City gate stations (CGSs) gas heaters require purified water, but the distilled water level inside the heater gradually decreases over time. Refilling the heater with fresh water is expensive and environmentally harmful. Therefore, utilizing the drinking water produced by a humidification-dehumidification (HDH) desalination unit is a sensible alternative. This study investigates the use of a HDH desalination device to produce freshwater from the waste heat of a CGS gas heater using seven thermosyphon heat pipes (THPs). The impacts of different air velocities on the application performance were also evaluated. The outcomes demonstrate that the best daily produced output, CPL, and exergoenviroeconomic parameters of the suggested HDH desalination system were around 3703 mL, 0.026 $/L, and 47.95$, respectively, at an air velocity of 0.6 m/s. Furthermore, the CO2 mitigations of the systems with air speeds of 0.4 m/s and 0.6 m/s were approximately 16.06% and 8.83% greater than the device with air speed of 0.2 m/s. The findings also revealed that the constructed HDH system had comparable fresh water costs to other systems.

The Non-destructive vibration based structural damage detection techniques have been developed in the recent decades. They are usually converted into a mathematical optimization problem that should be solved using optimization algorithms. In this paper, a new hybrid algorithm, using a particle swarm - genetic optimization, is proposed that is called Swarm Life Cycle Algorithm (SLCA). Additionally, Modified Total Modal Assurance Criterion (MTMAC) that is modal based and involved natural frequencies and mode shapes, is used as an objective function. A cantilever beam is modelled and simulated using finite element method as a numerical case study with several different damage scenarios. To compare the effectiveness of the proposed algorithm with GA and PSO, they are applied to detect the locations and severities of damages of numerical cases separately. To assess the robustness of them, the effects of environmental noise, coordinate and mode incompleteness on the accuracy of damage detection have investigated. For experimental validation of the proposed method, empirical studies of single and double crack aluminium cantilever beams were conducted. The numerical and experimental results show that the proposed algorithm has great potential in crack identification. It is observed that SLCA is able to detect the location and extent of damage irrespective of the noise level and perform well in the presence of mode and coordinate incompleteness.

Summary: A new inspection technique for complex mechanical structures is proposed in this paper, where a fuzzy inference system carries out structural inspection. The inputs to the fuzzy inference system are the elements of a fault signature, an array of numbers prepared with use of below 5 kHz resonance frequencies of faultless and a number of faulty specimens.Advantage: Below 5 kHz resonance frequencies are easier and less expensive to obtain compared to higher frequency ones.Limit: Due to high expenses of experiments, reliable finite element models were alternatively used to obtain resonance frequencies of the faulty specimens.Results: The developed fuzzy inference system in this research accurately located an under-surface fault in an engine cylinder block.

The aim of this study was to evaluate the effect of salicylic acid (SA), Aloe vera gel (AV), and SA + AV on quality parameters of strawberry over 15 days. Weight loss, decay, and firmness increased, while ascorbic acid (AAC), total anthocyanin (TAC), total phenolic (TPC) contents, total antioxidant activity (TAA), and sensory attributes decreased significantly during the storage time in all samples. All treatments suppressed water loss, decay, and firmness and maintained higher AAC, TAA, and TPC compared to the control. AAC loss followed a first-order kinetic model, but TPC and TAC loss followed a zero-order kinetic until day 5 or 10 and a first-order reaction until the end of storage. Most of the recorded quality attributes were better preserved in the SA + AV samples, followed by the AV and then the SA treatments. The data of this study confirmed that the postharvest application of 1 mM SA + AV can improve the quality attributes of strawberry during storage. Practical applications As strawberry is mainly lost during the postharvest period, it is important to take proper strategies to overcome this problem. The results of the present study showed that the coating of the strawberry fruit with AV + SA (especially at 1 mM) retained fruit firmness, AAC, TPC, sensory attributes, and TAA and delayed strawberry decay as well. Besides, the function of AV in keeping the quality parameters of the strawberry fruit was better than that of SA. When SA is to be used as a postharvest treatment, 2 mM SA might give better results in the retention of AAC, TAC, and TPC, and 1 mM SA might give fruits with more firmness and less decay. The results of this study showed that strawberry is a good source of AAC (276.35 mg/100 g) and TPC (1,146.69 mg gallic acid equivalent/100 g) that declined to 186 and 480 mg/100 g, respectively, in the control sample after 15 days of storage, which were still high values. Meanwhile, in the samples treated with 1 mM SA + AV, AAC and TPC were 240 and 758.54 mg/100 g after 15 days of storage, respectively. In conclusion, the use of SA and AV, either alone or particularly in combination, may enhance the health aspects of strawberry through retaining AAC and TPC and therefore, increasing TAA of strawberry and also, maintaining a lower rate of weight and firmness loss.

This article (1) proposes the use of a varying sensing resistor for digital charge estimators of piezoelectric actuators, (2) shows the usefulness of this proposal and (3) derives formulae to estimate the proposed varying sensing resistor. Digital charge estimators are used for charge-based precise position control of piezoelectric actuators. In existing digital charge estimators, an uncalculated resistor is used for a wide range of operating areas. Improper choice of the sensing resistor causes excessive drop in accuracy of charge estimation and/or in the driver voltage across the actuator. These issues are shown to nearly vanish with the use of proposed varying resistors.

