Experimental Performance Analysis Research Articles

Image encryption algorithm based on hyperchaos and DNA coding

AbstractA novel image encryption algorithm based on hyperchaos and DNA encoding is proposed in this paper. Unlike the traditional DNA‐based encoding method, a more fine‐grained encryption approach is adopted, which enhances the security of the system. To address the inherent binary arithmetic limitation of traditional DNA computing, the authors develop a novel symmetric and reversible DNA subtraction operation that fully utilizes the encryption advantage of DNA computing. To enhance security, the authors introduce a DNA crossover mechanism based on pixel, which can generate different ciphertexts even for the same pixel values. In the algorithm, the authors propose a diffusion strategy that combines left diffusion, right diffusion, and XOR parameters. This strategy not only ensures the avalanche effect, where even a single pixel change in the plaintext image will cause a drastic change in the ciphertext image, but also greatly enhances the security of the algorithm. Experimental results and performance analysis indicate that the authors’ proposed system has good encryption performance and the ability to resist noise attacks and clipping attacks.

Experimental and numerical analysis of the thermo-hydraulic performance of a cross-flow air-to-gas capsule-type plate heat exchanger

Energy loss is a major problem in the petrochemical industry. One of the ways to save energy and reduce fuel consumption is to recover waste heat in thermodynamic cycles. One potential solution is to utilize an air-to-gas plate heat exchanger, The mechanism that conveys the thermal energy from the waste gases in the combustion chimney of the boilers to preheat the air required for the combustion process within the same system, known as a heat recovery system. As gasses have a low heat transfer coefficient, capsules with different patterns have been designed on the plates of this heat exchanger to increase the heat transfer rate. The initial configuration of the heat exchanger incorporates both analytical and numerical approaches in its design. In addition, to achieve an optimal hydrothermal performance of the exchanger, the pattern and placement of capsules and arrangement of plates have been numerically investigated. 4 novel models were studied (IC, IP, IIC, IIP), and results showed that theIICmodel had better performance in comparison with other models. The Nusselt and friction factor equations in capsule-type channels have been extracted by numerical simulations. By defining the performance evaluation criteria, it was demonstrated that the heat transfer improvement in the channel with capsules is more significant than the impact of increased pressure drop compared to a simple rectangular channel. Therefore, the use of the capsuled channel is justified. TheIICmodel illustrated the best performance compared to the simple channel, as indicated by the increase infandNuvalues by 35–44% and 28–55%, respectively, for gas side channels in the Reynolds number range of 3500–14000. Finally, the heat exchanger (with the selected capsule pattern) is constructed and installed in the relevant unit for applying experimental tests. The results of this study indicate that the maximum deviation among the calculated results and the corresponding experimental data is 13.9%.

Numerical and experimental analysis in seismic performance of post-earthquake reinforced concrete frame retrofitted with ECC

In order to further demonstrate the effectiveness of engineered cementitious composites (ECC) in repairing and strengthening the post-earthquake damaged structure, at the overall structural level, experimental and numerical comparative analysis of structural seismic performance before and after “retrofitted with ECC” is conducted in this paper. A 1:2-scale reinforced concrete frame is tested under cyclic reversed loading and a new ECC material’s constitutive model is proposed in this paper for improving the accuracy and feasibility of numerical modelling. The modelling method and newly proposed constitutive model of ECC has been demonstrated to be workable and accurate. Based on numerical and experimental data, the increase of the average yielding displacement after the installation of ECC is relatively significant (80.4% to 156.4%), and the repairing method using ECC in post-earthquake damaged RC frame can restore and even exceed the original frame’s load bearing capacity. Comparing the ultimate inter-story drift ratio, the ratio with ECC is about 31.0% higher, indicating that ECC has good deformation capacity and the usage of ECC is indeed an effective method to improve deformation capacity in repairing and strengthening post-earthquake damaged structures. The results confirm the effectiveness and superiority of retrofitting ECC in post-earthquake damaged structures for the reason that the repaired structure can reach the same level of seismic performance as the original structure. The “repairable” characteristic can be used in the design of earthquake resilient structures.

