Critical Technical Issues Research Articles

Open data and energy analytics - An analysis of essential information for energy system planning, design and operation

Energy transitions are reshaping global and national energy systems and appropriate decision-making strategies are needed to drive an effective change in response to pressing global issues. Governmental institutions, industry, academia, and civil society are all participating to this global change, playing different roles. Open energy models and associated data are essential to promote open science practices, and create an effective science-policy interaction. For example, they can foster multi-disciplinary research addressing the co-evolution of energy technologies and human behaviour more transparently and, more in general, they can improve the interaction of multiple linked models and data, by improving them with respect to the current state of the art. In this paper, we present an analysis of features of open energy models and data, highlighting essential information that can be shared among communities of researchers in the energy field to foster multidisciplinary research. This information inherently embodies different key concepts and perspectives in modelling that affect both simulation and optimization processes employed for energy systems planning, design and operation. Indeed, this shared knowledge is crucial to overcome critical technical issues (e.g. end-use energy efficiency improvements, energy conversion processes, energy infrastructures operation, etc.) that may inhibit successful energy transitions. Finally, ecosystems of interacting open data and models are key assets for the development of next generation energy services and technologies, based on innovative business models in which the problem of monitoring, verifying and tracking performance transparently (at multiple levels) will be fundamental.

Study on Coupling Mechanism of Carbon-Water Symbiosis System and Regulation and Control of Water Resources in the Context of Regional Collaborative Development

In the aspect of theoretical research, the regional carbon-water coupling mechanism has not yet formed a complete conceptual framework, so there is an urgent need to build an academic system of the carbon-water coupling under a unified physical device. Therefore, based on the overall identification of the coupling mechanism of the water cycle and carbon balance, this paper systematically analyses the characteristics of carbon capture and release in the process of water resources and energy development, puts forward the connotation, symptoms and overall tasks of water resources allocation based on low-carbon development model, and constructs a technical framework supported by regional carbon-water coupling simulation and water resources allocation. The critical technical issues such as water resources allocation, model construction process, countermeasures and safeguard measures based on the low-carbon model. The safety early warning model of water quality and quantity in regional carbon-water symbiosis system is put forward, which provides a method reference for the regulation and control of local water resources.

Structure parameter optimization and bearing limit analysis of the expansion unit of three-roller tube expander.

The critical technical issues for the structure design of three-roller tube expander were first studied and analysed in this paper. Then, the major design parameters of the expansion unit structure and the bearing limit of 12¼″ three-roller tube expander were optimized and investigated by finite-element numerical simulation method. Results from study show that the required expansion force increases when the taper angle of the roller outer surface gets larger, taking the axial expansion force as the quantitative indicators. It is suggested that the roller tape angle of the expansion unit should be in the range of 9–12° considering the proper length of the roller and the non-self-locking tube expansion process. The required expansion force of the bellows first decreases and then increases when the gauge length of the expansion unit becomes longer. The optimal value of the gauge length is 50 mm considering the proper length of the roller. And according to the numerical simulation results, the designed three-roller tube expander meets the strength requirements. The results of this study are of great significance to the expend bellows drilling technology.

A multi-objective evolutionary approach for planning and optimal condition restoration of secondary distribution networks

A secondary distribution network (SDN), corresponding to the final user low voltage distribution circuit, is continuously growing due to a persistent increase in load demand. Consequently, the performance of any optimized design will inevitably degrade over time. To avoid the associated repercussions such as faults, congestion, voltage drops, and other major quality issues, we are eventually prompted to redesign this part of the grid. To do so, we propose a Two-Stage Multi-Objective Evolutionary Approach (TS-MOEAP), which is able to find a new optimal network configuration, circumventing the associated quality issues. The proposed approach is oriented to improve the performance of SDNs by combining the concepts of network reconfiguration (NR) and optimal placement of distribution transformers (DTs). Due to the large and complex topology of SDNs, we deal with a hard combinatorial, non-convex, and nonlinear optimization problem. Consequently, to facilitate the resolution of the problem, the proposal is divided into two stages: (1) optimal placement and sizing of distribution transformers, as well as conductor sizing and branch routing, and (2) optimal network reconfiguration. For the first stage, an improved particle swarm optimization technique (IPSO) combined with a greedy algorithm is used, and for the second stage, an improved nondominated sorting genetic algorithm with a heuristic mutation operator (NSGA-HO) is implemented. The approach redesigns SDNs by minimizing total power loss and investment costs while satisfying quality issues and technical constraints. The proposed approach is validated by improving a real-life SDN with critical quality and technical issues. We also compare the results with respect to other state-of-the-art algorithms.

