bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐cost periodontal therapy
Authors: Slots Jørgen
Published: August 2012

Periodontitis is a complex infectious disease that affects low‐income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low‐cost periodontal therapy that involves professional and patient‐administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone‐iodine and sodium hypochlorite have all the characteristics for becoming the first‐choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin‐metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle‐aged patients, and ciprofloxacin‐metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent use of inexpensive antimicrobial agents can significantly retard or arrest progressive periodontitis in the great majority of patients.
Periodontal disease in HIV/AIDS
Authors: Ryder Mark I. , Nittayananta Wipawee , Coogan Maeve , Greenspan Deborah , Greenspan John S.
Published: August 2012

Since the early 1990's, the death rate from AIDS among adults has declined in most developed countries, largely because of newer antiretroviral therapies and improved access to these therapies. In addition, from 2006 to 2011, the total number of new cases of HIV infection worldwide has declined somewhat and has remained relatively constant. Nevertheless, because of the large numbers of existing and new cases of HIV infection, the dental practitioner and other healthcare practitioners will still be required to treat oral and periodontal conditions unique to HIV/AIDS as well as conventional periodontal diseases in HIV‐infected adults and children. The oral and periodontal conditions most closely associated with HIV infection include oral candidiasis, oral hairy leukoplakia, Kaposi’s sarcoma, salivary gland diseases, oral warts, other oral viral infections, linear gingival erythema and necrotizing gingival and periodontal diseases. While the incidence and prevalence of these oral lesions and conditions appear to be declining, in part because of antiretroviral therapy, dental and healthcare practitioners will need to continue to diagnose and treat the more conventional periodontal diseases in these HIV‐infected populations. Finding low‐cost and easily accessible and acceptable diagnostic and treatment approaches for both the microbiological and the inflammatory aspects of periodontal diseases in these populations are of particular importance, as the systemic spread of the local microbiota and inflammatory products of periodontal diseases may have adverse effects on both the progression of HIV infection and the effectiveness of antiretroviral therapy approaches. Developing and assessing low‐cost and accessible diagnostic and treatment approaches to periodontal diseases, particularly in developing countries, will require an internationally coordinated effort to design and conduct standardized clinical trials.
Systemic sclerosis – dermatological aspects. Part 1: Pathogenesis, epidemiology, clinical findings
Authors: Sticherling Michael
Published: August 2012

Systemic sclerosis is a chronic inflammatory multiorgan disease belonging to the group of collagen‐vascular disorders. With a prevalence of 10/100,000 inhabitants it may be regarded a rather rare disease. Its etiology and pathogenesis have still not been elucidated in detail, especially with regard to the differential involvement of skin and the cause of the clinically heterogeneous disease courses. Various components of the vasculature, connective tissue as well as the immune system are involved in a yet unknown sequence and significance. Patients need to be cared for in an interdisciplinary fashion depending on the individual organ involvement. Apart from the skin, the heart, kidneys and lungs are mainly affected in addition to frequent gastrointestinal and musculoskeletal symptoms. Clinically two distinct subsets may be separated, acral (also termed limited) and diffuse scleroderma, which are characterized by anti‐centromere and anti‐Scl‐70/topoisomerase‐1 antibodies, respectively. Recent data demonstrate a poor prognosis even in limited disease when pulmonary arterial hypertension develops at an early stage. In diffuse disease sudden and rapid onset will result in a sclerosis of major internal organs and early death in many cases.
Exploring Middle‐Eastern mothers’ perceptions and experiences of breastfeeding in Canada: an ethnographic study
Authors: Jessri Mahsa , Farmer Anna P. , Olson Karin
Published: August 2012

The aim of this study was to explore from the Middle‐Eastern mothers’ perspective, the experience of breastfeeding and their perceptions of attributes of the health care system, community and society on their feeding decisions after migration to Canada. New immigrant mothers from the Middle East (n = 22) were recruited from community agencies in Edmonton, Canada. Qualitative data were collected through four focus groups using an ethnographic approach to guide concurrent data collection and analysis. Survey data were collected on socio‐demographic characteristics via pre‐tested questionnaires. All mothers, but one who was medically exempt, breastfed their infants from birth and intended to continue for at least 2 years. Through constant comparison of data, five layers of influence emerged which described mothers’ process of decision making: culture/society, community, health care system, family/friends and mother–infant dyad. Religious belief was an umbrella theme that was woven throughout all discussions and it was the strongest determining factor for choosing to breastfeed. However, cultural practices promoted pre‐lacteal feeding and hence, jeopardising breastfeeding exclusivity. Although contradicted in Islamic tradition, most mothers practised fasting during breastfeeding because of misbeliefs about interpretations regarding these rules. Despite high rates of breastfeeding, there is a concern of lack of breastfeeding exclusivity among Middle‐Eastern settlers in Canada. To promote successful breastfeeding in Muslim migrant communities, interventions must occur at different levels of influence and should consider religious beliefs to ensure cultural acceptability. Practitioners may support exclusive breastfeeding through cultural competency, and respectfully acknowledging Islamic beliefs and cultural practices.
Structural determination of the phosphorylation domain of the ryanodine receptor
Authors: Sharma Parveen , Ishiyama Noboru , Nair Usha , Li Wenping , Dong Aiping , Miyake Tetsuaki , Wilson Aaron , Ryan Tim , MacLennan David H. , Kislinger Thomas , Ikura Mitsuhiko , Dhe‐Paganon Sirano , Gramolini Anthony O.
Published: August 2012

