bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of speech nasality in children with Robin Sequence
Authors: Prado-Oliveira Rosana , Marques Ilza Lazarini , Souza Luiz de , Souza-Brosco Telma Vidoto de , Dutka Jeniffer de Cássia Rillo
Published: April 2015

PURPOSE: To report the outcomes of primary palatoplasty in Robin Sequence (RS); to verify the relationship between modalities of assessment of nasality; to compare nasality between techniques at palatoplasty. METHODS: This study involved the identification of hypernasality in four modalities: live assessment with 4-point scale; live assessment with cul-de-sac test; multiple listeners' ratings of recorded phrase; nasometric assessment. Live ratings of speech nasality and nasalance scores were retrieved from charts, while a recorded phrase was rated by listeners for occurrence of hypernasality. Agreement between the modalities was established as well as association between nasality, nasal turbulence and age at surgery and at assessment. Fisher's exact test was used to compare findings between surgical techniques. RESULTS: Agreement between nasalance, live assessment with 4-point scale, live assessment with cul-de-sac, and multiple listeners' ratings of recorded samples ranged between reasonable (0.32) and perfect (1.00). Percentage occurrence of hypernasality varied largely between assessment modalities. Mean occurrence of hypernasality was lower for the group submitted to Furlow technique (26%) than the group that received von Langenbeck technique (53%). Only findings obtained live were statistically significant (scale: p=0.012; cul-de-sac: p<0.001). Listeners identified nasal turbulence for 22 (32%) samples out of the 69 recordings, and an association was found between hypernasality and nasal turbulence. CONCLUSION: Lower occurrence of hypernasality was identified for patients with RS in Furlow group. Identification of hypernasality varied largely among the four assessment modalities.
Quality of life evaluation in children with cochlear implants
Authors: Almeida Renata Paula de , Matas Carla Gentile , Couto Maria Inês Vieira , Carvalho Ana Claudia Martinho de
Published: April 2015

PURPOSE: To evaluate the quality of life of children with cochlear implants from the perspective of their parents. METHODS: A clinical and cross-sectional study was conducted with 15 parents of children using cochlear implants of both genders aged between 2 and 12 years old. Parents of these children answered the questionnaire "Children with Cochlear Implants: Parental Perspective" (CCIPP). Data related to auditory category and time of cochlear implants use were collected from medical records of the children. The percentages of responses on the CCIPP domains were tabulated and descriptively and inferentially analyzed. RESULTS: The cochlear implants had a positive effect on the quality of life of children in the self-reliance (58.9%) and social relationships (56.7%) domains. No correlation was observed between the time of cochlear implants activation (months) and any of the CCIPP domains. However, children with 24 months or less of cochlear implant use presented higher percentages on the communication domain than those with more than 24 months of cochlear implants use. A negative correlation was observed between the auditory category and the effects of the implant domain. CONCLUSION: From the perspective of parents, the use of cochlear implants improves the quality of life of their children; the shorter the time of cochlear implants use, the higher the improvement in quality of life; and the more developed the auditory skills, the lower the percentage of quality of life improvement with the cochlear implants.
Acoustic characteristics of the metallic voice quality
Authors: Fadel Congeta Bruniere Xavier , Dassie-Leite Ana Paula , Santos Rosane Sampaio , Rosa Marcelo de Oliveira , Marques Jair Mendes
Published: April 2015

PURPOSE: To characterize the fundamental frequency and the frequency of the formants F1, F2, F3, and F4 from vocal emissions of amateur singers with metallic voice quality. METHODS: There were 60 amateur female singers aged between 18 and 60 years old; 30 women with metallic voice quality forming the study group (SG) and 30 women without such a vocal quality forming control group (CG). The sample was selected through voice screening confirmed by reviewers after reaching a consensus. Regarding data collection, sustained vowel emissions in usual tone and at two predetermined frequencies, by which the values of F0 and frequency of the formants F1, F2, F3, and F4 were obtained, were recorded and analyzed. RESULTS: Comparing the emissions in usual tone, no difference for F0 was found, but the values of the formants F2, F3, and F4 were higher in the SG. In the preestablished tones, there was a difference between the two groups in the formants F3 and F4 for both tones. CONCLUSION: It is possible to characterize metallic voice quality as a normal fundamental frequency, with increasing frequency of the F2 formant, and values of frequencies of formants F2, F3, and F4 higher when compared to the CG.
Study of the long-term effects of frequency compression by behavioral verbal tests in adults
Authors: Marchesin Vanessa Clarizia , Iório Maria Cecília Martinelli
Published: April 2015

