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Jelwan J.,Holy Spirit University of Kaslik
Journal of Applied Mechanics and Technical Physics | Year: 2017

This paper re-examines the creep life methodology based on the continuum damage mechanics (CDM) of the Kachanov and Rabotnov theory. Uniaxial creep and multiaxial creep rupture formulations are presented taking into account the primary creep effect. The scalar damage parameter is computed up to time-to-rupture as a function of time and stress. The methodology implemented is based on the uniaxial time-to-rupture obtained experimentally. The times-to-rupture for bars with different notches are calculated. It is demonstrated that the use of the damage parameter is vital to indicate the critical damage location where failure occurs. Results are compared to those obtained experimentally. It is shown that the primary creep inclusion has a significant effect on the damage distribution zone. © 2017, Pleiades Publishing, Ltd.

Karavetian M.,Maastricht University | de Vries N.,Maastricht University | Rizk R.,Holy Spirit University of Kaslik | Elzein H.,Lebanese National Kidney Registry
Nutrition Reviews | Year: 2014

Strategies to enhance knowledge of and adherence to dietary guidelines for management of hyperphosphatemia in hemodialysis patients have been studied extensively over the past decade. This review is the first to compile all of them (2003-2013) and conduct a meta-analysis through calculation of effect size, with the aim of identifying the optimal nutrition education methods for effective management of hyperphosphatemia in hemodialysis patients. The following strategies were identified as being effective in changing dietary behavior: 1) use of self-evaluation and self-regulation techniques within educational tools, along with easy-to-apply skills; 2) individualized counseling by a renal dietitian provided just before the hemodialysis session; 3) high-intensity education; and 4) long duration of interventions. Future studies should focus on conducting randomized controlled trials with powered samples to help generate stronger evidence. © 2014 International Life Sciences Institute.

De Laat J.,University of Poitiers | Dao Y.H.,University of Poitiers | Hamdi El Najjar N.,University of Poitiers | Daou C.,Holy Spirit University of Kaslik
Water Research | Year: 2011

The decomposition rate of H 2O 2 by iron(III)-nitrilotriacetate complexes (Fe IIINTA) has been investigated over a large range of experimental conditions: 3 < pH < 11, [Fe(III)] T,0: 0.05-1 mM; [NTA] T,0/[Fe(III)] T,0 molar ratios: 1-250; [H 2O 2] 0: 1 mM-4 M) and concentrations of HO radical scavengers: 0-53 mM. Spectrophotometric analyses revealed that reactions of H 2O 2 with Fe IIINTA (1 mM) at neutral pH immediately lead to the formation of intermediates (presumably peroxocomplexes of Fe IIINTA) which absorb light in the region 350-600 nm where Fe IIINTA and H 2O 2 do not absorb. Kinetic experiments showed that the decomposition rates of H 2O 2 were first-order with respect to H 2O 2 and that the apparent first-order rate constants were found to be proportional to the total concentration of Fe IIINTA complexes, were at a maximum at pH 7.95 ± 0.10 and depend on the [NTA] T,0/[Fe(III)] T,0 and [H 2O 2] 0/[Fe(III)] T,0 molar ratios. The addition of increasing concentrations of tert-butanol or sodium bicarbonate significantly decreased the decomposition rate of H 2O 2, suggesting the involvement of HO radicals in the decomposition of H 2O 2. The decomposition of H 2O 2 by Fe IIINTA at neutral pH was accompanied by a production of dioxygen and by the oxidation of NTA. The degradation of the organic ligand during the course of the reaction led to a progressive decomplexation of Fe IIINTA followed by a subsequent precipitation of iron(III) oxyhydroxides and by a significant decrease in the catalytic activity of Fe(III) species for the decomposition of H 2O 2. © 2011 Elsevier Ltd.

This paper examines the return and volatility linkages between oil prices and the Lebanese stock market by applying the newly developed VAR-GARCH (Vector Autoregressive-Generalized Autoregressive Conditional Heteroskedasticity) model to weekly data from 30 January 1998 to 30 May 2014. To better understand the impact of the global financial crisis, we divide the data into three sub-periods: the pre-crisis period (02 February 1998-28 December 2007), the crisis period (02 January 2008-30 June 2009), and the post-crisis period (01 July 2009-30 May 2014). Contrary to previous studies showing the two-way transmission of return and volatility from oil prices to the stock markets of oil-exporting countries, our empirical results for the whole period reveal weak unidirectional return and volatility transmissions from oil prices to the Lebanese stock market. While the interrelationship between oil prices and Lebanese stocks increased during the crisis, it eased significantly in the post-crisis period. Our empirical results are important for policymakers involved in shock prevention and for portfolio managers seeking optimal portfolio allocation. © 2015 Elsevier Ltd.

