Synergistic Effect of Starch on the Antibacterial Activity of Honey

Laid Boukraa,Karim Amara 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.1

The role of amylase present in honey in enhancing its antibacterial activity was evaluated in the presence andabsence of starch. Two strains of pathogenic bacteria have been used: Staphylococcus aureusand Escherichia coli. For S. au-reus, the minimum inhibitory concentration (MIC) for the three varieties of honey tested without starch was 11%, 24%, and29% (vol/vol), respectively. When starch was added with honey to the media the MIC obtained was 5%, 19%, and 25%(vol/vol), respectively. For E. coli, the MIC for the three varieties without starch was 23%, 28%, and 25% (vol/vol), respec-tively. When starch was added with honey to media, the MIC was 19%, 26%, and 23% (vol/vol), respectively. It is specu-lated that the amylase present in honey hydrolyzed the starch chains to randomly produce dextrin and maltose and that thisincreased the osmotic effect of the media, which consequently increased the antibacterial activity.

Theoretical buckling analysis of inhomogeneous plates under various thermal gradients and boundary conditions

Laid Lekouara,Belgacem Mamen,Abdelhakim Bouhadra,Abderahmane Menasria,Kouider Halim Benrahou,Abdelouahed Tounsi,Mohammed A. Al-Osta 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.86 No.4

This study investigates the theoretical thermal buckling analyses of thick porous rectangular functionally graded (FG) plates with different geometrical boundary conditions resting on a Winkler-Pasternak elastic foundation using a new higherorder shear deformation theory (HSDT). This new theory has only four unknowns and involves indeterminate integral variables in which no shear correction factor is required. The variation of material properties across the plate’s thickness is considered continuous and varied following a simple power law as a function of volume fractions of the constituents. The effect of porosity with two different types of distribution is also included. The current formulation considers the Von Karman nonlinearity, and the stability equations are developed using the virtual works principle. The thermal gradients are involved and assumed to change across the FG plate’s thickness according to nonlinear, linear, and uniform distributions. The accuracy of the newly proposed theory has been validated by comparing the present results with the results obtained from the previously published theories. The effects of porosity, boundary conditions, foundation parameters, power index, plate aspect ratio, and side-to-thickness ratio on the critical buckling temperature are studied and discussed in detail.

Additive Action of Royal Jelly and Honey Against Staphylococcus aureus

Laid Boukraa,Abdellatif Niar,Hama Benbarek,Mokhtar Benhanifia 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.1

Four varieties of honey and one variety of freshly reaped royal jelly (RJ) were used to evaluate their additiveaction against Staphylococcus aureus(ATCC 29523). In a first step honey and RJ were used separately to determine theirminimum inhibitory concentration (MIC) against the tested strain. In a second step, lower concentrations of honey than theMIC were added to lower concentrations of RJ than the MIC and then incorporated into media to determine the minimum ad-ditive inhibitory concentration. When tested separately, the MIC of the four varieties of honey ranged between 20% and 21%(vol/vol), and that of RJ was 2% (vol/vol). When used jointly, all honey varieties had a more than 50% decrease in MIC with1% (vol/vol) RJ. A strong linear correlation was noted between the MIC decrease of all varieties of honey and RJ.

Sahara Honey Shows Higher Potency Against Pseudomonas aeruginosa Compared to North Algerian Types of Honey

Laid Boukraa,Abdellatif Niar 한국식품영양과학회 2007 Journal of medicinal food Vol.10 No.4

Six varieties of honey from different regions in Algeria were used to determine their potency againstPseudomonas aeruginosa. Four varieties originated from northern Algeria, and two from the Sahara. Three types of mediawere used. On nutrient agar the minimum inhibitory concentration (MIC) of the four northern varieties ranged between 30%(vol/vol) and 31% (vol/vol), while the MIC of the Sahara varieties was 11% (vol/vol) and 14% (vol/vol). On King A agar theMIC of the four northern varieties ranged from 25% (vol/vol) to 31% (vol/vol), whereas the MIC of the two varieties of Sa-hara honey was 12% (vol/vol) and 15% (vol/vol). On nutrient broth the MIC of the northern varieties ranged from 10%(vol/vol) to 21% (vol/vol), whereas the MIC of the two varieties of Sahara honey was 9% (vol/vol). The botanic flora of Sa-hara is known in Algeria for its medicinal uses, and thus the higher potency of the Sahara honey is most probably due to an-tibacterial substances in its plant derivates. These findings suggest that Sahara honey could be used for managing wounds andburns, which are mostly infected by P. aeruginosa.

NEW CONGRUENCES WITH THE GENERALIZED CATALAN NUMBERS AND HARMONIC NUMBERS

Elkhiri, Laid,Koparal, Sibel,Omur, Nese Korean Mathematical Society 2021 대한수학회보 Vol.58 No.5

In this paper, we give new congruences with the generalized Catalan numbers and harmonic numbers modulo p². One of our results is as follows: for prime number p > 3, $${\sum\limits_{k=(p+1)/2}^{p-1}}\;k^2B_{p,k}B_{p,k-(p-1)/2}H_k{\equiv}(-1)^{(p-1)/2}\(-{\frac{521}{36}}p-{\frac{1}{p}}-{\frac{41}{12}}+pH^2_{3(p-1)/2}-10pq^2_p(2)+4\({\frac{10}{3}}p+1\)q_p(2)\)\;(mod\;p^2),$$ where q_p(2) is Fermat quotient.

