Technologies In Terms Of Efficiency Research Articles

Intravascular Ultrasound in the Detection of Bridging Stent Graft Instability During Fenestrated and Branched Endovascular Aneurysm Repair Procedures: A Multicentre Study on 274 Target Vessels

The use of intravascular ultrasound (IVUS) reduces contrast medium use and radiation exposure during conventional endovascular aneurysm repair (EVAR). The aim of this study was to evaluate the safety and efficacy of IVUS in detecting bridging stent graft (bSG) instability during fenestrated and branched EVAR (F/B-EVAR). This was a prospective observational multicentre study. The following outcomes were evaluated: (1) technical success of the IVUS in each bSG, (2) IVUS findings compared with intra-operative angiography, (3) incidence of post-operative computed tomography angiography (CTA) findings not detected with IVUS, and (4) absence of IVUS related adverse events. Target visceral vessel (TVV) instability was defined as any branch or fenestration issues requiring an additional manoeuvre or re-intervention. Any IVUS assessment that detected stenosis, kinking, or any geometric TVV issue was considered to be branch instability. All procedures were performed in ad hoc hybrid rooms. Eighty patients (69% males; median age 72 years; interquartile range 59, 77 years) from four aortic centres treated with F/B-EVAR between January 2019 and September 2021 were included: 70 BEVAR (21 off the shelf; 49 custom made), eight FEVAR (custom made), and two F/B-EVAR (custom made), for a total of 300 potential TVVs. Two TVVs (0.7%) were left unstented and excluded from the analysis. The TVVs could not be accessed with the IVUS catheter in seven cases (2.3%). Furthermore, 17 (5.7%) TVVs could not be examined due to a malfunction of the IVUS catheter. The technical success of the IVUS assessment was 91.9% (274/298), with no IVUS related adverse events. Seven TVVs (2.5%) showed signs of bSG instability by means of IVUS, leading to immediate revisions. The first post-operative CTA at least 30 days after the index procedure was available in 268 of the 274 TVVs originally assessed by IVUS. In seven of the 268 TVVs (2.6%) a re-intervention became necessary due to bSG instability. This study suggests that IVUS is a safe and potentially valuable adjunctive imaging technology for intra-operative detection of TVV instability. Further long term investigations on larger cohorts are required to validate these promising results and to compare IVUS with alternative technologies in terms of efficiency, radiation exposure, procedure time, and costs.

Multi-fidelity cost-aware Bayesian optimization

Bayesian optimization (BO) is increasingly employed in critical applications such as materials design and drug discovery. An increasingly popular strategy in BO is to forgo the sole reliance on high-fidelity data and instead use an ensemble of information sources which provide inexpensive low-fidelity data. The overall premise of this strategy is to reduce the total sampling costs by querying inexpensive low-fidelity sources whose data are correlated with high-fidelity samples. Here, we propose a multi-fidelity cost-aware BO framework that dramatically outperforms the state-of-the-art technologies in terms of efficiency, consistency, and robustness. We demonstrate the advantages of our framework on analytic and engineering problems and argue that these benefits stem from our two main contributions: (1) we develop a novel acquisition function for multi-fidelity cost-aware BO that safeguards the convergence against the biases of low-fidelity data, and (2) we tailor a newly developed emulator for multi-fidelity BO which enables us to not only simultaneously learn from an ensemble of multi-fidelity datasets, but also identify the severely biased low-fidelity sources that should be excluded from BO.

Investigation of a robust pretreatment technique based on ultrasound-assisted, cost-effective ionic liquid for enhancing saccharification and bioethanol production from wheat straw

Application of cost-effective pretreatment of wheat straw is an important stage for massive bioethanol production. A new approach is aimed to enhance the pretreatment of wheat straw by using low-cost ionic liquid [TEA][HSO4] coupled with ultrasound irradiation. The pretreatment was conducted both at room temperature and at 130 °C with a high biomass loading rate of 20% and 20% wt water assisted by ultrasound at 100 W-24 kHz for 15 and 30 min. Wheat straw pretreated at 130 °C for 15 and 30 min had high delignification rates of 67.8% and 74.9%, respectively, and hemicellulose removal rates of 47.0% and 52.2%. Moreover, this pretreatment resulted in producing total reducing sugars of 24.5 and 32.1 mg/mL in enzymatic saccharification, respectively, which corresponds to saccharification yields of 67.7% and 79.8% with commercial cellulase enzyme CelluMax for 72 h. The ethanol generation rates of 38.9 and 42.0 g/L were attained for pretreated samples for 15 and 30 min, equivalent to the yields of 76.1% and 82.2% of the maximum theoretical yield following 48 h of fermentation. This demonstration provided a cheap and promising pretreatment technology in terms of efficiency and shortening the pretreatment time based on applying low-cost ionic liquid and efficient ultrasound pretreatment techniques, which facilitated the feasibility of this approach and could further develop the future of biorefinery.

