Current System Research Articles

Upgrade of the ATLAS Level-0 TGC Endcap Muon Trigger for HL-LHC

The Level-0 endcap muon trigger system for the ATLAS experiment at the HL-LHC, which performs a fast muon reconstruction using the Thin Gap Chamber (TGC), is being developed to cope with more than three times higher luminosity environment and achieve a better performance. The efficiency in the high-p T region was found to be 9% higher than the current system. The TGC hit signals digitized at the frontend electronics are sent to the backend, and muon candidates are reconstructed using the hits. Then, the candidates are combined with information from other detectors to refine transverse momentum (p T) reconstruction and reduce fake trigger candidates. The precise online estimation of p T allows us to apply highly efficient trigger condition to select events that contains muons with high p T.The Sector Logic (SL) is responsible for the online fast reconstruction in the L0 Muon Trigger system, and the algorithms are implemented in a large-scale modern FPGA on the SL. Each step of the reconstruction algorithms is first implemented as individual modules, and all trigger algorithms run sequentially as a chain in a combined firmware. The trigger algorithms are being tested on the prototype trigger board, the SL. The resource usage of the FPGA is reasonable and the trigger latency is within the acceptable limit.

Alert System to Prevent Drowning using IoT- A Survey

Swimming is a popular sport as it is a pleasant recreational hobby. Aside from its physical benefits, it also relieves stress and gives a sense of peace. So, it is highly preferred by children’s, adults, and sometimes even elderly people. Many countries have made swimming and other life skills compulsory activities in school to avoid fatalities in the event of disaster. While swimming has many advantages, safety precautions are paramount to avoid unintentional deaths. While various drowning prevention systems and technologies have been developed, many of them lack accuracy in detecting drowning incidents and fail to provide an effective rescue mechanism for swimmers in distress. To develop a smart anti-drowning and alert system, this study presents a comprehensive survey of existing drowning systems and suggests a proposed model in response to the identified gaps and challenges in current systems. The suggested framework includes Arduino microcontrollers, voice recognition technology, ultrasonic sensors, and alert generators. The proposed approach not only addresses the constraints of existing systems, but it also provides a cost-effective and scalable solution that can be used in a variety of water environments, including pools and natural bodies of water. The suggested system has the potential to reduce reaction times in emergency circumstances, adding to the overall enhancement of water safety. Future research could focus on practical implementation, testing, and improvement of the proposed model to improve its usefulness in reducing drowning accidents.

FACE IDENTIFICATION SYSTEM FOR IDENTIFYING THE CRIMINALS

We all know that our Face is a unique and crucial part of the human body structure that identifies a person. Therefore, we can use it to trace the identity of a criminal person. With the advancement in technology, we are placed CCTV at many public places to capture the criminal’s crime. Using the previously captured faces and criminal’s images that are available in the police station, the criminal face recognition system of can be implemented. In this paper, we propose an automatic criminal identification system for Police Department to enhance and upgrade the criminal distinguishing into a more effective and efficient approach. Using technology, this idea will add plus point in the current system while bringing criminals spotting to a whole new level by automating tasks. Technology working behind it will be face recognition, from the footage captured by the CCTV cameras; our system will detect the face and recognize the criminal who is coming to that public place. The captured images of the person coming to that public place get compared with the criminal data we have in our database. If any person’s face from public place matches, the system will display their image on the system screen and will give the message with their name that the criminal is found and present in this public place. This system matching more than 80% of the captured images with database images. keywords: Face Detection, Face Recognition, Open-CV, Image Processing

Study on the interannual variability of the Kerama Gap transport and its relation to the Kuroshio/Ryukyu Current system

Study on the interannual variability of the Kerama Gap transport and its relation to the Kuroshio/Ryukyu Current system

Investigating Statistical Features of the FX Bid Ask Series in a Small Economy with a Sizeable Informal Economy