PURPOSE: To verify the effect of long-term use of hearing aids with frequency compression for verbal behavior tests and daily activities. METHODS: Thirty-two adults, aged between 30 and 60 years old, with moderate to severe sensorineural hearing loss at high frequencies with steeply sloping configuration were divided into two groups: 16 with hearing aids with frequency compression algorithm enabled and 16 not enabled. All participants underwent the detection tests of consonant sounds, monosyllable recognition in quiet environments, identification of fricative monosyllables, and Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire in five times throughout a 12-month trial. RESULTS: Detection of consonant sounds, recognition of monosyllables in quiet environments and identification of fricative monosyllables improved significantly with frequency compression enabled. Participants had their APHAB scores improved whether they were adapted to the frequency compression or not. CONCLUSION: Frequency compression provides the anticipated improvement in audibility, detection of high-frequency consonant sounds, and recognition of monosyllables.
Teorizar em "português brasileiro"? (Monolinguismo, tradução, ex-apropriação)
Authors: Araújo Nabil
Published: April 2015

Esforçando-se por pensar um modo próprio de teorização lusófona no Brasil que escape tanto da importação/tradução aculturadora de textos teóricos estrangeiros que caracteriza em larga medida a vida intelectual e acadêmica do país quanto da teorização nacionalizante baseada numa "subtração" de tudo que seria estrangeiro, mas também da falsa solução a essa dicotomia representada pelo influente discurso da "Antropofagia", este ensaio delineia, com base em Derrida, a perspectiva da tradução ex-apropriadora em português brasileiro como prática discursiva contra-hegemônica.
A estranha instituição da literatura no multiverso dos espectros
Authors: Pinto Neto Moysés
Published: April 2015

O texto busca delinear os contornos gerais da espectrologia (hantologie) a partir das ideias de "economia geral" (Bataille) e da repercussão da psicanálise freudiana enquanto modelo do real inconsistente para Jacques Derrida. Sustenta, portanto, que o domínio dos fantasmas não pertence à ordem da representação, mas ao real enquanto tal com seus próprios direitos. Finalmente, aproxima a literatura do domínio dos fantasmas, apresentando a ficção como uma intervenção que cria o impossível.
Estéticas do animal-estar
Authors: Kempinska Olga
Published: April 2015

Este ensaio é uma leitura do texto de Derrida O animal que logo sou (A seguir) e uma reflexão sobre os possíveis usos da expressão animal-estar para a descrição dos desafios contemporâneos da estética. Assim, ao investigar o desconforto subjetivo envolvido no gesto de ultrapassar a fronteira entre homem e animal, e de desterritorializar o pensamento, o estudo se debruça sobre os efeitos da anulação da distância estética e sobre a exacerbação do componente "sensível" da expressão geral "experiência sensível". Resultado da falha da domesticação da percepção, relacionado também à atualização das emoções e das reações do corpo, o animal-estar do leitor possibilita uma subversão da reflexividade especular redutora.
A expressão da criatividade na aprendizagem da leitura e da escrita: um estudo de caso
Authors: Muniz Luciana Soares , Martínez Albertina Mitjáns
Published: April 2015

O presente artigo tem por objetivo destacar as formas em que a criatividade se expressa na aprendizagem da leitura e da escrita da criança. Assume-se como referencial teórico a concepção de aprendizagem criativa desenvolvida por Mitjáns Martínez. Segundo essa concepção, os processos criativos emergem nos contextos de ação do sujeito, mediante recursos subjetivos constituídos historicamente e que se organizam no momento da ação concreta. A expressão desse tipo de aprendizagem tem se configurado pela personalização da informação, confrontação com o dado e pela geração, produção de ideias novas que vão além do que está posto. Adota-se como eixo norteador a pesquisa qualitativa, apoiada nos princípios da epistemologia qualitativa desenvolvida por González Rey, com opção pelo estudo de caso utilizando instrumentos abertos e semiabertos, tais como: dinâmicas conversacionais, observações, entrevistas como processo e diário de ideias. A investigação foi desenvolvida em uma escola da rede pública, com alunos dos primeiros e segundos anos do ensino fundamental, na qual acompanhamos os aprendizes por dois anos consecutivos. Como conclusão, considera-se que a expressão da criatividade na aprendizagem da leitura e da escrita foi significativamente apresentada pelas características destacadas por Mitjáns Martínez, bem como pela relação lúdica da criança com sua aprendizagem.
Radon and Thoron Exhalation Rates from Surface Soil of Bangka - Belitung Islands, Indonesia
Authors: Syarbaini Syarbaini , Pudjadi E.
Published: April 2015

DOI:10.17014/ijog.2.1.35-42Radon and thoron exhalation rate from soil is one of the most important factors that can influence the radioactivity level in the environment. Radon and thoron gases are produced by the decay of the radioactive elements those are radium and thorium in the soil, where its concentration depends on the soil conditions and the local geological background. In this paper, the results of radon and thoron exhalation rate measurements from surface soil of Bangka Belitung Islands at thirty six measurement sites are presented. Exhalation rates of radon and thoron were measured by using an accumulation chamber equipped with a solid-state alpha particle detector. Furthermore, the correlations between radon and thoron exhalation rates with their parent nuclide (226Ra and 232Th) concentrations in collected soil samples from the same locations were also evaluated. The result of the measurement shows that mostly the distribution of radon and thoron is similar to 226Ra and 232Th, eventhough it was not a good correlation between radon and thoron exhalation rate with their parent activity concentrations (226Ra and 232Th) due to the environmental factors that can influence the radon and thoron mobilities in the soil. In comparison to a world average, Bangka Belitung Islands have the 222Rn and 220Rn exhalation rates higher than the world average value for the regions with normal background radiation.
Liquidity windfalls: the consequences of repo rehypothecation
Authors: Infante Sebastian
Published: April 2015

