scholarly journals Adsorption of Selected Pharmaceutical Compounds onto Activated Carbon in Dilute Aqueous Solutions Exemplified by Acetaminophen, Diclofenac, and Sulfamethoxazole

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
E.-E. Chang ◽  
Jan-Chi Wan ◽  
Hyunook Kim ◽  
Chung-Huei Liang ◽  
Yung-Dun Dai ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Effective Diffusion ◽  
Molecular Size ◽  
Adsorption Affinity ◽  
Water Partition Coefficient ◽  
Component Systems ◽  
Dilute Aqueous Solutions ◽  
Multiple Component ◽  
The One ◽  
Selection Of

The adsorption of three pharmaceuticals, namely, acetaminophen, diclofenac, and sulfamethoxazole onto granular activated carbon (GAC), was investigated. To study competitive adsorption, both dynamic and steady-state adsorption experiments were conducted by careful selection of pharmaceuticals with various affinities and molecular size. The effective diffusion coefficient of the adsorbate was increased with decease in particle size of GAC. The adsorption affinity represented as Langmuir was consistent with the ranking of the octanol-water partition coefficient,Kow. The adsorption behavior in binary or tertiary systems could be described by competition adsorption. In the binary system adsorption replacement occurred, under which the adsorbate with the smallerKowwas replaced by the one with largerKow. Results also indicated that portion of the micropores could be occupied only by the small target compound, but not the larger adsorbates. In multiple-component systems the competition adsorption might significantly be affected by the macropores and less by the meso- or micropores.

scholarly journals Insights into Equilibrium and Adsorption Rate of Phenol on Activated Carbon Pellets Derived from Cigarette Butts

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 934
Author(s):  
Nahum A. Medellín-Castillo ◽  
Raúl Ocampo-Pérez ◽  
Angélica Forgionny ◽  
Gladis J. Labrada-Delgado ◽  
Ana I. Zárate-Guzmán ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Effective Diffusion ◽  
Chemical Properties ◽  
Molecular Size ◽  
Maximum Adsorption Capacity ◽  
Leaching Tests ◽  
Solution Ph ◽  
Microporous Material ◽  
Cigarette Butts ◽  
Carbon Pellets

In the present work, the preparation of activated carbon pellets from cigarette butts by thermal treatment was evaluated. The morphological, textural, topological, and surface chemical properties were studied by SEM-EDX, N2 adsorption, Raman, and FTIR spectroscopy. For adsorption assays, activated carbon was tested for the adsorption of phenol as a model molecule at different solution pH, temperature, and type of water. In addition, leaching tests before and after carbonization were conducted to evaluate the lixiviation of ions present in the solid. The results revealed a microporous material, composed of cylindrical fibers (thickness of 13 µm) with a microporous area of 713 m2/g and narrow and uniform slit-shaped pores (0.4–0.8 nm). The surface chemistry analysis evidenced the presence of oxygenated groups (carboxylic, esters, and phenolics). Activated carbon leaching tests indicated that the concentrations of the leached ions did not exceed the maximum permissible limit for drinking water. Phenol adsorption revealed an exothermic process with a maximum adsorption capacity of 272 mg/g at 10 °C. Finally, it was confirmed that phenol diffusion was drastically affected by hindered phenomena due to the similarity in the molecular size of phenol and the average size of micropores, and as a result an effective diffusion coefficient between 6.10 × 10−0 and 5.50 × 10−12 cm2/s and a maximum tortuosity value of 3.3 were obtained.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Costumes and Choreography from Bodenwieser's Trunk: The Coat as Affective Memory

2019 ◽  
Vol 37 (1) ◽  
pp. 89-110
Author(s):  
Rachel Fensham
Keyword(s):  
Modern Dance ◽  
Human Condition ◽  
Personal Life ◽  
Creative Thought ◽  
Cain And Abel ◽  
Embodied Research ◽  
The Many ◽  
The One ◽  
Material Evidence ◽  
Selection Of

The Viennese modern choreographer Gertrud Bodenwieser's black coat leads to an analysis of her choreography in four main phases – the early European career; the rise of Nazism; war's brutality; and postwar attempts at reconciliation. Utilising archival and embodied research, the article focuses on a selection of Bodenwieser costumes that survived her journey from Vienna, or were remade in Australia, and their role in the dramaturgy of works such as Swinging Bells (1926), The Masks of Lucifer (1936, 1944), Cain and Abel (1940) and The One and the Many (1946). In addition to dance history, costume studies provides a distinctive way to engage with the question of what remains of performance, and what survives of the historical conditions and experience of modern dance-drama. Throughout, Hannah Arendt's book The Human Condition (1958) provides a critical guide to the acts of reconstruction undertaken by Bodenwieser as an émigré choreographer in the practice of her craft, and its ‘materializing reification’ of creative thought. As a study in affective memory, information regarding Bodenwieser's personal life becomes interwoven with the author's response to the material evidence of costumes, oral histories and documents located in various Australian archives. By resurrecting the ‘dead letters’ of this choreography, the article therefore considers how dance costumes offer the trace of an artistic resistance to totalitarianism.

