Educating Students Through Understanding the Pathology of Geotechnical Projects

Three projects of end of studies which are related to soil mechanics pathology case histories were undertaken by students at civil engineering department of National Engineering School of Tunis. The two first projects dealt with Joumine and Sidi Saâd earth dams cases. For Joumine dam, concrete slabs of the spillway have been affected by serious disorders. The first disorder is related to the swelling nature of soil foundation of concrete slabs. The second disorder is attributed to high excess pore pressure responsible of slabs up risings. As solution the jet grouting technique was designed to eliminate high pore pressure in the soil foundation of slabs. For Sidi Saâd dam disorders were attributed to high active soil pressures exerted on retaining walls of the spillway. As solution anchored cables were adopted to improve the stability of concrete walls. The third project dealt with four engineering structures crossing Tunis La Goulette express route. All approach slabs were affected by differential settlements due to the existence of highly compressible thick soft clay layers. As solution three soil improvement techniques (rigid inclusions, stone columns prefabricated vertical drains) were compared to stop non admissible consolidation settlements. For each case history, the methodology to diagnose causes of disorders is first presented, second, the utilized approaches, especially those involving finite element codes usage, are highlighted, finally proposal of remedies to re establish suitable exploitation of projects are exposed. This paper well illustrates the great importance for under graduated students, when preparing their works of end of projects, to more understand fundamentals in soil mechanics in parallel with treating serious problems of pathology of case histories

Deriving Product Line Requirements: the RED-PL Guidance Approach

Product lines (PL) modeling have proven to be an effective approach to reuse in software development.Several variability approaches were developed to plan requirements reuse, but only little of them actuallyaddress the issue of deriving product requirements.This paper presents a method, RED-PL that intends to support requirements derivation. The originality ofthe proposed approach is that (i) it is user-oriented, (ii) it guides product requirements elicitation andderivation as a decision making activity, and (iii) it provides systematic and interactive guidance assistinganalysts in taking decisions about requirements. The RED-PL methodological process was validatedin an industrial setting by considering the requirement engineering phase of a product line of blood analyzers

Solving Integer Constraint in Reuse Based Requirements Engineering

International audienceProduct Lines (PL) have proved an effective approach to reuse-based systems development. Several modelling languages were proposed so far to specify PL. Although they can be very different, these languages show two common features: they emphasize (a) variability, and (b) the specification of constraints to define acceptable configurations. It is now widely acknowledged that configuring a product can be considered as a constraint satisfaction problem. It is thus natural to consider constraint programming as a first choice candidate to specify constraints on PL. For instance, the different constraints that can be specified using the FODA language can easily be expressed using boolean constraints, which enables automated calculation and configuration using a SAT solver. But constraint programming proposes other domains than the boolean domain: for instance integers, real, or sets. The integer domain was, for instance, proposed by Benavides to specify constraints on feature attributes. This paper proposes to further explore the use of integer constraint programming to specify PL constraints. The approach was implemented in a prototype tool. Its use in a real case showed that constraint programming encompasses different PL modeling languages (such as FORE, OVM, or else), and allows to specify complex constraints that are difficult to specify with these languages

Using Integer Constraint Solving in Reuse Based Requirements Engineering

Product Lines (PL) have proved an effective approach to reuse-based systems development. Several modeling languages were proposed so far to specify PL. Although they can be very different, these languages show two common features: they emphasize (a) variability, and (b) the specification of constraints to define acceptable configurations. It is now widely acknowledged that configuring a product can be considered as a constraint satisfaction problem. It is thus natural to consider constraint programming as a first choice candidate to specify constraints on PL. For instance, the different constraints that can be specified using the FODA language can easily be expressed using boolean constraints, which enables automated calculation and configuration using a SAT solver. But constraint programming proposes other domains than the boolean domain: for instance integers, real, or sets. The integer domain was, for instance, proposed by Benavides to specify constraints on feature attributes. This paper proposes to further explore the use of integer constraint programming to specify PL constraints. The approach was implemented in a prototype tool. Its use in a real case showed that constraint programming encompasses different PL modeling languages (such as FORE, OVM, or else), and allows specifying complex constraints that are difficult to specify with these languages

Chemical auxiliaries free dyeing of cationized cotton with 1:2 metal complex dye

Application of 1:2 metal complex dyes on pre-cationized cotton has been studied. This unconventional process avoidsthe use of electrolyte required as exhausting agent in conventional dyeing of cotton fabric. Indeed, when we use a largeamount of salt, the discharged wastewater from dye house creates unavoidable environmental threats. The dyeing has beencarried out at the liquor ratio of 1:40 in a sealed stainless steel dyebath housed on the Ahiba Nuance speed varyingtemperature, contact time and sulphate concentration. Optimal conditions are determined using the experimental designsmethod. The results show the possibility of chemical auxiliaries free dyeing of cotton fabrics with 1:2 metal complex dye at75°C for 15 min by treating them with cationizer prior to dyeing. Adsorption kinetic and isotherm are also studied and theparallel exponential model is shown to fit experimental data with higher average regression coefficients

