bluuebunny/crossref_metadata_2025 huggingface dataset:
Esthetic Recovery of Smile Using Composite Resin and “Biological Posts” and Crowns
Authors: Vieira-Andrade RG , Ribondi JR , Botelho AM , Fernandes AM , Tavano KTA
Published: April 2015

The recovery of teeth that have been extensively destroyed by dental caries can be achieved through direct and indirect restorative procedures. This paper presents a case of the esthetic and functional recovery of permanent maxillary incisors with extensive dental caries in an adolescent patient through the use of a composite resin and “biological posts and crowns”. A case report was drafted to describe the direct restoration of central maxillary incisors using composite resin and endodontic treatment of the lateral maxillary incisors, the construction of dentinal posts, the adaptation and cementing of the posts to the root canals, preparation and molding of crown portions, model construction, the choice of extracted teeth and the making and cementing of “biological crowns”. The use of a composite resin and the cementing of “biological posts and crowns” reestablish dental esthetics and function. Biological restorations maintain all the characteristics of natural teeth and have a significant psychosocial impact on the patient's quality of life. However, it should be stressed that this technique was only indicated in the present case after the determination of a significant improvement in oral hygiene.
Clinical and Radiographic Outcomes Of Pulpotomized Primary Molars Treated with White or Gray Mineral Trioxide Aggregate And Ferric Sulfate -Long Term Follow-Up
Authors: Frenkel G , Kaufman A , Ashkenazi M
Published: April 2015

Aim: To compare the long term clinical and radiographic outcomes of pulpotomies in primary molars per-formed with white or gray Mineral Trioxide Aggregate (MTA) in combination with ferric sulfate (FS), when one package of MTA is used for multiple treatments. Design: Sixty eight children with 86 vital carious primary molars underwent pulpotomy with FS, and grey or white MTA. One package of MTA was used for 7-8 treatments. Clinical and radiographic evaluation was performed before and 6 to 47 months after treatment. Results: Success rates were similar for pulpotomies performed with white (60-teeth) and grey MTA (16 teeth) (p>0.05), and for those performed with the addition of FS to white or gray MTA when one package of MTA was used for multiple pulpotomies compared to one package of MTA alone. Conclusion: Gray and white MTA in conjunction with FS induce comparable clinical and radiographic success rate. The use of one package of MTA for multiple pulpotomies, combined with FS, is a cost-effective treatment.
Multiple Supernumeraries in a Non-Syndromic Patient
Authors: Ledesma-Montes C , Salcido-García JF , Hernández-Flores F , Garcés-Ortíz M
Published: April 2015

Presence of supernumerary teeth (ST) in non-syndromic patients is an exceptional event. The aim of this article is to present an unusual case of a non-syndromic 12 years old girl with 12 ST. In the reported case supernumeraries were found in three quadrants and the most common ST were bicuspids. All ST were surgically excised and occlusion and functionality was restored with prosthetic appliances. ST are an exceedingly uncommon event in the Pediatric Clinic. An extensive review of the literature dealing on non-syndromic cases comprising 10 or more ST and a discussion about the origin of the ST is presented.
Evaluation of Salivary Sialic Acid Levels in Acute Lymphoblastic Leukemic Children and Its Correlation with Dental Caries Experience
Authors: Joshi S , Hegde AM , Rai K , Shetty S
Published: April 2015

Aim- The aim of present study was to evaluate the salivary sialic acid levels in Acute Lymphoblastic Leukemic (ALL) children and to correlate it with dental caries experience. Method- A total of 120 children aged 4-10yrs were divided into 4 groups of 30 each. Dental caries experience was recorded followed by un-stimulated saliva collection. Results- The mean salivary sialic acid levels of the study group were much higher when compared with the control group, which was statistically significant. A linear relationship between salivary sialic acid levels and dental caries in leukemic children was observed. Conclusion - The findings of our study conclude that salivary sialic acid levels may have a potent activity in dental caries process and can be used as a useful marker in cancer.
Revascularızatıon/Regeneratıon Performed in Immature Molars: Case Reports
Authors: Sönmez IS , Akbay Oba A , Erkmen Almaz M
Published: April 2015

These 3 case reports the outcome of revascularization treatment in necrotic immature molars. During treatment, a tri antibiotic mix was used to disinfect the pulp for 2 weeks. Then a blood clot was created in the canal, over which mineral trioxide aggregate was placed. After 24 months, the immature molars showed continuation of root development. The patients were asymptomatic, no sinus tracts were evident and apical periodontitis was resolved. Results from these cases show that revascularization/regeneration using 3Mix-MP method could be effective for managing immature permanent molar teeth with pulpal necrosis.
Measuring the Impact of Quality of Life of Children Treated for Orofacial Clefts: A Case-Control Study
Authors: Tannure PN , Soares FMM , Küchler EC , Motta LG , Costa MC , Granjeiro JM
Published: April 2015