Improved electrocatalytic activity of Pt supported onto Fe-doped TiO2 toward ethanol oxidation in acid media

The low stability of Pt-based catalysts due to severe corrosion of carbon support is one of the most critical technical issues hindering the widespread application of proton exchange membrane fuel cells. Here, we report the successful deposition of Pt nanoparticles on both pure titanium dioxide (TiO2) and Fe-doped TiO2 powder by chemical reduction using formic acid and their performance toward ethanol oxidation in acid media. First, the supported TiO2 was synthesized by the sol–gel method, and its physical-chemical properties were modified by the incorporation of iron (5.0 and 10.0 wt% Fe) into the structure of TiO2. The supports and catalysts were characterized by photoacoustic spectroscopy (PAS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The PAS data show that the doping of TiO2 with iron ions (III) decreases the band gap from 2.95 eV (undoped TiO2) to lower values depending on the iron content in the support (1.97 eV and 1.90 eV for 5Fe–TiO2 and 10Fe–TiO2, respectively). The XRD and TEM results indicate the presence of small-sized (around 3.5 nm) Pt nanostructures deposited onto the supports. The XPS analyses reveal surfaces rich in metallic Pt and oxygen species (O2− species, OH− and O atoms) in the vicinity of oxygen vacancies, as well as strong interactions between Pt nanoparticles and the Fe–TiO2 support. The Pt/Fe–TiO2 electrocatalyst exhibits higher catalytic activity toward ethanol oxidation than Pt/TiO2 and commercial Pt/C electrocatalysts (used as reference). The efficiency of Pt utilization increases with the Fe content. The sample with 10 wt% (mol/mol) of iron is then the most active catalyst. The enhanced activity and stability of the Pt/Fe–TiO2 catalyst can be attributed to the synergic and electronic effect of the compounds, Pt, and Fe–TiO2.

P2592Combining home monitoring temporal trends and baseline patient risk profile for predicting impending heart failure hospitalizations. Results from the SELENE HF (BIO.Detect HF IV) study

Abstract Background/Introduction The lack of a validated method to efficiently combine information provided by Remote Monitoring (RM) of implantable defibrillators (ICD) and patient clinical profile has limited the use of RM in the prevention of worsening heart failure episodes. Purpose Our objective was to develop and validate an index combining RM temporal trends and a baseline risk score for predicting the first HF hospitalization after device implantation. Methods We prospectively enrolled 918 patients (81% male, median age 69, interquartile interval [QI], 61/76; Seattle Heart Failure Score [SHFS], 0.17, QI, −0.40/0.75) with indication to ICD (56%), or ICD with cardiac resynchronization therapy (44%). The Home Monitoring (HM) system was activated in all patients after implant to collect several technical and HF-related variables daily. Investigators were blinded to HM reports, and only received automatic alerts for critical technical issues. The primary endpoint was the first adjudicated HF hospitalization. The cohort was a posteriori 1:1 randomized in derivation and validation groups stratified by device type and primary endpoint occurrence. The SHFS was used for baseline risk assessment. Results During a median follow-up of 23 months (QI, 14/36), 62 first HF hospitalizations were adjudicated. In the derivation group, the index was constructed by combining the SHFS and temporal trends of 24-hour and rest mean heart rates, ventricular ectopic beat frequency, arrhythmic atrial burden, heart rate variability, physical exercise, and thoracic impedance. Variable selection was based on an automatic stepwise procedure, after applying appropriate transformations in variable-specific time frames to maximize the area under the receiver operating characteristics curve (AUC). The resulting index was associated to an AUC of 0.88 and an Odds Ratio of 2.72 (confidence interval [CI] 1.97–3.75, p<0.001) for index unitary increase. In the index validation test, first HF hospitalizations were predicted with a sensitivity of 73.3% (CI, 54.1%-87.7%), a median alerting time of 55 days (QI, 20/68), false alert rate of 0.75 (CI, 0.70–0.81) patient-year, and 95.1% false-alert-free days. Conclusion HM temporal trends of selected variables and the SHFS may be combined to timely and efficiently predict the first HF hospitalization after implant, with less than 1 expected per-patient false alert per year. Acknowledgement/Funding BIOTRONIK SE & Co. KG, Berlin, Germany

Predicting Future Driving Risk of Crash-Involved Drivers Based on a Systematic Machine Learning Framework.