Constraints: the Heart of Domain and Application Engineering in the Product Lines Engineering Strategy

International audienceDrawing from an analogy between features based Product Line (PL) models and Constraint Programming (CP), this paper explores the use of CP in the Domain Engineering and Application Engineering activities that are put in motion in a Product Line Engineering strategy. The start idea is simple: both CP and PL engineering deal with variables, and constraints that these variables must satisfy. Therefore, specifying a PL as a constraint program instead of a feature model, or another kind of PL formalism, carries out two important qualities of CP: expressiveness and direct automation. On the one hand, variables in CP can take values over boolean, integer, real or even complex domains (i.e., lists, arrays and trees) and not only boolean values as in most PL languages such as the Feature-Oriented Domain Analysis (FODA). Specifying boolean, arithmetic, symbolic and reified constraint, provides a power of expression that spans beyond that provided by the boolean dependencies in FODA models. On the other hand, PL models expressed as constraint programs can directly be executed and analyzed by off-the-shelf solvers. Starting with a working example, this paper explores the issues of (a) how to specify a PL model using CP, including in the presence of multi-model representation, (b) how to verify PL specifications, (c) how to specify configuration requirements and (d) how to support the product configuration activity. Tests performed on a benchmark of 50 PL models show that the approach is efficient and scales up easily to very large and complex PL specification

High-resolution molecular fingerprinting in the 11.6-15 μm range by a quasi-CW difference-frequency-generation laser source

We report an approach for high-resolution spectroscopy using a widely tunable laser emitting in the molecular fingerprint region. The laser is based on difference-frequency generation (DFG) in a nonlinear orientation-patterned GaAs crystal. The signal laser, a CO2 gas laser, is operated in a kHz-pulsed mode while the pump laser, an external-cavity quantum cascade laser, is finely mode-hop-free tuned. The idler radiation covers a spectral range of ∼11.6-15 μm with a laser linewidth of ∼ 2.3 MHz. We showcase the versatility and the potential for molecular fingerprinting of the developed DFG laser source by resolving the absorption features of a mixture of several species in the long-wavelength mid-infrared. Furthermore, exploiting the wide tunability and resolution of the spectrometer, we resolve the broadband absorption spectrum of ethylene (C2H4) over ∼13-14.2 μm and quantify the self-broadening coefficients of some selected spectral lines

High-resolution molecular fingerprinting in the 11.6-15 µm range by a quasi-CW difference-frequency-generation laser source

: We report an approach for high-resolution spectroscopy using a widely tunable laser emitting in the molecular fingerprint region. The laser is based on difference-frequency generation (DFG) in a nonlinear orientation-patterned GaAs crystal. The signal laser, a CO2 gas laser, is operated in a kHz-pulsed mode while the pump laser, an external-cavity quantum cascade laser, is finely mode-hop-free tuned. The idler radiation covers a spectral range of ∼11.6-15 µm with a laser linewidth of ∼ 2.3 MHz. We showcase the versatility and the potential for molecular fingerprinting of the developed DFG laser source by resolving the absorption features of a mixture of several species in the long-wavelength mid-infrared. Furthermore, exploiting the wide tunability and resolution of the spectrometer, we resolve the broadband absorption spectrum of ethylene (C2H4) over ∼13-14.2 µm and quantify the self-broadening coefficients of some selected spectral lines

Assessing the insecticidal impact of rosemary essential oils on the saw-toothed grain beetle Oryzeaphilus surinamensis

This work studied the fumigant toxicity of free and encapsulated rosemary (Rosmarinus officinalis) essential oils against adults of the saw-toothed grain beetle (Oryzeaphilus surinamensis) for three storage periods: 30, 45 and 60 days. Chitosan was used as encapsulation matrix. GC/MS analysis results showed that camphor and 1,8-cineole were the major components with respectively 18.04% and 39.67%. Mortality rates caused by the essential oils at 300 μL/L air after 10 days of storage were about 85.48%. The median lethal concentration (LC50) was 124.80 μL/ L air. Encapsulation efficacy was 25.8% and loading capacity was 1.9%. Encapsulated essential oils achieved an efficacy of 82%, 100% and 100% respectively after 30, 45 and 60 days of storage. Reference treatment with Phosphine revealed a toxicity of 100%, 96% and 71% after 30, 45 and 60 days of storage respectively. Results showed that encapsulated essential oils caused a very slight modification on semolina properties. Protein contents decreased at the end of the storage period less than 1% (from 13.61% after 30 days to 12.91% after 60 days of storage). Encapsulated essential oils might be considered as an alternative fumigant control way for semolina without deterioration of its quality during storage