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Sample records for acidulants

  1. Corrosion behavior of zirconia in acidulated phosphate fluoride

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    Anie Thomas

    2016-02-01

    Full Text Available ABSTRACT Objective The corrosion behavior of zirconia in acidulated phosphate fluoride (APF representing acidic environments and fluoride treatments was studied. Material and Methods Zirconia rods were immersed in 1.23% and 0.123% APF solutions and maintained at 37°C for determined periods of time. Surfaces of all specimens were imaged using digital microscopy and scanning electron microscopy (SEM. Sample mass and dimensions were measured for mass loss determination. Samples were characterized by powder X-ray diffraction (XRD to detect changes in crystallinity. A biosensor based on electrochemical impedance spectroscopy (EIS was used to detect ion dissolution of material into the immersion media. Results Digital microscopy revealed diminishing luster of the materials and SEM showed increased superficial corrosion of zirconia submerged in 1.23% APF. Although no structural change was found, the absorption of salts (sodium phosphate onto the surface of the materials bathed in 0.123% APF was significant. EIS indicated a greater change of impedance for the immersion solutions with increasing bathing time. Conclusion Immersion of zirconia in APF solutions showed deterioration limited to the surface, not extending to the bulk of the material. Inferences on zirconia performance in acidic oral environment can be elucidated from the study.

  2. Acidulant and oven type affect total anthocyanin content of blue corn cookies.

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    Li, Jian; Walker, Chuck E; Faubion, Jon M

    2011-01-15

    Anthocyanins, pink to purple water-soluble flavonoids, are naturally occurring pigments with claimed health benefits. However, they are sensitive to degradation by high pH, light and temperature. Blue corn (maize) contains high levels of anthocyanins. Cookies are popular snacks and might serve as a vehicle to deliver antioxidants. A cookie formula with a high level of blue corn was developed with added acidulents and baked in ovens with different heat transfer coefficients. The best whole-grain blue corn flour/wheat pastry flour ratio (80:20 w/w), guar gum level (10 g kg(-1), flour weight basis) and water level (215 g kg(-1), flour weight basis) were determined based on response surface methodology analysis. The interactions of citric and lactic acids and glucono-δ-lactone with three oven types having different heat transfer coefficients (impingement oven 179 °C/4 min, reel oven 204 °C/10 min and convection oven 182 °C/4 min) influenced the total anthocyanin content (TAC) remaining in blue corn-containing cookies after baking. Cookies baked with citric acid in the convection oven retained the maximum TAC (227 ± 3 mg kg(-1)). By baking rapidly at lower temperatures and adding acidulents, it may be possible to increase residual natural source antioxidants in baked foods. Copyright © 2010 Society of Chemical Industry.

  3. Field evaluation of partially acidulated phosphate rocks in a Ferralsol from Cuba

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    Rodriguez, R.; Herrera, J. [Ciego de Avila University, Ciego de Avila (Cuba)]. E-mail: herrera@uctr.unica.cu

    2002-05-15

    Phosphorus (P) is needed in large areas of developing countries to improve soil fertility for crop production. The use of phosphate rock (PR) is an alternative to costly soluble P fertilizers, but it is ineffective usually in non-acid soils unless it is modified i.e. partially acidulated (PAPR). A laboratory incubation study using the isotopic exchange kinetic method of {sup 32}P and field experiments were undertaken on a neutral Ferralsol of Cuba to evaluate the effectiveness of PAPRs as fertilizers for common bean (Phaseolus vulgaris, L.). Sulfuric-acid based PAPR using 40%, 50% and 60% of the acid required to produce single superphosphate were studied. In the laboratory experiment Trinidad de Guedes PAPR was effective in providing P to the soil, through increases in isotopically exchangeable P and the percentage of P derived from fertilizer (% Pdff). In the three field experiments carried out to compare the P sources, yields of common bean were increased by PAPR, though the response was less than with triple superphosphate (TSP). The relative agronomic effectiveness (RAE) of PAPR was greater than that of unacidulated PR. Taking into account the RAE values and the current cost of the P sources, the choice of Trinidad de Guedes PAPR instead of TSP could be economic, although the RAE value for PAPR was lower than that of TSP. This result indicates that PAPR could be used in the soil understudy to obtain the best economic return. DM yield, P uptake and grain yield of common bean were significantly increased by applying P as 50% PAPR. Low cost improvement of the agronomic value of PR can be achieved by partial acidulation, so this modification of the phosphate rock show promise for utilization of PR reserves indigenous to developing countries. (author)

  4. Field evaluation of partially acidulated phosphate rocks in a Ferralsol from Cuba

    International Nuclear Information System (INIS)

    Rodriguez, R.; Herrera, J.

    2002-01-01

    Phosphorus (P) is needed in large areas of developing countries to improve soil fertility for crop production. The use of phosphate rock (PR) is an alternative to costly soluble P fertilizers, but it is ineffective usually in non-acid soils unless it is modified i.e. partially acidulated (PAPR). A laboratory incubation study using the isotopic exchange kinetic method of 32 P and field experiments were undertaken on a neutral Ferralsol of Cuba to evaluate the effectiveness of PAPRs as fertilizers for common bean (Phaseolus vulgaris, L.). Sulfuric-acid based PAPR using 40%, 50% and 60% of the acid required to produce single superphosphate were studied. In the laboratory experiment Trinidad de Guedes PAPR was effective in providing P to the soil, through increases in isotopically exchangeable P and the percentage of P derived from fertilizer (% Pdff). In the three field experiments carried out to compare the P sources, yields of common bean were increased by PAPR, though the response was less than with triple superphosphate (TSP). The relative agronomic effectiveness (RAE) of PAPR was greater than that of unacidulated PR. Taking into account the RAE values and the current cost of the P sources, the choice of Trinidad de Guedes PAPR instead of TSP could be economic, although the RAE value for PAPR was lower than that of TSP. This result indicates that PAPR could be used in the soil understudy to obtain the best economic return. DM yield, P uptake and grain yield of common bean were significantly increased by applying P as 50% PAPR. Low cost improvement of the agronomic value of PR can be achieved by partial acidulation, so this modification of the phosphate rock show promise for utilization of PR reserves indigenous to developing countries. (author)

  5. Acidulants for japanese quails housed at high stocking rates at finishing phase

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    Ana Paula de Oliveira Saccomani

    2013-12-01

    Full Text Available The quail for being an alternative species will be able to supply a new market niche due to its fast growth, high laying rate, low feed intake, in addition to the increase of the acceptance of its products by the consumer. A growing interest in raising the stocking rates in the cages as an alternative to increase the performance of the stock is noticed; although studies demonstrate that high densities can result into unfavorable environment to the birds’ welfare with alterations in the performance of the flocks and as a stressing factor being able to alter the production and profitability of the flock. At high stocking rates, the birds become predisposed to aggressiveness reactions, presenting cannibalism behavior, besides the combination of factors such as pH, temperature, ventilation and humidity deficiency which create environmental conditions favorable for certain benign bacteria which utilize uric acid of the manure through their enzymatic complexes and produce ammonia, causing stress to birds and which can cause damages to performance with significant economic losses to the producer.  The experiment with 112-day duration was conducted with the objective of evaluating the inclusion of acidulants in the Japanese quails’ drinking water and verifying the effect on the stocking rate in cages. A completely randomized design with four treatments (2 stocking rates of quails x 2 additions of and 5 replications of 24 and 36 birds per cage, corresponding to the stocking rates of 141.67 and 94.44 cm2/bird, respectively, receiving or not acidulant in the water (acetic, lactic and phosphoric acid was utilized. Performance was evaluated through egg weight (EWg, egg yield (%Laying., egg mass (EMg/bird/day, feed intake (FIg/bird/day, feed conversion (FCkg/dz and FCkg/kg and mortality (%Mort. No significant statistical differences about the performance (P>0.05 were found. There was a significant effect (P<0.05 of the density for daily feed intake with

  6. The effect of acidulated phosphate fluoride application on dental enamel surfaces hardness

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    Edhie Arief P

    2007-09-01

    Full Text Available Enamel demineralization by acid is the first step of caries process. It has recently been shown that acidulated phosphate fluoride (APF can maintain the hardness of enamel surface. The aim of this study was examine the effect of APF application in the hardest of enamel surface. Fifty extracted teeth were cut at their crown, 40 teeth were taken randomly then divided into 4 groups, group 1 as the control, group 2 was treated with APF for 1 minute, group 3 for 4 minutes and group 4 for 7 minutes, then all the samples were washed with demineralized water. To see the effect of APF, all of the samples were soaked in lactic acid demineralization solution with pH 4,5 for 72 hours., the hardness of the surfaces of those samples before and after the treatment was measured by Micro Vickers Hardness Tester. The data were analyzed using One-Way ANOVA and LSD tests. In conclusion, 1.23% APF gel can reduce higher enamel demineralization.

  7. Water intake and digestive metabolism of broilers fed all-vegetable diets containing acidulated soybean soapstock

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    SL Vieira

    2006-09-01

    Full Text Available A study was conducted to compare live performance and digestive metabolism of broiler chickens fed all-vegetable diets (All-Veg compared to a regular diet including animal by-products. Three feeds were formulated and provided to broilers according to the feeding program: pre-starter from 1 to 10 days, starter from 11 to 21 days, and grower from 21 to 35 days. All feeds had corn and soybean meal as major ingredients; however, two of them were all-vegetable diets having either Degummed Soybean Oil (DSO or Acidulated Soybean Soapstock (ASS as fat sources. The third diet included poultry by-product and poultry fat. A total number of 360 day-old broiler chicks were allocated to 1m² battery cages, 10 chicks in each, and 12 replicates per treatment. Live performance was similar between groups of birds receiving the different diets with the exception of weight gain, which was increased for birds fed the All-Veg diet with ASS. Birds fed All-Veg diets had increased water intake and produced more excreta with a concurrent reduced feed metabolizability at both ages, regardless of fat source. Metabolizable Energy was not different for the three diets.

  8. Effect of Acidulated Phosphate Fluoride (APF on the Mcroleakage of Composite Flow and Fssure Sealant Restorations

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    Arash Poorsattar Bejeh Mir

    2012-09-01

    Full Text Available Background and Aims: A large number of investigations have revealed that physical and chemical alterations and weight loss could occur in composite materials exposed to acidic phosphate fluoride (APF gel. The purpose of this study was to assess the microleakage of a fissure sealant and a flow composite exposed to acidulated phosphate fluoride (APF gel. Materials and Methods: In this in vitro study, 60 intact human extracted premolar teeth were used. After preparing the occlusal groove, the teeth were divided into two groups (n=30. Teeth were filled with either Helioseal fissure sealant (Vivadent, Germany or Tetric flow composite (Vivadent, Germany. After that, each group was divided into two subgroups (n=15: 1.23% APF gel (Sultan, U.S.A was applied in the case subgroups, while control subgroups were preserved in normal saline solution. All of teeth were covered with 2 layers of nail varnish except for the filling zone and 1mm around the border of filling. After submerging in 0.5% fushin solution, specimens were sectioned bucco-lingually. Then dye penetration through the filling and fissure sealant was assessed by means of a stereo-microscope. The depth of dye penetration was scored. The data were analyzed using One-way ANOVA and Levene test. Results: The mean values of dye penetration were 1.26±1.09, 1.4±1.05, 1.2±1.37, and 1.4±1.35 for fissure sealant+gel, composite+gel, composite+normal saline, and normal saline groups, respectively. No significant difference was found in inter-groups (P=0.96. Conclusion: Considering the result of the present research, APF gel had no significant effect on the microleakage of Tetric flow composite filling and Helioseal fissure sealant and thus, it can be applied for routine usage.

  9. Formulation of Hydrocolloid-Agar, Sucrose, and Acidulant on Jam Leather Product Development

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    Wahyu Ramadhan

    2017-04-01

    Full Text Available Tallying agar powder as a texturizer in guava single sheet jam instigate the product more convenience to consumed. The aims of this research were to determine the best concentration of sucrose, citric acid and agar powder to form a good quality guava jam slice. The research method are optimization and formulationof sucrose, citric acid and agar-agar on making guava jam single sheets product. Physochemical and sensory tests were performed to reveal the best formulation of guava jam slice and the Bayes method used to determine the optimization of the selected formula. Based on the results of formulation and analysis, itwas obtained that  the guava jam slice with Acidulant concentration (0.02%, 0.04%, 0.06%, sucrose (70%, 80%, 90%, 100% and agar powder (0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2% had pH 3.63-3.90, sugar content 34.68 g/100 g – 35.76 g/100 g, color intensity L*, a*, b* with ΔE* value was 37,88-53,97, fiber content 1.01%-1.59%, and water activity 0.852-0.893. Rheology properties for texture profile (hardness, cohesiveness, springiness, adhesive force, and gumminess also showed significant value with agar powder formulation. Based on the Bayes test and hedonic test, it was found that the best formula was for guava jam slices with the addition of 90% sucrose, citric acid 0.04% and agar powder 0.9%. From the best formula, it was found the shelf life prediction model of Arrhenius formula was ln k = 20.222-6660.6(1/T and the nutrition facts contribute total energy 45 kcal, fat 0%, carbohydrate 9%, protein 2% and dietary fiber 3%.

  10. Surface degradation of glass ceramics after exposure to acidulated phosphate fluoride

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    CCAHUANA, Vanessa Zulema S.; ÖZCAN, Mutlu; MESQUITA, Alfredo Mikail Melo; NISHIOKA, Renato Sussumo; KIMPARA, Estevão Tomomitsu; BOTTINO, Marco Antonio

    2010-01-01

    Objective This study evaluated the surface degradation effect of acidulated phosphate fluoride (APF) gel exposure on the glassy matrix ceramics as a function of time. Material and methods Disc-shaped ceramic specimens (N = 120, 10/per ceramic material) were prepared in stainless steel molds (inner diameter: 5 mm, height: 2 mm) using 6 dental ceramics: 3 indicated for ceramic-fused-to-metal (Vita Omega 900, Carmen and Vita Titankeramik), 2 for all-ceramic (Vitadur Alpha and Finesse® Low Fusing) and 1 for both types of restorations (IPS d.SIGN). The specimens were wet ground finished, ultrasonically cleaned and auto-glazed. All specimens were subjected to calculation of percentage of mass loss, surface roughness analysis and topographical description by scanning electron microscopy (SEM) before (0 min) and after exposure to 1.23 % APF gel for 4 min and 60 min representing short- and long-term etching effect, respectively. The data were analyzed using two-way ANOVA with repeated measures and Tukey`s test (α=0.05). Results Significant effect of the type of the ceramics (p=0.0000, p=0.0031) and exposure time (p=0.0000) was observed in both surface roughness and percentage of mass loss values, respectively. The interaction factor between both parameters was also significant for both parameters (p=0.0904, p=0.0258). Both 4 min (0.44±0.1 - 0.81±0.2 µm) and 60 min (0.66±0.1 - 1.04±0.3 µm) APF gel exposure created significantly more surface roughness for all groups when compared to the control groups (0.33±0.2 - 0.68±0.2 µm) (p0.05) but at 60 min exposure, IPS d.SIGN showed the highest percentage of mass loss (0.1151±0.11). The mean surface roughness for Vita Titankeramik (0.84±0.2 µm) and Finesse® Low Fusing (0.74.±0.2 µm) was significantly higher than those of the other ceramics (0.59±0.1 µm - 0.49±0.1 µm) and Vita Titankeramik (pcorrosive attack on all of ceramics at varying degrees. Conclusions The ceramics indicated for either metal-ceramic or all

  11. Influence of food acidulants and antioxidant spices on the bioaccessibility of beta-carotene from selected vegetables.

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    Veda, Supriya; Platel, Kalpana; Srinivasan, Krishnapura

    2008-09-24

    Four common food acidulants--amchur, lime, tamarind, and kokum--and two antioxidant spices--turmeric and onion--were examined for their influence on the bioaccessibility of beta-carotene from two fleshy and two leafy vegetables. Amchur and lime generally enhanced the bioaccessibility of beta-carotene from these test vegetables in many instances. Such an improved bioaccessibility was evident in both raw and heat-processed vegetables. The effect of lime juice was generally more pronounced than that of amchur. Turmeric significantly enhanced the bioaccessibility of beta-carotene from all of the vegetables tested, especially when heat-processed. Onion enhanced the bioaccessibility of beta-carotene from pressure-cooked carrot and amaranth leaf and from open-pan-boiled pumpkin and fenugreek leaf. Lime juice and the antioxidant spices turmeric and onion minimized the loss of beta-carotene during heat processing of the vegetables. In the case of antioxidant spices, improved bioaccessibility of beta-carotene from heat-processed vegetables is attributable to their role in minimizing the loss of this provitamin. Lime juice, which enhanced the bioaccessibility of this provitamin from both raw and heat-processed vegetables, probably exerted this effect by some other mechanism in addition to minimizing the loss of beta-carotene. Thus, the presence of food acidulants (lime juice/amchur) and antioxidant spices (turmeric/onion) proved to be advantageous in the context of deriving maximum beta-carotene from the vegetable sources.

  12. In vitro DISSOLUTION OF ACIDULATED ROCK PHOSPHATE BY PHOSPHATE SOLUBILIZING MICROORGANISMS

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    Ángela Patricia Moreno Quevedo

    2015-05-01

    Full Text Available The low availability of phosphorus (P in the soil and the high cost of P fertilization are factors that limit agricultural productivity. A biotechnological alternative for to handle this problem is to use soil microorganisms capable of dissolving rock phosphate (RP, thus improving its effectiveness as a P fertilizer. This study was carried out with the objective of determining the effectiveness of Aspergillus niger –As-, Penicillium sp. –Pn-, Bacillus sp –B-. and an unidentified actinomycete –At- in the in vitro dissolution of two partially acidulated rock phosphates. The treatments consisted of 2x16 factorial arrangement [2 levels of RP: either Boyaca RP or Norte de Santander RP; 16 levels of inoculum: an uninoculated control, individual inoculations (with As, Pn, B, At, dual inoculations (AsPn, AsB, AsAt, PnB, PnAt, BAt, triple inoculations (AsPnB, AsPnAt, AsBAt, PnBAt, and quadruple inoculation (AsPnBAt]. Each treatment was replicated three times. Each treatment was replicated three times. It was found that the microbial effectiveness in the in vitro dissolution of RP depended on the type of RP, the composition of the inoculum used and the interaction of both factors. The best results were obtained with the Norte de Santander RP and A. niger used alone. When this fungus combined with the other microorganisms, its capacity to dissolve RP was significantly reduced. RESUMEN La baja disponibilidad de fósforo (P en el suelo y el costo de la fertilización fosfórica son limitantes para la productividad agrícola. Una alternativa biotecnológica para manejar este problema es mediante el uso de microorganismos del suelo capaces de disolver rocas fosfóricas (RP y así mejorar su efectividad como fertilizante fosfórico. Con este fin se realizó un ensayo para determinar la efectividad microbial en la disolución in vitro de dos RP (Norte de Santander y Boyacá parcialmente aciduladas. Los tratamientos consistieron en un arreglo factorial 2x

  13. Interaction of ionising radiation and acidulants on the growth of the microflora of a vacuum-packaged chilled meat product

    International Nuclear Information System (INIS)

    Farkas, J.; Andrássy, E.

    1993-01-01

    Microbiological effects of gamma irradiation dose of 2 kGy, with and without reduction of pH to 5.3-5.2, have been investigated with a vacuum-packaged, minced meat product prepared from pork and beef with spices and cereal fillings. Either glucono-delta-lactone or ascorbic acid were used as acidulants. Experimental batches were stored at 0-2 degrees C for 4 weeks. Effect of temperature abuse condition was also studied by transferring packages for one week to 10 degrees C after 2-week holding at 0-2 degrees C. The irradiation caused two decimal reduction of the aerobic viable cell count determined after incubation at room temperature and four decimal reduction in the Enterobacteriaceae count. Lactic acid bacteria appeared to be more radiation resistant and became the dominant component of the microflora during storage. Combination of pH-reduction and irradiation prevented growth of Enterobacteriaceae even at 10 degrees C incubation. (author)

  14. Glucono-delta-lactone and citric acid as acidulants for lowering the heat resistance of Clostridium sporogenes PA 3679 in HTST working conditions.

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    Silla Santos, M H; Torres Zarzo, J

    1995-04-01

    The heat resistance of Clostridium sporogenes PA 3679 spores has been studied to establish the influence of acidification with glucono-delta-lactone (GDL) and citric acid on the thermal resistance parameters (DT and z) of this microorganism and to compare their effect with phosphate buffer and natural asparagus as reference substrates. A reduction in DT values was observed in asparagus purée as the acidification level increased with both acidulants although this effect was more evident at the lower treatment temperatures studied (121-127 degrees C). Citric acid was more effective for reducing the heat resistance of spores than GDL at all of the temperatures. The reduction in pH diminished the value of the z parameter, although it was necessary to lower the pH to 4.5 to obtain a significant reduction.

  15. Controlling acrylamide in French fry and potato chip models and a mathematical model of acrylamide formation: acrylamide: acidulants, phytate and calcium.

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    Park, Yeonhwa; Yang, Heewon; Storkson, Jayne M; Albright, Karen J; Liu, Wei; Lindsay, Robert C; Pariza, Michael W

    2005-01-01

    We previously reported that in potato chip and French fry models, the formation of acrylamide can be reduced by controlling pH during processing steps, either by organic (acidulants) or inorganic acids. Use of phytate, a naturally occurring chelator, with or without Ca++ (or divalent ions), can reduce acrylamide formation in both models. However, since phytate itself is acidic, the question remains as to whether the effect of phytate is due to pH alone or to additional effects. In the French fry model, the effects on acrylamide formation of pH, phytate, and/or Ca++ in various combinations were tested in either blanching or soaking (after blanching) steps. All treatments significantly reduced acrylamide levels compared to control. Among variables tested, pH may be the single most important factor for reducing acrylamide levels, while there were independent effects of phytate and/or Ca++ in this French fry model. We also developed a mathematical formula to estimate the final concentration of acrylamide in a potato chip model, using variables that can affect acrylamide formation: glucose and asparagine concentrations, cut potato surface area and shape, cooking temperature and time, and other processing conditions.

  16. Performance of broilers fed increased levels energy in the pre-starter diet and on subsequent feeding programs having with acidulated soybean soapstock supplementation

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    SL Vieira

    2006-03-01

    Full Text Available This study aimed to evaluate broiler responses to increases in feed energy (2,870, 3,000 and 3,100 kcal ME/kg and the inclusion of Acidulated Soybean Soapstock (ASS when compared to Degummed Soybean Oil (DSO in feeds from placement to 7 days of age. From 7 to 42 days ASS or DSO were included in diets that contained similar energy and nutrient levels. Metabolizable energy values used to formulate the diets for ASS and DSO were 8,351 and 7,701 kcal ME/kg in the first week and 9,314 and 8,559 kcal ME/kg afterwards, respectively. Diets were based on corn and soybean meal and were fed to 1,600 one-d-old male broiler chicks randomly placed in 40 floor pens. No differences in performance due to fat source were seen at 7 days. However, the increase in energy levels to 3,100 kcal ME/kg reduced feed intake, whereas feed conversion was improved with energy at 3,000 kcal ME/kg. Live performance, and the yields of carcass and commercial cuts were not affected by the type of fat included in the feeds from 7 to 42 days, except for increased body weight at 21 and 35 days with ASS supplementation. Litter moisture at 7, 21, 35 and 42 days was not affected by any of the factors and there were no residual effects of treatments at 21, 35 and 42 days of age. On the other hand, body weight at 35 days was affected by the interaction of diets fed in the first week with those provided afterwards. The results showed that ME values used for DSO and ASS are adequate and that ASS may be used as fat source in broiler feeds from placement to 42 days of age.

  17. The Effect of Casein Phosphopeptide-Amorf Calcium Phosphate and Acidulated Phosphate Fluoride Gel on Dental Erosion in Primary Teeth: An in Vitro Study.

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    Maden, Eda Arat; Acar, Özge; Altun, Ceyhan; Polat, Günseli Güven

    This study aimed to investigate the effect of acidulated phosphate fluoride (APF) gel and casein phosphopeptide/amorphous calciumphosphate (CPP-ACP) on the dental erosion produced by carbonated soft drink in primary teeth. This study evaluated by an in vitro model the effect of APF gel and CPP-ACP on the dental enamel previously subjected to erosive challenge with carbonated soft drink. Sixty sound human primary molars were prepared by embedding the crown sections in acrylic resin blocks leaving the enamel surfaces exposed. The surface roughness of the enamel was measured with prophilometry at baseline. Specimens were randomly divided into three treatment groups (n:20): artificial saliva, CPP-ACP, 1.23% APF gel. All specimens were then exposed to an erosive challenge of carbonated soft drink and artificial saliva for 20 cycles of 20 seconds each. Demineralization-remineralization cycles was repeated twice at eight-hour intervals and roughness values were measured. Enamel samples were treated with artificial saliva, CPP-ACP, 1.23% APF gel applied for 10 min after erosive challenge. The arithmetic average roughness (Ra) readings were recorded after remineralization agents were applied. The mean surface roughness in all groups increased significantly after erosion process and decreased after remineralization treatment. After treatment, the mean surface roughness of the 1.23% APF gel group was significantly less than the other groups and the mean surface roughness of the artificial saliva group was significantly more than the other groups. 1.23% APF gel showed the highest protective effect against erosive enamel loss. Under the conditions of this study, artificial saliva, CPP-ACP and 1.23% APF treatments were able to reduce erosive enamel loss produced by carbonated soft drink in primary teeth. However, 1.23% APF gel showed the highest protective effect against erosive enamel loss.

  18. Acquired acid resistance of human enamel treated with laser (Er:YAG laser and Co 2 laser and acidulated phosphate fluoride treatment: An in vitro atomic emission spectrometry analysis

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    Anju Mathew

    2013-01-01

    Full Text Available Background: Dental caries is essentially a process of diffusion and dissolution. If the aspect of dissolution can be curtailed some degree of prevention can be achieved. Aims: The present study was carried out to evaluate and compare the effect of Er:YAG laser and Co 2 laser irradiation combined with acidulated phosphate fluoride treatment on in vitro acid resistance of human enamel. Design: An in vitro study was carried out on 30 human premolars to evaluate the enamel′s acid resistance using an atomic emission spectrometry analysis. Materials and Methods: A total of 60 enamel specimens were prepared from 30 human premolars and were randomly assigned to 6 groups: (1 Untreated (control; (2 1.23% acidulated phosphate fluoride (APF gel application alone for 4 min; (3 Er:YAG laser treatment alone; (4 Co 2 laser treatment alone; (5 Er:YAG laser + APF gel application; (6 Co 2 laser + APF gel application. The specimens were then individually immersed in 5 ml of acetate buffer solution (0.1 mol/L, pH 4.5 and incubated at 37°C for 24 h, and the acid resistance was evaluated by determining the calcium ion concentration using the atomic emission spectrometry. Statistical Analysis: An ANOVA model was constructed (P value of 0.05, followed by Tukey′s test for multiple pair wise comparisons of mean values. Results: Significant differences were found between the control group and the test groups ( P < 0.001. Conclusions: Combining acidulated phosphate fluoride with either Er:YAG or Co 2 laser had a synergistic effect in decreasing the enamel demineralization more than either fluoride treatment or laser treatment alone.

  19. Apparent metabolizable energy of by-products from the soybean oil industry for broilers: acidulated soapstock, glycerin, lecithin, and their mixture.

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    Borsatti, L; Vieira, S L; Stefanello, C; Kindlein, L; Oviedo-Rondón, E O; Angel, C R

    2018-01-01

    A study was conducted to determine the AMEn contents of fat by-products from the soybean oil industry for broiler chickens. A total of 390 slow-feathering Cobb × Cobb 500 male broilers were randomly distributed into 13 treatments having 6 replicates of 5 birds each. Birds were fed a common starter diet from placement to 21 d. Experimental corn-soy diets were composed of four fat sources, added at 3 increasing levels each, and were fed from 21 to 28 d. Fat sources utilized were acidulated soybean soapstock (ASS), glycerol (GLY), lecithin (LEC), and a mixture (MIX) containing 85% ASS, 10% GLY and 5% LEC. A 4 × 3 + 1 factorial arrangement was used with 4 by-products (ASS, GLY, LEC, or MIX), 3 inclusion levels and 1 basal diet. Each of the four fat by-product sources was included in the diets as follow: 2% of by-products (98% basal + 2% by-product), 4% (96% basal + 4% by-product), or 6% (94% basal + 6% by-product). Birds were submitted to 94, 96, 98, and 100% of ad libitum feed intake; therefore, the differences in AMEn consumption were only due to the added by-product. Total excreta were collected twice daily for 72 h to determine apparent metabolizable energy contents starting at 25 d. The AMEn intake was regressed against feed intake and the slope was used to estimate AMEn values for each fat source. Linear regression equations (P product were as follow: 7,153X - 451.9 for ASS; 3,916X - 68.2 for GLY; 7,051X - 448.3 for LEC, and 8,515X - 622.3 for MIX. Values of AMEn were 7,153, 3,916, 7,051, and 8,515 kcal/kg DM for ASS, GLY, LEC, and MIX, respectively. The present study generated AMEn for fat by-products data that can be used in poultry feed formulation. It also provides indications that, by adding the 3 by-products in the proportions present in the MIX, considerable economic advantage can be attained. © 2017 Poultry Science Association Inc.

