Low-energy System Research Articles

Low-Quality Irrigation Water Treated Using Waste Biofilters

Although in water-deficient regions, agricultural runoff, drainage water or surplus irrigation water is often used, there are constraints related to its quality to be considered (salinity, nutrients and pollutants). Thus, it is necessary to treat surplus irrigation water considering the low-energy supply systems available to farmers. This work focuses on a nature-based water treatment system consisting of two prototypes of anaerobic bioreactors with horizontal or vertical flow. To enhance the circular economy strategy, two different wastes (coarse sand and almond pruning) were used as bioreactor components. The aim of the research was to monitor the quality of the water (pH, electrical conductivity, suspended solids, chemical oxygen demand, alkalinity and bicarbonate, carbonate and nitrogen contents) before and after the treatment. All the parameters studied (except chemical oxygen demand) were reduced by the treatments, but with large variations. Furthermore, there was 100% nitrogen reduction in the horizontal water flow treatment with the filter bed formed by coarse sand and almond pruning. It was observed that the variation in the concentration of some parameters was associated with the type of filter bed (i.e., the C/N ratio of the residue) and with the design for water circulation flow. Although the findings are promising, further research is needed to achieve reductions in all studied parameters.

An open-source development based on photogrammetry for a real-time IORT treatment planning system

PurposeThis study presents a treatment planning system for intraoperative low-energy photon radiotherapy based on photogrammetry from real images of the surgical site taken in the operating room. Material and methodsThe study population comprised 15 patients with soft-tissue sarcoma. The system obtains the images of the area to be irradiated with a smartphone or tablet, so that the absorbed doses in the tissue can be calculated from the reconstruction without the need for computed tomography.The system was commissioned using 3D printing of the reconstructions of the tumor beds. The absorbed doses at various points were verified using radiochromic films that were suitably calibrated for the corresponding energy and beam quality. ResultsThe average reconstruction time of the 3D model from the video sequence in the 15 patients was 229,6±7,0 s. The entire procedure, including video capture, reconstruction, planning, and dose calculation was 520,6±39,9 s. Absorbed doses were measured on the 3D printed model with radiochromic film, the differences between these measurements and those calculated by the treatment planning system were 1.4% at the applicator surface, 2.6% at 1 cm, 3.9% at 2 cm and 6.2% at 3 cm. ConclusionsThe study shows a photogrammetry-based low-energy photon IORT planning system, capable of obtaining real-time images inside the operating room, immediately after removal of the tumor and immediately before irradiation. The system was commissioned with radiochromic films measurements in 3D-printed model.

Status report of the first AMS laboratory in the Czech Republic at the Nuclear Physics Institute, Řež

The first accelerator mass spectrometry (AMS) laboratory in the Czech Republic has been established and put into routine operation in February 2022. Here we briefly describe the facilities available, namely a 300 kV multi-isotope low-energy AMS system (MILEA) capable of determination 10Be, 14C, 26Al, 41Ca, 129I, isotopes of U, especially 236U, Pu and other actinoids, and accessories for 14C measurements, which include a gas interface system, a preparative gas chromatography system for compound-specific radiocarbon dating analysis, and an isotope-ratio mass spectrometer. The first results achieved for separation and measurement of the above radionuclides (except for 41Ca) are also reported, with the main focus on 14C measurements. A specimen breakdown of 729 graphitised samples analysed for 14C so far is presented, as well as a proof of measurement stability of the MILEA system obtained by analysis of radiocarbon standards and analytical blanks. For the other radionuclides, well proven or novel procedures for sample preparation and measurement are presented.

(Invited) Potential of Silicon Oxide Films for Low-Cost and High-Performance Resistive Switching Devices

This paper reviews our experimental studies on the resistive switching behaviors of sputter-deposited Si oxide films. Theoretical simulations are also demonstrated to elucidate the physical mechanisms of resistive switching behaviors. These suggest the various potential applications for low-energy sensor network systems, neuromorphic computing systems and low-cost commercial electronic systems.

