bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of transient climate response and associated sea level rise by deep-ocean mixing
Authors: Watanabe Michio , Tatebe Hiroaki , Suzuki Tatsuo , Tachiiri Kaoru
Published: April 2020

To evaluate uncertainty in the transient climate response (TCR) associated with microscale deep-ocean mixing processes induced by internal tidal wave breaking, a set of idealized climate model experiments with two different implementations of deep-ocean mixing is conducted under increasing atmospheric CO2 concentration 1% per year. The difference in TCR between the two experiments is 0.16 °C, which is about half as large as the multimodel spread of TCR in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The TCR difference can be attributed to the difference in the preindustrial climatological state. In the case where deep-ocean mixing works to enhance ocean stratification in the Pacific intermediate-to-deep layers, because the Pacific water mass is transported to the Southern Ocean by the Pacific meridional overturning circulation, the subsurface stratification in the Southern Ocean is also enhanced and deep wintertime convection there is suppressed. Our study shows that in this case during CO2 increase, ocean heat uptake from the atmosphere to deeper layers is suppressed and TCR is estimated to be higher than the other case. Diminished accumulation of oceanic heat in the deep layer also leads to the sea level depression of ∼0.4 m in the Southern Ocean when atmospheric CO2 concentration has quadrupled. Together with convective and cloud-radiative processes in the atmosphere and oceanic mesoscale processes, microscale deep-ocean mixing can be one of the major candidates in explaining uncertainty in future climate projections.
Study the Effect of Combination of Shoe Height and Slot Opening width to Reduce Cogging Torque in Permanent Magnet Generator
Authors: Siregar Marsul , Joe Liza E. , Nur Tajuddin
Published: April 2020

Cogging torque is one important problem in a permanent magnet generator. With a good understanding of the phenomenon, the cogging torque can be minimized by using the multi-objective technique. This paper presents a combination technique for cogging torque reduction by an appropriate small stator slot opening width, stator shoe height with fractional technique in Permanent Magnet Generator. Cogging torque waveforms, along with other relevant characteristics are investigated in this research and by analysis using the finite element method, the combination width shoe height and magnet edge slotting effect to decline the cogging torque peak value. A significant value of cogging torque, when slot opening width of 1.55 mm and shoe height of 2.3 mm, provide the peak value of cogging torque in the structure is 0.00062 N-m for positive value and about -0.00064 N-m for the negative value. It can be concluded that this type of slot opening width of 1.55 mm and shoe height of 2.3 mm is the best structure of the fractional 8 slot, because it has any significant low of cogging torque and least of unbalance magnetic pull
Design of Low Speed Generator 1 Phase Using Permanent Magnetic Type Neodymium
Authors: Syafriyudin  , Mujiman  , Buyung Irawadi
Published: April 2020

The need for electricity in Indonesia and throughout the world is increasing, while most of the energy sources for electricity generation are still using fossil fuels such as oil, natural gas and coal. Fossil energy has a high level of pollution which is the cause of global warming, it is necessary to replace fossil energy that is environmentally friendly, namely renewable energy. The construction of power plants such as micro hydro power plants (PLTMh) which are located in irrigation canals or rivers with relatively small water discharge will result in low wheel rotation. The waterwheel rotation in this PLTMh system has a low rotating speed of around 200 rpm, and has a low torque or no cogging torque effect. Based on the needs in the field, a permanent Neodymium Type (NdFeB) Permanent Magnet Axial Flux Generator is built, which is specifically designed for low speeds of 200 rpm and has no cogging torque or low rotational torque effects. And it is hoped that the design of this generator can be used according to the needs of PLTMH. The results obtained in this study are, the generator can produce a voltage at a rotational speed of 200 Rpm and a frequency of 50 Hz is 100 VAC.
Application of Greenhouse Gas Monitoring System Using General Packet Radio Service on GSM Network
Authors: Iswahyudi C , Novianta M A , Muchlis  , Suseno H P
Published: April 2020

Emissions of carbon dioxide (CO2) is the greatest influence on the air quality for the largest contribution to global warming is about 50%. These gases absorb and reflect radiation emitted waves of the earth, so that the heat will be stored on the surface of the earth. The absorption capacity on mangrove plants is one of the efforts to reduce CO2 emissions. In this work, a gas monitoring system was developed to monitor greenhouse gas utilizing GSM network using GPRS service. Based on experiment result, this system can monitor the absorption of CO2 emissions and the formation of O2 gas in mangrove plants as one of the efforts to reduce the impact of global warming. The information can be transmitted using SMS service on GSM network in less packet size and data transmission time, and also can be accessed through web-based application. As conclusion, the use of small and portable gas-sensing air pollution monitoring technologies can obtain more spatially and temporally representative air pollution data.
Improvement of Teacher’s Ability to Make IT-Based Teaching and Evaluation Materials Using Scribe, Camtasia and Quiz Creator (Case Study in SMK Negeri 1 Tembarak, Temanggung, Central Java, Indonesia)
Authors: Nurnawati E K , Sutanta E , Bekti R D
Published: April 2020

