scholarly journals Linear dimensional change in acrylic resin disinfected by microwave energy

2010 ◽  
Vol 9 (2) ◽  
Author(s):  
Rafael Leonardo X. Consani ◽  
Andréa Fabiana Lira ◽  
Marcelo F. Mesquita ◽  
Simonides Consani
Keyword(s):  
Room Temperature ◽  
Acrylic Resin ◽  
Dimensional Change ◽  
Conventional Technique ◽  
Microwave Energy ◽  
Reference Points ◽  
Linear Dimensions ◽  
Gypsum Mold ◽  
Before And After ◽  
Made In

The purpose of this study was to characterize the linear dimensional change in specimens made in aluminum rectangular dies (65.0x12.0x3.5mm), with 4 reference demarcations, using the Clássico, Onda-Cryl and QC-20 brands of acrylic resin. Wax patterns with 67.0x15.0x5.0mm were embedded in metallic or plastic flasks with stone gypsum, according to the conventional technique. After stone gypsum setting, the wax molds were removed and the aluminum dies impressed in the stone gypsum mold with silicone material. The powder/liquid proportion and acrylic resin were manipulated according to manufacturer’s instructions. The metallic flask pressure was achieved using the RS tension method. After polymerization in water at 74OC for 9 hours, ebullition water for 20 minutes or microwave energy (900 W) for 10 minutes, the specimens were cooled at room temperature and then removed from the flasks and submitted to conventional finishing. The distances between the A-B, C-D, A-C, and B-D reference points were measured before and after disinfection by microwave energy (650W for 3 minutes). The linear dimensional evaluation of the distances was performed by the same operator with an Olympus optical comparator microscope, with an accuracy of 0.0005mm. Obtained data were submitted to ANOVA and Tukey’s test (α=.05%). The disinfection by microwave energy did not alter the original linear dimensions of the specimens.

LR White acrylic resin polymerized by microwave energy for immuno-EM of Saccharomyces cerevisiae: A rapid method

1991 ◽  
Vol 49 ◽  
pp. 294-295 ◽  
Author(s):  
B. L. Giammara ◽  
A. O. Rose ◽  
J. S. Hanker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Low Temperature ◽  
Room Temperature ◽  
Acrylic Resin ◽  
Microwave Energy ◽  
Selective Medium ◽  
Polyester Resins ◽  
Low Viscosity ◽  
Lr White

Microwave embedment methods have been developed for epoxy and polyester resins. Because the thick yeast cell wall is known to inhibit penetration by many embedding media, we wished to use an embedding agent exhibiting favorable properties of hydrophilicity and low viscosity. The complex requirement for low temperature and curing using UV irradiation with the polymer Lowicryl, and recent advantages described for yeast using LR White, made the latter polymer a good candidate for our studies.Saccharomyces cerevisiae was grown at 30°C in selective medium to an OD640 = 1.0. A modification of the procedure of Tuinen and Riezman was used to fix the cells. Briefly, the cells were washed three times with Sorenson's buffer, pH 7.3, and fixed as a suspension in 3% paraformaldehyde, 0.25% glutaraldehyde in Sorenson's for 2 hours at room temperature. The cells were again washed three times followed by incubation in 1 % sodium meta-periodate at room temperature for one hour.

scholarly journals Strategies for Potential Toughening of Acrylic Denture Bases Polymerized With Microwave Energy

2020 ◽  
Vol 31 (5) ◽  
pp. 523-531
Author(s):  
Rafael Leonardo Xediek Consani ◽  
Andreia Bolzan de Paula ◽  
Ana Paula Piovezan Fugolin ◽  
Carmem S. Pfeifer
Keyword(s):  
Yield Strength ◽  
Dimensional Stability ◽  
Water Sorption ◽  
Acrylic Resin ◽  
Dimensional Change ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Denture Base ◽  
Post Hoc ◽  
The Impact