The ryanodine receptor (RyR) is a large, homotetrameric sarcoplasmic reticulum membrane protein that is essential for Ca2+ cycling in both skeletal and cardiac muscle. Genetic mutations in RyR1 are associated with severe conditions including malignant hyperthermia (MH) and central core disease. One phosphorylation site (Ser 2843) has been identified in a segment of RyR1 flanked by two RyR motifs, which are found exclusively in all RyR isoforms as closely associated tandem (or paired) motifs, and are named after the protein itself. These motifs also contain six known MH mutations. In this study, we designed, expressed and purified the tandem RyR motifs, and show that this domain contains a putative binding site for the Ca2+/calmodulin‐dependent protein kinase β isoform. We present a 2.2 Å resolution crystal structure of the RyR domain revealing a two‐fold, symmetric, extended four‐helix bundle stabilized by a β sheet. Using mathematical modelling, we fit our crystal structure within a tetrameric electron microscopy (EM) structure of native RyR1, and propose that this domain is localized in the RyR clamp region, which is absent in its cousin protein inositol 1,4,5‐trisphosphate receptor.

Database

The crystal structure of the RyR1 phosphorylation domain (amino acid residues 2734–2940) has been submitted to the Protein Data Bank under accession number 3RQR.

Structured digital abstract

RyR1 C3 physically interacts with CaMKIIβ by pull down (View interaction)

RyR1 C3 binds to CaMKIIβ by pull down (View interaction)

CaMKIIβ physically interacts with RyR1 C3 by anti tag coimmunoprecipitation (View Interaction: 1, 2)
A non‐canonical caleosin from Arabidopsis efficiently epoxidizes physiological unsaturated fatty acids with complete stereoselectivity
Authors: Blée Elizabeth , Flenet Martine , Boachon Benoît , Fauconnier Marie‐Laure
Published: August 2012

In plants, epoxygenated fatty acids (EFAs) are constituents of oil seeds as well as defence molecules and components of biopolymers (cutin, suberin). While the pleiotropic biological activities of mammalian EFAs have been well documented, there is a paucity of information on the physiological relevance of plant EFAs and their biosynthesis. Potential candidates for EFA formation are caleosin‐type peroxygenases which catalyze the epoxidation of unsaturated fatty acids in the presence of hydroperoxides as co‐oxidants. However, the caleosins characterized so far, which are mostly localized in seeds, are poor epoxidases. In sharp contrast, quantitative RT‐PCR analysis revealed that PXG4, a class II caleosin gene, is expressed in roots, stems, leaves and flowers of Arabidopsis. Expressed in yeast, PXG4 encodes a calcium‐dependent membrane‐associated hemoprotein able to catalyze typical peroxygenase reactions. Moreover, we show here that purified recombinant PXG4 is an efficient fatty acid epoxygenase, catalyzing the oxidation of cis double bonds of unsaturated fatty acids. Physiological linoleic and linolenic acids proved to be the preferred substrates for PXG4; they are oxidized into the different positional isomers of the monoepoxides and into diepoxides. An important regioselectivity was observed; the C‐12,13 double bond of these unsaturated fatty acids being the least favored unsaturation epoxidized by PXG4, linolenic acid preferentially yielded the 9,10‐15,16‐diepoxide. Remarkably, PXG4 catalyzes exclusively the formation of (R),(S)‐epoxide enantiomers, which is the absolute stereochemistry of the epoxides found in planta. These findings pave the way for the study of the functional role of EFAs and caleosins in plants.
Ideal vs. Non‐ideal Theory: A Conceptual Map
Authors: Valentini Laura
Published: August 2012

This article provides a conceptual map of the debate on ideal and non‐ideal theory. It argues that this debate encompasses a number of different questions, which have not been kept sufficiently separate in the literature. In particular, the article distinguishes between the following three interpretations of the ‘ideal vs. non‐ideal theory’ contrast: (i) full compliance vs. partial compliance theory; (ii) utopian vs. realistic theory; (iii) end‐state vs. transitional theory. The article advances critical reflections on each of these sub‐debates, and highlights areas for future research in the field.
The Bootstrapping Problem
Authors: Weisberg Jonathan
Published: August 2012

Bootstrapping is a suspicious form of reasoning that verifies a source's reliability by checking the source against itself. Theories that endorse such reasoning face the bootstrapping problem. This article considers which theories face the problem and surveys potential solutions. The initial focus is on theories like reliabilism and dogmatism, which allow one to gain knowledge from a source without knowing that it is reliable. But the discussion quickly turns to a more general version of the problem that does not depend on this allowance. Five potential solutions to the general problem are evaluated, and some implications for the literature on peer disagreement are considered.
Meaning Holism
Authors: Dresner Eli
Published: August 2012

