Changes in the Physical and Chemical Properties of Alder Wood in the Process of Thermal Treatment with Saturated Water Steam

The paper presents changes in color and selected physico-chemical properties of alder (Alnus glutinosa) wood during the process of thermal treatment of the wood with a saturated steam-air mixture or saturated water steam in the temperature range t = 95–125 °C for τ = 3 to 12 h. During the process of thermal treatment of alder wood, the original light white-gray color changes depending on the temperature and time of modification to soft reddish-brown to dark brown color shades. Color changes of alder wood expressed in the form of the total color difference are in the range of values ∆E* = 2.7–31.7. Measurements of the density of thermally treated alder wood in the dry state indicate that due to the thermal treatment of alder wood, the density decreases by ρ ≤ 4.6% compared to the average density of native alder wood. Due to the hydrolysis of hemicelluloses, in the process of thermal treatment of wet alder wood, its acidity changes in the range of values: pH = 4.9 to 3.1. Analyzes of ATR-FTIR spectroscopy indicate changes in alder wood extractants and hemicellulose degradation. A decrease in unconjugated and an increase in conjugated carbonyls was observed at all temperatures of thermal modification of alder wood. Measurements indicate changes in the lignin of alder wood and the fact that as the temperature increases, the formation of new carbonyls increases, which is reflected in the change of the chromophoric system.

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Influence of UV Radiation on the Color Change of the Surface of Steamed Maple Wood with Saturated Water Steam

Polymers ◽

10.3390/polym14010217 ◽

2022 ◽

Vol 14 (1) ◽

pp. 217

Author(s):

Ladislav Dzurenda ◽

Michal Dudiak ◽

Eva Výbohová

Keyword(s):

Uv Radiation ◽

Color Change ◽

Color Space ◽

Color Stability ◽

Color Difference ◽

Saturated Steam ◽

Water Steam ◽

Saturated Water ◽

Red Color ◽

Uv Lamp

The wood of maple (Acer Pseudopatanus L.) was steamed with a saturated steam-air mixture at a temperature of t = 95 °C or saturated steam at t = 115 °C and t = 135 °C, in order to give a pale pink-brown, pale brown, and brown-red color. Subsequently, samples of unsteamed and steamed maple wood were irradiated with a UV lamp in a Xenotest Q-SUN Xe-3-H after drying, in order to test the color stability of steamed maple wood. The color change of the wood surface was evaluated by means of measured values on the coordinates of the color space CIE L* a* b*. The results show that the surface of unsteamed maple wood changes color markedly under the influence of UV radiation than the surface of steamed maple wood. The greater the darkening and browning color of the maple wood by steaming, the smaller the changes in the values at the coordinates L*, a*, b* of the steamed maple wood caused by UV radiation. The positive effect of steaming on UV resistance is evidenced by the decrease in the overall color difference ∆E*. While the value of the total color diffusion of unsteamed maple wood induced by UV radiation is ∆E* = 18.5, for maple wood steamed with a saturated steam-air mixture at temperature t = 95 °C the ∆E* decreases to 12.6, for steamed maple wood with saturated water steam with temperature t = 115 °C the ∆E* decreases to 10.4, and for saturated water steam with temperature t = 135 °C the ∆E* decreases to 7.2. Differential ATR-FTIR spectra declare the effect of UV radiation on unsteamed and steamed maple wood and confirm the higher color stability of steamed maple wood.

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Evaluation of the process thermal treatment of maple wood saturated water steam in terms of change of pH and color of wood

BioResources ◽

10.15376/biores.15.2.2550-2559 ◽

2020 ◽

Vol 15 (2) ◽

pp. 2550-2559

Author(s):

Ladislav Dzurenda ◽

Anton Geffert ◽

Jarmila Geffertová ◽

Michal Dudiak

Keyword(s):