The assessment of the effect of the informal use of a foreign currency on the corresponding FX rates toward the national currency is a very difficult task, requiring direct calculation and modeling. It comes mostly because of the unknown quantity of foreign money used in the informal sector, but also because of the lack of quantitative calculation models. To overcome this gap and to realize a qualitative description of this effect in a concrete economic environment, we propose herein a comparative analysis between the behavior of two typical FX rate series recorded in the Albanian currency market, the Euro-ALL and USD-ALL, providing that the Euro is used commonly as a national currency substitute in the informal economy and the USD is not. So, we have evidenced that the un-stationarity degree of the Bid and Ask spread distribution for the Euro-ALL FX series is higher than for the corresponding USD-ALL case, but with a lower variance. Those features occurring simultaneously can be explained by assuming that informal use of the Euro acts as an additional perturbation on the FX system, imposing high nonstationary, but at the same time it provides reservoir or source features for the money disbalances, reducing the average fluctuations. Next, the depth of the market measured by the average Bid-Ask Spread has resulted in a smaller price for the Euro currency, indicating a lower cost of the transactions and reinforcing the assumption regarding the distribution’s in-stationarity features. Based on those indicatory findings, we propose to realize indirect evidence for our assumptions by comparing the reproduction of the corresponding distribution using autoregressive models. In this case, we have evidenced that the distribution of the FX Euro-ALL spread can be reproduced better if we include in standard ARCHX (m, n, p) models a term that mimics the informality measure. When applying the same procedure for the USD-ALL spread, the resulting distribution has not matched equally well with the original ones. Those findings have been discussed in the framework of an alternative description of the effect of the informal use of foreign currency in a small economy with a sizeable informal sector, which convene our current system under analysis, but we believe that they can be applicable for similar economic environments. Doi: 10.28991/HEF-2024-05-01-02 Full Text: PDF

Revised Magnetospheric Model Reveals Signatures of Field‐Aligned Current Systems at Mercury

AbstractMercury is the smallest and innermost planet of our solar system and has a dipole‐dominated internal magnetic field that is relatively weak, very axisymmetric and significantly offset toward north. Through the interaction with the solar wind, a magnetosphere is created. Compared to the magnetosphere of Earth, Mercury's magnetosphere is smaller and more dynamic. To understand the magnetospheric structures and processes we use in situ MESSENGER data to develop further a semi‐empiric model of the magnetospheric magnetic field, which can explain the observations and help to improve the mission planning for the BepiColombo mission en‐route to Mercury. We present this semi‐empiric KTH22‐model, a modular model to calculate the magnetic field inside the Hermean magnetosphere. Korth et al. (2015, https://doi.org/10.1002/2015JA021022, 2017, https://doi.org/10.1002/2017gl074699) published a model, which is the basis for the KTH22‐model. In this new version, the representation of the neutral sheet current magnetic field is more realistic, because it is now based on observations rather than ad‐hoc assumptions. Furthermore, a new module is added to depict the eastward ring shaped current magnetic field. These enhancements offer the possibility to improve the main field determination. In addition, analyzing the magnetic field residuals allows us to investigate the field‐aligned currents and their possible dependencies on external drivers. We see increasing currents under more disturbed conditions inside the magnetosphere, but no clear dependence on the z‐component of the interplanetary magnetic field nor on the magnetosheath plasma β.

Patient-planetary health co-benefit prescribing in a circumpolar health region: a qualitative study of physician voices from the Northwest Territories, Canada

BackgroundDespite climate change being described as a code red for humanity, health systems have been particularly slow in both climate mitigation and adaptation responses. The effects of climate change on...

A broadband transparent antenna applied in indoor mobile communication system

AbstractThis paper proposes a broadband optical transparent antenna using a transparent conductor film on a transparent polyethylene terephthalate (PET) substrate. The planar wide‐slot antenna coupling fed by microstrip has a wide impedance bandwidth, so it is selected to design the transparent antenna. The upper surface of the PET substrate is a microstrip line with a fork‐shaped tuning branch, and the lower surface is a wide slot. They were made of transparent conductor film. Finally, a new capacitive coupling method is used to feed the transparent antenna. The transparent conductor film used in the antenna is metal mesh, which was developed by 3M company. The metal mesh with an open area greater than 80% to achieve high transmittance. The measured results show that the impedance bandwidth is 177% (0.30–5.0 GHz), and the gain of the antenna varies from 5.06 to 7.8 dBi over the entire frequency band. Therefore, it can be well applied to the current indoor mobile communication system.

