scholarly journals Sintesis Nitroselulosa Dari Serat Rami (Boechmerianivea) Menggunakan Trietilamin

2021 ◽  
Vol 3 (1) ◽  
pp. 21-26
Author(s):  
Riza Rizkiah ◽  
Kenny Kencanawati ◽  
Ahmad Rosidin ◽  
Lingga Wibowo
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Rocket Engine ◽  
Power Source ◽  
Nitrogen Levels ◽  
Boehmeria Nivea ◽  
Activation Procedure ◽  
Kjeldahl Method ◽  
Fiber Plant ◽  
The Many

Nitrocellulose is cellulose that is titrated into an ester polymer which can be used as a major component in several types of ammunition and explosives and other materials. Hemp (Boehmeria nivea) is a type of fiber plant that is rich in cellulose and thrives in Indonesia. Until now, the need for nitrocellulose in Indonesia is still imported, even though there is a lot of potential for cellulose that can be exploited, one of which is by synthesizing nitrocellulose from the hemp plant. One of the many uses of nitrocellulose derivatives, one of which is propellant. The propellant is the fuel or power source of a rocket engine. Nitrocellulose that can be used for propellants is nitrocellulose with levels between 11-13.3% nitrogen. This study aims to produce nitrocellulose in levels that meet the standards for making propellants. The study was carried out with a cellulose activation procedure using 20% ​​sodium hydroxide and 1 ml of triethylamine per gram of cellulose. Cellulose nitration was carried out using sulfuric acid and nitric acid with the composition of A (1: 1), B (2: 1) and C (3: 1) which were refluxed for 3 hours. Nitrogen determination was carried out using the Kjeldahl method. The results showed that from 3 samples A, B, and C, nitrogen levels were obtained respectively 12.62%, 13.23%, and 12.97%. This shows that the nitrocellulose from the hemp plant (Boehmeria nivea) can be used for propellants.  Keywords: Hemp, nitrocellulose, nitration, triethylamine, propellant  

TIMETAL 35A

Alloy Digest ◽  
2001 ◽  
Vol 50 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
High Temperature ◽  
Nitric Acid ◽  
Physical Properties ◽  
Chlorine Dioxide ◽  
Heat Treating ◽  
Bend Strength ◽  
Temperature Performance ◽  
Sodium And Potassium

Abstract Titanium shows outstanding resistance to seawater and marine atmospheres. It is also resistant to attack by hot metallic chloride solutions, sodium and potassium hypochlorite, and chlorine dioxide. The metal is resistant to attack by hot nitric acid at concentrations up to 80% and is not attacked by sulfuric acid. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: TI-122. Producer or source: Timet.

Gallium Arsenide Integrated Circuits Decapsulation Technique Using Mixed Acid Chemistry For Die-Level Failure Analysis

2018 ◽  
Author(s):  
Harold Jeffrey M. Consigo ◽  
Ricardo S. Calanog ◽  
Melissa O. Caseria
Keyword(s):  
Gallium Arsenide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
Mixed Acid ◽  
Optimum Parameters ◽  
Plastic Package ◽  
Fuming Nitric Acid ◽  
Concentrated Sulfuric Acid

Abstract Gallium Arsenide (GaAs) integrated circuits have become popular these days with superior speed/power products that permit the development of systems that otherwise would have made it impossible or impractical to construct using silicon semiconductors. However, failure analysis remains to be very challenging as GaAs material is easily dissolved when it is reacted with fuming nitric acid used during standard decapsulation process. By utilizing enhanced chemical decapsulation technique with mixture of fuming nitric acid and concentrated sulfuric acid at a low temperature backed with statistical analysis, successful plastic package decapsulation happens to be reproducible mainly for die level failure analysis purposes. The paper aims to develop a chemical decapsulation process with optimum parameters needed to successfully decapsulate plastic molded GaAs integrated circuits for die level failure analysis.

The dichotomy between nitration of substituted 1,4-dimethoxybenzenes and formation of corresponding 1,4-benzoquinones by using nitric and sulfuric acid

2000 ◽  
Vol 2000 (3) ◽  
pp. 106-107 ◽  
Author(s):  
C. Waterlot ◽  
B. Haskiak ◽  
D. Couturier
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Oxidative Demethylation

Various alkyl-substituted p-dimethoxybenzenes (ArH) react readily with nitric acid and sulfuric to form nitro-products (ArNO2). When the nitric acid is used in excess, the nitro-product react via either nitration to dinitro-compound (Ar(NO2)2) or via oxidative demethylation to nitro- p-quinone (Q). As such, the competition between the nitration, polynitration and oxidative dealkylation is effectively modulated by the added nitric acid and the alkyl-substituted p-dimethoxybenzenes.