  20. Atomic force microscopic comparison of remineralization with casein-phosphopeptide amorphous calcium phosphate paste, acidulated phosphate fluoride gel and iron supplement in primary and permanent teeth: An in-vitro study

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    Nikita Agrawal

    2014-01-01

    Full Text Available Context: Demineralization of tooth by erosion is caused by frequent contact between the tooth surface and acids present in soft drinks. Aim: The present study objective was to evaluate the remineralization potential of casein-phosphopeptide-amorphous calcium phosphate (CPP-ACP paste, 1.23% acidulated phosphate fluoride (APF gel and iron supplement on dental erosion by soft drinks in human primary and permanent enamel using atomic force microscopy (AFM. Materials and Methods: Specimens were made from extracted 15 primary and 15 permanent teeth which were randomly divided into three treatment groups: CPP-ACP paste, APF gel and iron supplement. AFM was used for baseline readings followed by demineralization and remineralization cycle. Results and Statistics: Almost all group of samples showed remineralization that is a reduction in surface roughness which was higher with CPP-ACP paste. Statistical analysis was performed using by one-way ANOVA and Mann-Whitney U-test with P < 0.05. Conclusions: It can be concluded that the application of CPP-ACP paste is effective on preventing dental erosion from soft drinks.

  1. Studies in the preparation of /sup 32/P labelled compounds from high grade rock phosphate with high fluorine content. [Water soluble P/sub 2/O/sub 5/, acidulation, curing

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, T S; Cherian, S; Shivarudrappa, V; Subramanian, T K; Achari, P S [Bhabha Atomic Research Centre, Bombay (India). Primary Isotopes Section

    1981-01-01

    The labelled phosphate to be used for crop evaluation studies should have characteristics exactly similar to the industrial product employed in agriculture. For the preparation of /sup 32/P labelled compound from rock phosphate with high fluorine content, a number of parameters have been studied like particle size of the rock, temperature and amount of acid required, the curing time, etc. Because of the high reaction temperature, the curing time is reduced to experimental limits compared to the commercial product. This paper describes a method for the preparation of such a labelled phosphate and this yields a product with about 95% of the phosphate in the water soluble form.

  2. SHORT COMMUNICATION: Agronomic effectiveness of novel ...

    African Journals Online (AJOL)

    ) uptake and dry matter yield of maize. The relative agronomic effectiveness of DPR partially acidulated with 50% of the sulfuric acid (H2SO4) required for complete acidulation, in increasing P uptake and dry matter yield was 60% and 75%, ...

  3. Method for the recovery of uranium from phosphoric acid, originating from the wet-process of uraniferous phosphate ores

    International Nuclear Information System (INIS)

    Pyrih, R.Z.; Rickard, R.S.; Carrington, O.F.

    1978-01-01

    Improvement in the process for recoverying uranium from wet-process phosphoric acid solution derived from the acidulation of uraniferous phosphate ores by the use of two ion exchange circuits is described. (Auth.)

  4. short communication agronomic effectiveness of novel phosphate

    African Journals Online (AJOL)

    igneous Dorowa (Zimbabwe) phosphate rock was investigated in a greenhouse ... are higher than the levels considered desirable for acidulation was selected based on proportions ... The analysis for dry matter yield of and P uptake by maize ...

  5. Effect of lipid sources of diets on broiler performance

    OpenAIRE

    Lara,L.J.C.; Baião,N.C.; Aguilar,C.A.L.; Cançado,S.V.; Fiuza,M.A.; Ribeiro,B.R.C.

    2005-01-01

    A completely randomized design with six replicates of 30 birds per experimental unit was used to evaluate the effect of five fat sources of diets (soybean oil, poultry fat, acidulated soybean oil soapstock and a mix of soybean oil plus poultry fat and soybean oil plus acidulated soybean oil soapstock) on the performance of male Ross broilers, during the growing period (1-45 days of age). The diets for each phase were isonutritional. Broilers fed on soybean oil showed higher weight gain in com...

  6. Application of carbon and hydrogen stable isotope analyses to detect exogenous citric acid in Japanese apricot liqueur.

    Science.gov (United States)

    Akamatsu, Fumikazu; Oe, Takaaki; Hashiguchi, Tomokazu; Hisatsune, Yuri; Kawao, Takafumi; Fujii, Tsutomu

    2017-08-01

    Japanese apricot liqueur manufacturers are required to control the quality and authenticity of their liqueur products. Citric acid made from corn is the main acidulant used in commercial liqueurs. In this study, we conducted spiking experiments and carbon and hydrogen stable isotope analyses to detect exogenous citric acid used as an acidulant in Japanese apricot liqueurs. Our results showed that the δ 13 C values detected exogenous citric acid originating from C 4 plants but not from C 3 plants. The δ 2 H values of citric acid decreased as the amount of citric acid added increased, whether the citric acid originated from C 3 or C 4 plants. Commercial liqueurs with declared added acidulant provided higher δ 13 C values and lower δ 2 H values than did authentic liqueurs and commercial liqueurs with no declared added acidulant. Carbon and hydrogen stable isotope analyses are suitable as routine methods for detecting exogenous citric acid in Japanese apricot liqueur. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Physiological characterization of the high malic acid-producing Aspergillus oryzae strain 2103a-68

    DEFF Research Database (Denmark)

    Knuf, Christoph; Nookaew, Intawat; Remmers, Ilse

    2014-01-01

    Malic acid is a C4 dicarboxylic acid that is currently mainly used in the food and beverages industry as an acidulant. Because of the versatility of the group of C4 dicarboxylic acids, the chemical industry has a growing interest in this chemical compound. As malic acid will be considered as a bulk...

  8. Untitled

    Indian Academy of Sciences (India)

    An intimate mixture of resorcinol (20gm.) phenyl acetic acid (30 gm.) and powdered anhydrous zinc chloride (20 gm.) was heated in an oil-bath at 120° C. for two and half hours and then poured in acidulated ice-cold- water. The product was purified through alkali and crystallised from . alcohol in lustrous, long needles m.p. ...

  9. Effects of the low-intensity laser therapy on the prevention of dental caries induced in rats

    International Nuclear Information System (INIS)

    Mueller, Karin Praia

    2004-01-01

    The purpose of this study was to investigate the effects of low intensity laser therapy, associated or not to an acidulated phosphate fluoride, on the prevention of dental caries induced in rats. It was used 40 wistar rats, female, weaned with 18 days, fed with a cariogenic diet during 48 days and inoculated orally with Streptococcus mutans by three consecutive days starting from the second day of the diet. On the fifth day of experiment the animals were divided into five groups: G c (control) the animas were no submitted to any treatment; G L (laser) irradiation with low power laser (GaAlAs, λ=660 nm, P=30 mW, Δt=5 sec, 5 J/cm 2 ); G F (fluoride) topical application of acidulated phosphate fluoride (APF 1,23%) for four minutes; G LF (laser + fluoride) irradiation with low power laser followed by topical application of acidulated phosphate fluoride; G FL (fluoride + laser) topical application of acidulated phosphate fluoride followed by low power laser. The animals were sacrificed after 48 days; the molars were extracted and prepared to determine the dental caries lesions area by optical microscopy, enamel microhardness and analysis of the calcium and phosphorus ratio (Ca/P) by energy dispersive spectroscopy. The results were statistically analyzed by ANOVA (p LF was smaller than that for G F and G FL groups but no statistical difference was observed. There was no significant statistical difference between the microhardness of the G C and G L groups and among G FL , G LF and G F groups. Regarding to the calcium and phosphorus ratio, it was not observed significant statistical differences among the groups. These findings suggest that low-intensity laser radiation associated with acidulated phosphate fluoride reduces the caries area and could be an alternative in the prevention of the dental caries. (author)

  10. Enhancement of the agronomic effectiveness of phosphate rock in a ferralsol from Cuba

    International Nuclear Information System (INIS)

    Rodriguez, R.; Herrera, J.A.; Garcia, A.; Nuviola, A.

    2002-01-01

    The Ferralsols from Ciego de Avila, Cuba, have a pH near neutrality and very low exchangeable acidity, thus, they are not suitable for direct application of phosphate rock. In laboratory and greenhouse experiments, different P fertilizers were tested in order to assess their agronomic effectiveness through the use of nuclear and conventional methods. The phosphate rocks (PRs) came from different deposits (Higuanojo, La Pimienta and Trinidad de Guedes from Cuba; Riecito, Baja California and North Carolina from other countries). Partial acidulation (PA) of some of these rocks was also evaluated. Trinidad de Guedes PAPRs were found to be highly effective compared to their natural PR when evaluated through dry matter production, P uptake and isotopic parameters. Further field experiments are needed to validate the greenhouse results to enhance the agronomic effectiveness of the local Trinidad de Guedes PR through partial acidulation. (author)

  11. Direct and residual effect of rockphosphate with amendments on growth and uptake of P by mustard and moong crops grown in Typic Ustochrept

    International Nuclear Information System (INIS)

    Dravid, M.S.

    2000-01-01

    A considerable increase in drymatter accumulation and total phosphorus uptake by mustard was observed with the addition of partially acidulated rockphosphate (PARP) and rockphosphate (RP) pre-decomposed with biogas slurry treatments as compared to other combinations, while in case of moong RP amended with pyrite followed by PARP exhibited marked increase in yield and assimilation of P over the other treatments. The differences between control and rockphosphate or pyrite alone were significant in both the crops. The percent Pdff and its utilization from rockphosphate were highest under partially acidulated rockphosphate treatment. Among the different amendments, the performance of biogas slurry was superior to the pyrite and P solubiliser with respect to the Pdff and P utilization from rockphosphate. The available P in soil was depressed drastically after mustard, but it improved again after moong. (author)

  12. Red colorants from filamentous fungi: Are they ready for the food industry?

    OpenAIRE

    Dufossé , Laurent

    2017-01-01

    International audience; Food components of microbial-origin have a long history in food science and the food industry. Thickening and gelling agents, flavour enhancers, polyunsaturated fatty acids, flavour compounds, vitamins, essential amino acids, and acidulants are some examples of such ingredients. This paper will provide an update on the current worldwide situation for four different fungal reds: (i) carotenoid lycopene (simple compound, complex current status); (ii) molecular biology on...

  13. Sinergia entre edulcorantes no calóricos y el ácido fumárico

    OpenAIRE

    Restrepo Gallego, Mauricio

    2004-01-01

    Given the great demand of sugar-free products it is necessary to find new applications for traditional products and additives. This is the case of the fumaric acid, for which a sweetener or sweeteners mixture that grants a good level of synergy in products like powder beverages is being searched. The current investigations suggest that the encapsulation process is the best alternative to achieve a good balance between acidulants and sweeteners, taking advantage of t...

  14. Nd:YAG laser in caries prevention: a clinical study; Avaliacao clinica da eficiencia do laser de Nd:YAG associado ao fluor fosfato acidulado na prevencao de caries de sulcos e fissuras de criancas e adolescentes

    Energy Technology Data Exchange (ETDEWEB)

    Boari, Heloisa Gomes Dimiranda

    2000-07-01

    The caries prevention by using laser irradiation has been investigated during the last 30 years. The Nd: YAG laser associated with acidulated phosphate fluoride has been shown as a very promising technique for enamel caries prevention. The aim of this work was to clinically evaluate the efficiency of Nd: YAG laser associated with acidulated phosphate fluoride in pit and fissure caries prevention of children and adolescents. In this work it was determined the dye that enhance the effect of Nd: YAG laser in enamel. It was selected 242 pre-molar and molar teeth from 33 children and adolescents, aged from 7 to 15 years old. The selected teeth were free from caries or decalcification marks (active white marks) to the clinical and radiographic exams. The teeth were divided into two groups: the first group was laser irradiated and their homologous remained as a control. The right side teeth were dye-assisted Nd:YAG laser irradiated. The dye solution was a moisture of dust coal and equal parts of water and alcohol. The irradiation conditions were 60 mJ/10 Hz, optical fiber in contact mode, with diameter of 300 {mu}m, resulting in an energy density of 84,9 J/cm{sup 2}. The oclusal surface of the teeth was completely irradiated, specially on the slopes and in the deepest part of the pits and fissures. This procedure was repeated three times. In the sequence it was applied the acidulated phosphate fluoride for 4 minutes. On the left side teeth - control group- only acidulated phosphate fluoride was applied for the same time. The final examination considered the presence of caries and active white marks after a period of one year. There were statistical significant differences (p < 0.01) between the lased + fluoride group and the non irradiated group. The present study concluded that the technique used in this work can be an alternative clinical method for caries prevention. (author)

  15. Nd:YAG laser in caries prevention: a clinical study

    International Nuclear Information System (INIS)

    Boari, Heloisa Gomes Dimiranda

    2000-01-01

    The caries prevention by using laser irradiation has been investigated during the last 30 years. The Nd: YAG laser associated with acidulated phosphate fluoride has been shown as a very promising technique for enamel caries prevention. The aim of this work was to clinically evaluate the efficiency of Nd: YAG laser associated with acidulated phosphate fluoride in pit and fissure caries prevention of children and adolescents. In this work it was determined the dye that enhance the effect of Nd: YAG laser in enamel. It was selected 242 pre-molar and molar teeth from 33 children and adolescents, aged from 7 to 15 years old. The selected teeth were free from caries or decalcification marks (active white marks) to the clinical and radiographic exams. The teeth were divided into two groups: the first group was laser irradiated and their homologous remained as a control. The right side teeth were dye-assisted Nd:YAG laser irradiated. The dye solution was a moisture of dust coal and equal parts of water and alcohol. The irradiation conditions were 60 mJ/10 Hz, optical fiber in contact mode, with diameter of 300 μm, resulting in an energy density of 84,9 J/cm 2 . The oclusal surface of the teeth was completely irradiated, specially on the slopes and in the deepest part of the pits and fissures. This procedure was repeated three times. In the sequence it was applied the acidulated phosphate fluoride for 4 minutes. On the left side teeth - control group- only acidulated phosphate fluoride was applied for the same time. The final examination considered the presence of caries and active white marks after a period of one year. There were statistical significant differences (p < 0.01) between the lased + fluoride group and the non irradiated group. The present study concluded that the technique used in this work can be an alternative clinical method for caries prevention. (author)

  16. Effects of the low-intensity laser therapy on the prevention of dental caries induced in rats; Efeitos da radiacao laser em baixa intensidade na prevencao de carie dental induzida em ratos

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Karin Praia

    2004-07-01

    The purpose of this study was to investigate the effects of low intensity laser therapy, associated or not to an acidulated phosphate fluoride, on the prevention of dental caries induced in rats. It was used 40 wistar rats, female, weaned with 18 days, fed with a cariogenic diet during 48 days and inoculated orally with Streptococcus mutans by three consecutive days starting from the second day of the diet. On the fifth day of experiment the animals were divided into five groups: G{sub c} (control) the animas were no submitted to any treatment; G{sub L} (laser) irradiation with low power laser (GaAlAs, {lambda}=660 nm, P=30 mW, {delta}t=5 sec, 5 J/cm{sup 2}); G{sub F} (fluoride) topical application of acidulated phosphate fluoride (APF 1,23%) for four minutes; G{sub LF} (laser + fluoride) irradiation with low power laser followed by topical application of acidulated phosphate fluoride; G{sub FL} (fluoride + laser) topical application of acidulated phosphate fluoride followed by low power laser. The animals were sacrificed after 48 days; the molars were extracted and prepared to determine the dental caries lesions area by optical microscopy, enamel microhardness and analysis of the calcium and phosphorus ratio (Ca/P) by energy dispersive spectroscopy. The results were statistically analyzed by ANOVA (pacidulated phosphate fluoride reduces the caries area and could be an alternative in the prevention of the dental caries. (author)

  17. Acceptability and solubility of iron and zinc contents of modified Moringa oleifera sauces consumed in the Far-north region of Cameroon.

    Science.gov (United States)

    Mawouma, Saliou; Ponka, Roger; Mbofung, Carl Moses

    2017-03-01

    Consumption of Moringa oleifera leaves is a local and inexpensive solution to iron and zinc deficiencies in the Far-north region of Cameroon. However, traditional household's cooking techniques result in sauces with high pH levels and low leaves incorporation rates that compromise the bioavailability of iron and zinc. The aim of our study was to investigate the effect of modifying a standard Moringa sauce on consumer acceptability and the solubility of iron and zinc, which is an indicator of their bioavailability. Lime juice or tamarind pulp was added to a standard recipe in order to reduce the pH by about one unit, and Moringa leaf powder was incorporated in each acidulated sauce at three levels (1, 2, and 4 g/100 g of sauce). All the formulations were evaluated for their acceptability by 30 housewives using a five-point hedonic scale. The pH was measured by a digital electronic pH-meter. Moisture and ash were determined by AOAC methods. Total iron and zinc contents were determined by atomic absorption spectrophotometry, and soluble iron and zinc by HCl-extractability. The lime juice-acidulated sauce and the tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder were the most acceptable formulations with scores of 3.4 and 3.6, respectively. Their chemical analysis showed a reduced pH (6.4 and 6.1, respectively), compared to the Control (7.2). Lime juice-acidulated sauce improved iron and zinc solubility from 42.19 to 66.38% and 54.03 to 82.03%, respectively. Tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder showed a decrease in iron solubility from 42.19 to 38.26% and an increase in zinc solubility from 54.03 to 72.86%. These results confirm the beneficial effect of lime juice in improving iron and zinc bioavailability.

  18. Age determination of ground-waters by means of carbon 14

    International Nuclear Information System (INIS)

    Eichinger, L.

    1982-02-01

    At present the age determination of ground-waters aged between 1,500 and approximately 40,000 years is only possible by measuring their 14 C content. A precise age assignment can be established in slightly mineralised waters, whereas it becomes vague in mineralised waters, particularly in acidulous springs. In general, additional information and data are required about the 13 C, D, 18 O, 3 H, 85 Kr and the 39 Ar contents, about the ph value, temperature and the principal ions. (DG) [de

  19. Proceedings of the Second National Science and Technology Forum

    International Nuclear Information System (INIS)

    2005-01-01

    In Zambia, a lot of research work has been carried out in Science and Technology without a matching public awareness of the achievements and potential benefits. It is for this reason the National Science and Technology Council hosted the Second National Science and Technology Forum to publicise and promote broad national prioties in Science and Technology research. Highlights included the presentation of papers on residue effect of partially acidulated phosphate rock,the fluorencenceand absortion of white and dyed cotton fabricsand the intergation of indigenious knowledge and technologies in national development among others

  20. Effect of fertilizer type on cadmium and fluorine concentrations in clover herbage

    International Nuclear Information System (INIS)

    McLaughlin, M.J.

    2002-01-01

    This study investigated whether changing phosphatic fertilizer type affects the accumulation of cadmium (Cd) and fluorine (F) in pasture herbage. North Carolina phosphate rock and partially acidulated fertilizers derived from this rock generally have higher Cd and F concentrations compared to single superphosphate currently manufactured in Australia. Clover herbage from sites of the National Reactive Phosphate Rock (RPR) trial was collected and analysed for concentrations of Cd (11 sites) and F (4 sites). A comparison was made between pastures fertilized with 4 rates of single superphosphate, North Carolina phosphate rock, and partially acidulated phosphate rock having Cd concentrations of 283, 481, and 420 mg Cd/kg P respectively, and 170, 271, and 274 g F/kg P respectively. One site used Hemrawein (Egypt) phosphate rock (HRP) having a Cd and F concentration of 78 mg Cd/kg P and 256 g F/kg P respectively. To help identify differences in herbage Cd concentrations between sites, unfertilised soils from each site were analyzed for total and extractable Cd contents. At one site Cd concentrations in bulk herbage (clover, grasses and weeds) were related to infestation of the pasture by capeweed (Arctotheca calendula L. Levyns). There were no significant differences between F in herbage from plots fertilized with single superphosphate, partially acidulated phosphate rock or North Carolina phosphate rock, or between sites. Concentrations of F in herbage were low, generally less than 10 mg F /kg. However, there were large differences in Cd concentrations in herbage between sites, while differences between fertilizer treatments were small in comparison. The site differences were only weakly related to total or extractable (0.01 mol/L CaCl 2 ) Cd concentrations in soil. Significant differences in Cd concentrations in clover due to fertilizer type were found at 5 sites. North Carolina phosphate rock treatments had significantly higher Cd concentrations in clover compared to

  1. Aprovechamiento de las oleinas residuales procedentes del proceso de refinado de los aceites vegetales comestibles, para la fabricación de biodiesel

    OpenAIRE

    Álvarez Mateos, P.; Barriga Mateos, F.; Pereda Marín, J.

    2003-01-01

    A procedure to obtain Biodiesel from “Oleinas” is studied. Biodiesel is a suitable product to replace diesel oil currently used to power the Diesel engines. It consists of a mixture of methyl esters of the fatty acids presents as triglycerides in vegetables oils (olive, sunflower, soya, rape oils). As a result of the refining of these oils for their use as food, a waste product is formed, the “oleinas” (acidulated soapstock)....

  2. Synthetic transformation into liquid hydrocarbons of organic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, F P.A.

    1918-09-09

    The transformation is obtained by a pyrogenation descending in a closed vessel instead of recourse to distillation ascending as is usually done, the material poor in hydrogen being hydrogenated by a contribution from the gas during the pyrogenation; synthesis with the vapors from the treated material will also be realized. As a first product there is obtained an analogue of naphtha or crude gasoline containing in the liquid state all the bodies composing the material pyrogenated. This first product is purified and rectified by successive distillation, acidulation, washing, etc., according to methods in use for refining petroleum obtained from the ground.

  3. Extraction process

    International Nuclear Information System (INIS)

    Rendall, J.S.; Cahalan, M.J.

    1979-01-01

    A process is described for extracting at least two desired constituents from a mineral, using a liquid reagent which produces the constituents, or compounds thereof, in separable form and independently extracting those constituents, or compounds. The process is especially valuable for the extraction of phosphoric acid and metal values from acidulated phosphate rock, the slurry being contacted with selective extractants for phosphoric acid and metal (e.g. uranium) values. In an example, uranium values are oxidized to uranyl form and extracted using an ion exchange resin. (U.K.)

  4. The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphate fertilizers, in particular rock phosphate, in Venezuela: I. phosphorus uptake, utilization and agronomic effectiveness

    International Nuclear Information System (INIS)

    Casanova, E.; Salas, A.M.; Toro, M.

    2002-01-01

    Field experiments were conducted to evaluate the efficiency of natural and modified rock phosphate using conventional and isotopic techniques in an acid soil from El Pao, Cojedes state, Venezuela, using maize and sorghum with the application of different phosphate fertilizers to measure dry matter production, P accumulated in plant, efficiency parameters using isotopic techniques or yield. Finally, commercial plots were established with the application of soluble P fertilizers and rock phosphate products to validate the results obtained in the field experiments. The results showed highly significant differences between partially acidulated rock phosphate, natural rock phosphate, and the check plot in dry matter production, and P accumulation in plant and grain yield. When the efficiency parameters were evaluated in microplots with 32 P-TSP at 60 days of plant growth, it confirmed results obtained in semi commercial plots where the P in the plant derived from the fertilizer was 46% with partially acidulated rock phosphate (PAR) and 14% with natural Riecito rock phosphate (RR). Utilization coefficients of P by the plants were 34.2 and 8.8% for both treatments, respectively. The Substitution relation parameter showed that just 0.8 kg of P of PAR or 3.1 kg P of RR was required to produce the same yield as 1 kg P of TSP. These results were further validated in 5 ha commercial plots using corn and sorghum. (author)

  5. A study in vitro on radiation effects by Er:YAG laser combined with the fluorine therapy in the acid resistance of the dental enamel submitted to orthodontical brackets

    International Nuclear Information System (INIS)

    Yoshiyasu, Roseli Y.A.

    2001-01-01

    Several researches have been demonstrating an increase in the resistance acid of the enamel surface when irradiated by some lasers types as Nd:YAG, C0 2 , Er:YAG, and others, mainly when combined with the fluoride therapy after the irradiation of the laser. This study in vitro used the laser of Er:YAG which density of energy of 8.1 J/cm 2 on the enamel about of orthodontical brackets of teeth extracted pre-molars. These teeth were then submitted to a rich way in S. mutans for twenty one days. The cases were analyzed: (1) enamel surface without any treatment, (2) enamel surface without any irradiation laser, but with therapy with acidulated phosphate fluoride, (3) enamel surface irradiated with laser of Er:YAG and (4) enamel surface irradiated by laser of Er:YAG and with application of acidulated phosphate fluoride. The results were analyzed through optical microscopy and scanning electron microscopy. The morphologic changes observed to the scanning electron microscopy suggest increase in the acid resistance of the enamel surface. However, to the optical microscopy, it was still possible to visualize undesirable white stains in the surface of the enamel. (author)

  6. Uranium control in phosphogypsum

    International Nuclear Information System (INIS)

    Hurst, F.J.; Arnold, W.D.

    1980-01-01

    In wet-process phosphoric acid plants, both previous and recent test results show that uranium dissolution from phosphate rock is significantly higher when the rock is acidulated under oxidizing conditions than under reducing conditions. Excess sulfate and excess fluoride further enhance the distribution of uranium to the cake. Apparently the U(IV) present in the crystal lattice of the apatite plus that formed by reduction of U(IV) by FE(II) during acidulation is trapped or carried into the crystal lattice of the calcium sulfate crystals as they form and grow. The amount of uranium that distributes to hemihydrate filter cake is up to seven times higher than the amount that distributes to the dihydrate cake. About 60% of the uranium in hemihydrate cakes can be readily leached after hydration of the cake, but the residual uranium (20 to 30%) is very difficult to remove economically. Much additional research is needed to develop methods for minimizing uranium losses to calcium filter cakes

  7. Evaluation of crystalline changes and resistance to demineralization of the surface of human dental enamel treated with Er:YAG laser and fluoride using x-ray diffraction analysis and Vickers microhardness

    Science.gov (United States)

    Behroozibakhsh, Marjan; Shahabi, Sima; Ghavami-Lahiji, Mehrsima; Sadeghian, Safura; Sadat Faal Nazari, Neda

    2018-06-01

    This study aimed to investigate the changes in crystalline structure and resistance to demineralization of human dental surface enamel treated with erbium-doped yttrium aluminium garnet laser (Er:YAG) laser and fluoride. The enamel surfaces were divided into four groups according to the treatment process including, (L): irradiated with Er:YAG; (F): treated with acidulated phosphate fluoride gel (LF): Pre-irradiated surfaces with Er:YAG subjected to acidulated phosphate fluoride gel and (FL): laser irradiation was performed on the fluoridated enamel surface. Before and after the treatment procedure, the samples were evaluated using X-ray diffraction, scanning electron microscope (SEM) and the Vickers microhardness test. The surface microhardness values also were measured after a pH-cycling regime and acid challenge. The a-axis of all lased groups was contracted after treatment procedure. Measurement of the area under the peaks showed the highest crysallinity in the FL group. The hardness values of all laser treated samples significantly reduced after treatment procedure compared to the F group (p  ⩽  0.001). The morphological observations showed remarkable changes on the lased enamel surfaces including cracks, craters and exposed prisms. These findings suggest, irradiation of the Er:YAG laser accompanying with fluoride application can induce some beneficial crystalline changes regarding the acid-resistance properties of enamel, however, the craters and cracks produced by laser irradiation can promote enamel demineralization and consequently the positive effects of the Er:YAG laser will be eliminated.

  8. A study in vitro on radiation effects by Er:YAG laser combined with the fluorine therapy in the acid resistance of the dental enamel submitted to orthodontical brackets; Um estudo in vitro sobre os efeitos da irradiacao pelo laser de Er:YAG combinado com a terapia com fluor na resistencia acida do esmalte de dentes submetidos a aparelho ortodontico fixo

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiyasu, Roseli Y A

    2001-07-01

    Several researches have been demonstrating an increase in the resistance acid of the enamel surface when irradiated by some lasers types as Nd:YAG, C0{sub 2}, Er:YAG, and others, mainly when combined with the fluoride therapy after the irradiation of the laser. This study in vitro used the laser of Er:YAG which density of energy of 8.1 J/cm{sup 2} on the enamel about of orthodontical brackets of teeth extracted pre-molars. These teeth were then submitted to a rich way in S. mutans for twenty one days. The cases were analyzed: (1) enamel surface without any treatment, (2) enamel surface without any irradiation laser, but with therapy with acidulated phosphate fluoride, (3) enamel surface irradiated with laser of Er:YAG and (4) enamel surface irradiated by laser of Er:YAG and with application of acidulated phosphate fluoride. The results were analyzed through optical microscopy and scanning electron microscopy. The morphologic changes observed to the scanning electron microscopy suggest increase in the acid resistance of the enamel surface. However, to the optical microscopy, it was still possible to visualize undesirable white stains in the surface of the enamel. (author)

  9. Evaluation of available phosphorus and cadmium associated with phosphate rock for direct application

    International Nuclear Information System (INIS)

    Chien, S.H.