In the first section of this paper I define meaning holism (MH) and compare it to related theses. In the second section I review several theories of meaning that incorporate MH as a feature, and in the third section I discuss the question whether and how MH is consistent with the assignment of semantic values to linguistic expressions. Finally, in the fourth section I present the main objections raised against MH in the literature and the answers given to them.
Viral and bacterial aetiology of community‐acquired pneumonia in adults
Authors: Huijskens Elisabeth G. W. , van Erkel Adriana J. M. , Palmen Fernand M. H. , Buiting Anton G. M. , Kluytmans Jan A. J. W. , Rossen John W. A.
Published: August 2012

Please cite this paper as: Huijskens et al. (2012) Viral and bacterial aetiology of community‐acquired pneumonia in adults. Influenza and Other Respiratory Viruses 7(4), 567–573.

Background  Modern molecular techniques reveal new information on the role of respiratory viruses in community‐acquired pneumonia. In this study, we tried to determine the prevalence of respiratory viruses and bacteria in patients with community‐acquired pneumonia who were admitted to the hospital.

Methods  Between April 2008 and April 2009, 408 adult patients (aged between 20 and 94 years) with community‐acquired pneumonia were tested for the presence of respiratory pathogens using bacterial cultures, real‐time PCR for viruses and bacteria, urinary antigen testing for Legionella and Pneumococci and serology for the presence of viral and bacterial pathogens.

Results  Pathogens were identified in 263 (64·5%) of the 408 patients. The most common single organisms in these 263 patients were Streptococcus pneumoniae (22·8%), Coxiella burnetii (6·8%) and influenza A virus (3·8%). Of the 263 patients detected with pathogens, 117 (44·5%) patients were positive for one or more viral pathogens. Of these 117 patients, 52 (44·4%) had no bacterial pathogen. Multiple virus infections (≥2) were found in 16 patients.

Conclusion  In conclusion, respiratory viruses are frequently found in patients with CAP and may therefore play an important role in the aetiology of this disease.
Long‐term change of ant community structure in cacao agroforestry landscapes in Indonesia
Authors: Rizali Akhmad , Clough Yann , Buchori Damayanti , Hosang Meldy L.A. , Bos Merijn M. , Tscharntke Teja
Published: August 2012

Land‐use change and agricultural intensification can strongly affect biodiversity in agricultural landscapes. Although many studies investigate management impacts, data on the long‐term change of species communities in agroecosystems are scarce.

We analysed the long‐term change in diversity and composition of ant communities in cacao agroforestry systems in Central Sulawesi, Indonesia and attempted to disentangle the driving factors of this change. Ant communities were resampled in 2009 from sites for which previous surveys had been conducted either in 2001 (the rainforest‐poor Palolo region) or 2003 (the rainforest‐rich Kulawi region) using insecticide fogging.

Ant community composition changed significantly over time in Palolo and Kulawi. The change in ant species richness differed between regions. Species richness increased in Kulawi, probably due to the increasing availability of nest sites and microhabitats as trees grow larger and older. In the Palolo region, species richness decreased, suggesting that the high local intensification and landscape‐wide changes may have counteracted the effects of tree age. Changes in ant communities over time were significant, but were more difficult to explain than expected, despite clear difference in management changes within and between regions.

The findings suggest that the landscape‐scale differences between the two study regions play a more important role for species diversity and its composition than changes in local management. This highlights the importance of long‐term studies across contrasting landscapes for better understanding the consequences land‐use intensification has on tropical biodiversity.
An assessment of the effect of harvest time and harvest method on biomass loss for Miscanthus × giganteus
Authors: Meehan Peter G. , McDonnell Kevin P. , Finnan John M.
Published: August 2012

This study examines the amount of biomass loss occurring in Miscanthus × giganteus crop at harvest. The study assesses loss incurred as a direct result of the harvest systems employed to collect the material along with examining how the time of harvest effects the amount of loss occurring over the spring harvest window. Pre harvest losses of 4.8–5.1% were measured prior to harvest. There was no significant difference between pre harvest loss and post harvest loss when a self‐propelled forage harvester fitted with a maize harvesting header was used to harvest the crop. The use of a conditioner mower and baler significantly increased crop losses to 9.4–14.1%. This demonstrates that correct selection of the harvest system can significantly increase biomass recovery. Additional losses were measured at headlands when the mower/baler system was used, but headland losses will not occur when self‐propelled forage harvesters are utilized. Losses were significantly greater in the area beside the swath after the baler pass when compared to prior to baling. This study has shown that correct selection of harvest systems can significantly increase biomass recovery, with no significant difference in pre harvest loss or harvest loss occurring as a result of cutting the M. × giganteus crop at different dates during the harvest window (March 1st, March 25th, April 21st).
Epidemiology of Subclinical Salmonellosis in Wild Birds from an Area of High Prevalence of Pig Salmonellosis: Phenotypic and Genetic Profiles of Salmonella Isolates
Authors: Andrés S. , Vico J. P. , Garrido V. , Grilló M. J. , Samper S. , Gavín P. , Herrera‐León S. , Mainar‐Jaime R. C.
Published: August 2012

