Photon Multiplicity Measurements : From SPS to RHIC and LHC

Results from the photon multiplicity measurements using a fine granularity preshower photon multiplicity detector (PMD) at CERN SPS are discussed. These include study of pseudo-rapidity distributions of photons, scaling of photon multiplicity with number of participating nucleons, centrality dependence of mean transverse momentum of photons, event-by-event fluctuations in photon multiplicity and localised charged-neutral fluctuations. Basic features of the PMD to be used in STAR experiment at RHIC and in ALICE experiment at LHC are also discussed.Comment: 12 pages, Invited talk at the 4th International Conference on the Physcis and Astrophysics of the Quark-Gluon-Plasma, November 2001, Jaipur, India, to appear in Praman

Radiative rates and electron impact excitation rates for transitions in He II

We report calculations of energy levels, radiative rates, collision strengths, and effective collision strengths for transitions among the lowest 25 levels of the n <= 5 configurations of He~II. The general-purpose relativistic atomic structure package (GRASP) and Dirac atomic R-matrix code (DARC) are adopted for the calculations. Radiative rates, oscillator strengths, and line strengths are reported for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among the 25 levels. Furthermore, collision strengths and effective collision strengths are listed for all 300 transitions among the above 25 levels over a wide energy (temperature) range up to 9 Ryd (10**5.4 K). Comparisons are made with earlier available results and the accuracy of the data is assessed.Comment: 30 pages of text including 12 figures and 5 Tables will appear in ATOMS 5 (2017

Event-by-Event Search for Charged Neutral Fluctuations in Pb - Pb Collisions at 158-A-GeV

Results from the analysis of data obtained from the WA98 experiment at the CERN SPS have been presented. Some events have been filtered which show photon excess in limited $\eta-\phi$ zones within the overlap region of the charged particle and photon multiplicity detectors.Comment: 6 pages, 4 figure

Approximation Algorithms for the Max-Buying Problem with Limited Supply

We consider the Max-Buying Problem with Limited Supply, in which there are $n$ items, with $C_i$ copies of each item $i$, and $m$ bidders such that every bidder $b$ has valuation $v_{ib}$ for item $i$. The goal is to find a pricing $p$ and an allocation of items to bidders that maximizes the profit, where every item is allocated to at most $C_i$ bidders, every bidder receives at most one item and if a bidder $b$ receives item $i$ then $p_i \leq v_{ib}$. Briest and Krysta presented a 2-approximation for this problem and Aggarwal et al. presented a 4-approximation for the Price Ladder variant where the pricing must be non-increasing (that is, $p_1 \geq p_2 \geq \cdots \geq p_n$). We present an $e/(e-1)$-approximation for the Max-Buying Problem with Limited Supply and, for every $\varepsilon > 0$, a $(2+\varepsilon)$-approximation for the Price Ladder variant

Quantification of yield gaps in rain-fed rice, wheat, cotton and mustard in India

Rainfed farming / Crop yield / Simulation / Rice / Wheat / Cotton / Mustard / India

An investigation of Fe XV emission lines in solar flare spectra

Previously, large discrepancies have been found between theory and observation for Fe XV emission line ratios in solar flare spectra covering the 224-327 A wavelength range, obtained by the Naval Research Laboratory's S082A instrument on board Skylab. These discrepancies have been attributed to either errors in the adopted atomic data or the presence of additional atomic processes not included in the modelling, such as fluorescence. However our analysis of these plus other S082A flare observations (the latter containing Fe XV transitions between 321-482 A), performed using the most recent Fe XV atomic physics calculations in conjunction with a CHIANTI synthetic flare spectrum, indicate that blending of the lines is primarily responsible for the discrepancies. As a result, most Fe XV lines cannot be employed as electron density diagnostics for solar flares, at least at the spectral resolution of S082A and similar instruments (i.e. ~ 0.1 A). An exception is the intensity ratio I(321.8 A)/I(327.0 A), which appears to provide good estimates of the electron density at this spectral resolution.Comment: 6 pages, 3 figures, Astronomy & Astrophysics, in pres