Sub-Synchronous Oscillation Constrained Communication-Free Grid Frequency Control of Offshore Wind Farm Linked HVDC System

This paper proposes a frequency control method of a voltage source converter (VSC) high-voltage direct current (HVDC) system for large-scale offshore wind farms (OWFs) integration into an AC grid. Without frequency control, power output of OWFs varies with the wind velocity and it causes a grid frequency fluctuation. This fluctuation on the AC grid is becoming more severe as the level of wind power penetration increases. The previously suggested communication-free controls are vulnerable to continuously changing frequency fluctuations owing to concerns about its excessive energy releases. Therefore, our proposed control enables OWFs with HVDC to participate in grid frequency regulation continuously by considering its energy state when AC grid frequency fluctuates. In addition, there is a concern about sub-synchronous oscillation (SSO) instability owing to its cascading frequency control structure. A simplified small-signal model is developed to reveal out the existence of these SSO problems and its main factors in the frequency control scheme. Using developed model, overall system stability is comprehensively investigated. Also, a damping controller to mitigate SSO instability is also suggested and validated through simulation. To demonstrate the effectiveness of overall proposed frequency control, time-domain simulations were also carried out utilizing PSCAD/EMTDC under varying wind velocity condition.

Series and shunt FACTS controllers based optimal reactive power dispatch

Optimal reactive power dispatch involves the determination and management of reactive power resources in a power system to maintain voltage stability, improve power transfer capability, and minimize system losses. Reactive power is essential for maintaining voltage levels within acceptable limits and ensuring the reliable operation of electrical networks. The whale optimization algorithm (WOA) has been proposed to obtain the optimal location of flexible alternating current transmission system (FACTS) components. The efficacy of WOA is tested using conventional IEEE 14 and 30 bus test systems. Static var compensator (SVC) is used as shunt and the thyristor-controlled series capacitor (TCSC) as a series FACTS controller. The analysis is carried out for both the systems with and without FACTS controllers. Optimization techniques are applied to select the optimal control parameters. The suggested strategy is compared to other contemporary techniques such as particle swarm optimization (PSO) and grey wolf optimization (GWO). At various loading situations, the WOA-based technique outperforms other two techniques.

Abstract PR002: Proteomic profiling of endometrial carcinomas

Abstract While endometrial cancer (EC) has an overall favorable prognosis, some patients do poorly and may benefit from refinements of current classification systems. The TCGA-inspired pragmatic molecular classification tool Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) has been integrated into international guidelines for EC risk stratification and management. ProMisE stratifies ECs into four prognostic groups: POLEmut, NSMP (no specific molecular profile), MMRd (mismatch repair deficient), and p53abn, where POLEmut has the best prognosis and p53abn has the worst prognosis. Our objective was to determine if proteomic profiling could provide additional prognostic or predictive information for EC patients, across or within ProMisE molecular subtypes. Global proteome profiling of FFPE samples, that had clinicopathologic and outcome data, was performed on 184 ECs encompassing all four ProMisE subtypes, including replicate samples of the same tumor, and both biopsy and final hysterectomy specimens. To ensure representation of each subtype, we aimed for an approximately equal distribution; 40 (27 %) MMRd, 33 (22 %) POLEmut, 42 (28 %) NSMP and 33 (22 %) p53abn, rather than the population-based distributions. There was high reproducibility in the proteomic profiles of intra-tumor replicate samples, and between matched biopsy and hysterectomy tumor samples (Pearson’s correlation >0.9). Consensus clustering generated four clusters, named ‘Adhesion’, ‘Immune’, ‘Proliferation’, and ‘Metabolic’ based on proteins enriched in each cluster. The Proliferation Cluster had the worst outcomes and the highest proportion of stage III/IV, serous, and p53abn tumors than the other clusters. The Immune Cluster had the most favorable outcomes, despite having a relatively substantial proportion of stage III/IV, serous, and p53abn tumors. We correlated protein expression with common mutations, including ARID1A mutations that cause loss of ARID1A protein expression, found in up to 60% ECs. ARID1A positive tumors also express proteins in the retinoic acid signaling pathway, while ARID1A-deficient tumors express proteins indicative of neutrophil infiltration. Comparing molecular subtypes, we found p53abn ECs were enriched in proteins associated with poor outcomes in many tumor types, such as GRB7. We validated elevated GRB7 expression in p53abn tumors using immunohistochemistry and found an association with worse disease specific survival (DSS) across the whole cohort (HR=2.39). Nucleolin expression was associated with worse prognosis in the NSMP subtype (DSS HR=9.88), while BABAM1 expression was associated with better prognosis within p53abn tumors (DSS HR=2.43). Knockout of BABAM1 (part of the BRCA complex) in cell lines resulted in increased sensitivity to PARP inhibition. Proteomic analysis of EC identifies candidate prognostic markers that may further refine current molecular classification and help guide treatment decisions. New therapeutic interventions could be developed to target proteins and pathways identified by EC proteomic profiling. Citation Format: Dawn R. Cochrane, Gian Luca Negri, Jutta Huvila, Juliana Sobral de Barros, Forouh Kalantari, Nissreen Mohammad, David Farnell, Emily Thompson, Amy Lum, Sandra E. Spencer, Amy Jamieson, Samuel Leung, Derek Chiu, Martin Koebel, Stefan Kommoss, Friedrich Kommoss, Blake Gilks, Lien Hoang, David Huntsman, Gregg B. Morin, Jessica N. McAlpine. Proteomic profiling of endometrial carcinomas [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr PR002.

