Development of a microwave calorimeter for simultaneous thermal analysis,

An instrument has been developed for monitoring cure processes under microwave heating conditions. The main function of the instrument was a calorimeter for performing microwave thermal analysis. A single model resonant cavity was used as the heating cell in the microwave calorimeter. Thermal analysis measurements were obtained by monitoring the variation in the microwave power that was required to maintain controlled heating of the sample. The microwave thermal analysis data were analogous to conventional differential scanning calorimetry measurements. The dielectric properties of the sample, as a function of the extent of cure, have been obtained using perturbation theory from the changes in resonant frequency and quality factor of the microwave cavity during heating. Additionally, remote sensing fibre-optic probes have been employed to measure real time in situ infrared spectra of the sample during the cure reaction. In this paper, we describe the design and operation of the microwave calorimeter. Examples of experimental results are also presented

Relative timing of uplift along the Zagros Mountain Front Flexure (Kurdistan Region of Iraq): Constrained by geomorphic indices and landscape evolution modeling

The Mountain Front Flexure marks a dominant topographic step in the frontal part of the Zagros Fold–Thrust Belt. It is characterized by numerous active anticlines atop of a basement fault. So far, little is known about the relative activity of the anticlines, about their evolution, or about how crustal deformation migrates over time. We assessed the relative landscape maturity of three along-strike anticlines (from SE to NW: Harir, Perat, and Akre) located on the hanging wall of the Mountain Front Flexure in the Kurdistan Region of Iraq to identify the most active structures and to gain insights into the evolution of the fold–thrust belt. Landscape maturity was evaluated using geomorphic indices such as hypsometric curves, hypsometric integral, surface roughness, and surface index. Subsequently, numerical landscape evolution models were run to estimate the relative time difference between the onset of growth of the anticlines, using the present-day topography of the Harir Anticline as a base model. A stream power equation was used to introduce fluvial erosion, and a hillslope diffusion equation was applied to account for colluvial sediment transport. For different time steps of model evolution, we calculated the geomorphic indices generated from the base model. While Akre Anticline shows deeply incised valleys and advanced erosion, Harir and Perat anticlines have relatively smoother surfaces and are supposedly younger than the Akre Anticline. The landscape maturity level decreases from NW to SE. A comparison of the geomorphic indices of the model output to those of the present-day topography of Perat and Akre anticlines revealed that it would take the Harir Anticline about 80–100 and 160–200&thinsp;kyr to reach the maturity level of the Perat and Akre anticlines, respectively, assuming erosion under constant conditions and constant rock uplift rates along the three anticlines. Since the factors controlling geomorphology (lithology, structural setting, and climate) are similar for all three anticlines, and under the assumption of constant growth and erosion conditions, we infer that uplift of the Akre Anticline started 160–200&thinsp;kyr before that of the Harir Anticline, with the Perat Anticline showing an intermediate age. A NW-ward propagation of the Harir Anticline itself implies that the uplift has been independent within different segments. Our method of estimating the relative age difference can be applied to many other anticlines in the Mountain Front Flexure region to construct a model of temporal evolution of this belt.</p

Thermal modelling of gas generation and retention in the Jurassic organic-rich intervals in the Darquain field, Abadan Plain, SW Iran

The petroleum system with Jurassic source rocks is an important part of the hydrocarbons discovered in the Middle East. Limited studies have been done on the Jurassic intervals in the 26,500 km2 Abadan Plain in south-west Iran, mainly due to the deep burial and a limited number of wells that reach the basal Jurassic successions. The goal of this study was to evaluate the Jurassic organic-rich intervals and shale gas play in the Darquain field using organic geochemistry, organic petrography, biomarker analysis, and basin modelling methods. This study showed that organic-rich zones present in the Jurassic intervals of Darquain field could be sources of conventional and unconventional gas reserves. The organic matter content of samples from the organic-rich zones corresponds to medium-to-high-sulphur kerogen Type II-S marine origin. The biomarker characteristics of organic-rich zones indicate carbonate source rocks that contain marine organic matter. The biomarker results also suggest a marine environment with reducing conditions for the source rocks. The constructed thermal model for four pseudo-wells indicates that, in the kitchen area of the Jurassic gas reserve, methane has been generated in the Sargelu and Neyriz source rocks from Early Cretaceous to recent times and the transformation ratio of organic matter is more than 97%. These organic-rich zones with high initial total organic carbon (TOC) are in the gas maturity stage [1.5–2.2% vitrinite reflectance in oil (Ro)] and could be good unconventional gas reserves and gas source rocks. The model also indicates that there is a huge quantity of retained gas within the Jurassic organic-rich intervals

Brittle tectonic reconstruction of palaeo-extension inherited from Mesozoic rifting in West Zagros (Kermanshah, Iran)

International audienc

Stress state reconstruction of oblique collision and evolution of deformation partitioning in W-Zagros (Iran, Kermanshah)

Geophysical Journal International, v. 175, n. 2, p. 755-782, 2008. http://dx.doi.org/10.1111/j.1365-246X.2008.03916.xInternational audienc

Cenozoic post-collisional brittle tectonic history and stress reorientation in the high Zagros belt (Iran, Fars Province)

Tectonophysics, v. 432, n. 1-4, p. 101-131, 2007. http://dx.doi.org/10.1016/j.tecto.2006.12.007International audienc

Isolation and molecular characterization of the RecQsim gene in Arabidopsis, rice (Oryza sativa) and rape (Brassica napus)

In any organism that reproduces sexually, DNA Recombination plays vital roles in the generation of allelic diversity as well as in preservation of genome fidelity. Genome fidelity is particularly important in plants because mutations occurring during the development of flowering plants are heritable and can be passed onto the next generation. One of the gene families that play crucial roles in the regulation of DNA recombination and repair is the RecQ family of DNA helicases. In flowering plants, RecQ family members have only been characterized in Arabidopsis. Among all RecQ family members, the Arabidopsis RecQsim is distinct in that there is a substantial insertion (of around 100 amino acids) inside its helicase domain. We previously showed that this novel RecQ homologue is expressed in various organs of Arabidopsis and rice. We also showed that the Arabidopsis RecQsim gene when ectopically expressed in yeast RecQ deficient (sgs1) cells, can partially compensate for the absence of SGS1. Here, we perform an evolutionary analysis of RecQsim orthologues isolated from rice and rape together with other known plant RecQ family members. Furthermore, isolation and molecular characterization of two Arabidopsis recQsim knockout mutants is explained. The position of T-DNA integration suggests that the recQsim-1 is likely to be a real knockout while recQsim-2 is expected to be a knockdown mutant. Segregation analysis of the T-DNA selectable marker together with Southern hybridization revealed that in both isolated mutant lines a single copy of the T-DNA is inserted into the genome. Analysis of these mutant lines will provide evidence on the roles that RecQsim plays in DNA recombination and the regulation of leaf senescence in plants and may open new insights into how plants respond to various environmental challenges