This paper presents a model of repo rehypothecation in which dealers intermediate funds and collateral between cash lenders (e.g., money market funds) and prime brokerage clients (e.g., hedge funds). Dealers take advantage of their position as intermediaries, setting different repo terms with each counterparty. In particular, the difference in haircuts represents a positive cash balance for the dealer that can be an important source of liquidity. The model shows that dealers with higher default risk are more exposed to runs by collateral providers than to runs by cash lenders, who are completely insulated from a dealer's default. In addition, collateral providers' repo terms are sensitive to changes in a dealer's default probability and its correlation with the collateral's outcome, whereas cash lenders' repo terms are unaffected by these changes. This paper rationalizes the difference in haircuts observed in bilateral and tri-party repo markets, reconciles the partial evidence of the run on repo during the recent financial crisis, and presents new empirical evidence to support the model's main prediction on haircut sensitivities.
OPPORTUNITY COST ARE A KEY TO CASH PUZZLE OF THE COMPANY
Authors: Lutsenko S. I.
Published: April 2015

Features of influence of opportunity cost on the cash policy of the Russian companies are considered. The author analyzes relationship of cause and effect of escalating of cash. The author researched features of a choice the Russian companies of sources of financing. The author shows that availability of opportunity costs forces the companies to be reoriented on internal sources of financing. Opportunity costs are the indicator for a choice of optimum financing. The model (specification) presented in work is tested for determination of its adequacy, from the point of view of quality of forecasting. It is estimated three kinds of specifications: pooled regression, regression with a random effect and regression with the fixed effect. The purpose of work attempt to open cash puzzle of company disclosing of a puzzle. That is, to reduce opportunity costs for preserving of cash as the preventive motive, allowing to struggle with financial restrictions. Novelty of the presented work consists that the companies can rationally manage cash holdings, using negative shocks (signals) in the capital market, to expect them and without supposing the situations connected with financial restrictions.
Plant traits related to nitrogen uptake influence plant‐microbe competition
Authors: Moreau Delphine , Pivato Barbara , Bru David , Busset Hugues , Deau Florence , Faivre Céline , Matejicek Annick , Strbik Florence , Philippot Laurent , Mougel Christophe
Published: April 2015

Plant species are important drivers of soil microbial communities. However, how plant functional traits are shaping these communities has received less attention though linking plant and microbial traits is crucial for better understanding plant‐microbe interactions. Our objective was to determine how plant–microbe interactions were affected by plant traits. Specifically we analyzed how interactions between plant species and microbes involved in nitrogen cycling were affected by plant traits related to nitrogen nutrition in interaction with soil nitrogen availability. Eleven plant species, selected along an oligotrophic–nitrophilic gradient, were grown individually in a nitrogen‐poor soil with two levels of nitrate availability. Plant traits for both carbon and nitrogen nutrition were measured and the genetic structure and abundance of rhizosphere microbial communities, in particular the ammonia oxidizer and nitrate reducer guilds, were analyzed. The structure of the bacterial community in the rhizosphere differed significantly between plant species and these differences depended on nitrogen availability. The results suggest that the rate of nitrogen uptake per unit of root biomass and per day is a key plant trait, explaining why the effect of nitrogen availability on the structure of the bacterial community depends on the plant species. We also showed that the abundance of nitrate reducing bacteria always decreased with increasing nitrogen uptake per unit of root biomass per day, indicating that there was competition for nitrate between plants and nitrate reducing bacteria. This study demonstrates that nitrate‐reducing microorganisms may be adversely affected by plants with a high nitrogen uptake rate. Our work puts forward the role of traits related to nitrogen in plant–microbe interactions, whereas carbon is commonly considered as the main driver. It also suggests that plant traits related to ecophysiological processes, such as nitrogen uptake rates, are more relevant for understanding plant–microbe interactions than composite traits, such as nitrophily, which are related to a number of ecophysiological processes.
Doula, Sister, Aunt, Storyteller: A Midwife’s Retelling of Birth
Authors: Niles Mimi
Published: April 2015

As a midwife, delivering hundreds of babies a year in a busy city hospital, I rarely have the opportunity to reconnect with what made me pursue the path of midwifery. This is the story of the birth of my niece.
The Development and Implementation of a Prenatal Education Program for Expectant Parents of Multiples
Authors: Kuhnly Joan Esper , Juliano Marion , McLarney Patricia Swider
Published: April 2015