Mineralogy and phase transition mechanisms of atmospheric mineral particles: Migration paths, sources, and volatile organic compounds

Inorganic mineral particles play an important role in the formation of atmospheric aerosols in the Sichuan Basin. Atmospheric haze formation is accompanied by the phase transition of mineral particles under high humidity and stable climatic conditions. Backward trajectory analysis was used in this study to determine the migration trajectory of atmospheric mineral particles. Furthermore, Positive matrix factorization (PMF) was used to analyze the sources of atmospheric mineral particles. The phase transition mechanisms of atmospheric mineral particles were studied using ion chromatography, inductively coupled plasma emission spectrometry, total organic carbon analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy coupled with energy dispersive spectrometry, and grand canonical Monte Carlo methods. Three migration and phase transition paths were identified for the mineral particles. Sources of atmospheric mineral particles included combustion, vehicle emissions, industrial emissions, agricultural sources, and mineral dust. The main mineral phases in atmospheric particles, calcite and dolomite, were transformed into gypsum, and muscovite may be transformed into kaolinite. The phase transition of mineral particles seriously affects the formation of aerosols and worsens haze. Typically, along the Nanchong-Suining-Neijiang-Zigong-Yibin path, calcite is converted into gypsum under the influence of man-made inorganic pollution gases, which worsen the haze conditions and cause slight air pollution for 3–5 days. However, along the Guangyuan-Mianyang-Deyang-Chengdu-Meishan-Ya'an path, anthropogenic volatile organic compounds (VOCs) hindered gypsum formation from dolomite. Furthermore, dolomite and VOCs formed stable adsorption systems (system energies from −0.41 to −4.76 eV, long bonds from 0.20 to 0.24 nm). The adsorption system of dolomite and m/p-xylene, with low system energy (−1.46 eV/−1.33 eV) and significant correlation (r2 = 0.991, p < 0.01), was the main cause of haze formation. Consequently, calcite gypsification and dolomite–-VOC synergism exacerbated regional haze conditions. This study provides a theoretical reference for the mechanism of aerosol formation in basin climates.

A New Integrated Multilevel Inverter Topology for Renewable Energy Transformation

This paper presents a new three-phase integrated module multilevel inverter (IMMLI) with reduced component count which is suitable for low, medium and high voltage renewable energy systems. The proposed inverter is a resultant structure of a number of integrated module and each module is configured with a number of series connected basic blocks. Each block consists of a dc voltage source, a blocking diode and a semiconductor switch. A computational combination and summation among the dc sources from different blocks results in a high number of levels within the output voltage. This task is performed by controlling the switches equipping appropriate switching algorithm. Thus, a high level of output is obtained employing reduced number of components. Since the topology owns two degree of modularity, the total stress voltage (TSV) of the system is low and distributed among the switches. Hence, the proposed topology allows to be implemented in high power systems with reduced amount of costs. The inverter also offers enhanced efficiency, as the number of simultaneously conducting switch is low. Additionally, in order to operate the presented inverter with optimum ac power quality, a multi-carrier based level shifted PWM scheme is addressed in this paper. This paper also shows how to prepare balanced dc sources that are required to implement the inverter using high-frequency magnetic-link. The operating principle of the IMMLI is explained with the help of a fifteen level (15-L) single phase unit and its performance is evaluated in MATLAB/Simulink considering different conditions. Experimental validation is also presented to support the simulation results and to evaluate its superiority over the existing.

Stable and rapid degradation of tetracycline using a photoelectrochemical system comprising a Ag/N–TiO2 photoanode and P–Pd cathode

Herein, a highly stable and efficient photoelectrocatalytic system was developed for the rapid degradation of tetracycline. The photoelectrocatalytic system comprised two Ag/N-doped TiO2 nanotube photoanodes, a bipolar membrane, and a P–Pd cathode. The Ag/N-doped TiO2 nanotube photoanodes were coupled with a P–Pd cathode to enhance the hydroxyl free radical (·OH) generation at the cathode surface. The bipolar membrane can separate tetracycline pollutants and degradation products from the photoanodes, which can minimize the contamination of the photocatalyst by tetracycline or products, thereby enhancing the repeatability and stability of the photoelectrocatalytic system. photoelectrocatalytic uses ultraviolet–visible light as the input energy for the effective removal of tetracycline and total organic carbon. The initial pH in the cathode and photoanode chambers was 7.0. The Na2SO4 concentration in the photoanode chamber and the addition amount of H2O2 were 0.2 M and 4% (v/v), respectively. Under these conditions, 100 mL of 100 mg/L tetracycline was completely degraded within 60 min, and 82.3% total organic carbon was removed within 5 h. The pseudo-first-order reaction rate constant of the Ag/N-doped TiO2 nanotube with 0.15 M Ag was 0.0637 min-1, which was 12 times higher than that of N-doped TiO2 nanotube. The mechanisms underlying·OH generation and the tetracycline degradation pathway were also elucidated. The photoelectrocatalytic system, which is an eco-friendly and low-energy system, exhibits excellent stability and reliability toward tetracycline and total organic carbon degradation and significantly aids the development of wastewater remediation.