Utilization of poultry droppings in terms of non-waste technology

The processing of poultry droppings under anaerobic conditions, in special hermetic reactors – methane tanks is considered to be the most promising technology in terms of efficiency in agrochemical, environmental, and energy fields. Organic fertilizer in the methane tank is in the form of concentrated liquid, purified from disease causatives and weed seeds. It is easily absorbed by fermented plant mass and contains macro and micronutrients, amino acids and phytohormones that stimulate the development of the plant. The rare utilization of such facilities is explained by the lack of funds for their purchase. On the other hand, it is assumed that biogas is not a dominant factor in terms of economic efficiency, and organic fertilizer is also important. In this respect, the utilization of poultry droppings has also gained practical relevance. The paper covers the discussion of the feasibility of utilizing poultry droppings as a non-waste technology. The methodological approach is based on the evaluation of more rational technological projects. In logical modeling, the rules drawn up by highly qualified specialists are used. The rules determine how to act in a certain situation. Such rules are considered favorable for non-skilled performers. The results of the studies have allowed analyzing the dynamics of nitrogen preservation depending on the utilization technology of poultry droppings and impact factors. Based on a mathematical model, a computer methodology for research on improving the energy efficiency of a poultry farm has been developed. The number of LEDs (α=200, I0=20 kd) for a 66×12 m poultry house using a computer program N=273 pcs., the number of LEDs (α=200, I0=20 kd) for a building with dimensions of 78×18 m N=259 pcs. The design parameters of the lamps are substantiated

Exergetic Analysis of DME Synthesis from CO2 and Renewable Hydrogen

Carbon Capture and Utilization (CCU) is a viable solution to valorise the CO2 captured from industrial plants’ flue gas, thus avoiding emitting it and synthesizing products with high added value. On the other hand, using CO2 as a reactant in chemical processes is a challenging task, and a rigorous analysis of the performance is needed to evaluate the real impact of CCU technologies in terms of efficiency and environmental footprint. In this paper, the energetic performance of a DME and methanol synthesis process fed by 25% of the CO2 captured from a natural gas combined cycle (NGCC) power plant and by the green hydrogen produced through an electrolyser was evaluated. The remaining 75% of the CO2 was compressed and stored underground. The process was assessed by means of an exergetic analysis and compared to post-combustion Carbon Capture and Storage (CCS), where 100% of the CO2 captured was stored underground. Through the exergy analysis, the quality degradation of energy was quantified, and the sources of irreversibility were detected. The carbon-emitting source was a 189 MW Brayton–Joule power plant, which was mainly responsible for exergy destruction. The CCU configuration showed a higher exergy efficiency than the CCS, but higher exergy destruction per non-emitted carbon dioxide. In the DME/methanol production plant, the main contribution to exergy destruction was given by the distillation column separating the reactor outlet stream and, in particular, the top-stage condenser was found to be the component with the highest irreversibility (45% of the total). Additionally, the methanol/DME synthesis reactor destroyed a significant amount of exergy (24%). Globally, DME/methanol synthesis from CO2 and green hydrogen is feasible from an exergetic point of view, with 2.276 MJ of energy gained per 1 MJ of exergy destroyed.

Novel Fluorite-Structured Materials for Solid-State Refrigeration.

Refrigeration based on the electrocaloric effect can offer many advantages over conventional cooling technologies in terms of efficiency, size, weight, and power source. The discovery of ferroelectric and antiferroelectric properties in fluorite-based materials in 2011 has led to diverse applications related to memory (e.g., ferroelectric tunnel junctions, nonvolatile memory, and field-effect transistors) and energy fields (e.g., energy storage and harvesting, electrocaloric refrigeration, and infrared detection). Fluorite-based materials exhibit several properties not shared by most conventional materials (such as in terms of compatibility with complementary metal-oxide semiconductors and 3D nanostructures, deposition thickness at the nanometer scale, and simple composition). Here, the electrocaloric refrigeration properties of fluorite-based ferroelectric/antiferroelectric materials are reviewed by focusing on the advantages of ZrO2 - and HfO2 -based materials (e.g., relative to conventional perovskite- and polymer-based counterparts). Finally, the recent progress made in this research field are also discussed along with its future perspectives.