    2002-01-01

    Three greenhouse experiments were conducted to evaluate available P and Cd associated with the use of phosphate rock (PR) for direct application. These experiments were: (1) 'Estimation of Phosphorus Availability to Maize and Cowpea From Phosphate Rock as Enhanced by Water-Soluble Phosphorus'; (2) 'Modified Iron Oxide-Impregnated Paper Strip (Pi) Test for Soils Treated With Phosphate Fertilizers'; and (3) 'Effect of Acidulation of High Cadmium Containing Phosphate Rocks on Cadmium Uptake by Upland Rice'. In the first experiment, a medium-reactive Central Florida phosphate rock (PR) was used. The effectiveness of P sources in terms of increasing dry-matter yield and P uptake followed the order of TSP≥(PR+TSP)>PR for maize and TSP=(TSP+PR)>PR for cowpea. P uptake from PR in the presence of TSP was higher than P uptake from PR applied alone. With respect to P uptake from PR applied alone, the corresponding relative increase in P uptake from PR due to TSP influence was 165% for maize and 72% for cowpea. In the second experiment, a highly reactive North Carolina PR was used. Both Bray I and the Pi test (with CaCl 2 ) underestimated available P from PR with respect to TSP. Available P estimated by the Pi test with KCl was more closely related to P uptake with both PR and TSP. More P was extracted from PR by the Pi test with KCl than with CaCl 2 , whereas no effect was observed for TSP. In the third experiment, a low-reactive Togo PR and a highly reactive North Carolina PR were used. Both PRs were fully acidulated to SSP and Togo PR was also partially acidulated with H 2 SO 4 at 50% level to PAPR. Cd uptake by rice grain followed the order of NC-SSP > NC-PR and Togo-SSP > Togo PAPR > Togo PR. The results also showed that most of the Cd uptake was retained in rice root and straw. Total uptake of Cd, Ca, and P by the rice plant was higher from NC-PR than from Togo-PR. Cd concentration in rice grain showed no significant difference between NC-PR and Togo-PR, whereas Cd

  10. Uranium recovery from wet process phosphoric acid

    International Nuclear Information System (INIS)

    1980-01-01

    In the field of metallurgy, specifically processes for recovering uranium from wet process phosphoric acid solution derived from the acidulation of uraniferous phosphate ores, problems of imbalance of ion exchange agents, contamination of recycled phosphoric acid with process organics and oxidizing agents, and loss and contamination of uranium product, are solved by removing organics from the raffinate after ion exchange conversion of uranium to uranous form and recovery thereof by ion exchange, and returning organics to the circuit to balance mono and disubstituted ester ion exchange agents; then oxidatively stripping uranium from the agent using hydrogen peroxide; then after ion exchange recovery of uranyl and scrubbing, stripping with sodium carbonate and acidifying the strip solution and using some of it for the scrubbing; regenerating the sodium loaded agent and recycling it to the uranous recovery step. Economic recovery of uranium as a by-product of phosphate fertilizer production is effected. (author)

  11. Fumaric Acid Production: A Biorefinery Perspective

    Directory of Open Access Journals (Sweden)

    Victor Martin-Dominguez

    2018-05-01

    Full Text Available The increasing scarcity of fossil raw materials, together with the need to develop new processes and technology based on renewable sources, and the need to dispose of an increasing amount of biomass-derived waste, have boosted the concept of biorefineries. Both 1G and 2G biorefineries are focused on the obtention of biofuels, chemicals, materials, food and feed from biomass, a renewable resource. Fumaric acid, and most compounds involved in the Kreb cycle, are considered key platform chemicals, not only for being acidulants and additives in the food industry, but also for their prospective use as monomers. This review is focused on the biotechnological processes based on fungi, mainly of the Rhizopus genus, whose main product is fumaric acid, on the process conditions, the bioreactors and modes of operation and on the purification of the acid once it is produced.

  12. Nitrite, nitrite alternatives, and the control of Clostridium botulinum in cured meats.

    Science.gov (United States)

    Pierson, M D; Smoot, L A

    1982-01-01

    Historically, nitrite has been a component of meat-curing additives for several centuries. In recent years the safety of nitrite as an additive in cured meats has been questioned mainly because of the possible formation of carcinogenic nitrosamines. Nitrite has many important functions in meat curing including its role in color development, flavor, antioxidant properties, and antimicrobial activity. The inhibition of Clostridium botulinum growth and toxin production is an especially important antimicrobial property of nitrite. This review discusses the effects of processing, curing ingredients (especially nitrite), and storage of cured meats in relation to the control of C. botulinum. If nitrite is eliminated from cured meats or the level of usage decreased, then alternatives for the antibotulinal function of nitrite need to be considered. Several potential alternatives including sorbates, parabens, and biological acidulants are discussed.

  13. Interaction entre le fumier enrichi, le calcaire et les différentes sources de phosphore issues de la roche phosphatée de Matongo sur un ferralsol de la région du Bututsi (Burundi

    Directory of Open Access Journals (Sweden)

    Rwigema, JB.

    1993-01-01

    Full Text Available Interaction between enriched farmyard manure with fertilizers, lime and different phosphorus sources obtained from the phosphatic rock from Matongo on a ferralitic soil from the region of Bututsi (Burundi. This study on maize growing in pots shows that (i in combination with other inputs (farmyard manure and lime, the most soluble phosphorus sources (triple and simple superphosphate can be replaced by partially acidulated rock phosphate (50 % obtained by mixing simple superphosphate and rock phosphate both originating from the rock phosphate deposits in Matongo (Burundi, (ii the exchangeable Al can be reduced by both the addition of farmyard manure and lime, but the action of the different phosphorus 'source leave the most Bray-1 extractable phosphorus in the soil, the largest quantifies correspond to the highest doses of farmyard manure.

  14. Recovering phosphorus and uranium values from phosphate rock

    International Nuclear Information System (INIS)

    Sze, M.C.Y.; Long, R.H.

    1981-01-01

    Phosphate rock is acidulated with aqueous nitric acid to produce an aqueous solution containing phosphate values, calcium and uranium values. The aqueous solution is contacted with an extraction solvent for the uranium values: the extraction solvent comprising a water immiscible organic diluent, a dialkyl phosphoric acid having at least 10 carbon atoms, and an organic phosphorus compound having the formula R 1 R 2 R 3 P = O where R 1 , R 2 and R 3 are each either alkyl or alkoxy, the organic phosphorus compound having at least 10 carbon atoms. The uranium values are then recovered from the extraction solvent. In an example the extraction solvent is HDEHP and TOPO in kerosene. (author)

  15. Development of novel Alicyclobacillus spp. isolation medium.

    Science.gov (United States)

    Chang, S; Kang, D-H

    2005-01-01

    To develop a new isolation medium with higher recovery rates of Alicyclobacillus spp. SK agar was developed with optimized incubation temperature, pH, acidulant, Tween 80 concentration and divalent cation addition. Results indicate that detection of Alicyclobacillus spp. by SK agar was significantly higher (P > 0.05) than those obtained by K agar, orange serum agar, and potato dextrose agar. Current media used for Alicyclobacillus spp. isolation still resulted in high numbers of false negative products. The sensitivity of SK agar to Alicyclobacillus spp. allows detection of low numbers of Alicyclobacillus spp. and also provides a more higher isolation results compared with currently used media. SK agar will be useful to the fruit juice industry to obtain more accurate numbers of contaminant Alicyclobacillus spp. With this media, false negative samples can be reduced, and the likelihood of exported products being rejected can be greatly reduced.

  16. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  17. Biodiesel obtained from soapstock originated in a refining oil industry

    International Nuclear Information System (INIS)

    Tobio Pérez, Indira; Díaz Domínguez, Yosvany; Piloto-Rodríguez, Ramón

    2017-01-01

    In the vegetable oil chemical refining process is obtained a by-product commonly named as soapstock, due to its physical and aspect properties. The soapstock free fatty acid content can reach to 50%. The present work shows a survey of researches focused on biodiesel obtaining from this by-product. The biodiesel is obtained following different routes and catalyzers features. A variety of reports shown the effectivity of the use of this by-product derived from vegetable oil refining industry to produce biodiesel. Several studies are addressed to the acid oil recovering involving processes without soapstock acidulation, with the aim of lowering costs and finding more attractive yields closing to the concept of zero wastes. (author)

  18. Phosphate fertilisers and management for sustainable crop production in tropical acid soils

    International Nuclear Information System (INIS)

    Chien, S.H.; Friesen, D.K.

    2000-01-01

    Extensive research has been conducted over the past 25 years on the management of plant nutrients, especially N and P, for crop production on acidic infertile tropical soils. Under certain conditions, the use of indigenous phosphate rock (PR) and modified PR products, such as partially acidulated PR or compacted mixtures of PR with superphosphates, are attractive alternatives, both agronomically and economically, to the use of conventional water-soluble P fertilisers for increasing crop productivity on Oxisols and Ultisols. A combination of the effects of proper P and N management including biological N 2 fixation, judicious use of lime, and the use of acid-soil tolerant and/or P-efficient cultivars in cropping systems that enhance nutrient cycling and use efficiency, can provide an effective technology to sustainably increase crop productivity and production in tropical agro-ecosystems dominated by these acid soils. (author)

  19. Recovering phosphorus and uranium values from phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Sze, M C.Y.; Long, R H

    1981-02-11

    Phosphate rock is acidulated with aqueous nitric acid to produce an aqueous solution containing phosphate values, calcium and uranium values. The aqueous solution is contacted with an extraction solvent for the uranium values: the extraction solvent comprising a water immiscible organic diluent, a dialkyl phosphoric acid having at least 10 carbon atoms, and an organic phosphorus compound having the formula R/sub 1/ R/sub 2/ R/sub 3/ P = O where R/sub 1/, R/sub 2/ and R/sub 3/ are each either alkyl or alkoxy, the organic phosphorus compound having at least 10 carbon atoms. The uranium values are then recovered from the extraction solvent. In an example the extraction solvent is HDEHP and TOPO in kerosene.

  20. Process for treating oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1920-08-22

    A process for treating oil shale is characterized in that the shale is first finely ground, then heated in the presence of steam in a high-pressure retort at 1 to 50 atmospheres pressure at a temperature of 200/sup 0/ to 450/sup 0/C and then with large amounts of water with or without materials forming emulsions with water or with oil. Solution medium suitable for bitumen or paraffin is beaten up in a rapid hammer mill until all or most all of the oil or bitumen is emulsified. The emulsion is separated by filter-pressing and centrifuging from the solid shale residue and the oil or bitumen is again separated from the emulsion medium by heating, acidulating, standing, or centrifuging, and then in known ways is further separated, refined, and worked up.

  1. Efecto residual de dos rocas fosfóricas puras y parcialmente aciduladas, comparadas con SFT, sobre la aprovechabilidad del P por Panicum maximum L., en un oxisol de los Llanos Orientales de Colombia

    Directory of Open Access Journals (Sweden)

    Alejo M. Doris

    1986-03-01

    Full Text Available Panicum maximum L. se sembró, en condiciones de invernadero, en un Oxisol de los Llanos Orientales de Colombia, 18 meses después de la aplicación de las fuentes (rocas fosfóricas de Pesca - Colombia y Sechura - Perú crudas y aciduladas al 20 % con H3 P04, en dosis de 25, 50 Y 100 ppm de P. La roca fosfórica Sechura cruda y parcialmente acidulada junto con SFT, tuvieron el mejor efecto residual sobre el rendimiento y captación de P y mantuvieron los más altos niveles de P asimilable en el suelo al final del ensayo. Con las dosis superiores se obtuvo un nivel más alto de P asimilable en el suelo y mayor absorción de P por la planta.In order to study the residual effect of the Pesca (Colombia and Sechura (Perú phosphate rocks, both crude and acidulated in 20 % by H3P04, comparatively with SFT, Panicum rnaximum L. was planted under glasshouse conditions, in an Oxisol from the Eastern plains of Colombia, 18 months after sources application, with rates of 25. 50 and 100 ppm of P. Crude and partially acidulated Sechura phosphate rock, together with TSP, had the best residual effect on yield and P absorption and had the highest available P levels in the soil at the end of the trial. The highest available P level in the soil and P uptake by the plant was obtained with higher P rates.

  2. Improvement of the quality of wood derived biofuel-oils; Puuperaeisten biopolttooeljyjen laadun parantaminen. Raakasuovan terminen nestefaasikaesittely hiilivety-polttoaineiksi

    Energy Technology Data Exchange (ETDEWEB)

    Oasmaa, A; McKeough, P; Kuoppala, E; Kylloenen, H; Levander, J; Tapola, E; Haekkinen, R

    1996-12-31

    Liquid-phase thermochemical processing of tall oil soap has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation to yield crude tall oil and subsequent distillation of the oil at centralized refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock. Both catalytic hydrotreatment and liquid-phase thermal treatment of a mixed pine/birch soap have been investigated in the laboratory. Liquid and gaseous hydrocarbons were the principal products formed in both types of treatment. Although the liquid product formed under hydrotreatment conditions contained a higher proportion of aliphatic compounds, it was clear that the thermal treatment process would be, economically, the more favorable option. In the thermal process, a predominantly hydrocarbon oil product was obtained at 450 deg C using a residence time of at least 60 min. About 50 % of the energy content of the tall oil soap was recovered as oil product, about 30 % as gases, and about 20 % as organic material contained in an aqueous slurry phase. When the oil product was carefully separated from the aqueous slurry phase, only trace amounts of impurities, such as water, sodium and organic acid salts were present in the product. A techno-economic evaluation of the process concept has been performed. The economics of the thermal treatment process appear to be favorable in comparison with those of the conventional acidulation process

  3. Improvement of the quality of wood derived biofuel-oils; Puuperaeisten biopolttooeljyjen laadun parantaminen. Raakasuovan terminen nestefaasikaesittely hiilivety-polttoaineiksi

    Energy Technology Data Exchange (ETDEWEB)

    Oasmaa, A.; McKeough, P.; Kuoppala, E.; Kylloenen, H.; Levander, J.; Tapola, E.; Haekkinen, R.

    1995-12-31

    Liquid-phase thermochemical processing of tall oil soap has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation to yield crude tall oil and subsequent distillation of the oil at centralized refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock. Both catalytic hydrotreatment and liquid-phase thermal treatment of a mixed pine/birch soap have been investigated in the laboratory. Liquid and gaseous hydrocarbons were the principal products formed in both types of treatment. Although the liquid product formed under hydrotreatment conditions contained a higher proportion of aliphatic compounds, it was clear that the thermal treatment process would be, economically, the more favorable option. In the thermal process, a predominantly hydrocarbon oil product was obtained at 450 deg C using a residence time of at least 60 min. About 50 % of the energy content of the tall oil soap was recovered as oil product, about 30 % as gases, and about 20 % as organic material contained in an aqueous slurry phase. When the oil product was carefully separated from the aqueous slurry phase, only trace amounts of impurities, such as water, sodium and organic acid salts were present in the product. A techno-economic evaluation of the process concept has been performed. The economics of the thermal treatment process appear to be favorable in comparison with those of the conventional acidulation process

  4. Oral fluoride retention after professional topical application in children with caries activity: comparison between 1.23% fluoride foam and fluoride gel

    Directory of Open Access Journals (Sweden)

    Cecília Claudia Costa Ribeiro

    2008-01-01

    Full Text Available Objective: This study evaluated fluoride retention in the saliva of children with caries activity after topical fluoride application in the form of gel and foam. Methods: A cross-sectional, blind and randomized study, conducted with ten caries-active children aged between 8 and 10 years, in two stage, with a washout interval of two weeks between them. The treatments consisted of: a application of 2mL acidulated phosphate fluoride of the gel type in a mold and b application of 2mL acidulated phosphate fluoride of the foam type in a mold. After the washout, the treatments were inverted. Non-stimulated saliva was collected from the children at the times of 5, 15, 30 and 60 minutes after topical fluoride application. For statistical analysis the Student’s-t test was used, with a level of significance of 5%. Results: Saliva analysis was performed using a fluoride-specific electrode (ISE25F/ Radiometer, Copenhagen, Denmark at the Aquatic Science Center of the Federal University of Marana, which revealed differences after 5 minutes (p=0.0055 and 15 minutes (p=0.0208. The topical application of fluoride in the gel form revealed a higher concentration of fluoride in the saliva. Conclusion: There were differences in the retention of fluoride in the saliva of children with caries activity after the topical application of fluoride gel and the topical application of fluoride foam after 5 and 15 minutes of their application. The topical application of fluoride foam is recommended, on the basis of the lower probability of toxicity during its use.

  5. COMPONENŢA AMINOACIZILOR DIN BIOMASA ALGEI CIANOFITE NOSTOC GELATINOSUM (SCHOUSB ELENK.

    Directory of Open Access Journals (Sweden)

    Sergiu DOBROJAN

    2016-02-01

    Full Text Available În articol este analizată componenţa aminoacizilor din biomasa algei cianofite Nostoc gelatinosum (Schousb Elenk. colectate de pe mediul nutritiv Drew. Din grupa aminoacizilor esenţiali în biomasa algei Nostoc gelatinosum (Schousb Elenk. se conţine în cantităţi majore leucina (2,142±0,06 mg/100 mg, treonina (1,188±0,02 mg/100 mg şi valina (1,085±0,03 mg/100 mg. Din aminoacizii neesenţiali predomină acidul aspartic (4,523±0,11 mg/100 mg şi acidul glutamic (2,774±0,07 mg/100 mg. Alga Nostoc gelatinosum (Schousb Elenk. are un conţinut bogat de aminoacizi şi poate servi ca sursă pentru vaste domenii de aplicare.THE AMINO ACIDS COMPOSITION OF THE BLUE-GREEN ALGANOSTOC GELATINOSUM (SCHOUSB ELENKThis article presents the amino acid content of the blue-green alga Nostoc gelatinosum (Schousb Elenk. collected from the Drew nutritive medium. From the essential amino group in Nostoc gelatinosum (Schousb Elenk. biomass, major amounts are contained leucine (2,142 ± 0,06 mg/100 mg, threonine (1,188 ± 0,02 mg/100 mg and valine (1,085 ± 0,03 mg/100 mg. From nonessential amino acids predominates aspartic acid (4,523 ± 0,11 mg/100 mg and glutamic acid (2,774 ± 0.07 mg/100 mg. The alga Nostoc gelatinosum (Schousb Elenk. has a high content of amino acids and can serve as a source for vast areas of application. 

  6. Characterization of caries progression on dentin after irradiation with Nd:YAG laser by FTIR spectroscopy and fluorescence imaging

    Science.gov (United States)

    Ana, P. A.; Brito, A. M. M.; Zezell, D. M.; Lins, E. C. C. C.

    2015-06-01

    Considering the use of high intensity lasers for preventing dental caries, this blind in vitro study evaluated the compositional and fluorescence effects promoted by Nd:YAG laser (λ=1064 nm) when applied for prevention of progression of dentin caries, in association or not with topical application of acidulated phosphate fluoride (APF). Sixty bovine root dentin slabs were prepared and demineralized by 32h in order to create early caries lesions. After, the slabs were distributed into six experimental groups: G1- untreated and not submitted to a pH-cycling model; G2- untreated and submitted to a pH-cycling model; G3- acidulated phosphate fluoride application (APF); G4- Nd:YAG irradiation (84.9 J/cm2, 60 mJ/pulse); G5- treated with Nd:YAG+APF; G6- treated with APF+Nd:YAG. After treatments, the samples of groups G2 to G6 were submitted to a 4-day pH-cycling model in order to simulate the progression of early caries lesions. All samples were characterized by the micro-attenuated total reflection technique of Fourier transformed infrared spectroscopy (μATR-FTIR), using a diamond crystal, and by a fluorescence imaging system (FIS), in which it was used an illuminating system at λ= 405±30 nm. Demineralization promoted reduction in carbonate and phosphate contents, exposing the organic matter; as well, it was observed a significant reduction of fluorescence intensity. Nd:YAG laser promoted additional chemical changes, and increased the fluorescence intensity even with the development of caries lesions. It was concluded that the compositional changes promoted by Nd:YAG, when associated to APF, are responsible for the reduction of demineralization progression observed on root dentin.

  7. HPLC-UV Analysis Coupled with Chemometry to Identify Phenolic Biomarkers from Medicinal Plants, used as Ingredients in Two Food Supplement Formulas

    Directory of Open Access Journals (Sweden)

    Raluca Maria Pop

    2013-11-01

    Full Text Available . High performance liquid chromatography (HPLC with UV detection is nowadays the reference method to identify and quantify the biomarkers of quality and authenticity of plants and food supplements. Seven medicinal plants were collected from wild flora: Taraxacum officinalis (1, Cynara scolimus (2, Silybum marianum (3, Hypericum perforatum (4,  Chelidonium majus (5, Lycopodium clavatum (6 and  Hippophae rhamnoides (7  leaves and fruits.  Two products (A and B were obtained by mixing individual plant powders. Therefore product A was obtained by mixing dandelion, artichoke and milk thistle, 1:1:1 while product B by mixing St John’s wort, Celandine and Wolf’s claw, 1:1:1. The methanolic extracts of individual plants as well as three different extracts of products A and B (using acidulated water, neutral water and acidulated methanol were analyzed using HPLC-UV for their phenolics’ fingerprint and composition. The qualitative (untargeted analysis and quantitative (targeted analysis results were further compared using Principal Component Analysis (PCA in order to identify their specific biomarkers. Thus, quantitative evaluation of individual phenolics in case of individual plants and products A and B extracts, showed specific and significant differences of composition. Both products A and B contained elagic acid as major compound. For product A, good biomarkers were trans-cinnamic, chlorogenic, caffeic and p-coumaric acids, as well silymarin and silibine originating from milk thistle. For product B, good biomarkers were quercetin and kaempherol, gallic and protocatecuic acids, this product being rich in flavonoids. In conclusion, HPLC-UV coupled with PCA analysis proved to be a rapid and useful way to identify the main biomarkers of plants’ authentication, as well of final products’ quality and safety.

  8. Effectiveness of Direct Application of Phosphate Rock in Upland Acid Inceptisols Soils on Available-P and Maize Yield

    Directory of Open Access Journals (Sweden)

    Nurjaya

    2013-03-01

    Full Text Available Source of P fertilizer which is used by farmers in upland acid soils area is generally acidulated phosphate rock (PR,such as tripel super phosphate (TSP, super phosphate 36% P2O5 (SP-36, as well as partial acidulated phosphate rock (PAPR which contain 10-30% P2O5. Their effectiveness, however, varies and depends on the soil and planttypes. Phosphate rock fertilizers have a high prospects for acid soils because its effectiveness equals to the SP-36,cheaper, slow release, and its application can also leave the residual P in the soil that available for plants for next few seasons. Field experiment aimed to study the effectiveness of direct application of PR at upland acid soils and its effect on soil available-P as well as maize (Zea mays L. yield was conducted in Acid Inceptisols of Ciampea,Bogorin wet season years 2008/2009. The experiment was arranged by a Randomized Completely Block Design with 3 replications. Maize of P-12 variety was used as a plant indicator. The treatment consisted of 6 levels of phosphate rock: 0, 20, 30, 40, 50, and 60 kg P ha-1, as well as one level of SP-36 40 kg P ha-1 as standard fertilizer. In addition, urea of 300 kg ha-1 and KCl of 100 kg ha-1 were used as basal fertilization. The result showed that the application of PRin the amount ranging from 20 to 60 kg P ha-1 increased total-P and available-P, and pH, decreased exchangeable Al in the soils as well as increased maize straw and grain. Phosphate rock application at 40 kg P ha-1 level was equally effective as SP-36 in the tested soils. Critical level of soil P for maize grown in the soil was 675 and 5.00 mg P2O5 kg-1 extracted with HCl 25% and Bray I, respectively. The requirement of P for maize grown in the soil to achieve maximum profit was 38 kg P ha-1 and 17.5 kg P ha-1 or equivalent to PR of 583 and 268 kg ha-1 in low (soil P critical level soil P status, respectively.

  9. POTENŢIALUL NUTRIŢIONAL AL BIOMASEI ALGALE DE NOSTOC FLAGELLIFORME (BERK ET CURT ELENK.

    Directory of Open Access Journals (Sweden)

    Irina STRATULAT

    2016-05-01

    Full Text Available În prezentul studiu este prezentată componenţa biochimică a biomasei algei cianofite Nostoc flagelli­forme (Berk et Curt Elenk. cultivată în condiţii de laborator pe mediul mineral Z-8. Biomasa algei conţine: Mn – 683,9 mg/kg, Zn – 131,5 mg/kg, Pb – <10 mg/kg, Fe – 1,09 g/kg, Na+ – 2,10 g/kg, K+ – 8,01 g/kg, Mg 2+ – 5,40 g/kg, Ca2+ – 7,94 g/kg. În componenţa aminoacizilor predomină: acidul glutamic – 3,8012 mg/100 mg, acidul aspartic – 2,7838 mg/100 mg, leucina – 2,4651 mg/100 mg, alanina – 2,3513 mg/100 mg. Conform acestor rezultate, biomasa algei cianofite Nostoc flagelliforme poate fi utilizată ca sursă importantă de supli­mente alimentare. THE NUTRITIONAL POTENTIAL OF ALGAL BIOMASS OF NOSTOC FLAGELLIFORME (BERK ET CURT ELENK. In this study is presented the biochemical components of algal biomass Nostoc flagelliforme (Berk et Curt Elenk. cultivated in laboratory conditions in Z-8 medium. The algal biomass has the following chemical content: Mn – 683,9 mg/kg, Zn – 131,5 mg/kg, Pb – <10 mg/kg, Fe – 1,09 g/kg, Na+ - 2,10 g/kg, K+ – 8,01 g/kg, Mg2+ – 5,40 g/kg, Ca2+ – 7,94 g/kg. The highest amount of amino acids are specific for: glutamic acid – 3,8012 mg/100 mg, aspartic acid – 2,7838 mg/100 mg, leucine – 2,4651 mg/100 mg, alanine – 2,3513 mg/100 mg. According to these results the blue-green alga Nostoc flagelliforme can be considered an important potential source of nutritional supplements. 

  10. Uranium recovery from phosphate fertilizer in the form of a high purity compound

    International Nuclear Information System (INIS)

    Bunus, F.; Coroianu, T.; Filip, G.; Filip, D.

    2001-01-01

    Uranium recovery from phosphate fertilizer industry is based on a one cycle extraction-stripping process. The process was experimented on both sulfuric and nitric acid attack of phosphate rock when uranium is dissolved in phosphoric acid (WPA) or phosphonitric (PN) solution respectively. The WPA and PN solution must be clarified. In the first alternative by ageing and settling and in the second by settling in the presence of flocculant. The organic components must be removed on active carbon for WPA only since in the case of nitric attack calcined phosphates are used. In both alternatives uranium is extracted from aqueous acidic solutions in the same time with the rare earths (REE), by di(2-ethylhexyl) phosphate (DEPA) as basic extractants, eventually in the presence of octylphosphine oxide (TOPO) as synergic agent. The stripping process is carried out in two stages: in the first stage REE are stripped and precipitated by HF or NH 4 F + H 2 S0 4 and in the second stage uranium as U(VI) is stripped by the same reagents but in the presence of Fe(II) as reductant for U(VI) to U(IV) inextractible species. Tetravalent uranium is also precipitated as green cake either UF 4 xH 2 0 or (NH 4 ) 7 U 6 F 31 as dependent on reagents HF or NH 4 F + H 2 S0 4 . Uranium stripping is possible for PN solution only if HNO 3 partially extracted is previously washed out by a urea solution. The green cake washed and filtered is dissolved in nitric acid in presence of Al(OH)3 as complexant for F. The filtered nitric solution is adjusted to 3-5 mol/L HNO 3 and extracted by 20% TBP when uranium is transferred to the organic phase which after scrubbing is stripped in the classic way with acidulated (HN0 3 ) demineralized water. Uranium is precipitated as diuranate of high purity. Rare earths left in the aqueous raffinate are extracted by pure TBP from 8-10 mol/L HNO 3 medium. The stripping process takes place with acidulated water. Rare earths are precipitated as hydroxides. (author)

  11. Structural and functional annotation of citrate synthase from Aspergillus niger ANJ-120.

    Science.gov (United States)

    Mustafa, Ghulam; Arif, Rawaba; Bukhari, Shazia Anwer; Ali, Muhammad; Sharif, Sumaira; Atta, Asia

    2018-03-01

    Citrate synthase (CS) is involved in citric acid biosynthesis which is a well-established metabolic pathway. The condensation of acetyl-CoA with oxaloacetate is catalyzed by CS. Citric acid (CA) has a number of applications in pharmaceutical industry. CA in combination with bicarbonates is used as an effervescent in the preparations of tablets and powders. It has also been used as an anticoagulant and acidulant to form mild astringent. In current study, detailed structural and functional analyses of CS protein were carried out using various bioinformatics tools. Structural modeling was also done by building 3D model of CS from Aspergillus niger ANJ-120 using Modeller 9.16 software. The 3D Model was then evaluated using different online approaches. Furthermore, superimposition of query and template structures, Root Mean Squared Deviation and visualization of generated model were done through UCSF Chimera 1.5.3. Even though various roles of CS protein were already known and verified experimentally, here we presented a structural analysis of CS protein. The structural investigation of CS protein will be helpful for protein engineering strategies and understanding the interactions among proteins. Due to large number of applications, the production of citric acid by A. niger and its bioinformatics studies will offer substantial improvement in commercial scale intensification of this useful product.

