scholarly journals Post-synthesis incorporation of Al into germanosilicate ITH zeolites: the influence of treatment conditions on the acidic properties and catalytic behavior in tetrahydropyranylation

2015 ◽  
Vol 5 (5) ◽  
pp. 2973-2984 ◽  
Author(s):  
Mariya V. Shamzhy ◽  
Maksym V. Opanasenko ◽  
Francisca S. de O. Ramos ◽  
Libor Brabec ◽  
Michal Horáček ◽  
...  
Keyword(s):  
Acidic Properties ◽  
Catalytic Behavior ◽  
Treatment Conditions ◽  
Post Synthesis

Tuning of acidity and porosity of ITH germanosilicates by post-synthesis alumination.

Desilication of SSZ-33 zeolite – Post-synthesis modification of textural and acidic properties

2015 ◽  
Vol 243 ◽  
pp. 46-52 ◽  
Author(s):  
Martin Kubů ◽  
Maksym Opanasenko ◽  
Dana Vitvarová
Keyword(s):  
Acidic Properties ◽  
Post Synthesis

Acid Properties of MCM-36 Molecular Sieve and its Catalytic Behavior in Benzene Alkylation with Propylene

2014 ◽  
Vol 1015 ◽  
pp. 434-437 ◽  
Author(s):  
Fei Zhao ◽  
Yu Zhang ◽  
Wen Jing Jiang
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieve ◽  
Acid Sites ◽  
Velocity Space ◽  
Acidic Properties ◽  
Catalytic Behavior ◽  
Benzene Alkylation ◽  
Acid Properties ◽  
Ft Ir ◽  
Excellent Selectivity

Pillared layered MCM-36 zeolite was synthesized from pure MCM-22 precursor with polymeric silica as pillaring agent. Characterization results of acidic properties from FT-IR indicate a decrease in the amounts of Lewis acidic and Brønsted acidic. The catalytic behavior of pillared layered MCM-36 zeolite in benzene alkylation with propylene was studied. It was found that pillared MCM-36 zeolite shows stable catalytic activity in a 200h time-on-stream measurement under a relatively high propylene velocity space. The excellent selectivity to cumene over MCM-36 should be mainly due to the decrease in the amount of Brønsted acidity, while the improvement of the catalytic activity of MCM-36 can be mainly assigned to the presence of a larger amount of structurally accessible acid sites caused by the increment of mesoporous volume in this material.

Characterization and acidic properties of Al-SBA-15 materials prepared by post-synthesis alumination of a low-cost ordered mesoporous silica

2007 ◽  
Vol 180 (3) ◽  
pp. 1130-1140 ◽  
Author(s):  
M. Gómez-Cazalilla ◽  
J.M. Mérida-Robles ◽  
A. Gurbani ◽  
E. Rodríguez-Castellón ◽  
A. Jiménez-López
Keyword(s):  
Mesoporous Silica ◽  
Low Cost ◽  
Ordered Mesoporous Silica ◽  
Acidic Properties ◽  
Ordered Mesoporous ◽  
Post Synthesis

scholarly journals Renewable glycerol esterification over sulfonic-modified mesoporous silicas

2018 ◽  
Vol 83 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Margarita Popova ◽  
Hristina Lazarova ◽  
Agnes Szegedi ◽  
Magdolna Mihályi ◽  
Мojca Rangus ◽  
...  
Keyword(s):  
Mesoporous Materials ◽  
Solid State Nmr ◽  
Value Added ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Gravimetric Analysis ◽  
Acidic Properties ◽  
X Ray ◽  
Post Synthesis ◽  
Glycerol Esterification

SO3H-functionalised mesoporous materials with different pore structures (SBA-15 and SBA-16) were prepared by the post-synthesis surface modification. The materials were thoroughly characterized by X-ray powder diffraction, nitrogen physisorption, temperature-gravimetric analysis, elemental analysis and solid state NMR spectroscopy. The acidic properties were investigated by the temperature-programed desorption of ammonia. The catalytic performance of SO3H-functionalised mesoporous materials was studied in glycerol esterification with acetic acid.The different amount of silanol groups in the initial SBA-15 and SBA-16 silicas predetermined the different amount of propylsulfonic groups which are formed in them and therefore significantly influenced the acidity and the catalytic performance in glycerol esterification. Much higher amount of Br?nsted acid sites was generated in SO3H modified SBA-15 catalyst, which exhibited higher activity to value-added triacetyl glycerol.

