Contrast Between 1992 and 1997 High Latitude Spring Haloe Observations of Lower Stratospheric HCl

HCl measurements from HALOE in the northern hemisphere during mid-May 1997 revealed vortex fragments in which the chlorine reservoir partitioning was strongly pushed toward HCl (approx. 90% HCl, approx. 10% ClONO2), similar to partitioning previously observed in the Antarctic vortex region. In contrast, observations of ClONO2 and HCl in the northern polar spring, 1992, and in other years, show these species established the balance typical for gas phase photochemical reactions in this region (approx. 60% HCl, approx. 40% ClONO2). Annually, chlorine reservoirs in the winter lower stratosphere polar vortex are converted to chlorine radicals via heterogeneous reactions on particle surfaces at very cold temperatures (less than about 200 K). As temperatures warm in spring, the heterogeneous processes become insignificant compared with gas phase reactions, and the chlorine reservoirs are reformed. Measurements through the northern winter/spring in 1992 show rapid formation of ClONO2, followed by steady loss of ClONO2 and increasing HCl. Although ClONO2 measurements are not available for 1997, the HCl increase in 1997 is observed to be much more rapid and the eventual HCl mixing ratio is about 50% greater than that of 1992. The observations are examined through comparison with the Goddard three-dimensional chemistry and transport model. This model utilizes winds and temperatures from the Goddard Earth Observing System Data Assimilation System and a complete integration scheme for stratospheric photochemistry. Analysis of the evolution of HCl and ClONO2 shows that the observed difference in the overall rate of HCl formation is explained by the sensitivity of the gas-phase chemistry to the ozone mixing ratio and the temperature. The results show that the model accurately simulates HCl and ClONO2 evolution during these two winters. Model validity is further supported by comparisons with O3 and reactive nitrogen species NO and NO2. This analysis provides a sensitive test of the lower stratospheric chlorine photochemistry, particularly because the analysis considers constituent evolution at a time when the HCl and ClONO2 are far from a photochemical stationary state

65/Detektory MOSFET jako narzędzie do weryfikowania dawek terapeutycznych wiązek elektronów w radioterapii

CelZastosowanie detektorów MOSFET (Metal – Oxide Semiconductor Field Effect Transistor) do pomiaru dawki in vivo wiązek elektronów w radioterapii.Metody i materiałyWykonano pomiary fantomowe polegające na zbadaniu zależności wskazań detektorów MOSFET od: – wartości dawki wiązek elektronów, – temperatury otoczenia detektorów, – kierunku padania wiązki elektronów na detektor, – wielkości napromienianego pola.Zbadano także zmianę czułości detektorów w zależności od skumulowanej dawki. Detektory, ze względu na bardzo małe wymiary, umieszczano w odpowiednio zaprojektowanych nakładkach aluminiowych – w celu zapewnienia równowagi elektronowej podczas pomiaru dawki. Wskazania detektorów porównywano do wskazańkomory jonizacyjnej typu Markus, posiadającej świadectwowzorcowania. Pomiary wykonano z użyciem wiązek elektronów o energii 6, 9, 12, 15, 18,21 MeV.WynikiZbadane zależności i określone na ich podstawie współczynniki korekcyjne umożliwiają zmierzyć dawkę wiązki elektronów z dokładnością ±2.5%.WniosekDetektory MOSFET są dobrym narzędziemdo weryfikowania dawki wejściowej w radioterapii wiązkami elektronów

Penentuan Sifat Mekanis dan Fisis Batu Bata dengan Penambahan Arang Tempurung Kelapa Asal Alor

Telah dilakukan penelitian tentang penentuan sifat mekanis dan fisis batu bata dengan penambahan tempurung kelapa asal alor. Penenlitian ini bertujuan mengetahui kualitas batu bata yang memenuhi standar kelayakan sebagai bahan konstruksi dengan penambahan arang tempurung kelapa aal alor dengan presentasi 0%, 5%, 10%, 15% terhadap tanah liat (lempung). Batu bata dicetak dengan prosedur pemadatan, pengringn dan pembakaran. Setelah prosedur pencetakkan selesai kemudian di lanjutkan dengan pengujian sefat mekanis dan sifat fisis, yaitu uji kuat tekan (compression strength), densitas (density), porositas (porosity) hasil  kuat tekan batu bata didapatkan berdasarkan pengujian: a) uji kuat tekan, batu bata tanpa penambahan (0%) : 4,94 meemenuhi standar kuat tekan kelas 50 (SNI 15-2094-2000), b) uji porositas, batu bata 0% dan 5% : 3,82% dan 17,93% memenuhi standar porositas dengan batas maksimum 20% (SNI 15-2094-2000) dan uji densitas, batu bata tidak ada yang memenuhi standar (SII 0021-1978) Kata kunci: sifat mekanis, sifat fisis, tempurung kelapa, densitas, porositas, kuat teka

