Thermogravimetric Analysis of Dentin

1972 ◽  
Vol 51 (2) ◽  
pp. 509-514 ◽  
Author(s):  
J.J. Lim ◽  
A.R. Liboff
Keyword(s):  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Tricalcium Phosphate ◽  
Activation Energies ◽  
Zero Order ◽  
The Third

Four peaks were observed in the differential primary weight loss with temperatures up to 1,000 C. The first and second peaks correspond to the loss of water and the volatilization of protein. The third peak results from the carbonate. The fourth peak, which occurs at 700 to 800 C, probably is related to the transformation of hydroxyapatite to β-tricalcium phosphate. A zero order of reaction was assumed, and the activation energies in vacuum were determined to be 10.2 and 12.5 kcal/mol for loss of water and protein, respectively.

Activation Energies of Liquid Crystalline Thermoset Containing Rigid-Rod Epoxy

2011 ◽  
Vol 378-379 ◽  
pp. 628-631 ◽  
Author(s):  
Seung Hwan Byun ◽  
Seung Hyun Cho
Keyword(s):  
Differential Scanning Calorimetry ◽  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Liquid Crystalline ◽  
Activation Energies ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Rigid Rod ◽  
Liquid Crystalline Thermoset ◽  
Weight Loss Process

4,4’-Diglycidyloxy-α-methylstilbene (DOMS) was synthesized and characterized with cross-polarized optical microscopy (POM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Activation energies for decomposition (Ed) by TGA were determined as a function of conversion by weight loss process.

scholarly journals Thermogravimetric Analysis of Modified Montmorillonite Clay for Mycotoxin Decontamination in Cereal Grains

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Bunmi K. Olopade ◽  
Obinna C. Nwinyi ◽  
Joseph A. Adekoya ◽  
Isiaka A. Lawal ◽  
Olushola A. Abiodun ◽  
...  
Keyword(s):  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Nonparametric Test ◽  
Montmorillonite Clay ◽  
Cymbopogon Citratus ◽  
The Third ◽  
Significant Difference ◽  
Degradation Step ◽  
The Stability ◽  
Lemongrass Essential Oil

Thermogravimetric analysis (TGA) was carried out to study the stability of nanoformulations used for the decontamination of mycotoxins. The TGA patterns of the nanoformulations from montmorillonite clay and Cymbopogon citratus (lemongrass) extracts were assessed with temperature ranging from ambient (20°C) to 1000°C. The various nanoformulations studied included unmodified montmorillonite clay (Mont), montmorillonite washed with sodium chloride (Mont-Na), montmorillonite mixed with lemongrass essential oil (Mont-LGEO), and montmorillonite mixed with an equal quantity of lemongrass powder (Mont-LGP). There was no significant difference in the median of the various nanoformulations within 4 weeks at p < 0.05 using the Kruskal–Wallis nonparametric test. For the TGA, the first degradation for montmorillonite clay and the nanoformulations occurred at a temperature between 80 and 101°C and was attributed to the loss of lattice water outside the coordination sphere with a range of 3.5–6.5% weight loss. The second degradation occurred within the temperature of 338 to 344°C, and the third, at a temperature between 640 and 668°C for Mont and the formulations of Mont-Na, Mont-LGEO, and Mont-LGP. There were strong similarities in the degradation patterns of Mont and Mont-Na with the minimum difference being the relatively higher weight loss of the sodium-exchanged cation for Mont-Na at the third degradation step. Hence, the order of stability from the most resistant to the least resistant to degradation is as follows: Mont-LGEO ≥ Mont-Na ≥ Mont ≥ Mont-LGP.

scholarly journals Assessment of Protein Intake in the First Three Months after Sleeve Gastrectomy in Patients with Severe Obesity

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 771
Author(s):  
Lucrezia Bertoni ◽  
Romina Valentini ◽  
Alessandra Zattarin ◽  
Anna Belligoli ◽  
Silvia Bettini ◽  
...  
Keyword(s):  
Weight Loss ◽  
Sleeve Gastrectomy ◽  
Protein Intake ◽  
Severe Obesity ◽  
Protein Supplementation ◽  
Fat Free Mass ◽  
The Third ◽  
Total Protein Intake ◽  
Dietary Record ◽  
Protein Rich

An adequate protein intake prevents the loss of fat-free mass during weight loss. Laparoscopic sleeve gastrectomy (SG) jeopardizes protein intake due to post-operative dietary restriction and intolerance to protein-rich foods. The purpose of this study is to evaluate protein intake in the first three months after SG. We evaluated, 1 month and 3 months after surgery, 47 consecutive patients treated with SG. Protein intake, both from foods and from protein supplementation, was assessed through a weekly dietary record. Patients consumed 30.0 ± 10.2 g of protein/day on average from foods in the first month, with a significant increase to 34.9 ± 4.8 g of protein/day in the third month (p = 0.003). The use of protein supplementation significantly increased total protein intake to 42.3 ± 15.9 g protein/day (p < 0.001) in the first month and to 39.6 ± 14.2 g of protein/day (p = 0.002) in the third one. Compliance with supplement consumption was 63.8% in the first month and only 21.3% in the third month. In conclusion, both one and three months after SG, protein intake from foods was not sufficient. The use of modular supplements seems to have a significant impact on protein intake, but nevertheless it remains lower than recommended.

