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Basics in Foundation Engineering
Published in Chong Tang, Kok-Kwang Phoon, Model Uncertainties in Foundation Design, 2021
The RLT might be a good and economical alternative for the SLT on piles. One example of this test method is the Statnamic (Janes et al. 1991). Statnamic testing was conceived in 1985, and the first prototype test was performed in 1988 (Middendorp et al. 1992). The Statnamic loading system is essentially a rocket engine equipped with a heavy reaction mass that does not require an independent reaction system. The way in which Statnamic testing works can be described as follows. The rocket engine is fired by burning the fuel in a closed burning chamber to launch the reaction mass. The inertia of the reaction mass creates the load applied on the pile head. After some time, the load decreases quickly because of the increased volume of the burning chamber (the mass moves up) and the exhaustion of the rocket fuel (Hölscher and van Tol 2009). The duration of loading is about 100–200 milliseconds, five to twenty times longer than the time for a pile-driving impact. For this reason, Statnamic testing is a long duration impulse method. Guidance on the axial RLT is given in ASTM D7383 (2019).
Reaction Engineering of Step-Growth Polymerization
Published in Anil Kumar, Rakesh K. Gupta, Fundamentals of Polymer Engineering, 2018
However, if the condensation product is flashing, there will be a vapor–liquid equilibrium within the reactor. For simplicity, it is assumed that the reaction mass is a binary mixture consisting of the polymer and condensation product. Their mole fractions, xp and xw, are given by () xp=λ0λ0+[W] () xw=1−xp
The Sun
Published in Roger Messenger, Homayoon “Amir” Abtahi, Photovoltaic Systems Engineering, 2017
Roger Messenger, Homayoon “Amir” Abtahi
The Sun is composed of a mixture of gases with a predominance of hydrogen. As the Sun converts hydrogen to helium in a massive thermonuclear fusion reaction, mass is converted to energy according to Einstein’s famous formula, E = mc2. As a result of this reaction, the surface of the Sun is maintained at a temperature of approximately 5800 K. This energy is radiated away from the Sun uniformly in all directions, in close agreement with Planck’s blackbody radiation formula. The energy density per unit area, wλ, as a function of wavelength, λ, is given by wλ=2πhc2λ−5e(hc/λkT)−1(W/m2/unit wavelength in meters), where h = 6.63 × 10−34 W s2 (Planck’s constant), c = 3.00 × 108 m/s (speed of light in a vacuum), k = 1.38 × 10−23 J/K (Boltzmann’s constant), and T = absolute temperature of blackbody in K (Kelvin, where 0 K = −273.16°C).
Neural network-based prediction of ground time history responses
Published in European Journal of Environmental and Civil Engineering, 2020
Ismail Derbal, Nouredine Bourahla, Ahmed Mebarki, Ramdane Bahar
The purpose of the ANN is to predict the expected response signal Afj(t) at each location Ptj (field response), see Figures 6–7. The operational procedure is as follows:The response signals obtained by numerical simulation are the target time history signals. They are calculated by Finite Element Method simulation and denoted AfFE(t), so that AfFE,j(t) holds for the field signal at the j-th spot location. The set of target signals for each pair (source signal, distance Dj from the source to the j-th field location) is stored as the ANN database.The ANN output is the predicted acceleration response time history at any distance Dj from the reaction mass. The response signal predicted by the ANN is denoted AfNN(t), so that AfNN,j(t) holds for the predicted field signal at the j-th spot location. In practice, this response signal AfNN,j(t) is compared to the target signal AfFE,j(t) for each j-th spot location (j = 1 up to Np) at each time step ti, for each pair (A(t): source signal, Dj: distance to the field).
One-pot PEG-mediated syntheses of 2-(2-hydrazinyl) thiazole derivatives: novel route
Published in Journal of Sulfur Chemistry, 2018
Dattatraya G. Raut, Raghunath B. Bhosale
Aequimolar mixture of substituted acetophenone (3 mmol), thiosemicarbazide (3 mmol), and glacial acetic acid 2–3 drops in PEG-300 (20 mL) was heated at 70–75°C for 1.0–1.5 h. Then the substituted α-haloketones (3 mmol) were added slowly, and the product was precipitated within 5–10 min. The reaction mass was heated for 15 min more. The progress of reaction is monitored by TLC. The reaction mass was then cooled and poured into ice water, and the crude product was recrystallized from ethanol to give title compounds (4a–s).
Comparative study of ultrasound pretreatment method with conventional hydrodistillation method for extraction of essential oil from Piper betle L. (Paan)
Published in Indian Chemical Engineer, 2022
Nilesh L. Jadhav, Pravin A. Garule, Dipak V. Pinjari
The Clevenger distillation apparatus was used for the extraction of essential oil from the betel leaf. It consists of 1-l round bottom flask (RBF) equipped with condenser and distillation head fixed on heating mantle. The RBF was filled with 100 g of grinded betel leaves and 0.5 l of water (L/W ratio of 1:5). Reaction mass was refluxed for 3 h. The extracted liquid was collected in receiver tube. The yield of essential oil was calculated using Equation (1).