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Sample records for pulp chamber temperature

  1. Temperature variation in pulp chamber during dental bleaching in presence or absence of light activation

    OpenAIRE

    Mollica, Fernanda Brandão; Rocha, Daniel Maranha da; Travassos, Alessandro Caldas; Valera, Marcia Carneiro; Araujo, Maria Amélia Maximo de

    2010-01-01

    PURPOSE: In addition to the chemical damage due to bleaching gels penetration into the pulp during pulp vitality dental bleaching, another possible aggressive factor could be the heat generated by the exothermal oxidation reaction of the bleaching gel, which may also be aggravated by the use of light activation. This study assessed the temperature variation in the pulp chamber in human teeth, using three different bleaching gels with or without LED light activation. METHODS: Thirty human pre-...

  2. Temperature changes in the pulp chamber during dentin ablation with Er:YAG laser

    Science.gov (United States)

    Zhang, Xianzeng; Zhao, Haibin; Zhan, Zhenlin; Guo, Wenqing; Xie, Shusen

    2012-12-01

    To examine the temperature changes in the pulp chamber during cavity preparation in dentin with the Er:YAG laser (2940 nm), a total 20 intact premolars teeth were divided into 4 groups for dentin ablation with different radiant exposures at 4Hz and 8Hz with and without water spray. A K-type thermocouple was used to monitor the temperature changes in pulp chamber during laser treatment. The total time of irradiation was 70 sec. the water spray rate was 3 mL/min. It showed that maximum temperature rise increases with the increasing of radiant exposure and pulse repetition rate and the additional water cooling during laser ablation can significantly reduce the temperature rise in pulp chamber which will benefit to avoid or reduce thermal damage to tooth structure and dental pulp. The highest rise of temperature in the pulp was achieved with 20 J/cm2 and 8 Hz (19.83°C ). For all sample without water spray, the rise of temperature was exceed 5 °C . In contrast, with water spray, the temperature rise in the pulp can be firmly controlled under 1°C. The results also indicated that ablation rate and efficiency can be enhanced by increasing the incident radiant exposure and pulse repetition rate, which simultaneously producing more heat accumulation in dental tissue and causing thermal damage to dental tissue. By applying an additional water spray, thermal damage can be significantly reduced in clinical application.

  3. Influence of whitening gel on pulp chamber temperature rise by in-office bleaching technique

    Directory of Open Access Journals (Sweden)

    Sandro Cordeiro Loretto

    Full Text Available INTRODUCTION: Dental bleaching is a conservative method for the aesthetic restoration of stained teeth. However, whitening treatments are likely to cause adverse effects when not well planned and executed. OBJECTIVE: This study evaluated the influence of whitening gel on temperature rise in the pulp chamber, using the in-office photoactivated dental bleaching technique. MATERIAL AND METHOD: The root portion of an upper central human incisor was sectioned 3mm below the cemento-enamel junction. The root canal was enlarged to permit the insertion of the K-type thermocouple sensor (MT-401 into the pulp chamber, which was filled with thermal paste to facilitate the transfer of heat during bleaching. Three photosensitive whitening agents (35% hydrogen peroxide were used: Whiteness HP (FGM, Whiteness HP Maxx (FGM and Lase Peroxide Sensy (DMC. An LED photocuring light (Flash Lite - Discus Dental was used to activate the whitening gels. Six bleaching cycles were performed on each group tested. The results were submitted to one-way ANOVA and LSD t-test (α<0.05. RESULT: The lowest mean temperature variation (ºC was detected for Lase Peroxide Sensy (0.20, while the highest was recorded for Whiteness HP (1.50. CONCLUSION: The Whiteness HP and Whiteness HP Maxx whitening gels significantly affected the temperature rise in the pulp chamber during bleaching, and this variation was dependent on the type of whitening gel used.

  4. In Vitro Study of Temperature Changes in Pulp Chamber During Root Planing Procedure Using Er:YAG Laser.

    Science.gov (United States)

    Yaneva, Blagovesta K; Zagorchev, Plamen I; Firkova, Elena I; Glavinkov, Ivan T

    2016-09-01

    To assess temperature changes at specified time intervals during Er:YAG laser scaling and root planing of surfaces with dental calculus. Fifteen single-rooted teeth with advanced periodontal disease were extracted and fixed in a cylinder thermostat filled with distilled water at constant temperature (35.5°C). A specially designed thermal probe (type K thermocouple) accurate to ±0.1°C over the range from 20°C to 80°C was fitted into the pulp chamber of tooth sample. Scaling and root planing of the mesial and distal root surfaces was performed using an Er:YAG laser (Lite Touch, Syneron Dental, Israel) with a wavelength of 2940 nm, provided with a chisel tip, and at the following settings: output energy 100 mJ and 50 Hz, duration of irradiation - 40 sec, the tip in contact mode oblique to the root surface at an angle of approximately 10-15 degrees and water spray level 5-6. The temperature inside the pulp chamber was measured every 10 sec. The temperature in the pulp chamber taken every 10 seconds and compared with the temperature of 35.5°C at baseline decreased by 1.6°C, 2.4°C, 2.5°C, and 2.5°C for the first, second, third and fourth measurement, respectively. These changes did not reach statistical significance. The Er:YAG laser does not increase the temperature inside the pulp chamber. The assessed changes do not depend on the duration of irradiation which was kept within 40 seconds. Therefore, this treatment modality causes no thermal damage to the pulp under the above defined conditions and can be considered safe.

  5. Comparison of temperature rise in the pulp chamber with different light curing units: An in-vitro study

    OpenAIRE

    Rajesh Ebenezar A; Anilkumar R; Indira R; Ramachandran S; Srinivasan M

    2010-01-01

    Aims/Objectives : This in vitro study was designed to measure and compare the temperature rise in the pulp chamber with different light curing units. Materials and Methods : The study was done in two settings-in-vitro and in-vivo simulation. In in-vitro setting, 3mm and 6mm acrylic spacers with 4mm tip diameter thermocouple was used and six groups were formed according to the light curing source- 3 Quartz-Tungsten-Halogen (QTH) units and 3 Light-Emitting-Diode (LED) units. For the LED units...

  6. Comparison of temperature rise in the pulp chamber with different light curing units: An in-vitro study

    OpenAIRE

    Rajesh Ebenezar, A V; Anilkumar, R; Indira, R; Ramachandran, S; Srinivasan, M R

    2010-01-01

    Aims/Objectives: This in vitro study was designed to measure and compare the temperature rise in the pulp chamber with different light curing units. Materials and Methods: The study was done in two settings-in-vitro and in-vivo simulation. In in-vitro setting, 3mm and 6mm acrylic spacers with 4mm tip diameter thermocouple was used and six groups were formed according to the light curing source- 3 Quartz-Tungsten-Halogen (QTH) units and 3 Light-Emitting-Diode (LED) units. For the LED units, th...

  7. In vitro pulp chamber temperature rise from irradiation and exotherm of flowable composites.

    Science.gov (United States)

    Baroudi, Kusai; Silikas, Nick; Watts, David C

    2009-01-01

    The aim of this study was to investigate the pulpal temperature rise induced during the polymerization of flowable and non-flowable composites using light-emitting diode (LED) and halogen (quartz-tungsten-halogen) light-curing units (LCUs). Five flowable and three non-flowable composites were examined. Pulpal temperature changes were recorded over 10 min in a sample primary tooth by a thermocouple. A conventional quartz-tungsten-halogen source and two LEDs, one of which was programmable, were used for light curing the resin composites. Three repetitions per material were made for each LCU. There was a wide range of temperature rises among the materials (P < 0.05). Temperature rises ranged between 1.3 degrees C for Filtek Supreme irradiated by low-power LED and 4.5 degrees C for Grandio Flow irradiated by high-power LED. The highest temperature rises were observed with both the LED high-power and soft-start LCUs. The time to reach the exothermic peak varied significantly between the materials (P < 0.05). Pulpal temperature rise is related to both the radiant energy output from LCUs and the polymerization exotherm of resin composites. A greater potential risk for heat-induced pulp damage might be associated with high-power LED sources. Flowable composites exhibited higher temperature rises than non-flowable materials, because of higher resin contents.

  8. Comparison of temperature rise in the pulp chamber with different light curing units: An in-vitro study.

    Science.gov (United States)

    Rajesh Ebenezar, A V; Anilkumar, R; Indira, R; Ramachandran, S; Srinivasan, M R

    2010-07-01

    This in vitro study was designed to measure and compare the temperature rise in the pulp chamber with different light curing units. The study was done in two settings-in-vitro and in-vivo simulation. In in-vitro setting, 3mm and 6mm acrylic spacers with 4mm tip diameter thermocouple was used and six groups were formed according to the light curing source- 3 Quartz-Tungsten-Halogen (QTH) units and 3 Light-Emitting-Diode (LED) units. For the LED units, three modes of curing like pulse-cure mode, fast mode and ramp mode were used. For in-vivo simulation, 12 caries free human third molar tooth with fused root were used. K-type thermocouple with 1 mm tip diameter was used. Occlusal cavity was prepared, etched, rinsed with water and blot dried; bonding agent was applied and incremental curing of composite was done. Thermal emission for each light curing agent was noted. Temperature rise was very minimal in LED light cure units than in QTH light cure units in both the settings. Temperature rise was minimal at 6mm distance when compared to 3 mm distance. Among the various modes, fast mode produces the less temperature rise. Temperature rise in all the light curing units was well within the normal range of pulpal physiology. Temperature rise caused due to light curing units does not result in irreversible pulpal damage.

  9. In vitro penetration of bleaching agents into the pulp chamber

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  10. Evaluation of temperature variation in pulp chamber after high power diode laser irradiation (λ=830 nm) on dental enamel: 'in vitro' study

    International Nuclear Information System (INIS)

    Macri, Rodrigo Teixeira

    2001-01-01

    The aim of this study was to observe the variation of temperature in the pulp chamber caused by irradiation of a commercial diode laser operating in continuous wave with wavelength 830 nm over the dental enamel. In the first part of this study, two types of tooth models were tested: 3,5 mm slice and whole tooth. In the second part, we irradiated the buccal si de of the enamel in 2 primary lower incisors from cattle with Opus 10 diode laser for 10 s with power levels of 1 W and 2 W, always using an absorber. Two thermocouples were used. The first one was inserted in the dentin wall closest to the irradiation site, while the second was inserted in the middle of the pulp chamber. It was observed that the thermocouples registered different temperatures. Always, the dentin thermocouple registered higher temperatures. Considering the dentin records, the irradiation of 1 W for 10 s can be safe for the pulp. Further studies must be developed related to the correct positioning of the thermocouples inside the pulp chamber. This was a first step of using diode laser in enamel, and in this study, we concluded that the Opus 10 diode laser shown to be safe for this use, with 1 W power for 10 S. (author)

  11. Evaluation of the temperature rise in pulp chamber during class V preparation with Er:YAG laser

    International Nuclear Information System (INIS)

    Picinini, Leonardo Santos

    2001-01-01

    One of the major concerns regarding laser irradiation in the dentistry field is the overheating in dental tissue, specially pulpal tissue. A temperature raise over 5.5 deg C is considered to be harmful to its vitality. The current study evaluated the temperature increase in the pulp chamber, during class V preparation, performed with the laser Er:YAG in 36 bovine incisive extracted teeth. The samples were eroded on the outer side of the vestibular wall to obtain the dentinal thickness of 2.0 mm (group I), 1.0 mm (group II) and 0.5 mm (group III). Thermocouples were fixed to the inner part of the vestibular wall using thermal paste, through the palatine opening of the samples. Class V cavities were prepared in the vestibular side only in 1 mm 2 thick dentins. Irradiation parameters used were: 500 mJ/10 Hz, 850 mJ/10 Hz and 1 000 mJ/10 Hz for all the groups. The results were processed by a microcomputer. This study showed that the temperature increased into the pulpal cavity reached around 3 deg C for the groups I (2,0 mm thick dentine) and II (1.0 mm thick dentine). In the group III (0.5 mm thick) temperature was around 5.5 deg C. Thus, the parameters used for cavity preparation, using Er:YAG laser, were safe in relation to the temperature raise for dentinal thickness of 1,0 and 2,0 mm; in 0.5 mm thick dentins, temperature increase reached 5.5 deg C and an appropriate correction in the laser parameters was necessary. (author)

  12. Pulp chamber temperature rise during curing of resin-based composites with different light-curing units.

    Science.gov (United States)

    Durey, Kathryn; Santini, Ario; Miletic, Vesna

    2008-01-01

    The purpose of the present study was to measure the intrapulpal temperature rise occurring during polymerisation of different shades of resin-based composites (RBCs), and two light-emitting diode (LED) units. Seventy non-carious permanent molars, that had been extracted for orthodontic purposes and stored in 2% thymol for not more than four months, were selected. Patient age range was 11-18 years. Standard cavity preparation with standardised remaining dentine thickness and placement of thermocouples (TCs) was prepared using a novel split-tooth technique. Cavities were filled with one of two shades of RBC (A2 and C4, Filtek Z250, 3M ESPE, Seefeld, Germany), and cured with two LED high-intensity units (Elipar Freelight2, 3M ESPE, Seefeld, Germany; Bluephase, Ivoclar Vivadent, Schaan, Liechtenstein) and a conventional halogen light-curing unit (LCU) (Prismetics Lite 2, Dentsply, Weybridge, Surrey, UK) as a control. Pulp temperature rises during bonding [A2 results: H;2.67/0.48:E;5.24/1.32;B;5.99/1.61] were always greater than during RBC curing [A2 results: 2.44/0.63;E3.34/0.70;B3.38/0.60], and these were significant for both LED lights but not for the halogen control, irrespective of shade (Mann-Whitney test: 95% confidence limits). Temperature rises were at times in excess of the values normally quoted as causing irreversible pulp damage. Pulp temperature rises during bonding were higher with the LED lights than with the halogen control. There was no significant difference in temperature rise between the two LED lights when bonding but there was a significant difference between the two LED lights and the halogen control LCUs (Kruskal-Wallis Test: 95% confidence limits). The results support the view that there is a potential risk for heat-induced pulpal injury when light-curing RBCs. The risk is greater during bonding and with high energy, as compared to low-energy output systems. As the extent of tolerable thermal trauma by the pulp tissues is unknown, care and

  13. Comparison of the Amount of Temperature Rise in the Pulp Chamber of Teeth Treated With QTH, Second and Third Generation LED Light Curing Units: An In Vitro Study.

    Science.gov (United States)

    Mahant, Rajesh Harivadanbhai; Chokshi, Shraddha; Vaidya, Rupal; Patel, Pruthvi; Vora, Asima; Mahant, Priyanka

    2016-01-01

    Introduction: This in vitro study was designed to measure and compare the amount of temperature rise in the pulp chamber of the teeth exposed to different light curing units (LCU), which are being used for curing composite restorations. Methods: The study was performed in two settings; first, an in vitro and second was mimicking an in vivo situation. In the first setup of the study, three groups were formed according to the respective three light curing sources. i.e. quartz-tungsten-halogen (QTH) unit and two light-emitting diode (LED) units (second and third generations). In the in vitro setting, direct thermal emission from three light sources at 3 mm and 6 mm distances, was measured with a k-type thermocouple, and connected to a digital thermometer. For a simulation of an in vivo situation, 30 premolar teeth were used. Class I Occlusal cavity of all the teeth were prepared and they were restored with incremental curing of composite, after bonding agent application. While curing the bonding agent and composite in layers, the intrapulpal temperature rise was simultaneously measured with a k-type thermocouple. Results: The first setting of the study showed that the heat produced by irradiation with LCU was significantly less at 6 mm distance when compared to 3 mm distance. The second setting of the study showed that the rise of intrapulpal temperature was significantly less with third generation LED light cure units than with second generation LED and QTH light cure units. Conclusion: As the distance from the light source increases, less irradiation heat is produced. Third generation LED lights cause the least temperature change in the pulp chamber of single rooted teeth.

  14. Evaluation of temperature variation in pulp chamber after high power diode laser irradiation ({lambda}=830 nm) on dental enamel: 'in vitro' study; Avaliacao da variacao da temperatura na camara pulpar apos a irradiacao de diodo laser de alta potencia de 830 nanometros em esmalte dental: estudo 'in vitro'

    Energy Technology Data Exchange (ETDEWEB)

    Macri, Rodrigo Teixeira

    2001-07-01

    The aim of this study was to observe the variation of temperature in the pulp chamber caused by irradiation of a commercial diode laser operating in continuous wave with wavelength 830 nm over the dental enamel. In the first part of this study, two types of tooth models were tested: 3,5 mm slice and whole tooth. In the second part, we irradiated the buccal si de of the enamel in 2 primary lower incisors from cattle with Opus 10 diode laser for 10 s with power levels of 1 W and 2 W, always using an absorber. Two thermocouples were used. The first one was inserted in the dentin wall closest to the irradiation site, while the second was inserted in the middle of the pulp chamber. It was observed that the thermocouples registered different temperatures. Always, the dentin thermocouple registered higher temperatures. Considering the dentin records, the irradiation of 1 W for 10 s can be safe for the pulp. Further studies must be developed related to the correct positioning of the thermocouples inside the pulp chamber. This was a first step of using diode laser in enamel, and in this study, we concluded that the Opus 10 diode laser shown to be safe for this use, with 1 W power for 10 S. (author)

  15. Evaluation of the temperature rise in pulp chamber during class V preparation with Er:YAG laser; Avaliacao da temperatura na camara pulpar durante preparo classe V com laser de Erbio:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Picinini, Leonardo Santos

    2001-07-01

    One of the major concerns regarding laser irradiation in the dentistry field is the overheating in dental tissue, specially pulpal tissue. A temperature raise over 5.5 deg C is considered to be harmful to its vitality. The current study evaluated the temperature increase in the pulp chamber, during class V preparation, performed with the laser Er:YAG in 36 bovine incisive extracted teeth. The samples were eroded on the outer side of the vestibular wall to obtain the dentinal thickness of 2.0 mm (group I), 1.0 mm (group II) and 0.5 mm (group III). Thermocouples were fixed to the inner part of the vestibular wall using thermal paste, through the palatine opening of the samples. Class V cavities were prepared in the vestibular side only in 1 mm{sup 2} thick dentins. Irradiation parameters used were: 500 mJ/10 Hz, 850 mJ/10 Hz and 1 000 mJ/10 Hz for all the groups. The results were processed by a microcomputer. This study showed that the temperature increased into the pulpal cavity reached around 3 deg C for the groups I (2,0 mm thick dentine) and II (1.0 mm thick dentine). In the group III (0.5 mm thick) temperature was around 5.5 deg C. Thus, the parameters used for cavity preparation, using Er:YAG laser, were safe in relation to the temperature raise for dentinal thickness of 1,0 and 2,0 mm; in 0.5 mm thick dentins, temperature increase reached 5.5 deg C and an appropriate correction in the laser parameters was necessary. (author)

  16. Low Temperature Soda-Oxygen Pulping of Bagasse.

    Science.gov (United States)

    Yue, Fengxia; Chen, Ke-Li; Lu, Fachuang

    2016-01-13

    Wood shortages, environmental pollution and high energy consumption remain major obstacles hindering the development of today's pulp and paper industry. Energy-saving and environmental friendly pulping processes are still needed, especially for non-woody materials. In this study, soda-oxygen pulping of bagasse was investigated and a successful soda-oxygen pulping process for bagasse at 100 °C was established. The pulping parameters of choice were under active alkali charge of 23%, maximum cooking temperature 100 °C, time hold at maximum temperature 180 min, initial pressure of oxygen 0.6 MPa, MgSO4 charge 0.5%, and de-pithed bagasse consistency 12%. Properties of the resultant pulp were screened yield 60.9%, Kappa number 14, viscosity 766 dm³/kg, and brightness 63.7% ISO. Similar pulps were also obtained at 110 °C or 105 °C with a cooking time of 90 min. Compared with pulps obtained at higher temperatures (115-125 °C), this pulp had higher screened yield, brightness, and acceptable viscosity, while the delignification degree was moderate. These results indicated that soda-oxygen pulping at 100 °C, the lowest cooking temperature reported so far for soda-oxygen pulping, is a suitable process for making chemical pulp from bagasse. Pulping at lower temperature and using oxygen make it an environmental friendly and energy-saving pulping process.

  17. Low Temperature Soda-Oxygen Pulping of Bagasse

    Directory of Open Access Journals (Sweden)

    Fengxia Yue

    2016-01-01

    Full Text Available Wood shortages, environmental pollution and high energy consumption remain major obstacles hindering the development of today’s pulp and paper industry. Energy-saving and environmental friendly pulping processes are still needed, especially for non-woody materials. In this study, soda-oxygen pulping of bagasse was investigated and a successful soda-oxygen pulping process for bagasse at 100 °C was established. The pulping parameters of choice were under active alkali charge of 23%, maximum cooking temperature 100 °C, time hold at maximum temperature 180 min, initial pressure of oxygen 0.6 MPa, MgSO4 charge 0.5%, and de-pithed bagasse consistency 12%. Properties of the resultant pulp were screened yield 60.9%, Kappa number 14, viscosity 766 dm3/kg, and brightness 63.7% ISO. Similar pulps were also obtained at 110 °C or 105 °C with a cooking time of 90 min. Compared with pulps obtained at higher temperatures (115–125 °C, this pulp had higher screened yield, brightness, and acceptable viscosity, while the delignification degree was moderate. These results indicated that soda-oxygen pulping at 100 °C, the lowest cooking temperature reported so far for soda-oxygen pulping, is a suitable process for making chemical pulp from bagasse. Pulping at lower temperature and using oxygen make it an environmental friendly and energy-saving pulping process.

  18. Study of pulp chamber morphology of primary mandibular molars using spiral computed tomography.

    Science.gov (United States)

    Selvakumar, Haridoss; Kavitha, Swaminathan; Vijayakumar, Rajendran; Eapen, Thomas; Bharathan, Rajendran

    2014-11-01

    The purpose of this study was to evaluate the pulp chamber morphology in primary mandibular molars using spiral computed tomography (SCT). Sixty extracted primary mandibular molars were scanned using SCT for the (i) distance between the central fissure to furcation, (ii) distance between the central fissure to the floor of the pulp chamber, (iii) height of the pulp chamber (roof-floor), (iv) distance between the floor of the pulp chamber to the furcation. The mean and standard deviation was analyzed using statistical package for the social sciences (SPSS) program. The results of this study show that the average mean distance from the central fissure to the floor of the pulp chamber is 5.07 mm in first mandibular primary molar and 5.54 mm in second mandibular primary molar. It can be concluded that the greatest depth to which a bur can go during access opening without perforating the furcation in first primary mandibular molar is 5.07 mm and 5.54 mm in second primary mandibular molar.

  19. Adhesion to pulp chamber dentin: Effect of ethanol-wet bonding technique and proanthocyanidins application

    Directory of Open Access Journals (Sweden)

    Pallavi Sharma

    2015-01-01

    Full Text Available Aim: To evaluate the microleakage of a simplified etch-and-rinse adhesive bonded to pulp chamber dentin with water-wet bonding (WWB or ethanol-wet bonding (EWB with and without proanthocyanidins (PA application. Materials and Methods: Total 88 non-carious extracted human molar teeth were sectioned horizontally to expose the pulp chambers 1.5 mm coronal to the cemento-enamel junction. After the pulp tissue extirpation, canal orifices were enlarged and the root ends were sealed. The samples were randomly divided equally into following four groups according to the four bonding techniques performed using Adper Single Bond 2 [SB] adhesive (1 WWB; (2 EWB; (3 WWB and PA application [WWB + PA]; (4 EWB and PA application [EWB + PA]. Composite resin restorations were performed in all the pulp chambers. Total 20 samples from each group were subjected to microleakage evaluation, and two samples per group were assessed under scanning electron microscope for interfacial micromorphology. Results: The least microleakage score was observed in group 2 (EWB with similar results seen in group 4 (EWB + PA (P = 0.918. Group 2 (EWB showed significantly less microleakage than group 1 (WWB; P = 0.002 and group 3 (WWB + PA; P = 0.009. Group 4 (EWB + PA also depicted significantly reduced microleakage as compared with group 1 (WWB; P = 0.001 and group 3 (WWB + PA; P = 0.003. Conclusion: The use of EWB technique in a clinically relevant simplified dehydration protocol significantly reduced microleakage in simplified etch-and-rinse adhesive, Adper Single Bond 2, bonded to pulp chamber dentin. Application of PA had no significant effect on the microleakage of the adhesive bonded with either WWB or EWB.

  20. Effects of the concentration and composition of in-office bleaching gels on hydrogen peroxide penetration into the pulp chamber.

    Science.gov (United States)

    Mena-Serrano, A P; Parreiras, S O; do Nascimento, E M S; Borges, C P F; Berger, S B; Loguercio, A D; Reis, A

    2015-01-01

    In tooth whitening, the hydrogen peroxide (HP) diffuses in the enamel and dentin, reaching the pulp. This in vitro study aimed to quantify the penetration of HP in the pulp chamber in teeth submitted to bleaching agents of different concentrations of HP without calcium (HP 20% [20CF], HP 35% [35CF]) and with calcium (HP 20% [20CC], HP 35% [35CC]). Fifty human premolars were sectioned 3 mm from the cemento-enamel junction and the pulp tissue was removed. The teeth were divided into five groups according to treatment and with a control group (n=10). An acetate buffer solution was placed in the pulp chamber of all teeth. The control group was exposed only to distilled water, while the other groups were treated with a bleaching procedure, according to the manufacturer's recommendations. After treatment, the acetate buffer solution was transferred to a glass tube in which leuco-crystal violet and peroxidase solutions were added, resulting in a blue solution. The optical density of this blue solution was determined spectrophotometrically and converted into micrograms equivalent to the HP. Data were analyzed using analysis of variance and Tukey tests (α=0.05). The HP concentration did not affect the HP inside the pulp chamber, but the presence of calcium significantly reduced it (p<0.0001). The amount of HP that reaches the pulp chamber depends on the bleaching protocol and the product employed, and it seems to be less affected by HP concentration.

  1. Temperature Studies for ATLAS MDT BOS Chambers

    CERN Document Server

    Engl, A.; Biebel, O.; Mameghani, R.; Merkl, D.; Rauscher, F.; Schaile, D.; Ströhmer, R.

    Data sets with high statistics taken at the cosmic ray facility, equipped with 3 ATLAS BOS MDT chambers, in Garching (Munich) have been used to study temperature and pressure effects on gas gain and drifttime. The deformation of a thermally expanded chamber was reconstructed using the internal RasNik alignment monitoring system and the tracks from cosmic data. For these studies a heating system was designed to increase the temperature of the middle chamber by up to 20 Kelvins over room temperature. For comparison the temperature effects on gas properties have been simulated with Garfield. The maximum drifttime decreased under temperature raise by -2.21 +- 0.08 ns/K, in agreement with the results of pressure variations and the Garfield simulation. The increased temperatures led to a linear increase of the gas gain of about 2.1% 1/K. The chamber deformation has been analyzed with the help of reconstructed tracks. By the comparison of the tracks through the reference chambers with these through the test chamber ...

  2. Liquid-filled ionization chamber temperature dependence

    Energy Technology Data Exchange (ETDEWEB)

    Franco, L. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain)]. E-mail: luciaff@usc.es; Gomez, F. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Iglesias, A. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pardo, J. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pazos, A. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pena, J. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Zapata, M. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain)

    2006-05-10

    Temperature and pressure corrections of the read-out signal of ionization chambers have a crucial importance in order to perform high-precision absolute dose measurements. In the present work the temperature and pressure dependences of a sealed liquid isooctane filled ionization chamber (previously developed by the authors) for radiotherapy applications have been studied. We have analyzed the thermal response of the liquid ionization chamber in a {approx}20 deg. C interval around room temperature. The temperature dependence of the signal can be considered linear, with a slope that depends on the chamber collection electric field. For example, a relative signal slope of 0.27x10{sup -2}K{sup -1} for an operation electric field of 1.67x10{sup 6}Vm{sup -1} has been measured in our detector. On the other hand, ambient pressure dependence has been found negligible, as expected for liquid-filled chambers. The thermal dependence of the liquid ionization chamber signal can be parametrized within the Onsager theory on initial recombination. Considering that changes with temperature of the detector response are due to variations in the free ion yield, a parametrization of this dependence has been obtained. There is a good agreement between the experimental data and the theoretical model from the Onsager framework.

  3. Temperature uniformity in the CERN CLOUD chamber

    Directory of Open Access Journals (Sweden)

    A. Dias

    2017-12-01

    Full Text Available The CLOUD (Cosmics Leaving OUtdoor Droplets experiment at CERN (European Council for Nuclear Research investigates the nucleation and growth of aerosol particles under atmospheric conditions and their activation into cloud droplets. A key feature of the CLOUD experiment is precise control of the experimental parameters. Temperature uniformity and stability in the chamber are important since many of the processes under study are sensitive to temperature and also to contaminants that can be released from the stainless steel walls by upward temperature fluctuations. The air enclosed within the 26 m3 CLOUD chamber is equipped with several arrays (strings of high precision, fast-response thermometers to measure its temperature. Here we present a study of the air temperature uniformity inside the CLOUD chamber under various experimental conditions. Measurements were performed under calibration conditions and run conditions, which are distinguished by the flow rate of fresh air and trace gases entering the chamber at 20 and up to 210 L min−1, respectively. During steady-state calibration runs between −70 and +20 °C, the air temperature uniformity is better than ±0.06 °C in the radial direction and ±0.1 °C in the vertical direction. Larger non-uniformities are present during experimental runs, depending on the temperature control of the make-up air and trace gases (since some trace gases require elevated temperatures until injection into the chamber. The temperature stability is ±0.04 °C over periods of several hours during either calibration or steady-state run conditions. During rapid adiabatic expansions to activate cloud droplets and ice particles, the chamber walls are up to 10 °C warmer than the enclosed air. This results in temperature differences of ±1.5 °C in the vertical direction and ±1 °C in the horizontal direction, while the air returns to its equilibrium temperature with a time constant of about 200 s.

  4. Penetration of 35% hydrogen peroxide into the pulp chamber in bovine teeth after LED or Nd:YAG laser activation.

    Science.gov (United States)

    Camargo, Samira Esteves Afonso; Cardoso, Paula Elaine; Valera, Marcia Carneiro; de Araújo, Maria Amélia Máximo; Kojima, Alberto Noriyuki

    2009-01-01

    This aim of the present study was to evaluate the pulp chamber penetration of 35% hydrogen peroxide activated by LED (light-emitting diode) or Nd:YAG laser in bovine teeth, after an in-office bleaching technique. Forty-eight bovine lateral incisors were divided into four groups, acetate buffer was placed into the pulp chamber and bleaching agent was applied as follows: for group A (n = 12), activation was performed by LED; for group B (n = 12), activation was performed by Nd:YAG laser (60 mJ, 20 Hz); group C (n = 12) received no light or laser activation; and the control group (n = 12) received no bleaching gel application or light or laser activation. The acetate buffer solution was transferred to a glass tube and Leuco Crystal Violet and horseradish peroxidase were added, producing a blue solution. The optical density of this solution was determined spectrophotometrically and converted into microgram equivalents of hydrogen peroxide. The results were analysed using ANOVA and Tukey's test (5%). It was verified that the effect of activation was significant, as groups activated by LED or laser presented greater hydrogen peroxide penetration into the pulp chamber (0.499 +/- 0.622 microg) compared with groups that were not (0.198 +/- 0.218 microg). There was no statistically significant difference in the penetration of hydrogen peroxide into the pulp chamber between the two types of activation (LED or laser). The results suggest that activation by laser or LED caused an increase in hydrogen peroxide penetration into the pulp chamber.

  5. Penetration of 38% hydrogen peroxide into the pulp chamber in bovine and human teeth submitted to office bleach technique.

    Science.gov (United States)

    Camargo, Samira Esteves Afonso; Valera, Marcia Carneiro; Camargo, Carlos Henrique Ribeiro; Gasparoto Mancini, Maria Nadir; Menezes, Marcia Maciel

    2007-09-01

    This study evaluated the pulp chamber penetration of peroxide bleaching agent in human and bovine teeth after office bleach technique. All the teeth were sectioned 3 mm apical of the cement-enamel junction and were divided into 2 groups, A (70 third human molars) and B (70 bovine lateral incisors), that were subdivided into A1 and B1 restored by using composite resin, A2 and B2 by using glass ionomer cement, and A3 and B3 by using resin-modified glass ionomer cement; A4, A5, B4, and B5 were not restored. Acetate buffer was placed in the pulp chamber, and the bleaching agent was applied for 40 minutes as follows: A1-A4 and B1-B4, 38% hydrogen peroxide exposure and A5 and B5, immersion into distilled water. The buffer solution was transferred to a glass tube in which leuco crystal violet and horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to analysis of variance and Dunnett, Kruskal-Wallis, and Tukey tests (5%). A higher level of hydrogen peroxide penetrated into the pulp chamber in resin-modified glass ionomer cements in bovine (0.79 +/- 0.61 microg) and human (2.27 +/- 0.41 microg) groups. The bleaching agent penetration into the pulp chamber was higher in human teeth for any experimental situation. The penetration of the hydrogen peroxide depends on restorative materials, and under the conditions of this study human teeth are more susceptible to penetration of bleaching agent into the pulp chamber than bovine teeth.

  6. Low Temperature Soda-Oxygen Pulping of Bagasse

    OpenAIRE

    Fengxia Yue; Ke-Li Chen; Fachuang Lu

    2016-01-01

    Wood shortages, environmental pollution and high energy consumption remain major obstacles hindering the development of today’s pulp and paper industry. Energy-saving and environmental friendly pulping processes are still needed, especially for non-woody materials. In this study, soda-oxygen pulping of bagasse was investigated and a successful soda-oxygen pulping process for bagasse at 100 °C was established. The pulping parameters of choice were under active alkali charge of 23%, maximum coo...

  7. Topography of the pulp chamber in the maxillary primary molars of a Tunisian children

    Directory of Open Access Journals (Sweden)

    Chiraz Baccouche

    2013-01-01

    Conclusion: Mesiodistal dimension of the pulp cavity is not proportional to that of the dental crown. Endodontic access cavity have to be shifted to the distal and vestibular sides from the first to the second upper molar.

  8. Age estimation based on pulp chamber volume of first molars from cone-beam computed tomography images.

    Science.gov (United States)

    Ge, Zhi-pu; Ma, Ruo-han; Li, Gang; Zhang, Ji-zong; Ma, Xu-chen

    2015-08-01

    To establish a method that can be used for human age estimation on the basis of pulp chamber volume of first molars and to identify whether the method is good enough for age estimation in real human cases. CBCT images of 373 maxillary first molars and 372 mandibular first molars were collected to establish the mathematical model from 190 female and 213 male patients whose age between 12 and 69 years old. The inclusion criteria of the first molars were: no caries, no excessive tooth wear, no dental restorations, no artifacts due to metal restorative materials present in adjacent teeth, and no pulpal calcification. All the CBCT images were acquired with a CBCT unit NewTom VG (Quantitative Radiology, Verona, Italy) and reconstructed with a voxel-size of 0.15mm. The images were subsequently exported as DICOM data sets and imported into an open source 3D image semi-automatic segmenting and voxel-counting software ITK-SNAP 2.4 for the calculation of pulp chamber volumes. A logarithmic regression analysis was conducted with age as dependent variable and pulp chamber volume as independent variables to establish a mathematical model for the human age estimation. To identify the precision and accuracy of the model for human age estimation, another 104 maxillary first molars and 103 mandibular first molars from 55 female and 57 male patients whose age between 12 and 67 years old were collected, too. Mean absolute error and root mean square error between the actual age and estimated age were used to determine the precision and accuracy of the mathematical model. The study was approved by the Institutional Review Board of Peking University School and Hospital of Stomatology. A mathematical model was suggested for: AGE=117.691-26.442×ln (pulp chamber volume). The regression was statistically significant (p=0.000volume of first molar is a useful index for the estimation of human age with reasonable precision and accuracy. Copyright © 2015 Elsevier Ireland Ltd. All rights

  9. Rheological behavior of Brazilian Cherry (Eugenia uniflora L. pulp at pasteurization temperatures

    Directory of Open Access Journals (Sweden)

    Alessandra Santos Lopes

    2013-03-01

    Full Text Available The rheological behavior of Brazilian Cherry (Eugenia uniflora L. pulp in the range of temperatures used for pasteurization (83 to 97 °C was studied. The results indicated that Brazilian Cherry pulp presented pseudoplastic behavior, and the Herschel-Bulkley model was considered more adequate to represent the rheological behavior of this pulp in the range of temperatures studied. The fluid behavior index (n varied in the range from 0.448 to 0.627. The effect of temperature on the apparent viscosity was described by an equation analogous to Arrhenius equation, and a decrease in apparent viscosity with an increase in temperature was observed.

  10. Development of a combined piezoresistive pressure and temperature sensor using a chemical protective coating for Kraft pulp digester process monitoring

    International Nuclear Information System (INIS)

    Mohammadi, Abdolreza R; Chiao, Mu; Bennington, Chad P J

    2011-01-01

    We have developed an integrated piezoresistive pressure and temperature sensor for multiphase chemical reactors, primarily Kraft pulp digesters (pH 13.5, temperatures up to 175 °C, reaching a local maximum of 180 °C and pressures up to 2 MPa). The absolute piezoresistive pressure sensor consisted of a large square silicon diaphragm (1000 × 1000 µm 2 ) and high resistance piezoresistors (10 000 Ω). A 4500 Ω buried piezoresistive wire was patterned on the silicon chip to form a piezoresistive temperature sensor which was used for pressure sensor compensation and temperature measurement. A 4 µm thick Parylene HT® coating, a chemically resistant epoxy and a silicone conformal coating were deposited to passivate the pressure sensor against the caustic environment in Kraft digesters. The sensors were characterized up to 2 MPa and 180 °C in an environment chamber. A maximum thermal error of ±0.72% full-scale output (FSO), an average sensitivity of 0.116 mV (V kPa) −1 and a power consumption of 0.3 mW were measured in the pressure sensor. The sensors' resistances were measured before and after test in a Kraft pulping cycle and showed no change in their values. SEM pictures and topographical surfaces were also analyzed before and after pulp liquor exposure and showed no observable changes.

  11. The Design of Temperature and Humidity Chamber Monitor and Controller

    OpenAIRE

    Tibebu, Simachew

    2016-01-01

    The temperature and humidity chamber, (climate chamber) is a device located at the Technobothnia Education and Research Center that simulates different climate conditions. The simulated environment is used to test the capabilities of electrical equipment in different temperature and humidity conditions. The climate chamber, among other things houses a dedicated computer, the control PC, and a control software running in it which together are responsible for running and control-ling these simu...

  12. Study on the Temperature Separation Phenomenon in a Vortex Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Ye, A Ran; Guang, Zhang; Kim, Heuy Dong [Andong National University, Andong (Korea, Republic of)

    2014-09-15

    A vortex chamber is a simple device that separates compressed gas into a high-temperature stream and a low-temperature stream. It is increasing in popularity as a next-generation heat exchanger, but the flow physics associated with it is not yet well understood. In the present study, both experimental and numerical analyses were performed to investigate the temperature separation phenomenon inside the vortex chamber. Static pressures and temperatures were measured using high-sensitivity pressure transducers and thermocouples, respectively. Computational fluid dynamics was applied to simulate 3D unsteady compressible flows. The simulation results showed that the temperature separation is strongly dependent on the diameter of the vortex chamber and the supply pressure at the inlet ports, where the latter is closely related to the viscous work. The previous concept of a pressure gradient wave may not be a reasoning for temperature separation phenomenon inside the vortex chamber.

  13. High-alkali low-temperature polysulfide pulping (HALT) of Scots pine.

    Science.gov (United States)

    Paananen, Markus; Sixta, Herbert

    2015-10-01

    High-alkali low-temperature polysulfide pulping (HALT) was effectively utilised to prevent major polysaccharide losses while maintaining the delignification rate. A yield increase of 6.7 wt% on wood was observed for a HALT pulp compared to a conventionally produced kappa number 60 pulp with comparable viscosity. Approximately 70% of the yield increase was attributed to improved galactoglucomannan preservation and 30% to cellulose. A two-stage oxygen delignification sequence with inter-stage peroxymonosulphuric acid treatment was used to ensure delignification to a bleachable grade. In a comparison to conventional pulp, HALT pulp effectively maintained its yield advantage. Diafiltration trials indicate that purified black liquor can be directly recycled, as large lignin fractions and basically all dissolved polysaccharides were separated from the alkali-rich BL. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Age estimation by assessment of pulp chamber volume: a Bayesian network for the evaluation of dental evidence.

    Science.gov (United States)

    Sironi, Emanuele; Taroni, Franco; Baldinotti, Claudio; Nardi, Cosimo; Norelli, Gian-Aristide; Gallidabino, Matteo; Pinchi, Vilma

    2017-11-14

    The present study aimed to investigate the performance of a Bayesian method in the evaluation of dental age-related evidence collected by means of a geometrical approximation procedure of the pulp chamber volume. Measurement of this volume was based on three-dimensional cone beam computed tomography images. The Bayesian method was applied by means of a probabilistic graphical model, namely a Bayesian network. Performance of that method was investigated in terms of accuracy and bias of the decisional outcomes. Influence of an informed elicitation of the prior belief of chronological age was also studied by means of a sensitivity analysis. Outcomes in terms of accuracy were adequate with standard requirements for forensic adult age estimation. Findings also indicated that the Bayesian method does not show a particular tendency towards under- or overestimation of the age variable. Outcomes of the sensitivity analysis showed that results on estimation are improved with a ration elicitation of the prior probabilities of age.

  15. Computational investigation of the temperature separation in vortex chamber

    International Nuclear Information System (INIS)

    Anish, S.; Setoguchi, T.; Kim, H. D.

    2014-01-01

    The vortex chamber is a mechanical device, without any moving parts that separates compressed gas into a high temperature region and a low temperature region. Functionally vortex chamber is similar to a Ranque-Hilsch vortex tube (RVHT), but it is a simpler and compact structure. The objective of the present study is to investigate computationally the physical reasoning behind the energy separation mechanism inside a vortex chamber. A computational analysis has been performed using three-dimensional compressible Navier Stokes equations. A fully implicit finite volume scheme was used to solve the governing equations. A commercial software ANSYS CFX is used for this purpose. The computational predictions were validated with existing experimental data. The results obtained show that the vortex chamber contains a large free vortex zone and a comparatively smaller forced vortex region. The physical mechanism that causes the heating towards periphery of the vortex chamber is identified as the work done by the viscous force. The cooling at the center may be due to expansion of the flow. The extent of temperature separation greatly depends on the outer diameter of the vortex chamber. A small amount of compression is observed towards the periphery of the vortex chamber when the outer diameter is reduced.

  16. Optical Pressure-Temperature Sensor for a Combustion Chamber

    Science.gov (United States)

    Wiley, John; Korman, Valentin; Gregory, Don

    2008-01-01

    A compact sensor for measuring temperature and pressure in a combusti on chamber has been proposed. The proposed sensor would include two optically birefringent, transmissive crystalline wedges: one of sapph ire (Al2O3) and one of magnesium oxide (MgO), the optical properties of both of which vary with temperature and pressure. The wedges wou ld be separated by a vapor-deposited thin-film transducer, which wou ld be primarily temperaturesensitive (in contradistinction to pressur e- sensitive) when attached to a crystalline substrate. The sensor w ould be housed in a rugged probe to survive the extreme temperatures and pressures in a combustion chamber.

  17. Chamber for uniaxial pressure application at low temperatures

    International Nuclear Information System (INIS)

    Grillo, M.L.N.; Carmo, L.C.S. do; Picon, A.P.

    1984-08-01

    A chamber for alignment of low temperature ferroelastic domains in crystals by the use of uniaxial stress was built. The system allows the use of EPR and optical techniques, as well as X-ray irradiation at temperatures as low as 77K. (Author) [pt

  18. Optimizing residence time, temperature and speed to improve TMP pulp properties and reduce energy

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, M.; Xu, E.; Cort, B.; Boileau, I.; Waller, A.

    1997-04-01

    The concept of reducing energy consumption in pulp mills by increasing the disc speed of refining has been established using single disc and double disc refiners in both pilot plant and mill applications. The RTS study evaluated in this paper reviews the effect of high-speed single disc refining coupled with shortdwell-high pressure retention conditions. Coupling these variables permitted evaluation of an optimum residence time, temperature and speed (RTS) operational window. The objective of the RTS conditions to sufficiently soften the wood chips through high temperature such that the fibre is more receptive to initial defiberization at high intensity. The improved pulp from the primary refiner at high intensity could potentially demonstrate improvements in physical pulp properties at a reduced specific energy requirement. The spruce/fir RTS-TMP described here required significantly less specific energy and produced TMP with slightly improved strength properties and equivalent optical properties compared to conventional TMP pulp. Studies on the radiate pine furnish indicated that the physical pulp property/specific energy relationships could be adjusted by manipulating the residence time. 4 refs., 10 tabs., 10 figs.

  19. Distributed remote temperature monitoring system for INDUS-2 vacuum chambers

    International Nuclear Information System (INIS)

    Bhange, N.J.; Gothwal, P.; Fatnani, P.; Shukla, S.K.

    2011-01-01

    Indus-2, a 2.5 GeV Synchrotron Radiation Source (SRS) at Indore has a large vacuum system. The vacuum envelope of Indus-2 ring comprises of 16 dipole chambers as vital parts. Each chamber has 4 photon absorbers and three beam line ports blanked with end flanges. Temperature monitoring of critical vacuum components during operation of Indus-2 ring is an important requirement. The paper discusses a distributed, 160 channel remote temperature monitoring system developed and deployed for this purpose using microcontroller based, modular Temperature Monitoring Units (TMU). The cabling has been extensively minimized using RS485 system and keeping trip relay contacts of all units in series. For ensuring proper signal conditioning of thermocouple outputs (K-type) and successful operation over RS485 bus, many precautions were taken considering the close proximity to the storage ring. We also discuss the software for vacuum chamber temperature monitoring and safety system. The software developed using LabVIEW, has important features like modularity, client-server architecture, local and global database logging, alarms and trips, event and error logging, provision of various important configurations, communications handling etc. (author)

  20. Effect of Mixing Temperature of CMP Pulp and Cellulose Nanofiber on Paper Properties

    Directory of Open Access Journals (Sweden)

    Sahba Alinia

    2013-06-01

    Full Text Available Several processing parameters affect the function of cellulose nanofiber as an environmentally friend cellulosic reinforcer. One of the potential parameters can be the mixing temperature of pulp and cellulose nanofiber that has been investigated in this study. In order to study the influence of this parameter, mixing drainage velocity and the air permeability and strength properties of resulting paper were measured. A mixture of chemi-mechanical pulp suspensions (with concentration of 0.2 wt% and freeness of 250 ml, CSF containing 5 wt% cellulose nanofiber were prepared. This mixture was then stirred at 25, 50, and 70 ◦C using a magnetic stirrer for 1 hour followed by draining using vacuum filtration to make wet handsheet. The wet handsheet was first pressed, and then dried in oven at 100 ◦C for 24 hours. The test’ results showed that the increase of mixing temperature led to decreasing drainage time and air permeability. The strength properties of paper reinforced by nanofibers were positively affected by mixing temperature (i.e. the more mixing temperature, the higher strength. The data of tensile strength index was considerably increased. The tear strength of paper increased approximately by 200% over rising mixing temperature.

  1. Bioactive Compounds of Chamber-Dried Blueberries at Controlled Temperature and Wines Obtained from Them

    Directory of Open Access Journals (Sweden)

    Juan Martin-Gomez

    2017-01-01

    Full Text Available The effects of chamber drying under controlled temperature and moisture conditions and fermentation process on blueberry juices to obtain three wines were studied in this work. Drying was carried out with a view to increase the sugar content and obtain wines with an ethanol content similar to a commercial grape wine or to obtain sweet wines. Analyses included color parameters; browning index; and anthocyanin, flavonols, flavan-3-ol derivatives, and tannin concentrations, as well as vitamin C concentration and antioxidant activity. Based on the results, drying increases color and the concentration of anthocyanins and tannins most probably by the effect of dehydration of the berries and diffusion of the colored compounds from the skin to the pulp due to the structural alterations in their skin. In addition, drying decreases flavonols, flavan-3-ol derivatives, and vitamin C concentrations. The browning index, anthocyanins, and tannins decreased with the fermentation time, and vitamin C was constant with the fermentation time. The sensory analysis showed that the wines with the best sensory characteristics were those with residual sugar, partial fermented wines 1 and 2.

  2. Self-contained high-pressure chambers for study on the Moessbauer effect at low temperatures

    International Nuclear Information System (INIS)

    Stepanov, G.N.

    1980-01-01

    Designs of two high-pressure chambers intended for studying the Moessbauer effect at low temperatures are described. The high-pressure chamber of the Bridgman anvil type is made of non magnetic materials and intended for operation at helium temperatures. The chamber employs a superconducting pressure gage. A sample and superconducting pressure gage are surrounded with a liquid medium of a high pressure at a room temperature. Measurements of the pressure were taken during heating the chamber in the vapours of liquid helium according to the known dependence of the lead superconducting transition temperature on pressure. The other high-pressure chamber of the piston-to-cylinder type can be used to study the Moessbauer effect at temperatures ranging from 4 to 300 K. Pressure in the chamber is measured by means of the superconducting pressure gage. The maximum pressure obtained in the chamber constitutes 25 kbar

  3. Modeling of thermal and optical effects in dental pulp during the irradiation with neodymium and diode lasers

    International Nuclear Information System (INIS)

    Farhat, Patricia Bahls de Almeida

    2003-01-01

    During the development of applications of high intensity lasers in the enamel and dentine, adverse thermal effects into the entire dental structure, including the pulp, must be verified. The measurement of the temperature in the intact pulp, however, is not a solved problem. For this purpose, models have been used frequently, using extracted teeth, with pulpal cavities filled with materials that simulate only thermal properties of the pulp. Current models, however, do not simulate optical properties of the pulp, not taking the remaining radiation in the pulp chamber into account. The aim of this study was to verify if the remaining radiation from neodymium and diode lasers that reach the pulp chamber, at the models using extracted bovine teeth, can cause local thermal effects. For this purpose, two models were developed, using extracted bovine teeth with their pulp chambers filled with water (simulating pulp thermal characteristics) without (model 1) and with (model 2) an optical absorbent. Models were radiated with 1 W. The obtained results show that, for both lasers, the temperature rise in model 2 pulp chamber is: up to 11 % higher than in the model 1 when the enamel is radiated; and up to 37% higher than in the model 1 when dentine is radiated (1 mm from the pulp), indicating that the level of the remaining radiation is relevant for the construction of models excited by the neodymium and diode lasers. (author)

  4. Temperature Stabilization of the NIFFTE Time Projection Chamber

    Science.gov (United States)

    Hicks, Caleb

    2017-09-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) is a collaboration measuring nuclear fission cross sections for use in advanced nuclear reactors. A neutron beam incident on targets of Uranium-235, Uranium-238, and Plutonium-239 is used to measure the neutron induced fission cross sections for these isotopes. A Time Projection Chamber (TPC) is used to record these reactions. Significant heat is generated by the readout cards mounted on the TPC, which are cooled by fans. One proposed measurement of the experiment is to compare the cross sections of the target to a proton target of gaseous hydrogen. A constant temperature inside the TPC's pressure vessel is desirable to maintain a constant number of hydrogen target atoms. In addition, a constant temperature minimizes the strain and wrinkles on an amplifying mesh inside the TPC. This poster describes the successful work to develop, build, and install a fan controller using a Raspberry Pi, an Arduino, and a custom circuit board to implement an algorithm called Proportional-Integral-Derivative control. This research was supported by US DOE MENP Grant DE-FG02-03ER41243.

  5. Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed.

    Science.gov (United States)

    Haeussler, Silvia; Luepke, Matthias; Seifert, Hermann; Staszyk, Carsten

    2014-02-21

    In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity.To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp.

  6. Gambaran densitas kamar pulpa gigi sulung menggunakan cone beam CT-3D (Description of pulp chamber density in deciduous teeth using cone beam CT-3D

    Directory of Open Access Journals (Sweden)

    Herdiyati Y

    2013-06-01

    Full Text Available Background: Dental caries is the most common chronic diseases. Detection of caries is needed, especially on the deciduous teeth. An examination such as radiological examination is essential. The radiographic figures distinguish radiolucent of the crown. Digital radiography cone beam computed tomography (CBCT is able to show a more detailed picture. Purpose: This study was aimed to get value of the density of pulp chamber of caries and non caries deciduous teeth using CBCT radiographs. Methods: The study was conducted by using simple descriptive. The samples were all the data CBCT of pediatric patients aged 7-10 years who visited the Dental Hospital of the Faculty of Dentistry, University of Padjadjaran. The samples were teeth with single and double root. Results: The results showed that the value of the normal pulp density is 422.56 Hu, while the condition of caries decreased becomes -77.89 Hu. Conclusion: The tooth with caries showed a lower density than the non caries/tooth.Latar belakang: Karies gigi merupakan penyakit kronis yang sering terjadi. Deteksi terhadap karies sangat diperlukan terutama pada gigi decidius. Pemeriksaan penunjang berupa pemeriksaan radiologis sangat diperlukan. Secara umum gambaran radiografi dapat membedakan karies berupa gambaran radiolusent pada mahkota. Radiografi digital cone beam computed tomografi (CBCT, merupakan jenis radiografi yang mampu memperlihatkan gambaran yang lebih detail. Tujuan: Penelitian ini bertujuan mendapatkan nilai densitas kamar pulpa gigi sulung yang karies dan non karies menggunakan radiografi CBCT. Metode: Penelitian dilakukan dengan metode simple deskriptif. Sampel penelitian adalah semua data CBCT dari pasien anak berusia 7 - 10 tahun yang berkunjung ke RSGM Fakultas Kedokteran Gigi Universitas Padjadjaran. Gigi yang dianalisa meliputi gigi berakar tunggal dan berakar ganda. Hasil: Hasil penelitian menunjukkan bahwa nilai densitas pulpa normal adalah 422,56 Hu, sedangkan pada kondisi

  7. Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles

    Science.gov (United States)

    Maqsood, Omar Shahzada

    Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

  8. Modeling of thermal and optical effects in dental pulp during the irradiation with neodymium and diode lasers; Modelagem dos efeitos termicos e opticos na polpa dentaria durante a irradiacao com os lasers de diodo de neodimio

    Energy Technology Data Exchange (ETDEWEB)

    Farhat, Patricia Bahls de Almeida

    2003-07-01

    During the development of applications of high intensity lasers in the enamel and dentine, adverse thermal effects into the entire dental structure, including the pulp, must be verified. The measurement of the temperature in the intact pulp, however, is not a solved problem. For this purpose, models have been used frequently, using extracted teeth, with pulpal cavities filled with materials that simulate only thermal properties of the pulp. Current models, however, do not simulate optical properties of the pulp, not taking the remaining radiation in the pulp chamber into account. The aim of this study was to verify if the remaining radiation from neodymium and diode lasers that reach the pulp chamber, at the models using extracted bovine teeth, can cause local thermal effects. For this purpose, two models were developed, using extracted bovine teeth with their pulp chambers filled with water (simulating pulp thermal characteristics) without (model 1) and with (model 2) an optical absorbent. Models were radiated with 1 W. The obtained results show that, for both lasers, the temperature rise in model 2 pulp chamber is: up to 11 % higher than in the model 1 when the enamel is radiated; and up to 37% higher than in the model 1 when dentine is radiated (1 mm from the pulp), indicating that the level of the remaining radiation is relevant for the construction of models excited by the neodymium and diode lasers. (author)

  9. High temperature fission chambers. Fast breeder reactor research and development program

    International Nuclear Information System (INIS)

    Berlin, C.; Perrigueur, J.C.

