bluuebunny/crossref_metadata_2025 huggingface dataset:
Vascular injuries of the upper extremity
Authors: Shalabi Raafat , Al Amri Yoysifh , khoujah Elham
Published: March 2007

OBJECTIVE: This study analyzes the causes of injuries, presentations, surgical approaches, outcome and complications of vascular trauma of the upper limbs, in spite of limited hospital resources. METHODS: A 5-year retrospective analysis. From 01/01/2001 to 31/12/2005, 165 patients were operated for vascular injuries at King Fahd Hospital, Medina, Saudi Arabia. Of all peripheral vascular trauma patients (115), upper limb trauma was present in 58. Diagnosis was made by physical examination and hand-held Doppler alone or in combination with Doppler scan/angiography. Primary vascular repair was performed whenever possible; otherwise, the interposition vein graft was used. Fasciotomy was considered when required. Patients with unsalvageable lower extremity injury requiring primary amputation were excluded from the study. RESULTS: Fifty patients were male (86%) and eight were female (14%), aged between 2.5-55 years (mean 23 years). Mean duration of presentation was 8 h after the injury. The most common etiological factor was road traffic accidents, accounting for 50.5% in the blunt trauma group and 33% among all penetrating and stab wound injuries. Incidence of concomitant orthopedic injuries was very high in our study (51%). The brachial artery was the most affected (51%). Interposition vein grafts were used in 53% of the cases. Limb salvage rate was 100%. CONCLUSION: Patients who suffer vascular injuries of the upper extremities should be transferred to vascular surgery centers as soon as possible. Decisive management of peripheral vascular trauma will maximize patient survival and limb salvage. Priorities must be established in the management of associated injuries, and delay must be avoided when ischemic changes are present.
Effect of surface treatments on the spreading velocity of simplified adhesive systems
Authors: Pazinatto Flávia B. , Lopes Fernanda A. , Marquezini Junior Luiz , Castro Fabrício L. A. de , Atta Maria Teresa
Published: March 2007

OBJECTIVES: To determine the roughness of glass surfaces submitted to different treatments and to correlate it with the spreading velocity of two adhesive systems. MATERIALS AND METHODS: Glass slides were used as substrates to evaluate the spreading velocity of Single Bond and Prime & Bond NT adhesive systems. Six different surface treatments were compared: 1) no treatment; 2) silanization (SL); 3) sandblasting (SB); 4) SB + SL; 5) 10% hydrofluoric acid treatment (HF); 6) HF + SL. Before and after treatments, surface roughness was measured by a profilometer (Ra, µm). Drop volumes (10 µl) of the adhesive systems were deposited onto substrates with a micropipette to observe materials spreading during 30s. Data were expressed in mm/s as spreading velocity. Statistical significances among groups were analyzed using one-way and two-way-ANOVA designs and the SNK test. RESULTS: Significant differences in spreading velocity were found between materials (p < 0.001) and among treatments (p < 0.001). Silanization decreased the spreading velocity for both adhesives in comparison to groups where it was not performed (p < 0.05). Differences in roughness were found only for SB surfaces that were rougher than the others (p < 0.05). Silanization decreased the roughness of SB surfaces (p < 0.05). Linear regression did not indicate any correlation between spreading velocity and roughness (R = 0.173). CONCLUSION: Although surface treatments yielded different roughness, they did not provide differences in the spreading velocity of the simplified bonding systems studied. Silanization decreased bonding systems' spreading velocities.
Effect of 2% iodine disinfecting solution on bond strength to dentin
Authors: Silva Nelson Renato Franca Alves da , Calamia Christine S. , Coelho Paulo G. , Carrilho Marcela Rocha de Oliveira , Carvalho Ricardo Marins de , Caufield Page , Thompson Van P.
Published: March 2007

INTRODUCTION: Disinfection of dentin surfaces is desirable so long as it does not interfere with subsequent bonding of adhesive resins. OBJECTIVE: To test the null hypothesis that bond strengths to dentin are not affected by previous application of an iodine disinfecting solution. MATERIALS AND METHODS: Twenty-four extracted non-carious molars were selected. Occlusal enamel was removed producing a flat dentin substrate. Test teeth were all treated with 2% Iodine disclosing/disinfecting solution (I2DDS) for 20 sec and rinsed for 20 sec followed by the application of self- or total- etching bonding systems, generating five adhesive groups (n=3): Single Bond; ; Prime & Bond NT; Clearfil SE Bond; Opti-Bond Plus. The control groups (n=3 per adhesive) had no disclosing/disinfectant application prior to adhesive application. A 4-mm thick resin restoration was built up on each tooth for microtensile testing. Statistical analyses between experimental and control groups were performed by student's t-test (alpha= 0.05). RESULTS: In general, experimental groups (previously treated with I2DDS) showed significantly lower bond strength values when compared with their respective controls (p<0.05), except for group Prime &Bond I2 that did not significantly differ from its control (p>0.05). CONCLUSION: Acetone-base adhesive systems seem not to be affected by the application of I2DDS prior to etching and bonding procedures.
Evaluating noise in digitized radiographic images by means of histogram
Authors: Rubira-Bullen Izabel Regina Fischer , Escarpinati Maurício Cunha , Schiabel Homero , Vieira Marcelo Andrade da Costa , Rubira Fischer , Lauris José Roberto Pereira
Published: March 2007