Hage F.E.,Holy Spirit University of Kaslik | Durgeau A.,Integrated Research Cancer Institute in Villejuif | Mami-Chouaib F.,Integrated Research Cancer Institute in Villejuif
Annals of the New York Academy of Sciences | Year: 2013

We identified that the antigen preprocalcitonin (ppCT) is recognized on a human lung carcinoma by a cytotoxic T lymphocyte clone derived from autologous tumor-infiltrating lymphocytes. The antigenic peptide ppCT16-25 is encoded by the gene calcitonin-related polypeptide alpha (CALCA), which codes for CT and is overexpressed in several lung carcinomas compared with normal tissues. The ppCT peptide is derived from the C-terminal region of the signal peptide and is processed independently of proteasomes and the transporter associated with antigen processing (TAP)1/TAP2 heterodimeric complexes. Instead, processing occurs within the endoplasmic reticulum by a novel mechanism involving signal pepsidase (SP) and signal peptide peptidase (SPP). Although lung cancer cells bearing the ppCT16-25 epitope displayed low levels of TAP, restoration of TAP expression by interferon (IFN)-γ treatment or by TAP1/TAP2 gene transfer inhibited ppCT antigen presentation. Thus, the ppCT16-25 human tumor epitope requires low TAP expression for efficient presentation. These results indicate that emerging SP-generated peptides represent alternative T cell targets that permit cytotoxic T lymphocytes to destroy TAP-impaired tumors, a process that helps to overcome tumor escape from CD8+ T cell immunity. Additionally, our data suggest that ppCT is a promising candidate for cancer immunotherapy. © 2013 The New York Academy of Sciences.

Bouri E.,Holy Spirit University of Kaslik
Energy Economics | Year: 2015

The role of oil price volatility in predicting the stock-market volatility of small oil-importing countries that have a substantial number of investors from neighboring oil-exporting countries remains unexplored. To refine our basic understanding of this role, this paper proposes a methodological extension of the recently developed causality-in-variance procedure and considers the case of Lebanon and Jordan. These two heavy importers of oil are interesting in the sense that they are located in a region with a large number of rich oil-exporting countries, so their stock markets are tied to oil-exporters by way of foreign investors. The conditional mean and variance of returns are modeled within an ARMAX-GARCH framework that accommodates three salient features of the data, namely: autocorrelation, day-of-the-week effects, and movements in international markets. For comparison purposes, the stock markets of Morocco and Tunisia are also included in the study. Empirical analyses highlight the dynamic effects of the global financial crisis on the volatility spillovers between oil and the stock markets of oil-importing countries and provide more insights into the seemingly contradictory effects of being oil-importers while having investors from oil-exporting countries. The main results indicate that the volatility spillover is much more apparent from the world oil market to the stock market of Jordan than the other way around, whereas oil volatility is not a good predictor of Lebanese stock market volatility. Finally, policy/practical implications and conclusions for future research are drawn. © 2015 Elsevier B.V.

Matar S.F.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Pottgen R.,University of Munster | Ouaini N.,Holy Spirit University of Kaslik
Solid State Sciences | Year: 2012

The electronic structure of the ternary silicide LiYSi (ZrNiAl type, P62m N°189, a = 702.3, c = 421.2 pm) is examined from ab initio with an assessment of the properties of chemical bonding. The compound is found semi-conducting with a very small gap and the chemical bonding is found mainly between Y and Si as well as Li-Si with differentiated Li-Si1/Li-Si2. The structure with totally de-intercalated Li keeps the characteristics of LiYSi with a reduction of the c/a ratio and of the volume albeit with less stability than binary YSi with orthorhombic CrB type structure. The electronic structure calculations indicate the possibility of an at least partial delithiation Li 1-xYSi while keeping the hexagonal structure. © 2011 Elsevier Masson SAS. All rights reserved.

Fares C.,Holy Spirit University of Kaslik
3rd International Conference on Digital Information Processing and Communications, ICDIPC 2013 | Year: 2013

In this paper we are presenting an intelligent system to extract objects in an image. We have to specify the shapes that need to be detected as well as its dimensions. Examples are given in the radar application in order to detect license plate in a radar image. A comparative study is done in order to show the most effective contour detection method for this application. The masks used for this comparison are: Sobel, Canny, Prewitt, Roberts, Log and Zerocorss. The study shows that Sobel is the most effective for such type of applications. Then three methods were used for the object extraction. Two known methods were used: Hough Transform and Watershed. The third method is a new Hybrid Segmentation algorithm. Results show that the proposed algorithm is the fastest with a time of execution of 0.8 seconds for images of size 658x486 pixels. © 2013 SDIWC.

Marx F.,Orange S.A. | Farah J.,Holy Spirit University of Kaslik
IEEE Vehicular Technology Conference | Year: 2015

In this paper, we present a novel iterative approach for canceling the phase noise generated by imperfect local oscillators in Orthogonal Frequency Division Multiplexing receivers. After the cancellation of Common Phase Error (CPE), an iterative technique is introduced which estimates Inter-Carrier Interference (ICI) components in the frequency domain and cancels their contribution in the time domain. Simulations are conducted in order to investigate the influence of several parameters, such as the modulation scheme, the number of carriers and the phase noise bandwidth on the system's performance. Channel coding is used in conjunction with our iterative algorithm, for the correction of residual errors. Simulation results are presented for the case of AWGN and multi-path fading channels. © 2005 IEEE.

Within the new developed causality-in-variance approach, this paper builds up a broad methodological framework to more accurately capture the risk spillover effects between global oil prices and Jordanian stock market returns during the period 1 March 2003-31 January 2014. The sample period is divided, on the basis of the 2008 financial crisis, into pre-crisis and post-crisis periods. Results for the pre-crisis period show a lack of risk spillovers between global oil and the Jordanian stock market. After the crisis, however, we find evidence for one-way risk spillover running from the oil market. These findings have implications for the design of appropriate asset allocation and regulatory policies to manage risk spillover effects. © 2015 Elsevier Ltd.

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