Investigating optimal features in log files for anomaly detection using optimization approach

<p><span lang="EN-US">Logs have been frequently utilised in different software system administration activities. The number of logs has risen dramatically due to the vast scope and complexity of current software systems. A lot of research has been done on log-based anomaly identification using machine learning approach. In this paper, we proposed an optimization approach to select the optimal features from the logs. This will provide the higher classification accuracy on reduced log files. In order to predict the anomalies three phases are used: i) log representation ii) feature selection and iii) Performance evaluation. The efficacy of the proposed model is evaluated using benchmark datasets such as BlueGene/L (BGL), Thunderbird, spirit and hadoop distributed file system (HDFS) in terms of accuracy, converging ability, train and test accuracy, receiver operating characteristic (ROC) measures, precision, recall and F1-score. The results shows that the feature selection on log files outperforms in terms all the evaluation measures.</span></p>

Learned helplessness and anxiety among a sample of primary school students with learning difficulties

Introduction. In primary education, understanding the psychological experiences of students with learning difficulties is of utmost importance. Among the various psychological factors that can impact their well-being, learned helplessness and anxiety have been identified as significant contributors. Learned helplessness refers to a state of perceived powerlessness and a belief that one's actions do not influence their outcomes. Coupled with anxiety, it can create a debilitating cycle that hinders academic progress and emotional well-being. This study explores the relationship between learned helplessness and anxiety among a sample of primary school students with learning difficulties. By shedding light on these interrelated factors, this research seeks to provide insights that can inform targeted interventions and support strategies to enhance the educational experiences and overall well-being of students facing learning challenges. Aim. This study aimed to identify the level of learning disability and anxiety among primary school students with learning difficulties in the Karak governorate in Jordan. Materials and methods. The study followed the descriptive survey approach, and the study sample consisted of (150) students from the fifth basic class students in the Karak governorate in Jordan, and to achieve the objectives of the study, the researcher used the learning disability scale and anxiety scale. The results. Students were found to have significant levels of learning impairment, with 19 questions rated as "very difficult" or "very difficult to do." These items revealed students' difficulties with group work tasks, emotions of hopelessness, and perceptions of their own weakness. In one set of data, the statement "I cannot engage in activities of a group work nature" got a mean score of 3.99 and a standard deviation of 1.21. In fact, only 3 items obtained average ratings, with "I avoid tough chores and duties" receiving the lowest score (mean = 3.60, standard deviation = 1.31). High levels of anxiety were also reported by students, with the highest levels being related to problems concentrating and breathing (mean anxiety scores of 4.57 and 4.47, respectively). Traditional teaching methods, overcrowded classrooms, family upbringing, and the educational environment are all hypothesised to contribute to the elevated anxiety levels seen in students with learning impairments. Pervasive difficulties affecting the students' well-being and educational experiences are indicated by the mean scores of 3.78 (SD = 1.12) and 3.89 (SD = 1.08) for learning disability and anxiety, respectively. Conclusions. Primary school kids in Karak governorate, Jordan, who were having difficulty learning found to have high levels of acquired helplessness and anxiety, indicating severe emotional suffering, according to this study. It was speculated that factors such as traditional teaching methods, overcrowded classrooms, parental involvement, and the general educational atmosphere all played a role. The results highlight the immediate need for educational method improvements and the provision of holistic support to lessen the effect of these psychological obstacles on students, with the ultimate goal of bettering their educational experience and general well-being. In light of these findings, it is imperative that educators, politicians, and carers reevaluate and restructure the current educational and support systems to better accommodate students with learning impairments.

Skin-Attached Arrayed Piezoelectric Sensors for Continuous and Safe Monitoring of Oculomotor Movements.