PROMETHEE-based ranking of project managers based on the five personality traits

Kybernetes ◽  
2019 ◽  
Vol 49 (4) ◽  
pp. 1083-1102
Author(s):  
Georgios N. Aretoulis ◽  
Jason Papathanasiou ◽  
Fani Antoniou
Keyword(s):  
Personality Traits ◽  
Questionnaire Survey ◽  
Multicriteria Decision Making ◽  
Project Managers ◽  
Preference Ranking ◽  
Infrastructure Projects ◽  
Public Infrastructure ◽  
Content Type ◽  
The One ◽  
Selection Of

Purpose This paper aims to rank and identify the most efficient project managers (PMs) based on personality traits, using Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEE) methodology. Design/methodology/approach The proposed methodology relies on the five personality traits. These were used as the selection criteria. A questionnaire survey among 82 experienced engineers was used to estimate the required weights per personality trait. A second two-part questionnaire survey aimed at recording the PMs profile and assess the performance of personality traits per PM. PMs with the most years of experience are selected to be ranked through Visual PROMETHEE. Findings The findings suggest that a competent PM is the one that scores low on the “Neuroticism” trait and high especially on the “Conscientiousness” trait. Research limitations/implications The research applied a psychometric test specifically designed for Greek people. Furthermore, the proposed methodology is based on the personality characteristics to rank the PMs and does not consider the technical skills. Furthermore, the type of project is not considered in the process of ranking PMs. Practical implications The findings could contribute in the selection of the best PM that maximizes the project team’s performance. Social implications Improved project team communication and collaboration leading to improved project performance through better communication and collaboration. This is an additional benefit for the society, especially in the delivery of public infrastructure projects. A lot of public infrastructure projects deviate largely as far as cost and schedule is concerned and this is an additional burden for public and society. Proper project management through efficient PMs would save people’s money and time. Originality/value Identification of the best PMbased on a combination of multicriteria decision-making and psychometric tests, which focus on personality traits.

scholarly journals Gradient boosting for linear mixed models

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Colin Griesbach ◽  
Benjamin Säfken ◽  
Elisabeth Waldmann
Keyword(s):  
Random Effects ◽  
Mixed Models ◽  
Selection Procedure ◽  
Classification Theory ◽  
Gradient Boosting ◽  
Random Structure ◽  
Boosting Algorithm ◽  
The One ◽  
Biased Estimates ◽  
Selection Of

Abstract Gradient boosting from the field of statistical learning is widely known as a powerful framework for estimation and selection of predictor effects in various regression models by adapting concepts from classification theory. Current boosting approaches also offer methods accounting for random effects and thus enable prediction of mixed models for longitudinal and clustered data. However, these approaches include several flaws resulting in unbalanced effect selection with falsely induced shrinkage and a low convergence rate on the one hand and biased estimates of the random effects on the other hand. We therefore propose a new boosting algorithm which explicitly accounts for the random structure by excluding it from the selection procedure, properly correcting the random effects estimates and in addition providing likelihood-based estimation of the random effects variance structure. The new algorithm offers an organic and unbiased fitting approach, which is shown via simulations and data examples.

scholarly journals A comparison of two methods for predicting changes in the distribution of gene frequency when selection is applied repeatedly to a finite population

1969 ◽  
Vol 13 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Derek J. Pike
Keyword(s):  
Iterative Procedure ◽  
Gene Frequency ◽  
Finite Population ◽  
Transition Matrices ◽  
Single Cycle ◽  
Gene Frequencies ◽  
Mean And Variance ◽  
The Mean ◽  
The One ◽  
Selection Of

Robertson (1960) used probability transition matrices to estimate changes in gene frequency when sampling and selection are applied to a finite population. Curnow & Baker (1968) used Kojima's (1961) approximate formulae for the mean and variance of the change in gene frequency from a single cycle of selection applied to a finite population to develop an iterative procedure for studying the effects of repeated cycles of selection and regeneration. To do this they assumed a beta distribution for the unfixed gene frequencies at each generation.These two methods are discussed and a result used in Kojima's paper is proved. A number of sets of calculations are carried out using both methods and the results are compared to assess the accuracy of Curnow & Baker's method in relation to Robertson's approach.It is found that the one real fault in the Curnow-Baker method is its tendency to fix too high a proportion of the genes, particularly when the initial gene frequency is near to a fixation point. This fault is largely overcome when more individuals are selected. For selection of eight or more individuals the Curnow-Baker method is very accurate and appreciably faster than the transition matrix method.