To evaluate the performance of three digital devices regarding the noise added to digital radiographic images containing different optical densities. METHODS: A radiographic image was digitized repeatedly ten times using two scanners (HP 4c/T and HP 5370C) and a digital camera (Nikon 990). A histogram tool measured a mean pixel value and the standard deviation of the region of interest in each image. Both values were used to calculate the image noise at the different optical densities. RESULTS: The noise values found were different for all devices and optical densities. There was a statistically significant difference (p<0.05) between the scanner HP 4c/T and the digital camera regarding the noise values. There was a significant correlation (p<0.05) between the noise values found for the HP 4c/T scanner and the digital camera and between both scanners (p<0.01). CONCLUSION: The noise added to the image was higher for scanner HP 4c/T and less for the digital camera. The noise was higher at the lower optical densities for the scanners. It seems that depending on the equipment and the optical density, a variable amount of noise can be incorporated to the images.
Bond strength of hard chairside reline resins to a rapid polymerizing denture base resin before and after thermal cycling
Authors: Neppelenbroek Karin Hermana , Pavarina Ana Cláudia , Gomes Mauricio Neves , Machado Ana Lucia , Vergani Carlos Eduardo
Published: March 2007

PURPOSE: This study assessed the shear bond strength of 4 hard chairside reline resins (Kooliner, Tokuso Rebase Fast, Duraliner II, Ufi Gel Hard) to a rapid polymerizing denture base resin (QC-20) processed using 2 polymerization cycles (A or B), before and after thermal cycling. MATERIALS AND METHODS: Cylinders (3.5 mm x 5.0 mm) of the reline resins were bonded to cylinders of QC-20 polymerized using cycle A (boiling water-20 minutes) or B (boiling water; remove heat-20 minutes; boiling water-20 minutes). For each reline resin/polymerization cycle combination, 10 specimens (groups CAt e CBt) were thermally cycled (5 and 55 ºC; dwell time 30 seconds; 2,000 cycles); the other 10 were tested without thermal cycling (groups CAwt ad CBwt). Shear bond tests (0.5 mm/min) were performed on the specimens and the failure mode was assessed. Data were analyzed by 3-way ANOVA and Newman-Keuls post-hoc test (alpha=.05). RESULTS: QC-20 resin demonstrated the lowest bond strengths among the reline materials (P<.05) and mainly failed cohesively. Overall, the bond strength of the hard chairside reline resins were similar (10.09±1.40 to 15.17±1.73 MPa) and most of the failures were adhesive/cohesive (mixed mode). However, Ufi Gel Hard bonded to QC-20 polymerized using cycle A and not thermally cycled showed the highest bond strength (P<.001). When Tokuso Rebase Fast and Duraliner II were bonded to QC-20 resin polymerized using cycle A, the bond strength was increased (P=.043) after thermal cycling. CONCLUSIONS: QC-20 displayed the lowest bond strength values in all groups. In general, the bond strengths of the hard chairside reline resins were comparable and not affected by polymerization cycle of QC-20 resin and thermal cycling.
The influence of gender and bruxism on the human maximum bite force
Authors: Calderon Patrícia dos Santos , Kogawa Evelyn Mikaela , Lauris José Roberto Pereira , Conti Paulo César Rodrigues
Published: March 2007

The objective of this research was to evaluate the influence of gender and bruxism on the maximum bite force. The concordance for the physical examination of bruxism between examiners was also evaluated. One hundred and eighteen individuals, from both genders, bruxists and non-bruxists, with an average age of 24 years, were selected for this purpose. For group establishment, every individual was submitted to a specific physical examination for bruxism (performed by three different examiners). Subjects were then divided into four groups according to gender and the presence of bruxism. The maximum bite force was measured using a gnathodynamometer at the first molar area, three times on each side, performed twice. The two measurements were made with a 10-day interval. The highest value was recorded. The mean maximum bite force was statistically higher for males (587.2 N) when compared to females (424.9 N) (p<0.05), regardless of the presence of bruxism. The presence of bruxism did not influence the bite force (mean maximum bite force value for bruxists: 490.1 N, and for non bruxists: 522.1 N) (p>0.05). The concordance between examiners for physical examination of bruxism was considered optimal.
Efficacy of biofilm disclosing agent and of three brushes in the control of complete denture cleansing
Authors: Silva Cláudia Helena Lovato da , Paranhos Helena de Freitas Oliveira
Published: March 2007