Abnormal oculomotor movements are known to be linked to various types of brain disorders, physical/mental shocks to the brain, and other neurological disorders, hence its monitoring can be developed into a simple but effective diagnostic tool. To overcome the limitations in the current eye-tracking system and electrooculography, a piezoelectric arrayed sensor system is developed using single-crystalline III-N thin-film transducers, which offers advantages of mechanical flexibility, biocompatibility, and high electromechanical conversion, for continuous monitoring of oculomotor movements by skin-attachable, safe, and highly sensitive sensors. The flexible piezoelectric eye movement sensor array (F-PEMSA), consisting of three transducers, is attached to the face temple area where it can be comfortably wearable and can detect the muscles' activity associated with the eye motions. Output voltages from upper, mid, and lower sensors (transducers) on different temple areas generate discernable patterns of output voltage signals with different combinations of positive/negative signs and their relative magnitudes for the various movements of eyeballs including 8 directional (lateral, vertical, and diagonal) and two rotational movements, which enable various types of saccade and pursuit tests. The F-PEMSA can be used in clinical studies on the brain-eye relationship to evaluate the functional integrity of multiple brain systems and cognitive processes.

Parameterizing Mesoscale Eddy Buoyancy Transport Over Sloping Topography

AbstractMost of the ocean's kinetic energy is contained within the mesoscale eddy field. Models that do not resolve these eddies tend to parameterize their impacts such that the parameterized transport of buoyancy and tracers reduces the large‐scale available potential energy and spreads tracers. However, the parameterizations used in the ocean components of current generation Earth System Models rely on an assumption of a flat ocean floor even though observations and high‐resolution modeling show that eddy transport is sensitive to the potential vorticity gradients associated with a sloping seafloor. We show that buoyancy transport coefficient diagnosed from idealized eddy‐resolving simulations is indeed reduced over both prograde and retrograde bottom slopes (topographic wave propagation along or against the mean flow, respectively) and that the reduction can be skilfully captured by a mixing length parameterization by introducing the topographic Rhines scale as a length scale. This modified “GM” parameterization enhances the strength of thermal wind currents over the slopes in coarse‐resolution, non‐eddying, simulations. We find that in realistic global coarse‐resolution simulations the impact of topography is most pronounced at high latitudes, enhancing the mean flow strength and reducing temperature and salinity biases. Reducing the buoyancy transport coefficient further with a mean‐flow dependent eddy efficiency factor, has notable effects also at lower latitudes and leads to reduction of global mean biases.

Smart AC-DC Coupled Hybrid Railway Microgrids Integrated with Renewable Energy Sources: Current and Next Generation Architectures

In recent years, there has been increasing interest in integrating the smart grid concept into railway networks, which has been driven by the need to enhance energy efficiency and reduce air pollution in such energy-intensive systems. Consequently, experts have actively sought innovative solutions with which to tackle these challenges. One promising strategy involves integrating renewable energy sources (RESs), energy storage systems (ESSs), and electric vehicle charging stations (EVCSs) into current electric railway systems (ERSs). This study begins by examining the concept of implementing smart grids in railway systems through bibliometric analysis. It then delves into the realization of a hybrid railway microgrid (H-RMG) designed to enhance power flow capacities, improve energy efficiency, and address power quality issues in traditional AC railway networks. This paper introduces various future AC–DC-coupled hybrid railway microgrid (ADH-RMG) architectures centered around a shared DC bus acting as a DC hub for upgrading conventional AC railway systems utilizing interfacing static converters. Through an exploration of different possible ADH-RMG configurations, this research aims to offer valuable insights and a roadmap for the modernization and reconstruction of existing railway networks using smart grid technologies. The integration of RESs and EV charging infrastructures within the ADH-RMG concept presents a promising pathway toward establishing more sustainable and environmentally friendly railway systems.

