bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of nitrite in regulation of fetal cephalic circulation in sheep
Authors: Truong Giang T. , Schröder Hobe J. , Liu Taiming , Zhang Meijuan , Kanda Eriko , Bragg Shannon , Power Gordon G. , Blood Arlin B. 
Published: February 2014

Key points
Recent evidence in adult humans demonstrates that nitrite, at physiological concentrations, can be converted into vasodilating amounts of NO, thus constituting an alternative to NO production by NO synthases.
Nitrite reacts with deoxyhaemoglobin to produce NO, a reaction proposed to mediate the vasodilating effects of nitrite. We have demonstrated previously that the rate of this reaction is ∼2‐fold faster with fetal haemoglobin than adult haemoglobin. Thus, we hypothesized that nitrite would be a potent vasodilator in the cephalic vasculature served by the carotid artery in the fetal sheep.
In conflict with human adult forearm studies, we find that nitrite is not a vasodilator in the fetal sheep cephalic vasculature, despite the fact that nitrite is converted to NO more efficiently by fetal haemoglobin.
The results suggest that the vasodilatory effects of nitrite are age‐ and species‐specific, and that the reaction of nitrite with deoxyhaemoglobin is not rate limiting with respect to its ability to decrease vascular tone.
AbstractNitrite has been postulated to provide a reservoir for conversion to nitric oxide (NO), especially in tissues with reduced oxygen levels as in the fetus. Nitrite would thus provide local vasodilatation and restore a balance between oxygen supply and need, a putative mechanism of importance especially in the brain. The current experiments test the hypothesis that exogenous nitrite acts as a vasodilator in the cephalic vasculature of the intact, near term fetal sheep. Fetuses were first instrumented to measure arterial blood pressure and carotid artery blood flow and then studied 4–5 days later while in utero without anaesthesia. Initially l‐nitro‐arginine (LNNA) was given to block endogenous NO production. Carotid resistance to flow increased 2‐fold from 0.54 ± 0.01 (SEM) to 1.20 ± 0.08 mmHg min ml−1 (in 13 fetuses, P < 0.001), indicating NO tonically reduces cerebral vascular tone. Sodium nitrite (or saline as control) was then infused in increasing step‐doses from 0.01 to 33 μm in half‐log increments over a period of 2 h. Carotid artery pressure, blood flow and vascular resistance did not change compared to fetuses receiving saline, even at plasma nitrite concentrations two orders of magnitude above the physiological range. The results indicate that while cephalic vascular tone is controlled by endogenous nitric oxide synthase activity, exogenously administered nitrite is not a vasodilator at physiological concentrations in the vasculature served by the carotid artery of fetal sheep.
Reduction in maternal Polycomb levels contributes to transgenerational inheritance of a response to toxic stress in flies
Authors: Stern Shay , Snir Orli , Mizrachi Eran , Galili Matana , Zaltsman Inbal , Soen Yoav 
Published: February 2014

Key points
Previous work on epigenetic transgenerational phenomena focused on chromatin modifications or small RNAs as potential carriers of non‐genetic transgenerational influence.
We describe a hitherto non‐appreciated mode of trans‐generational influence by which physiological stress in one generation can impact multiple generations of non‐exposed offspring.
This mode of transfer involves persistent changes in the composition of maternal RNA in the early offspring embryos.
In particular we show that reduction in maternal Polycomb gene levels have a functional contribution to trans‐generational inheritance of induced gene expression.
Our findings extend the mechanistic repertoire of epigenetic inheritance by providing evidence connecting changes in maternal RNA with trans‐generational inheritance of induced phenotypes.
AbstractTransgenerational persistence of parental responses to environmental stimuli has been reported in various organisms, but the underlying mechanisms remain underexplored. In one of these reported examples, we have shown that exposure of fly larvae to G418 antibiotic leads to non‐Mendelian inheritance of ectopic induction of certain developmental genes. Here we investigate if this inheritance involves changes in mRNA composition within the early, maternal‐stage offspring embryos of exposed flies. Exposure to G418 in F1 modified the maternal RNA levels of many genes in their early (F2) embryos. This includes reduction of maternal Polycomb group genes which persisted in the following generation of embryos (F3). To investigate the functional meaning of this reduction, we compared genetically normal embryos of Polycomb mutant females to normal embryos of normal females. Analysis with two different alleles of Polycomb, Pc1 and Pc3, revealed that maternal reduction in Polycomb gene dosage has a positive influence on the inheritance of induced expression. Together, this shows that exposure to G418 stress reduces the maternal levels of Polycomb in the offspring embryos and this reduction contributes to the inheritance of induced expression.
Improving the Environmental Sustainability of a Waste Processing Plant
Authors: Turner Tom , Watson Stuart 
Published: February 2014

