Water Coordination, Proton Mobility, and Lewis Acidity in HY Nanozeolites: A High-Temperature ¹H and ²⁷Al NMR Study

Katsiotis, Marios S.,Fardis, Michael,Al Wahedi, Yasser,Stephen, Samuel,Tzitzios, Vasilios,Boukos, Nikolaos,Kim, Hae Jin,Alhassan, Saeed M.,Papavassiliou, Georgios American Chemical Society 2015 The Journal of Physical Chemistry Part C Vol.119 No.6

<P>A nanosized HY zeolite was synthesized and studied by means of <SUP>1</SUP>H and <SUP>27</SUP>Al NMR during thermal dehydration in the temperature range 20–600 °C. The nanozeolite is comprised of a mixture of well-crystallized ultrathin platelets and octahedral nanocrystals, dressed with pentacoordinated extraframework Al<SUP>(V)</SUP>. <SUP>1</SUP>H NMR spin–lattice (<I>T</I><SUB>1</SUB>) and spin–spin (<I>T</I><SUB>2</SUB>) relaxation measurements in combination with <SUP>27</SUP>Al 3Q-MAS NMR reveal two different interaction paths between water molecules and the nanozeolite solid matrix: (i) water molecules strongly interacting with Al<SUP>(V)</SUP> cations, indicated by the high <I>T</I><SUB>1</SUB>/<I>T</I><SUB>2</SUB> ratio, and (ii) water molecules with amply smaller <I>T</I><SUB>1</SUB>/<I>T</I><SUB>2</SUB> ratio, interacting moderately with Al<SUP>(IV)</SUP> and Al<SUP>(VI)</SUP> cations. Relevant measurements on bulk HY rich in extraframework Al<SUP>(VI)</SUP> show the presence of the second relaxation channel only, indicating that the enhanced water adsorption observed for the nanozeolite originates partly from its extended surface and partly from the Al<SUP>(V)</SUP> decoration. Al<SUP>(IV)</SUP> sites in the nanozeolite appear to be highly resilient during heating, even while the framework starts to collapse and Al<SUP>(VI)</SUP> transforms to Al<SUP>(V)</SUP>. Finally, <SUP>1</SUP>H NMR shows that water protons interact particularly strongly with the Al sites in the nanozeolite at temperatures as high as 500 °C, unveiling the important role of the Al<SUP>(V)</SUP> decoration on this nanocatalyst.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2015/jpccck.2015.119.issue-6/jp513030w/production/images/medium/jp-2014-13030w_0013.gif'></P>

The effect of three-variable viscoelastic foundation on the wave propagation in functionally graded sandwich plates via a simple quasi-3D HSDT

Saeed I. Tahir,Abdelouahed Tounsi,Abdelbaki Chikh,Mohammed A. Al-Osta,Salah U. Al-Dulaijan,Mesfer M. Al-Zahrani 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.4

Earthquake Resistant Design Philosophy seeks (a) no damage, (b) no significant structural damage, and (c) significant structural damage but no collapse of normal buildings, under minor, moderate and severe levels of earthquake shaking, respectively. A procedure is proposed for seismic design of low-rise reinforced concrete special moment frame buildings, which is consistent with this philosophy; buildings are designed to be ductile through appropriate sizing and reinforcement detailing, such that they resist severe level of earthquake shaking without collapse. Nonlinear analyses of study buildings are used to determine quantitatively (a) ranges of design parameters required to assure the required deformability in normal buildings to resist the severe level of earthquake shaking, (b) four specific limit states that represent the start of different structural damage states, and (c) levels of minor and moderate earthquake shakings stated in the philosophy along with an extreme level of earthquake shaking associated with the structural damage state of no collapse. The four limits of structural damage states and the three levels of earthquake shaking identified are shown to be consistent with the performance-based design guidelines available in literature. Finally, nonlinear analyses results are used to confirm the efficacy of the proposed procedure.

Used lubricating oil regeneration by various solvent extraction techniques

SAEED M. AL ZAHRANI,Meilana Dharma Putra 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

The used lubricating oil regeneration using extraction technique has been widely known as one of the cheapest and most competent processes. The best performance of solvent was shown by R-11 as the lowest percent oil losses, followed by CFC-113, MEK, 1-butanol, and 2-propanol. This performance sequence could be also evaluated by method of solubility parameter difference (Es) using Hildebrand and Peng–Robinson EoS approaches. The effectiveness of extraction parameters was also studied. The percent oil losses decreased with the extraction temperature. The values of optimum ratio of solvent to oil obtained by the Es method gave reasonable results compared to the experimental method.