The objective of this paper is to predict the future driving risk of crash-involved drivers in Kunshan, China. A systematic machine learning framework is proposed to deal with three critical technical issues: 1. defining driving risk; 2. developing risky driving factors; 3. developing a reliable and explicable machine learning model. High-risk (HR) and low-risk (LR) drivers were defined by five different scenarios. A number of features were extracted from seven-year crash/violation records. Drivers’ two-year prior crash/violation information was used to predict their driving risk in the subsequent two years. Using a one-year rolling time window, prediction models were developed for four consecutive time periods: 2013–2014, 2014–2015, 2015–2016, and 2016–2017. Four tree-based ensemble learning techniques were attempted, including random forest (RF), Adaboost with decision tree, gradient boosting decision tree (GBDT), and extreme gradient boosting decision tree (XGboost). A temporal transferability test and a follow-up study were applied to validate the trained models. The best scenario defining driving risk was multi-dimensional, encompassing crash recurrence, severity, and fault commitment. GBDT appeared to be the best model choice across all time periods, with an acceptable average precision (AP) of 0.68 on the most recent datasets (i.e., 2016–2017). Seven of nine top features were related to risky driving behaviors, which presented non-linear relationships with driving risk. Model transferability held within relatively short time intervals (1–2 years). Appropriate risk definition, complicated violation/crash features, and advanced machine learning techniques need to be considered for risk prediction task. The proposed machine learning approach is promising, so that safety interventions can be launched more effectively.

A Hierarchical Control Structure for Distributed Energy Storage System in DC Micro-Grid

To adapt to the rapid development of the renewable generations, DC micro-grid has been becoming an attractive technical route. Energy storages are widely employed in DC micro-grid to balance the power generation and usage. Therefore, the coordination and energy control among these distributed energy storage systems are critical technical issues to guarantee the overall efficiency and security. In this paper, the concept and characteristic of the distributed energy storage system in DC micro-grid are first analyzed. A hierarchical control system for power sharing is proposed to achieve the state-of-charge (SOC) balancing among energy storage units (ESU). In the lower layer of the control system, the DC droop control is applied to allocate the output power of each ESU based on its maximum output power. In the upper layer, consensus algorithm is utilized to adjust the output power reference of each ESU to reduce the SOC difference. Finally, a Matlab/Simulink model is built to verify the proposed approaches. The simulation results indicate that the proposed method can achieve the SOC balancing robust operation in distributed energy storage system.

Signal and pointing accuracy of ultraviolet laser in micro-pattern gaseous detector

In the study of the gas detectors, it is an important calibration method to use the ultraviolet (UV) laser with two-photon ionization mechanism for producing ionized signal. In the last decades, micro pattern gas detector, especially gaseous electron multiplier and micromesh gaseous detector, has been widely used in high energy experiments. These kinds of gaseous detectors have the advantages of higher ion backflow suppression ability, smaller <b><i>E</i></b> × <b><i>B</i></b> effect and good radiation resistance under the relatively higher count rate environment. To obtain a higher spatial resolution with a UV laser calibration system in gaseous electron multiplier detector, two critical technical issues remain to be resolved: the measurability of the laser signal and the accuracy of the laser beam position. In this paper, the studies in simulation and experiment are conducted to discuss these two critical questions. In the simulation section, the simulation results provide an estimation of signal in the gaseous electron multiplier detector with UV laser of 266 nm wavelength in the mixture working gases of Ar/CO<sub>2</sub> (70/30), and give an evaluation of the laser pointing accuracy and the possible relative error of the electron drift velocity. In the experiment section, a UV laser calibration prototype is designed and developed. A pulsed laser of 266 nm wavelength is used as a signal source, which has a Gaussian-like cross section with a frequency of 10 Hz. The experimental results indicate that the signal of the UV laser in a triple gaseous electron multiplier detector reaches 400 mV for a readout strip width of 6 mm, a gain of detector of 5000, and a gain of amplifier of 10 mV/fC. For the calibration laser, the angle accuracy is discussed and tested. The angle uncertainty of the laser can be kept under 5′, and the accuracy of the drift velocity can reach 6.4 × 10<sup>−4</sup> with a shift of 0.33 mm in the <i>z</i> direction when the laser beam transmits a distance of 400 mm in the gas chamber. All of these results show that the laser beam specific parameters are the main reference for designing the prototype detector. According to the optimal parameters, a gaseous prototype detector will be tested in the next study.

