INTRODUCTION:Pattern of leukemia is known to vary widely throughout the world. The characterization of distribution patterns of different subtypes of leukemia in Nepal needs further study. We wanted to study the leukemia pattern in our institute.METHODS:A retrospective study of 196 cases of leukemia, diagnosed at BPKIHS, between January 1997 to December 2002 was done. We analyzed the pattern of leukemia at BPKIHS by morphological subtype, gender, age at diagnosis, time period of diagnosis (seasonality), and geographic distribution.RESULTS:Morphological sub typing showed that 121 cases were of acute leukemia and 75 of chronic leukemia. Chronic myeloid leukemia constituted the single largest group comprising 35.2 % of all cases, followed by acute myeloid leukemia (28.57 %) and acute lymphoid leukemia (19.9 %). Maximum numbers of cases were from the lowlands while least number of cases were from the mountain districts. Results were compared with literature from Nepal and other countries. This is the second series of leukemia from Nepal.CONCLUSIONS:The data published in this study reflects the leukemia pattern in the eastern region of Nepal. The pattern and distribution of AML, CML, ALL was similar to that in the developed western countries while the lesser frequency of CLL was similar to that in Southeast Asian regionKey Words:leukemia, pattern, eastern Nepal, seasonality.

The passivation behavior of the sputter-deposited amorphous or/and nanocrystalline W-Ni alloys is studied in different concentrations of NaOH solutions at 25°C, open to air using corrosion tests, electrochemical measurements and confocal scanning laser microscopic (CSLM) techniques. The corrosion rates of the W-Ni alloys containing about 60-80 at% nickel are nearly two orders of magnitude lower than that of tungsten and even lower than that of nickel metal in 1 M NaOH solution at 25°C. The pitting corrosion is observed in the tungsten-rich W-9Ni alloy from CSLM studies. The open circuit potentials of all the examined W-Ni alloys are located between those of tungsten and nickel metals in 0.01, 0.1 and 1 M NaOH solutions. The stability of the passive films formed on the sputter-deposited W-Ni alloys increased with decreasing the concentrations of NaOH solutions. DOI: 10.3126/jncs.v22i0.517Journal of Nepal Chemical Society Vol. 22, 2007 pp. 7-16

The role of alloying elements on the passivity of the sputter−deposited amorphous or nanocrystalline W−xCr−yNi alloys in 12 M HCl, 0.5 M NaCl and 1 M NaOH solutions open to air at 30°C was studied by corrosion tests and electrochemical measurements. All the examined sputter-deposited W-(42-75)Cr-(4-15)Ni alloys, which are composed of either amorphous or nanocrystalline single phase solid solution, showed higher corrosion resistance than those of alloying elements (i.e. tungsten, chromium and nickel) in 12 M HCl, 0.5 M NaCl and 1 M NaOH solutions. All the alloys used in this study showed higher corrosion resistance than those of the alloying elements in the aggressive environments. Anodic current densities of the alloys decreased with increasing chromium contents and became lower than that of chromium. Transpassive dissolution of chromium was significantly enhanced by the simultaneous additions of tungsten, chromium and nickel in aggressive environments of 12 M HCl, 0.5 M NaCl and 1 M NaOH. Hence the synergistic effect of chromium addition in enhancing the corrosion resistance of the W-xCr-yNi alloys was clearly observed from the present study.

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Aviation turbine fuel is a mixture of various hydrocarbons and additives. Some fuel-soluble chemicals are added in small amounts to enhance or to maintain the properties related to fuel performance. In the present study, the influence of microbes on corrosion in aviation turbine fuel transporting pipeline is reported. Chemical and biological analyses of the corrosion product collected from aviation turbine fuel pipeline were carried out. While examining the topography of the pipeline, the possibilities of some water stagnant points were noticed. The reason for the corrosion in the aviation turbine fuel transporting pipeline is investigated and discussed.