Experimental performance and economic analysis of finned solar receiver for parabolic dish solar collector

The solar receiver is a vital component of concentrated solar collectors that absorbs solar radiation and converts it into heat. One of the challenges the research community faces is minimizing heat loss from the receiver at higher temperatures to maximize the thermal performance of parabolic dish collectors and achieve the system's cost-effectiveness. Cavity receivers have a complex design that makes them more challenging to manufacture and entails higher costs for improved thermal performance. Implementing innovative receiver designs is essential to maximize the absorption of solar radiation and minimize heat losses. In this experimental study, a cost-effective solar receiver was fabricated with fins to study heat transfer. The solar receiver is examined using water as heat transfer fluid with three flow rates of 0.097 kg/s, 0.125 kg/s, and 0.152 kg/s. The residence time of water is increased by adopting integrated fin receiver designs. The provision of fins in the solar receiver enhances heat transfer by increasing the turbulence in the fluid flow and results in higher thermal efficiency. The average energy and exergy efficiencies are 67.81 % and 8.93 %, respectively, with a 0.152 kg/s flow rate. At the highest water flow rate (0.152 kg/s) considered in this study, a lesser heat loss of about 3776.2 W occurred due to the effective heat transfer. The cost metrics, like levelized cost of electricity, net present value, and the payback period, are about 0.21 $/kWh, 923 $, and 3.38 years, respectively, at 0.152 kg/s flow rate. The proposed solar receiver produces optimal thermo-economic performance and lower initial investment for steam generation than other receiver designs. The current experimental study's findings could benefit the entire solar industry by presenting an effective solar receiver design for solar collectors.

Experimental Study on Double-Joint Soft Actuator and Its Dexterous Hand.

In this paper, we propose a pneumatic double-joint soft actuator based on fiber winding and build a dexterous hand with 11 degrees of freedom. Firstly, soft actuator structural design is carried out according to the actuator driving principle and gives the specific manufacturing process. Then, an experimental analysis of the bending performance of a single soft actuator, including bending angle, speed, and force magnitude, is carried out by building a pneumatic control experimental platform. Finally, a series of dexterous robotic hand-grasping experiments is conducted. Different grasping methods are used to catch the objects and measure the objects' change in height, length, and rotation angle during the experiment. The results show that the proposed soft actuator is more consistent with the bending rule of human fingers, and that the gestures of the dexterous hand are more imaginable and flexible when grasping objects. The soft actuator can carry out horizontal and vertical movements, and rotation of the object in the dexterous hand, thus achieving better human-computer interaction.

Experimental investigation and performance analysis of box-type standard solar cooker with an inclined cover (BTSCIC).

This work proposes a novel transparent solar cooker design, and its performance is evaluated using a set of experiments. The cooker is fabricated from transparent and non-transparent, and lightweight material. The study was conducted at the Renewable energy laboratory in India (MNNIT Prayagraj). For thermal performance assessment of Box-type standard solar cooker with an inclined cover (BTSCIC) is compared with a box-type standard solar cooker (BSSC). The area, heat input, and thermal efficiency have all increased significantly. The total absorbing area increases by 32%, total solar radiation by 189%, absorber plate temperature by 19.8%, inner air temperature by 16.5%, pot water temperature by 17.1%, and inner wall average temperature by 58%, as compared to box-type Standard Solar Cooker. The average exergy was 4.2% (BTSCIC) and 2.61% (BSSC), respectively. The cost payback period of BTSCIC was 2.22years and BSSC 1.5years.

Experimental performance analysis of photovoltaic systems applied to an positive energy community based on building renovation

Global carbon neutrality can be achieved by reducing greenhouse gas emissions in the building sector using various renewable energy systems, such as photovoltaic (PV) systems, at the community level. In this study, various PV systems were applied to a community consisting of two residential and two nonresidential buildings, and a comparative analysis was conducted to achieve a net yearly positive energy balance at the community level. The PV systems included building-attached PV (BAPV), building-integrated PV (BIPV), and BIPV–thermal (BIPVT) systems. An analysis of the empirical data over a year revealed that the annual net energy balance of the proposed community was 139%, the self-sufficiency of building energy consumption was 33.2%, and the self-consumption of solar power generation was 76.7%. Based on these empirical data, the initial investment cost savings of the PV system and payback period were analyzed through carbon credit trading. The results showed that the payback period ranged from 9 to 17 years.

