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Spinal ependymoma, the most common intramedullary tumour in adults, is generally located intradurally and intramedullarily. The presence of this tumor in the bulbo-medullary region is rarely documented in the medical literature.We present the case of a 33-year-old man with persistent torticollis and severe neck pain. Spinal cord magnetic resonance imaging revealed a lesion in the bulbo-medullary region. Subtotal resection of this lesion was performed, and anatomopathological and immunohistochemical analysis confirmed the diagnosis of ependymoma. Following surgery, the patient underwent post-operative radiotherapy.The standard therapeutic management of ependymoma is total tumor resection. However, the role of post-operative radiotherapy remains to be determined, although it is recommended in cases of subtotal resection. &nbsp

Identifying species and updating marine biodiversity is fundamental to understanding the evolution of ecosystems and adopting appropriate management strategies. These ecosystems are threatened by climate change causing species mobility, mortality, etc. An important zoological group in the marine ecosystem, octocoral gorgonians have a wide geographic and bathymetric distribution. However, the knowledge of their presence on the Atlantic West African coasts remains limited. Herein, we note the accurate geographic distribution of two species,Leptogorgia dakarensis(Stiasny, 1936) andEunicella racemosa(Milne Edwards & Haime, 1857), reporting their northern distributional limits. The gaps in the previous knowledge hypothesis of the oceanic warming effects explaining the northward mobility of these species are discussed here.

Dans cet article, bien que la mesure de la performance sociale soit difficile, en raison d’une myriade d’indicateurs de réflexion contingente, nous avons proposé une vision holistique de management de la performance sociale en tant que concept agrégé d’impact social. Après avoir examiné les raisons pour lesquelles la mesure de la performance sociale est devenu extrêmement importante pour divers intervenants dans la structure organisationnelle, nous avons essayé de conceptualiser cette notion en synthétisant à travers une grille d’analyse littéraire le socle des recherches empiriques antérieurs et en proposant des lignes directrices qui peuvent aider les praticiens et les chercheurs à élaborer une stratégie de mesure de la performance sociale qui répond à leurs besoins spécifiques.

L’objectif de cet article est d’identifier les facteurs affectant le comportement d'achat en ligne du consommateur marocain. En positionnant la présente recherche dans le courant positiviste au travers une approche hypothético-déductive, une étude quantitative utilisant un échantillonnage de convenance de 7395 utilisateurs d'achats en ligne a été réalisée. Les données ont été recueillies à l'aide d'un questionnaire. L'analyse factorielle est effectuée pour identifier la structure et la fiabilité interne des échelles de mesures identifiées en utilisant le logiciel SPSS version 24. En nous basant sur le logiciel SMART PLS version 3.0, nous avons mis en œuvre la méthode des équations structurelles afin de tester les hypothèses. Les résultats de l'étude suggèrent que le comportement des consommateurs d'achat en ligne est affecté par plusieurs facteurs tels que la Commodité, la Variété, la Confiance, le Prix perçu et le Risque perçu. Ce dernier facteur est lié à la performance, au paiement en ligne, au livraison et à l’attente de la vie privée. L’ensemble de ces facteurs jouent un rôle important dans le comportement d’achats en ligne.

This work describes the spatiotemporal analysis of microplastics (MPs) pollution in sediments collected on a high urbanized beach located in Taghazout coast, central Atlantic part of Morocco. The study area is mainly composed of moderately well-sorted fine sands with an average density of MPs that ranged between 915 MPs/kg in 2018 and 1448 MPs/kg in 2019. The most polluted sites were in the south part of Taghazout coast, close to facilities of where beachgoers are often found. Microplastic Pollution Index (MPPI), Microplastic Impact Coefficient (CMPI), Agglomerative Hierarchical Clustering (AHC), and Multidimensional Scaling (MDS) revealed spatiotemporal variation of MPs pollution. Thus, the principal component analysis (PCA) showed a low correlation between the sediment characteristics (i.e., grain size, sorting, skewness) and MPs densities. Overall, the outputs of this baseline recommend implementing plastic management strategies to eliminate or at least minimize the collateral effects generated by MPs pollution in sediments of urbanized beaches. Also see: https://micro2022.sciencesconf.org/423883/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

The aim of the present study is the first to evaluate the ecotoxic state of the marine environment in Anza-Taghazout coasts (Morocco) after installation of two Wastewater Treatment Plants using a natural population of marine bivalves M. galloprovincialis. These coasts are exposed to many discharges generating, thus, different sources of pollutants. These pollutants can modulate the physiological responses of marine bivalves to environmental stress. In this context, a multi-biomarker approach consisting of a battery of biomarkers evaluation was used to assess the response of these species to stress. In the whole soft tissues of M. galloprovincialis, four biomarkers were evaluated: Acetylcholinesterase (AChE), Glutathione S-transferase (GST), Catalase (Cat) and malondialdehyde activity (MDA). In parallel, physico-chemical parameters were measured in the marine water of Anza-Taghazout within three selected sites: S1 considered as ‘hotspot’ located at Anza city; S2 located near of Aourir city and the third site, S3 ‘reference’ located in Imouran beach. Our results showed that activities of both Gluthation-S-Transferase and Catalase were higher in M. galloprovincialis collected from site S1, but high values of Malondialdehyde and Acetylcholinesterase activities were observed successively at S3 and S2. Application of Integrated Biomarker Response index (IBR) was suitable for classifying the stress response in the M. galloprovincialis but did not allow to evaluate the level of the xenobiotic exposure in the studied sites. The statistical results did not show any significant differences between the three studied sites and therefore S1 has recently become clean due to the installation of two wastewater treatment plants.