Preparing expectant parents of multiples required a unique prenatal education program. A thorough explanation of the course layout, curriculum, and content the faculty developed for this unique 9-hour program is presented. The unique implications for parenting multiples was highlighted throughout the program, which included expectations for late pregnancy, preparation for labor and birth, assuring infant safety, learning how to provide infant care, identifying sources of support, breastfeeding information and support, potential for neonatal intensive care, postpartum depression, and providing a multiple parent’s personal perspective. All classes were interactive and used active learner-based teaching strategies.
Cementing Operation in Underbalanced Casing Drilling: A Successful Case History in an Unconventional Shale Reservoir in Argentina
Authors: Medina Jonatan , Krasuk Raul
Published: April 2015

In the Unconventional Loma Campana Oil Field, located in Neuquen, Argentina, the primary target is the Vaca Muerta shale, and the secondary target is the Quintuco carbonate. Both formations are naturally fractured and present high formation pressures and a narrow mud weight operating window. Those conditions generate operational issues (influx or fluid losses) and are the primary reason for the use of the Under Balanced Drilling (UBD) technology through problematic zones.

When using conventional BHA for UBD operations, after reaching TD, it is necessary to kill the well, by increasing mud weight, in order to pull out of hole and run the casing. This heavier mud exerts high ECD during the cement job causing partial or total loses of returns. In other cases, when the formation pressures are too high to be controlled with the mud weight, it is necessary to unload the well until reservoir pressure decreases to the manageable level. This operation has high impact on both time and cost of the well.

By the use of the casing drilling technology and with the knowledge of the operating window it is possible to perform managed pressure cementing (MPC). This is done by exerting back pressure needed to adjust the ECD within the operating window detected in the region of interest for each stage of the operation. With this technique there is no need to kill the well. The main goal, to reach the desired height of cement, is achieved by minimizing fluid losses and controlling influxes.

This paper contains information that will help develop cementing fluid design, pump schedule, and required back pressure in each stage of cementing job.
MPD Operation Solved Drilling Challenges in Sour HPHT Asphalt Formation in Y filed
Authors: Huawei Zhang , Zaifu Huang , Xinjin Chen , Xiaowang Pang , Xiangyang Zhao
Published: April 2015

In Y Field, three wells were temporarily abandoned, which were based on conventional technology while drilling through this sour active HPHT asphalt formation (Kazh). MPD Operation & technology were introduced and finally solved the problem and successfully delivered the said three wells in time.

Conventional MPD was focusing on Constant bottom-hole pressure (CBHP), which is widely used in narrow operation window while drilling. During drilling those three wells, different concept were set to control asphalt invasion and hole stability, which was referred as “dynamic bottom hole pressure difference while drilling” by means of MPD operations.

The paper addressed feasibility studies to adopt MPD in active asphalt formation in Y Field prior to the real operation; “fit-for purpose” MPD operation design & operations while drilling through the first well in Y field; MPD equipment and parameters modifications after acquired experience from the first well; associated necessary knowledge and technologies to successfully drilled through abovementioned asphalt formation, Running Casing, Cement the same were also mentioned inside the paper. In order to completely introduce this different utilization in Y Filed, another case of drilling through formation Kazh (Asphalt formation in Y Field) with MPD under mud cap when hole is in total loss, is also introduced in this paper.

In conclusion, the paper indicated that knowing the character of Kazh formation stood the first position before introduce any new technology. While distribution of asphalt was not clear, a dedicated size of casing to seal off other formations in the original same open hole (e.g.: well F21) is still the option. If none of the above can be obtained, to analyze/investigate invasion speed of asphalt under different assumptions & conditions, utilizing MPD with controlled flow rate to selected asphalt shall be one of the best options, meanwhile, drilling fluid & tools should also be updated to adapt to this option. In case of failure of controlled flowing rate efforts, drilling asphalt with MPD and Mud Cup in order to quickly drill through will be the last solution to asphalt formation in Y field.
Physical Concept Validation Testing Performed for a Pore and Fracture Pressure Margin Prediction System During Offshore MPD Operations
Authors: Piccolo B. , Leuchtenberg C.
Published: April 2015

A pressure determination system (PDS) was field tested to progress Managed Pressure Drilling (MPD) from a reactive system to one that prevents well control events from initiating. Physical testing performed on an offshore drilling operation successfully demonstrated the capability of the PDS to detect a simulated, unsafe change in fracture margin without incurring significant losses in August 2014. The test methods and results will be discussed in detail this report.

