Studies Regarding Production of the Moulding Form from Calcined Gypsum

2013 ◽  
Vol 837 ◽  
pp. 206-211
Author(s):  
Gheorghe Simionescu ◽  
Mirela Gheorghian
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Sodium Chloride ◽  
Boric Acid ◽  
Zinc Chloride ◽  
Research Work ◽  
Mechanical Resistance ◽  
Calcined Gypsum ◽  
Wax Models

In the pressing form made from calcined gypsum fixed in metal, wax can be cast with pressure. The device used to tide the pressing form should not bend. If the handling work is done carefully and correct one pressing form made from gypsum can be used for multiple wax models. To be used in construction the pressing forms, calcined gypsum must meet certain requirements regarding its constitution and functionality. To provide these requirements research work must be done to investigate characteristics such as: minimum compressive strength (wet and dry state), hardening time of calcined gypsum, gypsum dilatation after curing. To produce the pressing forms from calcined gypsum the following methods and operations have been used: operations concerning production of gypsum with the best physicochemical and mechanical properties in order to be used for construction of pressing forms (determining the quality of gypsum based on water and plaster ratio; establishing the influence of epoxy and curing solution on the mechanical resistance of the obtained gypsum; determining the influence of lime, boric acid, zinc chloride, sodium chloride on the hardening period of calcined gypsum); production of the models from wood and metal; fixing the model on the gypsum cushion; finding on the model the separation line and restrict the area used for gypsum moulding; applying grease on the model, on the plate under the model, on the walls and on all parts that come in contact with liquid gypsum to be poured; preparation of the gypsum solution.

Determination of Relationship between Chemical Composition of Electrolyte and Surface Sample Quality

2015 ◽  
Vol 669 ◽  
pp. 150-157
Author(s):  
Peter Michal ◽  
Alena Vagaská ◽  
Miroslav Gombár
Keyword(s):  
Sodium Chloride ◽  
Chemical Composition ◽  
Oxalic Acid ◽  
Boric Acid ◽  
Oxide Layer ◽  
Surface Finish ◽  
Chemical Factors ◽  
Substrate Sample

Paper tracks experimentally confirmed relationship between chemical composition of electrolyte and resulting surface finish quality of created oxide layer during the process of anodic oxidation of aluminium. Examined chemical factors were: concentrations of sulphuric acid, oxalic acid, boric acid and sodium chloride. Aggressive effects of electrolyte were chosen as indicator of resulting layer quality – presence and extent of etching of used substrate sample.

scholarly journals The Effect of Borax Solution as Preservative to the Mechanical Properties of Bamboo

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
M.A.P Handana ◽  
◽  
Besman Surbakti ◽  
Rahmi Karolina ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Bending Strength ◽  
Environmentally Friendly ◽  
Preservative Solution ◽  
Borax Solution ◽  
Preservative Solutions

The use of borax solution as a preservative in wood and bamboo materials is well known in the community. A borax solution is an environmentally friendly liquid that can dissolve in water, so it is suitable to be used as a preservative within cold or hot soaking techniques. The ability of borax to resist insects and fungus attacks on bamboo has been proven, but the effect of the solution on the strength of bamboo must also be investigated. This study conducts to investigate the effects of borax and its additives as preservative solutions to the mechanical properties of bamboos. The bamboos preservations were conducted by cold conditions of immersion, while the mechanical properties were performed to understand the effects of preservatives. The result of this study indicated that 30% to 50% borax in the preservative solution is sufficient to provide significant increase in strength for compressive strength, tensile strength, and bending strength of bamboo specimen. From this study, the use of borax solution in preserving the bamboos materials improved the quality of bamboos based on its mechanical properties.

Rice Bran/Poly(lactic acid) Composites in Packaging Product

2014 ◽  
Vol 931-932 ◽  
pp. 57-62
Author(s):  
Rapeephun Dangtungee ◽  
Rapeeporn Srisuk ◽  
Suchart Siengchin
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Lactic Acid ◽  
Rice Bran ◽  
Food Packaging ◽  
Pressure Range ◽  
Research Work ◽  
Magnesium Stearate ◽  
Poly Lactic Acid ◽  
Molding Process

This research work was carried out on the production of rice bran/poly (lactic acid) (PLA) composites. The composition during the batch molding process included rice bran, PLA, glycerol, and magnesium stearate (mold released agent). Afterwards, the composition was molded by bio-compression at temperature of 170°C for 5 min, and a pressure range of 50-100 kg/cm3. The result showed that the composition of rice bran, PLA, and glycerol could be used in the formation of food packaging. Also the mechanical properties, such as compressive strength and hardness, were investigated. It could be concluded that the most appropriate formulation of rice bran packaging was 5 phr PLA and 3 phr glycerol and 2 phr magnesium stearate. Moreover, FTIR results indicated the non-toxic nature of this method of food packaging.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