The large tokamak JT-60: a history of the fight to achieve the Japanese fusion research mission

Fusion research was driven by the oil shocks in 1970’s and the concern about climate change during 20th century. This paper addressed the scientific research history of JT-60, the tokamak that achieved record fusion performances and opened the way toward the continuous operation of a tokamak fusion reactor through its scientific discoveries. The paper also highlighted technical struggles to improve machine capabilities and to solve technical issues faced during the JT-60 project. The missions of JT-60 were to achieve equivalent energy break-even (Q = PDTequi. / Pheat ≥ 1) and to establish a scientific basis for fusion reactor. The JT-60 made several modifications to reach equivalent break-even condition and continued efforts were made by the JT-60 team to solve critical technical issues during 23 years of research operation. Scientific success of JT-60 led to current ITER projects and the modification of JT-60 to a superconducting tokamak, JT-60SA. This paper is intended to be useful for the future researchers and managers of large-scale project by giving dynamical evolutions and highlighting key players. I dedicate this paper to Hiroshi Kishimoto, who made an outstanding contribution in managing the JT-60 research project.

Compensation of image noise induced by difference in optical characteristics of array-LED chips of LED print head

There are various applied electro-optical devices, which utilize light emitting didoe (LED) chip array for applications to displays and opto-electronic sensors. In those devices, it is the one of the critical technical issues to minimize uncertain fluctuations including optical power and optical density. Due to variation in operating environment of a device, those are not corrected precisely by controlling parameters based on simple relation between parameters and resultant abovementioned outputs. Therefore, there is essential need to correct outputs in real-time based on correction function generated from the consideration on various operation condition. In this article, we introduce an output correction method through reporting real-time image noise reduction in the application to electro-photography with LED print head. In the technology of LED print head, as differences in optical characteristics between each LED cause vertical image noise, it should be corrected in order to obtain images that are comparable or better in quality compared to those produced by the conventional laser scanning method. Even though it seems that the method used to obtain uniform light power from each LED can solve this problem, it does not work well for high-resolution printing. Therefore, a scan method involving correction by a printed and scanned pattern is introduced through this work. The scan method is composed of correction patterns to minimize printing noise by its shape, the correction algorithm to calculate the optimized value and the printing algorithm to control gray levels in real-time precisely. We believe that the developed correction method upgrades the printing quality of the LPH printer better than commercial printers. The developed correction method can also be applied to various application areas that use an array-type light source such as display systems and lighting systems.

Cooperation in 5G HetNets: Advanced Spectrum Access and D2D Assisted Communications

The evolution of conventional wireless communication networks to 5G is driven by an explosive increase in the number of wireless mobile devices and services, as well as their demand for any time and everywhere connectivity, high data rates, low latency, high energy efficiency, and improved quality of service. To address these challenges, 5G relies on key technologies, such as full duplex, D2D communications, and network densification. In this article, a heterogeneous networking architecture is envisioned, where cells of different sizes and radio access technologies coexist. Specifically, collaboration for spectrum access is explored for both full-duplex and cognitive-based approaches, and cooperation among devices is discussed in the context of the state-ofthe- art D2D assisted communication paradigm. The presented cooperative framework is expected to advance the understandings of the critical technical issues toward dynamic spectrum management for 5G heterogeneous networks.

