Mechanical characteristics of a classical concrete lightened by the addition of treated straws

Kammoun, Zied,Trabelsi, Abderraouf Techno-Press 2018 Advances in concrete construction Vol.6 No.4

This experimental work aims at developing and investigating a lightened concrete by the addition of treated straws. The used formulation is based on that of an ordinary concrete which is composed of sand and gravel as the main aggregates. The properties of the straws are improved by using one of two treatments before their use: the hot water and bitumen. Henceforth, the main objective of this study is to assess the mechanical characteristics of different formulations with different compositions and treatments on straws. The obtained results have shown that the addition of straws improves its lightness property. However, it decreases the compressive and flexural strengths as well as decreases the modulus of elasticity and increases the dimensional variations. Set into comparison to the concrete with untreated straws, the treatment of straws by hot water or by bitumen improves most of the characteristics.

HaptiSole: Wearable Haptic System in Vibrotactile Guidance Shoes for Visually Impaired Wayfinding

Slim Kammoun,Rahma Bouaziz,Faisal Saeed,Sultan Noman Qasem,Tawfik Al-Hadhrami 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.11

During the last decade, several Electronic Orientation Aids devices have been proposed to solve the autonomy problems of visually impaired people. When hearing is considered the primary sense for Visually Impaired people (VI) and it is generally loaded with the environment, the use of tactile sense can be considered a solution to transmit directional information. This paper presents a new wearable haptic system based on four motors implemented in shoes, while six directions can be played. This study aims to introduce an interface design and investigate an appropriate means of spatial information delivery through haptic sense. The first experiment of the proposed system was performed with 15 users in an indoor environment. The results showed that the users were able to recognize, with high accuracy, the directions displayed on their feet. The second experiment was conducted in an outdoor environment with five blindfolded users who were guided along 120 meters. The users, guided only by the haptic system, successfully reached their destinations. The potential of tactile-foot stimulation to help VI understand Electronic Orientation Aids (EOA) instructions was discussed, and future challenges were defined.

Route Selection Algorithm for Blind Pedestrian

Slim Kammoun,Florian Dramas,Bernard Oriolaand,Christophe Jouffrais 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

The vast majority of existing route selection processes is designed for vehicle navigation. In this paper we describe an adapted routing algorithm for visually impaired pedestrians based on users needs. Our aim was to find the most adapted route that connects origin and destination points, and which can provide the Blind with a sparse but helpful mental representation of the itinerary and surroundings. Based on multiple brainstorming sessions and interviews with blind people and an orientation and mobility (O&M) instructor, different classes of objects were defined and tagged in the Geographical Information System. The optimal route was then selected using the Dijkstra algorithm. This method will be used in NAVIG (Navigation Assisted by Artificial VIsion and GNSS), an assistive device for the Blind, whose aim is to improve orientation, mobility and objects localization.

Estimation of the parameters of a Wishart extension on symmetric matrices

Ghorbel Emna,Kammoun Kaouthar,Louati Mahdi,Sallem Akram 한국통계학회 2022 Journal of the Korean Statistical Society Vol.51 No.4

This paper deals with the parameters of a natural extension of the Wishart distribution, that is the Riesz distribution on the space of symmetric matrices. We estimate the shape parameter using two different approaches. The first one is based on the method of moments, we give its expression and investigate some of its properties. The second represents the maximum likelihood estimator. Unfortunately, in this case we do not have an explicit formula for this estimator. This latter is expressed in terms of the digamma function and sample mean of log-gamma variables. However, we derive the strong consistency and asymptotic normality properties of this estimator. A numerical comparative study between the two estimators is carried out in order to test the performance of the proposed approaches. For the second parameter, that is the scale parameter, we prove that the distribution of the maximum likelihood estimator given by Kammoun et al. (J Statist Prob Lett 126:127–131, 2017) is related to the Riesz distribution. We examine some properties concerning this estimator and we assess its performance by a numerical study.