Impact of Plasticizers on Technological Properties of Gypsum

2016 ◽  
Vol 865 ◽  
pp. 130-134 ◽  
Author(s):  
Dušan Dolák ◽  
Karel Dvořák
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Research Work ◽  
High Strength ◽  
Building Industry ◽  
Technological Properties ◽  
Accurate Comparison

Sulphate binders based on gypsum are widely used in building industry. This research work was focused on testing the influence of Melflux plasticizers on the final properties of the gypsum mixture. The aim was to determine the correct concentration of the plasticizer considering workability and improvement of mechanical properties, especially the compressive strength. Different concentrations of plasticizers were tested in mixture of alfa and beta plaster. Each batch was created as paste of normal consistency to create accurate comparison. The results of experiment show significant improvements of mechanical strength of the hardened mixture while maintaining same consistency. This knowledge can be utilized in the design of high-strength sulphate binders.

scholarly journals Mechanical properties and carbon footprint of 3D-printable cement mortars with biochar additions

2020 ◽  
Vol 323 ◽  
pp. 01017
Author(s):  
Devid Falliano ◽  
Dario De Domenico ◽  
Salvatore Quattrocchi ◽  
Paolo Cosenza ◽  
Giuseppe Ricciardi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Research Work ◽  
Point Of View ◽  
Maximum Diameter ◽  
Future Research ◽  
Cement Mortars ◽  
Fresh State ◽  
High Consistency

This contribution focuses on the design and the characterization of innovative mix designs of high consistency mortars with biochar additions in different percentage with respect to the cement weight. Biochar is a by-product material that gives the cementitious mix a sustainable connotation from an environmental point of view. The mix designs presented here are characterized by a good dimensional stability in the fresh state, peculiarity that gives them the possibility to be extruded and so, to be used in automated construction processes. In addition to the mechanical properties (flexural and compressive strength), the assessment of the CO2 emission of representative mixes is presented. Different biochar content and maximum diameter of the aggregate are studied, obtaining interesting indications on these parameters to optimize mechanical properties. Finally, on the basis of the CO2 emission assessment, certain venues for future research work to minimize CO2 emissions are reported.

scholarly journals ОЦІНКА ФАРМАКОЛОГІЧНОЇ ЕФЕКТИВНОСТІ ТРАУМЕЛЮ (AD US.VET) ТА ФОСФОРУ-ГОМАККОРД (AD US.VET) ПРИ БРОНХОПНЕВМОНІЇ СОБАК

2016 ◽  
Vol 18 (2(66)) ◽  
pp. 206-212
Author(s):  
Yu.O. Chubov ◽  
V.Yu. Kushnir
Keyword(s):  
Sodium Chloride ◽  
Research Work ◽  
Control Group ◽  
Control Groups ◽  
East European ◽  
The Third ◽  
Isotonic Sodium Chloride ◽  
Experimental Group ◽  
Tools And Methods

The mucous membrane of the respiratory tract is easily the immediate effects of the environment, while contact with air that is inhaled, so pneumonia is common in dogs. For the treatment of dogs, sick with  catarrhal bronchopneumonia there are a number of tools and methods, but they are not always effective. Moreover, many of these methods have long waiting period of action and significant side effects. Thet is why the purpose of our research  work was to find effective and biologically safe treatment of dogs, sick with catarrhal bronchopneumonia and installation pharmacological effectiveness of complex antihomotoxic preparations Traumel (ad us.vet) and Phosphor-Homakkord (ad us.vet). The material for the study were 40 dogs aged 1 to 3 years old, weighing 34 to 43 kg (German and East-European sheep-dog), sick with acute catarrhal bronchopneumonia. Each animal was subjected to clinical and hematology research. Sick animals were divided in to four groups: ten animals to each group. First and second – control groups, third and fourth – experimental groups. In the first group we used mukaltyn 0.5 g orally twice a day up to recovery, bitsillin 3 50 th. UA / kg once every three days by intramuscular injection, dissolving in 2 ml of isotonic sodium chloride and vitamin B12 1 ml once a day subcutaneously for 10 days. In the second control group instead of bitsillin-3 was used antibiotic combi-kell 1 ml per 10 kg weight of body subcutaneously once every three days up to recover.In the third and fourth groups we used the lymphotropic complex antihomotoxic therapy with using the homeopathic preparations Traumel and Phosphor-Homakkord in conjunction with traditional means. Thus, in the third group was used inside mukaltyn 0.5 g twice a day up to recovery, bitsillin 3 50 th.UA / kg once every three days vnutrishom'yazovo dissolving in 2 ml of isotonic sodium chloride lidasa intradermally 32 IU with 1 ml of 0.5% solution of novocaine 3 days in a row, then 3 times a week, Traumel regional lymphotropic three consecutive days to 1 ml intradermally, then every three days and Phosphor- Homakkord lymphotropic regionally 1 ml 1 every 3 days to recovery . In the fourth experimental group used the same treatment, but instead of bitsillin-3 was used Combi-Kell 1 ml / 10 kg subcutaneously once every three days to recover.The results of our researches show that using of complex anthyhomotoxic therapy is appropriate and therapeutically effective versus conventional therapy.So despite the fact that there are a wide number of preparations and methods for treatment of dogs, sick with catarrhal bronchopneumonia, they are not always effective. As shown by our researches, using of compex anthyhomotoxic lymphotropic with the preparations Traumel and Phosphor-Homakkord reduces the duration and improve the quality of treatment.

