Thermal analysis of mineral soils before and after oxidationwith sodium hypochlorite

2006 ◽  
Vol 86 (3) ◽  
pp. 845-848 ◽  
Author(s):  
J. Leifeld ◽  
M. Zimmermann
Keyword(s):  
Thermal Analysis ◽  
Sodium Hypochlorite ◽  
Before And After ◽  
Mineral Soils

scholarly journals Effect of repeated cycles of chemical disinfection in microhardness of acrylic resins of complete denture base

2017 ◽  
Vol 65 (3) ◽  
pp. 196-201
Author(s):  
Elisa das Graças MARTINS ◽  
Rafael Tobias MORETTI NETO
Keyword(s):  
Sodium Hypochlorite ◽  
Knoop Hardness ◽  
Sodium Hypochlorite Solution ◽  
Chlorhexidine Digluconate ◽  
Water Control ◽  
Denture Base ◽  
Acrylic Resins ◽  
Hardness Tests ◽  
Before And After ◽  
Edentulous Patients

ABSTRACT Objective: To evaluate the microhardness of specimens of acrylic resins VipiCril® (thermally polymerized resin) and Bosworth New Truliner® (self-polymerized resin), before and after immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control), testing the null hypothesis that the mouthwashes and chemicals used to disinfect complete dentures do not interfere with the superficial microhardness, and can therefore be used as adjuncts to oral hygiene of edentulous patients. Methods: Sixty specimens of resin VipiCril®(thermally polymerized resin) and 60 specimens of resin Bosworth New Truliner® (self-polymerized resin) measuring 16 mm of diameter and 6 mm of height were prepared, which were randomly divided into four groups of 15 specimens each, undergoing Knoop hardness tests (KHN) both before and after cycles of immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control). Results: The specimens of resins VipiCril and Bosworth immersed in solutions of 0.12% chlorhexidine, Corega Tabs® and water showed decreased microhardness. Conclusion: The 1% sodium hypochlorite solution caused least damage to the denture structure, not leading to decrease of the superficial microhardness.

Oxidation of Carboxymethyl Starch with Sodium Hypochlorite

1977 ◽  
Vol 47 (3) ◽  
pp. 209-211 ◽  
Author(s):  
I. Abd El-Thalouth ◽  
H. L. Hanna ◽  
A. Hebeish
Keyword(s):  
Sodium Hypochlorite ◽  
Reaction Temperature ◽  
Water Soluble ◽  
Shearing Stress ◽  
Carboxymethyl Starch ◽  
Before And After

Water-soluble carboxymethyl starch (CMS) was oxidized with sodium hypochlorite under different conditions. It was found that the rate of oxidation increases by increasing the hypochlorite concentration and/or reaction temperature. The viscosity of CMS before and after oxidation decreases as the shearing stress increases. Moreover, for a given shearing stress the viscosity decreases sharply by increasing the chlorine consumption.

Comparative characteristics of microflora root dentine at the use of different variants of medicamentous treatment of root canals

10.12737/4791 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 1-4
Author(s):  
Беленова ◽  
I. Belenova ◽  
Красичкова ◽  
Olga Krasichkova
Keyword(s):  
Sodium Hypochlorite ◽  
Ultrasonic Treatment ◽  
Root Canal ◽  
Economic Effect ◽  
Scientific Data ◽  
Tooth Pulp ◽  
Root Canals ◽  
Antiseptic Treatment ◽  
Before And After ◽  
Abutment Teeth

Application of ultrasonic treatment combined with conventional methods of endodontic treatment contributes to reduce the cases of relapses and the time of treatment, and causes the highest economic effect. The proposed method allows to successfully treating chronic granulating periodontitis and to save the need for prosthetics abutment teeth. The purpose of this study is to increase the effectiveness of treatment of granulating periodontitis by optimizing antiseptic treatment of root canals by means of ultrasound. In a series of studies the material of the examination and treatment of patients in the therapeutic department «Lipetsk municipal dental polyclinic №2» was examined. The basis for receiving scientific data – contingent of 127 patients from 26 to 51 years with granulating form of chronic periodontitis, of these were 83 women and 44 men. Depending on the tactics of the treatment the patients were divided into two groups: the 1st group – 43 patients who were treated by the traditional method of treatment of periodontitis; the 2nd group – 84 persons were treated by means of ultrasound. Clinical examination of patients included visual diagnostics, sensing, thermometry, percussion, determination of conductivity of the tooth pulp, radiovisiographic and x-ray study. It is established, that after use of a 3% solution of sodium hypochlorite the changes are observed not qualitative composition of the microflora, but quantitative. The methods of ultrasonic treatment of chronic granulating periodontitis are developed. The ultrasound effect on the microflora of each root channel is conducted during 30 seconds with the frequency of 30 kHz. The structure of the dentin of the root canal with the help of scanning electronic microscopy, before and after the influence of ultrasound is studied and described. After exposure to 3% of sodium hypochlorite, activated by ultrasound, on the wall of the root canal by granulating periodontitis the growth of microorganisms didn’t revealed in 94,8% of cases.