FIXED POINT THEOREMS OF EXTENSION AND MODIFIED EXTENSION α-F-CONTRACTION ON COMPLETE METRIC SPACE

Saeed A. A. Al-Salehi,V.C. Borkar 경남대학교 수학교육과 2024 Nonlinear Functional Analysis and Applications Vol.29 No.2

The concept of an extension $\alpha$-$F$-contraction and it's modified counterpart represents an advancement in the theory of metric space contractions. Through our study of the contraction principles and it's relationship to extension and modified extension, we found different conditions somewhat lengthy. In our paper, we create a development of the conditions for the extension of $\alpha$-$F$-contraction and a modified $\alpha$-$F$-contraction by reducing the conditions and make them easier. Our propose conditions are notably simple and effective. They serve as the foundation for proving theorems and solving examples that belong to our study. Moreover, they have remarkable significance in the condition of mathematical analysis and problem-solving. Thus, we find that these new conditions that we mention in the definitions achieve what is require and through them, we choose $\lambda = 1$ and we choose $\lambda\in(0, 1)$ to clarify our ideas.

Why is Hepatocellular Carcinoma Less Attributable to Viral Hepatitis in Yemen?

Saeed, Nadeem Mohammed,Bawazir, Amen Ahmed,Al-Zuraiqi, Masuod,Al-Negri, Fadhel,Yunus, Faisel Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

The hepatitis B virus (HBV) and the hepatitis C virus (HCV) are still public health problems in Yemen, with older individuals having much higher prevalence than younger generations. However, research on the prevalence of viral hepatitis in association with hepatocellular cancer (HCC) has not yet been undertaken in Yemen. The aim of this study was to determine the prevalence of HBV and HCV infection among HCC patients and to estimate the risk of these infections being associated with the development of HCC. A cross-sectional study was conducted on patients attending oncology outpatient in Sana'a, Yemen, through the period 2008-mid 2010 with confirmed diagnosis of HCC. A total of 88 cases were studied thoroughly with different investigations such as CT-scan, ultrasound, tumour marker, alpha-feto-protein and histopathological biopsy. A structured questionnaire was also applied and physical examination done to assess the general condition of the patients. Statistical package (SPSS version 16) was used for analysis of the data. The mean age of the cases was 61.2 years (${\pm}12.6$) with half over 60 years. There were fewer male patients (36%) compared to females and most (97%) only had basic /no formal education. Seventy nine (89%) were diagnosed as HCC cases with histopathological biopsy while the rest were diagnosed by ultrasound, CT scan, tumour marker, and alpha-feto-protein. Around one-third of the subjects were positive for HBsAg and HCV antibodies. Multivariate analysis showed infection with HCV and use of smoking was associated with HCC diagnosis. Although an association was observed between the occurrence of HCC and viral hepatitis (either HBV or HCV) and cigarette smoking, but the rate of viral infection was lower than what has been reported elsewhere.

Fabrication of g-C3N4 nanosheets on stainless steel mesh for effective separation of oil from water

Al-Kindi Nada Saeed,Marzouqi Faisal Al,Khraisheh Majeda,Kim Younghun,Selvaraj Rengaraj 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.11

Most industries depend mainly on oil and oil-based processes, which resulted in producing large volumes of oily wastewater. One of the most common methods used for the treatment of oily contaminated water is filtration by modified surfaces. In this research g-C3N4 nanostructured material was prepared via thermal condensation method. The samples were characterized by advanced techniques such as XRD, XPS, FTIR scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrophotometry (EDX). The result showed that g-C3N4 were crystallized in tri-s-triazine phases and their mean crystalline sizes of these nanostructures were 12.17 nm. The high-magnification microscopy images show that the morphology of g-C3N4 was nanosheet. A stainless-steel mesh was modified and coated with the prepared g-C3N4 nanostructured materials to be used for the separation of oil and water mixture. Due to the hydro-phobic nature of the modified meshes, oil drops spread over the mesh surface and the water drops form spherical shapes. The most efficient coating among all the modified meshes was g-C3N4, which was functionalized using silane moiety. The separation efficiency of this coated mesh reached 74.87% and it resulted in fast separation. This mesh can separate different types of oil from the oil/water mixture, such as toluene, mineral oil, 2-ethyl-1-hexanol, and n-pentane with good efficiency. Separation was repeated up to 40 times using the same mesh, and the separation efficiency was measured each time.

A new study in Euclid's metric space contraction mapping and pythagorean right triangle relationship

Saeed A.A Al-Salehi,Mohammed M.A. Taleb,V.C. Borkar 한국전산응용수학회 2024 Journal of applied mathematics & informatics Vol.42 No.2

Our study explores the connection between the Pythagorean theorem and the Fixed-point theorem in metric spaces. Both of which center around the concepts of distance transformations and point relationships. The Pythagorean theorem deals with right triangles in Euclidean space, emphasizing distances between points. In contrast, fixed-point theorems pertain to the points that remain unchanged under specific transformations thereby preserving distances. The article delves into the intrinsic correlation between these concepts and presents a novel study in Euclidean metric spaces, examining the relationship between contraction mapping and Pythagorean Right Triangles. Practical applications are also discussed particularly in the context of image compression. Here, the integration of the Pythagorean right triangle paradigm with contraction mappings results in efficient data representation and the preservation of visual data relationships.This illustrates the practical utility of seemingly abstract theories in addressing real-world challenges.