    1984-04-01

    Development of a high temperature fission chamber and experimentations of measuring channels (detectors and electronic devices) in similar conditions as those of power plants: development of measuring channels (impulses and current) of the Super Phenix neutronic measures auxiliary system, development of a measuring channel with impulses for the surveillance system of the clad failures, based on integrated detectors, and development of a fission chamber for experimentations in similar conditions as in Superphenix [fr

  10. Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems : influence of grinding head position and rotational speed

    OpenAIRE

    Haeussler, Silvia; Luepke, Matthias; Seifert, Hermann; Staszyk, Carsten

    2014-01-01

    BACKGROUND: In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5degreesC temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity.To obtain reliable data on the int...

  11. Effect of temperature on the multi-gap resistive plate chamber operation

    International Nuclear Information System (INIS)

    Zhao, Y.E.; Wang, X.L.; Liu, H.D.; Chen, H.F.; Li, C.; Wu, J.; Xu, Z.Z.; Shao, M.; Zeng, H.; Zhou, Y.

    2005-01-01

    In order to obtain a quantitative understanding of the influence of temperature on the multi-gap resistive plate chamber (MRPC) operation, we tested the performance of a 6-gap, 6.1x20 cm 2 active area MRPC with cosmic rays at different temperatures. Results of measurements of noise rate, dark current and detection efficiency are presented

  12. A zero-power warming chamber for investigating plant responses to rising temperature

    Science.gov (United States)

    Lewin, Keith F.; McMahon, Andrew M.; Ely, Kim S.; Serbin, Shawn P.; Rogers, Alistair

    2017-09-01

    Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate the mean daily air temperature by ˜ 1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be ˜ 2-3 °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW) chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. The approach we describe is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming approaches is desired.

  13. A zero-power warming chamber for investigating plant responses to rising temperature

    Directory of Open Access Journals (Sweden)

    K. F. Lewin

    2017-09-01

    Full Text Available Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate the mean daily air temperature by  ∼  1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be  ∼  2–3 °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. The approach we describe is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming

  14. Rectal temperature changes and oxygen toxicity in dogs treated in a monoplace chamber.

    Science.gov (United States)

    Shmalberg, Justin; Davies, Wendy; Lopez, Stacy; Shmalberg, Danielle; Zilberschtein, Jose

    2015-01-01

    Hyperbaric oxygen treatments are increasingly administered to pet dogs, using veterinary-specific monoplace chambers. The basic physiologic responses, chamber performance and oxygen toxicity rates have not yet been evaluated in dogs in a clinical setting. As a result, a series of consecutive 45-minute, 2-atmospheres absolute (atm abs) hyperbaric treatments with 100% oxygen were evaluated in a veterinary rehabilitation center (n = 285). 65 dogs with a mean body weight of 21 ± 15 kg (1.4-71 kg) were treated with an average of four sessions each. The mean rectal temperature of canine patients decreased 0.07 degrees C (0.1 degrees F) during treatments (p = 0.04). Intra-chamber temperature and humidity both increased: +1.0 degrees C (1.7 degrees F, p 0.75) were identified between body weights, body condition scores, maximal oxygen concentrations, starting or ending rectal temperature, chamber humidity and chamber temperature. Oxygen toxicity was not observed during the observational period. Patients were most commonly treated for intervertebral disc disease (n = 16 dogs) and extensive traumatic wounds (n = 10 dogs), which represented a large number of the total study sessions (19% and 16%, respectively).

  15. Electromagnetic Characterization of Materials Using a Dual Chambered High Temperature Waveguide

    Science.gov (United States)

    to just one day through simultaneous measurement of the sample and the empty second chamber. A vector network analyzer (VNA) will be used to run X-band...calculated from the Nicolson-Ross-Weir inversion algorithm for computing permittivity and permeability using VNA measured S-parameters at increasing temperatures.

  16. The physics and chemistry of room-temperature liquid-filled ionization chambers

    International Nuclear Information System (INIS)

    Holroyd, R.A.

    1985-01-01

    The properties of excess electrons in non-polar liquids, such as tetramethylsilane and 2,2,4,4-tetramethylpentane, which are suitable for room-temperature liquid-filled ionization chambers are reviewed. Such properties as mobility, ionization yield, conduction band energy, trapping, and the influence of the electric field are considered. (orig.)

  17. Assessment of the high temperature fission chamber technology for the French fast reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Jammes, C.; Filliatre, P.; Geslot, B.; Domenech, T.; Normand, S. [Commissariat a l' Energie Atomique, CEA (France)

    2011-07-01

    High temperature fission chambers are key instruments for the control and protection of the sodium-cooled fast reactor. First, the developments of those neutron detectors, which are carried out either in France or abroad are reviewed. Second, the French realizations are assessed with the use of the technology readiness levels in order to identify tracks of improvement. (authors)

  18. The Chamber for Studying Rice Response to Elevated Nighttime Temperature in Field

    Directory of Open Access Journals (Sweden)

    Song Chen

    2013-01-01

    Full Text Available An in situ temperature-controlled field chamber was developed for studying a large population of rice plant under different nighttime temperature treatments while maintaining conditions similar to those in the field during daytime. The system consists of a pipe hoop shed-type chamber with manually removable covers manipulated to provide a natural environment at daytime and a relatively stable and accurate temperature at night. Average air temperatures of 22.4 ± 0.3°C at setting of 22°C, 27.6 ± 0.4°C at 27°C, and 23.8 ± 0.7°C ambient conditions were maintained with the system. No significant horizontal and vertical differences in temperature were found and only slight changes in water temperatures were observed between the chambers and ambient conditions at 36 days after transplanting. A slight variation in CO2 concentration was observed at the end of the treatment during the day, but the 10-μmol CO2 mol−1 difference was too small to alter plant response. The present utilitarian system, which only utilizes an air conditioner/heater, is suitable for studying the effect of nighttime temperature on plant physiological responses with minimal perturbation of other environmental factors. At the same time, it will enable in situ screening of many rice genotypes.

  19. Note: A versatile mass spectrometer chamber for molecular beam and temperature programmed desorption experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tonks, James P., E-mail: james.tonks@awe.co.uk [Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); AWE Plc, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Galloway, Ewan C., E-mail: ewan.galloway@awe.co.uk; King, Martin O. [AWE Plc, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Kerherve, Gwilherm [VACGEN Ltd, St. Leonards-On-Sea, East Sussex TN38 9NN (United Kingdom); Watts, John F. [Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2016-08-15

    A dual purpose mass spectrometer chamber capable of performing molecular beam scattering (MBS) and temperature programmed desorption (TPD) is detailed. Two simple features of this design allow it to perform these techniques. First, the diameter of entrance aperture to the mass spectrometer can be varied to maximize signal for TPD or to maximize angular resolution for MBS. Second, the mass spectrometer chamber can be radially translated so that it can be positioned close to the sample to maximize signal or far from the sample to maximize angular resolution. The performance of this system is described and compares well with systems designed for only one of these techniques.

  20. The relationship between pulp calcifications and salivary gland calcifications

    OpenAIRE

    Kaswan, Sumita; Patil, Santosh; Maheshwari, Sneha; Rahman, Farzan; Khandelwal, Suneet

    2014-01-01

    Aim: Pulp stones are discrete calcified bodies found in the dental pulp. Sialolithasis is the most common salivary gland disease. The aim of the present study was to determine the relationship between the pulp stones and salivary gland stones. Material and Methods: 196 patients were randomly selected from the out patient department for the study. The periapical radiographs for all patients were evaluated for the presence or absence of the narrowing of dental pulp chambers and pulp canals. The...

  1. AUTOMATIC CONTROL SYSTEM FOR REGULATED HIGH TEMPERATURE MAIN COMBUSTION CHAMBER OF MANEUVERABLE AIRCRAFT MULTIMODE GAS TURBINE ENGINE

    Directory of Open Access Journals (Sweden)

    T. V. Gras’Ko

    2014-01-01

    Full Text Available The paper describes choosing and substantiating the control laws, forming the appearance the automatic control system for regulated high temperature main combustion chamber of maneuverable aircraft multimode gas turbine engine aimed at sustainable and effective functioning of main combustion chamber within a broad operation range.

  2. He leaks in the CERN LHC beam vacuum chambers operating at cryogenic temperatures

    CERN Document Server

    Baglin, V

    2007-01-01

    The 27 km long large hadron collider (LHC), currently under construction at CERN, will collide protons beam at 14 TeV in the centre of mass. In the 8 arcs, the superconducting dipoles and quadrupoles of the FODO cells operate with superfluid He at 1.9 K. In the 8 long straight sections, the cold bores of the superconducting magnets are held at 1.9 or 4.5 K. Thus, in the LHC, 75% of the beam tube vacuum chamber is cooled with He. In many areas of the machine, He leaks could appear in the beam tube. At cryogenic temperature, the gas condenses onto the cold bores or beam screens, and interacts with the circulating beam. He leaks creates a He front propagating along the vacuum chambers, which might cause magnet quench. We discuss the consequences of He leaks, the possible means of detections, the strategies to localise them and the methods to measure their size.

  3. Is Pulp Inflammation a Prerequisite for Pulp Healing and Regeneration?

    Directory of Open Access Journals (Sweden)

    Michel Goldberg

    2015-01-01

    Full Text Available The importance of inflammation has been underestimated in pulpal healing, and in the past, it has been considered only as an undesirable effect. Associated with moderate inflammation, necrosis includes pyroptosis, apoptosis, and nemosis. There are now evidences that inflammation is a prerequisite for pulp healing, with series of events ahead of regeneration. Immunocompetent cells are recruited in the apical part. They slide along the root and migrate toward the crown. Due to the high alkalinity of the capping agent, pulp cells display mild inflammation, proliferate, and increase in number and size and initiate mineralization. Pulp fibroblasts become odontoblast-like cells producing type I collagen, alkaline phosphatase, and SPARC/osteonectin. Molecules of the SIBLING family, matrix metalloproteinases, and vascular and nerve mediators are also implicated in the formation of a reparative dentinal bridge, osteo/orthodentin closing the pulp exposure. Beneath a calciotraumatic line, a thin layer identified as reactionary dentin underlines the periphery of the pulp chamber. Inflammatory and/or noninflammatory processes contribute to produce a reparative dentinal bridge closing the pulp exposure, with minute canaliculi and large tunnel defects. Depending on the form and severity of the inflammatory and noninflammatory processes, and according to the capping agent, pulp reactions are induced specifically.

  4. High Temperature Fission Chamber for He- and FLiBe-cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Zane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, Dominic R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lance, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Roger G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warmack, Robert J. Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    We have evaluated candidate technologies for in-core fission chambers for high-temperature reactors to monitor power level via measurements of neutron flux from start-up through full power at up to 800°C. This research is important because there are no commercially available instruments capable of operating above 550 °C. Component materials and processes were investigated for fission chambers suitable for operation at 800 °C in reactors cooled by molten fluoride salt (FLiBe) or flowing He, with an emphasis placed on sensitivity (≥ 1 cps/nv), service lifetime (2 years at full power), and resistance to direct immersion in FLiBe. The latter gives the instrument the ability to survive accidents involving breach of a thimble. The device is envisioned to be a two-gap, three-electrode instrument constructed from concentric nickel-plated alumina cylinders and using a noble gas–nitrogen fill-gas. We report the results of measurements and calculations of the response of fill gasses, impurity migration in nickel alloy, brazing of the alumina insulator, and thermodynamic calculations.

  5. Analysis of a water-coolant leak into a very high-temperature vitrification chamber

    International Nuclear Information System (INIS)

    Felicione, F. S.

    1998-01-01

    A coolant-leakage incident occurred during non-radioactive operation of the Plasma Hearth Process waste-vitrification development system at Argonne National Laboratory when a stray electric arc ruptured az water-cooling jacket. Rapid evaporation of the coolant that entered the very high-temperature chamber pressurized the normally sub-atmospheric system above ambient pressure for over 13 minutes. Any positive pressurization, and particularly a lengthy one, is a safety concern since this can cause leakage of contaminants from the system. A model of the thermal phenomena that describe coolant/hot-material interactions was developed to better understand the characteristics of this type of incident. The model is described and results for a variety of hypothetical coolant-leak incidents are presented. It is shown that coolant leak rates above a certain threshold will cause coolant to accumulate in the chamber, and evaporation from this pool can maintain positive pressure in the system long after the leak has been stopped. Application of the model resulted in reasonably good agreement with the duration of the pressure measured during the incident. A closed-form analytic solution is shown to be applicable to the initial leak period in which the peak pressures are generated, and is presented and discussed

  6. Design of automatic control system of temperature in radon chamber controlled by air-condition based on 485 BUS

    International Nuclear Information System (INIS)

    Man Zaigang; Wang Renbo; Zhang Xiongjie; Zhu Zhifu; Tang Bin

    2009-01-01

    Radon chamber can be widely used in various radon measurement instruments for calibration, testing and radon environment experiment. According to requisition, radon chamber temperature should be controllable from +10 degree C to +30 degree C, and the temperature control accuracy of the system reaches ±1 degree C. The design of automatic temperature controlled by air-condition based on 485 BUS is introduced. The software and hardware techniques of how the ATMEL89S52 micro controller controls air-condition and communicates with computer are elaborated on. (authors)

  7. Anode-supported SOFC operated under single-chamber conditions at intermediate temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Morales, M.; Roa, J.J.; Segarra, M. [Department of Materials Science and Metallurgical Engineering, University of Barcelona, E-08028, Barcelona (Spain); Capdevila, X.G. [Center of Design and Optimization in Avanced Materials, Parc Cientific of Barcelona, E-08028, Barcelona (Spain); Pinol, S. [Institute of Materials Science of Barcelona (CSIC), Campus of the UAB, Bellaterra E-08193, Barcelona (Spain)

    2011-02-15

    Anode-supported SOFC was fabricated using gadolinia doped ceria (GDC) as the electrolyte (15 {mu}m of thickness), Ni-GDC as the anode and La{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}}-GDC as the cathode. Catalytic activities of the electrodes and electrical properties of the cell were determined, using mixtures of methane + air, under single-chamber conditions. This work assessed with special and wide emphasis the effect of temperature, gas composition and total flow rate on the cell performance. As a result, operational temperature range of the fuel cell was approximately between 700 and 800 C, which agrees with the results corresponding to the catalytic activities of electrodes. While Ni-GDC anode was enough active towards methane partial oxidation at cell temperatures higher than 700 C, the LSC-GDC cathode was enough inactive towards partial and total oxidation of methane at cell temperatures lower than 800 C. Under optimised gas compositions (CH{sub 4}/O{sub 2}) ratio (1) and total flow rate (530 mL min {sup -1}), power densities of 145 and 235 mW cm {sup -2} were obtained at 705 and 764 C, respectively. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Distribution of temperature and moisture content fields in a rectangular beet pulp particle during convection drying

    Directory of Open Access Journals (Sweden)

    A. N. Ostrikov

    2018-01-01

    Full Text Available The mathematical model describing distribution of fields of temperatures and moisture contents in a particle of a squared beet press at convective drying is given. As the initial equations the differential equations of material and thermal balances in which transfer of warmth and weight is caused by phase transformations have been accepted. The algorithm of the numerical solution of a non-stationary regional problem of heat conductivity with variable heat and mass transfer coefficients of the dried-up product, boundary and entry conditions and also phase transition with mobile limit of the section of phases is developed for the solution of mathematical model. At the same time the initial system of the equations is given to a dimensionless look. For the solution of a problem of non-stationary heat conductivity the zone method of calculation of temperature fields when drying a beet press is used. Process of drying broke into some time intervals. Within each interval geometrical form of a particle, its density, heatphysical and mass-exchanged characteristics; initial distribution of temperature and moisture content on particle volume and also density of a mass and thermal stream with the evaporated moisture are constant. The zone method of the solution of a problem of the non-stationary three-dimensional equation of heat conductivity for a parallelepiped taking into account internal sources of warmth has been checked on experimental data of stationary drying of a beet press with use of basic data. For realization of a zone method dependences of change of the linear size of a particle of a beet press on spatial coordinate x and its moisture content in the course of drying are received. At constant values of moisture content and the sizes of the party of the dried-up particle on each step the method of a machine experiment has found the current values of coefficient of phase transformation on condition of the maximum rapprochement of settlement and

  9. Soot temperature and KL factor for biodiesel and diesel spray combustion in a constant volume combustion chamber

    KAUST Repository

    Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

    2013-01-01

    This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm

  10. Portable mini-chamber for temperature dependent studies using small angle and wide angle x-ray scattering

    Science.gov (United States)

    Dev, Arun Singh; Kumar, Dileep; Potdar, Satish; Pandit, Pallavi; Roth, Stephan V.; Gupta, Ajay

    2018-04-01

    The present work describes the design and performance of a vacuum compatible portable mini chamber for temperature dependent GISAXS and GIWAXS studies of thin films and multilayer structures. The water cooled body of the chamber allows sample annealing up to 900 K using ultra high vacuum compatible (UHV) pyrolytic boron nitride heater, thus making it possible to study the temperature dependent evolution of structure and morphology of two-dimensional nanostructured materials. Due to its light weight and small size, the chamber is portable and can be accommodated at synchrotron facilities worldwide. A systematic illustration of the versatility of the chamber has been demonstrated at beamline P03, PETRA-III, DESY, Hamburg, Germany. Temperature dependent grazing incidence small angle x-ray scattering (GISAXS) and grazing incidence wide angle x-ray scattering (GIWAXS) measurements were performed on oblique angle deposited Co/Ag multilayer structure, which jointly revealed that the surface diffusion in Co columns in Co/Ag multilayer enhances by increasing temperature from RT to ˜573 K. This results in a morphology change from columnar tilted structure to densely packed morphological isotropic multilayer.

  11. Investigation of parameters of the working substance - low temperature plasma in the ionization resonator chamber of the RF reactive engine

    International Nuclear Information System (INIS)

    Vdovin, V.S.; Zajtzev, B.V.; Kobetz, A.F.; Bomko, V.A.; Rashkovan, V.M.; Bazyma, L.A.; Belokon, V.I.

    2003-01-01

    This paper is the extension of investigations of the RF engine designed for orientation and stabilization of the spacecrafts orbit, and it is undertaken for measuring of plasma parameters of RF discharge in the ionization resonator chamber. The experiments were performed at the frequency of 80 MHz on the model engine, in which a length of coaxial line with shortening capacities at the ends was used as the ionization resonator chamber. As the result of the experiments, conditions of the RF discharge ignition in the resonator chamber are studied; dependencies of plasma density and temperature versus applied power and working body pressure are obtained for various gases. The measurements of the thrust were performed at the special-purpose test bench

  12. Pulp stem cells: implication in reparative dentin formation.

    Science.gov (United States)

    Dimitrova-Nakov, Sasha; Baudry, Anne; Harichane, Yassine; Kellermann, Odile; Goldberg, Michel

    2014-04-01

    Many dental pulp stem cells are neural crest derivatives essential for lifelong maintenance of tooth functions and homeostasis as well as tooth repair. These cells may be directly implicated in the healing process or indirectly involved in cell-to-cell diffusion of paracrine messages to resident (pulpoblasts) or nonresident cells (migrating mesenchymal cells). The identity of the pulp progenitors and the mechanisms sustaining their regenerative capacity remain largely unknown. Taking advantage of the A4 cell line, a multipotent stem cell derived from the molar pulp of mouse embryo, we investigated the capacity of these pulp-derived precursors to induce in vivo the formation of a reparative dentin-like structure upon implantation within the pulp of a rodent incisor or a first maxillary molar after surgical exposure. One month after the pulp injury alone, a nonmineralized fibrous matrix filled the mesial part of the coronal pulp chamber. Upon A4 cell implantation, a mineralized osteodentin was formed in the implantation site without affecting the structure and vitality of the residual pulp in the central and distal parts of the pulp chamber. These results show that dental pulp stem cells can induce the formation of reparative dentin and therefore constitute a useful tool for pulp therapies. Finally, reparative dentin was also built up when A4 progenitors were performed by alginate beads, suggesting that alginate is a suitable carrier for cell implantation in teeth. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Lightweight Ultrahigh Temperature CMC-Lined C/C Combustion Chambers, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA and DoD are seeking high-performance, lightweight liquid rocket combustion chambers with future performance goals that cannot be achieved using state-of-the-art...

  14. H2 Equilibrium Pressure with a Neg-Coated Vacuum Chamber as a Function of Temperature and H2 Concentration

    CERN Document Server

    Rossi, Adriana

    2006-01-01

    Non Evaporable Getter (NEG) coating is used in the Large Hadron Collider (LHC) room-temperature sections to ensure a low residual gas pressure for its properties of distributed pumping, low outgassing and desorption under particle bombardment; and to limit or cure electron cloud build-up due to its low secondary electron emission. In certain regions of the LHC, and in particular close to the beam collimators, the temperature of the vacuum chamber is expected to rise due to energy deposition from particle losses. Hydrogen molecules are pumped by the NEG via dissociation on the surface, sorption at the superficial sites and diffusion into the NEG bulk. In the case of hydrogen, the sorption is thermally reversible, causing the dissociation pressure to increase with NEG temperature and amount of H2 pumped. Measurements were carried out on a stainless steel chamber coated with TiZrV NEG as a function of the H2 concentration and the chamber temperature, to estimate the residual gas pressure in the collimator region...

  15. [Vital pulp therapy of damaged dental pulp].

    Science.gov (United States)

    Xuedong, Zhou; Dingming, Huang; Jianguo, Liu; Zhengwei, Huang; Xin, Wei; Deqin, Yang; Jin, Zhao; Liming, Chen; Lin, Zhu; Yanhong, Li; Jiyao, Li

    2017-08-01

    The development of an expert consensus on vital pulp therapy can provide practical guidance for the improvement of pulp damage care in China. Dental pulp disease is a major type of illness that adversely affects human oral health. Pulp capping and pulpotomy are currently the main methods for vital pulp therapy. Along with the development of minimal invasion cosmetic dentistry, using different treatment technologies and materials reasonably, preserving healthy tooth tissue, and extending tooth save time have become urgent problems that call for immediate solution in dental clinics. This paper summarizes the experiences and knowledge of endodontic experts. We develop a clinical path of vital pulp therapy for clinical work by utilizing the nature, approach, and degree of pulp damage as references, defense and self-repairing ability of pulp as guidance, and modern technologies of diagnosis and treatment as means.

  16. RF HEATING AND TEMPERATURE OSCILLATIONS DUE TO A SMALL GAP IN A PEP-II VACUUM CHAMBER

    International Nuclear Information System (INIS)

    Novokhatski, Alexander

    2003-01-01

    Wake fields excited in a small gap of a vacuum chamber by ampere beams can have enough amplitude to heat the chamber. The electric component of these fields can be above the arcing limit. Usually flange connections in a vacuum chamber contain a vacuum gasket and an inner RF gasket. If a small gap occurs between the RF gasket and flange surface, wake fields can heat the flanges. The flanges are usually made of stainless steel, which efficiently absorbs RF power. Some flanges consist of two parts (like a vacuum valve flange) and are mechanically connected but have poor thermal contact. A temperature rise can lengthen the inner part of the flange and make firmer the thermal contact to the outer part of the flange. The heat will then flow to the outer part of the flange, which is air and water-cooled. This cooling lowers the flange temperature and the thermal contact becomes poor again. This ''quasi'' periodic mechanism can explain the nature of temperature oscillations observed at several locations in PEP-II, the SLAC B-factory

  17. Optimization of pulping conditions of abaca. An alternative raw material for producing cellulose pulp.

    Science.gov (United States)

    Jiménez, L; Ramos, E; Rodríguez, A; De la Torre, M J; Ferrer, J L

    2005-06-01

    The influence of temperature (150-170 degrees C), pulping time (15-45 min) and soda concentration (5-10%) in the pulping of abaca on the yield, kappa, viscosity, breaking length, stretch and tear index of pulp and paper sheets, was studied. Using a factorial design to identify the optimum operating conditions, equations relating the dependent variables to the operational variables of the pulping process were derived that reproduced the former with errors lower than 25%. Using a high temperature, and a medium time and soda concentration, led to pulp that was difficult to bleach (kappa 28.34) but provided acceptable strength-related properties (breaking length 4728 m; stretch 4.76%; tear index 18.25 mN m2/g), with good yield (77.33%) and potential savings on capital equipment costs. Obtaining pulp amenable to bleaching would entail using more drastic conditions than those employed in this work.

  18. An Assessment on Temperature Profile of Jet-A/Biodiesel Mixture in a Simple Combustion Chamber with Plain Orifice Atomiser

    Science.gov (United States)

    Ng, W. X.; Mazlan, N. M.; Ismail, M. A.; Rajendran, P.

    2018-05-01

    The preliminary study to evaluate influence of biodiesel/kerosene mixtures on combustion temperature profile is explored. A simple cylindrical combustion chamber configuration with plain orifice atomiser is used for the evaluation. The evaluation is performed under stoichiometric air to fuel ratio. Six samples of fuels are used: 100BD (pure biodiesel), 100KE (pure Jet-A), 20KE80BD (20% Jet-A/80% Biodiesel), 40KE60BD (40% Jet-A/60% Biodiesel), 60KE40BD (60% Jet-A/40% Biodiesel), and 80KE20BD (80% Jet-A/20% Biodiesel). Results showed that the oxygen content, viscosity, and lower heating value are key parameters in affecting the temperature profile inside the chamber. Biodiesel is known to have higher energy content, higher viscosity and lower heating value compared to kerosene. Mixing biodiesel with kerosene improves viscosity and caloric value but reduces oxygen content of the fuel. High oxygen content of the biodiesel resulted to the highest flame temperature. However the flame temperature reduce as the percentage of biodiesel in the fuel mixture reduces.

  19. Soot temperature and KL factor for biodiesel and diesel spray combustion in a constant volume combustion chamber

    KAUST Repository

    Zhang, Ji

    2013-07-01

    This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm and 650. nm, 10. nm FWHM). After calibration, statistical analysis shows that the uncertainty of the two-color temperature is less than 5%, while it is about 50% for the KL factor. This technique is then applied to the spray combustion of biodiesel and diesel fuels under an ambient oxygen concentration of 21% and ambient temperatures of 800, 1000 and 1200. K. The heat release result shows higher energy utilization efficiency for biodiesel compared to diesel under all conditions; meanwhile, diesel shows a higher pressure increase due to its higher heating value. Biodiesel yields a lower temperature inside the flame area, a longer soot lift-off length, and a smaller soot area compared to diesel. Both the KL factor and the total soot with biodiesel are lower than with diesel throughout the entire combustion process, and this difference becomes larger as the ambient temperature decreases. Biodiesel shows approximately 50-100. K lower temperatures than diesel at the quasi-steady stage for 1000 and 1200. K ambient temperature, while diesel shows a lower temperature than biodiesel at 800. K ambient. This result may raise the question of how important the flame temperature is in explaining the higher NO. x emissions often observed during biodiesel combustion. Other factors may also play an important role in controlling NO. x emissions. Both biodiesel and diesel temperature measurements show a monotonic dependence on the ambient temperature. However, the ambient temperature appears to have a more significant effect on the soot formation and oxidation in diesel combustion, while biodiesel combustion soot characteristics shows relative insensitivity to the ambient temperature. © 2013 Elsevier Ltd.

  20. The potential effect of differential ambient and deployment chamber temperatures on PRC derived sampling rates with polyurethane foam (PUF) passive air samplers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Karen, E-mail: k.kennedy@uq.edu.a [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Hawker, Darryl W. [Griffith University, School of Environment, Nathan QLD 4111 (Australia); Bartkow, Michael E. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Carter, Steve [Queensland Health Forensic and Scientific Services, Coopers Plains QLD 4108 (Australia); Ishikawa, Yukari; Mueller, Jochen F. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia)

    2010-01-15

    Performance reference compound (PRC) derived sampling rates were determined for polyurethane foam (PUF) passive air samplers in both sub-tropical and temperate locations across Australia. These estimates were on average a factor of 2.7 times higher in summer than winter. The known effects of wind speed and temperature on mass transfer coefficients could not account for this observation. Sampling rates are often derived using ambient temperatures, not the actual temperatures within deployment chambers. If deployment chamber temperatures are in fact higher than ambient temperatures, estimated sampler-air partition coefficients would be greater than actual partition coefficients resulting in an overestimation of PRC derived sampling rates. Sampling rates determined under measured ambient temperatures and estimated deployment chamber temperatures in summer ranged from 7.1 to 10 m{sup 3} day{sup -1} and 2.2-6.8 m{sup 3} day{sup -1} respectively. These results suggest that potential differences between ambient and deployment chamber temperatures should be considered when deriving PRC-based sampling rates. - Internal deployment chamber temperatures rather than ambient temperatures may be required to accurately estimate PRC-based sampling rates.

  1. Electricity generation of single-chamber microbial fuel cells at low temperatures

    KAUST Repository

    Cheng, Shaoan; Xing, Defeng; Logan, Bruce E.

    2011-01-01

    Practical applications of microbial fuel cells (MFCs) for wastewater treatment will require operation of these systems over a wide range of wastewater temperatures. MFCs at room or higher temperatures (20-35°C) are relatively well studied compared

  2. Study in vitro of dental enamel irradiated with a high power diode laser operating at 960 nm: morphological analysis of post-irradiation dental surface and thermal effect analysis in pulp chamber due to laser application

    International Nuclear Information System (INIS)

    Quinto Junior, Jose

    2001-01-01

    Objectives: This study examines the structural and thermal modifications induced in dental enamel under dye assisted diode laser irradiation. The aim of this study is to verify if this laser-assisted treatment is capable to modify the enamel surface by causing fusion of the enamel surface layer. At the same time, the pulpal temperature rise must be kept low enough in order not to cause pulpar necrosis. To achieve this target, it is necessary to determine suitable laser parameters. As is known, fusion of the enamel surface followed by re-solidification produce a more acid resistant layer. This surface treatment is being researched as a new method for caries prevention. Method and Materials: A series of fourteen identically prepared enamel samples of human teeth were irradiated with a high power diode laser operating at 960 nm and using fiber delivery. Prior to irradiation, a fine layer of cromophorous ink was applied to the enamel surface. In the first part of the experiment the best parameter for pulse duration was determined. In the second part of the experimental phase the same energy density was used but with different repetition rates. During irradiation we monitored the temperature rise in the pulpal cavity. The morphology of the treated samples was analysed under SEM. Results: The morphology of the treated samples showed a homogeneously re-solidified enamel layer. The results of the temperature analysis showed a decrease of the pulpal temperature rise with decreasing repetition rate. Conclusion: With the diode laser it is possible to cause morphological alterations of the enamel surface, which is known to increase the enamel resistance against acid attack, and still maintain the temperature rise in the pulpar chamber below damage threshold. (author)

  3. A pressurized ion chamber monitoring system for environmental radiation measurements utilizing a wide-range temperature-compensated electrometer

    International Nuclear Information System (INIS)

    Stevenick, W. Van

    1994-01-01

    The performance of a complete pressurized ion chamber (PIC) radiation monitoring system is described. The design incorporates an improved temperature-compensated electrometer which is stable to ±3 · 10 -16 A over the environmental range of temperature (-40 to +40 C). Using a single 10 11 Ω feed-back resistor, the electrometer accurately measures currents over a range from 3 · 10 -15 A to 3 · 10 -11 A. While retaining the sensitivity of the original PIC system (the instrument responds readily to small background fluctuations on the order of 0.1 μR h -1 ), the new system measures radiation levels up to the point where the collection efficiency of the ion chamber begins to drop off, typically ∼27 pA at 1 mR h -1 . A data recorder and system controller was designed using the Tattletale trademark Model 4A computer. Digital data is stored on removable solid-state, credit-card style memory cards

  4. Low temperature combustion of organic coal-water fuel droplets containing petrochemicals while soaring in a combustion chamber model

    Directory of Open Access Journals (Sweden)

    Valiullin Timur R.

    2017-01-01

    Full Text Available The paper examines the integral characteristics (minimum temperature, ignition delay times of stable combustion initiation of organic coal-water fuel droplets (initial radius is 0.3-1.5 mm in the oxidizer flow (the temperature and velocity varied in ranges 500-900 K, 0.5-3 m/s. The main components of organic coal-water fuel were: brown coal particles, filter-cakes obtained in coal processing, waste engine, and turbine oils. The different modes of soaring and ignition of organic coal-water fuel have been established. The conditions have been set under which it is possible to implement the sustainable soaring and ignition of organic coal-water fuel droplets. We have compared the ignition characteristics with those defined in the traditional approach (based on placing the droplets on a low-inertia thermocouple junction into the combustion chamber. The paper shows the scale of the influence of heat sink over the thermocouple junction on ignition inertia. An original technique for releasing organic coal-water fuel droplets to the combustion chamber was proposed and tested. The limitations of this technique and the prospects of experimental results for the optimization of energy equipment operation were also formulated.

  5. Electricity generation of single-chamber microbial fuel cells at low temperatures

    KAUST Repository

    Cheng, Shaoan

    2011-01-01

    Practical applications of microbial fuel cells (MFCs) for wastewater treatment will require operation of these systems over a wide range of wastewater temperatures. MFCs at room or higher temperatures (20-35°C) are relatively well studied compared those at lower temperatures. MFC performance was examined here over a temperature range of 4-30°C in terms of startup time needed for reproducible power cycles, and performance. MFCs initially operated at 15°C or higher all attained a reproducible cycles of power generation, but the startup time to reach stable operation increased from 50h at 30°C to 210h at 15°C. At temperatures below 15°C, MFCs did not produce appreciable power even after one month of operation. If an MFC was first started up at temperature of 30°C, however, reproducible cycles of power generation could then be achieved at even the two lowest temperatures of 4°C and 10°C. Power production increased linearly with temperature at a rate of 33±4mW°C-1, from 425±2mWm-2 at 4°C to 1260±10mWm-2 at 30°C. Coulombic efficiency decreased by 45% over this same temperature range, or from CE=31% at 4°C to CE=17% at 30°C. These results demonstrate that MFCs can effectively be operated over a wide range of temperatures, but our findings have important implications for the startup of larger scale reactors where low wastewater temperatures could delay or prevent adequate startup of the system. © 2010 Elsevier B.V.

  6. Effects of ambient temperature and water vapor on chamber pressure and oxygen level during low atmospheric pressure stunning of poultry.

    Science.gov (United States)

    Holloway, Paul H; Pritchard, David G

    2017-08-01

    The characteristics of the vacuum used in a low atmospheric pressure stunning system to stun (render unconscious) poultry prior to slaughter are described. A vacuum chamber is pumped by a wet screw compressor. The vacuum pressure is reduced from ambient atmospheric pressure to an absolute vacuum pressure of ∼250 Torr (∼33 kPa) in ∼67 sec with the vacuum gate valve fully open. At ∼250 Torr, the sliding gate valve is partially closed to reduce effective pumping speed, resulting in a slower rate of decreasing pressure. Ambient temperature affects air density and water vapor pressure and thereby oxygen levels and the time at the minimum total pressure of ∼160 Torr (∼21 kPa) is varied from ∼120 to ∼220 sec to ensure an effective stun within the 280 seconds of each cycle. The reduction in total pressure results in a gradual reduction of oxygen partial pressure that was measured by a solid-state electrochemical oxygen sensor. The reduced oxygen pressure leads to hypoxia, which is recognized as a humane method of stunning poultry. The system maintains an oxygen concentration of air always reduces the oxygen concentrations to a value lower than in dry air. The partial pressure of water and oxygen were found to depend on the pump down parameters due to the formation of fog in the chamber and desorption of water from the birds and the walls of the vacuum chamber. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.

  7. Effects of Soda-Anthraquinone Pulping Variables on the Durian Rind Pulp and Paper Characteristics: A Preliminary Test

    Science.gov (United States)

    Rizal Masrol, Shaiful; Irwan Ibrahim, Mohd Halim; Adnan, Sharmiza; Rahmad Talib, Mohd; Sian, Lau Lee

    2017-08-01

    Good combination of pulping variables is required to obtain the quality pulp and paper characteristics. Thus, in this preliminary work, naturally dried durian rind were pulped under Soda-Anthraquinone (Soda-AQ) pulping process with 18% to 22% alkali charge, 0% to 0.1% Anthraquinone (AQ) charge, 90 minutes to 150 minutes of cooking time and 150°C to 170°C to investigate the effect of pulping variables on the characteristics of the pulp and paper. Pulping condition with 0% of AQ charge was also conducted for comparison. Results indicated that the best screen yield percentage, reject yield percentage, freeness, drainage time, tear index, number of folds and optical properties were shown by the pulp produced with combination of the highest active alkali (22%), AQ charge (0.1%), cooking time (150 minutes) and cooking temperature (170°C) except apparent density, tensile index and burst index. This preliminary result shows that the optimum quality of durian rind pulp as a potential papermaking raw material pulp could be produced by selecting the good combination of pulping variables which influences the pulp and paper characteristics.

  8. Temperature setting and thermal regulation system for liquid hydrogen bubble chamber; Systeme de mise en temperature et de regulation thermique de chambres a bulles a hydrogene liquide

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J; Prugne, P; Roubeau, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    Hydrogen bubble chamber cooling and constant temperature maintenance in the 25/28 deg. K, range by means of liquid hydrogen boiling under atmospheric pressure (20.4 deg. K) need a device, if possible automatic allowing the introduction of a variable amount of cold to counterbalance the heat transfer either static or due to the chamber operation. A variable impedance heat exchanger has been designed, built and experimented for this purpose. This device, which takes little space (less than 1000 cm{sup 3}) allows transfer of a variable cold power between 0 and 500 watts (0 to 50 liter of evaporated hydrogen). (author) [French] Pour le refroidissement des chambres a bulles a hydrogene et pour le maintien d'une temperature constante dans la gamme 25/28 deg. K au moyen d'hydrogene a l'ebullition sous pression atmospherique (20,4 deg. K), on a besoin d'un dispositif, si possible automatique, permettant l'introduction d'une quantite variable de froid pour compenser le transfert de chaleur, soit statique, soit du a l'operation de la chambre. Un echangeur de chaleur a impedance variable a ete concu, construit et essaye pour cet usage. Ce dispositif qui est peu encombrant (en dessous de 1000 cm{sup 3} ) permet le transfert d'une puissance frigorifique, variable entre 0 et 500 watts (0 a 50 litres d'hydrogene evapore). (auteur)

  9. Characterization and Degradation of Pectic Polysaccharides in Cocoa Pulp.

    Science.gov (United States)

    Meersman, Esther; Struyf, Nore; Kyomugasho, Clare; Jamsazzadeh Kermani, Zahra; Santiago, Jihan Santanina; Baert, Eline; Hemdane, Sami; Vrancken, Gino; Verstrepen, Kevin J; Courtin, Christophe M; Hendrickx, Marc; Steensels, Jan

    2017-11-08

    Microbial fermentation of the viscous pulp surrounding cocoa beans is a crucial step in chocolate production. During this process, the pulp is degraded, after which the beans are dried and shipped to factories for further processing. Despite its central role in chocolate production, pulp degradation, which is assumed to be a result of pectin breakdown, has not been thoroughly investigated. Therefore, this study provides a comprehensive physicochemical analysis of cocoa pulp, focusing on pectic polysaccharides, and the factors influencing its degradation. Detailed analysis reveals that pectin in cocoa pulp largely consists of weakly bound substances, and that both temperature and enzyme activity play a role in its degradation. Furthermore, this study shows that pulp degradation by an indigenous yeast fully relies on the presence of a single gene (PGU1), encoding for an endopolygalacturonase. Apart from their basic scientific value, these new insights could propel the selection of microbial starter cultures for more efficient pulp degradation.

  10. Potassium hydroxide pulping of rice straw in biorefinery initiatives.

    Science.gov (United States)

    Jahan, M Sarwar; Haris, Fahmida; Rahman, M Mostafizur; Samaddar, Purabi Rani; Sutradhar, Shrikanta

    2016-11-01

    Rice straw is supposed to be one of the most important lignocellulosic raw materials for pulp mill in Asian countries. The major problem in rice straw pulping is silica. The present research is focused on the separation of silica from the black liquor of rice straw pulping by potassium hydroxide (KOH) and pulp evaluation. Optimum KOH pulping conditions of rice straw were alkali charge 12% as NaOH, cooking temperature 150°C for 2h and material to liquor ratio, 1:6. At this condition pulp yield was 42.4% with kappa number 10.3. KOH pulp bleached to 85% brightness by D0EpD1 bleaching sequences with ClO2 consumption of 25kg/ton of pulp. Silica and lignin were separated from the black liquor of KOH pulping. The amount of recovered silica, lignin and hemicelluloses were 10.4%, 8.4% and 13.0%. The papermaking properties of KOH pulp from rice straw were slightly better than those of corresponding NaOH pulp. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. PEMUTIHAN PULP DENGAN HIDROGEN PEROKSIDA

    Directory of Open Access Journals (Sweden)

    Ahmad M. Fuadi

    2012-01-01

    Full Text Available The use of bleaching agent has increased as the result of increasing of paper consumption. The conventional bleaching agent that commonly used is material containing of chlorine. This material is not environmentally friendly and should be replaced by environmentally benign chemical, such as H2O2. About 40 gram of dry Akasia pulp was mixed with 600 ml of distilled water was put into plastic bag heated in a water bath. When the temperature reached 630C, a solution of 4 % of H2O2 and distilled water was added to obtain 5 % consistency. This mixture was put into water bath and was heated for 2 hours. The same procedure was conducted with various concentration of H2O2, time and pH. At the end of the process, the pulp was dewatered and washed. The filtrate obtained from the initial dewatering was used to determine the residual of H2O2. The pulp was analyzed to determine brightness, fiber strength and kappa number. The maximum achievement of brightness was 62,1 % ISO, 6.86 of kappa number and 1.02 kg/15 mm of fiber strength, which are reached at16 % of the use of H2O2, pH 11 and 5 hours of bleaching time. This achievement is similar to bleaching result by the additional of 4% H2O2. Inefficient usage of H2O2 was caused by some metal ions in the pulp which facilitate the decomposition of H2O2 to produce oxygen and water which has not effect on increasing the brightness. To improve the bleach ability of H2O2, initial treatment to remove metal ions from pulp should be done. Seiring dengan meningkatnya kebutuhan kertas, kebutuhan bahan pemutih juga mengalami kenaikan. Saat ini bahan pemutih yang banyak digunakan adalah senyawa yang mengandung khlor. Senyawa ini sangat tidak ramah lingkungan, oleh karena itu, perlu dicari bahan yang ramah lingkungan untuk menggantikannya. Salah satunya adalah hidrogen peroksida. Pulp dari pohon akasia sebanyak 40 gram kering dicampur dengan 600 ml aquadest dimasukkan dalam kantung plastik dipanaskan dalam water bath

  12. Drying kinetics of atemoya pulp

    Directory of Open Access Journals (Sweden)

    Plúvia O. Galdino

    Full Text Available ABSTRACT This study was conducted in order to obtain drying curves of whole atemoya pulp through the foam-mat drying method. The suspension was prepared with whole atemoya pulp mixed with 2% of Emustab® and 2% of Super Liga Neutra® with mixing time of 20 min, and dried in a forced-air oven at different temperatures (60; 70 and 80 °C and thicknesses of the foam layer (0.5, 1.0 and 1.5 cm. The drying rate curves were plotted against the water content ratio and the semi-theoretical models of Henderson & Pabis, Page and Midilli were used. All tested models showed coefficient of determination (R2 above 0.993, and the Midilli model showed the best fit for all conditions. Drying curves were affected by temperature and layer thickness.

  13. Investigating heat and temperature regime of the combustion chamber furnace screen of the TP 100A steam generator in the Varna thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mikhlevski, A; Buchinski, B; Dashkiev, Yu; Radzievski, V; Petkov, Kh [Kievski Politekhnicheski Institut (USSR)

    1988-01-01

    In the course of 10 year operation of six TP 100A steam generators 72 emergency operation interruptions occurred due to the piercing of screen pipes in the combustion chamber. According to investigations carried out by the NPO, CKT, VTI, KPI and Soyuzenergo institutes, the damage occurred mainly because of the destructive influence of external gas corrosion processes, overheating and fatigue of metallic pipes, as well as unstable heat and temperature regime in the combustion chamber. Large-scale measurements of the main thermodynamic parameters of the combustion chamber of the TP-100A steam generator were carried out in order to increase service life of screen pipes. It was found that the temperature of screen pipes increases 2.5 C/month because of deposition of sediments. Regular cleaning of screen pipes in intervals of 18 months is recommended as a very efficient means of prolonging their service life. 1 ref.

  14. Development of a nano-tesla magnetic field shielded chamber and highly precise AC-susceptibility measurement coil at μK temperatures

    Science.gov (United States)

    Kumar, Anil; Prakash, Om; Ramakrishanan, S.

    2014-04-01

    A special sample measurement chamber has been developed to perform experiments at ultralow temperatures and ultralow magnetic field. A high permeability material known as cryoperm 10 and Pb is used to shield the measurement space consisting of the signal detecting set-up and the sample. The detecting setup consists of a very sensitive susceptibility coil wound on OFHC Cu bobbin.

  15. Experimental determination of temperatures of the inner wall of a boiler combustion chamber for the purpose of verification of a CFD model

    Directory of Open Access Journals (Sweden)

    Petr Trávníček

    2011-01-01

    Full Text Available The paper focuses on the non-destructive method of determination of temperatures in the boiler combustion chamber. This method proves to be significant mainly as regards CFD (Computational Fluid Dynamics simulations of combustion processes, in case of which it is subsequently advisable to verify the data calculated using CFD software application with the actually measured data. Verification of the method was based on usage of reference combustion equipment (130 kW which performs combustion of a mixture of waste sawdust and shavings originating in the course of production of wooden furniture. Measuring of temperatures inside the combustion chamber is – considering mainly the high temperature values – highly demanding and requires a special type of temperature sensors. Furthermore, as regards standard operation, it is not possible to install such sensors without performing structural alterations of the boiler. Therefore, for the purpose of determination of these temperatures a special experimental device was constructed while exploiting a thermal imaging system used for monitoring of the surface temperature of outer wall of the reference boiler. Temperatures on the wall of the boiler combustion chamber were determined on the basis of data measured using the experimental device as well as data from the thermal imaging system. These values might serve for verification of the respective CFD model of combustion equipment.

  16. TH-AB-201-08: Ion Chamber Dose Measurements - Problems with the Temperature-Pressure Correction Factor

    Energy Technology Data Exchange (ETDEWEB)

    Bourgouin, A [Carleton University, Ottawa, Ontario (Canada); McEwen, M [National Research Council, Ottawa, ON (Canada)

    2016-06-15

    Purpose: To investigate the behavior of ionization chambers over a wide pressure range. Methods: Three cylindrical and two parallel-plate designs of ion chamber were investigated. The ion chambers were placed in vessel where the pressure was varied from atmospheric (101 kPa) down to 5 kPa. Measurements were made using 60Co and high-energy electron beams. The pressure was measured to better than 0.1% and multiple data sets were obtained for each chamber at both polarities to investigate pressure cycling and dependency on the sign of the charge collected. Results: For all types of chamber, the ionization current, corrected using the standard PTP, showed a similar behaviour. Deviations from the standard theory were generally small for Co-60 but very significant for electron beams, up to 20 % below P = 10 kPa. The effect was found to be always larger when collecting negative charge, suggesting a dependence on free-electron collection. The most likely source of such electrons is low-energy electrons emitted from the electrodes. This signal would be independent of air pressure within the chamber cavity. The data was analyzed to extract this signal and it was found to be a non-negligible component of the ionization current at atmospheric pressure. In the case of the parallel plate chambers, the effect was approximately 0.25 %. For the cylindrical chambers the effect was larger - up to 1.2 % - and dependent on the chamber type, which would be consistent with electron emission from different wall materials. For the electron beams, the correction factor was dependent on the electron energy and approximately double that observed in 60Co. Conclusion: Measurements have indicated significant deviations of the standard pressure correction that are consistent with electron emission from chamber electrodes. This has implications for both primary standard and reference ion chamber-based dosimetry.

  17. Co-pyrolysis of lignite and sugar beet pulp

    International Nuclear Information System (INIS)

    Yilgin, M.; Deveci Duranay, N.; Pehlivan, D.

    2010-01-01

    Today, worldwide studies have been undertaken on the biomass usage and co-conversion of biomass and coal to seek out alternative fuels for supplying energy in an environmental friendly way. The objective of this work is to study co-pyrolysis of lignite and sugar beet pulp in 50/50 (wt./wt.) ratio of blend pellets, to elucidate their thermal behaviour under pyrolysis conditions and to assess major decomposition products in terms of their yields. A special chamber, which has enabled very fast heating rates, was used in the pyrolysis experiments carried at 600 deg. C. The results were interpreted in the light of liquid, solid and gaseous yields, resulting from thermal decomposition, and kinetics of thermogravimetric analysis. Proximate volatile matter and ash contents of the blends were different compared to those found by using individual values. Sugar beet pulp decomposed faster within a relatively narrow temperature range than lignite and underwent a significant shrinkage during pyrolysis. It was found that the chars left behind after the flash pyrolysis of these pellets at 600 deg. C have substantial amounts of volatile matter that would evolve upon further heating.

  18. The Kraft Pulp And Paper Properties of Sweet Sorghum Bagasse (Sorghum bicolor L Moench

    Directory of Open Access Journals (Sweden)

    Widya Fatriasari

    2015-05-01

    Full Text Available This study investigated the potency of sweet sorghum (Sorghum bicolor bagasse as raw material for pulp and paper using kraft pulping. The effects of alkali and sulfidity loading on kraft pulp and paper properties were also investigated. The pulping condition of the kraft pulp consisted of three levels of alkali loading (17, 19 and 22% and sulfidity loading (20, 22 and 24%. The maximum cooking temperature was 170°C for 4 h with a liquid to wood ratio of 10:1. Kraft pulping of this Numbu bagasse produced good pulp indicated by high screen yield and delignification selectivity with a low Kappa number (< 10. The unbleached pulp sheet produced a superior brightness level and a high burst index. The increase of active alkali loading tended to produce a negative effect on the pulp yield, Kappa number and paper sheet properties. Therefore, it is suggested to use a lower active alkaline concentration.

  19. Efeito da temperatura e taxa de cisalhamento nas propriedades de escoamento da polpa de Cupuaçu (T. grandiflorum Schum integral Effect of temperature and shear rate in the properties of whole flow Cupuassu pulp (Theobroma grandiflorum

    Directory of Open Access Journals (Sweden)

    Gilvanete Maria Ferreira

    2008-06-01

    Full Text Available O comportamento reológico da polpa de cupuaçu integral foi determinado na faixa de temperatura de 10 a 60ºC. Os efeitos da temperatura e da taxa de deformação foram avaliados por meio de testes em cisalhamento estacionário. As análises reológicas foram conduzidas num reômetro Thermo Haake RheoStress 1. Os reogramas foram descritos pelos modelos reológicos de Ostwald-de-Waelle e o de Herschel-Bulkley. As curvas de escoamento mais bem ajustadas pelo modelo de Ostwald-de-Waelle. O produto apresentou comportamento pseudoplástico, e o índice de comportamento de fluxo (n decresceu com o aumento da temperatura. O efeito da temperatura sobre a viscosidade aparente foi descrita por uma equação tipo Arrhenius e discutida em termos de energia de ativação. Essa energia aumentou com o aumento da taxa de deformação, sendo obtidos valores na faixa de 1 a 2 kcal/gmol.The rheological behavior of the entire cupuassu pulp was determined in the temperature range 10 - 60ºC. The effects of temperature and deformation rate were evaluated by means of shear flow tests. Rheometry analyses were conducted with a Thermo Haake RheoStress 1 system. Rheograms were described by models by Ostwald-of-Waelle and Herschel-Bulkley. The Ostwald-of-Waelle model successfully represented pulp flow behavior. The product presented shear-thinning behavior and the flow behavior index (n decreased with the increase of temperature. The effect of temperature on the apparent viscosity in cupuassu pulp was described by an Arrhenius equation and discussed in terms of activation energy. The increase in shear rate caused an energy increase, and values were obtained in the range of a line from 1 to 2 kcal/gmol.

  20. The role of bound chlorine in the brightness reversion of bleached hardwood kraft pulp

    Directory of Open Access Journals (Sweden)

    Kátia Maria Morais Eiras

    2009-01-01

    Full Text Available Our previous paper showed fragmentary evidence that pulp brightness reversion may be negatively affected by its organically bound chlorine (OX content. A thorough investigation on eucalyptus kraft pulp led to the conclusion that OX increases reversion of certain pulps but this trend is not universal. Alkaline bleaching stages decrease reversion regardless of pulp OX content. Pulps bleached with high temperature chlorine dioxide revert less than those bleached with conventional chlorine dioxide in sequences ending with a chlorine dioxide stage but similarly in sequences ending with a final peroxide stage. The use of secondary condensate for pulp washing decreases reversion.

  1. Pulp and paper from oil palm fronds: Wavelet neural networks modeling of soda-ethanol pulping

    OpenAIRE

    Zarita Zainuddin; Wan Rosli Wan Daud; Pauline Ong; Amran Shafie

    2012-01-01

    Wavelet neural networks (WNNs) were used to investigate the influence of operational variables in the soda-ethanol pulping of oil palm fronds (viz. NaOH concentration (10-30%), ethanol concentration (15-75%), cooking temperature (150-190 ºC), and time (60-180 min)) on the resulting pulp and paper properties (viz. screened yield, kappa number, tensile index, and tear index). Performance assessments demonstrated the predictive capability of WNNs, in that the experimental results of the dependen...

  2. Soybean leaf hydraulic conductance does not acclimate to growth at elevated [CO2] or temperature in growth chambers or in the field.

