Exergy and Exergy Cost Analysis of production systems incorporating renewable energy sources

Exergy is a thermodynamic quantity capable of measuring the conversion of material and energy flows into comparable terms based on the capacity of such flows to generate mechanical work as a useful effect and identifying and quantifying the thermodynamic inefficiencies of a generic process by means of the exergy destruction term. Because of its properties, an exergy is a convenient tool for the calculation of the global resource consumption of both natural and engineering processes. Therefore, there are different exergy-based approaches. Every exergy-based approach has its advantages and its drawbacks. It even has its own spatial and temporal domain [1]. There are different exergy-based approaches that have been reviewed which are EMergy, Extended Exergy, Cumulative Exergy Consumption, Exergetic life cycle assessment, and Thermoeconomics. Reviewing different exergy approaches, especially the approaches that introduce the externalities like Labour, Capital, and environmental cost with their equivalent exergy values will help to develop an approach that avoids the drawbacks and take advantage of other approaches. Exergy-based account methodologies do not account for the ecological processes and products. This is something savior if sustainability is the aim and the goal. The indirect cost of resource consumption must be counted. The exergy cost of mineral resources which are not renewable is not their chemical exergy embodied in them only but also the cost of exergy that has been to be spent to reconcentrate these resources to be available for the upcoming generations [2]. As it is a matter of sustainability, considering the indirect exergy cost is very important. Each exergy-based methodology has its own spatial and temporal boundary. Some of them account only for the exergy consumed during the operation phase like the basic exergy analysis and some of them extend its spatial boundary to include the ecological cumulative exergy cost of a specific product [3]. The ecological cumulative exergy consumption ECEC approach has been introduced by Szarjut. Another approach extends its spatial boundary including the economy of the region or a country where the analysis takes place. This allows some other externalities like money and labor to be accounted in form of exergy. This approach is the extended exergy analysis EEA. This thesis presents a conceptual development of sustainability evaluation, through an exergy-based Indicator, by using the new concept of the Thermoeconomic Environment (TEE). The exergy-based accounting methods here considered as a background are the Extended Exergy Accounting (EEA), which can be used to quantify the exergy cost of externalities like labor, monetary inputs, and pollutants, and the Cumulative Exergy Consumption (CExC), which can be used to quantify the consumption of primary resources “embodied” in a final product or service. Also, the new concept of bioresource stock replacement cost is presented, highlighting how the framework of the TEE offers an option for evaluating the exergy cost of products of biological systems. The sustainability indicator is defined based on the exergy cost of all resources directly and indirectly consumed by the system, the equivalent exergy cost of all externalities implied in the production process and, the exergy cost of the final product.Exergy is a thermodynamic quantity capable of measuring the conversion of material and energy flows into comparable terms based on the capacity of such flows to generate mechanical work as a useful effect and identifying and quantifying the thermodynamic inefficiencies of a generic process by means of the exergy destruction term. Because of its properties, an exergy is a convenient tool for the calculation of the global resource consumption of both natural and engineering processes. Therefore, there are different exergy-based approaches. Every exergy-based approach has its advantages and its drawbacks. It even has its own spatial and temporal domain [1]. There are different exergy-based approaches that have been reviewed which are EMergy, Extended Exergy, Cumulative Exergy Consumption, Exergetic life cycle assessment, and Thermoeconomics. Reviewing different exergy approaches, especially the approaches that introduce the externalities like Labour, Capital, and environmental cost with their equivalent exergy values will help to develop an approach that avoids the drawbacks and take advantage of other approaches. Exergy-based account methodologies do not account for the ecological processes and products. This is something savior if sustainability is the aim and the goal. The indirect cost of resource consumption must be counted. The exergy cost of mineral resources which are not renewable is not their chemical exergy embodied in them only but also the cost of exergy that has been to be spent to reconcentrate these resources to be available for the upcoming generations [2]. As it is a matter of sustainability, considering the indirect exergy cost is very important. Each exergy-based methodology has its own spatial and temporal boundary. Some of them account only for the exergy consumed during the operation phase like the basic exergy analysis and some of them extend its spatial boundary to include the ecological cumulative exergy cost of a specific product [3]. The ecological cumulative exergy consumption ECEC approach has been introduced by Szarjut. Another approach extends its spatial boundary including the economy of the region or a country where the analysis takes place. This allows some other externalities like money and labor to be accounted for in form of exergy. This approach is the extended exergy analysis EEA. This thesis presents a conceptual development of sustainability evaluation, through an exergy-based Indicator, by using the new concept of the Thermoeconomic Environment (TEE). The exergy-based accounting methods here considered as a background are the Extended Exergy Accounting (EEA), which can be used to quantify the exergy cost of externalities like labor, monetary inputs, and pollutants, and the Cumulative Exergy Consumption (CExC), which can be used to quantify the consumption of primary resources “embodied” in a final product or service. Also, the new concept of bioresource stock replacement cost is presented, highlighting how the framework of the TEE offers an option for evaluating the exergy cost of products of biological systems. The sustainability indicator is defined based on the exergy cost of all resources directly and indirectly consumed by the system, the equivalent exergy cost of all externalities implied in the production process and, the exergy cost of the final product