Exploring novel approaches for estimating fractional stochastic processes through practical applications

Nabil Laiche,Laid Gasmi,Raman Vinoth,Halim Zeghdoudi 한국전산응용수학회 2024 Journal of applied mathematics & informatics Vol.42 No.2

In this paper, our primary focus revolves around the examination of a set of fractional stochastic models. Through our investigation, we can establish the presence of a solution and its distinctiveness. Additionally, we employ a moment-based algorithm to estimate the coefficients within these models and provide evidence that these estimations maintain their asymptotic characteristics. To support this claim, we conduct experimental studies using simulations and numerical examples.

Flexural behaviour of reinforced low-strength concrete beams strengthened with CFRP plates

Boukhezar, Mohcene,Samai, Mohamed Laid,Mesbah, Habib Abdelhak,Houari, Hacene Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

This paper summarises the results of an experimental study to investigate the flexural behaviour of reinforced concrete beams strengthened using carbon-fibre reinforced polymer (CFRP) laminate in four-point bending. The experimental parameters included are the reinforcing bar ratio ${\rho}_s$ and preload level. Four bar ratios were selected (${\rho}_s=0.13$ to 0.86%), representing the section of two longitudinal tensile reinforcements, with diameters of 8, 14, 16, and 20 mm in order to reveal the effect of bar ratio on failure load and failure mode. Eight beams that could be considered "full-scale" in size, measuring 200 mm in width, 400 mm in total height and 2300 mm in length, were tested. Three beams were selected with different bar ratios (${\rho}_1$, ${\rho}_2$, ${\rho}_3$), and considered as control specimens (without ), while three other beams identical to the control beams with the same CFRP laminates ratio and a seventh beam with ${\rho}_{min}$ (the lowest bar ratio) were also used. In the second part of the study, two beams with the bar ratio ${\rho}_2$ were preloaded at two levels, 50 and 100% of their ultimate loads, and then repaired. This experimental investigation was consolidated using an analytical model. The experimental and analytical results indicate that the flexional capacity and stiffness of strengthened and repaired beams using CFRP laminate were increased compared to those of control beams, and the behaviour of repaired beams was nearly similar to the undamaged and strengthened beams; unlike the ductility of strengthened beams, which was greatly reduced compared to the control.

Flexural behaviour of reinforced low-strength concrete beams strengthened with CFRP plates

Mohcene Boukhezar,Mohamed Laid Samai,Habib Abdelhak Mesbah,Hacène Houari 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.6

This paper summarises the results of an experimental study to investigate the flexural behaviour of reinforced concrete beams strengthened using carbon-fibre reinforced polymer (CFRP) laminate in fourpoint bending. The experimental parameters included are the reinforcing bar ratio ps and preload level. Four bar ratios were selected (ps = 0.13 to 0.86%), representing the section of two longitudinal tensile reinforcements, with diameters of 8, 14, 16, and 20 mm in order to reveal the effect of bar ratio on failure load and failure mode. Eight beams that could be considered "full-scale" in size, measuring 200 mm in width, 400 mm in total height and 2300 mm in length, were tested. Three beams were selected with different bar ratios (p1, p2, p3), and considered as control specimens (without ), while three other beams identical to the control beams with the same CFRP laminates ratio and a seventh beam with pmin (the lowest bar ratio) were also used. In the second part of the study, two beams with the bar ratio p2 were preloaded at two levels, 50 and 100% of their ultimate loads, and then repaired. This experimental investigation was consolidated using an analytical model. The experimental and analytical results indicate that the flexional capacity and stiffness of strengthened and repaired beams using CFRP laminate were increased compared to those of control beams, and the behaviour of repaired beams was nearly similar to the undamaged and strengthened beams; unlike the ductility of strengthened beams, which was greatly reduced compared to the control.

Correction of pressure drop in a heavily loaded hybrid bearing when starting by using a constant flow lubrication system- Application to a rotary cement mill

Mawhoub Soubih,Miloud Tahar Abbes,Laid Ketrouci,Benyahia Touam,Fatima Mahnah 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.2

We analyzed a lubricated journal plain bearing supporting heavy loaded rotary mill. During start-up operating, after the shaft is lifted by high external pressure lubricant, the speed of the shaft grows from 0 to the operating hydrodynamic speed when, suddenly after the first thirty seconds of shaft rotation, the pressure drops in one recess causing excessive damage to the pad bearing interface. The aim was to understand and provide some answers to the pressure drop in order to give an appropriate correction. Misalignment between the shaft and bearing surfaces was considered and analyzed in first part of the study. According to the obtained results the proposed correction is to use a suitable constant flow lubrication system which avoids the pressure to drop in recesses. A real application was made on a partial pad bearing supporting a heavy rotary cement mill localized at the cement plant of Chlef in Algeria.

Adaptive Fourier Series Neural Network PID Controller

Mohamed Benrabah,Kamel Kara,Oussama AitSahed,Mohamed Laid Hadjili 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.10

In this work, an Adaptive Neural Networks PID controller structure, called Adaptive Fourier Series Neural Networks PID controller (AFSNNPID), is developed. The main objective is to obtain a simple controller for nonlinear systems that can be tuned online to reject perturbations effect and compensate the system parameters variation. Due to its simple architecture and very attractive proprieties, the Fourier Series Neural Network (FSNN)is used to online adjust the parameters of the PID controller. Furthermore, using the delta-rule algorithm, the adaptation dynamics of the FSNN is globally stable.The design procedure of the proposed controller and the stability analysis of the closed loop system using the small gain theorem are given. To assess the effectiveness of the proposed control scheme, the control of a 3-DOF robot arm manipulator is considered and a comparative study, usingthe adaptive neural network PID controller and the particle swarm optimization based PID controller, is carried out. The obtained results, through the experimental study, indicate that the AFSNNPID controller presents better control performance than the other controllers