    Science.gov (United States)

    Locke, Anna M; Sack, Lawren; Bernacchi, Carl J; Ort, Donald R

    2013-09-01

    Leaf hydraulic properties are strongly linked with transpiration and photosynthesis in many species. However, it is not known if gas exchange and hydraulics will have co-ordinated responses to climate change. The objective of this study was to investigate the responses of leaf hydraulic conductance (Kleaf) in Glycine max (soybean) to growth at elevated [CO2] and increased temperature compared with the responses of leaf gas exchange and leaf water status. Two controlled-environment growth chamber experiments were conducted with soybean to measure Kleaf, stomatal conductance (gs) and photosynthesis (A) during growth at elevated [CO2] and temperature relative to ambient levels. These results were validated with field experiments on soybean grown under free-air elevated [CO2] (FACE) and canopy warming. In chamber studies, Kleaf did not acclimate to growth at elevated [CO2], even though stomatal conductance decreased and photosynthesis increased. Growth at elevated temperature also did not affect Kleaf, although gs and A showed significant but inconsistent decreases. The lack of response of Kleaf to growth at increased [CO2] and temperature in chamber-grown plants was confirmed with field-grown soybean at a FACE facility. Leaf hydraulic and leaf gas exchange responses to these two climate change factors were not strongly linked in soybean, although gs responded to [CO2] and increased temperature as previously reported. This differential behaviour could lead to an imbalance between hydraulic supply and transpiration demand under extreme environmental conditions likely to become more common as global climate continues to change.

  3. Estudo do efeito da temperatura nas propriedades reológicas da polpa de butiá (Butia eriospatha / Study of temperature effect on rheological parameters of the butia pulp (Butia eriospatha

    Directory of Open Access Journals (Sweden)

    Maurício Rigo

    2010-04-01

    Full Text Available O objetivo deste trabalho foi estudar o efeito da temperatura no comportamento reológico da polpa de butiá, na forma integral, e a influência da geometria de medida na determinação do comportamento reológico da polpa de butiá. O reômetro utilizado foi da marca Haake Rotovisco, modelo RV-20, com cilindros concêntricos ou placas paralelas. Os dados experimentais dos reogramas para a polpa de butiá foram bem ajustados pelos modelos de Herschell-Bulkley, Casson e Ostwald-de-Waelle. O melhor ajuste se deu pelo modelo de Herschell-Bulkley. Para polpa de butiá, a viscosidade diminui com aumento da temperatura. Os índices de comportamentos obtidos dos dados experimentais foram menores do que um para todas as temperaturas investigadas, o que caracteriza comportamento pseudoplástico da polpa. O sistema de medida de placas paralelas se mostrou inadequado para o estudo do comportamento reológico de polpa de butiá. Portanto é necessária a padronização do sistema de medida empregado para determinação da análise reológica. O modelo de Arrhenius descreve o efeito da temperatura sobre a viscosidade aparente da polpa de butiá.AbstractRheological parameters of Butia (Butia eriospatha pulp were determined at different temperatures (10-60°C using a concentric cylinder Haake Rotovisco rheometer, model RV-20, with concentric cylinders and parallel plate. Butia pulp was found to exhibit non-Newtonian, pseudoplastic behavior at all temperatures investigated and the rheological parameters were adequately described by the Herschel-Bulkley, Ostwald-de-Waelle and Casson models. Yield stress, flow behavior index, and consistency coefficient were significantly affected by temperature. The apparent viscosity calculated through the Herschel-Bulkley model decreased with an increase in temperature. The Arrhenius model gave a good description of temperature effect on apparent viscosity of the pulp. The measurement system of parallel plate was inadequate to

  4. Estudo do efeito da temperatura sobre o comportamento reológico das polpas de gabiroba e goiaba = Study of temperature effect on rheological behavior of gabiroba and guava pulps

    Directory of Open Access Journals (Sweden)

    Ricardo Cardoso de Oliveira

    2011-01-01

    Full Text Available Neste trabalho um estudo sobre o comportamento reológico das polpas degabiroba e goiaba foi estudado na faixa de temperatura de 20 – 35ºC. As medidas reológicas foram feitas em rêometro Brookfield equipados com cilindro coaxial. Os reogramas foram ajustados a partir dos dados experimentais para os modelos de Ostwald de Waale, Bingham e Herschell-Buckley pela metodologia Bayesiana. Para ambas as polpas foram verificadas o comportamento pseudoplástico e sendo a pseudoplasticidade maior em baixas temperaturas. Considerando o modelo de Ostwald de Waale, a viscosidade aparente e o índice deconsistência diminuíram com o aumento da temperatura ao passo que índice de comportamento aumentou com o aumento de temperatura.In this work a study on the rheological behavior of the guava and gabiroba pulp were studied in temperature range from 20 – 35ºC. The rheological measurements were made in Brookfield rheometer equipped with coaxial cylinder. The rheograms were adjusted from the experimental data for the models of Ostwald de Waale, Bingham andHerschell-Buckley by Bayesian methodology. For both the pulps the pseudo plastic behavior was found, and pseudo plasticity was bigger at low temperatures. Considering the Ostwald de Waale model, the viscosity and consistency index decreased with the rising of the temperature while index of behavior increased with the rising of the temperature.

  5. Dry Kraft Pulping at Ambient Pressure for Cost Effective Energy Saving and Pollution Deduction

    Energy Technology Data Exchange (ETDEWEB)

    Yulin Deng; Art Ragauskas

    2012-08-28

    Sponsored by the DOE Industrial Energy Efficiency Grand Challenge program, our research team at the Georgia Institute of Technology conducted laboratory studies and confirmed the concept of making wood pulp using a dry pulping technology. This technology is a new process different from any prior pulping technology used in Kraft and CTMP pulping. Three different kinds of dry pulping methods were investigated. (a) Dry Pulping at Atmospheric Pressure: The first one is to dry and bake the pretreated woodchips in a conventional oven at atmospheric pressure without the use of a catalyst. (b) Dry Pulping at Reduced Pressure: The second method is to dry the pretreated woodchips first in a vacuum oven in the presence of anthraquinone (AQ) as a pulping catalyst, followed by baking at elevated temperature. (c) Liquid Free Chemical Pulping, LFCP. The third method is to first remove the free water of pretreated woodchips, followed by dry pulping using a conventional Kraft pulping digester with AQ and triton as additives. Method one: Experimental results indicated that Dry Pulping at Atmospheric Pressure could produce pulp with higher brightness and lower bulk than conventional Kraft pulp. However, tensile strength of the acquired pulp is much lower than traditional Kraft pulp, and their Kappa number and energy consumption are higher than conventional Kraft pulp. By fully analyzing the results, we concluded that wood fibers might be damaged during the drying process at elevated temperature. The main reason for wood fiber damage is that a long drying time was used during evaporation of water from the woodchips. This resulted in an un-uniform reaction condition on the woodchips: the outside layer of the woodchips was over reacted while inside the woodchips did not reacted at all. To solve this problem, dry pulping at reduced pressure was investigated. Method two: To achieve uniform reaction throughout the entire reaction system, the water inside the pretreated woodchips was

  6. 变温环境室空调系统实验研究%Experimental Study on Air Conditioning System of Variable Temperature Ambient Chamber

    Institute of Scientific and Technical Information of China (English)

    张柱; 吴蔚兰

    2017-01-01

    This paper introduces experimental facilities on air conditioning system of variable temperature ambient chamber.Researching and analysis the operating parameters of temperature distribution,compressor start-stop cycle and cooling capacity and COP changes.The results showed that the closer chamber controlled temperature is located to the ambient temperature,the smaller the temperature fluctuations is,temperature difference is also smaller;compared with the theoretical value,with ambient chamber temperature rising,compressor cooling capacity and COP rise;theoretical cooling capacity is more than the actual cooling capacity and compression of the start-stop,regardless of the theoretical value or experimental values,showed a downward trend from low to high,but the low temperature test values close to the theoretical value,when the high temperature is lower than the theoretical value.%介绍了变温环境室空调系统实验装置,研究分析了不同工况下室内温度分布、压缩机启停周期、制冷量及COP等运行参数的变化情况.实验结果表明:室内控制温度越接近坐落环境温度,温度波动幅度越小,不同位置的温差也越小;与理论值相比,压缩机的制冷量及COP随环境室温度升高而升高,理论制冷量大于实际制冷量;而压缩机启停比,无论理论值还是实验值,均呈现从低温到高温下降的趋势,但低温时实验值接近于理论值,高温时低于理论值.

  7. Ionization chamber

    International Nuclear Information System (INIS)

    Jilbert, P.H.

    1975-01-01

    The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

  8. Anthraquinone-A Review of the Rise and Fall of a Pulping Catalyst

    Science.gov (United States)

    Peter W. Hart; Alan W. Rudie

    2014-01-01

    The application of anthraquinone (AQ) as a pulping catalyst has been well documented in scientific studies and mill applications. AQ is known to increase the rate of delignification, enabling a reduction in pulping time, temperature, or chemical charge and an increase in pulp yield. Specific details of AQ use are not extensively reviewed in this work. The review...

  9. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  10. Development and application of a high-temperature sampling probe for burning chamber conditions of fluidized-bed combustion; Korkean laempoetilan naeytteenottosondin kehittaeminen ja soveltaminen leijukerrospolton tulipesaeolosuhteisiin

    Energy Technology Data Exchange (ETDEWEB)

    Larjava, K.; Paerkkae, M.; Jormanainen, P.; Roine, J.; Paakkinen, K. [VTT Chemistry, Espoo (Finland); Linna, V. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-01

    A sampling probe for the burning chamber conditions of fluidized-bed combustion will be developed in this project. The probe will be suitable for sampling vaporous heavy and alkali metals and other condensing compounds (e.g. chlorides) as well combustion gases and alternatively also flue gas particles at high temperatures. The knowledge gained with the probe will help understanding, developing and modeling combustion processes and will thus aid the manufacturers of the boilers. (author)

  11. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....

  12. PULP OBTAINING METHOD FOR PACKAGE PRODUCTION

    Directory of Open Access Journals (Sweden)

    V. V. Kuzmich

    2015-01-01

    Full Text Available The paper presents a new method for obtaining pulp which is used for production of cardboard, paper and package while using carbon dioxide and hydrazine hydrate and neutral-sulfite  shive cooking. Output increase of  the desired product can be explained by reduction in destruction of plant raw material carbohydrates during its cooking process. Quality improvement of the desired product (improvement in bleaching and output is attributed to the fact that usage of carbon dioxide and hydrazine contributes to provision of polysaccharide chain resistance to destruction due to the presence of  end links having structure of metasaccharinic and aldonic acids.The author has developed a new method for pulp obtaining on the basis of the executed investigations  and literature data.  СО2 and hydrazine hydrate have been used for obtaining pulp. Method invention concerns pulp obtaining and it can be used for paper and cardboard package manufacturing in pulp and paper industry.The method is to be carried in the following way: pulp-containing plant raw material is loaded into an autoclave and then aqua solution of sodium monosulfite containing hydrazine hydrate that constitutes 4–5 % of absolute dry pulp-containing raw material mass with liquid module 1:6–1:8 is supplied into the autoclave. The autoclave is closed for operation under pressure and the solution is carbonated under pressure which constitutes 5–8 % of absolute dry plant raw material (shover. Temperature is subsequently raised up to 180 °С in the space of 2 hours and cooking is carried out in the course of 4 hours. Usage of  the proposed method for shover cooking makes it possible to reduce monosulfite cooking process and improve qualitative characteristics and output of the desired product.  In addition to above mentioned fact there is a possibility to improve bleaching and final product output. 

  13. Biogas generation apple pulp.

    Science.gov (United States)

    Llaneza Coalla, H; Blanco Fernández, J M; Morís Morán, M A; López Bobo, M R

    2009-09-01

    In view of the pressing problem that appears in our region (Asturias, north of Spain) with the residues from the cider production, it was decided to test this kind of material as a co-substrate joint with slaughterhouse waste in a laboratory unit. The anaerobic digestion of apple pulp was investigated for biogas production. This paper presents the results where apple pulp was co-digested with slaughterhouse waste (pig intestine and bovine stomach content) in a biogas laboratory unit (10 l CSTR reactor). The production of biogas has reached very satisfactory values during the whole test (0.8m(3)kg(-1)OTS), verifying that the process is kept in stable conditions of pH (near 8.0), and the volatile fatty acids was always underneath 3000 mg/l, when the pulp amount was lower than 100g in mesophilic conditions. The fat concentration into the digester remained always below the value that causes inhibition of the methanogenic bacteria, 500 mg/l. Finally, methane concentration (77-80%) and H(2)S concentration (400 ppm) in the biogas, they were similar to those obtained when the test was run out in the absence of apple pulp. The process efficiency with respect to COD removal was high, near 80% of the total COD. Finally, inhibitory effects of methanogenic bacteria were observed when pulp concentration was around 10% in the input material.

  14. The Mobile Chamber

    Science.gov (United States)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  15. Decellularized Swine Dental Pulp as a Bioscaffold for Pulp Regeneration

    Directory of Open Access Journals (Sweden)

    Lei Hu

    2017-01-01

    Full Text Available Endodontic regeneration shows promise in treating dental pulp diseases; however, no suitable scaffolds exist for pulp regeneration. Acellular natural extracellular matrix (ECM is a favorable scaffold for tissue regeneration since the anatomical structure and ECM of the natural tissues or organs are well-preserved. Xenogeneic ECM is superior to autologous or allogeneic ECM in tissue engineering for its unlimited resources. This study investigated the characteristics of decellularized dental pulp ECM from swine and evaluated whether it could mediate pulp regeneration. Dental pulps were acquired from the mandible anterior teeth of swine 12 months of age and decellularized with 10% sodium dodecyl sulfate (SDS combined with Triton X-100. Pulp regeneration was conducted by seeding human dental pulp stem cells into decellularized pulp and transplanted subcutaneously into nude mice for 8 weeks. The decellularized pulp demonstrated preserved natural shape and structure without any cellular components. Histological analysis showed excellent ECM preservation and pulp-like tissue, and newly formed mineralized tissues were regenerated after being transplanted in vivo. In conclusion, decellularized swine dental pulp maintains ECM components favoring stem cell proliferation and differentiation, thus representing a suitable scaffold for improving clinical outcomes and functions of teeth with dental pulp diseases.

  16. Decellularized Swine Dental Pulp as a Bioscaffold for Pulp Regeneration.

    Science.gov (United States)

    Hu, Lei; Gao, Zhenhua; Xu, Junji; Zhu, Zhao; Fan, Zhipeng; Zhang, Chunmei; Wang, Jinsong; Wang, Songlin

    2017-01-01

    Endodontic regeneration shows promise in treating dental pulp diseases; however, no suitable scaffolds exist for pulp regeneration. Acellular natural extracellular matrix (ECM) is a favorable scaffold for tissue regeneration since the anatomical structure and ECM of the natural tissues or organs are well-preserved. Xenogeneic ECM is superior to autologous or allogeneic ECM in tissue engineering for its unlimited resources. This study investigated the characteristics of decellularized dental pulp ECM from swine and evaluated whether it could mediate pulp regeneration. Dental pulps were acquired from the mandible anterior teeth of swine 12 months of age and decellularized with 10% sodium dodecyl sulfate (SDS) combined with Triton X-100. Pulp regeneration was conducted by seeding human dental pulp stem cells into decellularized pulp and transplanted subcutaneously into nude mice for 8 weeks. The decellularized pulp demonstrated preserved natural shape and structure without any cellular components. Histological analysis showed excellent ECM preservation and pulp-like tissue, and newly formed mineralized tissues were regenerated after being transplanted in vivo. In conclusion, decellularized swine dental pulp maintains ECM components favoring stem cell proliferation and differentiation, thus representing a suitable scaffold for improving clinical outcomes and functions of teeth with dental pulp diseases.

  17. Ussing Chamber

    NARCIS (Netherlands)

    Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

    2015-01-01

    The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

  18. Pectin methyl esterase activity in apple and orange pulps

    International Nuclear Information System (INIS)

    Abdullaev, A.; Djumaev, B.B.; Djumaev, N.B.; Mukhidinov, Z.K.

    2008-01-01

    The results of pectin methyl esterase activity from apple, orange pulp and orange peel depending of ph and temperature are discussed. It's shown that the methyl esterase activity form apple and orange pulps higher in range of temperatures from +37...+60 d ig C . The analysis of dependence of its activity from ph has shown that in both case the enzyme activity increase with increase of ph

  19. Development and application of a high-temperature sampling probe for burning chamber conditions in fluidized-bed combustion; Korkean laempoetilan naeytteenottosondin kehittaeminen ja soveltaminen leijukerrospolton tulipesaeolosuhteisiin

    Energy Technology Data Exchange (ETDEWEB)

    Larjava, K.; Paerkkae, M. [VTT Chemical Technology, Espoo (Finland); Linna, V. [VTT Energy, Jyvaeskylae (Finland). Environmental Technology

    1997-10-01

    Determination of heavy and alkali metals and other condensing compounds (e.g. chlorides) in combustion chamber conditions is limited by the poor suitability of traditional methods for sampling at high temperatures. IFRF has developed a high-temperature sampling probe for sampling HCN and NH{sub 3}, which has been tested for sampling of NH{sub 3} by Chalmers University of Technology in Sweden. VTT Chemical Technology and Chalmers University of Technology have in their preliminary experiments determined contents of vaporous heavy metals in the combustion chamber of a 12 MW circulating fluidized-bed boiler using this probe. According to the results, the modified probe is suitable for heavy metal determination in combustion chamber. Based on this series of experiments, modification of the probe has been started on the own financing of VTT Chemical Technology and a field measurement was performed in November 1994 to test the present version of the probe. Based on the results of that measurement, the probe has been modified further on as a part of this LIEKKI 2 project. Similar kind of a principle has been applied in the probe which has been developed by VTT Energy during 1994. The probe is built for determination of gas composition of fluidized bed in full-scale boilers. The purpose of this project is to develop and test a sampling probe for fluidized bed combustion. The main advantage of the probe is that condensation losses in sampling due to high temperature gradients can be avoided. Thus, the probe is very suitable for sampling vaporous heavy and alkali metals and other condensing species as well as burning gases and alternatively also solids at high temperatures

  20. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  1. Investigation of pulping and paper making potential of weeds

    Directory of Open Access Journals (Sweden)

    omid Ghaffarzadeh Mollabashi

    2017-08-01

    Full Text Available Increasing use of wood products accompanying with resource constraint has revealed the importance of nonwood based material. In this study, pulping and papermaking potential of three varieties of weeds including Xanthium spinosum, Carthamus tinctorius and Cyperus papyrus have been considered. At first, chemical components of the samples i.e. cellulose, lignin and extractives have been measured following TAPPI standard test methods. Afterwards, pulping process based as soda and Kraft has been carried out and the pulp properties i.e. screen yield and reject, kappa number, caliper, bust index, tear index, brightness have been considered. According to the results, the amount cellulose, lignin and extractives have been measured for the Xanthium spinosum %38.15, %13.5 and 4.72, respectively. Theses parameters have been estimated about %38.25, %10.3 and % 2.95 for Carthamus tinctorius and %38.8, %19.2 and 4.4 in case of papyrus. The yield of soda and Kraft pulp of the papyrus was more than Xanthium spinosum and Carthamus tinctorius. Among all treatments, the highest screen yield related to soda pulping of Cyperus papyrus by %39.8 which has been obtained by 175 centigrade as a maximum temperature, L/W: 6/1, active alkaline: %30 and 90 minutes as the time at temperature. The lowest and highest amounts of the tear index were related to soda pulp sample of the Carthamus tinctorius and Kraft pulp sample of Xanthium spinosum by 2.49 and 8.1, respectively. In addition, the lowest and highest amounts of the bursting index were related to soda pulp sample of the Cyperus papyrus and Kraft pulp sample of Xanthium spinosum by 0.61and 2.48, respectively. Meanwhile, soda pulp sample of the Cyperus papyrus showed the highest amount of brightness with %45 ISO.

  2. In vitro study of the effects of cooling water temperature during the use of Er:YAG laser on dentin

    International Nuclear Information System (INIS)

    Pinto, Ismael Lucas

    2004-01-01

    This study measured the pulp chamber and the target surface with 2 thermocouples, in order to determine whether cooling with water spray, with Er:YAG laser (Kavo Key 2), was overcooling the tooth, much beyond the necessary, during laser irradiation, within variation limits of 2.2 deg C of body temperature. The parameters used were: E p =250 mJ per pulse, with frequency ranging between 2 to 4 Hz, for a total DE of 80.20 J/cm 2 , at an angle of incidence of approximately 90 deg, during an exposure period of 1 minute, totaling 120 to 240 pulses. In the first 40 seconds, the spray cooled the tooth rapidly, from 36.5 deg C to below 30 deg C. It was impossible to control the spray output temperature with a simple increase in reservoir temperature, for when water at temperatures ranging between 90 and 100 deg C is placed in the reservoir, the heat dissipates completely during the trajectory. The water jet does not present the same characteristics as a spray, which makes it impossible to conduct a perfect comparative analysis between them. The increase and maintenance of the spray output temperature, by reducing the temperature differential between that of the body and that of the spray of the Er:YAG laser, proved to be extremely promising. The pulp chamber temperature followed that of the spray or water jet, so that when a temperature that is lower than body temperature is used, the temperature of the pulp chamber is decreases, and when body temperature is surpassed, the temperature of the pulp chamber increases. (author)

  3. Drift chamber

    International Nuclear Information System (INIS)

    Inagaki, Yosuke

    1977-01-01

    Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

  4. Temporary storage of jussara palm seeds: effects of time, temperature and pulp on germination and vigor Armazenamento temporário de sementes da palmeira juçara: efeitos do tempo, temperatura e polpa na germinação e vigor

    Directory of Open Access Journals (Sweden)

    Cibele C. Martins

    2004-06-01

    Full Text Available Seeds of jussara palm (Euterpe edulis Mart. are recalcitrant, presenting low longevity, high sensitivity to dehydration and to low temperatures of storage. Temperature conditions for temporary preservation of those seeds, with and without pulp, were studied. Mature fruits were harvested from 24 plants belonging to the palm collection of the Instituto Agronômico (IAC located at Ubatuba, São Paulo State, Brazil, and taken in moisture-proof containers to the Universidade Estadual de São Paulo, in Botucatu, São Paulo State. Half of the fruits were shelled and the seeds stored, with and without pulp, in sealed plastic bags (20 µm thick maintained in chambers with temperatures of 5; 10; 15 and 20-30ºC. Samples for the quality tests were taken at 0; 3; 6; 9 and 12 days after fruit harvest. Seeds stored with pulp were immediately shelled before test installation. Several characteristics were evaluated, especially seed water content, germination rate, seedling length and dry matter. There is a positive after-ripening effect on Euterpe edulis seeds. A period of storage of 9 to 12 days, after fruit harvest and before sowing, favored germination and vigor of jussara seeds. These effects were higher in shelled seeds when compared to unshelled ones. Short-term storage temperatures ranging from 5 to 20-30ºC are equally adequate for the preservation of seeds without pulp, but should not exceed 20ºC for those with pulp, since a decrease in germination and vigor, and an increase in rotted germinative button and dead seeds were observed at 20-30ºC temperature.As sementes da palmeira juçara (Euterpe edulis Mart. são recalcitrantes, apresentando baixa longevidade e sensibilidade à desidratação e ao armazenamento em temperaturas baixas. Neste trabalho foram estudadas condições de temperatura mais adequadas ao armazenamento temporário destas sementes com e sem a polpa. Frutos maduros foram colhidos em 24 plantas provenientes da coleção de palmeiras

  5. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  7. Biomechanical pulping of kenaf

    Science.gov (United States)

    Aziz Ahmed; Masood Akhtar; Gary C. Myers; Gary M. Scott

    1999-01-01

    The objective of this study was to investigate the effect of fungal pretreatment of whole kenaf prior to refining on refiner electrical energy consumption, paper strength, and optical properties. We also explored the suitability of whole kenaf biomechanical pulp for making newsprint in terms of ISO brightness and strength properties. Kenaf was sterilized by autoclaving...

  8. Infection and Pulp Regeneration

    Directory of Open Access Journals (Sweden)

    Sahng G. Kim

    2016-03-01

    Full Text Available The regeneration of the pulp-dentin complex has been a great challenge to both scientists and clinicians. Previous work has shown that the presence of prior infection may influence the characteristics of tissues formed in the root canal space after regenerative endodontic treatment. The formation of ectopic tissues such as periodontal ligament, bone, and cementum has been observed in the root canal space of immature necrotic teeth with apical periodontitis, while the regeneration of dentin and pulp has been identified in previously non-infected teeth. The current regenerative endodontic therapy utilizes disinfection protocols, which heavily rely on chemical irrigation using conventional disinfectants. From a microbiological point of view, the current protocols may not allow a sufficiently clean root canal microenvironment, which is critical for dentin and pulp regeneration. In this article, the significance of root canal disinfection in regenerating the pulp-dentin complex, the limitations of the current regenerative endodontic disinfection protocols, and advanced disinfection techniques designed to reduce the microorganisms and biofilms in chronic infection are discussed.

  9. Ionization chamber

    International Nuclear Information System (INIS)

    1977-01-01

    An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  10. Ionization chambers

    International Nuclear Information System (INIS)

    Boag, J.W.

    1987-01-01

    Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

  11. Optimization of Dithionite Bleaching of High Yield Bagasse Pulp

    International Nuclear Information System (INIS)

    Mohamed, E.

    2005-01-01

    High yield bagasse pulp was prepared by soaking bagasse in 10 % cold sodium hydroxide for 24 hours and then refluxing for two hours at 95 degree C. Optimization of dithionite bleaching was attained by investigation of different parameters as consistency, temperature, time and ph. Effect of additives as chelating agent (EDTA) or stabilizing of bleaching solution (Zn compound and hexamethylene tetramine) was considered. The effect of air content was also studied. One and two stages bleaching of the pulp were investigated by using sodium dithionite (D) as a sole bleaching agent or after application of one stage bleaching by hydrogen peroxide to attain high brightness for high yield pulp

  12. Growth responses, biomass partitioning, and nitrogen isotopes of prairie legumes in response to elevated temperature and varying nitrogen source in a growth chamber experiment.

    Science.gov (United States)

    Whittington, Heather R; Deede, Laura; Powers, Jennifer S

    2012-05-01

    Because legumes can add nitrogen (N) to ecosystems through symbiotic fixation, they play important roles in many plant communities, such as prairies and grasslands. However, very little research has examined the effect of projected climate change on legume growth and function. Our goal was to study the effects of temperature on growth, nodulation, and N chemistry of prairie legumes and determine whether these effects are mediated by source of N. We grew seedlings of Amorpha canescens, Dalea purpurea, Lespedeza capitata, and Lupinus perennis at 25/20°C (day/night) or 28/23°C with and without rhizobia and mineral N in controlled-environment growth chambers. Biomass, leaf area, nodule number and mass, and shoot N concentration and δ(15)N values were measured after 12 wk of growth. Both temperature and N-source affected responses in a species-specific manner. Lespedeza showed increased growth and higher shoot N content at 28°C. Lupinus showed decreases in nodulation and lower shoot N concentration at 28°C. The effect of temperature on shoot N concentration occurred only in individuals whose sole N source was N(2)-fixation, but there was no effect of temperature on δ(15)N values in these plants. Elevated temperature enhanced seedling growth of some species, while inhibiting nodulation in another. Temperature-induced shifts in legume composition or nitrogen dynamics may be another potential mechanism through which climate change affects unmanaged ecosystems.

  13. Design of a Turbulence Generator of Medium Consistency Pulp Pumps

    Directory of Open Access Journals (Sweden)

    Hong Li

    2012-01-01

    Full Text Available The turbulence generator is a key component of medium consistency centrifugal pulp pumps, with functions to fluidize the medium consistency pulp and to separate gas from the liquid. Structure sizes of the generator affect the hydraulic performance. The radius and the blade laying angle are two important structural sizes of a turbulence generator. Starting with the research on the flow inside and shearing characteristics of the MC pulp, a simple mathematical model at the flow section of the shearing chamber is built, and the formula and procedure to calculate the radius of the turbulence generator are established. The blade laying angle is referenced from the turbine agitator which has the similar shape with the turbulence generator, and the CFD simulation is applied to study the different flow fields with different blade laying angles. Then the recommended blade laying angle of the turbulence generator is formed to be between 60° and 75°.

  14. [Impact of different degree pulpitis on cell proliferation and osteoblastic differentiation of dental pulp stem cell in Beagle immature premolars].

    Science.gov (United States)

    Ling, L; Zhao, Y M; Ge, L H

    2016-10-18

    To compare the proliferation and osteoblastic differentiation of dental pulp stem cell (DPSC) isolated from normal and inflamed pulps of different degrees in Beagle immature premolars, and provide evidence for the use of inflammatory DPSC (IDPSC). This study evaluated 14 Beagle's young premolars (21 roots). In the experiment group, irreversible pulpitis was induced by pulp exposure and the inflamed pulps were extracted 2 weeks and 6 weeks after the pulp chamber opening.For the control group, normal pulps were extracted immediately after the exposure. HE staining and real-time PCR were performed to confirm the inflammation. The cells were isolated from the inflamed and normal pulps (IDPSC and DPSC). Cell proliferation and osteoblastic differentiation potentials of the two cells were compared. Inflammation cells infiltration was observed in the inflamed pulps by HE staining. The expression of inflammatory factor was much higher in the 6 week inflamed pulp. IDPSC had higher potential of cell proliferation and osteoblastic differentiation potentials. Furthermore, the osteoblastic differentiation potentials of IDPSC from 2 week inflamed pulp were higher than those from 6 week inflamed pulp. The potential of cell proliferation and osteoblastic differentiation of DPSC was enhanced at early stage of irreversible pulpitis, and reduced at late stage in Beagle immature premolars.

  15. Intrapulpal temperature during preparation with the Er:YAG laser: an in vitro study

    International Nuclear Information System (INIS)

    Geraldo-Martins, Vinicius Rangel

    2003-01-01

    This study evaluated the variation of the pulp chamber temperature when dentine, with 2,0 mm of thickness, adjacent to the pulp, was irradiated by the Er:YAG laser. Seventy two bovine incisors were used, that had the enamel and dentine of the buccal surface weared until to reach the thickness used in this study. The teeth were divided in 3 groups, according with the repetition rate used ( Group I = 2 Hz; Group II = 4 Hz and Group III = 6 Hz), and irradiated, with or without water cooling, using 250, 300 and 350 mJ of energy per pulse. Thermocouples were introduced inside the pulp chamber through the palatine opening of the samples and fixed to the vestibular wall of the pulp chamber using a thermal paste. After the statistical analysis, it was verified that there was a decrease of the intrapulpal temperature for all of the parameters in the group I irradiated with water cooling. In the same group, but without cooling, occurred increases of the intrapulpal temperature, however they were less than 2 deg C. In the group 11, only the para meter 350 mJ/4 Hz/ with water cooling presented decrease of the temperature (-0,08 deg C). The other irradiations presented increase of the intrapulpal temperature, varying from 1,5 to 1,9 deg C for irradiations without cooling and of 0,03 the 0,58 deg C for the samples irradiated under water cooling. In the group III, all of the samples presented increase of the intrapulpal temperature, however, they were smaller than to 2,5 deg C. The conditions of this study allow to conclude that the use of the laser of Er:YAG promoted acceptable temperature increases inside the pulp chamber, not reaching the critical level of 5,5 deg C. However, in spite of the temperature variations inside the pulp chamber have not reached critical levels, this procedure should not be recommended because macroscopic observations of the dentine irradiated without water cooling showed dark lesions, suggesting carbonization of this tissue. (author)

  16. EFFECTS OF ALKALINE PRE-IMPREGNATION AND PULPING ON MALAYSIA CULTIVATED KENAF (HIBISCUS CANNABINUS

    Directory of Open Access Journals (Sweden)

    Lin Suan Ang

    2010-05-01

    Full Text Available This study was carried out to identify an appropriate alkaline pulping condition for Malaysia cultivated kenaf (Hibiscus cannabinus L.. The chemical composition of the kenaf bast and core fibers, and also whole stalk with different growing time were examined prior to pulping attempts. The results of various soda-AQ pulping showed that the degree of carbohydrate degradation and delignification increased with the increase of active alkali and cooking temperature, but decreased with the increase of liquor to material (L:M ratio. The most satisfactory properties of pulp and handsheets from bast could be attained by employing soda-AQ pulping with 19.4% active alkali, 0.10% AQ, and L:M ratio of 7:1 cooked for 2 hours at 160˚C. Besides, it was also found that a mild alkaline pre-impregnation prior pulping improved the pulp viscosity and handsheets’ strength properties, especially the tensile index and folding endurance effectively. Moreover, among the three alkaline pulping processes—kraft, kraft-AQ, and soda-AQ—the results of pulp and handsheet properties showed that the soda-AQ pulp was comparable or even slightly of higher quality than the kraft pulps. Between the unbeaten bast and core soda-AQ handsheets, the strength properties of the core were higher than the bast, as the thin-walled core fibers exhibited much better conformability than the thick-walled bast fibers.

  17. Can dental pulp calcification predict the risk of ischemic cardiovascular disease?

    Science.gov (United States)

    Khojastepour, Leila; Bronoosh, Pegah; Khosropanah, Shahdad; Rahimi, Elham

    2013-09-01

    To report the association of pulp calcification with that of cardiovascular disease (CVD) using digital panoramic dental radiographs. Digital panoramic radiographs of patients referred from the angiography department were included if the patient was under 55 years old and had non-restored or minimally restored molars and canines. An oral and maxillofacial radiologist evaluated the images for pulpal calcifications in the selected teeth. The sensitivity, specificity, positive predictive value and negative predictive value of panoramic radiography in predicting CVD were calculated. Out of 122 patients who met the criteria, 68.2% of the patients with CVD had pulp chamber calcifications. Pulp calcification in panoramic radiography had a sensitivity of 68.9% to predict CVD. This study demonstrates that patients with CVD show an increased incidence of pulp calcification compared with healthy patients. The findings suggest that pulp calcification on panoramic radiography may have possibilities for use in CVD screening.

  18. Cloud Chamber

    DEFF Research Database (Denmark)

    Gfader, Verina

    Cloud Chamber takes its roots in a performance project, titled The Guests 做东, devised by Verina Gfader for the 11th Shanghai Biennale, ‘Why Not Ask Again: Arguments, Counter-arguments, and Stories’. Departing from the inclusion of the biennale audience to write a future folk tale, Cloud Chamber......: fiction and translation and translation through time; post literacy; world picturing-world typing; and cartographic entanglements and expressions of subjectivity; through the lens a social imaginary of worlding or cosmological quest. Art at its core? Contributions by Nikos Papastergiadis, Rebecca Carson...

  19. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  20. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  1. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  2. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  3. Analysis of Knock Phenomenon Induced in a Constant Volume Chamber by Local Gas Temperature Measurement and Visualization

    Science.gov (United States)

    Moriyoshi, Yasuo; Kobayashi, Shigemi; Enomoto, Yoshiteru

    Knock phenomenon in SI engines is regarded as an auto-ignition of unburned end-gas, and it has been widely examined by using rapid compression machines (RCM), shock-tubes or test engines. Recent researches point out the importance of the low temperature chemical reaction and the negative temperature coefficient (NTC). To investigate the effects, analyses of instantaneous local gas temperature, flow visualization and gaseous pressure were conducted in this study. As measurements using real engines are too difficult to analyze, the authors aimed to make measurements using a constant volume vessel under knock conditions where propagating flame exists during the induction time of auto-ignition. Adopting the two-wire thermocouple method enabled us to measure the instantaneous local gas temperature until the moment when the flame front passes by. High-speed images inside the unburned region were also recorded simultaneously using an endoscope. As a result, it was found that when knock occurs, the auto-ignition initiation time seems slightly early compared to the results without knock. This causes a higher volume ratio of unburned mixture and existence of many hot spots and stochastically leads to an initiation of knock.

  4. Measurements of VOC/SVOC emission factors from burning incenses in an environmental test chamber: influence of temperature, relative humidity, and air exchange rate.

    Science.gov (United States)

    Manoukian, A; Buiron, D; Temime-Roussel, B; Wortham, H; Quivet, E

    2016-04-01

    This study investigates the influence of three environmental indoor parameters (i.e., temperature, relative humidity, and air exchange rate) on the emission of 13 volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) during incense burning. Experiments have been carried out using an environmental test chamber. Statistical results from a classical two-level full factorial design highlight the predominant effect of ventilation on emission factors. The higher the ventilation, the higher the emission factor. Moreover, thanks to these results, an estimation of the concentration range for the compounds under study can be calculated and allows a quick look of indoor pollution induced by incense combustion. Carcinogenic substances (i.e., benzene, benzo(a)pyrene, and formaldehyde) produced from the incense combustion would be predicted in typical living indoors conditions to reach instantaneous concentration levels close to or higher than air quality exposure threshold values.

  5. Process parameters affecting the delignification of eucalyptus kraft pulp with peroxyacetic acid

    Directory of Open Access Journals (Sweden)

    Chandranupap, P.

    2004-11-01

    Full Text Available Various process parameters affecting eucalyptus kraft pulp delignification with peroxyacetic acid were investigated. The results showed that pH was an important factor. The delignification rate increased with increasing pH to the value of 6. High delignification rate was obtained when the pulp was chelated with Na4-EDTA prior to the peroxyacetic acid stage. Therefore, delignification reaction rate depends on peroxyacid charge, temperature, pH and metal content of pulp.

  6. EFFECTS OF ALKALINE PRE-IMPREGNATION AND PULPING ON MALAYSIA CULTIVATED KENAF (HIBISCUS CANNABINUS

    OpenAIRE

    Lin Suan Ang; Cheu Peng Leh; Chong Chat Lee

    2010-01-01

    This study was carried out to identify an appropriate alkaline pulping condition for Malaysia cultivated kenaf (Hibiscus cannabinus L.). The chemical composition of the kenaf bast and core fibers, and also whole stalk with different growing time were examined prior to pulping attempts. The results of various soda-AQ pulping showed that the degree of carbohydrate degradation and delignification increased with the increase of active alkali and cooking temperature, but decreased with the increas...

  7. Electron temperature profiles in axial field 2.45 GHz ECR ion source with a ceramic chamber

    Science.gov (United States)

    Abe, K.; Tamura, R.; Kasuya, T.; Wada, M.

    2017-08-01

    An array of electrostatic probes was arranged on the plasma electrode of a 2.45 GHz microwave driven axial magnetic filter field type negative hydrogen (H-) ion source to clarify the spatial plasma distribution near the electrode. The measured spatial distribution of electron temperature indicated the lower temperature near the extraction hole of the plasma electrode corresponding to the effectiveness of the axial magnetic filter field geometry. When the ratio of electron saturation current to the ion saturation current was plotted as a function of position, the obtained distribution showed a higher ratio near the hydrogen gas inlet through which ground state hydrogen molecules are injected into the source. Though the efficiency in producing H- ions is smaller for a 2.45 GHz source than a source operated at 14 GHz, it gives more volume to measure spatial distributions of various plasma parameters to understand fundamental processes that are influential on H- production in this type of ion sources.

  8. Research on Ambient Temperature Change Law in Mine Refuge Chamber during Temperature Rise%升温期煤矿避难硐室内环境温度变化规律研究

    Institute of Scientific and Technical Information of China (English)

    周方年

    2014-01-01

    针对煤矿避难硐室内人员避灾过程中人体和设备产热引起的热环境对人员避灾的影响,研究了在无降温措施情况下密闭避难硐室内的空气与围岩壁面的动态耦合传热规律。采用理论分析与试验验证的方法,得出室内避灾过程中的人体与设备产热量计算方法和硐室内空气升温规律。研究结果对避难硐室内的热湿环境控制具有一定的理论指导意义。%To counter to the influence of thermal environment caused by the heat produced by human bodies and equipment on the persons in the mine refuge chamber, study was made on the dynamic coupled heat transfer regularity of air and surrounding rock wall in a sealed refuge chamber without any cooling measures. By using the theoretical analysis and tests, the calculation method for heat produced by human bodies and equipment and the temperature rise regularity in the refuge chamber in the escape period were obtained. This research result has a certain theoretical guiding significance for the control of the hot-moist environment in the mine refuge chamber.

  9. The choice of rational parameters of beet pulp drying process in a pulsed low-pressure vibro-boiling layer

    Directory of Open Access Journals (Sweden)

    A. V. Drannikov

    2017-01-01

    Full Text Available Beet pulp is the main sugar industry by-product obtained with traditional production technology. It has high nutritional qualities, but in its raw form it turns sour quickly so it must be preserved. One of the most common methods is drying. Drying of the beet pulp with superheated vapor of reduced pressure in the pulsating vibro-boiling layer allows to improve the quality of the finished product by lowering of the drying agent temperature, thereby retaining a significant amount of nutrients in the initial product. To study the kinetic and hydrodynamic dependencies of the drying process, an experimental apparatus was developed that makes it possible to obtain the most accurate and reproducible results. In the course of the work, a lot of experiments were carried out. Drying curves, drying rate curves and heating curves were made based on these experiments results. According to the nature of the changes the corresponding conclusions were drawn. To study the interaction of various factors affecting the beet pulp drying process, the mathematical methods of experiment planning are applied. A mathematical description of this process can be obtained empirically. At the same time, its mathematical model has the form of a regression equation, determined by statistical methods on the basis of experiments. As a result of statistical processing of experimental data, regression equations were obtained that adequately describe the beet pulp drying process in a pulsed low-pressure vibro-boiling layer in the experimental apparatus. With reference to this drying apparatus, such technological modes of its operation were determined that ensure a minimum specific energy consumption of the drying process per kilogram of evaporated moisture and the maximum drying chamber moisture stress.

  10. Effect of temperature and humidity on post-gel shrinkage, cusp deformation, bond strength and shrinkage stress - Construction of a chamber to simulate the oral environment.

    Science.gov (United States)

    Bicalho, Aline Aredes; de Souza, Silas Júnior Boaventura; de Rosatto, Camila Maria Peres; Tantbirojn, Daranee; Versluis, Antheunis; Soares, Carlos José

    2015-12-01

    Evaluate the effect of environment on post-gel shrinkage (Shr), cuspal strains (CS), microtensile bond strength (μTBS), elastic modulus (E) and shrinkage stress in molars with large class II restorations. Sixty human molars received standardized Class II mesio-oclusal-distal cavity preparations. Restorations were made with two composites (CHA, Charisma Diamond, Heraus Kulzer and IPS Empress Direct, Ivoclar-Vivadent) using three environment conditions (22°C/50% humidity, 37°C/50% humidity and 37°C/90% humidity) simulated in custom developed chamber. Shr was measured using the strain gauge technique (n=10). CS was measured using strain gauges. Half of the teeth (n=5) were used to assess the elastic modulus (E) and Knoop hardness (KHN) at different depths using microhardness indentation. The other half (n=5) was used to measure the μTBS. The composites and environment conditions were simulated in a two-dimensional finite element analysis of a tooth restoration. Polymerization shrinkage was modeled using Shr data. The Shr, CS, μTBS, KHN and E data were statistically analyzed using two-way ANOVA and Tukey test (significance level: 0.05). Both composites had similar Shr, CS, μTBS and shrinkage stress. CHA had higher elastic modulus than IPS. Increasing temperature and humidity significantly increased Shr, CS and shrinkage stress. μTBS were similar for groups with lower humidity, irrespective of temperature, and higher with higher humidity. E and KHN were constant through the depth for CHA. E and KHN values were affected by environment only for IPS, mainly deeper in the cavity. Shrinkage stress at dentin/composite interface had high inverse correlation with μTBS. Shrinkage stress in enamel had high correlation with CS. Increasing temperature and humidity caused higher post-gel shrinkage and cusp deformation with higher shrinkage stresses in the tooth structure and tooth/restoration interface for both composites tested. The chamber developed for simulating the

  11. Midday stomatal closure in Mediterranean type sclerophylls under simulated habitat conditions in an environmental chamber : II. Effect of the complex of leaf temperature and air humidity on gas exchange of Arbutus unedo and Quercus ilex.

    Science.gov (United States)

    Tenhunen, J D; Lange, O L; Braun, M

    1981-08-01

    Shrubs of the Mediterranean sclerophyllous species Arbutus unedo and Quercus ilex were studied under simulated habitat conditions in an environmental chamber. Temperature, humidity, and light intensity were altered stepwise to simulate diurnal changes in conditions similar to those measured in an evergreen macchia in Sobreda, Portugal. Leaves were enclosed in cuvettes which reproduced the growth chamber climate and which allowed measurement of gas exchange. Increasing atmospheric stress in the form of higher temperature and lower humidity on successive days gradually results in midday depression of transpiration rate and net photosynthesis rate of leaves due to midday stomatal closure.

  12. Pequi pulp ( Caryocar brasiliense Cambess): Drying kinetics and ...

    African Journals Online (AJOL)

    The entropy values found were -251.01, -250.38 and -250.05 (J.Mol-1K-1) for the same temperatures. The values obtained from the Gibbs free energy for the drying of Pequi pulp increased with increasing temperature. The obtained data were consistent to the drying process, and the mathematical equations were effective ...

  13. Factors affecting the optimal performance of a high-yield pulping operation

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, G [Noranda Technology Centre, Pointe-Claire, PQ (Canada); Paris, J [Ecole Polytechnique, Montreal, PQ (Canada); Valada, J L [Quebec Univ., Trois-Rivieres, PQ (Canada)

    1995-06-01

    Strategies for operating a chemical-mechanical pulp mill were investigated from data based on process models from some one hundred pilot scale pulping runs. Optimal values for 55 process and pulp quality variables have been calculated by applying a genetic algorithm search to a fuzzy model of the overall system. Best pulp quality was achieved and maintained when the chemical pretreatment was conducted at moderately low temperatures using a high SO{sub 2} concentration, which produced high sulphonation and high yield at the same time. By characterizing the quality of the pulp at the fibre level, optimization results were said to be more easily transferable to other high yield pulping systems. 19 refs., 6 tabs.

  14. Application of C/C composites to the combustion chamber of rocket engines. Part 1: Heating tests of C/C composites with high temperature combustion gases

    Science.gov (United States)

    Tadano, Makoto; Sato, Masahiro; Kuroda, Yukio; Kusaka, Kazuo; Ueda, Shuichi; Suemitsu, Takeshi; Hasegawa, Satoshi; Kude, Yukinori

    1995-04-01

    Carbon fiber reinforced carbon composite (C/C composite) has various superior properties, such as high specific strength, specific modulus, and fracture strength at high temperatures of more than 1800 K. Therefore, C/C composite is expected to be useful for many structural applications, such as combustion chambers of rocket engines and nose-cones of space-planes, but C/C composite lacks oxidation resistivity in high temperature environments. To meet the lifespan requirement for thermal barrier coatings, a ceramic coating has been employed in the hot-gas side wall. However, the main drawback to the use of C/C composite is the tendency for delamination to occur between the coating layer on the hot-gas side and the base materials on the cooling side during repeated thermal heating loads. To improve the thermal properties of the thermal barrier coating, five different types of 30-mm diameter C/C composite specimens constructed with functionally gradient materials (FGM's) and a modified matrix coating layer were fabricated. In this test, these specimens were exposed to the combustion gases of the rocket engine using nitrogen tetroxide (NTO) / monomethyl hydrazine (MMH) to evaluate the properties of thermal and erosive resistance on the thermal barrier coating after the heating test. It was observed that modified matrix and coating with FGM's are effective in improving the thermal properties of C/C composite.

  15. Free toe pulp flap for finger pulp and volar defect reconstruction

    Directory of Open Access Journals (Sweden)

    Jyoshid R Balan

    2016-01-01

    Full Text Available Background: Fingertip injury requiring flap cover is very common in the modern era. The ideal cover should fulfill both functional and aesthetic improvement. Materials and Methods: From June 2015 to April 2016, we performed seven free toe pulp flaps for finger defect reconstruction. All patients were males. Five flaps were done in emergency post-traumatic cases, and two were done in elective set up. The cases included reconstruction of three thumbs, one index and one ring finger in an emergency set up and two ring fingers in the elective. Thumb reconstruction was done with great toe lateral pulp and the other digits reconstructed with second toe pulp flap. Follow-up evaluation included both functional and aesthetic assessment. Results: Five flaps survived completely, one suffered partial loss, and one flap failed completely. The median follow-up period was 9 months. The median duration of surgery was 255 min (range 210 to 300 min. The median two-point discrimination was 6.5 mm (range 4–8 mm. There was the return of temperature sensation in all patients; two had cold intolerance. The Semmes-Weinstein monofilament score varied from 3.61 to 5.07 (median filament index value 4.31/pressure value of 2 g/mm2. Three patients had delayed donor site wound healing. Conclusions: The free toe pulp flap is an efficient choice for fingertip and volar finger defects reconstruction with an excellent tissue match.

  16. Effects of ambient temperature and oxygen concentration on diesel spray combustion using a single-nozzle injector in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei; Roberts, William L.; Fang, Tiegang

    2013-01-01

    This work investigates the effects of ambient conditions on diesel spray combustion in an optically accessible, constant volume chamber using a single-nozzle fuel injector. The ambient O2 concentration was varied between five discrete values from 10% to 21% and three different ambient temperatures (800 K, 1000 K, and 1200 K). These conditions simulate different exhaust gas recirculation (EGR) levels and ambient temperatures in diesel engines. Both conventional diesel combustion and low temperature combustion (LTC) modes were observed under these conditions. A transient analysis and a quasi-steady state analysis are employed in this article. The transient analysis focuses on the flame development from beginning to the end, illustrating how the flame structure changes during this process; the quasi-steady state analysis focuses on the stable flame structure. The transient analysis was conducted using high-speed imaging of both OH* chemiluminescence and natural luminosity (NL). In addition, three different images were acquired using an ICCD camera, corresponding to OH* chemiluminescence, narrow-band flame emission at 430 nm (Band A) and at 470 nm (Band B), and were used to investigate the quasi-steady state combustion process. From the transient analysis, it was found that the NL signal becomes stronger and confined to narrow regions when the temperature and O2 concentration increase during the development of flame. The OH* intensity is much lower for the 10% ambient O2 and 800 K conditions compared to the higher temperatures and O2 levels. This implies the occurrence of LTC under these conditions. Results from the quasi-steady combustion stage indicate that high-temperature reactions effectively oxidize the soot in the downstream locations where only OH* signal is observed. In addition, an area was calculated for each spectral region, and results show that the area of Band A and Band B emissions in these images is larger than the area of OH* emissions at the lower O2

  17. Effects of ambient temperature and oxygen concentration on diesel spray combustion using a single-nozzle injector in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei

    2013-09-02

    This work investigates the effects of ambient conditions on diesel spray combustion in an optically accessible, constant volume chamber using a single-nozzle fuel injector. The ambient O2 concentration was varied between five discrete values from 10% to 21% and three different ambient temperatures (800 K, 1000 K, and 1200 K). These conditions simulate different exhaust gas recirculation (EGR) levels and ambient temperatures in diesel engines. Both conventional diesel combustion and low temperature combustion (LTC) modes were observed under these conditions. A transient analysis and a quasi-steady state analysis are employed in this article. The transient analysis focuses on the flame development from beginning to the end, illustrating how the flame structure changes during this process; the quasi-steady state analysis focuses on the stable flame structure. The transient analysis was conducted using high-speed imaging of both OH* chemiluminescence and natural luminosity (NL). In addition, three different images were acquired using an ICCD camera, corresponding to OH* chemiluminescence, narrow-band flame emission at 430 nm (Band A) and at 470 nm (Band B), and were used to investigate the quasi-steady state combustion process. From the transient analysis, it was found that the NL signal becomes stronger and confined to narrow regions when the temperature and O2 concentration increase during the development of flame. The OH* intensity is much lower for the 10% ambient O2 and 800 K conditions compared to the higher temperatures and O2 levels. This implies the occurrence of LTC under these conditions. Results from the quasi-steady combustion stage indicate that high-temperature reactions effectively oxidize the soot in the downstream locations where only OH* signal is observed. In addition, an area was calculated for each spectral region, and results show that the area of Band A and Band B emissions in these images is larger than the area of OH* emissions at the lower O2

  18. Influence of Soda Pulping Variables on Properties of Pineapple (Ananas comosus Merr. Leaf Pulp and Paper Studied by Face-Centered Composite Experimental Design

    Directory of Open Access Journals (Sweden)

    Jantharat Wutisatwongkul

    2016-01-01

    Full Text Available Face-centered composite design (FCC was used to study the effect of pulping variables: soda concentration (4-5 wt%, temperature (90–130°C, and pulping time (20–60 min on the properties of pineapple leaf pulp and paper employing soda pulping. Studied pulp responses were screened yield and lignin content (kappa number. Paper properties, which include tensile index, burst index, and tear index, were also investigated. Effects of the pulping variables on the properties were statistically analyzed using Minitab 16. The optimum conditions to obtain the maximum tensile index were soda concentration of 4 wt%, pulping temperature of 105°C, and pulping time of 20 min. The predicted optimum conditions provided tensile index, burst index, tear index, screened yield, and kappa number of 44.13 kN·m/kg, 1.76 kPa·m2, 1.68 N·m2/kg, 21.29 wt%, and 28.12, respectively, and were experimentally confirmed.

  19. Chapter 6: Prehydrolysis Pulping with Fermentation Coproducts

    Science.gov (United States)

    T.H. Wegner; C.J. Houtman; A.W. Rudie; B.L. Illman; P.J. Ince; E.M. Bilek; T.W. Jeffries

    2013-01-01

    Although the term “integrateed biorefinery” is new, the concept has long been familiar to the pulp and paper industry, where processes include biomass boilers providing combined heat and power, and byproducts of pulping include turpentine, fatty acids and resin acids. In the dominant kraft (or sulfate) pulping process, dissolved lignin and chemicals from the pulp...

  20. Carbon dioxide exchange of buds and developing shoots of boreal Norway spruce exposed to elevated or ambient CO2 concentration and temperature in whole-tree chambers.

    Science.gov (United States)

    Hall, Marianne; Räntfors, Mats; Slaney, Michelle; Linder, Sune; Wallin, Göran

    2009-04-01

    Effects of ambient and elevated temperature and atmospheric carbon dioxide concentration ([CO2]) on CO2 assimilation rate and the structural and phenological development of shoots during their first growing season were studied in 45-year-old Norway spruce trees (Picea abies (L.) Karst.) enclosed in whole-tree chambers. Continuous measurements of net assimilation rate (NAR) in individual buds and shoots were made from early bud development to late August in two consecutive years. The largest effect of elevated temperature (TE) was manifest early in the season as an earlier start and completion of shoot length development, and a 1-3-week earlier shift from negative to positive NAR compared with the ambient temperature (TA) treatments. The largest effect of elevated [CO2] (CE) was found later in the season, with a 30% increase in maximum NAR compared with trees in the ambient [CO2] treatments (CA), and shoots assimilating their own mass in terms of carbon earlier in the CE treatments than in the CA treatments. Once the net carbon assimilation compensation point (NACP) had been reached, TE had little or no effect on the development of NAR performance, whereas CE had little effect before the NACP. No interactive effects of TE and CE on NAR were found. We conclude that in a climate predicted for northern Sweden in 2100, current-year shoots of P. abies will assimilate their own mass in terms of carbon 20-30 days earlier compared with the current climate, and thereby significantly contribute to canopy assimilation during their first year.