The epidemiology of subclinical salmonellosis in wild birds in a region of high Salmonella prevalence in pigs was studied. Three hundred and seventy‐nine faecal samples from 921 birds trapped in 31 locations nearby pig premises, and 431 samples from 581 birds of 10 natural settings far from pig farms were analysed for the presence of Salmonella spp. Positive samples were serotyped and analysed for antimicrobial resistance (AR). Phage typing and pulsed‐field gel electrophoresis (PFGE) on Salmonella Typhimurium isolates were also carried out. The overall proportion of Salmonella‐positive samples was 1.85% (95% CI = 0.93, 2.77). Salmonella isolation was positively associated with samples collected from birds in the proximity of a pig operation (OR = 16.5; 95% CI = 5.17, 52.65), and from non‐migratory (or short‐distance migration) birds (OR = 7.6; 95% CI = 1.20, 48.04) and negatively related to mostly granivorous birds (OR = 0.4; 95% CI = 0.15, 1.13). Salmonella Typhimurium was the most prevalent serotype and four different XbaI PFGE patterns were observed that matched the four phage types identified (U310, U311, DT164 and DT56). Only 20% of the strains showed multi‐AR. In three farms, a high degree of homogeneity among isolates from different birds was observed. These findings suggested that pig farms may act as amplifiers of this infection among wild birds, and the degree of bird density may have much to do on this transmission. Some of the Salmonella serotypes isolated from bird faeces were of potential zoonotic transmission and associated with AR. Monitoring salmonellosis in wild bird is advised.
Polyphenols prevent ageing‐related impairment in skeletal muscle mitochondrial function through decreased reactive oxygen species production
Authors: Charles Anne‐Laure , Meyer Alain , Dal‐Ros Stéphanie , Auger Cyril , Keller Nathalie , Ramamoorthy Thanuja Gali , Zoll Joffrey , Metzger Daniel , Schini‐Kerth Valérie , Geny Bernard
Published: August 2012

New findings

What is the central question of this study?

Ageing impairs muscle function, which is a strong predictor of falls, hospital admission and mortality. Mitochondrial impairment and oxidative stress play a key role in this process. Polyphenols modulate oxidative stress, but whether they might protect muscles against ageing is unknown.

What is the main finding and its importance?

For the first time, this study demonstrated that intake of polyphenols starting at a young age totally restored muscle maximal mitochondrial oxidative capacity, normalized production of reactive oxygen species and enhanced antioxidant defence, therefore protecting aged muscle. This might open new therapeutic perspective for maintaining healthy muscle function in aged humans.

Ageing is associated with skeletal muscle impairment. Changes in mitochondrial homeostasis are thought to play a key role in this process. This study examined whether chronic intake of polyphenols (PPs), which are known to be modulators of oxidative stress, might prevent the age‐related decline of mitochondrial functions in skeletal muscle. Three groups of 10 Wistar rats were investigated. Rats aged 16 weeks were compared with rats aged 40 weeks that were given 75 mg kg−1 day−1 PPs or solvent in the drinking water starting at week 16. Mitochondrial respiratory chain complex activities were measured in saponin‐skinned fibres of soleus muscles using glutamate–malate (Vmax), succinate (Vsucc) and N,N,N′,N′‐tetramethyl‐p‐phenylenediamine dihydrochloride–ascorbate (VTMPD). Production of reactive oxygen species was assessed using dihydroethidium staining. Transcript levels of genes involved in antioxidant defence were determined using RT‐PCR. Ageing reduced muscle Vmax (from 8.8 ± 0.45 to 6.17 ± 0.51 μmol O2 min−1 g−1, −30.5%, P < 0.01), VTMPD (from 20.67 ± 1.24 to 16.55 ± 1.16 μmol O2 min−1 g−1, −19.9%, P < 0.05), increased production of reactive oxygen species (from 100 ± 9.9 to 351.1 ± 31.7%) and decreased transcripts of mitochondrial superoxide dismutase 2 (−59.3%, P < 0.01), peroxisome proliferator‐activated receptor γ coactivator‐1β (PGC‐1β; −61.5%, P < 0.05) and sirtuin 1 (−54.2%, P < 0.05). Chronic PP intake normalized Vmax (8.63 ± 0.63 μmol O2 min−1 g−1), decreased production of reactive oxygen species (141.7 ± 16.7%, P < 0.001) and enhanced antioxidant defence (superoxide dismutase 2 expression, +151.3%, P < 0.05) and PGC‐1β expression (+185.7%, P < 0.05) in comparison to age‐matched untreated rats. The present data indicate that regular intake of PPs starting at a young age prevents age‐related mitochondrial respiratory impairment in skeletal muscle, probably through decreased oxidative stress and enhancement of PGC‐1β expression.
Characteristic Flow Field Behind a Square-Cylinder Using Upstream Mesh Fences
Authors: Yen Shun C. , Yang Chen W.
Published: August 2012

