An Index of Soil Structure Derived from Water Retention Data and Particle Size Distribution

Daniel Gimenez,Attila Nemes,Daniel Hirmas,Sigrun Kvaerno 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Extracorporeal Pedicles for Free Flap Reconstruction in Diabetic Lower Extremity Wounds

Alejandro R. Gimenez,Daniel Lazo,Salomao Chade,Alex Fioravanti,Olimpio Colicchio,Daniel Alvarez,Ernani Junior,Sarth Raj,Amjed Abu-Ghname,Marco Maricevich 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.6

Diabetic foot ulcers are a severe complication of diabetes, and their management requires a multidisciplinary approach for optimal management. When treating these ulcers, limb salvage remains the ultimate goal. In this article, we present the “hanging” free flap for the reconstruction of chronic lower extremity diabetic ulcers. This twostaged approach involves standard free flap harvest and inset; however, following inset the “hanging” pedicle is covered within a skin graft instead of making extraneous incisions within the undisturbed soft tissues or tunnels that can compress the vessels. After incorporation, a second-stage surgery is performed in 4 to 6 weeks which entails pedicle division, flap inset revision, and end-to-end reconstruction of the recipient vessel. Besides decreasing the number of incisions on diabetic patients, our novel technique utilizing the “hanging” pedicle simplifies flap monitoring and inset and allows reconstruction of recipient vessels to reestablish distal blood flow.

Review of Soil Structure Quantification from Soil Images

전현정,Daniel Gimenez,윤성원,박찬원,문용희,손연규,현병근 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.3

Soil structure plays an important role in ecological system, since it controls transport and storage of air, gas,nutrients and solutions. The study of soil structure requires an understanding of the interrelations and interactions between the diverse soil components at various levels of organization. Investigations of the spatial distribution of pore/particle arrangements and the geometry of soil pore space can provide important information regarding ecological or crop system. Because of conveniences in image analyses and accuracy,these investigations have been thrived for a long time. Image analyses from soil sections through impregnated blocks of undisturbed soil (2 dimensional image analyses) or from 3 dimensional scanned soils by computer tomography allow quantitative assessment of the pore space. Image analysis techniques can be used to classify pore types and quantify pore structure without inaccurate or hard labor in laboratory. In this paper, the last 50years of the soil image analyses have been presented and measurements on various soil scales were introduced,as well. In addition to history of image analyses, a couple of examples for soil image analyses were displayed. The discussion was made on the applications of image analyses and techniques to quantify pore/soil structure.

Use of the Quantitatively Transformed Field Soil Structure Description of the US National Pedon Characterization Database to Improve Soil Pedotransfer Function

윤성원,Daniel Gimenez,Attila Nemes,전현정,장용선,손연규,강성수,김명숙,김유학,하상건 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.5

Soil hydraulic properties such as hydraulic conductivity or water retention which are costly to measure can be indirectly generated by soil pedotransfer function (PTF) using easily obtainable soil data. The field soil structure description which is routinely recorded could also be used in PTF as an input to reduce the uncertainty. The purposes of this study were to use qualitative morphological soil structure descriptions and soil structural index into PTF and to evaluate their contribution in the prediction of soil hydraulic properties. We transformed categorical morphological descriptions of soil structure into quantitative values using categorical principal component analysis (CATPCA). This approach was tested with a large data set from the US National Pedon Characterization database with the aid of a categorical regression tree analysis. Six different PTFs were used to predict the saturated hydraulic conductivity and those results were averaged to quantify the uncertainty. Quantified morphological description was successively used in multiple linear regression approach to predict the averaged ensemble saturated conductivity. The selected stepwise regression model with only the transformed morphological variables and structural index as predictors predicted the Ksat with r2 = 0.48 (p = 0.018), indicating the feasibility of CATPCA approach. In a regression tree analysis, soil structure index and soil texture turned out to be important factors in the prediction of the hydraulic properties. Among structural descriptions size class turned out to be an important grouping parameter in the regression tree. Bulk density, clay content, W33 and structural index explained clusters selected by a two step clustering technique, implying the morphologically described soil structural features are closely related to soil physical as well as hydraulic properties. Although this study provided relatively new method which related soil structure description to soil structure index, the same approach should be tested using a datasets containing the actual measurement of hydraulic properties. More insight on the predictive power of soil structure index to estimate hydraulic properties would be achieved by considering measured the saturated hydraulic conductivity and the soil water retention.

