Kinematic Self-Similar Cylindrically Symmetric Solutions

This paper is devoted to find out cylindrically symmetric kinematic self-similar perfect fluid and dust solutions. We study the cylindrically symmetric solutions which admit kinematic self-similar vectors of second, zeroth and infinite kinds, not only for the tilted fluid case but also for the parallel and orthogonal cases. It is found that the parallel case gives contradiction both in perfect fluid and dust cases. The orthogonal perfect fluid case yields a vacuum solution while the orthogonal dust case gives contradiction. It is worth mentioning that the tilted case provides solution both for the perfect as well as dust cases.Comment: 22 pages, accepted for publication in Int. J. of Mod. Phys.

On Physical Properties of Cylindrically Symmetric Self-Similar Solutions

This paper is devoted to discuss some of the features of self-similar solutions of the first kind. We consider the cylindrically symmetric solutions with different homotheties. We are interested in evaluating the quantities acceleration, rotation, expansion, shear, shear invariant and expansion rate. These kinematical quantities are discussed both in co-moving as well as in non-co-moving coordinates (only in radial direction). Finally, we would discuss the singularity feature of these solutions. It is expected that these properties would help in exploring some interesting features of the self-similar solutions.Comment: 16 pages, accepted for publication in Int. J. of Mod. Phys.

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

Analisis Customer Value Index dalam Memilih Atribut Hotel Bintang Dua di Kota Jakarta

Penelitian ini adalah penelitian kuantitatif yang dilaksanakan menggunakan metode konjoin, pengambilan sampel menggunakan metode non probapility purposive sampling. Studi ini didasarkan pada data primer yang dilakukan melalui survey dari 394 konsumen yang pernah menginap di hotel bintang dua di Kota Jakarta. Dalam analisis konjoin ini, mengidentifikasi bahwa hotel bintang dua yang paling diminati oleh konsumen jika memiliki fasilitas jaringan internet gratis di kamar dan di lobby, sarapan gratis, akses gratis untuk layanan kopi dan teh, tersedia layanan penjemputan bandara dengan biaya tambahan, dan harga kamar lebih dari Rp 500.000. Hasil dari penelitian ini menunjukkan bahwa tersedia layanan penjemputan bandara dengan biaya tambahan adalah value driver bagi konsumen dalam memilih hotel bintang dua di Kota Jakarta. Saran dari penelitian ini adalah industri perhotelan di Kota Jakarta dapat membuat hotel bintang dua dengan menyediakan layanan penjemputan bandara dengan biaya tambah dalam pengembangan hotel untuk menghadapi persaingan. Dimana konsumen hotel bintang dua di Kota Jakarta menyukai layanan tersebut ketika membuat keputusan pembelian

Optimizing the regeneration process parameters for forward osmosis to produce clean water at low temperature

One-fifth of the world will face sever water shortage by 2040 as climate change and a growing population pushes up demand. Recently, Qatar water resources are becoming strained and stressed as Qatar only gets seven inches of rain per year. Furthermore, World Resources Institute (WRI) ranked all the countries over the world according to the severity of water crisis and the Middle East was one of the worst regions. Nine countries were considered extremely susceptible and Qatar was ranked as a number 3, after Bahrain and Kuwait. While the country (Qatar) population is growing – as today, 2.5 million residents are forecast to multiply eightfold by 2050. Thermal processes produce more than 90% of desalinated water, where the desalination process is energy intensive, and affecting the environment. The scope of the present work is to develop a process to produce clean water at low operating conditions (temperature Please click Additional Files below to see the full abstract

Phaeanthine and Limacine from Phaeanthus crassipetalus Becc.

Phaeanthus crassipetalus Becc.(Fam: Annonaceae) has been studied. Two major alkaloids have been isolated and characterised based on their spectral information. The alkaloids, phaeanthine (l) and limacine (II), show antibacterial properties against Gram positive and Gram negative bacteria