Experimental performance analysis of a biogas energy assisted hybrid milk cooling system

Biogas energy assisted hybrid milk cooling system was investigated experimentally, in this study. The system operated in a cycle. Primarily, biogas was obtained from the residues of animals in the farm environment and an internal combustion gas engine is started with this gas. Then, the gas engine provided the power required for the compressor of the cooling system to operate. The main purpose of the study was to encounter the energy required for milk cooling only from the biomass potential of animal wastes and in this way, it was to bring a system with high energy efficiency for milk cooling process to the literature and industry. In experiments, 150 liters of milk in the first milking and 300 liters of milk in the last milking were cooled. It was determined that the energy consumption in the first and last milking is 2.29 kWh and 2.54 kWh. The results revealed that this developed system was 45.61% and 41.61% more advantageous for first and last milking, respectively, compared to conventional milk cooling systems in terms of energy consumption. When the system compared to other alternative energy source assisted milk cooling technologies with similar milk cooling capacity, It was observed that 14.55% and 24.40% more efficient with regards to energy consumption for the first and last milking. Additionally, experimental and Carnot COP values of the cooling system were determined as 4.29 and 8.26, respectively. These data revealed that the hybrid system had a higher performance of 38.4% compared to other milk cooling techniques.

A VEHICLE ROUTING PROBLEM OPTIMIZATION WITH DRONE USING TABU SEARCH ALGORITHM AND ANALYTICAL HIERARCHY PROCESS

This research presents optimization of the fastest route using Drone. Vehicle Routing Problem with Drones (VRPD) is used for planning the mapping of areas with minimal makespan. Drone point route design aims to mapping the area with considering the boundaries. In this paper, an optimization method using the Tabu Search algorithm and Analytical Hierarchy Process (AHP) to resolve VRPD problems is proposed. Tabu Search algorithm is suitable for the implementation of Vehicle Routing Problem because it is able to find the closest distance optimally with guiding other processes using a series of movements to change one solution to another. The optimization process using Tabu Search can find a suitable pair of points so that the closest route can be found. AHP is used for the weighting process and determining the hierarchy of route selection by prioritizing routes that meet the criteria and the appropriate weights. The optimization resulted in a 7.08% reduction in the distance and significantly reduce the makespan as well as the metaheuristic approach. Experimental processes and performance analysis are carried out to find that this method can consistently produce better and optimal solutions.

Experimental analysis of energy storage performance of phase change materials in horizontal double-glazing applications

In this study, phase change material (PCM) energy storage performance was experimentally investigated for horizontal double-glazing applications. In this context, it was aimed to use PCM for energy storage in horizontal insulating glass applications, and optimize amount of PCM in the glass and the effect of the surface area it occupies on the indoor light level were analyzed. In this regard, the temperature variation in the glass with the amount of PCM was observed and the optimum amount of PCM was evaluated. The experiments were carried out on an insulated test cabin using double-glazed test elements with different PCM ratios as 0 %, 15 %, 30 %, 45 %, and 100 %. An external light source was used to create constant radiation conditions during the experiments and temperature measurements, thermal camera images, as well as light intensity measurements were taken in the test cabin. The results revealed that the increase in the energy storage capacity with the amount of PCM is limited, while the light transmittance decreases continuously due to the solid PCM shading. In other words, as the amount of used PCM increases, the energy storage capacity increases and thermal comfort conditions improve. However, this increase stopped at a certain point and a constant trend was observed. It was concluded that, this situation occurs due to the blocking of the radiation entering the indoor environment and the decrease in the radiation intensity. For the 30 % area ratio, the cooling period was extended by 450 min compared to the reference case, and longer thermal comfort conditions were provided.

