scholarly journals Temperature Effect on the Physical Properties of Enamel Paint Layer on Cement Plaster

2021 ◽  
Vol 12 (2) ◽  
pp. 103-108
Author(s):  
Samiul Kaiser ◽  
Mohammad Salim Kaiser

The heating effect on the stability and visual colour of enamel paint on cement plaster is evaluated through light intensity ratio of three primary colours (RGB). The painted cement plaster is isochronally heated in an electric resistance furnace at different temperatures for one hour. The investigation of optical images reveals that the original colour of the paint layer on the plaster samples remains more or less unchanged up to heating at 100°C. However, thermal degradation of the samples becomes evident in colour when they are heated beyond 200°C and at 350°C the colour becomes already burned. The microstructural images of the samples at room temperature show fine and uniform grains. But at higher heating condition the microstructure of the colour sample is characterized by coarsening grain. The colour of the heated samples are then studied through tristimulus colour ‘L*’, ‘a*’ ‘b*’ and ‘E*’ values which were analyzed and evaluated in MATLAB software. The results show that after 200°C the hunter ‘L*’ value starts to decrease greatly up to 250°C. The hunter ‘a*’ value shows an increasing trend up to 100°C and then begins to decrease until 200°C. After 200°C the same increasing character is showed till 300°C. The change of hunter ‘b*’ value remains insignificant up to 100°C and shows decreasing trend between 100°C-250°C range and an increase after 250°C up to 300°C. It is graphically shown that the proportion of all three colours decreases with the increasing temparature. The overall change of colour ‘E*’ occurs with increasing heating temperature due to moisture releasing, chemical changes and thermal degradation simulteneously. The thickness of enamel paint layer comply the above degradation by showing the nature of decresing trend. Journal of Engineering Science 12(2), 2021, 103-108

2021 ◽  
Vol 869 (1) ◽  
pp. 012007
Author(s):  
A Yuslan ◽  
N Nasir ◽  
H Suhaimi ◽  
A Arshad ◽  
N W Rasdi

Abstract Copepods with a wide range of sizes, species, and nutritional compositions are preferred as live food for rearing of Betta splendens larvae. This research focuses on evaluating the efficiency of copepod enrichment diets in improving the coloration and feeding rate of B. splendens. Copepod were enriched with Chlorella sp. (T1), capsicum (T2), mixed vegetable (carrot + spinach), (T3), yeast (T4) and rice bran (T5) in 24 hours prior the feeding tests. As a result, proximate analysis of enriched-copepods showed that T1 (70.88±0.41) has highest protein content and T5 (22.01±0.59) has the highest lipid content. The specific growth rate and survival rate of B. splendens was highest in the treatment T1 (2.56±0.07%; 91.11±1.92%) and followed closely by T3 (2.49±0.51%; 85.55±8.39%). Feeding rate, T3 (70.08±3.88%) presented highest rate compared to other treatments. The different enrichment diets used were significantly impact the coloration test on body of L* value (P=0.001, P<0.05), T3 (66.11±3.60) appeared darker in color in contrast to others. As for a* value, the coloration was not impacted with the use of different enrichment on copepods (P=0.158, P>0.05) was detected for T1 (2.84±0.73) that gave a redder shade than other treatments did. T3 (2.40±0.30) exerted a more yellowish shade than the rest for b* value with a significant difference (P=0.015, P<0.05). The current study demonstrates that, rice bran, capsicum and mixed vegetable enrichment (carrot and spinach) have the potential to be an effective means of increasing B. splendens coloring and feeding rate. This potential diet can be further used as a substitution to artificial foods in producing sustainable culture of ornamental fish in the aquaculture industry.