Teachers are an important element in the formal education system, both in primary, secondary, and high education. The ability of teachers to prepare teaching materials is very influential on student learning outcomes. Learning materials that are easy to understand and look interesting will be preferred and easily understood by students. Evaluation is one of the benchmarks for knowing the results achieved by students. Success in delivering subject matter certainly influences the results achieved in student evaluation. This study aims to measure the extent to which training in making teaching materials and exam questions based on information and communication technology (ICT) affects improving the ability of teachers in the learning process and evaluation of students. The method used in this study is a method of collecting data with experimental methods for teachers before and after training. The software used in this training was Scribe 1.0.4 and Camtasia 8.0 video for making IT-based learning material and Quiz Creator 4.5.1 used for making student evaluation materials. Survey data collection was conducted on forty teachers who attended training and sixty students at SMK N 1 Tembarak Temanggung. Wilcoxon Test is used to analyse survey data. The results of this study are that there is a significant correlation with the ability of teachers to develop teaching materials before and after training. The results of a survey of students found that 80% of students preferred teachers to use ICT-based teaching materials and 75% of students preferred to work on ICT-based questions rather than conventional exam questions, 87% teachers found to benefit from the training. The Wilcoxon test proves that the teacher’s ability to make teaching materials and exam materials increases after training.
Low Cycle Fatigue Properties of Aluminizing Coating on Cold-Drawn AISI 1018 Steel
Authors: Badaruddin M , Kurniawan R D , Sugiyanto  , Pambudi A
Published: April 2020

The mechanical and the low cycle fatigue (LCF) properties of cold-drawn AISI 1018 steel (CDS 1018) with and without hot-dip aluminizing (HDA) coating had been experimentally investigated at room temperature. The tensile properties and the LCF properties were determined from tensile test results and cyclic strain-fatigue test results, respectively. The aluminide coating on the CDS 1018 significantly decreases the mechanical properties and the strain-fatigue life of the steel. With increasing in strain amplitude levels, CDS 1018 experienced continuously cyclic softening behaviour after cyclic loading in few cycles. By contrast, the cyclic softening of HDA steel was observed in few cycles and HDA steel continuously exhibits the stably cyclic hardening behaviour until failure. CDS 1018 with aluminide coating results the longer transition fatigue cycles (Nt) than those of CDS 1018 without aluminide coating by a factor of ∼3.0. CDS 1018 with HDA coating can be used for material components which the components are safely designed under cyclic loading below the yield strength of the material.
Analysis of Availability and Water Demand: A Case Study in Sumberejo Village Tanggamus Regency
Authors: Anwar  , Novilyanza Elza , Abdul Fatah Kemas Muhammat
Published: April 2020

Clean water is a basic need for humans so that it is normal if clean water gets priority in handling and fulfilling it. The spring in Sumberejo Village, Sumberejo Subdistrict, Tanggamus District Is needed to facilitate. The purpose of this study is to identify the potential sources of raw water (clean water) in Sumberejo Village. The EPANET 2.0 program was implemented by calculative the number of people to be served as well as the need for clean water, reservoir capacity, and planning for distribution network. The methods used in water availability include measurement of discharge, topographic data, and water quality and for water requirements are projections of population, total water requirements and pipeline network pressure. The results of the analysis and projections of the number of villagers up to 2030 with a total of 2443 people, total water needs of 2842 liters/second, the availability debit in Sumberejo water eyes was 2,979 liters/second, the discharge was still sufficient for water needs until 2030. Hydraulic analysis using EPANET 2.0 obtained pressure at the highest location is 24.75 meters and the lowest is 2.95 meters. The study indicates that availability and water demand is sufficient until 2030
The analysis of Tsunami evacuation route based on geographic information system: a case study in the coast of Lampung Bay
Authors: Febrina Rina , Evan D K , Afriani Lusmeilia , Retno Rr M I , Susilorini  , Fitra Helmia Adita
Published: April 2020

The most fundamental issues for local people who are potentially at risk to tsunami threat are awareness and preparedness. The aim of this paper is to define the effectiveness of tsunami evacuation routes toward tsunami hazard along the coast of Lampung bay. The parameter applied in this study were elevation and slope created based on Aster GDEM while the coastline distance was made based on vector map and tsunami inundation obtained by Hills and Mader equation. In addition, the road network was derived from Development Planning Agency at Sub-National Level. AHP process was applied in determining the weight of the parameter by using pair-wise comparison via five normalized matrix iteration. Thus, there are five vulnerability classes that were classified. Weighted overlay through spatial analysis in geographic information system (GIS) was used in this study in order to make the final tsunami vulnerability map. The Network Analysis through Closest Facility Analysis in GIS was used to create the effective evacuation route and to point out 34 effective evacuation locations that could be reached by the people before the tsunami strikes. The results presented in this paper could eventually facilitate the improvement in the basic data for city planning related to evacuation process and management strategy during disaster.
Improvement of Cogging Torque Reduction by Combining the Magnet Edge Shaping and Dummy Slot in Stator Core of Fractional Slot Number in Permanent Magnet Machine
Authors: Nur Tajuddin , Mawar Sri
Published: April 2020

