Western Coals—Laboratory Characterization and Field Evaluations of Cleaning Requirements

1976 ◽  
Vol 98 (1) ◽  
pp. 97-102 ◽  
Author(s):  
G. F. Moore ◽  
R. F. Ehrler

Many discussions have pointed out the differences in the characteristics of eastern and western coals. Low rank western coals have higher moistures, lower calorific values, and the ash constituents are more basic. Slagging and fouling indexes based on the ash chemistry of eastern bituminous coals are not applicable for low rank western coals. These differences led to dissimilarities in the behavior of eastern and western coals, so we have directed our efforts toward a study of the behavior of low rank western coals and how they differ from eastern coals. Three nonroutine laboratory tests: (1) burning profiles, (2) coal ash sintering strengths, and (3) viscosity temperature relationship of coal ash were used to distinquish the difference in the behavior of these coals. Three generating stations were selected to compare slagging and fouling predictions with soot blower performance. The coals burned at these stations were: (1) a North Dakota lignite, (2) a Montana subbituminous coal, and (3) an Illinois bituminous coal. Excellent results were noted as the observed soot blower performance and the performance predicted by our evaluation of the slagging and fouling characteristics of the coals were in agreement.

Author(s):  
Andrew Briggs ◽  
Hans Halvorson ◽  
Andrew Steane

Two scientists and a philosopher aim to show how science both enriches and is enriched by Christian faith. The text is written around four themes: 1. God is a being to be known, not a hypothesis to be tested; 2. We set a high bar on what constitutes good argument; 3. Uncertainty is OK; 4. We are allowed to open up the window that the natural world offers us. This is not a work of apologetics. Rather, the text takes an overview of various themes and gives reactions and responses, intended to place science correctly as a valued component of the life of faith. The difference between philosophical analysis and theological reflection is expounded. Questions of human identity are addressed from philosophy, computer science, quantum physics, evolutionary biology and theological reflection. Contemporary physics reveals the subtle and open nature of physical existence, and offers lessons in how to learn and how to live with incomplete knowledge. The nature and role of miracles is considered. The ‘argument from design’ is critiqued, especially arguments from fine-tuning. Logical derivation from impersonal facts is not an appropriate route to a relationship of mutual trust. Mainstream evolutionary biology is assessed to be a valuable component of our understanding, but no exploratory process can itself fully account for the nature of what is discovered. To engage deeply in science is to seek truth and to seek a better future; it is also an activity of appreciation, as one may appreciate a work of art.


2021 ◽  
pp. 1-13
Author(s):  
Yuxuan Gao ◽  
Haiming Liang ◽  
Bingzhen Sun

With the rapid development of e-commerce, whether network intelligent recommendation can attract customers has become a measure of customer retention on online shopping platforms. In the literature about network intelligent recommendation, there are few studies that consider the difference preference of customers in different time periods. This paper proposes the dynamic network intelligent hybrid recommendation algorithm distinguishing time periods (DIHR), it is a integrated novel model combined with the DEMATEL and TOPSIS method to solved the problem of network intelligent recommendation considering time periods. The proposed method makes use of the DEMATEL method for evaluating the preference relationship of customers for indexes of merchandises, and adopt the TOPSIS method combined with intuitionistic fuzzy number (IFN) for assessing and ranking the merchandises according to the indexes. We specifically introduce the calculation steps of the proposed method, and then calculate its application in the online shopping platform.


Biometrika ◽  
2020 ◽  
Author(s):  
S Na ◽  
M Kolar ◽  
O Koyejo

Abstract Differential graphical models are designed to represent the difference between the conditional dependence structures of two groups, thus are of particular interest for scientific investigation. Motivated by modern applications, this manuscript considers an extended setting where each group is generated by a latent variable Gaussian graphical model. Due to the existence of latent factors, the differential network is decomposed into sparse and low-rank components, both of which are symmetric indefinite matrices. We estimate these two components simultaneously using a two-stage procedure: (i) an initialization stage, which computes a simple, consistent estimator, and (ii) a convergence stage, implemented using a projected alternating gradient descent algorithm applied to a nonconvex objective, initialized using the output of the first stage. We prove that given the initialization, the estimator converges linearly with a nontrivial, minimax optimal statistical error. Experiments on synthetic and real data illustrate that the proposed nonconvex procedure outperforms existing methods.


