scholarly journals Oxidation of Ethanol in Cu-Faujasites Studied by IR Spectroscopy

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2669
Author(s):  
Łukasz Kuterasiński ◽  
Jerzy Podobiński ◽  
Jerzy Datka
Keyword(s):  
Ethanol Oxidation ◽  
Produced Water ◽  
Acid Sites ◽  
No Adsorption ◽  
Ir Studies ◽  
Oxygen Donor ◽  
Before And After ◽  
Acetate Formation ◽  
Back Donation

In this study, IR studies of the coadsorption of ethanol and CO on Cu+ cations evidenced the transfer of electrons from ethanol to Cu+, which caused the lowering of the frequency of the band attributed to CO bonded to the same Cu+ cation due to the more effective π back donation of d electrons of Cu to antibonding π* orbitals of CO. The reaction of ethanol with acid sites in zeolite HFAU above 370 K produced water and ethane, polymerizing to polyethylene. Ethanol adsorbed on zeolite Cu(2)HFAU containing acid sites and Cu+exch also produced ethene, but in this case, the ethene was bonded to Cu+ and did not polymerize. C=C stretching, which is IR non-active in the free ethene molecule, became IR active, and a weak IR band at 1538 cm−1 was present. The reaction of ethanol above 370 K in Cu(5)NaFAU zeolite (containing small amounts of Cu+exch and bigger amounts of Cu+ox, Cu2+exch and CuO) produced acetaldehyde, which was further oxidized to the acetate species (CH3COO-). As oxygen was not supplied, the donors of oxygen were the Cu species present in our zeolite. The CO and NO adsorption experiments performed in Cu-zeolite before and after ethanol reaction evidenced that both Cu+ox and Cu2+ (Cu2+exch and CuO) were consumed by the ethanol oxidation reaction. The studies of the considered reaction of bulk CuO and Cu2O as well as zeolites, in which the contribution of Cu+ox species was reduced by various treatments, suggest that ethanol was oxidized to acetaldehyde by Cu2+ox (the role of Cu+ox could not be elucidated), but Cu+ox was the oxygen donor in the acetate formation.

scholarly journals The guiding role of pre-coking on the coke deposition over ZSM-5 in methanol to propylene

2019 ◽  
Vol 6 (9) ◽  
pp. 190218 ◽  
Author(s):  
Lin Wang ◽  
Jing Qi ◽  
Hongqiao Jiao ◽  
Liangcheng An ◽  
Chong Guan ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermogravimetric Analysis ◽  
Methanol Conversion ◽  
Acid Sites ◽  
Coke Deposition ◽  
Steam Treatment ◽  
Elementary Analysis ◽  
Before And After ◽  
Propylene Selectivity

Deposition of carbonaceous compounds was used to improve the propylene selectivity of ZSM-5 by deactivating some acid sites meanwhile maintaining the high activity for methanol conversion. The carbonaceous species of pre-coked samples before and after MTP reactions were investigated by elementary analysis and thermogravimetric analysis (TGA). The results showed that pre-coke formed at low temperature (250°C) was unstable and easy to transform into polyaromatics species at the high reacting temperature, while combining 5% pre-coking process with 95% steam treatment at high temperature (480°C) was effective in inhibiting the formation of coke deposits and presented a significant improvement in the propylene selectivity.

Modelling of catalysts and its relation to experimental problems

1992 ◽  
Vol 341 (1661) ◽  
pp. 255-268 ◽  
Keyword(s):  
Small Molecules ◽  
Active Sites ◽  
Thermal Activation ◽  
Porous Metal ◽  
Acid Sites ◽  
Zeolite Catalysts ◽  
Before And After ◽  
Porous Metal Oxides ◽  
And Diffusion

We illustrate the role of both computer simulation and the evaluation of electronic structure in the study of solid heterogeneous catalysis by reference to recent work in this laboratory on ( a ) microporous materials (that have a spatially uniform distribution of accessible active sites) and ( b ) non-porous metal oxides. Computational methodologies may be used to model, first, the structure of the uniform catalysts both before and after thermal activation, second, the docking and diffusion of molecules in solids and on their surfaces; and, third, the reaction pathways of molecules at the active site. We highlight recent successes in modelling (i) the structures of zeolitic solids, (ii) the sorption of hydrocarbons within them, (iii) the protonation of small molecules at the Bronsted acid sites in uniform solid acid (zeolite) catalysts, and (iv) the reactions of small molecules on CeO 2 and MgO surfaces.

Propane oxydehydrogenation reaction on a VPO/TiO2 catalyst. Role of the nature of acid sites determined by dynamic in-situ IR studies

1996 ◽  
Vol 32 (1-4) ◽  
pp. 57-61 ◽  
Author(s):  
L. Savary ◽  
J. Saussey ◽  
G. Costentin ◽  
M.M. Bettahar ◽  
M. Gubelmann-Bonneau ◽  
...  
Keyword(s):  
Acid Sites ◽  
Tio2 Catalyst ◽  
Ir Studies ◽  
In Situ Ir

Child and Adolescent Suicides in Bosnia and Herzegovina Before and After the War (1992–1995)

Crisis ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 160-164 ◽  
Author(s):  
Almir Fajkic ◽  
Orhan Lepara ◽  
Martin Voracek ◽  
Nestor D. Kapusta ◽  
Thomas Niederkrotenthaler ◽  
...  
Keyword(s):  
Bosnia And Herzegovina ◽  
Age Differences ◽  
Suicide Risk ◽  
Child And Adolescent ◽  
Youth Suicide ◽  
Southeastern Europe ◽  
Suicide Rates ◽  
Before And After ◽  
Sex And Age Differences

