scholarly journals A Novel Conceptual Approach to Objectively Determine JRC Using Fractal Dimension and Asperity Distribution of Mapped Fracture Traces

2018 ◽  
Vol 52 (4) ◽  
pp. 1041-1054 ◽  
Author(s):  
Martin Stigsson ◽  
Diego Mas Ivars
Keyword(s):  
Fractal Dimension ◽  
Conceptual Approach ◽  
Asperity Distribution

Use of fractals to describe microstructures of porous thick-film platinum electrodes

1992 ◽  
Vol 50 (1) ◽  
pp. 314-315
Author(s):  
Steven D. Toteda
Keyword(s):  
Fractal Dimension ◽  
Power Plants ◽  
Electrical Response ◽  
Cubic Phase ◽  
Platinum Electrodes ◽  
Fine Grained ◽  
Impedance Response ◽  
Platinum Particles ◽  
Energy Surfaces ◽  
Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

Comment on "On the fractal dimension of stream networks"

1990 ◽  
Vol 26 (9) ◽  
pp. 2243-2244 ◽  
Author(s):  
David G. Tarboton
Keyword(s):  
Fractal Dimension ◽  
Stream Networks

Heterogeneity of Cerebral Blood Flow: a Fractal Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 37-42 ◽  
Author(s):  
P. Hartikainen ◽  
J. T. Kuikka
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Fractal Dimension ◽  
Frontal Lobe ◽  
Fractal Analysis ◽  
Relative Dispersion ◽  
Emission Computed Tomography ◽  
Brain Blood Flow ◽  
Healthy Controls ◽  
Fractal Approach

Summary Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and singlephoton emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (= coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17 ± 0.05 (mean ± SD) for the left hemisphere and 1.15 ± 0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04 ± 0.03 than in healthy controls. Conclusion: Within the limits of spatial resolution of SPECT, the heterogeneity of brain blood flow is well characterized by a fractal dimension. Fractal analysis may help brain scientists to assess age-, sex- and laterality-related anatomic and physiological changes of brain blood flow and possibly to improve precision of diagnostic information available for patient care.

Encountering Ambiguity: Muʿtazilī and Twelver Shīʿī Approaches to the Qur'an's Ambiguous Verses

2016 ◽  
Vol 18 (3) ◽  
pp. 91-115 ◽  
Author(s):  
Tehseen Thaver
Keyword(s):  
Eleventh Century ◽  
Arabic Language ◽  
Conceptual Approach ◽  
Islamic Jurisprudence ◽  
Primary Determinant ◽  
Linguistic Challenges ◽  
Qur'anic Exegesis ◽  
Exegetical Tradition ◽  
Qur'an Commentaries ◽  
Early Islamic

Within the broader discipline of Qur'anic exegesis, the sub-genre of the mutashābihāt al-Qurʾān (the ambiguous verses of the Qur'an) is comprised of works dedicated to the identification and explication of those verses that present theological or linguistic challenges. Yet, the approach, style, and objective of the scholars who have written commentaries on the ambiguous verses are far from monolithic. This essay brings into focus the internal diversity of this important exegetical tradition by focusing on the Qur'an commentaries of two major scholars in fourth/eleventh-century Baghdad, al-Sharīf al-Raḍī (d. 406/1016) and Qāḍī ʿAbd al-Jabbār (d. 415/1025). Al-Raḍī was a prominent Twelver Shīʿī theologian and poet while ʿAbd al-Jabbār was a leading Muʿtazilī theologian during this period; al-Raḍī was also ʿAbd al-Jabbār's student and disciple. Through a close reading of their respective commentaries on two Qur'anic verses, I explore possible interconnections and interactions between Shīʿī and Muʿtazilī traditions of exegesis, and demonstrate that while ʿAbd al-Jabbār mobilised the language of Islamic jurisprudence, al-Raḍī primarily relied on early Islamic poetry and the etymology of the Arabic language. Methodologically, I argue against a conceptual approach that valorises sectarian and theological identity as the primary determinant of hermeneutical desires and sensibilities.