Sustainable transition towards greener and cleaner seaborne shipping industry: Challenges and opportunities

This study investigates the growing concerns surrounding seaborne shipping and increasing expectations in the maritime sector due to the technological revolution. This study aims to analyze the ongoing causes and unintended consequences driving this revolution in the maritime shipping industry, examining the current state and rising projections beyond 2030. This study employed a three-stage methodology that involved searching for relevant articles, evaluating sources to identify gaps and outlining a systematic approach to analyze the 88 documents that met the inclusion criteria. Findings revealed that the maritime industry is witnessing the development of simulated training, smart devices, unmanned vessels, 5G networks, drones, augmented reality, digital transformation in ports, smart ships, efficient ports, automated and autonomous vessels are anticipated to be the industry's future. The integration of information and communication technology enhance port productivity and support fleets' energy transition, while remote vessel operations and unmanned autonomous vessels improve operational flexibility and energy efficiency. The adoption of very low energy systems and emissions benefit future waterborne services. The research findings are valuable to researchers and experts in the maritime field and waterborne service industries.

New paradigms in sustainable energy systems with hydrogen

Climate change, disturbance of the energy security resulting from increasing fuel prices due to conflicts, and disruptions to production and supply chains caused by COVID-19 have highlighted the need for the world to be prepared for future challenges. The environmental and climate change impacts of heavy use of fossil fuels for energy production have yielded numerous crucial challenges and will even cause increasingly more severe effects in the years to come. This is particularly important, as the utilization of fossil fuels is the largest contributor to the increasing emissions of greenhouse gases in the atmosphere, which is leading to climate change and other problems. As a result, there is an emerging need to transition towards low or zero-emission energy systems where renewables and nuclear energy can play a critical role in the new energy equation and help establish the source ecosystem for hydrogen. Hydrogen, being the most abundant, clean, and energy-intensive element in nature, is an attractive alternative to fossil fuels. Furthermore, when produced using renewable energy sources, it is easier to reduce and control upstream emissions to produce or store hydrogen than fossil fuels. This study presents a framework for developing hydrogen technologies, building the necessary infrastructure, and selecting appropriate energy sources to help transition to a more sustainable and resilient energy system. There are also life cycle assessment studies conducted for various energy production technologies, including hydrogen, and their results are comparatively evaluated to confirm renewables and nuclear energy options would be the most suitable sources for hydrogen production. The global warming potential values of electricity production using nuclear and renewable energy are found to be 0.027 and 0.043 kg CO2 eq./kWh. Comparatively, the global warming potential for natural gas, oil and coal are found to be 0.2, 0.3 and 0.36 kg CO2 eq./kWh, respectively.

Efficiency of lagoon-based municipal wastewater treatment in removing microplastics

Municipal wastewater treatment plants act as a sink, but also are a source of microplastics in the environment. A conventional wastewater lagoon system and an activated sludge (AS)-lagoon system in Victoria (Australia) were investigated through a two-year sampling program to understand the fate and transport of MP in such treatment processes. The abundance (>25 μm) and characteristics (size, shape, and colour) of the microplastics present in the various wastewater streams were determined. The mean values of MP in the influent of the two plants were 55.3 ± 38.4 and 42.5 ± 20.1 MP/L, respectively. The dominant MP size of influent and final effluent was <500 μm, with 25–200 μm accounting for >65 % of the total MP; synthetic fibres were the dominant MP in all wastewater streams. Influent MP concentration was significantly higher in summer than in other seasons for both systems, which was related to the lower plant inflow due to less stormwater entering the sewer during summer. The promising MP removal capability of the lagoon system (97 %) was attributed to its lengthy wastewater detention time (total HRT >250 days, including the storage lagoons) that would allow effective separation of MP from the water column via various physical and biological pathways. For the AS-lagoon system, the high MP reduction efficiency (98.4 %) was attributed to the post-secondary treatment of the wastewater with the lagoon system, in which MP was further removed during the month-long detention in the lagoons. The results indicated the potential of such low-energy and low-cost wastewater treatment systems for MP control.