Bang for Your Buck: A Single-Case Experimental Design Study of Practice Amount and Distribution in Treatment for Childhood Apraxia of Speech

2019 ◽  
Vol 62 (9) ◽  
pp. 3160-3182 ◽  
Author(s):  
Edwin Maas ◽  
Christina Gildersleeve-Neumann ◽  
Kathy Jakielski ◽  
Nicolette Kovacs ◽  
Ruth Stoeckel ◽  
...  
Keyword(s):  
Single Case ◽  
Evidence Base ◽  
Distributed Practice ◽  
Single Subject ◽  
Single Subject Design ◽  
Apraxia Of Speech ◽  
Childhood Apraxia Of Speech ◽  
Opposite Pattern ◽  
Massed Practice ◽  
Treatment Conditions

Purpose The aim of this study was to examine 2 aspects of treatment intensity in treatment for childhood apraxia of speech (CAS): practice amount and practice distribution. Method Using an alternating-treatments single-subject design with multiple baselines, we compared high versus low amount of practice, and massed versus distributed practice, in 6 children with CAS. Conditions were manipulated in the context of integral stimulation treatment. Changes in perceptual accuracy, scored by blinded analysts, were quantified with effect sizes. Results Four children showed an advantage for high amount of practice, 1 showed an opposite effect, and 1 showed no condition difference. For distribution, 4 children showed a clear advantage for massed over distributed practice post treatment; 1 showed an opposite pattern, and 1 showed no clear difference. Follow-up revealed a similar pattern. All children demonstrated treatment effects (larger gains for treated than untreated items). Conclusions High practice amount and massed practice were associated with more robust speech motor learning in most children with CAS, compared to low amount and distributed practice, respectively. Variation in effects across children warrants further research to determine factors that predict optimal treatment conditions. Finally, this study adds to the evidence base supporting the efficacy of integral stimulation treatment for CAS. Supplemental Material https://doi.org/10.23641/asha.9630599

Optimal Experimental Design With Nesting of Persons in Organizations

2013 ◽  
Vol 221 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Gerard J. P. van Breukelen
Keyword(s):  
Repeated Measures ◽  
Optimal Number ◽  
Health Centers ◽  
Randomized Experiments ◽  
Optimal Sample ◽  
Treatment Conditions ◽  
Sampling Cost ◽  
Nested Designs ◽  
Simple Equations ◽  
Number Of Individuals

This paper introduces optimal design of randomized experiments where individuals are nested within organizations, such as schools, health centers, or companies. The focus is on nested designs with two levels (organization, individual) and two treatment conditions (treated, control), with treatment assignment to organizations, or to individuals within organizations. For each type of assignment, a multilevel model is first presented for the analysis of a quantitative dependent variable or outcome. Simple equations are then given for the optimal sample size per level (number of organizations, number of individuals) as a function of the sampling cost and outcome variance at each level, with realistic examples. Next, it is explained how the equations can be applied if the dependent variable is dichotomous, or if there are covariates in the model, or if the effects of two treatment factors are studied in a factorial nested design, or if the dependent variable is repeatedly measured. Designs with three levels of nesting and the optimal number of repeated measures are briefly discussed, and the paper ends with a short discussion of robust design.

Investigation of Plasma Treatment Conditions for Wafer-Scale Room-Temperature Bonding Using Ultrathin Au Films in Ambient Air

2019 ◽  
Vol 139 (7) ◽  
pp. 217-218
Author(s):  
Michitaka Yamamoto ◽  
Takashi Matsumae ◽  
Yuichi Kurashima ◽  
Hideki Takagi ◽  
Tadatomo Suga ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Room Temperature ◽  
Ambient Air ◽  
Wafer Scale ◽  
Treatment Conditions
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