The PDS is designed to oscillate the position size of a dedicated pressure control valve (PCV) in a repeatable and gradual fashion and analyze the resultant behavior of Applied Surface Back Pressure (ASBP), Bottom Hole Pressure (BHP), and Flow Out indicators over time. In the event that average BHP begins to near a margin, the behavior of the above indicators at the crest or trough of a wave cycle will momentarily deform indicating a pending well control event. Since, average BHP has continuously remained within drilling margins during this process, any resultant gain or loss is negligible. Once the threat of a well control event is detected, a dedicated MPD PCV will adjust average wellbore pressure to a safer value to prevent the occurrence of a well control event.

During field testing, the PDS concept was verified with two assessments, signal transmission reliability and simulated fracture detection. The signal transmission reliability test validated that the PDS can oscillate PCV position in a controlled and consistent fashion as well as create highly repeatable behaviors in ASBP, BHP, and flow rate waves over time. The simulated fracture margin test demonstrated that the PDS has the sensitivity to detect a fracture margin at 20 psi above the driller's intended wellbore pressure with a negligible volume of losses while the PDS PCV oscillated wellbore pressure as described above.

Both tests were performed in an open hole section of a medium depth well with a rotating and reciprocating drill string.

Prior to field testing, a SIT (System Integrity Test) was performed on the PDS equipment installed on MPO's MPD Pressure Control Manifold (PCM) to ensure the system was prepared for concept testing. The SIT was performed with the MPD PCM isolated from well bore riser returns in August 2014.

The field tests described above were previously performed as an initial test, at the MPO Dubai Training Center Flow Loop where the PDS concept was also successfully validated in a laboratory environment. During those tests, the sensitivity of the PDS system was also demonstrated by validating that a 4 inch Coriolis Coriolis meter in a small, closed loop system was able to detect less than a 1 gallon difference in flow.
Early Detection and Localization of Downhole Incidents in Managed Pressure Drilling
Authors: Willersrud Anders , Imsland Lars , Blanke Mogens , Pavlov Alexey
Published: April 2015

Downhole incidents such as kick, lost circulation, pack-off, and hole cleaning issues are important contributors to downtime in drilling. In managed pressure drilling (MPD), operations margins are typically narrow, implying a risk of more frequent incidents and more severe consequences than during conventional drilling. Detection and handling of symptoms of downhole drilling contingencies at an early stage are therefore crucial for the reliability and safety of MPD operations.

This paper describes a method for early detection and localization of incidents, based on a fit-for-purpose model of the downhole pressure hydraulics, distributed pressure measurements from wired pipe, and statistical change detection methods. Using statistical change detection methods, it is possible to detect the incidents and their location at a very early stage when small changes in process data are covered in measurement noise, which may be very hard to observe for a human operator.

The method has successfully been tested on experimental data from a medium-scale horizontal flow loop in Stavanger, Norway. The flow loop represents a 700 m borehole with emulation of the following downhole contingencies: drillstring washout, drill bit nozzle plugging, gas influx and fluid loss. In the tests, these incidents were successfully detected at an early stage. The developed detection and localization method could be included as a diagnosis tool in a drilling system with MPD or conventional drilling.
Offshore Implementation Factors for Managed Pressure Drilling
Authors: Patel Harish , Bruton Jay
Published: April 2015

Managed pressure drilling (MPD) has been used for more than a decade onshore to drill an increasing number of challenging wells. However, the offshore drilling industry has only recently begun to adopt this innovative drilling technique. This paper will address some of the reasons delaying the application of this proven drilling method to drill offshore. It will describe offshore implementation and risk factors to consider for MPD.

MPD methods deliver advantages in drilling operations and risk reduction compared to conventional drilling methods. Benefits such as drilling previously unreachable targets, better kick control, smaller kick size and increased safety have led offshore operators to deploy MPD for offshore wells. For this reason, MPD technology is moving offshore from land-based application, where operational practices and environmental conditions are different. Applying MPD offshore requires consideration of additional design, operational, maintenance and safety issues. This paper will discuss some of these high-level issues and mitigations based on ABS experience gained working on various MPD projects for high-specification offshore floating rigs. Issues are identified based on offshore drilling practices, rig configuration, integration, offshore environments, limited space, training and regulatory requirements.

Based on various project experiences, ABS determined that additional improvements are needed to most effectively operate MPD systems offshore. This paper summarizes major concerns to be addressed and provides necessary mitigation measures. Heightened awareness of drilling conditions during MPD will often eliminate unscheduled events, or lessen their duration, and help minimize drilling risk. The result is reduced time on location, a safer drilling operation and lower total well costs.
Field Trial of Well Control Solutions with a Dual Gradient Drilling System
Authors: Cohen John H. , Stave Roger , Hauge Espen , Molde Dag Ove
Published: April 2015

Well control has been a major obstacle for introducing dual gradient systems for deep water drilling, involving both new and more complex procedures and equipment. Here test results using a new dual gradient drilling (DGD) system to control simulated well control events are presented. After successfully drilling a Statoil well with Enhanced Drilling's dual gradient solution (EC-Drill) at the Troll (Kjøsnes et al. 2014) field on the Norwegian continental shelf, the well was plugged and made ready for 48 hours of controlled testing. Several tests were run, each designed to determine the functionality of the system; to detect and handle liquid loss, gas and liquid influx, gas migration in the riser, and circulation of gas through the subsea pump module. The detection tests were carried out with a reduced riser level and an open annular, to quantify the capability of the system to detect volume imbalances while drilling. Three circulation tests with increasing amount of gas injected through the drillstring were performed. After the influx was detected, the annular was closed, and the flow was routed from the well through a bypass line to the subsea pump module. A topside choke in the mud return line was actively used to apply backpressure with the objective to control bottom-hole pressure, while circulating the gas from the well. In the last test gas was allowed to migrate into the marine drilling riser with a reduced riser level and open annular.

