The Effect of Rootzone Mix and Compaction on Nitrogen Leaching in Kentucky bluegrass

이상국,Kevin W. Frank,James R. Crum 한국잔디학회 2010 Weed & Turfgrass Science Vol.24 No.1

Research on nitrate-nitrogen (NO3-N) leaching in turfgrass indicates that in most cases leaching poses minimal risk to the environment. Although there have been many studies investigating NO3-N leaching, there has been little research to investigate the effect of compaction level and rootzone mix on nitrogen (N) leaching. The research objective is to determine the effect of compaction level and rootzone mix on nitrogen leaching. The four rootzone mixes are 76.0:24.0, 80.8:19.2, 87.0:13.0 and 93.7:6.3 % (sand: soil). The four levels of compaction energies are 1.6,3.0, 6.1, and 9.1 J cm-2. Nitrogen was applied using urea at a rate of 147 kg ha-1 split among three applications. Rootzone was packed into a polyvinylchloride pipe with a perforated bottom to facilitate drainage. Rootzone depth was 30 cm over a 5 cm gravel layer. Each column was sodded with Poa pratensis L. Hoagland solution designed for coolseason grasses, minus N, was used to ensure adequate nutrition in the rootzone. Turf grass quality and clipping yield were recorded from each tube at two-week intervals. The clippings were oven-dried at a temperature of 67oC for 24 h and weighed. At the end of the study, root dry weight was determined by washing and oven-drying samples at 67℃ for 24 h. Leachate solution was collected weekly for analysis. More than 6.1 J cm-2 of compaction energy increased possibilities of surface runoff. The compaction energy between 3.0 and 6.1 J cm-2 produced more clipping dry weight and less N leaching than 9.1 J cm-2.

Commenting on “Atmospheric affect … gaining share of customer”

Barry J. Babin,Jill P. Attaway,Kevin W. James 한국마케팅과학회 2017 마케팅과학연구 Vol.27 No.3

In the year 2000, the Journal of Business Research (JBR) published “Atmospheric affect as a tool for creating value and gaining share of customer” by Babin and Attaway. Along with the help of reviewers and the audience at a prestigious retailing symposium hosted by Jean-Charles Chebat in Montreal a year or so earlier, the authors put together a contribution that appears to have stood the test of time. Through the past five years, the article continues to see nearly 100 citations annually. The comments presented here try to off er some thoughts on what makes this particular JBR article successful.

The Effect of Rootzone Mix and Compaction on Nitrogen Leaching in Kentucky bluegrass

이상국,케빈 프랭크,제임스 크럼,Lee, Sang-Kook,Frank, Kevin W.,Crum, James R. Turfgrass Society of Korea 2010 한국잔디학회지 Vol.24 No.1