The flow behaviors around a square cylinder were modulated using the passive mesh fence. The effects of Reynolds number (Re) and rotation angle (θ) on the square-cylinder flow fields using different turbulence intensity (TI) were also investigated. Additionally, various steel mesh fences with different mesh densities were installed between the nozzle outlet and the test-section inlet to adjust the free-stream TI. The Reynolds number and turbulence intensity used in this investigation are 3.0 × 104 ≤ Re ≤ 1.0 × 105 and 0.32% ≤ TI ≤ 0.82%. The flow fields are visualized using the surface oil-flow visualization scheme. Furthermore, the flow patterns are classified as—leading-edge bubble, separation bubble, separation, leading-edge separation, and boundary-layer attached modes. Specifically, the leading-edge bubble mode does not exist while θ and TI are low. Moreover, a hot-wire anemometer was placed in the wake to detect the vortex-shedding frequency. The experimental results indicate that Strouhal number (St) decreases with increasing the free-stream TI while TI < 0.45%. However, St approaches a constant as TI > 0.45%. Furthermore, the surface pressure was detected using a pressure scanner and the drag coefficient (CD) was obtained using the surface-pressure profile. The experimental results also reveal that CD decreases with increasing the free-stream TI. However, the change rate of CD for TI < 0.45% exceeds that for TI > 0.45%.
Effects of Bending Moments and Pretightening Forces on the Flexural Stiffness of Contact Interfaces in Rod-Fastened Rotors
Authors: Gao Jin , Yuan Qi , Li Pu , Feng Zhenping , Zhang Hongtao , Lv Zhiqiang
Published: August 2012

The rod-fastened rotor (RFR) is comprised of a series of discs clamped together by a central tie rod or several tie rods on the pitch circle diameter. The equivalent flexural stiffness of contact interfaces Kc in the RFR is the key concern for accurate rotor dynamic performance analysis. Each contact interface was modeled as a bending spring with a stiffness of Kc and a hinge in this study. The contact states of the contact interfaces, which depend on the pretightening forces and bending moments (static), have effects on Kc. The approach to calculating Kc in two contact states is presented. The first contact state is that the whole zone of the contact interface is in contact; Kc is determined by the contact layer, which consists of asperities of the contact surfaces. Hertz contact theory and the Greenwood and Williamson (GW) statistical model are used to calculate the equivalent flexural stiffness of the contact layer Kcc. The second contact state is that some zones of the contact interface are separated (when the bending moment is relatively large); the equivalent flexural stiffness of the rotor segment Ksf (not including Kcc) decreases, as the material in the separated zone has no contribution to the bending load-carrying capacity of the rotor. The strain energy, which is calculated by the finite element method (FEM), is used to determine Ksf. The stiffness Ksf is equivalent to the series stiffness of the discs of the rotor segment with flexural stiffness of Kd and a spring with bending stiffness of Kcf in the location of the contact interface, so Kc is equal to the series stiffness of Kcc and Kcf in the second contact state. The results of a simplified RFR indicate that, for a fixed pretightening force, Kcc decreases with bending moments in the first contact state, whereas increases with bending moments in the second contact state. In addition, Kcf and Kc decrease abruptly with the increase of bending moments in the second contact state when the rotor is subjected to a relatively large pretightening force. Finally, the multipoint exciting method was used to measure the modal parameters of the experimental RFR. It is found that the experimental modal frequencies decrease as the pretightening force decreases.
On the Effect of Thermal Energy Transport to the Performance of (Semi) Floating Ring Bearing Systems for Automotive Turbochargers
Authors: San Andrés Luis , Barbarie Vince , Bhattacharya Avijit , Gjika Kostandin
Published: August 2012

Bearing systems in engine-oil lubricated turbochargers (TCs) must operate reliably over a wide range of shaft speeds and withstand severe axial and radial thermal gradients. An engineered thermal management of the energy flows into and out of the bearing system is paramount in order to ensure the component’s mechanical integrity and the robustness of the bearing system. The bearings, radial and thrust type, act both as a load bearing and low friction support with the lubricant carrying away a large fraction of the thermal energy generated by rotational drag and the heat flow disposed from a hot shaft. The paper introduces a thermohydrodynamic analysis for the prediction of the pressure and temperature fields in a (semi) floating ring bearing (S)FRB system. The analysis simultaneously solves the Reynolds equation with variable oil viscosity and the thermal energy transport equation in the inner and outer films of the bearing system. Flow conditions in both films are coupled to the temperature distribution and heat flow through the (semi) floating ring. Other constraints include calculating the fluid films’ forces reacting to the externally applied load and to determine the operating journal and ring eccentricities. The predictions of performance for a unique realistic (S)FRB configuration at typical TC operating conditions reveal a distinct knowledge: (a) the heat flow from the shaft into the inner film is overwhelming, in particular, at the inlet lubricant plane where the temperature difference with the cold oil is largest; (b) the inner film temperature quickly increases as soon as the (cold) lubricant enters the film and is due to the large amount of energy generated by shear drag and the heat transfer from the shaft; (c) a floating ring develops a significant radial temperature gradient; (d) at all shaft speeds, low and high, the thermal energy carried away by the lubricant streams is no less than 70% of the total energy input; the rest is conducted through the TC casing. To warrant this thermal energy distribution, enough lubricant flow must be supplied to the bearing system. The efficient computational model offers a distinct advantage over existing lumped parameters thermal models and there is no penalty in the execution time.
Study of Submerged Jet for Suction of Fluid
Authors: Subudhi Sudhakar , Sreenivas K. R. , Arakeri Jaywant H.
Published: August 2012