Identification of Transmitting Antennas in Secure Internet of Things Networks

Bluetooth and WIFI channels are open to public users and have few security procedures. One security aspect is for a receiver to be able to verify the identity of the transmitter. This paper describes methods of identifying transmitters by the properties of their antennas

Antenna Modeling Technique for Digital Communication Systems

This paper demonstrates the characterization and modeling of an antenna to predict its effect when used in a digital communication system. The technique was applied to a commercial dual-band antenna. An equivalent circuit model was derived to characterize the antenna behavior in the frequency domain. A time domain system model was also derived to enable the estimation of the antenna effects in a digital system. The results show that the antenna caused symbol scattering and contributed to the error vector magnitude

Characterization of Wideband Antennas for Point-to-Point Communications

Antenna frequency response can be characterized in terms of effective aperture and gain. Antennas can also be characterized as a two-port network to ascertain the antenna transfer function (S21). This characterization is important in point-to-point (P2P) communication, as the frequency response can vary due to changes in the radiation pattern in the physical channel. This paper presents a process to investigate the frequency response of a wideband antenna in order to identify the best orientation of the antenna for P2P communication. The process predicts the antenna’s effective aperture and gain for each orientation. An equivalent circuit for the wideband antenna is also derived to obtain the total radiated power. The frequency-variant radiation pattern is ascertained from the S21 phase obtained from the equivalent circuit. For each orientation, the S21 phase is analyzed based on the linear, minimum, and all-pass phase components, which enables the derivation of an equivalent circuit. The variation of group delay for each orientation is also obtained and compared. The measurements between two identical antennas at the two orientations with a free-space channel were then modeled for simulation in a digital system. This simulation predicts the antenna effects for the two orientations used. Finally, this process was validated by using a non-minimum phase monopole ultra-wideband (UWB) antenna

The relation between the timing of coronary angiography and renal function post coronary artery bypass grafting

Background: Acute kidney injury is a serious complication after coronary artery bypass grafting (CABG). This work aimed to assess the impact of the timing of coronary angiography on kidney function after on-pump coronary artery bypass grafting.   Methods: We included 60 patients who underwent elective isolated on-pump coronary artery bypass grafting from 2017 to 2018 at the National Heart Institute and Benha University Hospital. We divided the patients into two groups; group І included 30 patients with coronary angiography performed less than seven days prior to CABG, and Group ІІ included 30 patients who had coronary angiography more than seven days prior to CABG. Postoperative acute kidney injury was defined according to the consensus kidney disease: Improving Global Outcomes Definition and Staging criteria. Results: The mean body mass index was significantly higher in group I (35.89±5.15 Kg/ m² vs. 31.72±4.99 Kg/ m², P = 0.002). The mean preoperative hemoglobin was higher in group II (12.7 ± 1.5 g/dl vs. 13.9 ± 1.5 g/dl, P = 0.004). The frequency of acute kidney damage was higher in patients who had coronary angiography less than seven days before CABG but did not reach a significant level (46.7 % vs. 30%, P =0.184). There was no difference in the creatinine postoperatively between both groups (1.2 ±0.5 vs. 1 ±0.3 mg/dl; p= 0.214). Conclusions: We found no association between the timing of coronary angiography before on-pump coronary artery bypass graft surgery and postoperative acute kidney injury

Effect of Concentrated Growth Factor alone and mixed with Hyaluronic Acid on Osseointegration of Delayed Implant.