  12. Microbial Production of Malic Acid from Biofuel-Related Coproducts and Biomass

    Directory of Open Access Journals (Sweden)

    Thomas P. West

    2017-04-01

    Full Text Available The dicarboxylic acid malic acid synthesized as part of the tricarboxylic acid cycle can be produced in excess by certain microorganisms. Although malic acid is produced industrially to a lesser extent than citric acid, malic acid has industrial applications in foods and pharmaceuticals as an acidulant among other uses. Only recently has the production of this organic acid from coproducts of industrial bioprocessing been investigated. It has been shown that malic acid can be synthesized by microbes from coproducts generated during biofuel production. More specifically, malic acid has been shown to be synthesized by species of the fungus Aspergillus on thin stillage, a coproduct from corn-based ethanol production, and on crude glycerol, a coproduct from biodiesel production. In addition, the fungus Ustilago trichophora has also been shown to produce malic acid from crude glycerol. With respect to bacteria, a strain of the thermophilic actinobacterium Thermobifida fusca has been shown to produce malic acid from cellulose and treated lignocellulosic biomass. An alternate method of producing malic acid is to use agricultural biomass converted to syngas or biooil as a substrate for fungal bioconversion. Production of poly(β-l-malic acid by strains of Aureobasidium pullulans from agricultural biomass has been reported where the polymalic acid is subsequently hydrolyzed to malic acid. This review examines applications of malic acid, metabolic pathways that synthesize malic acid and microbial malic acid production from biofuel-related coproducts, lignocellulosic biomass and poly(β-l-malic acid.

  13. RESEARCH ON THE TRENDS IN MILK PRODUCTION AND CONSUMPTION IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Agatha POPESCU

    2015-04-01

    Full Text Available The purpose of the paper was to analyze the main trends in the milk and dairy products market in Romania in the period 2007-2012 and to set up the forecast for the 2013-2015 horizon, based on the empirical data provided by the National Institute of Statistics and Eurostat and using the fixed basis index, average change method, and comparison method. Milk production for consumption reached 210 thou tons in 2012 registering a descending trend. Despite that milk production decreased in the period 2007-2012, the production diversification applied by dairies supported the growth of dairy products output as follows: by 13.54 % for milk, by 3.45 % for sour cream, and by 13 % for butter. The forecast for the year 2015 provides that the production of dairy products will account for: 223,936.6 tons milk for consumption, 48,709.4 tons sour cream, 166,674.2 tons acidulated milk, 9,937.6 tons butter and 66,584.4 tons cheese. The development of milk processing imposes the improvement of production technologies, products quality, efficiency and competitiveness. Due to the unbalanced demand/offer ratio, after the elimination of milk quota, the Romanian milk and dairy products market will be invaded by foreign products.

  14. The inevitable journey to being.

    Science.gov (United States)

    Russell, Michael J; Nitschke, Wolfgang; Branscomb, Elbert

    2013-07-19

    Life is evolutionarily the most complex of the emergent symmetry-breaking, macroscopically organized dynamic structures in the Universe. Members of this cascading series of disequilibria-converting systems, or engines in Cottrell's terminology, become ever more complicated-more chemical and less physical-as each engine extracts, exploits and generates ever lower grades of energy and resources in the service of entropy generation. Each one of these engines emerges spontaneously from order created by a particular mother engine or engines, as the disequilibrated potential daughter is driven beyond a critical point. Exothermic serpentinization of ocean crust is life's mother engine. It drives alkaline hydrothermal convection and thereby the spontaneous production of precipitated submarine hydrothermal mounds. Here, the two chemical disequilibria directly causative in the emergence of life spontaneously arose across the mineral precipitate membranes separating the acidulous, nitrate-bearing CO2-rich, Hadean sea from the alkaline and CH4/H2-rich serpentinization-generated effluents. Essential redox gradients-involving hydrothermal CH4 and H2 as electron donors, CO2 and nitrate, nitrite, and ferric iron from the ambient ocean as acceptors-were imposed which functioned as the original 'carbon-fixing engine'. At the same time, a post-critical-point (milli)voltage pH potential (proton concentration gradient) drove the condensation of orthophosphate to produce a high energy currency: 'the pyrophosphatase engine'.

  15. KNOWLEDGE, ATTITUDE AND PRACTICES OF CONSUMPTION OF CARBONATED BEVERAGES: A CROSS SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Talha Mufeed Siddiqui

    2017-06-01

    Full Text Available A soft drink or a carbonated drink is a non-alcoholic drink that commonly contains water, a sweetener, carbon dioxide, acidulants, colorings, preservatives, antioxidants, and/or foaming agents, and a flavoring agent. A total of 200 adult patients of low socioeconomic status, aged 18-35 years, were selected to participate in the study. A questionnaire with 26 closed ended questions was designed for the present study which consists of questions regarding knowledge, attitude and practice of consumption of sweetened carbonated beverages. One hundred and ninety nine (99.5% of the subjects enjoyed drinking soft drinks. Out of 200 subjects only 8 (4% responded that they will stop drinking soft drinks. The present study results showed that all the target population heard about soft drinks but very few of them were aware of the ill effects on general health and on teeth. So there is a need to spread awareness among people about the adverse effects of the carbonated beverages consumption and thus there is a need to plan health education programs.

  16. Local indigenous fruit-derived juices as alternate source of acidity regulators.

    Science.gov (United States)

    D'souza, Cassandra; Fernandes, Rosaline; Kudale, Subhash; Naik, Azza Silotry

    2018-03-01

    Acidity regulators are additives that alter and control food acidity. The objective of this study was to explore local indigenous fruits as sources of natural acidity regulators. Juices extracted from Garcinia indica (kokum), Embilica officinalis (amla) and Tamarindus indica (tamarind) were used as acidulants for media such as coconut milk and bottle gourd juice. The buffering capacity β, acid composition, antioxidant activity and shelf-life study of the acidified media were estimated. Potentiometric titration showed G. indica to possess the highest buffering capacity in both ranges. High-performance liquid chromatography analysis showed T. indica contained a high level of tartaric acid (4.84 ± 0.01 mg g -1 ), while G. indica had citric acid (22.37 ± 0.84 mg g -1 ) and E. officinalis had citric acid (2.75 ± 0.02 mg g -1 ) along with ascorbic acid (2.68 ± 0.01 mg g -1 ). 1,1-Diphenyl-2-picrylhydrazyl scavenging activity was high for E. officinalis (91.24 ± 0.66%) and T. indica (90.93 ± 0.817%) and relatively lower for G. indica (34.61 ± 3.66%). The shelf-life study showed total plate count to be within the prescribed limits up to a week, in accordance with safety regulations. This investigation confirmed the suitability of indigenous fruit juices as alternatives to existing acidity regulators. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. The effect of fractional CO2 laser irradiation on remineralization of enamel white spot lesions.

    Science.gov (United States)

    Poosti, Maryam; Ahrari, Farzaneh; Moosavi, Horieh; Najjaran, Hoda

    2014-07-01

    This study investigated the combined effect of fractional CO(2) laser irradiation and fluoride on treatment of enamel caries. Sixty intact premolars were randomly assigned into four groups and then stored in a demineralizing solution to induce white spot lesions. Tooth color was determined at baseline (T1) and after demineralization (T2). Afterwards, the teeth in group 1 remained untreated (control), while group 2 was exposed to an acidulated phosphate fluoride (APF) gel for 4 min. In groups 3 and 4, a fractional CO(2) laser was applied (10 mJ, 200 Hz, 10 s) either before (group 3) or through (group 4) the APF gel. The teeth were then immersed in artificial saliva for 90 days while subjected to daily fluoride mouthrinse and weekly brushing. Color examinations were repeated after topical fluoride application (T3) and 90 days later (T4). Finally, the teeth were sectioned, and microhardness was measured at the enamel surface and at 30 and 60 μ from the surface. In both lased groups, the color change between T1 and T4 stages (∆E(T1-T4)) was significantly lower than those of the other groups (p Laser irradiation followed by fluoride application (group 3) caused a significant increase in surface microhardness compared to APF alone and control groups (p laser before fluoride therapy is suggested for recovering the color and rehardening of demineralized enamel.

  18. Effects of the low-intensity red laser radiation on the fluoride uptake in enamel. A clinical trial

    International Nuclear Information System (INIS)

    Nakasone, Regina Keiko

    2004-01-01

    Fluoride has been the most important preventive method on development of the caries. This in vivo study evaluated the effects of low-intensity red laser radiation on the fluoride uptake in enamel. Ten healthy participants were recruited for this study. The two maxillary central incisors of each volunteer to be biopsied were used and divided into 4 groups: group G C (control, which was untreated; group G F (fluoride), which received topical acidulated phosphate fluoride (APF) 1,23% treatment for 4 minutes; group G LF (laser + fluoride), which was irradiated with a low-intensity diode laser (λ= 660 nm and dose= 6 J/cm 2 ) with APF application after irradiation and group G FL (fluoride + laser), which received APF before irradiation using the same parameters as G LF . The determination of fluoride was performed using a fluoride ion electrode after an acid-etch enamel biopsy. The results show a significant increase of the fluoride uptake in enamel for groups G F , G LF and G FL when compared to control group. Although a percentage increase of 57% was observed for G LF with respect to G F , there were no statistical differences among treated groups. These findings suggest that low-intensity laser radiation used before APF could be employed in the clinical practice to prevent dental caries. (author)

  19. The management of nutrients and water in the west African semi-arid tropics

    International Nuclear Information System (INIS)

    Bationo, A.; Bielders, C.L.; Duivenbooden, N. van; Buerkert, A.C.; Seyni, F.

    1998-01-01

    At present, the farming systems in the west African semi-arid tropics are unsustainable, low in productivity, and destructive to the environment. A striking feature of the soils is their inherently low fertility, with negative plant-nutrient balance in many cropping systems. Research in N-use efficiency (NUE) indicated that calcium ammonium nitrate (CAN) significantly outperformed urea on millet. Fertilizer losses, greater for urea (53%) than for CAN (25%) were believed to be due to ammonia volatilization. Continuous cropping resulted in lower yields compared to a cereal grown after cowpea or groundnut, and NUE was improved with crop rotation. Phosphorus deficiency is a major constraint. Phosphate rock (PR), indigenous to the region, e.g. at Tahoua in Niger and Tilemsi in Mali, is suitable for direct application. Partial acidulation of low-solubility PR improves agronomic effectiveness. Long-term soil-fertility management trials indicate that although application of mineral fertilizers increase yields, they alone cannot sustain productivity. When mineral fertilizers are combined with other technologies, such as the return of crop residues and manure, productive and sustainable production systems are possible. Water-use efficiency increased dramatically with the addition of plant nutrients. Technologies for land surface management and water harvesting, and appropriate cropping systems with careful varietal selection all contribute to the optimization of soil-water use. Future research should focus on water and nutrient interactions and on understanding why presently available improved technologies are not adopted by farmers even when using a participatory approach. (author)

  20. Use of residual soapstock from the refining of edible vegetable oils to make biodiesel; Aprovechamiento de las oleinas residuales procedentes del proceso de refinado de los aceites vegetales comestibles, para la fabricaciond e biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Marin, P.; Barriga Mateos, F.; Alvarez Mateos, P. [Universidad de Sevilla (Spain)

    2003-07-01

    A procedure to obtain Biodiesel from Oiliness is studied. Biodiesel is a suitable product to replace diesel oil currently used to power the Diesel engines. It consists of a mixture of methyl esters of the fatty acids presents as triglycerides in vegetables oils (oil, sunflower, soya, rape oils). As a result of the refining of these oils for their use as food, a waste product is formed, the oleins (acidulated soapstock). The oiliness consist of a mixture of triglycerides and free fatty acids, the latter amounting to 50% or more of the mixture and are subject to a fluctuating market, therefore it exist at times a problem for their disposal. In our research work we have tried to obtain biodiesel from oiliness. The process resulting from our experimental work is as follows. 1. Scarification of the free fatty acids with methanol, by acid catalysis, centrifuging the reaction product and removal of the acid-methanol phase. Drying of the latter. At this stage we have a product containing about 70% of methyl esters. 2. Transesterification of the triglycerides present in the sterified product with methanol by alkaline catalysis, washing the reaction product with a water methanol solution. Centrifuging and removal of the water-methanol phase. At this stage a biodiesel products is obtained containing about 90% of methyl esters. 3. Fractional vacuum distillation of the 90% biodiesel gives a final product with a methyl esters content higher than 98%. (Author)

  1. Preservation of semi-perishable food and development of convenience food using a combination of irradiation and other physicochemical treatments

    International Nuclear Information System (INIS)

    Choudhury, N.; Siddiqui, A.K.; Chowdhury, N.A.; Youssouf, Q.M.; Rashid, H.; Begum, A.A.; Alam, M.K.

    1998-01-01

    Studies were carried out on the development and irradiation preservation of semi-dried fish, e.g. Labeo rohita (Ruhi) and Cirrhiuas mrigala (Mrigel), the extension of shelf-life at ambient temperature, and the improvement in the microbiological quality of sealed, ready to eat, commercially prepared fish kebabs by a combination of gamma irradiation with spices and an acidulant such as ascorbic acid. In the processing of semi-dried fish, the combination treatment of a salt dip and irradiation at a dose of 4 kGy extended the shelf-life by more than 3 months. Kebabs prepared in the laboratory and irradiated at a dose of 5 kGy were found to have a shelf-life of up to 6 months at room temperature. With commercially prepared fish kebabs collected from ordinary and sophisticated food shops, the maximum shelf-life extension was 14 days for the 5 kGy treated samples stored at ambient temperature. The microbiological quality of such kebabs indicated that the fish used was of poor quality, resulting in a limited shelf-life, even after chemical and irradiation treatments. Inoculated pack studies of Clostridium botulinum spores showed that when oil fried, the kebab size had a definite effect on heat penetration, and consequent spore reduction. No spores were recovered from the 5 kGy irradiated fried kebabs. (author)

  2. Listeria innocua and Lactobacillus delbrueckii subsp. bulgaricus employ different strategies to cope with acid stress

    DEFF Research Database (Denmark)

    Shabala, Lana; McMeekin, Tom; Budde, Birgitte Bjørn

    2006-01-01

    '-dichlorofluorescein diacetate succinimidyl ester (CDCFDA-SE) was employed that enabled reliable measurements of intracellular pH (pHi) to a minimum pHi of 4.0. Changes in pHi and H+ fluxes from immobilised bacteria were measured using fluorescence ratio imaging microscopy (FRIM) and a non-invasive ion flux measuring...... technique (MIFE), respectively. L. innocua maintained a relatively constant pHi of 5.5-6.1 at pHex 4 and 5 via H+ extrusion. In contrast, L. delbrueckii subsp. bulgaricus progressively lowered pHi towards pHex over the entire pHex range examined. The type of acidulant used influenced pH regulation with both...... pHi and H+ -fluxes being more severely affected by LA compared to HCl. Overall, our data demonstrated different adaptive strategies in these two bacteria. While L. innocua expels protons to maintain a constant pHi, L. delbrueckii subsp. bulgaricus allows proton entry after acidic treatment so that pHi...

  3. Quantification of Carbonyl Compounds Generated from Ozone-Based Food Colorants Decomposition Using On-Fiber Derivatization-SPME-GC-MS

    Directory of Open Access Journals (Sweden)

    Wenda Zhu

    2014-12-01

    Full Text Available Fruit leathers (FLs production produces some not-to-specification material, which contains valuable ingredients like fruit pulp, sugars and acidulates. Recovery of FL for product recycling requires decolorization. In earlier research, we proved the efficiency of an ozone-based decolorization process; however, it produces carbonyls as major byproducts, which could be of concern. A headspace solid-phase microextraction with on-fiber derivatization followed by gas chromatography-mass spectrometry was developed for 10 carbonyls analysis in ozonated FL solution/suspension. Effects of dopant concentration, derivatization temperature and time were studied. The adapted method was used to analyze ozonated FL solution/suspension samples. Dopant concentration and derivatization temperature were optimized to 17 mg/mL and 60 °C, respectively. Competitive extraction was studied, and 5 s extraction time was used to avoid non-linear derivatization of 2-furfural. The detection limits (LODs for target carbonyls ranged from 0.016 and 0.030 µg/L. A much lower LOD (0.016 ppb for 2-furfural was achieved compared with 6 and 35 ppb in previous studies. Analysis results confirmed the robustness of the adapted method for quantification of carbonyls in recycled process water treated with ozone-based decolorization. Ethanal, hexanal, 2-furfural, and benzaldehyde were identified as byproducts of known toxicity but all found below levels for concern.

  4. Bioconversion of Cheese Waste (Whey)

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, G.W.

    1998-03-11

    The US dairy industry produces 67 billion pounds of cheese whey annually. A waste by-product of cheese production, whey consists of water, milk sugar (lactose), casein (protein), and salts amounting to about 7% total solids. Ultrafiltration is used to concentrate cheese whey into a protein-rich foodstuff; however, it too produces a waste stream, known as ''whey permeate,'' (rejected water, lactose, and salts from the membrane). Whey permeate contains about 4.5% lactose and requires treatment to reduce the high BOD (biological oxygen demand) before disposal. Ab Initio, a small business with strong chemistry and dairy processing background, desired help in developing methods for bioconversion of whey permeate lactose into lactic acid. Lactic acid is an organic acid primarily used as an acidulant in the food industry. More recently it has been used to produce polylactic acid, a biodegradable polymer and as a new method to treat meat carcasses to combat E. coli bacteria. Conversion of whey permeate to lactic acid is environmentally sound because it produces a valued product from an otherwise waste stream. FM&T has expertise in bioconversion processes and analytical techniques necessary to characterize biomass functions. The necessary engineering and analytical services for pilot biomass monitoring, process development, and purification of crude lactic acid were available at this facility.

  5. Influence of disinfectant solutions on the tensile bond strength of a fourth generation dentin bonding agent

    Directory of Open Access Journals (Sweden)

    BOCANGEL Jorge Saldivar

    2000-01-01

    Full Text Available The purpose of the present study was to evaluate the influence of different disinfectant solutions on the tensile bond strength of a fourth generation dentin bonding agent. Forty non carious human molars were selected. Teeth were embedded in acrylic resin and ground until the exposure of a flat superficial dentin surface. Teeth were randomly divided in 4 groups and treated as follows: Group 1 - 2.5% NaOCl for 40 seconds; Group 2 - 2% chlorhexidine for 40 seconds; Group 3 - 1.23% acidulated fluoride for 4 minutes; and Group 4 - control (without disinfectant solution. Following treatments, Scotchbond Multipurpose Plus® (3M was used according to the manufacturer's instructions. After that, the test specimens were built with composite resin (Z100®-3M, using a standard Teflon matrix. The specimens were stored in distilled water for 24 hours at a temperature of 37ºC. The tensile strength test was performed using a Mini Instrom testing machine. The mean values obtained for each group, in MPa, were: Group 1 - 7.37 (± 2.51; Group 2 - 11.25 (± 4.65; Group 3 - 9.80 (± 3.11; and Group 4 - 10.96 (± 3.37. The results were submitted to statistical analysis using the ANOVA test, and no statistical significant differences among the groups were found. It can be concluded that the different disinfectant substances used in this research do not adversely affect dentin adhesion.

  6. Production of poly(malic acid) from sugarcane juice in fermentation by Aureobasidium pullulans: Kinetics and process economics.

    Science.gov (United States)

    Wei, Peilian; Cheng, Chi; Lin, Meng; Zhou, Yipin; Yang, Shang-Tian

    2017-01-01

    Poly(β-l-malic acid) (PMA) is a biodegradable polymer with many potential biomedical applications. PMA can be readily hydrolyzed to malic acid (MA), which is widely used as an acidulant in foods and pharmaceuticals. PMA production from sucrose and sugarcane juice by Aureobasidium pullulans ZX-10 was studied in shake-flasks and bioreactors, confirming that sugarcane juice can be used as an economical substrate without any pretreatment or nutrients supplementation. A high PMA titer of 116.3g/L and yield of 0.41g/g were achieved in fed-batch fermentation. A high productivity of 0.66g/L·h was achieved in repeated-batch fermentation with cell recycle. These results compared favorably with those obtained from glucose and other biomass feedstocks. A process economic analysis showed that PMA could be produced from sugarcane juice at a cost of $1.33/kg, offering a cost-competitive bio-based PMA for industrial applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Relationship between nano/micro structure and physical properties of TiO2-sodium caseinate composite films.

    Science.gov (United States)

    Montes-de-Oca-Ávalos, Juan Manuel; Altamura, Davide; Candal, Roberto Jorge; Scattarella, Francesco; Siliqi, Dritan; Giannini, Cinzia; Herrera, María Lidia

    2018-03-01

    Films obtained by casting, starting from conventional emulsions (CE), nanoemulsions (NE) or their gels, which led to different structures, with the aim of explore the relationship between structure and physical properties, were prepared. Sodium caseinate was used as the matrix, glycerol as plasticizer, glucono-delta-lactone as acidulant to form the gels, and TiO 2 nanoparticles as reinforcement to improve physical behavior. Structural characterization was performed by SAXS and WAXS (Small and Wide Angle X-ray Scattering, respectively), combined with confocal and scanning electron microscopy. The results demonstrate that the incorporation of the lipid phase does not notably modify the mechanical properties of the films compared to solution films. Films from NE were more stable against oil release than those from CE. Incorporation of TiO 2 improved mechanical properties as measured by dynamical mechanical analysis (DMA) and uniaxial tensile tests. TiO 2 macroscopic spatial distribution homogeneity and the nanostructure character of NE films were confirmed by mapping the q-dependent scattering intensity in scanning SAXS experiments. SAXS microscopies indicated a higher intrinsic homogeneity of NE films compared to CE films, independently of the TiO 2 load. NE-films containing structures with smaller and more homogeneously distributed building blocks showed greater potential for food applications than the films prepared from sodium caseinate solutions, which are the best known films. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Micro energy-dispersive x-ray fluorescence spectrometry study of dentin coating with nanobiomaterials

    Science.gov (United States)

    Soares, Luís. Eduardo Silva; Nahorny, Sídnei; Marciano, Fernanda Roberta; Zanin, Hudson; Lobo, Anderson de Oliveira

    2015-06-01

    New biomaterials such as multi-walled carbon nanotubes oxide/graphene oxide (MWCNTO/GO), nanohydroxyapatite (nHAp) and combination of them together or not to acidulated phosphate fluoride gel (F) have been tested as protective coating before root dentin erosion. Fourteen bovine teeth were cleaned, polished, divided into two parts (n=28) and assigned to seven groups: (Control) - without previous surface treatment; F treatment; nHAp; MWCNTO/GO; F+nHAp; F+MWCNTO/GO and F+MWCNTO/GO/nHAp composites. Each sample had two sites of pre-treatments: acid etched area and an area without treatment. After the biomaterials application, the samples were submitted to six cycles (demineralization: orange juice, 10 min; remineralization: artificial saliva, 1 h). Micro energy-dispersive X-ray fluorescence spectrometry (μ-EDXRF) mapping area analyses were performed after erosive cycling on both sites (n=84). μ-EDXRF mappings showed that artificial saliva and MWCNTO/GO/nHAp/F composite treatments produced lower dentin demineralization than in the other groups. Exposed dentin tubules allowed better interaction of nanobiomaterials than in smear layer covered dentin. Association of fluoride with other biomaterials had a positive influence on acid etched dentin. MWCNTO/GO/nHAp/F composite treatment resulted in levels of demineralization similar to the control group.

  9. An In-vitro Study of the Load Deflection Characteristics of the Thermal Wires Immersed in Different Fluoride Prophylactic Agents

    Directory of Open Access Journals (Sweden)

    Sami K. Al-Joubori

    2018-04-01

    Full Text Available Background: Fluoridated prophylactic agents have been reported to cause corrosion and discoloration of titanium alloys. Degradation in the mechanical properties lead to a decrease in a suitable orthodontic force, thereby causing delayed leveling of crooked teeth. This study was designed to evaluate the load deflection characteristics of thermal nickel titanium arch wires during unloading phase after ninety minutes immersion in three different fluoride agents. Material and methods: Forty specimens of thermal wires were obtained from Ortho Technology Company, which had 0.019” × 0.025” rectangular in cross section. Ten specimens from the wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or Phos-Flur® mouth rinse or in the controlled medium of normal saline and incubated at 37°C for ninety minutes. A Wp 300 universal material testing machine was modified and used to perform a three-point bending test in a water path at 37 ± 1°C. The statistical difference between the different agents was analyzed using ANOVA and least significant difference tests. Results: The unloading forces at 0.5 mm, 1.0 mm, and 1.5 mm where significantly reduced especially in acidulated phosphate fluoride treated specimens followed by neutral fluoride treated specimens. Conclusion: Based on the results found in this study it can be preferred to use fluoride prophylactic agents with the least acidity and fluoride ions concentration.

  10. Bioconversion of Cheese Waste (Whey)

    International Nuclear Information System (INIS)

    Bohnert, G.W.

    1998-01-01

    The US dairy industry produces 67 billion pounds of cheese whey annually. A waste by-product of cheese production, whey consists of water, milk sugar (lactose), casein (protein), and salts amounting to about 7% total solids. Ultrafiltration is used to concentrate cheese whey into a protein-rich foodstuff; however, it too produces a waste stream, known as ''whey permeate,'' (rejected water, lactose, and salts from the membrane). Whey permeate contains about 4.5% lactose and requires treatment to reduce the high BOD (biological oxygen demand) before disposal. Ab Initio, a small business with strong chemistry and dairy processing background, desired help in developing methods for bioconversion of whey permeate lactose into lactic acid. Lactic acid is an organic acid primarily used as an acidulant in the food industry. More recently it has been used to produce polylactic acid, a biodegradable polymer and as a new method to treat meat carcasses to combat E. coli bacteria. Conversion of whey permeate to lactic acid is environmentally sound because it produces a valued product from an otherwise waste stream. FM and T has expertise in bioconversion processes and analytical techniques necessary to characterize biomass functions. The necessary engineering and analytical services for pilot biomass monitoring, process development, and purification of crude lactic acid were available at this facility

  11. The effect of varying air injection rates on tall oil soap skimming efficiency for low fatty acid/resin acid ratio soaps produced by pulping mountain pine beetle-infected wood

    Energy Technology Data Exchange (ETDEWEB)

    Uloth, V.; Guy, E. [FPInnovations, Prince George, BC (Canada). PAPRICAN Div.

    2009-07-01

    This study was conducted to assess the impact of higher air injection rates on the skimmer performance of an evaporator soap skimmer at a mill in British Columbia (BC). Tests previously indicated that only 13 to 38 percent of the total soap in the feed liquor was skimmed for low acid number and low fatty acid and resin acid ratio soaps. A 2-day trial demonstrated that there were extended periods when soap skimming stopped completely and soap levels in the liquor equalled or exceeded levels observed in the feed liquor. Higher air injection rates had little impact on soap-skimming efficiency. The higher air injection rates decreased soap density by approximately 8 percent, and increased black liquor entrainment in the skimmed soap by approximately 35 percent. The use of higher air injection rates was not recommended, as high percentages of black liquor are known to cause high H{sub 2}S emissions during soap acidulation. 16 refs., 1 tab., 5 figs.

  12. Hydrolytic stability of heavy metal compounds in fly ash of a heat power plant

    International Nuclear Information System (INIS)

    Suslova, E.P.; Pertsikov, I.Z.