Wastewater treatment plants (WWTPs) are some of the main sources of microplastics (MPs) in the environment. However, studies on the occurrence and removal efficiency of MPs in WWTPs are still scarce, especially in African countries. Thus, the aim of this work was to study the abundance of MPs in the influent and effluent of two WWTPs (Aourir and M'zar) from the Agadir metropolis (Moroccan Atlantic). The two WWTPs receive different wastewater inputs (domestic and industrial). In addition, the impacts of seasonality on the fate and removal efficiency were investigated. The results showed that the MPs abundance in the wastewater decreased from 188 MPs/L in the influent to 50 MPs/L in the effluent for Aourir WWTP (domestic inputs); while the abundance was greater in the M'zar WWTP (urban and industrial inputs) recording a mean value of 519 MPs/L and 86 MPs/L in the influent and effluent, respectively. MPs collected in the Aourir WWTP ranged from 290 to 3200 μm, while MPs from the M'zar WWTP, ranged from 330 to 4200 μm. Overall, the size range of 100-500 μm was the most abundant for both WWTPs. Fibers were the highest MPs morphotype found, followed by fragments. MP colors were mainly red, black, blue, and transparent for both treatment plants. Additionally, FTIR spectroscopy showed the presence of eight different polymers, mainly polyethylene (PE), polypropylene (PP), and polystyrene (PS). Seasonal variation analysis showed that MPs abundance in summer was significantly higher compared to other seasons. However, the comparison of the removal efficiency (RE) between the different seasons indicated that the winter season (74 %) recorded the highest RE for Aourir WWTP. Conversely, spring (87 %) recorded the highest RE for M'zar WWTP. SEM/EDX micrographs showed different degrees of weathering and chemical elements adhering to the surface of the MPs. The findings of the current study will serve as a baseline for future considerations about management strategies, wastewater reuse, as well as the understanding of the occurrence of microplastic pollution along the marine ecosystems of Morocco.

The restrictions related to the COVID-19 pandemic have led to a global hiatus in anthropogenic activities; several scientists have utilized this unique opportunity to assess the human impact on biological systems. In this study, the study describes for a period of five years (2018-2022) how the faunal community have been affected by human disturbances, as well as the effect of the "anthropause" period driven by the COVID-19 lockdown. The results confirmed human disturbances on faunal communities related to coastal urbanization. It was found that the "anthropause" period showed the highest values of abundance and biomass, hence the "COVID-19 lockdown" allowed recovery of faunal communities. The findings highlight the impact of human disturbances and that the community showed resilience. Overall, the authorities must perform restrictive measures aiming to mitigate the impact of anthropogenic activities in the study area including the banning of off-road and recreational vehicles, carrying out efficient cleaning and grooming operations, monitoring the severe harvesting of edible species, as well as penalizing the disposal of anthropogenic waste and sewage discharge from the touristic facilities. Likewise, management actions such as the temporal beach closures and the regular surveillance could be advantageous to provide a more sustainable exploitation of sandy beaches.

BACKGROUND: Agadir city plans to reuse treated wastewater on a large scale to irrigate these green spaces. This study aims to evaluate the risk of intestinal parasites, to which human and animal populations are exposed during the reuse of treated wastewaters. METHODS: Over 21 months, wastewater samples were collected in Bensergao and Mzar wastewater treatment plants, in Agadir city, southern Morocco. The occurrences and removal of intestinal parasites were inspected using the modified Bailenger method. RESULTS: The biodiversity of helminths is higher than protozoa, while the protozoa cysts are more abundant and more prevalent. Generally, the highest parasitic loads were recorded during the hot season. For raw waters, the average concentration of protozoa cysts was 173.33 ± 70.81 cysts per L for Bensergao plant and 179.33 ± 129.22 cysts per L for Mzar plant. However, the helminths average concentration was 48.70 ± 39.91 eggs/larvae per L for Bensergao plant and 51.10 ± 31.76 eggs/larvae per L for Mzar plant. The purified water of the Mzar plant does not contain parasites, unlike the Bensergao plant where a small numbers of parasites were detected, included 2.33 ± 1.53 cysts per L for protozoa and 0.45 ± 0.58 eggs/larvae per L for helminths. CONCLUSIONS: Considering parasitological risks, the purified waters of Bensergao plant cannot be used without risks to the public health and environment. In contrast, the purified waters and the purified waters disinfected by ultraviolet radiation from the Mzar plant can be used safely to water the green spaces of Agadir city.