Objective: The aim of this study was to assess the quality of life (QoL) of children previously treated for cleft lip and/or palate (CL/P) and compare with non-cleft children. Method: A case-control study with 70 children between 5 and 12 years old was carried out. The case group consisted of 35 individuals previously treated for non-syndromic CL/P and presently receiving assessment at a rehabilitation hospital in Brazil. The children had received primary surgical treatment for CL/P reconstruction during early childhood. The control group consisted of 35 healthy children selected to ensure close similarity to the cleft group in age, gender and socioeconomic status. QoL was measured using the AUQEI questionnaire. Results: Cleft lip and palate had no significant influence on the QoL in children (p=0.44). A higher percentage of the cleft lip and palate group of children reported a lower QoL than the cleft lip or cleft palate groups. Gender had no significant difference on the quality of life in CL/P children (p=0.2) and in control group (p=1.0). Conclusion: The QoL in children with CL/P was found to be similar to the non-cleft group. Our results confirm that clefts repaired during earlier childhood associated with a health care program, including psychological support, is beneficial for CL/P children.
Molecular Detection of Aggregatibacter Actinomycetemcomitans and Porphyromonas Gingivalis in Subgingival Plaque of Healthy Young Children
Authors: Arangannal P , Nallasivam KU , Vijayaprabha K , Vishnurekha C , Jeevarathan J , Hariharan VS , Mahalakshmi K , Padmavathy K
Published: April 2015

Objective: The aim of the present study was to evaluate the presence of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis) in subgingival plaque of healthy young children aged between 3 and 15 years using Polymerase Chain Reaction (PCR) and to compare their presence in children in their primary, mixed and permanent dentitions. Method: Subgingival plaque samples were collected from 120 healthy children and were grouped as Group I-Deciduous dentition, Group II- Mixed dentition and Group III- Permanent dentition, and were subjected to PCR assay. Results: Binomial test and Proportions test were used for statistical analysis. A. actinomycetemcomitans and P. gingivalis were detected in 5% and 35%, 12.5% and 20%, and 0% and 27.5% samples in group I, II and III respectively Conclusion: Both the microorganisms were present in group I and II. In group III only P. gingivalis was present. The results from this study do not necessarily pertain to differences in dentition but possibly to inter-individual differences.
Salivary pH Levels and Caries among Siblings and Parents within Families
Authors: Basch Y , Peretz B
Published: April 2015

Background: High level of caries activity is related to organisms in the dental plaque with high acidogenesis capacity. Aim: To test salivary pH in children of the same family and compare it with their caries status. To compare pH levels between children and their parents. To examine the relationship between pH and caries status among children of the same family and their parents. Study design: We examined 123 children and adolescents aged 3-18, (73 boys and 50 girls) and 33 adults, (12 men and 21 women), parents of these children. Caries status was examined clinically, using DMF index. Salivary pH measurements were made by a digital pH meter. Results: Among adults, increase in patient age led to increased DMF (p = 0.005). The higher the pH, the lower the DMF (p = 0.037). Among men, DMF was lower by 3 compared to women (p = 0.049). Children's pH correlated with the parents’ (p = 0.004). Children's DMF correlated to their pH (p = 0.001). Children's pH was the best predictor of their DMF (R2 = 0.309, p = 0.001). Conclusions: Among children, the higher the pH, the lower the DMFT. Children's pH was the best predictor of their DMF.
Microbiological Assessment of Root Canals Following Use of Rotary and Manual Instruments in Primary Molars
Authors: Subramaniam P , Tabrez TA , Girish Babu KL
Published: April 2015

To assess the microflora of root canals in primary molars following use of rotary NiTi files and conventional hand NiTi and stainless steel files. Study design: This randomized clinical trial consisted of a total of 60 first and second primary molars requiring root canal treatment, who were selected from children aged 5-9 years. Based on type of root canal instrumentation, the teeth were randomly assigned to three groups of twenty teeth each; Group A: Rotary NiTi files, Group B: Hand NiTi files and Group C: Hand stainless steel files. Following administration of local anesthesia, isolation with rubber dam was carried out. For the purpose of instrumentation and sampling, the palatal canal of maxillary molars and the distal canal of mandibular molars were selected. Prior to sampling, the orifices of other canals in these teeth were sealed, so as to prevent any contamination. Instrumentation was carried out in each group using respective instruments along with intermittent saline irrigation. Root canal samples were obtained both before and after instrumentation, using sterile absorbent paper points and transferred to a sterile vial with transport fluid. Serial dilutions were prepared and cultured on suitable agar media. Both aerobic and anaerobic microbial counts were made. Data obtained was subjected to statistical analysis using Wilcoxon signed rank test and one-way Analysis of variance. Results: In all three groups, there was a significant reduction in both aerobic and anaerobic mean microbial count following root canal instrumentation. (p<0.001). Conclusion: Rotary NiTi files were as efficient as conventional hand instruments in significantly reducing the root canal microflora.
Mandibular Condylar Aplasia Treated with a Functional Approach
Authors: Mejia-Gomez C M , Ramirez-Yanez G O
Published: April 2015