Thermal Treatment ◽

Color Change ◽

Ph Value ◽

Statistical Processing ◽

Color Difference ◽

Acer Pseudoplatanus ◽

Water Steam ◽

Saturated Water ◽

Before And After ◽

Total Color Difference

Changes in maple wood’s pH and color (Acer pseudoplatanus) were evaluated before and after thermal treatment process with saturated water steam. Maple wood was thermally treated at temperatures: tI = 105 ± 2.5 °C, tII = 125 ± 2.5 °C, and tIII = 135 ± 2.5 °C for τ ≤ 12 hours. Direct pH measurement of maple wood with a moisture content above the fiber saturation point (FSP) was performed using a pH-meter SI 600 with a Lance FET + H puncture probe. The polynomial dependence of pH and total color difference ∆E* on temperature t time τ was calculated by statistical processing of measured results. The correlation between the total color difference ∆E* of maple wood in the process of thermal color modification and the pH value is expressed y the equation: ∆E* = 4.5516∙(pH)2 – 48.405∙(pH) + 134.35. This dependence is a suitable tool for assessing the achieved color change based on the change of wood pH in the technological process.

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Comparison of color indexes for tomato ripening

Horticultura Brasileira ◽

10.1590/s0102-05362004000300006 ◽

2004 ◽

Vol 22 (3) ◽

pp. 534-537 ◽

Cited By ~ 144

Author(s):

Andrés F. López Camelo ◽

Perla A. Gómez

Keyword(s):

Color Index ◽

Human Perception ◽

Color Difference ◽

Color Classification ◽

Color Changes ◽

Color Categories ◽

Visual Color ◽

Postharvest Life ◽

Range Of Values

Color in tomato is the most important external characteristic to assess ripeness and postharvest life, and is a major factor in the consumer's purchase decision. Degree of ripening is usually estimated by color charts. Colorimeters, on the other hand, express colors in numerical terms along the L*, a* and b* axes (from white to black, green to red and blue to yellow, respectively) within the CIELAB color sphere which are usually mathematically combined to calculate the color indexes. Color indexes and their relationship to the visual color classification of tomato fruits vine ripened were compared. L*, a* and b* data (175 observations from eleven cultivars) from visually classified fruits at harvest in six ripening stages according to the USDA were used to calculate hue, chroma, color index, color difference with pure red, a*/b* and (a*/b*)². ANOVA analysis were performed and means compared by Duncan's MRT. Color changes throughout tomato ripening were the result of significant changes in the values of L*, a* and b*. Under the conditions of this study, hue, color index, color difference and a*/b* expressed essentially the same, and the color categories were significantly different in terms of human perception, with hue showing higher range of values. Chroma was not a good parameter to express tomato ripeness, but could be used as a good indicator of consumer acceptance when tomatoes are fully ripened. The (a*/b*)² relationship had the same limitations as chroma. For vine ripened fruits, hue, color index, color difference and a*/b* could be used as objective ripening indexes. It would be interesting to find out what the best index would be if ripening took place under inadequate conditions of temperature and ilumination.

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Physico-Chemical Investigation of Endodontic Sealers Exposed to Simulated Intracanal Heat Application: Hydraulic Calcium Silicate-Based Sealers

Materials ◽

10.3390/ma14040728 ◽

2021 ◽

Vol 14 (4) ◽

pp. 728

Author(s):

David Donnermeyer ◽

Magdalena Ibing ◽

Sebastian Bürklein ◽

Iris Weber ◽

Maximilian P. Reitze ◽

...

Keyword(s):

Heat Treatment ◽

Thermal Treatment ◽

Film Thickness ◽

Physical Properties ◽

Calcium Silicate ◽

Setting Time ◽

Chemical Properties ◽

Chemical Changes ◽

Time Flow ◽

Heat Application

The aim of this study was to gain information about the effect of thermal treatment of calcium silicate-based sealers. BioRoot RCS (BR), Total Fill BC Sealer (TFBC), and Total Fill BC Sealer HiFlow (TFHF) were exposed to thermal treatment at 37 °C, 47 °C, 57 °C, 67 °C, 77 °C, 87 °C and 97 °C for 30 s. Heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate application of warm obturation techniques. Thereafter, specimens were cooled to 37 °C and physical properties (setting time/flow/film thickness according to ISO 6876) were evaluated. Chemical properties (Fourier-transform infrared spectroscopy) were assessed after incubation of the specimens in an incubator at 37 °C and 100% humidity for 8 weeks. Statistical analysis of physical properties was performed using the Kruskal-Wallis-Test (P = 0.05). The setting time, flow, and film thickness of TFBC and TFHF were not relevantly influenced by thermal treatment. Setting time of BR decreased slightly when temperature of heat application increased from 37 °C to 77 °C (P < 0.05). Further heat treatment of BR above 77 °C led to an immediate setting. FT-IR spectroscopy did not reveal any chemical changes for either sealers. Thermal treatment did not lead to any substantial chemical changes at all temperature levels, while physical properties of BR were compromised by heating. TFBC and TFHF can be considered suitable for warm obturation techniques.

