Pulp Temperature Research Articles

Impact of the Enamel Cleaning Procedure during Debonding on Endodontium Temperature: In Vitro Tests

Interference with live tooth tissue during dental treatment affects the temperature within the pulp. The pulp is sensitive to temperature changes, which can cause its inflammation. The aim of this study was to analyze the dynamics of pulp chamber temperature changes in response to the enamel cleaning procedure after orthodontic treatment. In the presented in vitro studies, by using a thermal imaging camera, the change in the temperature of the vestibular wall of the pulp chamber of the incisors and premolars was assessed as a function of time under the influence of polishing the enamel with the silicone rubber and aluminum oxides used during the debonding procedure after completion of orthodontic treatment with fixed appliances. The relationship between dentin density and enamel from changing the chamber temperature was evaluated by using Micro computed tomography, microtomography (micro-CT). The maximum achieved tooth surface temperature during polishing was 52.34 °C without water cooling and 43.15 °C using water cooling. The time after which a safe pulp temperature of 40 °C was obtained without water cooling was 29.4 s, while the time with water cooling was 34.6 s. The correlation between the maximum and average temperature achieved and the density of the teeth was analyzed based on micro-CT scans. No correlation between enamel or dentin density and rise in temperature was found.

Postharvest quarantine vapour heat treatment attenuates disease incidence, maintains eating quality and improves bioactive compounds of ‘Gola’ and ‘Surahi’ guava fruits

Fruit fly infestation is the major concern in commercial guava production globally, which limits its marketing opportunities, especially export to high end markets. Vapour heat treatment (VHT) technology is used for quarantine purposes in various tropical fruits for export, however, detailed information is lacking on its impacts on fruit quality and shelf life of guava. In current studies, the effect of VHT was evaluated on two commercial guava cultivars (Gola’ and ‘Surahi) of Pakistan. Mature green guava fruits were subjected to VHT at a commercial certified facility, maintaining core pulp temperature of 47.5 °C for 0, 12 and 25 min, followed by keeping fruit at ambient conditions (28 ± 2 °C) for six days. The fruits treated with VHT maintaining core temp of 47.5 °C for 25 min displayed higher marketability index, cosmetic quality, firmness and pulp color with lower disease incidence, ion leakage, and weight loss during ambient storage conditions. Soluble solid contents (SSC), sugar acid ratio, ascorbic acid contents and total phenolic contents were also higher with better eating quality in fruits treated with VHT-25 min, compared with VHT-12 min, and untreated control. However, total antioxidants (% DPPH inhibition activity) and titratable acidity of fruits were not affected by VHT duration. Conclusively, VHT (47.5 °C for 25 min) could be employed as eco-friendly and safe quarantine treatment for both guava cultivars, with maintained physical, biochemical and eating quality.

Vanadyumun Silis Kumundan Liç Yöntemi ile Ekstraksiyonunda Organik Asitlerin Performansının İncelenmesi

In this study, performance of organic acids in the extraction of vanadium from silica sand, a potential vanadium source, were investigated by leaching method. Silica sand samples used in this study was obtained from a silica sand beneficiation plant operating in Istanbul, Turkey. In the context of experimental studies, detailed characterization tests and leaching tests with organic and inorganic acids were performed on the representative samples obtained from the desliming unit of the plant, and the optimum extraction conditions for vanadium were determined. The obtained results showed that the best result for vanadium extraction was obtained with hydrofluoric acid. The extraction efficiency of vanadium was found to be 76% under optimal leaching conditions of 2 h of leaching time, 800 kg/ton of HF amount and 40oC pulp temperature. On the other hand, the best results among the organic acids were obtained with oxalic acid. The extraction efficiency of vanadium was found to be 50% under optimal leaching conditions of 2 h of leaching time, 200 kg/ton of oxalic acid amount and 40oC pulp temperature.