Abstract Thiourethane additives have been shown to improve properties in several dental polymer applications. The aim of this study was to verify the effect of the addition of thiourethane oligomers and acrylamide or isobornyl-based plasticizers on the physical properties of the denture base acrylic resin polymerized with microwaves. Thiourethane oligomer (TU) was synthetized and added to microwaved acrylic resin in proportions varying between 3 and 14 wt%. Separate experimental groups included the addition of dimethyl acrylamide (DMAM) and isobornyl methacrylate as plasticizers, at concentrations varying from 5 to 20 wt%. Samples were polymerized using microwave energy at 500 Watts for 3 min, deflasked at room temperature, stored in water at 37 °C for 24 h, and evaluated for: linear dimensional change, gloss, Knoop hardness, surface roughness, impact strength, yield strength, elastic modulus, toughness, yield strength, viscosity, glass transition temperature and network heterogeneity, and water sorption/solubility. Data were analyzed with ANOVA/Tukey’s post-hoc test (a=5%). The addition of TU led to properties that were similar or worse than the materials to which it was not added, except for dimensional stability. The impact on properties was statistically significant for all materials above 20% addition of TU. The addition of DMAM at 5 wt% or isobornyl methacrylate at 10 wt% improved yield strength and modulus, but increased water sorption and solubility. Except for dimensional stability, the addition of thiourethane oligomers to acrylic denture base materials compromised most tested properties. The use of DMAM and isobornyl methacrylate improved properties for selected compositions.

1989 göçü sonrası Bulgaristan göçmenlerinin yemek kültüründeki değişim

2017 ◽  
Vol 4 (2) ◽  
pp. 227-245
Author(s):  
Cahit Kahraman ◽  
İlhan Güneş ◽  
Nanae Kahraman
Keyword(s):  
Eating Habits ◽  
Supply And Demand ◽  
Food Culture ◽  
Rapid Progress ◽  
Canned Food ◽  
Product Range ◽  
The World ◽  
Before And After ◽  
Day By Day ◽  
Made In

1989 göçü öncesi, dünyada eşzamanlı olarak gittikçe gelişen ve zenginleşen mutfak kültürü, Bulgaristan Türklerini de etkilemiştir. Pazardaki çeşitlilik arttıkça, yemek alışkanlıkları da değişime uğramıştır. Büyük göçten sadece 30-40 sene evvel kısıtlı imkânlar ile sınırlı sayıda yemek çeşidi üretilirken, alım gücünün artmasıyla yemek kültüründe de hızlı gelişmeler olmuştur. Artan ürün çeşitliliği yemeklere de yansımış, farklı lezzetler mutfaklara girmiştir. Göçmen yemekleri denilince hamur işleri, börek ve pideler akla gelir. Ayrıca, göçmenlerin çok zengin turşu, komposto ve konserve kültürüne sahip oldukları da bilinir. Bu çalışma, 1989 öncesi Bulgaristan’ın farklı bölgelerinde yaşayan Türklerin yemek alışkanlıklarına ışık tutmakla birlikte, göç sonrasında göçmen mutfak kültüründe bir değişiklik oluşup oluşmadığını konu almaktadır. Bu amaçla, 1989 yılında Türkiye’ye göç etmiş 50 kişiye 8 sorudan oluşan anket düzenlenmiştir. Bu verilerden yola çıkarak oluşan bulgular derlenmiş ve yeni tespitler yapılmıştır. Ayrıca, Türkiye’nin farklı bölgelerine yerleşen göçmenler, kendi göçmen pazarlarını kurmuşlardır. Bulgaristan’dan getirilen ürünlerin bu pazarlarda satılması böyle bir arz talebin hala devam ettiğine işaret etmektedir.ABSTRACT IN ENGLISHThe Diversity in Cuisine Culture of the Immigrants from Bulgaria After 1989 MigrationThe Cuisine culture that has been developing and getting rich day by day contemporaneously in the world before 1989 migration has also had an impact on Bulgarian Turks. By the increase in diversity in the market, eating habits have changed. While producing a limited number of food types with limited opportunities just some 30 or 40 years before the ‘Big Migration’, there has been a rapid progress in food culture by the help of the increase in purchase power. Enhancing product range has been reflected in food, and different tastes have entered the cuisines. When we say immigrant, the first things that come to our mind are pastry, flan and pitta bread. Moreover, it is also known that immigrants have a very rich cuisine culture of pickle, stewed fruit, and canned food. This study aims both to disclose the eating habits of Turks living in different regions of Bulgaria before 1989 and to determine whether there has been a difference in immigrant cuisine culture before and after the migration. For this purpose, a questionnaire consisting of 8 questions has been administered to 50 people who migrated to Turkey in 1989. The results gathered from these data have been compiled and new determinations have been made. In addition, immigrants that settled in different regions of Turkey have set their own immigrant markets. The fact that the products brought from Bulgaria are being sold in these markets shows that this kind of supply and demand still continues.