    1991-01-01

    Ash and slag from solid fuels are utilized widely in building materials and road surfaces, and in agriculture for soil acidulation. For all these uses it is important to know the amount and form of heavy metal compounds contained in ash and their likely behavior when ash and slag wastes are utilized. Studying the behavior of heavy metals in ash residues at contact with water media is important also because, for most trace elements, the authors lack experimental data that would enable us to predict their behavior after prolonged storage and industrial utilization. The present paper describes a study of lixiviation (at various pH in static conditions) of heavy metals form fly ash obtained by burning Azeisk coal. Homogenized ash selected from electric filter sections 1-4 was used, which has the following composition (%): SiO 2 59.8; Al 2 O 3 ; Fe 23 O 3 7.1; CaO 4.1; MgO 1.3; other 2.8. In a neutral medium, Ni, Cu, Zn, Pb, and Mn lixiviation was slight, amounting to 0.01-0.4%. During coal combustion, these elements apparently form compounds that are slightly soluble in water, although it is also possible that ash retains high adsorptivity for heavy metals. As a result, in these conditions the reverse process of sorption of heavy metals from the solution by fly ash is also possible, which would reduce the heavy metal concentration in the solution

  13. Biological treatment of the liquid effluents of a paper industry

    International Nuclear Information System (INIS)

    Mejia, Juan Felipe; Ramirez, Gladys Eugenia; Arias Zabala, Mario

    2001-01-01

    The objective of this paper is to determine the effect of the microorganisms Candida utilis and Candida tropicalis in the reduction of the chemical oxygen demand (COD) of the liquid effluents of a producing factory of paper kraft type, by means of fermentations made to pH of 5 and a 30 centigrade degrees during 6 days. The biological processing is preceded by a physicochemical process of directed acidulation to reduce pH of the effluent (liquor black) from its initial value, of approximately 13, to 5, in order to it is adapted for the growth of yeast. In this process, which forms precipitated, that is necessary to eliminate by centrifugation and filtration to facilitate the growth of the microorganisms, with is obtained one first removal of the COD of the order of 70 %. With the biological processing obtains for both yeasts a percentage of removal of 45 -50% of the COD surplus. The total removal of the COD, that is to say, obtained with the pre-cure and the fermentation it is of the order of 84% for the yeast. Additionally the possibility studied of implementing some complementary procedures to the biological processing, with a view to obtaining greater growth of yeast in the black liquor and thus obtaining additional reductions in the OCD of the same one

  14. Potency of Agroindustrial Wastewaters to Increase the Dissolution of Phosphate Rock Fertilizers

    Directory of Open Access Journals (Sweden)

    Ainin Niswati

    2014-06-01

    Full Text Available The used of agroindustrial wastewaters are not maximum yet in Lampung Province, althought it can be used as an acid solvent because of its acidic properties. This study was aimed to explore the most potential agroindustrial wastewaters in dissolving phosphate rock through acidulation in the laboratory scale. The experiment was arranged in a factorial. The first factor was origined of phosphate rock (Sukabumi, west Java and Selagailingga, central Lampung and the second factor was solvent types (agroindustrial wastewaters which were pineapple, tapioca, tofu industry, and palm oil as well as conventional acid solvents which were HCl, H2SO4, and CH3COOH. The incubation processes were 0, 1, 2, and 3 months. The results showed that agroindustrial wastewaters that have the highest potency to solubize phosphate rock was industrial tofu wastewaters and followed by industrial wastewaters of tapioca, palm oil, and pineapple. Both the conventional acid and agroindustrial wastewaters solvent had a big potency to solubilize phosphate rock, however, its highest soluble P-value did not match with the ISO criteria for phosphate fertilizers Quality I (SNI because it did not reach the solubility of 80% of its total P2O5, but it has been qualified as a fertilizer both the quality phosphate A, B, and C (SNI.

  15. Effects of the low-intensity red laser radiation on the fluoride uptake in enamel. A clinical trial; Avaliacao dos efeitos da radiacao laser de emissao vermelha em baixa intensidade na incorporacao de fluor no esmalte. Estudo clinico

    Energy Technology Data Exchange (ETDEWEB)

    Nakasone, Regina Keiko

    2004-07-01

    Fluoride has been the most important preventive method on development of the caries. This in vivo study evaluated the effects of low-intensity red laser radiation on the fluoride uptake in enamel. Ten healthy participants were recruited for this study. The two maxillary central incisors of each volunteer to be biopsied were used and divided into 4 groups: group G{sub C} (control, which was untreated; group G{sub F} (fluoride), which received topical acidulated phosphate fluoride (APF) 1,23% treatment for 4 minutes; group G{sub LF} (laser + fluoride), which was irradiated with a low-intensity diode laser ({lambda}= 660 nm and dose= 6 J/cm{sup 2}) with APF application after irradiation and group G{sub FL} (fluoride + laser), which received APF before irradiation using the same parameters as G{sub LF}. The determination of fluoride was performed using a fluoride ion electrode after an acid-etch enamel biopsy. The results show a significant increase of the fluoride uptake in enamel for groups G{sub F}, G{sub LF} and G{sub FL} when compared to control group. Although a percentage increase of 57% was observed for G{sub LF} with respect to G{sub F}, there were no statistical differences among treated groups. These findings suggest that low-intensity laser radiation used before APF could be employed in the clinical practice to prevent dental caries. (author)

  16. Effects of dietary lipid sources on performance and apparent total tract digestibility of lipids and energy when fed to nursery pigs.

    Science.gov (United States)

    Mendoza, S M; van Heugten, E

    2014-02-01

    Acidulated fats and oils are by-products of the fat-refining industry. They contain high levels of FFA and are 10% to 20% less expensive than refined fats and oils. Two studies were designed to measure the effects of dietary lipid sources low or high in FFA on growth performance and apparent total tract digestibility (ATTD) of lipids and GE in nursery pigs. In Exp. 1, 189 pigs at 14 d postweaning (BW of 9.32 ± 0.11 kg) were used for 21 d with 9 replicate pens per treatment and 3 pigs per pen. Dietary treatments consisted of a control diet without added lipids and 6 diets with 6% inclusion of lipids. Four lipid sources were combined to create the dietary treatments with 2 levels of FFA (0.40% or 54.0%) and 3 degrees of fat saturation (iodine value [IV] = 77, 100, or 123) in a 2 × 3 factorial arrangement. Lipid sources were soybean oil (0.3% FFA and IV = 129.4), soybean-cottonseed acid oil blend (70.5% FFA and IV = 112.9), choice white grease (0.6% FFA and IV = 74.8), and choice white acid grease (56.0% FFA and IV = 79.0). Addition of lipid sources decreased ADFI (810 vs. 872 g/d; P = 0.018) and improved G:F (716 vs. 646 g/kg; P source. Fat increased (P sources.

  17. Inhibition of enamel demineralisation using "Nd-YAG and diode laser assisted fluoride therapy".

    Science.gov (United States)

    Chand, B R; Kulkarni, S; Mishra, P

    2016-02-01

    This in vitro study was to evaluate the irradiation efficacy of the Diode laser and the Nd-YAG laser either un-assisted or assisted by acidulated phosphate fluoride (APF) treatment on enamel's acid resistance. Seventy-two enamel samples, obtained from 12 extracted human molars, were randomly assigned to 6 groups as follows: (1) Control (C); (2) Exposed to APF gel (F); (3) Diode laser (DL); (4) Irradiated with Diode laser through APF gel (DL/F); (5) Nd-YAG laser (NL) and (6) Irradiated with Nd-YAG laser through APF gel (NL/F). The specimens were individually demineralised in an acidified hydroxyethylcellulose system, and the acid resistance was evaluated by determining the calcium ion dissolution using atomic absorption spectrometry. The average concentration of the calcium ion determined in groups 1 to 6 was 901, 757, 736, 592, 497 and 416 parts per million micrograms/gram, respectively. The results showed that demineralisation in the NL/F group was significantly less than the other groups and the control group was significantly greater than the other groups (P laser irradiation, used alone or in combination with APF, in decreasing the enamel demineralisation was greater than all the other groups.

  18. Variation on Molecular Structure, Crystallinity, and Optical Properties of Dentin Due to Nd:YAG Laser and Fluoride Aimed at Tooth Erosion Prevention

    Science.gov (United States)

    Freitas, Anderson Z.; Bachmann, Luciano; Benetti, Carolina; Ana, Patricia A.

    2018-01-01

    This in vitro study evaluated the compositional, crystalline, and morphological effects promoted by Nd:YAG laser on root dentin, and verified the effects of laser and topical acidulated phosphate fluoride application (APF-gel) on dentin erosion. 180 bovine dentin slabs were randomized into 4 groups (n = 45): G1–untreated, G2–APF-gel (1.23% F−, 4 min), G3–Nd:YAG (1064 nm, 84.9 J/cm2, 10 Hz), and G4–APF-gel application followed by Nd:YAG laser irradiation. The compositional, crystalline, and morphological effects promoted by treatments were investigated on five samples of each experimental group. The other samples were submitted to a 5-day, 10-day, or 15-day erosive and abrasive demineralization and remineralization cycling in order to create erosion lesions. The area and depth of lesions, as well as the optical attenuation coefficient, were assessed, and all data were statistically analysed (p laser promoted the reduction of carbonate, the formation of tetracalcium phosphate, as well as the melting and recrystallization of the dentin surface. Laser significantly decreased the area and depth of erosion lesions and altered the optical attenuation coefficient when compared to untreated and APF-gel groups, but the association of APF-gel and laser did not promote an additional effect. Nd:YAG laser irradiation can be a promissory treatment to prevent dentin erosion and the abrasion process. PMID:29389868

  19. SUPPLEMENTATION OF GLYCEROL OR LECITHIN IN DIFFERENT LEVELS OF FREE FAT ACIDS IN BROILER DIETS SUPLEMENTAÇÃO DE GLICEROL OU DE LECITINA EM DIFERENTES NÍVEIS DE ÁCIDOS GRAXOS LIVRES EM DIETAS PARA FRANGOS DE CORTE

    Directory of Open Access Journals (Sweden)

    Alexandre de Mello Kessler

    2009-09-01

    Full Text Available A metabolism trial was carried out with 95 male broilers, 24 day-old, of commercial line, subjected to 18+1 treatments with 5 replications. Three levels of free fat acid (FFA inclusion by the usage of soybean oil (SO, acidulated soybean soapstock (ASS, and the mixture between the two oils (50:50%, in two levels of inclusion (4 and 8% in the basal diet (BD and the supplementation of glycerol or emulsifier (0.5%, in substitution to starch were tested. The trial was conducted for 8 days. Birds performance, metabolizability coefficient of dry matter (MCDM, fat (MCCF and energy (MCCE were evaluated and the comparison among oils and supplements. The performance and the metabolism were not affected (P>0.05 by FFA levels or supplements tested.  It was observed that the use of lecithin improved added crude fat metabolism (P<0.01 and that birds used equally SO and ASS. Both SO and ASS are good sources of fat for broilers.

    KEY WORDS: Acidulated soybean soapstock, emulsification, lecithin, metabolism, performance.
    Realizou-se um experimento com 95 frangos de corte machos de 24 dias de idade, de linhagem comercial, submetidos a 18+1 tratamentos e cinco repetições. Testaram-se três níveis de inclusão de ácidos graxos livres (AGL,  pelo uso de óleo degomado de soja (ODS, óleo ácido de soja (OAS e a mistura entre os dois óleos (50:50%, em dois níveis de inclusão de óleo (4 e 8% na dieta basal e a suplementação glicerol ou lecitina (0,5% em substituição ao amido. Desenvolveu-se o ensaio em oito dias, com avaliação do desempenho das aves, do coeficiente de metabolizabilidade da matéria seca (CMMS, da gordura bruta (CMGB e da energia bruta (CMEB das dietas e comparação dos óleos e suplementos. O desempenho e o metabolismo não foram afetados (P>0,05 pelos níveis de AGL ou suplementos testados. Observou-se que o uso de lecitina proporcionou melhor aproveitamento da gordura bruta adicionada às dietas (P<0

  20. Efficacy of various topical agents to prevent enamel demineralization

    Directory of Open Access Journals (Sweden)

    Priska Lestari Hendrawan

    2011-09-01

    Full Text Available Background: Enamel demineralization is a common and undesirable side effect of fixed appliance orthodontic treatment. Many sudies showed that the prevalence varied between 2–96%. There are many ways to prevent demineralization and increased remineralization such as oral hygiene instruction and by topical application such as acidulated phosphate fluor (APF casein phospo peptide-amorphous calcium phosphate (CPP-ACP, casein phospo peptide-amorphous calcium phosphate plus (CPP-ACPF. Purpose: The purpose of this in-vitro study was to evaluate the efficacy of various topical agents to prevent enamel demineralization. Methods: Fourty extracted human premolars were allocated to 1 of 4 groups: 1.23% APF gel; 10% CPP-ACP paste; 10% CPP-ACPF paste; and untreated control. All samples were subjected to pH cycling treatment for 12 days through a daily procedure of demineralization solution with pH 4 for 6 hours and remineralization solution with pH 7 for 18 hours. Microhardness testing were done before and after pH cycling and the delta hardness values were determined. Results: APF, CPP-ACP and CPP-ACPF application significantly prevent lowering of enamel microhardness value compared with untreated control group. Kruskal-Wallis, ANOVA, Mann-Whitney U, Tukey and Bonferroni Post-Hoc multiple comparison test showed significant difference between mean delta microhardness value of CPP-ACPF and CPP-ACP group with APF group, but there is no significant difference between mean delta microhardness value of CPP-ACPF and CPP-ACP group. Conclusion: APF, CPP-ACP and CPP-ACPF prevent enamel demineralization. CPP-ACP and CPP-ACPF prevent demineralization more than APF.Latar belakang: Demineralisasi email merupakan efek samping negatif yang sering dijumpai pada perawatan ortodontik cekat. Beberapa penelitian menyatakan bahwa prevalensinya bervariasi 2–96 persen. Ada beberapa cara untuk mencegah demineralisasi dan meningkatkan remineralisasi, misalnya dengan instruksi

  1. Influência da aplicação de flúor sobre a rugosidade superficial do ionômero de vidro Vitremer e adesão microbiana a este material Influence of the application of fluoride on the superficial roughness of Vitremer glass ionomer cement and microbial adhesion to this material

    Directory of Open Access Journals (Sweden)

    Denise PEDRINI

    2001-03-01

    Full Text Available Os cimentos ionoméricos representam importante opção de material restaurador em Odontologia e sua adesão à estrutura dental, diminuindo a infiltração marginal, somada à liberação de flúor, inibindo o metabolismo de microrganismos acidogênicos e favorecendo a remineralização dental, podem diminuir a ocorrência de cárie secundária. A aplicação tópica de géis acidulados ou neutros contendo flúor tem sido largamente utilizada em Odontologia. No entanto, este procedimento pode afetar a integridade dos materiais restauradores, aumentando sua rugosidade e a retenção de placa bacteriana. Dessa forma, o presente estudo avaliou o período de tempo no qual o cimento ionomérico Vitremer mantém sua capacidade inibitória sobre Streptococcus mutans ATCC 25175 e a adesão dos mesmos sobre a superfície do material, bem como a influência da aplicação tópica de flúor acidulado e neutro sobre esses parâmetros microbiológicos e as características superficiais daquele material. Verificou-se que a atividade antimicrobiana do cimento ionomérico Vitremer se mantém por aproximadamente quatro dias e não é recuperada com o uso de flúor gel acidulado ou neutro. Observou-se, também, que Streptococcus mutans ATCC 25175 adere ao material restaurador testado sendo que a aplicação tópica de flúor não influenciou esta adesão. As características superficiais desses materiais não se alteraram com a aplicação dos géis.Glass ionomer cements are important options in restorative and preventive dentistry due to their adhesion to the tooth surface and to fluoride release, which can decrease the risk of recurrent caries. The topical use of acidulated and neutral fluoride gels has been frequent in dentistry. However, this procedure can adversely affect the surface of restorative materials, increasing their roughness and the retention of dental plaque. Thus, this study evaluated the period in which Vitremer glass ionomer cement maintains

  2. Sulphursoil - Delano Development Corporation

    Energy Technology Data Exchange (ETDEWEB)

    None

    1985-06-01

    A sizable amount of technical information has been accumulated on the effects of agricultural applications of the natural mineral product called Sul-Fe. This technical information supports the field observations of farmers, landscapers and gardeners who have used the product. Sul-Fe is often evaluated in terms of its sulphur content alone. When compared to elemental sulphur (100% sulphur), the 18 to 21% sulphur content of Sul-Fe seems relatively low. However, as the following technical data indicates, when judged on actual effects, Sul-Fe's complex mixture of minerals has several advantages over elemental sulphur. When judged on the basis of soil acidulation, Sul-Fe has more immediate effects than elemental sulphur. The rapid acidifying effect is due to Sul-Fe's content of crystalline sulphuric acid. Sul-Fe also has long-term effects on soil pH due to its content of sulphur and sulfides and the time required to oxidize these materials. Elemental sulphur contains sulphur in only one chemical form which must be microbially oxidized before it becomes reactive in the soil solution, a reaction that takes quite some time in some soils. Sul-Fe is thus better than elemental sulphur in terms of immediate effects and comparable in terms of long term effects. Applied blends of Sul-Fe supplemented with elemental sulphur may provide for a maximization of both short and long term effects. An additional benefit derived from the use of Sul-Fe is the addition to the soil of a variety of trace nutrients including iron, calcium, zinc, copper, manganese, magnesium, and molybdenum.

  3. Evaluating agronomic effectiveness of phosphate rocks using nuclear and related techniques: Results from an FAO/IAEA co-ordinated research project

    International Nuclear Information System (INIS)

    Zapata, F.

    2000-01-01

    An FAO/IAEA Co-ordinated Research Project, 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilisers, in particular rock phosphates', was in operation during the period 1993-98. The research network comprised twenty-three scientists, of whom seventeen were in developing countries, with six in industrialized nations. Conventional and 32 P-isotope techniques were utilized to assess the bioavailability of P in soils amended with phosphate rock (PR) and water-soluble fertilisers, and to evaluate the agronomic effectiveness of PR products. No single chemical extraction method was found to be suitable for all soils and fertilisers. The Pi strip method showed promising results, but more testing is needed with tropical acid soils. The 32 P-phosphate-exchange kinetics method allowed a complete characterization of P dynamics, and provided basic information for estimating the kinetic pools of soil P. The agronomic effectiveness (AE) of PRs depends on their solubility (reactivity), which is related to the degree of carbonate substitution for phosphate in the apatite structure. Rock phosphates of low reactivity were unsuitable for direct application to annual crops. Research in Venezuela, China, Cuba, Brazil, and Thailand demonstrated that AE can be increased by partial acidulation, or by mixing with organic materials or a water-soluble source. The AE can be enhanced also through inoculation with mycorrhizal fungi and rhizobacteria. The AE, which depends on species, is particularly high in crops such as canola and lupin that exude organic acids from the roots. Agronomic effectiveness of PR is higher on soils with low pH, low available P, low exchangeable Ca, high cation exchange capacity and high organic-matter content. The 32 P-techniques are powerful tools for studying the factors that affect AE. Information from field trials was used to create a database for validating a model for providing recommendations for PR

  4. Evaluating agronomic effectiveness of phosphate rocks using nuclear and related techniques: Results from an FAO/IAEA co-ordinated research project

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, F [International Atomic Energy Agency, Vienna (Austria)

    2000-06-01

    An FAO/IAEA Co-ordinated Research Project, 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilisers, in particular rock phosphates', was in operation during the period 1993-98. The research network comprised twenty-three scientists, of whom seventeen were in developing countries, with six in industrialized nations. Conventional and {sup 32}P-isotope techniques were utilized to assess the bioavailability of P in soils amended with phosphate rock (PR) and water-soluble fertilisers, and to evaluate the agronomic effectiveness of PR products. No single chemical extraction method was found to be suitable for all soils and fertilisers. The Pi strip method showed promising results, but more testing is needed with tropical acid soils. The {sup 32}P-phosphate-exchange kinetics method allowed a complete characterization of P dynamics, and provided basic information for estimating the kinetic pools of soil P. The agronomic effectiveness (AE) of PRs depends on their solubility (reactivity), which is related to the degree of carbonate substitution for phosphate in the apatite structure. Rock phosphates of low reactivity were unsuitable for direct application to annual crops. Research in Venezuela, China, Cuba, Brazil, and Thailand demonstrated that AE can be increased by partial acidulation, or by mixing with organic materials or a water-soluble source. The AE can be enhanced also through inoculation with mycorrhizal fungi and rhizobacteria. The AE, which depends on species, is particularly high in crops such as canola and lupin that exude organic acids from the roots. Agronomic effectiveness of PR is higher on soils with low pH, low available P, low exchangeable Ca, high cation exchange capacity and high organic-matter content. The {sup 32}P-techniques are powerful tools for studying the factors that affect AE. Information from field trials was used to create a database for validating a model for providing recommendations

  5. Methane: Fuel or Exhaust at the Emergence of Life?

    Science.gov (United States)

    Russell, Michael J; Nitschke, Wolfgang

    2017-10-01

    As many of the methanogens first encountered at hydrothermal vents were thermophilic to hyperthermophilic and comprised one of the lower roots of the evolutionary tree, it has been assumed that methanogenesis was one of the earliest, if not the earliest, pathway to life. It being well known that hydrothermal springs associated with serpentinization also bore abiotic methane, it had been further assumed that emergent biochemistry merely adopted and quickened this supposed serpentinization reaction. Yet, recent hydrothermal experiments simulating serpentinization have failed to generate methane so far, thus casting doubt on this assumption. The idea that the inverse view is worthy of debate, that is, that methanotrophy was the earlier, is stymied by the "fact" that methanotrophy itself has been termed "reverse methanogenesis," so allotting the methanogens the founding pedigree. Thus, attempting to suggest instead that methanogenesis might be termed reverse methanotrophy would require "unlearning"-a challenge to the subconscious! Here we re-examine the "impossibility" of methanotrophy predating methanogenesis as in what we have termed the "denitrifying methanotrophic acetogenic pathway." Advantages offered by such thinking are that methane would not only be a fuel but also a ready source of reduced carbon to combine with formate or carbon monoxide-available in hydrothermal fluids-to generate acetate, a target molecule of the first autotrophs. And the nitrate/nitrite required for the putative oxidation of methane with activated NO would also be a ready source of fixed nitrogen for amination reactions. Theoretical conditions for such a putative pathway would be met in a hydrothermal green rust-bearing exhalative pile and associated chimneys subject to proton and electron counter gradients. This hypothesis could be put to test in a high-pressure hydrothermal reaction chamber in which a cool carbonate/nitrate/nitrite-bearing early acidulous ocean simulant is juxtaposed

  6. Delayed tooth replantation after root surface treatment with sodium hypochlorite and sodium fluoride: histomorphometric analysis in rats.

    Science.gov (United States)

    Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

    2006-04-01

    In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin- embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other.

  7. Comparison of Antibacterial Effect of Fluoride and Chlorhexidine on Two Cariogenic Bacteria: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Poureslami HR

    2014-09-01

    Full Text Available Statement of problem: Dental plaque is the main source for dental caries and there is no proper vaccine that can affect dental plaques. Objectives: Daily use of an efficient anti-plaque product can be very beneficial in plaque control and, thus, prevention of caries. This study aims to evaluate the antibacterial effects of four products of Chlorhexidine and Fluoride on two types of cariogenic bacteria. Materials and Methods: In this in vitro study, the antibacterial effect of Chlorhexidine and Fluoride (gel and solution against Streptococci Sanguis and Sobrinus was evaluated. Chlorhexidine gluconate 1% gel (Corosodyl, France, Chlorhexidine gluconate 2% solution (Consepsis, Ultradent, US, Sodium fluoride 0.2% solution (Oral-B, US and Acidulated Phosphate Fluoride 1.23% gel ( Denti-Care, Canada were used. The disc diffusion method was used for testing bacterial sensitivity. The data were analyzed using paired t-test and Chi-square test. Results: In comparison with the negative control, each of the four gels and solutions showed antibacterial effects but the effects were not statistically significant for fluoride solution (P=0.217. For S. Sobrinus, the mean diameter of inhibition zone around the discs coated with fluoride gel (F g, fluoride solution (F s, Chlorhexidine gel (CHX g and Chlorhexidine solution (CHX s were 19, 9, 21.5 and 27.5mm, respectively. For S. Sanguis, the mean diameter of inhibition zone around the discs coated with F g, F s, CHX g and CHX s were 17, 11, 17 and 25mm, respectively. CHX s had the most effect on both bacteria and F s had the least. CHX g and F g were less effective than CHX s, respectively. Conclusion: The results demonstrated that 2% CHX s and 1.23% F g can be effective on inhibition of the growth of some of cariogenic bacteria. Therefore, these agents can be used in the prevention of Early Childhood Caries.

  8. Uranium recovery from wet process phosphoric acid

    International Nuclear Information System (INIS)

    Carrington, O.F.; Pyrih, R.Z.; Rickard, R.S.

    1981-01-01

    Improvement in the process for recovering uranium from wetprocess phosphoric acid solution derived from the acidulation of uraniferous phosphate ores by the use of two ion exchange liquidliquid solvent extraction circuits in which in the first circuit (A) the uranium is reduced to the uranous form; (B) the uranous uranium is recovered by liquid-liquid solvent extraction using a mixture of mono- and di-(Alkyl-phenyl) esters of orthophosphoric acid as the ion exchange agent; and (C) the uranium oxidatively stripped from the agent with phosphoric acid containing an oxidizing agent to convert uranous to uranyl ions, and in the second circuit (D) recovering the uranyl uranium from the strip solution by liquid-liquid solvent extraction using di(2ethylhexyl)phosphoric acid in the presence of trioctylphosphine oxide as a synergist; (E) scrubbing the uranium loaded agent with water; (F) stripping the loaded agent with ammonium carbonate, and (G) calcining the formed ammonium uranyl carbonate to uranium oxide, the improvement comprising: (1) removing the organics from the raffinate of step (B) before recycling the raffinate to the wet-process plant, and returning the recovered organics to the circuit to substantially maintain the required balance between the mono and disubstituted esters; (2) using hydogren peroxide as the oxidizing agent in step (C); (3) using an alkali metal carbonate as the stripping agent in step (F) following by acidification of the strip solution with sulfuric acid; (4) using some of the acidified strip solution as the scrubbing agent in step (E) to remove phosphorus and other impurities; and (5) regenerating the alkali metal loaded agent from step (F) before recycling it to the second circuit

  9. Nanostructural effect of acid-etching and fluoride application on human primary and permanent tooth enamels

    International Nuclear Information System (INIS)

    Cheong, Youjin; Choi, Samjin; Kim, So Jung; Park, Hun-Kuk

    2012-01-01

    This study examined the nanostructural effects of fluoride application and the acid-etching time with respect to the time elapsed after fluoride application on the primary and permanent tooth enamel layers using atomic force microscopy (AFM) and scanning electron microscopy (SEM). 192 non-carious teeth were assigned to sixteen experimental groups (n = 12) including primary (1 to 8) and permanent (9 to 16) teeth, based on the timing of acid-etching with 37% phosphoric acid after an acidulated phosphate fluoride (APF) pre-treatment. The APF pre-treatment led to a decrease in surface roughness in both the primary and permanent teeth. After the APF treatment, the roughness in both primary and permanent teeth increased with the time elapsed. An acid-etching time of 40 s led to increased nanostructural changes in the enamel surfaces compared to the conventional acid-etching time of 20 s. This acid-etching process led to a higher roughness changes in the primary teeth than in the permanent teeth. To obtain proper enamel adhesion of a sealant after APF pre-treatment, it is important to apply acid-etching two weeks after pre-treatment. In addition, the acid-etching time should be prolonged to apply etching more quickly than two weeks, regardless of the primary and permanent teeth. Highlights: ► APF pre-treatment led to decreased surface roughness in the enamel. ► After APF treatment, the more roughness increased with increasing time elapsed. ► Acid-etching should be performed two weeks after fluoride application.

  10. The drive to life on wet and icy worlds.

    Science.gov (United States)

    Russell, Michael J; Barge, Laura M; Bhartia, Rohit; Bocanegra, Dylan; Bracher, Paul J; Branscomb, Elbert; Kidd, Richard; McGlynn, Shawn; Meier, David H; Nitschke, Wolfgang; Shibuya, Takazo; Vance, Steve; White, Lauren; Kanik, Isik

    2014-04-01

    This paper presents a reformulation of the submarine alkaline hydrothermal theory for the emergence of life in response to recent experimental findings. The theory views life, like other self-organizing systems in the Universe, as an inevitable outcome of particular disequilibria. In this case, the disequilibria were two: (1) in redox potential, between hydrogen plus methane with the circuit-completing electron acceptors such as nitrite, nitrate, ferric iron, and carbon dioxide, and (2) in pH gradient between an acidulous external ocean and an alkaline hydrothermal fluid. Both CO2 and CH4 were equally the ultimate sources of organic carbon, and the metal sulfides and oxyhydroxides acted as protoenzymatic catalysts. The realization, now 50 years old, that membrane-spanning gradients, rather than organic intermediates, play a vital role in life's operations calls into question the idea of "prebiotic chemistry." It informs our own suggestion that experimentation should look to the kind of nanoengines that must have been the precursors to molecular motors-such as pyrophosphate synthetase and the like driven by these gradients-that make life work. It is these putative free energy or disequilibria converters, presumably constructed from minerals comprising the earliest inorganic membranes, that, as obstacles to vectorial ionic flows, present themselves as the candidates for future experiments. Key Words: Methanotrophy-Origin of life. Astrobiology 14, 308-343. The fixation of inorganic carbon into organic material (autotrophy) is a prerequisite for life and sets the starting point of biological evolution. (Fuchs, 2011 ) Further significant progress with the tightly membrane-bound H(+)-PPase family should lead to an increased insight into basic requirements for the biological transport of protons through membranes and its coupling to phosphorylation. (Baltscheffsky et al., 1999 ).