Adsorption and desorption of butyl xanthate on chalcopyrite

Reagent removal is an indispensable step to further separation of the copper sulfide ore flotation mixed concentrate, and xanthate is one of the most commercially used collectors for chalcopyrite flotation. In this work, the adsorption/desorption quantity of butyl xanthate was measured by the spectrophotometric method. Three adsorption models of Langmuir, Freundlich, and Temkin were used to fit the xanthate adsorption quantity dates. The results show that the adsorptions of sodium butyl xanthate on chalcopyrite match the Langmuir model best in the experimental conditions. Sodium sulfide dosage, pH value, ultrasonic wave, and temperature all show effects on butyl xanthate desorption. Butyl xanthate desorption can promote by increasing the dosage of sodium sulfide, ultrasonic wave intensity, temperature, and acidity or alkalinity of pulp. The order of the effectiveness of four conditions is sodium sulfide dosage, temperature, pH, and ultrasonic.

Studies on Physicochemical and Sensory Attributes of Potatoes Stored During Winter in High-Altitude Cold Desert, Ladakh, India

This study assessed the feasibility of providing a regular supply of locally produced potatoes during landlocked winter months in Ladakh region. Potato tubers were stored (January–May) in semi-underground stores where conditions were between 0.2–13.6 °C and 87–96% relative humidity. Periodical sample analysis was carried out on sensory attributes and the physicochemical attributes firmness, sprouting, pulp temperature, total soluble solutes, sugar level, vitamin B6, dry matter, weight loss and CIPC residue level, to evaluate the quality of the stored potatoes. Pearson’s correlation analysis measured the relationship between various physicochemical attributes that helped improve understanding of potato variability. CIPC residue concentration was within the recommended limit of 30 mg/kg tuber in peeled and unpeeled tubers ranging from 0.02 to 0.12 mg/kg and 0.04 to 3.90 mg/kg, respectively. Tubers stored during extreme winter conditions showed the highest level of total sugar 927 ± 8.54 mg/100 g after 5 months of storage. Vitamin B6 was 0.276 mg/100 g in CIPC treated potato and 0.190 mg/100 g in non-treated potato which is approximately 15% of recommended daily vitamin B6 intake. Based on the results of this study, potatoes stored in zero energy–based semi-underground stores were in good quality after a period of 5 months and suitable for consumption.

The effect of laser-activated bleaching with 445 nm and 915 nm diode lasers on enamel micro-hardness; an in vitro study.

The appearance of the teeth is of great importance to patients, particularly tooth color. In recent years, tooth whitening has been one of the most popular ways to restore tooth color. Bleaching gels can be affected by heat, light or laser, which can improve its effects. This study intends to examine the effects of two different wavelengths of diode laser (445 & 915 nm) after the bleaching process, on the enamel micro-hardness. A total of 65 caries-free humans third molars were randomly divided into five groups (N = 13): first group: bleaching gel activated with 915 nm diode laser (1.5 W), second: bleaching gel activated with 915-nm (2.5 W), third: bleaching gel activated with 445-nm (1 W), fourth: bleaching gel activated with 445-nm (1.5 W), fifth (control group): bleaching gel without laser activation. Micro-hardness test (Vickers test) was performed before and after the treatment. The data were submitted to repeated measurement ANOVA and Tukey's HSD post hoc test (α = 0.05). Enamel micro-hardness did not change significantly in groups 3 and 4 but decreased in groups 1 and 2. Group 2 showed the most reduction in micro-hardness. There were no significant changes in the control group. According to the results of this study, 445 nm Diode laser did not reduce enamel micro-hardness, making it suitable for bleaching treatments. However, more studies are required to consider other factors, such as color changes and pulp temperature.

Temperature Sequential Data Fusion Algorithm Based on Cluster Hierarchical Sensor Networks.

