Multi-Response Optimization For Industrial Processes

Process optimization is a very important point in modern industry. There are many classical optimization methods, which can be applied when some mathematical conditions are verified. Real situations are not very simple so that classical methods may not succeed in optimizing; as in cases when the optimization has several contradictory objectives (Collette, 2002). The purpose of this work is to propose an optimization method for industrial processes with multiple inputs and multiple outputs (MIMO), for which the optimization objectives are generally contradictory and for which some objectives are not maximum or minimum but performance criteria. The first step of this method is modeling each process response by a quadratic model. After establishing the model, we use a simplified numerical optimization algorithm in order to determine values of the parameters allowing optimizing the different responses, for MIMO processes. This method will also allow finding optimum target values for multiple inputs single output processes

The influence of humic acids extracted from Chaouia soil on the behavior of transition metal ions and pesticides

      Humic acid (HA) and fulvic acid (FA) exist ubiquitously in environments and have a variety of functional groups, which allow them to complex with metal ions and pesticides. Furthermore, these interactions can not only alter the environmental behavior, but also influence the removal and transportation of those pollutants. The study of the interaction between Cu (II), VO (II) and Mn (II) with HAs provides environmental information on the oxidation states of paramagnetic metals and their mechanisms of binding to humic acids. Electron spin resonance (ESR) study demonstrates that VO (II) and Cu (II) ions are bound with oxygen ligands to HAs, while the Mn (II) complex occurs as [Mn(H2O)6]2+. Additionally, Cu (II) ions are more strongly bound than Mn (II) ions to soil HAs. The effect of the presence of HA on photolysis of Tribenuron-methyl (TRB) and Imazapyr (IMAZ) herbicides in water was studied by irradiation of different mixtures of HA/herbicide (0.5:1 and 1:1 by volume). The obtained results clearly demonstrate that HA substances exhibit a screening effect on the photochemical degradation of the two herbicides. The protective effect of HAs on the TRB and IMAZ degradation could be explained with an inclusion and/or adsorption of the herbicide molecules in the humic matrix

Study of the effect of chromium on the germination parameters of Fenugreek (Trigonella foenum-gracium L.) and Lens (Lens culinaris)

Received: September 21st, 2022 ; Accepted: January 2nd, 2023 ; Published: February 8th, 2023 ; Correspondence: [email protected] contamination by heavy metals is a global environmental problem. This contamination affects agricultural crops in the area concerned. In the present study, chromium, which is a heavy metal, is evaluated for its diverse effects on seed germination and lateral growth of fenugreek and lens seeds. A chromium solution was prepared at increasing concentrations: 0, 0.02, 0.04, 0.06, 0.08, 0.1, and 0.2 mg L-1 for the addition of germinating seeds in petri dishes for ten days. After two days, the germination rate is calculated. For the following days the length of radicle, stem, and number of leaves are measured. The germination rate of fenugreek varies between 100 and 73.33% for the control and 0.02 mg L-1 of chromium respectively. However, the germination rate of the lens varies between 100% for the control and 90% for the 0.02 mg L-1 . The elongation of fenugreek radicle with chromium solutions shows a significant effect. However, there is no significant difference in the lens at the different concentrations. For the growth of the fenugreek stalk, it is noticed that the concentration 0.02 shows a length of 2.83 cm compared to their control which is 2.30 cm. Consequently, chromium at 0.02 mg L-1 stimulates growth, but at 0.2 mg L-1 , it inhibits it. For lens the length of the stems shows also a significant difference compared to their control. So the effect of chromium on germination parameters depends on their concentrations, as well as on the seed response itself. For our research the response of fenugreek compared to the lens at the same concentrations is different

Severe Tricuspid Valve Endocarditis Related to Tunneled Catheters in Chronic Hemodialysis Patients: When Should the Catheter be Removed?

Introduction: Hemodialysis (HD) patients are predisposed to infective endocarditis (IE) mainly due to repeated manipulation of the vascular access. However, catheter seeding and IE may also result from a distant infection site.Case series: A diabetic patient who was maintained on regular HD through a permanent catheter in the right internal jugular vein presented with septicemia of urinary origin due to Pseudomonas aeruginosa. He was treated with injectable antibiotics for 15 days. Few days after the end of the treatment period he presented with inflammation of the catheter exit site. Blood cultures revealed Pseudomonas aeruginosa and echocardiography showed a large vegetation on the tricuspid valve, confirming the diagnosis of IE. The patient improved after catheter removal and treatment with ceftazidime, vancomycin and amikacin. Another patient who was maintained on chronic HD through a tunneled catheter in the right internal jugular vein presented with a limited infection in the sub-cutaneous tunnel of the catheter that improved after treatment with injectable antibiotics. Two months later, he presented with severe sepsis without signs of local infection of the catheter. Chest radiography showed right sided infiltrates. Injectable antibiotic therapy was given without improvement. Blood cultures were negative but echocardiography showed a large tricuspid valve vegetation. Antibiotic regimen was modified to include vancomycin, amikacin and ceftazidime and the catheter was removed. Unfortunately, the patient died two days after diagnosing IE.Conclusion: catheter seeding and IE may be a consequence of sepsis originating away from the HD catheter site. Tunneled catheters may need to be pre-emptively removed in such situations to prevent serious IE.Keywords: Hemodialysis; Infective Endocarditis; Tricuspid Valv

A Probabilistic Assessment Approach for Wind Turbine-Site Matching

This article provides a new methodology for wind turbine-site matching by using a probabilistic approach. The random behavior of the wind speed climate and the uncertainties of wind turbine characteristics are important to take into account in models used to evaluate the performance of the wind turbine. The proposed formulation of the wind turbine-site matching is derived based on the probabilistic reliability assessment approach. It was experimented using different power curve approximation models, for different random conditions, using time series of wind speed in two sites in Morocco: Dakhla and Essaouira. A comparison based on methods used in literature for the estimation of two-parameter of the Weibull function to fit the wind speed distribution is also carried out. The results revealed that the introduced performance indicators are less sensitive to the models used to approximate the wind power curves compared to the deterministic conventional indicator that leads to different rankings and problems of over-sizing or under-sizing. However, those performance indicators are more sensitive to the variation of the wind speed distribution parameter’s and can help on accurately estimate the wind power. Moreover, the proposed formulation allows a global sensitivity analysis using Sobol’s indices to observe the influence of each input parameter on the observed variances of the performance of a wind turbine. A numerical application illustrates the interpretation of sensitivity indices and shows the impact of the wind speed and the rated wind speed on the variance of the wind turbine performance. This method can help wind energy developers and manufacturers to optimally select WTGs for their future project and accurately forecast the performance of their WTGs for monitoring and maintenance scheduling under uncertainty

A Bayesian Regularized Artificial Neural Network for Up-Scaling Wind Speed Profile

Maximizing gains from wind energy potential is the principle objective of the wind power sector. Consequently, wind tower size is radically increasing. However, choosing an appropriate wind turbine for a selected site requires having an accurate estimation of vertical wind profile. This is also imperative from the cost and maintenance strategy point of view. Installing tall towers or other expensive devices such as LIDAR or SODAR raises the costs of a wind power project. In this work, we aim to investigate the ability of a Neural Network trained using the Bayesian Regularization technique to estimate wind speed profile up to a height of 100m based on knowledge of wind speed at lower heights. Results show that the proposed approach can achieve satisfactory predictions and prove the suitability of the proposed method for generating wind speed profile and probability distributions based on knowledge of wind speed at lower heights