The paper will present the planning and preparations as well as the results.
Retrofitting Conventional Drilling Rigs With MPD: A Profitable Challenge Between Available Technologies
Authors: Carini Nicola , Allara Paolo
Published: April 2015

The integration of an MPD system during a new drilling floater design phase is today a common practice. While working on a brand new project, different MPD technologies could be evaluated choosing the one that suit best next well campaign properties of each drilling contractor. At the design phase, technically speaking, almost everything can be arranged and integrated. Now, given the high appeal that MPD systems are reaching today within Oil Companies, and considering the best possible delivery time for a new floater, are we sure we will be granted all this time to wait? The idea of limiting MPD chances to new builds seems not to be wise, thus, the profitability of retrofitting this new philosophy on an existing drilling rig should be properly evaluated. Developing this assessment, it is easy to notice how the implementation of an MPD set up on a conventional drilling plant impose the designer a different approach. Limitations in space on decks, integration between new and existing equipment and need for crew training are just some of the criticalities the drilling contractor will face choosing the best solution for them within the increasing number of potential providers. Let's say “constrains” will drive the choice.

The two major technologies available in the MPD market - and relevant set up - have been analysed on a “retrofitting point of view”, highlighting benefits and deficiencies of each in a critical trade-off between drilling development and operative constrains.
Managed Pressure Drilling System Provided Value to Offshore Drilling Operation
Authors: Onifade James , Patel Bhavin , Ertas Engin , Sammat Essam , Sahin Benhur
Published: April 2015

The pore and fracture pressure provides the boundaries during drilling operation. Nominal disparities between pore pressure and fracture pressure gradients cause the drilling window to be narrow, hence the term, “narrow margin wells.” Using conventional drilling methods, the drilling of narrow margin wells can be very challenging, hence the industry has begun exploring various methods of drilling through the narrow windows in a safe and effective manner. Managed Pressure Drilling MPD has evolved as a drilling method, which if properly engineered and implemented, could enable drilling through narrow margins in a safe and effective manner with significant reduction in drilling problems.

MPD utilizes the application of Surface Back Pressure (SBP) in order to manipulate the bottomhole pressure (BHP) within the confines of the pore and fracture pressure and enables precise navigation while drilling through the narrow margins. According to Fredericks et al, the effective control provided by MPD allows a more precise and better management of the annular pressure profile, allows accurate management of bottomhole pressure while drilling, during connections and even during well control operations.

The Weatherford MPD system was installed on an offshore Jack-Up rig to fulfill various requirements of the drilling operation. With the proven capability of the MPD system to “walk the line” between the pore and fracture pressure limits, the MPD system provided immense value to the entire drilling operation and enabled the operator to drill to the target depth.

This paper will detail a case study of this MPD operation and also describe significant values provided by the MPD system to the overall drilling objective. The MPD system enabled early kick and loss detection, ability to maintain constant bottomhole pressure during drilling and during pumps - off events and ability to utilize the Annular Pressure Control mode (APC) to automatically displace heavy mud cap at specific depths in order to maintain the static overbalance when the drill string is out of hole. The MPD system was incorporated into the existing rig system with minimal disruptions to rig operations and equipment. Drilling process safety and operational efficiencies were greatly improved with the adoption of MPD.
Water compliance challenges: how do Canadian small water systems respond?
Authors: Kot Megan , Gagnon Graham A. , Castleden Heather
Published: April 2015

Fundamental to community health and well-being is the capacity to access a sustainable supply of safe drinking water. Small community drinking water systems are the most vulnerable to contamination, and struggle to secure the funds necessary to improve water treatment and delivery systems, and meet increasingly stringent drinking water quality regulations. Little is known of the contextual and cultural differences between communities and the impact this has on regulatory compliance. This study explored the experiences and impact of individual actors within seven small community drinking water systems in locations across Canada. Qualitative, in-person interviews were conducted with water operators, consumers, and decision-makers in each community, and these findings were analysed thematically. Findings from the study show that communities approach and align with compliance challenges in three distinct ways: by adopting regulator-provided or regulator-driven solutions, by adopting an existing improvement framework (i.e. regionalization), or through reinvention to address a new issue or concern. Policy-makers looking to align small communities with appropriate water quality goals may benefit from a consideration of these contextual and cultural differences.
Membrane process for spring water treatment in the Tula Valley: assessment of physicochemical and microbiological parameters in a non-conventional water source
Authors: Chávez Alma , Torner Francisco J. , Barrios Jose A. , Maya Catalina , Lucario Emilia , Navarro Inés , Jiménez Blanca
Published: April 2015