2021 ◽  
pp. 232020682110443
Author(s):  
Murat Eskitaşçıoğlu ◽  
Mehmet Şerif Akdeniz ◽  
Beyza Ünalan Değirmenci

Aims: To evaluate the color changes that occur after accelerated aging in feldspathic ceramic crowns cemented with three different dual-cured resin cements. Materials and Methods: For each of the A2-colored RelyX U200, G-CEM LinkForce, and Panavia V5 cement groups, 45 dies from A2-colored zirconia blocks and 45 crowns from CEREC blocks were prepared. Color measurements after 24 h of cementation (T1) and after cycles of aging of 1750 (T2), 3500 (T3), and 7000 (T4) in the thermal cycle device were made using SpectroShade Micro device. The coordinates of the color were used L*, a*, and b* as base and the color change was calculated with ∆ E00 in determining the color. One-way analysis of variance test was used to compare the times in terms of ∆ L*, ∆ a*, and ∆ b* values. Results: It was found that ∆ L* value decreased significantly in period of the T2, T3, and T4 times compared to T1 in all groups ( P < .05), whereas the change between period of T2, T3, and T4 times was not significant ( P > .05). The ∆ a* value increased significantly in the period of T3 and T4 times compared to T1 in the only G-CEM LinkForce group, whereas the ∆ b* value increased significantly in the period of T4 time compared to T1 in the only Panavia V5 group. The changes in ∆ E00 values, which were observed in all period of times, were found to be between 0.43 and 1.04, 0.43 and 1.43, and 0.40 and 0.97 in RelyX U200, G-CEM LinkForce, and Panavia V5 groups, respectively. Conclusion: After accelerated aging, it was found that the color of all cements became darker and the G-CEM LinkForce group turned red and the Panavia V5 group turned yellow. However, it was found that the color changes that occurred were within clinically acceptable visible levels.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1748
Author(s):  
Maria-Ioana Socaciu ◽  
Melinda Fogarasi ◽  
Cristina Anamaria Semeniuc ◽  
Sonia Ancuţa Socaci ◽  
Mihaela Ancuţa Rotar ◽  
...  

The effects of heat treatment and the addition of tarragon essential oil on physical and mechanical properties of films prepared with 5% whey protein isolate (WPI) and 5% glycerol were investigated in this study. Heat treatment of the film-forming solution caused increases in thickness, moisture content, swelling degree, water vapor permeability (WVP), b*-value, ΔE*-value, transmittance values in the 200–300-nm region, transparency, and puncture resistance of the film, but decreases in water solubility, L*-value, a*-value, transmittance values in the 350–800-nm region, and puncture deformation. When incorporated with tarragon essential oil, heat-treated films have the potential to be used as antimicrobial food packaging. The addition of tarragon essential oil in film-forming solution caused increases in moisture content, solubility in water, WVP, a*-value, b*-value, ΔE*-value, and transparency of the film; decreases in transmittance values in the range of 600–800 nm; and variations in swelling degree, L*-value, transmittance values in the range of 300–550 nm, puncture resistance, and puncture deformation. Nevertheless, different tendencies were noticed in UNT (untreated) and HT (heat-treated) films with regards to transparency, light transmittance, puncture resistance, and puncture deformation. Based on these findings, HT films show improved physical and mechanical properties and, therefore, are more suitable for food-packaging applications.


Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 139 ◽  
Author(s):  
Karen Alissa ◽  
Yu-Chi Hung ◽  
Chih Yao Hou ◽  
GiGi Chin Wen Lim ◽  
Jhih-Ying Ciou

Avocado (Persea Americana Mill.) generates byproducts, especially the avocado seeds. Hence, the aim of this study was to investigate the potential utilization of avocado seed as a very important, high phenolic content, climacteric fruit with unique characteristics and high nutritional properties. As such, theantioxidative test is conducted, then spray drying is used to produce avocado seed powder. The objective of this study was to develop an avocado seed powder using the spray drying technique by investigating the solution stability with different avocado seed extract concentrations, and to determine the physical properties of spray dried avocado powder that consists of powder yield, moisture, water activity, solubility, and color. The avocado seed extract was mixed with maltodextrin and water and homogenized for 10 min at 8000 rpm. The avocado seed solution was then spray dried with different inlet temperatures and feed flow rates. The spray dried avocado seed powder was analyzed for its yield, moisture content, water activity, solubility, and color. It was reported that the solution with the least avocado extract concentration (10 g) had the best stability in terms of presence of solute particles and color. The avocado seed powder obtained from this experiment had yield ranges from 24.46–35.47%, moisture content ranges from 7.18–7.96%, water activity ranges from 0.27–0.34, solubility ranges from 55.50–79.67 seconds, L* value ranges from 38.38–41.05, a* value ranges from 6.20–7.25, and b* value ranges from 13.33–15.17. In addition, increasing inlet temperature resulted in an increase in powder yield, solubility, a* value, and b*value, as well as a decrease in moisture, water activity, and L* value. Meanwhile, increasing the feed flow rate resulted in an increase in powder yield, moisture, water activity, and all L*, a*, b* values, as well as a decrease in solubility. In conclusion, spray drying technology is able to develop avocado seed powder.