OBJECTIVE: This report evaluated the efficacy of three brushes and one biofilm disclosing agent in complete denture cleansing. METHODS: Twenty-seven wearers of maxillary dentures were distributed into three groups and received different brushes: Oral B40, conventional toothbrush (Oral B); Denture, denture-specific brush (Condor); Johnson & Johnson, denture-specific brush (Johnson & Johnson). The 60-day experimental period was divided into two techniques: I - brushing (brush associated with a paste - Dentu Creme, Dentco) three times a day; II - brushing and daily application of 1% neutral red on the denture internal surface. Biofilm quantification was carried out weekly and the areas with dye biofilm were obtained by means of Image Tool 2.02 software. RESULTS: Biofilm removal was more effective during Technique II (Wilcoxon test: p=0.01) for the three groups of brushes. When the brushes were compared in Technique I, the Kruskal Wallis test indicated statistical difference between Denture X Johnson & Johnson and Denture X Oral B40, in which the Denture was more efficient. For Technique II, there was no statistical difference between brushes (p>0.05). CONCLUSION: The disclosed application promoted more efficacy on biofilm removal, regardless of the brush used. Denture (Condor) was more efficient than the other brushes during Technique I.
Evaluation of apical deviation in root canals instrumented with K3 and ProTaper systems
Authors: Santos Mariana Diniz Bisi dos , Marceliano Marília Fagury , Souza Patrícia Rodrigues de Almeida Silva e
Published: March 2007

OBJECTIVES: this study evaluated the apical deviation of curved root canals instrumented with K3 and ProTaper systems. MATERIAL AND METHODS: twenty root canals of human maxillary and mandibular first molars were employed, which were divided into 2 groups: group A (10 teeth) was instrumented with the K3 system, and group B (10 teeth) with the ProTaper system. Evaluation of deviation was performed by double radiographic exposure. Radiographs were achieved before and after instrumentation, with 0.3-second, thus allowing superimposition of images. Three-dimensional computerized tomograph was performed in 3 specimens in each group, as an additional means to evaluate the apical deviation. RESULTS: were evaluated by the parametric test Student-Newman-Keuls at 5%, which did not reveal significance between groups concerning the apical deviation. The results of computerized tomograph images demonstrated that the larger deviation of the root canal occurred at the distolingual area for both systems. CONCLUSIONS: both techniques produced a mild apical deviation. Computerized microtomography was shown to be accurate for experimental endodontics studies.
Long-term stability of an anterior open-bite malocclusion treated in the mixed dentition: a case report
Authors: Almeida Márcio Rodrigues de , Almeida Renato Rodrigues de , Conti Ana Claúdia de Castro Ferreira , Navarro Ricardo de Lima , Correa Giovani de Oliveira , Oliveira Cristiane Aparecida de , Oltramari Paula Vanessa Pedron
Published: March 2007

A clinical case with anterior open-bite, treated in the mixed dentition, is presented. This approach demonstrates one of the possible approaches of treatment, which is capable of interfering with growth and redirecting its vectors. Orthodontic and orthopedic methods were used, consisting of slow maxillary expansion, through a fixed palatal crib soldered in a bi-helix appliance, and high-pull traction on the mandible for 16 hours a day. After eight years of follow-up, stable outcomes were accomplished. These results may be explained by the fact that treatments were performed at the appropriate period of development, thus establishing perioral muscular equilibrium, matching the final period of facial growth. The combination of orthodontic and orthopedic treatments was necessary to prevent the need of further orthognathic surgery treatment.
Vestibular schwannoma (acoustic neuroma) mimicking temporomandibular disorders: a case report
Authors: Bisi Maurício A. , Selaimen Caio M. P. , Chaves Karen D. , Bisi Melissa C. , Grossi Márcio L.
Published: March 2007

Approximately 6 to 16% of patients with trigeminal neuralgia symptoms present intracranial tumors, the most common being the vestibular schwannoma (acoustic neuroma). Some symptoms reported by patients include hearing loss, tinnitus, headaches, vertigo and trigeminal disturbances. An increased muscle response in the surrounding head and neck musculature may also be observed, which mimics signs and symptoms of temporomandibular disorders. In these cases, magnetic resonance imaging (MRI) has proved to be a useful tool in tumor diagnosis. The differential diagnosis between myofascial and neuralgic pain is important, as both may present similar characteristics, while being of different origin, and demanding special treatment approaches. The purpose of this paper is to demonstrate the relationship among trigeminal neuralgia symptoms, intracranial tumors and temporomandibular dysfunction by presenting a clinical case.
Production of monoclonal antibodies against Streptococcus mutans antigens
Authors: Canettieri Antonio Carlos Victor , Kretchetoff Fujiko Yamasiro , Koga-Ito Cristiane Yumi , Moreira Daniella , Fujarra Fabio José Condino , Unterkircher Carmelinda Schmidt
Published: March 2007

Several studies have been conducted in the last decades aiming to obtain an anti-caries vaccine, however some studies have demonstrated cross reactivity between Streptococcus mutans surface antigens and the human cardiac tissue. In this work, the reactivity of five anti-Streptococcus mutans monoclonal antibodies (MoAb) (24A, 56G, C8, E8 and F6) was tested against oral streptococci, cardiac antigens and skeletal and cardiac myosins, aiming to evaluate the specificity of these MoAb. The hybrid producers of immunoglobulins of the IgG2b class were cloned by limit dilution and expanded in vivo. MoAb were tested by ELISA. The hybrid 24A reacted with S. mutans CCT 1910, S. salivarius CCT 0365 and S. pyogenes T23. No reactivity difference was observed among the tested species. Cross reactivity with heart and cardiac myosin was not confirmed and only reaction with myosin of skeletal muscle was observed (p = 0.0381). The hybrid 56G reacted with all the tested microorganisms and there was statistically significant difference between S. mutans and S. pyogenes T23 (p < 0.001). This hybrid also reacted with myosin of skeletal muscle (p = 0.0095). C8, E8 and F6 presented low reactivity against oral streptococci strains and no reactivity against cardiac antigens. The data of this study showed that the 24A and 56G anti-S. mutans MoAb presented reactivity with S. pyogenes and S. salivarius, reinforcing the occurrence of common antigens between these species. The tested MoAb presented low cross-reactivity with myosin of skeletal muscle, but anti-heart activity could not be confirmed.
Relationship between maternal periodontal disease and birth of preterm low weight babies
Authors: Alves Renata Tolêdo , Ribeiro Rosangela Almeida
Published: March 2007

It has been recently suggested that periodontal disease is an associated factor for prematurity and low birth weight. The aim of this work was to assess the periodontal status of puerperae and determine its possible relationship with preterm low birth weight (PLBW) delivery. The sample included 59 women seen at two maternity hospitals in Juiz de Fora, MG, Brazil. Nineteen mothers had premature and low birth weight babies (gestational age below 37 weeks and birth weight below 2,500 g - group I), and 40 had mature, normal weight babies (gestational age over 37 weeks and birth weight over 2,500 g - group II). The mothers' data were obtained from medical files, interview, and periodontal clinical examination carried out up to 48 hours after delivery. The Periodontal Screening and Recording (PSR) was used for periodontal assessment. The association between periodontal disease and PLBW was expressed as odds ratio (OR). There was a higher rate of periodontal disease in group I (84.21% - 16/19) as compared with group II (37.5% - 15/40). The data also showed a significant association between periodontal disease and PLBW (OR = 8.9 - 95% CI: 2.22-35.65 - p = 0.001). It was concluded that maternal periodontal disease was an associated factor for prematurity and low birth weight in this sample.
Hardness of a bleaching-shade resin composite polymerized with different light-curing sources
Authors: Gomes Giovana Mongruel , Calixto Abraham Lincoln , Santos Fabio André dos , Gomes Osnara Maria Mongruel , D'Alpino Paulo Henrique Perlatti , Gomes João Carlos
Published: March 2007

The microhardness of a bleaching-shade resin composite polymerized with different light-curing units was evaluated. Composite samples (3M ESPE Filtek Supreme) were applied to brass rings (2 mm in thickness, 5 mm in diameter). Three commercial LED lights were used to polymerize the specimens and the results were compared to those of a conventional halogen light. The light sources used in the present study were: Demetron Optilux 401 (QTH), 3M ESPE Elipar FreeLight (LED 1); Kerr L.E.Demetron I (LED 2), and ColtoluxLED lights (LED 3). The microhardness of the top and bottom surfaces was assessed with a digital Vickers hardness-measuring instrument, under load. At the bottom surface, no significant difference among the light sources was observed (two-way ANOVA). At the top surface, the QTH light source presented significantly higher hardness values compared to the values observed when LED 1 and LED 3 were used. There were no significant differences between the QTH and LED 2 light sources. Significantly higher hardness values were also found at the top surface when compared to the values observed at the bottom surface. The power density of the polymerization light sources seemed to be responsible for the observed resin composite hardness, not their irradiance.
Retention of radicular posts varying the application technique of the adhesive system and luting agent
Authors: Fonseca Tabajara Sabbag , Alfredo Edson , Vansan Luiz Pascoal , Silva Ricardo Gariba , Sousa Yara T. Correa Silva , Saquy Paulo César , Sousa-Neto Manoel D.
Published: March 2007

This study evaluated in vitro the retention of intracanal cast posts cemented with dual-cure resin varying the application method of the primer/adhesive solution and luting agent in the prosthetic space prepared to receive the posts. Sixty endodontically treated maxillary canines had their crowns discarded, and their roots were embedded in acrylic resin. The prosthetic spaces were prepared with Largo burs mounted on a low-speed handpiece coupled to a parallelometer in order to maintain length and diameter of intraradicular posts constant and to guarantee that the preparations were parallel after casting. Two groups (n = 30) were randomly formed according to the device used to apply the adhesive system: microbrush or standard bristle brush (control). Each group was divided into 3 subgroups (n = 10) according to the technique used to place the luting agent into the root canal: using only a lentulo spiral before setting the post, applying it onto the post surface, or combining both methods. After 72 hours, the tensile force required to dislodge each post was determined by a universal testing machine (Instron 4444) set at a speed of 1 mm/min. The results indicated that the use of the microbrush yielded higher bond strength values (0.1740 ± 0.04 kN) than those recorded for the bristle brush tip (0.1369 ± 0.04 kN, p < 0.001). Bonferroni's test demonstrated a higher retention (p < 0.001) in radicular post cemented with the technique that combined both methods (lentulo + post: 0.1787 ± 0.03 kN) than that obtained with lentulo (0.1461 ± 0.065 kN) or post (0.1416 ± 0.03 kN) alone. The interactions between the adhesive system and luting agent application techniques presented statistical difference (p < 0.001). It was concluded that the best performance in terms of tensile strength among the tested conditions was obtained when the adhesive system was applied with a microbrush and the luting agent was taken into the root canal with lentulo spirals alone (0.1961 ± 0.04 kN) and combining both methods (lentulo + post: 0.1911 ± 0.02 kN).
Association between clinical parameters and the presence of active caries lesions in first permanent molars
Authors: Quaglio Juliana Maria , Sousa Marcela Bernardes , Ardenghi Thiago Machado , Mendes Fausto Medeiros , Imparato José Carlos Pettorossi , Pinheiro Sérgio Luiz
Published: March 2007

The aim of the present study was to evaluate the association between clinical parameters and the presence of active caries lesions on the occlusal surface of first permanent molars. Forty eight children (5.8-13.8 years-old) with at least one first permanent molar present were selected. The clinical parameters evaluated were gender, age, DMF-T and dmf-t, presence of active white spots in other teeth, general plaque index, tooth's dental arch (upper or lower), tooth's side (right or left), presence of visible plaque and eruption degree of the first permanent molars. The first permanent molars were evaluated through visual inspection by two examiners in order to assess the presence of active or inactive caries lesions on the occlusal surface. Univariate and multivariate analyses for determination of the association between clinical parameters and the presence of active caries lesions in these teeth were performed. The presence of active white spots in other teeth was associated with the presence of active caries lesions in the first permanent molars, in both univariate and multivariate analyses (Odds ratio = 8.8 and 1.9, respectively). The presence of abundant visible plaque on the occlusal surface of the first permanent molars (Odds ratio = 3.5 in the univariate analysis, and 3.9 in the multivariate one) also presented a significant association. In conclusion, the presence of active white spots in other teeth and the presence of considerable visible plaque were associated with the presence of active caries lesions on the occlusal surfaces of first permanent molars.
Jackup Mobilization in Hazardous Soils
Authors: Kostelnik Andre , Guerra Mike , Alford Jake , Vazquez Jose , Zhong Jack
Published: March 2007

This paper presents two case histories of jackup rig mobilizations to locations identified as high risk for uncontrolled leg penetration or punchthrough. The punchthrough risk is defined through an overview of the soil analysis work completed for each location. The effectiveness of remedial operations, known as "swiss cheese" drilling, in mitigating the punchthrough risk for the subsequent jackup mobilizations is reviewed. It is concluded that "swiss cheese" drilling can be effective in reducing punchthrough risk. Advance planning is important, and recommendations are provided to assist in effective punchthrough mitigation.
Expandable Tubular Completions for Carbonate Reservoirs
Authors: Marketz F. , Welling R. W. F. , van Noort R. H. J. , Baaijens M. N.
Published: March 2007

A major Middle East operator has applied expandable tubular solutions for water shutoff and zonal isolation in fractured carbonate reservoirs. In this paper, we review the operator's experience with the implementation of this emerging well technology. Expandable tubular solutions have proven successful in terms of installation reliability, isolation of fractures, and zonal isolation without cement to segment horizontal wells.

Case histories highlight the benefits, risks, and performance of expandable tubular completions. Post-installation production performance proves the viability of mechanical inflow profile control for better management of unwanted production of water in fractured carbonate reservoirs.
Application of Vacuum–Insulated Tubing to Mitigate Annular Pressure Buildup
Authors: Azzola J. H. , Tselepidakis D. P. , Pattillo P. D. , Richey J. F. , Tinker S. J. , Miller R. A. , Segreto S. J.
Published: March 2007

Vacuum-insulated tubing (VIT) has been used successfully to mitigate the potentially harmful effects of annular pressure buildup (APB). In a recent deepwater installation, the subject well had lost alternate APB mitigation capability through a series of events. VIT was then chosen as the only viable technology.

A common design companion of VIT is gelled brine, chosen to decrease annular natural convection driven by heat loss around the VIT connections. There are, however, several drawbacks to the indiscriminate use of gelled brine:

Tight clearances around the tubing hanger running tool, creating the potential for debris plugging and/or tool-recovery issues from the subsea wellhead. Limitations imposed by VIT collapse and hydrostatic packer setting pressures. Unknown temperature/viscosity response and associated quality-control requirements for displacement through a subsea wellhead. A need to reduce operational time and cost.

These issues led to the consideration of alternative means of controlling natural convection, and an effort was made to understand, improve, and deploy external coupling insulators.

An in-ground vertical experiment with two connected joints of VIT was conducted with and without coupling insulators. Temperatures were monitored at multiple locations. Test results confirm the effectiveness of external coupling insulators. Several theoretical models using different numerical techniques (finite difference, lumped mass/resistance, finite element, and computational fluid dynamics) were found to be consistent with experimental results. These were compared with critical APB temperatures calculated with a commercial wellbore simulator. The net result of these studies was to adopt the external insulators.

This paper reviews the experimental data and presents several models of a vertically aligned VIT in a deepwater completion. A comparison of thermally effective APB solutions is presented, together with a critical assessment of modeling and experimental accuracy.
Application of Flux-Based Sand-Control Guidelines to the Na Kika Deepwater Fields
Authors: Keck Richard G. , Colbert Jason R. , Hardham William D.
Published: March 2007

The Na Kika offtake guidelines were developed jointly by Shell and BP using a blending of recent sand control operational methodologies from each company. This paper focuses on the use of the Bpflux™ guidelines, which give maximum safe operating rates for sand-control completions and allow wells with excellent completion quality to produce at twice the rate of wells with lower completion quality.