A new technique in reducing the cogging torque by combining the magnet edge shaping and dummy slot in stator core of fractional slot number in permanent magnet machine was studied in this paper. The cogging torque is the most issue in permanent magnet application, since it effects to reduce the machine performance. A permanent magnet machine of fractional slot number with 24 slot/20 pole was presented in the paper. Firstly, the permanent magnet machine with conventional both of magnet structure and stator structure has been investigated as the basic reference of initial structure. Secondly, the magnet edge shaping with conventional stator core was investigated. Thirdly, in proposed structure, the combination of magnet edge shaping with dummy slot in stator was employed. The three different structures of the permanent magnet machine then analysed and compared. By implementation of magnet edge shaping combined with dummy slot in stator core has increased the interaction between magnet and stator core. This leads to increase the cogging torque frequency and reduce the peak value the cogging torque of the machine. Using the FEMM, the cogging torque value of the permanent magnet machine was analysed and computed. It was found that cogging torque reduction of the proposed structure as much as 99.47 % compared with the initial structure.
Study the Influence of Edge Points of Magnet Surface and Stator Core on the Cogging Torque Reduction in Permanent Magnet Machine
Authors: Mawar Sri , Nur Tajuddin
Published: April 2020

Cogging torque in permanent magnet machine application effects to some undesirable vibration and noises. To minimize the cogging torque in permanent magnet machine’s the most important issue recently. Influence the number of edge points in the magnet of one and two steps of magnet edge slotting was studied in this paper’. For purpose of study, the structure of permanent magnet machine with 18 slot / 8 pole has been chosen, and the magnetic flux of all magnets was radial. The finite element of 2D based on FEMM 4.2 software was implemented to analysis the magnet flux distribution in air gap. Simulation results showed that by improvement of edge point at magnet edge of the two steps of slotting in magnet edge could reduce the cogging torque of permanent magnet significantly when compared with the initial structure. Employing the numerical simulation, both of the machine structures were analysed. It has been found that, the cogging torque reduction of edge points with 8 points has the highest reduction around 98.84 % compared with initial structure of the permanent magnet machine.
Modelling Uranium in Vicinity of Groundwater Population by Neural Networks of Multilayers Perceptron
Authors: Lukman Iing , Ibrahim Noor Akma , Natalina
Published: April 2020

The existent of Uranium in vicinity of groundwater population can give a threat to the water supplier for human consumption. The objective of the research was to find the most important variables to the existence of the Uranium. This paper shows some modelling process for above matters by applying Neural Networks of Multilayers Perceptron. Data taken from US Department of Energy. Neural Networks used in this study were learning the representation of the model inside the data, and how best it relation with the output variable that we obtained from prediction. The results showed that the training samples was 87 out of 127, and the testing samples was 40 out of 127. The results were not giving indication that a mathematical model obtained. The conclusion was Conductivity becoming the most important variable to the existence of Uranium, which followed by the second importance that was Arsenic, the third importance was Selenium, the fourth important was Total Alkalinity.
Simulation of Mach-Zehnder Interferometer plastic optical fibre for temperature and refractive index measurement
Authors: Yulianti Ian , Putra N. M. Dharma , Fianti  , Maimanah S. , Rumiana H. , Noor M. Y. M. , Supa’at A. S. M. , Kurdi O.
Published: April 2020

This work presents simulation of light propagation inside tapered structure-plastic optical fibre (POF) subjected to various surrounding temperatures and refractive index (RI). The tapered structure served as Mach-Zehnder interferometer (MZI) which split light into core modes and clad modes that recombined at the end of the taper. Simulation was done by using Beam Propagation Method (BPM) solved using Finite Difference Method (FDM). The light launched in to the MZI was varied from 611nm to 655nm. In order to give temperature effect, the temperature was varied from 30°C to 80°C with increment of 10°C. The results showed that the free spectral range (FSR) of the MZI are shifted as temperature increased. The sensitivity for the peak and dip of the FSR are -0.0158 nm/°C and -0.0153 nm/°C, respectively. For RI sensitivity investigation, the surrounding RI was varied from 1.333 to 1.349. The sensitivity of peak FSR and dip FSR to RI change are -98.638 nm/RIU and 105.4 nm/RIU. Therefore, the MZI can be used to measure RI and temperature simultaneously.
Analysis of productivity and the need for heavy equipment on grade B aggregate foundation layers work (case study: Pekan Gedang road section, Batang Asai – Muaro Talang District, Sarolangun)
Authors: Dwiretnani Annisaa , Henriadi
Published: April 2020

Grade B aggregate foundation layers are part of the road foundation that is located between subgrade and grade A foundation layers. The function of grade B aggregate foundation layers is to minimize the spread of loads to the subgrade. Road infrastructure is one of the factors that support an area development. Road improvements aimed to improve the social economy and open access to isolated areas of considerable potential for the development of natural resources. This research analyses productivity and the need for 5 types of heavy equipment on grade B aggregate foundation layers work (case study: Pekan Gedang road section, Batang Asai – Muaro Talang District, Sarolangun). Noted that heavy equipment specifications were used in project site same as the planned. The results showed that based on time schedule and project volume in this research can be completed properly and on time if using 5 units of dump trucks and 1 unit each for wheel loader, vibratory roller, motor grader and water tank truck, with productivity for wheel loader is 125.42 m3, dump truck is 2.69 m3, vibratory roller is 87.15 m3, motor grader is 57.24 m3 and water tank truck is 71.14 m3.
Investigation on the dynamic properties of propeller structure with different number of blades
Authors: Abdullah N.A.Z. , Brapakaran P. , Sani M.S.M. , Marcel M.W. , Agung E.H.
Published: April 2020