Developing an Integrated Energy Demand-Supply Modeling Framework for Scenario Analysis of the Low Carbon Emission Energy System in Zambia

This study develops an integrated modeling approach to analyze the effects of different scenarios compared to a baseline (2019) scenario on energy demand and supply in Zambia. Aiming at minimizing costs, the model combines available resources and technologies, adhering to techno-economic and environmental limits. On the demand side, the study uses time series analysis to forecast future electricity demand in Zambia. The supply-side energy model identifies the optimal combination of resources and technologies needed to satisfy exogenously specified electricity demand levels at the least cost. The baseline scenario results revealed that the power outages in Zambia, especially at peak times, have been attributed to reliance on imported fuel for power generation, the slow-paced integration of renewable resources, and not fully utilizing resource potential for the supply side. To overcome the power outages and meet the electricity demand in 2035, a comprehensive scenario analysis was conducted, including the main scenarios of 30% integration of renewable energy, no coal power generation, and low emission targets (10%, 20%, 30%, 40%, and 50% reduction from the baseline). The expected CO2 reductions from the renewable energy scenario, no coal scenario, and 50% low emission target are estimated at 5222 kilotons in 2035, respectively.

Routine performance and biomedical/pharmaceutical applications of the HVE low-energy 14C AMS system

The HVE 4102Bo-AMS dedicated to 14C analyses minimizes measurement background by using a charge state selector in the accelerator terminal. The measured blank 14C/12C level for solid samples was determined to be 5.6 × 10-16, corresponding to more than 60,000 radiocarbon years.Tests on ion source memory indicated a prompt (<10 sec) decrease from OxII 14C/12C ratio (1.58 × 10-12) to ∼1.2 × 10-15 for the next sample (>3 orders of magnitude) followed by an approx. 40 s decay time to the background level of 5 × 10-16. The AMS system demonstrated its capability of supporting biomedical/pharmaceutical applications using CO2 samples from blood plasma with 14C activities ranging from 1002 to 0.752 mBq/mL in a qualification test performed with an external partner.

The hidden cochlear implant.

The hidden cochlear implant concept has two data transmission methods: Bluetooth low energy and transtympanic optical data transfer systems. This study aimed to present the hidden cochlear implant and compare the test results with the existing fully implanted cochlear implant. The Bluetooth low energy module was implanted into the implant bed. For the transtympanic optical data transfer tests, a receiver was passed through the posterior tympanotomy, and the transmitter was placed in the ear canal. The Bluetooth low energy module range was 5.2-17.5 m. Transtympanic optical data transfer reached a rate of 1 Mbit/s and had 99.22 per cent accuracy. Despite various obstacles, the accuracy of the transtympanic optical data transfer was more than 99 per cent with a 250 Kbit/s rate. The average power consumption was 310 mW for the implanted Bluetooth low energy module and 41 mW for the transtympanic optical data transfer receiver. Bluetooth low energy is suitable to be used transcutaneously. Transtympanic optical data transfer is an effective and promising technology. Hidden use cochlear implants aim to have the aesthetics of a fully implantable cochlear implant with higher reliability and a magnet-free design with smart device integration.

Low-energy deuteron–alpha elastic scattering in cluster effective field theory

In this paper, we study the low-energy $$d{-}\alpha $$ elastic scattering within the two-body cluster effective field theory (EFT) framework. The importance of the $$d(\alpha ,\alpha ) d$$ scattering in the $$^6 \text {Li} $$ production reaction leads us to study this system in an effective way. In the beginning, the scattering amplitudes of each channel are written in a cluster EFT with two-body formalism. Using the effective range expansion analysis for the elastic scattering phase shift of S, P and D partial waves, the unknown EFT low-energy coupling constants are determined and the leading and next-to-leading orders EFT results for the phase shift in each channel are presented. To verify the accuracy of the results, we compare experimental phase shift and differential cross section data with obtained results. The accuracy of the EFT results and consistency with the experimental data indicate that the EFT is an effective approach for describing low-energy systems.

Majorana nanowires, Kitaev chains, and spin models

Motivated by the fact that the idealized Kitaev chain toy model and the experimental semiconductor-superconductor Majorana nanowire can both host the Majorana zero modes, we theoretically investigate the question to what extent the two models are equivalent or similar, using the perspective of the corresponding dual spin models for both. We start with the duality between the Kitaev chain and the transverse-field XY spin model through the Jordan-Wigner transformation with the goal of establishing the connection between the Kitaev chain and the nanowire. By applying the Jordan-Wigner transformation to the nanowire, we find that the corresponding bosonic spin model is a generalized spin cluster model, containing 3-spin and 4-spin terms, with staggered couplings. By projecting out the upper band of the bare semiconductor with higher energy, we obtain an effective low-energy spinless system from the spinful nanowire system deep in the topological regime. Finally, we establish the connection between the Kitaev chain and Majorana nanowire by showing that the spinless Kitaev chain can be viewed as the first-order approximation of the spinful Majorana nanowire deep in the topological regime.