  1. In vitro study of the effects of cooling water temperature during the use of Er:YAG laser on dentin; Estudo in vitro dos efeitos da temperatura da agua de refrigeracao no uso de laser de Er:YAG em dentina

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Ismael Lucas

    2004-07-01

    This study measured the pulp chamber and the target surface with 2 thermocouples, in order to determine whether cooling with water spray, with Er:YAG laser (Kavo Key 2), was overcooling the tooth, much beyond the necessary, during laser irradiation, within variation limits of 2.2 deg C of body temperature. The parameters used were: E{sub p}=250 mJ per pulse, with frequency ranging between 2 to 4 Hz, for a total DE of 80.20 J/cm{sup 2}, at an angle of incidence of approximately 90 deg, during an exposure period of 1 minute, totaling 120 to 240 pulses. In the first 40 seconds, the spray cooled the tooth rapidly, from 36.5 deg C to below 30 deg C. It was impossible to control the spray output temperature with a simple increase in reservoir temperature, for when water at temperatures ranging between 90 and 100 deg C is placed in the reservoir, the heat dissipates completely during the trajectory. The water jet does not present the same characteristics as a spray, which makes it impossible to conduct a perfect comparative analysis between them. The increase and maintenance of the spray output temperature, by reducing the temperature differential between that of the body and that of the spray of the Er:YAG laser, proved to be extremely promising. The pulp chamber temperature followed that of the spray or water jet, so that when a temperature that is lower than body temperature is used, the temperature of the pulp chamber is decreases, and when body temperature is surpassed, the temperature of the pulp chamber increases. (author)

  2. Decellularized Swine Dental Pulp as a Bioscaffold for Pulp Regeneration

    OpenAIRE

    Hu, Lei; Gao, Zhenhua; Xu, Junji; Zhu, Zhao; Fan, Zhipeng; Zhang, Chunmei; Wang, Jinsong; Wang, Songlin

    2017-01-01

    Endodontic regeneration shows promise in treating dental pulp diseases; however, no suitable scaffolds exist for pulp regeneration. Acellular natural extracellular matrix (ECM) is a favorable scaffold for tissue regeneration since the anatomical structure and ECM of the natural tissues or organs are well-preserved. Xenogeneic ECM is superior to autologous or allogeneic ECM in tissue engineering for its unlimited resources. This study investigated the characteristics of decellularized dental p...

  3. Chamber transport

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2001-01-01

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system

  4. An overview of the dental pulp: its functions and responses to injury.

    Science.gov (United States)

    Yu, C; Abbott, P V

    2007-03-01

    The dental pulp is a unique tissue and its importance in the long-term prognosis of the tooth is often ignored by clinicians. It is unique in that it resides in a rigid chamber which provides strong mechanical support and protection from the microbial rich oral environment. If this rigid shell loses its structural integrity, the pulp is under the threat of the adverse stimuli from the mouth, such as caries, cracks, fractures and open restoration margins, all of which provide pathways for micro-organisms and their toxins to enter the pulp. The pulp initially responds to irritation by becoming inflamed and, if left untreated, this will progress to pulp necrosis and infection. The inflammation will also spread to the surrounding alveolar bone and cause periapical pathosis. The magnitude of pulp-related problems should not be underestimated since their most serious consequence is oral sepsis, which can be life threatening, and hence correct diagnosis and management are essential. Clinicians must have a thorough understanding of the physiological and pathological features of the dental pulp as well as the biological consequences of treatment interventions.

  5. Effect of Flotation Time on the Deinking Process and Properties of Deinked Pulp

    Directory of Open Access Journals (Sweden)

    Sami İmamoğlu

    2012-11-01

    Full Text Available This paper discusses the influence of flotation time on the ink removal and physical properties of resulting deinked pulp. Flotation deinking of high quality office paper, printed in a digital duplicating machine based on screen-printing system, was studied using a laboratory cell with a nominal capacity of 10 L. Formamidine sulfinic acid was used in a pulper and pulping conditions such as temperature, retention time, chemical dosage and consistency were held constant prior to flotation process. During the flotation process while pulp consistency, agitation speed, air flow rate and other conditions keeping constant, only flotation time were analyzed in terms of physical properties of resulting pulp quality, pulp yield, filler and fibre balance and waste water quality aspects at 0, 3, 6, 9, 12 and 15 minutes. Increased flotation time substantially affected optical properties of pulp up to some point then became steady. Yield losses increased as might be expected with increasing flotation time by the 9th minute as flotation sludge skimmed off on top of the flotation cell. Filler content of flotation sludge increased with increasing flotation time while fibre content was decreasing to a certain extent. Thanks to removal of ink and filler materials from pulp physical properties of evaluated handsheets enhanced. The overall results demonstrate that increasing flotation time increased physical and optical properties of resulting pulp. On the other hand flotation time should be increased up to critical point. Exceeding critical point increased yield losses, consumed time and energy without gaining significant pulp qualities.

  6. Effect of Partial Pre-Extraction of Hemicelluloses on the Properties of Pinus radiata Chemimechanical Pulps

    Directory of Open Access Journals (Sweden)

    Pablo Reyes

    2015-09-01

    Full Text Available Extraction of hemicelluloses prior to pulping and conversion of the extracted hemicelluloses to other bioproducts could provide additional revenue to traditional pulp and paper industries. The effect of hemicelluloses pre-extraction with a hydrothermal (HT process on Pinus radiata chemimechanical pulp (CMP properties was investigated in this study. The HT extraction resulted in a release of 7% to 58% of the initial amount of hemicelluloses from the wood. The extraction yield increased with temperature and extraction time. This hemicellulosic fraction was in the form of low molar mass oligomers with molecular weights varying from 1.5 to 100 kDa. Compared with the control (unextracted CMP pulp, the HT pre-extraction significantly reduced the refining energy to obtain a given fibrillation degree (freeness. The pulp yield with the HT/CMP process was in the range of 56% to 75%. Fiber properties of the pulps from pre-extracted wood, such as fiber length, were reduced, while increases in fiber width, fines content, fiber coarseness, and kink index were observed in comparison with the control pulps. The strength properties of CMP pulps decreased with increasing amounts of hemicellulose removal during the stage prior to pulping.

  7. EVALUATION OF CONDITION OF THE PULP BY PULSE OXIMETRY.

    Directory of Open Access Journals (Sweden)

    Dimitar Kosturkov

    2015-12-01

    Full Text Available Purpose: To conduct pulse oximetry (PO and electric pulp test (EPT on intact frontal teeth in clinically healthy patients aged between 18 and 25 years who do not have periodontal disease. Material/Methods: To achieve the aim 1058 teeth of 31 patients were studied. The following inclusion criteria for the study were set: 1. Age – 18-25 years. 2. Clinically healthy patient, who does not have any systemic diseases, do not take any medicine systematically. 3. Intact frontal teeth – without carious lesions, restorations or root canal treatment. 4. Lack of periodontal disease. Research was conducted with a pulse oximeter Contec™ - CMS60D and a custom made probe holder. Results: Average values obtained by pulse oximetry in upper jaw vary between 83% and 85%. In lower jaw – between 82% and 85%. 99% is the maximum and 48% is the minimum registered value. The average value of the measurement of all the teeth is 84%. The average saturation measured on the small finger of the right hand of the patient is 98%. The average value of EPT for all teeth is 4 μA. The maximum measured value is 20 μA, and the minimum - 1 μA. Conclusions: 1. Adequate study of the pulp includes two complementary methods – electric pulp test (evaluation of innervation and pulse oximetry (assessment of pulp microcirculation. 2. Teeth that are larger in size have larger values of PO and EPT, which is in direct relation to the size of their pulp chamber. 3. The total saturation, measured in the little finger of the right hand is greater than the one of the teeth.

  8. MOLYBDENUM CATALYZED ACID PEROXIDE BLEACHING OF EUCALYPTUS KRAFT PULP

    Directory of Open Access Journals (Sweden)

    Marcos S. Rabelo

    2008-08-01

    Full Text Available Molybdenum catalyzed peroxide bleaching (PMo Stage consists of pulp treatment with hydrogen peroxide under acidic conditions in the presence of a molybdenum catalyst. Molybdenum is applied in catalytic doses (50-200 mg/kg pulp and may originate from various sources, including (NH46Mo7O24.4H2O, Na2MoO4.2H2O, siliconmolybdate, etc. This work is aimed at optimizing the PMo stage and evaluating its industrial application in the OAZDP sequence. Optimum PMo stage conditions for bleaching eucalyptus pulp were 90 ºC, pH 3.5, 2 h, 0.1 kg/adt Mo and 5 kg/adt H2O2. The PMo stage was more efficient to remove pulp hexenuronic acids than lignin. Its efficiency decreased with increasing pH in the range of 1.5-5.5, while it increased with increasing temperature and peroxide and molybdenum doses. The application of the PMo stage as replacement for the A-stage of the AZDP sequence significantly decreased chlorine dioxide demand. The PMo stage caused a decrease of 20-30% in the generation of organically bound chlorine. The quality parameters of the pulp produced during the PMo stage mill trial were comparable to those obtained with the reference A-stage.

  9. Intrapulpal temperature during preparation with the Er:YAG laser: an in vitro study; Avaliacao da temperatura intrapulpar de incisivos bovinos irradiados com o laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo-Martins, Vinicius Rangel

    2003-07-01

    This study evaluated the variation of the pulp chamber temperature when dentine, with 2,0 mm of thickness, adjacent to the pulp, was irradiated by the Er:YAG laser. Seventy two bovine incisors were used, that had the enamel and dentine of the buccal surface weared until to reach the thickness used in this study. The teeth were divided in 3 groups, according with the repetition rate used ( Group I = 2 Hz; Group II = 4 Hz and Group III = 6 Hz), and irradiated, with or without water cooling, using 250, 300 and 350 mJ of energy per pulse. Thermocouples were introduced inside the pulp chamber through the palatine opening of the samples and fixed to the vestibular wall of the pulp chamber using a thermal paste. After the statistical analysis, it was verified that there was a decrease of the intrapulpal temperature for all of the parameters in the group I irradiated with water cooling. In the same group, but without cooling, occurred increases of the intrapulpal temperature, however they were less than 2 deg C. In the group 11, only the para meter 350 mJ/4 Hz/ with water cooling presented decrease of the temperature (-0,08 deg C). The other irradiations presented increase of the intrapulpal temperature, varying from 1,5 to 1,9 deg C for irradiations without cooling and of 0,03 the 0,58 deg C for the samples irradiated under water cooling. In the group III, all of the samples presented increase of the intrapulpal temperature, however, they were smaller than to 2,5 deg C. The conditions of this study allow to conclude that the use of the laser of Er:YAG promoted acceptable temperature increases inside the pulp chamber, not reaching the critical level of 5,5 deg C. However, in spite of the temperature variations inside the pulp chamber have not reached critical levels, this procedure should not be recommended because macroscopic observations of the dentine irradiated without water cooling showed dark lesions, suggesting carbonization of this tissue. (author)

  10. National Ignition Facility Target Chamber

    International Nuclear Information System (INIS)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-01-01

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

  11. Engineering structural integrity issues in the pulp and paper industry

    International Nuclear Information System (INIS)

    Garner, A.; Singbeil, D.

    2002-01-01

    ESI issues for Pulp and Paper (P and P) plant are reviewed. Five typical processes are covered, namely: Chemical Pulping, Bleaching, Chemical Recovery, Mechanical Pulping and Papermaking. Equipment, chemical environments and failure modes are summarized with examples from each process. Pressure, temperature, corrosion and rotation are typical sources of risk, which is managed by appropriate inspection. The nature of the P and P Industry and its technology supply is summarized: current trends are consolidation and outsourcing. Three examples are presented to illustrate typical ESI issues: deaerator cracking where the P and P Industry alerted others to this serious cross-industry problem; pressure vessel safety factors and inconsistent international codes; and caustic cracking in continuous kraft digesters, which required rapid and concerted action to diagnose and control. In the future better predictability, data-bases, more formal risk based inspection and fitness-for-service assessments are envisaged. (author)

  12. Fermentation Process of Cocoa Based on Optimum Condition of Pulp PectinDepolymerization by Endogenous Pectolityc Enzymes

    OpenAIRE

    Ganda-Putra, G.P; Wrasiati, L.P; Wartini, N.M

    2010-01-01

    Pulp degradation during cocoa fermentation can be carried out by depolymerization process of pulp pectin using endogenous pectolytic enzymes at optimum condition. The objectives of this research were to study the effect of fermentation process based on optimum condition in terms of temperature and pH of pulp pectin depolymerization using endogenous pectolytic enzymes polygalakturonase (PG) and pectin metyl esterase (PME) and fermentation period in cocoa processing on quality characteristics o...

  13. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  14. Hygroscopic behavior of lyophilized acerola pulp powder

    Directory of Open Access Journals (Sweden)

    Luciana C. Ribeiro

    2016-03-01

    Full Text Available ABSTRACT Powder products are characterized by their practicality and long life. However, fruit powders have high hygroscopicity and tend to agglomerate due to its hydrophilic nature. The isotherms of equilibrium moisture content apply to the study of dehydrated food preservation potential. Acerola is a nutritionally rich fruit, with great economic and industrial potential. The objective of this study was to analyse acerola powder adsorption isotherms obtained by lyophilization and characterize the powder obtained from lyophilized acerola pulp. Analysis of hygroscopicity, solubility and degree of caking were performed. Isotherms were represented by the mathematical models of GAB, BET, Henderson and Oswin, at temperatures of 25, 35 and 45 °C. According to the results, the obtained powder showed hygroscopicity of 5.96 g of absorbed water 100g-1 of solids, solubility of 95.08% and caking of 14.12%. The BET model showed the best fit to the adsorption isotherms of the acerola pulp powder obtained by lyophilization. The obtained isotherm was of type III, with a "J" shape. There was an inversion of the effect of temperature on the isotherms of acerola powders.

  15. Evaluation of a value prior to pulping-thermomechanical pulp business concept. Part 2.

    Science.gov (United States)

    Ted Bilek; Carl Houtman; Peter Ince

    2011-01-01

    Value Prior to Pulping (VPP) is a novel biorefining concept for pulp mills that includes hydrolysis extraction of hemicellulose wood sugars and acetic acid from pulpwood prior to pulping. The concept involves conversion of wood sugars via fermentation to fuel ethanol or other chemicals and the use of remaining solid wood material in the pulping process. This paper...

  16. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  17. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1980-01-01

    A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

  18. Kraft pulping of industrial wood waste

    Science.gov (United States)

    Aziz. Ahmed; Masood. Akhtar; Gary C. Myers; Gary M. Scott

    1998-01-01

    Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for energy and/or landfilled. In this study, kraft pulp from industrial wood waste was evaluated and compared with softwood (loblolly pine, Douglas-fir) and hardwood (aspen) pulp. Pulp bleachability was also evaluated. Compared to loblolly pine...

  19. Pulp Obliteration in a Patient with Sclerodermatous Chronic Graft-versus-Host Disease.

    Science.gov (United States)

    Gomes, Camilla Borges Ferreira; Treister, Nathaniel Simon; Miller, Brian; Armand, Philippe; Friedland, Bernard

    2016-04-01

    Dental pulp calcification is a common finding associated with localized dental trauma, genetic disorders, and systemic inflammatory diseases. Chronic graft-versus-host disease (cGVHD) is a frequent complication after allogeneic hematopoietic cell transplantation (allo-HCT) characterized by immune-mediated injury to the skin, mouth, eyes, liver, and other tissues, resulting in significant disability and reduced quality of life. We report a patient with sclerodermatous cGVHD who presented with general pulp calcification in all teeth 5 years after allo-HCT. A review of full mouth dental radiographs obtained just before allo-HCT revealed normal-appearing pulp chambers. Based on prior reports of generalized pulp calcification associated with progressive systemic sclerosis, we hypothesized that the etiology was likely related to the presence of cGVHD with associated vascular and fibrotic tissue changes within the pulp vasculature. Clinicians should consider cGVHD in the differential diagnosis of generalized pulp calcification. Copyright © 2016 American Association of Endodontists. All rights reserved.

  20. A new method to extract dental pulp DNA: application to universal detection of bacteria.

    Directory of Open Access Journals (Sweden)

    Lam Tran-Hung

    Full Text Available BACKGROUND: Dental pulp is used for PCR-based detection of DNA derived from host and bacteremic microorganims. Current protocols require odontology expertise for proper recovery of the dental pulp. Dental pulp specimen exposed to laboratory environment yields contaminants detected using universal 16S rDNA-based detection of bacteria. METHODOLOGY/PRINCIPAL FINDINGS: We developed a new protocol by encasing decontaminated tooth into sterile resin, extracting DNA into the dental pulp chamber itself and decontaminating PCR reagents by filtration and double restriction enzyme digestion. Application to 16S rDNA-based detection of bacteria in 144 teeth collected in 86 healthy people yielded a unique sequence in only 14 teeth (9.7% from 12 individuals (14%. Each individual yielded a unique 16S rDNA sequence in 1-2 teeth per individual. Negative controls remained negative. Bacterial identifications were all confirmed by amplification and sequencing of specific rpoB sequence. CONCLUSIONS/SIGNIFICANCE: The new protocol prevented laboratory contamination of the dental pulp. It allowed the detection of bacteria responsible for dental pulp colonization from blood and periodontal tissue. Only 10% such samples contained 16S rDNA. It provides a new tool for the retrospective diagnostic of bacteremia by allowing the universal detection of bacterial DNA in animal and human, contemporary or ancient tooth. It could be further applied to identification of host DNA in forensic medicine and anthropology.

  1. Comparative pulping of sunflower stalks

    Directory of Open Access Journals (Sweden)

    Valerii Barbash

    2016-03-01

    Full Text Available The procedure of holocellulose content determination in non-wood plant raw materials was developed. The strength properties of pulp obtained from sunflower stalks by neutral-sulphite, soda, alkaline sulphite-anthraquinone-ethanol and peracetic methods of delignification were studied. Methodology of comparison of plant materials delignification methods using new lignin-carbohydrate diagram was proposed. It was shown, that the alkaline sulphite-anthraquinone-ethanol method of pulping is characterized by the highest delignification degree and is the most efficient among the studied methods

  2. Comparison between two methods to evaluate temperature changes produced by composite light curing units and polymerization techniques.

    Science.gov (United States)

    Loureiro, F H F; Consani, S; Guiraldo, R D; Consani, R L X; Berger, S B; Carvalho, R V; Correr-Sobrinho, L; Sinhoreti, M A C

    2011-10-01

    This study evaluated the temperature change into the pulp chamber during the light curing of composite resin by direct (bovine tooth) and indirect (matrix) methods. Direct method: fifty standardized cavities (2x2x2 mm) were prepared in bovine incisors, which were randomly assigned to evaluation of the temperature changes in the pulp chamber. Indirect method: temperature changes were evaluated through a dentine slice of 1.0 mm thickness in a elastomer cubic mold (2x2x2 mm). Filtek Z250 composite resin (3M/ESPE) was photo-activated using three light curing units: quartz-tungsten-halogen (QTH) by continuous, soft-start or intermittent light modulations; light emitting diode (LED); and plasma arc-curing (PAC). Ten groups (N.=10) were established according to technique evaluation and photo-activation methods. All experiments were carried out in a controlled environment (37 °C and 50 ± 10% relative humidity). The temperature changes were recorded using a digital thermometer attached to a type-K thermocouple in contact with the dentin slice (indirect method) or in contact with the axial wall (dentin) of pulp chamber (direct method). The results were submitted to ANOVA and Tukey's test (α=0.05). Temperature changes were statistically higher for the matrix indirect method (2.56 ºC) than bovine teeth direct method (1.17ºC). The change temperature was statistically higher for the PAC (1.77 ºC) when compared to other photo-activation modes in bovine teeth direct method. The two methods of temperature evaluation were different, however indirect method detected the higher temperature increase. Higher energy density arising from the light curing units and polymerization techniques promoted higher temperature increase.

  3. Alkaline pulping of some eucalypts from Sudan.

    Science.gov (United States)

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper.

  4. Effect of organosolv and soda pulping processes on the metals content of non-woody pulps.

    Science.gov (United States)

    González, M; Cantón, L; Rodríguez, A; Labidi, J

    2008-09-01

    In this work the effect of different pulping processes (ethyleneglycol, diethyleneglycol, ethanolamine and soda) of tow abounded raw materials (empty fruit bunches - EFB and rice straw) on the ash, silicates and metals (Fe, Zn, Cu, Pb, Mn, Ni and Cd) content of the obtained pulps have been studied. Results showed that pulps obtained by diethyleneglycol pulping process presented lower metals content (756 microg/g and 501 microg/g for EFB and rice straw pulp, respectively) than soda pulps (984 microg/g and 889 microg/g). Ethanolamine pulps presented values of holocellulose (74% and 77% for EFB and rice straw pulp, respectively), alpha-cellulose (74% and 69%), kappa number (18.7 and 18.5) and viscosity (612 and 90 6ml/g) similar to those of soda pulp, and lower lignin contents (11% and 12%).

  5. Advances on fission chamber modelling

    International Nuclear Information System (INIS)

    Filliatre, Philippe; Jammes, Christian; Geslot, Benoit; Veenhof, Rob

    2013-06-01

    In-vessel, online neutron flux measurements are routinely performed in mock-up and material testing reactors by fission chambers. Those measurements have a wide range of applications, including characterization of experimental conditions, reactor monitoring and safety. Depending on the application, detectors may experience a wide range of constraints, of several magnitudes, in term of neutron flux, gamma-ray flux, temperature. Hence, designing a specific fission chamber and measuring chain for a given application is a demanding task. It can be achieved by a combination of experimental feedback and simulating tools, the latter being based on a comprehensive understanding of the underlying physics. A computation route that simulates fission chambers, named CHESTER, is presented. The retrieved quantities of interest are the neutron-induced charge spectrum, the electronic and ionic pulses, the mean current and variance, the power spectrum. It relies on the GARFIELD suite, originally developed for drift chambers, and makes use of the MAGBOLTZ code to assess the drift parameters of electrons within the filling gas, and the SRIM code to evaluate the stopping range of fission products. The effect of the gamma flux is also estimated. Computations made with several fission chambers exemplify the possibilities of the route. A good qualitative agreement is obtained when comparing the results with the experimental data available to date. In a near future, a comprehensive experimental programme will be undertaken to qualify the route using the known neutron sources, mock-up reactors and wide choice of fission chambers, with a stress on the predictiveness of the Campbelling mode. Depending on the results, a refinement of the modelling and an effort on the accuracy of input data are also to be considered. CHESTER will then make it possible to predict the overall sensitivity of a chamber, and to optimize the design for a given application. Another benefit will be to increase the

  6. Definition and characterization of enzymes for maximal biocatalytic solubilization of prebiotic polysaccharides from potato pulp

    DEFF Research Database (Denmark)

    Thomassen, Lise Vestergaard; Larsen, Dorte Møller; Mikkelsen, Jørn Dalgaard

    2011-01-01

    of these polysaccharides from the potato pulp. The pH and temperature optima of two selected pectin lyases from Emericella nidulans (formerly known as Aspergillus nidulans) and Aspergillus niger were determined to 8.6 and 4.0, respectively, at ≥100°C within 1min of reaction. The optima for the two selected......Potato pulp is a high-volume co-processing product resulting from industrial potato starch manufacturing. Potato pulp is particularly rich in pectin, notably galactan branched rhamnogalacturonan I polysaccharides, which are highly bifidogenic when solubilized. The objective of the present study...

  7. Statistically designed optimisation of enzyme catalysed starch removal from potato pulp

    DEFF Research Database (Denmark)

    Thomassen, Lise Vestergaard; Meyer, Anne S.

    2010-01-01

    to obtain dietary fibers is usually accomplished via a three step, sequential enzymatic treatment procedure using a heat stable alpha-amylase, protease, and amyloglucosidase. Statistically designed experiments were performed to investigate the influence of enzyme dose, amount of dry matter, incubation time...... and temperature on the amount of starch released from the potato pulp. The data demonstrated that all the starch could be released from potato pulp in one step when 8% (w/w) dry potato pulp was treated with 0.2% (v/w) (enzyme/substrate (E/S)) of a thermostable Bacillus licheniformis alpha-amylase (Termamyl(R) SC...

  8. Mineral Trioxide Aggregate (MTA direct pulp capping: 10 years clinical results

    Directory of Open Access Journals (Sweden)

    Lucio Daniele

    2017-06-01

    After 10-years follow-up period, 6 out of 80 teeth required an endodontic treatment, we did not find an increase of pulp calcifications, root resorptions, endodontic lesions. All teeth still alive have responded positively to the cold-temperature test. The three lesions had disappeared at the last X-ray control. All four symptomatic teeth preserved their pulp vitality. The successful treatment rate was 92.5%. Direct pulp capping with MTA can be considered an effective treatment of exposure due to tooth decay and can be considered a valid treatment option for teeth with a diagnosis of not-severe reversible pulpitis.

  9. Calculation of gas temperature at the outlet of the combustion chamber and in the air-gas channel of a gas-turbine unit by data of acceptance tests in accordance with ISO

    Science.gov (United States)

    Kostyuk, A. G.; Karpunin, A. P.

    2016-01-01

    This article describes a high accuracy method enabling performance of the calculation of real values of the initial temperature of a gas turbine unit (GTU), i.e., the gas temperature at the outlet of the combustion chamber, in a situation where manufacturers do not disclose this information. The features of the definition of the initial temperature of the GTU according to ISO standards were analyzed. It is noted that the true temperatures for high-temperature GTUs is significantly higher than values determined according to ISO standards. A computational procedure for the determination of gas temperatures in the air-gas channel of the gas turbine and cooling air consumptions over blade rims is proposed. As starting equations, the heat balance equation and the flow mixing equation for the combustion chamber are assumed. Results of acceptance GTU tests according to ISO standards and statistical dependencies of required cooling air consumptions on the gas temperature and the blade metal are also used for calculations. An example of the calculation is given for one of the units. Using a developed computer program, the temperatures in the air-gas channel of certain GTUs are calculated, taking into account their design features. These calculations are performed on the previously published procedure for the detailed calculation of the cooled gas turbine subject to additional losses arising because of the presence of the cooling system. The accuracy of calculations by the computer program is confirmed by conducting verification calculations for the GTU of the Mitsubishi Comp. and comparing results with published data of the company. Calculation data for temperatures were compared with the experimental data and the characteristics of the GTU, and the error of the proposed method is estimated.

  10. Pulp regeneration: Current approaches and future challenges

    Directory of Open Access Journals (Sweden)

    Jingwen eYANG

    2016-03-01

    Full Text Available Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α, basic Fibroblast Growth Factor (bFGF, Platelet Derived Growth Factor (PDGF, stem cell factor (SCF, and Granulocyte Colony-Stimulating Factor (G-CSF were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration.

  11. Glove box chamber

    International Nuclear Information System (INIS)

    Cox, M.E.; Cox, M.E.

    1975-01-01

    An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

  12. USE OF GROWTH CHAMBERS FOR CABBAGE BREEDING

    Directory of Open Access Journals (Sweden)

    L. L. Bondareva

    2014-01-01

    Full Text Available Use of the growth chambers for cabbage breeding allows the reducing of certain stages of the breeding process and the growing biennial varieties of cabbage in a one-year cycle. In these growth chambers, the nutritional conditions, temperature, and lighting of plants are under control; the open pollination is eliminated.

  13. ALKALI EXTRACTION OF HEMICELLULOSE FROM DEPITHED CORN STOVER AND EFFECTS ON SODA-AQ PULPING

    OpenAIRE

    Heli Cheng; Huaiyu Zhan; Shiyu Fu; Lucian A. Lucia

    2011-01-01

    A biorefinery using the process of hemicellulose pre-extraction and subsequent pulping provides a promising way for the utilization of straw biomass and resolution of problems related to silicon. In this work, hemicellulose was extracted from depithed corn stover with sodium hydroxide solution before soda-AQ pulping. Components of the extracts were quantified by ion chromatography. The parameters (alkali concentration and temperature) affecting hemicellulose pre-extraction were optimized. The...

  14. Temperature rise during adhesive and composite polymerization with different light-curing sources.

    Science.gov (United States)

    Pereira Da Silva, A; Alves Da Cunha, L; Pagani, C; De Mello Rode, S

    2010-05-01

    This study evaluated the temperature rise of the adhesive system Single Bond (SB) and the composite resins Filtek Z350 flow (Z) and Filtek Supreme (S), when polymerized by light-emitting diode (LED XL 3000) and quartz-tungsten halogen (QTH Biolux). Class V cavities (3 yen2 mm) were prepared in 80 bovine incisors under standardized conditions. The patients were divided as follows: G1: Control; G2: SB; G3: SB + Z; G4: SB + S. The groups were subdivided into two groups for polymerization (A: QTH, B: LED). Light curing was performed for 40 s and measurement of temperature changes during polymerization was performed with a thermocouple positioned inside the pulp chamber. Data were statistically analyzed using ANOVA and Tukey tests. The factors material (P<0.00001) and curing unit (P<0.00001) had significant influence on temperature rise. The lowest temperature increase (0.15 degrees C) was recorded in G2 B and the highest was induced in G1 A (0.75 degrees C, P<0.05). In all groups, lower pulp chamber temperature measurements were obtained when using LED compared to QTH (P<0.05). QTH caused greater increases in tooth temperature than LED. However, both sources did not increase pulpal temperature above the critical value that may cause pulpal damage.

  15. Physicochemical and functional characteristics of residual pulp of potato

    Directory of Open Access Journals (Sweden)

    Webber Tavares de CARVALHO

    Full Text Available Abstract Starch-rich liquid effluent is generated after peeling, cutting and washing of tubers during the fries processing. After sedimentation of this effluent is recovered a wet residual pulp, and after drying is obtained dry residual pulp or simply named in this study residual pulp of potato (RPP. In order to convert the effluent into a material easy to store for long periods (such as the potato starch, which would make it suitable for various applications. The aim of this study was to evaluate the effect of the drying conditions, specifically variables temperature and air flow on the drying time and water activity, pH, titratable acidity, instrumental colour parameters, water absorption index, water solubility index and oil absorption capacity of dry RPP. Central Composite Design was used, with temperature levels from 50.0 to 70.0 °C and air flow from 0.06 to 0.092 m3 m–2 s–1. Temperature and airflow affected the study characteristics, except for lightness (L*, water solubility index and oil absorption capacity. It was concluded that milder conditions (lower temperatures and intermediate air flow resulted in higher-quality final products (lighter, less acidic, although requiring higher drying time. Therefore, depending on the product application, different drying conditions can be used.

  16. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  17. [Daily practice and pulp diseases].

    Science.gov (United States)

    Calmein, S; Claisse, A

    1990-09-01

    Constructive or destructive processes of pulp tissue depend on many factors: anatomic topography, particular physiology, or intensity and duration of infectious, mechanical and chemical aggression. Also irritation of the pulpo-dentinal complex induce histologic and physiologic changes. The positive diagnosis of hyperemia, acute or chronic pulpitis, pulpal necrosis and acute or chronic apical abscess is performed by clinical investigations which allow a differential diagnosis with other dental or extra-dental diseases. These multiple steps lead to an adapted and appropriate treatment.

  18. EVALUATION OF LINERBOARD PROPERTIES FROM MALAYSIAN CULTIVATED KENAF SODA-ANTHRAQUINONE PULPS VERSUS COMMERCIAL PULPS

    OpenAIRE

    Ahmad Azizi Mossello; Jalaluddin Harun; Rushdan Ibrahim; Hossien Resalati; Seyed Rashid Fallah Shamsi; Paridah Md Tahir; Mohd Nor Mohad Yusoff

    2010-01-01

    Malaysian cultivated kenaf has been identified as a suitable raw material for linerboard production. This study examines the soda-antraquinone (soda-AQ) pulp of kenaf fibers versus old corrugated container (OCC) and unbleached softwood kraft pulps as the main sources for linerboard production. The results showed significant differences among the pulp properties. The unbleached kraft pulp with very high freeness required high beating to reach an optimized freeness and produced paper with the h...

  19. Dual ionization chamber

    International Nuclear Information System (INIS)

    Mallory, J.; Turlej, Z.

    1981-01-01

    Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

  20. Can Dental Pulp Calcification Predict the Risk of Ischemic Cardiovascular Disease?

    Directory of Open Access Journals (Sweden)

    Leila Khojastepour

    2013-01-01

    Full Text Available Objective: To report the association of pulp calcification with that of cardiovascular disease (CVD using digital panoramic dental radiographs.Materials and Methods: Digital panoramic radiographs of patients referred from the angiography department were included if the patient was under 55 years old and had non-restored or minimally restored molars and canines. An oral and maxillofacial radiologist evaluated the images for pulpal calcifications in the selected teeth. The sensitivity, specificity, positive predictive value and negative predictive value of panoramic radiography in predicting CVD were calculated.Results: Out of 122 patients who met the criteria, 68.2% of the patients with CVD had pulp chamber calcifications. Pulp calcification in panoramic radiography had a sensitivity of 68.9% to predict CVD.Conclusion: This study demonstrates that patients with CVD show an increased incidence of pulp calcification compared with healthy patients. The findings suggest that pulp calcification on panoramic radiography may have possibilities for use in CVD screening.

  1. Optical and Physical Properties of ONP Deinked Pulp

    Directory of Open Access Journals (Sweden)

    Iman Akbarpoor

    2012-01-01

    Full Text Available Enzymes are protein molecules with complex structures that accelerate the biochemical reactions. Activity of these chemical compounds is accomplished at limited range of pH, temperature and concentration. In this study, the effects of different concentrations of cellulose enzyme were investigated on deinking of old newsprint. Old newsprint (ONP was repulped at 5% consistency for 10 minutes in disintegrator with total revolution number of 26500. Enzymatic treatments of recycled ONP pulp were done under constant conditions (10% consistency,treatment time of 15 minutes, pH range of 5-5.5 at different cellulose concentrations of 0.025, 0.05, 0.1 and 0.2% (based on oven-dry waste paper. The optical and physical properties of the standard paper (60g/m2 made at different concentrations of cellulose were evaluated in comparison with control pulp (untreated ONP pulp with cellulase. Overall, the results achieved by comparison the optical properties of the paper produced indicated that using cellulase in deinking of ONP led to increase the brightness and the yellowness and decrease the opacity. The brightness was improved to a maximum level of 47.5 ISO %, but the yellowness was decreased to a minimum level of 11.3 ISO %, while the brightness reduced and the yellowness increased at higher concentrations than 0.05% cellulase. The highest opacity of 99.3 ISO % was achieved using 0.1% cellulase even higher than control pulp. The results gained by comparison the physical properties of the paper showed that using cellulase resulted in decrease of paper calliper, air resistance and density and improve the freeness of pulp

  2. Cassava Pulp as a Biofuel Feedstock of an Enzymatic Hydrolysis Proces

    Directory of Open Access Journals (Sweden)

    Djuma’ali Djuma’ali

    2013-03-01

    Full Text Available Cassava pulp, a low cost solid byproduct of cassava starch industry, has been proposed as a high potential ethanolic fermentation substrate due to its high residual starch level, low ash content and small particle size of the lignocellulosic fibers. As the economic feasibility depends on complete degradation of the polysaccharides to fermentable glucose, the comparative hydrolytic potential of cassava pulp by six commercial enzymes were studied. Raw cassava pulp (12% w/v, particle size <320 μm hydrolyzed by both commercial pectinolytic (1 and amylolytic (2 enzymes cocktail, yielded 70.06% DE. Hydrothermal treatment of cassava pulp enhanced its susceptibility to enzymatic cleavageas compared to non-hydrothermal treatment raw cassava pulp. Hydrothermal pretreatment has shown that a glucoamylase (3 was the most effective enzyme for hydrolysis process of cassava pulp at temperature 65 °C or 95 °C for 10 min and yielded approximately 86.22% and 90.18% DE, respectively. Enzymatic pretreatment increased cassava pulp vulnerability to cellulase attacks. The optimum conditions for enzymatic pretreatment of 30% (w/v cassava pulp by a potent cellulolytic/ hemicellulolytic enzyme (4 was achieves at 50 °C for 3, meanwhile for liquefaction and saccharification by a thermo-stable α-amylase (5 was achieved at 95 °C for 1 and a glucoamylase (3 at 50 °C for 24 hours, respectively, yielded a reducing sugar level up to 94,1% DE. The high yield of glucose indicates the potential use of enzymatic-hydrothermally treated cassava pulp as a cheap substrate for ethanol production.

  3. Diabetes induces metabolic alterations in dental pulp.

    Science.gov (United States)

    Leite, Mariana Ferreira; Ganzerla, Emily; Marques, Márcia Martins; Nicolau, José

    2008-10-01

    Diabetes can interfere in tissue nutrition and can impair dental pulp metabolism. This disease causes oxidative stress in cells and tissues. However, little is known about the antioxidant system in the dental pulp of diabetics. Thus, it would be of importance to study this system in this tissue in order to verify possible alterations indicative of oxidative stress. The aim of this study was to evaluate some parameters of antioxidant system of the dental pulp of healthy (n = 8) and diabetic rats (n = 8). Diabetes was induced by streptozotocin in rats. Six weeks after diabetes induction, a pool of the dental pulp of the 4 incisors of each rat (healthy and diabetic) was used for the determination of total protein and sialic acid concentrations and catalase and peroxidase activities. Data were compared by a Student t test (p pulps from both groups presented similar total protein concentrations and peroxidase activity. Dental pulps of diabetic rats exhibited significantly lower free, conjugated, and total sialic acid concentrations than those of control tissues. Catalase activity in diabetic dental pulps was significantly enhanced in comparison with that of control pulps. The result of the present study is indicative of oxidative stress in the dental pulp caused by diabetes. The increase of catalase activity and the reduction of sialic acid could be resultant of reactive oxygen species production.

  4. PRODUCTION OF DISSOLVING GRADE PULP FROM ALFA

    Directory of Open Access Journals (Sweden)

    Baya Bouiri

    2010-02-01

    Full Text Available Alfa, also known as Stipa tenacissimaI or “halfa”, is grown in North Africa and south Spain. Due to its short fiber length, paper made from alfa pulp retains bulk and takes block letters well. In this study alfa was evaluated for bleached pulp production. Two cellulose pulps with different chemical compositions were pulped by a conventional kraft process. One sample was taken from the original alfa material and another from alfa that had been pretreated by diluted acid. The pulp produced from the pretreated alfa was bleached by the elemental-chlorine-free sequences DEPD and DEDP. The yield, Kappa number, brightness, and α- cellulose content of bleached and unbleached pulps were evaluated. The results showed that during the chemical pulping process, treated alfa cooked more easily than the original alfa. The treated alfa pulp also showed very good bleaching, reaching a brightness level of 94.8% ISO with a yield of 93.6% at an α-cellulose content 96.8(% with a DEDP bleaching sequence, compared to 83.2% ISO brightness level, 92.8% yield, and 95.1% α-cellulose content for bleached pulp with a DEPD bleaching sequence. Therefore, this alfa material could be considered as a worthwhile choice for cellulosic fiber supply.

  5. Eucalyptus kraft pulp production: Thermogravimetry monitoring

    International Nuclear Information System (INIS)

    Barneto, Agustin G.; Vila, Carlos; Ariza, Jose

    2011-01-01

    Highlights: → Thermogravimetric analysis can be used to monitor the pulping process in a pulp mill. → ECF bleaching process affects the crystalline cellulose volatilization. → The fibre size has an influence on composition and thermal behavior of pulp. - Abstract: Under oxidative environment the thermal degradation of lignocellulosic materials like wood or pulp is sensitive to slight composition changes. For this, in order to complement the chemical and X-ray diffraction results, thermogravimetric analyses (TGA) were used to monitor pulp production in a modern pulp mill. Runs were carried out on crude, oxygen delignified and bleached pulps from three eucalyptus woods from different species and geographical origins. Moreover, with the modeling of thermogravimetric data, it was possible to obtain an approximate composition of samples which includes crystalline and amorphous cellulose. TGA results show that pulping has an intensive effect on bulk lignin and hemicellulose, but it has limited influence on the removal of these substances when they are linked to cellulose microfibril. The stages of oxygen delignification and bleaching, based in chlorine dioxide and hydrogen peroxide, increase the crystalline cellulose volatilization rate. These changes are compatible with a more crystalline microfibril. The influence of the fibre size on pulp composition, crystallinity and thermal degradation behavior was observed.

  6. Organo mercurials in pulp and paper industry

    Energy Technology Data Exchange (ETDEWEB)

    Bouveng, H O

    1967-01-01

    Today phenyl mercury acetate (PMA) is used in the paper and pulp industry for two purposes: slime control in paper machine systems and impregnation of wet mechanical pulp. PMA is a commonly used slimicide. It is used for slime control in such a way that a minor part (5-20% depending on mill operation) will reach the watercourse with the waste water and contaminate aquatic life. PMA used for impregnation concerns wet mechanical pulp produced for export as raw material, mostly for newsprint. Treatment of this pulp with PMA is necessary to avoid changes caused by molds and rot fungi.

  7. Pulp and paper production from Spruce wood with kraft and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... optical properties of resultant paper were included to determine the properties of these pulp samples. ... pulping compounds in the kraft method are Na2S and .... Scanning electron microscope (SEM) measurement of pulp.

  8. Dental pulp stone formation during orthodontic treatment: A ...

    African Journals Online (AJOL)

    2015-06-21

    Jun 21, 2015 ... the presence of dental pulp stone, gender, age, tooth type and arches. Results: Dental pulp ... primary and permanent dentition.[1] Dental pulp stones .... interpretation provided training to familiarize the other observer with the ...

  9. Catalase activity in healthy and inflamed pulp tissues of permanent ...

    African Journals Online (AJOL)

    2015-11-02

    Nov 2, 2015 ... pulps, which is due to pulpitis in comparison to healthy dental pulp. Key words: .... human dental pulp cells by Porphyromonas endodontalis lipopolysaccharide. J Endod ... Biology of disease: Free radicals and tissue injury.

  10. Influence of different types of light on the response of the pulp tissue in dental bleaching: a systematic review.

    Science.gov (United States)

    Benetti, Francine; Lemos, Cleidiel Aparecido Araújo; de Oliveira Gallinari, Marjorie; Terayama, Amanda Miyuki; Briso, André Luiz Fraga; de Castilho Jacinto, Rogério; Sivieri-Araújo, Gustavo; Cintra, Luciano Tavares Angelo

    2018-05-01

    This systematic review (PROSPERO register: CRD42016053140) investigated the influence of different types of light on the pulp tissue during dental bleaching. Two independent authors conducted a systematic search and risk of bias evaluations. An electronic search was undertaken (PubMed/Medline, Embase, The Cochrane Library, and other databases) until May 2017. The population, intervention, comparison, outcomes (PICO) question was: "Does the light in dental bleaching change the response of the pulp to the bleaching procedure?" The intervention involved pulp tissue/cells after bleaching with light, while the comparison involved pulp tissue/cells after bleaching without light. The primary outcome was the inflammation/cytotoxicity observed in pulp after bleaching. Out of 2210 articles found, 12 articles were included in the review; four were in vivo studies (one study in dogs/others in human), and eight were in vitro studies (cell culture/with artificial pulp chamber or not). The light source used was halogen, light-emitting diode (LED), and laser. Only one in vivo study that used heat to simulate light effects showed significant pulp inflammation. Only two in vitro studies demonstrated that light influenced cell metabolism; one using halogen light indicated negative effects, and the other using laser therapy indicated positive effects. Given that animal and in vitro studies have been identified, there remain some limitations for extrapolation to the human situation. Furthermore, different light parameters were used. The effects of dental bleaching on the pulp are not influenced by different types of light, but different light parameters can influence these properties. There is insufficient evidence about the influence of different types of light on inflammation/cytotoxicity of the pulp.

  11. Double chamber ion source

    International Nuclear Information System (INIS)

    Uman, M.F.; Winnard, J.R.; Winters, H.F.

    1978-01-01

    The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

  12. Effect of freezing and processing technologies on the antioxidant capacity of fruit pulp and jelly

    Directory of Open Access Journals (Sweden)

    Cristine Maso Jeusti Bof

    2012-02-01

    Full Text Available The effect of freezing and processing technology on the antioxidant capacity of grape (Vitis vinifera, apple (Malus domestica, strawberry (Fragaria x Anassa, pear (Pyrus communis L., guava (Psidium guajava L., and fig (Ficus carica L. was evaluated for 90 days. Under a storage temperature of -15 º C, there was no significant difference in the antioxidant capacity of grape and fig pulp, and a higher antioxidant capacity was found for guava pulp (27 µmol/g. While the technological processing did not affect the antioxidant capacity of pear and apple jellies, all other jellies studied showed a reduced antioxidant capacity. The processing reduced the antioxidant capacity of grapes in 45%. Among the fruit products, the highest antioxidant activities were found for guava pulp and jelly (27 and 25 µmol/g, respectively, followed by grape pulp (22 µmol/g.

  13. Dilution refrigeration with multiple mixing chambers

    International Nuclear Information System (INIS)

    Coops, G.M.

    1981-01-01

    A dilution refrigerator is an instrument to reach temperatures in the mK region in a continuous way. The temperature range can be extended and the cooling power can be enlarged by adding an extra mixing chamber. In this way we obtain a double mixing chamber system. In this thesis the theory of the multiple mixing chamber is presented and tested on its validity by comparison with the measurements. Measurements on a dilution refrigerator with a circulation rate up to 2.5 mmol/s are also reported. (Auth.)

  14. Cálculo de la temperatura en el interior de la cámara de combustión en motores de combustión interna. // Calculation of temperature into combustion chamber of internal combustion engines.

    Directory of Open Access Journals (Sweden)

    F. Soto Pau

    2002-05-01

    Full Text Available El trabajo aquí presentado tiene como objetivo llegar a expresiones de cálculo de la temperatura en el interior de la cámarade combustión como vía de diagnostico de la combustión en motores térmicos. Este trabajo consiste en un modelo físicomatemático,el cual usa como herramientas fundamentalmente, los valores de presión medidos en el interior de la cámarade combustión, las características geométricas del motor y todos los valores normalmente medidos en el bancodinamométrico. El procesamiento teórico de este modelo consiste fundamentalmente en la determinación de la evoluciónde la combustión a partir de la curva de presión, basada en la Primera Ley de la Termodinámica, adoptando Modelo deGases Perfectos. A partir de la posición angular de cierre de la válvula de admisión es posible calcular la derivada de latemperatura en relación a la posición angular del cigüeñal para los gases quemados T&b y no quemados T&u . Teniendo estosvalores de T&u y T&b calculados, es posible integrar numéricamente las temperaturas utilizando el método de integración deEuler. Conociendo la composición química del combustible, es posible calcular la temperatura adiabática de llama, estesería el valor de temperatura inicial Tb que nos permitiría calcular un valor de entalpía específica de los gases quemados. Deigual forma con el valor de la temperatura inicial para los gases no quemados Tu se tiene el valor de temperatura inicial parael proceso de integración.Palabras claves: Proceso de combustión en motores térmicos, temperatura en el interior de la cámara decombustión, presión en el interior de la cámara de combustión.____________________________________________________________________________Abstract.This paper presents calculation expressions of the temperature inside the combustion chamber in order to diagnose thecombustion in termic engines. This analysis consists in a physical-mathematical model, which uses

  15. Kraft pulp bleaching with molybdenum activated acid peroxide (PMo stage)

    International Nuclear Information System (INIS)

    Rabelo, Marcos Sousa

    2009-01-01

    Optimum conditions to run the P Mo stage for bleaching eucalyptus kraft pulp were 90 deg C, pH 3.5, 2 h, 0.1 kg/t Mo and 5 kg/t H 2 O 2 . The P Mo stage efficiency increased with decreasing pH (1.5-5.5) and increasing temperature (75-90 deg C), time (2-4 h), and hydrogen peroxide (3-10 kg/t) and molybdenum concentration (0.1-0.4 kg/t). The implementation of the P Mo stage, as replacement for the A stage, decreased total active chlorine demand of the OAZDP sequence by 6 kg/t to reach 90% ISO, both in laboratory and mill scale. Such practice resulted in decreased bleaching chemical costs to produce fully bleached pulp of 90% ISO. (author)

  16. PULP DEMAND IN THE INTERNATIONAL MARKET

    Directory of Open Access Journals (Sweden)

    Edmilson Santos Cruz

    2003-01-01

    Full Text Available This study aimed at analyzing the international pulp market, taking into account themain exporting countries and importing regions, with the objective of estimating, for each market, theown-price and cross-price elasticity in relation to the demand of the pulp, differentiated for country oforigin. The model considers that imports are differentiated by origin; therefore they are not perfect substitutes. The demand from Europe, North America and the Rest of the World for the pulp from theUnited States,Canada, Sweden, Finland, Portugal and Brazil was inelastic. The Asian demand for thissome pulp was elastic. Europe and the Rest of the World showed negative cross-price elasticity, i. e.,and the imported pulp from other countries are complementary products. North America and Asiashowed positive crow-price elasticity, i. e., they consider the pulp produced in other countries assubstitute products. The net effect of the variation on the price of pulp in a country h, over the amountof pulp that goes to the region i depends on the matching of values related to the elasticity ofsubstitution and the price elasticity of the total demand.

  17. Characterization of sugar beet pulp derived oligosaccharides

    NARCIS (Netherlands)

    Leijdekkers, M.

    2015-01-01

    Abstract

    This thesis aimed at characterizing complex mixtures of sugar beet pulp derived oligosaccharides, in order to be able to monitor and optimize the enzymatic saccharification of sugar beet pulp.

    Hydrophilic interaction chromatography with on-line evaporative

  18. Pulp quality from small-diameter trees.

    Science.gov (United States)

    G.C. Myers; S. Kumar; R.R. Gustafson; R.J. Barbour; S.M. Abubakr

    1997-01-01

    Kraft and thermomechanical (TMP) pulps were prepared and evaluated from lodgepole pine and mixed Douglas-fir/western larch sawmill residue chips; lodgepole pine, Douglas-fir, and western larch submerchantable logs; and lodgepole pine, Douglas-fir, and western larch small trees and tops. Kraft pulp from small trees and tops was identical to that from submerchantable...

  19. Enzymes improve ECF bleaching of pulp

    Directory of Open Access Journals (Sweden)

    Lachenal, D.

    2006-07-01

    Full Text Available The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction in chlorine dioxide consumption was obtained when the same laccase treated pulp was subjected to an acid treatment after the extraction stage followed by the DEPD sequence. Elemental-chlorine free bleaching was also performed using the xylanase-laccase treated pulp. Xylanase treatment was incorporated to the laccase mediator system in the elemental-chlorine free bleaching both sequentially and simultaneously. The bleaching sequence DEPD followed and in both the cases, the reduction in chlorine dioxide consumption was greater in comparison to the control. The chlorine dioxide consumption was reduced further when xylanase-laccase treated pulp was given an additional acid treatment. The final pulp properties of the treated pulps were comparable to the control pulp.

  20. Utilizing Chamber Data for Developing and Validating Climate Change Models

    Science.gov (United States)

    Monje, Oscar

    2012-01-01

    Controlled environment chambers (e.g. growth chambers, SPAR chambers, or open-top chambers) are useful for measuring plant ecosystem responses to climatic variables and CO2 that affect plant water relations. However, data from chambers was found to overestimate responses of C fluxes to CO2 enrichment. Chamber data may be confounded by numerous artifacts (e.g. sidelighting, edge effects, increased temperature and VPD, etc) and this limits what can be measured accurately. Chambers can be used to measure canopy level energy balance under controlled conditions and plant transpiration responses to CO2 concentration can be elucidated. However, these measurements cannot be used directly in model development or validation. The response of stomatal conductance to CO2 will be the same as in the field, but the measured response must be recalculated in such a manner to account for differences in aerodynamic conductance, temperature and VPD between the chamber and the field.

  1. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  2. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  3. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  4. High levels of hydrogen peroxide in overnight tooth-whitening formulas: effects on enamel and pulp.

    Science.gov (United States)

    Pugh, George; Zaidel, Lynette; Lin, Nora; Stranick, Michael; Bagley, Daniel

    2005-01-01

    Limited data are available to assess the safety of high levels of hydrogen peroxide in overnight tooth-whitening formulas. The purpose of this study was to assess the effects of hydrogen peroxide on enamel microhardness, pulp penetration, and enamel morphology. Colgate Platinum Professional Overnight Whitening System (Colgate Oral Pharmaceuticals, Inc., Canton, MA, USA) (10% carbamide peroxide, equivalent to 3.5% hydrogen peroxide) was compared with two prototype formulations containing either 7.0% or 12.0% hydrogen peroxide. In the pulp chamber studies, human extracted teeth were exposed to 3.5%, 7.0%, or 12.0% hydrogen peroxide for 30 minutes, 4 hours, or 7 hours. Microhardness, electron spectroscopy for chemical analysis, and atomic force microscopy evaluations were made from enamel blocks cut from human extracted molars. The enamel blocks were evaluated following 14 7-hour treatments (98 h total). At 7 hours' post-treatment, hydrogen peroxide penetrated the pulp chamber at 23.12 +/- 10.09, 24.58 +/- 6.90, and 26.39 +/- 5.43 microg for 3.5%, 7.0%, and 12.0% hydrogen peroxide, respectively. With regard to enamel morphology, pulp penetration, microhardness, and elemental composition, no statistically significant differences were observed between treatment groups following 98 hours of treatment. Hydrogen peroxide does not adversely affect enamel morphology or microhardness. The levels recovered in pulp indicate that hydrogen peroxide is not expected to inhibit pulpal enzymes. Overnight tray products containing levels of hydrogen peroxide of 3.5%, 7.0%, and 12.0% are not expected to adversely affect the enamel or pulpal enzymes. Additional safety studies are needed to assess the potential for tooth sensitivity and gingival irritation.

  5. Wood-plastic composites using thermomechanical pulp made from oxalic acid-pretreated red pine chips

    Science.gov (United States)

    J.E. Winandy; N.M. Stark; E. Horn

    2008-01-01

    The characteristics and properties of wood fiber is one of many factors of critical importance to the performance of wood-plastic composites. In commercial thermo-mechanical pulping (TMP) of wood chips to produce fibers, high temperatures (>100°C) are used to separate the fibers during TMP refining. These mechanical pressures and temperatures are usually modulated...

  6. Multispecimen dual-beam irradiation damage chamber

    International Nuclear Information System (INIS)

    Packan, N.H.; Buhl, R.A.