This paper describes how the level of environmental sustainability at the Solid Waste Processing plant at Research Sites Restoration Ltd (RSRL) Harwell was measured and improved. It provides reasons to improve environmental performance in an organisation, states best practice on how improvement should be conducted, and gives first-hand experience on how changes were implemented. In this paper sustainability is defined as “meeting the needs of the present without compromising the ability of future generations to meet their own needs”.
A baseline for environmental sustainability was created, by looking at multiple attributes. From this, a matrix was created to show how the baseline environmental performance compared to best practice, and a gap analysis was performed. Results from this analysis showed areas for potential systematic improvement, and actions were created. Nearly all actions were implemented within one year, and environmental sustainability improved significantly. Most improvements cost no money to implement, and the few that did had to pass criteria in a business case.
Results from a company-wide survey showed that the vast majority of employees felt that environmental issues were important, and that they were willing to help improve performance. Environmental awareness training was given to everyone in the department, and individuals were given measurable improvement targets. A focus group was set up and met regularly to agree improvements and monitor results. Environmental performance was publicised regularly to highlight successes and seek further engagement and improvement. Improvement ideas were encouraged and managed in a transparent way which showed clear prioritisation and accountability.
The culture of environmental improvement changed visibly and results at the end of the first year showed that electricity consumption had reduced by 12.5%, and gas consumption had reduced by 7.3%. In less than two years over £60,000 was saved on utility bills in the Waste Processing Plant.
Monitoring Critical Facilities by Using Advanced RF Devices
Authors: Tsai Hanchung , Liu Yung Y. , Shuler James 
Published: February 2014

The ability to monitor critical environment parameters of nuclear plants at all times, particularly during and after a disruptive accident, is vital for the safety of plant personnel, rescue and recovery crews, and the surrounding communities. Conventional hard-wired assets that depend on supplied power may be decimated as a result of such events, as witnessed in the Japanese Fukushima nuclear power plant in March 2011. Self-powered monitoring devices operating on a wireless platform, on the other hand, may survive such calamity and remain functional. The devices would be prepositioned at strategic locations, particularly where the dangerous build-up of contamination and radiation may preclude subsequent manned entrance and surveillance. Equipped with sensors for β-γ radiation, neutrons, hydrogen gas, temperature, humidity, pressure, and water level, as well as with criticality alarms and imaging equipment for heat, video, and other capabilities, these devices can provide vital surveillance information for assessing the extent of plant damage, mandating responses (e.g., evacuation before impending hydrogen explosion), and enabling overall safe and efficient recovery in a disaster.
A radio frequency identification (RFID)-based system — called ARG-US — may be modified and adapted for this task. Developed by Argonne for DOE, ARG-US (meaning “watchful guardian”) has been used successfully to monitor and track sensitive nuclear materials packages at DOE sites. It utilizes sensors in the tags to continuously monitor the state of health of the packaging and promptly disseminates alarms to authorized users when any of the preset sensor thresholds is violated. By adding plant-specific monitoring sensors to the already strong sensor suite and adopting modular hardware, firmware, and software subsystems that are tailored for specific subsystems of a plant, a Remote Area Modular Monitoring (RAMM) system, built on a wireless sensor network (WSN) platform, is being developed by Argonne National Laboratory. ARG-US RAMM, powered by on-board battery, can sustain extended autonomous surveillance operation during and following an incident. The benefits could be invaluable to such critical facilities as nuclear power plants, research and test reactors, fuel cycle manufacturing centers, spent-fuel dry-cask storage facilities, and other nuclear installations.
Design and Implementation of an Intensified Coprecipitation Reactor for the Treatment of Liquid Radioactive Wastes
Authors: Flouret Julie , Barré Yves , Muhr Hervé , Plasari Edouard 
Published: February 2014