This work presents preliminary results about abundance, distribution, characteristics, sources, and fate of microplastics (MPs) in the Central Atlantic Ocean (CAO) of Morocco. The investigation was conducted into three subsections, each characterized by different types of human activities and covering rural, village, and urban areas. MPs were detected in 100 % of the sampling sites. The abundances varied from 0.048 to 3.305 items/m

Downtimes due to ice formation on rotor blades reduce the economic efficiency of wind turbines. An accurate ice prediction is required to operate active de-icing measures such as blade heating as an anti-icing system. Building upon our previous research, this paper proposes the use of a convolutional neural network model with dual inputs and one-dimensional convolution filters using historical data from the wind turbine as well as weather forecasts to predict the ice situation for the next 24 hours. The model is validated using data from three different wind farms and shows an average balanced accuracy of 97.9%.

In the era of digitalization, electronic Kanban (e-Kanban) extends the traditional Kanban with additional data and information sharing that allows for more flexible and optimized inventory planning. The lack of automated fill level measurements for load carriers still hinders the full automation of the process. Our aim is to develop a self-learning e-Kanban system that automatically triggers replenishment orders using machine learning and data from low cost, autonomous sensor modules that measure the fill level of load carriers. This paper explains the concept and presents a first version of the mentioned sensor module that consists of an Intel Realsense sensor and an NVIDIA Jetson Nano. An evaluation is presented as well using small load carriers, which shows the suitability of the proposed method.

Ice formation on rotor blades of wind turbines cause significant downtimes in cold regions. Existing ice sensors can detect, but cannot predict ice. Therefore, our research aims to develop an ice prediction system based on historical and forecasted data. In a first step, the detection process is analyzed in this research paper. Two machine learning models are trained using minimalistic input parameters. A full-factorial experiment design is performed for the models, using the fl-score as the response variable. The most significant input parameter was the external temperature for both models.

Ice formed on wind turbines not only causes economic damage but also poses a risk to nearby humans. Countermeasuring ice formation requires reliable detection systems. Existing ice detection solutions have improved with time, but are still not sufficiently accurate. This paper investigates the use of different convolutional neural networks (CNNs) and RGB images taken from cameras installed on the nacelle of wind turbines to detect ice on the rotor blades. In our research, the VGG19 model achieved the best performance with an accuracy and an f1-score of (96 ± 2) %.

This study describes the contamination, accumulation, and ecological risk assessment of five trace metals (Cd, Pb, Cu, Zn, and Cr) in sediments of an urbanized beach in the central Atlantic coastline of Morocco. The two-year investigation (2018 and 2019) included six sampling sites along a 6 km coastal reach. In both years, none of the studied trace metals exceeded the background or the sediment quality guidelines (SQGs). The eco-toxicological indices revealed low degree of contamination, unpolluted ecosystem, and low ecological risk of metals. However, Cd exceeded the background value and some SQGs following the increase of anthropogenic activities in 2019. Likewise, it indicated unpolluted to moderately polluted sediment as well as moderate ecological risk. Overall, it is highly recommended to mitigate the avoidable anthropogenic activities (marine litter generation, sewage discharge, intense urbanization, and vehicle traffic on the beach) that lead to the elevation of metal pollution in the study area.

In cold regions like Northern Europe or Northern America, formation of ice on wind turbines not only reduces the power output of the system, but also leads to wind turbine breakdowns and poses a risk to nearby vehicles and people. Economical solutions for anti-icing systems such as preventive heating are required. Purely meteorological icing predictions are not sufficient to accurately predict icing on wind turbines. Therefore, this paper proposes an icing prediction approach that uses historical weather data and data from a supervisory control and data acquisition (SCADA) system plus methods from supervised machine learning to predict the risk of icing. The first results of the prediction model show its capability to predict most of the icing events. The discussion shows that the model should consider more meteorological data that describe the icing risk such as humidity or liquid water content to achieve better prediction results. The final aim is a prediction system that will use real-time data to determine icing risks hours beforehand, allowing the operation of existing anti-icing systems more efficiently.

Digital twins perform process-accompanying services of machining processes or even of complete production systems. This article examines the interconnection between a physical production system and its digital twin, focusing on required sensors and the number of synchronization points to realize a dedicated control by the digital twin. Therefore, the physical system is modeled within AnyLogic to simulate different sensor configurations and breakdowns. A simulation-based digital twin is implemented to control the production system over a TCP/IP interface. As a result, a simulation-based examination of sensor configurations and their impact on the overall production system’s performance is proposed.

This work describes the spatiotemporal analysis of microplastics (MPs) pollution in sediments collected on a high urbanized beach located in Taghazout coast, central Atlantic part of Morocco. The study area is mainly composed of moderately well-sorted fine sands with an average density of MPs that ranged between 915 MPs/kg in 2018 and 1448 MPs/kg in 2019. The most polluted sites were in the south part of Taghazout coast, close to facilities of where beachgoers are often found. Microplastic Pollution Index (MPPI), Microplastic Impact Coefficient (CMPI), Agglomerative Hierarchical Clustering (AHC), and Multidimensional Scaling (MDS) revealed spatiotemporal variation of MPs pollution. Thus, the principal component analysis (PCA) showed a low correlation between the sediment characteristics (i.e., grain size, sorting, skewness) and MPs densities. Overall, the outputs of this baseline recommend implementing plastic management strategies to eliminate or at least minimize the collateral effects generated by MPs pollution in sediments of urbanized beaches.