2011 ◽  
Vol 306-307 ◽  
pp. 1673-1677
Author(s):  
M. Yu ◽  
Shao Peng Wu

This paper carried out the applications of grey system theory to correlate asphalt compositions and heating conditions which consist of asphalt mass, heating temperature and length of heating time. To clarify the influences of the heating conditions, the asphalt compositions were determined, including four generic components, namely asphaltenes, resins, aromatics and saturates, the total contents of asphaltenes and resins replaced by A value, the total contents of aromatics and saturates replaced by B value, and the ratio of A and B(A/B value). Results show that all the four generic components are affected obviously by different conditions and none of the four generic is affected by the largest. The component most affected by asphalt mass is A/B value. In additionally, A value is influenced mainly by the length of heating time while B value by heating temperature.


2006 ◽  
Vol 69 (8) ◽  
pp. 1913-1919 ◽  
Author(s):  
D. M. ANANG ◽  
G. RUSUL ◽  
SON RADU ◽  
JAMILAH BAKAR ◽  
L. R. BEUCHAT

Oxalic acid was evaluated as a treatment for reducing populations of naturally occurring microorganisms on raw chicken. Raw chicken breasts were dipped in solutions of oxalic acid (0, 0.5, 1.0, 1.5, and 2.0%, wt/vol) for 10, 20, and 30 min, individually packed in oxygen-permeable polyethylene bags, and stored at 4°C. Total plate counts of aerobic bacteria and populations of Pseudomonas spp. and Enterobacteriaceae on breasts were determined before treatment and after storage for 1, 3, 7, 10, and 14 days. The pH and Hunter L, a, and b values of the breast surface were measured. Total plate counts were ca. 1.5 and 4.0 log CFU/g higher on untreated chicken breasts after storage for 7 and 14 days, respectively, than on breasts treated with 0.5% oxalic acid, regardless of dip time. Differences in counts on chicken breasts treated with water and 1.0 to 2.0% of oxalic acid were greater. Populations of Pseudomonas spp. on chicken breasts treated with 0.5 to 2.0% oxalic acid and stored at 4°C for 1 day were less than 2 log CFU/g (detection limit), compared with 5.14 log CFU/g on untreated breasts. Pseudomonas grew on chicken breasts treated with 0.5% oxalic acid to reach counts not exceeding 3.88 log CFU/g after storage for 14 days. Counts on untreated chicken exceeded 8.83 log CFU/g at 14 days. Treatment with oxalic acid caused similar reductions in Enterobacteriaceae counts. Kocuria rhizophila was the predominant bacterium isolated from treated chicken. Other common bacteria included Escherichia coli and Empedobacter brevis. Treatment with oxalic acid caused a slight darkening in color (decreased Hunter L value), retention of redness (increased Hunter a value), and increase in yellowness (increased Hunter b value). Oxalic acid has potential for use as a sanitizer to reduce populations of spoilage microorganisms naturally occurring on raw chicken, thereby extending chicken shelf life.


Author(s):  
Somayeh Heydari ◽  
Roya Rezaei ◽  
Gholam Hossein Haghayegh

Saffron (Crocus sativus) has cyanic color flowers with major colorant of anthocyanin. Attractive color and functional properties of anthocyanins make them a good substitute for synthetic pigments in the food industry. These natural soluble water colorants are rather unstable and influenced by final processing treatment. The drying process is critical to the stability of saffron petals anthocyanins. Four different dehydration methods were evaluated: traditional method (at room temperature and under the sun); dehydration with electrical oven at different temperatures; and dehydration with microwave at different powers. The results showed that the highest amount of anthocyanin was obtained when saffron petals treated by traditional methods (at room temperature and under the sun). According to the results, the stability of saffron petals anthocyanins gradually accessed with increase of the heating temperature and decrement of heating time until 100 °C. However, heated at 120 and 140 °C, the anthocyanins could break down, and their residual amounts declined within 20 min and 10 min, respectively. The results suggested that saffron petals anthocyanins tended to degrade at high temperatures (>100 °C). Between these methods, drying at room temperature and drying with microwave at 900 W obtained the highest and the lowest results respectively.