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Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

Clinical Oral Investigations ◽

10.1007/s00784-021-04009-0 ◽

2021 ◽

Author(s):

Ralf Krug ◽

C. Ortmann ◽

S. Reich ◽

B. Hahn ◽

G. Krastl ◽

...

Keyword(s):

Calcium Silicate ◽

In Vitro Study ◽

Color Difference ◽

Blood Contamination ◽

Tooth Color ◽

Color Changes ◽

Gutta Percha ◽

Tooth Discoloration ◽

Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

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Effect of Saturated Steam Heat Treatment on Physical and Chemical Properties of Bamboo

Molecules ◽

10.3390/molecules25081999 ◽

2020 ◽

Vol 25 (8) ◽

pp. 1999 ◽

Cited By ~ 2

Author(s):

Qiuyi Wang ◽

Xinwu Wu ◽

Chenglong Yuan ◽

Zhichao Lou ◽

Yanjun Li

Keyword(s):

Heat Treatment ◽

Moisture Content ◽

Treatment Time ◽

Flexural Modulus ◽

Initial Moisture Content ◽

Chemical Properties ◽

Saturated Steam ◽

Xrd Patterns ◽

Physical And Chemical ◽

Steam Heat

The aim of this study was to investigate the effects of the heat treatment time and initial moisture content of bamboo on the corresponding chemical composition, crystallinity, and mechanical properties after saturated steam heat treatment at 180 °C. The mechanism of saturated steam heat treatment of bamboo was revealed on the micro-level, providing a theoretical basis for the regulation of bamboo properties and the optimization of heat treatment process parameters. XRD patterns of the treated bamboo slices were basically the same. With the increase in the initial moisture content of bamboo, the crystallinity of bamboo increased first and then decreased after treatment. Due to the saturated steam heat treatment, the content of cellulose and lignin in bamboo slices increased while the content of hemicellulose decreased, but the content of cellulose in bamboo with a 40% initial moisture content increased first and then decreased. The shear strength of treated bamboo changed little within 10 min after saturated steam heat treatment, and then decreased rapidly. During the first 20 min with saturated steam heat treatment, the compressive strength, flexural strength, and flexural modulus of elasticity of the treated bamboo increased, and then decreased.

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Development of the composition and production technology of injection medication for intra-articular introduction based on sodiun hyaluronate

Farmatsevtychnyi zhurnal ◽

10.32352/0367-3057.5.19.08 ◽

2019 ◽

pp. 75-85

Author(s):

O. O. Saliy ◽

O. V. Los ◽

O. P. Baula ◽

K. F. Matsiutsia

Keyword(s):