17-alpha hydroxyprogesterone caproate for the prevention of recurrent preterm birth among singleton pregnant women with a prior history of preterm birth: a systematic review and meta-analysis of six randomized controlled trials

( Saeed Baradwan ),( Sahar Hassan Abdulghani ),( Mohammed Abuzaid ),( Khalid Khadawardi ),( Majed Saeed Alshahrani ),( Abdulrahman Al-matary ),( May A. Alrasheed ),( Najlaa Talat Miski ),( Aroob Abdul 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.6

To perform a systematic review and meta-analysis of all randomized controlled trials (RCTs) that investigated the clinical benefits of 17-alpha hydroxyprogesterone caproate (17OHPC) in the prevention of recurrent preterm birth (PTB) among singleton pregnant women with a previous history of PTB. We searched four major databases up till April 2021 and assessed the risk of bias in the included studies. We meta-analyzed various maternal-neonatal endpoints (n=18) and pooled them as mean difference or risk ratio (RR) with 95% confidence interval (CI) using the random-effects model. Six RCTs met the inclusion criteria, comprising 2,573 patients (17OHPC=1,617, control=956). RCTs revealed an overall low risk of bias. The rates of PTB <35 weeks (n=5 RCTs; RR, 0.77; 95% CI, 0.63-0.93; P=0.008), PTB <32 weeks (n=3 RCTs; RR, 0.68; 95% CI, 0.51-0.91; P=0.009), neonates with low birth weight (<2.5 kg) at delivery (n=3 RCTs; RR, 0.63; 95% CI, 0.5-0.79; P<0.001), and neonatal death (n=4 RCTs; RR, 0.41; 95% CI, 0.20-0.84; P=0.02) were significantly reduced in the 17OHPC group compared with the control group. Moreover, 17OHPC treatment correlated with a significantly decreased rate of retinopathy (n=2 RCTs; RR, 0.42; 95% CI, 0.18-0.97; P=0.004). However, there were no significant differences in the rates of neonatal intensive care unit admission, cesarean delivery, and other pretermrelated complications between both the groups. Among singleton pregnant women with a prior history of PTB, 17OHPC may favorably decrease the risks of recurrent PTB and reduce the rate of neonatal death.

Drosophila melanogaster as a Model for Studying Aspergillus fumigatus

( Hadeel Saeed Al-maliki ),( Suceti Martinez ),( Patrick Piszczatowski ),( Joan W. Bennett ) 한국균학회 2017 Mycobiology Vol.45 No.4

Drosophila melanogaster is a useful model organism that offers essential insights into developmental and cellular processes shared with humans, which has been adapted for large scale analysis of medically important microbes and to test the toxicity of heavy metals, industrial solvents and other poisonous substances. We here give a brief review of the use of the Drosophila model in medical mycology, discuss the volatile organic compounds (VOCs) produced by the opportunistic human pathogen, Aspergillus fumigatus, and give a brief summary of what is known about the toxicity of some common fungal VOCs. Further, we discuss the use of VOC detection as an indirect indicator of fungal growth, including for early diagnosis of aspergillosis. Finally, we hypothesize that D. melanogaster has promise for investigating the role of VOCs synthesized by A. fumigatus as possible virulence factors.

Factors Associated with Health-Related Quality of Life among Saudi Patients with Type 2 Diabetes Mellitus: A Cross-Sectional Survey

Ayman A. Al Hayek,Asirvatham A. Robert,Abdulghani Al Saeed,Aus A. Alzaid,Fahad S. Al Sabaan 대한당뇨병학회 2014 Diabetes and Metabolism Journal Vol.38 No.3

Background: Diabetes mellitus (DM) is associated with high mortality, morbidity, poor general health, and loss of health-related quality of life (HRQOL). The objective of the study was to assess the factors associated with HRQOL among patients with type 2 diabetes mellitus (T2DM). Methods: This was a cross sectional study conducted among 283 T2DM patients during June 2011 and September 2012 at a major tertiary hospital in Riyadh, Saudi Arabia. The respondents were purposively and conveniently selected according to their availability during their routine visit to the outpatient clinics and they were interviewed using the Arabic version of the Short-Form 36-item survey (SF-36) to assess the HRQOL. Results: The mean age of the participants was 56.4±13.2 years. Around 63% (178) were males and 37% (105) were females. Glycosylated hemoglobin level was found to be significantly higher among female and HRQOL was higher among male. Respondents who were more than 50 years old had poor HRQOL than less than 50 years age group. Poor economic status, reported diabetic complications and longer duration of diabetes were significantly associated with poor HRQOL. The respondents treated with combination of therapies (oral medication plus insulin) indicated better HRQOL than patients with insulin therapy alone. Multivariate analysis indicated that gender, economic status (except subscale energy), and complications of DM (except subscale energy) as independent risk factor for HRQOL. Conclusion: Gender, economic status, and complication of DM were independent risk factors for majority of the subscales of HRQOL.