DNA Inspirited Rational Construction of Nonconventional Luminophores with Efficient and Color-Tunable Afterglow

2020 ◽  
Author(s):  
Yunzhong Wang ◽  
Saixing Tang ◽  
Yating Wen ◽  
Shuyuan Zheng ◽  
Bing Yang ◽  
...  
Keyword(s):  
Rational Design ◽  
Room Temperature ◽  
Double Helix ◽  
Mechanical Grinding ◽  
Room Temperature Phosphorescence ◽  
Color Tunable ◽  
Potential Applications ◽  
Rational Construction ◽  
Double Helix Structure ◽  
Made In

<div>Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive </div><div>due to its fundamental importance and potential applications in molecular imaging, </div><div>sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in </div><div>obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7. </div><div>The origin of color-tunable p-RTP and the rational design of such luminogens, </div><div>particularly those with explicit structure and molecular packing, remain challenging. </div><div>Noteworthily, nonconventional luminophores without significant conjugations generally </div><div>possess excitation-dependent photoluminescence (PL) because of the coexistence of </div><div>diverse clustered chromophores6,8, which strongly implicates the possibility to achieve </div><div>color-tunable p-RTP from their molecular crystals assisted by effective intermolecular </div><div>interactions. Here, inspirited by the highly stable double-helix structure and multiple </div><div>hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on </div><div>hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP </div><div>from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP </div><div>efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are </div><div>resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust, </div><div>color-tunable and highly efficient p-RTP render the luminophores promising for varying </div><div>applications. These findings provide mechanism insights into the origin of color-tunable </div><div>p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.</div>

scholarly journals On the measurement of the ratio of the specific heats using small volumes of gas.—The ratios of the specific heat of air and of hydrogen at atmospheric pressure and a temperatures between 20°C. and —183°C

1925 ◽  
Vol 107 (743) ◽  
pp. 510-543 ◽  
Keyword(s):  
Systematic Error ◽  
Low Temperatures ◽  
Room Temperature ◽  
Expansion Chamber ◽  
Small Vessels ◽  
Specific Heats ◽  
Large Expansion ◽  
Before And After ◽  
The One ◽  
Chamber Capacity

Introduction .—In nearly all the previous determinations of the ratio of the specific heats of gases, from measurements of the pressures and temperature before and after an adiabatic expansion, large expansion chambers of fror 50 to 130 litres capacity have been used. Professor Callendar first suggests the use of smaller vessels, and in 1914, Mercer (‘Proc. Phys. Soc.,’ vol. 26 p. 155) made some measurements with several gases, but at room temperature only, using volumes of about 300 and 2000 c. c. respectively. He obtained values which indicated that small vessels could be used, and that, with proper corrections, a considerable degree of accuracy might be obtained. The one other experimenter who has used a small expansion chamber, capacity about 1 litre, is M. C. Shields (‘Phys. Rev.,’ 1917), who measured this ratio for air and for hydrogen at room temperature, about 18° C., and its value for hydroger at — 190° C. The chief advantage gained by the use of large expansion chambers is that no correction, or at the most, a very small one, has to be made for any systematic error due to the size of the containing vessels, but it is clear that, in the determinations of the ratio of the specific heats of gases at low temperatures, the use of small vessels becomes a practical necessity in order that uniform and steady temperature conditions may be obtained. Owing, however, to the presence of a systematic error depending upon the dimensions of the expansion chamber, the magnitude of which had not been definitely settled by experiment, the following work was undertaken with the object of investigating the method more fully, especially with regard to it? applicability to the determination of this ratio at low temperatures.