Structural modification of nanohydroxyapatite Ca10(PO4)6(OH)2 related to Eu3+ and Sr2+ ions doping and its spectroscopic and antimicrobial properties

The Eu3+ and Sr2+ ions co-doped hydroxyapatite nanopowders (Ca10(PO4)6(OH)2) were synthesized via a precipitation method and post heat-treated at 500 °C. The concentration of Eu3+ ions was established in the range of 0.5–5 mol% to investigate the site occupancy preference. The concentration of Sr2+ ions was set at 5 mol%. The structural and morphological properties of the obtained materials were studied by an X-ray powder diffraction, a transmission electron microscopy techniques and infrared spectroscopy. As synthesized nanoparticles were in the range of 11–17 nm and annealed particles were in the range of 20–26 nm. The luminescence properties in dependence of the dopant concentration and applied temperature were investigated. The 5D0 → 7F0 transition shown the abnormally strong intensity for annealed materials connected with the increase of covalency character of Eu3+–O2− bond, which arise as an effect of charge compensation mechanism. The Eu3+ ions occupied three possible crystallographic sites in these materials revealed in emission spectra: one Ca(1) site with C3 symmetry and two Ca(2) sites with Cs symmetry arranged as cis and trans symmetry. The antibacterial properties of Eu3+ and Sr2+ ions doped and co-doped hydroxyapatite nanopowders were also determined against Gram-negative pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. Obtained results suggest that both europium and strontium ions may implement antibacterial properties for hydroxyapatites. In the most cases, better antibacterial effect we noticed for dopants at 5 mol% ratio. However, the effect is strongly species- and strain-dependent feature

Using CO 2 spatial variability to quantify representation errors of satellite CO 2 retrievals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95625/1/grl24793.pd

Pancreatic exocrine insufficiency: a rare cause of nonalcoholic steatohepatitis

This is an electronic version of an Article published in the American Journal of Gastroenterology 2008; 103(1): 245-246.ArticleAmerican journal of gastroenterology. 103(1): 245-246 (2008)journal articl

Cytotoxic Effects of Pistacia khinjuk Seed Extracts on Different Cell Lines and its Mitogenic Effects on Blood Lymphocyte In Vitro

Reports indicated that extract Pistacia khinjuk has anti-inflammatory, antipyretic, antibacterial, and antiviral, in treating of diarrhea and throat infections and has hepatoprotective effects against acetaminophen and carbon tetrachloride. This study was undertaken to investigate the possible cytotoxic effects of methanolic and aqueous seeds extract of P. khinjuk on different tumors (rhabdomyosarcoma [RD] and murine mammary adenocarcinoma [Ahmed-Mohammed-Nahi-2003 (AMN-3)]) and normal cell lines (murine fibroblast) and its mitogenic effects on blood lymphocytes. The cytotoxic effects of P. khinjuk seed extracts were evaluated on two tumor cell lines, RD and murine mammary adenocarcinoma (AMN-3) and one normal cell line, murine fibroblast (L20B). Moreover, the mitogenic effects of the plant extract were studied, on human blood lymphocytes. Both methanolic and aqueous seed extracts of P. khinjuk significantly induced tumor cell lines and the normal cell line proliferation, especially in highest concentrations. The results show that the extracts induced significant increases in human blood lymphocyte proliferation at 72 h. This activity of plant extracts recommends it as a good mitogenic agent in researches; in conclusion, seed extracts of P. khinjuk induced proliferation of all tested cell lines. High concentrations of both aqueous and methanolic seed extracts of P. khinjuk showed mitogenic effects

Fall vortex ozone as a predictor of springtime total ozone at high northern latitudes

Understanding the impact of atmospheric dynamical variability on observed changes in stratospheric O₃ is a key to understanding how O₃ will change with future climate dynamics and trace gas abundances. In this paper we examine the linkage between interannual variability in total column O₃ at northern high latitudes in March and lower-to-mid stratospheric vortex O₃ in the prior November. We find that these two quantities are significantly correlated in the years available from TOMS, SBUV, and POAM data (1978-2004). Additionally, we find that the increase in March O₃ variability from the 1980s to years post-1990 is also seen in the November vortex O₃, i.e., interannual variability in both quantities is much larger in the later years. The cause of this correlation is not clear, however. Interannual variations in March total O₃ are known to correspond closely with variations in winter stratospheric wave driving consistent with the effects of varying residual circulation, temperature, and chemical loss. Variation in November vortex O₃ may also depend on dynamical wave activity, but the dynamics in fall are less variable than in winter and spring. We do not find significant correlations of dynamic indicators for November such as temperature, heat flux, or polar average total O₃ with the November vortex O₃, nor with dynamical indicators later in winter and spring that might lead to a connection to March. We discuss several potential hypotheses for the observed correlation but do not find strong evidence for any considered mechanism. We present the observations as a phenomenon whose understanding may improve our ability to predict the dependence of O₃ on changing dynamics and chemistry