Automatic condition monitoring of electromechanical system based on MCSA, spectral kurtosis and SOM neural network

Condition monitoring and fault diagnosis play the most important role in industrial applications. The gearbox system is an essential component of mechanical system in fault identification and classification domains. In this paper, we propose a new technique which is based on the Fast-Kurtogram method and Self Organizing Map (SOM) neural network to automatically diagnose two localized gear tooth faults: a pitting and a crack. These faults could have very different diagnostics; however, the existing diagnostic techniques only indicate the presence of local tooth faults without being able to differentiate between a pitting and a crack. With the aim to automatically diagnose these two faults, a dynamic model of an electromechanical system which is a simple stage gearbox with and without defect driven by a three phase induction machine is proposed, which makes it possible to simulate the effect of pitting and crack faults on the induction stator current signal. The simulated motor current signal is then analyzed by using a Fast-Kurtogram method. Self-organizing map (SOM) neural network is subsequently used to develop an automatic diagnostic system. This method is suitable for differentiating between a pitting and a crack fault

Conceptual Architecture for Agent-Based Modelling of Supplier Selection Conducted by a Supply Chain Dyad

Within the fourth stage of industrialization, artificial intelligence and in particular the multi-agent systems paradigm is highly adopted. Within the agent approach, the industrial resources are defined as intelligent agents that negotiate with each other to implement dynamic reconfiguration and reach agility and higher customer satisfaction. In this paper a smart configuration of the agent-based system for multi-product dyadic supplier selection is proposed. The objective is to select suppliers for multiple products simultaneously in a vertical collaboration context while involving the customer of the purchasing company and considering its preferences. Negotiation experiments are conducted for initial validation of the proposed conceptual architecture

Advanced optimization model of resource allocation in B2C supply chain

Resource allocation plays a critical role in the strategic, tactical, and operational planning of the supply chain. The study focuses on aspects of resource allocation in the case of pure players, manufacturers, and Clicks & Mortars that have launched online sales. These e-retailers offer a wide selection of customized services and so need an efficient management on every level and process. The goal of the research was to explore a concrete approach to improve customer satisfaction, reduce costs and risks and to maintain the benefits of e-retailers and of its collaborators. Our contribution is a decision support system and a tool to improve operational resources allocation in B2C supply chains. Hence, we started by modeling operations and the different scenarios. Then we introduced an optimization model founded on the analysis of resource allocation in B2C supply chains and applicable on any B2C e-retailer. It helps in choosing the most optimal resources for each order. The model is based on a multi-objective optimization approach that takes into consideration the collaboration of resources throughout the supply chain operations process including dynamic costs and collaborator capabilities as well as associated risks and the quality of delivered services

Influence of Abiotic Factors on the Phytochemical Profile of Two Species of Artemisia: A. herba alba Asso and A. mesatlantica Maire

The species of Artemisia are well known in the Mediterranean region, especially in Morocco, for their traditional uses and health benefit. In this study, we were interested in two species of Artemisia, namely A. herba alba Asso and A. mesatlantica Maire. These species were collected from different soils of the Central Middle Atlas (loamy, stony, limestone and rocky soil) with different atmospheres. Extraction of essential oils from the leaves and flowering tops was carried out by hydrodistillation in Clevenger apparatus. Chemical composition analysis was further carried out using gas chromatography coupled with mass spectrometry (GC-MS). Principal component analysis (PCA) was performed to determine the similarities and dissimilarities in the chemical compositions of these six essential oils. The results obtained showed that the essential oil contents extracted from the flowering tops vary from one species to another according to the place of harvest, altitude, soil type and climate. The essential oil yield is between 0.84% and 2.19% (mL/100 g). Chemical analysis revealed that the chemotype of A. herba alba in limestone soil with a subhumid to humid atmosphere is trans-thujone (33.78%), while camphor (46.19%) is for limestone soil with a semi-arid atmosphere, vetivenic acid (14.91%) and davana ether (14.64%) are for limestone soil with a semi-arid and arid atmosphere and camphor (18.39%) is for loamy and stony soil with a semi-arid atmosphere. As for A. mesatlantica from a rocky soil on limestone with a subhumid to humid atmosphere, the main component is camphor (44.86%), and that of limestone soil with a subhumid to the humid atmosphere trans-thujone (41.08%). In addition, HCA affirmed the PCA and allowed us to distinguish between four groups. Our findings observed differences in the chemical compositions of the isolated essential oils most likely related to many factors such as the climates in the regions of the samples collected, altitudes and soil types

Advanced supplier selection: A hybrid multi-agent negotiation protocol supporting supply chain dyadic collaboration

This paper proposes a novel form of supplier selection involving the supply chain dyad as the buyer and the suppliers as sellers. The main proposed contribution is a multi-attribute decision hybrid protocol for supplier selection based on collaboration and negotiation, adapted to dyadic collaboration in a supply chain context. Suppliers and the purchasing dyad can reach an agreement on the details of the products simultaneously and exploit the preferences of the customer dyadic partner to enlarge the criteria choices of the products. For this, the proposed protocol combines a one-to-one bilateral dyadic collaboration protocol inside the purchasing dyad along with a one-to-many multi-bilateral bargaining protocol between the purchasing dyad and suppliers. Illustrative multi-agent simulation experiments were carried out to prove the effectiveness of the proposed protocol. The protocol implementation shows better negotiation results than the classic supplier selection process, along with expected higher customer partner satisfaction and a more embedded dyadic relationship