1998 ◽  
Vol 25 (2) ◽  
pp. 99-103 ◽  
Author(s):  
C. C. Grimm ◽  
E. T. Champagne ◽  
T. H. Sanders

Abstract Peanut maturity has previously been correlated with the color of the mesocarp of the peanut hull going from light to dark as the peanut matures. In this study, peanuts were sorted into maturity classes of yellow, orange A, orange B, brown and black based on the hull scrape method of Williams and Drexler. The Hunter L*, a*, and b* values were also measured on the dry pods for each class. The color of the mesocarp of freshly harvested peanuts was determined using a Hunter colorimeter. Hunter L*, a*, and b* values on individual peanuts, representative of each class using wet and dry hulls, were reproducibly determined with standard deviations of less than 0.8%. Yellow peanut pods had a median L* value of 70.0, while mature black peanut pods had a median L* value of 51.7 and median values for orange A, orange B and brown pods were, 68.0, 63.7, 57.0, respectively. A similar inverse relationship was observed for the b* value and maturity, while the a* value reached a maximum at orange A. No correlation was observed between the peanut maturity and L*, a*, and b* values acquired with the exocarp intact. Hunter L* and b* values of mesocarps show potential for determining physiological maturity of peanuts.


2006 ◽  
Vol 12 (5) ◽  
pp. 429-435 ◽  
Author(s):  
M. A. Oliver ◽  
J. Polo ◽  
N. Panella ◽  
J. Arnau ◽  
M. Contreras ◽  
...  

The effect of the addition of pork haem pigment on the colour, colour stability and texture of cooked hams from pale, soft and exudative meat (PSE hams) was studied. A total of 62 hams were selected at 15h post mortem on the basis of pH, electrical conductivity (EC) and L* value in semimembranosus (SM) and biceps femoris (BF) muscles. Hams were divided into three groups to be manufactured as cooked hams: group 1 (control, with normal meat quality hams, n 20), group 2 (control, with PSE hams, n 21) and group 3 (with PSE hams to which 0.04% of pork haem pigment was added, n 21). The stability of the colour ( L*, a*, b*) was followed at 0, 30 and 120min after slicing. Pigment content and the instrumental texture of the hams were also evaluated. L* value after slicing was lower in group 3 than in group 2 for both muscles at all three times studied. Colour a* value (redness) was significantly higher for group 3 than for groups 1 and 2 at the three times and in the two muscles. Accordingly, there was an increase in visual redness in BF and SM of hams from group 3 with respect to groups 1 and 2. Iridescence was higher in PSE hams. The muscle pigment content showed no significant differences among groups - neither in the fresh nor in the cooked hams. No effect of the pork pigment was found on the texture properties studied. In conclusion, the addition of stabilised pork haem pigment in the processing of PSE hams resulted in cooked hams with lower L* values and higher a* values and more visual redness, whereas colour stability and texture of hams were not affected.


2019 ◽  
Vol 57 (9) ◽  
pp. 778-783
Author(s):  
V E Shiryaeva ◽  
A A Korolev ◽  
T P Popova ◽  
A Y Kanateva ◽  
A A Kurganov

Abstract Chromatographic determination of the thermodynamic parameters of sorption for light hydrocarbons retention on a stationary phase based on poly [trimethylsilyl (propyn-1)] (PTMSP) was performed and the effect of column preheating at temperatures up to 260°C on the retention of analytes was investigated. It was shown that heating the column to 130°C does not affect the retention of the analytes. At temperatures above 130°C, the gradual decrease of the retention of analytes on PTMSP stationary phase is observed. The process is non-selective and proceeds at the same extent for all the studied hydrocarbons, regardless of the size and geometry of the molecule. Values of enthalpy and entropy of sorption of light hydrocarbons are determined for the original column and after its aging at 200°C. The enthalpy of sorption of the analytes at the PTMSP phase is practically independent on the heating temperature of the PTMSP phase, whereas the loss of entropy increases after heating. The increase of the entropy factor after the heating of the PTMSP stationary phase is associated with its aging and is confirmed by the construction of compensation functions for treated and untreated columns.


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