The process of extracting gold by biological oxidation involves oxidizing the refractory high-sulfur and high-arsenic ore with the help of bacteria to decompose the wrapping material of gold to extract the gold. Therefore, maximizing the activity of bacteria will directly affect the efficiency of gold extraction, for which it is particularly important to maintain the pulp temperature in the oxidation tank at the optimal bacteria breeding temperature. However, gold mines are generally located in mountainous areas, and the large temperature difference between day and night in winter, coupled with the influence of wind and snow, creates variations in the temperature in the oxidation tank. The traditional temperature measurement method cannot fully reflect the temperature change of the oxidation tank. As a multi-field application method, sensor information fusion can effectively address the problem of pulp temperature measurement. First, we analyzed the heat transfer principle inside the oxidation tank, and designed the cluster hierarchical sensor network according to the spatial position of each oxidation tank and the environmental interference factors. The network structure is divided into three layers; the bottom of the sensor to collect pulp temperature data shows a spiral distribution in the inner wall of the oxidation tank. Each cluster head node sensor is used as an intermediate layer to complete local measurement fusion estimation. Finally, the fusion center is taken as the upper layer to realize the global state fusion estimation. Secondly, in the data processing of the bottom temperature sensor, the traditional unscented Kalman filter (UKF) algorithm is improved and the fading memory matrix is added to improve the identification of nonlinear modeling errors. The sequential observation fusion estimator (SOFE) algorithm is embedded in the measurement update to improve the performance of local measurement fusion. Finally, in the global state fusion estimation, the sequential analysis is combined with the inverse covariance intersection, and the sequential analysis and inverse covariance intersection-global state fusion estimation (SICI-GSFE) algorithm is proposed. Through calculation and simulation, the results show that the external interference can be reduced by combining all the temperature state estimations, and the accuracy of the best global temperature state estimation is improved.

Effect of high-irradiance light curing on exposure times and pulpal temperature of adequately polymerized composite.

This study investigated the effect of high-irradiance light-curing on exposure time and pulpal temperature of adequately-cured composite. Composite placed in a molar preparation was cured using high-irradiance light-curing units (Flashmax P3, Valo, S.P.E.C. 3 LED, Cybird XD) and tested for hardness occlusal-gingivally. The first group had exposure times set according to manufacturer settings (recommended), second group to yield 80% of maximum hardness at the 2 mm depth (experimental), and third group was set at 20 s (extended). Exposure time necessary to adequately polymerize the composite at 2 mm depth was 9 s for the Cybird XD and Valo and 12 s for S.P.E.C. 3 LED and Flashmax P3. None of the high-irradiance light-curing units adequately polymerized the composite at the manufacturer-recommended minimum-exposure times of 1-3 s. Exposure times necessary to adequately polymerize composite at 2 mm resulted in a maximum pulpal-temperature increase well below the temperature associated with possible pulpal necrosis.

In vivo temperature rise and acute inflammatory response in anesthetized human pulp tissue of premolars having Class V preparations after exposure to Polywave® LED light curing units

ObjectiveTo evaluate the influence of light emitted from two Polywave®, LED light-curing units (LCU) on in vivo pulp temperature (PT) rise and signs of acute inflammatory response in pulps of human premolar having deep Class V preparations. MethodsSixty intact, first premolars from 15 volunteers requiring extraction received infiltrative anesthesia. A sterile thermocouple probe was inserted within the pulp tissue through a minute occlusal pulp exposure in only 45 teeth (n = 9) to continuously monitor PT (°C). A deep buccal Class V preparation was created, and the surface was exposed to light from a commercial Polywave LCU (Bluephase 20i (20i), Ivoclar Vivadent) or from an experimental LCU (Exp) using the exposure modes (EM): 1s/Exp and 2s/Exp, 10s/20i, 20s/20i, and 60s/20i. Peak PT and PT rise values above baseline (ΔT) data were evaluated using a one-way ANOVA followed by Tukey’s post-hoc test (α = 5%). Teeth used for histological and immunohistochemical analyses (n = 3) were extracted approximately 2 h after exposure to the LCU. ResultsNo significant difference in peak PT and ΔT values was noted between 2s/Exp and 20s/20i groups, which both exhibited higher values than 1s/Exp and 10s/20i groups (p < 0.001). Dilated and congested blood vessels were seen after exposure to 1s/Exp, 2s/Exp, or 60s/20i EMs. The expression of IL-1β and TNF-α tended to be more intense when higher irradiance was delivered. SignificanceAlthough higher irradiance delivered over a short exposure caused lower PT rise than 5.5 °C, such EMs should be used with caution, as they have more potential to harm the pulp tissue.