A propeller is mainly used for propelling the movement for an aircraft or ship. As it gives major contribution towards the performance of an aircraft or ship, study on propeller structure has become popular. In this study, the dynamic or modal characteristics of propeller structure with different number of blade of the same design are investigated. Modal properties of two blades, three blades and four blades propeller that are obtained through computational analysis are compared after validation of three blades propeller is conducted. It has been observed that the four blades propeller has the lowest nominal value of natural frequencies and shows most mode shapes deflection. The results confirm that as the propeller has more number of blades, it will produce more energy and hence has lower natural frequency.
New Topology Multilevel Inverter Type Diode Clamped Five Level Single Phase
Authors: Matalata Hendi , Yusiana Venny
Published: April 2020

Multilevel inverter is a converter that converts DC power sources into AC power sources with the voltage output higher than two levels. Conventional multilevel inverter topology for five levels that is currently developing generally uses eight components of power switches. In this paper, a five-level multilevel inverter topology is proposed by reducing the power switch component to four and aided with two pin diodes and capacitors as voltage couplings. The simulation with MATLAB that has been done shows various advantages of this topology compared to conventional multilevel inverter topologies. Results and discussion This topology compare the switching techniques used between Pulse Width Modulation (PWM) and Sinus Pulse Width Modulation (SPWM) for five-level multilevel inverter. Cohesiveness in switching techniques topology is proposed and validated by using passive filter. The harmonic analysis performed by the proposed topology could reduce the output voltage with the low harmonics.
Coating of Polyaniline-Titanium Dioxide (PAni-TiO2) Composite for Corrosion Protection in Low Carbon Steel
Authors: Sulistyaningsih E , Lestari N
Published: April 2020

Carbon Steel is used as an industrial component and an electronic component that has a lifetime or a certain lifetime. Steel is not a rust-resistant material, so it can corrode over time, especially Indonesia is a tropical country that has high rainfall and humidity. Almost all industrial sectors have problems with corrosion. Problems that arise can be in the form of damage, age of use of goods that do not meet expectations until the security factor is inadequate. This study aims to investigate the inhibiting efficiency of coating on Low Carbon Steel with semiconductor materials and morphology changes on Low Carbon Steel. The semiconductor material used is a combination of PAni-TiO2. Coating of PAni-TiO2 composite on low carbon steel was carried out by electrodeposition method on acidic medium. The corrosion process is carried out with acid and salt media. Effectiveness is based on inhibition efficiency. The highest inhibition efficiency was produced on plate 3 with a composition of 10−2 M PAni-10−3 TiO2 with a corrosion rate 0.003560 mpy. Uncoated specimens have a highest corrosion rate of 0.007359 mpy, so it suffers the most damage. From the results of visual observations conducted samples undergoing corrosion in the form of uniform corrosion.
Strategic Study of Thermal Treatment of European Radioactive Wastes
Authors: Doudou S , Swain-Phipps E K , Fuller A J , Wickham S M , Daniels N , Fourcy E , Fournier M , Frasca B , Meert K , Mikusova A , Olin M , Poskas R , Scales C
Published: April 2020

Under Work Package 2 (WP2) of THERAMIN, strategic reviews of thermal treatment technologies and European radioactive waste streams for which thermal treatment could bring benefits have been undertaken. This paper presents the outcomes of an international review of inventory information concerning European wastes potentially suitable for thermal treatment, a review of thermal treatment technologies, and a strategic gap analysis to identify countries where there are significant waste arisings with potential benefits for thermal treatment, but little prospect of these countries developing thermal treatment facilities independently.
Assessing the value of thermal treatment technologies
Authors: Fuller A J , Doudou S , Kent J E , Harvey E J , Wickham S M
Published: April 2020

Work Package 2 of the THERAMIN project provides a framework to support decision making on the potential use of thermal technologies to treat various radioactive wastes. To do this, a methodology based on multi-attribute decision analysis has been devised to identify the benefits of applying thermal treatment techniques to a range of radioactive waste streams. The value assessment methodology used in THERAMIN follows an attribute-based approach with the potential benefits of the treatment technology assessed against different criteria, considering performance over the whole waste management lifecycle, from pre-treatment through to final disposal. The attribute groups considered are: operational safety, environmental impact, impact on disposability/long term safety, implementation, timescale, technical readiness, and cost impact. To guide the decision maker, each attribute in split into data categories (sub-criteria) and a summary of topics to be considered under each attribute is provided. The assessment attributes have been compiled by drawing on knowledge from across the THERAMIN partner organisations to make them as comprehensive as possible. Consideration is given to the whole of the waste lifecycle and to different European regulatory contexts.
Gasification-based thermal treatment of Low and Intermediate Level Waste containing organic matter
Authors: Nieminen M , Laatikainen-Luntama J , Olin M
Published: April 2020

