Vortical dissipation in two-dimensional shear flows

An exact expression is derived for the viscous dissipation function of a real homogeneous and isotropic fluid, which has terms associated with the square of vorticity, wave radiation, and dilatation. The implications of the principle of maximal dissipation rate, are explored by means of this equation for a parallel channel flow and a cylindrical vortex flow. The consequences of a condition of maximum dissipation rate on the growth of disturbances in an unsteady, laminar shear layer are apparently consistent with predictions and observations of maximum growth rate of vortical disturbances. Finally, estimates of the magnitudes of several dissipative components of an unsteady vortex flow are obtained from measurements of a periodic wall jet

Extrema principles of entrophy production and energy dissipation in fluid mechanics

A survey is presented of several extrema principles of energy dissipation as applied to problems in fluid mechanics. An exact equation is derived for the dissipation function of a homogeneous, isotropic, Newtonian fluid, with terms associated with irreversible compression or expansion, wave radiation, and the square of the vorticity. By using entropy extrema principles, simple flows such as the incompressible channel flow and the cylindrical vortex are identified as minimal dissipative distributions. The principal notions of stability of parallel shear flows appears to be associated with a maximum dissipation condition. These different conditions are consistent with Prigogine's classification of thermodynamic states into categories of equilibrium, linear nonequilibrium, and nonlinear nonequilibrium thermodynamics; vortices and acoustic waves appear as examples of dissipative structures. The measurements of a typical periodic shear flow, the rectangular wall jet, show that direct measurements of the dissipative terms are possible

SERAT DARMA SONYA (SUNTINGAN TEKS LAN WAWASAN SEMIOTIKA)