A technology assessment of the proposed Cardiff–Weston tidal barrage, UK

Several tidal power schemes have been proposed for the Severn estuary between south-west England and Wales, UK. In this paper the so-called Cardiff–Weston barrage is evaluated using various sustainability appraisal techniques to determine its net energy output, carbon dioxide footprint and financial investment criteria, alongside various critical technical and environmental issues. The barrage would be located seaward of the Severn Road crossings, involve an estimated cost of £21 billion to construct and could potentially generate some 16·8 TWh/year – about 4·4% of the UK electricity demand. An indicative energy technology assessment is undertaken to evaluate this tidal power scheme over its foreseen lifespan of 120 years in terms of its ‘cradle-to-site’, operation and maintenance requirements. The present analysis suggests that the proposed Cardiff–Weston barrage would yield relatively attractive ‘figures of merit’ in terms of its net energy and carbon dioxide emissions, although its financial performance is poorer than that of alternative power generators. Comparisons are also made with the much smaller Shoots barrage scheme proposed upstream of the Severn Road crossings, which is favoured by environmental groups due to its more benign ecological and environmental impacts.

Local Excision Techniques for Rectal Cancer After Neoadjuvant Chemoradiotherapy: What Are We Doing?

Recent evidence shows that the majority of rectal cancers demonstrate occult tumor scatter after neoadjuvant chemoradiotherapy that can extend for several centimeters under adjacent normal-appearing mucosa beside the residual mucosal abnormality or scar. This systematic review aimed to determine all of the published selection criteria and technical descriptions for local excision to date with regard to this phenomenon. PubMed, MEDLINE, and Embase were searched using the following key words: rectal cancer, local excision, radiotherapy, and neoadjuvant. Studies that assessed local excision of rectal cancer after neoadjuvant chemoradiotherapy were included. Duplicate series were excluded from final analysis. All of the data points were tabulated and analyzed using Microsoft Excel. Criteria for patient selection, surgical technique, clinical restaging, pathologic assessment, and indications for completion surgery were analyzed. After exclusions, data from 25 studies that in total evaluated local excision in 1001 patients were included. Compared with the single accepted technique of total mesorectal excision, described techniques for local excision after neoadjuvant therapy demonstrate significant variability in many critical technical issues, such as marking/tattooing original tumor margins before neoadjuvant therapy, using pretreatment tumor size/stage as exclusion criteria, and specifically stating lateral excision margins. Where detailed, the majority of local recurrences occurred in patients with clear pathological margins, yet significant variation existed for pathological assessment and reporting, with few studies detailing R status and some not reporting margin status at all. Significant variability also existed for adverse tumor features that mandated completion surgery, and, importantly, many series describe patients refusing completion surgery where indicated. We were unable to perform meta-analysis because studies lacked sufficient methodologic homogeneity to synthesize. The observations from this study prompt additional study, standardization of technique, and cautious use of local excision of rectal cancer in the setting of neoadjuvant chemoradiotherapy.

Significant Change Spotting for Periodic Human Motion Segmentation of Cleaning Tasks Using Wearable Sensors.

The proportion of the aging population is rapidly increasing around the world, which will cause stress on society and healthcare systems. In recent years, advances in technology have created new opportunities for automatic activities of daily living (ADL) monitoring to improve the quality of life and provide adequate medical service for the elderly. Such automatic ADL monitoring requires reliable ADL information on a fine-grained level, especially for the status of interaction between body gestures and the environment in the real-world. In this work, we propose a significant change spotting mechanism for periodic human motion segmentation during cleaning task performance. A novel approach is proposed based on the search for a significant change of gestures, which can manage critical technical issues in activity recognition, such as continuous data segmentation, individual variance, and category ambiguity. Three typical machine learning classification algorithms are utilized for the identification of the significant change candidate, including a Support Vector Machine (SVM), k-Nearest Neighbors (kNN), and Naive Bayesian (NB) algorithm. Overall, the proposed approach achieves 96.41% in the F1-score by using the SVM classifier. The results show that the proposed approach can fulfill the requirement of fine-grained human motion segmentation for automatic ADL monitoring.

Editorial: Systems Biology of Transcription Regulation

Editorial: Systems Biology of Transcription Regulation

Genome engineering through CRISPR/Cas9 technology in the human germline and pluripotent stem cells.