VTT has developed a gasification-based technology for processing low- and intermediate-level waste (LILW) rich in organic matter. VTT’s process is based on well-controlled thermal fluidised-bed gasification followed by efficient gas cleaning, gas conditioning/oxidation, wet scrubbing of the oxidised gas (flue gas), and finally, filtering through a high efficiency particulate air (HEPA) filter, which acts as a backup cleaning system. In the case of an organic ion exchange resin (IXR) the primary product from thermal gasification is fine filter dust. In addition, the process produces some bottom ash, which consists mainly of the bed material. The wet scrubber liquid may also contain some activity. Demonstration trials were carried out using unspent organic IXR containing a small amount of added stable Cs in order to simulate Cs content in spent IXR. Gasification tests confirmed the capability of the process to remove organic matter from the IXR and clean the resulting off-gas as required. Simulated waste IXR was reduced to approximately 1 wt-% of its original mass before immobilisation. Filter dust and bottom ash have to be immobilised before final disposal. VTT has previously developed an advanced immobilisation technology based on geopolymerisation and this has been applied to samples from the THERAMIN test trials. VTT’s technology has been designed as a compact process, which can be operated at the nuclear power plant site. Until now, all development and verification test trials have used simulated waste materials. The next step is the demonstration of the process using real radioactive waste.
Pyrolysis of Radioactive Spent Resins in the PRIME Installation
Authors: Hansen J , Deckers J
Published: April 2020

Montair and Belgoprocess developed the pilot PRIME (Pyrolysis Resins In Mobile Electric) Installation for treatment of spent resins in one single reactor without pre-treatment and without intermixing of other waste, allowing for easy traceability and isotopic characterization of the end product. Both low level waste (LLW, < 2 mSv/h) and medium level waste (MLW, > 2 mSv/h) can be treated in the installation. The PRIME pilot installation is designed to treat 2 batches of 100 litre of saturated ion exchange resins over a period of 24 hours. The pyrolysis reactor contains a special design mechanical stirrer and can operate at a temperature of up to 600°C under inert conditions. As a result, the organic molecules will decompose at an accelerated rate until only carbon-rich and mineralised product free of hydrocarbons remains. Gases that are released during drying and pyrolysis are treated in a thermal oxidizer, which uses an innovative, electrically heated design instead of a traditional natural gas- or fuel oil secondary combustion chamber design. After passing through the thermal oxidizer, the gases are cooled down to saturation temperature and treated in the wet scrubbing system. An induced draft fan keeps the system under negative pressure to prevent the possibility of any off-gas leakage out of the system. The pyrolysing reactor and oxidiser are fully electrically powered which creates also a higher safety level. A series of tests were performed successfully with wet cationic resins, anionic resins and a mixture of both. The results of these tests are described in the presentation. For intellectual property protection, the system and process of pyrolysis of organic waste and the system of thermal oxidation of pyrolysis gases described in this paper are patent pending.
Hot isostatic pressing: thermal treatment trials of inactive and radioactive simulant UK intermediate level waste
Authors: Gardner L J , Walling S A , Hyatt N C
Published: April 2020

Hot Isostatic Pressing (HIPing) is a batch process thermal treatment technology where wastes are heated and compressed within a sealed stainless steel canister; typically resulting in durable, high density ceramics or glasses with minimal loss of volatile elements, and accountability of active inventories. The University of Sheffield has a small-scale research HIP with capability to process simulant wasteforms containing radioactive materials, to help underpin larger-scale industrial applications of this technology. It was under this remit that a series of trials were undertaken, to produce small simulant radioactive wasteforms incorporating problematic UK waste streams such as Magnox sludges and clinoptilolite ion-exchange material. Each trial was successfully batched, sealed, and HIPed at 1250 °C, resulting in solidified products entirely contained within the steel HIP canisters. The ability to safely produce active wasteforms within the same facility validates the active furnace isolation chamber (AFIC) system. Overall the success of these trials demonstrate the ability of smaller research HIP facilities to build up the scientific and technical case for further implementation of HIP technology as a viable waste treatment option.
Advanced Gas-cooled Reactor SIMFuel Fabricated by Hot Isostatic Pressing: a Feasibility Investigation
Authors: Ding H , Gardner L J , Mohun R , Corkhill C L , Stennett M C , Hyatt N C
Published: April 2020

The manufacture of a simulant UK Advanced Gas Cooled Reactor (AGR) spent nuclear fuel (SIMFuel) was achieved by Hot Isostatic Pressing (HIP). Characterisation of HIP AGR SIMFuels, tailored to burn ups of 25 GWd/t U and 43 GWd/t U (after 100 years cooling) demonstrated fission product partitioning, phase assemblage, microstructure and porosity in good agreement with spent nuclear fuels and SIMFuels, and AGR fuels in particular. A pivotal advantage of the application of the HIP manufacturing method is the retention of volatile fission products within the resultant SIMFuel as the result of using a hermetically-sealed container. This new approach to SIMFuel manufacture should enable the production of more accurate spent nuclear fuel surrogates to support research on spent fuel management, recycle, and disposal, and the thermal treatment of fuel residues and debris.
Geopolymerisation of gasified ion-exchange resins, mechanical properties and short-term leaching studies
Authors: Vehmas Tapio , Myllykylä Emmi , Nieminen Matti , Laatikainen-Luntama Jaana , Leivo Markku , Olin Markus
Published: April 2020