    1980-06-01

    An irradiation damage chamber that can be used to rapidly simulate fast neutron damage in fission or fusion materials has been designed and constructed. The chamber operates in conjunction with dual Van de Graaff accelerators at ORNL to simulate a wide range of irradiation conditions, including pulsed irradiation. Up to six experiments, each with up to nine 3-mm disk specimens, can be loaded into the ultrahigh vacuum chamber. Specimen holders are heated with individual electron guns, and the temperature of each specimen can be monitored during bombardment by an infrared pyrometer. Three different dose levels may be obtained during any single bombardment, and the heavy-ion flux on each of the nine specimens can be measured independently with only a brief interruption of the beam. The chamber has been in service for nearly three years, during which time approximately 250 bombardments have been successfully carried out. An appendix contains detailed procedures for operating the chamber

  7. DORIOT CLIMATIC CHAMBERS

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

  8. Gas microstrip chambers

    International Nuclear Information System (INIS)

    McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

    1992-01-01

    The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

  9. Breeding Strategy To Generate Robust Yeast Starter Cultures for Cocoa Pulp Fermentations

    Science.gov (United States)

    Meersman, Esther; Steensels, Jan; Paulus, Tinneke; Struyf, Nore; Saels, Veerle; Mathawan, Melissa; Koffi, Jean; Vrancken, Gino

    2015-01-01

    Cocoa pulp fermentation is a spontaneous process during which the natural microbiota present at cocoa farms is allowed to ferment the pulp surrounding cocoa beans. Because such spontaneous fermentations are inconsistent and contribute to product variability, there is growing interest in a microbial starter culture that could be used to inoculate cocoa pulp fermentations. Previous studies have revealed that many different fungi are recovered from different batches of spontaneous cocoa pulp fermentations, whereas the variation in the prokaryotic microbiome is much more limited. In this study, therefore, we aimed to develop a suitable yeast starter culture that is able to outcompete wild contaminants and consistently produce high-quality chocolate. Starting from specifically selected Saccharomyces cerevisiae strains, we developed robust hybrids with characteristics that allow them to efficiently ferment cocoa pulp, including improved temperature tolerance and fermentation capacity. We conducted several laboratory and field trials to show that these new hybrids often outperform their parental strains and are able to dominate spontaneous pilot scale fermentations, which results in much more consistent microbial profiles. Moreover, analysis of the resulting chocolate showed that some of the cocoa batches that were fermented with specific starter cultures yielded superior chocolate. Taken together, these results describe the development of robust yeast starter cultures for cocoa pulp fermentations that can contribute to improving the consistency and quality of commercial chocolate production. PMID:26150457

  10. Breeding Strategy To Generate Robust Yeast Starter Cultures for Cocoa Pulp Fermentations.

    Science.gov (United States)

    Meersman, Esther; Steensels, Jan; Paulus, Tinneke; Struyf, Nore; Saels, Veerle; Mathawan, Melissa; Koffi, Jean; Vrancken, Gino; Verstrepen, Kevin J

    2015-09-01

    Cocoa pulp fermentation is a spontaneous process during which the natural microbiota present at cocoa farms is allowed to ferment the pulp surrounding cocoa beans. Because such spontaneous fermentations are inconsistent and contribute to product variability, there is growing interest in a microbial starter culture that could be used to inoculate cocoa pulp fermentations. Previous studies have revealed that many different fungi are recovered from different batches of spontaneous cocoa pulp fermentations, whereas the variation in the prokaryotic microbiome is much more limited. In this study, therefore, we aimed to develop a suitable yeast starter culture that is able to outcompete wild contaminants and consistently produce high-quality chocolate. Starting from specifically selected Saccharomyces cerevisiae strains, we developed robust hybrids with characteristics that allow them to efficiently ferment cocoa pulp, including improved temperature tolerance and fermentation capacity. We conducted several laboratory and field trials to show that these new hybrids often outperform their parental strains and are able to dominate spontaneous pilot scale fermentations, which results in much more consistent microbial profiles. Moreover, analysis of the resulting chocolate showed that some of the cocoa batches that were fermented with specific starter cultures yielded superior chocolate. Taken together, these results describe the development of robust yeast starter cultures for cocoa pulp fermentations that can contribute to improving the consistency and quality of commercial chocolate production. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Longitudinal changes of nerve conduction velocity, distal motor latency, compound motor action potential duration, and skin temperature during prolonged exposure to cold in a climate chamber.

    Science.gov (United States)

    Maetzler, Walter; Klenk, Jochen; Becker, Clemens; Zscheile, Julia; Gabor, Kai-Steffen; Lindemann, Ulrich

    2012-09-01

    Changes of nerve conduction velocity (NCV), distal motor latency (DML), compound motor action potential (CMAP) duration, and skin temperature with regard to cold have been investigated by use of ice packs or cold water baths, but not after cooling of environmental temperature which has higher ecological validity. The aim of this study was to investigate these parameters during cooled room temperature. NCV, DML, and CMAP duration of the common fibular nerve, and skin temperature were measured in 20 healthy young females during exposure to 15°C room temperature, coming from 25°C room. We found that NCV decreased and DML increased linearly during 45 min observation time, in contrast to CMAP duration and skin temperature which changes followed an exponential curve. To the best of our knowledge, this is the first study investigating changes of these parameters during exposure to environmental cold. The results may pilot some new hypotheses and studies on physiological and pathological changes of the peripheral nervous system and skin to environmental cold, e.g., in elderly with peripheral neuropathies.

  12. PENGGUNAAN ASAM PERASETAT PADA PROSES DELIGNIFIKASI PULP ACETOSOLV DARI AMPAS TEBU DAN BAMBU BETUNG

    Directory of Open Access Journals (Sweden)

    Ahmad Sapta Zuidar

    2014-07-01

    Full Text Available Acetosolv process produced dark pulp because of the high lignin content.  Therefore ,  delignification  process is needed. This process uses peracetic acid to improve pulp qualities. The objective of this research was to determine the effect of different concentrations of peracetic acid against the characteristics of pulp acetosolv from bagasse and bamboo betung.  The research was arranged in a Complete Randomized Block Design with a single treatment and 4 replications.  The treatment used peracetic acid with six levels concentration (9%, 11%, 13%, 15%, 17%, 19% at a temperature of 85oC for 3 hours. The homogenity and additivity of the data were  analyzed using Bartlett and Tuckey Tests, then they were analyze for ANOVA to see if there is any difference among means, and then processed further using  Least Significant Difference at level of 1% and 5%.  The results showed that the concentration of peracetic acid had significant effect on yield, cellulose, hemicellulose, lignin, and organoleptic color pulp from bagasse and bamboo betung.  The best results showed that the concentration of peracetic acid 15% with cooking duration of  3 hours gave the best pulp. The pulp contained 85.837% of cellulose , 7.757% of hemicellulose , 1.758% of lignin , 73.048% of yield  and  the average organoleptic score for the pulp color was 4.3. Keywords:   acetosolv pulp,  baggase, bamboo,  delignification, paracetic acid

  13. Bioactive Glass Scaffolds for Dental Pulp and Dentin Tissue Engineering

    Science.gov (United States)

    Shawli, Hassan Talat

    Current and historical endodontic "root canal" treatments employ inert obturating materials inserted into the teeth's pulp chambers and root canals, often saving teeth but without adequate function. Furthermore, the occurrence of pulpal necrosis in the immature permanent tooth is considered to be a challenging situation, clinically, in treatment because the thin and often short roots increase the risk of fracture. The ideal treatment would be to promote continued root development. This work demonstrated that endodontically-shaped and durable scaffolds of slowly resorbable fibrous (HT) glass and faster-resorbing small-particle Bioglass can be sintered at 900 degrees C for such placement, and that cell growth of osteoblasts in these scaffolds shows good early results. Retained bioactivity in the sintered specimen was revealed by Multiple Attenuated Internal Reflection Infrared Spectroscopy.

  14. Effect of time and storage conditions on the physical and physico-chemical characteristics of the pulp of yellow and purple passion fruit

    Directory of Open Access Journals (Sweden)

    Letícia da Silva ARAÚJO

    Full Text Available Abstract The aim of this study was evaluate the physical and physico-chemical characteristics of extracted fruit pulp of passion fruit with different skin color (yellow, light and dark purple under refrigeration temperatures and storage times. The extracted pulp of passion fruit was stored at different temperatures: 10 °C, 25 °C; - 30 °C and - 80 °C and at four different storage periods: 0; 10; 20 and 30 days. The following physical and physico-chemical characteristics of the fruit were evaluated: color of fruit peel, fruit weight, diameter, length and width of the fruit, peel thickness, peel mass, pulp mass, pulp color, juice yield, pH, soluble solids, titratable acidity and ratio. The physical and physico-chemical results indicate that all the passion fruit pulp, in natura as well as refrigerated, presented values in conformity to the identity and quality standards. The coloration of the fruit peel influenced the preservation of pulp color during the storage period and conditions. Purple fruits showed no change in the color of the pulp, even under different conservation procedures. The passion fruit pulp can be stored up to 30 days while preserving the physical and physico-chemical characteristics, similar to the pulp in natura.

  15. Analysis of the internal temperature of the combustion chamber of a compact system of co-generation; Analise das temperaturas internas da camara de combustao de um sistema compacto de co-geracao

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Joao B.F. [Universidade de Fortaleza (UNIFOR), CE (Brazil)], email: furlan@unifor.br; Couto, Heraldo S. [Instituto Nacional de Pesquisas Espaciais (INPE), Cachoeira Paulista, SP (Brazil)], email: heraldo@lcp.inpe.br; Holanda, Carlos A.M. de [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Metalurgica e de Materiais], email: almir@metalmat.ufc.br

    2008-07-01

    Nowadays, the energy deficit represents one of the biggest governmental challenges, since there is still a great number of communities living in areas without electricity energy; and thus without access to electro-electronic equipment such as television, refrigerators, computers. The main focus of this work is to present the possibility of electricity energy generation in conjunction with the frozen or hot water production in for places without electricity transmission nets or even any type of alternative power plants. The system is based on the standard air cycle called Brayton cycle composed of a turbo-compressor model 4LGZ from BorgWarner, a combustion chamber, a power turbine, a heat exchanger, a water-ammonia chiller, a 5.0 kV A generator, and a command panel for automation and distribution of energy. This system that uses natural gas or LPG, will supply electric energy from the generator, hot water from the heat exchange with the gases of combustion, and water frozen from chiller using as the hot source the gases proceeding from the power system. The prototype is already being tested and the first results obtained are excellent. In this paper, we analyze the internal combustion chamber temperatures. (author)

  16. Pulping Variables, Storage Time and Pitch Deposit | Ogunwusi ...

    African Journals Online (AJOL)

    Pulp resin is also influenced by effective alkali concentration of the pulping medium. With increase in effective alkali concentration from 13% to 15%, pulp pitch is reduced. The interaction effect of storage and effective alkali concentration was not significant indicating that reduction in pulp pitch caused by effective alkali ...

  17. Pulp mill as an energy producer

    International Nuclear Information System (INIS)

    Kaulamo, O.

    1998-01-01

    The recovery boilers of pulp mills are today the most significant producers of wood energy. The power-to-heat ratio of the power plant process, i.e., power yield, is poor in existing applications. In the study, an alternative of improving the power yield of conventional pulp mills significantly was studied by applying solutions used in power plants to a pulp mill. Extensive conversion of wood energy into electricity is possible only in the recovery boiler of the pulp mill and in a large combustion boiler of bark, wood waste and wood chips integrated to this boiler. Hence, the harvest and transports of wood raw materials, i.e. pulp wood and energy wood, are integrated, and the fraction going to cook and the energy wood fraction are separated at the pulp mill. The method guarantees competitive supply of energy wood. As a result a SELLUPOWER mill was designed, where the recovery boiler combusting black liquor and the large power plant boiler combusting energy wood are integrated to one unit and constructed to a power plant process with a high power-to-heat ratio. Necessary technical solutions, project costs and economical feasibility compared to a conventional pulp mill were determined, and the effect of different production-economical parameters was also studied. (orig.)

  18. High-yield pulping effluent treatment technologies

    International Nuclear Information System (INIS)

    Su, W.X.; Hsieh, J.S.

    1993-03-01

    The objective of this report is to examine the high-yield (mechanical) pulp processes with respect to environmental issues affected by the discharge of their waste streams. Various statistics are given that support the view that high-yield pulping processes will have major growth in the US regions where pulp mills are located, and sites for projects in the development phase are indicated. Conventional and innovative effluent-treatment technologies applicable to these processes are reviewed. The different types of mechanical pulping or high-yield processes are explained, and the chemical additives are discussed. The important relationship between pulp yield and measure of BOD in the effluent is graphically presented. Effluent contaminants are identified, along with other important characteristics of the streams. Current and proposed environmental limitations specifically related to mechanical pulp production are reviewed. Conventional and innovative effluent-treatment technologies are discussed, along with their principle applications, uses, advantages, and disadvantages. Sludge management and disposal techniques become an intimate part of the treatment of waste streams. The conclusion is made that conventional technologies can successfully treat effluent streams under current waste-water discharge limitations, but these systems may not be adequate when stricter standards are imposed. At present, the most important issue in the treatment of pulp-mill waste is the management and disposal of the resultant sludge

  19. An electrodeless drift chamber

    International Nuclear Information System (INIS)

    Allison, J.; Barlow, R.J.; Bowdery, C.K.; Duerdoth, I.; Rowe, P.G.

    1982-01-01

    We describe a chamber in which the drift field is controlled by the deposition of electrostatic charge on an insulating surface. The chamber operates with good efficiency and precision for observed drift distances of up to 45 cm, promises to be extremely robust and adaptable and offers a very cheap way of making particle detectors. (orig.)

  20. High resolution drift chambers

    International Nuclear Information System (INIS)

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 μm resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs

  1. Plastic flashtube chambers

    International Nuclear Information System (INIS)

    Frisken, W.R.

    1977-01-01

    A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

  2. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  3. BEBC bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  4. DELPHI time projection chamber

    CERN Multimedia

    1989-01-01

    The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  5. Innovative Comparison of Transient Ignition Temperature at the Booster Interface, New Stainless Steel Pyrovalve Primer Chamber Assembly "V" (PCA) Design Versus the Current Aluminum "Y" PCA Design

    Science.gov (United States)

    Saulsberry, Regor L.; McDougle, Stephen H.; Garcia,Roberto; Johnson, Kenneth L.; Sipes, William; Rickman, Steven; Hosangadi, Ashvin

    2011-01-01

    An assessment of four spacecraft pyrovalve anomalies that occurred during ground testing was conducted by the NASA Engineering & Safety Center (NESC) in 2008. In all four cases, a common aluminum (Al) primer chamber assembly (PCA) was used with dual NASA Standard Initiators (NSIs) and the nearly simultaneous (separated by less than 80 microseconds) firing of both initiators failed to ignite the booster charge. The results of the assessment and associated test program were reported in AIAA Paper AIAA-2008-4798, NESC Independent Assessment of Pyrovalve Ground Test Anomalies. As a result of the four Al PCA anomalies, and the test results and findings of the NESC assessment, the Mars Science Laboratory (MSL) project team decided to make changes to the PCA. The material for the PCA body was changed from aluminum (Al) to stainless steel (SS) to avoid melting, distortion, and potential leakage of the NSI flow passages when the device functioned. The flow passages, which were interconnected in a Y-shaped configuration (Y-PCA) in the original design, were changed to a V-shaped configuration (V-PCA). The V-shape was used to more efficiently transfer energy from the NSIs to the booster. Development and qualification testing of the new design clearly demonstrated faster booster ignition times compared to the legacy AL Y-PCA design. However, the final NESC assessment report recommended that the SS V-PCA be experimentally characterized and quantitatively compared to the Al Y-PCA design. This data was deemed important for properly evaluating the design options for future NASA projects. This test program has successfully quantified the improvement of the SS V-PCA over the Al Y-PCA. A phase B of the project was also conducted and evaluated the effect of firing command skew and enlargement of flame channels to further assist spacecraft applications.

  6. Study in vitro of dental enamel irradiated with a high power diode laser operating at 960 nm: morphological analysis of post-irradiation dental surface and thermal effect analysis in pulp chamber due to laser application; Estudo in vitro do esmalte dental irradiado com laser de diodo de alta potencia em 960 nm: analise morfologica da superficie dental pos-irradiada e analise do comportamento termico na camara pulpar devido a aplicacao laser

    Energy Technology Data Exchange (ETDEWEB)

    Quinto Junior, Jose

    2001-07-01

    Objectives: This study examines the structural and thermal modifications induced in dental enamel under dye assisted diode laser irradiation. The aim of this study is to verify if this laser-assisted treatment is capable to modify the enamel surface by causing fusion of the enamel surface layer. At the same time, the pulpal temperature rise must be kept low enough in order not to cause pulpar necrosis. To achieve this target, it is necessary to determine suitable laser parameters. As is known, fusion of the enamel surface followed by re-solidification produce a more acid resistant layer. This surface treatment is being researched as a new method for caries prevention. Method and Materials: A series of fourteen identically prepared enamel samples of human teeth were irradiated with a high power diode laser operating at 960 nm and using fiber delivery. Prior to irradiation, a fine layer of cromophorous ink was applied to the enamel surface. In the first part of the experiment the best parameter for pulse duration was determined. In the second part of the experimental phase the same energy density was used but with different repetition rates. During irradiation we monitored the temperature rise in the pulpal cavity. The morphology of the treated samples was analysed under SEM. Results: The morphology of the treated samples showed a homogeneously re-solidified enamel layer. The results of the temperature analysis showed a decrease of the pulpal temperature rise with decreasing repetition rate. Conclusion: With the diode laser it is possible to cause morphological alterations of the enamel surface, which is known to increase the enamel resistance against acid attack, and still maintain the temperature rise in the pulpar chamber below damage threshold. (author)

  7. ANTHRAQUINONE ADDITION IN THE ALKALINE PULPING OF Eucalyptus saligna

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Jerônimo

    2009-10-01

    Full Text Available The present work evaluated different alkaline pulping conditions for Eucalyptus saligna wood. The objective was to evaluate the influence of the anthraquinone (AQ on the reduction of the total reduced sulfur (TRS in the aerial emissions, by reducing the sulfidity. The experiment consisted of 8 cooking with active alkali varying from  19 to 21%, sulfidity from  0 to 20% and anthraquinone from 0 to 0.1%, aiming to obtain  kappa numbers in the range 15.5±1.5. The H factor was used to control the relation time/temperature along cooking. The addition of anthraquinone increased the delignification rate allowing sulfidity reduction. The kraft/AQ pulping with sulfidities of 5 and 10% presented satisfactory results, making it possible the replacement of conventional kraft cooking, giving a reduction in process sulfidity without harms in pulping. In spite of a slightly lower performance, the soda/AQ cooking has potential to be used where the smell is a critical problem in the industrial operation.

  8. The Low Temperature Chamber Testing of the Compression Ignition Engine and System of the Armoured Personnel Carrier (APC) M113A1.

    Science.gov (United States)

    1981-06-01

    shutdown. Before start up the hot oil would be pumped ( auxillary pump) back through the engine on the high pressure side of the engine’ s oil pump. This...insulation heating was applied. Temperature plots Figure 14* to Figure 16* show the battery cooling curves for auxillary heating when 37mm of medium

  9. Recruitment of dental pulp cells by dentine and pulp extracellular matrix components.

    Science.gov (United States)

    Smith, J G; Smith, A J; Shelton, R M; Cooper, P R

    2012-11-01

    The present study aimed to determine whether dentine tissue and preparations of extracellular matrix (ECM) from pulp (pECM) and dentine (dECM), and breakdown products, influenced pulp cell migration. Chemotaxis transwell and agarose spot assays demonstrated that both dentine and pulp ECM molecules acted as chemoattractants for primary pulp cells. Chemoattractant activities of dECM and pECM were enhanced when subjected to acid and enzymatic breakdown, respectively. This enhanced activity following physiologically relevant breakdown may be pertinent to the disease environment. Pulp cell migration in response to dental ECMs was dependent on an active rho pathway. Recruited cells exhibited increased stem cell marker expression indicating that dental ECMs and their breakdown products selectively attract progenitor cells that contribute to repair processes. In conclusion, combined these results indicate that ECM molecules contribute to cell recruitment necessary for regeneration of the dentine-pulp complex after injury. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Vital Pulp Therapy—Current Progress of Dental Pulp Regeneration and Revascularization

    Directory of Open Access Journals (Sweden)

    Weibo Zhang

    2010-01-01

    Full Text Available Pulp vitality is extremely important for the tooth viability, since it provides nutrition and acts as biosensor to detect pathogenic stimuli. In the dental clinic, most dental pulp infections are irreversible due to its anatomical position and organization. It is difficult for the body to eliminate the infection, which subsequently persists and worsens. The widely used strategy currently in the clinic is to partly or fully remove the contaminated pulp tissue, and fill and seal the void space with synthetic material. Over time, the pulpless tooth, now lacking proper blood supply and nervous system, becomes more vulnerable to injury. Recently, potential for successful pulp regeneration and revascularization therapies is increasing due to accumulated knowledge of stem cells, especially dental pulp stem cells. This paper will review current progress and feasible strategies for dental pulp regeneration and revascularization.

  11. Effect of cell phone radiofrequency radiation on body temperature in rodents: Pilot studies of the National Toxicology Program's reverberation chamber exposure system.

    Science.gov (United States)

    Wyde, Michael E; Horn, Thomas L; Capstick, Myles H; Ladbury, John M; Koepke, Galen; Wilson, Perry F; Kissling, Grace E; Stout, Matthew D; Kuster, Niels; Melnick, Ronald L; Gauger, James; Bucher, John R; McCormick, David L

    2018-04-01

    Radiofrequency radiation (RFR) causes heating, which can lead to detrimental biological effects. To characterize the effects of RFR exposure on body temperature in relation to animal size and pregnancy, a series of short-term toxicity studies was conducted in a unique RFR exposure system. Young and old B6C3F1 mice and young, old, and pregnant Harlan Sprague-Dawley rats were exposed to Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) RFR (rats = 900 MHz, mice = 1,900 MHz) at specific absorption rates (SARs) up to 12 W/kg for approximately 9 h a day for 5 days. In general, fewer and less severe increases in body temperature were observed in young than in older rats. SAR-dependent increases in subcutaneous body temperatures were observed at exposures ≥6 W/kg in both modulations. Exposures of  ≥10 W/kg GSM or CDMA RFR induced excessive increases in body temperature, leading to mortality. There was also a significant increase in the number of resorptions in pregnant rats at 12 W/kg GSM RFR. In mice, only sporadic increases in body temperature were observed regardless of sex or age when exposed to GSM or CDMA RFR up to 12 W/kg. These results identified SARs at which measurable RFR-mediated thermal effects occur, and were used in the selection of exposures for subsequent toxicology and carcinogenicity studies. Bioelectromagnetics. 39:190-199, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

  12. Effects of hot water pre-extraction on surface properties of bagasse soda pulp.

    Science.gov (United States)

    Cordeiro, Nereida; Ashori, Alireza; Hamzeh, Yahya; Faria, Marisa

    2013-03-01

    In this work, the effects of hot water pre-extraction of depithed bagasse on the soda pulping and surface properties were studied. The conditions of hot water pre-extraction were: maximum temperature 170 °C, heat-up time 90 min, time at maximum temperature 10 min, and solid to liquor ratio (S:L) 1:8. Consequently, the pre-extracted and un-extracted bagasse chips were subjected to soda pulping at 160 °C for 1h with 11, 14 and 17% active alkali charge and an S:L of 1:5. The results showed that the hot water pre-extraction increased bagasse surface texture porosity by hemicellulose degradation. Therefore, the delignification was faster for pulping of pre-extracted samples. At a certain charge of alkali, pre-extracted samples showed higher screened yield and lower Kappa number. For instance, at 17% alkali charge, pre-extracted bagasse gave 11.3% higher pulp yield compared with the un-extracted ones. Inverse gas chromatography (IGC) results showed that the hot water pre-extraction changed the active sites on the bagasse surface, decreasing the dispersive energy and the basicity character, and affected the particle morphology. The pulping process decreased the hydrophobicity and the basicity of the bagasse surface. The surfaces of un-extracted and pre-extracted bagasse pulps had similar properties but different morphology. The pulps present higher surface area and permeability with more reactive capacity. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Heat processing (HTST of umbu (Spondias tuberosa Arruda Câmara pulp

    Directory of Open Access Journals (Sweden)

    Emanuelle Araújo de Oliveira

    2011-12-01

    Full Text Available Umbu pulp is an important product in the economy of the northeastern region of Brazil, and its preservation can be ensured by heat treatment. A complete factorial design with 2 factors (time and temperature and 3 central points was used to verify the effect of the HTST process on the physicochemical, chemical, physical, microbiological, and sensory qualities of umbu pulps. The results showed that the heat treatments applied resulted in products without significant alterations on the physicochemical, chemical, and microbiological characteristics. With respect to color, the parameters L and a* were altered by increases in temperature indicating by darkening of color. The sensory evaluation indicated that a treatment of 88 °C for 10 seconds was the best processing condition due to the greater similarity of the resulting product to the reference sample (blanched pulp.

  14. Use of perborate in the bleaching of ethanolamine pulp from olive wood

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, E.; Torre, M.J. de la; Gutiérrez, J.C.

    2016-11-01

    In this work, we studied the influence of the bleacher concentration(2.5-5.5%), temperature (60-80 ºC) and time (60-180 min) on the reagent (perborate) consumption by dry pulp, various properties of the bleached pulp (yield, kappa number, brightness and viscosity/kappa numberratio), and some physical properties of paper sheets obtainedfrom it (tear index, burst index, stretch and breakinglength). The pulp was previously obtained by ethanolamine-soda-anthraquinone cooking of olive wood. A face-centred composite factor design was used to derive equations relating the pulp properties to the operational variables with a view to identifying the optimum operating conditions. The equations thus obtained reproduced the experimental results with errors less than 10% in all cases.The most suitable operating conditions were found to be alow temperature (60 ºC), a long time (180 min) and a highperborate concentration (5,5%). Because the pulp brightness achieved never exceeded 63% -not even under themost drastic conditions-, the process should not be used with one-step bleaching sequences. (Author)

  15. Use of perborate in the bleaching of ethanolamine pulp from olive wood

    International Nuclear Information System (INIS)

    Ramos, E.; Torre, M.J. de la; Gutiérrez, J.C.

    2016-01-01

    In this work, we studied the influence of the bleacher concentration(2.5-5.5%), temperature (60-80 ºC) and time (60-180 min) on the reagent (perborate) consumption by dry pulp, various properties of the bleached pulp (yield, kappa number, brightness and viscosity/kappa numberratio), and some physical properties of paper sheets obtainedfrom it (tear index, burst index, stretch and breakinglength). The pulp was previously obtained by ethanolamine-soda-anthraquinone cooking of olive wood. A face-centred composite factor design was used to derive equations relating the pulp properties to the operational variables with a view to identifying the optimum operating conditions. The equations thus obtained reproduced the experimental results with errors less than 10% in all cases.The most suitable operating conditions were found to be alow temperature (60 ºC), a long time (180 min) and a highperborate concentration (5,5%). Because the pulp brightness achieved never exceeded 63% -not even under themost drastic conditions-, the process should not be used with one-step bleaching sequences. (Author)

  16. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  17. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. 21 CFR 872.1720 - Pulp tester.

    Science.gov (United States)

    2010-04-01

    ... battery powered device intended to evaluate the pulpal vitality of teeth by employing high frequency current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b) Classification...

  19. Improvement of Swirl Chamber Structure of Swirl-Chamber Diesel Engine Based on Flow Field Characteristics

    Directory of Open Access Journals (Sweden)

    Wenhua Yuan

    2014-10-01

    Full Text Available In order to improve combustion characteristic of swirl chamber diesel engine, a simulation model about a traditional cylindrical flat-bottom swirl chamber turbulent combustion diesel engine was established within the timeframe of the piston motion from the bottom dead centre (BDC to the top dead centre (TDC with the fluent dynamic mesh technique and flow field vector of gas in swirl chamber and cylinder; the pressure variation and temperature variation were obtained and a new type of swirl chamber structure was proposed. The results reveal that the piston will move from BDC; air in the cylinder is compressed into the swirl chamber by the piston to develop a swirl inside the chamber, with the ongoing of compression; the pressure and temperature are also rising gradually. Under this condition, the demand of diesel oil mixing and combusting will be better satisfied. Moreover, the new structure will no longer forma small fluid retention zone at the lower end outside the chamber and will be more beneficial to the mixing of fuel oil and air, which has presented a new idea and theoretical foundation for the design and optimization of swirl chamber structure and is thus of good significance of guiding in this regard.

  20. Clean production of corn stover pulp using KOH+NH4OH solution and its kinetic during delignification

    OpenAIRE

    Sun Yong; Yang Gang; Zhang Jin-Ping; Yao Ming-Shun

    2012-01-01

    The self-made KOH together with NH4OH pulping of corn stover was investigated. The combined alkaline system could effectively remove lignin during pulping. There are three stages of lignin removal during delginification. Approximately 90% of lignin could be removed after temperature reached 150ºC for over 30 minutes. The p-hydroxyl phenol groups in lignin could be completely removed during the delignification reaction. The tendency of the increase of the crystalline degree of cellulose ...

  1. Three-dimensional analysis of the pulp cavity on surface models of molar teeth, using X-ray micro-computed tomography

    DEFF Research Database (Denmark)

    Markvart, Merete; Bjørndal, Lars; Darvann, Tron Andre

    2012-01-01

    . In summary, three-dimensional surface models were made with a high precision; an increased accumulation of mineral deposits was noted in molars with small pulp chambers and combined with the consistent pattern of intra-radicular connections, the potential endodontic treatment complexity is underlined...

  2. Acoustic-Levitation Chamber

    Science.gov (United States)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  3. Optical spark chamber

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    An optical spark chamber developed for use in the Omega spectrometer. On the left the supporting frame is exceptionally thin to allow low momentum particles to escape and be detected outside the magnetic field.

  4. Vacuum chamber 'bicone'

    CERN Multimedia

    1977-01-01

    This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

  5. Miniature ionization chamber

    International Nuclear Information System (INIS)

    Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

    1976-01-01

    A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

  6. Reference ionization chamber

    International Nuclear Information System (INIS)

    Golnik, N.; Zielczynski, M.

    1999-01-01

    The paper presents the design of ionization chamber devoted for the determination of the absolute value of the absorbed dose in tissue-equivalent material. The special attention was paid to ensure that the volume of the active gas cavity was constant and well known. A specific property of the chamber design is that the voltage insulators are 'invisible' from any point of the active volume. Such configuration ensures a very good time stability of the electrical field and defines the active volume. The active volume of the chamber was determined with accuracy of 0.3%. This resulted in accuracy of 0.8% in determination of the absorbed dose in the layer of material adherent to the gas cavity. The chamber was applied for calibration purposes at radiotherapy facility in Joint Institute for Nuclear Research in Dubna (Russia) and in the calibration laboratory of the Institute of Atomic Energy in Swierk. (author)

  7. Gridded ionization chamber

    International Nuclear Information System (INIS)

    Houston, J.M.

    1977-01-01

    An improved ionization chamber type x-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is disposed adjacent the anode and is maintained at a voltsge intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting toward the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  8. ALICE Time Projection Chamber

    CERN Multimedia

    Lippmann, C

    2013-01-01

    The Time Projection Chamber (TPC) is the main device in the ALICE 'central barrel' for the tracking and identification (PID) of charged particles. It has to cope with unprecedented densities of charges particles.

  9. Gridded Ionization Chamber

    International Nuclear Information System (INIS)

    Manero Amoros, F.

    1962-01-01

    In the present paper the working principles of a gridded ionization chamber are given, and all the different factors that determine its resolution power are analyzed in detail. One of these devices, built in the Physics Division of the JEN and designed specially for use in measurements of alpha spectroscopy, is described. finally the main applications, in which the chamber can be used, are shown. (Author) 17 refs

  10. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  11. The influence of substrate temperature and spraying distance on the properties of plasma sprayed tungsten and steel coatings deposited in a shrouding chamber

    Czech Academy of Sciences Publication Activity Database

    Matějíček, Jiří; Vilémová, Monika; Nevrlá, Barbara; Kocmanová, Lenka; Veverka, Jakub; Halasová, Martina; Hadraba, Hynek

    2017-01-01

    Roč. 318, May (2017), s. 217-223 ISSN 0257-8972. [International Meeting on Thermal Spraying (RIPT)/7./. Limoges, 09.12.2015-11.12.2015] R&D Projects: GA ČR GB14-36566G EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 ; RVO:68081723 Keywords : Tungsten * Steel * Atmospheric plasma spraying * Shrouding * Substrate temperature * Fusion reactor materials * Plasma facing components Subject RIV: JK - Corrosion ; Surface Treatment of Materials; JK - Corrosion ; Surface Treatment of Materials (UFM-A) OBOR OECD: Coating and films; Coating and films (UFM-A) Impact factor: 2.589, year: 2016 http://www.sciencedirect.com/science/ article /pii/S0257897216310520

  12. A novel role for Twist-1 in pulp homeostasis.

    Science.gov (United States)

    Galler, K M; Yasue, A; Cavender, A C; Bialek, P; Karsenty, G; D'Souza, R N

    2007-10-01

    The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/-) mice revealed phenotypic changes that involved an earlier onset of dentin matrix formation, increased alkaline phosphatase activity, and pulp stones within the pulp. RT-PCR analyses revealed Twist-1 expression in several adult organs, including pulp. Decreased levels of Twist-1 led to higher levels of type I collagen and Dspp gene expression in perivascular cells associated with the pulp stones. In mice heterozygous for both Twist-1 and Runx2 inactivation, the phenotype of pulp stones appeared completely rescued. These findings suggest that Twist-1 plays a key role in restraining odontoblast differentiation, thus maintaining homeostasis in dental pulp. Furthermore, Twist-1 functions in dental pulp are dependent on its interaction with Runx2.

  13. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  14. Hydrothermal carbonization of autoclaved municipal solid waste pulp and anaerobically treated pulp digestate

    Science.gov (United States)

    In this study, the autoclaved organic fraction of municipal solid waste pulp (OFMSW) and the digestate from OFMSW pulp after anaerobic digestion (AD) were processed by hydrothermal carbonization (HTC) at 200, 250, and 300 °C for 30 min and 2 h. The focus of this work was to evaluate the potential fo...

  15. Extracellular matrix of dental pulp stem cells: Applications in pulp tissue engineering using somatic MSCs

    Directory of Open Access Journals (Sweden)

    Sriram eRavindran

    2014-01-01

    Full Text Available Dental Caries affects approximately 90% of the world’s population. At present, the clinical treatment for dental caries is root canal therapy. This treatment results in loss of tooth sensitivity and vitality. Tissue engineering can potentially solve this problem by enabling regeneration of a functional pulp tissue. Dental pulp stem cells (DPSCs have been shown to be an excellent source for pulp regeneration. However, limited availability of these cells hinders its potential for clinical translation. We have investigated the possibility of using somatic mesenchymal stem cells from other sources for dental pulp tissue regeneration using a biomimetic dental pulp extracellular matrix (ECM incorporated scaffold. Human periodontal ligament stem cells (PDLSCs and human bone marrow stromal cells (HMSCs were investigated for their ability to differentiate towards an odontogenic lineage. In vitro real-time PCR results coupled with histological and immunohistochemical examination of the explanted tissues confirmed the ability of PDLSCs and HMSCs to form a vascularized pulp-like tissue. These findings indicate that the dental pulp stem derived ECM scaffold stimulated odontogenic differentiation of PDLSCs and HMSCs without the need for exogenous addition of growth and differentiation factors. This study represents a translational perspective toward possible therapeutic application of using a combination of somatic stem cells and extracellular matrix for pulp regeneration.

  16. EVALUATION OF LINERBOARD PROPERTIES FROM MALAYSIAN CULTIVATED KENAF SODA-ANTHRAQUINONE PULPS VERSUS COMMERCIAL PULPS

    Directory of Open Access Journals (Sweden)

    Ahmad Azizi Mossello

    2010-06-01

    Full Text Available Malaysian cultivated kenaf has been identified as a suitable raw material for linerboard production. This study examines the soda-antraquinone (soda-AQ pulp of kenaf fibers versus old corrugated container (OCC and unbleached softwood kraft pulps as the main sources for linerboard production. The results showed significant differences among the pulp properties. The unbleached kraft pulp with very high freeness required high beating to reach an optimized freeness and produced paper with the highest strength properties, except for tear resistance. The OCC gave paper with the lowest strength properties. In the case of kenaf fractions, bast pulp with high freeness needed less beating than softwood and produced paper with high tear resistance. Core fiber, which had the lowest freeness and highest drainage time, led to paper with high strength but very low tear resistance. Kenaf whole stem pulp showed intermediate properties between core and bast and close to those of unbleached softwood pulp, but with very lower beating requirement. Finally, kenaf whole stem, due to its strength properties, moderate separation cost, and simple pulping process, was judged to be more suitable for commercialization for linerboard production in Malaysia.

  17. Design of an ionization diffusion chamber detector

    International Nuclear Information System (INIS)

    Sugiarto, S.

    1976-01-01

    Prototype of an Ionization Diffusion Chamber detector has been made. It is a silindrical glass, 20 cm in diameter, 13,5 cm in height, air gas filled, operated at room pressure and room temperature at the top of this instrument while for the box temperature dry ice (CO 2 solid) temperature is used. This detector is ready for seeing alpha and beta particle tracks. (author)

  18. Bioceramic/Poly (glycolic-poly (lactic acid composite induces mineralized barrier after direct capping of rat tooth pulp tissue

    Directory of Open Access Journals (Sweden)

    Alfonso Gala-Garcia

    2010-03-01

    Full Text Available The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC and poly (glycolic-poly (lactic acid (PLGA material or a calcium hydroxide [Ca(OH2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.

  19. Efficacy of soil solarization, Trichoderma harzianum, and coffee pulp amendment against Armillaria sp

    NARCIS (Netherlands)

    Otieno, W.; Termorshuizen, A.J.; Jeger, M.J.

    2003-01-01

    Soil solarization was evaluated singly or in combination with Trichoderma harzianum infestation or coffee pulp amendment for its effect on wood-borne inoculum of an Armillaria sp. pathogenic on tea. Solarization increased maximum soil temperatures at 10 cm depth by 9-12degreesC and reduced viability

  20. Kinetics of Strong Acid Hydrolysis of a Bleached Kraft Pulp for Producing Cellulose Nanocrystals (CNCs)

    Science.gov (United States)

    Qianqian Wang; Xuebing Zhao; J.Y. Zhu

    2014-01-01

    Cellulose nanocrytals (CNCs) are predominantly produced using the traditional strong acid hydrolysis process. In most reported studies, the typical CNC yield is low (approximately 30%) despite process optimization. This study investigated the hydrolysis of a bleached kraft eucalyptus pulp using sulfuric acid between 50 and 64 wt % at temperatures of 35−80 °C...

  1. REPLACEMENT OF SOFTWOOD KRAFT PULP WITH ECF-BLEACHED BAMBOO KRAFT PULP IN FINE PAPER

    Directory of Open Access Journals (Sweden)

    Guanglei Zhao

    2010-06-01

    Full Text Available Non-wood fibers such as bamboo and wheat straw have been playing important roles in the pulp and paper industry in China. In this study an ECF-bleached bamboo kraft pulp was compared with a bleached softwood kraft pulp (NBSK as the reinforcement pulp in fine paper production. Areas that were examined include the refining of pure fibers, influence of bamboo on dewatering, retention, and sizing. The influence of bamboo kraft pulp as a part of a furnish replacing NBSK was compared as well. Results show that fiber shortening was more prominent with bamboo when refined. This resulted in a higher amount of fines, and addition wet-end chemicals may be required to compensate. Handsheets with bamboo as a reinforcement fiber showed similar mechanical and optical properties to handsheets containing NBSK.

  2. Extraction and Characterization of Nanocellulose Structures from Linter Dissolving Pulp Using Ultrafine Grinder.

    Science.gov (United States)

    Ghasemi, Somayeh; Behrooz, Rabi; Ghasemi, Ismail

    2016-06-01

    The objective of this study was to extract cellulose nanofibrils (CNFs) from Linter dissolving pulp through a simple and environmentally friendly physical method of refining pretreatment coupled with ultrafine grinder. The morphology, structure and properties of the Linter pulp and obtained NFCs were investigated using Optical Microscopy (OM), electron microscopy (SEM), Atomic Force Microscopy (AFM), Fourier transformed infrared (FTIR) spectra, X-ray diffraction (XRD) and Thermogravimetric (TG) analysis. The OM results indicate that, the Linter Pulp had length and wide mainly ranged 1.3 mm and 13 μm respectively. Based on AFM images, most of extracted nanocellulose had spherical shape and the average of nanocellulose diameter was varied between 30-70 nm when measured by AFM and SEM. Also the FTIR spectra confirmed that the basic structure of nanocellulose was maintained and no derivative was formed. The X-ray results show that by this method of extraction, the crystallinity index of Nanocellulose isolated (62%) decreased in compared to Linter Pulp (79.5%). Also Linter pulp decomposes at higher temperature (280 degrees C) than isolated nanocellulose (240 degrees C).

  3. [Correlation between PMI and DNA degradation of costicartilage and dental pulp cells in human being].

    Science.gov (United States)

    Long, Ren; Wang, Wei-ping; Xiong, Ping

    2005-08-01

    To probe the correlation between the postmortem interval (PMI) and the DNA degradation of costicartilage and dental pulp cells in human being after death, and to seek a new method for estimating PMI. The image cytometry was used to measure the DNA degradation under different ambient temperatures (30-35 degrees C, 15-20 degrees C) in 0-15 days after death. The average DNA content of two kinds of tissue was degradated with the prolongation of PMI. But there was a plateau period of 0-4 days for dental pulp cells of human being in 15-20 degrees C. There was a high negative correlativity PPMI. PMI could be estimated accurately according to the DNA degradation of costicartilage and dental pulp cells in human being after death.

  4. Effects of some extrusion variables on physicochemical characteristics of extruded corn starch-passion fruit pulp (Passiflora edulis) snacks.

    Science.gov (United States)

    Cortés, R Nallely Falfán; Guzmán, Iñigo Verdalet; Martínez-Bustos, Fernando

    2014-12-01

    The aim of this work was to study the effect of the addition of passion fruit pulp (PFP: 0-7%), the variation of barrel temperature in the third zone extruder (BT: 80-140 °C) and feed moisture (FM:16-30%) in a blend of corn starch and passion fruit pulp on different physicochemical characteristics of directly expanded snacks by extrusion technology. Single-screw laboratory extruder and a central, composite, rotatable experimental design were used. Expansion index of extrudates ranged between 1.0 and 1.8. Decreasing of feed moisture (18%), passion fruit pulp concentration (1.42%) and the increasing of barrel temperature (127 °C) resulted in higher expansion index. The increasing of feed moisture and passion fruit pulp concentration resulted in higher penetration force values of extrudates. The passion fruit pulp concentration showed a highly significant effect (p ≤ 0.01) on the L *, a * and b * parameters. Passion fruit pulp has a reasonable source of β-carotene, proteins and dietary fibers that can be added to expanded snacks.

  5. Swelling and hydrolysis kinetics of Kraft pulp fibers in aqueous 1-butyl-3-methylimidazolium hydrogen sulfate solutions.

    Science.gov (United States)

    Mao, Jia; Abushammala, Hatem; Pereira, Laura Barcellos; Laborie, Marie-Pierre

    2016-11-20

    1Butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) is efficient at extracting cellulose nanocrystals from pulp fibers. To shed some light on the respective contributions of swelling and hydrolysis of pulp fibers by [Bmim]HSO4, the physical, structural and morphological characteristics of hardwood Kraft pulp fibers were monitored under various conditions of temperature, water content and time. Swelling was largely compounded by hydrolysis at the highest temperatures (120°C) as evidenced by mass loss and reduced degree of polymerization (DPn) at this temperature. At 120°C only, water content appeared to play a significant role on the extent of hydrolysis. At this temperature, a heterogeneous kinetic model involving weak links and amorphous regions best described the experimental data. Hydrolysis rates were maximum at 25% water content in the aqueous ionic liquid. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Wire chambers: Trends and alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Regler, Meinhard

    1992-05-15

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

  7. Dental pulp stem cells in regenerative dentistry.

    Science.gov (United States)

    Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

    2011-01-01

    Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

  8. Epigenetic regulation in dental pulp inflammation

    Science.gov (United States)

    Hui, T; Wang, C; Chen, D; Zheng, L; Huang, D; Ye, L

    2016-01-01

    Dental caries, trauma, and other possible factors could lead to injury of the dental pulp. Dental infection could result in immune and inflammatory responses mediated by molecular and cellular events and tissue breakdown. The inflammatory response of dental pulp could be regulated by genetic and epigenetic events. Epigenetic modifications play a fundamental role in gene expression. The epigenetic events might play critical roles in the inflammatory process of dental pulp injury. Major epigenetic events include methylation and acetylation of histones and regulatory factors, DNA methylation, and small non-coding RNAs. Infections and other environmental factors have profound effects on epigenetic modifications and trigger diseases. Despite growing evidences of literatures addressing the role of epigenetics in the field of medicine and biology, very little is known about the epigenetic pathways involved in dental pulp inflammation. This review summarized the current knowledge about epigenetic mechanisms during dental pulp inflammation. Progress in studies of epigenetic alterations during inflammatory response would provide opportunities for the development of efficient medications of epigenetic therapy for pulpitis. PMID:26901577

  9. BLEACHING EUCALYPTUS PULPS WITH SHORT SEQUENCES

    Directory of Open Access Journals (Sweden)

    Flaviana Reis Milagres

    2011-03-01

    Full Text Available Eucalyptus spp kraft pulp, due to its high content of hexenuronic acids, is quite easy to bleach. Therefore, investigations have been made attempting to decrease the number of stages in the bleaching process in order to minimize capital costs. This study focused on the evaluation of short ECF (Elemental Chlorine Free and TCF (Totally Chlorine Free sequences for bleaching oxygen delignified Eucalyptus spp kraft pulp to 90% ISO brightness: PMoDP (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide, PMoD/P (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide, without washing PMoD(PO (Molybdenum catalyzed acid peroxide, chlorine dioxide and pressurized peroxide, D(EPODP (chlorine dioxide, extraction oxidative with oxygen and peroxide, chlorine dioxide and hydrogen peroxide, PMoQ(PO (Molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide, and XPMoQ(PO (Enzyme, molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide. Uncommon pulp treatments, such as molybdenum catalyzed acid peroxide (PMo and xylanase (X bleaching stages, were used. Among the ECF alternatives, the two-stage PMoD/P sequence proved highly cost-effective without affecting pulp quality in relation to the traditional D(EPODP sequence and produced better quality effluent in relation to the reference. However, a four stage sequence, XPMoQ(PO, was required to achieve full brightness using the TCF technology. This sequence was highly cost-effective although it only produced pulp of acceptable quality.

  10. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  11. SUSTAINABLE PAPER - Biotechnical modification of mechanical pulp. Final report; KESTAeVAe PAPERI - Mekaanisen massan biotekninen muokkaus. Loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    Pere, J.; Liukkonen, S.; Gullichsen, J.; Viikari, L.

    1997-12-31

    -stage secondary refining of TMP reject, energy savings of 10-15 % as compared with the reference were attained with CBH I and no deterioration of pulp quality was detected. White water from a GW and a TMP plant did not have any acute inhibitory effect on the activity of CBH I. CBH I maintained its hydrolytic activity for a couple of hours at 65 deg C, which is rather close to the temperatures (70-75 deg C) of circulating waters prevailing at the mills. Re-use of the enzyme solution (CBH I) was possible and so circulation of the enzyme solution could be one alternative to improve the economy of the enzymatic method. (orig.)

  12. Climate chamber for environmentally controlled laboratory airflow experiments.

    Science.gov (United States)

    Even-Tzur, Nurit; Zaretsky, Uri; Grinberg, Orly; Davidovich, Tomer; Kloog, Yoel; Wolf, Michael; Elad, David

    2010-01-01

    Climate chambers have been widely used in in vitro and in vivo studies which require controlled environmental temperature and humidity conditions. This article describes a new desktop climate chamber that was developed for application of respiratory airflows on cultured nasal epithelial cells (NEC) under controlled temperature and humidity conditions. Flow experiments were performed by connecting the climate chamber to an airflow generator via a flow chamber with cultured NEC. Experiments at two controlled climate conditions, 25 degrees C and 40% relative humidity (RH) and 37 degrees C and 80%RH, were conducted to study mucin secretion from the cultures inresponse to the flow. The new climate chamber is a relatively simple and inexpensive apparatus which can easily be connected to any flow system for climate controlled flow experiments. This chamber can be easily adjusted to various in vitro experiments, as well as to clinical studies with animals or human subjects which require controlled climate conditions.

  13. Coronal pulp biomarker: A lesser known age estimation modality

    Directory of Open Access Journals (Sweden)

    Smrithi D Veera

    2014-01-01

    Full Text Available Introduction: The evolving state of art digital technology currently available is opening new avenues in forensic odontology for age estimation methods which are subject to debate in terms of accuracy and precision. A study was carried to analyze efficacy and practical application for age estimation using digital panoramic radiographs on South Indian population. Aims and Objectives: 1. To study reduction of coronal pulp chamber using Tooth Coronal Index (TCI on panoramic radiographs and correlate with chronologic age. 2. To establish accuracy of digital panoramic radiographs as a simple, non-invasive tool. Materials and Methods: The study illustrates the potential value of a little known aging method. The study groups comprised a total of 100 subjects of both sexes in age range of 20 and 60 years each who were subjected to panoramic radiography. A panoramic radiographic examination using digital panoramic machine was conducted on selected individuals. The TCI was calibrated using AGFA computer software for accuracy and precision. The values obtained were subjected to regression analysis, results calculated and correlated with chronologic age. In the present study a population of known age was studied and subjected to digital panoramic radiographic examination. The correlation between reduction of coronal pulp cavity and chronological age was examined. TCI was computed for each tooth and regressed on real age. Statistical Analysis Used: Pearson correlation co-efficient was used to find the significance of relationship between age and TCI. Regression analysis has been used for predicting age using TCI for premolar and molar. Inaccuracy and bias have been determined to assess the precision of prediction equations. Results and Conclusion: Prediction potential of TCI comes down for ages above 50 years and is comfortably good below 50 years without much difference between premolars and molars. This study demonstrates the potential value of TCI for age

  14. Radon diffusion chamber

    International Nuclear Information System (INIS)

    Pretzsch, G.; Boerner, E.; Lehmann, R.; Sarenio, O.

    1986-01-01

    The invention relates to the detection of radioactive gases emitting alpha particles like radon, thoron and their alpha-decaying daughters by means of a diffusion chamber with a passive detector, preferably with a solid state track detector. In the chamber above and towards the detector there is a single metallized electret with negative polarity. The distance between electret and detector corresponds to the range of the alpha particles of radon daughters in air at the most. The electret collects the positively charged daughters and functions as surface source. The electret increases the sensitivity by the factor 4

  15. The Honeycomb Strip Chamber

    International Nuclear Information System (INIS)

    Graaf, Harry van der; Buskens, Joop; Rewiersma, Paul; Koenig, Adriaan; Wijnen, Thei

    1991-06-01

    The Honeycomb Strip Chamber (HSC) is a new position sensitive detector. It consists of a stack of folded foils, forming a rigid honeycomb structure. In the centre of each hexagonal cell a wire is strung. Conducting strips on the foils, perpendicular to the wires, pick up the induced avalanche charge. Test results of a prototype show that processing the signals form three adjacent strips nearest to the track gives a spatial resolution better than 64 μm for perpendicular incident tracks. The chamber performance is only slightly affected by a magnetic field. (author). 25 refs.; 21 figs

  16. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1982-01-01

    An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector

  17. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  19. Integrating black liquor gasification with pulping - Process simulation, economics and potential benefits

    Science.gov (United States)

    Lindstrom, Erik Vilhelm Mathias

    Gasification of black liquor could drastically increase the flexibility and improve the profit potential of a mature industry. The completed work was focused on research around the economics and benefits of its implementation, utilizing laboratory pulping experiments and process simulation. The separation of sodium and sulfur achieved through gasification of recovered black liquor, can be utilized in processes like modified continuous cooking, split sulfidity and green liquor pretreatment pulping, and polysulfide-anthraquinone pulping, to improve pulp yield and properties. Laboratory pulping protocols have been developed for these modified pulping technologies and different process options evaluated. The process simulation work around BLG has led to the development of a WinGEMS module for the low temperature MTCI steam reforming process, and case studies comparing a simulated conventional kraft process to different process options built around the implementation of a BLG unit operation into the kraft recovery cycle. Pulp yield increases of 1-3% points with improved product quality, and the potential for capital and operating cost savings relative to the conventional kraft process have been demonstrated. Process simulation work has shown that the net variable operating cost for a pulping process using BLGCC is highly dependent on the cost of lime kiln fuel and the selling price of green power to the grid. Under the assumptions taken in the performed case study, the BLGCC process combined with split sulfidity or PSAQ pulping operations had net variable operating cost 2-4% greater than the kraft reference. The influence of the sales price of power to the grid is the most significant cost factor. If a sales price increase to 6 ¢/KWh for green power could be achieved, cost savings of about $40/ODtP could be realized in all investigated BLG processes. Other alternatives to improve the process economics around BLG would be to modify or eliminate the lime kiln unit

  20. Enzymatic pulp upgrade for producing high-value cellulose out of a Kraft paper pulp.

    Science.gov (United States)

    Hutterer, Christian; Kliba, Gerhard; Punz, Manuel; Fackler, Karin; Potthast, Antje

    2017-07-01

    The high-yield separation of polymeric parts from wood-derived lignocellulosic material is indispensable in biorefinery concepts. For the separation of cellulose and xylan from hardwood paper pulps to obtain pulps of high cellulose contents, simple alkaline extractions were found to be the most suitable technology, although having certain limitations. These are embodied by residual alkali resistant xylan incorporated in the pulp matrix. Further purification in order to produce pure cellulose with a low uniformity could be achieved selectively degrading residual xylan and depolymerizing the cellulose macromolecules by xylanase and cellulase. The latter help to adjust cellulose chain lengths for certain dissolving pulp grades while reducing the demand for ozone in subsequent TCF bleaching. Experiments applying different commercially available enzyme preparations revealed the dependency of xylanase performance on the residual xylan content in pulps being stimulated by additional cellulase usage. The action of the latter strongly depends on the cellulose allomorphy confirming the impact of the pulp morphology. Hence, the combined application of both types of enzymes offers a high potential for upgrading pulps in order to produce a pure and high-value cellulose product. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Innervated boomerang flap for finger pulp reconstruction.

    Science.gov (United States)

    Chen, Shao-Liang; Chiou, Tai-Fung

    2007-11-01

    The boomerang flap originates from the dorsolateral aspect of the proximal phalanx of an adjacent digit and is supplied by the retrograde blood flow through the vascular arcades between the dorsal and palmar digital arteries. To provide sensation of the boomerang flap for finger pulp reconstruction, the dorsal sensory branch of the proper digital nerve and the superficial sensory branch of the corresponding radial or ulnar nerve are included within the skin flap. After transfer of the flap to the injured site, epineural neurorrhaphies are done between the digital nerves of the pulp and the sensory branches of the flap. We used this sensory flap in five patients, with more than 1 year follow-up, and all patients achieved measurable two-points discrimination. The boomerang flap not only preserves the proper palmar digital artery but also provides an extended and innervated skin paddle. It seems to be an alternative choice for one-stage reconstruction of major pulp defect.

  2. Integrated chemical plants at the pulp mill

    Energy Technology Data Exchange (ETDEWEB)

    Ehtonen, P.; Hurme, M.; Jaervelaeinen, M.