Mandibular condyle aplasia is a congenital or acquired malformation, which can be or not associated to some head and neck syndromes. Its treatment involves either a surgical approach or a more conservative treatment with orthopedic functional appliances. This clinical report presents a case of mandibular condyle aplasia treated with a modified KLAMT functional appliance, after a surgical procedure failed to stimulate mandibular condyle remodelling. The successful results presented here, with an orthopedic functional approach, support treatment with functional appliances as an alternative, producing similar results to those reported with surgery. Therefore, functional appliances are proposed as a valid alternative to stimulate mandibular condyle remodelling in patients with mandibular condyle aplasia. Treatment provided at an early age appears to be relevant for a successful result.
Pulpal Response to Nano Hydroxyapatite, Mineral Trioxide Aggregate and Calcium Hydroxide when Used as a Direct Pulp Capping Agent: An in Vivo study
Authors: Swarup SJ , Rao A , Boaz K , Srikant N , Shenoy R
Published: April 2015

Nano hydroxyapatite (Nano-HA) and Mineral Trioxide Aggregate (MTA) because of its better qualities can be used as an alternative to calcium hydroxide in direct pulp capping procedures. The aim of the study was to compare the response of exposed human pulp to Nano-HA, Mineral Trioxide Aggregate and calcium hydroxide. Study design: The study was done on 30 premolars, ranging from patients between 11-15 years. Intentional pulp capping was done using one of the experimental materials. The extracted teeth were then subjected to staining procedure and evaluated for dentin bridge and pulpal response after 15 and 30 days. Intragroup comparisons of the observed values were analyzed using Chi-square test. Results: Nano-HA and MTA produced continuous dentin bridges. Dentin bridge that was formed in MTA group had regular pattern of dentinal tubules but no tubules were seen in the nano-HA group. Dentin bridge was not observed in Dycal group for the 15 days period in majority of the sample and by 30 days dentin bridge was observed that were both continuous and interrupted in equal number of samples. The initial inflammatory response and necrosis was more with Nano-HA and calcium hydroxide which reduced with time. Conclusion: MTA showed no inflammatory changes in majority of the samples in both the study periods. Necrosis was least observed in MTA group followed by Nano-HA. Vascularity increased in Nano-HA group in the initial periods which reduced with increasing time. Based on the ability of nano-HA to produce complete dentinal bridges, favorable cellular and vascular response, the material could be considered as an substitute and could be tried used as a direct pulp capping agent.
The Effects of Dentin Adhesives and Liner Materials on the Microleakage of Class II Resin Composite Restorations in Primary and Permanent Teeth
Authors: Güngör H C , Canoğlu E , Çehreli Z C
Published: April 2015

>Purpose: To compare the occlusal and gingival microleakage of Class-II composite restorations utilizing etch-and-rinse and self-etch adhesives and different liner materials in primary and permanent teeth. Study design: Standardized class-II cavities were prepared in freshly-extracted sound primary and permanent molars (n=80/each), with all cavosurface margins involving enamel. The main experimental groups were; A. Single Bond 2/primary teeth; B. Adper SE Plus/primary teeth; C. Single Bond 2/permanent teeth; and D. Adper SE Plus/permanent teeth. Each group comprised 4 subgroups (n=10/each) with respect to the liner material employed (n=10/subgroup): 1. Fuji VII; 2. Fuji Triage; 3. Filtek Supreme XT Flowable Composite, and 4. No liner. All teeth were restored with Filtek Supreme XT Universal Nanofilled Composite. Following thermocycling and immersion in basic fuchsin, the extent of microleakage was measured on crown sections using image analysis. The data were analyzed with Wilcoxon Signed Ranks Test, Mann-Whitney U-Test and Kruskal-Wallis One-Way ANOVA at ?=0.05. Results: In both primary and permanent teeth the use of etch-and-rinse adhesive resulted in similar occlusal and gingival microleakage values (p>0.05). As for the self-etch adhesive, similar results were observed (p>0.05) with the exception of significantly less occlusal leakage in the Fuji Triage VII and Fuji Triage subgroups of primary teeth than those of permanent teeth (pÃ0.05). When the effects of liner material and the type of adhesive were disregarded, significantly more gingival microleakage was observed in primary teeth than in permanent teeth (pÃ0.01), while the occlusal microleakage values were similar (p>0.05). Irrespective of the tooth type and adhesive material, comparison of subgroups containing a liner material with those without one revealed no significant differences for both occlusal and gingival microleakage values (p>0.05). Conclusions: Occlusal microleakage was similar in both primary and permanent teeth, while a lesser extent of gingival seal was observed in primary teeth. Overall, placement of a liner material did not improve resistance to microleakage.
Does Casein Phosphopeptid Amorphous Calcium Phosphate Provide Remineralization on White Spot Lesions and Inhibition of Streptococcus mutans?
Authors: Aykut-Yetkiner Arzu , Kara Nazan , Ateş Mustafa , Ersin Nazan , Ertuğrul Fahinur
Published: April 2015