환경문제를 야기 시킬수 있는 질소의 용탈에 관한 문제는 수많은 연구를 통해 그 결과를 문헌에서 찾아볼 수 있다. 그러나 대부분의 연구가 질소의 토양내 용탈에 관해서 이루어진 반면에 토양의 답압과 토양의 종류에 따라 질소의 용탈 정도에 관한 연구는 그 결과를 문헌에서 찾아 보기가 어렵다. 본 연구는 토양의 종류와 답압의 정도가 질소의 용탈에 미치는 영향 그리고 토양에 잔류된 질소가 켄터키블루그래스의 성장에 주는 영향에 대해서 알아보기 위하여 수행 되었다. 질소는 총 147 kg $ha^{-1}$이 12주 동안 3회에 걸쳐 나누어 시비되었다. 토양의 종류는 성분비율에 따라 76.0:24.0, 80.8:19.2, 87.0:13.0 그리고 93.7:6.3% (sand:soil)의 4가지로 구성이 되었다. 토양은 PVC 파이프에 30 cm 깊이로 조성이 되었으며 토양층 밑에 5 cm의 자갈층으로 구성되었다. PVC 파이프 밑부분의 구멍을 통해 질소용탈수의 수집을 용이하게 하였으며 질소외 영양성분을 위해 Hoagland solution에서 질소만 제외하여 사용되었다. 켄터키블루그래스의 질과 예초량이 매주 측정이 되었으며 예초물은 건물량 측정을 위해 예초후 67도에서 24시간 동안 건조되었다. 질소용탈수는 매주 PVC 파이프의 밑부분을 통해 매주 수집이 되었다. 6.1 J $cm^{-2}$ 이상의 답압에너지는 더 많은 표면배수의 가능성을 야기 시킬 수 있다. 3.0과 6.1 J $cm^{-2}$ 사이의 답압에너지는 다른 처리구에 비해 더 많은 건물량이 측정이 되었고 적은 질소가 용탈이 되었다. Research on nitrate-nitrogen ($NO_3-N$) leaching in turfgrass indicates that in most cases leaching poses minimal risk to the environment. Although there have been many studies investigating $NO_3-N$ leaching, there has been little research to investigate the effect of compaction level and rootzone mix on nitrogen (N) leaching. The research objective is to determine the effect of compaction level and rootzone mix on nitrogen leaching. The four rootzone mixes are 76.0:24.0, 80.8:19.2, 87.0:13.0 and 93.7:6.3 % (sand:soil). The four levels of compaction energies are 1.6, 3.0, 6.1, and 9.1 J $cm^{-2}$. Nitrogen was applied using urea at a rate of 147 kg $ha^{-1}$ split among three applications. Rootzone was packed into a polyvinylchloride pipe with a perforated bottom to facilitate drainage. Rootzone depth was 30 cm over a 5 cm gravel layer. Each column was sodded with Poa pratensis L. Hoagland solution designed for coolseason grasses, minus N, was used to ensure adequate nutrition in the rootzone. Turf grass quality and clipping yield were recorded from each tube at two-week intervals. The clippings were oven-dried at a temperature of $67^{\circ}C$ for 24 h and weighed. At the end of the study, root dry weight was determined by washing and oven-drying samples at $67^{\circ}C$ for 24 h. Leachate solution was collected weekly for analysis. More than 6.1 J $cm^{-2}$ of compaction energy increased possibilities of surface runoff. The compaction energy between 3.0 and 6.1 J $cm^{-2}$ produced more clipping dry weight and less N leaching than 9.1 J $cm^{-2}$.

Combining a distributed flow manifold and 3D woven metallic lattices to enhance fluidic and thermal properties for heat transfer applications

Zhao, Longyu,Ryan, Stephen M.,Lin, Sen,Xue, Ju,Ha, Seunghyun,Igusa, Takeru,Sharp, Keith W.,Guest, James K.,Hemker, Kevin J.,Weihs, Timothy P. Elsevier 2017 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.108 No.2

<P><B>Abstract</B></P> <P>The fluidic and heat transfer capabilities of 3D woven lattice materials were reported recently under axial and bifurcated flow patterns, but three critical performance indices – pressure drop, average surface temperature and temperature uniformity – could not be optimized simultaneously using these flow patterns. Here we combine the 3D weaves with manifolds to create a novel 3D flow pattern that enhances temperature uniformity, while also maintaining low pressure drops and surface temperatures. These three properties were characterized at room temperature for a range of flow rates using water as the working fluid. Three different weaves thicknesses were investigated: 12.7mm, 6.4mm, and 3.2mm, with manifold thicknesses of 12.7mm, 19.0mm, and 22.2mm, respectively, to provide a constant, combined weave-manifold thickness of 25.4mm. The properties of this new weave/manifold system are compared to those obtained using just the manifold (with no weave) and just the weave (with no manifold). Comparisons show that the addition of the weave lowers the average substrate temperature and temperature variations significantly, although pressure drop is increased. They also show that the addition of the manifold improves temperature uniformity significantly, and also lowers the average substrate temperature and the pressure drop. No specific ratio of weave to manifold thickness was found to be superior in all of the performance indices. The thermal performances are then evaluated at different pumping powers: the weave/manifold system and its distributed array flow pattern prevail. Finite element simulations were performed on a reduced and simplified model to explain the observed experimental trends, and manifold opening patterns were manipulated to demonstrate further potential property enhancements. The multiple benefits of this manifold system can be extended to common heat exchanger media beyond weaves.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Propose and design novel flow manifold that is combined with 3D woven lattices. </LI> <LI> Characterization of pressure drop, average temperature and temperature uniformity. </LI> <LI> Much superior thermal performance with 3D woven lattices than open spaces. </LI> <LI> Comparison of the new distributive flow pattern with axial and bifurcated flow cases. </LI> <LI> Trends between experiments and simulations are in good agreement. </LI> </UL> </P>