    1995-12-31

    The goal of this paper is to present how the chemical plants can be integrated to the pulp mill. The integration renders possible to balance the chemical consumptions. The total mass balance of a pulp mill with the incoming fuel material and the outgoing waste and flue gases are discussed. The balance figures are presented for the chemicals of the modern fibre line, which will produce fully bleached softwood pulp with an improved effluent quality. The main benefits are lower chemical and transportation costs. The principal over-all plant process block diagrams and process descriptions are presented. The presented info system provides real time information on process and production status at overall mill and department levels. (author)

  3. Sisal organosolv pulp as reinforcement for cement based composites

    OpenAIRE

    Joaquim, Ana Paula; Tonoli, Gustavo Henrique Denzin; Santos, Sérgio Francisco Dos; Savastano Junior, Holmer

    2009-01-01

    The present work describes non-conventional sisal (Agave sisalana) chemical (organosolv) pulp from residues of cordage as reinforcement to cement based materials. Sisal organosolv pulp was produced in a 1:1 ethanol/water mixture and post chemically and physically characterized in order to compare its properties with sisal kraft pulp. Cement based composites reinforced with organosolv or kraft pulps and combined with polypropylene (PP) fibres were produced by the slurry de-watering and pressin...

  4. Is Climate Simulation in Growth Chambers Necessary?

    Science.gov (United States)

    Z.M. Wang; K.H. Johnsen; M.J. Lechowicz

    1999-01-01

    In the expression of their genetic potential as phenotypes, trees respond to environmental cues such as photoperiod, temperature and soil and atmospheric water. However, growth chamber experiments often utilize simple and standard environmental conditions that might not provide these important environmental signals. We conducted a study to compare seedling growth in...

  5. 40 CFR 92.110 - Weighing chamber and micro-balance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Weighing chamber and micro-balance. 92... Weighing chamber and micro-balance. (a) Ambient conditions—(1) Temperature. The temperature of the chamber... shall be 45±8 percent during all filter conditioning and weighing. The dew point shall be 6.4 to 12.4 °C...

  6. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  7. Heavy liquid bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  8. The KLOE drift chamber

    International Nuclear Information System (INIS)

    Ferrari, A.

    2002-01-01

    The design and construction of the large drift chamber of the KLOE experiment is presented. The track reconstruction is described, together with the calibration method and the monitoring systems. The stability of operation and the performance are studied with samples of e + e - , K S K L and K + K - events

  9. Drift chamber detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez Laso, L.

    1989-01-01

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  10. Drift Chambers detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez laso, L.

    1989-01-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs

  11. OPAL Muon Chamber

    CERN Multimedia

    OPAL was one of the 4 experiments installed at the LEP particle accelerator from 1989 to 2000. This is a slice of the outermost layer of OPAL : the muon chambers. This outside layer detects particles which are not stopped by the previous layers. These are mostly muons.

  12. Improvements in ionization chambers

    International Nuclear Information System (INIS)

    Whetten, N.R.; Zubal, C.

    1980-01-01

    A method of reducing mechanical vibrations transmitted to the parallel plate electrodes of ionization chamber x-ray detectors, commonly used in computerized x-ray axial tomography systems, is described. The metal plate cathodes and anodes are mounted in the ionizable gas on dielectric sheet insulators consisting of a composite of silicone resin and glass fibres. (UK)

  13. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  14. MISSING: BUBBLE CHAMBER LENS

    CERN Multimedia

    2001-01-01

    Would the person who borrowed the large bubble chamber lens from the Microcosm workshops on the ISR please return it. This is a much used piece from our object archives. If anybody has any information about the whereabouts of this object, please contact Emma.Sanders@cern.ch Thank you

  15. Ion chamber instrument

    International Nuclear Information System (INIS)

    Stephan, D.H.

    1975-01-01

    An electrical ionization chamber is described having a self-supporting wall of cellular material which is of uniform areal density and formed of material, such as foamed polystyrene, having an average effective atomic number between about 4 and about 9, and easily replaceable when on the instrument. (auth)

  16. Review of straw chambers

    International Nuclear Information System (INIS)

    Toki, W.H.

    1990-03-01

    This is a review of straw chambers used in the HRS, MAC, Mark III, CLEO, AMY, and TPC e + e - experiments. The straws are 6--8 mm in diameter, operate at 1--4 atmospheres and obtain resolutions of 45--100 microns. The designs and constructions are summarized and possible improvements discussed

  17. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  18. Wire chamber conference

    International Nuclear Information System (INIS)

    Bartl, W.; Neuhofer, G.; Regler, M.

    1986-02-01

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  19. Arundo donax L. reed: new perspectives for pulping and bleaching. Part 4. Peroxide bleaching of organosolv pulps.

    Science.gov (United States)

    Shatalov, A A; Pereira, H

    2005-05-01

    A comparative study on TCF (totally chlorine-free) bleachability of organosolv pulps from the annual fibre crop Arundo donax L. (giant reed) was carried out using a simple three-stage peroxide bleaching sequence without oxygen pre-bleaching. ASAM (alkali-sulfite-anthraquinone-methanol), Organocell (alkali-anthraquinone-methanol) and ethanol-soda organosolv pulps were bleached and compared with kraft pulp, as a reference. The final brightness of 76-78% ISO was attained for all tested pulps. The chemical charge required to reach this level of brightness varied for different pulps (despite the equal initial content of the residual lignin) and directly related to starting brightness values. No direct correlation between brightness improvement and lignin removal during bleaching was found, indicating the influence of the specific pulp properties introduced by pulping process on bleaching chemistry. The general higher bleaching response of organosolv pulps from A. donax was noted in comparison with kraft.

  20. Effects of transportation time after extraction on the magnetic cryopreservation of pulp cells of rat dental pulp

    Directory of Open Access Journals (Sweden)

    Mao-Suan Huang

    2011-03-01

    Conclusions: The freezing technique used in this animal study provided positive effects on pulp cell storage. In addition, the storage time before the freezing procedure is an important issue for cryopreserving pulp cells in intact teeth.

  1. Ranking mechanical pulps for their potential to photoyellow

    Science.gov (United States)

    Umesh P. Agarwal

    2000-01-01

    Recently found experimental evidence has provided strong support for an alternative photoyellowing mechanism that suggests that pulp- photoyellowing occurs due to direct photooxidation of hydroquinones (present in mechanical pulps) top-quinones. Because hydroquinones were found to be present in pulps, it may be possible to quantify them. Quantification of mechanical-...

  2. 78 FR 31315 - Kraft Pulp Mills NSPS Review

    Science.gov (United States)

    2013-05-23

    ... Kraft Pulp Mills NSPS Review; Proposed Rule #0;#0;Federal Register / Vol. 78 , No. 100 / Thursday, May...-OAR-2012-0640; FRL-9815-9] RIN 2060-AR64 Kraft Pulp Mills NSPS Review AGENCY: Environmental Protection... performance standards for kraft pulp mills. These revised standards include particulate matter emission limits...

  3. Comparative study of percentage yield of pulp from various Nigerian ...

    African Journals Online (AJOL)

    user

    also other applications like in the chemical industry. (Biermann, 1993). Therefore pulp is a very .... digester was maintained at an operating condition of. 170°C, pressure of 2 bars, with liquor to wood ratio of 4:1. Cooking ... The effects of different concentrations of pulping liquor on the yield of pulp from the wood species are ...

  4. Organosolv pulping and test paper characterization of fiber hemp

    NARCIS (Netherlands)

    Zomers, F.H.A.; Gosselink, R.J.A.; Dam, van J.E.G.; Tjeerdsma, B.F.

    1995-01-01

    The autocatalyzed ethanol pulping of hemp to produce chemical-grade pulp was examined. Batch delignification conditions were developed for hemp core, hemp bast, and hemp whole stem. Although successful pulping of both hemp core and bast fibre is possible, further research is necessary.

  5. Betatron activation analysis of cupriferous flotation pulp

    International Nuclear Information System (INIS)

    Kaminski, R.; Matenko, J.; Mencel, J.; Janiczek, J.; Kielsznia, J.

    1974-01-01

    A method of copper determination in cupriferous flotation pulp by photo-activation analysis using betatron and another equipments of existent ''analytical line'' intended for copper determination in dry samples has been described. An activation has been achieved with 14.9 MeV γ-photons. The excitation activity was investigated by using two scintillation detectors and a fast coincidence circuit with resolution time 80 ns. The precision of method was determined as +- 4.25% in 0.95 confidence level for pulp with concentration 5% Cu and +- 24% for 0.06% Cu. (author)

  6. Cold Weather Test Method Research of High Pressure Steering Oil Hose Based on Temperature Compensation in Environmental Chamber%基于环境舱温度补偿的转向高压油管冬季试验方法研究

    Institute of Scientific and Technical Information of China (English)

    范韬; 王晖; 武文超; 王海沛

    2015-01-01

    According to the analysis of the ambient temperature and the performance of the high pressure steering oil hose, a winter test method of the high pressure steering oil hose is proposed based on temperature compensation of environment chamber. This test method combines the low temperature environmental chamber with road test to verify the components which miss the winter test cycles. The test results show that the winter test of high temperature steering oil pipe with environmental chamber temperature compensation has good correlation with winter test under real low temperature environment.%通过对环境温度以及转向高压油管性能的分析,提出了基于环境舱温度补偿的转向高压油管冬季试验方法。该试验将低温环境舱与道路试验相结合,可以对错失自然环境冬季试验周期的相关零件进行有效验证。试验结果表明,利用环境舱温度补偿方法进行的转向高压油管冬季试验,与在真实低温环境下进行的冬季试验具有很好的相关性。

  7. Physical and Flavor Profiles of Arabica Coffee as Affected by Cherry Storage Before Pulping

    Directory of Open Access Journals (Sweden)

    Yusianto .

    2014-08-01

    Full Text Available Harvesting and pulping process of coffee cherry in the same day is inaccesible. Storage of coffee cherry before pulping was carried out incorrectly. Some storage treatments before pulping of Arabica coffee cherry had been examined at Indonesian Coffee and Cocoa Research Institute using Arabica coffee cherries from Andungsari Experimental Garden, Bondowoso, East Java. Treatments of the experiment were method and period of cherry storage. Methods of coffee cherry storage were put in plastic sacks; immerse in water, without water replacement; and immerse in water with daily water replacement. Period of coffee cherry storage were 0, 1, 2, 3, 4, 5, 6, and 7 days. After storage treatments, the coffee cherries were pulped, fermented, washed, sundried, and dehulled. The experiment were carried out using randomized block design with three replications. Observation of coffee cherry during storage periods was done on the physical and temperature. Observation of the green coffee were done on the color dan bulk density. The green coffee were roasted at medium roast level for sensory analysis. Observation of roasting profile were out-turn, bulk density and pH of roasted coffee. Sensory analysis used Specialty Coffee Association of America method. Methods and period of cherry storage before pulping significanly influence on the cherry color, parchment color, green coffee color, and the flavor profile of Arabica coffee. Color of dry parchment changed to be red-brown becouse of cherry immersed in water for two days or more. In plastic sacks, Arabica coffee cherry may be stored only for two days, but underwater with or without water replacement, should be not more than five days. Green and sensory quality of Arabica coffee will be deteriorated after five days storage underwater. Coffee cherry storage immerse in water with daily replacing water may improve sensory quality of Arabica coffee.Key word: Arabica coffe, storage, pulping, flavor, physical

  8. Radon chamber for soil gas detectors

    International Nuclear Information System (INIS)

    Andersson, P.

    1987-01-01

    Swedish Geological Co (SGAB) has designed and constructed a chamber for the calibration of detectors and instruments intended for the measurement of radon-222 in soil gas. In the chamber radon detectors may be exposed in a model environment which simulates ground conditions with respect to radon concentration, temperature and humidity. Also included in the research project is the development of methods for calibration procedures, together with test measurements. In general, these measurements indicate that the radon detectors tested are sufficiently accurate and reliable for radon measurements in Swedish soils if they are calibrated in an environment which simulates ground conditions. (orig./HP)

  9. Method for rapidly determining a pulp kappa number using spectrophotometry

    Science.gov (United States)

    Chai, Xin-Sheng; Zhu, Jun Yong

    2002-01-01

    A system and method for rapidly determining the pulp kappa number through direct measurement of the potassium permanganate concentration in a pulp-permanganate solution using spectrophotometry. Specifically, the present invention uses strong acidification to carry out the pulp-permanganate oxidation reaction in the pulp-permanganate solution to prevent the precipitation of manganese dioxide (MnO.sub.2). Consequently, spectral interference from the precipitated MnO.sub.2 is eliminated and the oxidation reaction becomes dominant. The spectral intensity of the oxidation reaction is then analyzed to determine the pulp kappa number.

  10. Effect of Urea Addition on Soda Pulping of Oak Wood

    OpenAIRE

    Cho, Nam-Seok; Matsumoto, Yuji; Cho, Hee-Yeon; Shin, Soo-Jeong; Oga, Shoji

    2008-01-01

    Many studies have been conducted to find a sulfur-free additive for alkaline pulping liquors that would have an effect similar to that of sulfide in kraft pulping. Some reagents that partially fulfill this role have been found, but they are too expensive to be used in the quantities required to make them effective. As an alternative method to solve air pollution problem and difficulty of pulp bleaching of kraft pulping process, NaOH-Urea pulping was applied. The properties of NaOH-Urea pul...

  11. Characterization of Coronal Pulp Cells and Radicular Pulp Cells in Human Teeth.

    Science.gov (United States)

    Honda, Masaki; Sato, Momoko; Toriumi, Taku

    2017-09-01

    Dental pulp has garnered much attention as an easily accessible postnatal tissue source of high-quality mesenchymal stem cells (MSCs). Since the discovery of dental pulp stem cells (DPSCs) in permanent third molars, stem cells from human exfoliated deciduous teeth and from supernumerary teeth (mesiodentes) have been identified as a population distinct from DPSCs. Dental pulp is divided into 2 parts based on the developing stage: the coronal pulp and the radicular pulp. Root formation begins after the crown part is completed. We performed a sequential study to examine the differences between the characteristics of coronal pulp cells (CPCs) and radicular pulp cells (RPCs) from permanent teeth, mesiodentes, and deciduous teeth. Interestingly, although we have not obtained any data on the difference between CPCs and RPCs in permanent teeth, there are some differences between the characteristics of CPCs and RPCs from mesiodentes and deciduous teeth. The MSC characteristics differed between the RPCs and CPCs, and the reprogramming efficiency for the generation of induced pluripotent stem cells was greater in RPCs than in CPCs from deciduous teeth. The proportion of CD105 + cells in CPCs versus that in RPCs varied in mesiodentes but not in permanent teeth. The results indicate that the proportion of CD105 + cells is an effective means of characterizing dental pulp cells in mesiodentes. Taken together, the stem cells in deciduous and supernumerary teeth share many characteristics, such as a high proliferation rate and an immunophenotype similar to that of DPSCs. Thus, mesiodentes accidentally encountered on radiographs by the general dental practitioner might be useful for stem cell therapy. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Fungal biomass production from coffee pulp juice

    Energy Technology Data Exchange (ETDEWEB)

    De Leon, R.; Calzada, F.; Herrera, R.; Rolz, C.

    1980-01-01

    Coffee pulp or skin represents about 40% of the weight of the fresh coffee fruit. It is currently a waste and its improper handling creates serious pollution problems for coffee producing countries. Mechanical pressing of the pulp will produce two fractions: coffee pulp juice (CPJ) and pressed pulp. Aspergillus oryzae, Trichoderma harzianum, Penicillium crustosum and Gliocladium deliquescens grew well in supplemented CPJ. At shake flask level the optimum initial C/N ratio was found to be in the range of 8 to 14. At this scale, biomass values of up to 50 g/l were obtained in 24 hours. Biomass production and total sugar consumption were not significantly different to all fungal species tested at the bench-scale level, even when the initial C/N ratio was varied. Best nitrogen consumption values were obtained when the initial C/N ratio was 12. Maximum specific growth rates occurred between 4-12 hours for all fungal species tested. (Refs. 8).

  13. Enrichment of coal pulps by selective flocculation

    Energy Technology Data Exchange (ETDEWEB)

    Blaschke, Z

    1977-01-01

    The results are presented of selective flocculation of coal pulps using different reagents. In some tests the coal particles were flocculated, and in others the coal remained in suspension and the dirt was flocculated. Selective flocculation makes it possible to obtain coal concentrates with a very low ash content from slurries with a high ash content. (In Polish)

  14. Enrichment of coal pulps by selective flocculation

    Energy Technology Data Exchange (ETDEWEB)

    Blaschke, Z

    1977-01-01

    The results are presented of selective flocculation of coal pulps using different reagents. In some tests the coal particles were flocculated, and in others the coal remained in suspension and the dirt was flocculated. Selective flocculation makes it possible to obtain coal concentrates with a very low ash content from slurries with a high ash content.

  15. Pulp-Capping with Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Peycheva Kalina

    2015-11-01

    Full Text Available There are two considerations for direct pulp capping - accidental mechanical pulp exposure and exposure caused by caries. Mineral trioxide aggregate (MTA was used as pulp-capping material to preserve the vitality of the pulpal tissues. Follow-up examinations revealed that treatment was successful in preserving pulpal vitality and continued development of the tooth. On the basis of available information, it appears that MTA is the material of choice for some clinical applications. Material and methods: Cases 18 - 8 teeth with grey MTA, 10 teeth with white MTA; diagnose: Pulpitis chronica ulcerosa, Electro pulpal test (EOD - 30-35 μA, pre-clinical X-ray - without changes in the structures, follow ups for 4 years. Successful treatments: without clinical symptoms and changes in the X-rays: 5 teeth with grey MTA, 8 teeth with white MTA for period of 4 years. Unsuccessful treatments: Clinical symptoms and sometimes changes in the X-ray: 3 with grey MTA, 2 with white MTA. MTA is an appropriate material for pulp-capping and follow-up examinations revealed that the treatment was successful in preserving pulpal vitality.

  16. Cocoa pulp in beer production: Applicability and fermentative process performance.

    Science.gov (United States)

    Nunes, Cassiane da Silva Oliveira; de Carvalho, Giovani Brandão Mafra; da Silva, Marília Lordêlo Cardoso; da Silva, Gervásio Paulo; Machado, Bruna Aparecida Souza; Uetanabaro, Ana Paula Trovatti

    2017-01-01

    This work evaluated the effect of cocoa pulp as a malt adjunct on the parameters of fermentation for beer production on a pilot scale. For this purpose, yeast isolated from the spontaneous fermentation of cachaça (SC52), belonging to the strain bank of the State University of Feira de Santana-Ba (Brazil), and a commercial strain of ale yeast (Safale S-04 Belgium) were used. The beer produced was subjected to acceptance and purchase intention tests for sensorial analysis. At the beginning of fermentation, 30% cocoa pulp (adjunct) was added to the wort at 12°P concentration. The production of beer on a pilot scale was carried out in a bioreactor with a 100-liter capacity, a usable volume of 60 liters, a temperature of 22°C and a fermentation time of 96 hours. The fermentation parameters evaluated were consumption of fermentable sugars and production of ethanol, glycerol and esters. The beer produced using the adjunct and yeast SC52 showed better fermentation performance and better acceptance according to sensorial analysis.

  17. Cocoa pulp in beer production: Applicability and fermentative process performance.

    Directory of Open Access Journals (Sweden)

    Cassiane da Silva Oliveira Nunes

    Full Text Available This work evaluated the effect of cocoa pulp as a malt adjunct on the parameters of fermentation for beer production on a pilot scale. For this purpose, yeast isolated from the spontaneous fermentation of cachaça (SC52, belonging to the strain bank of the State University of Feira de Santana-Ba (Brazil, and a commercial strain of ale yeast (Safale S-04 Belgium were used. The beer produced was subjected to acceptance and purchase intention tests for sensorial analysis. At the beginning of fermentation, 30% cocoa pulp (adjunct was added to the wort at 12°P concentration. The production of beer on a pilot scale was carried out in a bioreactor with a 100-liter capacity, a usable volume of 60 liters, a temperature of 22°C and a fermentation time of 96 hours. The fermentation parameters evaluated were consumption of fermentable sugars and production of ethanol, glycerol and esters. The beer produced using the adjunct and yeast SC52 showed better fermentation performance and better acceptance according to sensorial analysis.

  18. Laser all-ceramic crown removal and pulpal temperature--a laboratory proof-of-principle study.

    Science.gov (United States)

    Rechmann, P; Buu, N C H; Rechmann, B M T; Finzen, F C

    2015-11-01

    The objective of this proof-of-principle laboratory pilot study was to evaluate the temperature increase in the pulp chamber in a worst case scenario during Er:YAG laser debonding of all-ceramic crowns. Twenty extracted molars were prepared to receive all-ceramic IPS E.max CAD full contour crowns. The crowns were bonded to the teeth with Ivoclar Multilink Automix. Times for laser debonding and temperature rise in the pulp chamber using micro-thermocouples were measured. The Er:YAG was used with 560 mJ/pulse. The irradiation was applied at a distance of 5 mm from the crown surface. Additional air-water spray for cooling was utilized. Each all-ceramic crown was successfully laser debonded with an average debonding time of 135 ± 35 s. No crown fractured, and no damage to the underlying dentin was detected. The bonding cement deteriorated, but no carbonization at the dentin/cement interface occurred. The temperature rise in the pulp chamber averaged 5.4° ± 2.2 °C. During 8 out of the 20 crown removals, the temperature rise exceeded 5.5 °C, lasting 5 to 43 s (average 18.8 ± 11.6 s). A temperature rise of 11.5 °C occurred only once, while seven times the temperature rise was limited to 6.8 ± 0.5 °C. Temperature rises above 5.5 °C occurred only when the laser was applied from one side and additional cooling from the side opposite the irradiation. Er:YAG laser energy can successfully be used to efficiently debond all-ceramic crowns from natural teeth. Temperature rises exceeding 5.5 °C only occur when an additional air/water cooling from a dental syringe is inaccurately directed. To avoid possible thermal damage and to allow further heat diffusion, clinically temperature-reduced water might be applied.

  19. Pulp regeneration by transplantation of dental pulp stem cells in pulpitis: a pilot clinical study.

    Science.gov (United States)

    Nakashima, Misako; Iohara, Koichiro; Murakami, Masashi; Nakamura, Hiroshi; Sato, Yayoi; Ariji, Yoshiko; Matsushita, Kenji

    2017-03-09

    Experiments have previously demonstrated the therapeutic potential of mobilized dental pulp stem cells (MDPSCs) for complete pulp regeneration. The aim of the present pilot clinical study is to assess the safety, potential efficacy, and feasibility of autologous transplantation of MDPSCs in pulpectomized teeth. Five patients with irreversible pulpitis were enrolled and monitored for up to 24 weeks following MDPSC transplantation. The MDPSCs were isolated from discarded teeth and expanded based on good manufacturing practice (GMP). The quality of the MDPSCs at passages 9 or 10 was ascertained by karyotype analyses. The MDPSCs were transplanted with granulocyte colony-stimulating factor (G-CSF) in atelocollagen into pulpectomized teeth. The clinical and laboratory evaluations demonstrated no adverse events or toxicity. The electric pulp test (EPT) of the pulp at 4 weeks demonstrated a robust positive response. The signal intensity of magnetic resonance imaging (MRI) of the regenerated tissue in the root canal after 24 weeks was similar to that of normal dental pulp in the untreated control. Finally, cone beam computed tomography demonstrated functional dentin formation in three of the five patients. Human MDPSCs are safe and efficacious for complete pulp regeneration in humans in this pilot clinical study.

  20. Radiation -adsorption treatment of pesticides by using wood pulp and bagasse pulp

    International Nuclear Information System (INIS)

    Abd El-Aal, S.E.; Sokker, S.S.; Dessooki, A.M.

    2005-01-01

    Alkaline pulping of pulp wood and bagasse using sodium hydroxide resulted in the reduction of lignin from the wood and bagasse fibers and consequently increase adsorption of the pesticide pollutants to these fibers. Three different types of pesticides were used in this study namely, metalaxyl, dicloran and arelon. which were irradiated at a dose of 4 kGy before adsorption treatment.The results show that moderate adsorption was observed for all pesticides when adsorption was carried out without alkaline pulping and irradiation. This is due to the presence of lignin which retard the adsorption process. Batch sorption experiments at different pH values (3, 7, 9) for the retention of these pesticides by pulp wood and pulp bagasse fibers indicated that sorption is governed by the interaction of the ionized form of these compounds with the polyhydroxyl structure of cellulose. The study shows that alkaline pulping of pulpwood and bagasse improves its ability towards adsorption of the radiation degraded pesticide molecules

  1. Multiwire proportional chamber development

    Science.gov (United States)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  2. Radial semiconductor drift chambers

    International Nuclear Information System (INIS)

    Rawlings, K.J.

    1987-01-01

    The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

  3. Vienna Wire Chamber Conference

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    After those of 1978 and 1980, a third Wire Chamber Conference was held from 15-18 February in the Technical University of Vienna. Eight invited speakers covered the field from sophisticated applications in biology and medicine, via software, to the state of the art of gaseous detectors. In some forty other talks the speakers tackled in more detail the topics of gaseous detectors, calorimetry and associated electronics and software

  4. Wire chamber gases

    International Nuclear Information System (INIS)

    Va'vra, J.

    1992-04-01

    In this paper, we describe new developments in gas mixtures which have occurred during the last 3--4 years. In particular, we discuss new results on the measurement and modeling of electron drift parameters, the modeling of drift chamber resolution, measurements of primary ionization and the choice of gas for applications such as tracking, single electron detection, X-ray detection and visual imaging. In addition, new results are presented on photon feedback, breakdown and wire aging

  5. Kinetics of Adsorbable Organic Halides (AOX Reduction in Laccase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp

    Directory of Open Access Journals (Sweden)

    Xueping Song

    2016-07-01

    Full Text Available This paper presents a kinetic model of the laccase-aided chlorine dioxide bleaching of bagasse pulp. The kinetic model was based on the rate of reduction of adsorbed organic halogen (AOX. The effects of the laccase enzyme dosage, the mediator 1-hydroxybenzotriazole (HBT dosage, and the reaction temperature on the AOX content of the bleaching effluent are discussed. Good fits were obtained for the experimental data obtained from the different laccase enzyme dosages, HBT dosages, and reaction temperatures, indicating the feasibility of the kinetic model as a means of predicting the optimal operation conditions for the laccase-aided chlorine dioxide bleaching of bagasse pulp in the future.

  6. A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

    Science.gov (United States)

    Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

    2015-11-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

  7. A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

    Science.gov (United States)

    Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

    2016-03-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

  8. Nanofibrillated cellulose as paper additive in Eucalyptus pulps

    Directory of Open Access Journals (Sweden)

    Israel González

    2012-11-01

    Full Text Available In this work, the physical and mechanical properties of bleached Eucalyptus pulp reinforced with nanofibrillated cellulose (NFC are compared with those of traditional beaten pulp used in the making of writing/printing and offset printing papers. For this purpose, three different types of hardwood slurries were prepared: beaten pulps, unbeaten pulps reinforced with NFC, and slightly beaten pulps also reinforced with NFC. Physical and mechanical tests were performed on handsheets from these different slurries. The results showed that adding NFC to unbeaten pulps results in physical and mechanical properties similar to those in pulps used for printing/writing papers. Nevertheless, the best results were obtained in slurries previously beaten at slight conditions and subsequently reinforced with NFC. These results demonstrate that the addition of NFC allows a reduction in beating intensity without decreasing the desired mechanical properties for this specific purpose.

  9. Double chambered right ventricle

    International Nuclear Information System (INIS)

    Cho, Chul Koo; Yu, Yun Jeong; Yeon, Kyung Mo; Han, Man Chung

    1983-01-01

    Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and autopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows: 1. Among 14 cases, 6 cases were male and 8 cases were female. Age distribution was from 4 years to 36 years. 2. In chest x-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressure chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricle was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catheterization is an essential procedure

  10. Double chambered right ventricle

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Yu, Yun Jeong; Yeon, Kyung Mo; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1983-12-15

    Fourteen cases of double chambered right ventricle were diagnosed angiographically and of these nine cases were confirmed after operation and autopsy at Seoul National University Hospital in recent four years since 1979. The clinical and radiological findings with the emphasis on the cinecardiographic findings were analysed. The summaries of the analysis are as follows: 1. Among 14 cases, 6 cases were male and 8 cases were female. Age distribution was from 4 years to 36 years. 2. In chest x-ray findings, pulmonary vascularity was increased in 8 cases, decreased in 4 cases, and normal in 2 cases. Cardiomegaly was observed in 8 cases and other showed normal heart size. 3. In cinecardiography, 11 cases had interventricular septal defect. Among these 11 cases, VSD located in proximal high pressure chamber was in 2 cases and located in distal low pressure chamber was in 9 cases. 4. The location of aberrant muscle bundle in sinus portion of right ventricle was in 8 cases. In the rest 6 cases, the aberrant muscle bundle was located below the infundibulum of right ventricle. 5. For accurate diagnosis and differential diagnosis with other congenital cardiac anomalies such as Tetralogy of Fallot or isolated pulmonic stenosis, biplane cineangiography and catheterization is an essential procedure.

  11. Argus drift chamber

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, M; Nagovizin, V; Hasemann, H; Michel, E; Schmidt-Parzefall, W; Wurth, R; Kim, P

    1983-11-15

    The ARGUS detector came into operation at the DORIS-II e/sup +/s/sup -/ storage ring at the end of 1982. Its two meter long drift chamber contains 5940 sense and 24588 field wires organized in uniform 18x18.8 mm/sup 2/ drift cells filling the whole volume. These cells form 36 layers, 18 of which provide stereo views. Each sense wire is equipped with a single hit TDC and ADC for coordinate and dE/dx measurements. The chamber is operated with propane to improve momentum and dE/dx resolution. The drift chamber design and initial performance are presented. With a very crude space-time relation approximation and without all the necessary corrections applied a spatial resolution of about 200 ..mu..m was obtained for half of the drift cell volume. Further corrections should improve this result. An intrinsic dE/dx resolution of 4.2% and an actual resolution of 5% were obtained for cosmic muons and also for Bhabha scattered electrons. An actual dE/dx resolution of 5.6% was obtained for pions from e/sup +/e/sup -/ annihilation data with almost no track selection. A relativistic rise of 30% was observed in good agreement with theory. The long-term stability is still to be investigated.

  12. Argus target chamber

    International Nuclear Information System (INIS)

    Rienecker, F. Jr.; Glaros, S.S.; Kobierecki, M.

    1975-01-01

    A target chamber for application in the laser fusion program must satisfy some very basic requirements. (1) Provide a vacuum on the order of 10 -6 torr. (2) Support a microscopically small target in a fixed point in space and verify its location within 5 micrometers. (3) Contain an adjustable beam focusing system capable of delivering a number of laser beams onto the target simultaneously, both in time and space. (4) Provide access for diagnostics to evaluate the results of target irradiation. (5) Have flexibility to allow changes in targets, focusing optics and number of beams. The ARGUS laser which is now under construction at LLL will have a target chamber which meets these requirements in a simple economic manner. The chamber and auxiliary equipment are described, with reference to two double beam focusing systems; namely, lenses and ellipsoidal mirrors. Provision is made for future operation with four beams, using ellipsoidal mirrors for two-sided illumination and lens systems for tetragonal and tetrahedral irradiation

  13. Performance studies of solar tunnel dryer for drying aonla (Embilica Officinalis) pulp

    International Nuclear Information System (INIS)

    Seveda, M. S.

    2012-01-01

    A solar tunnel dryer was constructed and evaluated the performance for drying aonla pulp. The dryer consists of a transparent UV stabilized plastic covered solar collector cum drying unit. Evaluation parameters are air temperature, solar insolation, moisture content, relative humidity and airflow rate. A minimum of 111.18 m 2 solar collector area is required to dry a batch 1000 kg aonla pulp in 16 hours (two days drying period). The initial and final moisture content considered were 424.93 and 10.08% dry basis, respectively. It was observed that on an average 43 per cent of higher temperature was obtained in solar tunnel dryer over the ambient temperature. The results obtained during the test period denoted that the maximum gained energy occurred at 13 o'clock hour and then gradually declined since the maximum solar radiation occurred at this time. (author)

  14. TESTING OF PULP VITALITY BY PULSOXIMETRY

    Directory of Open Access Journals (Sweden)

    Gabriela CIOBANU

    2012-06-01

    Full Text Available The methods applied for diagnosing the health condition of the pulp tissue are numerous, however, nowadays, an increasingly higher number of conventional tests are replaced by some objective, non-invasive, painless and reliable tests. Among them, pulse oximetry is a method for the investigation of pulp vitality based on oxygen saturation (SaO2 of the hemoglobin from the blood present in the pulp vascular bed, as a means of differentiating among the vital and the non-vital teeth. In the present study, registrations were made on a group of 120 frontal maxillary teeth, in patients with ages between 20 and 40 years, on using a digital sensor modified by the pulse oximeter with which the pulse and the values of oxygen saturation were measured at the level of both teeth and right hand finger. The mean SaO2 value in the pulp blood of the vital teeth was of 83.30% for the central incisor, of 78.51% for the lateral one and of 84.56%, respectively, for the canine; the value recorded at finger level was of 97%. In the non-vital teeth, the SaO2 value measured on the pulse oximeter was of 0%. Pulse registration showed mean values of 70.56 beatings/min at tooth level and of 70.88 beatings/min, respectively, at finger level. The results of the present study may confirm that pulse oximetry represents a simple, non-traumatic, efficient and objective method for testing the vitality condition of the dental pulp.

  15. Wire chambers: Trends and alternatives

    International Nuclear Information System (INIS)

    Regler, Meinhard

    1992-01-01

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

  16. Improved climatic chamber for desiccation simulation

    Directory of Open Access Journals (Sweden)

    Lozada Catalina

    2016-01-01

    Full Text Available The climatic chamber at the Universidad de Los Andes was improved for modeling desiccation in soil layers. This chamber allows the measurement of different environmental variables. In this research, evaporation tests were conducted in water imposing boundary conditions for drying, and then these tests were performed in a soil layer. The soil was prepared from a slurry state and was drying controlling the temperature, the infrared radiation, the wind velocity, and the relative humidity. In the first part of this paper, a description of the climatic chamber, operation ranges and theoretical work principles of the climatic chamber are presented. Then, the second part shows the results for desiccation in water and soil. The desiccation tests performed with the climatic chamber allow simulating all environmental conditions accurately during drying coupling the effect of all environmental variables. As a result, the evaporation rate increases with infrared radiation in soil and water. The rate at the beginning of the desiccation tests in clays is the same as in water. However, this evaporation rate decreases as the soil becomes desiccated.

  17. Criteria for controlled atmosphere chambers

    International Nuclear Information System (INIS)

    Robinson, J.N.

    1980-03-01

    The criteria for design, construction, and operation of controlled atmosphere chambers intended for service at ORNL are presented. Classification of chambers, materials for construction, design criteria, design, controlled atmosphere chamber systems, and operating procedures are presented. ORNL Safety Manual Procedure 2.1; ORNL Health Physics Procedure Manual Appendix A-7; and Design of Viewing Windows are included in 3 appendices

  18. Human dental pulp stem cells with highly angiogenic and neurogenic potential for possible use in pulp regeneration.

    Science.gov (United States)

    Nakashima, Misako; Iohara, Koichiro; Sugiyama, Masahiko

    2009-01-01

    Dental caries is a common public health problem, causing early loss of dental pulp and resultant tooth loss. Dental pulp has important functions to sustain teeth providing nutrient and oxygen supply, innervation, reactionary/reparative dentin formation and immune response. Regeneration of pulp is an unmet need in endodontic therapy, and angiogenesis/vasculogenesis and neurogenesis are critical for pulp regeneration. Permanent and deciduous pulp tissue is easily available from teeth after extraction without ethical issues and has potential for clinical use. In this review, we introduce some stem cell subfractions, CD31(-)/CD146(-) SP cells and CD105(+) cells with high angiogenic and neurogenic potential, derived from human adult dental pulp tissue. Potential utility of these cells is addressed as a source of cells for treatment of cerebral and limb ischemia and pulp inflammation complete with angiogenesis and vasculogenesis.

  19. Modélisation de la déshydratation de la pulpe des fruits du Canarium schweinfurthii Engl

    Directory of Open Access Journals (Sweden)

    Parmentier, M.

    2004-01-01

    Full Text Available Modelling of the Dehydration of Canarium schweinfurthii Engl. Fruit Pulp. In this work, we obtained drying kinetic of Canarium schweinfurthii Engl. pulp fruit, under conditions of air velocity ranging between 1 and 3 m/s, relative humidity between 40 and 60%, temperature between 40 and 70 °C. The experiments were made in drying tunnel where properties of hot air flow are determined and controlled. It is observed from the drying kinetics that there is no constant rate phase. Modelling of the results was performed using the caracteristic curve of drying. Futhermore, we determined aiele pulp desorption isotherms in differents temperatures (40, 50, 60 and 70 °C, the Guggenheim, Anderson and de Boer model proved to be satisfactory to describe them.

  20. Effect of Soda-Anthraquinone Pulping Conditions and Beating Revolution on the Mechanical Properties of Paper made from Gigantochloa scortechinii (Semantan Bamboo)

    International Nuclear Information System (INIS)

    Nurul Husna Mohd Hassan; Suhaimi Muhammed

    2013-01-01

    The effect of soda-AQ pulping conditions and beating revolution on the mechanical properties of paper made from Semantan bamboo (Gigantochloa scortechinii) was studied. The bamboo chips were pulped using MK digester pulping unit with 10 to 20 % alkali charge and 150 to 170 degree Celsius cooking temperature. The screened yield varies from 38.7 to 48.4 %, and each yield went through beating process at 1000 or 8000 beating revolutions. The bamboo pulp was then made into 60 g/ m 2 laboratory scale papers and their mechanical properties were assessed conforming to TAPPI standards. The results revealed that tensile index, bursting index, tearing index and folding endurance ranged from 42.04 to 91.09 Nm/ g, 2.68 to 7.10 kPa.m 2 /g, 11.03 to 26.64 mN.m 2 /g and 30 to 1127 double folds, respectively. The highest paper properties were found from pulping condition of 15 % alkali charge and 150 degree Celsius cooking temperature based on the fibre bonding index, with tensile index at 87.71 Nm/g, bursting index at 6.94 kPa.m 2 / g, tearing index at 12.72 mN.m 2 / g and folding endurance at 613 double folds. Such findings indicate that comparable high strength mechanical properties of paper can be produced from Semantan bamboo pulp with more environmentally friendly pulping process compared to the kraft pulping process that had been used in bamboo pulping. (author)

  1. Viscoelastic Properties of Dental Pulp Tissue and Ramifications on Biomaterial Development for Pulp Regeneration.

    Science.gov (United States)

    Erisken, Cevat; Kalyon, Dilhan M; Zhou, Jian; Kim, Sahng G; Mao, Jeremy J

    2015-10-01

    A critical step in biomaterial selection effort is the determination of material as well as the biological properties of the target tissue. Previously, the selection of biomaterials and carriers for dental pulp regeneration has been solely based on empirical experience. In this study, first, the linear viscoelastic material functions and compressive properties of miniature pig dental pulp were characterized using small-amplitude oscillatory shear and uniaxial compression at a constant rate. They were then compared with the properties of hydrogels (ie, agarose, alginate, and collagen) that are widely used in tissue regeneration. The comparisons of the linear viscoelastic material functions of the native pulp tissue with those of the 3 hydrogels revealed the gel-like behavior of the pulp tissue over a relatively large range of time scales (ie, over the frequency range of 0.1-100 rps). At the constant gelation agent concentration of 2%, the dynamic properties (ie, storage and loss moduli and the tanδ) of the collagen-based gel approached those of the native tissue. Under uniaxial compression, the peak normal stresses and compressive moduli of the agarose gel were similar to those of the native tissue, whereas alginate and collagen exhibited significantly lower compressive properties. The linear viscoelastic and uniaxial compressive properties of the dental pulp tissue reported here should enable the more appropriate selection of biogels for dental pulp regeneration via the better tailoring of gelation agents and their concentrations to better mimic the dynamic and compressive properties of native pulp tissue. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Immunolocalization of bone-resorptive cytokines in rat pulp and periapical lesions following surgical pulp exposure.

    Science.gov (United States)

    Tani-Ishii, N; Wang, C Y; Stashenko, P

    1995-08-01

    The bone-resorptive cytokines interleukin 1 (IL-1) and tumor necrosis factor (TNF) have been implicated in the pathogenesis of many chronic inflammatory diseases, including pulpitis and apical periodontitis.To further elucidate their role in these disorders, we have identified cells that express IL-1 alpha and TNF alpha in infected pulps and in developing rat periapical lesions after surgical pulp exposure. As detected by immunohistochemistry, IL-1 alpha- and TNF alpha-positive cells were present as early as 2 days after pulp exposure in both the pulp and periapical region. The numbers of cytokine-expressing cells increased up to day 4 in the pulp and up to day 30 in the periapex. In contrast, cells expressing IL-1 beta and TNF beta, the homologous forms of these mediators, were not found in pulp or periapical lesions during this period. Cells expressing IL-1 alpha and TNF alpha were identified primarily as macrophages and fibroblasts, with occasional staining of polymorphonuclear leukocytes. Osteoblasts and osteoclasts were also positive, whereas lymphocytes were negative. In general, cytokine-expressing cells were located proximal to abscesses and the root apex. These findings demonstrate that cells that express bone-resorptive cytokines IL-1 alpha and TNF alpha are present immediately after pulp exposure in this model, which supports the hypothesis that these mediators play a key role in pulpal and periapical pathogenesis, including the concomitant bone destruction. They also indicate that both resident connective tissue cells as well as infiltrating cells express bone-resorptive cytokines in response to infection in these lesions.

  3. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  4. Low temperature carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, A A

    1934-01-10

    A process is described in which coal is passed through a distillation chamber in one retort at a comparatively low temperature, then passing the coal through a distillation chamber of a second retort subjected to a higher temperature, thence passing the coal through the distillation chamber of a third retort at a still higher temperature and separately collecting the liquid and vapors produced from each retort.

  5. Durability of pulp fiber-cement composites

    Science.gov (United States)

    Mohr, Benjamin J.

    Wood pulp fibers are a unique reinforcing material as they are non-hazardous, renewable, and readily available at relatively low cost compared to other commercially available fibers. Today, pulp fiber-cement composites can be found in products such as extruded non-pressure pipes and non-structural building materials, mainly thin-sheet products. Although natural fibers have been used historically to reinforce various building materials, little scientific effort has been devoted to the examination of natural fibers to reinforce engineering materials until recently. The need for this type of fundamental research has been emphasized by widespread awareness of moisture-related failures of some engineered materials; these failures have led to the filing of national- and state-level class action lawsuits against several manufacturers. Thus, if pulp fiber-cement composites are to be used for exterior structural applications, the effects of cyclical wet/dry (rain/heat) exposure on performance must be known. Pulp fiber-cement composites have been tested in flexure to examine the progression of strength and toughness degradation. Based on scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), a three-part model describing the mechanisms of progressive degradation has been proposed: (1) initial fiber-cement/fiber interlayer debonding, (2) reprecipitation of crystalline and amorphous ettringite within the void space at the former fiber-cement interface, and (3) fiber embrittlement due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. Finally, as a means to mitigate kraft pulp fiber-cement composite degradation, the effects of partial portland cement replacement with various supplementary cementitious materials (SCMs) has been investigated for their effect on mitigating kraft pulp fiber-cement composite mechanical property degradation (i.e., strength and toughness

  6. Application of response surface methodology to optimize uranium biological leaching at high pulp density

    International Nuclear Information System (INIS)

    Fatemi, Faezeh; Arabieh, Masoud; Jahani, Samaneh

    2016-01-01

    The aim of the present study was to carry out uranium bioleaching via optimization of the leaching process using response surface methodology. For this purpose, the native Acidithiobacillus sp. was adapted to different pulp densities following optimization process carried out at a high pulp density. Response surface methodology based on Box-Behnken design was used to optimize the uranium bioleaching. The effects of six key parameters on the bioleaching efficiency were investigated. The process was modeled with mathematical equation, including not only first and second order terms, but also with probable interaction effects between each pair of factors.The results showed that the extraction efficiency of uranium dropped from 100% at pulp densities of 2.5, 5, 7.5 and 10% to 68% at 12.5% of pulp density. Using RSM, the optimum conditions for uranium bioleaching (12.5% (w/v)) were identified as pH = 1.96, temperature = 30.90 C, stirring speed = 158 rpm, 15.7% inoculum, FeSO 4 . 7H 2 O concentration at 13.83 g/L and (NH 4 ) 2 SO 4 concentration at 3.22 g/L which achieved 83% of uranium extraction efficiency. The results of uranium bioleaching experiment using optimized parameter showed 81% uranium extraction during 15 d. The obtained results reveal that using RSM is reliable and appropriate for optimization of parameters involved in the uranium bioleaching process.

  7. Application of response surface methodology to optimize uranium biological leaching at high pulp density

    Energy Technology Data Exchange (ETDEWEB)

    Fatemi, Faezeh; Arabieh, Masoud; Jahani, Samaneh [NSTRI, Tehran (Iran, Islamic Republic of). Nuclear Fuel Cycle Research School

    2016-08-01

    The aim of the present study was to carry out uranium bioleaching via optimization of the leaching process using response surface methodology. For this purpose, the native Acidithiobacillus sp. was adapted to different pulp densities following optimization process carried out at a high pulp density. Response surface methodology based on Box-Behnken design was used to optimize the uranium bioleaching. The effects of six key parameters on the bioleaching efficiency were investigated. The process was modeled with mathematical equation, including not only first and second order terms, but also with probable interaction effects between each pair of factors.The results showed that the extraction efficiency of uranium dropped from 100% at pulp densities of 2.5, 5, 7.5 and 10% to 68% at 12.5% of pulp density. Using RSM, the optimum conditions for uranium bioleaching (12.5% (w/v)) were identified as pH = 1.96, temperature = 30.90 C, stirring speed = 158 rpm, 15.7% inoculum, FeSO{sub 4} . 7H{sub 2}O concentration at 13.83 g/L and (NH{sub 4}){sub 2}SO{sub 4} concentration at 3.22 g/L which achieved 83% of uranium extraction efficiency. The results of uranium bioleaching experiment using optimized parameter showed 81% uranium extraction during 15 d. The obtained results reveal that using RSM is reliable and appropriate for optimization of parameters involved in the uranium bioleaching process.

  8. Activated carbon prepared from coffee pulp: potential adsorbent of organic contaminants in aqueous solution.

    Science.gov (United States)

    Gonçalves, Maraisa; Guerreiro, Mário César; Ramos, Paulize Honorato; de Oliveira, Luiz Carlos Alves; Sapag, Karim

    2013-01-01

    The processing of coffee beans generates large amounts of solid and liquid residues. The solid residues (pulp, husk and parchment) represent a serious environmental problem and do not have an adequate disposal mechanism. In this work, activated carbons (ACs) for adsorption of organic compounds were prepared from coffee pulp by controlled temperature at different pulp/Na2HPO4 ratios (4:1, 2:1, 5:4 and 1:1). The N2 adsorption/desorption isotherms showed ACs with high quantities of mesopores and micropores and specific surface areas of 140, 150, 450 and 440 m(2)g(-1) for AC 4:1, AC 2:1, AC 5:4 and AC 1:1, respectively. The prepared material AC 5:4 showed a higher removal capacity of the organic contaminants methylene blue (MB), direct red (DR) and phenol than did a Merck AC. The maximum capacities for this AC are approximately 150, 120 and 120 mg g(-1) for MB, DR and phenol, respectively. Thus, a good adsorbent was obtained from coffee pulp, an abundant Brazilian residue.

  9. Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

    Directory of Open Access Journals (Sweden)

    Maria Angélica Marques Pedro

    2010-12-01

    Full Text Available The sorption behavior of dry products is generally affected by the drying method. The sorption isotherms are useful to determine and compare thermodynamic properties of passion fruit pulp powder processed by different drying methods. The objective of this study is to analyze the effects of different drying methods on the sorption properties of passion fruit pulp powder. Passion fruit pulp powder was dehydrated using different dryers: vacuum, spray dryer, vibro-fluidized, and freeze dryer. The moisture equilibrium data of Passion Fruit Pulp (PFP powders with 55% of maltodextrin (MD were determined at 20, 30, 40 and 50 ºC. The behavior of the curves was type III, according to Brunauer's classification, and the GAB model was fitted to the experimental equilibrium data. The equilibrium moisture contents of the samples were little affected by temperature variation. The spray dryer provides a dry product with higher adsorption capacity than that of the other methods. The vibro-fluidized bed drying showed higher adsorption capacity than that of vacuum and freeze drying. The vacuum and freeze drying presented the same adsorption capacity. The isosteric heats of sorption were found to decrease with increasing moisture content. Considering the effect of drying methods, the highest isosteric heat of sorption was observed for powders produced by spray drying, whereas powders obtained by vacuum and freeze drying showed the lowest isosteric heats of sorption.

  10. Evaluation of bleachability on pine and eucalyptus kraft pulps

    Directory of Open Access Journals (Sweden)

    Marcela Freitas Andrade

    2013-09-01

    Full Text Available In recent decades, the pulp industry has been changing and improving its manufacturing processes in order to enhance production capacity, product quality and environmental performance. The aim of this study was to evaluate the bleachability effect on the efficient washing and alkaline leaching in eucalyptus and pine Kraft pulps using three different bleaching sequences: AD(EPD, A/D(EPDP and DHT(EPDP. This study was carried out in two stages. In the first part, the optimum conditions for pulp bleaching in order to achieve a brightness of 90% ISO were established. The second step was a comparative study between the pulps that received alkaline leaching and efficient washing with reference pulp (without treatment. The brightness, viscosity, kappa number and HexA in pulp were analyzed. The three sequences studied reached the desired brightness, but the sequence AD(EPD produced a lower reagent consumption for the same brightness. In the three sequences studied, the efficient washing of the pulp after oxygen delignification has contributed significantly to the removal of dissolved organic and inorganic materials in the pulp and the alkaline leaching decreased significantly the pulp kappa number due to a higher pulp delignification and bleachability.

  11. Evaluating pulp stiffness from fibre bundles by ultrasound

    Science.gov (United States)

    Karppinen, Timo; Montonen, Risto; Määttänen, Marjo; Ekman, Axel; Myllys, Markko; Timonen, Jussi; Hæggström, Edward

    2012-06-01

    A non-destructive ultrasonic tester was developed to measure the stiffness of pulp bundles. The mechanical properties of pulp are important when estimating the behaviour of paper under stress. Currently available pulp tests are tedious and alter the fibres structurally and mechanically. The developed tester employs (933 ± 15) kHz tweezer-like ultrasonic transducers and time-of-flight measurement through (9.0 ± 2.5) mm long and (0.8 ± 0.1) mm thick fibre bundles kept at (19.1 ± 0.4) °C and (62 ± 1)% RH. We determined the stiffness of soft wood pulps produced by three kraft pulping modifications: standard kraft pulp, (5.2 ± 0.4) GPa, prehydrolysis kraft pulp, (4.3 ± 0.4) GPa, and alkali extracted prehydrolysis kraft pulp, (3.3 ± 0.4) GPa. Prehydrolysis and alkali extraction processes mainly lowered the hemicellulose content of the pulps, which essentially decreased the fibre-wall stiffness hence impairing the stiffness of the fibre networks. Our results indicate that the method allows ranking of pulps according to their stiffness determined from bundle-like samples taken at an early phase of the papermaking process.

  12. Performance of Schizolobium amazonicum Wood in Bleached Kraft Pulp Production

    Directory of Open Access Journals (Sweden)

    Camila Sarto

    2015-05-01

    Full Text Available This study aimed to evaluate the characteristics of Schizolobium amazonicum wood, specifically its performance in bleached kraft pulp production and the characteristics of its pulp. Chips of Schizolobium amazonicum and Eucalyptus grandis x Eucalyptus urophylla (reference were used. The following parameters were evaluated in the wood: basic density, total extractives, total lignin, holocellulose, and fiber morphology. The pulping simulations were carried out in a laboratory digester, with parameters set to obtain pulp with kappa number 19 ± 0.5. Both pulps were bleached in a PFI mill and submitted to physical-mechanical tests. The results showed that S. amazonicum wood has low basic density and higher content of extractives when compared to E. grandis x E. urophylla wood. For pulping, S. amazonicum required higher alkali charge and H factor to achieve the same delignification level of E. grandis x E. urophylla, resulting in a lower yield, pulp with lower viscosity, and higher wood specific consumption. During bleaching, the brightness gain and final viscosity of S. amazonicum pulp were lower than E. grandis x E. urophylla pulp. Moreover, S. amazonicum pulp had worse physical-mechanical characteristics than E. grandis x E. urophylla.

  13. Pulp and paper from blue agave waste from tequila production.

    Science.gov (United States)

    Idarraga, G; Ramos, J; Zuñiga, V; Sahin, T; Young, R A

    1999-10-01

    Pulping of blue agave waste, from the production of tequila, was evaluated by both chemical and biomechanical pulping processes. Two conventional and two organosolv systems were used to pulp the agave waste under a standard set of conditions. The soda-ethanol process was superior in terms of delignification and pulp properties in comparison to the soda and ethanol organosolv processes for pulping of agave waste; however, the kraft process gave the best strength properties. In general, the strength of the agave waste pulps was rather poor in comparison to wood and other agro-based pulps; however, the tear strength was relatively high. This result is typical of poorly bonded sheets and may be due to the coarseness of the agave fibers and/or loss of hemicelluloses in the steaming process for the tequila production. Fungal treatment of the agave waste with Ceriporiopsis subvermispora reduced the energy consumption for mechanical refining but gave biomechanical pulps with inferior strength properties. The blue agave chemical pulps should be suitable for blending with softwood kraft pulps for publication grade paper.

  14. Review of wire chamber aging

    International Nuclear Information System (INIS)

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  15. Space plasma simulation chamber

    International Nuclear Information System (INIS)

    1986-01-01

    Scientific results of experiments and tests of instruments performed with the Space Plasma Simulation Chamber and its facility are reviewed in the following six categories. 1. Tests of instruments on board rockets, satellites and balloons. 2. Plasma wave experiments. 3. Measurements of plasma particles. 4. Optical measurements. 5. Plasma production. 6. Space plasms simulations. This facility has been managed under Laboratory Space Plasma Comittee since 1969 and used by scientists in cooperative programs with universities and institutes all over country. A list of publications is attached. (author)

  16. Stability of Streamer Chamber

    Science.gov (United States)

    Wada, Toshiaki; Ogawa, Masato; Takahashi, Kaoru; Sugiyama, Tsunetoshi; Kobayashi, Shigeharu; Kohno, Hirobumi

    1982-08-01

    The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result.

  17. Stability of streamer chamber

    International Nuclear Information System (INIS)

    Wada, Toshiaki; Ogawa, Masato; Takahashi, Kaoru; Sugiyama, Tsunetoshi; Kobayashi, Shigeharu; Kohno, Hirobumi.

