3,761 research outputs found
On the expected diameter, width, and complexity of a stochastic convex-hull
We investigate several computational problems related to the stochastic
convex hull (SCH). Given a stochastic dataset consisting of points in
each of which has an existence probability, a SCH refers to the
convex hull of a realization of the dataset, i.e., a random sample including
each point with its existence probability. We are interested in computing
certain expected statistics of a SCH, including diameter, width, and
combinatorial complexity. For diameter, we establish the first deterministic
1.633-approximation algorithm with a time complexity polynomial in both and
. For width, two approximation algorithms are provided: a deterministic
-approximation running in time, and a fully
polynomial-time randomized approximation scheme (FPRAS). For combinatorial
complexity, we propose an exact -time algorithm. Our solutions exploit
many geometric insights in Euclidean space, some of which might be of
independent interest
Pengaruh Lama Fermentasi terhadap Kadar Bioetanol dari Fermentasi Glukosa Hasil Hidrolisis Selulosa Tandan Kosong Kelapa Sawit( Elaeis Guineensis Jack ) dengan Hcl 30% Menggunakan Ragi Roti
Telah dilakukan penelitian pengaruh lama fermentasi terhadap kadar bioetanol dari fermentasi glukosa hasil hidrolisis selulosa tandan kosong kelapa sawit ( Elaeis guineensis Jack ) dengan HCl 30% dengan menggunakan ragi roti. Dari penelitian yang telah dilakukan diperoleh bahwa tandan kosong kelapa sawit mengandung selulosa sebesar 24,1298%. Selulosa diisolasi dari tandan kosong kelapa sawit yang kemudian dihidrolisis dengan HCl 30% untuk menghasilkan glukosa yang kadarnya dianalisa dengan metode Nelson-Somogyi dimana kadar glukosa yang diperolah sebesar 17,1051%. Fermentasi glukosa menggunakan variasi lama fermentasi 2 hari, 4 hari dan 6 hari dengan penambahan ragi roti 6 g. Kadar bioetanol dianalisa dengan titrasi volumetrik menggunakan metode oksidasi kalium dikromat. Dari hasil penelitian didapatkan bahwa kadar etanol tertinggi yaitu 7,3922 % yang diperoleh pada lama fermentasi 6 hari dan penambahan ragi roti 6 gram
The diffuse X-ray spectrum from 14-200 keV as measured on OSO-5
The measurement of energy spectrum of the diffuse component of cosmic X-ray flux made on the OSO-5 spacecraft is described. The contributions to the total counting rate of the actively shielded X-ray detector are considered in some detail and the techniques used to eliminate the non-cosmic components are described. Positive values for the cosmic flux are obtained in seven energy channels between 14 and 200 keV and two upper limits are obtained between 200 and 254 keV. The results can be fitted by a power law spectrum. A critical comparison is made with the OSO-3 results. Conclusions show that the reported break in the energy spectrum at 40 keV is probably produced by an erroneous correction for the radioactivity induced in the detector on each passage through the intense charged particle fluxes in the South Atlantic anomaly
Recovery of Niobium and Tantalum from Low Grade Tin Slag - A Hydrometallurgical Approach
.Niobium and tantalum are known to co-occur with cassiterite deposits.During the process of extraction of tin by cassiterite smelting, these metals join the slag phase and the slag is processed for the recovery of niobium
and tantalum. The processed slag rich in niobium and tantalum is digested with hydrofluric acid, and subjected to solvent extraction for the removal of additional impurities as well as for the separation of niobium
and tantalum. This paper reports on the upgradation of tin slag typically containing 3.4% Nb205 and 3.0% Ta205 by a combination of chemical treatments. In the process, unwanted associations in the slag viz. alumina, silica,
calcia, iron oxide etc., are selectively solubilized by a sequential treatment with alkali and acid leaching leaving a residue containing 10.6% Nb205 and 10.4% Ta205 with a recovery of 86.5 and 95.5% respectively. The product represents an enrichment of about 3.24 times and was found
to be suitable for the extraction of niobium and tantalum by HF-H2SO4 dissolution
Does R&D Intensity and Innovative Activities drive Indian Pharmaceutical Exports?
664-666R&D intensity is critical to the growth of hi-tech sectors like pharmaceuticals and information technology and is aimed at boosting innovation. In turn, innovation brings new products that could earn revenues to further boost R&D intensity1. Indian pharmaceutical industry earns nearly sixty percent of its revenues from exports and is a leader in global generics market with largest share of ANDA and DMF filings. Significant increase in patenting activity is also observed post India’s accession to TRIPS agreement in 1995 and subsequent introduction of Product Patent Regime in 20052. This study aims at establishing a causal relationship amongst R&D intensity, patents, regulatory filings and export intensity. Also, the impact of these variables on export intensity of Indian Pharmaceutical sector has been studied by fitting them into an econometric model
Does R&D Intensity and Innovative Activities drive Indian Pharmaceutical Exports?