Before the Na Kika field started up, completion quality was estimated by reviewing 20 different elements of completion design and operations. These estimates were used to set the initial offtake limits for each zone. As the wells started producing, pressure buildups were used to measure the actual completion quality (skin), and the maximum operating rates were adjusted accordingly.

By use of this methodology early in the field life, the field could be brought up to targeted production rates without unnecessarily compromising long-term sand control reliability. As the field matures, opportunities will be identified to extend the production plateau, which will provide an incremental production impact. Finally, later in the field life, the number of workovers required is expected to be reduced, which will provide an additional cost saving from using these guidelines.
Increasing the Wellbore Pressure Containment in Gulf of Mexico HP/HT Wells
Authors: Traugott David , Sweatman Ron , Vincent Randy
Published: March 2007

This article discusses the application of two wellbore pressure-containment integrity (WPCI) treatments that substantially increased the pressure-containment integrity in 852 ft of open hole in the last sidetrack for a production hole section. These treatments ultimately made it unnecessary to set pipe early, which could have jeopardized the commercial discovery of the lower gas sand. Earlier sidetracks attempted unsuccessfully to bypass the loss/flow problems that would not allow drilling ahead and increasing the 18.0-lb/gal mud weight (MW) to drill into a high-pressure zone on a deep, high-pressure/high-temperature (HP/HT) well in the western Gulf of Mexico shelf in offshore Louisiana. Various conventional lost-circulation material (LCM) treatments were used without success, increasing the hole's pressure containment.

The WPCI treatments raised the leakoff test (LOT) across the entire 852 ft of open hole to 19.1 pounds per gallon equivalent (ppge) vs. the lower LOT of 18.26 ppge before the first WPCI job. LOTs were performed before and after each of the two WPCI treatments to measure improvement in the open hole's pressurecontainment integrity. This LOT data indicated that apparent fracture gradients can be simultaneously increased in multiple rock layers with various types of weak formations exposed in long, open holes by inducing near-wellbore stress fields created from WPCI treatments (Webb et al. 2001; Kelley Sweatman and Heathman 2001; Sweatman et al. 2001; Sanad and Waheed 2003). This approach can then allow use of increased mud weights (MW) and drilling pressures to prevent excessive gas influx from high-pressure sands without lost circulation (LC) in adjacent weak zones.

Also discussed are the WPCI treatment design and job procedures, including treatment optimization by the analysis of data from openhole wireline/logging while drilling (OHWL/LWD) logs, cuttings lithology, fracture-seal location indicators (torque on bit [TOB]/weight on bit [WOB]), and before/after LOT pressures. Real-time operations (Kulakofsky et al. 2002) (also described) enabled remote expert analysis and support so that wellsite personnel could: (1) interpret formation characteristics for optimized treatment design, and (2) analyze treatment pressure/rate data for selective placement of WPCI sealants.
Data mining and multivariate statistical analysis for ecological system in coastal waters
Authors: Chau Kwok-wing , Muttil Nitin
Published: March 2007

In this study, data mining using box plots and multivariate statistical analysis using factor analysis are employed for a spatio-temporal analysis of coastal water quality data from Tolo Harbour, Hong Kong. The analysis of box plots reveals pronounced spatial heterogeneity of the parameters studied. The spatial analysis clearly shows monitoring station TM2 in the Harbour Subzone to be most susceptible to eutrophication with the highest nutrient and algal biomass concentrations. The factor analysis brings to light dominant parameters to the ecological system under the coastal marine environment. The temporal analysis confirms the considerable decline in nutrient levels in recent years. In spite of this decline, the factor analysis indicates that nutrient processes play an important role even in recent years, suggesting an adequate supply of nutrients. It seems that they are being released from sources other than known point sources, possibly from nutrients accumulated in the sediments, necessitating steps to be undertaken for their control also. This study demonstrates the use of data mining techniques in the ecological system in Tolo Harbour.
Data mining to improve management and reduce costs of environmental remediation
Authors: Farrell Dara M. , Minsker Barbara S. , Tcheng David , Searsmith Duane , Bohn Jane , Beckman Dennis
Published: March 2007

In this paper, data from 105 soil and groundwater remediation projects at BP gasoline service stations located in the state of Illinois were mined for lessons to reduce cost and improve management of remediation sites. Data mining software called D2K was used to train decision tree, stepwise linear regression and instance-based weighting models that relate hydrogeologic, sociopolitical, temporal and remedial factors in the site closure reports to remediation cost. The most important factors influencing cost were found to be the amount of soil excavated and the number of groundwater monitoring wells installed, suggesting that better management of excavation and well placement could result in significant cost savings. The best model for predicting cost classes (low, medium and high cost) was the decision tree, which had a prediction accuracy of approximately 73%. The misclassification of approximately 27% of the sites by even the best model suggests that remediation costs at service stations are influenced by other site-specific factors that may be difficult to accurately predict in advance.
An object-oriented approach to the modelling of free-surface flows
Authors: Kutija V. , Murray M. G.
Published: March 2007