Objective: The aim of this study was to evaluate the remineralization effect of Casein Phosphopeptid Amorphous Calcium Phosphate (CPP-ACP) on white spot lesions (WSL) and its inhibitory effect on Streptococcus mutans colonization. Study design: The study group consisted of 60 children exhibiting at least 1-WSL. Subjects were randomly divided into 2 groups: a test group of using CPP-ACP cream (Tooth Mousse, GC Europe N.V., Leuven, Belgium) and a control group using only fluoride containing toothpaste for a period of 3-months. Baseline WSLs were scored using DIAGNOdent device (KaVo Germany) and the saliva samples were collected to measure S. mutans counts. After the 3-month period the WSLs were again recorded and the saliva sample collection was repeated. Wilcoxon Signed Ranks Test was used for statistical analysis. Results: DIAGNOdent measurements were increased by time (p=0.002) in control group and no statistically significant difference (p=0.217) was found in test group by the 3-month period. In both groups, the mutans counts were decreased in 3-month experimental period. Conclusions: These clinical and laboratory results suggested that CPP-ACP containing cream had a slight remineralization effect on the WSL in the 3-month evaluation period however longer observation is recommended to confirm whether the greater change in WSLs is maintained.
Multiple Teeth Fractures in Dentinogenesis Imperfecta: A Case Report
Authors: Min B , Song J S , Lee J H , Choi B J , Kim K M , Kim S O
Published: April 2015

Dentinogenesis imperfecta (DGI) is a hereditary defect consisting of opalescent teeth composed of irregularly formed and hypomineralized dentin. This paper presents the multiple fractures of DGI-affected teeth and suggests the reason of low fracture resistance by observing the dentin microstructures directly using scanning electron microscope (SEM) and by measuring its surface hardness using the Vickers hardness test. .SEM revealed that while the enamel microstructure was similar in the DGI-affected and normal teeth, the microstructure of the DGI-affected dentin was poorly woven and more loosely packed than that of the normal dentin. The Vickers hardness of the DGI-affected dentin was 4.89 times softer than the normal dentin. The low fracture resistance of DGI-affected teeth can be attributed to the poorly woven microstructure of their dentin, which leads to a reduction in hardness.
Lidocaine versus Mepivacaine in Sedated Pediatric Dental Patients: Randomized, Prospective Clinical Study
Authors: Çalış Aylin Sipahi , Cagiran Esra , Efeoglu Candan , Ak Aslı Topaloglu , Koca Huseyın
Published: April 2015

Dental anxiety is usually seen in the pediatric patients. specially in the case of minor oral surgical procedures and exodontia, cooperation of the patients and their families with the dentist will lead to superior treatment outcomes. Pain control is important in dentistry. The aim of this randomized prospective clinical study is to compare the local anaesthetic and haemodynamic effects of 2% lidocaine (Group 1) and 3% mepivacaine (Group 2) in sedated pediatric patients undergoing primary tooth extraction. Study design: 60 pediatric patients undergoing sedation for elective primary tooth extraction was prospectively included in the study in a randomized fashion. Inclusion and exlusion criteria were assigned. Patients were given premedication via oral route. Local anesthesia was achieved before extraction(s). Results: There were no significant differences between the groups in patient demographics, number of teeth extracted, duration of the operation and time from the end of the procedure to discharge (p≯0.05). FLACC pain scale scores were not statistically significant between the groups, except at 20 minutes post-operatively when the score is significantly lower in Group 2 (p=0.029). Conclusion: Prevention of pain during dental procedures can nurture the relationship of the patient and dentist. Tooth extraction under sedation in pediatric patients could be safe with both local anesthetics.
Microabrasion: A Treatment Option For White Spots
Authors: Souza de Barros Vasconcelos MQ , Almeida Vieira K , da Consolação Canuto Salgueiro M , Almeida Alfaya T , Santos Ferreira C , Bussadori SK
Published: April 2015

The aim of the present study was to describe a clinical protocol for the treatment of white spots with the use of an abrasive material. A four-year-old patient presented with a white spot on tooth 51 and a white spot associated with a carious lesion in the cervical region of tooth 52. Treatment was planned with microabrasion and restoration of the upper right lateral incisor. Prophylaxis was first performed, followed by protection with a dental dam and the application of the abrasive material (silicon carbide and hydrochloric acid 6%). Five applications were needed to remove the spots. The restoration of the upper right lateral incisor was then performed with a resin composite. A good esthetic outcome was achieved and both the patient and her guardians were satisfied with the results. Microabrasion is a conservative treatment option that achieves satisfactory results with regard to tooth color.
Salivary Cortisol Levels and its Implication on Behavior In Children with Autism during Dental Treatment
Authors: Abdulla AM , Hegde AM
Published: April 2015

The aim of the study was to estimate the diurnal variations of salivary cortisol in children with autism and healthy children and it's implication on behavior during non-invasive dental procedures. Study design: 50 children with autism and 50 healthy children in the age group between 6 to 12 years of both genders with the need for dental treatment were included in the study. Whole unstimulated saliva was collected from them during early hours of the day and during evenings for 2 consecutive days . The collected saliva was then subjected to electrochemiluminescence assay . Minimum invasive dental procedures like hand scaling, pit and fissure sealants and glass ionomer cement restorations were performed for the participants each time after the saliva sample collection and their behavior during the procedures was rated using Frankl's Behavior Rating Scale. Results:Significant correlation was seen between cortisol levels and behavior in children with autism. As cortisol levels increased in children with autism, behavior worsened and as the cortisol levels decreased they showed positive behaviour. Conclusion: Cortisol acts as a stress marker and studying the diurnal variations of salivary cortisol can help us in attaining better knowledge about the behavior pattern and thereby assist us in modifying the behavior modification procedures and treatment planning in this group of special children.
Efficacy and Tolerance of Papain Gel with Conventional Drilling Method: A Clinico-Microbiological Study
Authors: Goyal PA , Kumari R , Kannan VP , Madhu S
Published: April 2015