Soda-anthraquinone pulping optimization of oil palm empty fruit bunch

The influence of soda-anthraquinone (AQ) pulping conditions on paper properties of oil palm empty fruit bunches was studied using Response Surface Methodology (RSM) based on Central Composite Design (CCD). The alkali charge, NaOH (A), pulping temperature (T), and pulping time (t) ranged between 20 and 30%, 160 and 180 °C, and 60 and 120 minutes, respectively. The mechanical properties evaluated for the handsheets produced were the tensile index, tearing index, bursting index, folding endurance, zero-span tensile strength, and the optical properties (brightness and opacity). The effects of soda-AQ pulping conditions on oil palm empty fruit bunch paper were elucidated by the regression models obtained. The optimum pulping condition were at 27.3% alkali charge, 160 °C, and 60 min that produced paper properties with 26.8 N.m/g tensile index, 7.95 mN.m2/g tearing index, 5.32 kPa.m2/g bursting index, 1.70 log10 folding endurance, 46.2 N zero-span tensile strength, 51.8% brightness, and 95.8% opacity.

Thermal effect of Er:YAG and Er,Cr:YSGG used for debonding ceramic and metal orthodontic brackets: An experimental analysis.

In orthodontics, erbium (Er:YAG) lasers can be used for bracket debonding. To assess the changes in temperature of pulp and enamel during laser debonding of brackets. A total of 13 brackets (n = 13; 2 metal and 11 ceramic brackets) were bonded to 13 caries-free premolars extracted for orthodontic reasons. Brackets were irradiated with 2 lasers. Laser No. 1 was an erbium-chromium (Er,Cr:YSGG) laser (Waterlase Express; Biolase, Irvine, USA) with a wavelength of 2,780 nm at a power of 2.78-2.85 W, energy of 185-190 mJ, fluence of 10 ns, frequency of 25 Hz, pulse duration of 300 μs, tip diameter of 0.6 mm, air/fluid cooling of 3.5 mL/s, and time of irradiation of 5-25 s. Laser No. 2 was an Er:YAG laser (LiteTouch; Light Instruments Ltd., Yokneam, Israel) with a wavelength of 2,940 nm at a power of 4 W, energy of 200 mJ, fluence of 10 ns, frequency of 20 Hz, pulse duration of 300 μs, tip diameter of 0.8 mm, air/fluid cooling of 3.5 mL/s, and time of irradiation of 5-15 s. Two thermographic cameras (FLIR Zenmuse XT and FLIR P65; FLIR Systems, Wilsonville, USA) and type K thermocouple (Zhangzhou Weihua Electronic Co., Fujian, China) were used for precise temperature measurement on the surface of the teeth and inside them. When laser No. 1 was in use, the mean difference between the inner and outer temperature of the examined teeth (1.4°C) was higher than when the laser No. 2 was in use (0.6°C) (p = 0.0974). The study found that the temperature inside the tooth did not increase, and it even decreased during treatment with Er:YAG laser using water cooling, provided that appropriate proportion of water and air was used. For laser No. 1, confidence interval (CI) was between 0.7 and 2.2 and for laser No. 2 it was between 0.500 and 1.23. Only experiment for ceramic brackets was described. These findings confirm that the use of Er:YAG family lasers for orthodontic bracket debonding in an in vitro study is safe and effective.

Flotation performance and adsorption mechanism of a new collector 2-(carbamoylamino) lauric acid on quartz surface

To investigate the effect of an amide group on the flotation performance of a fatty acid collector, a novel surfactant, 2-(carbamoylamino) lauric acid (2-CLA), was synthesized by introducing an amide group to the α-C position of lauric acid (LA). Flotation tests on pure quartz indicated that under suitable flotation conditions, pH of 11.5, 50 mg/L of CaCl2, and 100 mg/L of 2-CLA, the quartz recovery of 2-CLA flotation was above 98% and almost unaffected by pulp temperatures between 10 °C and 40 °C. For comparison, the quartz recovery of LA flotation was only 80% at high temperatures above 35 °C. The adsorption mechanisms of 2-CLA on the quartz surface were investigated using Fourier transform-infrared spectra, zeta potential measurements, and X-ray photoelectron spectroscopy analysis, which demonstrated that 2-CLA was adsorbed onto the surface of activated quartz by strong chemisorption and hydrogen bonding. This study also revealed that an additional amide group at the α-C position of fatty acids enhanced both the chemical bonding interaction and hydrogen bonding synergy during the adsorption of 2-CLA on the activated quartz surface.