This paper deals with the study of a submerged jet for the suction of unwanted fluid. This submerged jet is caused by the fluid coming out from a source. The presence of a sink in front of this source facilitates the suction of the fluid depending upon the source and sink flow rates, the axial and lateral separations of the source and sink, and the angle between the axes of the source and sink. The main purpose is the determination of the sink flow rate for 100% removal of the source fluid as a function of these parameters. The experiments have been carried using a source nozzle 6 mm in diameter and two sizes for the sink pipe diameter: 10 mm and 20 mm. The main diagnostics used are flow visualization using dye and particle image velocimetry (PIV). The dependence of the required suction flow rate to obtain 100% effectiveness on the suction tube diameter and angle is relatively weak compared to the lateral separation.
Spatial Resolution of the Axisymmetric Turbulent Statistics Along Thin Circular Cylinders at High Transverse Curvatures and Low-Re
Authors: Jordan Stephen A.
Published: August 2012

After three decades of accumulated experimental and numerical results, a comprehensive understanding of the spatial evolution of axisymmetric turbulent boundary layers (ATBL) along long thin cylinders still eludes both scientists and engineers. While experimentalists dealt with axial alignment complexities, computationalists lacked proper inflow boundary conditions. Herein, we correct this latter deficiency and initiate an investigation of the thin cylinder turbulence under low Reynolds numbers and high transverse curvatures (boundary layer thicknesses to radius). Using the large-eddy simulation (LES) methodology, we are particularly interested in the radial propagation of the transverse curvature on the ATBL statistics. A ten-simulation matrix was constructed to examine these effects with validation against the experimental evidence. These tests investigated the ATBL maturity up to transverse curvatures approaching 2 orders of magnitude. A recently developed turbulent inflow procedure for the thin cylinder was implemented that couples a dynamic form of Spalding’s expression for rescaling the mean streamwise velocity with recycling of all superimposed turbulent fluctuations. The technique specifically circumvents intensive computations from the cylinder leading edge, and the rescaling-recycling combination minimizes the inflow turbulent regeneration length under very high transverse curvatures. After the initial transition phase in each LES computation, the respective numerical uncertainty was quantified to ensure sufficient spatial resolution within the discretized domain for resolving the energy-bearing scales of the turbulent motion. For the present low-Re conditions, the strength of the log layer steadily diminishes under continuous rise in the transverse curvature whereas the scaled fluctuating intensities elevate (except for the dominate shear stresses) with no sign towards full maturity. Each simulation reveals a boundary layer thickness that grows downstream by a factor of 7 relative to the momentum thickness with a linear influence of the transverse curvature on the wall-shear stress coefficient.
Curing Time Effect on the Fraction of 137Cs From Immobilized Radioactive Evaporator Sludge by Portland Cement
Authors: Plecas Ilija , Dimovic Slavko , Pesic Radojica
Published: August 2012

Traditional methods of processing evaporator concentrates from Nuclear Power Plants are evaporation and cementation. These methods allow transforming a liquid radioactive waste into a more inert form, suitable for a final disposal. To assess the safety for disposal of radioactive mortar-waste composition, the leaching of 137Cs from immobilized radioactive evaporator concentrate into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Incremental leaching rates Rn (cm/d) of 137Cs from evaporator concentrates after 1825 days were measured. The results presented in this paper are examples of results obtained in a 30-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing center.
Immobilisation of Radwaste in Synthetic Rock: An Alternative to Cementation
Authors: Rottner Bernard
Published: August 2012