Experimental performance analysis for reverse osmosis pilot plant subjected to different brackish salinity spectrum

The main obstacles to reverse osmosis desalination processes are high energy intensity and long-term continuity. Temperature and pressure have the greatest and most significant effects on energy use. The main objectives of the current study are to determine the pressure and temperature-dependent optimal operating parameters for a membrane desalination unit. To determine the ideal operating settings for a membrane unit, the impact of changing pressure and temperature on its performance was investigated. These two elements are closely connected to the energy consumption per cubic meter under various operating situations. The present work is experimentally carried out in a research laboratory for capacity building and future research studies in the desalination field established in the National Center of Water Research – Egypt. This laboratory is Egypt’s first multi-functional Desalination Research Station for seawater, brackish water, and related water treatment areas. The plant is equipped with online instrumentation and Data Acquisition System and 13 sensors for most physical parameters which economically affect membrane performance and desalination processes. These parameters, particularly pressure and temperature, are measured, evaluated and analyzed. According to the findings in this study, feed salinity and feed pressure both have significant impacts.At 13 bar pressure, the maximum salt rejection was 98.8%. When feed pressure is increased from 5 to 13 bars, there is a 73.3% decrease in permeate salinity. Additionally, applying a 13 bar feed pressure to water with a salinity of 1000 ppm results in the best water quality of 12 ppm. The relationship between feed pressure, brine salinity, and membrane water recovery appeared to be approximately linear and positive. More crucially, it was discovered that feed pressure, salinity, and water recovery are all constants for water permeability. A prototype for the maximum pressure (ranges from 15.6 to 10.8) and temperature (ranges from 21 to 35) at which the optimal recovery of the laboratory occurred was developed. Moreover, the developed prototype includes the corresponding permeate TDS and a specific energy for each optimal point.

Spectrum Sensing Based on Hybrid Spectrum Handoff in Cognitive Radio Networks.

The rapid advancement of wireless communication combined with insufficient spectrum exploitation opens the door for the expansion of novel wireless services. Cognitive radio network (CRN) technology makes it possible to periodically access the open spectrum bands, which in turn improves the effectiveness of CRNs. Spectrum sensing (SS), which allows unauthorized users to locate open spectrum bands, plays a fundamental part in CRNs. A precise approximation of the power spectrum is essential to accomplish this. On the assumption that each SU's parameter vector contains some globally and partially shared parameters, spectrum sensing is viewed as a parameter estimation issue. Distributed and cooperative spectrum sensing (CSS) is a key component of this concept. This work introduces a new component-specific cooperative spectrum sensing model (CSCSSM) in CRNs considering the amplitude and phase components of the input signal including Component Specific Adaptive Estimation (CSAE) for mean squared deviation (MSD) formulation. The proposed concept ensures minimum information loss compared to the traditional methods that consider error calculation among the direct signal vectors. The experimental results and performance analysis prove the robustness and efficiency of the proposed work over the traditional methods.

Experimental Analysis of Watertightness Performance of Interfaces between Masonry and Steel Structures Subjected to Accelerated Aging

Steel buildings often experience failure at the interfaces between their vertical exterior enclosure systems (VEESs) and structural elements. This phenomenon generates various pathological manifestations in steel buildings, resulting in the precocious decay of the structure and the diminishment of its service life. The treatment of these interfaces is essential for ensuring their proper performance and watertightness, and to protect the durability of the steel structure. This paper proposes a method for treating common interface joints between masonry and steel structures with the application of an EPDM (ethylene propylene diene monomer) elastomer membrane. The main goal of this building technique is to ensure the durability and watertightness of the interface’s joints when they are subjected to aging triggered by heat exposure and thermal shock. The experimental models tested consisted of a steel frame and a conventional masonry vertical enclosure system with ceramic blocks plastered with cement mortar. The models were subjected to ten cycles of heat exposure and thermal shock for the purpose of simulating accelerated aging, followed by a watertightness experiment that simulated the action of both rain and wind pressure. The interfaces between masonry and the steel structure proposed in this study allowed adequate differential movements between the parts, without damage to joints and masonry. Only small cracks were observed in the outer test region of all of the interfaces tested. In the regions of the joints treated with the EPDM membrane, no alterations were visible to the naked eye. During the cycles of the heat exposure and thermal shock test, the maximum relative horizontal displacements observed in the joints were 0.743 mm for vertical joints and 0.230 mm for horizontal joints, indicating the accurate reproduction of the behavior expected from an untied interface. The results obtained in the previously mentioned watertightness test showed that no humidity stains were found on the inner face of any of the specimens, even after the continuous application of a pneumatic pressure of 400 Pa for eight hours. Therefore, the results indicated satisfactory performance in terms of durability and watertightness in all evaluated cases, indicating that the application of an EPDM membrane can be effective in preventing water leaks in the interfaces between masonry and steel elements, thus contributing to ensuring the steel structure’s durability.