With the recent development of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 genome editing technology, the possibility to genetically manipulate the human germline (gametes and embryos) has become a distinct technical possibility. Although many technical challenges still need to be overcome in order to achieve adequate efficiency and precision of the technology in human embryos, the path leading to genome editing has never been simpler, more affordable, and widespread. In this narrative review we seek to understand the possible impact of CRISR/Cas9 technology on human reproduction from the technical and ethical point of view, and suggest a course of action for the scientific community. This non-systematic review was carried out using Medline articles in English, as well as technical documents from the Human Fertilisation and Embryology Authority and reports in the media. The technical possibilities of the CRISPR/Cas9 technology with regard to human reproduction are analysed based on results obtained in model systems such as large animals and laboratory rodents. Further, the possibility of CRISPR/Cas9 use in the context of human reproduction, to modify embryos, germline cells, and pluripotent stem cells is reviewed based on the authors' expert opinion. Finally, the possible uses and consequences of CRISPR/cas9 gene editing in reproduction are analysed from the ethical point of view. We identify critical technical and ethical issues that should deter from employing CRISPR/Cas9 based technologies in human reproduction until they are clarified. Overcoming the numerous technical limitations currently associated with CRISPR/Cas9 mediated editing of the human germline will depend on intensive research that needs to be transparent and widely disseminated. Rather than a call to a generalized moratorium, or banning, of this type of research, efforts should be placed on establishing an open, international, collaborative and regulated research framework. Equally important, a societal discussion on the risks, benefits, and preferred applications of the new technology, including all relevant stakeholders, is urgently needed and should be promoted, and ultimately guide research priorities in this area.

Technical Issues and Challenges in Building Human Body Sensor Networks

In this research work, an exploration is done for identification of critical technical issues, problems, challenges in area of wireless body network sensors, which are continuous emerging as integral part of health monitoring systems. All this is possible due to the concept of ‘Internet of Things’ [5], in which day to day consumer devices, equipment are connected onto the network enabling information gathering and management of many vital signals. The first section gives introduction to wireless network developments in recent context, and then it is followed by discussion on existing work done in context of physical, Media access control and other aspects like energy consumption and security of such systems. The tabular summary on the gaps, limitations of Wireless body area network is done and based on this work; future directions are also suggested. Care has been taken to solicit high impact general paper for conducting this systematic study.

Demonstration of an Improved Total Partitioning Process for High Level Liquid Waste Using Annular Centrifugal Contactors

High level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, 90Sr, 137Cs, etc., and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P&T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. An improved total partitioning process, including a TRPO (tri-alkylphosphine oxide) process for the removal of actinides, a CESE (crown ether strontium extraction) process for the removal of Sr, and a calixcrown ether extraction process for the removal of Cs, has been developed to treat Chinese HLLW at the Institute of Nuclear and New Energy Technology (INET), Tsinghua University, China. A demonstration test of the improved total partitioning process was carried out using 74-stage 10-mm-dia annular centrifugal contactors and simulated HLLW. The test results showed that the decontamination factors were >1.2 × 106, 4600, and 7500 for Nd, Sr, and Cs, respectively. In the test, Nd was used to simulate Am. During the test, 74-stage 10-mm-dia annular centrifugal contactors worked stable continuously with no stage failing or interruption of the operation.

Radioactive Tracer Tests of Two Improved TRPO Processes for High-Level Liquid Waste Using Annular Centrifugal Contactors

High-level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, and fission products, and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P&T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. Two improved trialkylphosphine oxide (TRPO) processes for the removal of actinides have been developed to treat Chinese HLLW, based on the original TRPO process. In one improved process N,N-diethylhydroxylamine as a reducing agent was used for reducing Np(V) and Np(VI) to Np(IV) in order to improve the extraction efficiency of Np. In the other improved process, ammonium vanadate as an oxidizing agent was used for oxidizing Np(V) and Np(IV) to Np(VI) in order to improve the extraction efficiency of Np. Radioactive tracer tests of two improved TRPO processes were carried out using 30-stage 10-mm-diam annular centrifugal contactors and simulated HLLW containing U, Np, Pu, and Am. The test results showed that the decontamination factor of total α activity was >1 × 105. During the test, 30-stage 10-mm-diam annular centrifugal contactors worked in a stable manner continuously, with no stage failing or any interruption of the operation.