Background: Conventional methods of caries removal are commonly associated with pain, fear and discomfort. Chemomechanical methods were introduced to instill a positive dental attitude. Agents like GK-101, Caridex, Carisolv did not prove effective alternatives owing to their high cost, need of special instruments and taste of chlorine. A new chemomechanical agent, Papacarie®, has been introduced to overcome these deficiencies.Objective:This study was aimed to compare the effectiveness and tolerance of Papacárie® with the conventional method. Method:25 children with at least two primary teeth with broad cavitated occlusal or cervical lesion were selected. One carious tooth from each patient was randomly treated with each of Papacarie® and conventional drilling method, one after the other. Time taken for caries excavation, child's pain perception, change in anxiety levels, microbial flora and child's preference of treatment were recorded separately for both the methods. Result:Although the mean time taken for caries removal by the Papacarie® method was slightly longer (P≯0.05) but it led to reduction in pain and anxiety (p<0.05). The viable bacterial counts were significantly reduced by either of the two methods (P <0�0001). More patients preferred Papacarie® over conventional method of treatment (P<0.05). Conclusion: Papacárie® method seems to be a better alternative to conventional method of caries removal.
Effect of Three Different Pastes on Remineralization of Initial Enamel Lesion: An in Vitro Study
Authors: Vyavhare S , Sharma DS , Kulkarni VK
Published: April 2015

Objective: Dental caries in enamel is unique as enamel is both acellular and avascular. Fluoride is one of the most effective remineralizing agents in caries prevention. The purpose of the study was to assess whether nano-hydroxyapatite and CPP-ACP can be used as an alternative to fluoride for remineralization of early carious lesions. Study design: Initial artificial carious lesions were prepared in enamel with demineralization solution. The treatment materials used as remineralizing agents were Nano-hydroxyapatite (10%), CPP – ACP (10%), NaF (1000 ppm) and Deionized water (negative control). Surface microhardness (SMH) measurements were performed before/after demineralization and after 3, 6, 9 and 12 days of pH cycling and the percentage surface microhardness recovery (%SMHR) was calculated. The specimens were then examined by scanning electron microscope. Results: Percentage surface microhardness recovery of nano-hydroxyapatite and fluoride was significantly greater than CPP – ACP and negative control. There was no significant difference of %SMHR between n-HA and fluoride at different time periods in the pH cycling. SEM analysis revealed n-HA particles were deposited on the demineralized enamel surface which formed a new surface layer. When observed under SEM CPP – ACP failed to show any significant surface remineralization while surface globular crystal depositions with multiple discrete porosities were evident with fluoride. Conclusion: It was concluded that nano-hydroxyapatite and fluoride had the potential to remineralize initial enamel lesions. CPP – ACP can be used as an effective adjunct to fluoride therapy but cannot be used as an alternative to fluoride.
Metadata Retention and the Internet
Authors: Huston Geoff
Published: April 2015

The Metadata Retention measures being considered in Australia make some sweeping assumptions about the semantics of IP addresses and their association with individual subscribers to the Internet. But are these assumptions warranted? The exhaustion of the free pool of IPv4 addresses has prompted a new generation of Internet services that treat IP addresses as ephemeral shared conversation tokens, and retaining address use metadata in such an environment is an exercise in futility. The regulatory environment persists in treating the Internet in the same manner as the telephone network, and as a network-centric service utility, while the revolutionary change that the Internet bought to the communications environment was to reverse the roles of network and attached device, and form a device-centric model of communications. Unless our regulators can grasp the implications of this essential architectural change we will continue to see misplaced and ultimately futile regulatory measures imposed on the Internet, to the ultimate cost of the consumer.
Suspended Solids Specifications for Water Injection from Coreflood Tests
Authors: Eylander J. G. R.
Published: April 2015

A method, which is based on the results of laboratory core-flood tests, is proposed for predicting the injectivity decline rate of water injectors. The method aims to provide design specifications for water treatment and injection facilities and procedures with which well injectivity behaviour can be analysed.

A mathematical approach is outlined which describes impairment behaviour in terms of core plug filtration characteristics. The experimental procedure for isolating essential filter-cake properties required for the decline rate calculations consists of core flood tests at simulated inflow conditions done in conjunction with solids' characterisation via Coulter counter analysis of the injection water. When the extent and mechanism of plugging and also the filter-cake properties in terms of permeability and porosity have been established, it becomes possible to predict an injection well's half-life in relation to injection water quality.

To illustrate the results that can be obtained with the proposed method, data from core-flood tests are used to construct injectivity decline rate curves for an arbitrary injection well.
A Mathematical Model for the Scale Inhibitor Squeeze Process
Authors: Hong S-A. , Shuler P. J.
Published: April 2015

A mathematical model was developed to describe the scale inhibitor adsorption squeeze process. The objective of this study was to create a tool that will predict the duration of a squeeze treatment, given the operating parameters and the rock and inhibitor properties.