SOGETER is a waste conditioning process for Low Level radwaste (LLW) or Intermediate Level radwaste (ILW) such as sludge, soil, ashes, evaporator concentrate, concrete rubble, asbestos or sand. Such radioactive waste is usually solidified into a cement matrix, resulting in a 2 to 5 times volumetric waste increase, i.e. 1 m3 of initial raw waste generates 2 to 5 m3 of solidified waste. Sogeter melts the waste at high temperature - up to 2000 K, and produces a synthetic rock. The main component of the matrix is the waste itself; therefore 1 m3 of initial raw waste generates only 0.2 to 0.5 m3 of solidified waste. Compared to cementation, synthetic rock decreases the volume to be disposed of by a factor of 4 up to a factor of 25. By mixing different types of waste, or using additives, the composition of the waste is adjusted so that a fluid melt is obtained at temperatures less than 2000 K and the final 200 L ingot can be cooled within 2 days, without shattering or disaggregating. A wide range of compositions have been tested demonstrating that almost every type of waste can be conditioned with Sogeter. An industrial facility has been designed based on very robust and proven heating and off-gas treatment technology. Industrial tests have been carried out on more than 2 tons of simulated, non-radioactive waste, producing blocks of treated matter weighing up to 250 kg. During these tests all process parameters, including electrical consumption, throughput and robustness, have been checked.
Decommissioning the BELGONUCLEAIRE Dessel MOX Plant: Presentation of the Project and Situation on 30/06/2011
Authors: Cuchet J. M. , Libon H. , Verheyen C. , Bily J. , Custers J. , Walthe´ry R.
Published: August 2012

BELGONUCLEAIRE has been operating the Dessel MOX plant at industrial scale between 1986 and 2006. In this period, 40 metric tons of plutonium (HM) has been processed into 90 reloads of MOX fuel for commercial light water reactors. The decision to stop the production in 2006 and to decommission the MOX plant was the result of the shrinkage of the MOX fuel market owing to political and customer’s factors. As a significant part of the decommissioning project of the Dessel MOX plant, about 170 medium-sized glove boxes and about 1.300 metric tons of structure and equipment outside the glove boxes are planned for decommissioning. The license for the decommissioning of the MOX plant was granted by Royal Decree in 2008 and the decommissioning works started in March 2009; the decommissioning works are executed by an integrated organization under leadership and responsibility of BELGONUCLEAIRE with 3 specialized contractors, namely TECNUBEL N.V., the joint venture (THV) BELGOPROCESS / SCK·CEN and STUDSVIK GmbH. In this paper, after having described the main characteristics of the project, the authors introduce the different organisational and technical options considered for the decommissioning of the glove boxes, and the main decision criteria (qualification of personnel and of processes, confinement, cutting techniques & radiation protection, safety aspects, alpha-bearing waste management) are analyzed as well. The progress, the feedback and the lessons learned mid 2011 are presented, giving the principal’s and contractors point of view as well.
An Innovative Process for Segmenting of Guide Tubes
Authors: Gobert Patrick , Ponchon Pierre-Henri , Fallstro¨m Stefan , Boucau Joseph
Published: August 2012

The purpose of this paper is to describe an innovative process for segmenting PWR Guide Tubes (GT’s) and the service (training and execution) that can be performed successfully and safely. Over time, some utilities are replacing control rod GT’s and store them in temporary disposal facilities. Due to lack of space, as the case for the BCOT (EDF – France / Tricastin), it is sometimes needed to cut and condition them in waste packages for final disposal and waste treatment. Based on its experience, Westinghouse has recently developed a complete solution for cutting and consolidating GT’s. One of the challenges related to such equipment is to consider two routes for the waste management: one for the activated segments and another for the less activated segments. Depending on the regulation and of the storage acceptance criteria’s, the length of the segments has been defined to minimize the volume of highly activated waste and therefore develop a process which is adapted to the size of containers specified by the customer. A model with five cutting operations and generating six segments has been chosen. In order to minimize risks and ensure safety for personnel and facilities, radiological studies were performed for various configurations. All cutting techniques previously used by Westinghouse in similar applications have been evaluated. Underwater mechanical cutting with a band saw has been selected.
The Science, Assaying and Waste Sentencing of Activated Bioshields
Authors: Adsley Ian
Published: August 2012

Nuclear operations with reactors and particle accelerators lead to the generation of neutrons, with a consequent activation of surrounding shielding materials. In general these materials consist of a concrete bioshield with associated metal work from steel reinforcement and support structures. This paper considers the interaction mechanisms of the neutrons in the concrete and the distribution and activity profile of activated materials. The most common source of high thermal neutron fluxes is of course from fission reactor systems. However, there are also other systems such as fusion reactors, which generate a far higher energy neutron flux, as the requirement for electrical confinement of the plasma means that the available bioshielding close to the power source is more limited. In addition, there are also neutron generation mechanisms from particle accelerator systems such synchrotrons and Van De Graaf devices. This study examines the interaction mechanisms of the neutrons in the bioshields, the radioelement abundances of the activated products generated, in-situ and ex-situ measurement of their concentration and profile of the radionuclides and finally methods of assaying and sentencing such materials. Examples of decommissioning operations of reactor and accelerator systems will be given as practical examples of the use of the assaying methodologies developed.
A Fully Operational Pilot Plant for Eliminating Radioactive Oils Mixed With Chlorinated Solvents
Authors: Jacobs A. , Everett W.
Published: August 2012