A nanofiltration (NF) membrane pilot plant was tested to treat water from a spring located in the Tula Valley. Conventional physicochemical parameters and the pathogenic content were analyzed at the inlet and outlet (permeate) of the process. Ninety-five per cent removal of heterotrophic bacteria was obtained by the membrane and complete removal of all other pathogens was achieved. The membrane process performed better than the municipal chlorination facility. The NF process also removed most of the organic matter and removal of emerging pollutants varied from 5 to 100%, depending on the compound. A softening process prevented the membrane system from clogging, and continuous operation was carried out for more than 1 month with minimal maintenance.
Confirmation of the correlation between membrane fouling in microfiltration and biopolymer concentrations in various Japanese surface waters
Authors: Kimura K. , Tanaka K. , Watanabe Y.
Published: April 2015

A variety of surface waters used for drinking water sources were collected from different parts of Japan to investigate a correlation between the concentration of hydrophilic biopolymer (e.g. proteins and polysaccharides) in the feed water and membrane fouling in microfiltration. Hollow-fiber membranes made from polyvinylidene fluoride with a nominal pore size of 0.1 μm were used in the series of experiments involving the constant-flow mode of operation with automatic periodical backwashing. Easily available indexes of water quality, such as dissolved organic carbon, UV absorbance, Ca concentration and turbidity could not explain the degree of fouling encountered in the filtration tests. In contrast, a clear correlation between the concentrations of biopolymers determined by liquid chromatography with organic carbon detection (LC-OCD) and membrane fouling was confirmed in this study. The concentrations of humics exhibited a weak correlation. The impacts of seasonal variation of feed water and coagulant dosage on membrane fouling were also explained well by biopolymer concentrations. Concentrations of biopolymers can be a useful indicator of the fouling potential of feed water in microfiltration.
Nutrient removal in reverse osmosis concentrates using a biological aerated filter
Authors: Choi H. J.
Published: April 2015

The aim of this study is to employ a biological aerated filter (BAF) in the treatment of reverse osmosis (RO) concentrate received from reuse of treatment plant wastewater. Furthermore, the influence of chemical oxygen demand (COD)/N ratio on the nutrient removal was analyzed to find the detailed removal pathways of nutrients. The result was found to be high efficiency for biochemical oxygen demand removal (95.86%) compared to that of COD (88.95%) and suspended solids (81.12%). The total phosphorus (TP) (67.66%) and PO4-P (61.42%) removal efficiencies were relatively lower than that of total nitrogen (TN) (81.42%) and NO3-N (76.70%). This may be due to the fact that the biochemical oxygen demand (BOD)/TP ratio (8.01) was relatively low. Decreasing the COD/N ratio decreased TP and PO4-P removal efficiency. However, the removal efficiency of TN and NH4-N was increased from 47.60 to 64.54 and 54.17 to 73.72% with decreasing of COD/N ratio from 8.19 to 7.64, respectively. In addition, the denitrification rate and nitrification rate were increased from 211.8 to 301.0 mg/L d and 87.7 to 109.4 mg/L d, respectively, when COD/N ratios changed from 8.19 to 7.64. Therefore, in order to reuse the RO concentrate, the BAF process could effectively treat the RO concentrate.
Reclaimed water for the Tarragona petrochemical park
Authors: Sanz J. , Suescun J. , Molist J. , Rubio F. , Mujeriego R. , Salgado B.
Published: April 2015

The Camp de Tarragona Water Reuse Project is an emblematic example of how regional water scarcity can be overcome by considering reclaimed secondary effluent, which would otherwise be disposed of in the Mediterranean Sea, as an essential component of integrated water resources management. An advanced water reclamation plant (AWRP) was completed in 2011 to reclaim municipal secondary effluent from Tarragona and Vilaseca-Salou wastewater treatment plants. The reclaimed effluent is used for cooling and process water at the nearby Tarragona petrochemical park. The AWRP's current (2014) capacity is 19,000 m3/d (Phase I), and further expansions are planned to produce 29,000 m3/d (Phase II) and 55,000 m3/d (Phase III) in coming years. This locally available additional water supply will replace surface water supplies currently transferred from the Ebro River for use at the petrochemical park; as a result, an equivalent volume of surface water will be available for urban water supply in the coastal areas of Tarragona province. By developing this new and locally available water supply source, industrial growth in a water scarce region has been supported, while promoting local industry's sustainability. This industrial water reuse project provided 0.20 hm3 of water from September to December 2012, its first operational year, and 1.37 hm3 in 2013. The paper presents and discusses the planning, design, construction and operation phases of this water reclamation and reuse project, including start-up and commissioning, facilities preservation protocols from construction completion to servicing start-up, and the operational, management and economic arrangements adopted to provide a reliable source of reclaimed water for cooling water systems and demineralized water for boiler feed at the Tarragona petrochemical park and a nearby cogeneration power plant.
A history of water distribution systems and their optimisation
Authors: Mala-Jetmarova Helena , Barton Andrew , Bagirov Adil
Published: April 2015