Assuming there is local equilibrium between the inhibitor in solution and on the rock, the mathematical model was solved analytically via the method of characteristics. Algebraic equations were derived to calculate the scale inhibitor concentration in the produced water and the squeeze lifetime. The validity of the model is demonstrated by comparing its predictions with field and laboratory data. Sensitivity of the squeeze lifetime to variables associated with the process is presented. One important conclusion is that scale inhibitors should be screened on the basis of their adsorption characteristics as well as their effectiveness at low concentrations in preventing scale formation.

Finally, the complete mathematical model, which allows for time-dependent adsorption/desorption of the inhibitor, is solved numerically. Accurate predictions of the squeeze process require incorporation of these kinetic effects when the residence time is short compared to the time required to reach equilibrium. As demonstrated here, this can be significant especially in laboratory tests performed to measure squeeze lifetime. Scaling-up laboratory results for the field should be done with caution because these kinetic effects tend to increase squeeze lifetime. The equilibrium model gives the most conservative prediction of squeeze lifetime.
CO2 Generation During Steamflooding: A Geologically Based Kinetic Theory That Includes Carbon Isotope Effects and Application to High-Temperature Steamfloods
Authors: Cathles L. M. , Schoell M. , Simon R.
Published: April 2015

CO2 is commonly produced during steamflooding. In the higher temperature steamfloods the amount of CO2 produced is such that the only viable source is carbonate minerals. It is shown by reference to CO2 concentrations in natural geothermal systems that in most common rocks and sediments, CO2 will be naturally generated under hydrothermal (~300°C) conditions by the dissolution of carbonate minerals. The solubility of CO2 is a strong positive function of temperature and, at 300°C, is more than sufficient to account for high CO2 concentrations such as those encountered at Chevron's Buena Vista Hills (B.V. Hills) steamflood pilot test. A linear kinetic model Is developed to describe chemical equilibration and the generation of CO2 in the hot parts of the reservoir. The model also describes the precipitation of CO2 in the cooler parts of the rock formation where the fluid moves ahead of the thermal front. Changes in Carbon isotope concentration are included in the model. The small difference between the 13C in the produced gas and the source carbonates at B.V. Hills suggests little CO2 is precipitated as carbonate within that reservoir – a prediction that can be tested by post-steamflood coring.
An Experimental Investigation into the Effect of Chemical Type on CO2/Heavy-Hydrocarbon Phase Behavior
Authors: Wilburn D. L. , Bankston B. A. , Monger T. G.
Published: April 2015

This paper provides PVT and compositional data for seven CO2/synthetic-oil systems. The oils were composed of light paraffins plus heavy hydrocarbons selected from one or two of the three main chemical types; namely, paraffins, naphthenes, and aromatics. The PVT data were used to generate pressure-composition phase diagrams and swelling index profiles. The compositional data were smoothed to produce equilibrium phase compositions, K-values, and extraction indexes. Results for the different oils are contrasted using the comparison basis of equivalent molar averaged normal boiling point. This parameter is easy to calculate and provides a means by which chemical effects can be quantified in the presence of oil volatility effects.

The results demonstrate that two oil compositional effects control the extent of hydrocarbon extraction by CO2, and subsequently the development of CO2/synthetic-oil miscibility. The major effect is usually the oil volatility, but effects of hydrocarbon chemical type can be dominant. For example, a paraffinic-aromatic synthetic oil exhibited considerably greater miscibility with CO2 than a paraffinic-naphthenic synthetic oil of similar molecular weight and volatility. The substitution of naphthenes into a paraffinic mixture resulted in no appreciable increase in CO2 solubility for the heavy paraffins present, even though the volatility of the oil was increased. A similar substitution of aromatics enhanced the extraction of heavy paraffins by CO2. The data suggest a trend for the influence of chemical type on oil miscibility with CO2; namely, paraffins are beneficial, aromatics are nearly as beneficial as paraffins, and naphthenes are detrimental. The effect of chemical type on oil swelling is also significant. At near-miscible conditions, swelling was most extensive in the presence of aromatics. Swelling was insensitive to paraffins, with naphthenes showing intermediate behavior. The results also illustrate that near-critical liquid-liquid K-values exhibit trends similar to those reported in the literature for liquid-vapor K-values.
Towards the Preservation of the Scientific Memory
Authors: Matthews Brian , Crompton Shirley , Jones Catherine , Lambert Simon
Published: April 2015

In this paper we consider the requirements for preserving the memory of science.Â  This is becoming more challenging as data volumes and rates continue to increase.Â  Further, to capture a full picture of the scientific memory we need to move beyond the bit preservation challenge to consider how to capture research in context, represent the meaning of the data, and how to interpret data in relation to other scientific artefacts distributed in multiple information spaces. We review the progress of scientific research into the digital preservation of science over the last decade, emphasising in particular the research and development programme of STFC. We conclude with a number of observations into the future directions of research and also the practical deployment of policy and infrastructure to effectively preserve the scientific memory.
Interpreting Effectiveness Evidence in Pain: Short Tour of Contemporary Issues
Authors: O'Connell Neil E. , Moseley G. Lorimer , McAuley James H. , Wand Benedict M. , Herbert Robert D.
Published: April 2015