Phytochemical Analysis, Antimicrobial and Antioxidant Properties of Thymus zygis L. and Thymus willdenowii Boiss. Essential Oils

Essential oils (EOs) are chemical products produced by odoriferous glands from a variety of plants. These essential oils have many health benefits: antiseptic, anti-inflammatory and antimicrobial activities. So due to these medicinal properties, the present study was designed to analyze essential oils of Thymus zygis L. and Thymus willdenowii Boiss. for their chemical composition and biological activities. These two thyme species were collected from the region of Ifrane, Middle Atlas of Morocco. The EO was obtained by hydrodistillation, and the yields were 5.25% for T. zygis and 3.00% for T. willdenowii. The chemical composition of the EOs was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and the results showed that T. zygis EO is dominated by carvacrol (52.5%), o-cymene (23.14%), and thymol (9.68%), while the EO of T. willdenowii contains germacrene D (16.51%), carvacrol (16.19%), and geranyl acetate (8.35%) as major compounds. The antioxidant activity assessed by Diphenylpicrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays revealed that both EOs have excellent antioxidant activities; by DPPH it resulted in IC50 = 6.13 ± 0.11 for T. zygis and 6.78 ± 0.3 µg/mL for T. willdenowii, while the one by FRAP yielded EC50 = 2.46 ± 0.01 (T. zygis) and 5.17 ± 0.2 (T. willdenowii) µg/mL. The antimicrobial activity of the two essential oils was evaluated against six bacterial strains and five fungal strains by the disk diffusion method to determine the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC). The EOs revealed variable antimicrobial activities against the different tested microbial strains and showed strong antimicrobial activities, even against strains known as multi-resistant to antibiotics (Acinetobacter baumannii) at low concentrations (2 µL/mL). T. zygis EO showed the most powerful activity against all the studied bacteria, while that of T. willdenowii recorded moderate activity when tested against Shigella dysenteriae and Salmonella Typhi. With inhibition diameters that vary between 75 mm and 84 mm for concentrations of 2 µL/mL up to 12 µL/mL, S. aureus was shown to be the most sensitive to T. zygis EO. For the antifungal activity test, T. zygis EO showed the best inhibition diameters compared to T. willdenowii EO. These results showed that T. zygis EO has more powerful antioxidant and antimicrobial activities than T. willdenowii EO, therefore, we deduce that thyme EOs are excellent antioxidants, they have strong antimicrobial properties, and may in the future represent new sources of natural antiseptics that can be used in pharmaceutical and food industry

Chemical Composition, Antioxidant and Antibacterial Activities of Thymus broussonetii Boiss and Thymus capitatus (L.) Hoffmann and Link Essential Oils

Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and gamma-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 +/- 0.05 and 4.88 +/- 0.04 mu L/mL and EC50 of 0.12 +/- 0.01 and 0.20 +/- 0.02 mu L/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections.Peer reviewe

Chemical Composition, Antioxidant and Antibacterial Activities of Thymus broussonetii Boiss and Thymus capitatus (L.) Hoffmann and Link Essential Oils

Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and γ-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 ± 0.05 and 4.88 ± 0.04 μL/mL and EC50 of 0.12 ± 0.01 and 0.20 ± 0.02 μL/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections

Influence of Abiotic Factors on the Phytochemical Profile of Two Species of Artemisia : A. herba alba Asso and A. mesatlantica Maire

The species of Artemisia are well known in the Mediterranean region, especially in Morocco, for their traditional uses and health benefit. In this study, we were interested in two species of Artemisia, namely A. herba alba Asso and A. mesatlantica Maire. These species were collected from different soils of the Central Middle Atlas (loamy, stony, limestone and rocky soil) with different atmospheres. Extraction of essential oils from the leaves and flowering tops was carried out by hydrodistillation in Clevenger apparatus. Chemical composition analysis was further carried out using gas chromatography coupled with mass spectrometry (GC-MS). Principal component analysis (PCA) was performed to determine the similarities and dissimilarities in the chemical compositions of these six essential oils. The results obtained showed that the essential oil contents extracted from the flowering tops vary from one species to another according to the place of harvest, altitude, soil type and climate. The essential oil yield is between 0.84% and 2.19% (mL/100 g). Chemical analysis revealed that the chemotype of A. herba alba in limestone soil with a subhumid to humid atmosphere is trans-thujone (33.78%), while camphor (46.19%) is for limestone soil with a semi-arid atmosphere, vetivenic acid (14.91%) and davana ether (14.64%) are for limestone soil with a semi-arid and arid atmosphere and camphor (18.39%) is for loamy and stony soil with a semi-arid atmosphere. As for A. mesatlantica from a rocky soil on limestone with a subhumid to humid atmosphere, the main component is camphor (44.86%), and that of limestone soil with a subhumid to the humid atmosphere trans-thujone (41.08%). In addition, HCA affirmed the PCA and allowed us to distinguish between four groups. Our findings observed differences in the chemical compositions of the isolated essential oils most likely related to many factors such as the climates in the regions of the samples collected, altitudes and soil typesPeer reviewe

Chemical Composition, Antioxidant and Antibacterial Activities of Thymus broussonetii Boiss and Thymus capitatus (L.) Hoffmann and Link Essential Oils

Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and γ-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 ± 0.05 and 4.88 ± 0.04 μL/mL and EC50 of 0.12 ± 0.01 and 0.20 ± 0.02 μL/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections