bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystallography for University Research: Some Basic Case Studies
Authors: Crochet Aurelien
Published: June 2014

An overview of commonly available, state-of-the-art diffraction techniques for university research is presented based on some chemical case studies. Examples from the Fribourg crystallography service are presented, aimed at scientists who would like to learn about the principal possibilities
that X-ray powder and single-crystal diffraction can offer, how these methods can serve to determine the structure of a given material, and how they can help to identify polymorphs, surface coatings and enantiomers.
A Manly Art: Plowing, Plowing Matches, and Rural Masculinity in Ontario, 1800–1930
Authors: Wilson Catharine Anne
Published: June 2014

Abstract:

This article draws on recent studies of masculinity, labour and recreation to consider rural men. More Canadian men worked in farming than any other single occupation and yet we know little about their sense of masculine identity. This article examines the processes of fashioning, practising and performing masculinity associated with the archetypal farming skill passed down from father to son – plowing. In the early 1800s improving farmers created the plowing match, an educational and sporting event. The author analyzes media representations of the match, reporters' rhetoric, visual images and interviews with plowmen and spectators. She argues that their depictions and discussions of plowing at home and at the match shed light on their masculine ideals, ideals that were challenged with the introduction of the tractor. Rural men continued to value a rugged individualism and mastery over nature, but the value of being a skilled horseman, stoic toiler, and muscled man gave way to new masculine ideals based on speed, comfort, and expertise with machines. In the process farmers helped reposition the countryside in the shifting cultural hierarchy and moved in parallel with other Canadian men who were refashioning concepts of manliness, skill, fatherhood and recreation in the new industrial age.
Épisodes d’inactivité et revenus criminels dans une trajectoire de délinquance
Authors: Ouellet Frédéric , Tremblay Pierre
Published: June 2014

The instability of criminal activity over time is already well documented. However, little is known of the circumstances that can explain these short-term variations. It is possible that short-term transitions and changes precede turning points in criminal careers. For example, conditions that account for the temporary interruption of criminal activity might help explain a more definitive desistance from crime. Therefore, it appears appropriate to improve our knowledge of these factors. The study is based on the trajectories of 172 offenders involved in lucrative forms of crime. It focuses on changes in criminal earnings and episodes of temporary desistance within a window period of 36 months. The life history calendars method, combined with hierarchical models, is used for the analysis of the role of static (individual characteristics) and dynamic (life circumstances) factors in order to understand variations in criminal activity on a monthly basis. Results highlight the importance of events that mark offenders’ lifestyles and the parameters that characterize criminal involvement in predicting variations in observed trajectories. They also emphasize the importance of criminal achievement in explaining the decision of offenders to temporarily stop their illegal activities.
Neophytenbekämpfung an Gewässern im Spannungsfeld gesetzlicher Zielkonflikte (Essay)
Authors: Kräuchi Norbert
Published: June 2014

Control of non-native plant species along streams: an area of conflict caused by legal trade-offs (essay)

Driven by global trade and supported by climate change, we increasingly encounter new species in our ecosystems. Certain of these species, for example Asian Knotweeds (Reynoutria japonica, R. sachalinensis, R. × bohemica), exhibit immense growth rates and thereby suppress existing vegetation in revitalized reaches and biotopes deserving particular protection. The ecological damage accompanying the loss of biodiversity can only be contained by effective and efficient control measures. Contradictory legal guidelines at Federal level lead in practice to a conflict of aims, making goal-oriented control impossible. On the one hand the Chemical Risk Reduction Ordinance prohibits the use of pesticides in a 3-m strip along water stretches. On the other hand, numerous laws – such as the Federal Act on the Protection of Nature and Cultural Heritage, the Water Protection Law and the Ordinance on the Handling of Organisms in the Environment infer that it is a responsibility to protect riparian zones and river banks as ecologically valuable habitats, and to take measures against invasive neophytes. As long-term investigations in the Canton of Aargau have shown, chemical control sustainably weakens the Asian Knotweed. Further, a fluorescent tracer experiment demonstrated that with careful implementation, the use of pesticides along a 3-m strip along riverbanks poses no threat to the stretch of water. Therefore the Canton of Aargau hopes that these findings contribute to the fastest possible resolution of this conflict of aims, so that investments made over the past years towards restoring stretches of water may be protected promptly from the threat of Asian Knotweed.
Invasive Gehölzinsekten: Bedrohung für den Schweizer Wald?
Authors: Wermelinger Beat
Published: June 2014

Invasive tree insects: a menace to the Swiss forests?

The rate of introduction of non-native insects and other arthropods to Europe has been exponentially increasing in recent decades, amounting to 20 species per year in the past ten years. By 2008, a total of 1590 species had been introduced since the discovery of America. The main causes are the intensification and globalization of international trade. The most important pathways are trade in ornamental plants and import of goods in infested wooden crates. Most often new species first establish in residential areas, where the normally mild climate favors the survival of exotic species. Three species recently introduced from East Asia to Switzerland are particularly relevant to forests: the box tree moth (Cydalima perspectalis) has infested box tree stands near Basel, the chestnut gall wasp (Dryocosmus kuriphilus) now covers almost all of southern Switzerland, with single infestations also on the Swiss Central Plateau, and two infestation spots of the Asian longhorned beetle (Anoplophora glabripennis) have been identified. Potential future species of invasive insects are discussed. The largescale introduction of foreign tree species in forests needs to be critically examined, as they may be hosts of current and future non-native insects.
Qualitative Analysis of the Helical Electronic Energy of Inherently Chiral Calix[4]arenes: An Approach to Effectively Assign Their Absolute Configuration
Authors: Zheng Shuang , Chang Ming-Liang , Zhou Jing , Fu Jing-Wei , Zhang Qing-Wei , Li Shao-Yong , Qiao Wei , Liu Jun-Min
Published: June 2014

For all microhelices on aromatic rings of inherently chiral calix[4]arene, an expression was derived from one approximation and one hypothesis on the basis of the electron-on-a-helix model of Tinoco and Woody as follows: 1/E = μ (H − K Δα2) , where μ = 1 for the right-handed microhelix and μ = −1 for the left-handed microhelix; and H and K are constant and greater than zero. The expression correlates microhelical electronic energy (E) with the atom polarizability difference (Δα) on both microhelix ends, which intuitively and clearly shows the impact of helical substituent polarizability on helical electronic energy. The case analysis almost entirely proves that the qualitative analysis of the helical electronic energy of inherently chiral calix[4]arenes with the expression is scientific and can be used to effectively assign their absolute configuration
High Cytoplasmic Expression of Krüppel-like Factor 4 Is an Independent Prognostic Factor of Better Survival in Hepatocellular Carcinoma
Authors: Hsu Hui-Ting , Wu Pei-Ru , Chen Chih-Jung , Hsu Li-Sung , Yeh Chung-Min , Hsing Ming-Tai , Chiang Yi-Shan , Lai Ming-Tsung , Yeh Kun-Tu
Published: June 2014

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality in the world. Hepatocarcinogenesis is complex, with an extraordinary molecular heterogeneity. Krüppel-like factor 4 (KLF4) plays an important role in cell proliferation and differentiation, and it can function as a tumor suppressor or an oncoprotein, depending on tissue type. The role of KLF4 in HCC remains controversial. The aim of this study was to explore the clinical significance of KLF4 expression in HCC. The study included 205 patients with surgical resection. We performed immunostaining for KLF4 and Ki-67 to investigate the correlations of the clinicopathological parameters of HCC and to examine the proliferative index. KLF4 staining was observed in the cytoplasm of non-tumorous hepatocytes and tumor cells. We subdivided the immunohistological staining results for KLF4 into low expression (Staining 0 and 1+) and high expression (Staining 2+ and 3+) subgroups. The expression of KLF4 was significantly correlated with tumor differentiation (p = 0.001). The Ki-67 proliferative index was significantly lower in well-differentiated HCCs (0.781% ± 1.02% vs. 2.16% ± 3.14%, p = 0.012), but not significantly different between low-KLF4 expression and high-KLF4 expression (1.87% ± 2.93% vs. 2.51% ± 3.28%, p = 0.32). Kaplan–Meier analysis showed that a high expression of KLF4 was significantly correlated with a longer disease-specific survival (p = 0.019). Univariate and multivariate analyses showed that high KLF4 expression was an independent predictor of a better disease-specific survival (p = 0.017; hazard ratio = 0.398; 95% confidence interval: 0.19–0.85). High cytoplasmic expression of KLF4 was associated with better disease-specific survival and was an independently favorable prognostic factor in hepatocellular carcinoma. These promising results suggest that KLF4 may play an anti-oncogenic role in hepatocarcinogenesis.
Synthesis of Caffeic Acid Amides Bearing 2,3,4,5-Tetra-hydrobenzo[b][1,4]dioxocine Moieties and Their Biological Evaluation as Antitumor Agents
Authors: Yuan Ji-Wen , Qiu Han-Yue , Wang Peng-Fei , Makawana Jigar , Yang Yong-An , Zhang Fei , Yin Yong , Lin Jie , Wang Zhong-Chang , Zhu Hai-Liang
Published: June 2014

A series of caffeic acid amides D1-D17 bearing 2,3,4,5-tetrahydrobenzo-[b][1,4]dioxocine units has been synthesized and their biological activities evaluated for potential antiproliferative and EGFR inhibitory activity. Of all the compounds studied, compound D9 showed the most potent inhibitory activity (IC50 = 0.79 μM for HepG2 and IC50 = 0.36 μM for EGFR). The structures of compounds were confirmed by 1H-NMR, ESI-MS and elemental analysis. Among all, the structure of compound D9 ((E)-N-(4-ethoxyphenyl)-3-(2,3,4,5-tetrahydrobenzo[b][1,4]dioxocin-8-yl)acrylamide) was also determined by single-crystal X-ray diffraction analysis. Compound D9 was found to be a potential antitumor agent according to biological activity, molecular docking, apoptosis assay and inhibition of HepG2.
The Enigma of H. Costenoble – The Long Search for the Author of Die Chamoro Sprache
Authors: Salazar Marlies
Published: June 2014

Cette note retrace l’histoire des recherches visant à trouver la vraie identité de l’auteur d’une étude sur la langue Chamorro parue, en 1940, à la Haye et évoque les fausses pistes suivies par certains chercheurs. Il s’agit en fait de Hermann Costenoble, un linguiste amateur d’origine allemande qui vécut aux Carolines, au Guam et aux Philippines et qui mourut en 1942 à la suite de l’invasion des Philippines par les Japonais.
Quand un sultan d’Aceh devient turc à la suite du tsunami [Épigraphie islamique d’Aceh. 1]
Authors: Guillot Claude , Kalus Ludvik
Published: June 2014

The first note shows how tradition can supersede history. In Banda Aceh, an ancient sacred tombstone locally thought to be that of a Syrian or Turkish gunner was, after the tsunami, transformed by the Turkish Red Crescent into a large cemetery of “ Ottoman commanders and soldiers” supposed to have come to Sumatra to fight the Portuguese on the side of Aceh. Yet, the Arabic inscription still reads that the grave belongs to an Acehnese Sultan of the 16th century. The second one draws attention on two other sacred tombstones of the 16th century in Aceh which present the typical “ Chinese” style of the Islamic funeral art of Brunei.
Stèle funéraire d’Aristoménès de Stagire, exécuteur testamentaire d’Aristote (IG II² 10744 + IG II 3421)
Authors: Follet Simone
Published: June 2014

Deux fragments d’une stèle funéraire attique, IG II²10744 et IG II 3421 = EM 9217 + EM 9311, ont été rapprochés par D. Peppas Delmousou, qui a reconnu le nom d’Aristoménès de Stagire. Sont présentées ici une description et une photographie de la stèle, des remarques sur la gravure et la mise en page, la provenance et les éditions antérieures des deux fragments. Le défunt peut être identifié comme l’un des exécuteurs testamentaires nommés dans le testament d’Aristote cité par Diogène Laërce, V 12, ce qui permet de dater l’inscription de la fin du IVème siècle ou du début du IIIème, après 322 a. C. Cette épitaphe nous apprend qu’Aristoménès était citoyen de Stagire et qu’il est mort à Athènes.
Notes linguistiques et critiques sur le Livre IV des Coniques d’Apollonius de Pergè
Authors: Federspiel Michel
Published: June 2014

Follow-up of the former articles devoted to Books I, II, and III of the Conics, and published in this Revue. It can also be used to serve as a complement to the Dictionnaire historique de la terminologie géométrique des Grecs by Ch. Mugler. – As an appendix, there is a special study of the last three propositions of Book IV, and of the testimony of Apollonius about content and subdivisions of this Book.
Automne 1579: l’affaire Stubbs ou comment un pamphlet a privé la Reine d’Angleterre d’un mariage français
Authors: Daniel Marie-Céline
Published: June 2014

In 1579, John Stubbs wrote his «Gaping Gulf » , a pamphlet in which he denounced the likely union between Queen Elizabeth and the king of France’s brother. After a short trial, the author and the distributor of the text had their right hands cut off. The news spread instantly, in England as well as in continental Europe. This led to a textual war, in which famous characters like Sir Philip Sidney and Henry Howard, earl of Northampton, took part. Scholars from England and from the Continent exchanged letters which testified to their uneasiness in front of the improving relations between England and France. In many ways, the Stubbs affair is revealing. It shows how European Protestants kept an eye on the fate of England and of her queen. It is telling of the authorities’ growing mistrust for the printed text. It testifies to the potential yet increasingly oppositional strength of the English stationers.
‘In Adam’s Fall / We Sinned All’: Puritan Writing and American Interiority
Authors: Ludwig Sämi
Published: June 2014

The Puritan origins of Anglo-American culture have never been questioned, though they have later been overruled by more enlightened, modern views, culminating in the multicultural paradigm of the late 20th century. With the recent rise of the religious right and the crisis of the Iraq War, however, a renewed interest in American mainstream values justifies another look at the cultural work of the Pilgrims and the quality of their enduring influence. The Puritans left records of their experience that have greatly influenced historiography and offered ample material for myth-making. At the same time, they established the first institutions of higher education and thus laid the foundations of New England''s dominant role in the university landscape of the later United States. This raises some fundamental questions about the deterministic vs. liberating nature of Puritan “ writing.”
Destruction and Survival of the Written Word in Joseph Addison’s Periodical Prose
Authors: Junqua Amélie
Published: June 2014

Joseph Addison’s periodical essay is a provocative and fragile construction into which he often reflects the metamorphoses of the written word as paper written, printed and read, making the annihilation of printed paper a recurrent theme in his prose. If literate readers considered written or printed artefacts as familiar objects, why did Addison so often draw their attention to their annihilation ? Not only did Addison exorcize the inevitable fate that awaited his creation, he also highlighted the ease with which the written word was interpreted as a material, an ornament or a valuable receptacle. Yet such versatility is not just a compliment paid to his readers. It may also sound a sober warning, since commerce trivializes the written word into a commodity, to sometimes degrading extremes. Addison thus alludes to a telling anecdote gleaned from his own father’s prose where the danger of devaluation affects the divine written word.
The Art of Cursing : The Circulation of Shandean Fragments in Pamphlets and Prints (1815-1821)
Authors: Friant-Kessler Brigitte
Published: June 2014

The bookseller and pamphleteer William Hone was known for combining the art of parody and his taste for literary citations. This article discusses to what extent two distinctive fragments from Sterne’s Tristram Shandy (the curse of Ernulphus and Uncle Toby’s oath) contributed to cross-fertilising an ideological rationale and formed part of what Ben Wilson has named “ the laughter of triumph”. Furthermore, since theatricality pervades Hone’s works, it is argued that orality may be construed as an active feature of the dissemination of his parodies. When records of Hone’s 1817 trials for blasphemy, which circulated both in print and etchings, are examined, Cruikhshank’s visual renderings offer simul-taneously a contribution to making Hone’s line of defence public and evidence for a particular mode of spreading Sterne’s work.
Entre dogmatisme et scepticisme, la bonne parole selon John Lily : Euphues, the Anatomy of Wit (1578) et Euphues and his England (1580)
Authors: Couton Marie
Published: June 2014

Dans les deux récits en prose de John Lyly, la trame narrative est au service d’une rhétorique foisonnante et ostentatoire et cette éloquence des personnages est souvent jubilatoire ; mais elle soulève plus de questions qu’elle n’apporte de réponses. Si les paradoxes et les antithèses des figures donnent à voir le merveilleux insolite de la nouvelle culture de la curiosité, Lyly et ses personnages vivent dans la regio dissimilitudinis sans le secours des certitudes antérieures : l’auteur réécrit les analogies humanistes d’Érasme pour en donner une version sceptique. Il adopte la vision esthétique des grotesques et souligne les apories de la représentation de la réalité pour les peintres et les écrivains.
THE ROLE OF PH IN HEAVY METAL CONTAMINATION OF URBAN SOIL
Authors: KAZLAUSKAITĖ-JADZEVIČĖ Asta , VOLUNGEVIČIUS Jonas , GREGORAUSKIENĖ Virginija , MARCINKONIS Saulius
Published: June 2014

The aim of this study to assess interdependence between urban soil pH and its accumulation of heavy metals. The article meant to be a contribution to a better knowledge of peculiarities and diagnostics of urban soil and its anthropogenic transformation. The hypothesis assumes that relationship between urban soil pH and its accumulation of heavy metals may be determined by the origin and age of parent material as well as the nature and degree of the anthropogenic impact. The spatial variability of topsoil pH level was performed in 100 points in eldership of Šnipiškės of the city Vilnius. Laboratory analysis was based on ISO 10390:2005. Samples were collected from 20 cm topsoil layer in the same sampling points where have been analysed concentrations of topsoil chemical elements using optical atomic emission spectrophotometry. The contamination of urban soils exhibits somewhat different compared to agricultural soils. In contradiction to earlier studies in Lithuanian agricultural soils where strong correlation between soil pH and Cr, Cd, Pb, Ni, Cu and Zd found, the conducted analysis shows a statistically reliable, but very weak (<0.3) correlation between the soil pH and concentration of contaminants. The proof to this correlation is provided by an existing relationship between pH and the concentration of copper (r = 0.20), mercury (r = 0.15), strontium (r = –0.12) and the overall contamination index (r = 0.12). The applied statistical analysis, however, failed to reveal the nature of interdependence between the soil pH and its contamination with studied heavy metals there concentration of contaminant chemical elements depends on the pH range of the soil and, conversely, the chemical reactivity of the soil changes affect on the concentration of studied chemical elements.
Oral administration of Lactobacillus paracasei alleviates clinical symptoms of colitis induced by dextran sulphate sodium salt in BALB/c mice
Authors: Pan T. , Guo H.Y. , Zhang H. , Liu A.P. , Wang X.X. , Ren F.Z.
Published: June 2014

The aim of this study was to investigate the alleviating effect of Lactobacillus paracasei subsp. paracasei LC-01 (LC-01) on the murine model of colitis induced by dextran sulphate sodium (DSS). 50 pathogen-free, 6-week-old male BALB/c mice were divided randomly into 5 groups, including a control group and four DSS-LC-01-treated groups (DSS, DSS-106, DSS-108, and DSS-1010 with 0, 1×106, 1×108 and 1×1010 cfu/ml LC-01, respectively). To test the effectiveness of LC-01 as a prophylactic it was administered for 7 days before the onset of the disease in DSS-LC-01-treated mice. After 7 days, colitis was induced by administration of 2.5% (w/v) DSS in drinking water for a further 7 days. The disease activity index (DAI), histological score, myeloperoxidase (MPO) activity and the level of the pro-inflammatory cytokines interleukin-1β (IL-1β) and tumour necrosis factor α (TNF-α) were measured. DAI, histological scores and MPO activity of mice treated with a medium or high dose of LC-01 were significantly lower compared to a low-dose of LC-01 and DSS treatment alone (P<0.05). Colon length shortening could be prevented with increasing dose of LC-01. In addition, the levels of IL-1β and TNF-α were suppressed significantly by treatment with a medium and high dose of LC-01. However, no significant difference in the indices mentioned above were observed between a low dose of LC-01 and treatment with DSS alone (P≯0.05). An appropriate dose of LC-01 can prevent intestinal damage in mice with DSS-induced colitis. The expression of inflammatory cytokines related to pathogenesis of DSS-induced colitis decreased following treatment with LC-01.
Soil Parameters Required to Simulate the Dynamic Lateral Response of Model Piles in Stiff Clay
Authors: Brown Roger A. , Coyle Harry M.
Published: June 2014

Methods to obtain the soil parameters needed to simulate the dynamic response of a laterally loaded pile were developed in this research. Instrumented model piles of various diameters and embedded lengths were driven into stiff clay and tested laterally under free vibration conditions. Field data of bending moments and accelerations versus time were obtained.

The dynamic response of the model piles is predicted using an analytical solution. The nonlinear soil load-displacement characteristics are modeled with a modified Kelvin-Voight rheological model. The field data and the predicted response of the piles are compared and correlated. Using the correlation and laboratory triaxial tests on the soil, the soil parameters required to achieve satisfactory agreement between the field and predicted response of the pile are evaluated.

Results of this study indicate that the soil spring and soil quake are functions of the pile diameter. Together, these two soil parameters govern the magnitude and distribution of the bending moments with depth. The amount of soil damping is a function of the pile velocity or frequency of vibration, and is significant for the velocities and frequencies encountered in this study.

Introduction

Many types of offshore structures have recently evolved for many different purposes. The oil companies are perhaps the largest single industry intimately involved with offshore structures and their design. Drilling platforms are being located in deeper water as demands for oil are ever increasing. Storage structures for oil are being built below the ocean surface. Defense installations and weather retrieving devices are also constructed offshore. As structures are built farther offshore, the design complexities multiply as a result of the more severe sea conditions encountered.

Most offshore structures are supported by piles driven deep into the ocean bottom. In the design of these structures, frequently the lateral loads imposed by wind, waves, and ice are the critical design factors. These forces are repetitive, and are time-dependent. In some instances, such as a breaking wave, these forces could be considered impulsive. In the past, these dynamic effects have been given little consideration because of their complexities and the design engineer?s inability to cope with them. With the development of the high speed computer, it is now feasible to consider dynamic effects in design of offshore structures. Knowledge of the soil/pile interaction and water/ pile interaction is imperative if the dynamic response of the pile is to be accurately predicted. A review of the literature shows that much work has been done concerning the soil pile/ interaction under static lateral load conditions. However, very little work has been concerning the dynamic water/pile interaction.
Subsea Through Tubing Rotary Drilling
Authors: Garnier A. , Fraboulet B. , Andersen Stein Kristian , Bois A.-P.
Published: June 2014

The subsea Through Tubing Rotary Drilling (TTRD) is in principle a concept to construct new drainage points by utilising as much of the existing well path as possible, thus saving a significant amount of time and cost. A new fit for purpose system for subsea TTRD consisting of a small size (7") combined BOP/LRP solution, incorporating a surface BOP solution and a high pressure (HP) riser, will be delivered to Statoil in the 2.nd quarter of 2007.

This technology is applicable for all wells where the production from the "mother bore" has declined to a level where the option is to shut in the well and redrill to a new target. Furthermore, Statoil is currently funding the development of through-tubing multilateral systems, which will enable TTRD-sidetracks in producing wells and production from the two bores simultaneously. Traditionally a sidetrack has been done by pulling tubing and parts of the 9 5/8" (and possibly the 13 3/8") casing string(s), prior to a side track. By drilling the side track "through tubing" the cost will be significantly reduced.

The cost for a new well can be in the order of 40 - 50 million US $ when the subsea well slot is readily available, and even up to 70+ million US $ when a new well slot must be installed subsea. Utilising TTRD technology we envisage new drainage points to a cost in the order of 10 million US $. With a step change of this magnitude, the assets will be able to produce much more of the remaining oil from the reservoirs, hence increase the oil recovery.

Background

Statoil has to date performed 20 Through Tubing Drilling operations and all have achieved the technical goals. The two TTRD operations already performed on sub sea templates, through marine riser, were the world's first to be performed from floating mobile drilling units. The experience and know how obtained by these activitities has been systematically used in order to evaluate the potential for the TTRD technology in the future.

Statoil has identified "low cost drainage points" in sub sea fields as a major contributor to reach the ambition of 55% recovery from our sub sea fields on an average basis. From our platform fields we see that the recovery increases significantly with the number of drainage points constructed and well interventions performed. The same effect has not clearly been seen or realised in sub sea fields. Due to the high cost related to sub sea operations, Statoil has looked at novel and much more cost effective ways to construct the drainage points. One of these concepts is a new subsea Through Tubing Rotary Drilling (TTRD) concept. As can be seen from figure 1 the potential in TTRD operations subsea appears to be significant in terms of cost per drainage point.

Additional Drainage Point - Alternative TTRD

Figure 1 (available in paper): The TTRD potential

Note: The figure for a new well has risen substantially the last couple of years due to the extensively high rig rates.
Potential Failure Mechanisms in Floatover Deck Mating Systems
Authors: Byle Steven
Published: June 2014

A Deck Mating System is entrusted to facilitate the transfer a topsides facility by Floatover method from a free-floating transport vessel to a fixed or floating substructure. These critical systems have moving parts, complex dynamic properties, and structural design considerations that are little understood by most designers. Yet, these systems may be employed with inadequate engineering, design and analysis. They may be manufactured and assembled by multiple, generalized contractors, rather than by a single, specialized vendor. And they may have their function tested for the first time during the actual Floatover operation.

There are inherent risks in this type of operation, and failures have occurred. As a result, some clients have grown more cautious. They have tightened specifications, limited procurement to specialized vendors, and required comprehensive testing of a fully assembled unit. Fortunately, no failure has yet resulted in the total loss of a topsides.

However, as there has been no dramatic, publicized failure, many clients continue to cut corners on this critical area and test poorly designed, engineered, and manufactured system in the field.

Primarily, this paper seeks to assist a designer, purchaser, or end user of a Deck Mating System by pointing out critical design considerations and by providing a set of recommended practices. The paper first provides a brief overview of the components of a Deck Mating System and their functions. It then outlines the potential design hazards, from obvious, catastrophic failures to often hidden failures to meet performance requirements. Finally, a list of recommended practices is provided in the form of an example specification. This paper draws from experience through 18 floatover operations and a larger number of design developments and engineering studies.
Recommended Practice on Riser Interference
Authors: Rustad Anne Marthine , Kalleklev Arve Johan , Sødahl Nils
Published: June 2014

A new recommended practice on riser interference (DNV-RP-F203) will be issued in 2009. The objective of the recommended practice is twofold:to recommend a methodology for engineering analysis, providing a rational design criteria and guidance for assessment of riser interference, andto achieve and document the industry consensus.

Assessment of collision between adjacent risers becomes more important with increasing water depth. The space between risers is limited both at the topside onboard the vessel as well as the riser gateway and at the seabed. Riser interference comprises complex physical phenomena, not yet fully understood, and research is still ongoing. When several risers/umbilicals are needed in a limited space, clearance between risers and risers and mooring lines should be documented.

The overall focus has changed somewhat since the draft was released for industry hearing in 2005. The 2005 version covered only top tensioned riser systems in steady current. The updated version covers all dynamic riser system including dynamic umbilicals and the focus is to document properly that no collision occurs. The scope is first of all to propose a framework for feasible analysis strategy and practical design procedures with focus on how to assess whether the risers collide or not. This paper presents the methodology for analysis, and the criteria which are the basis for the recommended practice.

Introduction

A more accurate methodology for assessing riser interference has become increasingly important when oil and gas exploration moves to deeper water. The risk of interference between Top-Tensioned-Risers (TTRs) increases with increasing riser length.

The general design practice is that riser collisions are not allowed under normal or even extreme conditions. The recommended practice considers analysis procedures and design criteria for riser interference assessment. The overall objective of the document is to recommend a methodology for engineering analysis, and to provide rational design criteria and guidance for assessment of riser interference. Riser interference comprises of complex physical phenomena, not yet fully understood, and research is ongoing. The aim is to achieve and document the industry consensus as per today.

The scope of work is first of all to propose a framework for feasible analysis strategy and practical design procedures with focus on how to assess if the risers collide or not. Whenever the terminology " risers?? is used it generally also applies for umbilicals and flexible risers in addition to TTRs. In order to derive a complete framework for feasibility and practical design procedures, the following topics need to be considered:overall framework and design approach;safety philosophy;environmental conditions and loads;analysis strategies and hydrodynamic interaction models, andacceptance criteria and fundamental requirements.
Frigg Decommissioning Offshore Work
Authors: Vivet S.
Published: June 2014

The Frigg Field was a natural gas reservoir that extends across the border between the Norwegian and the British sectors of the North Sea Continental Shelf. The Frigg Field was developed in accordance with the provisions of one agreement, known as Frigg Treaty, signed by the governments of Norway. Development of the Frigg Field took place between 1973 and 1977 and consisted of five plarforms with export of the gas to the St Fergus gas terminal in Scotland through two 32?? pipelines and one intermediate riser/compression platform located midway of the export lines. Three of the platforms were located in the UK water, the two others in the Norwegian sector and the United Kingdom. Under the provisions of the Frigg Treaty, Elf Norge now Total E&P Norge was defined as the Operator of the Frigg Field while Total Oil Marine now Total E&P UK was defined as the Operator of the gas export system.

The Frigg cessation offshore operation lasted from 2004 to 2009 resulting in the removal of all the platform topsides, all the jackets, all the infield and interfield sealines within the 500 m zone around the Frigg complex, all the external steel from de concrete substructures that were allowed to be left in place.

In line with the Frigg treaty, TOTAL E&P Norge was in charge of removing of the platforms located on the Norwegian sector (DP2, TCP2) but as well as the platforms located on the UK sector (QP, TP1, CDP1) of the Frigg field. The intermediate riser/compression platform (MCP01) was added by Total E&P UK to the scope of the Frigg decommissioning to be performed by Total E&P Norge.

In total 87000 tons of steel were brought back onshore for disposal either at Stord (72000t) in Norway and at Lervick (15000t) in Shetland.
Integration of Numerical Well Testing and Deconvolution Algorithm for Analyzing Permanent Down-hole Gauge (PDG) Data
Authors: Li Xiaogang , Qiu Maojun , Zheng Shiyi
Published: June 2014

The reservoir system in the real world is a dynamic system which the reservoir properties is changed with time. Considering the data in which PDGs record, one of the most defining characteristics is the inherent combination of short-term transients and long-term trendy. These characters permit dual application of these data to infer short-term effects (e.g., skin effect) and longer-term effects such as pressure depletion or changes in reservoir mechanism. The current approach to analyze the PDG data includes two directions. PDG data are analyzed with the traditional well testing approach to get the changed reservoir properties with respect to the transient character. With respect to the longer-term changes, PDG data are especially useful for history matching in the reservoir simulation.

Our approach tries to use the dual character of the PDG data. The transient character is mainly expressed in the log-log plot which is always used in traditional well testing. The long-term character is expressed in the Cartesian plot which is always used in the history matching of reservoir simulation. The numerical welltesting is approach to achieve the two direction. But the numerical well testing can not be used for the multi-rate pressure in dynamic system. Our idea is to linearize the nonlinear system to linear system with deconvolution. The deconvolution makes mistake to get the constant rate system response when the reservoir parameter changes because it can only be applied for linear system. This phenomena is used to diagnostic the critical point where the reservoir parameter changes. The critical points series divide the nonlinear system into different linear periods, and the numerical well testing is conducted to do forward modeling in every parts.

Introduction

The traditional well testing approach can get the changed reservoir information from the separated BU. However, this information can not guide the long term reservoir information because the DD part of PDG data has not been analyzed. The numerical well testing approach can help to analyze the complex geological model. But, it still suffers from multi-rate and nonlinear data. Currently, the deconvolution approach is introduced. This approach can transfer the multi-rate pressure into unit-response of reservoir in the linear system. However, the reservoir system in the real world is a dynamic system in which the reservoir's properties changed with time. The PDG data recorded from nonlinear system can not analyzed with current approach because the theory of current approach is based on the linear system. There are two approaches to analyze the nonlinear system data. The first approach is to linearize the nonlinear system into separated linear system. The current approach can be applied in every linear part. The second approach is to build a nonlinear model for nonlinear system. This study considers the first approach because the nonlinear model is hard to build and is not easy to solve.
Minimum Bending Radius (MBR) Tests of Flexible Pipes: An Experimental Approach Via Optical Motion Capture and Image Processing
Authors: Tanaka Rafael Loureiro , Gonalves Rodolfo Trentin , Ferreira Teófilo Barbosa , Rosetti Guilherme Feitosa , Pesce Celso Pupo , Fujarra Andre Luis , Godinho Carlos
Published: June 2014

A new optical measurement approach for minimum bending radius (MBR) tests of flexible pipes is presented. The method is based on an accurate tracking of the elastica through image processing. The new approach shows to be not only appropriate to the standard measurement requirements but also enables a comprehensive understanding of the structural mechanisms embedded in the problem. Samples were made from two distinct flexible pipes, with inner diameters of 2.5 and 4 inches.

A progressive set of tests was performed using five types of samples, obtained by dissecting each flexible pipe up to a certain layer. Sample 1 is made up with the internal carcass only. Sample 2 is constructed up to the liner (the internal plastic sheath covering the carcass). Sample 3 is mounted up to the pressure armor. Sample 4 is manufactured up to the external tensile armor. Sample 5 is made from the entire pipe, up to the external polymeric sheath.

The experimental methodology is given in detail. The samples are bent through the pulling of a cable linked to the extremities. The traction is measured by a load cell. A special stereoscopic system is used to optically obtain the geometry of the elastic line of the bent sample. From the measured elastica, the curvature is calculated. Results of bending moment at any section may be also calculated from the elastic line. In particular, bending moment vs. curvature, measured at the vertex of the arch, are calculated for each sample.

Introduction

Flexible Pipes are increasingly used for the transport of oil & gas, due to their flexibility, reliability and high resistance to the several types of loads inherent to this type of application. These loads include high pressures, both internal and external, tensions and curvatures and the flexible pipe resistance to these different loads is obtained by a construction with many component layers, each one responsible for the resistance to a given load (See Figure 2 for the different layers, represented by the different samples used in the test).

Since they are slender structures, a significant amount of bending is induced during their operation and must be taken into account in its design. This paper describes an experimental methodology to relate bending moment and imposed curvature, which is specially suited for the validation of a design methodology, since its results allow the developer of such methodology to have insights into details of the mechanical behavior of the tested structure, on a layer-by-layer basis. The test was applied to obtain the maximum curvatures that different layers of two flexible pipes can reach without damage.
Impact Loads and Protection of Subsea Structures on the Seabed from Floating Iceberg Keels
Authors: Ralph Freeman , Soper Steve , Stuckey Paul , McNeil Andrew , Barrett John
Published: June 2014

In iceberg prone regions, subsea substructures placed on the seabed are atrisk of impacts from free-floating and scouring iceberg keels. Here themethodology for assessing iceberg loads and two mitigation strategies aredescribed. The iceberg load model was an extension of previous work forestimating iceberg impact loads on offshore surface-piercing structures. Components of the algorithms were modified such that global design loads fromkeel contacts account for the change in contact location (i.e., longer leverarm in the vertical direction resulting in greater rotation effects). Theiceberg eccentricity model and the relationship between contact area andpenetration distance were also modified to account for iceberg keel contactswith a generic low profile structure on the seabed. One concept considered wasa single wellhead structure fitted with a special weak shear link incorporatedinto the design at the expected scour level. The shear link, or failure joint, would act as a mechanical fuse designed to fail in a combination of shear, tension and buckling during keel loading. The failure joint minimizes downholestructural response during iceberg keel loading on the production tree. Thedesigned failure mechanism would allow the well to be re-entered by protectingthe well casing from damage. Another concept considered was a steel truncatedcone structure installed over the well installation and fixed to the seabed byone of several identified foundation concepts. The protection structure absorbsenergy through crushing of the ice keel and encourages the iceberg to deflectaround and over the structure. The steel structure would be designed accordingto ultimate limit states accounting for energy absorption through elastic andplastic deformation of the structure. Design loads would correspond to anAbnormal Level Ice Event (ALIE) with an annual exceedance probability of 10–4. The size of the frame is governed by the size of the wellhead and tree system, Remotely Operated Vehicle (ROV) access requirements, and slope to encourageiceberg keel deflection. Piles may be the best option for securing a protectionstructure to the seabed, especially if a local vessel can be sourced to performthe installation. As an alternative to piles, using a drill rig to install wellcasings may be an option; however, market conditions for drilling rigs maydictate economic feasibility.
Physical and Numerical Modeling of a Sub-Surface Caisson for Protection of Subsea Facilities against Scouring Icebergs
Authors: King Tony , Ralph Freeman , Barrett John , Zakeri Arash
Published: June 2014

A simple, rectangular sub-surface caisson was evaluated using physical andnumerical modeling to develop a method for protecting subsea installationsagainst scouring keels of icebergs on the Grand Banks. This protection strategywas developed to assess the feasibility of the structure as an alternative tocostly excavations used to protect subsea equipment on the Grand Backs. Thescenario considered was an ice keel (i.e., iceberg) scouring over a buriedcaisson, avoiding direct contact but with minimal clearance. A centrifugetesting program, consisting of five tests, formed the basis for calibration ofa finite element model. The first four centrifuge tests were carried out withwater as the pore fluid in order to simulate drained conditions during thekeel-soil-structure interaction. In the field, fully drained conditions may notexist; hence the fifth centrifuge test was conducted using a viscous pore fluidto simulate the partially drained conditions. The numerical analyses wereconducted using the commercially available finite element software packageABAQUS. This study demonstrated that the Coupled Eulerian Langrangian (CEL)technique is capable of modeling slow keel-soil-structure interaction events insand. The numerical model performed satisfactorily in simulating the centrifugetests. The results indicated that such a system can potentially provide theprotection needed for subsea installations in ice infested waters. Althoughthis work was based on the conditions encountered on the Grand Banks, theconcept would be applicable to other regions. Future work should involveevaluating various ice keel-soil-structure interaction scenarios and attackangles, development of Inspection, Repair and Maintenance (IRM) strategies aswell as a detailed assessment of construction and installation issues.