2021 ◽  
Vol 11 (10) ◽  
pp. 4582
Author(s):  
Kensuke Tanioka ◽  
Satoru Hiwa

In the domain of functional magnetic resonance imaging (fMRI) data analysis, given two correlation matrices between regions of interest (ROIs) for the same subject, it is important to reveal relatively large differences to ensure accurate interpretation. However, clustering results based only on differences tend to be unsatisfactory and interpreting the features tends to be difficult because the differences likely suffer from noise. Therefore, to overcome these problems, we propose a new approach for dimensional reduction clustering. Methods: Our proposed dimensional reduction clustering approach consists of low-rank approximation and a clustering algorithm. The low-rank matrix, which reflects the difference, is estimated from the inner product of the difference matrix, not only from the difference. In addition, the low-rank matrix is calculated based on the majorize–minimization (MM) algorithm such that the difference is bounded within the range −1 to 1. For the clustering process, ordinal k-means is applied to the estimated low-rank matrix, which emphasizes the clustering structure. Results: Numerical simulations show that, compared with other approaches that are based only on differences, the proposed method provides superior performance in recovering the true clustering structure. Moreover, as demonstrated through a real-data example of brain activity measured via fMRI during the performance of a working memory task, the proposed method can visually provide interpretable community structures consisting of well-known brain functional networks, which can be associated with the human working memory system. Conclusions: The proposed dimensional reduction clustering approach is a very useful tool for revealing and interpreting the differences between correlation matrices, even when the true differences tend to be relatively small.


1974 ◽  
Vol 11 (04) ◽  
pp. 383-392
Author(s):  
David R. Pedrick

The difference in the effects of rough water on similar sailing yachts has been one of the intriguing puzzles that sailors, designers, and researchers have long tried to understand. It is not uncommon for two yachts of equal performance in smooth-sea conditions to have their speed or pointing ability reduced by different amounts when encountering waves. To investigate the causes of such behavior, it is important to have a rational procedure to analyze how changes in hull form, weight distribution, rig, and other design features affect the speed and motions of sailing yachts. This paper discusses the relationship of wind to rough water and of motions and added resistance to wave length and height. It then describes a procedure to predict motions, sailing speed, and speed-made-good to windward in realistic windward sailing conditions. The procedure utilizes results of heeled and yawed model tests of 12-metre yachts in oblique regular waves to predict performance in a Pierson-Moskowitz sea state corresponding closely to the equilibrium true wind speed.


2021 ◽  
Vol 10 (1) ◽  
pp. 1-12
Author(s):  
Noviana Norrohmat ◽  
Umar Nimran ◽  
Kusdi Raharjo ◽  
Hamidah Nayati Utami ◽  
Endang Siti Astuti

The purpose of this research is to determine the organizational support for professionalism that has never been done before. The research approach is to conceptualize the structure of the relationship of variables from a study. Verification research is to test the hypothesis through data collection in the field using two methods, namely descriptive survey and explanatory survey. The use of both methods aims to analyze the causality relationship between research variables in accordance with the hypothesis quantitatively. There is significant influence between the variables of organizational support to professional variables. However, different results are found on the influence of organizational support variables on OCB and performance that have no significant effect. There is also an indirect influence between organizational support variables on OCB and performance through intermediary intervening professionalism variables. The difference between this research and the previous research are the use of constructs and the measurement in the unit of analysis being used.


2012 ◽  
Vol 22 (5) ◽  
pp. 645-650 ◽  
Author(s):  
Wei Qian ◽  
Qiang Xie ◽  
Yuyi Huang ◽  
Jiatao Dang ◽  
Kaidi Sun ◽  
...  

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