Age-related decrease in rod bipolar cell density of the human retina: an immunohistochemical study

During normal ageing, the rods (and other neurones) undergo a significant decrease in density in the human retina from the fourth decade of life onward. Since the rods synapse with the rod bipolar cells in the outer plexiform layer, a decline in rod density (mainly due to death) may ultimately cause an associated decline of the neurones which, like the rod bipolar cells, are connected to them. The rod bipolar cells are selectively stained with antibodies to protein kinase C-α. This study examined if rod bipolar cell density changes with ageing of the retina, utilizing donor human eyes (age: 6-91 years). The retinas were fixed and their temporal parts from the macula to the mid-periphery sectioned and processed for protein kinase C-α immunohistochemistry. The density of the immunopositive rod bipolar cells was estimated in the mid-peripheral retina (eccentricity: 3-5 mm) along the horizontal temporal axis. The results show that while there is little change in the density of the rod bipolar cells from 6 to 35 years (2.2%), the decline during the period from 35 to 62 years is about 21% and between seventh and tenth decades, it is approximately 27%

Comparison of open versus laparoscopic appendectomy

Background: Although laparoscopic cholecystectomy has now considered the gold standard for the management of gall stone disease, laparoscopic appendectomy has not attained the same degree of popularity and acceptance. Aim of this study is to assess and compare the role of laparoscopic appendectomy with open appendectomy in acute appendicitis as well as in the patients planned for interval appendectomy.Methods: Total number of fifty cases over the age of 12 years were studied prospectively. Out of 50 number of total cases, 20 cases were those who have been operated laparoscopically while 30 cases were of open appendectomy group. The two groups were compared with respect to operative time, length of hospital stay, post-operative pain and nausea, complication rate and time to return to normal activity.Results: The mean age was 22.8±2(6.83) and 26.7±2(9.22) years in the laparoscopic and open groups respectively, with the range of 14 to 42 in the laparoscopic group and 13 to 50 years in the open group. The Average operating time was more in the laparoscopic appendectomy as compared to the time taken in performing open appendectomy. However, this was not statistically significant with p<0,05. Overall, there was no significant difference in the incidence of complications between open and laparoscopic groups.Conclusions: The laparoscopic appendectomy is safe, simple and efficient technique for treatment of acute appendicitis with result comparable to the open appendectomy, if not better

Малая автоматизация на ЦВМ "Урал-11Б"

Wireless communication technologies like GPRS, UMTS and WLAN, combined with the availability of high-end, affordable mobile devices enable the development of the advanced and innovative mobile services. Devices such as mobile phones and Personal Digital Assistants let the users access a wide range of new offerings whenever and wherever they happen to be. A strategic approach for the quality assurance of these mobile data services should take into account a number of characteristics unique to the mobile paradigm, the increased complexity of emerging handheld devices, the greater sensitivity to security and load related problems in wireless infrastructure and increased complexities of scale. This paper identifies the major factors influencing the development and testing strategies for these applications and accordingly elaborates effective quality assurance principles to ensure productive and scalable mobile data services

Electron Impact Excitation Cross Sections for Hydrogen-Like Ions

We present cross sections for electron-impact-induced transitions n --> n' in hydrogen-like ions C 5+, Ne 9+, Al 12+, and Ar 17+. The cross sections are computed by Coulomb-Born with exchange and normalization (CBE) method for all transitions with n < n' < 7 and by convergent close-coupling (CCC) method for transitions with n 2s and 1s --> 2p are presented as well. The CCC and CBE cross sections agree to better than 10% with each other and with earlier close-coupling results (available for transition 1 --> 2 only). Analytical expression for n --> n' cross sections and semiempirical formulae are discussed.Comment: RevTeX, 5 pages, 13 PostScript figures, submitted to Phys. Rev.