Stress behaviour across human tooth by temperature gradient resulting of laser irradiation

The authors report the simulation of temperature distribution and thermally induced stress in the premolar tooth under ND-YAG pulsed laser beam. The Three-Phase-Lag (TPL) non-Fourier model is proposed to describe the heat conduction in the human tooth with nonhomogeneous inner structures. A premolar tooth comprising enamel, dentin, and pulp with real shapes and thicknesses are considered and a numerical method of finite difference was adopted to solve the time-dependent TPL bio-heat transfer, strain and stress equations. The surface heating scheme is applied for simulation of laser therapy. The aim of this laser therapy is that the temperature of pulp reaches to 47oC. The results are achieved as a function of laser heat flux showed when laser beam is irradiated downward (from the top of the tooth), the temperature and thermally induced stress increase as a function of time. The temperature increment is high on the top layers of tooth that is a result of strong absorption of beams by enamel. The thermal stress and strain in the enamel and dentin layers are more than the pulp layer that is a result of weak thermal expansion of them proportional to the pulp layer.

The Role of Gangue Mineralogy on Flowsheet Development in Fluorite Processing

Fluorite, CaF2, is considered a strategically important mineral as it is a raw material for many strategic industries. Froth flotation is reported to be the most efficient and economically viable process for the production of an acid-grade product with a CaF2 content of at least 97%. Selective flotation of fluorite from gangue minerals, e.g., calcite and barite, is challenging because these minerals have similar physicochemical properties. This study employed batch flotation tests coupled with mineralogical analysis to design suitable customised flowsheets and efficiently optimised reagent regimes for optimum production of acid-grade fluorite concentrate from two different fluorite ores by the froth flotation process. The effect of pulp temperature on fluorite flotation was investigated in this study with the objective of lowering pulp temperatures in fluorite flotation. The results showed that an acid-grade CaF2 concentrate could be obtained from the flotation of both ores at ambient pulp temperatures. This eliminates the requirement for high-temperature pulp treatment, which would result in a significant reduction in thermal energy costs. This study showed that an understanding of gangue mineralogy is key to process optimisation for acid-grade CaF2 production. Although an acid-grade CaF2 concentrate could be produced from both ores, the flowsheets and reagent regimes were markedly different. For instance, the production of an acid-grade CaF2 product from a high quartz and calcite ore was achieved by employing a simple rougher–multiple cleaner flotation circuit using tannin and sodium silicate as calcite and quartz depressants, respectively. On the other hand, the production of an acid-grade CaF2 product from the flotation of the pyritic ore required a pre-sulphide flotation stage for upfront sulphur removal and the use of a sulphide depressant. Multiple stages of cleaning were required for improved selectivity in the flotation of both ores.

Pulp vitality during ultrasonic tooth preparation. Part 2.