Abstrak Naskah Serat Darma Sonya kalebu ing periodisasi Sastra Jawa Anyar, ditulis nganggo aksara Jawa lan nggunakake basa Jawa Anyar. Naskah iki minangka serat pralambang, kang lambang-lambange diwawas nganggo wawasan semiotika. Undherane panliten yaiku: (1) kepriye deskripsi naskah Serat Darma Sonya, (2) kepriye suntingan teks sajrone naskah Serat Darma Sonya, lan (3) kepriye isine naskah Serat Darma Sonya. Salaras karo undherane panliten mau, tujuwan panliten iki yaiku (1) ngandharake deskripsi naskah Serat Darma Sonya, (2) ngandharake suntingan teks sajrone naskah Serat Darma Sonya, lan (3) ngandharake isine naskah Serat Darma Sonya. Paedah saka panliten naskah Serat Darma Sonya yaiku diajab bisaa menehi kawruh ngenani sastra Jawa Anyar kang awujud gancaran, ngerteni deskripsi-ne naskah Serat Darma Sonya, ngerteni suntingan teks naskah Serat Darma Sonya, lan ngerteni wawasan semiotika kang ana ing naskah Serat Darma Sonya iki. Landhesan teori kang dianggo sajrone panliten yaiku teori filologi modern, lan wawasan semiotika. Metodhe panliten kang dianggo yaiku metodhe deskriptif kualitatif lan hermeneutika.Sumber dhata ing panliten iki yaiku naksah Serat Darma Sonya lan dhata saka panliten iki yaiku jinise tandha kang awujud simbol sajrone tetembungan lan ukara kang ana ing teks naskah Serat Darma Sonya. Instrumen panliten kang utama yaiku panliti lan instrumen panyengkuyung pangumpulane dhata yaiku nggunakake kartu cathetan utawa kartu dhata. Teknik pangumpulane dhata disengkuyung karo teknik kartu dhata. Dene teknik pangolahe dhata yaiku naskah ditransliterasikan, deskripsi naskah, mujudake suntingan teks, lan ngolah dhata adhedhasar wawasan semiotika banjur ndudut asile panliten. Asile analisis dhata sajrone panliten yaiku deskripsi naskah, suntingan teks kang dumadi saka 24 teks, lan wawasan semiotika kang awujud simbol. Simbol mau sabanjure ditapsirake miturut wawasane panliti. Tembung wigati: naskah, teks, suntingan, wawasan, filologi, semiotika, tandha. Abstrak Naskah Serat Darma Sonya termasuk dalam periodisasi Sastra Jawa Baru, yang ditulis memakai huruf Jawa dan menggunakan bahasa Jawa Baru. Naskah ini merupakan serat pralambang, dimana lambang-lambang yang terdapat dalam naskah akan dikaji dengan wawasan semiotika. Rumusan masalah dalam penelitian ini,  yaitu (1) bagaimana deskripsi naskah Serat Darma Sonya, (2) bagaimana suntingan teks naskah Serat Darma Sonya, dan (3) bagaimana isi naskah Serat Darma Sonya. Sesuai dengan rumusan masalah penelitian tersebut, maka tujuan penelitian ini yaitu (1) menjelaskan deskripsi naskah Serat Darma Sonya, (2) menjelaskan suntingan teks naskah Serat Darma Sonya, dan (3) menjelaskan isi naskah Serat Darma Sonya. Manfaat dari penelitian naskah Serat Darma Sonya yaitu diharapkan bisa memberi pengetahuan tentang salah satu karya sastra Jawa Baru yang berupa prosa, memahami deskripsi naskah Serat Darma Sonya, memahami suntingan teks naskah Serat Darma Sonya,dan memahami wawasan semiotika yang ada pada naskah Serat Darma Sonyaini. Dasar teori yang digunakan dalam penelitian naskah Serat Darma Sonya yaitu teori filologi modern dan wawasan semiotika. Metode penelitian yang digunakanyaitu metode deskriptif kualitatifdan metode hermeneutika.Sumber data pada penelitian ini yaitu naksahSerat Darma Sonya dan data dari penelitian ini yaitu jenis tanda yang berupa  simbol, yang terdapat pada kata maupun kalimat yang ada dalam teks naskah Serat Darma Sonya. Instrumen penelitian yang utama yaitu peneliti, serta menggunakan kartu catatan atau kartu data sebagai  instrumen pendukungnya. Teknik pengumpulan data didukung oleh teknik kartu data. Sedangkan teknik pengolahan data yaitu dengan cara naskah ditransliterasikan, deskripsi naskah, melakukan suntingan teks, danmengolah databerdasarkan wawasan semiotika lalu memberi kesimpulan atas hasil penelitian. Hasil analisis data yang diperoleh dari penelitian yaitu deskripsi naskah, suntingan teks yang terdiri dari 24 teks, dan wawasan semiotika yang berupa simbol. Simbol ini kemudian ditafsirkan berdasarkan wawasan  peneliti. sebagai sumber pengetahuan dan sumber pelajaran. Kata kunci: naskah, teks, suntingan, wawasan, filologi, semiotika, tanda

Finite Temperature Behavior of Small Silicon and Tin Clusters: An Ab Initio Molecular Dynamics Study

The finite temperature behavior of small Silicon (Si$_{10}$, Si$_{15}$, and Si$_{20}$) and Tin (Sn$_{10}$ and Sn$_{20}$) clusters is studied using isokinetic Born-Oppenheimer molecular dynamics. The lowest equilibrium structures of all the clusters are built upon a highly stable tricapped trigonal prism unit which is seen to play a crucial role in the finite temperature behavior of these clusters. Thermodynamics of small tin clusters (Sn$_{10}$ and Sn$_{20}$) is revisited in light of the recent experiments on tin clusters of sizes 18-21 [G. A. Breaux et. al. Phys. Rev. B {\bf 71} 073410 (2005)]. We have calculated heat capacities using multiple histogram technique for Si$_{10}$, Sn$_{10}$ and Si$_{15}$ clusters. Our calculated specific heat curves have a main peak around 2300 K and 2200 K for Si$_{10}$ and Sn$_{10}$ clusters respectively. However, various other melting indicators such as root mean square bond length fluctuations, mean square displacements show that diffusive motion of atoms within the cluster begins around 650 K. The finite temperature behavior of Si$_{10}$ and Sn$_{10}$ is dominated by isomerization and it is rather difficult to discern the temperature range for transition region. On the other hand, Si$_{15}$ does show a liquid like behavior over a short temperature range followed by the fragmentation observed around 1800 K. Finite temperature behavior of Si$_{20}$ and Sn$_{20}$ show that these clusters do not melt but fragment around 1200 K and 650 K respectively.Comment: 9 figure