Production Technology ◽

Sodium Hyaluronate ◽

Chemical Properties ◽

Quality Criterion ◽

Quality Criteria ◽

Saturated Steam ◽

Critical Parameters ◽

Injection Solution ◽

Physical Chemical ◽

Sterilization Mode

Osteoarthrosis is the most widespread disease of musculoskeletal system, which leads to different level of disability in 10–30% of cases. The age of the person is one of the key risk factors for the development of such disease. The most effective resolution is a surgery in which joints are replaced, but this method is very risky and expensive especially for elderly people. That is why development of the composition and research in new technological aspects of biotechnological medication is an actual course in pharmacy. The aim of research: development of the composition and production technology of injection solution of hyaluronic acid as sodium hyaluronate for the therapy of degenerate inflammatory disease of articulation. The object of the study is an injection with sodium hyaluronate for intra-articular administration. Evaluation of the test results when choosing the optimal technology for preparing the injection solution was carried out by the visual method (description, transparency), and by the method of rotational viscometry (viscosity). The suitability of the sterilization regime was determined by physicochemical methods (appearance, transparency, viscosity, pH of the solution) and microbiological method (sterility) according to the requirements of SPhU. The quantitative content of sodium hyaluronate was determined by spectrophotometry (SPhU, 2.2.25) using a carbazole reagent. The results of the studies has been developed the optimal composition of the drug based on stabilized sodium hyaluronate by the excipient BDE. The resulting solution in its physical-chemical properties are a clear, highly viscous aqueous solution. The developed composition contains (in %): Sodium hyaluronate with a molecular weight of ~ 2 MDA (in terms of 100% substance) – 1.0; BDE – 0.75; sodium chloride – 0.85; phosphate buffer – up to pH from 5.0 to 8.5; water for injection – up to 100%. The critical parameters of the technological stages for the production of a drug with sodium hyaluronate are determined experimentally. Specific critical parameters are the degassing of a viscous solution, filtration and the conditions of the sterilization mode of the injection solution. It was experimentally established that the optimal parameters for the filtration stage are the use of a Durapore hydrophilic membrane made of polyvinyl difluoride (PVDF), the temperature of the solution is 50 ± 0.5 °C and the use of back pressure mode to reduce the volume wich is filtered per unit time. It was determined that the sterilization mode with saturated steam at a temperature of 121 °C for 8 min is optimal and ensures the quality of the solution in quality criterion of «Sterility». Samples of the experimental series of injection solution, obtained by the developed technology, comply with the requirements of SPhU for drugs for parenteral use according to physical-chemical and biological quality criteria as appearance, transparency, viscosity, pH of the solution, sterility, assay sodium hyaluronate.

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PENGARUH RESIN TERHADAP PERUBAHAN WARNA PADA CAT TEMBOK

Jurnal Sains Natural ◽

10.31938/jsn.v5i2.264 ◽

2019 ◽

Vol 5 (2) ◽

pp. 132

Author(s):

Nurlela Nurlela ◽

Risnawati Risnawati

Keyword(s):

Film Thickness ◽

Vinyl Acetate ◽

Polyvinyl Acetate ◽

Color Change ◽

Color Difference ◽

Background Color ◽

Color Changes ◽

Synthetic Resins ◽

Color Background

The Influence of Resin against the Change of Color on the Wall PaintThe quality of the paint is determined by the resin used. Synthetic resins for polymer paints are made by combining several monomers to achieve various characteristics. The incorporation of some monomers such as polyvinyl acetate resin, acrylic vinyl resin and acrylic styrene resin which act as a binder can affect the quality of the paint especially the color change. The purpose of this study is to find the color changes that occur on the wall paint by using Poly Styrene Acrylic , Poly Vinyl Acetate and Poly Vinyl Acrylic. From the results of the measurement of color difference, significant color change occurs in the Poly Vinyl Acetate (PVAc) + Poly Vinyl Acrylic (PVA) and Poly Styrene Acrylic (PSA). The results of the quality test of the three resins based on pH test, scrub test and viscosity test, PSA has better quality compared to PVA + PVAc and PVA resin. From the color difference measurement test, some things need to be considered, are temperature, film thickness, substrate color/background color and measurement conditions (measured in wet sample/in plate/dry surface) and test on resin added additive according to the type of each resin.Keywords: Paint, Resin, Color Changes, Poly Vinyl Acetate, Poly Styrene.ABSTRAK Kualitas dari cat sangat ditentukan oleh resin yang digunakan. Resin sintetis untuk cat berupa polimer yang dibuat dengan menggabung beberapa monomer untuk mencapai berbagai karakteristik. Penggabungan dari beberapa monomer seperti resin poli vinil asetat, resin vinil akrilik dan resin stirena akrilik yang berfungsi sebagai pengikat mampu mempengaruhi kualitas cat terutama dari perubahan warna. Tujuan dari penelitian ini adalah untuk mengetahui perubahan warna yang terjadi pada cat tembok dengan menggunakan Poli Stirena Akrilik, Poli Vinil asetat dan Poli Vinil Akrilik. Dari hasil pengukuran perbedaan warna, perubahan warna cukup signifikan terjadi pada resin Poli vinil Asetat (PVAc) + Poli Vinil Akrilik (PVA) dan resin Poli Stirena Akrilik (PSA). Hasil uji Kualitas cat dari ketiga resin berdasarkan uji pH, uji scrub dan uji viscositas, PSA memiliki kualitas yang lebih baik dibandingkan dengan resin PVA+PVAc dan PVA. Dari pengujian pengukuran perbedaan warna, beberapa hal yang perlu di perhatikan, yaitu suhu, film thickness, warna substrat/background color dan kondisi pengukuran (diukur dalam keadaan wet sample/dalam bentuk plate/dry surface) dan pengujian terhadap resin yang ditambahkan zat aditif yang sesuai dengan tipe masing-masing resin tersebut.Kata Kunci: Cat, Resin, Perubahan Warna, Poli Vinil, Poli Stirena.

