Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

On the applicability of self-affinity concept in scale of three-dimensional rock joints

[[abstract]]Joint failure causes large instabilities in rock structures. The failure is highly dominated by surface topography of joints. Since measuring the entire surface is not possible, examining a portion of it and its attribution to the entire surface is used in the literature. Self-affinity is a common way for such approach. The best methods for measuring the surface topography are first introduced. Using such methods, the applicability of self-affinity concept in scale of joints is then examined and it is demonstrated as deficient. In this way, there is no relationship between the roughness of a portion of the joint surface and that of the entire surface.[[incitationindex]]SCI[[booktype]]紙

Effect of asperity order on the shear response of three-dimensional joints by focusing on damage area

[[incitationindex]]SCI[[booktype]]紙

Fractal analysis of rainfall-induced landslide and debris flow spread distribution in the Chenyulan Creek Basin, Taiwan

[[abstract]]The Chenyulan Stream in Central Taiwan follows the Chenyulan fault line which is a major boundary fault in Taiwan. In recent years, many destructive landslides have occurred in the Chenyulan Creek Basin after heavy rainfall accompanied by several strong typhoons. Three examples of landslide distributions in the Chenyulan Creek Basin, before and after 1996 and after 2004 are analyzed. The box dimension and two-point correlation dimension are employed to describe the landslide area size distribution and distance distribution between every two landslides, respectively. It is found that the number of landslides increased in this period. However, the average landslide area decreased. The correlation dimension gradually increased from 1.15 to 1.32 during this period (before and after 1996 and after 2004). This implies that the landslide distribution in the Chenyulan Creek Basin has become diffuse and extensive. The box dimension value shows the degree of the landslide density occupied in a space. The box dimension also increased from 0.3 to 0.69 during this period. The increasing box dimension means that the landslide presented in this creek basin has gradually increased. This indicates that the slopes of this creek basin have become more unstable and susceptible.[[notice]]補正完

Rainfall Landslide in Sedimentary and Sub-Metamorphic Rock an Example in Kaoping River Basin

[[abstract]]Many researches employed several landslide-related factors such as the slope-aspect, size, lithology etc. to study the landslide assessment. Utilizing the landslide inventory delineated by 1:5000 high resolution aerial photo, this article explored the landslide characteristics, such as the landslide area, slump direction and air current for two different rock types in Kaoping River basin during the period of 2009 Typhoon Morakot. It is found that the air current direction is the dominant factor for landslides triggered by a heavy rainfall in Kaoping River basin. The number and size of landslides in slate is larger than the sedimentary rock. This indicates the slate region in Kaoping River basin is more likely to take place landslide; however, the landslide characteristic in size distribution is similar

A directional method for directly calculating the fractal parameters of joint surface roughness

[[notice]]待補摘要[[journaltype]]國際[[booktype]]紙本[[countrycodes]]GB

[[alternative]]Simulating the Mechanical Properties of Sedimentary Rocks in Taiwan

[[sponsorship]]中國地質學會; 成功大學地球科學系; 行政院國家科學委員會[[conferencedate]]19970320~19970322[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺南, 臺

[[alternative]]An Index of Describing the Anisotropic Characteristic of Joint Surfaces

[[abstract]]岩石節理面之剪力強度主要受剖面粗糙度的影響,且具有明顯的異向性行為。本文基於統計觀念將節理面凹凸不平的分布以碎形布朗運動(fBm)軌跡模擬之,因此可以Hurst指數(H)來表示節理剖面之粗糙性質,H值具有方向性故與剪動方向有關,而優於一般常用的JRC或碎形維度D等係數表示法。文中,並以H值描述一人工節理特徵,與不同剪動方向所造成的異向性粗糙度與剪力強度。[[abstract]]This paper uses the Hurst exponent that based on the theory of fractional Brownian motion (fBm), to represent the anisotropic characteristic of the joint surface. The Hurst exponent that is dependent of the sequence of sampling can memory the past height history of asperity. Thus it can represent the anisotropic roughness characteristic of a profile according to the different sampling order and the shearing directions. Then the fractal dimension and the JRC can calculate from the Hurst exponent for a profile. Hence, the anisotropic shear strength of joints based on the Barton's empirical formula is also investigated.[[sponsorship]]中華民國力學學會; 台灣工業技術學院; 教育部[[conferencedate]]19961214~19961215[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺北市, 臺

[[alternative]]Fractal Analysis of Miscanthus Floridulus Root System

[[abstract]]芒草(五節芒)因根面積比大且根域廣所能提供的根力大，因此常為整治崩塌地導入之最佳草種。根系越錯綜複雜其碎形維度越大，對土壤之網結補強能力越高，然而根為一具生命的有機體，根系分佈除了繁雜更處在一動態變動狀況。因此，根力研究必須統計分析藉以達較佳的結果。碎形理論正是統計數學方法一支且具有記憶性，適可用於分析此類繁瑣的根系幾何分佈問題。本文採取高矮芒草之根系，輔以影像分析概念以量化根系參數，並利用網格覆蓋法獲得根系碎形維度，據以量化芒草根系網絡複雜程度之演變，並用以評估其力學效應。[[abstract]]Miscanthus floridulus is one of the best species of the replanting ecological vegetation for the landslide area. Usually, several parameters of the root system were required to estimate the reinforced effect in soil slope. However, it is a heavy duty to quantify the complicated growth of root system. The fractal dimension in fractal theory is capable of capturing the complex distribution of root system. In this paper, the fractal characteristic of Miscanthus floridulus root-system in various heights is examined. The photo image technique is employed to estimate the root parameters.[[sponsorship]]淡江大學土木工程學; 系三力工程顧問; 介興營造[[conferencetype]]國內[[conferencetkucampus]]淡水校園[[conferencedate]]20050908~20050910[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺北縣, 臺

[[alternative]]A Study on the Cause of Earthquake Induced by Fault Slip： Stick Slip

[[abstract]]本文由室內節理岩體模擬結果之滯動現象,探討引起此種地震的原因。研究結果發現引起規則滯動或地震的原因可能是斷層間碎屑之相互摩擦行為所控制,而非僅由斷層面靜、動摩擦係數差異引起,尚必須考慮節瘤破碎後對節理面摩擦性質之改變。[[abstract]]This paper aims at the topic of earthquakes induced by stick-slip friction on faults. It shows that The stick- slip behavior is dominated by the motion of fault debris. To clarify the mechanism of earthquake, the effect on frictional properties of faults by asperity rupture is suggested to be taken into account.[[sponsorship]]中國地質學會; 台灣師範大學地球科學系; 中央研究院地球科學研究所[[conferencedate]]19960418~19960419[[booktype]]紙本[[iscallforpapers]]Y[[conferencelocation]]臺北市, 臺