  11. The Australian national reactive phosphate rock project - Aims, experimental approach, and site characteristics

    International Nuclear Information System (INIS)

    McLaughlin, M.J.

    2002-01-01

    Field-based cutting trials were established across Australia in a range of environments to evaluate the agronomic effectiveness of 5 phosphate rocks, and 1 partially acidulated phosphate rock, relative to either single super-phosphate or triple superphosphate. The phosphate rocks differed in reactivity, as determined by the degree of carbonate substitution for phosphate in the apatite structure and solubility of phosphorus present in the fertilizers in 2% formic acid, 2% citric acid and neutral ammonium citrate. Sechura (Bayovar) and North Carolina phosphate rocks were highly reactive (>70% solubility in 2% formic acid), whilst Khouribja (Moroccan) and Hamrawein (Egypt) phosphate rock were moderately reactive. Duchess phosphate rock from Queensland was relatively unreactive ( 2 , from 4.0 to 5.1, and Colwell extractable phosphorus ranged from 3 to 47 μg/g prior to fertilizer application. Two core experiments were established at each site. The first measured the effects of phosphate rock reactivity on agronomic effectiveness, while the second core experiment measured the effects of the degree of water solubility of the phosphorus source on agronomic effectiveness. The National Reactive Phosphate Rock Project trials provided the opportunity to confirm the suitability of accepted procedures to model fertilizer response and to develop new approaches for comparing different fertilizer responses. The Project also provided the framework for subsidiary studies such as the effect of fertilizer source on soil phosphorus extractability; cadmium and fluorine concentrations in herbage; evaluation of soil phosphorus tests; and the influence of particle size on phosphate rock effectiveness. The National Reactive Phosphate Rock Project presents a valuable model for a large, Australia-wide, collaborative team approach to an important agricultural issue. The use of standard and consistent experimental methodologies at every site ensured that maximum benefit was obtained from data

  12. Thermal reduction and U-recovery from uraniferous phosphorite concentrate of phosphatic sandstone deposit of G. Qatrani, western desert, Egypt

    International Nuclear Information System (INIS)

    Abdel Monem, H.M.

    1988-01-01

    The produced uraniferous phosphorite concentrate from cationic floatation of phosphatic sandstone of G. Qatrani contain 32.01% P 2 O 5 , 0.39% eU and 5.65% SiO 2 . Thermal reduction technique using a high calorific hydrocarbon (Mazout) is used to recover U and P 2 O 5 . At elevated temperature ranging from 500 to 800 0 C, reducing gases mainly, Co are evolved due to mazout cracking; beside a carbon film is precipitated around the treated phosphate grains. These conditions have proved quite beneficial in reducing U+6 into U+4, as well as creating a sufficiently low redox potential below 350 mV in the subsequent leach solution. The effect of different relevant factors are studied and optimized as 700 C, 30 minutes and 20% (wt/wt) ratio for reducing temperature, duration time and amount of reductant added respectively. Hydrochloric acid of 8 N appears to offer the best potential for acidulation of the reduced phosphates at room temperature (25 0 C) and 30 minutes retention time of agitation leaching. The results showed that, more than 98% of P 2 O 5 reports in solution as phosphoric acid and about 97% of uranium is retained in an insoluble form (U+4). Applying oxidizing roast of the leached reduced materials at 800 0 C in the presence of 2% NaCl, would result in both removing the carbon content and oxidizing the contained U+4 to U+6. By subsequent leaching with dilute acidic solution (2N HCl) more than 98% of the contained U+6 is readily soluble

  13. Formulation of single super phosphate fertilizer from rock phosphate of Hazara, Pakistan

    Directory of Open Access Journals (Sweden)

    Matiullah Khan

    2012-05-01

    Full Text Available Phosphorus deficiency is wide spread in soils of Pakistan. It is imperative to explore the potential and economics of indigenous Hazara rock phosphate for preparation of single super phosphate fertilizer. For the subject study rock phosphate was collected from Hazara area ground at 160 mesh level with 26% total P2O5 content for manual preparation of single super phosphate fertilizer. The rock phosphate was treated with various concentrations of sulfuric acid (98.9%, diluted or pure in the field. The treatments comprised of 20 and 35% pure acid and diluted with acid-water ratios of 1:5, 1:2, 1:1 and 2:1 v/v for acidulation at the rate of 60 liters 100 kg-1 rock phosphate. The amount was prior calculated in the laboratory for complete wetting of rock phosphate. A quantity of 150 kg rock phosphate was taken as treatment. The respective amount of acid was applied with the spray pump of stainless steel or poured with bucket. After proper processing, chemical analysis of the products showed a range of available P2O5 content from 9.56 to 19.24% depending upon the amount of acid and its dilution. The results reveal at that 1:1 dilutions gave the highest P2O5 content (19.24%, lowest free acid (6 % and 32% weight increase. The application of acid beyond or below this combination either pure or diluted gave hygroscopic product and higher free acids. The cost incurred upon the manual processing was almost half the prevailing rates in the market. These results lead to conclude that application of sulfuric acid at the rate of 60 liters 100 kg-1 with the dilution of 50% (v/v can yield better kind of SSP from Hazara rock phosphate at lower prices.

  14. Turnstiles and bifurcators: the disequilibrium converting engines that put metabolism on the road.

    Science.gov (United States)

    Branscomb, Elbert; Russell, Michael J

    2013-02-01

    The Submarine Hydrothermal Alkaline Spring Theory for the emergence of life holds that it is the ordered delivery of hydrogen and methane in alkaline hydrothermal solutions at a spontaneously precipitated inorganic osmotic and catalytic membrane to the carbon dioxide and other electron acceptors in the earliest acidulous cool ocean that, through these gradients, drove life into being. That such interactions between hydrothermal fuels and potential oxidants have so far not been accomplished in the lab is because some steps along the necessary metabolic pathways are endergonic and must therefore be driven by being coupled to thermodynamically larger exergonic processes. But coupling of this kind is far from automatic and it is not enough to merely sum the ΔGs of two supposedly coupled reactions and show their combined thermodynamic viability. An exergonic reaction will not drive an endergonic one unless 'forced' to do so by being tied to it mechanistically via an organized "engine" of "Free Energy Conversion" (FEC). Here we discuss the thermodynamics of FEC and advance proposals regarding the nature and roles of the FEC devices that could, in principle, have arisen spontaneously in the alkaline hydrothermal context and have forced the onset of a protometabolism. The key challenge is to divine what these initial engines of life were in physicochemical terms and as part of that, what structures provided the first "turnstile-like" mechanisms needed to couple the partner processes in free energy conversion; in particular to couple the dissipation of geochemically given gradients to, say, the reduction of CO(2) to formate and the generation of a pyrophosphate disequilibrium. This article is part of a Special Issue entitled: The evolutionary aspects of bioenergetic systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. FT-Raman spectroscopic analysis of Nd:YAG and Er,Cr:YSGG laser irradiated enamel for preventive purposes

    Science.gov (United States)

    Ana, P. A.; Kauffmann, C. M. F.; Bachmann, L.; Soares, L. E. S.; Martin, A. A.; Gomes, A. S. L.; Zezell, D. M.

    2014-03-01

    This study evaluated the effect of combining laser irradiation with fluoride on an enamel microstructure and demineralization by FT-Raman spectroscopy (FTRS). Eighty human enamel slabs were divided into eight groups: (G1) untreated; (G2) acidulated phosphate fluoride application (APF—1.23% F- for 4 min) (G3) Nd:YAG irradiation (84.9 J cm-2, 60 mJ/pulse) (G4) Nd:YAG + APF; (G5) APF + Nd:YAG; (G6) Er,Cr:YSGG irradiation (2.8 J cm-2, 12.5 mJ/pulse) (G7) Er,Cr:YSGG + APF; and (G8) APF + Er,Cr:YSGG. After treatment, the samples were submitted to a ten-day pH-cycling model. Chemical changes were determined on the slabs before and after treatment, and also after pH-cycling, by FTRS in the range 400-4000 cm-1. The inorganic bands at 440, 590, 870, 960, 1100 cm-1, and the organic bands at 1270, 1450, 1670, 2945 cm-1 were considered. Demineralization promoted reduction in organic contents; Nd:YAG laser irradiation promoted loss of carbonate and organic content, while Er,Cr:YSGG did not produce significant changes in the relative band intensities of organic and inorganic contents of the enamel. In lased samples, no effects caused by pH-cycling on enamel were observed. In conclusion, laser treatment and its association with fluoride can somehow interfere with the demineralization dynamics, reducing its effects over the enamel.

  16. FT-Raman spectroscopic analysis of Nd:YAG and Er,Cr:YSGG laser irradiated enamel for preventive purposes

    International Nuclear Information System (INIS)

    Ana, P A; Kauffmann, C M F; Gomes, A S L; Bachmann, L; Soares, L E S; Martin, A A; Zezell, D M

    2014-01-01

    This study evaluated the effect of combining laser irradiation with fluoride on an enamel microstructure and demineralization by FT-Raman spectroscopy (FTRS). Eighty human enamel slabs were divided into eight groups: (G1) untreated; (G2) acidulated phosphate fluoride application (APF—1.23% F − for 4 min); (G3) Nd:YAG irradiation (84.9 J cm −2 , 60 mJ/pulse); (G4) Nd:YAG + APF; (G5) APF + Nd:YAG; (G6) Er,Cr:YSGG irradiation (2.8 J cm −2 , 12.5 mJ/pulse); (G7) Er,Cr:YSGG + APF; and (G8) APF + Er,Cr:YSGG. After treatment, the samples were submitted to a ten-day pH-cycling model. Chemical changes were determined on the slabs before and after treatment, and also after pH-cycling, by FTRS in the range 400−4000 cm −1 . The inorganic bands at 440, 590, 870, 960, 1100 cm −1 , and the organic bands at 1270, 1450, 1670, 2945 cm −1 were considered. Demineralization promoted reduction in organic contents; Nd:YAG laser irradiation promoted loss of carbonate and organic content, while Er,Cr:YSGG did not produce significant changes in the relative band intensities of organic and inorganic contents of the enamel. In lased samples, no effects caused by pH-cycling on enamel were observed. In conclusion, laser treatment and its association with fluoride can somehow interfere with the demineralization dynamics, reducing its effects over the enamel. (paper)

  17. Upgrading of raw tall oil soap into fuel oils and lubricants; Raakasuovan jalostus poltto- ja voiteluoeljyksi

    Energy Technology Data Exchange (ETDEWEB)

    Oasmaa, A; Arpiainen, V; McKeough, P; Tapola, E; Haekkinen, R; Kuoppala, E; Koskela, K [VTT Energy, Jyvaeskylae (Finland). Energy Production Technologies

    1997-12-01

    Thermochemical processing of tall oil soap originating from various mixtures of birch and pine has been experimentally investigated. The organic matter of tall oil soap, which is a by- product of Kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation with sulphuric acid to yield crude tall oil and subsequent distillation of the oil at centralised refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock. Furthermore, thermochemical processing of tall oil soap does not introduce sulphur into the chemical recovery cycle. This would be a significant advantage in future mills employing closure of water circuits and/or sulphur-free pulping. In small-scale experiments tall oil soaps from wood mixtures with high birch content have been processed using both liquid-phase thermal treatment and pyrolysis. The liquid-phase thermal treatment at 450 deg C under a nitrogen atmosphere yielded a good-quality oil product at high yield (about 50 % of the energy content of the tall oil soap). In the atmospheric pyrolysis of birch tall oil soap a separation of inorganic and organic constituents was obtained. The energy value of the product gases was high. Both processes are promising, but the pyrolysis alternative has the greater economic potential, providing that the promising preliminary experimental results have given a true picture of the performance of the full-scale pyrolysis process. (orig.)

  18. Ozonation-based decolorization of food dyes for recovery of fruit leather wastes.

    Science.gov (United States)

    Zhu, Wenda; Koziel, Jacek A; Cai, Lingshuang; Brehm-Stecher, Byron F; Ozsoy, H Duygu; van Leeuwen, J Hans

    2013-08-28

    Commercial manufacture of fruit leathers (FL) usually results in a portion of the product that is out of specification. The disposition of this material poses special challenges in the food industry. Because the material remains edible and contains valuable ingredients (fruit pulp, sugars, acidulates, etc.), an ideal solution would be to recover this material for product rework. A key practical obstacle to such recovery is that compositing of differently colored wastes results in an unsalable gray product. Therefore, a safe and scalable method for decolorization of FL prior to product rework is needed. This research introduces a novel approach utilizing ozonation for color removal. To explore the use of ozonation as a decolorization step, we first applied it to simple solutions of the commonly used food colorants 2-naphthalenesulfonic acid (Red 40), tartrazine (Yellow 5), and erioglaucine (Blue 1). Decolorization was measured by UV/vis spectrometry at visible wavelengths and with a Hunter colorimeter. Volatile and semivolatile byproducts from ozone-based colorant decomposition were identified and quantified with solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Removal of Yellow 5, Red 40 and Blue 1 of about 65%, 80%, and 90%, respectively, was accomplished with 70 g of ozone applied per 1 kg of redissolved and resuspended FL. Carbonyl compounds were identified as major byproducts from ozone-induced decomposition of the food colorants. A conservative risk assessment based on quantification results and published toxicity information of potentially toxic byproducts, determined that ozone-based decolorization of FL before recycling is acceptable from a safety standpoint. A preliminary cost estimate based on recycling of 1000 tons of FL annually suggests a potential of $275,000 annual profit from this practice at one production facility alone.

  19. Uppgrading of raw tall oil soap into fuel oils and lubricants; Raakasuovan jalostus poltto- ja voiteluoeljyksi

    Energy Technology Data Exchange (ETDEWEB)

    Oasmaa, A.; Arpiainen, V.; McKeough, P.; Tapola, E. [VTT Energy, Espoo (Finland)

    1998-12-31

    Thermochemical processing of tall oil soap originating from various mixtures of birch and pine has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation with sulphuric acid to yield crude tall oil and subsequent distillation of the oil at centralised refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock. Furthermore, thermochemical processing of tall oil soap does not introduce sulphur into the chemical recovery cycle. This would be a significant advantage in future mills employing closure of water circuits and/or sulphur-free pulping. In small-scale experiments tall oil soaps from wood mixtures with high birch content have been processed using both liquid-phase thermal treatment and pyrolysis. The liquid-phase thermal treatment at 450 deg C under a nitrogen atmosphere yielded a good-quality oil product at high yield (about 50% of the energy content of the tall oil soap). In the atmospheric pyrolysis of birch tall oil soap a separation of inorganic and organic constituents was obtained. The energy value of the product gases was high. Both processes are promising, but the pyrolysis alternative has the greater economic potential, providing that the promising preliminary experimental results have given a true picture of the performance of the full-scale pyrolysis process. (orig.)

  20. Gasification of tall oil soap for lime kiln fuel. Suovan kaasutus meesauunin polttoaineeksi

    Energy Technology Data Exchange (ETDEWEB)

    Saviharju, K.; McKeough, P.; Pyykkoenen, M.; Oasmaa, A. (Technical Research Centre of Finland, Espoo (Finland). Lab. of Fuel and Process Technology)

    1993-01-01

    The energy delivered to a modern pulp mill in the form of material unsuitable for fibre production exceeds the energy demand of the mill by about 30 %. Purchased lime kiln fuel further increases the surplus by 5-10 %. On the other hand, acidulation of tall oil soap adds about 1-3 kg SO[sub 2] for t of pulp onto the difficult-to-manage sulphur balance of the mill. Pyrolysis or gasification of tall oil soap could alleviate both these problems. In this study, gasification of tall oil soap was investigated in laboratory experiments as well as on a 200 kW test gasifier. In the laboratory experiments tall oil soap was pyrolyzed both on a heated-grid unit and on a thermobalance at heating rates of 600 K/s and 10 K/min, respectively. The maximum temperature was 675 deg C. The amount of volatiles formed was high, about 77 %, the amount of coke and inorganic salts being 7 % and 16 %, respectively. In the 200 kW gasifier, tests were carried out with mixed soap (pine and birch) such that the gas outlet temperature was 680-690 deg C. Because of the low gasification temperature complete gasification of the char was not achieved. The heat content of the product gas, including the sensible heat, was about 5.8 MJ/m[sup 3]n, which was estimated to be sufficient for lime calcination. Typical of the product gas were high tar content (20 g/m[sup 3]n), high acetylene content, and the absence of hydrogen sulphide. Overall, the results of this study indicated that the most significant subjects for future research are the atomization properties of tall oil soap, the effects of different amounts of input sodium on the operability of the lime kiln, and the economics of the proposed gasification process

  1. The yeast spectrum of the 'tea fungus Kombucha'.

    Science.gov (United States)

    Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

    1995-01-01

    The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably

  2. Multi-walled carbon nanotubes/graphene oxide hybrid and nanohydroxyapatite composite: A novel coating to prevent dentin erosion.

    Science.gov (United States)

    Nahorny, Sídnei; Zanin, Hudson; Christino, Vinie Abreu; Marciano, Fernanda Roberta; Lobo, Anderson Oliveira; Soares, Luís Eduardo Silva

    2017-10-01

    To date is emergent the development of novel coatings to protect erosion, especially to preventive dentistry and restorative dentistry. Here, for the first time we report the effectiveness of multi-walled carbon nanotube/graphene oxide hybrid carbon-base material (MWCNTO-GO) combined with nanohydroxyapatite (nHAp) as a protective coating for dentin erosion. Fourier transform Raman spectroscopy (FT-Raman), scanning electron (SEM), and transmission electron (TEM) microscopy were used to investigated the coatings and the effect of acidulated phosphate fluoride gel (APF) treatment on bovine teeth root dentin before and after erosion. The electrochemical corrosion performance of the coating was evaluated. Raman spectra identified that: (i) the phosphate (ν 1 PO 4 3- ) content of dentin was not significantly affected by the treatments and (ii) the carbonate (ν 1 CO 3 2- ) content in dentin increased when nHAp was used. However, the nHAp/MWCNTO-GO composite exposited lower levels of organic matrix (CH bonds) after erosion compared to other treatments. Interesting, SEM micrographs identified that the nHAp/MWCNTO-GO formed layers after erosive cycling when associate with APF treatment, indicating a possible chemical bond among them. Treatments of root dentin with nHAp, MWCNTO-GO, APF_MWCNTO-GO, and APF_nHAp/MWCNTO-GO increased the carbonate content, carbonate/phosphate ratio, and organic matrix band area after erosion. The potentiodynamic polarization curves and Nyquist plot showed that nHAp, MWCNT-GO and nHAp/MWCNT-GO composites acted as protective agents against corrosion process. Clearly, the nHAp/MWCNTO-GO composite was stable after erosive cycling and a thin and acid-resistant film was formed when associated to APF treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Fluoride influences nickel-titanium orthodontic wires′ surface texture and friction resistance

    Directory of Open Access Journals (Sweden)

    Mona Aly Abbassy

    2016-01-01

    Full Text Available Objectives: The aim of this study was to investigate the effects exerted by the acidulated fluoride gel on stainless steel and nickel-titanium (Ni-Ti orthodontic wires. Materials and Methods: Sixty stainless steel and Ni-Ti orthodontic archwires were distributed into forty archwires used for in vitro study and twenty for in situ study. Fluoride was applied for 1 h in the in vitro experiment while it was applied for 5 min in the in situ experiment. The friction resistance of all wires with ceramic brackets before/after topical fluoride application was measured using a universal testing machine at 1 min intervals of moving wire. Moreover, surface properties of the tested wires before/after fluoride application and before/after friction test were examined by a scanning electron microscope (SEM. Dunnett′s t-test was used to compare frictional resistance of as-received stainless steel wires and Ni-Ti wires to the wires treated by fluoride in vitro and in situ (P < 0.05. Two-way ANOVA was used to compare the effect of fluoride application and type of wire on friction resistance in vitro and in situ (P < 0.05. Results: Ni-Ti wires recorded significantly high friction resistance after fluoride application when compared to stainless steel wires in vitro, P < 0.05. Fluoride application did not significantly affect the friction resistance of the tested wires in situ, P < 0.05. SEM observation revealed deterioration of the surface texture of the Ni-Ti wires after fluoride application in vitro and in situ. Conclusions: The in vitro fluoride application caused an increase in friction resistance of Ni-Ti wires when compared to stainless steel wires. In vitro and in situ fluoride application caused deterioration in surface properties of Ni-Ti wires.

  4. Influence of resin-modified glass ionomer and topical fluoride on levels of Streptococcus mutans in saliva and biofilm adjacent to metallic brackets

    Directory of Open Access Journals (Sweden)

    Marcela Cristina Damião ANDRUCIOLI

    Full Text Available Abstract Decalcification of enamel during fixed orthodontic appliance treatment remains a problem. White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. The use of fluoride-containing orthodontic materials has shown inconclusive results on their ability to reduce decalcification. The aims of this investigation were to compare the levels of Streptococcus mutans (SM in saliva and biofilm adjacent to orthodontic brackets retained with a resin-modified glass ionomer cement (RMGIC (Fuji ORTHO LC and a light cured composite resin (Transbond XT, and to analyze the influence of topical application of the 1.23% acidulated phosphate fluoride (APF on SM counts. In a parallel study design, two groups (n=14/15 were used with random allocation and high salivary SM counts before treatment. Biofilm was collected from areas adjacent to the brackets on teeth 13, 22, 33, and 41. Both saliva and biofilm were collected on the 7th, 21st, 35th, and 49th days after appliance placement. Topical fluoride application was carried out on the 35th day. Bonding with RMGIC did not alter SM counts in saliva or biofilm adjacent to the brackets. On the other hand, the biofilm adjacent to brackets retained with composite resin showed a significant increase in SM counts along the trial period. Topical application of 1.23% APF did not reduce salivary or biofilm SM counts regardless of the bonding material. In conclusion, fluoride topical application did not show efficacy in reducing SM. The use of RMGIC as bonding materials allowed a better control of SM cfu counts in dental biofilm hindering the significant increase of these microorganisms along the trial period, which was observed in the biofilm adjacent to the composite material.

  5. Development of a phosphating process for corrosion protection in NdFeB magnets

    International Nuclear Information System (INIS)

    Silva, Adonis Marcelo Saliba

    2001-01-01

    NdFeB magnets are important materials, which produce better energy efficiency in electrical devices, but they are rather vulnerable to corrosion. In this study, a phosphating treatment for protection against corrosion of NdFeB magnets has been investigated. Phosphating is generally used as a pretreatment in the application of protective coatings. This treatment increases the corrosion assistance in defective areas of the coating as well as improves the adhesion between coating and substrate. A commercial NdFeB magnet produced by powder metallurgy has been used and the effect of the following parameters on phosphating was studied: time of phosphating; pH of phosphating solution; anodic polarization and molybdate addition to the phosphating solution. The results showed a significant increase in the corrosion resistance of magnets phosphated in a solution concentrated between 10-20 g/L NaH 2 PO 4 , pH in the range of 3 to 4.6, acidulated preferably with H 3 PO 4 at room temperature (20±1) deg C. Conversion coatings formed at solutions of pH 3.8 showed better corrosion resistance. Phosphating times longer than 4 hours increased the magnet corrosion resistance 10 to 20 times. This resistance improves with higher immersion times. Anodic polarization of the magnet in the range 200-400 mV SCE accelerated phosphating. Results indicated that molybdate interacts preferentially with Nd rich phase of the magnet. In addition to the newly developed technology in this work for NdFeB corrosion protection, two methodologies have been introduced to facilitate electrochemical analyses: selection of samples of similar electrochemical behavior, based on the current density after 200s of constant anodic polarization; and evaluation of the corrosion protection provided by conversion coatings by monitoring of gas evolution during corrosion in acid solution. (author)

  6. CO2 laser irradiation enhances CaF2 formation and inhibits lesion progression on demineralized dental enamel-in vitro study.

    Science.gov (United States)

    Zancopé, Bruna R; Rodrigues, Lívia P; Parisotto, Thais M; Steiner-Oliveira, Carolina; Rodrigues, Lidiany K A; Nobre-dos-Santos, Marinês

    2016-04-01

    This study evaluated if Carbon dioxide (CO2) (λ 10.6 μm) laser irradiation combined with acidulated phosphate fluoride gel application (APF gel) enhances "CaF2" uptake by demineralized enamel specimens (DES) and inhibits enamel lesion progression. Thus, two studies were conducted and DES were subjected to APF gel combined or not with CO2 laser irradiation (11.3 or 20.0 J/cm(2), 0.4 or 0.7 W) performed before, during, or after APF gel application. In study 1, 165 DES were allocated to 11 groups. Fluoride as "CaF2 like material" formed on enamel was determined in 100 DES (n = 10/group), and the surface morphologies of 50 specimens were evaluated by scanning electron microscopy (SEM) before and after "CaF2" extraction. In study 2, 165 DES (11 groups, n = 15), subjected to the same treatments as in study 1, were further subjected to a pH-cycling model to simulate a high cariogenic challenge. The progression of demineralization in DES was evaluated by cross-sectional microhardness and polarized light microscopy analyses. Laser at 11.3 J/cm(2) applied during APF gel application increased "CaF2" uptake on enamel surface. Laser irradiation and APF gel alone arrested the lesion progression compared with the control (p enamel surface and a synergistic effect was found. However, regarding the inhibition of caries lesion progression, no synergistic effect could be demonstrated. In conclusion, the results have shown that irradiation with specific laser parameters significantly enhanced CaF2 uptake by demineralized enamel and inhibited lesion progression.

  7. Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization

    International Nuclear Information System (INIS)

    Kato, Ilka Tiemy

    2004-01-01

    The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm 2 , 3.7 J/cm 2 , 5.6 J/cm 2 , 7.4 J/cm 2 and 9.3 J/cm 2 ) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

  8. Effect of pretreatment with an Er:YAG laser and fluoride on the prevention of dental enamel erosion.

    Science.gov (United States)

    dos Reis Derceli, Juliana; Faraoni-Romano, Juliana Jendiroba; Azevedo, Danielle Torres; Wang, Linda; Bataglion, César; Palma-Dibb, Regina Guenka

    2015-02-01

    The aim of this study was to evaluate the effect of the Er:YAG laser and its association with fluoride (1.23% acidulate phosphate fluoride gel) on the prevention of enamel erosion. Sixty specimens were obtained from bovine enamel (4 × 4 mm), which were ground flat, polished, and randomly divided into five groups according to the preventive treatments: control-fluoride application; L--Er:YAG laser; L+F--laser + fluoride; F+L--fluoride + laser; L/F--laser/fluoride simultaneously. Half of the enamel surface was covered with nail varnish (control area), and the other half was pretreated with one of the preventive strategies to subsequently be submitted to erosive challenge. When the laser was applied, it was irradiated for 10 s with a focal length of 4 mm and 60 mJ/2 Hz. Fluoride gel was applied for 4 min. Each specimen was individually exposed to regular Coca-Cola® for 1 min, four times/day, for 5 days. Wear analysis was performed with a profilometer, and demineralization was assessed with an optical microscope. Data were analyzed using the Kruskal-Wallis test (wear)/Dunn test and ANOVA/Fisher's exact tests. The group L/F was similar to control group. The other groups showed higher wear, which did not present differences among them. In the demineralization assessment, the groups F+L and L/F showed lower demineralization in relation to the other groups. It can be concluded that none preventive method was able to inhibit dental wear. The treatments L/F and F+L showed lower enamel demineralization.

