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The present work is undertaken to investigate the aerosol volume and mass size distribution, concentration of Particulate Matter (PM) and its source apportionment by using GRIMM spectrometer data in the city of Peshawar, Northern Pakistan. In Peshawar, the concentration of Particulate matter (PM 2.5 and PM 10 ) was noticed to increase day by day due to rapid urbanization and industrialization. The use of several transportation activities, construction of buildings, roads and overhead bridges has badly affected the atmosphere of this region. Positive Matrix Factorization (PMF) Model has been used to find out different sources of PM in Peshawar. The data were collected for twenty days in April 2011 for both morning and afternoon periods. It has been observed that the values of aerosol volume size distribution were almost high during morning and afternoon rush hours. The mean concentrations of PM 10 and PM 2.5 were determined to be 480 µg/m 3 and 172 µg/m 3 , respectively. A reasonably significant correlation (R 2 = 0.65) was also found between observed and expected PM mass. The PMF result revealed five (05) sources in Peshawar, which were re-suspended road/soil dust, vehicular, industrial, brick kiln emission and household combustion emission.

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Ceramics in the solid solution, LixAg1−xNbO3 (LAN) with 0 ≤ x ≤ 0.20, have been synthesized by the mixed oxide method. X-ray diffraction (XRD) revealed that only compositions with x ≤ 0.05 were single phase which were indexed according to Pbcm symmetry with a unit cell, √2ap × √2ap × 4ap (where ap is the fundamental perovskite lattice parameter). For compositions with x ≥ 0.1, second phase peaks attributed to LiNbO3 were observed and the matrix phase transformed to a metrically rhombohedral structure according to XRD. A phase transition at 0.05 < x ≤ 0.1 was confirmed by Raman spectroscopy and electron diffraction but the latter technique revealed superstructure reflections for x ≥ 0.1 at ±1/6{00l} and 1/2{ooo} ± 1/6{00l} (where o = odd). These support the premise that Li doping invokes a new complex modulated tilt system with a √2ap × √2ap × 6ap unit cell rather than √2ap × √2ap × 4ap (Pbcm). Reflections of the type ±1/6{00l} are, however, streaked along the [001] direction indicating that the structure may be incommensurate or only partially ordered. The appearance of the √2ap × √2ap × 6ap structure is associated with strong asymmetry in the peak in permittivity attributed to the M3–M2 and a decrease in intensity of the peak in permittivity associated with the M2–M1 transition. Slim polarization versus field curves characteristic of weak ferroelectricity were observed for compositions with x ≤ 0.05 but for higher values of x the loops were unsaturated albeit with larger remanent polarization.

This paper investigates the repayment behavior of borrowers of a Pakistani microfinance institution (MFI) using a unique dataset of approximately 45,000 installment records over the period 1998-2007. In early 2005, the MFI introduced reforms that included improved enforcement of contingent renewal. The reforms led to a healthy situation with almost zero default rates. We hypothesize that strategic default under the joint liability mechanism was encouraged by weak enforcement of contingent renewal and was one of the factors responsible for the pre-reform failure. To support this hypothesis, we show that before the reforms, a borrower's delay in installment repayment was correlated with other group members' repayment delays beyond the level explained by possible correlation of project failures due to locally covariate shocks. Such excessive correlation disappeared after the reforms, including the period after the 2005 Kashmir earthquake. The empirical evidence thus demonstrates the existence and seriousness of the strategic default under weak dynamic incentives.