The coprecipitation is a robust and inexpensive process for the treatment of important volumes of low and intermediate radioactive level liquid wastes. Its major inconvenient is the huge volume of sludge generated. The purpose of this work is to optimize the industrial coprecipitation continuous process by achieving the following objectives:
- maximize the decontamination efficiency;
- minimize the volume of sludge generated by the process;
- reduce the treatment cost decreasing the installation volume.
An innovative reactor with an infinite recycling ratio was therefore designed. It is a multifunctional reactor composed of two zones: a perfectly mixed precipitation zone and a classifier to perform liquid-solid separation.
The experiments are focused on the coprecipitation of strontium by barium sulphate. The effluent containing sulphate ions and the barium nitrate solution are injected in the reaction zone where strontium and barium coprecipitate as sulphates. The produced solid phase is returned into the reaction zone by the classifier and goes out slowly from the reactor bottom with a residence time much higher than the liquid phase. This creates both a high concentration of solid phase in the reaction zone and a high efficiency of decontamination. The experimental conditions simulate the industrial effluents. The total treatment flow rate is 17 L/h, with an effluent flow rate of 16 L/h and a reactive flow rate of 1 L/h, hence a mean residence time of 10 minutes. In these experimental conditions, the molar ratio sulphate/barium after mixing corresponds to 4.9. These conditions are used in the reprocessing plant of La Hague.
The decontamination factor reached in these experimental conditions is excellent: DF = 1500. The decontamination factor obtained with the classical continuous process is only equal to 60. Different process parameters are studied in order to optimize the reactor/classifier: residence time, barium nitrate flow rate and racking flow rate. The decrease of barium nitrate flow rate reduces the volume of sludge generated by the process keeping a high efficiency of strontium decontamination: DF = 400. An excess of sulphate is necessary to perform an efficient decontamination, but the molar ratio sulphate/barium can be reduced to 3 instead of 4.9 used industrially.
The reactor/classifier also represents an efficient device for the coprecipitation process intensification. Indeed, it can sensibly reduce the final installation size while treating important volume of effluents. This innovative reactor optimizes both the decontamination efficiency of radioactive liquid wastes and the reduction of sludge volume. A reduction of sulphate ions in the discharge is also possible, which is environmentally friendly.
“Strategy is a Commodity, Implementation is an Art”: 2 Years of Implementation of the UK National LLW Strategy
Authors: Cassidy Helen , Rossiter David 
Published: February 2014

The Low Level Waste Repository (LLWR) is the primary facility for disposal of Low Level Waste (LLW) in the United Kingdom (UK), serving the UK nuclear industry and a diverse range of other sectors. Management of LLW in the UK historically was dominated by disposal to the LLWR. The value of the LLWR as a national asset was recognised by the 2007 UK Governmental Policy on management of solid LLW. At this time, analysis of the projected future demand for disposal at LLWR against facility capacity was undertaken identifying a credible risk that the capacity of LLWR would be insufficient to meet future demand if existing waste management practices were perpetuated.
To mitigate this risk a National Strategy for the management of LLW in the UK was developed by the Nuclear Decommissioning Authority (NDA), partnered with LLW Repository Ltd. (the organisation established in 2008 to manage the LLWR on behalf of NDA). This strategy was published in 2010 and identified three mechanisms for protection of the capacity of LLWR – application of the Waste Hierarchy by waste producers; optimised use of existing assets for LLW management; and opening of new waste treatment and disposal routes to enable diversion of waste away from the LLWR.
Since publication of the National Strategy, there have been significant efforts made by LLWR (on behalf of NDA) to drive strategy implementation and to optimise LLW management practices across the UK. This paper seeks to illustrate the challenges of strategy implementation in the context of the 2010 LLW National Strategy to provide a demonstration that “strategy is a commodity, execution is an art”. The paper describes: the key themes of the National Strategy; the key barriers to strategy implementation; the measures implemented by LLWR since publication of the National Strategy to support transformation of LLW management behaviours, with emphasis on how the initiative supports achieving the behavioural change; and providing a review of the past two years and a look forward to the planned evolution of National Strategy implementation over the next five years.
Conditioning of Pretreated LLW Generated by the Decontamination of VVR-S Nuclear Research Reactor Primary Circuit
Authors: Nicu Mihaela I. , Ionascu Laura A. , Dragolici Felicia N. , Turcanu Corneliu N. , Rotarescu Gheorghe Gh. , Dogaru Gheorghe C. 
Published: February 2014

Concentration of complexing acids solutions (oxalic acid, tartaric acid and citric acid) used in radioactive decontamination by chemical method affects both the mechanical stability and the chemical stability of cement matrix.
The paper presents the works performed related to the chemical pretreatment of these organic acids solutions using as neutralizing agent Ca(OH)2. In this way it was possible to increase the concentration of organic acids solutions used and the soluble complex radionuclides passing in chemical precipitates, these affecting in a smaller manner the mechanical stability of the cement matrix.
The chemical pretreatment the effluents improve the precipitation and conditioning performances by cementation. Were prepared compositions with complexing agents and compositions for oxidative degradation tests to simulate the concentrations of secondary radioactive waste obtained from the primary circuit decontamination of the VVR-S research reactor.
It has been studied the influence of chemical pretreatment of complexing acids solutions of different concentrations on the setting time. Also it was determined the compressive strength of mortar samples in which were embedded these solutions of chemically pretreated organic acids.
The results shown that an optimum cement–solution ratio doesn’t have a significant impact on the setting time or on the mechanical properties.
Processing Liquid Organic Wastes at the NNL Preston Laboratory
Authors: Coppersthwaite Duncan , Greenwood Howard , Docrat Tahera , Allinson Sarah , Sultan Ruqayyah , May Sarah 
Published: February 2014