Soil Entropy Measure Derived from the Soil Water Retention Characteristic Curve

( Sung Won Yoon ),( Daniel Gimenez ),( Hyen Chung Chun ),( Seong Soo Kang ),( Myung Sook Kim ),( Yoo Hak Kim ),( Sang Keun Ha ) 한국토양비료학회 2011 한국토양비료학회 학술발표회 Vol.2011 No.-

Review of Soil Structure Quantification from Soil Images

Chun, Hyen-Chung,Gimenez, Daniel,Yoon, Sung-Won,Park, Chan-Won,Moon, Yong-Hee,Sonn, Yeon-Kyu,Hyun, Byung-Keun Korean Society of Soil Science and Fertilizer 2011 한국토양비료학회지 Vol.44 No.3

Soil structure plays an important role in ecological system, since it controls transport and storage of air, gas, nutrients and solutions. The study of soil structure requires an understanding of the interrelations and interactions between the diverse soil components at various levels of organization. Investigations of the spatial distribution of pore/particle arrangements and the geometry of soil pore space can provide important information regarding ecological or crop system. Because of conveniences in image analyses and accuracy, these investigations have been thrived for a long time. Image analyses from soil sections through impregnated blocks of undisturbed soil (2 dimensional image analyses) or from 3 dimensional scanned soils by computer tomography allow quantitative assessment of the pore space. Image analysis techniques can be used to classify pore types and quantify pore structure without inaccurate or hard labor in laboratory. In this paper, the last 50 years of the soil image analyses have been presented and measurements on various soil scales were introduced, as well. In addition to history of image analyses, a couple of examples for soil image analyses were displayed. The discussion was made on the applications of image analyses and techniques to quantify pore/soil structure.

Use of the Quantitatively Transformed Field Soil Structure Description of the US National Pedon Characterization Database to Improve Soil Pedotransfer Function

Yoon, Sung-Won,Gimenez, Daniel,Nemes, Attila,Chun, Hyen-Chung,Zhang, Yong-Seon,Sonn, Yeon-Kyu,Kang, Seong-Soo,Kim, Myung-Sook,Kim, Yoo-Hak,Ha, Sang-Keun Korean Society of Soil Science and Fertilizer 2011 한국토양비료학회지 Vol.44 No.5

Soil hydraulic properties such as hydraulic conductivity or water retention which are costly to measure can be indirectly generated by soil pedotransfer function (PTF) using easily obtainable soil data. The field soil structure description which is routinely recorded could also be used in PTF as an input to reduce the uncertainty. The purposes of this study were to use qualitative morphological soil structure descriptions and soil structural index into PTF and to evaluate their contribution in the prediction of soil hydraulic properties. We transformed categorical morphological descriptions of soil structure into quantitative values using categorical principal component analysis (CATPCA). This approach was tested with a large data set from the US National Pedon Characterization database with the aid of a categorical regression tree analysis. Six different PTFs were used to predict the saturated hydraulic conductivity and those results were averaged to quantify the uncertainty. Quantified morphological description was successively used in multiple linear regression approach to predict the averaged ensemble saturated conductivity. The selected stepwise regression model with only the transformed morphological variables and structural index as predictors predicted the $K_{sat}$ with $r^2$ = 0.48 (p = 0.018), indicating the feasibility of CATPCA approach. In a regression tree analysis, soil structure index and soil texture turned out to be important factors in the prediction of the hydraulic properties. Among structural descriptions size class turned out to be an important grouping parameter in the regression tree. Bulk density, clay content, W33 and structural index explained clusters selected by a two step clustering technique, implying the morphologically described soil structural features are closely related to soil physical as well as hydraulic properties. Although this study provided relatively new method which related soil structure description to soil structure index, the same approach should be tested using a datasets containing the actual measurement of hydraulic properties. More insight on the predictive power of soil structure index to estimate hydraulic properties would be achieved by considering measured the saturated hydraulic conductivity and the soil water retention.