Enrichment of ruminant meats with health enhancing fatty acids and antioxidants: feed-based effects on nutritional value and human health aspects – invited review

Optimising resource use efficiency in animal- agriculture-production systems is important for the economic, environmental, and social sustainability of food systems. Production of foods with increased health enhancing aspects can add value to the health and wellbeing of the population. However, enrichment of foods, especially meat with health enhancing fatty acids (HEFA) increases susceptibility to peroxidation, which adversely influences its shelf life, nutritional value and eating quality. The meat industry has been challenged to find sustainable strategies that enhance the fatty acid profile and antioxidant actions of meat while mitigating oxidative deterioration and spoilage. Currently, by-products or co-products from agricultural industries containing a balance of HEFA and antioxidant sources seem to be a sustainable strategy to overcome this challenge. However, HEFA and antioxidant enrichment processes are influenced by ruminal lipolysis and biohydrogenation, HEFA-antioxidant interactions in rumen ecosystems and muscle biofortification. A deep understanding of the performance of different agro-by-product-based HEFA and antioxidants and their application in current animal production systems is critical in developing HEFA-antioxidant co-supplementation strategies that would benefit modern consumers who desire nutritious, palatable, safe, healthy, affordable, and welfare friendly meat and processed meat products. The current review presents the latest developments regarding discovery and application of novel sources of health beneficial agro-by-product-based HEFA and antioxidants currently used in the production of HEFA-antioxidant enriched ruminant meats and highlights future research perspectives.

David versus Goliath: Early career researchers in an unethical publishing system.

The publish-or-perish culture in academia has catalysed the development of an unethical publishing system. This system is characterised by the proliferation of journals and publishers-unaffiliated with learned societies or universities-that maintain extremely large revenues and profit margins diverting funds away from the academic community. Early career researchers (ECRs) are particularly vulnerable to the consequences of this publishing system because of intersecting factors, including pressure to pursue high impact publications, rising publication costs and job insecurity. Moving towards a more ethical system requires that scientists advocate for structural change by making career choices that come with risks, many of which disproportionately impact ECRs. We illuminate major issues facing ECRs in Ecology and Evolution under the current publishing system, and propose a portfolio of actions to promote systemic change that can be implemented by ECRs and established researchers.

An efficient high performance reconfigurable canonical sign digit architecture for software defined radio

Software defined radios (SDRs) are highly motivated for wireless device modelling due to their flexibility and scalability over alternative wireless design options. The evolutionary structure of finite impulse response (FIR) filters was designed for a proposed reconfigurable canonical sign digit (CSD) approach. Considering the complex trade-off, this is accomplished with many FIR taps, which is a challenging assignment. On the baseband processing side, design is given with parameterization-controlled FIR filter tap selection. Optimal processing models to overcome the reconfigurable design issues associated with the SDR system for a multi-standard wireless communication system root cosine filter standard are often used to implement multiple FIR channelization topologies, each of which is tied to a particular in-phase and quadrature (IQ) symbol. Additionally, it demonstrates the viability of using a multi-modulation baseband modulator in the SDR system for next-generation wireless communication systems to maximise adaptability with the least amount of computational complexity overhead. The proposed multiplier-less FIR filter-based reconfigurable baseband modulator, according to the experimental results, offers a 6% complexity reduction and a 47% improvement in performance efficiency over the current SDR system.

Minimum work associated with separating nitrogen from air: An exergy analysis

Background Nitrogen is essential for a variety of industries, including heat treatment, laser cutting, fire protection, and food packaging. Many companies in these industries obtain nitrogen via on-premises air separation processes. The three main processes for separating nitrogen from ambient air are cryogenic distillation, membrane separation, and pressure-swing adsorption (PSA). Improvements to these processes will likely focus on increasing efficiency, resulting in reduced environmental impact owing to less electrical power demand and opportunities for economic incentives. Regardless of the process utilized, a minimum theoretical amount of work input is required to obtain nitrogen gas at different pressures and concentrations compared to ambient conditions. Methods An equation was derived to evaluate the total exergy (including thermo-mechanical and chemical exergy) of product and exhaust mixtures resulting from air separation, indicating the minimum theoretical work input as a function of the product pressure, purity, and process recovery rate. This analysis considered an air separation system as a black box, with the input, output, and exhaust assumed to be ideal gas mixtures of nitrogen and oxygen at 15°C. The analysis applies to cryogenic distillation if the product and exhaust mixtures return to the gas phase. Results In general, the minimum required work input increases with product purity and recovery rate. Plots of minimum theoretical work versus product purity and recovery rate were made for two product pressures (atmospheric and 800 kPa) to show the behavior of the derived equation. Conclusions The analysis allows for direct efficiency (based on the second law of thermodynamics) comparisons between existing processes and future technological innovations in the field of air separation. Actual air separation systems have low efficiencies compared to ideal systems; actual PSA systems were estimated to have second law efficiencies of 5.5–11.2%. Therefore, there is great potential for improvements to current air separation systems.