1,721,061 research outputs found
Indirect input identification by modal filter technique
No full textThis paper is a study on modal model method in estimating system inputs from vibration responses, which is one of the indirect input identification methods in frequency domain. The method has advantages over the direct inverse method especially when points of operational inputs are inaccessible for artificial excitation but accessible for response measurement. Systematic procedures of an extended modal model method are proposed and checked by numerical experiments. Mechanisms of error propagation, i.e. how errors in modal parameters such as poles and mode shape vectors affect estimation of the input forces, are illustrated. Then, in order to counteract the error propagation, discrete modal filter approach is used in this paper to compute the inversion of modal matrix in which most serious errors seem to be generated. Further, a reduced form of modified reciprocal modal vector (MRMV) is proposed to estimate multiple inputs, which is shown to have orthogonality errors smaller than by the MRMV filter. (C) 1999 Academic Press
Influence of sulfite on radiolytic conversion of nitrate and nitrite in dilute aqueous solutions
No full textNitrate and nitrite ions are reduced in deaerated diluted aqueous solutions in the presence of sulfite under the action of electron beam
Treatment of landfill leachate using activated sludge process and electron-beam radiation
No full textElectron-beam (EB) radiation technology was applied to the Kimpo coastal landfill leachate to treat the biologically refractory substances remaining after an activated sludge process. Kimpo landfill leachates were analyzed in terms of molecular weight distribution (MWD) and aquatic humic substances (AHS) before and after the activated sludge process and EB radiation. When the raw leachate with an initial BOD of 1370 mg/l was treated by the activated sludge process, about 98% of BOD was successfully removed during the 72-h batch test. However, the biodegradability of leachate, defined as BOD/DOC, decreased from 1.3 to 0.1 due to the presence of biologically refractory organic matter. Fractionation of organic matter using an ultrafiltration apparatus revealed that large organics. above MW 30,000, were the most refractory component. However, this high organic component was sharply reduced after EB radiation. The AHS of the raw leachate and the effluent from activated sludge process (AS(eff)) were estimated to be 57.7 and 64.1% of DOG, respectively. When the AS(eff) was subjected to EB radiation at a dose of 30 kGy and pH 3, DOC concentration decreased from 324 to 215 mg/l and AHS content also fell from 68.6 to 52.9%. The efficiency of EB radiation was affected by pH condition and dose. In the case of AS,(eff), pH condition was the most important parameter affecting the efficiency of EB radiation. (C) 1999 Elsevier Science Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Feasibility and clinical utility of stone extraction balloon catheter-assisted endoscopic stenting for malignant distal duodenal and proximal jejunal obstruction (with video)
No full textBACKGROUND: Endoscopic stenting for malignant distal duodenal and jejunal obstructions is challenging because the length of conventional gastroscopes is insufficient to reach the obstruction point. A fully inflated balloon catheter freely navigates the duodenum and jejunum without causing bowel injury by burying the catheter tip. It easily changes its direction for guidewire relocation, conforming to the angulation of the small bowel flexures. This study evaluated the feasibility and efficacy of stone extraction balloon catheter-assisted endoscopic stenting for malignant distal duodenal and proximal jejunal obstructions. METHODS: Patients with malignant distal duodenal or jejunal obstructions who underwent stone extraction balloon catheter-assisted duodenal stenting between January 2015 and December 2022 were retrospectively analyzed. RESULTS: We evaluated 30 patients in this study. Pancreatic cancer is the primary cause of duodenal obstruction, with the third portion of the duodenum being the most common obstruction site. Technical success was achieved in 100% of cases, and the clinical success rate was 100%. The median procedure time was 35 min, and the mean gastric outlet obstruction score (GOOSS) improved from 1.20 (pre-procedure) to 2.87 (post-procedure). Early stent migration was encountered in one patient. During follow-up, stent dysfunction was noted in nine (30%) patients, and the overall stent patency time was 145 days. CONCLUSION: Stone extraction balloon catheter-assisted endoscopic stenting is an effective and reproducible technique for treating malignant distal duodenal and jejunal obstructions
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Optimizing Vancomycin Area under the Concentration-Time Curve Targets in Enterococcal Bacteremia: Balancing Efficacy and Nephrotoxicity
No full textPURPOSE: Vancomycin is critical in treating enterococcal bacteremia; however, its optimal pharmacokinetic (PK)/pharmacodynamics (PD) targets remain unclear. This study evaluates the association between vancomycin PK/PD parameters and clinical outcomes in patients with enterococcal bacteremia. MATERIALS AND METHODS: This retrospective cohort study included 70 patients with enterococcal bacteremia treated with vancomycin at a university-affiliated teaching hospital. The primary and secondary outcomes were unfavorable clinical outcome (30-day mortality or persistent bacteremia) and nephrotoxicity, respectively. Vancomycin area under the concentration-time curve (AUC)/minimal inhibitory concentration (MIC) was calculated using Bayesian methods. Receiver operating curve (ROC) analysis determined AUC/MIC thresholds for predicting unfavorable clinical outcomes and nephrotoxicity. Logistic regression analysis identified risk factors for clinical outcomes. RESULTS: Unfavorable outcome occurred in 21 patients (30.0%), and 10 (14.3%) experienced nephrotoxicity. The ROC-derived AUC(2)(4)/MIC cutoff for unfavorable outcome and nephrotoxicity were AUC(2)(4)/MIC >/=466.0 [AUC=0.740; 95% confidence interval (CI), 0.618-0.862] and >/=643.2 (AUC=0.963; 95% CI, 0.922-1.000), respectively. Clinical success was achieved in 44.9% (22/49) of patients with an AUC(2)(4)/MIC <400, whereas 47.6% (10/21) experienced unfavorable outcome despite having an AUC(2)(4)/MIC of 400-600. Nephrotoxicity [adjusted odds ratio (aOR)=15.05; 95% CI, 2.15-105.14; p=0.006] and Charlson Comorbidity Index (CCI) (aOR=1.57; 95% CI, 1.18-2.08; p=0.002) were independent risk factors for unfavorable outcome. High AUC(2)(4)/MIC and CCI were associated with nephrotoxicity (aOR=1.03; 95% CI, 1.01-1.04; p=0.005, and aOR=1.83; 95% CI, 1.01-3.35; p=0.045). CONCLUSION: Nephrotoxicity and multiple comorbidities were stronger risk factors for unfavorable outcomes than vancomycin AUC/MIC. These findings highlight the need for individualized strategies to optimize efficacy while minimizing toxicity. Further large-scale studies are warranted to refine the optimal AUC/MIC threshold
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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