Water distribution systems have a very long and rich history dating back to the third millennium B.C. Advances in water supply and distribution were followed in parallel by discoveries and inventions in other related fields. Therefore, it is the aim of this paper to review both the history of water distribution systems and those related fields in order to present a coherent summary of the complex multi-stranded discipline of water engineering. Related fields reviewed in this paper include devices for raising water and water pumps, water quality and water treatment, hydraulics, network analysis, and optimisation of water distribution systems. The review is brief and concise and allows the reader to quickly gain an understanding of the history and advancements of water distribution systems and analysis. Furthermore, the paper gives details of other existing publications where more information can be found.
Assessment of water quality in Little Vermillion River watershed using principal component and nearest neighbor analyses
Authors: Li Shiyang , Bhattarai Rabin , Wang Li , Cooke Richard A. , Ma Fang , Kalita Prasanta K.
Published: April 2015

Because of increased use of fertilizers to feed the increasing global population, the nutrient loads in surface and subsurface water have increased substantially in the last few decades. Many studies have been conducted to investigate the factors affecting nitrate load in surface and subsurface flow. The objective of this study is to investigate the relationship between the various factors affecting nitrate transport using principal component analysis (PCA) and nearest neighborhood analysis methods. Hydrological and biogeochemical data from a small (<500 km2) agricultural watershed in east central Illinois, USA for the duration of 10 years have been used in this study. The PCA approach divided various factors that influence nitrate transport into three principal components. The first component contained air temperature, cover phenotype, evapotranspiration, cover factor and dry mass factors. The second component contained precipitation and flow, which was defined as the hydrologic component. The third component included tillage practices and nitrogen application and was termed the anthropogenic component. The results from the PCA approach suggested all three components had significant influence on nitrate transportation and transformation. Among these three components, the hydrological components had the highest contribution on both surface and subsurface nitrate load. The nearest neighborhood analysis yielded a similar conclusion.
Coagulation performance and floc properties of Microcystis aeruginosa in the presence of humic acid
Authors: Cheng Peixia , Ge Fei , Liu Xingwang , Zeng Xiaoshuang , Chen Biao
Published: April 2015

Coagulation removal of algae in raw water could be significantly affected by humic acid (HA). A series of jar-tests were conducted to investigate the coagulation performance with polyaluminum chloride and floc properties of Microcystis aeruginosa, a unicellular cyanobacteria, in the presence of HA. Meanwhile the coagulation mechanism was explored through the measurement of zeta potential of the supernatant. The results showed that an optimal removal efficiency of chlorophyll-a (Chl-a) was obtained at pH 8.0 with a low concentration of HA (2 mg/L) and at pH 6.0 with a high concentration of HA (8 mg/L). The floc structure was more compact and bigger-sized and the calculated fractal dimension (Df) was larger at maximum coagulation efficiency. The variation of Df was consistent with that of Chl-a removal efficiency under the same coagulation conditions. Charge neutralization was inferred to be the dominant mechanism to remove algal cells with low concentration of HA, while charge neutralization, gathering and the bridging process worked together to remove algal cells with a high concentration of HA. These results provide insight on how to achieve an optimal removal efficiency of algae in the presence of different concentrations of HA in water treatment.
The City Blueprint of Amsterdam: an assessment of integrated water resources management in the capital of the Netherlands
Authors: Van Leeuwen C. J. , Sjerps R. M. A.
Published: April 2015

In this study the sustainability of integrated water resources management in Amsterdam has been reviewed using the City Blueprint approach. The City Blueprint® is a set of 24 dedicated indicators divided over eight categories, i.e., water security, water quality, drinking water, sanitation, infrastructure, climate robustness, biodiversity and attractiveness, and governance including public participation. In 2006 the various urban water-related services in Amsterdam were brought under one roof, culminating in the country's first water cycle company called Waternet. Waternet is responsible for surface water (rivers, canals, ditches and lakes), groundwater, stormwater, drinking water supply and waste water treatment. The city's unique water cycle approach has proved highly beneficial. Currently Amsterdam is the best performing city of the 30 cities assessed so far. This can be explained by: (1) a long-term vision and a multi-level water governance approach, (2) integration of water, energy and material flows (e.g., struvite production), (3) the entanglement between urban quality and water management, and (4) the transparent communication to and feed-back from customers, i.e., farmers and citizens. Surface water quality and biodiversity remain future challenges.