    1982-01-01

    The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result. (author)

  18. Microencapsulation of pequi pulp oil by complex coacervation

    Directory of Open Access Journals (Sweden)

    Priscilla Narciso Justi

    2018-04-01

    Full Text Available Abstract Pequi pulp oil, Caryocar brasiliense, is rich in carotenoids, antioxidant compound easily oxidized by the presence of heat, light and oxygen. In order to improve its stability, pequi oil was microencapsulated by complex coacervation using gelatin and Arabic gum as encapsulating agents. Twenty formulations were prepared using a 23 central composite rotational design. The influence of temperature, stirring velocity and core material in the oil coacervation were evaluated, aiming to preserve carotenoids present in the oil. The best yield values and carotenoids content were obtained at the midpoint of the design (7.5g core, 15.000rpm and 50°C. Particles showed asymmetric distribution, with diameter ranging from 15 to 145 µm and the efficiency of the encapsulation process, obtained by the retention of oil in the microcapsule, ranged from 66.58 to 96.50%, thus demonstrating the encapsulation efficiency of this method.

  19. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units.

    Science.gov (United States)

    Mousavinasab, Sayed-Mostafa; Khoroushi, Maryam; Moharreri, Mohammadreza; Atai, Mohammad

    2014-08-01

    Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05). Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

  20. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units

    Directory of Open Access Journals (Sweden)

    Sayed-Mostafa Mousavinasab

    2014-08-01

    Full Text Available Objectives Light-curing of resin-based materials (RBMs increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs of three different RBMs using quartz tungsten halogen (QTH and light-emitting diode (LED units (LCUs. Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12 during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey, a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE, and a giomer (Beautifil II, Shofu GmbH, was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05. Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

  1. Integration of the Mini-Sulfide Sulfite Anthraquinone (MSS-AQ) Pulping Process and Black Liquor Gasification in a Pulp Mill

    Energy Technology Data Exchange (ETDEWEB)

    Hasan Jameel, North Carolina State University; Adrianna Kirkman, North Carolina State University; Ravi Chandran,Thermochem Recovery International Brian Turk Research Triangle Institute; Brian Green, Research Triangle Institute

    2010-01-27

    produced a comparable tensile and burst index pulps. Product gas composition determined using computer simulations The results demonstrate that RVS-1 can effectively remove > 99.8% of the H2S present in simulated synthesis gas generated from the gasification of black liquor. This level of sulfur removal was consistent over simulated synthesis gas mixtures that contained from 6 to 9.5 vol % H2S.A significant amount of the sulfur in the simulated syngas was recovered as SO2 during regeneration. The average recovery of sulfur as SO2 was about 75%. Because these are first cycle results, this sulfur recovery is expected to improve. Developed WINGems model of the process.The total decrease in variable operating costs for the BLG process compared to the HERB was in excess of $6,200,000 per year for a mill producing 350,000 tons of pulp per year. This represents a decrease in operating cost of about $17.7/ton of oven dry pulp produced. There will be additional savings in labor and maintenance cost that has not been taken into account. The capital cost for the MSSAQ based gasifier system was estimated at $164,000,000, which is comparable to a High Efficiency Recovery Boiler. The return on investment was estimated at 4%. A gasifier replacement cannot be justified on its own, however if the recovery boiler needs to be replaced the MSSAQ gasifier system shows significantly higher savings. Before black liquor based gasifer technology can be commercialized more work is necessary. The recovery of the absorbed sulfur in the absorbent as sulfur dioxide is only 75%. This needs to be greater than 90% for economical operation. It has been suggested that as the number of cycles is increased the sulfur dioxide recovery might improve. Further research is necessary. Even though a significant amount of work has been done on a pilot scale gasifiers using liquors containing sulfur, both at low and high temperatures the lack of a commercial unit is an impediment to the implementation of the MSSAQ

  2. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  3. Cardiac chamber scintiscanning

    International Nuclear Information System (INIS)

    Goretzki, G.

    1981-01-01

    The two methods of cardiac chamber scintiscanning, i.e. 'first pass' and 'ECG-triggered' examinations, are explained and compared. Two tables indicate the most significant radiation doses of the applied radio tracers, i.e. 99m-Tc-pertechnetate and 99m-Tc-HSA, to which a patient is exposed. These averaged values are calculated from various data given in specialised literature. On the basis of data given in literature, an effective half-life of approximately 5 hours in the intravascular space was calculated for the erythrocytes labelled with technetium 99m. On this basis, the radiation doses for the patients due to 99m-Tc-labelled erythrocytes are estimated. The advantages and disadvantages of the two methods applied for cardiac chamber scintiscanning are put into contrast and compared with the advantages and disadvantages of the quantitative X-ray cardiography of the left heart. The still existing problems connected with the assessment of ECG-triggered images are discussed in detail. The author performed investigations of his own, which concerned the above-mentioned problems. (orig./MG) [de

  4. Expression of high mobility group box 1 in inflamed dental pulp and its chemotactic effect on dental pulp cells

    International Nuclear Information System (INIS)

    Zhang, Xufang; Jiang, Hongwei; Gong, Qimei; Fan, Chen; Huang, Yihua; Ling, Junqi

    2014-01-01

    Highlights: • HMGB1 translocated from nucleus to cytoplasm during dental pulp inflammation. • HMGB1and its receptor RAGE were up-regulated in hDPCs under LPS stimulation. • HMGB1 enhanced hDPCs migration and induces cytoskeleton reorganization. • HMGB1 may play a critical role in dental pulp repair during inflamed state. - Abstract: High mobility group box 1 protein (HMGB1) is a chromatin protein which can be released extracellularly, eliciting a pro-inflammatory response and promoting tissue repair process. This study aimed to examine the expression and distribution of HMGB1 and its receptor RAGE in inflamed dental pulp tissues, and to assess its effects on proliferation, migration and cytoskeleton of cultured human dental pulp cells (DPCs). Our data demonstrated that cytoplasmic expression of HMGB1 was observed in inflamed pulp tissues, while HMGB1 expression was confined in the nuclei in healthy dental pulp. The mRNA expression of HMGB1 and RAGE were significantly increased in inflamed pulps. In in vitro cultured DPCs, expression of HMGB1 in both protein and mRNA level was up-regulated after treated with lipopolysaccharide (LPS). Exogenous HMGB1 enhanced DPCs migration in a dose-dependent manner and induced the reorganization of f-actin in DPCs. Our results suggests that HMGB1 are not only involved in the process of dental pulp inflammation, but also play an important role in the recruitment of dental pulp stem cells, promoting pulp repair and regeneration

  5. Expression of high mobility group box 1 in inflamed dental pulp and its chemotactic effect on dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xufang, E-mail: xufang.zhang@student.qut.edu.au [Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059 (Australia); Jiang, Hongwei, E-mail: jianghw@163.com [Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Gong, Qimei, E-mail: gongqmei@gmail.com [Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Fan, Chen, E-mail: c3.fan@student.qut.edu.au [Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059 (Australia); Huang, Yihua, E-mail: enu0701@163.com [Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Ling, Junqi, E-mail: lingjq@mail.sysu.edu.cn [Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China)

    2014-08-08

    Highlights: • HMGB1 translocated from nucleus to cytoplasm during dental pulp inflammation. • HMGB1and its receptor RAGE were up-regulated in hDPCs under LPS stimulation. • HMGB1 enhanced hDPCs migration and induces cytoskeleton reorganization. • HMGB1 may play a critical role in dental pulp repair during inflamed state. - Abstract: High mobility group box 1 protein (HMGB1) is a chromatin protein which can be released extracellularly, eliciting a pro-inflammatory response and promoting tissue repair process. This study aimed to examine the expression and distribution of HMGB1 and its receptor RAGE in inflamed dental pulp tissues, and to assess its effects on proliferation, migration and cytoskeleton of cultured human dental pulp cells (DPCs). Our data demonstrated that cytoplasmic expression of HMGB1 was observed in inflamed pulp tissues, while HMGB1 expression was confined in the nuclei in healthy dental pulp. The mRNA expression of HMGB1 and RAGE were significantly increased in inflamed pulps. In in vitro cultured DPCs, expression of HMGB1 in both protein and mRNA level was up-regulated after treated with lipopolysaccharide (LPS). Exogenous HMGB1 enhanced DPCs migration in a dose-dependent manner and induced the reorganization of f-actin in DPCs. Our results suggests that HMGB1 are not only involved in the process of dental pulp inflammation, but also play an important role in the recruitment of dental pulp stem cells, promoting pulp repair and regeneration.

  6. Pembuatan Pulp dari Alang-alang

    OpenAIRE

    Ivan Wibisono Aylianawati

    2011-01-01

    Alang-alang merupakan tanaman gulma yang jumlahnya cukup besar di Indonesia. Hingga saat ini pemanfaatan dalam jumlah yang besar terhadap alang-alang di Indonesia belum ada. Alang-alang mempunyai kandungan selulosa yang cukup tinggi. Pada penelitian pendahuluan terhadap bahan baku alang-alang mengandung kadar alfa selulosa sekitar 41,7% dan mempunyai bilangan Kappa sebesar 37,1886. Maka alang-alang bisa dijadikan sebagai bahan dari pulp untuk pembuatan kertas. Tujuan penelitian ini adalah ...

  7. An environmental chamber for investigating the evaporation of volatile chemicals.

    Science.gov (United States)

    Dillon, H K; Rumph, P F

    1998-03-01

    An inexpensive test chamber has been constructed that provides an environment appropriate for testing the effects of temperature and chemical interactions on gaseous emissions from test solutions. Temperature, relative humidity, and ventilation rate can be controlled and a well-mixed atmosphere can be maintained. The system is relatively simple and relies on heated tap water or ice to adjust the temperature. Temperatures ranging from 9 to 21 degrees C have been maintained. At an average temperature of 15.1 degrees C, temperatures at any location within the chamber vary by no more than 0.5 degree C, and the temperature of the test solution within the chamber varies by no more than 0.1 degree C. The temperatures within the chamber are stable enough to generate precise steady-state concentrations. The wind velocities within the chamber are reproducible from run to run. Consequently, the effect of velocity on the rate of evaporation of a test chemical is expected to be uniform from run to run. Steady-state concentrations can be attained in less than 1 hour at an air exchange rate of about 5 per hour.

  8. Numerical analysis of whole-body cryotherapy chamber design improvement

    Science.gov (United States)

    Yerezhep, D.; Tukmakova, A. S.; Fomin, V. E.; Masalimov, A.; Asach, A. V.; Novotelnova, A. V.; Baranov, A. Yu

    2018-05-01

    Whole body cryotherapy is a state-of-the-art method that uses cold for treatment and prevention of diseases. The process implies the impact of cryogenic gas on a human body that implements in a special cryochamber. The temperature field in the chamber is of great importance since local integument over-cooling may occur. Numerical simulation of WBC has been carried out. Chamber design modification has been proposed in order to increase the uniformity of the internal temperature field. The results have been compared with the ones obtained for a standard chamber design. The value of temperature gradient formed in the chamber containing curved wall with certain height has been decreased almost twice in comparison with the results obtained for the standard design. The modification proposed may increase both safety and comfort of cryotherapy.

  9. The effect and the amendment of thermoregulation to the stability of radon concentration in radon chamber

    International Nuclear Information System (INIS)

    Zhang Xiongjie; Wang Renbo; Qu Jinhui; Tang Bin; Zhu Zhifu; Man Zaigang

    2010-01-01

    When the temperature in the airtight radon chamber was adjusted, it would induce the frequent changes of the air pressure in chamber, then the radon concentration in the radon chamber would continuously reduce, which could seriously destroy the stability of the radon concentration in radon chamber. In this paper, on the study of the effect reasons to the stability of radon concentration in airtight radon chamber due to the thermoregulation, a new amendment scheme was put forward, and the solutions of the relevant parameters were discussed. The amendment scheme had been successfully applied to HD-6 radon chamber, and achieved good results. (authors)

  10. Dentin and pulp sense cold stimulus.

    Science.gov (United States)

    Tokuda, Masayuki; Tatsuyama, Shoko; Fujisawa, Mari; Morimoto-Yamashita, Yoko; Kawakami, Yoshiko; Shibukawa, Yoshiyuki; Torii, Mistuso

    2015-05-01

    Dentin hypersensitivity is a common symptom, and recent convergent evidences have reported transient receptor potential (TRP) channels in odontoblasts act as mechanical and thermal molecular sensor, which detect stimulation applied on the exposed dentin surface, to drive multiple odontoblastic cellular functions, such as sensory transduction and/or dentin formation. In the present study, we confirmed expression of TRP melastatin subfamily member-8 (TRPM8) channels in primary cultured cells derived from human dental pulp cells (HPCs) and mouse odontoblast-lineage cells (OLCs) as well as in dentin matrix protein-1 (DMP-1) and dentin sialoprotein (DSP) positive acutely isolated rat odontoblasts from dental pulp tissue slice culture by immunohistochemical analyses. In addition, we detected TRPM8 channel expression on HPCs and OLCs by RT-PCR and Western blotting analyses. These results indicated that both odontoblasts and dental pulp cells express TRPM8 channels in rat, mouse and human, and therefore we hypothesize they may contribute as cold sensor in tooth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Potential for biohydrogen and methane production from olive pulp

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Skiadas, Ioannis V.; Ahring, Birgitte Kiær

    2005-01-01

    The present study investigates the potential for thermophilic biohydrogen and methane production from olive pulp, which is the semi-solid residue coming from the two-phase processing of olives. It focussed on: a) production of methane from the raw olive pulp, b) anaerobic bio-production of hydrogen...... from the olive pulp, and c) subsequent anaerobic treatment of the hydrogen-effluent with the simultaneous production of methane. Both continuous and batch experiments were performed. The hydrogen potential of the olive pulp amounted to 1.6 mmole H-2 per g TS. The methane potential of the raw olive pulp...... and hydrogen-effluent was as high as 19 mmole CH4 per g TS. This suggests that olive pulp is an ideal substrate for methane production and it shows that biohydrogen production can be very efficiently coupled with a subsequent step for methane production....

  12. Citric Acid Production by Aspergillus niger Cultivated on Parkia biglobosa Fruit Pulp

    OpenAIRE

    Auta, Helen Shnada; Abidoye, Khadijat Toyin; Tahir, Hauwa; Ibrahim, Aliyu Dabai; Aransiola, Sesan Abiodun

    2014-01-01

    The study was conducted to investigate the potential of Parkia biglobosa fruit pulp as substrate for citric acid production by Aspergillus niger. Reducing sugar was estimated by 3,5-dinitrosalicylic acid and citric acid was estimated spectrophotometrically using pyridine-acetic anhydride methods. The studies revealed that production parameters (pH, inoculum size, substrate concentration, incubation temperature, and fermentation period) had profound effect on the amount of citric acid produced...

  13. Dental Pulp Defence and Repair Mechanisms in Dental Caries

    OpenAIRE

    Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J.; Cooper, Paul R.

    2015-01-01

    Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and red...

  14. Testing fireproof materials in a combustion chamber

    Directory of Open Access Journals (Sweden)

    Kulhavy Petr

    2017-01-01

    Full Text Available This article deals with a prototype concept, real experiment and numerical simulation of a combustion chamber, designed for testing fire resistance some new insulating composite materials. This concept of a device used for testing various materials, providing possibility of monitoring temperatures during controlled gas combustion. As a fuel for the combustion process propane butane mixture has been used and also several kinds of burners with various conditions of inlet air (forced, free and fuel flows were tested. The tested samples were layered sandwich materials based on various materials or foams, used as fillers in fire shutters. The temperature distribution was measured by using thermocouples. A simulation of whole concept of experimental chamber has been carried out as the non-premixed combustion process in the commercial final volume sw Pyrosim. The result was to design chamber with a construction suitable, according to the international standards, achieve the required values (temperature in time. Model of the combustion based on a stoichiometric defined mixture of gas and the tested layered samples showed good conformity with experimental results – i.e. thermal distribution inside and heat release rate that has gone through the sample.

  15. INVESTIGATION OF AQUEOUS BIPHASIC SYSTEMS FOR THE SEPARATIONS OF LIGNINS FROM CELLULOSE IN THE PAPER PULPING PROCESS. (R826732)

    Science.gov (United States)

    In efforts to apply a polymer-based aqueous biphasic system (ABS) extraction to the paper pulping process, the study of the distribution of various lignin and cellulosic fractions in ABS and the effects of temperature on system composition and solute partitioning have been inv...

  16. Diogene pictorial drift chamber

    International Nuclear Information System (INIS)

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive)

  17. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  18. Simulation of chamber experiments

    International Nuclear Information System (INIS)

    Ivanov, V.G.

    1981-01-01

    The description of the system of computer simulation of experiments conducted by means of track detectors with film data output is given. Considered is the principle of organization of computer model of the chamber experiment comprising the following stages: generation of events, generation of measurements, ge-- neration of scanning results, generation of distorbions, generated data calibration, filtration, events reconstruction, kinematic identification, total results tape formation, analysis of the results. Generation programs are formed as special RAM-files, where the RAM-file is the text of the program written in FORTRAN and divided into structural elements. All the programs are a ''part of the ''Hydra'' system. The system possibilities are considered on the base of the CDSC-6500 computer. The five-beam event generation, creation data structure for identification and calculation by the kinematic program take about 1s of CDC-6500 computer time [ru

  19. Nucleation in bubble chambers

    International Nuclear Information System (INIS)

    Harigel, G.G.

    1988-01-01

    Various sources and mechanisms for bubble formation in superheated liquids are discussed. Bubble chambers can be filled with a great variety of liquids, such as e.g. the cryogenic liquids hydrogen, deuterium, neon, neon/hydrogen mixtures, argon, nitrogen, argon/nitrogen mixtures, or the warm liquids propane and various Freon like Freon-13B1. The superheated state is normally achieved by a rapid movement of an expansion piston or membrane, but can also be produced by standing ultrasonic waves, shock waves, or putting liquids under tension. Bubble formation can be initiated by ionizing particles, by intense (laser) light, or on rough surfaces. The creation of embryonic bubbles is not completely understood, but the macroscopic growth and condensation can be calculated, allowing to estimate the dynamic heat load [fr

  20. Association between dental pulp stones and calcifying nanoparticles.

    Science.gov (United States)

    Zeng, Jinfeng; Yang, Fang; Zhang, Wei; Gong, Qimei; Du, Yu; Ling, Junqi

    2011-01-07

    The etiology of dental pulp stones, one type of extraskeletal calcification disease, remains elusive to date. Calcifying nanoparticles (CNPs), formerly referred to as nanobacteria, were reported to be one etiological factor in a number of extraskeletal calcification diseases. We hypothesized that CNPs are involved in the calcification of the dental pulp tissue, and therefore investigated the link between CNPs and dental pulp stones. Sixty-five freshly collected dental pulp stones, each from a different patient, were analyzed. Thirteen of the pulp stones were examined for the existence of CNPs in situ by immunohistochemical staining (IHS), indirect immunofluorescence staining (IIFS), and transmission electron microscope (TEM). The remaining 52 pulp stones were used for isolation and cultivation of CNPs; the cultured CNPs were identified and confirmed via their shape and growth characteristics. Among the dental pulp stones examined in situ, 84.6% of the tissue samples staines positive for CNPs antigen by IHS; the corresponding rate by IIFS was 92.3 %. In 88.2% of the cultured samples, CNPs were isolated and cultivated successfully. The CNPs were visible under TEM as 200-400 nm diameter spherical particles surrounded by a compact crust. CNPs could be detected and isolated from a high percentage of dental pulp stones, suggesting that CNPs might play an important role in the calcification of dental pulp.

  1. The caries process and its effect on the pulp

    DEFF Research Database (Denmark)

    Bjørndal, Lars

    2008-01-01

    The understanding of the caries process and its effect on the pulp is presented in the context that caries does develop in various rates of progression. Early in the caries process, the pulp reflects changes within lesion activity. Thus, the early pulp response is reversible. Later, the rate...... of caries progression is reflected by the quality of the tertiary dentin. Slowly progressing lesions create tertiary dentin resembling normal tubular dentin. Rapidly progressing lesions lead to the production of a tubular dentin or complete absence of tertiary dentin, as well as pulp necrosis and apical...

  2. A modified efficient method for dental pulp stem cell isolation.

    Science.gov (United States)

    Raoof, Maryam; Yaghoobi, Mohammad Mehdi; Derakhshani, Ali; Kamal-Abadi, Ali Mohammadi; Ebrahimi, Behnam; Abbasnejad, Mehdi; Shokouhinejad, Noushin

    2014-03-01

    Dental pulp stem cells can be used in regenerative endodontic therapy. The aim of this study was to introduce an efficient method for dental pulp stem cells isolation. In this in-vitro study, 60 extracted human third molars were split and pulp tissue was extracted. Dental pulp stem cells were isolated by the following three different methods: (1) digestion of pulp by collagenase/dispase enzyme and culture of the released cells; (2) outgrowth of the cells by culture of undigested pulp pieces; (3) digestion of pulp tissue pieces and fixing them. The cells were cultured in minimum essential medium alpha modification (αMEM) medium supplemented with 20% fetal bovine serum(FBS) in humid 37°C incubator with 5% CO 2. The markers of stem cells were studied by reverse transcriptase polymerase chain reaction (PCR). The student t-test was used for comparing the means of independent groups. P third method, we obtained stem cells successfully with about 60% efficiency after 2 days. The results of RT-PCR suggested the expression of Nanog, Oct-4, and Nucleostemin markers in the isolated cells from dental pulps. This study proposes a new method with high efficacy to obtain dental pulp stem cells in a short time.

  3. Method of increasing efficiency of uranium sorption from acid pulp

    International Nuclear Information System (INIS)

    Parobek, P.; Hinterholzinger, O.; Baloun, S.; Homolka, V.; Vanek, J.; Vebr, Z.

    1989-01-01

    Acid pulp containing uranium is adjusted to pH 2.5 to 4 with alkaline agents, such as alkaline pulp, lime milk, finely ground limestone or soda, or a combination thereof. The treated pulp is put into contact with an ion exchanger whose pH has been adjuste to a range of 2.5 to 4. Partial pulp neutralization causes the hydrolysis of the iron present and an overall reduction in salt contents and a significant increase in the ion exchanger sorptio capacity and thus the overall sorption efficiency. The quality o the eluate and of the uranium concentrate improves. (B.S.)

  4. Kinetic modeling of formic acid pulping of bagasse.

    Science.gov (United States)

    Tu, Qiliang; Fu, Shiyu; Zhan, Huaiyu; Chai, Xinsheng; Lucia, Lucian A

    2008-05-14

    Organic solvent or organosolv pulping processes are alternatives to soda or kraft pulping to delignify lignocellulosic materials for the production of paper pulp. Formic acid, a typical organosolv system, has been presently examined under atmospheric pressure to pulp bagasse fibers. It was shown that efficient bagasse pulping was achieved when the formic acid concentration was limited to 90% (v/v). A statistical kinetic model based on the experimental results for the delignification of bagasse during formic acid pulping was developed that can be described as follows: D (delignification) = 0.747 x C(formicacid) (1.688) x (1 - e(-0.05171t)), an equation that can be used to predict the lignin content in formic acid during the pulping process. The delignification of bagasse by 90% formic acid was almost completed after approximately 80 min, while extended pulping did not improve the delignification but tended to degrade the carbohydrates in bagasse, especially the hemicelluloses, which were rapidly hydrolyzed at the onset of pulping.

  5. Pulping and paper properties of Palmyra palm fruit fibers

    Directory of Open Access Journals (Sweden)

    Waranyou Sridach

    2010-05-01

    Full Text Available Palmyra palm fruit fibers have the properties to be used as an alternative raw material of cellulosic pulps for papermaking.Acid and alkali pulping were investigated by using nitric acid and caustic soda on a laboratory scale, with the purpose of producing printing or writing grade pulp. The chemical composition of fiber strands from palmyra palm fruits were examined, such as holocellulose, cellulose, pentosan, lignin and extractives. The yields of acid and soda pulps were below 40%. The main physical and mechanical properties of hand sheets produced from acid and soda processes were evaluated on 80 g/m2 test sheets as functions of the following parameters: tensile index, tear index, and brightness. The mechanical properties of soda pulps were developed by twin-roll press while it was not necessary to fibrillate acidic pulps through the beating step. The soda pulp sheets presented a lower brightness than that of acidic pulp sheets. The mechanicaland physical properties of the acidic and alkaline pulps verified that they were of an acceptable quality for papermaking.

  6. Proteomic analysis of human tooth pulp: proteomics of human tooth.

    Science.gov (United States)

    Eckhardt, Adam; Jágr, Michal; Pataridis, Statis; Mikšík, Ivan

    2014-12-01

    The unique pulp-dentin complex demonstrates strong regenerative potential, which enables it to respond to disease and traumatic injury. Identifying the proteins of the pulp-dentin complex is crucial to understanding the mechanisms of regeneration, tissue calcification, defense processes, and the reparation of dentin by dental pulp. The lack of knowledge of these proteins limits the development of more efficient therapies. The proteomic profile of human tooth pulp was investigated and compared with the proteome of human dentin and blood. The samples of tooth pulp were obtained from 5 sound permanent human third molars of 5 adults (n = 5). The extracted proteins were separated by 2-dimensional gel electrophoresis, analyzed by nano-liquid chromatography tandem mass spectrometry, and identified by correlating mass spectra to the proteomic databases. A total of 342 proteins were identified with high confidence, and 2 proteins were detected for the first time in an actual human sample. The identified tooth pulp proteins have a variety of functions: structural, catalytic, transporter, protease activity, immune response, and many others. In a comparison with dentin and blood plasma, 140 (pulp/dentin) shared proteins were identified, 37 of which were not observed in plasma. It can be suggested that they might participate in the unique pulp-dentin complex. This proteomic investigation of human tooth pulp, together with the previously published study of human dentin, is one of the most comprehensive proteome lists of human teeth to date. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Functionalized scaffolds to control dental pulp stem cell fate

    Science.gov (United States)

    Piva, Evandro; Silva, Adriana F.; Nör, Jacques E.

    2014-01-01

    Emerging understanding about interactions between stem cells, scaffolds and morphogenic factors has accelerated translational research in the field of dental pulp tissue engineering. Dental pulp stem cells constitute a sub-population of cells endowed with self-renewal and multipotency. Dental pulp stem cells seeded in biodegradable scaffolds and exposed to dentin-derived morphogenic signals give rise to a pulp-like tissue capable of generating new dentin. Notably, dentin-derived proteins are sufficient to induce dental pulp stem cell differentiation into odontoblasts. Ongoing work is focused on developing ways of mobilizing dentin-derived proteins and disinfecting the root canal of necrotic teeth without compromising the morphogenic potential of these signaling molecules. On the other hand, dentin by itself does not appear to be capable of inducing endothelial differentiation of dental pulp stem cells, despite the well known presence of angiogenic factors in dentin. This is particularly relevant in the context of dental pulp tissue engineering in full root canals, where access to blood supply is limited to the apical foramina. To address this challenge, scientists are looking at ways to use the scaffold as a controlled release device for angiogenic factors. The aim of this manuscript is to present and discuss current strategies to functionalize injectable scaffolds and customize them for dental pulp tissue engineering. The long-term goal of this work is to develop stem cell-based therapies that enable the engineering of functional dental pulps capable of generating new tubular dentin in humans. PMID:24698691

  8. Final Technical Report Steam Cycle Washer for Unbleached Pulp

    Energy Technology Data Exchange (ETDEWEB)

    Starkey, Yvonne; Salminen, Reijo; Karlsnes, Andy

    2008-09-22

    Project Abstract for “Steam Cycle Washer for Unbleached Pulp” When completed, the patented SC Washer will provide an innovative, energy efficient demonstration project to wash unbleached pulp using a pressure vessel charged with steam. The Port Townsend Paper Corporation’s pulp mill in Port Townsend, WA was initially selected as the host site for conducting the demonstration of the SCW. Due to 2006 and 2007 delays in the project caused by issues with 21st Century Pulp & Paper, the developer of the SCW, and the 2007 bankruptcy proceedings and subsequent restructuring at Port Townsend Paper, the mill can no longer serve as a host site. An alternate host site is now being sought to complete the commercial demonstration of the Steam Cycle Washer for Unbleached Pulp. Additionally, estimated costs to complete the project have more than doubled since the initial estimates for the project were completed in 2002. Additional grant funding from DOE was sought and in July, 2008 the additional DOE funds were procured under a new DOE award, DE-PS36-08GO98014 issued to INL. Once the new host site is secured the completion of the project will begin under the management of INL. Future progress reports and milestone tracking will be completed under requirements of new DOE Award Number DE-PS36-08GO98014. The following are excerpts from the project Peer Review completed in 2006. They describe the project in some detail. Additional information can be found by reviewing DOE Award Number: DE-PS36-08GO98014. 5. Statement of Problem and Technical Barriers: The chemical pulping industry is one of the major users of fresh water in the United States. On average the industry uses over 80 tons of water to produce one ton of pulp, some states use up to 50% more (Washington 120 and Wisconsin 140). In order to process one ton of pulp using 80 tons of process water, a large amount of: • energy is used in process heat and • power is required for pumping the large volume of pulp slurries

  9. EFFECT OF LIGNIN CONTENT OF Eucalyptus globulus WOOD IN KRAFT PULPING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Gabriel Valim Cardoso

    2011-03-01

    Full Text Available In this research, it was analyzed the lignin content effect of Eucalyptus globulus wood in kraft pulping optimization. Seventy-two laboratory cooking were made with wood chips obtained from six Eucalyptus globulus trees selected from a group of 50 trees. The wood chips from three trees with the lowest lignin content, with average 20,53%, were mixed proportionally based on the tree weights, obtaining the sample of low lignin content wood. The same was made to obtain the sample for wood chips with the highest lignin content, with average 23,02%. The two lignin levels were statistically different. The two wood samples had basic densities statistically not different. Using three maximum temperatures levels (160, 165 and 170ºC, and three active alkali charged (17, 18,5 and 20%, the wood chips were converted to kraft pulps. The pulps were then characterized to analyze the influence of the distinct treatments employed in the cooking on their properties. The effect of the cooking conditions was expressed by mathematical models in order to determine the optimum points for each of the evaluated properties. The optimization process indicated maximum temperature of 168ºC, and active alkali of 19%, for maximum kraft pulping yield to achieve kappa number 18; this result was for woods with low lignin content. For woods containing the high lignin content, the optimization showed maximum cooking temperature of 169ºC and active alkali of 19% for kappa number of 18. The average reduction of 2,49% in wood lignin content resulted a correspondent gain of 2,2% in the kraft yield (o.d. basis and a reduction on the active alkali charge of 1,2% (o.d. basis to achieve kappa numbers from 16 to 19, preserving pulp properties. If the option is to work with kappa number 19 instead of 16, the gain in kraft yield is approximately 2%. Therefore, when working with low lignin content wood and kappa number 19 instead of 16, a substantial gain of approximately 4,2% is obtained

  10. Hydrogen production from carrot pulp by the extreme thermophiles Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana

    NARCIS (Netherlands)

    Vrije, de G.J.; Budde, M.A.W.; Lips, S.J.J.; Bakker, R.R.; Mars, A.E.; Claassen, P.A.M.

    2010-01-01

    Hydrogen was produced from carrot pulp hydrolysate, untreated carrot pulp and (mixtures of) glucose and fructose by the extreme thermophiles Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana in pH-controlled bioreactors. Carrot pulp hydrolysate was obtained after enzymatic hydrolysis

  11. In vitro optical detection of simulated blood pulse in a human tooth pulp model.

    Science.gov (United States)

    Niklas, A; Hiller, K-A; Jaeger, A; Brandt, M; Putzger, J; Ermer, C; Schulz, I; Monkman, G; Giglberger, S; Hirmer, M; Danilov, S; Ganichev, S; Schmalz, G

    2014-01-01

    Noninvasive optical methods such as photoplethysmography, established for blood pulse detection in organs, have been proposed for vitality testing of human dental pulp. However, no information is available on the mechanism of action in a closed pulp chamber and on the impairing influence of other than pulpal blood flow sources. Therefore, the aim of the present in vitro study was to develop a device for the optical detection of pulpal blood pulse and to investigate the influence of different parameters (including gingival blood flow [GBF] simulation) on the derived signals. Air, Millipore water, human erythrocyte suspensions (HES), non-particulate hemoglobin suspension (NPHS), and lysed hemoglobin suspension (LHES) were pulsed through a flexible (silicone) or a rigid (glass) tube placed within an extracted human molar in a tooth-gingiva model. HES was additionally pulsed through a rigid tube around the tooth, simulating GBF alone or combined with the flow through the tooth by two separate peristaltic pumps. Light from high-power light-emitting diodes (625 nm (red) and 940 nm (infrared [IR]); Golden Dragon, Osram, Germany) was introduced to the coronal/buccal part of the tooth, and the signal amplitude [∆U, in volts] of transmitted light was detected by a sensor at the opposite side of the tooth. Signal processing was carried out by means of a newly developed blood pulse detector. Finally, experiments were repeated with the application of rubber dam (blue, purple, pink, and black), aluminum foil, and black antistatic plastic foil. Nonparametric statistical analysis was applied (n = 5; α = 0.05). Signals were obtained for HES and LHES, but not with air, Millipore water, or NPHS. Using a flexible tube, signals for HES were higher for IR compared to red light, whereas for the rigid tube, the signals were significantly higher for red light than for IR. In general, significantly less signal amplitude was recorded for HES with the rigid glass tube than with the

  12. Peltier-based cloud chamber

    Science.gov (United States)

    Nar, Sevda Yeliz; Cakir, Altan

    2018-02-01

    Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

  13. Pulp nerve fibers distribution of human carious teeth: An immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Tetiana Haniastuti

    2010-12-01

    Full Text Available Background: Human dental pulp is richly innervated by trigeminal afferent axons that subserve nociceptive function. Accordingly, they respond to stimuli that induce injury to the pulp tissue. An injury to the nerve terminals and other tissue components in the pulp stimulate metabolic activation of the neurons in the trigeminal ganglion which result in morphological changes in the peripheral nerve terminals. Purpose: The aim of the study was to observe caries-related changes in the distribution of human pulpal nerve. Methods: Under informed consents, 15 third molars with caries at various stages of decay and 5 intact third molars were extracted because of orthodontic or therapeutic reasons. All samples were observed by micro-computed tomography to confirm the lesion condition 3-dimensionally, before decalcifying with 10% EDTA solution (pH 7.4. The specimens were then processed for immunohistochemistry using anti-protein gene products (PGP 9.5, a specific marker for the nerve fiber. Results: In normal intact teeth, PGP 9.5 immunoreactive nerve fibers were seen concentrated beneath the odontoblast cell layer. Nerve fibers exhibited an increased density along the pulp-dentin border corresponding to the carious lesions. Conclusion: Neural density increases throughout the pulp chamber with the progression of caries. The activity and pathogenicity of the lesion as well as caries depth, might influence the degree of neural sprouting.Latar belakang: Pulpa gigi manusia diinervasi oleh serabut saraf trigeminal yang berespon terhadap stimuli penyebab perlukaan dengan menimbulkan rasa sakit. Perlukaan pada akhiran saraf dan komponen lain dari pulpa akan menstimulasi aktivasi metabolik dari neuron pada ganglion trigeminal sehingga mengakibatkan perubahan morfologi pada akhiran saraf perifer. Tujuan: Penelitian ini bertujuan untuk mengamati perubahan distribusi saraf pada pulpa gigi manusia yang disebabkan oleh proses karies. Metode: Penelitian ini menggunakan

  14. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping.

    Science.gov (United States)

    Borrega, Marc; Tolonen, Lasse K; Bardot, Fanny; Testova, Lidia; Sixta, Herbert

    2013-05-01

    The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Pemanfaatan Limbah Pulp Buah Semangka (Citrullus vulgaris, Schard) Untuk Pembuatan Nata De Watermelon Pulp Dengan Menggunakan Bakteri Acetobacter xylinum

    OpenAIRE

    Mawaddah

    2011-01-01

    This research done to know can or not the waste of watermelon pulp use to produce nata and how the effect of mass variation using to nata’s quality. This research was done with mass variation of watermelon pulp that is 10 g, 20 g, 30 g, 40 g, 50 g, 60 g, and watermelon pulp without adding sugar as control. Statistical analysis count the thickness, water content, ash content, fiber content and organoleptic test of texture, color, aroma, and taste of nata de watermelon pulp. The result show...

  16. A Histopathological Study of Direct Pulp Capping with Adhesive Resins

    Directory of Open Access Journals (Sweden)

    J. Salhenejad

    2004-12-01

    Full Text Available Statement of Problem: Recently, it has been proposed that different adhesive materials can be used for direct pulp capping. Previous studies have demonstrated that multi steps dentin adhesives could form reparative dentin similar to calcium hydroxide (CH.Purpose: The aim of this study was to evaluate the histological pulp response of ninety mechanically exposed cat pulps to two adhesive resins (Scotch Bond MP and Single Bond 3M were compared with a calcium hydroxide cement (Dycal, Dentsply.Materials and Methods : Class V facial cavities with similar pulpal exposures were prepared in canines. In the experimental groups phosphoric acid was used to etch the enamel and dentin and pulp exposure, and after it dentin adhesives was applied. The exposure point of the control group was capped with Dycal then the remainder of the cavities was etched and a dentin adhesive (single bond was applied. All of the cavities were restored with a composite resin (Z 100 in usual manner. The animals were scarified after 7, 30 and 60 days (n=30, and the pulp evaluated histologically, statistical analysis was carried out with Kruskal- Wallis test (a=0.05.Results: The data showed that most of the cases had mild inflammation of pulp tissue.There was no significant difference in inflammatory reaction of pulp by Dycal and two adhesive systems, severe inflammatory reaction of pulp was observed only in most of the 30- day Single Bond group. Soft tissue organization of dentin bridge was less than ScotchBond and Dycal groups, the differentiation of dentin bridge was less than Scotch Bond group after 7 days.Conclusion: Slight inflammatory cell infiltration was the main reaction of exposed pulp when two commercially available adhesive resins were placed directly on the exposed pulp.There was no significant difference in inflammatory reaction of pulp between Dycal and two adhesive systems after 7 days and 60 days. After 7 days most of the specimens showed an amount of predentin

  17. Stability of fragrance patch test preparations applied in test chambers.

    Science.gov (United States)

    Mowitz, M; Zimerson, E; Svedman, C; Bruze, M

    2012-10-01

    Petrolatum patch test preparations are for practical reasons often applied in test chambers in advance, several hours or even days before the patient is tested. As many fragrance compounds are volatile it may be suspected that petrolatum preparations applied in test chambers are not stable over time. To investigate the stability of petrolatum preparations of the seven chemically defined components in the fragrance mix (FM I) when stored in test chambers. Samples of petrolatum preparations applied in test chambers stored at room temperature and in a refrigerator for between 4 and 144 h were analysed using liquid chromatographic methods. The concentration decreased by ≥ 20% within 8 h in four of seven preparations stored in Finn chambers at room temperature. When stored in a refrigerator only the preparation of cinnamal had decreased by ≥ 20% within 24 h. The stability of preparations of cinnamal stored in IQ chambers with a plastic cover was slightly better, but like the preparations applied in Finn chambers, the concentration decreased by ≥ 20% within 4 h at room temperature and within 24 h in a refrigerator. Cinnamal and cinnamyl alcohol were found to be more stable when analysed as ingredients in FM I compared with when analysed in individual preparations. Within a couple of hours several fragrance allergens evaporate from test chambers to an extent that may affect the outcome of the patch test. Application to the test chambers should be performed as close to the patch test occasion as possible and storage in a refrigerator is recommended. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  18. Cell-derived micro-environment helps dental pulp stem cells promote dental pulp regeneration.

    Science.gov (United States)

    Zhang, Xuexin; Li, Hui; Sun, Jingjing; Luo, Xiangyou; Yang, Hefeng; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

    2017-10-01

    The function of the dental pulp is closely connected to the extracellular matrix (ECM) structure, and ECM has received significant attention due to its biological functions for regulating cells. As such, the interaction between the ECM niche and cells is worth exploring for potential clinical uses. In this study, dental pulp stem cell (DPSC)-derived ECM (DPM) was prepared through cell culture and decellularization to function as the cell niche, and changes in DPSC behaviour and histological analysis of dental pulp tissue regeneration were evaluated following the DPM culture. DPM promoted the replication of DPSCs and exhibited retention of their mineralization. Then, the DPM-based culture strategy under odontogenic culture medium was further investigated, and the mineralization-related markers showed that DPSCs were regulated towards odontogenic differentiation. Dental pulp-like tissue with well-arranged ECM was harvested after a 2-month subcutaneous implantation in nude mice with DPM application. Additionally, DPSCs cultured on the plastic culture surface showed the up-regulation of mineralization makers in vitro, but there was a disorder in matrix formation and mineralization when the cells were cultured in vivo. DPM-based cultivation could serve as a cell niche and modulate DPSC behaviour, and this method also provided an alternative to harvest tissue-specific ECM and provided a strategy for ECM-cell interaction. © 2017 John Wiley & Sons Ltd.

  19. The little holographic bubble chambers

    International Nuclear Information System (INIS)

    Herve, A.

    1983-01-01

    The lifetime study of the charmed particles has readvanced the idea to use holography for the little fast-cycle bubble chambers. A pilot experiment has been realised in 1982 with a little bubble chamber filled up with freon-115. 40000 holograms have been recorded [fr

  20. Conservation of jucara pulp (Euterpe edulis) submitted to gamma radiation, pasteurization, lyophilization and spray drying

    International Nuclear Information System (INIS)

    Silva, Paula Porrelli Moreira da

    2013-01-01

    In Brazil there are unexplored fruit species, which represent an opportunity for producers to access special markets, where consumers appreciate the exotic character and presence of nutrients capable of preventing degenerative diseases. In this context, jucara palm (Euterpe edulis), native of the Atlantic Forest, has long been explored only for the removal of the stem, but currently the pulp of its fruit is becoming more popular. The intense purple color is due to the presence of anthocyanins, powerful antioxidants that act by inhibiting or decreasing the effects unleashed by free radicals. The pulp is highly perishable and its preservation is impossible at room temperature, lowering its market value in sales. In face of this, we need technologies that minimize nutritional and sensorial losses in order to produce healthy, tasty and long lasting foods. This study consists of five experiments with jucara pulp, which aimed to: evaluate the physico-chemical, mineral and lipid composition; realize the sensory characterization by Quantitative Descriptive Analysis (QDA); evaluate the physico-chemical and sensory conservation when submitted to radiation gamma, acidification and pasteurization, and dehydration by spray and freeze drying. The fruits have been obtained at Parque das Neblinas (Mogi das Cruzes/SP) and depulped at Agribusiness, Food and Nutrition Department (ESALQ/USP). Was verified that jucara pulp is excellent source of energy and minerals K, Fe, Co, Mg, Cu, Zn, Mn and Mo; rich in anthocyanins and fatty oils of good quality (palmitic, oleic and linoleic). The irradiation of pulp was performed at the Institute of Energy and Nuclear Research (IPEN - Sao Paulo, SP) at doses 0,0, 2,5, 5,0, 7,5 and 10,0 kGy and stored at 6 degree C for 30 days (fortnightly assessments). That process was not promising for the conservation of the product at 6 degree C, because the degradation of anthocyanins and phenolic compounds was accelerated and the color changed from purple to

  1. Mill Integration-Pulping, Stream Reforming and Direct Causticization for Black Liquor Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Adriaan van Heiningen

    2007-06-30

    agglomeration problems of the conversion of Na{sub 2}CO{sub 3} to (high sodium) titanates during gasification of black liquor in the presence of (low sodium) titanates or TiO{sub 2} (Task 2). MTCI/ThermoChem tested the performance and operability of the combined technology of steam reforming and direct causticization in their Process Development Unit (PDU) (Task 3). The specific objectives were: (1) to investigate how split sulfidity and polysulfide (+ AQ) pulping can be used to increase pulp fiber yield and properties compared to conventional kraft pulping; (2) to determine the economics of black liquor gasification combined with these pulping technologies in comparison with conventional kraft pulping and black liquor recovery; (3) to determine the effect of operating conditions on the kinetics of the titanate-based direct causticization reaction during black liquor gasification at relatively low temperatures ({le} 750 C); (4) to determine the mechanism of particle agglomeration during gasification of black liquor in the presence of titanates at relatively low temperatures ({le} 750 C); and (5) to verify performance and operability of the combined technology of steam reforming and direct causticization of black liquor in a pilot scale fluidized bed test facility.

  2. Drift velocity monitoring of the CMS muon drift chambers

    CERN Document Server

    Sonnenschein, Lars

    2010-01-01

    The drift velocity in drift tubes of the CMS muon chambers is a key parameter for the muon track reconstruction and trigger. It needs to be monitored precisely in order to detect any deviation from its nominal value. A change in absolute pressure, a variation of the gas admixture or a contamination of the chamber gas by air affect the drift velocity. Furthermore the temperature and magnetic field influence its value. First data, taken with a dedicated Velocity Drift Chamber (VDC) built by RWTH Aachen IIIA are presented.

  3. The CLEO III drift chamber

    CERN Document Server

    Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

    2002-01-01

    The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

  4. Interappointment emergencies in teeth with necrotic pulps.

    Science.gov (United States)

    Alaçam, Tayfun; Tinaz, Ali Cemal

    2002-05-01

    The incidence of interappointment emergencies in symptomatic and asymptomatic teeth with necrotic pulps was evaluated, and severity of flare-ups was determined by a quantitative method using a flare-up index. There were no significant differences in the incidence of flare-ups attributable to gender, age, diameter of lesion, taking analgesics, placebos, or no medication, or preoperative symptomatic or asymptomatic tooth diagnoses (p > 0.05). There were significantly more painful flare-ups in mandibular teeth than in maxillary (p < 0.05).

  5. Computational fluid dynamic (CFD) investigation of thermal uniformity in a thermal cycling based calibration chamber for MEMS

    Science.gov (United States)

    Gui, Xulong; Luo, Xiaobing; Wang, Xiaoping; Liu, Sheng

    2015-12-01

    Micro-electrical-mechanical system (MEMS) has become important for many industries such as automotive, home appliance, portable electronics, especially with the emergence of Internet of Things. Volume testing with temperature compensation has been essential in order to provide MEMS based sensors with repeatability, consistency, reliability, and durability, but low cost. Particularly, in the temperature calibration test, temperature uniformity of thermal cycling based calibration chamber becomes more important for obtaining precision sensors, as each sensor is different before the calibration. When sensor samples are loaded into the chamber, we usually open the door of the chamber, then place fixtures into chamber and mount the samples on the fixtures. These operations may affect temperature uniformity in the chamber. In order to study the influencing factors of sample-loading on the temperature uniformity in the chamber during calibration testing, numerical simulation work was conducted first. Temperature field and flow field were simulated in empty chamber, chamber with open door, chamber with samples, and chamber with fixtures, respectively. By simulation, it was found that opening chamber door, sample size and number of fixture layers all have effects on flow field and temperature field. By experimental validation, it was found that the measured temperature value was consistent with the simulated temperature value.

  6. CD146 positive human dental pulp stem cells promote regeneration of dentin/pulp-like structures.

    Science.gov (United States)

    Matsui, Mikiko; Kobayashi, Tomoko; Tsutsui, Takeo W

    2018-04-01

    CD146 and STRO-1 are endothelial biomarkers that are co-expressed on the cellular membranes of blood vessels within human dental pulp tissue. This study characterized the percentage of dentin-like structures produced by CD146-positive (CD146 + ) human dental pulp stem cells (DPSCs), compared with their CD146-negative (CD146 - ) counterparts. DPSC populations were enriched using magnetic-activated cell sorting (MACS), yielding CD146 + and CD146 - cells, as well as mixtures composed of 25% CD146 + cells and 75% CD146 - cells (CD146 +/- ). Cell growth assays indicated that CD146 + cells exhibit an approximate 3-4 h difference in doubling time, compared with CD146 - cells. Cell cycle distributions were determined by flow cytometry analysis. The low percentage of CD146 + cells' DNA content in G 0 /G 1 phase were compared with CD146 - and non-separated cells. In contrast to CD146 - and non-separated cells, prompt mineralization was observed in CD146 + cells. Subsequently, qRT-PCR revealed high mRNA expression of CD146 and Alkaline phosphatase in mineralization-induced CD146 + cells. CD146 + cells were also observed high adipogenic ability by Oil red O staining. Histological examinations revealed an increased area of dentin/pulp-like structures in transplanted CD146 + cells, compared with CD146 - and CD146 +/- cells. Immunohistochemical studies detected dentin matrix protein-1 (DMP1) and dentin sialophosphoprotein (DSPP), as well as human mitochondria, in transplanted DPSCs. Co-expression of CD146 and GFP indicated that CD146 was expressed in transplanted CD146 + cells. CD146 + cells may promote mineralization and generate dentin/pulp-like structures, suggesting a role in self-renewal of stem cells and dental pulp regenerative therapy.

  7. Culture of human dental pulp cells at variable times post-tooth extraction

    Directory of Open Access Journals (Sweden)

    BENÍCIO Daniela Ferreira Araújo

    2018-02-01

    Full Text Available Abstract The aim of this study was to investigate the viability of human dental pulp cells from extracted teeth kept at standard room temperature and atmospheric pressure for different periods of time. Twenty-one healthy permanent teeth were used. They were divided into five groups according to the expected time from extraction to processing. One group was tested immediately after extraction; the other groups were each tested at one of the following time points: 30 minutes, 1 hour, 2 hours, and 5 hours post-extraction. Cell morphology was analysed by light microscopy; cell proliferation was analysed using MTT assay and by counting the viable cells in a haemocytometer. Similar results were observed in all groups (p < 0.05. A delay of up to five hours for tooth processing and tissue collection does not preclude the establishment of dental pulp cell cultures, affect the morphology of these cells, or reduce their proliferative potential.

  8. Chemical pulping of waste pineapple leaves fiber for kraft paper production

    Directory of Open Access Journals (Sweden)

    Waham Ashaier Laftah

    2015-07-01

    Full Text Available The main objective of this study is to evaluate the implementation of acetone as a pulping agent for pineapple leaves. Mixtures of water and acetone with concentration of 1%, 3%, 5%, 7%, and 10% were used. The effects of soaking and delignification time on the paper properties were investigated. Thermal and physical properties of paper sheet were studied using thermogravimetric analysis (TGA and tearing resistance test respectively. The morphological properties were observed using microscope at 200× magnification. The paper sheet produced from pulping with 3% acetone concentration shows the highest mechanical properties. Papers strength was improved by increasing the delignification time. The delignification time was reduced by cooking the pineapple leaves at a temperature of 118 °C under applied pressure of 80 kPa which has remarkable effect on paper strength.

  9. Influence of moderate to severe chronic periodontitis on dental pulp.

    Science.gov (United States)

    Fatemi, K; Disfani, R; Zare, R; Moeintaghavi, A; Ali, Saadat A; Boostani, H R

    2012-10-01

    The relationship between periodontal disease and dental pulp changes is controversial and has been debated for many years. This human study was performed to evaluate the possible effects of moderate to advanced periodontal disease on the different aspect of dental pulp structure. Twenty hopeless permanent teeth were extracted from systemically healthy adults because of moderate to advanced chronic periodontitis, with a bone loss of >6 mm and a mobility of grade 2 or 3. Upon extraction, the apical 2 to 3 mm of the roots were immediately sectioned. Four to five sections were mounted on each slide, and every third slide was stained with hematoxylin and eosin. The specimens were histologically processed and examined by an oral pathologist. Non-inflamed pulp, with partial or complete necrosis in some sections and several non-necrotic sections, was found in only 6.3% of teeth. Most teeth (58.3%) displayed edematous pulps. Slightly fibrotic pulps were seen in 52.1% of sections. Odontoblastic integrity was seen in 31.3% of teeth. Most teeth (77.1%) displayed no pulp stones. In 43.8% of teeth, the pulp vessels displayed dilatation. Moderate to advanced periodontal disease can affect the dental pulp. Careful consideration of diagnostic and treatment planing in patients with endodontic-periodontal involvement is therefore recommended.

  10. Influence of moderate to severe chronic periodontitis on dental pulp

    Science.gov (United States)

    Fatemi, K; Disfani, R; Zare, R; Moeintaghavi, A; Ali, Saadat A.; Boostani, H. R

    2012-01-01

    Background: The relationship between periodontal disease and dental pulp changes is controversial and has been debated for many years. This human study was performed to evaluate the possible effects of moderate to advanced periodontal disease on the different aspect of dental pulp structure. Materials and Methods: Twenty hopeless permanent teeth were extracted from systemically healthy adults because of moderate to advanced chronic periodontitis, with a bone loss of >6 mm and a mobility of grade 2 or 3. Upon extraction, the apical 2 to 3 mm of the roots were immediately sectioned. Four to five sections were mounted on each slide, and every third slide was stained with hematoxylin and eosin. The specimens were histologically processed and examined by an oral pathologist. Results: Non-inflamed pulp, with partial or complete necrosis in some sections and several non-necrotic sections, was found in only 6.3% of teeth. Most teeth (58.3%) displayed edematous pulps. Slightly fibrotic pulps were seen in 52.1% of sections. Odontoblastic integrity was seen in 31.3% of teeth. Most teeth (77.1%) displayed no pulp stones. In 43.8% of teeth, the pulp vessels displayed dilatation. Conclusions: Moderate to advanced periodontal disease can affect the dental pulp. Careful consideration of diagnostic and treatment planing in patients with endodontic-periodontal involvement is therefore recommended. PMID:23493524

  11. Differentiation ability of rat postnatal dental pulp cells in vitro.

    NARCIS (Netherlands)

    Zhang, W.; Walboomers, X.F.; Wolke, J.G.C.; Bian, Z.; Fan, M.W.; Jansen, J.A.

    2005-01-01

    The current rapid progression in stem cell research has enhanced our knowledge of dental tissue regeneration. In this study, rat dental pulp cells were isolated and their differentiation ability was evaluated. First, dental pulp cells were obtained from maxillary incisors of male Wistar rats.

  12. 78 FR 38877 - Kraft Pulp Mills NSPS Review

    Science.gov (United States)

    2013-06-28

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 60 [EPA-HQ-OAR-2012-0640] FRL-9829-3 RIN 2060-AR64 Kraft Pulp Mills NSPS Review AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... comments on the May 23, 2013, proposed rule titled, ``Kraft Pulp Mills NSPS Review'' is being extended by...

  13. Eggshells – assisted hydrolysis of banana pulp for biogas production

    African Journals Online (AJOL)

    KARAKANA

    In this study, pretreatment of banana pulp using eggshells in both calcined and un-calcined forms to examine the ... Key words: Anaerobic digestion, banana pulp hydrolysis biogas, eggshells. .... obtain fine powder. ..... using pig waste and cassava peels. ... from bioethanol waste: the effect of pH and urea addition to biogas.

