Laws of thermodynamics

Ciminelli and Osseo-Asare, 1995; Lowson, 1982). Anderson (1951) reported 26 kJ/mol in the study of oxidation kinetics of galena (PbS) while Stenhouse and Armstrong (1952) reported an activation energy of 20 kJ/mol for the alkaline oxidation of pyrite. Koslides and Ciminelli (1992) suggested that during alkaline oxidation of sulphides, there is a change from chemical (activation energy > 40 kJ/mol) to diffusion (activation energy < 40 kJ/mol) control as the rate determining step when…

Abstract In this study equilibrium isotherms, kinetics and thermodynamics of ciprofloxacin on seven sediments in a batch sorption process were examined. The effects of contact time, initial ciprofloxacin concentration, temperature and ionic strength on the sorption process were studied. The Kd parameter from Linear sorption model was determined by linear regression analysis, while the Freundlich and Dubinin–Radushkevich (D–R) sorption models were applied to describe the equilibrium isotherms by…

Symmetry Writing Exercise Paragraph 1 The research paper written by J. Haines, O. Cambon and S. Hull aims to understand how Iron III phosphate (FEPO4) behaves under high temperatures and at which temperature would we start to observe structural transition of Iron III phosphate. As found by the researchers, the temperature where one is able to witness a structural change of Iron III phosphate, a transition from α-β would be at the temperature of 980K. As the researchers have highlighted, there…

INTRODUCTION: Exercise 3.1 - Osmosis: Toward the start of lab, we found out about diffusion which can happen as active transport or passive transport. Diffusion is known as delivering a net development of solute particles from locales of higher focus to districts of lower concentration. Active transport is the development of an atom over the plasma layer. Active transport is when atoms move against their focus slopes. We discovered that dynamic transport requires vitality, and the motivation…

3.2 N2O decomposition over Cs-doped Cu50Ce50Ox catalysts Fig.8. Conversion of N2O over different Cs-doped Cu50Ce50Ox catalysts Conditions: 2600 ppm N2O, balance He, 0.3 Mpa, GHSV-19,000 h-1. Fig.9. The T50 and T100 of different Cs-doped Cu50Ce50Ox catalysts The activities of the catalysts with different Cs content for N2O decomposition are shown in Fig.8, and the T50 and T100 (the temperature at which 50% and 100% conversion of N2O decomposition is achieved) are shown in Fig.9. It’s found…

2.2. Instrumentation The residual concentration of metal ion in the filtrate were analyzed by GBC, Sensaa Series Atomic Absorption Spectrometry (computerized AAS) with air-acetylene flame under the optimum instrumental conditions as shown in (Table 1). The solution pH was measured using digital pH meter (Hanna instrument model HI 8519, Italy). Fourier transform infrared (FT-IR) spectra were measured on Nicolet is 10 FTIR spectrometer in the range of (4000 to 400 cm-1). Scanning electron…

Mathematical model Heat and mass transfer properties of counter flow wet cooling tower are obtained through the balance of mass and energy equations. The assumptions made for deriving the governing equations are listed below [14, 15]: • Heat and mass transfer take place only normal to the flow direction. • Heat transfer to the environment through the walls are negligible. • Heat transfer from cooling-tower fan is negligible. • Specific heats of water and dry air are constant. • Heat and mass…

1. Insulator is a material that does not transmit heat, sound or electricity from one end to another. It hinders the free flow of electrons from atom to atom and molecule to molecule. This is because the electrons are tightly bond to the atoms leaving no space for there to be any free electrons to transmit electrical energy. Examples of insulators are glass, rubber, wood and paper. Conductor is an object or type of material that can transmit heat, sound, light or electricity. It does this by…

Abstract The paper present the investigation on the effect of temperature, time and current density on surface roughness in electropolishing process on 316L stainless steel. The cathode material under study was 316L stainless steel. The electrolyte was composed of sulfuric acid, phosphoric acid, and DI water. Full factorial design method was used. ANNOVA technique has been used to assess the quantitative influence of the different process factors of the EP. The surface roughness will be…

6. The first step in metabolism of ethanol in humans is the oxidation of ethanol to acetyldehyde by the enzyme alcohol dehydrogenase (ADH). At 298 K and pH=7.0, ethanol is incubated with ADH and the concentration of ethanol and acetyldehydee is measured over time. a. Using the results above, calculate the standard free energy change (ΔGº’) for this reaction. Explain your calculations. The standard free energy change can be expressed through the formula ΔGº’=-R(gas constant) T(temp in Kelvin)…