There is no shortage of treatment approaches offered to people with pain. The maze of options presents patients and clinicians with difficult choices. Key to making those choices is evidence of treatment effectiveness provided by clinical trials and systematic reviews. Recent growth in the number of clinical trials and systematic reviews, of both high and low quality, makes it vital that users of this evidence—clinicians, researchers, patients, and policy makers—have the skills and knowledge to critically interpret these studies. In this review, we discuss some contemporary issues regarding evidence of effectiveness derived from clinical trials and systematic reviews—issues that we think are critical to understanding the field. We focus on evidence of treatment effectiveness in pain, although many of these issues are relevant to and transferable across the spectrum of evidence-based practice.
Optical properties and weakening of elastic moduli with increasing glass transition temperature (T
g) in (80–x)TeO2-xBaO-20ZnO glasses
Authors: Ismail Muliana , Supardan Siti Nurbaya , Yahya Ahmad Kamal , Abd-Shukor Roslan
Published: April 2015

BaO addition to ternary (80–x)TeO2-20ZnO-xBaO (x = 0–20 mol.%) glasses resulted in a decrease in ultrasonic velocities and independent elastic moduli; this result indicated that the rigidity of the glass network weakened possibly because non-bridging oxygen increased. Thermal analysis results showed that glass transition temperature increased as BaO content increased because of the stabilizing effect of Ba2+ on the glass network. Additional analyses using bulk compression and ring deformation models revealed that the ratio between theoretical bulk modulus and experimental bulk modulus increased; this result indicated that the compression mechanism mainly involved isotropic ring compression. Furthermore, the increase in non-bridging oxygen formation with BaO addition caused a decrease in optical energy gap and an increase in refractive index. An increase in Urbach energy indicated that the degree of disorder in the glass system also increased.
Können Windwurfschäden vermindert werden? Eine Analyse von Einflussgrössen
Authors: Hanewinkel Marc , Albrecht Axel , Schmidt Matthias
Published: April 2015

Can windthrow damage be minimized? An analysis of predictors

The paper deals with different influencing factors that determine storm damage to forests and the question how this damage can be minimized. The influence factors include tree-related parameters like species, tree height and h/d-relation, terrain-related parameters (encompassing wind speed and soil condition), and type of forest management as well as stand structure. The analysis of a multitude of studies including empirical as well as mechanistic models reveals that coniferous species, especially Norway spruce, show a higher vulnerability towards storm damage than broadleaves. Many investigations point at a significant influence of tree height on storm damage probability, while the h/d-value does not have the same importance. Besides that, the influence of management operations, stand structure and surrounding forest stands as well as the vulnerability of selection forests (“plenter forest”) are analysed. Silvicultural treatment, mostly timing and intensity of the interventions, plays a role for determining damage severity, as well as soil water content (waterlogged soils) and exposure towards the main wind direction. Plenter forests appeared not to be very vulnerable to storm damage in the existing investigations in Switzerland, however, due to the lack of sufficient data, a general superiority of these uneven-aged forests compared to even-aged ones cannot be proved at the moment. Based on a discussion on the importance of the different parameters, measures to reduce storm damage to forests are discussed. Hereby mainly the choice of tree species, the limitation of the dominant height of forest stands as well as early and intensive thinning are investigated.
Landscape Democracy, Three Sets of Values, and the Connoisseur Method
Authors: Arler Finn , Mellqvist Helena
Published: April 2015

The European Landscape Convention has brought up the question of democracy in relation to landscape transformation, but without a clear definition of democracy. This paper conceptualises democracy in relation to three main sets of values related to self-determination, co-determination and respect for argument. It examines various methods that have been used to try to make landscape decisions more democratic. In the last part of the paper the connoisseur method is introduced. This method emphasises stakeholder participation in deliberative processes with a particular focus on place-based knowledge. It has been used in Sweden as a means of involving local stakeholders in the democratic process of defining goals and objectives of their landscapes. In the conclusion, this method is recommended despite its dependence on favourable conditions, particularly continuity and commitment, and a few suggestions about possible improvements are presented.
The Capabilities Approach and Environmental Sustainability: The Case for Functioning Constraints
Authors: Peeters Wouter , Dirix Jo , Sterckx Sigrid
Published: April 2015

The capabilities approach of Amartya Sen and Martha Nussbaum has become an influential viewpoint for addressing issues of social justice and human development. It has not yet, however, given adequate theoretical consideration to the requirements of environmental sustainability. Sen has focussed on the instrumental importance of human development for achieving sustainability, but has failed to consider the limits of this account, especially with respect to consumption-reduction. Nussbaum has criticised constraining material consumption for its paternalistic prescription of one particular conception of the good life, without considering it as an imperative of justice. We discuss two possible extensions of the capabilities approach. First, the concept of capability ceilings contains several attractive elements, but it also suffers from some shortcomings. Therefore, second, we advocate constraining people's combinations of functionings in accordance with a personal budget which consists of a fair share of environmental resources.
Heme Degradation by Heme Oxygenase Protects Mitochondria but Induces ER Stress via Formed Bilirubin
Authors: Müllebner Andrea , Moldzio Rudolf , Redl Heinz , Kozlov Andrey , Duvigneau J.
Published: April 2015

