analysis and impact assessments were conducted by social and environmental life cycle assessment (LCA). The assessed green concrete represented not just the variety of geographic representation but also the product designs (three different slag contents) and the potential difference occurring from the corporate efforts, where four classes were introduced. The investigation of the social and environmental hotspots of the green concrete revealed a difference in the relation between the sustainability performance and steel slags. While the increased slag content resulted in worse social performance, the increase improved the environmental performance in all six investigated case countries. This trade-off between the social and environmental performance implied the limits of the sustainable product design and suggested the effectiveness of the supply chain management for improving the two sustainability performances for the green concrete.

1 January 1990 in Japanese Circulation Journal
Verified
Journal Article
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MHMinoru Hongo
Minoru Hongo
TMTakuo Misawa
Takuo Misawa
OKOsamu Kinoshita
Osamu Kinoshita
HYHiroyoshi Yamada
Hiroyoshi Yamada
JKJun Kono
Jun Kono
MSMorie Sekiguchi
Morie Sekiguchi
To determine left ventricular diastolic properties in patients with familial amyloid polyneuropathy, 23 patients were studied by digitized M-mode echocardiography and were compared with 15 age-matched normal subjects. None of the patients had restrictive ventricular physiology and all but two showed normal left ventricular fractional shortening. Both the normalized peak rate of diastolic increase in left ventricular internal dimension and the normalized peak rate of diastolic thinning of posterior wall were significantly lower in patients than in normal subjects (2.0 ± 0.8 vs 3.0 ± 0.4 sec-1 ; p<0.001, and 2.5 ± 1.2 vs 5.8 ± 1.0 sec-1 ; p<0.001, respectively). The left ventricular isovolumic relaxation time in patients was 91.5 ± 22.2 msec, compared with 64.0 ± 2.6 msec in normal subjects (p<0.001). Of the 18 patients without clinical evidence of overt heart disease, 12 had normal ventricular wall thickness and normal fractional shortening, but 10 of the 12 exhibited some abnormalities in diastolic properties. In addition, indexes of diastolic function were significantly related to ventricular wall thickness alone. These findings indicate that left ventricular diastolic abnormalities precede the development of clinically overt heart disease, ventricular wall thickening, and systolic dysfunction and may be related to intramyocardial amyloid infiltration with resultant fibrosis in patients with familial amyloid polyneuropathy.