Developments and major changes in the industrial units in different dimensions come into being discourages many new methods and systems to allocate valuable place in the meantime, And efforts in the areas of deployment of such systems will move to improve efficiency and productivity has increased as a result. This research is based on methods such as, Fast Fourier analysis, curve waveform, the bearing rollers and phase angle in frequency space were analyzed, followed by imperfections and their possible origin have been nominated. After surveying data and survey results, the disadvantage caused by the unbalance of electric monetary and non‐monetary alignment in transmission was measured.The vibration amplitude and phase angle errors associated with the use of changes and fixes have been identified.

One of the common methods of structural damage detections and identification of location and severity of the damage in structures is investigation of changes in modal parameters before and after damage. These methods which are mostly based on optimization techniques use an objective function based on natural frequencies and mode shapes. This paper reviews previous researches in damage detection techniques based on modal parameters and common objective functions used in the optimization stage in the damage detection process. To this end, damage detection methods based on natural frequency, mode shape, curvature mode shape and both of mode shape and natural frequency are reviewed. In the following, due to high importance of objective function in the damage detection process, objective functions based on modal assurance criterion, flexibility matrix and natural frequency and mode shapes are compared.

In this article, a new objective function which is formed by using generalized flexibility matrix is presented with the aim of solving the constrained optimization problem in damage detection procedure. The main purpose is to decrease the effects of truncation error which ensue from cutting off the higher order modes. Two different case studies are used to evaluate the proposed approach. These cases include, a 2D-frame and a Howe-Truss structure. In this study, each structure is modeled by finite element method and damages are induced by considering a reduction in the stiffness of the elements. Finally, the inverse problem of damage identification is solved by using the Imperialist Competitive Algorithm (ICA) for each damage scenario. Not only the effect of noise on the obtained results is studied but also a comparison is drawn between the proposed method based on ICA and other conventional optimization algorithms, namely PSO and GA.

 Abstract—This paper proposes a new approach to fault detection of gas pipes using mechanical waves which are much cheaper and easier to generate and measure compared to currently employed ultrasound waves. The proposed method includes finite element modelling (FEM), transferring the acceleration data to frequency domain and use of statistical and artificial intelligence techniques. Besides a fault detection algorithm, the applicable length and bandwidth of the method is also investigated and found. equations. Therefore, despite several years of research, no practical use of this method has been reported. In opposite, ultrasound waves have been successfully used to detect leaks of gas pipelines. The main shortcomings of this method is its limited range of operations (tens of meters) and high expense of generators and detectors of ultrasound waves. This paper proposes a new approach: the use of mechanical waves, which are much less expensive to generate/detect than ultrasound waves and can progress much further along the pipeline due to their lower frequency. However, extraction of useful data for health monitoring of pipelines from mechanical waves is not as straight forward as from ultrasound waves. Finite element modelling (FEM) , statistical and intelligent techniques were employed in this research to tackle this complexity. All the employed techniques are detailed in quadruple subsection of Section II, followed by results, conclusion and references.

In this study, a model-based method is employed to identify damage of structure. First, a hybrid objective function is proposed based on vibration data, which consists of frequency and modal strain energy. Then, the inverse problem of damage detection is solved by the single-objective optimization algorithm called ICA. Accuracy of the proposed method is shown by utilizing two different case studies (numerical and experimental). The obtained results of ICA are compared with other commonly used optimization algorithms in damage identification, i.e. particle swarm optimization (PSO).

In recent years the control of vibration amplitude of the flexible structures using tuned vibration absorbers has attracted much attention and has been studied by many authors. Vibration absorbers are usually designed using the Finite Element (FE) model of structures. However, the FE models of vibrating systems are not always available due to the complexity of structures. Moreover, the FE models are not precise due to inaccurate estimation of the physical properties of structure, discretization errors of distributed parameters, poor approximation of boundary conditions, inadequate modelling of joints and computational errors. In this paper, a method is proposed to suppress the vibration amplitude of two arbitrary points on a linear structure subjected to harmonic excitation by attaching two sprung mass absorbers. The method is based on the Structural Modification Using experimental frequency Response Functions (SMURF) technique and determines the impedances of the absorbers at the excitation frequency. The advantage of this approach is that there is no need to have the theoretical or FE models of the structure and it is not restricted to certain geometry. A cantilever beam is considered for the numerical case study and two sprung mass are designed to suppress the vibration amplitude of beam at two arbitrary points. Also, a free-free beam has been tested for the experimental validation of the method. The experimental results show that the designed absorbers are effective and can considerably decrease the vibration amplitude of beam at two selected points.

In recent years Finite Element (FE) modeling has become one of the most popular techniques in structural dynamic analysis. However, the dynamic responses obtained from FE analysis are rarely in perfect agreement with the modal testing results. In contrast, the modal models are generally considered to be correct or at least close to the real dynamic behavior of the structure. Therefore, a model updating procedure should be introduced in order to adjust the analytical model so that the theoretical and experimental results agree. In this paper, a new FRF-based model updating method is proposed based on the Structural Modification Using experimental frequency Response Functions (SMURF) method. It is shown that the method updates the parameters accurately using just a few FRFs from the mis-modeled regions. A six Degrees Of Freedom (DOF) mass-spring system is considered as a test case in a simulated experiment. The convergence of the method and the accuracy with which it corrects the FE model are studied. Moreover, the effect of the number of modes, the frequency range of interest used in the calculations, the coordinate incompleteness and measurement in the noisy environment on the quality of the updated model are investigated. The updated models are compared in terms of the predicted natural frequencies, mode shapes and frequency response functions.