Ultrasonic devices have a lot of dental application specially in hygiene and surgery. However there are some disadvantages like cut slowness and heat production. Prosthodontics application is less investigated. In particular the heat production could be an important factor for the clinician. In fact more than 5.5 °C temperature increasing could determine pulp necrosis during tooth preparation. The aim of this study is to investigate the increasing of temperature during finishing line repositioning and polishing phases using ultrasounds inserts and to verify if it remains within the limit of 5.5 °C. A sample of 32 human molars (extracted for periodontal reasons) was selected. The teeth were endodontically treated and prepared with burs in order to obtain a prosthetic round chamfer preparation, leaving the apical portion pervious for inserting the thermocouple probe. Then, they were inserted in plaster cubes up to the cement-enamel junction. A wall has been selected for each tooth for margin repositioning and finishing and prepared with the piezoelectric instrument (Multipiezo Touch with TipHolder DB2, Mectron, Carasco, Genoa, Italy). A mechanical arm was used to standardize the operator-dependent parameters. These parameters were: the pressure exerted on the dental wall, the cutting length and the time required for margin repositioning and finishing. The test phase consisted in a first stage of margin repositioning using an regular ultrasound tip with a diamond grain of 120 micron (DB120, Mectron, Carasco, Italy) (group 1), followed by a second finishing step conducted by a extra fine ultrasound tip with a diamond grain of 60 micron (DB60, Mectron, Carasco, Italy) (group 2). Each test lasted 60 seconds: this was the time that the mechanical arm needed to accomplish 32 rides. During these stages the intrapulpal temperature has been recorded thanks to a thermocouple. The obtained temperature data were analyzed by Kruskal-Wallis test and Mann-Withney post-hoc test, without Bonferroni correction (P<0.001). The average pulpal temperature increase was 4.65 °C with a standard deviation of 0.99 °C for the DB 120 ultrasonic tip and 5.40 °C with a standard deviation of 0.84 °C for the DB 60 ultrasonic tip. However, neither of the instruments reach the medium critical level of 5.5°C reported in the literature, there are some single values who exceed it. There is statistically significant difference using tips with different granulometries within the two groups (P value =0.013). Ultrasonic tools are very performing to achieve results in repositioning and polishing of prepared tooth. The in-vitro analysis show that the pulp temperature increasing remains within the safe limits literature shows. It is important underline the polishing phase is the most critical and the clinicians have to pay attention to irrigation and pression to avoid pulp damages. Additional clinical studies have to be performed to confirm these results.

An Experimental Research on Cationic Reverse Flotation of Anshan-Type Iron Ores

The mineral processing technology of Anshan-type iron ores has been developed in a rapid speed in recent years, and the combined flowsheet at the core of anionic reverse flotation has become a mainstream in the beneficiation of Anshan-type iron ores in china. With the successful application of this combined flowsheet, some obvious problems are also emerging. Such as high requirement of pulp temperature, complex reagent system, high cost of reagent consumption and so on. In view of this,we have carried out an experimental study on the separation of Anshan type iron ore by cationic reverse flotation . A new collector (named KBD) which is mixed amines have been developed . On this basis, the actual mineral separation experiment is carried out in the laboratory.With KBD as the collector,and starch and sodium hexametaphoshate as the depressant, has resulted in an iron concentrate of 68.16% and recovery rate of 89.71%. The determination of the electrokinetic potential and the infra-red spectroscopic analysis show that KBD can effectively and priorly adsorbed to the surface of quartz, and has greatly change the elecrtokinetic potential of quartz.The interaction of the depressing agent has increased the differences of the floatabilities in quartz and hermitite and changed the surface electric property so that the effective separation has been realized.

Physicochemical Attributes in Mango Fruit (Mangifera indica) as Influenced by Storage Temperature and Hot Water Treatment

Background: The temperature being the most important environmental factor that influences the deterioration of perishable commodities. It is often critical that fresh produce rapidly reach the optimal pulp temperature for short term storage if it is to maintain its highest visual quality, flavour, texture and nutritional content (Kader, 2013).&#x0D; Aims: The effects of storage temperature and hot water at various temperature and duration on chemical and textural characteristics of the Keitt mango fruit were evaluated for the 2015/16 growing season in Botswana.&#x0D; Materials and Methods: The treatments were fruits dipped in distilled water at room temperature (25±2ºC- control), fruits dipped in hot water at 50 and 55ºC for a duration of 3, 5 and 10 minutes, and storage temperatures at 4, 7, 10, 13, or 25±2ºC, plus 95% RH.&#x0D; Results: The results showed that as the storage temperature and water temperature decreased, the proline content and electrolyte leakage increased significantly (P ≤ 0.0001). The interactions of storage temperature and hot water temperature, and duration in which mango fruit was treated with hot water, significantly (P ≤ 0.01) maintained vitamin C content, firmness and reduced fruit weight loss during storage and seven days after storage when the fruit was kept at room temperature.&#x0D; Conclusion: Chemical and physical attributes of Keitt mango fruits were significantly improved by the interactions between storage temperature, hot water temperature and duration.