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Heat transfer enhancement during condensation of water steam on inclined pipe

Journal of Physics Conference Series ◽

10.1088/1742-6596/2039/1/012031 ◽

2021 ◽

Vol 2039 (1) ◽

pp. 012031

Author(s):

S Z Sapozhnikov ◽

V Yu Mityakov ◽

A V Mityakov ◽

A Yu Babich ◽

E R Zainullina

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Heat Transfer Enhancement ◽

Unit Area ◽

Experimental Results ◽

Transfer Enhancement ◽

Water Steam ◽

Saturated Water ◽

Informative Content ◽

Inclined Pipe

Abstract This paper presents experimental study of heat transfer during film condensation of saturated water steam on the outer surface of the inclined pipe by gradient heatmetry. Heat flux per unit area was measured by gradient heat flux sensors made of a single-crystal bismuth. The experimental results are presented in the graphs of heat flux per unit area dependence on time and azimuthal angle. The highest average heat transfer coefficient during condensation of α = 6.94 kW/(m2 • K) was observed when the pipe was inclined at the angle of ψ = 20 °. This value exceeds one obtained on a vertical pipe by 14.9 %. Heat transfer enhancement during condensation of saturated water steam on inclined pipe is associated with changes in condensate film flow. Another part of experiments was made by simultaneously using of gradient heatmetry and condensate flow visualization. Experimental results confirmed the applicability and high informative content of proposed comprehensive method. Comprehensive study of heat transfer during condensation confirmed that heat flux per unit area pulsations may be explained by the formation of individual drops, their coalescence, and drainage from the sensor surface.

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Preparation and Characterization of Natural Bleaching Gels Used in Cosmetic Dentistry

Materials ◽

10.3390/ma12132106 ◽

2019 ◽

Vol 12 (13) ◽

pp. 2106 ◽

Cited By ~ 1

Author(s):

Amalia Mazilu (Moldovan) ◽

Codruta Sarosi ◽

Marioara Moldovan ◽

Filip Miuta ◽

Doina Prodan ◽

...

Keyword(s):

Artificial Saliva ◽

Dental Materials ◽

Color Difference ◽

Cytotoxicity Test ◽

Color Changes ◽

Vis Spectroscopy ◽

Color Shift ◽

Follicle Stem Cells ◽

Bleaching Gels

The novelty of this study consists of the formulation and characterization of three experimental bleaching gels with hydroxylapatite oxides and fluorine (G28®, G29®, G30®) based on natural fruit extracts compared to the commercial Opalescence 15% (GC, Ultradent, South Jordan, UT, USA). Studies have been conducted on the effect that the experimental bleaching gels have on the color and morphology of different restorative materials (Nanofill®-Schulzer, P.L. Superior Dental Materials GmbH, Hamburg, Germany, and experimental nanocomposites (P11®, P31®, P61®)), immersed in coffee and artificial saliva (for 10 days and 30 days). The study also includes a cytotoxicity test on the gels and nanocomposites after bleaching, with ISO 109993-5 protocols on human dental follicle stem cells. UV-VIS spectroscopy, computerized measurement, and fluorescence spectrometry were used in order to observe the color changes, while the microstructure of the surface was investigated by Scanning Electron Microscopy (SEM). All of the samples immersed in coffee showed the highest color shift in comparison to the baseline. The color difference ΔE values obtained using the two methods (UV-Vis, computerized based on digital images) both after coloring and bleaching, respectively, were different for all four types of nanocomposites stored in the coffee, while no difference was observed in those stored in artificial saliva. The studied experimental gels and nanocomposites had a low cytotoxic effect on cell cultures after bleaching.

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