Organic compounds of various kinds have been used in the nuclear industry for numerous duties in uranium chemical, metal and ceramic processing plants. In the course of the various operations undertaken, these organic compounds have become contaminated with uranic material, either accidentally or as an inevitable part of the process. Typically, the chemical/physical form and/or concentration of the uranic content of the organics has prevented disposal.
In order to address the issue of contaminated liquid organic wastes, the National Nuclear Laboratory (NNL) has developed a suite of treatments designed to recover uranium and to render the waste suitable for disposal. The developed processes are operated at industrial scale via the NNL Preston Laboratory Residue Processing Plant.
The Oil Waste Leaching (OWL) Process is a fully industrialised process used for the treatment of contaminated oils with approximately 200 tonnes of uranium contaminated oil being treated to date. The process was originally developed for the treatment of contaminated tributyl phosphate and odourless kerosene which had been adsorbed onto sawdust. However, over the years, the OWL process has been refined for a range of oils including “water emulsifiable” cutting oils, lubricating oils, hydraulic oils/fluids and “Fomblin” (fully fluorinated) oils.
Chemically, the OWL process has proved capable of treating solvents as well as oils but the highly volatile/flammable nature of many solvents has required additional precautions compared with those required for oil treatment. These additional precautions led to the development of the Solvent Treatment Advanced Rig (STAR), an installation operated under an inert atmosphere. STAR is a small “module” (100 dm3 volume) which allows the treatment of both water miscible and immiscible solvents.
This paper discusses the challenges associated with the treatment of liquid organic wastes and the process developments which have allowed a wide range of materials to be successfully treated.
Modelling Study to Evaluate Two Variants for Accessing a Deep Geological Repository From the Point of View of Long-Term Safety
Authors: Poller Andreas , Smith Paul , Mayer Gerhard , Hayek Mohamed , Schneider Jürg W. , Zuidema Piet 
Published: February 2014

Siting a deep geological repository for radioactive waste essentially involves two interrelated steps: deciding on an appropriate geological environment for the underground facilities and selecting a suitable location for the associated surface facility. An acceptable solution is more easily achieved if some flexibility exists for siting the surface facility, irrespective of the exact position of the underground facilities. Such flexibility is available if a ramp is used as the main access route from the surface facility to the underground facilities. Another option is to use a combination of shafts and (sub)horizontal tunnels as the main access route. Both variants include shafts for ventilation, etc.
In this paper, the two variants (i) main access via ramp and (ii) main access via shaft are compared in terms of long-term safety. To this end, the entire network of underground tunnels of a deep geological repository is implemented in an analytical resistor network flow model. Radionuclide release through the tunnel system and the host rock is then calculated with a numerical network transport model, using as input the results from the flow model. The results clearly indicate that, even in case of hypothetically deficient horizontal and subhorizontal sealing elements, the choice between ramp and shaft as the main access route is irrelevant to long-term safety.
Immobilization of Inorganic Ion-Exchanger Into Biopolymer Foams: Application to Cesium Sorption
Authors: Barrè Yves , Hertz Audrey 
Published: February 2014

Nickel-potassium ferrocyanide (along with other ferrocyanide sub-products, as shown by mineralization, SEM-EDX analyses) has been immobilized in highly porous discs of chitin for the sorption of Cs(I) from near neutral solutions.
The immobilization process allows synthesizing stable materials that can bind up to 80 mg Cs g−1 (i.e., 240 mg Cs g−1 ion-exchanger). The pseudo-second order rate equation fits well kinetic profiles: the rate coefficient increases with the flow rate of recirculation (to force the access to potentially non-interconnected pores), as an evidence of the control of uptake kinetics by diffusion properties. Preliminary tests performed on 137Cs spiked solutions confirm the efficiency of the material for the treatment of effluents bearing radionuclides.
Characterization of Beta Emitters for Decommissioning
Authors: Fichet Pascal , Leskinen Anumaija , Guegan Sylvie , Goutelard Florence 
Published: February 2014

Radioactive waste management is nowadays, after nearly 50 years of concern, a technical and economical challenge faced by existing nuclear power countries. In decommissioning of nuclear facilities after removal of the nuclear equipment (laboratory materials, glove boxes, etc.), the radioactive inventory of the various building materials is needed to state the working condition for dismantling. Thus, characterization is essential for decommissioning and moreover for radioactive waste classification and management.
A radionuclide imaging technique, the Digital Autoradiography (DA), also known as storage phosphor technology, has been studied for decommissioning projects because of its advantages such low price, easy utilization and sensitivity. DA has been proven to be an efficient technic in localization of beta emitter (especially C-14 and H-3) contamination remaining in nuclear facilities under dismantling. Samples have been collected where C-14 or H-3 have been observed by DA and analyzed by the classical technique : pyrolysis followed by liquid scintillation counting.
Real applications to classify potential waste coming from a laboratory under dismantling are described in this paper.