scholarly journals Comparison of disinfection protocol of irreversible hydrocolloid (alginate) impressions through plastic and metallic trays

2014 ◽  
Vol 17 (3) ◽  
pp. 54 ◽  
Author(s):  
Luiz Kiyoaki Okazaki ◽  
Cidney Hiroaki Cato ◽  
Lúcia Teramoto ◽  
Anna Carolina Borges Pereira Costa ◽  
Marcelo Fava ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Sodium Hypochlorite ◽  
Cross Infection ◽  
Percentage Reduction ◽  
Effective Time ◽  
Colony Forming Unit ◽  
Tukey Test ◽  
Before And After ◽  
Irreversible Hydrocolloid ◽  
The Ideal

<p class="normal"><strong>Introduction</strong>: Many studies have evaluated the disinfection of irreversible hydrocolloid impressions through different disinfecting agents. However, impression trays can be source of cross-infection requiring disinfection. This study aimed to determine which would be the most suitable tray (metallic or plastic), available in dental market, and the ideal time to achieve disinfection by using 1% sodium hypochlorite poured into the alginate impression. <strong>Material and methods</strong>: Thirty dental impressions from the patients aged from 7-12 years and treated in the Discipline of Orthodontics of the institution were divided into two groups according to the impression tray type: 15 impressions through plastic tray (Morelli) and 15 impressions through metallic tray (Tecnodent). The material collection was performed before and after the application of 1% sodium hypochlorite for 3, 5 and 10 minutes. After the incubation period of 48 hours at 37ºC, the microorganism colonies were counted on the plates presenting from 30 to 300 colonies to determine the colony-forming unit (CFU) per mL. CFU/mL results were transformed into logarithm and submitted to statistical analysis by applying ANOVA and Tukey test (<em>p</em> ≤ 0.05). <strong>Results</strong>: Greater CFU percentage reduction occurred in alginate after three minutes, in both tray types. Concerning to tray types, it could be observed that the plastic tray showed 100% of reduction after 5 minutes while the metallic tray exhibited 81.49% of reduction after 3 minutes.<strong> Conclusion</strong>: 1 – The plastic tray showed the most effective disinfection after 5 minutes, with 100% of CFU reduction; 2 – The most effective time of disinfection with 1% sodium hypochlorite poured into the impression was 5 minutes, for both tray types.</p>

scholarly journals Evaluation of the efficiency of some disinfectants on the viability of Hymenolepis nana eggs isolated from wastewater and faecal sludge in Yaounde (Cameroon): importance of some abiotic variables

2021 ◽  
Author(s):  
Fotseu Kouam Arnold Landry ◽  
Ajeagah Gideon Aghaindum ◽  
Amoah Isaac Dennis ◽  
Okoa Amougou Thérèse Nadège ◽  
Tsomene Namekong Pierre
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hypochlorite ◽  
Optical Microscope ◽  
Parasitic Infections ◽  
Contributory Factor ◽  
Chemical Parameters ◽  
Hymenolepis Nana ◽  
Physico Chemical ◽  
Before And After ◽  
Set Up