Carbon Capture Performance of Amino-Modified MIL-101 at Room Temperature

2013 ◽  
Vol 395-396 ◽  
pp. 637-640
Author(s):  
Yi Yang ◽  
Zheng Ping Wang ◽  
Ling Meng ◽  
Lian Jun Wang
Keyword(s):  
Carbon Dioxide ◽  
Specific Surface ◽  
Pore Structure ◽  
Carbon Capture ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
Carbon Dioxide Adsorption ◽  
Before And After

MIL-101, a metal-organic framework material, was synthesized by the high-temperature hydrothermal method. Triethylenetetramine (TETA) modification enabled the effective grafting of an amino group onto the surface of the materials and their pore structure. The crystal structure, micromorphology, specific surface area, and pore structure of the samples before and after modification were analyzed with an X-ray diffractometer, scanning electron microscope, specific surface and aperture tester, and infrared spectrometer. The carbon dioxide adsorption properties of the samples were determined by a thermal analyzer before and after TETA modification. Results show that moderate amino modification can effectively improve the microporous structure of MIL-101 and its carbon dioxide adsorption properties. After modification, the capacity of MIL-101 to adsorb carbon dioxide decreased only by 0.61 wt%, and a high adsorption capacity of 9.45 wt% was maintained after six cycles of adsorption testing at room temperature and ambient pressure.

Coronary Care in a General Hospital

1971 ◽  
Vol 16 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Gavin Shaw ◽  
Bernard Groden ◽  
Evelyn Hastings
Keyword(s):  
Myocardial Infarction ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
General Hospital ◽  
First Year ◽  
Duration Of Stay ◽  
Before And After ◽  
The Mean ◽  
Coronary Care ◽  
Made In

The establishment, staffing and structure and observations made in the first year of the existence of coronary care in an intensive care unit in a general hospital are recorded. Two hundred and twenty eight patients were admitted during the year in whom the diagnosis of myocardial infarction was confirmed. There were 29 deaths in the unit and 14 deaths occurred in the wards of the hospital after discharge from the unit. 49.1 per cent of the patients were admitted within 4 hours of the onset of symptoms and the mean duration of stay in the unit was 86.5 hours. The type of arrhythmia detected in the unit, and the treatment given to the patients both before and after admission to the intensive care unit are described.

A New Hafnium-Beryllium System Prioduced by Ion Implantation and Annealing Techniques

1983 ◽  
Vol 27 ◽  
Author(s):  
J.C. Soares ◽  
A.A. Melo ◽  
M.F. DA Silva ◽  
E.J. Alves ◽  
K. Freitag ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Low Dose ◽  
Correlation Method ◽  
High Dose ◽  
Tetrahedral Sites ◽  
Time Differential ◽  
Before And After ◽  
Beryllium Foil

ABSTRACTLow and high dose hafnium imolanted beryllium samoles have been prepared at room temperature by ion implantation of beryllium commercial foils and single crystals. These samples have been studied before and after annealing with the time differential perturbed angular correlation method (TDPAC) and with Rutherford backscattering and channeling techniques. A new metastable system has been discovered in TDPAC-measurements in a low dose hafnium implanted beryllium foil annealed at 500°C. Channeling measurements show that the hafnium atoms after annealing, are in the regular tetrahedral sites but dislocated from the previous position occupied after implantation. The formation of this system is connected with the redistribution of oxygen in a thin layer under the surface. This effect does not take place precisely at the same temperature in foils and in single crystals.

The Phase Analysis of Panzhihua Vanadic Titanomagnetite Ore before and after Heat Treatment

2013 ◽  
Vol 807-809 ◽  
pp. 2110-2114
Author(s):  
Shu Quan Wan ◽  
De Jun Lan ◽  
Hong Bo Han ◽  
Cai Long Zhou
Keyword(s):  
Heat Treatment ◽  
Phase Analysis ◽  
Room Temperature ◽  
Before And After

The phases of Panzhihua vanadic titanomagnetite ore were studied by using XRF and XRD. XRF results show that the original ore mainly contain the elements, Fe, Ti, Si, Ca, Al, S, Mg, P, Mn, V and etc. XRD results show that the main substances in original ore were Fe3O4 and FeTiO3, and the minor phases cannot be clearly studied by XRD. After heat treatment for 10h at 573K in atmospheric ambient, the phases of the ore have been slightly changed. And after heat treatment for 10h at 1073K in atmospheric ambient, then cooled for 48h to room temperature, the main phases of the ore have almost been changed to Fe2O3 and Fe2TiO5.

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