This study describes the use of D. trunculus as a bioindicator of microplastic (MPs) pollution due to beach urbanization related to the development of the Taghazout Bay tourist resort in Morocco. In six sites located on the coast, MPs densities ranged from 1.75 to 5.93 items per gram of D. trunculus wet weight. MPs contamination was significantly influenced spatiotemporally by the urbanization degree in the area. The shapes found were fibers (90.5%) and fragments (9.5%). The Fourier Transform Infrared Spectroscopy (FTIR) analysis reported two polymers: polyethylene (65%) and polypropylene (35%). MPs colors were dark and light, with a predominance of light blue (23.8%). The species ingested different sizes of MPs, mainly the 0.1 and 0.5 mm fractions. Scanning Electron Microscope coupled with an energy dispersive X-ray analyzer (SEM/EDX) revealed weathered MPs with chemical elements adhered to their surface (Cu, Fe, Mg, S, Cl, etc.). The results of this study recommend the use of D. trunculus as a new bioindicator of MPs pollution following an urban change in the coastal scenery. Also, a sustainable coastal management must be implemented in the study area.

La question du roulement volontaire des médecins spécialistes a suscité un intérêt croissant dans de nombreux pays à travers le monde. À cet égard, les pays devraient être alertés par le taux de roulement volontaire de cette catégorie du personnel soignant en raison des impacts négatifs qu’il pourrait engendrer sur la santé de leurs citoyens. L’objectif de cet article consiste à réaliser une étude qualitative de type exploratoire. Cela nous permet d’avoir une parfaite connaissance des particularités contextuelles du milieu hospitalier public marocain. Une telle connaissance est susceptible d’enrichir notre modèle de recherche doctorale. Les résultats analysés, à travers le logiciel NVIVO 11, de notre échantillon composé de vingt trois médecins spécialises, montrent que les participants ont une forte intention de roulement volontaire, ce qui permet de conclure que les interviewés envisagent souvent de quitter leur emploi actuel.

Algorithm evaluation metrics are used to measure and compare the performance of diagnostic and prognostic algorithms. However, there is no consensus on which of the various metrics are the most suitable for classifiers' performance evaluation. This paper examines the applicability of common evaluation metrics for predictive maintenance applications in production systems. It is intended to clarify (1) which metrics are well suited for this use case, and (2) whether they are sufficient as a sole decision criterion for algorithm selection. Further, (3) the significance of evaluation metrics concerning the practical impact on the production system's performance is investigated. Moreover, we analyze (4) how increasing the production system's complexity affects the correlation between algorithm evaluation metrics and performance. We conducted 960 simulation runs of a flexible flow shop production system to examine the impact of machine breakdowns and different failure distributions with varying confusion matrices. In addition, two different configurations of the production system, which differ in system complexity, were investigated. Eventually, we determined the product-moment correlation coefficient between common evaluation metrics and the production system's performance. The simulation results reveal that metrics that are sensitive to false negative values (FN), like the False Omission Rate (FOR), are very well suited. Nevertheless, a detailed analysis shows that even (FOR) can only provide reliable statements combined with other metrics. We found that as the system becomes more complex, the informative value of the metrics in terms of their impact on the production system's performance decreases. Finally, we propose parameters that could be relevant for developing new metrics considering the current system configuration.

The increasing use of personal protective equipment (PPE) as a sanitary measure against the new coronavirus (SARS-CoV-2) has become a significant source of many environmental risks. The majority of the governments enforce the use of PPE in public areas, such as beaches. Thus, the use and disposal of PPE have compromised most solid waste management strategies, ultimately leading to the occurrence of PPE polluting the marine environment. The present study aimed to monitor the PPE pollution associated with COVID-19 along the coastline of Agadir, Morocco. In parallel, the influence of the activities carried out in each sampled beach before and after the lockdown break was reported. Overall, a total number of 689 PPE items were identified, with a mean density of 1.13 × 10−5 PPE m−2 (0–1.21 × 10−4 PPE m−2). The majority of the PPE items found were face masks (96.81%), out of which 98.4% were surgical masks and 1.6% were reusable cloth masks. The most polluted sites were the beaches with recreational activities, followed by surfing, and fishing as the main activity. Importantly, PPE density increased significantly after lockdown measures. Additionally, the discarded PPE sampled in the supralittoral zone was higher than PPE recorded in the intertidal zone. This confirms that PPE items are driven by the beachgoers during their visit. PPE items are a source of microplastic and chemical pollutants, a substrate to invasive species colonization, and a potential threat of entanglement, ingestion, and/or infection among apex predators. In the specific case of Agadir beaches, significant efforts are required to work on the lack of environmental awareness and education. It is recommended to improve beach cleaning strategies and to penalize incorrect PPE disposal. Additional alternatives may be adopted, as the involvement of biodegradable materials in PPE manufacturing, recycling through pyrolysis, and encouraging reusable and washable masks., Graphical abstract Unlabelled Image