Electronic Warfare: Electrophilic Substitution

Reactions ◽  
2011 ◽  
Author(s):  
Peter Atkins
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Electrophilic Substitution ◽  
Proton Acceptor ◽  
Acid Molecule ◽  
Electronic Warfare ◽  
Hexagonal Ring ◽  
Initial Outcome ◽  
Concentrated Sulfuric Acid ◽  
Electron Clouds

Benzene, 1, is a hard nut to crack. The hexagonal ring of carbon atoms each with one hydrogen atom attached has a much greater stability than its electronic structure, with an alternation of double and single carbon–carbon bonds, might suggest. But for reasons fully understood by chemists, that very alternation, corresponding to a continuous stabilizing cloud of electrons all around the ring, endows the hexagon with great stability and the ring persists unchanged through many reactions. The groups of atoms attached to the ring, though, may come and go, and the reaction type responsible for replacing them is commonly ‘electrophilic substitution’. Whereas the missiles of Reaction 15 sniff out nuclei by responding to their positive electric charge shining through depleted regions of electron clouds, electrophiles, electron lovers, are missiles that do the opposite. They sniff out the denser regions of electron clouds by responding to their negative charge. Let’s suppose you want to make, for purposes you are perhaps unwilling to reveal, some TNT; the initials denote trinitrotoluene. You could start with the common material toluene, which is a benzene ring with a methyl group (–CH3) in place of one H atom, 2. Your task is to replace three of the remaining ring H atoms with nitro groups, –NO2, to achieve 3. And not just any of the H atoms: you need the molecule to have a symmetrical array of these groups because other arrangements are less stable and therefore dangerous. It is known that a mixture of concentrated nitric and sulfuric acids contains the species called the ‘nitronium ion’, NO2+, 4, and this is the reagent you will use. Before we watch the reaction itself, it is instructive to see what happens when concentrated sulfuric acid and nitric acid are mixed. If we stand, suitably protected, in the mixture, we see a sulfuric acid molecule, H2SO4, thrust a proton onto a neighbouring nitric acid molecule, HNO3. (Funnily enough, according to the discussion in Reaction 2, nitric ‘acid’ is now acting as a base, a proton acceptor! I warned you of strange fish in deep waters.) The initial outcome of this transfer is unstable; it spits out an H2O molecule which wanders off into the crowd. We see the result: the formation of a nitronium ion, the agent of nitration and the species that carries out the reaction for you.

Effect of hydrogen ion changes on vascular resistance in isolated artery segments

1964 ◽  
Vol 207 (1) ◽  
pp. 169-172 ◽  
Author(s):  
Oliver Carrier ◽  
Meredith Cowsert ◽  
John Hancock ◽  
Arthur C. Guyton
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Perfusion Pressure ◽  
Control Level ◽  
Linear Increase ◽  
Hydrogen Ion ◽  
Isolated Artery ◽  
Ph Range

Isolated arterial segments, 1 cm in length and 0.5–1.0 mm in diameter, were perfused with Tyrode's solution titrated to various levels of pH. Po2, Pco2, and temperature were held at physiological levels; the perfusion pressure was held at 100 mm Hg, and flow was measured by a drop counter. There was a linear increase in flow as the pH was decreased from 7.4, 0.05 units at a time, with an increase of 87% obtained at pH 7.15. As the pH was further decreased, the flow dropped until at pH 6.8 it leveled off slightly above control level. When the pH was raised, there was an initial 35% decrease in flow by the time pH 7.50 was reached, followed by an increase, reaching 50% above control level at 7.65. At still higher pHs a precipitous decrease in conductance occurred, flow leveling off slightly below control level at pH 7.80. Consistent results were obtained on 45 vessels using Tyrode's solution titrated to the desired pH with lactic acid, hydrochloric acid, acetic acid, sulfuric acid, nitric acid, sodium hydroxides, or sodium bicarbonate. These results indicate that vessels have a very narrow pH range in which they maintain physiological tone.

scholarly journals Effect of Surface Modification with Different Acids on the Functional Groups of AF 5 Catalyst and Its Catalytic Effect on the Atmospheric Leaching of Enargite

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Jahromi ◽  
Ghahreman
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Elemental Sulfur ◽  
Catalytic Properties ◽  
Copper Recovery ◽  
Pre Treatment ◽  
Sulfur Adsorption

Carbon-based catalysts can assist the oxidative leaching of sulfide minerals. Recently, we presented that AF 5 Lewatit® is among the catalysts with superior enargite oxidation capacity and capability to collect elemental sulfur on its surface. Herein, the effect of acid pre-treatment of the AF 5 catalyst was studied on the AF 5 surface, to further enhance the catalytic properties of AF 5. The AF 5 catalyst was pretreated by hydrochloric acid, nitric acid and sulfuric acid. The results showed that the acid treatment drastically changes the surface properties of AF 5. For instance, the concentration of quinone-like functional groups, which are ascribed to the catalytic properties of AF 5, is 45.4% in the sulfuric acid pre-treatment AF 5 and only 29.8% in the hydrochloric acid-treated AF 5. Based on the C 1s X-ray photoelectron spectroscopy (XPS) results the oxygenated carbon is 30.6% in the sulfuric acid-treated AF 5, 29.2% in the nitric acid-treated AF 5 and 28.3% in the hydrochloric acid-treated AF 5. The nitric acid pre-treated AF 5 resulted in the highest copper recovery during the oxidative enargite leaching process, recovering 98.8% of the copper. The sulfuric acid-treated AF 5 recovered 97.1% of the enargite copper into the leach solution. Among different leaching media and pre-treatment the lowest copper recovery was achieved with the HCl pre-treated AF 5 which was 88.6%. The pre-treatment of AF 5 with acids also had modified its elemental sulfur adsorption capacity, where the sulfur adsorption on AF 5 was increased from 30.9% for the HCl treated AF 5 to 51.1% for the sulfuric acid-treated AF 5.

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