Field experimental test and performance analysis of a novel hybrid CdTe PV glass module integrated with phase change materials

In this study, a novel hybrid semi-transparent CdTe PV glass module integrated with a middle phase change materials (PCMs) layer is proposed and fabricated. Detailed fabrication process of the CdTe-PCM PV glass module (CdTe-PCMG) is illustrated. A field experimental test rig was constructed to evaluate and compare its comprehensive performance with the single CdTe PV glass (CdTe-SG). Several groups of continuous full-day experiments were conducted under different ambient condition days in Hefei. Main results are: (1) Utilization of PCM can effectively improve the PV module's electrical output, with an average daily increase ratio of 6.67% on the daily total electricity generation compared with SG among the ten investigated sunny days. Daily average ηe were respectively 7.63% and 8.31% for SG and PCMG; (2) PCM has realized effective cooling to the PV glass, with the maximum temperature differences between SG's and PCMG's external PV surface of 16.56 °C, 26.32 °C and 18.60 °C for the three groups of experiments. Average temperature decrement factors of the PCMG external surface were respectively 0.76, 0.72 and 0.67 compared with SG. This novel PCMG module has a promising application potential in energy-saving and indoor thermal comfort improvement when applied as building window.

Solid desiccant air conditioning system using desiccant dehumidifiers with cooling technique and thermal recovery unit: Experimental investigation and performance analysis

The displayed experimental investigation pursues to design and fabricate high-efficient desiccant air conditioner that achieves the sustainable development by protecting the environment from harmful emissions, achieving thermal comfort conditions, and rationalizing energy consumption. To achieve this, smart innovative desiccant dehumidifiers and energy recovery unit were incorporated with the suggested air conditioner. The smart innovative desiccant dehumidifiers aimed to improve the air dehumidification capacity and avoid the effect of the adsorption heat by using larger cooling rates to cool the process air. To minimize power consumption, regeneration air was pre-heated using an energy recovery unit. The results showed that the ultra-efficient desiccant air conditioner suggested in the present study represents an effective design because it could achieve thermal comfort conditions and rationalize energy consumption. The ultra-efficient desiccant air conditioner could supply the cooling air with average temperature and humidity ratio varying between 11.9 and 14.6 °C and 6.89–8.9 gw/kgda, respectively. Also, the energy analysis presented that the proposed desiccant air conditioner is high-efficient where the average values of thermal coefficient of performance and electrical coefficient of performance reached 3.68 and 3.79, respectively. Moreover, the average saving in thermal energy was varying between 21.9 and 28%.

CaFANet: Causal-Factors-Aware Attention Networks for Equipment Fault Prediction in the Internet of Things.

Existing fault prediction algorithms based on deep learning have achieved good prediction performance. These algorithms treat all features fairly and assume that the progression of the equipment faults is stationary throughout the entire lifecycle. In fact, each feature has a different contribution to the accuracy of fault prediction, and the progress of equipment faults is non-stationary. More specifically, capturing the time point at which a fault first appears is more important for improving the accuracy of fault prediction. Moreover, the progress of the different faults of equipment varies significantly. Therefore, taking feature differences and time information into consideration, we propose a Causal-Factors-Aware Attention Network, CaFANet, for equipment fault prediction in the Internet of Things. Experimental results and performance analysis confirm the superiority of the proposed algorithm over traditional machine learning methods with prediction accuracy improved by up to 15.3%.