This paper presents a quantitative and qualitative diagnosis of the current state of marine litter along the northern coastline of Agadir, located on the central Atlantic coast of Morocco. For this, three beaches were surveyed: Taghazout beach, Aourir beach, and Anza beach. Litter densities were highest at Anza beach (D = 1.041 items/m2), followed by Aourir beach (D = 0.339 items/m2), and then Taghazout beach (D = 0.226 items/m2). Plastics represent 79% of all collected items, and they are mainly composed of caps/lids, food containers, other plastic, cigarette butts and filters, polystyrene pieces, small plastic bags, and drink bottles. Metal is the second litter item in number, followed by paper/cardboard, rubber, cloth/textile, wood, and glass/ceramic. The Clean Coast Index (CCI) shows a clean and moderately clean state in the Taghazout and Aourir beaches, while Anza beach is more polluted. The EA/NALG classification showed that all three beaches are classified as “D,” i.e., dirty or poor-quality beaches. Dendrogram analysis showed very highly polluted areas (Anza 1), highly polluted areas (Taghazout 4 and 5; Anza 2; Aourir 3), moderately polluted areas (Taghazout 1 and 2; Aourir 1), and lightly polluted areas (Taghazout 3). Based on the obtained results, we can conclude that tourism and recreational activities were the primary source of marine litter (over 50%), followed by fishing activity (25%). Efforts are necessary to improve the quality of beaches located on the central Atlantic coast of Morocco. The typology of solutions suggested in this work can be divided into four approaches: cleaning, prevention, mitigation, and the most important … behavior change.

This study was conducted to assess the physiological parameters of reproduction (sex ratio and gametogenic cycle), parasitism and biological indices (condition index and gonadal index) in Donax trunculus. Samples were collected monthly over two years (from 2016 to 2017) from three sites along the coast of Taghazout (in Southern Morocco) hosting the tourist resort Taghazout Bay. Five stages were depicted by histological examination of gonads: undifferentiated, developing, mature, spawning, and spent. The results of this histological study of the gonads of D. trunculus show that the reproductive cycle of this species has two periods: the first one is characterized by high sexual activity and extends from February to June and the second one corresponds to sexual rest and lasts from July to October. In all three stations and during both years, individuals in the undifferentiated stage (sexual rest) are encountered from July to October. Two spawning periods were observed: the first in March followed by a resumption of activity in April, and the second from May–June. Seasonal variations of the biological indices (GI and CI) were associated with the reproductive and nutritive status of bivalves. The study of parasitism by the trematode Bacciger Bacciger revealed that all the infected individuals were females in the sporocyst stage with a total prevalence between 0 and 9% in August and September respectively. Our results serve as a warning for future management measures and justify the necessity of taking into account the biology of the species in a particular area for better management of resources.

This present contribution examines by means of a discrete event and agent-based simulation the potential of a joint use of resources in the installation phase of offshore wind energy. To this end, wind farm projects to be installed simultaneously are being examined, the impact of weather restrictions on the processes of loading, transport and installation are also taken into consideration, and both the wind farm specific resource allocation and the approach of a resource pool or resource sharing, respectively, are being implemented. This study is motivated by the large number of wind farms that will be installed in the future and by the potential savings that might be realized through resource sharing. While, so far, the main driver of the resource sharing approach has been the end consumer market, it has been applied in more and more areas, even in relatively conservative industries such as logistics. After the presentation of the backgrounds and of the underlying methodology, and the description of the prior art in this context, the network of the offshore wind energy installation phase will be described. This is the basis for the subsequent determination of the savings potential of a shared resource utilization, which is determined by the performance indicators such as the total installation time and degree of utilization of the resources. The results of the simulation show that weather restrictions have a significant effect on the installation times and the usage times of the resources as well as on their degree of utilization. In addition, the resource sharing approach, has been identified to have significant savings potential for the offshore wind energy installation.

Kurzfassung In diesem Beitrag wird eine Simulationsstudie zur Betrachtung des Einflusses der Wettervorhersagegenauigkeit auf die logistischen Prozesse der Instandhaltungsaktivitäten von Offshore-Windenergieanlagen vorgestellt. Das Ziel der Simulation ist es zu untersuchen, inwieweit durch genauere Wetterprognosen die Kosten der Servicelogistik reduziert werden können und folglich wie hoch eine Senkung der Betriebskosten sowie eine Steigerung der Anlagenverfügbarkeit ausfallen. Die Ergebnisse der Simulationsstudie belegen, dass durch eine verbesserte Prognosequalität, insbesondere für die maximale Wellenhöhe als entscheidendes Einsatzkriterium, Kosteneinsparungen realisiert werden können.