Parametric analysis of the damage characterization tests of aluminum bulk material

Chaima Hammami,Nouha Kammoun,Hamdi Hentati,Mounir Ben Amar,Mohamed Haddar 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

Several models have been developed to study materials behaviors under different states of stress. In manufacturing processes, several types of stresses are observed in workpieces. In this context, this paper presents an analysis of the failure behavior of aluminum bulk specimens through parametric characterization tests covering most of these solicitations. The goal is to choose better configuration to reduce experimental tests costs later. First, numerical models used for damage characterization tests are described and validated. Johnson Cook models and stress triaxiality parameter are introduced to study the ductile damage mechanism in the material. Second, the influence of specimens geometries on characterization tests results is under investigation. Tension, compression, shear, torsion, and combined torsion-tension tests are carried out using finite element models and thermo-mechanical coupling method.

Optimization of Submerged Aspergillus oryzae S2 α-Amylase Production

Belgacem Naili,Mouna Sahnoun,Samir Bejar,Radhouane Kammoun 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.1

Use of 4 agro-industrial by products and organic materials as nitrogen sources for production of Aspergillus oryzae S2 α-amylase in liquid culture was investigated. The 2 agro-industrial byproducts maltose and saccharose, and also lactose and starch were individually evaluated for use as carbon sources. A Box-Behnken experimental design was used to determine optimal conditions for production of α-amylase. A maximum amylase activity of 750 U/mL was obtained at a temperature of 24oC, a urea concentration of 1 g/L, and a C/N ratio of 2. Laboratory scale application of optimal conditions in a 7 L fermentor produced a final α-amylase activity of 770 U/mL after 3 days of batch cultivation. Addition of 10% starch to the culture medium each 12 h immediately after the stationary phase of cell growth led to a production yield of 1,220 U/mL at the end of fed-batch cultivation.

Optimization of Aspergillus oryzae S2 α-amylase, ascorbic acid, and glucose oxidase combination for improved French and composite Ukrainian wheat dough properties and bread quality using a mixture design approach

Sahnoun, Mouna,Kriaa, Mouna,Besbes, Souhail,Jardak, Mohamed,Bejar, Samir,Kammoun, Radhouane 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5

A simplex-centroid experimental design was used for the optimization of both reducing and oxidizing improvers, namely Aspergillus oryzae S2 ${\alpha}$-amylase (Amy), ascorbic acid (Asc), and glucose oxidase (GOD). This optimization was performed to enhance the dough and breadmaking qualities of soft French wheat flour and a composite counterpart that contained 30% Ukrainian wheat flour. Statistically significant correlations were calculated between the W index and textural parameters (e.g., dough chewiness and bread cohesiveness). The findings revealed that while the best mixture for French flour comprised 21.8% of Amy, 41.2% of Asc, and 37% of GOD, for the composite counterpart, it comprised 2.3% of Amy, 66% of Asc, and 31.7% of GOD. These optimized mixtures rearranged soft French wheat flour and its composite counterpart to a good quality and an improved flour texture, respectively. Additionally, they increased the loaf specific volumes of the breads made from soft French wheat flour and its counterpart by 25.8 and 45.43%, respectively, significantly decreased the breads' susceptibility to microbial contamination, and reclassified the breads as "good" in terms of sensory attributes.

Optimization of Aspergillus oryzae S2 α-amylase, ascorbic acid, and glucose oxidase combination for improved French and composite Ukrainian wheat dough properties and bread quality using a mixture design approach

Mouna Sahnoun,Mouna Kriaa,Souhail Besbes,Mohamed Jardak,Samir Bejar,Radhouane Kammoun 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5

A simplex-centroid experimental design was used for the optimization of both reducing and oxidizing improvers, namely Aspergillus oryzae S2 α-amylase (Amy), ascorbic acid (Asc), and glucose oxidase (GOD). This optimization was performed to enhance the dough and breadmaking qualities of soft French wheat flour and a composite counterpart that contained 30% Ukrainian wheat flour. Statistically significant correlations were calculated between the W index and textural parameters (e.g., dough chewiness and bread cohesiveness). The findings revealed that while the best mixture for French flour comprised 21.8% of Amy, 41.2% of Asc, and 37% of GOD, for the composite counterpart, it comprised 2.3% of Amy, 66% of Asc, and 31.7% of GOD. These optimized mixtures rearranged soft French wheat flour and its composite counterpart to a good quality and an improved flour texture, respectively. Additionally, they increased the loaf specific volumes of the breads made from soft French wheat flour and its counterpart by 25.8 and 45.43%, respectively, significantly decreased the breads’ susceptibility to microbial contamination, and reclassified the breads as “good” in terms of sensory attributes.