Evaluation of Soda Delignification and Single-Stage Hydrogen Peroxide Bleaching for the Ethiopian Sugarcane Bagasse for Paper Production

The present study investigated the Ethiopian sugarcane bagasse during its delignification via the sulfur-free soda pulping process and bleaching by the single-stage hydrogen peroxide process. The multilevel categoric experimental design was used to assess the effects of the three independent process variables (pulping temperature, NaOH concentration and time) on the pulp yield and kappa number, during the soda pulping process. The effect of the independent bleaching variables (bleaching temperature, time and H2O2 concentration) on the pulp yield, brightness and whiteness was assessed by using the response surface methodology (central composite experimental design). The soda pulps from the Ethiopian sugarcane bagasse were of varying yield and kappa number and hence were classified according to the sugarcane bagasse providing the highest pulp yield (pulp-SA) with 88.07% and that providing the lowest pulp yield (pulp-SB) with 85.17%. Their corresponding kappa numbers were 16.73 and 8.27, respectively. The brightness and whiteness for the pulp-SA were 62.02% and 84.43%, respectively, whereas for the pulp-SB, the corresponding values were 71.86% and 90.47%, respectively. The study further shows that the paper produced from the pulp-SA had higher mechanical properties. Thus, the promising valorization of the Ethiopian sugarcane bagasse for paper production using the adopted methodology, namely the soda pulping and single-stage hydrogen peroxide bleaching routes, is validated.

The inner temperature of the olives (cv. Leccino) before processing affects the volatile profile and the composition of the oil.

The effects of pre-processing decreasing temperature (19, 15 and 10°C) of olive fruit (cv. Leccino) harvested at three developmental stages (semi-ripe, ripe, advanced ripening) have been evaluated on oil in terms of basic quality parameters, composition, organoleptic traits, and aroma profiles. A total of 40 metabolites (volatiles and non-volatiles) were identified by 1H NMR and GC/MS analyses. Multivariate statistical analysis showed that samples obtained from ripe and advanced ripe olives cooled at 10 and 15°C better correlated with C6 aldehydes, mainly associated with herbal/green olfactory traits. Compounds responsible for sweet/fruity traits were more abundantly present in oil extracted from 19°C olive samples. Decreasing pulp temperature before crushing also resulted in reduced presence of 1-penten-3-ol, 1-penten-3-one, acetic acid and ethyl alcohol, associated with specific defects of the oil. Results indicate that slightly lowering fruit temperature just before crushing modulates oil composition by reducing oil off flavours while enhancing green and fresh attributes in particular when ripe olives are processed.

Real-time pulp temperature change at different tooth sites during fabrication of temporary resin crowns

AimTo record the pulp temperature at different tooth sites during fabrication of two different temporary crown systems. MethodologyTwo temporary crown systems were investigated; a conventional direct fabricated and a preformed thermoplastic resin system. Extracted caries-free human teeth (incisor, premolar and molar) were prepared for full coverage ceramic restoration with roots sectioned below the cemento-enamel junction. Thermocouple wires were secured at the surface of crown material, the cut dentine and inside the pulp cavity. Provisional crowns (n = 10/group) from each system were formed prior to placement in a water bath of 37 °C to simulate pulpal temperature. Temperatures were recorded using a K-type thermocouple data logger to collect the mean and peak temperature during crown fabrication. Statistical analysis was carried out on all tested groups and heat flow was calculated. ResultsFor direct fabricated crowns, the mean rise in pulpal temperature recorded was 0.1 °C with the mean temperature range of 37.3 °C–37.8 °C. For the preformed thermoplastic crowns, the mean rise in pulpal temperature recorded was 37.3 °C–45.1 °C. The increase in temperature was significantly higher (6.5 °C for the incisor group, 7.5 °C for the premolar group, and 6.7 °C for the molar group). For both crown systems, the temperature difference between the three different sites; pulp, crown and tooth surface showed a statistical difference (P < 0.01). ConclusionsThe direct fabrication system showed minimal temperature changes within the teeth, while the preformed thermoplastic fabrication system showed larger temperature change in the teeth.