Sorption-enhanced propane partial oxidation hydrogen production for solid oxide fuel cell (SOFC) applications

Solid oxide fuel cells (SOFC), as high-temperature fuel supply systems, are regarded as one of the most adaptable technologies in terms of efficiency, flexibility, and environmental friendliness. Catalytic propane partial oxidation is recognized as an efficient gas supply method for SOFC applications. However, incombustible by-product CO2 would decrease the purity of hydrogen, thereby reducing the power of fuel cells. Sorption-enhanced propane partial oxidation is an efficient way to adapt to SOFC operating conditions while improving hydrogen production and reducing carbon dioxide emissions. This paper introduces a cage-like porous Ce1-xCaxMO3-λ (M = Co, Fe and Cu) sorbent for providing high carbon dioxide sorption capacity and improving hydrogen purity over the Ni/Al2O3 catalyst. As obtained, Ce1-xCaxFeO3-λ and Ni/Al2O3 sorbent-catalyst performed the best, with the highest hydrogen yield up to 1654 μmol/gcat·s which was 1055 μmol/gcat·s higher than that of pure Ni/Al2O3. The produced reforming gas is served as a fuel in the proposed SOFC system. A maximum output power density of 581 mW/cm2 was reached. This work offered a simple and viable way of combining inexpensive and robust catalyst-sorbent for sorption-enhanced propane partial oxidation in terms of efficient indirect hydrogen supply toward SOFC power generation.

The use of digital technologies in the professional training of bachelors of arts in the context of distance learning

In the context of a pandemic and the introduction of quarantine measures, the issue of proper organization of the educational process without interfering with the curriculum becomes especially relevant. Distance learning is a way to solve this problem, but for this type of learning to be effective, it is necessary to understand what digital technologies will help to master the educational program. Therefore, the purpose of the study was to identify which of the modern digital technologies are the most effective for distance learning and based on the analysis to develop a model of online training for Bachelor of Arts. The study applied an analysis, which helped to evaluate modern digital technologies in terms of efficiency for use in distance learning, and modelling, which helped to create an optimal learning model in terms of distance learning.

The Use of Computer Technologies in the Professional Training of Bachelors of Arts in the Context of Distance Learning

In the context of a pandemic and the introduction of quarantine measures, the issue of proper organisation of the educational process without interfering with the curriculum becomes especially relevant. Distance is a way to solve this problem, but for this type of to be effective, it is necessary to understand what digital technologies will help to master the educational programme. Therefore, the purpose of the study was to identify which of the modern digital technologies are the most effective for learning, and based on the analysis to develop a model of online training for bachelors of arts. The study applied an analysis, which helped to evaluate modern digital technologies in terms of efficiency for use in learning, and modelling, which helped to create an optimal model in terms of learning. The analysis considered the concept of distance learning and the system of its implementation in the educational process. Six main stages that will ensure a rapid and effective transition to were identified, which almost all educational institutions in Ukraine had to face. It was found that the provision of digital technologies and the necessary technical equipment is one of the most pressing issues of the modern education system. The analysis of online resources has shown that at the present time the mastering of the curriculum of art specialities is significantly complicated by the transition to and a number of shortcomings. The practical significance of the study is that the developed model of online is ready for implementation, and the recommendations can be used when developing an educational programme for learning.

Non-Propellant Eddy Current Brake and Traction in Space Using Magnetic Pulses

The safety of on-orbit satellites is threatened by space debris with large residual angular velocity and the space debris removal is becoming more challenging than before. This paper explores the non-contact despinning and traction problem of high-speed rotating targets and proposes an eddy current brake and traction technology for space targets without any propellant consumption. The principle of the conventional eddy current brake is analyzed in this article and the concept of eddy current brake and traction without propellant is put forward for the first time. Secondly, according to the key technical requirements, a brand-new structure of a satellite generating artificial magnetic field is designed accordingly. Then the control mechanism of eddy current brake and traction without propellant is analyzed qualitatively by simplifying the model and conditions. Then, the magnetic pulse control method is proposed and analyzed quantitatively. Finally, the feasibility of the technology is verified by the numerical simulation method. According to the simulation results, the eddy current brake and traction technology based on magnetic pulses can make the angular speed of target decrease linearly without propellant during the process. This technology has huge advantages compared with conventional eddy current brake technology in terms of efficiency and reduced propellant consumption.