Over the past 40 years many hydraulic modelling systems for free-surface flows have been developed and successfully used in research and engineering practice. These systems were, in general, developed using sequential programming techniques while object-oriented programming approaches have only been used in the development of their visual parts. This paper outlines the approach used in the development of the NOAH modelling systems (Newcastle Object-oriented Advanced Hydroinformatics), developed entirely within the object-oriented paradigm. This novel approach has made NOAH modelling systems computationally highly efficient and yet easy to maintain and extend. NOAH 1D and NOAH 2D are designed to model free-surface flows in one and two dimensions, respectively. NOAH 1D is based on the full de Saint-Venant equations while NOAH 2D is based on the Shallow Water equations. Beside the basic ideas behind the development of NOAH modelling systems this paper also presents their main features and discusses general benefits of the application of the object-oriented programming approach in the development of numerical codes.
Comparison of two methodologies for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in activated sludge samples from a sewage treatment plant in the city of Campinas, São Paulo State, Brazil
Authors: Rondello Bonatti Taís , Bueno Franco Regina Maura , Cantusio Neto Romeu
Published: March 2007

Giardia spp. and Cryptosporidium spp. are recognized worldwide as highly infectious protozoan parasites that can cause severe gastrointestinal disease in humans and animals. The detection of these pathogens in activated sludge samples becomes interesting since there is an increasing trend for the use of sewage sludge (biosolids) in agriculture. A total of 22 samples were collected and evaluated by means of Centrifugal – Concentration, followed or not followed by a purification process (ether clarification and sucrose flotation). Student t tests for comparison of the two procedures indicated a higher recovery rate of Giardia cysts with Centrifugal – Concentration; with regard to Cryptosporidium oocysts, no significant differences were found between the two methods, as only two samples were positive. The Centrifugal – Concentration procedure was shown to be the simplest and cheapest to perform, as emphasized by the efficiency recovery results.
First investigations into the prevalence of Cryptosporidium and Giardia spp. in Hungarian drinking water
Authors: Plutzer J. , Takó M. H. , Márialigeti K. , Törökné A. , Karanis P.
Published: March 2007

Safe drinking water is a top priority in preventing disease outbreaks and is of general concern to everyone. This study examines the occurrence of Cryptosporidium and Giardia in Hungarian drinking water supplies for the first time. A total of 76 raw and drinking water samples were examined using the U.S. EPA Method 1623. From these 15 of 34 (48.4%) raw water samples tested positive for Giardia and 7 (26.6%) for Cryptosporidium. Twelve of 45 (26.7%) drinking water samples were positive for Giardia and 6 (13.3%) for Cryptosporidium. Overall, Giardia cysts and/or Cryptosporidium oocysts were detected in 48% of the raw water samples and 35% of the drinking water samples. The highest levels in drinking water were found to be 3 oocysts/100 litres of Cryptosporidium and 63.6 cysts/100 litres for Giardia, enough to cause giardiasis. The highest levels in raw water were 1,030 cysts/100 litres for Giardia and 50 oocysts/100 litres for Cryptosporidium and higher oocyst densities were associated with source water receiving effluents from sewage treatment plants or originating from a forest environment. In addition to this monitoring, riverbank filtrated water and raw water from the River Danube in Budapest were monitored in order to ascertain protozoan removal efficiency of riverbank filtration (RBF). A total of 157 samples, including 87 samples from the River Danube and 70 samples post RBF, were examined. Cryptosporidium and Giardia were detected regularly in the river water but never in riverbank filtered water suggesting the effectiveness of RBF as a purification method.

The occurrence of Cryptosporidium oocysts and Giardia cysts in the investigated water supplies may require the water utilities and water authorities in Hungary to apply additional monitoring and treatment and/or watershed controls.
Drinking water microbiological survey of the Northwestern State of Sinaloa, Mexico
Authors: Chaidez Cristobal , Soto Marcela , Martinez Celida , Keswick Bruce
Published: March 2007

A potable water survey, in two important municipalities of the state of Sinaloa, Mexico was conducted. Culiacan, capital city of Sinaloa and its neighboring municipality, Navolato were selected to enumerate Aeromonas hydrophila, Escherichia coli, fecal and total coliforms, Pseudomonas aeruginosa, and Heterotrophic plate count bacteria from 100 households' taps. Manganese; residual chlorine; pH; temperature and turbidity were also examined. Overall, Aeromonas hydrophila was not detected in any of the samples, 3% contained Escherichia coli, 28% had fecal and 46 total coliforms, P. aeruginosa was present in 15% of the samples. HPC bacteria were found in all of the samples but 43% had numbers greater than 500 CFU per ml. The average numbers obtained for the physico-chemical parameters were 0.15 mg/L; 0.32 mg/L; 6.5; 28.7°C and 2.92 NTU for manganese, residual chlorine, pH, temperature and turbidity, respectively. The findings of the current study demonstrate that potable water from both municipalities can harbor substantial numbers of indicator and opportunistic pathogens suggesting that additional treatment in the household may be needed.
Disinfection by-product formation and mitigation strategies in point-of-use chlorination of turbid and non-turbid waters in western Kenya
Authors: Lantagne D. S. , Blount B. C. , Cardinali F. , Quick R.
Published: March 2007