Purpose: The aim of current study was evaluating effect of concentrated growth factor alone and mixed with hyaluronic acid on osseointegration of delayed implant. Subject and Methods: A total of 12 patients, ranging in age from 20 to 45 years old, were divided into two groups in random manner. Group A: Dental implants were placed associating with concentrated growth factor. Group B: Dental implants were placed associating with concentrated growth factor and hyaluronic acid. Treatment changes were evaluated for each group and compared between groups. Results: In the mean of implant stability a statistically significant difference existed within group A as implant stability increased from base line immediately after implant insertion to follow up period after six months, also statistically significant difference existed in the mean of Implant Stability within group B as implant stability decreased from base line immediately after implant insertion to follow up period after six months. Also, there was statistically significant difference in the mean of Implant Stability between the two groups. Conclusions: Concentrated growth factor alone have positive effect on bone osseointegration

Evaluation of a low-cost inkjet printed slot antenna for energy harvesting applications

A circularly polarized patch antenna fabricated using commercially available, low-cost, printers is described. Two additive processes are combined for the fabrication: stereolithography (SLA) and inkjet printing of silver inks. A widely available SLA 3D printer is employed to fabricate the substrate of the antenna. Inkjet printing is used to deposit the metallic layers of the radiating element on the substrate. The two machines employed are very low-cost in comparison to those used in previously reported work. Good adhesion of the metallic patterns to the substrates is observed. Furthermore, the resistance of the added metallic patch is relatively low. The aim is to demonstrate the use of alternative, inexpensive machines, for the prototyping and manufacturing of antennas on 3D printed substrates. In this work, the antenna operates at the 1.575GHz GPS frequency band. Finite-difference-time-domain simulations compare well with the practical experiments

Wideband Transmitarray With Reduced Profile

This letter presents a wideband transmitarray (TA) with reduced profile. A novel unit cell based on a wideband bandpass filter is developed and applied to the design of the TA. The TA consists of two identical tri-layer frequency selective surfaces (FSS), thus it has a lower profile compared to traditional designs which use at least four FSS layers separated by quarterwavelength air gaps to obtain the 360o phase shift range. The FSS has a pair of square patches printed on the top and bottom layers, and a square slot loaded by four microstrip lines printed on the middle layer. The phase shift is achieved by simultaneously adjusting the size of the square patches. Within the frequency band of interest, the developed unit cell shows low insertion loss and sufficient phase shift range. An equivalent circuit model is developed to better understand the operating principles of the FSS. To validate the design concept, one prototype operating at 13.5 GHz is designed, fabricated and measured. The measurement results show that the designed TA achieves 16% 1-dB gain bandwidth and 60% aperture efficiency. The developed unit cell has symmetric configurations so it can also be applied to the design of dual-polarized or circularly polarized TAs

RFID monitoring for Assistive Technologies beyond the Clinic

A UHF RFID tilt angle and location sensing system is described for tracking users of assistive or rehabilitative technologies in their homes. Results show 3-axis accelerometer angles can be read at 10 Hz, and location within a room can be determined within 0.5 m resolution. A skinmounted microstrip patch antenna is proposed for the RFID communications and power harvesting

RFID monitoring for Assistive Technologies beyond the Clinic

A UHF RFID tilt angle and location sensing system is described for tracking users of assistive or rehabilitative technologies in their homes. Results show 3-axis accelerometer angles can be read at 10 Hz, and location within a room can be determined within 0.5 m resolution. A skinmounted microstrip patch antenna is proposed for the RFID communications and power harvesting