Study of Thermal Behaviour of EPDM/SBR Blends and Carbon Nanocoatings Deposited by Sputtering

2021 ◽  
Vol 875 ◽  
pp. 116-120
Author(s):  
Muhammad Alamgir ◽  
Faizan Ali Ghauri ◽  
Waheed Qamar Khan ◽  
Sajawal Rasheed ◽  
Muhammad Sarfraz Nawaz ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Thermal Behavior ◽  
Thermal Behaviour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.

scholarly journals Microbiota indigenous milk, mesophilic lipolytic and proteolytic colonial cheese matured, produced at different times of the year

2017 ◽  
Vol 18 (4) ◽  
pp. 549-559
Author(s):  
Elisângela Borsoi Pereira ◽  
Magali Soares dos Santos Pozza ◽  
Paula Martins Olivo ◽  
Osmar Dalla Santa ◽  
Suzana da Cruz Pires ◽  
...  
Keyword(s):  
Weight Loss ◽  
Lactic Acid ◽  
Experimental Design ◽  
Relative Humidity ◽  
Water Activity ◽  
Cultural Importance ◽  
The Third ◽  
Randomized Experimental Design ◽  
Double Factorial ◽  
Production Period

SUMMARY Cheese is the oldest form of preserving milk nutrients having nutritional, economic and cultural importance. The objective of this study was to identify the best time of the year for production, and period, in months, for maturation of traditional colonial cheese, through analysis of water activity, weight loss and counts of lactic acid, mesophilic microorganisms—proteolytic and lipolytic. Records of temperature and relative humidity (RH) were maintained. A completely randomized experimental design was used in a double factorial scheme, considering production periods and maturation times. For all production periods evaluated, there was a significant reduction in the periods for water activity values. The counts of lactic acid bacteria ranged from 104 to 109 CFU/g. There was also stability in the number of colonies for lipolytic mesophilic microorganisms, until the third month of maturation. Low counts of proteolytic mesophiles were observed for the samples produced in May and June (5.70 and 5.53 log), respectively. The production period for the months of May and June corresponding to RH of 80% and average temperatures of 15°C were the most effective for production. Due to the presence of Listeria, it is recommended to respect the minimum time of 60 days of maturation for commercialization.

Spectroscopic Study of Photosensitized Oxidation of Polyisoprene

1977 ◽  
Vol 50 (4) ◽  
pp. 704-713 ◽  
Author(s):  
M. A. Golub ◽  
M. L. Rosenberg ◽  
R. V. Gemmer
Keyword(s):  
Zero Order ◽  
Double Bonds ◽  
Photosensitized Oxidation ◽  
The Third ◽  
Type Process ◽  
Zero Order Kinetics ◽  
Hydroperoxide Formation ◽  
Cis And Trans ◽  
In Cis ◽  
Suitable Measure

Abstract The microstructural changes which occur in cis- and trans-1,4-polyisoprenes and in squalene during photosensitized oxidation were investigated with the aid of infrared and proton and carbon-13 NMR spectroscopy. The singlet oxygenation of these isoprenic compounds resulted in allylic hydroperoxides with shifted double bonds, according to the expected “ene”-type process. In contrast to trans-1,4-polyisoprene and squalene, which displayed the three possible double bond shifts, cis-1,4-polyisoprene showed essentially two of the shifts (to di- and trisubstituted double bonds) and very little of the third (to exomethylene groups). A suitable measure of the extent of hydroperoxidation was afforded by the absorbance ratio, A3400/A1440≡A′. Similar correlations of A′ with oxygen uptake were obtained for the three isoprenic compounds, using chlorophyll or methylene blue as sensitizer. The use of rose bengal gave erratic results indicative of some autoxidation accompanying the hydroperoxide formation. The singlet oxygenation followed zero-order kinetics, the relative rates for cis- and trans-1,4-polyisoprenes being approximately 1.0:1.5.

scholarly journals Wilkie’s Syndrome Following Weight Loss in a Trauma Patient

2020 ◽  
pp. 1-3
Author(s):  
George Oosthuizen ◽  
George Oosthuizen
Keyword(s):  
Weight Loss ◽  
Trauma Patient ◽  
Superior Mesenteric Artery ◽  
Mesenteric Artery ◽  
Treatment Options ◽  
Rare Condition ◽  
Feeding Tube ◽  
Significant Weight Loss ◽  
The Third ◽  
Wilkie’S Syndrome