Optimal Density Determination of Bouguer Anomaly Using Fractal Analysis (Case of study: Charak area,IRAN)

2005 ◽  
Vol 1 (1) ◽  
pp. 21-24
Author(s):  
Hamid Reza Samadi
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Fractal Analysis ◽  
Fractal Geometry ◽  
Host Rock ◽  
Bouguer Anomaly ◽  
Research Area ◽  
Density Difference ◽  
Optimal Density

In exploration geophysics the main and initial aim is to determine density of under-research goals which have certain density difference with the host rock. Therefore, we state a method in this paper to determine the density of bouguer plate, the so-called variogram method based on fractal geometry. This method is based on minimizing surface roughness of bouguer anomaly. The fractal dimension of surface has been used as surface roughness of bouguer anomaly. Using this method, the optimal density of Charak area insouth of Hormozgan province can be determined which is 2/7 g/cfor the under-research area. This determined density has been used to correct and investigate its results about the isostasy of the studied area and results well-coincided with the geology of the area and dug exploratory holes in the text area

The Validity of Rector�s Circular Letter on the Covid-19 Pandemic

2020 ◽  
Vol 7 (1) ◽  
pp. 126 ◽  
Author(s):  
Fradhana Putra Disantara
Keyword(s):  
Legal Theory ◽  
Legal Issues ◽  
State Universities ◽  
Ministry Of Education ◽  
Conceptual Approach ◽  
State Of Emergency ◽  
Circular Letter ◽  
The Status ◽  
The Government

This study aims to analyze the relevance of the �health emergency� status to the existing legal theory and condition as well as to identify the validity of the Circular Letter of the Rector of State Universities. To this end, this study applied the statute and conceptual approach. The study was conducted by inventorying primary and secondary legal materials to obtain a proper and critical review of the legal issues under study. The results showed that the determination of the �health emergency� status by the government was inappropriate due to the uncertainty of the regulations issued by the government to determine the current condition. Thus, the status of the COVID-19 pandemic is a �legal emergency� status. Further, the Rector�s policy through the Circular Letter is valid judicially, sociologically, and philosophically. The determination of the �legal emergency� status can be done by issuing a Perppu without a �state of emergency� from the President. Finally, it is suggested to firstly get an approval from the Ministry of Education and Culture regarding the issuance of the Rector�s Circular Letter. Besides, further study is needed as this study was conducted during the COVID-19 pandemic.�Keabsahan Surat Edaran Rektor Perguruan Tinggi dalam Pandemi Covid-19Tujuan dari penelitian ini adalah untuk menganalisa relevansi status �darurat kesehatan� dengan teori hukum dan kondisi yang ada dan keabsahan atas Surat Edaran Rektor Perguruan Tinggi Negeri. Metode yang digunakan dalam penelitian ini adalah statute approach dan conseptual approach. Penelitian dilakukan dengan menginventarisasi bahan hukum primer dan sekunder, guna mendapatkan kajian yang seyogianya dan telaah kritis terkait isu hukum. Hasil penelitian menyatakan penetapan status darurat kesehatan oleh pemerintah kurang tepat, dikarenakan tidak menentu-nya peraturan yang dikeluarkan oleh pemerintah untuk menetapkan kondisi saat ini. Sehingga, status pandemi COVID-19 merupakan status darurat hukum. Kebijakan rektor melalui Surat Edaran adalah absah secara aspek yuridis, sosiologis, dan filosofis. Penetapan darurat hukum cukup dilakukan dengan menerbitkan Perppu tanpa pernyataan darurat dari Presiden. Saran peneliti adalah di perlukan persetujuan pada Kementerian Pendidikan dan Kebudayaan terkait terbitnya Surat Edaran Rektor, dan dibutuhkan penelitian lebih lanjut dikarenakan penelitian ini dilakukan pada masa COVID-19 yang bersifat temporal.�

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