Over 1.1 billion people in the world lack access to improved drinking water. Diarrheal and other waterborne diseases cause an estimated 2.2 million deaths per year. The Safe Water System (SWS) is a proven household water treatment intervention that reduces diarrheal disease incidence in users in developing countries. Because the SWS recommends the addition of sodium hypochlorite to unfiltered water sources, concerns have been raised about the potential long-term health effects of disinfection by-products to SWS users. This study investigated the production of trihalomethanes (THMs) in water treated with sodium hypochlorite from six sources used for drinking water in western Kenya. The turbidity values of these sources ranged from 4.23 NTU to 305 NTU. THM concentrations were analysed at 1, 8, and 24 hours after addition of sodium hypochlorite. No sample exceeded the World Health Organization (WHO) guideline values for any of the four THMs: chloroform, bromodichloromethane, dibromochloromethane, or bromoform. In addition, no sample exceeded the WHO additive total THM guideline value. These results clearly show that point-of-use chlorination of a variety of realistic source waters used for drinking did not lead to THM concentrations that pose a significant health risk to SWS users.
Prevalence of Acanthamoeba and other naked amoebae in South Florida domestic water
Authors: Shoff M. E. , Rogerson A. , Kessler K. , Schatz S. , Seal D. V.
Published: March 2007

The purpose was to identify the prevalence of naked amoebae in tap water in south Florida to ascertain the risk of amoebal infections of the cornea in contact lens wearers.

Over the course of a 2-year period, water samples were collected from sites throughout Broward, Palm Beach, and Dade counties, Florida. The presence of amoebae in samples was based on an enrichment cultivation method appropriate for Acanthamoeba. Amoebae were identified using diagnostic features discernable by light microscopy.

A total of 283 water samples were processed and amoebae were noted in 80 of these. Acanthamoeba were found on 8 occasions (2.8%). The genera Hartmannella and Vahlkampfia, rarely involved in keratitis cases, were found in 3.5% and 2.8% of samples, respectively. A total of 19 different naked amoebae were recorded and amoebae (regardless of genus) were present in 19.4% of all samples.

Previous surveys in England and Korea have shown that acanthamoebae are found in 15 to 30% of tap water samples in the home and have been associated with corneal infection in contact lens wearers. The incidence of acanthamoebae infection in the USA (2.8%) has been found to be lower than that in the UK and it has been postulated that this is related to the lack of a storage water tank in the roof loft space. However, the level of treatment of municipal water is clearly not effective at killing amoebal cysts (or trophozoites) as evidenced by the high occurrence of amoebae (19.4%) in this study.
Identification of Escherichiacoli from groups A, B1, B2 and D in drinking water in Brazil
Authors: Orsi Renato H. , Stoppe Nancy C. , Sato Maria Inês Z. , Ottoboni Laura M. M.
Published: March 2007

The presence of Escherichia coli in drinking water is an indication of fecal contamination and can represent a risk of waterborne diseases. Forty-nine E.coli strains isolated from different sources of drinking water (distribution system, well, spring and mineral water) were placed into the phylogenetic groups A (15 strains), B1 (19 strains), B2 (2 strains) and D (13 strains). Approximately 30% of the strains analyzed belonged to groups B2 and D, which usually include potentially extraintestinal pathogenic strains. Moreover, the assignment of the strains to different phylogenetic groups indicates that different contamination events occurred in these waters. These results were compared with the distribution of E. coli strains isolated from two rivers and two dams into the phylogenetic groups. A significant difference was observed when the distribution of drinking water strains into the phylogenetic groups was compared to the results obtained from the Guarapiranga Dam and the Jaguari and Sorocaba Rivers. The results obtained in this work suggest that PCR-based methods can be used for a rapid assessment of potentially pathogenic E. coli strains in water samples.
Evaluation of the use of subcutaneous implantable vascular access ports in feline blood donors
Authors: Morrison Jo Ann , Lauer Susanne K. , Baldwin Claudia J. , Evans Richard B. , Andreasen Claire B. , Kinyon Joanne M. , Swanson Elizabeth
Published: March 2007

Objective—To compare the ease and effects of collecting blood from cats by use of subcutaneous totally implantable vascular access ports (VAPs) with collection via conventional jugular phlebotomy.

Design—Prospective randomized experimental study.

Animals—8 healthy cats.

Procedures—Cats in the port group (n = 4) underwent monthly blood donation by use of VAPs and manual restraint, and cats in the nonport group (4) underwent monthly blood donation by use of conventional jugular phlebotomy and sedation, for 6 months.

Results—Postsurgical VAP-related complications developed in 3 cats and included port erosion (n = 1), disconnection of the port from the catheter (1), and seroma formation (1). Blood was successfully collected 24 of 24 and 20 of 20 times in the nonport and port groups, respectively. Results of bacterial culture of blood were negative in 22 of 24 and 15 of 20 nonport and port collections, respectively. No differences in RBC morphology were observed between groups. Mean blood collection and total donation times were significantly longer for the nonport group. Collection time was more variable in the nonport group, and cats were less tolerant of handling during venipuncture, compared with cats in the port group. Blood collection required a mean of 2.4 persons for the nonport group and 2.1 persons for the port group.

Conclusions and Clinical Relevance—Positive results for blood collections via VAPs were increased donor acceptance, decreased number of personnel required, and decreased collection time. Drawbacks included contamination of blood products and port-related complications.