  9. Nanostructural effect of acid-etching and fluoride application on human primary and permanent tooth enamels

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Youjin [Department of Biomedical Engineering and Healthcare Industry Research Institute, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Choi, Samjin [Department of Biomedical Engineering and Healthcare Industry Research Institute, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Department of Orthodontics, College of Dental Medicine, Kyung Hee University, Seoul (Korea, Republic of); Kim, So Jung [Department of Pediatric Dentistry, College of Dental Medicine, Kyung Hee University, Seoul (Korea, Republic of); Park, Hun-Kuk, E-mail: sigmoidus@khu.ac.kr [Department of Biomedical Engineering and Healthcare Industry Research Institute, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Program of Medical Engineering, Kyung Hee University, Seoul (Korea, Republic of)

    2012-07-01

    This study examined the nanostructural effects of fluoride application and the acid-etching time with respect to the time elapsed after fluoride application on the primary and permanent tooth enamel layers using atomic force microscopy (AFM) and scanning electron microscopy (SEM). 192 non-carious teeth were assigned to sixteen experimental groups (n = 12) including primary (1 to 8) and permanent (9 to 16) teeth, based on the timing of acid-etching with 37% phosphoric acid after an acidulated phosphate fluoride (APF) pre-treatment. The APF pre-treatment led to a decrease in surface roughness in both the primary and permanent teeth. After the APF treatment, the roughness in both primary and permanent teeth increased with the time elapsed. An acid-etching time of 40 s led to increased nanostructural changes in the enamel surfaces compared to the conventional acid-etching time of 20 s. This acid-etching process led to a higher roughness changes in the primary teeth than in the permanent teeth. To obtain proper enamel adhesion of a sealant after APF pre-treatment, it is important to apply acid-etching two weeks after pre-treatment. In addition, the acid-etching time should be prolonged to apply etching more quickly than two weeks, regardless of the primary and permanent teeth. Highlights: Black-Right-Pointing-Pointer APF pre-treatment led to decreased surface roughness in the enamel. Black-Right-Pointing-Pointer After APF treatment, the more roughness increased with increasing time elapsed. Black-Right-Pointing-Pointer Acid-etching should be performed two weeks after fluoride application.

  10. Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization; Estudo in vitro dos efeitos promovidos pelo laser de diodo em 960 nm no esmalte dental humano: analise de temperatura, analise morfologica e avaliacao da resistencia a desmineralizacao

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Ilka Tiemy

    2004-07-01

    The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm{sup 2}, 3.7 J/cm{sup 2}, 5.6 J/cm{sup 2}, 7.4 J/cm{sup 2} and 9.3 J/cm{sup 2}) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

  11. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces at 0.355, 2.94, and 9.4 μm on surface morphology, permeability, and acid resistance.

    Science.gov (United States)

    Chang, Nai-Yuan N; Jew, Jamison M; Simon, Jacob C; Chen, Kenneth H; Lee, Robert C; Fried, William A; Cho, Jinny; Darling, Cynthia L; Fried, Daniel

    2017-12-01

    Ultraviolet (UV) and infrared (IR) lasers can be used to specifically target protein, water, and mineral, respectively, in dental hard tissues to produce varying changes in surface morphology, permeability, reflectivity, and acid resistance. The purpose of this study was to explore the influence of laser irradiation and topical fluoride application on the surface morphology, permeability, reflectivity, and acid resistance of enamel and dentin to shed light on the mechanism of interaction and develop more effective treatments. Twelve bovine enamel surfaces and twelve bovine dentin surfaces were irradiated with various combinations of lasers operating at 0.355 (Freq.-tripled Nd:YAG (UV) laser), 2.94 (Er:YAG laser), and 9.4 μm (CO 2 laser), and surfaces were exposed to an acidulated phosphate fluoride gel and an acid challenge. Changes in the surface morphology, acid resistance, and permeability were measured using digital microscopy, polarized light microscopy, near-IR reflectance, fluorescence, polarization sensitive-optical coherence tomography (PS-OCT), and surface dehydration rate measurements. Different laser treatments dramatically influenced the surface morphology and permeability of both enamel and dentin. CO 2 laser irradiation melted tooth surfaces. Er:YAG and UV lasers, while not melting tooth surfaces, showed markedly different surface roughness. Er:YAG irradiation led to significantly rougher enamel and dentin surfaces and led to higher permeability. There were significant differences in acid resistance among the various treatment groups. Surface dehydration measurements showed significant changes in permeability after laser treatments, application of fluoride and after exposure to demineralization. CO 2 laser irradiation was most effective in inhibiting demineralization on enamel while topical fluoride was most effective for dentin surfaces. Lasers Surg. Med. 49:913-927, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Fluoride release and surface roughness of a new glass ionomer cement: glass carbomer

    Directory of Open Access Journals (Sweden)

    Célia Maria Condeixa de França LOPES

    2018-02-01

    Full Text Available Abstract Objective This study analyzed the fluoride release/recharge and surface roughness of glass carbomer compared to other encapsulated glass ionomer cements (GICs. Material and method The GICs tested were Glass Fill® (GC-GCP Dental, Riva Self Cure® (RS-SDI, Riva Light Cure® (RL-SDI, Equia Fil® (EF-GC Europe. The composite resin Luna® (LU-SDI was used as control. Five samples of each material were prepared and kept in a humidifier for 24 hours (37 °C, 100% relative humidity. Fluoride release was measured in two times: before (T1: days 1, 2, 7, 14 and after topical application of fluoride (T2: days 15, 16, 21 and 28. The surface roughness was also measured in both times (T1: days 1 and 14; T2: days 15 and 28. All samples were submitted to a single topical application of acidulated fluoride phosphate (Fluor Care - FGM. Two-way ANOVA with repeated measures and Tukey's post-test (p <0.05 were used in the statistical analysis. Result Equia Fil presented the highest fluoride release in both evaluation periods, with a higher release in T1 (p <0.05. The other materials tested, including glass carbomer presented similar release in both periods (T1 and T2. Regarding surface roughness, no significant differences were observed in the interaction between the material × time factors (T1 and T2 (p=0.966. Conclusion The GICs tested presented fluoride release and recharge ability and showed no surface roughness increase by topical application of fluoride.

  13. Effects of minimal processing on the respiration rate and quality of rambutan cv. ‘Rong-Rien’

    Directory of Open Access Journals (Sweden)

    Buncha Ooraikul

    2008-04-01

    Full Text Available Respiration rate at 4oC and minimal processing of rambutan cv. ‘Rong-Rien’ were investigated. Rambutan was harvested from Amphur Ban Na San, Surat Thani Province, at the stage when its skin was turning into a combination of red, green and yellow. After harvesting, the fruits were size-graded to 27-30 fruits/kg, hydrocooled to 14oC, packed with ice in Styrofoam boxes and transported to the laboratory at Prince of Songkla University within 6 h. The respiration rate of fresh rambutan fruits was monitored. For minimal processing, the fruits were soaked in warm solution (55oC of 100 ppm sodium hypochlorite for one min and immediately cooled in cold water until their internal temperature reached 14oC. The minimal process included peeling, with and without coring. The peeled and peeled and cored rambutan samples were immersed in a solution of 0.5% citric acid + 0.5% CaCl2 at 4oC for 2 min. The average respiration rates (within 6 h at 4oC of whole fruit, peeled, and peeled and cored rambutan samples were measured and found to be 122, 134 and 143 mg CO2/kg/h, respectively. These findings indicated that a preparation style as peeled rambutan without coring, nylon/LLDPE bag, storage temperature of 4.0±1oC, were suitably applied for processed rambutans. To obtain a longer extended shelf life (>12 days of minimally processed peeled rambutans, further study on food additives, including acidulants and preservative used and gas composition in modified atmosphere packaging (MAP is needed.

  14. Corrosion and hydrogen absorption of commercially pure zirconium in acid fluoride solutions

    International Nuclear Information System (INIS)

    Yokoyama, Ken’ichi; Yamada, Daisuke; Sakai, Jun’ichi

    2013-01-01

    Highlights: •Zirconium corrodes and absorbs hydrogen in acid fluoride solutions. •Hydrogen thermal desorption is observed at 300–700 °C. •The resistance to hydrogen absorption of zirconium is higher than that of titanium. -- Abstract: The corrosion and hydrogen absorption of commercially pure zirconium have been investigated in acidulated phosphate fluoride (APF) solutions. Upon immersion in 2.0% APF solution of pH 5.0 at 25 °C, a granular corrosion product (Na 3 ZrF 7 ) deposits over the entire side surface of the specimen, thereby inhibiting further corrosion. In 0.2% APF solution, marked corrosion is observed from the early stage of immersion; no deposition of the corrosion product is observed by scanning electron microscopy. A substantial amount of hydrogen absorption is confirmed in both APF solutions by hydrogen thermal desorption analysis. The amount of absorbed hydrogen of the specimen immersed in the 2.0% APF solution is smaller than that in the 0.2% APF solution in the early stage of immersion. The hydrogen absorption behavior is not always consistent with the corrosion behavior. Hydrogen thermal desorption occurs in the temperature range of 300–700 °C for the specimen without the corrosion product. Under the same immersion conditions, the amount of absorbed hydrogen in commercially pure zirconium is smaller than that in commercially pure titanium as reported previously. The present results suggest that commercially pure zirconium, compared with commercially pure titanium, is highly resistant to hydrogen absorption, although corrosion occurs in fluoride solutions

  15. The effect of antibrowning agents on inhibition of potato browning, volatile organic compound profile, and microbial inhibition.

    Science.gov (United States)

    Mosneaguta, Ruslan; Alvarez, Valente; Barringer, Sheryl A

    2012-11-01

    Burbank and Norkotah potato slices were dipped into 3% sodium acid sulfate (SAS), citric acid (CA), sodium erythorbate (SE), malic acid (MA), sodium acid pyrophosphate (SAPP), or a combination of SAS-CA-SE. Browning by polyphenol oxidase (PPO) obtained from potato extract with 0.04 to 0.016 g/mL of antibrowning solutions at pH 2.0 to 6.9 were measured by UV-Vis spectroscopy. The color of slices dipped in antibrowning solutions at pHs 2 to 7 and stored at 4 °C for 15 d was measured every 5 d by colorimeter. Headspace analysis of volatiles in raw and cooked potato samples was performed by selected ion flow tube mass spectrometer (SIFT-MS) and soft independent modelling by class analogy (SIMCA) analysis of the calculated odor activity values (OAV) determined interclass distances. Microbial growth was measured at 15 d. At unadjusted pHs (1.1 to 7.1), the PPO browning of the control and samples with SAPP was not significantly different, SAS, CA, and MA produced some inhibition and SE and SAS-CA-SE prevented browning. At pH 5 to 7, only SE and SAS-CA-SE were effective browning inhibitors. Based on the color of potato slices, SE was the most effective at pH 2 to 7, but SAS was most effective at unadjusted pH. Cooking increased volatile levels in the treated potatoes and decreased differences between volatile profiles. Differences between cooked samples may not be noticeable by the consumer because volatiles with high discriminating powers have low OAVs. SAS, CA, and SAS-CA-SE treatments inhibited microbial growth but SAPP, control, and SE did not, most likely due to pH. Antibrowning agents inhibit polyphenol oxidase, increasing shelf life and consumer acceptability of processed raw potato products by preserving the color. Their effectiveness was shown to be mainly due to a pH effect, except SE, which was not pH dependent. MA, CA, and SAS-CA-SE are better acidulants for inhibition of color change as well as growth of spoilage bacteria, yeast, and mold than SAPP, the

  16. Repairability of Compomers with Different Methods of Surface Conditioning

    Directory of Open Access Journals (Sweden)

    P.Samimi

    2005-06-01

    Full Text Available Statement of Problem: Considering the cost and amount of time and also the quantity of tooth loss in the process of cavity preparation, repair of the restoration instead of itsreplacement would be much more efficient.Purpose: The aim of this study was to determine the effect of different methods of surface conditioning on the shear bond strength of repaired compomers.Materials and Methods: Sixty blocks of compomer were prepared in acrylic molds and then they were randomly divided into five groups of 12. Group I (control groupreceived no treatment. The remaining samples were immersed in 37 ºC distilled water for one week, then the surfaces were roughened with a coarse diamond bur. Samples ineach group were prepared by different surface treatment and conditioning: In group II specimens were conditioned with 35% phosphoric acid for 20s. Specimens in group III were etched with 10% polyacrylic acid for 20s. In group IV 1.23% acidulated phosphatefluoride was applied for 30s, and compomer surfaces were sandblasted with 50μm Al2O3 powder in group V. After the initial preparations, all groups were treated with silane and resin before bonding of the second mix of compomer. Shear forces were applied with a universal testing machine at a cross-head speed of 5mm/min. The data were analyzed using one-way ANOVA and Duncan's multiple range tests.Results: The mean shear bond strengths and standard deviations (in parentheses for groups I to V were 31.56(10.86, 20.02(5.49, 17.74(7.34, 19.31(4.31 and 27.7(6.33MPa, respectively. The mean bond strengths for Groups I and V were significantly higher than that of the other groups (P<0.05.Conclusion: The results showed that among the surface treatments used in this study,sandblasting with alumina could be the best surface preparation method for repairing compomer restorations.

  17. Trace elements in rock phosphates and P containing mineral and organo-mineral fertilizers sold in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Kratz, Sylvia, E-mail: sylvia.kratz@jki.bund.de; Schick, Judith; Schnug, Ewald

    2016-01-15

    68 rock phosphates and 162 P containing (organo-)mineral fertilizers sold in Germany were evaluated with regard to trace element contents. While Al, As, B, Be, Cd, Cr, Mo, Ni, Pb, Sb, Se, Tl, U, and Zn were higher in sedimentary than in igneous rock phosphates, the opposite was true for Co, Cu, Sn, Mn, Ti, Fe, and Sr. Comparing element concentrations to the currently valid legal limit values defined by the German Fertilizer Ordinance, it was found that some PK and many straight P fertilizers (superphosphate, triple superphosphate, partly acidulated rock phosphates) exceeded the limit of 50 mg Cd/kg P{sub 2}O{sub 5}. Mean values for As, Ni, Pb, and Tl remained below legal limits in almost all cases. While no legal limit has been defined for U in Germany yet, the limit of 50 mg U/kg P{sub 2}O{sub 5} for P containing fertilizers proposed by the German Commission for the Protection of Soils was clearly exceeded by mean values for all fertilizer types analyzed. A large share of the samples evaluated in this work contained essential trace elements at high concentrations, with many of them not being declared as such. Furthermore, trace elements supplied with these fertilizers at a fertilization rate leveling P uptake would exceed trace element uptake by crops. This may become most relevant for B and Fe, since many crops are sensitive to an oversupply of B, and Fe loads exceeding plant uptake may immobilize P supplies for the crops by forming Fe phosphate salts. The sample set included two products made from thermochemically treated sewage sludge ash. The products displayed very high concentrations of Fe and Mn and exceeded the legal limit for Ni, emphasizing the necessity to continue research on heavy metal removal from recycled raw materials and the development of environmentally friendly and agriculturally efficient fertilizer products. - Highlights: • Mineral fertilizers (MF) sold in Germany often exceed legal limits for Cd • MF sold in Germany contain high

  18. Evaluation of frictional resistance and surface characteristics after immersion of orthodontic brackets and wire in different chemical solutions: A comparative in vitrostudy.

    Science.gov (United States)

    Nanjundan, Kavitha; Vimala, G

    2016-01-01

    To evaluate the changes of static and kinetic frictional forces between the brackets and wires following exposure to a soft drink, acidic food ingredient, and acidulated fluoride prophylactic agents. Two types of Roth prescription mandibular incisor brackets were used: 3M Unitek Victory stainless steel (SS) brackets (n = 40) and Transcend 6000 polycrystalline alumina (PCA) brackets (n = 40) as well as eighty 0.019 × 0.025" dimension ortho technology SS wires of 50 mm length each. Subsequently, brackets tied with SS wires divided into eight subgroups (n = 10) and were immersed in vinegar (pH = 3.5 ± 0.5), Pepsi ® (pH = 2.46), Colgate Phos-Flur mouth rinse (pH = 5.1), and artificial saliva (control group pH = 7) for 24 h. Changes in surface morphology under scanning electron microscope ×1000, surface roughness (Ra) with surface profilometer (single bracket and single wire from each subgroup), and frictional resistance using universal testing machine were evaluated. Highest mean (standard deviation) static frictional force of 2.65 (0.25) N was recorded in Pepsi ® followed by 2.57 (0.25) N, 2.40 (0.22) N, and 2.36 (0.17) N for Vinegar, Colgate Phos-Flur mouth rinse, and artificial saliva groups, respectively. In a similar order, lesser mean kinetic frictional forces obtained. PCA brackets revealed more surface deterioration and higher frictional force values than SS brackets. A significant positive correlation was observed between frictional forces and bracket slot roughness (r = 0.861 and 0.802, respectively, for static and kinetic frictional forces, p < 0.001 for both) and wire roughness (r = 0.243 and 0.242, respectively, for static and kinetic frictional forces, p < 0.05 for both). Findings may have long-term implications when acidic food substances are used during fixed orthodontic treatment. Further, in vivo studies are required to analyze the clinical effect of acidic mediums in the oral environment during orthodontic treatment.

  19. Evaluation of frictional resistance and surface characteristics after immersion of orthodontic brackets and wire in different chemical solutions: A comparative in vitrostudy

    Directory of Open Access Journals (Sweden)

    Kavitha Nanjundan

    2016-01-01

    Full Text Available Aim: To evaluate the changes of static and kinetic frictional forces between the brackets and wires following exposure to a soft drink, acidic food ingredient, and acidulated fluoride prophylactic agents. Materials and Methods: Two types of Roth prescription mandibular incisor brackets were used: 3M Unitek Victory stainless steel (SS brackets (n = 40 and Transcend 6000 polycrystalline alumina (PCA brackets (n = 40 as well as eighty 0.019 × 0.025" dimension ortho technology SS wires of 50 mm length each. Subsequently, brackets tied with SS wires divided into eight subgroups (n = 10 and were immersed in vinegar (pH = 3.5 ± 0.5, Pepsi ® (pH = 2.46, Colgate Phos-Flur mouth rinse (pH = 5.1, and artificial saliva (control group pH = 7 for 24 h. Changes in surface morphology under scanning electron microscope ×1000, surface roughness (Ra with surface profilometer (single bracket and single wire from each subgroup, and frictional resistance using universal testing machine were evaluated. Results: Highest mean (standard deviation static frictional force of 2.65 (0.25 N was recorded in Pepsi ® followed by 2.57 (0.25 N, 2.40 (0.22 N, and 2.36 (0.17 N for Vinegar, Colgate Phos-Flur mouth rinse, and artificial saliva groups, respectively. In a similar order, lesser mean kinetic frictional forces obtained. PCA brackets revealed more surface deterioration and higher frictional force values than SS brackets. A significant positive correlation was observed between frictional forces and bracket slot roughness (r = 0.861 and 0.802, respectively, for static and kinetic frictional forces, p < 0.001 for both and wire roughness (r = 0.243 and 0.242, respectively, for static and kinetic frictional forces, p < 0.05 for both. Conclusions: Findings may have long-term implications when acidic food substances are used during fixed orthodontic treatment. Further, in vivo studies are required to analyze the clinical effect of acidic mediums in the oral environment during

  20. In vitro study of morphological and chemical modification threshold of bovine dental enamel irradiated by the holmium laser

    International Nuclear Information System (INIS)

    Eduardo, Patricia Lerro de Paula

    2001-01-01

    The aim of this study is to investigate the Ho:YLF laser effects on the dental enamel surface with regards to its morphology, thermal variations during its irradiation in the pulp chamber and its increased resistance to demineralization through quantitative analysis of calcium and phosphorous atoms reactive concentrations in samples. Twenty samples of bovine enamel were used and divided in four groups: control - acidulated phosphate fluoride (APF) application followed by demineralization treatment with lactic acid; irradiation with Ho:YLF laser (100 J/cm 2 ) followed by APF topic application and demineralization treatment with lactic acid; irradiation with Ho:YLF laser (350 J/cm 2 ) followed by APF topic application and demineralization treatment with lactic acid: and irradiation with Ho:YLF laser ( 450 J/cm 2 ) followed by APF topic application and demineralization treatment with lactic acid. Ali samples were quantified according to their calcium and phosphorous atoms relative concentrations before and after the treatments above. X-Ray fluorescence spectrochemical analysis and scanning electron microscopy were carried out. It was observed an increase on the calcium and phosphorous atoms concentration ratio and therefore the enamel demineralization reduction as a result of the lactic acid treatment in the samples irradiated with the holmium laser followed by the APF application. In order to evaluate the feasibility of this study for clinical purposes, morphological changes caused by the holmium laser irradiation were analyzed. Such modifications were characterized by melted and re-solidified regions of the enamel with consequent changes on its permeability and solubility. Temperature changes of ten human pre-molars teeth irradiated with 350 J/cm 2 and 450 J/cm 2 were also monitored in the pulp chamber in real time. Temperature increases over 4,20 C did not occur. The results obtained from this study along with the results from previous researches developed at

  1. Phosphorus availability from phosphate rock and sewage sludge as influenced by the addition of water soluble phosphate fertilizer

    International Nuclear Information System (INIS)

    Zapata, F.; Zaharah, A.R.

    2002-01-01

    Phosphorus (P) inputs are required for sustainable agricultural production in most acid soils of the tropics and subtropics. Phosphate rocks (PR) and organic materials have been suggested as alternative P sources in these soils. Quantitative information on the P availability from sewage sludge (SL) is scanty. Methods to improve the effectiveness of PR such as partial acidulation and compaction with water-soluble P sources have been recommended. The objective of this greenhouse study was to evaluate the relative agronomic effectiveness (RAE) of Florida PR and sewage sludges (irradiated and non-irradiated) applied alone and in mixture with a water-soluble source (triple superphosphate, TSP) at two rates (50 and 150 mg P kg -1 soil). The 32 P isotope dilution technique was utilised to determine the proportion of P in the plant taken up from the P fertilizer treatments. Wheat was grown on an acid loamy sand Dystric Eutrocrepts and harvested 6 weeks after planting. Results on total P uptake and the RAE of the P fertilizer sources tested indicated that the addition of 50 mg P kg -1 soil as TSP was adequate in supplying P to the 6-week-old wheat plants as compared to PR and sewage sludge. Intermediate values were obtained for the mixtures. Similar responses were observed for the high P rate. For a given P rate, phosphorus uptake from PR and SL in presence of TSP was higher than P uptake from these sources alone, indicating an enhancement effect of TSP on the effectiveness of these non-readily available sources. With respect to P uptake from PR applied alone, the relative increases in P uptake from PR due to TSP influence were 52 and 67% for the low and high P rates, respectively. The relative increases in P uptake from SL due to TSP when compared to P uptake from SL alone were 102 and 59% for the low and high P rates of application. Application of a water-soluble P fertilizer together with a non-readily available P source shows an enhancement on the P uptake from the non

  2. Antibiotic Susceptibility Profiles of Listeria monocytogenes Strains Isolated from Food Products and Clinical Samples

    Directory of Open Access Journals (Sweden)

    Caplan Marius Eduard

    2014-06-01

    Full Text Available Listeria monocytogenes are o distribuţie ubiquitară în natură şi poate contamina produsele alimentare de origine animală, provocând infecţii severe la om. Până în prezent există foarte puține date cu privire la profilurile de rezistenţă ale tulpinilor circulante în România. Scopul acestui studiu a fost determinarea pattern-urilor de rezistenţă la antibiotice ale unor tulpini de L. monocytogenes (n=37 izolate din produse alimentare de origine animală şi din probe clinice. Probele din alimente (carne şi produse lactate, au fost colectate în perioada 2009-2013. Probele clinice au fost recoltate de la pacienţi cu septicemie, meningită/meningo-encefalită, cazuri de avort spontan şi nou-născuţi, spitalizaţi în perioada Aprilie 2010 - Aprilie 2013 în trei Instituţii Medicale din Bucureşti: Spitalul Elias, Spitalul Victor Babes si Institutul Naţional de Boli Infecţioase (INBI Matei Bals. Toate tulpinile testate au prezentat rezistenţă la cefalosporine şi acidul nalidixic; o tulpină izolată din melci fierţi a fost rezistentă la Trimetoprim/sulfametoxazol. Rezistenţa unora dintre tulpinile analizate la ampicilina, antibiotic de elecţie pentru terapia infecţiilor cauzate de L. monocytogenes, subliniază necesitatea testării in vitro a sensibilitatii la antibiotice a fiecarui izolat clinic pentru a stabili eficienţa diferitelor antibiotice, precum şi a unor studii epidemiologice extinse în scopul stabilirii profilurilor de rezistenţă ale tulpinilor de L. monocytogenes circulante în ţara noastră.

  3. Geodynamic and metabolic cycles in the Hadean

    Directory of Open Access Journals (Sweden)

    M. J. Russell

    2005-01-01

    Full Text Available High-degree melting of hot dry Hadean mantle at ocean ridges and plumes resulted in a crust about 30km thick, overlain in places by extensive and thick mafic volcanic plateaus. Continental crust, by contrast, was relatively thin and mostly submarine. At constructive and destructive plate boundaries, and above the many mantle plumes, acidic hydrothermal springs at ~400°C contributed Fe and other transition elements as well as P and H2 to the deep ocean made acidulous by dissolved CO2 and minor HCl derived from volcanoes. Away from ocean ridges, submarine hydrothermal fluids were cool (≤100°C, alkaline (pH ~10, highly reduced and also H2-rich. Reaction of solvents in this fluid with those in ocean water was catalyzed in a hydrothermal mound, a natural self-restoring flow reactor and fractionation column developed above the alkaline spring. The mound consisted of brucite, Mg-rich clays, ephemeral carbonates, Fe-Ni sulfide and green rust. Acetate and glycine were the main products, some of which were eluted to the ocean. The rest, along with other organic byproducts were retained and concentrated within Fe-Ni sulfide compartments. These compartments, comprising the natural hydrothermal reactor, consisted partly of greigite (Fe5NiS8. It was from reactions between organic modules confined within these inorganic compartments that the first prokaryotic organism evolved. These acetogenic precursors to the bacteria diversified and migrated down the mound and into the ocean floor to inaugurate the 'deep biosphere'. Once there they were protected from cataclysmic heating events caused by large meteoritic impacts. Geodynamic forces led to the eventual obduction of the deep biosphere into the photic zone where, initially protected by a thin veneer of sediment, the use of solar energy was mastered and photosynthesis emerged. The further evolution to oxygenic photosynthesis was effected as catalytic [Mn,Ca]-bearing molecules that otherwise would have been

  4. Disponibilidade de cádmio e chumbo para milho em solo adubado com fertilizantes fosfatados Cadmium and lead availability to corn in soil amended with phosphorus fertilizers

    Directory of Open Access Journals (Sweden)

    Eriberto Vagner de Souza Freitas

    2009-12-01

    and Pb concentrations were found in Gafsa rock phosphate. For the acidulated phosphates, simple superphosphate was the richest in Cd and Pb, while the Pb concentration was highest in Yoorin thermophosphate. Gafsa application induced the highest Pb concentration in corn shoots in the first crop cycle. This fertilizer was also responsible for the highest Cd concentration in plants in the second crop. Citric acid was the most efficient extractant for predicting the available soil Cd contents, whereas DTPA estimated Pb availability best.