A combination of gasification of low and intermediate level radioactive waste (LILW) and conditioning of the resulting product within a geopolymer matrix is a potential alternative for vitrification technologies as an immobilisation method. Geopolymer matrices have demonstrated good retention capability for radionuclides in many studies and the technology has been implemented at an industrial scale in Slovakia and Czech Republic. However, the practical waste loading has been limited by the mechanical properties of the encapsulated matrix. Even a small amount of ion exchange resin (IXR) decreases the strength of the matrix and cohesion of the matrix is lost when the fraction of resin exceeds 15-20%. In this study, the potential to combine gasification as thermal treatment and various inorganic binders as encapsulation matrices was evaluated. After gasification, the mechanical properties were not similarly sensitive to the encapsulation of IXR. Gasification enabled substantially higher loading of IXR into the sample. Also, gasification of the IXR decreased matrix apparent Caesium diffusion. Very low apparent diffusion coefficients of Cs were calculated when gasified resin was encapsulated in metakaolin matrix. Theoretically, the amount of Cs within the same volume of encapsulated material could be increased by 800 times following gasification and encapsulation within an alkali-activated metakaolin (MK) binder.
Synthesis and characterisation of high ceramic fraction brannerite (UTi2O6) glass-ceramic composites
Authors: Dixon Wilkins M C , Maddrell E R , Stennett M C , Hyatt N C
Published: April 2020

Brannerite, UTi2O6, glass-ceramic composites have been prepared, using UO2 and TiO2 as the ceramic phase precursors. A range of cold-press and sinter samples with varying glass:ceramic ratios have been prepared under argon at 1200 °C to investigate the effect of glass content on formation of brannerite. Ceramic brannerite formed well in all compositions, even at low (10% by weight) glass fractions, with UO2 as a minor product. Three further brannerite glass-ceramics have been prepared by hot isostatic pressing to investigate the compatibility of this system to HIPing. The samples HIPed at 1200 °C form brannerite, with UO2 as a minor phase with slightly higher abundance than in the cold-press and sinter samples.
Ce and U speciation in wasteforms for thermal treatment of plutonium bearing wastes, probed by L3 edge XANES
Authors: Bailey D J , Stennett M C , Sun S K , Gardner L J , Walling S A , Corkhill C L , Ravel B , Hyatt N C
Published: April 2020

X-ray absorption spectroscopy was applied to understand the speciation of elements relevant to the immobilisation and disposal of radioactive plutonium bearing wastes, utilizing Ce as a Pu surrogate. Ce L3 XANES (X-ray Absorption Near Edge Structure) characterisation of a crystallised glass material produced by cold crucible plasma vitrification, at demonstration scale, evidenced incorporation as Ce3+ within the glass phase, providing an important validation of laboratory scale studies. U and Ce L3 XANES investigation of brannerite ceramics, U0.9Ce0.1Ti2O6, synthesized under oxidizing, neutral and reducing conditions, established the charge compensation mechanism as incorporation of Ce3+ through formation of U5+ and/or U6+ In each of these examples, X-ray Absorption Spectroscopy has provided a pivotal understanding of element speciation in relation to the mechanism of incorporation within the host wasteform intended for geological disposal.
Sandstone 3D compositional microstructure analysis with synchrotron-based multi-energy x-ray micro-CT
Authors: Kong Huihua , Li Ruru , Yang Yushuang , Bai Bin , Wang Haipeng
Published: April 2020

Three-dimensional (3D) characterization of materials microstructure is important in understanding their physical and chemical properties. In this paper, the compositional microstructure of a sandstone sample from Yaodian area of Yan’an in Erdors Basin is analyzed using synchrotron-based multi-energy x-ray micro-CT data. The x-ray CT data of the sample are acquired at beam energies 25 KeV, 35 KeV and 45 KeV. The strip artifact in the sinogram images are corrected with a least square fitting method. The corrected sinogram image data are reconstructed with the X-tract software, and the reconstructed images under different energy spectra are calibrated. Finally, the multi-energy least square segmentation method is used to characterize the 3D microstructure of sandstone sample with the Data-Constrained Modeling (DCM) software. The results show that the sample has 71.8% of quartz and albite which is displayed as blue, calcite (22.3%) is displayed as red, pyrite (0.6%) is displayed as yellow and porosity (5.3%) is displayed as white.
Photocatalytic upgrading α-Fe2O3 nanoparticles by incorporating MoS2/rGO nanosheets
Authors: Lejbini M Behtaj , Sangpour P , Tajabadi F , Kolahi A
Published: April 2020

