Trend analysis of rainfall time series for Sindh river basin in India

The main goal of this paper is to estimate a set of optimal seasonal, daily, and hourly values of atmospheric turbidity and surface radiative parameters Ångström’s turbidity coefficient (β), Ångström’s wavelength exponent (α), aerosol single scattering albedo (ω_o), forward scatterance (F_c) and average surface albedo (ρ_g), using the Brute Force multidimensional minimization method to minimize the difference between measured and simulated solar irradiance components, expressed as cost functions. In order to simulate the components of short-wave solar irradiance (direct, diffuse and global) for clear sky conditions, incidents on a horizontal surface in the Metropolitan Area of Rio de Janeiro (MARJ), Brazil (22° 51′ 27″ S, 43° 13′ 58″ W), we use two parameterized broadband solar irradiance models, called CPCR2 and Iqbal C, based on synoptic information. The meteorological variables such as precipitable water (u_w) and ozone concentration (u_o) required by the broadband solar models were obtained from moderate-resolution imaging spectroradiometer (MODIS) sensor on Terra and Aqua NASA platforms. For the implementation and validation processes, we use global and diffuse solar irradiance data measured by the radiometric platform of LabMiM, located in the north area of the MARJ. The data were measured between the years 2010 and 2012 at 1-min intervals. The performance of solar irradiance models using optimal parameters was evaluated with several quantitative statistical indicators and a subset of measured solar irradiance data. Some daily results for Ångström’s wavelength exponent α were compared with Ångström’s parameter (440–870 nm) values obtained by aerosol robotic network (AERONET) for 11 days, showing an acceptable level of agreement. Results for Ångström’s turbidity coefficient β, associated with the amount of aerosols in the atmosphere, show a seasonal pattern according with increased precipitation during summer months (December–February) in the MARJ.     

The effect of hydrothermal impregnation of Ni,Co, and Cu on HZSM-5 in the nitrogen oxide removal

The selective catalytic reduction (SCR) of nitrogen oxides on M/ZSM-5 (M = Cu, Ni, Co) catalysts was investigated. The catalysts were prepared using hydrothermal impregnation of the metal chlorides and nitrates on ZSM-5. The catalysts were characterized by nitrogen absorption/desorption, X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible diffusion reflection spectroscopy (UV–Vis DRS), temperature-programmed reduction (TPR), N₂O chemisorption and ammonia temperature-programmed desorption. The performance tests for SCR of NO were carried out in a fixed-bed reactor from 250 to 400 °C. During the impregnation, part of the aluminum was eliminated from the zeolite framework due to the acidity of the metal salt solution and heating process as indicated by the reduction in the intensity of XRD peaks and variations in the positions of the FTIR vibrational bands. The Cu(Cl)/ZSM-5 catalyst exhibited NO conversions over 90% over the entire temperature range. The other catalysts showed comparable activities, but the catalysts prepared with chloride salt precursors demonstrated higher activity than those based on nitrate as the precursor. Moreover, the TPR reduction peaks of the metal ion in catalysts prepared with chloride precursor were lower, and their UV–Vis absorption bands revealed bathochromic transfers with higher intensities. Concurrent with these changes, the activity of the catalyst increased. The TPR profiles indicated that Cu and Ni both had an oxidation number of +2, whereas Co was present in the oxidation number of +2 and +3. The mass transfer limitation analysis showed that for particles in millimeter size range or larger significant intra-particle mass transfer limitation would be expected.     

Simulating coseismic deformation of quartz in the middle crust and fabric evolution during postseismic stress relaxation — An experimental study

Non-steady state deformation and annealing experiments on vein quartz are designed to simulate earthquake-driven episodic deformation in the middle crust. Three types of experiments were carried out using a modified Griggs-type solid medium deformation apparatus. All three start with high stress deformation at a temperature of 400 °C and a constant strain rate of 10^− 4 s^− 1 (type A), some are followed by annealing in the stability field of α-quartz for 14–15 h at zero nominal differential stress and temperatures of 800–1000 °C (type A + B), or by annealing for 15 h at 900 °C and at a residual stress (type A + C).The quartz samples reveal a very high strength > 2 GPa at a few percent of permanent strain. The microstructures after short-term high stress deformation (type A) record localized brittle and plastic deformation. Statisc annealing (type A + B) results in recrystallisation restricted to the highly damaged zones. The new grains aligned in strings and without crystallographic preferred orientation, indicate nucleation and growth. Annealing at non-hydrostatic conditions (type A + C) results in shear zones that also develop from deformation bands or cracks that formed during the preceding high stress deformation. In this case, however, the recrystallised zone is several grain diameters wide, the grains are elongate, and a marked crystallographic preferred orientation indicates flow by dislocation creep with dynamic recrystallisation. Quartz microstructures identical to those produced in type A + B experiments are observed in cores recovered from Long Valley Exploratory Well in the Quaternary Long Valley Caldera, California, with considerable seismic activity.The experiments demonstrate the behaviour of quartz at coseismic loading (type A) and subsequent static annealing (type A + B) or creep at decaying stress (type A + C) in the middle crust. The experimentally produced microfabrics allow to identify similar processes and conditions in exhumed rocks.     

