Firms Growth Dynamics, Competition and Power Law Scaling

We study the growth dynamics of the size of manufacturing firms considering competition and normal distribution of competency. We start with the fact that all components of the system struggle with each other for growth as happened in real competitive bussiness world. The detailed quantitative agreement of the theory with empirical results of firms growth based on a large economic database spanning over 20 years is good .Further we find that this basic law of competition leads approximately a power law scaling over a wide range of parameters. The empirical datas are in accordance with present theory rather than a simple power law.Comment: 10 pages, 8 figure

A review of regulatory instruments to control environmental externalities from the transport sector

This study reviews regulatory instruments designed to reduce environmental externalities from the transport sector. The study finds that the main regulatory instruments used in practice are fuel economy standards, vehicle emission standards, and fuel quality standards. Although industrialized countries have introduced all three standards with strong enforcement mechanisms, most developing countries have yet to introduce fuel economy standards. The emission standards introduced by many developing countries to control local air pollutants follow either the European Union or United States standards. Fuel quality standards, particularly for gasoline and diesel, have been introduced in many countries mandating 2 to 10 percent blending of biofuels, 10 to 50 times reduction of sulfur from 1996 levels, and banning lead contents. Although inspection and maintenance programs are in place in both industrialized and developing countries to enforce regulatory standards, these programs have faced several challenges in developing countries due to a lack of resources. The study also highlights several factors affecting the selection of regulatory instruments, such as countries'environmental priorities and institutional capacities.Transport Economics Policy&Planning,Transport and Environment,Energy Production and Transportation,Environmental Economics&Policies,Environment and Energy Efficiency

Fiscal policy instruments for reducing congestion and atmospheric emissions in the transport sector : a review

This paper reviews the literature on the fiscal policy instruments commonly used to reduce transport sector externalities. The findings show that congestion charges would reduce vehicle traffic by 9 to 12 percent and significantly improve environmental quality. The vehicle tax literature suggests that every 1 percent increase in vehicle taxes would reduce vehicle miles by 0.22 to 0.45 percent and CO2 emissions by 0.19 percent. The fuel tax is the most common fiscal policy instrument; however its primary objective is to raise government revenues rather than to reduce emissions and traffic congestion. Although subsidizing public transportation is a commonpractice, reducing emissions has not been the primary objective of such subsidies. Nevertheless, it is shown that transport sector emissions would be higher in the absence of both public transportation subsidies and fuel taxation. Subsidies are also the main policy tool for the promotion of clean fuels and vehicles. Although some studies are very critical of biofuel subsidies, the literature is mostly supportive of clean vehicle subsidies.Transport Economics Policy&Planning,Environmental Economics&Policies,Transport and Environment,Taxation&Subsidies,Transport in Urban Areas

Analysis of melt-textured YBCO with nanoscale inclusions

Recently, particles with the chemical composition Y2Ba 4CuMOx where M U, Nb, Zr, etc., and sizes in the range of 50 - 200 nm have been generated within the YBCO matrix of bulk, melt-processed superconductors in order to serve as effective flux pinning sites. By means of AFM and electron backscatter diffraction (EBSD) measurements, we analyse the spatial distribution and the size distribution of these nanoparticles within the superconducting YBCO matrix

Investigation of grain orientations of melt-textured HTSC with addition of uranium oxide, Y2O3 and Y2BaCuO5

Local grain orientations were studied in melt-textured YBCO samples processed with various amounts of depleted uranuim oxide (DU) and Y 2O3 by means of electron backscatter diffraction (EBSD) analysis. The addition of DU leads to the formation of Ucontaining nanoparticles (Y2Ba4CuUOx) with sizes of around 200 nm, embedded in the superconducting Y-123 matrix. The orientation of the Y 2BaCuO5 (Y-211) particles, which are also present in the YBCO bulk microstructure, is generally random as is the case in other melttextured Y-123 samples. The presence of Y-211 particles, however, also affects the orientation of the Y-123 matrix in these samples

Pengaruh Faktor Lingkungan Fisik Kerja Terhadap Waktu Penyelesaian Pekerjaan:Studi Laboratorium

Lingkungan fisik kerja merupakan bagian dari lingkungan secara keseluruhan, sebab lingkungan fisik kerja adalah salah satu bagian dari 14 (empat belas) asas ilmu lingkungan. Dalam asas kesepuluh menyebutkan bahwa “Pada lingkungan yang stabil, perbandingan antara biomassa dengan produktivitas (B/P) dalam perjalanan waktu akan naik mencapai sebuah asimtot”. Pada asas tersebut dapat diartikan bahwa sistem biologi itu menjalani evolusi yang mengarah pada peningkatan efisiensi penggunaan energi dalam lingkungan fisik yang memungkinkan keanekaragaman berkembang, untuk itu lingkungan fisik jika tidak terkontrol (melebihi Nilai Ambang Batas) akan menjadi penyebab pencemaran lingkungan. Jika hal ini terjadi dalam lingkungan pabrik, perkantoran, dan lain-lain akan memberikan dampak negatif terhadap kemampuan kerja dari para karyawan atau pekerja. Penelitian yang dilakukan adalah meneliti pengaruh faktor lingkungan fisik kerja terhadap waktu penyelesaian pekerjaan (studi laboratorium). Faktor yang diteliti adalah faktor tingkat kebisingan yang diteliti meliputi 3 (tiga) perlakuan, yaitu 50 dB, 85 dB, dan 95 dB, faktor intensitas pencahayaan meliputi 3 (tiga) perlakuan, yaitu 30 lux, 200 lux, dan 350 lux, dan faktor temperatur terdiri dari 3 (tiga) perlakuan, yaitu 200 C, 270 C, dan 350 C. Berdasarkan hasil Anava pada tingkat kepercayaan 95%, faktor utama, yaitu tingkat kebisingan, intensitas pencahayaan, dan temperatur memberikan pengaruh yang signifikans terhadap waktu penyelesaian pekerjaan. Interaksi 2 (dua) faktor, memberikan pengaruh yang signifikans terhadap waktu penyelesaian pekerjaan. Demikian pula pada interaksi 3 (tiga) faktor, memberikan pengaruh yang signifikans terhadap waktu penyelesaian pekerjaan

EBSD characterisation of Y2Ba4CuUOx phase in melttextured YBCO with addition of depleted uranium oxide

Melt-textured YBCO samples processed with added Y2O3 and depleted uranium oxide (DU) contain nano-particles, which have been identified previously as Y2Ba4CuUOx (U-411). This phase has a cubic unit cell, which is clearly distinct from the orthorhombic Y-123 and Y-211 phases within the YBCO system. In samples with a high amount of DU addition (0.8 wt-% DU), U-2411 particles have sizes between 200 nm and several νm, so identification of the Kikuchi patterns of this phase becomes possible. Together with a parallel EDX analysis, the particles embedded in the Y-123 matrix can be identified unambiguously. In this way, a three-phase EBSD scan becomes possible, allowing also the identification of nanometre-sized particles in the sample microstructure