Three Dimensional Measurements of Pore Morphological and Hydraulic Properties

Hyen-Chung Chun(전현정),Daniel Gimenez,Sung-Won Yoon(윤성원),Richard Heck,Laise Ziska,Kate Geaorge,Yeon-Kyu Sonn(손연규),Sang-Keun Ha(하상건),Tom Elliot 한국토양비료학회 2010 한국토양비료학회지 Vol.43 No.4

포어 네트웍 모델들 (Pore network model)은 토양 공극의 구조를 조사할 때 유용한 도구들이다. 이런 모델들은 삼차원 이미지들에서 공극의 구조와 관련된 양적 정보를 제공한다. 이 연구는 포어 네트웍 모델을 이용하여 공극의 구조와 수리학적 특성들을 양적으로 측정하였다. 연구목표는 큰 크기의 이미지에서 공극의 구조에 관한 양적 정보를얻기 위해 포어 네트웍 모델을 적용하고, 토양수분특성과 수리 전도도를 삼차원 이미지로부터 계산하고 이 값들은 실험을 통해 얻어진 실험값들과 결합하여 토양의 수리적 특성을 분석하는 것이었다. 토양 시료들은 발티모아 도시 중심에 있는발티모어 과학센터에 위치한 실험부지에서 채취되었다. 불교란 원주형 시료들이 채취되었고, 22 μm 의 해상도로 x선 단층 촬영되었다. 포어 네트웍은 중심축 변형에 의해 공극에서 축출되었고 이를 바탕으로 공극 구조가 계산되었다. 토양수분특성과 불포화 수리 전도도 값들은 토양 이미지에서 계산 되었다. 토양 밀도, 토양수분특성과 불포화 수리 전도도들은 3 토양 시료들로부터 실험을 통해 구하였다. 삼차원 이미지 분석은 토양 공극의 특성들을, 예를 들어 공극 부피, 길이, 굴곡도, 가장 정확히 분석하였다. 이런 정확한 분석은 토양 내 수문학적 정보를 정확히 산출할 수 있게 하였다. 계산된 값과 실험을 통한 실험치의 결합은 공극에 대한 더 광범한 범위를 분석할 수 있게 하였다. 이 연구를 통해 이미지에서 계산되고 측정된 수문학적 자료들은 토양내 대기공과 소기공을 모두 다 설명해 줄 수 있는 방법이라는 것이 밝혀졌다. Pore network models are useful tools to investigate soil pore geometry. These models provide quantitative information of pore geometry from 3D images. This study presents a pore network model to quantify pore structure and hydraulic characteristics. The objectives of this work were to apply the pore network model to characterize pore structure from large images to quantify pore structure, calculate water retention and hydraulic conductivity properties from a three dimensional soil image, and to combine measured hydraulic properties from experiments with calculated hydraulic properties from image. Soil samples were taken from a site located at the Baltimore science center, which is located inside of the city. Undisturbed columns were taken from the site and scanned with a computer tomographer at resolutions of 22 μm. Pore networks were extracted by medial-axis transformation and were used to measure pore geometry from one of the scanned samples. Water retention and unsaturated hydraulic conductivity values were calculated from the soil image. Properties of soil bulk density, water retention and unsaturated hydraulic conductivity were measured from three replicates of scanned soil samples. 3D image analysis provided accurate detailed pore properties such as individual pore volumes, pore length, and tortuosity of all pores. These data made possible to calculate accurate estimations of water retention and hydraulic conductivity. Combination of the calculated and measured hydraulic properties gave more accurate information on pore sizes over wider range than measured or calculated data alone. We could conclude that the hydraulic property computed from soil images and laboratory measurements can describe a full structure of intra- and inter-aggregate pores in soil.

Soil Entropy Measure Derived from the Soil Water Retention Characteristic Curve

Sung Won Yoon,Daniel Gimenez,Hyen Chung Chun,Seong Soo Kang,Myung Sook Kim,Yoo Hak Kim,Sang Keun Ha 한국토양비료학회 2011 한국토양비료학회 학술발표회 초록집 Vol.2011 No.5