α-Fe2O3/MoS2/rGO nanocomposites was prepared by a two-step hydrothermal method and characterized by XRD, FESEM, EDS, FTIR, and UV–vis absorption spectroscopy. The results confirmed the formation of α-Fe2O3/MoS2-rGO (10 wt%) nanocomposites were composed of hematite nanoparticles with particle size of 30 nm and MoS2/rGO composite nanosheets with maximum sheet thickness of ∼ 10 nm. Upon addition of MoS2-rGO (8.0 wt%) nanosheets, the band gap of α-Fe2O3 nanoparticles decreased from 2.3 to 1.7 eV that was accompanied by light absorption enhancement. Owing to synergetic effect between rGO and MoS2 nanosheets leading to suppression of charge carrier recombination, prolongation of charge carrier lifetime, improvement of the interfacial charge transfer and increase in the number of active sites in α-Fe2O3 nanoparticles, as-synthesized α-Fe2O3/MoS2-rGO (10 wt%) nanocomposites nanocomposite showed highly enhanced photocatalytic performance for Rh B degradation under light irradiation so that complete degradation of Rh B organic dye was achieved within 30 min.
COVID-19 in older people: a rapid clinical review
Authors: Lithander Fiona E , Neumann Sandra , Tenison Emma , Lloyd Katherine , Welsh Tomas J , Rodrigues Jonathan C L , Higgins Julian P T , Scourfield Lily , Christensen Hannah , Haunton Victoria J , Henderson Emily J
Published: April 2020

Introduction

the COVID-19 pandemic poses a high risk to older people. The aim of this article is to provide a rapid overview of the COVID-19 literature, with a specific focus on older adults. We frame our findings within an overview of the disease and have also evaluated the inclusion of older people within forthcoming clinical trials.

Methods

we searched PubMed and bioRxiv/medRxiv to identify English language papers describing the testing, treatment and prognosis of COVID-19. PubMed and bioRxiv/medRxiv searches took place on 20 and 24 March 2020, respectively.

Results

screening of over 1,100 peer-reviewed and pre-print papers yielded n = 22 on COVID-19 testing, n = 15 on treatment and n = 13 on prognosis. Viral polymerase chain reaction (PCR) and serology are the mainstays of testing, but a positive diagnosis may be increasingly supported by radiological findings. The current evidence for the effectiveness of antiviral, corticosteroid and immunotherapies is inconclusive, although trial data are largely based on younger people. In addition to age, male gender and comorbidities, specific laboratory and radiology findings are important prognostic factors. Evidence suggests that social distancing policies could have important negative consequences, particularly if in place for an extended period.

Conclusion

given the established association between increasing age and poor prognosis in COVID-19, we anticipate that this rapid review of the current and emergent evidence might form a basis on which future work can be established. Exclusion of older people, particularly those with comorbidities, from clinical trials is well recognised and is potentially being perpetuated in the field of current COVID-19 research.
Interobserver Variability in Ductal Carcinoma In Situ of the Breast
Authors: Van Bockstal Mieke R , Berlière Martine , Duhoux Francois P , Galant Christine
Published: April 2020

Objectives

Since most patients with ductal carcinoma in situ (DCIS) of the breast are treated upon diagnosis, evidence on its natural progression to invasive carcinoma is limited. It is estimated that around half of the screen-detected DCIS lesions would have remained indolent if they had never been detected. Many patients with DCIS are therefore probably overtreated. Four ongoing randomized noninferiority trials explore active surveillance as a treatment option. Eligibility for these trials is mainly based on histopathologic features. Hence, the call for reproducible histopathologic assessment has never sounded louder.

Methods

Here, the available classification systems for DCIS are discussed in depth.

Results

This comprehensive review illustrates that histopathologic evaluation of DCIS is characterized by significant interobserver variability. Future digitalization of pathology, combined with development of deep learning algorithms or so-called artificial intelligence, may be an innovative solution to tackle this problem. However, implementation of digital pathology is not within reach for each laboratory worldwide. An alternative classification system could reduce the disagreement among histopathologists who use “conventional” light microscopy: the introduction of dichotomous histopathologic assessment is likely to increase interobserver concordance.

Conclusions

Reproducible histopathologic assessment is a prerequisite for robust risk stratification and adequate clinical decision-making. Two-tier histopathologic assessment might enhance the quality of care.
Lack of strong selection pressures maintains wide variation in floral traits in a food-deceptive orchid
Authors: Jacquemyn Hans , Brys Rein
Published: April 2020

Background and Aims

Angiosperms vary remarkably in traits such as colour, size and shape of flowers, yet such variation generally tends to be low within species. In deceptive orchids, however, large variation in floral traits has been described, not only between but also within populations. Nonetheless, the factors driving variation in floral traits in deceptive orchids remain largely unclear.

Methods

To identify determinants of variation in floral traits, we investigated patterns of fruit set and selection gradients in the food-deceptive orchid Orchis purpurea, which typically presents large within-population variation in the colour and size of the flowers. Using long-term data, fruit set was quantified in two populations over 16 consecutive years (2004–2019). Artificial hand pollination was performed to test the hypothesis that fruit set was pollinator-limited and that selfing led to decreased seed set and viability. Annual variation (2016–2019) in selection gradients was calculated for three colour traits (brightness, contrast and the number of spots on the labellum), flower size (spur length, labellum length and width) and plant size (number of flowers, plant height).

Key Results

Fruit set was, on average, low (~12 %) and severely pollinator-limited. Opportunities for selection varied strongly across years, but we found only weak evidence for selection on floral traits. In contrast, there was strong and consistent positive selection on floral display. Selfing led to reduced production of viable seeds and hence severe inbreeding depression (δ = 0.38).