Geochemistry of Ground and Groundwater Pertinent to Chemical Attacks Mitigation on Concrete Foundations; A Case Study of the City of Rasht,Northern Iran

Presence of aggressive chemicals in ground and groundwater can deteriorate concrete foundations or its reinforcements. Concrete codes require preventive measures to assure durability of concrete foundations which is based on geochemistry information of the site. Construction in the city of Rasht, in the Iranian Caspian coast, is fast growing often without sufficient geochemistry data for residential buildings. The later may pose risk of chemical attacks on concrete foundations. To resolve this shortcoming, this study aimed at investigating geochemistry of ground and groundwater from the upper 10 m which can serve as a preliminary guideline for shallow foundation constructions in the city. The database for this study included previous geochemical investigations from 50 boreholes in the city as well as boring eleven test pits at various locations along with soil and groundwater geochemistry tests. The geochemistry experiments included measurement of sulfate, chloride, organic matter, as well as pH in soil and groundwater. Geochemistry of ground and groundwater in the city mostly fell within permissible limits set by a local concrete code. Based on current study, service environment for shallow concrete foundations in the city was categorized in a moderate class; hence, durability requirements from the same local concrete code were emphasized.     

Mineral chemical composition and geodynamic significance of peridotites from Nain ophiolite,central Iran

The peridotites from north of the town of Nain in central Iran consist of clinopyroxene-bearing harzburgite and lherzolite with small lenses of dunite and chromitite pods. The lherzolite contains aluminous spinel with a Cr number (Cr^# = Cr/[Cr + Al]) of 0.17. The Cr number of spinels in harzburgite and chromitite is 0.38–0.42 and 0.62, respectively. This shows that the lherzolite and harzburgite resulted from <18% of partial melting of the source materials. The estimated temperature is 1100 ± 200 °C for peridotites, the estimated pressure is <15 ± 2.3 kbar for harzburgites and >16 ± 2.3 kbar for lherzolites and estimated fo₂ is 10^?1±0.5 for peridotites. Discriminant geochemical diagrams based on mineral chemistry of harzburgites indicate a supra-subduction zone (SSZ) to mid-oceanic ridge (MOR) setting for these rocks. On the basis of their Cr^#, the harzburgite and lherzolite spinels are analogous to those from abyssal peridotites and oceanic ophiolites, whereas the chromites in the chromitite (on the basis of Cr^# and boninitic nature of parental melts) resemble those from SSZ ophiolitic sequences. Therefore, the Nain ophiolite complex most likely originated in an oceanic crust related to supra-subduction zone, i.e. back arc basin. Field observations and mineral chemistry of the Nain peridotites, indicating the suture between the central Iran micro-continent (CIM) block and the Sanandaj–Sirjan zone, show that these peridotites mark the site of the Nain–Baft seaway, which opened with a slow rate of ocean-floor spreading behind the Mesozoic arc of the Sanandaj–Sirjan zone as a result of change of Neo Tethyan subduction régime during middle Cretaceous.     

Simulating urban growth in a megalopolitan area using a patch‐based cellular automata

Although traditional cellular automata (CA)‐based models can effectively simulate urban land‐use changes, they typically ignore the spatial evolution of urban patches, due to their use of cell‐based simulation strategies. This research proposes a new patch‐based CA model to incorporate a spatial constraint based on the growth patterns of urban patches into the conventional CA model for reducing the uncertainty of the distribution of simulated new urban patches. In this model, the growth pattern of urban patches is first estimated using a developed indicator that is based on the local variations in existing urban patches. The urban growth is then simulated by integrating the estimated growth pattern and land suitability using a pattern‐calibrated method. In this method, the pattern of new urban patches is gradually calibrated toward the dominant growth pattern through the steps of the CA model. The proposed model is applied to simulate urban growth in the Tehran megalopolitan area during 2000–2006–2012. The results from this model were compared with two common models: cell‐based CA and logistic‐patch CA. The proposed model yields a degree of patch‐level agreement that is 23.4 and 7.5% higher than those of these pre‐existing models, respectively. This reveals that the patch‐based CA model simulates actual development patterns much better than the two other models.     

Cantilever beam analogy for modal analysis of rocking core-moment frames

Unlike conventional seismic resisting systems, rocking core-moment frame (RCMF) combinations as low-damage assemblies are being developed to mitigate, or even eliminate structural damage and residual deformations following a severe earthquake. Despite extensive studies on the performance of specific rocking cores, dynamic characteristics and strength demands of a generic RCMF have not been addressed. By utilizing cantilever beam analogy, the current article proposes a modal analysis method to formulate RCMF demands. The proposed model and obtained analytical charts provide a manual method for rapid study and preliminary design of low- to mid-rise RCMFs with relatively uniform properties over the height. An extensive parametric study investigates the effects of rocking core base-fixity and frame-to-core stiffness on demand values. An independent computer analysis verifies the validity and accuracy of the proposed formulas. Findings show significant higher-mode effects in several RCMF combinations.     

An Introduction to MODISI and SCMOD Methods for Correction of the MODIS Snow Assessment Algorithm

Detection, monitoring and precise assessment of the snow covered regions is an important issue. Snow cover area and consequently the amount of runoff generated from snowmelt have a significant effect on water supply management. To precisely detect and monitor the snow covered area we need satellite images with suitable spatial and temporal resolutions where we usually lose one for the other. In this study, products of two sensors MODIS and ASTER both on board of TERRA platform having low and high spatial resolution respectively were used. The objective of the study was to modify the snow products of MODIS by using simultaneous images of ASTER. For this, MODIS snow index image with high temporal resolution were compared with that of ASTER, using regression and correlation analysis. To improve NDSI index two methods were developed. The first method generated from direct comparison of ASTER averaged NDSI with those of MODIS (MODISI). The second method generated by dividing MODIS NDSI index into 10 codes according to their percentage of surface cover and then compared the results with the difference between ASTER averaged and MODIS snow indices (SCMOD). Both methods were tested against some 16 MODIS pixels. It is found that the precision of the MODISI method was more than 96%. This for SCMOD was about 98%. The RMSE of both methods were as good as 0.02.