Design and simulation of a low-energy single ion irradiation system for micro/nano-biosample investigation

A low-energy single ion irradiation system is developed in its initiation in Thailand to follow one of the trends in novel ion beam technology exploitation. Single ion irradiation of materials is a highly technological development of ion beam technology. The developed single ion irradiation systems worldwide are primarily in the MeV-energy range and for single cell studies, and recently the trend has been extended to the low-energy range (< 100 keV) but focused on microelectronic applications. Based on our previous research on low-energy ion beam irradiation of biological cells and DNA, we design and simulate a low-energy single ion implantation system, aiming at eventual construction of such a novel ion beam apparatus for applications to the biological studies. In the system, the ion energy is decreased to orders < 1 keV by the existing deceleration lens, then the low-energy ion beam passes through µm slits, and finally, low-energy single ions are obtained by beam scanning with appropriate frequencies from scanner plates and detected by a single ion detection device. Conceptual design, calculation and simulation of this single ion system are presented.

Computational approach for investigating nanoscale interfacial ice adhesion trends

For developing high performance, low-energy ice protection systems, it is vital to understand the icing physics at the interface of the ice and substrate. This can be achieved by modelling the interface at nanoscale and then studying the adhesion trends.

Stability of Co-amorphous Solid Dispersions: Physical and Chemical Aspects

Drug amorphization is one of the major approaches in pharmaceutical sciences to improve the solubility and dissolution rate of poorly water-soluble drugs. Amorphous solid dispersions are widely discussed approach to convert the drug into an amorphous state but due to its high energy state, the system tends to recrystallize upon storage. Co-amorphous system is a single-phase low energy system that falls under the glass solution, a type of solid dispersion. Being low-energy state and single-phase, co-amorphous dispersions are more stable than amorphous solid dispersions. In co-amorphous dispersions, the homogeneous single phase is formed only with low molecular weight co-formers, so the amount of co-former required is relatively low and this reduces the bulk of the system. This aspect of co-amorphous dispersions makes it popular over the amorphous solid dispersions in the area of solid dispersion researchers. This review provides an overview of co-amorphous dispersions and their recent advances. Particularly, this review will discuss various factors (physical and chemical) that affect and provide the stability of the co-amorphous dispersions formulation.

Energy-Aware Coded Transmission Strategy for Hierarchical Cooperative Caching Networks

With the rapid development of millions more edge base stations (EBSs) and billions of user devices in the future networks, the desire for low-energy system design and transmission strategy will be even more compelling. In this letter, we investigate the energy consumption issue of hierarchical cooperative caching networks (HCCNs) in which both EBSs and users are capable of storing content data in their local caches. A three-stage coded transmission strategy in HCCNs is proposed, and the closed expression of energy consumption of each stage is derived. In addition, we formulate a total energy consumption minimization problem with the constraint of EBSs’ cache sizes, and provide an algorithm to obtain the optimal cache placement matrix. We demonstrate by numerical results that, our optimized three-stage coded transmission strategy can achieve lower energy consumption than various multicast transmission strategies under the different users’ cache sizes.

Density of states for a low-energy point vortex gas on the sphere

Point vortex systems are useful models of two-dimensional fluids. The equilibrium statistical mechanical properties of point vortices in a planar region include some unusual features, such as negative temperature states, that depend on the details of the limiting process used. The limiting form of the density of states as the vortex number increases is of central importance. Esler et al. (2013, 2015) expressed the limiting density of states for point vortices modeling low-energy fluid systems in a planar region as the inverse Fourier transform of a function determined by the spectrum of a certain differential operator. In this paper random variables related to the density of states are found for systems of point vortices on the sphere using the theory of weighted U-statistics. The limiting distributions of these statistics were determined by limits of the Fourier transforms of the probability density function; the results take a form analogous to that found in those earlier works. Two systems are investigated. The first is a neutral or weakly non-neutral point vortex gas on the sphere, using the same low-energy limiting process. The second is a lattice model where the vortex positions are fixed and the circulations are random. In both cases the limiting form of the moment generating function is found in closed form, from which the density of states can be found by inverse Fourier transform.