Conclusion

Overall, these results demonstrate that the large variation in flower colour and size that is regularly observed in natural O. purpurea populations is maintained by the consistent lack of strong selection pressures on these traits through time.
The role of multiple reproductive barriers: strong post-pollination interactions govern cytotype isolation in a tetraploid–octoploid contact zone
Authors: Castro Mariana , Loureiro João , Husband Brian C , Castro Sílvia
Published: April 2020

Background and Aims

Polyploidy is an important contributor to sympatric speciation and assortative mating is a key mechanism driving cytotype interactions in contact zones. While strong reproductive barriers can mediate the coexistence of different cytotypes in sympatry, positive frequency-dependent mating disadvantage ultimately drives the transition to single-ploidy populations. However, comprehensive estimates of reproductive isolation among cytotypes and across multiple barriers are rare. We quantify the strength of isolation across multiple reproductive stages in a tetraploid–octoploid contact zone to understand the potential for coexistence.

Methods

Assortative mating due to flowering asynchrony, pollinator behaviour, morphological overlap, self-fertilization and gametic competition between tetraploid and octoploid Gladiolus communis in a contact zone in the Western Iberian Peninsula were assessed in natural and experimental populations to quantify reproductive isolation (RI) between cytotypes.

Key Results

Tetraploids and octoploids have a high degree of overlap in flowering time and similar floral morphology, and are visited by generalist insects without cytotype foraging preferences, resulting in weak pre-pollination RI (from 0.00 to 0.21). In contrast, post-pollination isolation resulting from gametic selection was a strong barrier to inter-cytotype mating, with ploidy composition in stigmatic pollen loads determining the levels of RI (from 0.54 to 1.00). Between-cytotype cross-incompatibility was relatively high (RI from 0.54 to 0.63) as was isolation acquired through self-pollination (RI of 0.59 in tetraploids and 0.39 in octoploids).

Conclusions

Total RI was high for both tetraploids (from 0.90 to 1.00) and octoploids (from 0.78 to 0.98). Such high rates of assortative mating will enable cytotype coexistence in mixed-ploidy populations by weakening the impacts of minority cytotype exclusion. This study reveals the key role of gametic selection in cytotype siring success and highlights the importance of comprehensive estimates across multiple reproductive barriers to understand cytotype interactions at contact zones.
Slow blood-to-brain transport underlies enduring barrier dysfunction in American football players
Authors: Veksler Ronel , Vazana Udi , Serlin Yonatan , Prager Ofer , Ofer Jonathan , Shemen Nofar , Fisher Andrew M , Minaeva Olga , Hua Ning , Saar-Ashkenazy Rotem , Benou Itay , Riklin-Raviv Tammy , Parker Ellen , Mumby Griffin , Kamintsky Lyna , Beyea Steven , Bowen Chris V , Shelef Ilan , O’Keeffe Eoin , Campbell Matthew , Kaufer Daniela , Goldstein Lee E , Friedman Alon
Published: April 2020

Repetitive mild traumatic brain injury in American football players has garnered increasing public attention following reports of chronic traumatic encephalopathy, a progressive tauopathy. While the mechanisms underlying repetitive mild traumatic brain injury-induced neurodegeneration are unknown and antemortem diagnostic tests are not available, neuropathology studies suggest a pathogenic role for microvascular injury, specifically blood–brain barrier dysfunction. Thus, our main objective was to demonstrate the effectiveness of a modified dynamic contrast-enhanced MRI approach we have developed to detect impairments in brain microvascular function. To this end, we scanned 42 adult male amateur American football players and a control group comprising 27 athletes practicing a non-contact sport and 26 non-athletes. MRI scans were also performed in 51 patients with brain pathologies involving the blood–brain barrier, namely malignant brain tumours, ischaemic stroke and haemorrhagic traumatic contusion. Based on data from prolonged scans, we generated maps that visualized the permeability value for each brain voxel. Our permeability maps revealed an increase in slow blood-to-brain transport in a subset of amateur American football players, but not in sex- and age-matched controls. The increase in permeability was region specific (white matter, midbrain peduncles, red nucleus, temporal cortex) and correlated with changes in white matter, which were confirmed by diffusion tensor imaging. Additionally, increased permeability persisted for months, as seen in players who were scanned both on- and off-season. Examination of patients with brain pathologies revealed that slow tracer accumulation characterizes areas surrounding the core of injury, which frequently shows fast blood-to-brain transport. Next, we verified our method in two rodent models: rats and mice subjected to repeated mild closed-head impact injury, and rats with vascular injury inflicted by photothrombosis. In both models, slow blood-to-brain transport was observed, which correlated with neuropathological changes. Lastly, computational simulations and direct imaging of the transport of Evans blue-albumin complex in brains of rats subjected to recurrent seizures or focal cerebrovascular injury suggest that increased cellular transport underlies the observed slow blood-to-brain transport. Taken together, our findings suggest dynamic contrast-enhanced-MRI can be used to diagnose specific microvascular pathology after traumatic brain injury and other brain pathologies.