Wilkie’s syndrome, or superior mesenteric artery syndrome, is a rare condition of duodenal obstruction caused by compression of the superior mesenteric artery on the third part of the duodenum. The diagnosis should be considered in a patient who has experienced significant weight loss and now presents with persistent vomiting, especially if the vomiting occurs with the patient in the supine position and is alleviated by the lateral or prone position. The diagnosis can be confirmed by imaging studies demonstrating compression of the third part of the duodenum, and the main aim of treatment should be to pass a feeding tube beyond the point of obstruction to allow enteral feeding. The condition improves spontaneously with weight gain. Further treatment options include parenteral feeding and operative bypass in select cases. Here we present a case of Wilkie’s syndrome in a trauma patient with significant weight loss, together with a review of the literature on this interesting topic.

scholarly journals PRODUCTION OF BIOETHANOL FROM RICE AND MILLET HUSKS

2021 ◽  
pp. 1-12
Author(s):  
Gwandu AZ ◽  
Farouq AA ◽  
Baki AS ◽  
Peni DN
Keyword(s):  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Rice Husk ◽  
Sugar Content ◽  
Proximate Analysis ◽  
Reducing Sugar ◽  
High Yield ◽  
Bioethanol Production ◽  
Alternative Source ◽  
Fermentation Period

This study was based on the production of bioethanol as an alternative source of fuel using rice and millet husks. Proximate, elemental and thermogravimetric analysis (TGA) were conducted of the biomass. The proximate analysis revealed that millet husk had the highest moisture content of 26.67±0.58% when compared with rice husk 8.17±0.29%. The TGA of rice husk had a high endset temperature of 355.510C and a weight loss of -48.23%, millet husk had low endset temperature of 349.210C and a weight loss of -44.25%. When thirty grams (30g) of the substrates was used, rice husk revealed the highest reducing sugar content of 2.59±1.24mol/dm3 when compared to millet husk that had 1.63±0.68 mol/dm3. Rice husk indicated low yield after 7 days of fermentation period but showed a significantly high yield in the volume of ethanol produced 68.67±17.69g/l and millet husk had a yield of 79.80±0.93g/l. This indicated that both rice and millet husks were potent for bioethanol production with millet husk having the highest yield.

Coatings Formed on Steel by Cathodic Protection And Their Evaluation by Polarization Measurements

CORROSION ◽  
1963 ◽  
Vol 19 (2) ◽  
pp. 59t-68t ◽  
Author(s):  
W. J. SCHWERDTFEGER ◽  
RAUL J. MANUELE
Keyword(s):  
Weight Loss ◽  
Cathodic Protection ◽  
Protective Coatings ◽  
Salt Water ◽  
The Other ◽  
Carbon Anode ◽  
Zinc Anode ◽  
The Third ◽  
Corrosion Rates ◽  
City Water

Abstract Three steel specimens were continuously exposed in the laboratory for almost 5 years in city water to which was added 3 percent by weight of sodium chloride. Two of these specimens were under continuous cathodic protection, one by current from a zinc anode, and the other by current from a rectifier through a carbon anode. The third specimen was left to corrode freely. As a result of the cathodic protection, carbonates and silicates formed protective coatings which eventually reduced the current density required for protection from about 5 to 0.02 ma/sq ft. A coated specimen, after being without protective current for 32 days (including 12 days out of the salt water), required only 0.3 ma/sq ft for initial protection. The instantaneous corrosion rates on the coated specimens (scratched and unscratched) while without protective currents were measured by changes-in-slope (breaks) in polarization curves. The currents at which breaks occurred in the cathodic curves were found to be related to ΔV/ΔI values from the curves, which values in turn bore a relation to the corrosion rates as measured by weight loss.

Co-gasification of Hydrochar and Petroleum Coke Blended With Different Ratios

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Nan Zhang ◽  
Xiaojun Ning ◽  
Guangwei Wang ◽  
Jianliang Zhang ◽  
Jian Guo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Petroleum Coke ◽  
Activation Energies ◽  
Research Results ◽  
Char Gasification ◽  
Gasification Process ◽  
Two Stages

Abstract The co-gasification characteristics of petroleum coke (PC), hydrochar (PS), and their blends with different ratios were studied by using thermogravimetric analysis. The Coats–Redfern model was employed to calculate the gasification activation energies of different samples. The results manifested that the gasification process of PS and blends could be classified into two stages: pyrolysis and char gasification, but for PC, there was only one primary char gasification stage. The activation energy of the pyrolysis stage was significantly smaller than the char gasification stage. In the latter stage, with the increase in the ratio of PS from 20% to 80%, the activation energy was reduced from 114.1 kJ/mol to 82.8 kJ/mol, which indicated that the PS had a significant promoting influence on the PC gasification. The research results can provide a theoretical guiding significance for the efficient use of PS and PC.

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