  14. Conditioning of vacuum chamber by RF plasma

    International Nuclear Information System (INIS)

    Elizondo, J.I.; Nascimento, I.C. do

    1985-01-01

    A new conditioning vaccum chamber system is presented. It consists in hydrogen plasm generation by microwaves with low electronic temperature (Te approx. 5eV) and low ionization degree. The ions and neutral atoms generated in the reaction: e + H 2 -> H+ H+ e, bomb the chamber walls combinig themselves to impurities of surface and generating several compounds: H 2 O, CO, CH 4 , CO 2 etc. The vacuum system operates continuosly and remove these compounds. A microwave system using magnetron valve (f=2,45 GHz, P=800W) was constructed for TBR (Brazilian tokamak). The gas partial pressures were monitored before, during and after conditioning showing the efficiency of the process. (M.C.K.) [pt

  15. Plasma Chamber Design and Fabrication Activities

    Science.gov (United States)

    Parodi, B.; Bianchi, A.; Cucchiaro, A.; Coletti, A.; Frosi, P.; Mazzone, G.; Pizzuto, A.; Ramogida, G.; Coppi, B.

    2006-10-01

    A fabrication procedure for a typical Plasma Chamber (PC) sector has been developed to cover all the manufacturing phases, from the raw materials specification (including metallurgical processes) to the machining operations, acceptance procedures and vacuum tests. Basically, the sector is made of shaped elements (forged or rolled) welded together using special fixtures and then machined to achieve the final dimensional accuracy. An upgraded design of the plasma chamber's vertical support that can withstand the estimated electromagnetic loads (Eddy and Halo current plus horizontal net force resulting from the worst plasma disruption scenario VDE, Vertical Displacement Event) has been completed. The maintenance of the radial support can take place hands-on with a direct access from outside the cryostat. With the present design, vacuum tightness is achieved by welding conducted with automatic welding heads. On the outer surface of the PC a dedicated duct system, filled by helium gas, is included to cool down the PC to room temperature when needed.

  16. Investigation of thermal and temporal responses of ionization chambers in radiation dosimetry.

    Science.gov (United States)

    AlMasri, Hussein; Funyu, Akira; Kakinohana, Yasumasa; Murayama, Sadayuki

    2012-07-01

    The ionization chamber is a primary dosimeter that is used in radiation dosimetry. Generally, the ion chamber response requires temperature/pressure correction according to the ideal gas law. However, this correction does not consider the thermal volume effect of chambers. The temporal and thermal volume effects of various chambers (CC01, CC13, NACP parallel-plate, PTW) with different wall and electrode materials have been studied in a water phantom. Measurements were done after heating the water with a suitable heating system, and chambers were submerged for a sufficient time to allow for temperature equilibrium. Temporal results show that all chambers equilibrate quickly in water. The equilibration time was between 3 and 5 min for all chambers. Thermal results show that all chambers expanded in response to heating except for the PTW, which contracted. This might be explained by the differences in the volumes of all chambers and also by the difference in wall material composition of PTW from the other chambers. It was found that the smallest chamber, CC01, showed the greatest expansion. The magnitude of the expansion was ~1, 0.8, and 0.9% for CC01, CC13, and parallel-plate chambers, respectively, in the temperature range of 295-320 K. The magnitude of the detected contraction was <0.3% for PTW in the same temperature range. For absolute dosimetry, it is necessary to make corrections for the ion chamber response, especially for small ion chambers like the CC01. Otherwise, room and water phantom temperatures should remain within a close range.

  17. Nemesia root hair response to paper pulp substrate for micropropagation.

    Science.gov (United States)

    Labrousse, Pascal; Delmail, David; Decou, Raphaël; Carlué, Michel; Lhernould, Sabine; Krausz, Pierre

    2012-01-01

    Agar substrates for in vitro culture are well adapted to plant micropropagation, but not to plant rooting and acclimatization. Conversely, paper-pulp-based substrates appear as potentially well adapted for in vitro culture and functional root production. To reinforce this hypothesis, this study compares in vitro development of nemesia on several substrates. Strong differences between nemesia roots growing in agar or in paper-pulp substrates were evidenced through scanning electron microscopy. Roots developed in agar have shorter hairs, larger rhizodermal cells, and less organized root caps than those growing on paper pulp. In conclusion, it should be noted that in this study, in vitro microporous substrates such as paper pulp lead to the production of similar root hairs to those found in greenhouse peat substrates. Consequently, if agar could be used for micropropagation, rooting, and plant acclimatization, enhancement could be achieved if rooting stage was performed on micro-porous substrates such as paper pulp.

  18. Path analysis for selection of feijoa with greater pulp weight

    Directory of Open Access Journals (Sweden)

    Joel Donazzolo

    Full Text Available ABSTRACT: The objective of this paper was to identify the direct and indirect effects of feijoa fruits (Acca sellowiana traitson pulp weight, in order to use these traits in indirect genotypes selection. Fruits of five feijoa plants were collected in Rio Grande do Sul, in the years of 2009, 2010 and 2011. Six traits were evaluated: diameter, length, total weight, pulp weight, peel thickness and number of seeds per fruit. In the path analysis, with or without ridge regression, pulp weight was considered as the basic variable, and the other traits were considered as explanatory variables. Total weight and fruit diameter had high direct effect, and are the main traits associated with pulp weight. These traits may serve as criteria for indirect selection to increase feijoa pulp weight, since they are easy to be measured.

  19. Gamma ray induced chromophore modification of softwood thermomechanical pulp

    International Nuclear Information System (INIS)

    Robert, S.; Daneault, C.; Viel, C.; Lepine, F.

    1992-01-01

    This study focuses on bleaching a softwood (black spruce, balsam fur) thermomechanical pulp with gamma rays. Gamma rays are known for their enormous penetrating power, along with their ionizing properties. They can generate highly energetic radicals capable of oxidizing lignin chromophores. The authors studied the influence of isopropyl alcohol, sodium borohydride, oxygen, hydrogen peroxide, nitrogen dioxide and water along with gamma ray irradiation of the pulps. The authors measured the optimal dose and dose rate, along with the influence of the radical scavengers like oxygen on the bleaching effect of gamma irradiated pulps. They observe various degrees of bleaching of these pulps. Evidence relates this bleaching to the generation of perhydroxyl anions upon irradiation of water. Also, they were able to pinpoint the influence of the dose rate on the rate of formation and disappearance of these perhydroxyl anions and their influence on bleaching kinetics. Stability toward photoyellowing, and photoyellowing's kinetic of papers from these pulps was also studied

  20. Holdup time measurement by radioactive tracers in pulp production

    International Nuclear Information System (INIS)

    Roetzer, H.; Donhoffer, D.

    1988-12-01

    A batch of pulp was to be labelled before passing two bleaching towers of a pulp plant. Activated glass fibres were used as a tracer, which contained 24-Na with a half-life of 15 hours. It was shown in laboratory tests, that the glass fibres were suitable for transport studies of wood pulp. For use in the tests the fibres were activated and suspended in water. Due to the small diameter of the fibres (2-5 micrometers) this suspension shows physical properties very similar to the pulp. For detection six scintillation probes were mounted at different positions outside the bleaching tower. Radiation protection during the test was very easy due to the low total activity of the tracer material. Residence time distributions for both towers were measured. The successful tracer experiments show, that the method of labelling is suited for investigations of material transport in the pulp and paper industry. 3 figs., 11 refs., 2 tabs. (Author)

  1. Development of hemicelluloses biorefineries for integration into kraft pulp mills

    Science.gov (United States)

    Ajao, Olumoye Abiodun

    The development and wide spread acceptance of production facilities for biofuels, biochemicals and biomaterials is an important condition for reducing reliance on limited fossil resources and transitioning towards a global biobased economy. Pulp and paper mills in North America are confronted with high energy prices, high production costs and intense competition from emerging economies and low demand for traditional products. Integrated forest biorefineries (IFBR) have been proposed as a mean to diversify their product streams, increase their revenue and become more sustainable. This is feasible because they have access to forest biomass, an established feedstock supply chain and wood processing experience. In addition, the integration of a biorefinery process that can share existing infrastructure and utilities on the site of pulp mill would significantly lower investment cost and associated risks. Kraft pulping mills are promising receptor processes for a biorefinery because they either possess a prehydrolysis step for extracting hemicelluloses sugars prior to wood pulping or it can be added by retrofit. The extracted hemicelluloses could be subsequently transformed into a wide range of value added products for the receptor mill. To successfully implement hemicelluloses biorefinery, novel processes that are technically and economically feasible are required. It is necessary to identify products that would be profitable, develop processes that are energy efficient and the receptor mill should be able to supply the energy, chemicals and material demands of the biorefinery unit. The objective of this thesis is to develop energy efficient and economically viable hemicelluloses biorefineries for integration into a Kraft pulping process. A dissolving pulp mill was the reference case study. The transformation of hemicellulosic sugars via a chemical and biochemical conversion pathway, with furfural and ethanol as representative products for each pathway was studied. In

  2. Incidence and growth of Salmonella enterica on the peel and pulp of avocado (Persea americana) and custard apple (Annona squamosa).

    Science.gov (United States)

    Rezende, Ana Carolina B; Crucello, Juliana; Moreira, Rafael C; Silva, Beatriz S; Sant'Ana, Anderson S

    2016-10-17

    The aim of this study was to assess the incidence and to estimate the growth kinetic parameters (maximum growth rate, μ; lag time, λ; and maximum population, κ) of Salmonella on the peel and pulp of avocado (Perseaamericana var. americana) and custard apple (Annona squamosa L.) as affected by temperature (10-30°C). The incidence of Salmonella was assessed on the peel and pulp of the fruits (n=200 of each fruit), separately, totalizing 800 analyses. Only three samples of custard apple pulp were positive for Salmonella enterica and the three isolates recovered belonged to serotype S. Typhimurium. Salmonella was not recovered from avocado and custard apple peels and from avocado pulp. Generally, the substrate (pulp or peel) of growth did not affect μ values of S. enterica (p>0.05). Very similar μ values were found for S. enterica inoculated in custard apple and avocado. S. enterica presented the highest λ in the peel of the fruits. The growth of S. enterica resulted in larger λ in custard apple in comparison to avocado. For example, the λ of S. enterica in the pulp of custard apple and avocado were 47.0±0.78h and 10.0±3.78h, respectively. The lowest values of κ were obtained at the lower storage temperature conditions (10°C). For instance, κ values of 3.7±0.06log CFU/g and 2.9±0.03log CFU/g were obtained from the growth of S. enterica in avocado and custard apple pulps at 10°C (pavocado led to a κ value of 6.5±0.25log CFU/g, while in the peel led to a κ value of 4.6±0.23log CFU/g (pavocado comprises a better substrate than custard apple for the growth of S. enterica. The square root model fitted to the data obtained in this study and to the growth data available in the literature for other tropical low acid fruits indicated high variability in μ and λ of Salmonella. The results obtained in this study show that whole low acid tropical fruits can harbor Salmonella, and that this foodborne pathogen can not only survive but also grow both on the

  3. Evaluation of temperature change during antimicrobial photodynamic therapy with two different photosensitizers in dental caries.

    Science.gov (United States)

    Mirzaie, Mansoreh; Yassini, Esmael; Ashnagar, Sajjad; Hadadi, Azadeh; Chiniforush, Nasim

    2016-06-01

    Many attempts have been made in elimination of bacteria in infected and demineralized dentin to not only provide efficient bactericidal potential, but to have minimal damage for tooth structure. The aim of this study was to assess the temperature change during aPDT with ICG and TBO compared with conventional Diode laser irradiation. 48 premolar teeth which were selected for this study. A class I cavity was drilled in each teeth, with dimensions of 2mm width, 4mm length and depth of 2.5-3.5mm, providing a dentinal wall of approximately 0.5mm for pulp chamber. Then teeth were randomly allocated in 4 experimental groups (n=12); Group 1: TBO+LED, Group 2: ICG+Diode Laser, Group 3: Diode laser with output power of 0.5W, Group 4: Diode laser with output power of 1W. Thermocouple device was held by experimenter hand and the sensor was in pulp chamber of the teeth. Heat generated during irradiation was reported on LCD screen by NUX Plus software. Repeated measure ANOVA was used in order to compare the temperature before and after laser application. Tukey HSD was used to compare the results between groups. Temperature was risen for about 0.54±0.05°C for group 1, 1.67±0.14°C for group 2, 4.21±0.83°C for group 3, and 4. 50±0.32°C for group 4. The difference between group 1 & 2, 1 & 3 and 1 & 4 was significant (p<0.0001). According to results of this study, Diode (with or without photosensitizer- 0.5 and 1W) can be safely used as alternative approach for disinfection after caries removal in thermal point of view. Copyright © 2016. Published by Elsevier B.V.

  4. Isolation and Characterization of Human Dental Pulp Stem Cells from Cryopreserved Pulp Tissues Obtained from Teeth with Irreversible Pulpitis.

    Science.gov (United States)

    Malekfar, Azin; Valli, Kusum S; Kanafi, Mohammad Mahboob; Bhonde, Ramesh R

    2016-01-01

    Human dental pulp stem cells (DPSCs) are becoming an attractive target for therapeutic purposes because of their neural crest origin and propensity. Although DPSCs can be successfully cryopreserved, there are hardly any reports on cryopreservation of dental pulp tissues obtained from teeth diagnosed with symptomatic irreversible pulpitis during endodontic treatment and isolation and characterization of DPSCs from such cryopreserved pulp. The aim of this study was to cryopreserve the said pulp tissues to propagate and characterize isolated DPSCs. A medium consisting of 90% fetal bovine serum and 10% dimethyl sulfoxide was used for cryopreservation of pulp tissues. DPSCs were isolated from fresh and cryopreserved pulp tissues using an enzymatic method. Cell viability and proliferation were determined using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. DPSC migration and interaction were analyzed with the wound healing assay. Mesenchymal characteristics of DPSCs were verified by flow cytometric analysis of cell surface CD markers. The osteogenic and adipogenic potential of DPSCs was shown by von Kossa and oil red O staining methods, respectively, and the polymerase chain reaction method. We found no significant difference in CD marker expression and osteogenic and adipogenic differentiation potential of DPSCs obtained from fresh and cryopreserved dental pulp tissue. Our study shows that dental pulp can be successfully cryopreserved without losing normal characteristics and differentiation potential of their DPSCs, thus making them suitable for dental banking and future therapeutic purposes. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Efficient energy conversion in the pulp and paper industry: application to a sulfite wood pulping process

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, F.

    2007-07-01

    This report measures the actions performed in 2006 and the actions planned for 2007 within the framework of the project Efficient Energy Conversion in the Pulp and Paper Industry. In addition to the data reconciliation models of the steam and condensate networks and of the process of Borregaard Schweiz AG, process models have been developed with the goal of defining the heat requirements of the process. The combination of utility system data reconciliation with the process models allows to considerably reduce the need for detailed process modelling and for on-site data collection and measurement. A systematic definition of the hot and cold streams in the process has been developed in order to compute the minimum energy requirement of the process. The process requirements have been defined using the dual representation concept where the energy requirement of the process unit operations are systematically analysed from their thermodynamic requirement and the way they are satisfied by the technology that implements the operation. Corresponding to the same energy requirement but realised with different temperature allows on one hand to define the exergy efficiency of the heat transfer system in each of the process unit operations and to identify possible energy savings by heat exchange in the system. The analysis has been completed by the definition of the possible energy recovery from waste streams. The minimum energy requirement of the process using the different requirement representation has been realised and the analysis of the energy savings opportunities is now under preparation. This new step will first concern the definition of the utility system integration and the systematic analysis of the energy savings opportunities followed by the techno-economic evaluation of the most profitable energy savings options in the process. The national and international collaborations constitute also an important part of this project. The project is done in close

  6. Micro plate fission chamber development

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Jiang Li; Liu Rong; Wang Dalun

    2014-01-01

    To conduct the measurement of neutron flux and the fission rate distribution at several position in assemblies, the micro plate fission chamber was designed and fabricated. Since the requirement of smaller volume and less structure material was taken into consideration, it is convinient, commercial and practical to use fission chamber to measure neutron flux in specific condition. In this paper, the structure of fission chamber and process of fabrication were introduced and performance test result was presented. The detection efficiency is 91.7%. (authors)

  7. Pelletron general purpose scattering chamber

    International Nuclear Information System (INIS)

    Chatterjee, A.; Kailas, S.; Kerekette, S.S.; Navin, A.; Kumar, Suresh

    1993-01-01

    A medium sized stainless steel scattering chamber has been constructed for nuclear scattering and reaction experiments at the 14UD pelletron accelerator facility. It has been so designed that several types of detectors, varying from small sized silicon surface barrier detectors to medium sized gas detectors and NaI detectors can be conveniently positioned inside the chamber for detection of charged particles. The chamber has been planned to perform the following types of experiments : angular distributions of elastically scattered particles, fission fragments and other charged particles, angular correlations for charged particles e.g. protons, alphas and fission fragments. (author). 2 figs

  8. Hygroscopic trend of lyophilized ‘mangaba’ pulp powder

    Directory of Open Access Journals (Sweden)

    Juliana Conegero

    Full Text Available ABSTRACT Mangaba is a widely-consumed fruit in the Northeast of Brazil, which is usually exploited through extractivism. This fruit is rich in various nutrients, especially in vitamin C, with pleasant taste and aroma. The lyophilization process transforms these fruits into amorphous powders, which must be analyzed regarding their properties and hygroscopic trend. Thus, the objective of this study was to characterize and evaluate the physico-chemical properties of adsorption isotherms of the lyophilized ‘mangaba’ pulp powder, with addition of maltodextrin (DE 20. The pH, titratable acidity, soluble solids, ascorbic acid and water activity were analyzed. Regarding the isotherms, the mathematical models of GAB, BET, Oswin, and Henderson were used at temperatures of 25, 30, 35 and 40 °C. The obtained powder presented pH of 3.14, titratable acidity of 1.95 mg of citric acid 100g-1 of powder, soluble solid contents of 99 ºBrix, ascorbic acid content of 55.97 mg 100g-1 and water activity of 0.16. Henderson was the mathematical model that best fitted the data of the adsorption isotherms at the four evaluated temperatures, with average errors ranging from 5.76 to 9.70% and R2 from 0.9974 to 0.9995.

  9. Proton beam monitor chamber calibration

    International Nuclear Information System (INIS)

    Gomà, C; Meer, D; Safai, S; Lorentini, S

    2014-01-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

  10. A small flat fission chamber

    International Nuclear Information System (INIS)

    Li Yijun; Wang Dalun; Chen Suhe

    1999-01-01

    With fission materials of depleted uranium, natural uranium, enriched uranium, 239 Pu, and 237 Np, the authors have designed and made a series of small flat fission chamber. The authors narrated the construction of the fission chamber and its technological process of manufacture, and furthermore, the authors have measured and discussed the follow correct factor, self-absorption, boundary effect, threshold loss factor, bottom scatter and or so

  11. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  12. The OPAL vertex drift chamber

    International Nuclear Information System (INIS)

    Carter, J.R.; Elcombe, P.A.; Hill, J.C.; Roach, C.M.; Armitage, J.C.; Carnegie, R.K.; Estabrooks, P.; Hemingway, R.; Karlen, D.; McPherson, A.; Pinfold, J.; Roney, J.M.; Routenburg, P.; Waterhouse, J.; Hargrove, C.K.; Klem, D.; Oakham, F.G.; Carter, A.A.; Jones, R.W.L.; Lasota, M.M.B.; Lloyd, S.L.; Pritchard, T.W.; Wyatt, T.R.

    1990-01-01

    A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar. (orig.)

  13. Performance of a Horizontal Triple Cylinder Type Pulping Machine

    Directory of Open Access Journals (Sweden)

    Sukrisno Widyotomo

    2011-05-01

    Full Text Available Pulping is one important step in wet coffee processing method. Pulping process usually uses a machine which constructed by wood or metal materials. A horizontal single cylinder type of fresh coffee cherries pulping machine is the most popular machine in coffee processing. One of the weaknesses of a horizontal single cylinder type of fresh coffee cherries pulping machine is higher in broken beans. Broken bean is one of mayor aspects in defect system that contribute to low quality. Indonesian Coffee and Cocoa Research Institute has designed and tested a horizontal double cylinder type of fresh coffee cherries pulping machine which resulted in 12.6—21.4% of broken beans. To reduce percentage of broken beans, Indonesian Coffee and Cocoa Research Institute has developed and tested a horizontal triple cylinder type of fresh coffee cherries pulping machine. Material tested was fresh mature Robusta coffee cherries, 60—65% (wet basis moisture content; has classified on 3 levels i.e. unsorted, small and medium, and clean from metal and foreign materials. The result showed that the machine produced 6,340 kg/h in optimal capacity for operational conditions, 1400 rpm rotor rotation speed for unsorted coffee cherries with composition 55.5% whole parchment coffee, 3.66% broken beans, and 1% beans in wet skin.Key words : coffee, pulp, pulper, cylinder, quality.

  14. Dental Pulp Defence and Repair Mechanisms in Dental Caries.

    Science.gov (United States)

    Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J; Cooper, Paul R

    2015-01-01

    Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo.

  15. Dental Pulp Defence and Repair Mechanisms in Dental Caries

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Farges

    2015-01-01

    Full Text Available Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo.

  16. Sisal organosolv pulp as reinforcement for cement based composites

    Directory of Open Access Journals (Sweden)

    Ana Paula Joaquim

    2009-09-01

    Full Text Available The present work describes non-conventional sisal (Agave sisalana chemical (organosolv pulp from residues of cordage as reinforcement to cement based materials. Sisal organosolv pulp was produced in a 1:1 ethanol/water mixture and post chemically and physically characterized in order to compare its properties with sisal kraft pulp. Cement based composites reinforced with organosolv or kraft pulps and combined with polypropylene (PP fibres were produced by the slurry de-watering and pressing method as a crude simulation of the Hatschek process. Composites were evaluated at 28 days of age, after exposition to accelerated carbonation and after 100 soak/dry cycles. Composites containing organosolv pulp presented lower mechanical strength, water absorption and apparent porosity than composites reinforced with kraft pulp. The best mechanical performance after ageing was also achieved by samples reinforced with kraft pulp. The addition of PP fibres favoured the maintenance of toughness after ageing. Accelerated carbonation promoted the densification of the composites reinforced with sisal organosolv + PP fibres.

  17. Scaffolds to Control Inflammation and Facilitate Dental Pulp Regeneration

    Science.gov (United States)

    Colombo, John S.; Moore, Amanda N.; Hartgerink, Jeffrey D.; D’Souza, Rena N.

    2014-01-01

    In dentistry, the maintenance of a vital dental pulp is of paramount importance, as teeth devitalized by root canal treatment may become more brittle and prone to structural failure over time. Advanced carious lesions can irreversibly damage the dental pulp by propagating a sustained inflammatory response throughout the tissue. While the inflammatory response initially drives tissue repair, sustained inflammation has an enormously destructive effect on the vital pulp, eventually leading to total necrosis of the tissue and necessitating its removal. The implications of tooth devitalization have driven significant interest in the development of bioactive materials that facilitate the regeneration of damaged pulp tissues by harnessing the capacity of the dental pulp for self-repair. In considering the process by which pulpitis drives tissue destruction, it is clear that an important step in supporting the regeneration of pulpal tissues is the attenuation of inflammation. Macrophages, key mediators of the immune response, may play a critical role in the resolution of pulpitis due to their ability to switch to a pro-resolution phenotype. This process can be driven by the resolvins, a family of molecules derived from fatty acids that show great promise as therapeutic agents. In this review, we outline the importance of preserving the capacity of the dental pulp to self-repair through the rapid attenuation of inflammation. Potential treatment modalities, such as shifting macrophages to a pro-resolving phenotype with resolvins are described, and a range of materials known to support the regeneration of dental pulp are presented. PMID:24698696

  18. Microarray expression profiling of human dental pulp from single subject.

    Science.gov (United States)

    Tete, Stefano; Mastrangelo, Filiberto; Scioletti, Anna Paola; Tranasi, Michelangelo; Raicu, Florina; Paolantonio, Michele; Stuppia, Liborio; Vinci, Raffaele; Gherlone, Enrico; Ciampoli, Cristian; Sberna, Maria Teresa; Conti, Pio

    2008-01-01

    Microarray is a recently developed simultaneous analysis of expression patterns of thousand of genes. The aim of this research was to evaluate the expression profile of human healthy dental pulp in order to find the presence of genes activated and encoding for proteins involved in the physiological process of human dental pulp. We report data obtained by analyzing expression profiles of human tooth pulp from single subjects, using an approach based on the amplification of the total RNA. Experiments were performed on a high-density array able to analyse about 21,000 oligonucleotide sequences of about 70 bases in duplicate, using an approach based on the amplification of the total RNA from the pulp of a single tooth. Obtained data were analyzed using the S.A.M. system (Significance Analysis of Microarray) and genes were merged according to their molecular functions and biological process by the Onto-Express software. The microarray analysis revealed 362 genes with specific pulp expression. Genes showing significant high expression were classified in genes involved in tooth development, protoncogenes, genes of collagen, DNAse, Metallopeptidases and Growth factors. We report a microarray analysis, carried out by extraction of total RNA from specimens of healthy human dental pulp tissue. This approach represents a powerful tool in the study of human normal and pathological pulp, allowing minimization of the genetic variability due to the pooling of samples from different individuals.

  19. Alberta Chamber of Resources : 1997 resources guide and directory

    International Nuclear Information System (INIS)

    1997-01-01

    The Alberta Chamber of Resources (ACR) is composed of 140 member companies from the oil and gas industry, forestry, pulp and paper, mining, oil sands, utilities, contractors, suppliers, consultants, banking and other service groups, as well as representatives from universities and governments. ACR's activities during 1996 were reviewed. These included supporting or sponsoring a careers forum, and various other networking and information sharing opportunities, a study of the potential for Alberta's minerals industry, and exploring opportunities for research in the forestry sector and the further development of Alberta's oil sands. Studies of the transportation and infrastructures strategies for Alberta's resources, royalty regimes, tenure and compensation issues associated with oil sands reservoirs that are 'capped' by natural gas reservoirs, taxation issues related to oil sands development, mineral rights tenure, and toll design and royalty issues affecting Alberta's natural gas sector rounded out the Chamber's activities. The annual review also profiled a number of ACR member companies, among them Koch Oil Company Ltd., Pardee Equipment Ltd., Interprovincial Pipe Line Inc., Clearwater Welding and Fabricating Ltd., and Weldwood of Canada. A listing of all ACR members was also provided

  20. PEP quark search proportional chambers

    Energy Technology Data Exchange (ETDEWEB)

    Parker, S I; Harris, F; Karliner, I; Yount, D [Hawaii Univ., Honolulu (USA); Ely, R; Hamilton, R; Pun, T [California Univ., Berkeley (USA). Lawrence Berkeley Lab.; Guryn, W; Miller, D; Fries, R [Northwestern Univ., Evanston, IL (USA)

    1981-04-01

    Proportional chambers are used in the PEP Free Quark Search to identify and remove possible background sources such as particles traversing the edges of counters, to permit geometric corrections to the dE/dx and TOF information from the scintillator and Cerenkov counters, and to look for possible high cross section quarks. The present beam pipe has a thickness of 0.007 interaction lengths (lambdasub(i)) and is followed in both arms each with 45/sup 0/ <= theta <= 135/sup 0/, ..delta..phi=90/sup 0/ by 5 proportional chambers, each 0.0008 lambdasub(i) thick with 32 channels of pulse height readout, and by 3 thin scintillator planes, each 0.003 lambdasub(i) thick. Following this thin front end, each arm of the detector has 8 layers of scintillator (one with scintillating light pipes) interspersed with 4 proportional chambers and a layer of lucite Cerenkov counters. Both the calculated ion statistics and measurements using He-CH/sub 4/ gas in a test chamber indicate that the chamber efficiencies should be >98% for q=1/3. The Landau spread measured in the test was equal to that observed for normal q=1 traversals. One scintillator plane and thin chamber in each arm will have an extra set of ADC's with a wide gate bracketing the normal one so timing errors and tails of earlier pulses should not produce fake quarks.

  1. A modified efficient method for dental pulp stem cell isolation

    Directory of Open Access Journals (Sweden)

    Maryam Raoof

    2014-01-01

    Full Text Available Background: Dental pulp stem cells can be used in regenerative endodontic therapy. The aim of this study was to introduce an efficient method for dental pulp stem cells isolation. Materials and Methods: In this in-vitro study, 60 extracted human third molars were split and pulp tissue was extracted. Dental pulp stem cells were isolated by the following three different methods: (1 digestion of pulp by collagenase/dispase enzyme and culture of the released cells; (2 outgrowth of the cells by culture of undigested pulp pieces; (3 digestion of pulp tissue pieces and fixing them. The cells were cultured in minimum essential medium alpha modification (αMEM medium supplemented with 20% fetal bovine serum(FBS in humid 37°C incubator with 5% CO 2 . The markers of stem cells were studied by reverse transcriptase polymerase chain reaction (PCR. The student t-test was used for comparing the means of independent groups. P <0.05 was considered as significant. Results: The results indicated that by the first method a few cell colonies with homogenous morphology were detectable after 4 days, while in the outgrowth method more time was needed (10-12 days to allow sufficient numbers of heterogeneous phenotype stem cells to migrate out of tissue. Interestingly, with the improved third method, we obtained stem cells successfully with about 60% efficiency after 2 days. The results of RT-PCR suggested the expression of Nanog, Oct-4, and Nucleostemin markers in the isolated cells from dental pulps. Conclusion: This study proposes a new method with high efficacy to obtain dental pulp stem cells in a short time.

  2. CLINICAL, HISTOLOGICAL AND RADIOLOGICAL ASPECTS REGARDING THE INFLUENCE OF SOME EXTERNAL FACTORS ON THE PULP-DENTIN COMPLEX

    Directory of Open Access Journals (Sweden)

    C. Giuroiu

    2012-12-01

    Full Text Available The present study aimed at assesssing – by clinical, histological and radiological investigations – the influence of some external factors on the pulp-dentin complex, and at providing a causal interpretation of the structural changes observed. Materials and methods. Clinical and radiological exams were performed on 65 old patients with ages between 60-75, and also on 40 young patients with ages between 20-35, presenting different dental-periodontal pathologies. The pulp-dentin complex was submitted to a morphopathological examination, to highlight the structural changes observed at microscopic level. Fragments of dental pulp were imersed in a 4% formaldehyde solution with phosphate buffer 0.1 M., pH 7.2, for 12 -14 hours, at a temperature of 4ºC, and 3-5 µm thick slices were prepared. The slices were coloured with hematoxylin-eosine (HE, by the trichromic technique – Masson. Photographies were taken with a Zeiss microscope, with Kodak 200 ASA. Results. Significant differences were observed, between the two groups of patients, as to the external factors that produce structural changes on pulp-dentin organ. In the group of young patients dental caries and coronal fillings prevailed, while the group of old patients was mostly associated with atrition and chronic marginal periodontitis. Out of the 40 young patients, 30 presented chronic dental caries (75%, while, among the 65 old patients, only 24 presented dental caries (36.9%. The percentages of coronary fillings between the two study groups were close, which could be considered as one of the causes producing changes in the pulp-dentin organ, following aggresive preparation of cavities, the action of materials used for the protection of pulp-dentin complex or of the materials used for coronry fillings. Conclusions. Dental pulp has a remarkable ability to counteract the action of harmful factors, producing a mineral barrier and stimulating the reparatory processes. Changes in the endodontic

  3. Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers.

    Science.gov (United States)

    Hao, Xiaoli; Guo, Chenxin; Lin, Yaolin; Wang, Haiqiao; Liu, Heqing

    2016-05-20

    Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS) model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

  4. Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers

    Directory of Open Access Journals (Sweden)

    Xiaoli Hao

    2016-05-01

    Full Text Available Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

  5. Basic effects of pulp refining on fiber properties--a review.

    Science.gov (United States)

    Gharehkhani, Samira; Sadeghinezhad, Emad; Kazi, Salim Newaz; Yarmand, Hooman; Badarudin, Ahmad; Safaei, Mohammad Reza; Zubir, Mohd Nashrul Mohd

    2015-01-22

    The requirement for high quality pulps which are widely used in paper industries has increased the demand for pulp refining (beating) process. Pulp refining is a promising approach to improve the pulp quality by changing the fiber characteristics. The diversity of research on the effect of refining on fiber properties which is due to the different pulp sources, pulp consistency and refining equipment has interested us to provide a review on the studies over the last decade. In this article, the influence of pulp refining on structural properties i.e., fibrillations, fine formation, fiber length, fiber curl, crystallinity and distribution of surface chemical compositions is reviewed. The effect of pulp refining on electrokinetic properties of fiber e.g., surface and total charges of pulps is discussed. In addition, an overview of different refining theories, refiners as well as some tests for assessing the pulp refining is presented. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Micro fission chamber for the ITER neutron monitor

    International Nuclear Information System (INIS)

    Yamauchi, Michinori; Nishitani, Takeo; Ochiai, Kentaro; Ebisawa, Katsuyuki

    2004-01-01

    This paper describes the design and the fabrication of a prototype micro-fission chamber and test results under ITER relevant conditions including wide neutron spectrum and intense gamma-rays, and the performance as a ITER power monitor is discussed. A micro-fission chamber with 12 mg UO 2 and a dummy chamber without uranium were designed and fabricated for the in-vessel neutron flux monitoring of ITER. The measurement ability was tested with the FNS facility for 14 MeV neutrons and the 60 Co gamma-ray irradiation facility at JAERI-Takasaki. Employing the Campbelling mode in the electronics, the ITER requirement for the temporal resolution was satisfied. The excellent linearity of the detector output versus the neutron flux was confirmed in the temperature range from 20degC to 250degC. As a result, it was concluded that the developed micro-fission chamber is applicable for ITER. (author)

  7. Dehumidifier assisted drying of a model fruit pulp-based gel and sensory attributes.

    Science.gov (United States)

    Tiwari, Shipra; Ravi, Ramasamy; Bhattacharya, Suvendu

    2012-07-01

    Model fruit pulp-based gels were prepared by varying mango pulp (0% to 50%), sucrose (0% to 20%), and agar (1% to 3%) and according to a response surface experimental design followed by drying at a low temperature of 40 °C upto 15 h in a tray dryer assisted by a dehumidifier. The moisture content, shrinkage (SHR), and rheological parameters (failure strain, failure stress (FS), firmness, and energy for compression) were determined as a function of drying time. The composition of gel, particularly the agar content had a prominent effect on the characteristics of the dried gel. Detailed descriptive sensory analysis employing principle component analysis (PCA) biplot indicated two distinct groups of attributes; the first group comprised initial and final moisture contents, extent of moisture removal (EMR), and shrinkage. The fracture stress and energy formed the second group. The analysis of variance for failure stress showed that it depended only on the positive linear and quadratic effects of agar (significant at P ≤ 0.01 and 0.05, respectively). The theoretically predicted extent of moisture removal at 95.6% could be achieved when the level of agar was 1.2%; pulp and sucrose levels were also close to their lowest levels of 3.6% and 0.04%, respectively. Scope exists to develop gel-based fruit analogues wherein an appropriate hydrocolloid can be employed along with fruit juice/pulp. To provide a reasonable shelf-life of the developed intermediate moisture containing product, dehumidifier assisted drying is a pragmatic approach that affects sensory and rheological attributes of the dried fruit analogue. © 2012 Institute of Food Technologists®

  8. HYDROGEN PEROXIDE BLEACHING OF CMP PULP USING MAGNESIUM HYDROXIDE

    Directory of Open Access Journals (Sweden)

    Farhad Zeinaly

    2009-11-01

    Full Text Available Conventional bleaching of hardwood CMP pulp with magnesium hydroxide (Mg(OH2 show significant benefits over bleaching with sodium hydroxide (NaOH under various conditions. Magnesium hydroxide bleaching generate higher optical properties, higher pulp yield and lower effluent COD at the same chemical charge, but the physical properties were found to be similar for both processes. The initial freeness of the bleached pulps and refining value to reach a target freeness (about 350 ml. CSF were more for the Mg(OH2-based process. The residual peroxide of filtrate from the Mg(OH2-based process was very high as compared to conventional bleaching.

  9. Enzyme Enhanced Protein Recovery from Green Biomass Pulp

    DEFF Research Database (Denmark)

    Dotsenko, Gleb; Lange, Lene

    2017-01-01

    of local protein resources based on upgrade from e.g. green plant biomass. In present work we consider different strategies for protein recovery from white clover and ryegrass screw press pulps, using aqueous extraction, as well as carbohydrases and proteases enhanced extraction. Protein recovery...... in these studies was determined as a yield of solubilized protein with regard to the total protein in a screw press pulp. Aqueous extraction at pH 8.0 resulted in approx. 40 % protein recovery, while proteases application (Savinase 16.0L, Novozymes) enabled twice higher protein yield. Application of plant cell...... pulp proteolyzates, generated by Savinase 16.0L protease....

  10. Competitiveness of wood pulp production in different Brazilian states

    Directory of Open Access Journals (Sweden)

    Naisy Silva Soares

    2013-06-01

    Full Text Available This work aimed to analyze the competitiveness of wood pulp production in different Brazilian states, in May, 2008 (Minas Gerais, São Paulo, Espírito Santo and Bahia, using the Policy Analysis Matrix (PAM. The results obtained indicated that the private and social profitability of wood pulp production and commercialization was positive and greater in Bahia. The Brazilian companies were penalized by public policies adopted for the sector; the wood pulp production in São Paulo and Bahia were more competitive and less exposed to the negative effects of public policies that reduce the national company profits.

  11. Using renewable sources in the pulp and paper mills

    International Nuclear Information System (INIS)

    Hazi, Aneta; Hazi, Gheorghe

    2007-01-01

    The pulp and paper industry is a major consumer of natural sources (wood) and energy (fossil fuels, electricity) and a significant contributor of pollutant discharges to the environment. In this paper there are presented pulp and paper making process and steam and power generation using renewable sources. This paper includes also an exergy analysis of the steam and power generation process for a pulp and paper mill. Based on the analysis, two sustainability indicators were calculated: the exergetic efficiency and the exergy renewability. (authors)

  12. ON THE RECOVERY OF HEMICELLULOSE BEFORE KRAFT PULPING

    Directory of Open Access Journals (Sweden)

    Carlos Vila,

    2012-07-01

    Full Text Available To assess the feasibility of implementing hemicellulose recovery stages in kraft mills, Eucalyptus globulus wood samples were subjected to aqueous treatments with hot, compressed water (autohydrolysis processing to achieve partial dissolution of xylan. Autohydrolyzed solids were subjected to kraft pulping under selected conditions to yield a pulp of low kappa number, and to an optimized TCF bleaching sequence made up of three stages (alkaline oxygen delignification, chelating, and pressurized hydrogen peroxide, with minimized additions of pulping and bleaching chemicals. The final product had a relatively low kappa number (1.4, 641 mL/g ISO intrinsic viscosity, and 86.4% brightness.

  13. Chemi-thermomechanical pulping of para rubber waste wood

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, T.; Hosokawa, J.; Kobayashi, T.; Kobayashi, Y.

    1981-01-01

    The addition of NaOH to Na/sub 2/SO/sub 3/-treated waste wood chips (Hevea brasiliensis) increased long fiber fraction, Klason lignin content and bulk density, improved breaking length and tear factor, and decreased energy consumption in refining and brightness of resulting chemithermomechanical pulp. Lowering in brightness by alkali treatment was recovered by H/sub 2/O/sub 2/ bleaching, and bleaching with 8% H/sub 2/O/sub 2/ on pulp gave pulp with 61.3% brightness.

  14. Method and apparatus for assaying wood pulp fibers

    Science.gov (United States)

    Gustafson, Richard [Bellevue, WA; Callis, James B [Seattle, WA; Mathews, Jeffrey D [Neenah, WI; Robinson, John [Issaquah, WA; Bruckner, Carsten A [San Mateo, CA; Suvamakich, Kuntinee [Seattle, WA

    2009-05-26

    Paper pulp is added to a stain solution. The stain solution and pulp fibers are mixed to form a slurry. Samples are removed from the slurry and are admixed with dilution water and a bleach. Then, the fibers are moved into a flow cell where they are subjected to a light source adapted to stimulate fluorescence from the stained pulp fiber. Before the fiber slurry enters the flow cell it is mixed with a dilution water of bleach to reduce background fluorescence. The fluorescent light is collimated and directed through a dichroic filter onto a fluorescence splitting dichroic filter.

  15. Can Acceptable Pulp be Obtained from Eucalyptus globulus Wood Chips after Hemicellulose Extraction?

    OpenAIRE

    Francisco López; M. Trinidad García; Vicente Mena; J. Mauricio Loaiza; Minerva A. M. Zamudio; Juan C. García

    2014-01-01

    This study investigates the operating conditions used in the soda-anthraquinone pulping of Eucalyptus globulus wood after autohydrolysis pretreatment on the yield, kappa number, and brightness of the resulting unbleached pulp. Moreover, strength-related properties of the resulting handsheets was examined to identify the best pulping conditions and compare the outcome with that of a conventional soda-anthraquinone pulping process. The paper strength properties of the pulp were similar to or be...

  16. Directional muon jet chamber for a muon collider (Groovy Chamber)

    International Nuclear Information System (INIS)

    Atac, M.

    1996-10-01

    A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-ψ coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas

  17. Nutrient contents of the fresh pulps and dried pulp cakes of vitellaria paradoxa of Gulu District, Uganda

    DEFF Research Database (Denmark)

    Oryema, Christine; Oryem-Origa, Hannington; Roos, Nanna

    2016-01-01

    Vitellaria paradoxa Gaertn locally known as ‘Yaa’ in Acholi is a valuable edible indigenous wild fruit in Gulu District, northern Uganda. It is a multipurpose fruit tree and highly favoured by the inhabitants of this district. Its fruit pulps are eaten when fresh and/or made into cakes and dried....... This study determined the nutrient compositions of the fresh pulps and dried pulp cakes of V. paradoxa. Laboratory analyses were undertaken to determine the micro and macro nutrients in the samples on fresh (FM) and dry matter (DM) basis following standard procedures and protocols. The potassium, sodium...

  18. Anode-supported single-chamber solid oxide fuel cell based on cobalt-free composite cathode of Nd0.5Sr0.5Fe0.8Cu0.2O3-δ-Sm0.2Ce0.8O1.9 at intermediate temperatures

    Science.gov (United States)

    Yin, Jie-Wei; Zhang, Chunming; Yin, Yi-Mei; Shi, Huangang; Lin, Ye; Lu, Jun; Ma, Zi-Feng

    2015-07-01

    As a candidate of cathode material of single-chamber solid oxide fuel cell (SC-SOFC), cobalt-free mixed ionic electronic conductor (MIEC) Nd0.5Sr0.5Fe0.8Cu0.2O3-δ (NSFCu) is synthesized by sol-gel method with ethylene diamine tetraacetic acid and citric acid as co-complexing agents. The XRD shows NSFCu is stable after CO2 treatment and chemical compatible with SDC at high temperatures. CO2-TPD (CO2-temperature programmed desorption) demonstrates both CO2 adsorption and desorption phenomenon on NSFCu surface. However, the polarization resistances (Rp) of NSFCu and SDC (10:4 in weight) composite electrodes showed no decay in 5% CO2. Single cell using N2-O2-CH4 mixed gas (CH4 to O2 ratio = 1.5) as fuel shows maximum power density of 635 mW cm-2 at 700 °C. These results suggest that NSFCu-SDC is a promising composite cathode material for application in single-chamber solid oxide fuel cell.

  19. Preparation and Properties of Nanocellulose from Organosolv Straw Pulp

    Science.gov (United States)

    Barbash, V. A.; Yaschenko, O. V.; Shniruk, O. M.

    2017-03-01

    The object of this work is to present a study of nanocellulose preparation from organosolv straw pulp (OSP) and its properties. OSP was obtained through thermal treatment in the system of isobutyl alcohol-H2O-KOH-hydrazine followed by processing in the mixture of acetic acid and hydrogen peroxide for bleaching and removal of residual non-cellulosic components. We have obtained nanocellulose from OSP through acid hydrolysis with lower consumption of sulfuric acid and followed by ultrasound treatment. The structural change and crystallinity degree of OSP and nanocellulose were studied by means of SEM and XRD techniques. It has been established that nanocellulose has a density up to 1.3 g/cm3, transparency up to 70%, crystallinity degree 72.5%. The TEM and AFM methods shown that nanocellulose have diameter of particles in the range from 10 to 40 nm. Thermogravimetric analysis confirmed that nanocellulose films have more dense structure and smaller mass loss in the temperature range 220-260 °C compared with OSP. The obtained nanocellulose films had high Young's modulus up to 11.45 GPa and tensile strength up to 42.3 MPa. The properties of obtained nanocellulose from OSP exhibit great potential in its application for the preparation of new nanocomposite materials.

  20. ANTIOXIDANT CAPACITY OF PEQUI (Caryocar brasiliense Camb. PULP IS PRESERVED BY FREEZE-DRYING AND LIGHT-RESISTANT PACKAGING

    Directory of Open Access Journals (Sweden)

    NARA RÚBIA RODRIGUES DO NASCIMENTO

    Full Text Available ABSTRACT Pequi (Caryocar brasiliense Camb. pulp is rich in bioactive compounds. However, seasonality and perishability limit its availability in the market. This work aimed to determine the physicochemical characteristics, including phenolic compounds and carotenoid concentrations, as well as the antioxidant capacity of lyophilized pequi pulp during storage in various packaging materials for 180 days. Pequi fruits were pulped, ground, freeze-dried and then vacuum packaged in transparent polyethylene (TP, polyethylene coated by aluminum foil (PA and laminated foil (LA, respectively. The samples were stored under controlled temperature, humidity and luminosity. Proximate composition, phenolic compounds and carotenoids concentrations, and antioxidant capacity (DPPH• assay were determined at the beginning of the study and the end of each month, during 180 days. Lyophilized pequi pulp had 48.87, 6.17, and 4.20 g.100 g-1 lipids, proteins, and total dietary fiber, respectively, and 556.79 kcal.100 g-1 energy. PA and LA had similar effects against light-induced carotenoid oxidation. Negative correlations between the phenolic compound concentration and storage period, and antioxidant capacity and storage period; and a positive correlation between antioxidant capacity and phenolic compound content were observed. Light-resistant packaging decreased the carotenoid loss. Among the packaging, LA preserved the phenolic compounds and antioxidant capacity most effectively.

  1. Pulp Stone, Haemodialysis, End-stage Renal Disease, Carotid Atherosclerosis

    OpenAIRE

    Patil, Santosh; Sinha, Nidhi

    2013-01-01

    Objectives: The aim of this study was to determine the relationship between the presence of pulp calcification and carotid artery calcification on the dental panoramic radiographs in End Stage Renal Disease (ESRD) patients who were on haemodialysis.

  2. UTILIZATION OF Prosopis afiicana PULP FOR RABBIT FEEDING: 2

    African Journals Online (AJOL)

    IBB

    The formulated diets contained similar crude protein content of 18%. The apparent ... These results indicate that Prosopis africana pulp can completely replace maize in the diets of ... serum albumin were determined by Biuret reactions. (Bush ...

  3. Processing pineapple pulp into dietary fibre supplement | Ackom ...

    African Journals Online (AJOL)

    Processing pineapple pulp into dietary fibre supplement. ... The pasting characteristics or properties of wheat flour fortified with the product up to 20 ... of some popular foods to help increase the fibre intake and health of the general population.

  4. Effects of feeding cassava pulp fermented with Acremonium ...

    African Journals Online (AJOL)

    Acer

    2017-01-27

    #, T. .... Briefly, 10 kg steamed cassava pulp (87.5% DM) was soaked with sterile water (1 : 1). .... The data on digestibility and retention of broilers are presented in Table 3. .... Taken together, the antioxidant capacity of A.

  5. Partial pulp necrosis caused by excessive orthodontic force

    Directory of Open Access Journals (Sweden)

    Min-Young Kim

    2011-03-01

    Full Text Available As the dental pulp is encased with a rigid, noncompliant shell, changes in pulpal blood flow or vascular tissue pressure can have serious implication for the health of pulp. Numerous studies have demonstrated that orthodontic force application may influence both blood flow and cellular metabolism, leading degenerative and/or inflammatory responses in the dental pulp. The aim of this case report is to present a case about tooth with chronic periapical abscess which showed normal vital responses. Excessive orthodontic force is thought to be the prime cause of partial pulp necrosis. Owing to remaining vital tissue, wrong dianosis can be made, and tooth falsely diagnosed as vital may be left untreated, causing the necrotic tissue to destroy the supporting tissuses. Clinician should be able to utilize various diagnostic tools for the precise diagnosis, and be aware of the endodontic-orthodontic inter-relationship.

  6. Proximate and Mineral Composition of the Pulp of Chrysophyllum ...

    African Journals Online (AJOL)

    MBI

    2014-11-13

    Nov 13, 2014 ... The results showed that the fruit pulp of Chrysophyllum albidum contained essential ... seed of the plant is a good source of oil which is ... Sample Collection and Treatment ... AAS machine due to its good precision and.

  7. NIRS Characterization of Paper Pulps to Predict Kappa Number

    Directory of Open Access Journals (Sweden)

    Ana Moral

    2015-01-01

    Full Text Available Rice is one of the most abundant food crops in the world and its straw stands as an important source of fibres both from an economic and an environmental point of view. Pulp characterization is of special relevance in works involving alternative raw materials, since pulp properties are closely linked to the quality of the final product. One of the analytical techniques that can be used in pulp characterization is near-infrared spectroscopy (NIRS. The use of NIRS has economic and technical advantages over conventional techniques. This paper aims to discuss the convenience of using NIRS to predict Kappa number in rice straw pulps produced under different conditions. We found that the resulting Kappa number can be acceptably estimated by NIRS, as the errors obtained with that method are similar to those found for other techniques.

  8. Factors influencing cassava - pulp fermentation period for gari ...

    African Journals Online (AJOL)

    Factors influencing cassava - pulp fermentation period for gari processing among ... Result of probit model analysis at 5% significance level shows an R value ... Marital status (2.236**) and respondents' cultural influences (1.960**) were ...

  9. Claustral single cell reactions to tooth pulp stimulation in cats.

    Science.gov (United States)

    Jastreboff, P; Sikora, M; Frydrychowski, A; Słoniewski, P

    1983-01-01

    Single unit activity in the central region of the claustrum, evoked by electrical stimulation of tooth pulp or paws was studied on cats under chloralose anesthesia. The majority of cells responded in similar manner to stimulation of tooth pulp or paws, but there were cells with clear preference to a given type of stimulation. Latencies of reactions evoked by tooth pulp stimulation were significantly shorter than those for limb stimulation. In the former case latencies as short as 8 rns were observed. It is postulated that the central region of the claustrum receives a projection from the tooth pulp, and that in those cases with very short latency the projection is direct and does not involve the cerebral cortex.

  10. Prevalence and Analysis of Factors Related to Occurrence of Pulp ...

    African Journals Online (AJOL)

    Uche

    between pulp stone and pristine posterior teeth, chronic periodontitis and posterior teeth ... Conclusion: It is recommended that researchers should pay special care in case selections, and ... (1982) reported a PS prevalence rate of 20.7 % in.

  11. Plasma chemistry in wire chambers

    International Nuclear Information System (INIS)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55 Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  12. Modelling auto ignition of hydrogen in a jet ignition pre-chamber

    Energy Technology Data Exchange (ETDEWEB)

    Boretti, Alberto A. [School of Science and Engineering, University of Ballarat, PO Box 663, Ballarat, Victoria 3353 (Australia)

    2010-04-15

    Spark-less jet ignition pre-chambers are enablers of high efficiencies and load control by quantity of fuel injected when coupled with direct injection of main chamber fuel, thus permitting always lean burn bulk stratified combustion. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the pre-chamber, where it mixes with the air entering from the main chamber. Combustion of the air and fuel mixture then starts within the pre-chamber because of the high temperature of the hot glow plug, and then jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. The paper describes the operation of the spark-less jet ignition pre-chamber coupling CFD and CAE engine simulations to allow component selection and engine performance evaluation. (author)

  13. STUDIES ON HIBISCUS CANNABINUS, HIBISCUS SABDARIFFA, AND CANNABINUS SATIVA PULP TO BE A SUBSTITUTE FOR SOFTWOOD PULP- PART 1: AS-AQ DELIGNIFICATION PROCESS

    OpenAIRE

    Dharm Dutt; J. S. Upadhyaya; C. H. Tyagi

    2010-01-01

    Hibiscus cannabinus, Hibiscus sabdariffa, and Cannabinus sativa, which are renewable non-woody fiber resources having characteristics similar to that of softwood (bast fibers), when used together with hardwood (core fibers), gave higher pulp yield with good mechanical strength properties when using an alkaline sulphite-anthraquinone (AS-AQ) pulping process rather than a conventional kraft pulping process and bleached more readily than kraft and soda pulps with a CEHH bleaching sequence. A com...

  14. Design and construction of an inexpensive homemade plant growth chamber.

    Science.gov (United States)

    Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

    2015-01-01

    Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

  15. Design and construction of an inexpensive homemade plant growth chamber.

    Directory of Open Access Journals (Sweden)

    Fumiaki Katagiri

    Full Text Available Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W x 1.8 m (D x 2 m (H, providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant

  16. Timing of pulp extirpation for replanted avulsed teeth.

    LENUS (Irish Health Repository)

    Stewart, Chris

    2009-01-01

    A search was performed (April 2004) across four databases, namely Ovid Medline, Cochrane Library, PubMed and Web of Science, relevant to the proposed PICO ( Patient or problem, Intervention, Comparison, Outcome) question: (P) for a replanted avulsed permanent tooth, (I) is early pulp extirpation within 10-14 days of replantation, (C) compared with delayed pulp extirpation, (O) associated an increased likelihood of successful periodontal healing after tooth replantation. Only articles published in the English language were considered.

  17. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

    Energy Technology Data Exchange (ETDEWEB)

    Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J., E-mail: rosemarymj@lifecarehll.com

    2016-04-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

  18. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

    International Nuclear Information System (INIS)

    Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J.

    2016-01-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

  19. Pulp fictions of medieval England: Essays in popular romance

    OpenAIRE

    McDonald, Nicola

    2004-01-01

    Middle English popular romance is the most audacious and compendious testimony to the imaginary world of the English Middle Ages. Yet, with few exceptions, it remains under read and under studied. Pulp fictions of medieval England demonstrates that popular romance merits and rewards serious critical attention and that it is crucial to our understanding of the complex and conflicted world of medieval England. Pulp fictions of medieval England comprises ten essays on individual romances that, w...

  20. Active Nanomaterials to Meet the Challenge of Dental Pulp Regeneration

    OpenAIRE

    Keller, Laetitia; Offner, Damien; Schwint?, Pascale; Morand, David; Wagner, Quentin; Gros, Catherine; Bornert, Fabien; Bahi, Sophie; Musset, Anne-Marie; Benkirane-Jessel, Nadia; Fioretti, Florence

    2015-01-01

    The vitality of the pulp is fundamental to the functional life of the tooth. For this aim, active and living biomaterials are required to avoid the current drastic treatment, which is the removal of all the cellular and molecular content regardless of its regenerative potential. The regeneration of the pulp tissue is the dream of many generations of dental surgeons and will revolutionize clinical practices. Recently, the potential of the regenerative medicine field suggests that it would be p...