The main objective of this study is to characterize the industrial wastewater of the city of Anza located north of Agadir in southwestern Morocco in order to recommend an adequate treatment allowing their reuse, thus reducing the nuisances that undergo the receiving environment (Anza Beach). This study concerns four industrial canned and semi-preserved fish plants that directly discharge their wastewater into the Anza beach. The physicochemical characterization of raw wastewater throughout 2017 revealed that these liquid discharges are heavily loaded with organic matter in terms of COD (Avg = 10557 mg O2 / L) and BOD5 (Avg = 4877 mg O2 / L). ), in TSS (Avg = 3537 mg / L) in mineral matter expressed in terms of chlorides (Avg = 25749 mg / L), and in electrical conductivity (Avg = 68957 μs / cm) with a mean pH close to neutrality. The average levels of total nitrogen and total phosphorus are respectively of the order of 631 mg / L and 84 mg / L. Although these wastewaters have a high organic load (ratio BOD5 / COD = 0.46 and TSS / BOD5 = 0.72), they have a satisfactory biodegradability. Examination of the COD / BOD5 ratio of about 2.16 clearly underlines the biodegradability of the industrial wastewater studied. Biological treatment seems quite suitable.

The installation of offshore wind energy turbines is accompanied by great challenges arising from the dynamic environment, which influences logistics processes. Communication plays a major role for cost-efficient installation processes, due to the coordination needed between different partners involved in the offshore wind energy supply chain. A detailed process analysis revealed the importance of shared information about weather conditions, storage capacities and vessel availabilities. By applying a simulation study, which evaluates eight information sharing scenarios, the influence of the following execution time-related performance measures is investigated: average time in manufacturer storage, average time in port, total installation time and average vessel usage time. As a result, the simulation study verifies that sharing information between supply chain partners can contribute to more efficient logistics processes. However, the achievable prediction accuracy and the interdependencies between the information items have a major influence on the quality of results.

The study of the structure and the dynamics of populations exposed to environmental pollutants can be a useful investigative tool for finding the connections between different levels of biological organization Population dynamics on wedge clam, Donax trunculus is still unknown in Morocco. FiSAT software (FAO-ICLARM Stock Assessment Tools) was used for calculating population parameters of this species. The specimens of D. trunculus (Linnaeus, 1758) were collected monthly in the Agadir Marine Bay (South of Morocco) for two years (January 2016–December 2017) from three stations (S1, S2 and S3), which are directly exposed to eventual pollutants owing to the developing tourism resort Taghazout Bay. The study of the population dynamics of D. trunculus shows that the annual mean of density, biomass and condition index, presents significant seasonal variations depending on the physico-chemical parameters and the animal’s life cycle. The monitoring of age-class frequency distributions of D. trunculus individuals revealed a slighter difference at the three study stations. Asymptotic length (L ∞ ) was 37.96 mm and growth coefficient (K) was estimated at 1.93 year −1. Total mortality (Z) for D. trunculus was 3.30 year −1. Natural mortality (M) and fishing mortality (F) were 1.73 year−1 and 1.57 year − 1 respectively. Exploitation level (E) was computed as 0.48, indicating an optimum level of exploitation of D. trunculus in the coastal waters of Taghazout. It is well demonstrated that bimodal recruitment takes place twice a year; one in late summer–early autumn and the other in spring. The results of this study provide information on the health status of this ecosystem receiving Taghazout Bay project.

After a useful life of 20 to 25 years of existing offshore wind farms, the decommissioning will be a challenging task. In this context, an optimized planning of decommissioning enables savings of energy costs. Due to the lack of sufficient empirical data about decommissioning of offshore wind farms, simulation techniques represent a suitable analysis tool to investigate such planning problems. The present contribution examines the effects of tactical decisions in the decommission phase of offshore wind farms by the use of a discrete-event, agent-based simulation study. The variation in the number of used vessels as tactical decision in connection with weather conditions is investigated. The results show that adapting the number of vessels can reduce about 6% of the decommissioning duration.

The costs of the installation phase of the production system offshore wind energy plant have a considerable influence on the electricity production costs. For this reason, there are efforts undertaken to reduce the installation costs. The resources (e.g. installation vessels) and information (e.g. weather forecasts) play a vital role in the logistics installation network. This paper investigates the potential of a shared use of resources and the sharing of different information in the installation phase of the offshore wind energy by means of an event discrete, agent-based simulation. This is motivated by the large number of wind parks still to be installed in the future. To this end, simultaneously installed wind farm projects are examined and the effects of exchange of different information are investigated. The impact of weather restrictions on the processes of loading, transport and installation is taken into consideration. By means of the resource and information sharing approaches, significant savings potential was identified for the offshore wind energy installation.