Recent progress in the freeze-etching technique

1971 ◽  
Vol 261 (837) ◽  
pp. 121-131 ◽  
Keyword(s):  
High Vacuum ◽  
Molecular Size ◽  
Etching Technique ◽  
Structural Distortions ◽  
Shadow Casting ◽  
Structural Details ◽  
Freeze Etching ◽  
The One ◽  
Insight Into ◽  
Made In

The freeze-etching technique must be improved if structures at the molecular size level are to be seen. The limitations of the technique are discussed here together with the progress made in alleviating them. The vitrification of living specimens is limited by the fact that very high freezing rates are needed. The critical freezing rate can be lowered on the one hand by the introduction of antifreeze agents, on the other hand by the application of high hydrostatic pressure. The fracture process may cause structural distortions in the fracture face of the frozen specimen. The ‘double-replica’ method allows one to evaluate such artefacts and provides an insight into the way that membranes split. During etching there exists the danger of contaminating the fracture faces with condensable gases. Because of specimen temperatures below —110 °C, special care has to be taken in eliminating water vapour from the high vacuum. An improvement in coating freeze-etched specimens has resulted from the application of electron guns for evaporation of the highest melting-point metals. If heat transfer from gun to specimen is reduced to a minimum, Pt, Ir, Ta, W and C can be used for shadow casting. Best results are obtained with Pt-C and Ta-W . With the help of decoration effects Pt-C shadow castings give the most information about the fine structural details of the specimen.

A Novel Hydroxyapatite Carrier for Enrichment of Hydrocarbon Degradation Bacteria

2007 ◽  
Vol 336-338 ◽  
pp. 1914-1917
Author(s):  
Lei Yang ◽  
Zhen Yi Zhang ◽  
Xiao Shan Ning ◽  
Guang He Li
Keyword(s):  
Activated Carbon ◽  
Sol Gel ◽  
Hydrocarbon Degradation ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bacterial Enrichment ◽  
Bet Method ◽  
The One ◽  
Scanning Electron

In this paper, a novel and highly efficient hydroxyapatite (HA) carrier for cultivating hydrocarbon degradation bacteria (HDB) is introduced. The HA particles synthesized through a sol-gel method and different heat treatments were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET method. The microbial amount and activities of HDB cultivated on HA carriers were quantitatively investigated in order to assess their enriching capabilities. The results showed that HA synthesized at 550°C and the one without calcination could enrich HDB 3 and 2 magnitude orders more than the activated carbon, respectively. Mechanisms of bacterial enrichment on HA and activated carbon were also studied, and it is believed that the high bioactivity and the surface morphology of HA were responsible for the efficient reproduction of HDB. It is concluded that HA is a potential candidate to replace the conventionally used activated carbon as a novel carrier applied in the filed of bioremediation for oil contaminated soil.

PERCUTANEOUS RENAL BIOPSY IN CHILDREN

PEDIATRICS ◽  
1962 ◽  
Vol 30 (2) ◽  
pp. 287-296
Author(s):  
W. F. Dodge ◽  
C. W. Daeschner ◽  
J. C. Brennan ◽  
H. S. Rosenberg ◽  
L. B. Travis ◽  
...  
Keyword(s):  
Renal Disease ◽  
Renal Biopsy ◽  
Clinical Importance ◽  
Renal Diseases ◽  
Renal Lesion ◽  
Bleeding Tendency ◽  
Percutaneous Renal Biopsy ◽  
The One ◽  
Selection Of

Since 1951, when the percutaneous renal biopsy was introduced as an adjunctive method for study of patients with renal disease, reports of some 4,000 kidney biopsies have appeared in the literature. Only about 250 of these, however, have been performed in children. A biopsy specimen containing 5 to 10 glomeruli has been reported to be adequate for interpretation and to be representative of the total renal parenchyma in 84% of the cases with diffuse renal disease. Using a biopsy technique similar to that described by Kark, we have obtained an adequate specimen in 92% of 205 kidney biopsies performed in 168 children with diffuse renal diseases. Seven deaths have been previously reported in the literature. The circumstances surrounding the death of these seven patients and of the one death that occurred in our series are described. Perirenal hematoma has had a reported incidence of 0.4%. It has been our experience, as well as that of the other investigators, that if blood boss is replaced, the patient has an otherwise uneventful course and the mass subsequently disappears. Gross hematuria has had a reported incidence of 5.2%. Microscopic hematuria, lasting for 6 to 12 hours after biopsy, has been found to be the rule rather than the exception. The complications which have occurred have been associated with bleeding, and therefore a careful history concerning bleeding tendency and a study of the clotting mechanism is essential if the risk of needle renal biopsy is to be minimized. In addition to a bleeding tendency or defect in clotting mechanism, most investigators are agreed that the presence of only one kidney or an uncooperative patient are absolute contraindications to renal biopsy. The renal biopsy is primarily, at present, an additional and most useful investigative tool in the elucidation of the pathogenesis, natural history (by serial studies) and effectiveness of specific therapy upon the various renal diseases. It is of practical clinical importance in the selection of those patients with the nephrotic syndrome in whom glucocorticoid therapy is likely to be beneficial or the patient with anuria whose renal lesion is probably reversible with time; and, as a guide to the effectiveness of therapy in patients with pyelonephritis or lupus nephritis. It is not a technique that can be recommended for general or casual use. A classification of the pathohistobogic findings of diffuse glomerulonephritis, patterned after Ellis, is presented and discussed. This classification will be used in the description and discussion of various renal diseases and systemic diseases with associated nephritis in the three subsequent papers.

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