Abstract Hymenolepis nana is responsible for many parasitic infections in tropical areas, with its persistence in aquatic environments as major contributory factor. A study aimed at demonstrating the effectiveness of some disinfectants on the viability of Hymenolepis nana eggs was conducted in microcosm. Sampling consisted of taking wastewater and sewage sludge samples in sterilized containers and then transporting to the laboratory of Hydrobiology and Environmental Sciences for the determination of Hymenolepis nana eggs using standard protocols. The experimental set-up consisted of five replicates, four tests and a control. The test samples were successively treated with four disinfectants (calcium chlorite, hydrogen peroxide, gypsum and sodium hypochlorite). The physico-chemical parameters were measured before and after disinfection. The samples were then observed under an optical microscope after concentration of the sample through sedimentation and McMaster technique. The viability of the eggs was determined using incubation and staining techniques. The analysis revealed that, the selected disinfectants significantly reduced the physico-chemical parameters with an average yield ranging from 79.24 ± 19.43% to 99.24 ± 1.47%). These physico-chemical parameters can significantly influence the treatment of Hymenolepis nana eggs either by absorbing the disinfectant or by constituting a protective barrier for the eggs, and the physico-chemical nature of the disinfectant strongly influences the formation of disinfection by-products. Calcium chlorite showed a greater effectiveness in reducing eggs viability with efficiency rates of 93.12 ± 9.12% followed by hydrogen peroxide (89.57 ± 14.55%), sodium hypochlorite (82.51 ± 14.39%) and gypsum (80.85 ± 12.88%). The results obtained with gypsum are almost similar to those obtained with other disinfectants (calcium chlorite, hydrogen peroxide and sodium hypochlorite) and clearly show that this disinfectant can be used in water treatment because, unlike other chemical disinfectants, it has no known toxic effects.

AC Characterization of Heated Microcantilevers for Femtogram-Level Thermophysical Property Measurement

2010 ◽  
Author(s):  
Andrew M. Gauffreau ◽  
William DiPippo ◽  
Keunhan Park
Keyword(s):  
Thermal Analysis ◽  
Finite Element Analysis ◽  
High Frequency ◽  
Frequency Region ◽  
Element Analysis ◽  
High Frequency Region ◽  
Doped Silicon ◽  
Before And After ◽  
Property Measurement

This article investigates the electrothermal properties and responses of a doped silicon microcantilever under periodic (ac) Joule heating. To this end, a numerical model using a finite element analysis (FEA) was implemented to compute the steady periodic solutions in the frequency domain. The FEA results agree well with the cantilever ac behavior that was not possible with a previous 1-D analysis. Based on the acquired ac characteristics of the heated cantilever, its feasibility as a probe for nanoscale property measurement was studied by comparing the 3ω voltage signals before and after sampling 449 fg of polyethylene directly on the cantilever. The 3ω signal of the sampled cantilever is considerably different from that of the bare cantilever, suggesting that sample properties can be determined using the processes discussed here. The heater size effect on the ac behavior of the cantilever was also investigated, confirming that the high frequency region is closely related with the thermal diffusion at the heater. The obtained results willexpand the characterization and functionality of microcantilevers leading to advancements in localized thermal analysis.

Effect of Aging Treatment Technology on Properties of Al-Mg-Si-Cu-Zr-Er Alloy for Auto Sheets

2016 ◽  
Vol 850 ◽  
pp. 815-822 ◽  
Author(s):  
Qian Zhao ◽  
Xiao Guang Yuan ◽  
Hong Jun Huang ◽  
Peng Zhao
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Natural Aging ◽  
Performance Testing ◽  
Aging Treatment ◽  
Treatment Technology ◽  
Microstructure Observation ◽  
Β Phase ◽  
Before And After ◽  
Aging Hardening

The effect of natural aging, pre-aging and paint-bake aging technology on properties of Al-Mg-Si-Cu-Zr-Er alloy for auto sheets was investigated by performance testing, microstructure observation, and differential thermal analysis. The results showed that the natural aging alloy before and after paint-bake aging presented the double peaks feature of both the mechanical properties and hardness, the maximum value of strength and hardness appeared on the second aging peak, and the paint-bake aging softening occurred. The result of differential thermal analysis showed that, compared with the artificial aging, the precipitation of β′′ phase was delayed after the natural aging; the precipitates were mainly β′′ nuclei at the paint-bake aging, and it is difficult to achieve paint-bake aging hardening. After pre-aging and nature aging treatment, the precipitates were mainly composed of β′′ phase at the paint-bake aging, and the paint-bake aging hardening was realized. The addition of Er and Zr elements accelerated the precipitation of β′′ phase, the precipitation temperature of β′′ phase reduced and the time of the first natural aging peak and pre-aging was shortened. The parameters of pre-aging treatment of alloy sheets was solution and water quenching, and then age at 170 °C for 5 min.

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