  5. The radiological impact of the Belgian phosphate industry

    Energy Technology Data Exchange (ETDEWEB)

    Vanmarcke, H.; Paridaens, J. [Belgian Nuclear Research Centre, SCK.CEN, Boeretang 200, 2400 Mol (Belgium)

    2006-07-01

    The Belgian phosphate industry processes huge amounts of phosphate ore (1.5 to 2 Mton/year) for a wide range of applications, the most important being the production of phosphoric acid, fertilizers and cattle food. Marine phosphate ores show high specific activities of the natural uranium decay series (usually indicated by Ra-226) (e.g. 1200 to 1500 Bq/kg for Moroccan ore). Ores of magmatic origin generally contain less of the uranium and more of the thorium decay series (up to 500 Bq/kg). These radionuclides turn up in by-products, residues or product streams depending on the processing method and the acid used for the acidulation of the phosphate rock. Sulfuric acid is the most widely used, but also hydrochloric acid and nitric acid are applied in Belgium. For Flanders, the northern part of Belgium, we already have a clear idea of the production processes and waste streams. The five Flemish phosphate plants, from 1920 to 2000, handled 54 million ton of phosphate ore containing 65 TBq of radium-226 and 2.7 TBq of thorium- 232. The total surface area of the phosphogypsum and calcium fluoride sludge deposits amounts to almost 300 ha. There is also environmental contamination along two small rivers receiving the waste waters of the hydrochloric production process: the Winterbeek (> 200 ha) and the Grote Laak (12 ha). The data on the impact of the phosphate industry in the Walloon provinces in Belgium is less complete. A large plant produced in 2004 0.8 Mton of phosphogypsum, valorizing about 70 % of the gypsum in building materials (plaster, cement), in fertilizers, and in other products such as paper. The remainder was stored on a local disposal site. The radiological impact of the Belgian phosphate industry on the local population will be discussed. At present most contaminated areas are still recognizable as waste deposits and inaccessible to the population. However as gypsum deposits and other contaminated areas quickly blend in with the landscape, it is

  6. In vitro study of morphological and chemical modification threshold of bovine dental enamel irradiated by the holmium laser; Estudo in vitro das alteracoes morfologicas e quimicas do esmalte dental bovino irradiado pelo laser de holmio

    Energy Technology Data Exchange (ETDEWEB)

    Eduardo, Patricia Lerro de Paula

    2001-07-01

    The aim of this study is to investigate the Ho:YLF laser effects on the dental enamel surface with regards to its morphology, thermal variations during its irradiation in the pulp chamber and its increased resistance to demineralization through quantitative analysis of calcium and phosphorous atoms reactive concentrations in samples. Twenty samples of bovine enamel were used and divided in four groups: control - acidulated phosphate fluoride (APF) application followed by demineralization treatment with lactic acid; irradiation with Ho:YLF laser (100 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid; irradiation with Ho:YLF laser (350 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid: and irradiation with Ho:YLF laser ( 450 J/cm{sup 2}) followed by APF topic application and demineralization treatment with lactic acid. Ali samples were quantified according to their calcium and phosphorous atoms relative concentrations before and after the treatments above. X-Ray fluorescence spectrochemical analysis and scanning electron microscopy were carried out. It was observed an increase on the calcium and phosphorous atoms concentration ratio and therefore the enamel demineralization reduction as a result of the lactic acid treatment in the samples irradiated with the holmium laser followed by the APF application. In order to evaluate the feasibility of this study for clinical purposes, morphological changes caused by the holmium laser irradiation were analyzed. Such modifications were characterized by melted and re-solidified regions of the enamel with consequent changes on its permeability and solubility. Temperature changes of ten human pre-molars teeth irradiated with 350 J/cm{sup 2} and 450 J/cm{sup 2} were also monitored in the pulp chamber in real time. Temperature increases over 4,20 C did not occur. The results obtained from this study along with the results from previous

  7. Alkali-soluble fluoride deposition on enamel after professional application of topical fluoride in vitro Formação de flúor fracamente ligado ao esmalte após a aplicação tópica profissional de flúor in vitro

    Directory of Open Access Journals (Sweden)

    Mitsue Fujimaki Hayacibara

    2004-03-01

    Full Text Available Since the efficacy of topical fluoride products is related to the fluoride (F availability and its reactivity with enamel, this study was conducted. The F concentration of the following materials was verified: I- acidulated phosphate fluoride (APF gel (1.23% F, II- APF foam (1.23% F and III- Varnish (2.26% F. Forty blocks of bovine enamel were divided into 4 groups and treated according to the materials described, being one of them used as control. Loosely bound fluoride (''CaF2'' was determined on enamel after extraction with 1.0M KOH and analyzed by ion-selective electrode. Total F concentration found in gel was 12,642, in foam 12,755 and in varnish 23,183 mg F/g. All products formed statistically higher amounts of ''CaF2'' on enamel compared to the control group (p 0.05. Thus, ''CaF2'' formation was not proportional to the total F content in the products, suggesting that the pH and the vehicle used are more important.Considerando que a eficácia dos produtos para aplicação tópica profissional de flúor (géis, espumas e vernizes está relacionada com a reatividade do flúor (F com o esmalte e sendo esta dependente da disponibilidade do F em cada produto, este estudo foi conduzido. A concentração de F nos seguintes produtos foi estudada: I - Flúor Fosfato Acidulado (FFA gel (1,23% F, II - FFA espuma (1,23% F e III- Verniz fluoretado (2,26% F. Foram confeccionados 40 blocos de esmalte bovino, tratados de acordo com os grupos descritos, sendo um deles utilizado como controle. O F fracamente ligado (''CaF2'' ao esmalte foi determinado após a extração com 1.0 M KOH e analisado em eletrodo específico. A concentração de F encontrada no gel foi de 12.642, na espuma 12.755 e no verniz 23.183 mg F/g. Todos os produtos formaram uma quantidade significantemente maior de ''CaF2'' na superfície do esmalte, comparado ao grupo controle (p 0,05. Assim, a formação de ''CaF2'' na superfície do esmalte não foi proporcional ao conteúdo de F nos

  8. Phosphorus availability from phosphate rock and sewage sludge as influenced by the addition of water soluble phosphate fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, F. [Soil and Water Management and Crop Nutrition Section, International Atomic Energy Agency, Vienna (Austria)]. E-mail: F.Zapata@iaea.org; Zaharah, A.R. [Department of Land Management, Universiti Putra Malaysia, Serdang, Selangor (Malaysia)

    2002-05-15

    Phosphorus (P) inputs are required for sustainable agricultural production in most acid soils of the tropics and subtropics. Phosphate rocks (PR) and organic materials have been suggested as alternative P sources in these soils. Quantitative information on the P availability from sewage sludge (SL) is scanty. Methods to improve the effectiveness of PR such as partial acidulation and compaction with water-soluble P sources have been recommended. The objective of this greenhouse study was to evaluate the relative agronomic effectiveness (RAE) of Florida PR and sewage sludges (irradiated and non-irradiated) applied alone and in mixture with a water-soluble source (triple superphosphate, TSP) at two rates (50 and 150 mg P kg{sup -1} soil). The {sup 32}P isotope dilution technique was utilised to determine the proportion of P in the plant taken up from the P fertilizer treatments. Wheat was grown on an acid loamy sand Dystric Eutrocrepts and harvested 6 weeks after planting. Results on total P uptake and the RAE of the P fertilizer sources tested indicated that the addition of 50 mg P kg{sup -1} soil as TSP was adequate in supplying P to the 6-week-old wheat plants as compared to PR and sewage sludge. Intermediate values were obtained for the mixtures. Similar responses were observed for the high P rate. For a given P rate, phosphorus uptake from PR and SL in presence of TSP was higher than P uptake from these sources alone, indicating an enhancement effect of TSP on the effectiveness of these non-readily available sources. With respect to P uptake from PR applied alone, the relative increases in P uptake from PR due to TSP influence were 52 and 67% for the low and high P rates, respectively. The relative increases in P uptake from SL due to TSP when compared to P uptake from SL alone were 102 and 59% for the low and high P rates of application. Application of a water-soluble P fertilizer together with a non-readily available P source shows an enhancement on the P

  9. Nutrient digestibility and mass balance in laying hens fed a commercial or acidifying diet.

    Science.gov (United States)

    Wu-Haan, W; Powers, W J; Angel, C R; Hale, C E; Applegate, T J

    2007-04-01

    The objectives of the current study were to evaluate the effect of an acidifying diet (gypsum) combined with zeolite and slightly reduced crude protein (R) vs. a control diet (C) on nutrient retention in laying hens and compare 3 approaches to estimating nutrient excretion from hens: 1) mass balance calculation (feed nutrients - egg nutrient), 2) use of an indigestible marker with analyzed feed and excreta nutrient content, and 3) an environmental chamber that allowed for capturing all excreted and volatilized nutrients. Hens (n = 640) were allocated randomly to 8 environmental chambers for 3-wk periods. Excreta samples were collected at the end of each trial to estimate apparent retention of N, S, P, and Ca. No diet effects on apparent retention of N were observed (53.44%, P > 0.05). Apparent retention of S, P, and Ca decreased in hens fed R diet (18.7, - 11.4, and 22.6%, respectively) compared with hens fed the C diet (40.7, 0.3, and 28.6%, respectively; P < 0.05). Total N excretion from hens fed the C and R diet was not different (1.16 g/hen/d); however, mass of chamber N remaining in excreta following the 3-wk period was less from hens fed the C diet (1.27 kg) than from hens fed the R diet (1.43 kg). Gaseous emissions of NH(3) over the 3-wk period from hens fed the C diet (0.74 kg per chamber) were greater than emissions from hens fed the R diet (0.45 kg). The 3-wk S excretion mass (estimated using the calculation, indigestible marker, and environmental chamber methods, respectively) was greater from hens fed the R diet (1.85, 1.54, and 1.27 kg, respectively) compared with hens fed the C diet (0.24, 0.20, and 0.14 kg, respectively). The 3-wk P excretion was similar between diets (0.68 kg). Results demonstrate that feeding the acidified diet resulted in decreased N emissions, but because of the acidulant fed, greatly increased S excretion and emissions.

  10. Interaction of ionizing radiation with other physical and chemical factors in improving the safety and storage stability of foods

    International Nuclear Information System (INIS)

    Farkas, J.; Adrassy, E.; Nanati, D.; Horti, K.; Meszaros, L.; Reichart, O.

    1998-01-01

    Experiments on the preservation of a vacuum packed, ready to fry, chilled meat product (tenderloin rolls), using the combination of a 2 kGy radiation dose with a reduction in pH and/or a reduction in water activity, and on the fate of Listeria monocytogenes in this product were carried out. Irradiation caused a 1-2 decimal reduction in the aerobic viable cell counts, and a 4 decimal reduction in the Enterobacteriaceae counts. Lactic acid bacteria appeared to be more resistant, and were the dominant component of the microflora during chilled storage. Combination treatments prevented growth of Enterobacteriaceae, even at 10 deg. C refrigeration. The microbial stability of the chilled product at 2 deg. C was extended for at least 5 weeks by the triple combination of a dose of 2 kGy, pH reduction to approximately 5.6 and water activity reduction to about 0.960. The combined preserved product proved to be acceptable, both sensorially and from the point of view of the thiobarbituric acid values. The ascorbic acid (as the acidulant) and Na lactate (as the humectant) additives considerably reduced the radiolytic loss of thiamine. The Listeria inoculum survived well in the chilled, non-irradiated product, but diminished by 2 log cycles as a result of irradiation; it tended to decrease even further during post-irradiation storage. In model studies, the radiation survivors of L. monocytogenes showed significantly increased salt and pH sensitivities and an increased minimum temperature for growth in tryptic phosphate broth media, but were less sensitized when recovering in brain heat infusion broth media. A reduction in pH resulted in an increase in not only the apparent lag phase of growth of this test organism but also in the lag phase ratios between the irradiated and non-irradiated populations. The predictive mathematical equations that describe the combined effect of hydrogen ion and salt concentrations on the growth parameters at 30 deg. C were constructed for

  11. Why and How Life is Driven into Being at Ancient Submarine Alkaline Springs

    Science.gov (United States)

    Russell, Michael

    2016-07-01

    The disequilibria between volcanic CO2 plus NO dissolved in acidulous oceans, as against the H2 plus CH4 exhaling through hot alkaline springs on the ocean floors of young wet rocky worlds, cannot be relaxed, much less put to useful biological work, through mere geochemical reactions. Instead their dissipation must be coupled to the production of essential thermodynamically 'up-hill' products. A metabolic pathway, involving disequilibria converting nano-engines, is the only way to achieve such tasks as fixing the otherwise intractable CO2. Indeed, hydrogenating CO2 is life's contribution to entropy generation in the Universe. Long-lived alkaline springs could have supplied the low entropy nourishment in the form of H2 as electrons and CH4 as a carbon source, while the CO2, nitrate, photolytic Fe3+ and Mn4+ in the earliest ocean could have accepted the waste electrons, i.e., the 'breathing' [1]. But what of life's first boundaries? These could be generated spontaneously at the vent, where natural precipitates of iron oxyhydroxides and sulfides would have acted as precipitate membranes, separating the reduced alkaline hydrothermal fluid from the acidulous carbonic ocean, thus imposing steep redox and protonic (ambient pmf) gradients with the potential to drive otherwise endergonic reactions such as the reduction of CO2 to formate or CO, and the oxidation of CH4 to methyl and formyl entities. In turn, the CO and the methyl group reacted to form acetate. Acetate was then hydrogenated and carbonated to pyruvate. However, these endergonic reactions could not progress by catalysis or mass action chemistry as often assumed. They would have required natural processors acting as nanoengines to couple the endergonic driven processes to appropriate exergonic driving reactions. This is what the nano-engines do in life. These mechanochemical 'engines' are protein complexes that are each precisely tuned to the specific driving and driven disequilibria pairs being converted. They

  12. EVALUACIÓN DEL COLOR DURANTE EL ALMACENAMIENTO DE LA PULPA DE BANANO VERDE IMPREGNADA AL VACÍO CON SOLUCIONES ANTIPARDEANTES AVALIAÇÂO DA COR NO ARMAZENAMENTO DA POLPA DE BANANA VERDE IMPREGNADA A VACUUM USANDO SOLUÇÔES PARA EVITAR O PARDEAMENTO COLOR EVALUATION DURING STORAGE OF GREEN BANANAS PULP IMPREGNATED WITH ANTIBROWNNING SOLUTIONS UNDER VACCUM

    Directory of Open Access Journals (Sweden)

    MISAEL CORTÉS R

    2011-12-01

    /100 g PUB, acidulant (50, 150, 250 mg/100 g PUB using the vacuum impregnation (VI technique. The parameters of color were evaluated using CIEL *a *b *, in terms of lighting (L* and chromaticity a* and b*. The ANOVA test showed significant statistical differences (P <0,05 in all the parameters related to the times of storage, temperature, packing conditions, areas of the pulp, and concentration of the solutions. In all of the cases the core part of the pulp was darker than the external part. The storage of the Banana pulp at 4°C, packed under vacuum, allowed to get acceptable commercial characteristics of color during the 15 days of storage. The treatment with metabisulfites at 500 mg/kg PUB and the combination of Ascorbic (90 mg/100 g PUB and Citric (50 mg/100 g PUB acids, gave the best characteristics of color in time at the different temperatures and concentrations

  13. Aprovechamiento de las oleinas residuales procedentes del proceso de refinado de los aceites vegetales comestibles, para la fabricación de biodiesel

    Directory of Open Access Journals (Sweden)

    Álvarez Mateos, P.

    2003-06-01

    Full Text Available A procedure to obtain Biodiesel from “Oleinas” is studied. Biodiesel is a suitable product to replace diesel oil currently used to power the Diesel engines. It consists of a mixture of methyl esters of the fatty acids presents as triglycerides in vegetables oils (olive, sunflower, soya, rape oils. As a result of the refining of these oils for their use as food, a waste product is formed, the “oleinas” (acidulated soapstock. The oleinas consist of a mixture of triglycerides and free fatty acids, the latter amounting to 50% or more of the mixture and are subject to a fluctuating market, therefore it exist at times a problem for their disposal. In our research work we have tried to obtain biodiesel from oleinas. The process resulting from our experimental work is as follows: 1. Sterification of the free fatty acids with methanol, by acid catalysis, centrifuging the reaction product and removal of the acid-methanol phase. Drying of the latter. At this stage we have a product containing about 70% of methyl esters. 2. Transesterification of the triglycerides present in the sterified product with methanol by alkaline catalysis, washing the reaction product with a water methanol solution. Centrifuging and removal of the water-methanol phase. At this stage a biodiesel product is obtained containing about 90% of methyl esters. 3. Fractional vacuum distillation of the 90% biodiesel gives a final product with a methyl esters content higher than 98%.Se estudia un procedimiento para la obtención de Biodiesel a partir de las “Oleínas”. Biodiesel es un producto capaz de sustituir al combustible Diesel ordinario que se obtiene del petróleo y que consiste en una mezcla de ésteres metílicos de ácidos grasos. Las oleínas son unos residuos que resultan del proceso de refinado de aceites vegetales para su uso alimentario y se componen de una mezcla de triglicéridos y ácidos grasos libres, con un contenido de estos últimos

  14. Comparison of greenhouse and 32P isotopic laboratory methods for evaluating the agronomic effectiveness of natural and modified rock phosphates in some acid soils of Ghana

    International Nuclear Information System (INIS)

    Owusu-Bennoah, E.; Zapata, F.; Fardeau, J.C.

    2002-01-01

    factor and the fixation index of the soils were variable. Application of water-soluble P as TSP increased both the C P and E 1 values of all the soils above the critical levels. Togo PR was least effective among the fertilizers tested for all soil soils, except in Boi soil. Acidulation of Togo PR (Togo PAPR-50%) was an effective means to increase its agronomic effectiveness. Direct application of natural Togo PR would be only feasible in the Boi soil series as reflected by its high Pdff% value in soil solution. Incubation with the P fertilizers caused an increase in the soil pH and a decline in the effectiveness of the applied P fertilizers, irrespective of the soil and the fertilizer utilized. Based upon the results of the greenhouse pot experiment, the relative crop response index (RCRI) in terms of increasing dry matter yield and P uptake followed the order of TSP > PAPR = Mali PR >Togo PR = Control. Both the laboratory index, Pdff% in soil solution derived from the isotopic method and the RCRI values obtained from the pot experiment produced similar results in ranking the P fertilizers tested according to their agronomic effectiveness. The isotopic kinetic method may be considered as an alternative to both greenhouse and field methods in the evaluation of agronomic effectiveness of P fertilizers in tropical acid soils when it offers comparative advantages in assessing the soil P status and its changes. But trained staff and adequate laboratory facilities are needed to perform this technique. Also the method can be used as a reference for comparison purposes as in this case. Further research is needed to assess the overall agronomic effectiveness (immediate and residual effects) of PR sources in predominant cropping systems of this region of Ghana. (author)

  15. Evaluating the effectiveness of phosphate fertilizers in some Venezuelan soils

    International Nuclear Information System (INIS)

    Casanova, E.; Salas, A.M.; Toro, M.

    2002-01-01

    the greenhouse experiment, the crop response was related to the P fixing properties of the soil, the initial availability and the solubility of the P source used. The P in plant derived from the fertilizer and the Utilization Coefficient decreased significantly as the P fixing capacity of the soils increases indicating a lower availability of P for the the index plant (Agrostis sp.). The P in plant derived from the P fertilizers calculated by using the specific activity of each treatment and the one of the check plot showed that triple superphosphate had the highest values with acidulated Riecito rock phosphate (40%) having intermediate values, and Riecito rock phosphate having the lowest value. The use of 32 P techniques as a powerful method to study soil P dynamics and P uptake from different P sources and the effectiveness of phosphate rocks (natural and modified) produced in Venezuela with respect to the water-soluble P source (imported), are some of the practical implications of this study. (author)

  16. Impregnation Solution Influence on the Pulp Color of Plantains (Musa paradisiaca / Influencia de Soluciones de Impregnación en el Color de la Pulpa de Plátano (Musa paradisiaca

    Directory of Open Access Journals (Sweden)

    Cortés Rodríguez Misael

    2013-08-01

    Full Text Available Abstract. The influence of antioxidant (sodium metabisulphiteNa2S2O5 and ascorbic acid C6H8O6 and acidulant (citric acidC6H8O7 solutions on the color of vacuum impregnated greenplantain pulp (GPP, stored (0, 3, 6, 9, 12 and 15 days; 4,20 and 30 ºC and vacuum packed (VP or packed withoutvacuuming (WV, was evaluated. The color was determined bythe CIE-L*a*b* coordinates, where the lightness (L* was themost important parameter for browning control (L*critical=70.Component concentrations in the impregnation solutions wereestablished to achieve levels of sodium benzoate (1,000 mg,EDTA (75 mg and sulphites (500, 1,000 y 1,500 mg, per kgof fresh GPP; and ascorbic acid (60, 90 and 120 mg and citricacid (100, 150 and 250 mg, per 100 g of fresh GPP. Significant differences were seen (PL*critical for 15 days were: sodium metabisulphite (500 mg/kg of GPP, WV and 0 mg/kg of GPP, VP, ascorbic acid (90 mg/100 g of GPP, WV and 60 mg/100 g of GPP, VP, citric acid (100 mg/100 g of GPP, VP and for the mixture of ascorbic acid (90 mg: citric acid (100 mg/100 g of GPP, VP. / Resumen. Se evaluó la influencia de soluciones antioxidantes (metabisulfito de sodio Na2S2O5 y ácido ascórbico C6H8O6 y acidulantes (ácido cítrico C6H8O7 sobre el color de la pulpa de plátano verde (PPV impregnadas al vacío, almacenadas (0, 3,6, 9, 12 y 15 días; 4, 20 y 30 ºC y empacadas con vacío (CV y sin vacío (SV. El color se determinó mediante las coordenadas CIE-L*a*b*, siendo la luminosidad (L* el parámetro de mayor importancia para el control del pardeamiento (L*crítico=70. Las concentraciones de los componentes en las soluciones de impregnación se fijaron para obtener en la PPV impregnado niveles de benzoato de sodio (1000 mg, EDTA (75 mg y sulfitos (500, 1.000 y 1.500 mg, por kg de PPV fresco; y de ácido ascórbico (60, 90 y 120 mg y ácido cítrico (100, 150 y 250 mg, por 100 g de PPV fresco. Se presentaron diferencias significativas (PL*crítico fueron: metabisulfito

  17. Optimización del proceso de esterificación química del destilado de desodorización del aceite de soja previamente saponificado y acidulado

    Directory of Open Access Journals (Sweden)

    Barrera-Arellano, Daniel

    2002-06-01

    Full Text Available In this research work, it was optimized the reaction conditions for the chemistry esterification of unsaponifiable matter in soybean oil deodorizer distillate. The process involves (i alkaline hydrolysis of saponifiable matter; (ii acidulation of soaps and (iii acid catalyzed esterification of resulting total fatty acid. To determine the best process conditions to get the higher conversion rates of total fatty acids to ethylic esters, preserving the tocopherols, it was used, to analyze the results, the response surface methodology in a 2nd order factorial planning. In the step (i saponification of soybean oil deodorizer distillate saponifiable matter using NaOH:total fatty acids molar ratio = 2:1, temperature = 80º C and reaction time of 40 min. In the step (ii the resulting soaps were rapidly and stoichiometrically converted in free fatty acids with sulfuric acid (23 %, using an acid molar excess of 50 %, at 80º C, for 40 min and under atmospheric pressure. In the step (iii the optima conditions for the esterification reaction of soybean oil deodorizer distillate were: ethanol:total fatty acids molar ratio from 6.4 to 11.2:1, SO2H4 concentration from 0.9 to 1.5 % and reaction time from 1.3 to 2.6 h, with ethyl esters conversion rates up to 98 %. The mathematical model obtained is predictive and statistically significant (pEn esta investigación fueron optimizadas las condiciones de reacción de esterificación de la materia saponificable del destilado de desodorización del aceite de soja. El proceso engloba (i hidrólisis alcalina da materia saponificable; (ii acidulación de los jabones y (iii esterificación catalizada por ácido de los ácidos grasos totales resultantes. Las condiciones óptimas del proceso, para obtener el mayor rendimiento en ésteres etílicos y perdidas mínimas de tocoferoles, fueron determinadas usando la metodología de superficie de respuesta de un diseño factorial completo de 2a orden. Etapa (i saponificaci

  18. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser; Estudo in vitro da resistencia a desmineralizacao e da retencao de fluor em esmalte dental irradiado com laser de Er, Cr: YSGG

    Energy Technology Data Exchange (ETDEWEB)

    Ana, Patricia Aparecida da. E-mail: patriciadaana@yahoo.com.br

    2007-07-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser ({lambda} of 2.79 {mu}m) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm{sup 2}, 5,6 J/cm{sup 2} e 8,5 J/cm{sup 2} were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F{sup -}) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm{sup 2} and 8.5 J/cm{sup 2} promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm{sup 2} was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste

  19. In vitro comparison of the cariostatic effect between topical application of fluoride gels and fluoride toothpaste Comparação in vitro do efeito cariostático entre a aplicação tópica de flúor e dentifrício fluoretado

    Directory of Open Access Journals (Sweden)

    Alberto Carlos Botazzo Delbem

    2004-06-01

    Full Text Available The aim of this study was to compare the effect of topical fluoride products [acidulated phosphate fluoride (APF or neutral gel (NF x fluoride toothpaste (MFP], in respect to fluoride uptake and anticariogenic action. One hundred and twenty five blocks of human teeth, sorted in 5 groups according to the treatment, were submitted to pH cycling for ten days. The parameters analyzed were: fluoride uptake before and after pH cycling and surface (SMH and cross-sectional (CSMH microhardness of the enamel blocks. The results of fluoride concentration in enamel after the pH cycling showed an enhancement of fluoride uptake for all groups compared to sound control. No significant differences between APF and MFP were observed for surface microhardness, percentage change of surface microhardness and mineral loss. The volume percent mineral obtained from cross-sectional microhardness demonstrated that APF has a different lesion progression rate regarding subsurface carious lesion. The results suggest that professionally applied fluoride gel or frequent fluoride application in low concentration is a positive preventive measure for the control of dental caries.O objetivo do presente estudo foi comparar in vitro o efeito da aplicação tópica de flúor na forma de gel acidulado (FFA ou neutro (FFN com um dentifrício fluoretado (MFP, na incorporação e ação anticariogênica do flúor. Foram utilizados 125 blocos obtidos de esmalte humano, divididos em 5 grupos de acordo com o tratamento e submetidos à ciclagem de pH durante dez dias. Analisou-se o flúor incorporado antes e depois da ciclagem de pH; a microdureza superficial (SMH e a microdureza interna do esmalte (CSMH. Os resultados da concentração de flúor no esmalte após a ciclagem indicou uma maior quantidade de flúor incorporado para todos os grupos comparados ao grupo controle sadio. A microdureza superficial entre APF e MFP, assim como a porcentagem de alteração da microdureza superficial e

  20. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser

    International Nuclear Information System (INIS)

    Ana, Patricia Aparecida da.

    2007-01-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser (λ of 2.79 μm) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm 2 , 5,6 J/cm 2 e 8,5 J/cm 2 were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F - ) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm 2 and 8.5 J/cm 2 promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm 2 was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste + laser at 2.8 J/cm 2 + APF application

  1. Avaliação qualitativa do efeito de agentes de limpeza na camada de lama dentinária: estudo ultra-estrutural em microscopia eletrônica de varredura Smear layer removal: a qualitative scanning electron microscopy study

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Junho de ARAÚJO

    1998-04-01

    surface was then removed with a water-cooled high speed carbide bur # 56 in order to obtain the smear layer. Different solutions were applied on the dentin surface for 30 seconds, which was then rinsed and dried. The specimens were mounted on metallic holder stubs, prepared, and examined under the scanning electron microscope (DSM 95-Zeiss. Removal of the smear layer by the tested solutions was qualitatively observed, and the solutions, rated according to their performance in increasing order of extent of removal, as follows: 1. air/water spray; 2. 2% NaF; 3. sodium hypochloride/anodic detergent; 4. 3% H2O2; 5. sandblasting with 50 mm aluminum oxide; 6. 1.27% acidulated fluoride; 7. 25% polyacrylic acid; 8. 10% phosphoric acid. The best solutions for the removal of the smear layer were the acid ones.

  2. Delayed tooth replantation after root surface treatment with sodium hypochlorite and sodium fluoride: histomorphometric analysis in rats Reimplante dentário tardio após o tratamento da superfície radicular com hipoclorito de sódio e fluoreto de sódio: análise histomorfométrica em ratos

    Directory of Open Access Journals (Sweden)

    André Dotto Sottovia

    2006-04-01

    Full Text Available In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8, had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin- embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (pEm reimplante dentário tardio, o ligamento periodontal desvitalizado tem sido removido empregando-se o hipoclorito de sódio, buscando o controle da reabsorção radicular. Relatos de efeito irritante no tecido conjuntivo alveolar após o seu uso, têm sido descritos. Isso justificou a realização deste trabalho buscando minimizar esse inconveniente. Para isso 24 ratos, divididos em 3 grupos de 8 animais, tiveram o incisivo superior direito extra

  3. Characterization of the physical and chemical structures of biochar under simulated aging condition%生物炭老化后理化性质及微观结构的表征

    Institute of Scientific and Technical Information of China (English)

    林庆毅; 姜存仓; 张梦阳

    2017-01-01

    在长期降水淋洗或温室效应产生酸雨等环境影响下,施入土壤中的生物质炭会随时间的推移而逐渐发生老化作用,而其老化后理化性质及结构等如何改变是广受关注的新问题.本文通过水洗和酸化两种方法对花生壳生物炭进行模拟老化试验,并利用元素分析仪、扫描电镜(SEM)、X射线衍射光谱(XRD)和傅立叶红外光谱分析仪(FTIR)研究生物炭老化前后的理化性质及结构差异.结果表明:(1)生物炭经老化处理后pH值均下降,且酸化生物炭(acidulated biochar,AB)比水洗生物炭(washing biochar,WB)的下降程度大;另外,WB的O/C和(O+N)/C分别下降了8.89%和10.42%,而AB的O/C和(O+N)/C却升高了11.11%和14.58%,表明生物炭老化后其亲水性和极性发生改变;且WB和AB的碱性元素总量分别比原生物炭(primary biochar,PB)下降了26.53%和88.78%,说明生物炭老化后有较多的碱性元素被释放.(2)与原生物炭相比,生物炭水洗老化后表面较平整且微孔结构保持完好,而酸化老化后表面较粗糙、微孔结构严重破坏.(3)生物炭老化后,其表面Al2SiO5和SiO2晶体的含量均明显下降;与PB相比,WB新增加了1166 cm-1和1082 cm-1特征峰2个;而AB新出现了1705 cm-1、1622 cm-1和1546 cm-1特征峰3个,并减少了466 cm-1这个振动峰,且其他特征峰的吸光度较原生物炭整体降低,说明生物炭在老化过程中其含氧官能团增加,而其它官能团数量和其表面的晶体含量都有所减少.因此,生物炭在一定环境作用下,其老化过程中一些元素释放而含量减少,且导致物质结构的破坏.%Biochars added into the soil are agedas time goes on under the influence of the environment such as long-term precipitation leaching or acid rain caused by greenhouse effect.The change of physic-chemical properties and structure are the new problems which have attracted wide attention.The aim of this study was to investigate the aging