Disposal of organic liquid waste has become an increasing issue for many nuclear sites. Existing disposal solutions such as incineration or super critical water techniques are not compatible with wastes containing chlorinated solvents or fluorine owing to corrosion problems. As an example several hundred cubic meters of lubricating oils mixed with trichloroethylene (TCE) or perchloroethylene (PCE) are stockpiled on several French nuclear sites. For several years Dewdrops has been developing an original combination of mineralization processes for waste oils and solvents particularly well suited to the nuclear field. The patented technology relies on the alternation of chemical and biological oxidation mechanisms. The oxidized organic material predominately forms carbon dioxide, water and inorganic salts. This paper details the procedure and the results obtained for a particular case at the Tricastin nuclear site of Areva NC (South France). The organic waste used in this study was a 85/15 v/v ratio mix of lubricating oil and TCE. The pilot plant build upon the technology has a daily treatment capacity of approximately 10 liters. In the first step the TCE is mineralized by the photo Fenton reaction. Using hydrogen peroxide with an ultraviolet regenerated iron catalyst, TCE is transformed to carbon dioxide, water and hydrochloric acid. After neutralizing with caustic soda, the next step is a multi-stage biodegradation process to eliminate the remaining lubricating oil. Carefully selected microorganisms use the organic waste as an energy source for their metabolism. During oil biodegradation over 75% of the carbon is released as carbon dioxide while the remaining is incorporated into the biomass. The aqueous phase is continuously separated from the biomass using cross flow filters. The output aqueous phase is treated with ozone and ultraviolet light to eliminate the remaining organic compounds. The final effluent obtained is in conformance with European water standards and can be disposed by normal means. It can also be adjusted to local requirements. The radioactive elements and heavy metals present in these lubricating oils are trapped by the biomass. The excess of biomass is recovered by centrifugation and mineralized by catalytic ozonation technology. The result of the tests was a radioactive waste reduction factor of 15. The mineral residue is a concentrate of inorganic salts with traces of radioactive elements as well as heavy metals. The radioactive elements thus recovered can be consigned to an official repository.
Optimisation (Sampling Strategies and Analytical Procedures) for Site Specific Environment Monitoring at the Areas of Uranium Production Legacy Sites in Ukraine
Authors: Voitsekhovych Oleg V. , Lavrova Tatiana V. , Kostezh Alexander B.
Published: August 2012

There are many sites in the world, where Environment are still under influence of the contamination related to the Uranium production carried out in past. Author’s experience shows that lack of site characterization data, incomplete or unreliable environment monitoring studies can significantly limit quality of Safety Assessment procedures and Priority actions analyses needed for Remediation Planning. During recent decades the analytical laboratories of the many enterprises, currently being responsible for establishing the site specific environment monitoring program have been significantly improved their technical sampling and analytical capacities. However, lack of experience in the optimal site specific sampling strategy planning and also not enough experience in application of the required analytical techniques, such as modern alpha-beta radiometers, gamma and alpha spectrometry and liquid-scintillation analytical methods application for determination of U-Th series radionuclides in the environment, doesn’t allow to these laboratories to develop and conduct efficiently the monitoring programs as a basis for further Safety Assessment in decision making procedures. This paper gives some conclusions, which were gained from the experience establishing monitoring programs in Ukraine and also propose some practical steps on optimization in sampling strategy planning and analytical procedures to be applied for the area required Safety assessment and justification for its potential remediation and safe management.
Decommissioning Activities for Salaspils Research Reactor
Authors: Abramenkovs A. , Malnacs J.
Published: August 2012

In May 1995, the Latvian government decided to shut down the Salaspils Research Reactor (SRR). The reactor is out of operation since July 1998. A conceptual study for the decommissioning of SRR has been carried out by Noell-KRC-Energie- und Umwelttechnik GmbH at 1998–1999. The Latvian government decided to start the direct dismantling to “green field” in October 26, 1999. The upgrade of decommissioning and dismantling plan was performed in 2003–2004 years, which change the main goal of decommissioning to the “brown field”. The paper deals with the SRR decommissioning experience during 1999–2010. The main decommissioning stages are discussed including spent fuel and radioactive wastes management. The legal aspects and procedures for decommissioning of SRR are described in the paper. It was found, that the involvement of stakeholders at the early stages significantly promotes the decommissioning of nuclear facility. Radioactive waste management’s main efforts were devoted to collecting and conditioning of “historical” radioactive wastes from different storages outside and inside of reactor hall. All radioactive materials (more than 96 tons) were conditioned in concrete containers for disposal in the radioactive wastes repository “Radons” at Baldone site. The dismantling of contaminated and activated components of SRR systems is discussed in paper. The cementation of dismantled radioactive wastes in concrete containers is discussed. Infrastructure of SRR, including personal protective and radiation measurement equipment, for decommissioning purposes was upgraded significantly. Additional attention was devoted to the free release measurement’s technique. The certified laboratory was installed for supporting of all decommissioning activities. All non-radioactive equipments and materials outside of reactor buildings were released for clearance and dismantled for reusing or conventional disposing. Weakly contaminated materials from reactor hall were collected, decontaminated and removed for clearance measurements.