Post-biological treatment of yeast production wastewater using non-thermal plasma

Yeast production wastewater is one of the complex wastewater types, characterized by high organic content and color. This research on the application of non-thermal plasma in laboratory scale yeast production has demonstrated the superiority of this technology in terms of efficiency, treatment time and non- selectivity for pollutants. The wastewater treatment model is optimized in 3 minutes with a DC voltage of 100 V and a pH around 8.4, resulting in COD removal efficiency of over 75%, while color and TSS removal of 93%. The results of this study are the basis for practical application of wastewater at AB Mauri Vietnam after biological treatment stage (anaerobic, anoxic and aerobic) with a COD of greater than 5,000 mg/l and color over 26,000 Pt-Co.

A Study on Performance Verification for Remodeling of Existing Building with EnPI

In the present study, the performance verification for remodeling of existing building was conducted. The EnPI V4.0 which is issued from US DOE was applied for conduction of performance verification. The target building were remodeled four times from 2011 to 2016. The items of remodeling are consisted of passive and active items. The passive items are replacement from aging window to resolution window and installation of outer wall insulation panel. The active items are change from aging absorption chiller to high efficiency absorption chiller and replace from fluorescent light to LED light. Sum up the result, change from aging absorption chiller to high efficiency absorption chiller project has the highest energy saving. As the result of replacement for absorption chiller, 26.9 TOE was reduced annually. The replacement from aging window to resolution window and installation of outer wall insulation panel have the second highest energy saving. The effect of energy saving isn't big difference between active and passive technology. However, active technology can be considered as more effective to save the energy than passive technology in terms of efficiency.

Multi-MOSFET-Based Series Resonant Inverter for Improved Efficiency and Power Density Induction Heating Applications

Resonant converters featuring soft switching are commonly used in domestic induction heating applications due to their high efficiency and high power density. In this paper, the design and implementation procedure of an improved efficiency and low-profile resonant inverter for induction heating applications is presented. The proposed converter is based on a multi-MOSFET cell implementation, reducing the equivalent on-state resistance per chip-area. By using automotive-grade MOSFET devices, a converter capable of delivering up to 4 kW has been built, reducing conduction losses against the classical IGBT-based converter. In addition to this, the reduced switching times of MOSFET devices decrease switching losses, further increasing the conversion efficiency. The main design challenges including the device selection, gate drive circuit, and cooling have been addressed. As a conclusion, a low-profile implementation without fan and heat sink is obtained, which significantly improves state-of-the-art technology in terms of efficiency and power density.

Adoptability of grid computing technology in power systems analysis, operations and control

With the deregulation and constant expansion in power systems, the demand of high performance computing (HPC) for power system adequacy and security analysis has been increased rapidly. HPC also plays an important role in ensuring efficient and reliable communication for power system operation and control. In past few years, grid computing technology is catching up much attention from the power engineers and researchers. Grid computing technology is an infrastructure, which can provide HPC and communication mechanism for providing services in these areas of power system. A review is presented on the research which has been carried out in the last few years in this area regarding the applicability of grid computing technology in power system reliability and security analysis, operations, monitoring and control systems. We also introduce more grid computing applications for the future research directions in order to provide more open access and more efficient and effective computing services to meet the increasing needs of the power industry. This review presents a comprehensive and clear picture of the benefits of using this technology in terms of efficiency and cost.

High cost technology in health care: A benefit or a burden?

The influence of high cost technology goes beyond its consequences for the selected patient groups that benefit from its application. Past and future technological developments have a variety of social, economic and ethical implications which have to be taken into account when balancing its costs and benefits to society. Departing from an economic perspective we describe a number of mechanisms underlying the emergence of high cost technology which help us to understand some of the characteristics of high cost technology, such as its focus on quality enhancement rather than on economy. To assess the actual performance of high cost technology in terms of efficiency and equity is difficult as there may be debate about the perspective guiding such assessment and as there still is scarce information on high cost technology in terms of these economic indicators. The increasing technological opportunities have triggered a wider debate on the desired evolution of our health care systems. In some countries there is a tendency to diminish government involvement in health care and emphasize private (for profit) enterprise as a reaction to not being able to finance all new high cost technology. The risks of such strategies are discussed briefly. We conclude that the main actors in health care should adjust their behaviour in order to accomplish the introduction of more cost-effective technologies and to achieve a more socially efficient distribution of their benefits.