In the last decade, the erection of offshore wind turbines, especially in the northern sea, has been showing a significant growth and this trend will continue further in the next years. In order to make the offshore wind energy competitive and attractive, the different processes related to the overall life cycle cost of an offshore wind farm have to be optimized. In this context, the cost for operation and maintenance (O&M) is estimated between 15 and 30 % of the total costs generated by offshore wind farms. Thereby, the efficiency of the maintenance processes is a crucial factor to guarantee sustainable energy and improve the reliability and availability of an offshore wind turbine. Indeed, the maintenance activities in the offshore field are a challenging task especially due to the harsh maritime environment which leads to high material stress and low resource utilization. In this paper, we model the maintenance processes of an offshore wind farm by means of a discrete event and agent -based simulation model. The objective is to schedule the maintenance tasks taking into account all real restrictions based on historical data in order to determine important factors and potential operational improvement. As an example, the simulation will be used to determine the optimal number of resources needed to perform maintenance activities by keeping the resource utilization in an acceptable level.

Demand forecasting of fashion apparel products has to cope with serious difficulties in order to get more accurate forecasts early enough to influence production decisions. Demand has to be anticipated at an early date due to long production lead times. Due to the absence of historical sales data for new products, standard statistical forecasting methods, like, e.g., regression, cannot easily be applied. This contribution applies selected methods into improve forecasting customer demand of fashion or seasonal apparel products. We propose a model which uses retailer pre-orders of seasonal apparel articles before the start of their production to estimate later, additional post-orders of the same articles during the actual sales periods. This allows forecasting of total customer demand based on the pre-orders. The results show that under certain circumstances it is possible to find correlations between the pre-orders and post-orders of those articles, and thus better estimate total demand. The model contributes to the improvement of production volumes of apparel articles, and thus can help reduce article stock-outs or unwanted surpluses.

Operation and maintenance of offshore wind turbines (OWTs) play an important role to guaranty and improve the reliability, availability, and sustainability during the life time of an OWT. Common maintenance approaches from reactive to preventive maintenance show difficulties in being applied throughout offshore wind park operations. In the field of preventive maintenance, the condition-based maintenance shows a significant upturn. This paper gives a valuable insight into a modernized approach to “preactive” measures in different dimensions. To this end, existing approaches for condition-based maintenance are pointed out. Based on this knowledge, a new approach, using existing information and knowledge to encounter relevant events, is introduced. A maintenance strategy by context enables a dynamical adjustment of maintenance time slots based on different information, like, for example, weather, the general condition of a wind turbine, and availability of staff. Finally, the concept will be illustrated with an example.

Field investigations on the population dynamics of Nereis diversicolor were carried out from January 2002 to December 2003 in the estuary of Oued Souss (southwestern Morocco) to determine the changes caused by setting up of a domestic and industrial wastewater purification plant (M'zar) before and after by the end of wastewater discharges in November 2002 on the structure of the ecosystem. Samples of N. diversicolor were collected monthly in the intertidal zone at low tide before (during 2002) and after (during 2003) the end of wastewater discharges. Separation of cohorts using the Algorithm EM method (McLachlan, G.J., Krishnan, T., 1997. The EM algorithm and extensions. Wiley Series in Probability and Statistics. Wiley, New York, 274 pp.) allowed determination of the growth rate (mm day −1 ) by cohort and the annual production. The data showed significant differences between populations of Nereis diversicolor before and after the end of wastewater discharges. During the wastewater discharge period (2002), the population had a mean annual density of 1992 ind m −2 , a mean annual biomass of 75.52 g DW m −2 and an annual secondary production of 141.3 g DW m −2 with a P / B ratio of 1.87. After the end of discharges (2003), density, biomass and secondary production decreased significantly. The annual averages for these parameters were 740 ind m −2 , 14.16 g DW m −2 and 23.83 g DW m −2 , respectively, with a P / B ratio of 1.68. The important decrease observed in density, biomass and secondary production of Nereis diversicolor may be attributed (a) to the environmental changes observed after the end of wastewater discharges in the estuary of Oued Souss, namely the increase of salinity and the decrease of organic matter content, and (b) to the migration of this species towards other areas.

The aim of this study was to assess aquatic environmental quality of Oued Souss (Agadir, Morocco). This estuary has been subjected for a long time to large amounts of sewage discharges and industrial effluents. Since November 2002, no waste outlets have been discharged in this site due to their connection to a wastewater purification plant. Firstly, we have compared metal tolerance of the annelid polychaete (Nereis diversicolor) originating from Oued Souss and a relatively clean site (Oualidia, Morocco). Secondly, we have evaluated with a multi-marker approach (acetylcholinesterase [AChE], glutathione-S-transferases [GSTs], catalase, thiobarbituric acid reactive substances [TBARs]) responses of worms to the pollution gradient. Results have shown that worms from Oued Souss have acquired tolerance to copper and zinc due to a long-term sub-lethal metal exposure and this metal tolerance was maintained in spite of the end of wastewater discharges in this site. Higher catalase, GSTs and TBARs values have been observed in worms from Oued Souss sampled before implantation of wastewater treatment. The multi-marker approach confirms that these worms have been submitted to various contaminants. In contrast, high inhibition in AChE activities measured in worms from Oued Souss could be explained by the continuous agricultural influence of nearest areas. The level of contamination was probably maintained since biomarker values were generally higher in worms from Oued Souss when compared to Oualidia.