Painting the World Crimson: The Global Spread of Graduate Management Education as Facilitated by Harvard Business School

The growth and spread of business education worldwide is a phenomenon of contemporary interest, because it has enabled the expansion of a global managerial class that operates as social and economic elites worldwide in a time of growing inequality. I take a historic approach to this contemporary phenomenon by examining the role that Harvard Business School (HBS) played in the 1950s and 1960s in the conceptualization and launch of the now very prominent Indian Institute of Management (IIM) in Ahmedabad. Using the archival materials at the Special Collections of the Baker Library at Harvard Business School, my research uncovers which players were involved, how they communicated, their concerns, the context in which they were operating, and how they constructed themselves as influential and advanced institutional interests. In my first paper, I examine whether and how meritocracy is invoked or implied as a legitimating aim for elite business education. I use actor-network theory, which I show is well suited for tracing the flows of people and ideas, to track meritocracy, arguing that it is a “non-corporeal actant” that itself moves and changes across international players, settings, and moments. In my second paper, I bring a critical perspective to archives and how they are populated, considering the self-legitimation project as HBS steps into a global role in the spread of graduate management education. I examine the signaling moves in the saved correspondence, in terms of personal connections, decision points, explicitly stated interests, status markers or judgments of others, and reference to competitor institutions. I find that the web of connections among elites is intertwined with Cold War political considerations of HBS administrators. My third paper is an ethnographic case study of the physical spaces, rituals, and processes of the archive at Baker Library and how these serve to legitimate HBS to itself, while using the experience of visiting the archives at MIT containing records of the role of the MIT Sloan School in the formation of the IIM in Calcutta as a comparison. Overall, my dissertation explores an important historic moment when HBS helped set the stage for a global managerial elite

National Information Centre for Fishery Science : a proposal

A brief description of Fisheries in India is given. The users and their in for national needs are discussed. A general plan for the establishment of the National Information Centre for Fishery Science is given

Magic Melters' Have Geometrical Origin

Recent experimental reports bring out extreme size sensitivity in the heat capacities of Gallium and Aluminum clusters. In the present work we report results of our extensive {\it ab initio} molecular dynamical simulations on Ga$_{30}$ and Ga$_{31}$, the pair which has shown rather dramatic size sensitivity. We trace the origin of this size sensitive heat capacities to the relative order in their respective ground state geometries. Such an effect of nature of the ground state on the characteristics of heat capacities is also seen in case of small Gallium and Sodium clusters indicating that the observed size sensitivity is a generic feature of small clusters.Comment: 4 pages, 6 figure

Aeroacoustic and aerodynamic applications of the theory of nonequilibrium thermodynamics

Recent developments in the field of nonequilibrium thermodynamics associated with viscous flows are examined and related to developments to the understanding of specific phenomena in aerodynamics and aeroacoustics. A key element of the nonequilibrium theory is the principle of minimum entropy production rate for steady dissipative processes near equilibrium, and variational calculus is used to apply this principle to several examples of viscous flow. A review of nonequilibrium thermodynamics and its role in fluid motion are presented. Several formulations are presented of the local entropy production rate and the local energy dissipation rate, two quantities that are of central importance to the theory. These expressions and the principle of minimum entropy production rate for steady viscous flows are used to identify parallel-wall channel flow and irrotational flow as having minimally dissipative velocity distributions. Features of irrotational, steady, viscous flow near an airfoil, such as the effect of trailing-edge radius on circulation, are also found to be compatible with the minimum principle. Finally, the minimum principle is used to interpret the stability of infinitesimal and finite amplitude disturbances in an initially laminar, parallel shear flow, with results that are consistent with experiment and linearized hydrodynamic stability theory. These results suggest that a thermodynamic approach may be useful in unifying the understanding of many diverse phenomena in aerodynamics and aeroacoustics