664-666R&D intensity is critical to the growth of hi-tech sectors like pharmaceuticals and information technology and is aimed at boosting innovation. In turn, innovation brings new products that could earn revenues to further boost R&D intensity1. Indian pharmaceutical industry earns nearly sixty percent of its revenues from exports and is a leader in global generics market with largest share of ANDA and DMF filings. Significant increase in patenting activity is also observed post India’s accession to TRIPS agreement in 1995 and subsequent introduction of Product Patent Regime in 20052. This study aims at establishing a causal relationship amongst R&D intensity, patents, regulatory filings and export intensity. Also, the impact of these variables on export intensity of Indian Pharmaceutical sector has been studied by fitting them into an econometric model
Production of Ferromolybdenum from Indian Resources
In India, the resources of molybdenum are limited - primary sources are very low grade molysulphide deposits, molybdenum in low concentration co-occurs with copper and uranium deposits, processing of such deposits for copper and uranium yields small quantities of low grade molysulphide concentrate. Besides these, some quantities of molybdenum scrap andmolybdenum bearing effluents are generated as secondary sources in the countrv. This paper is concerned with the development of processes for
treating these indigenous sources. Thefirst part of the paper describes the chemical processes for preparing pure compounds of molybdenum which could be utilized as starting materials for various metallurgical products
of molybdenum. The second part of the paper deals with the production of ferroma! bdenum using these molybdenum intermediate compounds
Identification of miR-379/miR-656 (C14MC) cluster downregulation and associated epigenetic and transcription regulatory mechanism in oligodendrogliomas
Introduction
Although role of individual microRNAs (miRNAs) in the pathogenesis of gliomas has been well studied, their role as a clustered remains unexplored in gliomas.
Methods
In this study, we performed the expression analysis of miR-379/miR-656 miRNA-cluster (C14MC) in oligodendrogliomas (ODGs) and also investigated the mechanism underlying modulation of this cluster.
Results
We identified significant downregulation of majority of the miRNAs from this cluster in ODGs. Further data from The Cancer Genome Atlas (TCGA) also confirmed the global downregulation of C14MC. Furthermore, we observed that its regulation is maintained by transcription factor MEF2. In addition, epigenetic machinery involving DNA and histone-methylation are also involved in its regulation, which is acting independently or in synergy. The post- transcriptionally regulatory network of this cluster showed enrichment of key cancer-related biological processes such as cell adhesion and migration. Also, there was enrichment of several cancer related pathways viz PIK3 signaling pathway and glioma pathways. Survival analysis demonstrated association of C14MC (miR-487b and miR-409-3p) with poor progression free survival in ODGs.
Conclusion
Our work demonstrates tumor-suppressive role of C14MC and its role in pathogenesis of ODGs and therefore could be relevant for the development of new therapeutic strategies
Precise time and frequency intercomparison between NPL, India and PTB, Federal Republic of Germany via satellite symphonie-1
A time and frequency intercomparison experiment conducted using Earth stations in New Delhi, India and Raisting, FRG is described. The NPL clock was placed at New Delhi Earth Station and the Raisting Clock was calibrated with PTB/Primary standard via LORAN-C and travelling clocks. The random uncertainity of time comparisons, represented by two sample Allan Variance sigma (30 seconds), was less than 10 nanoseconds. The relative frequency difference between the NPL and Raisting Clocks, SNPL, RAIS, as measured over the 44 days period was found to be -15.7 x 10 to the -13th power. The relative frequency difference between PTB Primary Standard and Raisting Clock, SPTB, RAIS, during this period, was measured to be -22.8 x 10 to the -13th power. The relative frequency difference between NPL clock and PTB Primary Standard, SNPL, PTB, thus, is +7.1 x 10 to the -13th power. The clock rate (UTC, India) of +7.1 + or - 0.5 x 10 to the -13th power, agrees well with that obtained via VLF phase measurements over one year period and with USNO travelling clock time comparisons made in September, 1980
Documentation of the data analysis system for the gamma ray monitor aboard OSO-H
The programming system is presented which was developed to prepare the data from the gamma ray monitor on OSO-7 for scientific analysis. The detector, data, and objectives are described in detail. Programs presented include; FEEDER, PASS-1, CAL1, CAL2, PASS-3, Van Allen Belt Predict Program, Computation Center Plot Routine, and Response Function Programs
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