Background: Evidence on youth suicides from Southeastern Europe is scarce. We are not aware of previous reports from Bosnia and Herzegovina, which experienced war from 1992 to 1995. Durkheim’s theory of suicide predicts decreased suicide rates in wartime and increased rates afterward. Aims: To compare child and adolescent suicides in Bosnia and Herzegovina before and after the war. Methods: Data on youth suicide for prewar (1986–90) and postwar (2002–06) periods were analyzed with respect to prevalence, sex and age differences, and suicide methods. Suicide data from 1991 through 2001 were not available. Results: Overall youth suicide rates were one-third lower in the postwar than in the prewar period. This effect was most pronounced for girls, whose postwar suicide rates almost halved, and for 15–19-year-old boys, whose rates decreased by about a one-fourth. Suicides increased among boys aged 14 or younger. Firearm suicides almost doubled proportionally and were the predominant postwar method, while the most common prewar method had been hanging. Conclusions: The findings from this study indicate the need for public education in Bosnia and Herzegovina on the role of firearm accessibility in youth suicide and for instructions on safe storage in households. Moreover, raising societal awareness about suicide risk factors and suicide prevention is needed.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

Ethanol Metabolism in Vivo and the Role of Hepatic Microsomal Ethanol Oxidation

1972 ◽  
Vol 33 (3) ◽  
pp. 751-755 ◽  
Author(s):  
Mary K. Roach ◽  
Myrna Khan ◽  
Marguerite Knapp ◽  
W. N. Reese
Keyword(s):  
Ethanol Oxidation ◽  
Ethanol Metabolism

SUBLINGUAL VITAMIN D3 DRUG THERAPY IN VITAMIN D DEFICIENCY PATIENTS AT PRAVARA RURAL HOSPITAL

2019 ◽  
pp. 18-20
Author(s):  
Sanjeeva Kumar Goud T ◽  
Rahul Kunkulol
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D3 ◽  
Serum Vitamin ◽  
Cross Sectional ◽  
Serum Vitamin D ◽  
Significant Difference ◽  
Before And After

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route

Arthroscopy in Arthrosis: Is It Worth it? A case Presentation

2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu
Keyword(s):  
Clinical Status ◽  
Loose Body ◽  
Point Of View ◽  
The Other ◽  
Joint Range Of Motion ◽  
Objective Evidence ◽  
Before And After ◽  
Total Knee ◽  
Joint Range

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.

Study of Possible Relation between Fasting Plasma Glucagon, Gestational Diabetes and Development of Type 2 DM

2020 ◽  
Vol 16 (2) ◽  
pp. 148-155 ◽  
Author(s):  
Ashraf Okba ◽  
Salwa Seddik Hosny ◽  
Alyaa Elsherbeny ◽  
Manal Mohsin Kamal
Keyword(s):  
Gestational Diabetes ◽  
Pregnant Women ◽  
Post Partum ◽  
Plasma Glucagon ◽  
Type 2 Dm ◽  
Fasting Plasma ◽  
Before And After ◽  
Two Phases

Background and Aims: Women who develop GDM (gestational diabetes mellitus) have a relative insulin secretion deficiency, the severity of which may be predictive for later development of diabetes. This study aimed to investigate the role of fasting plasma glucagon in the prediction of later development of diabetes in pregnant women with GDM. Materials and Methods: The study was conducted on 150 pregnant women with GDM after giving informed oral and written consents and being approved by the research ethical committee according to the declaration of Helsinki. The study was conducted in two phases, first phase during pregnancy and the second one was 6 months post-partum, as we measured fasting plasma glucagon before and after delivery together with fasting and 2 hour post-prandial plasma sugar. Results: Our findings suggested that glucagon levels significantly increased after delivery in the majority 14/25 (56%) of GDM women who developed type 2 DM within 6 months after delivery compared to 6/20 (30%) patients with impaired fasting plasma glucose (IFG) and only 22/105 (20%) non DM women, as the median glucagon levels were 80,76, 55, respectively. Also, there was a high statistical difference between fasting plasma glucagon post-delivery among diabetic and non-diabetic women (p ≤ 0.001). These results indicated the useful role of assessing fasting plasma glucagon before and after delivery in patients with GDM to predict the possibility of type 2 DM. Conclusion: There is a relatively high glucagon level in GDM patients, which is a significant pathogenic factor in the incidence of subsequent diabetes in women with a history of GDM. This could be important in the design of follow-up programs for women with previous GDM.

Sleep Problems During the Preschool Years and Beyond as a Marker of Risk and Resilience in Substance Use

2018 ◽  
Author(s):  
Maria M. Wong
Keyword(s):  
Substance Use ◽  
Alcohol Use ◽  
Sleep Problems ◽  
Problem Drinking ◽  
Alcohol Problems ◽  
Risk And Resilience ◽  
Regulatory Processes ◽  
Sleep Physiology ◽  
Before And After

Individuals with alcohol problems have well-described disturbances of sleep, but the development of these disturbances both before and after the onset of problem drinking is poorly understood. This chapter first discusses sleep physiology and its measurement in humans. It then examines the functions of sleep and its role in development. Next, it reviews recent research on the relationship between sleep and alcohol use and related problems. Whereas sleep problems (e.g., difficulties falling or staying asleep) increase the risk of early onset of alcohol use and related problems, sleep rhythmicity promotes resilience to the development of alcohol use disorder and problem substance use. Based on existing research, this chapter proposes a theoretical model of sleep and alcohol use, highlighting the role of self-regulatory processes as mediators of this relationship.

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