Dynamic Optimization of Autocatalytic Esterification in Semi Batch Reactor using Orthogonal Collocation and Control Vector Parameterization Method

Catalyzed Esterification of Propionic Anhydride with 2-Butanol is commonly applied in semi batch reactors where the process variables undergo significant changes during the duration of the batch. In this semi batch operation, there is no steady state and thus no constant setpoints around which the key variables can be regulated

Pendugaan Kedalaman Air Tanah Menggunakan Metode Geolistrik Konfigurasi Schlumberger Di Desa Bojongsari, Kecamatan Alian, Kabupaten Kebumen

Pendugaan kedalaman air tanah di Desa Bojongsari, Kecamatan Alian, Kabupaten Kebumen menggunakan metode Geolistrik konfigurasi Schlumberger telah dilaksanakan pada tanggal 9 Oktober 2015. Pengukuran geolistrik dilaksanakan dengan cara menginjeksikan arus listrik ke dalam bumi dan mengukur beda potensial yang terjadi di tiga titik lokasi yaitu Bojongsari 01, Bojongsari 02, dan Bojongsari 03. Pengolahan data dan pemodelan dilakukan hingga diperoleh data resistivitas yang merepresentasikan jenis-jenis lapisan batuan bawah permukaan di daerah penelitian. Pada titik Bojongsari 01 lapisan akuiferair tanah dangkal diperkirakan tersusun atas pasir berbutir halus (0,85 Wm) dengan kedalaman 7,35–10,78 m dan lempung pasiran (13,25 Wm) dengan kedalaman 10,78–29,44 m, sedangkan lapisanakuifer dalam tersusun atas pasir berbutir halus (0,44 Wm) pada kedalaman 33,72 – 85,76 m. Pada titik Bojongsari 02 lapisan akuifer dangkal diperkirakan tersusun atas lempung pasiran (19,43 Wm) pada kedalaman 7,61–26,65 m dan pasir lempungan (3,18 Wm) pada kedalaman 26,65–43,32 m, sedangkan lapisan akuifer dalam tersusun atas pasir lempungan (5,97 Wm) pada kedalaman 53,94 m. Pada titik Bojongsari 03 lapisan akuifer dangkal diperkirakan tersusun atas pasir berbutir halus (1,18 Wm) dengan kedalaman 11,28–38,25 m, sedangkan lapisan akuifer dalam tersusun atas lempungpasiran berbutir kasar (28,02 Wm) dengan kedalaman 77,25 m. Berdasarkan hasil pemodelan di atas, lapisan akuifer yang diperkirakan paling cocok dimanfaatkan untuk proyek pengadaan air bersih di Desa Bojongsari, Kecamatan Alian, Kabupaten Kebumen adalah lapisan akuiferair tanah dalam untuk titik Bojongsari 01

Kinematic Self-Similar Plane Symmetric Solutions

This paper is devoted to classify the most general plane symmetric spacetimes according to kinematic self-similar perfect fluid and dust solutions. We provide a classification of the kinematic self-similarity of the first, second, zeroth and infinite kinds with different equations of state, where the self-similar vector is not only tilted but also orthogonal and parallel to the fluid flow. This scheme of classification yields twenty four plane symmetric kinematic self-similar solutions. Some of these solutions turn out to be vacuum. These solutions can be matched with the already classified plane symmetric solutions under particular coordinate transformations. As a result, these reduce to sixteen independent plane symmetric kinematic self-similar solutions.Comment: 29 pages, accepted for publication in Classical Quantum Gravit

Jost Function for Singular Potentials

An exact method for direct calculation of the Jost function and Jost solutions for a repulsive singular potential is presented. Within this method the Schrodinger equation is replaced by an equivalent system of linear first-order differential equations, which after complex rotation, can easily be solved numerically. The Jost function can be obtained to any desired accuracy for all complex momenta of physical interest, including the spectral points corresponding to bound and resonant states. The method can also be used in the complex angular-momentum plane to calculate the Regge trajectories. The effectiveness of the method is demonstrated using the Lennard-Jones (12,6) potential. The spectral properties of the realistic inter-atomic He4-He4 potentials HFDHE2 and HFD-B of Aziz and collaborators are also investigated.Comment: 12 pages, latex, 2 eps-figures, submitted to Phys.Rev.

Comparative study on the accelerated thermal aging behavior between palm and rapeseed natural ester oils

The suitability of natural ester oils as an insulating medium in power transformers is discussed in this paper. Owing to environmental concerns, natural ester oils have great potential as mineral oil substitutes in power transformers. In this paper, the aging behaviors of palm and rapeseed natural ester oils were compared with that for mineral oil. The performance of these natural ester oils was assessed based on their properties (moisture content, acidity, and relative content of dissolved decay products) after accelerated thermal aging. The results showed that the palm oil has better performance compared to the rapeseed oil after accelerated thermal aging for 1500 h because of its lower acidity. This was further supported by the presence of sludge in the rapeseed oil after 1500 h of aging

Online Dynamic Optimization of Feed Flowrate and Temperature Trajectories in Semi Batch Esterification Reactor

In semi batch esterification process, an operating feed flowrate and temperature reactor has a significant effect on conversion that determines final product quality

Optimization of corrosion inhibition of essential oils of Alpinia galanga on mild steel using Response Surface Methodology

The use of plant extracts as corrosion inhibitors has gained prominence as replacement for synthetic organic compounds. The plant natural products have been found to be effective, cheap and eco-friendly anticorrosion agents. Corrosion inhibitions of essential oils of Alpinia galanga were investigated on mild steel in hydrochloric acid solution using weight loss method. The interactive effects of inhibitor concentration, temperature and time were optimized for maximum response of inhibition efficiency using Response Surface Methodology with Central Composite Design. The optimum inhibition efficiency of 88.5% at 775 ppm of inhibitor concentration, temperature of 320.4 K and reaction time of 3.75 hours was accomplished. The effectiveness of the inhibitor was also supported using scanning electron microscopy. The mechanism of interaction of both the inhibitor on mild steel surface was found to conform to the Langmuir adsorption isotherm

p53 and PCNA expression in benign, atypical and malignant meningiomas

Objective: Alterations: p53 genes are turning out to be the most common genetic alterations in human cancers. Due to long half-life of mutated p53, its detection is possible by immunohistochemistry. Proliferating cell nuclear antigen (PCNA) is expressed by dividing cells, hence has been shown to correlate with prognosis. We have used monoclonal antibodies protein DO-7 (p53) and PC10 (PCNA) to see whether their expression correlates with histological grading in meningethelial tumour.Material and Methods: a Twenty nine meningiomas (20 benign, 7 atypical and 2 malignant) were selected from the records of our laboratory. p53 and PCNA expression was sought by immunohistochemistry using Peroxidase Anti Peroxidase (PAP) technique.Results: Four benign and 2 atypical meningiomas showed weak staining for p53. Both malignant meningiomas showed strong positivity for p53. Six benign meningiomas had less than 5% PCNA positivity, one 10% positivity and three showed 20% positivity. PCNA positivity ranged for 10-80% in atypical meningiomas. In two malignant meningiomas PCNA positivity was 70% and 90%.Conclusion: It is worthwhile to include p53 and PCNA expression along with histologic assessment in predicting outcome of meningiomas. A larger series with complete follow-up is essential in assessing value of these markers which unfortunately remains a dream in our country