Le milieu marin joue un role socio-economique de grande importance dans la region d'Agadir (sud-ouest du Maroc) mais il est le siege de plusieurs sources de pollution. L'objectif de ce travail est d'etudier l'impact du rejet des eaux usees sur la qualite microbiologique des plages dans ce secteur. Des echantillons d'eau de mer et de sable ont ete preleves entre avril et octobre 1997 sur quatre plages de la baie d'Agadir (Agadir, Amadil, Anza et Taghazout) afin d'y rechercher les concentrations en coliformes (CF) et en streptocoques fecaux (SF). Sur les plages Agadir, Amadil et Taghazout, les concentrations moyennes de ces bacteries dans l'eau de mer sont respectivement de 12,7 CF et de 7,5 SF/100 ml pour le premier site, de 26,0 CF et de 5,5 SF/100 ml pour le second, et de 30,0 CF et de 10,7 SF/100 ml pour le troisieme. En revanche, sur la plage d'Anza, les concentrations moyennes sont de 8.104 CF et de 7,9.103 SF/100 ml : ces valeurs tres elevees peuvent s'expliquer par la presence de plusieurs emissaires d'eaux usees au voisinage immediat de cette plage. Malgre de legeres variations dans les concentrations des CF et SF, les resultats relatifs au sable sont similaires a ceux obtenus avec l'eau de mer. Les valeurs des CF et des SF dans les quatre sites ont ete traitees par une methode de probabilite lognormale afin de determiner les parametres de qualite suivants : CF80, CF95 et SF90. Ces dernieres valeurs sont au-dessous des normes europeennes guides, ce qui permet de classer les plages Agadir, Amadil et Taghazout dans la categorie A (bonne qualite des eaux pour la baignade). Meme si les valeurs obtenues correspondent a des echantillons preleves lors de la haute saison touristique, il est necessaire de renouveler chaque annee ce type de prelevement afin de suivre l'evolution de la pollution dans la baie d'Agadir.

In waste stabilisation pond systems the interactions between algae and bacteria have an important ecological effect and appeared to play a key role in the self-purification process. The aim of the present study is to evaluate the interactions between two axenic cyanobacteria: Synechocystis sp. and Pseudanabaena sp. with heterotrophic bacteria and some pathogenic bacteria: E. coli, Salmonella sp. and non-O1 V. cholerae. The results obtained showed that Synechocystis sp. (planktonic cyanobacterium) and Pseudanabaena sp. (benthic cyanobacterium) stimulated the growth and the survival of heterotrophic bacteria and non-O1 V. cholerae and reduced the survival of E. coli and Salmonella. Blooms of these cyanobacteria during hot periods which are a particularity in stabilisation ponds of Marrakech, could explain the dynamics of bacteria studied in this sewage treatment process. The presence of heterotrophic bacteria, showing relative high densities during hot periods, could be considered as an important bioticfactor which led to the cyanobacteria blooms in the Marrakech ponds which function under an arid Mediterranean climate.

Experimental study of the effects of sunlight and Synechocystis sp. (picocyanobacterium) on the incidence of antibiotic resistance in Salmonella sp. and faecal coliforms (FC), was carried out in wastewaters of Marrakesh stabilization ponds (Morocco). The effect of sunlight was found to be important on the incidence of antibiotic resistance of these enteric bacterial populations. In microcosms seeded with the mixed inoculum (40 different strains) of Salmonella or FC and exposed to sunlight, the overall resistance of these bacteria (72.5 and 57.5% respectively) was significantly higher than that noted in the dark (45 and 32.5% respectively). In microcosms seeded with a monobacterial inoculum, some FC isolates became resistant to the antibiotics cephalothin, amoxicillin or sulphamethoxazole, after their incubation in sunlight. Synechocystis appeared to have no significant effect on the incidence of bacterial antibiotic resistance. The ecological significance of sunlight and Synechocystis sp. in reducing densities and increasing antibiotic resistance of pathogenic bacteria through wastewater stabilization ponds is discussed.

During the functioning period of a sand filter, 254 and 234 faecal-coliform strains were isolated from raw wastewater and reclaimed effluent, respectively. When tested for their susceptibility to ampicillin, kanamycin, chloramphenicol, streptomycin and tetracycline, 53% of the strains from the raw sewage and 84% of those isolated from the effluent were resistant to at least one antibiotic. The high incidence of drug resistance in the effluent was connected with a high proportion of Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii.

The aim of this study was to investigate, in situ, the temporal effects of urban effluent discharge on energy reserves and steroid hormone levels in the intrasedimentary worm Nereis diversicolor. Results have shown no differences in energy reserves (glycogen, lipids) in organisms originating from a contaminated site (Oued Souss) and a comparatively clean site (Oualidia). Both sites are located on the Moroccan Atlantic coast. In contrast, steroid hormone (progesterone, testosterone, and 17β-estradiol) levels were significantly decreased in animals from Oued Souss. The differences in the responses suggest that organisms from the polluted site have been exposed to endocrine disruptors.

Studies have recently been conducted in Canada and Russia to test the behaviour of Hydroplus fusegates in extreme winter conditions. This paper presents the scope of this research, and summarizes the main results of the model tests at both laboratories.