Heme oxygenase (HO), in conjunction with biliverdin reductase, degrades heme to carbon monoxide, ferrous iron and bilirubin (BR); the latter is a potent antioxidant. The induced isoform HO-1 has evoked intense research interest, especially because it manifests anti-inflammatory and anti-apoptotic effects relieving acute cell stress. The mechanisms by which HO mediates the described effects are not completely clear. However, the degradation of heme, a strong pro-oxidant, and the generation of BR are considered to play key roles. The aim of this study was to determine the effects of BR on vital functions of hepatocytes focusing on mitochondria and the endoplasmic reticulum (ER). The affinity of BR to proteins is a known challenge for its exact quantification. We consider two major consequences of this affinity, namely possible analytical errors in the determination of HO activity, and biological effects of BR due to direct interaction with protein function. In order to overcome analytical bias we applied a polynomial correction accounting for the loss of BR due to its adsorption to proteins. To identify potential intracellular targets of BR we used an in vitro approach involving hepatocytes and isolated mitochondria. After verification that the hepatocytes possess HO activity at a similar level as liver tissue by using our improved post-extraction spectroscopic assay, we elucidated the effects of increased HO activity and the formed BR on mitochondrial function and the ER stress response. Our data show that BR may compromise cellular metabolism and proliferation via induction of ER stress. ER and mitochondria respond differently to elevated levels of BR and HO-activity. Mitochondria are susceptible to hemin, but active HO protects them against hemin-induced toxicity. BR at slightly elevated levels induces a stress response at the ER, resulting in a decreased proliferative and metabolic activity of hepatocytes. However, the proteins that are targeted by BR still have to be identified.
Synthesis and Surface Thermodynamic Functions of CaMoO4 Nanocakes
Authors: Li Xingxing , Fan Gaochao , Huang Zaiyin
Published: April 2015

CaMoO4 nanocakes with uniform size and morphology were prepared on a large scale via a room temperature reverse-microemulsion method. The products were characterized in detail by X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. By establishing the relations between the thermodynamic functions of nano-CaMoO4 and bulk-CaMoO4 reaction systems, the equations for calculating the surface thermodynamic functions of nano-CaMoO4 were derived. Then, combined with in-situ microcalorimetry, the molar surface enthalpy, molar surface Gibbs free energy, and molar surface entropy of the prepared CaMoO4 nanocakes at 298.15 K were successfully obtained as (19.674 ± 0.017) kJ·mol−1, (619.704 ± 0.016) J·mol−1, and (63.908 ± 0.057) J·mol−1·K−1, respectively.
Innovative Nuclear Energy Systems: State-of-the Art Survey on Evaluation and Aggregation Judgment Measures Applied to Performance Comparison
Authors: Kuznetsov Vladimir , Fesenko Galina , Schwenk-Ferrero Aleksandra , Andrianov Andrei , Kuptsov Ilya
Published: April 2015

This paper summarizes the experience gained in the application of multi-criteria decision making and uncertainty treatment methods to a comparative assessment of nuclear energy systems and related nuclear fuel cycles. These judgment measures provide a means for comprehensive evaluation according to different conflicting criteria, such as costs, benefits and risks, which are inevitably associated with the deployment of advanced technologies. Major findings and recommendations elaborated in international and national projects and studies are reviewed and discussed. A careful analysis is performed for multi-criteria comparative assessment of nuclear energy systems and nuclear fuel cycles on the basis of various evaluation and screening results. The purpose of this paper is to discuss the lessons learned, to share the identified solutions, and indicate promising future directions.
Utilization of Electric Vehicles and Their Used Batteries for Peak-Load Shifting
Authors: Aziz Muhammad , Oda Takuya , Mitani Takashi , Watanabe Yoko , Kashiwagi Takao
Published: April 2015

The utilization of electric vehicles (EV) and their used batteries in supporting small-scale energy management systems were studied. Both theoretical study and practical demonstration were performed to measure the feasibility of the developed system. Each five EVs and used EV batteries were used along with 20 kW photovoltaic (PV) panels as a renewable energy source. The main objective of the developed system is performing a peak-load shifting by utilizing EVs, used EV batteries and PV panels. The planning of load leveling was performed 24 h ahead for each 30 min period. The studies showed that the application of EVs and used EV batteries in supporting certain small-scale energy management systems is feasible. In addition, some findings during the demonstration test were listed and analyzed for the purpose of further system development and deployment.
Co-Production of Olefins, Fuels, and Electricity from Conventional Pipeline Gas and Shale Gas with Near-Zero CO2 Emissions. Part II: Economic Performance
Authors: Salkuyeh Yaser , II Thomas
Published: April 2015

In this paper, techno-economic analyses of a polygeneration system for the production of olefins, transportation fuels and electricity are performed, considering various process options. Derivative-free optimization algorithms were coupled with Aspen Plus simulation models to determine the optimum product portfolio as a function of a wide variety of market prices. The optimization results show that the proposed plant is capable of producing olefins with the same production costs as traditional petrochemical routes while having effectively zero process CO2 emissions (including the utilities). This provides an economic and more sustainable alternative to traditional naphtha cracking.