Experimental analysis of thermal performance of direct absorption parabolic trough collector integrating water based nanofluids for sustainable environment applications

Integration of nanofluids with solar collectors to enhance collector's thermal performance stands out as one of the most effective techniques owning to nanofluids favorable thermo-physical properties. By improving the thermo-physical properties of heat transfer fluids, nanofluids enhance the efficiency of thermal systems by improving the thermal energy storage capacity. This experimental study serves as a novel comparison between water-based Al2O3 (Alumina) and Multi-walled Carbon Nanotubes (MWCNTs) nanofluids in such mass concentrations (0.1%, 0.2%, and 0.3%) at fixed mass flow rates of 0.012 kg/s and 0.024 kg/s to investigate the impact on the performance of Direct Absorption Parabolic Trough Collectors (DAPTC) under the arid climatic conditions of Pakistan. The peak thermal efficiencies were found to be 40%, 56% and 58% for distilled water (DW), Al2O3-water and CNTs-water nanofluids, respectively. Thermal efficiency of DAPTC was improved by 18% in comparison with the basefluid alone on account of increased surface area, thermal conductivity and overall heat transfer capabilities. The CNTs-water nanofluids were observed to be more thermal efficient Heat Transfer Fluids (HTFs) owing to the black color and comparatively lower specific heat capacity. These thermal efficient fluids are of great use in the thermal energy storage systems. In addition, the use of nanofluids for heating and cooling purposes in industries is preferable as operational and manufacturing costs can also be lowered by reducing the systems size.

Experimental analysis of tribological performance of base ficus carica vegetable oil with different polymers as additives using four ball tribometer

The need to use vegetable lubricants has been driven by the widespread concern for environmental issues, especially in industries that overuse petroleum lubricants. This research examined the tribological characteristics of vegetable-based lubricants by adding additives such as ethylene–vinyl acetate (EVA) and Eichhornia crassipes carboxymethyl cellulose (EC-CMC) polymers to study the viscometric response of the lubricants. The test was conducted using four ball-tester, and analyzed in terms of coefficient of friction (COF), wear scar diameter (WSD), and wear scar rate, respectively. The results showed that with the addition of each additive enhanced the tribological properties significantly but yielded poor results with 0.5% additives for both samples. The characterization investigation showed that ficus carica (Fig) oil responded effectively to the addition of various additives when conducted thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. Under 100 kg load and speed of 1200 rpm, base Fig lubricant yielded a higher COF of 0.193, while blended EVA and EC-CMC gave lower COF of 0.161 and 0.171, while the lowest wear scar diameter was with 1.5 wt% EVA (0.39 mm) and 1 wt% EVA (0.41 mm), respectively. Comparing all the lubricants under 1500 rpm, the base Fig lubricant yielded 0.317, while 1.5 wt% EVA, 1.5 wt% EC-CMC, SEA 5W 30 gives COF of 0.287, 0.263, and 0.239, respectively. The study revealed that the reduction in the COF and wear scar diameter was due to the formation of the film by the included additive.

Experimental OFDM transmission performance analysis in a SOA - fiber cavity laser.

In this article, we present an experimental study of OFDM transmission using a specific bi-directional fiber cavity laser based on a semiconductor optical amplifier. We show that in the presence of sinusoidal modulation, its frequency response presents resonances relative to the optical cavity modes. We investigate first the performance of the system in terms of Error Vector Magnitude (EVM) for different configurations relative to the frequency position of the OFDM sub-carriers with respect to the frequency interval of the resonant modes. The obtained results show a significant improvement in the OFDM transmission EVM by increasing the OFDM subcarriers per frequency interval. We then analyze the impact of inter-symbol interference and inter-frame interference on the system's performance due to the round-trip echo and propose a pre-compensation method that added a small percentage of the previous symbol inversed before transmitting it inside the cavity where a decrease in the EVM is obtained respectively from 21.4% to 9.6% and from 26.8% to 13.2% for 4-QAM and 16-QAM data transmission.

Experimental and numerical analysis of shear performance of reinforced concrete beams with double openings

Experimental and numerical analysis of shear performance of reinforced concrete beams with double openings