scholarly journals COMPARATIVE EVALUATION OF EFFECT OF TWO LIGHT CURING UNITS ON MECHANICAL PROPERTIES OF FILTEK BULK FILL COMPOSITE

2021 ◽  
Vol 9 (02) ◽  
pp. 104-110
Author(s):  
Akshay Punjabi ◽  
◽  
Rahul Rao ◽  
Ashish K. Jain ◽  
Meenakshi Verma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Testing Machine ◽  
Dental Composite ◽  
Light Curing ◽  
Circular Rings ◽  
The Difference ◽  
Diametral Tensile Strength

Context:The quality of light curing units can profoundly influence mechanical properties of dental composite materials. Aim: To compare effect of Woodpecker RTA Mini-S and Elipar Deep Cure-L curing units onmechanical properties (compressive strength, diametral tensile strength and microhardness) of Filtek Bulk-Fill. Methods and Materials: A total of 32 samples of Filtek Bulk Fill composite were divided into 2 equal groups (n=16). 12 samples in each group were fabricated using a tooth shaped mold and 4 in circular rings to test compressive strength, microhardness and diametral tensile strength, respectively. Theblocks were evaluated for the above parameters using Universal Testing Machine and Vickers Microhardness Tester.Independent sample-t test was used in this study (p< 0.05). Results: The results of this study showed that the group of composites cured using Elipar Deep Cure-L curing unit showed better mechanical properties and the difference between the groups was statistically significant for compressive strength and diametral tensile strength (p < 0.05) Conclusion: It was concluded that a curing unit of higher intensity and quality of output used in conjugation with bulk fill composites are likely to give better results.

scholarly journals Effects of Carbonation on the Properties of Concrete

2019 ◽  
pp. 205-214
Author(s):  
Ikumapayi C. M. ◽  
Adeniji A. A. ◽  
Obisesan A. A. ◽  
Odeyemi O. ◽  
Ajayi J. A.
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Water Absorption ◽  
Research Work ◽  
Construction Materials ◽  
Accelerated Carbonation ◽  
Weight Changes ◽  
Carbonation Process

Concrete is one of the reliable, durable, economical and acceptable construction materials among the building and construction stakeholders worldwide. Performance of concrete could be threatened especially reinforced concrete by some processes such as corrosion, sulfate attack among others. Corrosion of reinforcement in reinforced concrete can be induced by carbonation process. Even though carbonation initiates corrosion, it has been gathered that carbonation could still be of immense benefits to building and construction industries if its mechanism of operation is understudied. This research work has therefore investigated the effect of carbonation on some selected mechanical properties of concrete such as compressive strength, flexural strength, water absorption and weight changes. Concrete cubes and beams of M15 grade with 0.5 % water-cement ratio were prepared and subjected to accelerated carbonation. Their compressive strength, flexural strength, water absorption and weight changes were determined in accordance with the relevant standards. The outcomes show that carbonation improves all the mechanical properties investigated. The use of carbonation can be positively explored in reinforced concrete provided there is adequate nominal cover.

scholarly journals Prediction of weldment mechanical properties in GMAW with robot-assisted using fuzzy logic systems

2021 ◽  
Author(s):  
P. Devendran ◽  
P. Ashoka Varthanan
Keyword(s):  
Mechanical Properties ◽  
Membership Function ◽  
Orthogonal Array ◽  
Fuzzy System ◽  
Research Work ◽  
Welding Process ◽  
Rule Base ◽  
Inference System ◽  
Material Characteristics

Abstract Welding operation decides the quality of product standards in all metal work products like automobiles, aerospace vehicles, and many more. The quality of the welding process is more reliable by automating the process with robots. In this research work, the GMAW operation is automated with the “Fanuc Robot Arc mate 100iC/12” robot. The material characteristics such as ultimate tensile strength, hardness, and impact strength of weldments are predicted using a fuzzy system using triangular membership function (TrMF) and trapezoidal membership function (TMF). The simulated results are validated by comparing with experimental work, the experiments are designed using orthogonal array L18, and material characteristics are studied using fractography test. The fuzzy system is trained with experimental results using the IF-Then rule base with the help of the L18 orthogonal array. The inference system has predicted the accuracy rate of weldment mechanical properties, showing a lower error rate.

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