A Review of Brittleness Index Correlations for Unconventional Tight and Ultra-Tight Reservoirs

Brittleness is a key parameter in the development of the unconventional shale and tight carbonate reservoirs as it plays a role in the design of the hydraulic fractures as well as the selection of the sweet-spot locations for perforation and fracture initiation. The brittleness index (BI) is utilized to indicate if the formation rocks are brittle, which are preferable to form a complex network of fractures, or ductile, which are occasionally desirable to seal the fractures from growing. However, there is a wide variety of BI methods in the literature that lead to inconclusive BI values. The Mineral-based brittleness index (MBI), which is a method based on the mineral composition of the formation, can be derived from mineral well logging data or laboratory core testing. Another approach in describing the brittleness is the Fracability Index (FI), which is a combination of Young’s modulus and Poisson’s ratio. Differentiation is also made between the dynamic FI, which is calculated from well logging data, and the static FI, which is derived from laboratory core testing such as uniaxial compressive strength, Brazilian tensile strength and triaxial testing. Hence, to understand the complexity of the brittleness, it is crucial to consider all dependencies such as the lithology, mineral composition, TOC, porosity, temperature and pressure amongst others. In this work, a comprehensive review and analysis of the existing equations and correlations for the calculation of the MBI and FI was conducted. These methods were applied on different low porosity and low permeability rocks. A thorough comparison has also been conducted between the MBI and FI correlations as well as between the dynamic FI and the static FI to ultimately clarify and improve the definition of brittleness as a function of lithology. High content of quartz and carbonates result in high values of MBI, and high Young’s modulus values yield high FI values. On the other hand, high clay content and high porosity lead to low MBI values

Perfect transfer of m-qubit GHZ states

By using some techniques such as spectral distribution and stratification associated with the graphs, employed in [1,2] for the purpose of Perfect state transfer (PST) of a single qubit over antipodes of distance-regular spin networks and PST of a $d$-level quantum state over antipodes of pseudo-distance regular networks, PST of an m-qubit GHZ state is investigated. To do so, we employ the particular distance-regular networks (called Johnson networks) J(2m,m) to transfer an m-qubit GHZ state initially prepared in an arbitrary node of the network (called the reference node) to the corresponding antipode, perfectly. Keywords: Perfect state transferenc, GHZ states, Johnson network, Stratification, Spectral distribution PACs Index: 01.55.+b, 02.10.YnComment: 17 page

Antibiotic Resistance in Food Poisoning Caused By Escherishia Coli O157:H7 in Hospitalized Patients At 5 Years in Iran

ABSTRACT Escherishia coliis bacteria that normally live in the intestines of humans. One particular Escherishia colistrain called 0157:H7 can cause severe diarrhea and kidney damage. The two major aims of this study were to detect this bacteria in stool of diarrheic patients and comparison between phenotypic and genotypic characterization of antibiotic resistantEscherishia coli0157:H7 strainin Iran. 325 diarrheal samples were collected through 2009-2013. Microbiological examinations were done to detect the E. coli O157:H7. PCR was used to identify dfrA1, sul1, citm,tetA, qnrgenes. Antibiotic resistance test was performed. Totally, 57 out of 325 sampleswere found to be contaminated withE. coli. Results showed the lowest resistance was for tetracycline (12.28%) while the highest resistance was for trimethoprim (71.92%). The resistance to sulfametoxazole, ciprofloxacin andampicillin was found in61.40%, 17.54% and47.36% of E. coli O157:H7 strains, respectively. The results of PCR showed 10 isolates contain sul1, 22 isolates containcitm, 6 isolates containtetA, 36 isolates containdfrA1, 9 isolates containqnr genes.Comparison between the phenotypic and genotypic of isolates revealed citm,tetA,dfrA1, qnr and sul1genes covered 38.59%, 10.52%, 63.15%, 15.78% and17.54%of the antibiotic resistances, respectively

Evaluation of diagnostic value of soluble urokinase-type plasminogen activator receptor in sepsis

Background: Sepsis is one of the most important causes of morbidity and mortality in the intensive care units (ICUs). It is difficult to accurately differentiate sepsis from similar diseases rapidly. Therefore, it becomes critical to identify any biomarker with the ability of differentiation between sepsis and nonsepsis conditions. The urokinase plasminogen activator receptor has been implicated as an important factor in regulation of leukocyte adhesion and migration. Objectives: In this study, we evaluated the value of soluble urokinase plasminogen activator receptor (suPAR), erythrocyte sedimentation (ESR), and C-reactive protein (CRP) serum levels in terms of their value for sepsis diagnosis in ICU patients. Patients and Methods: We enrolled 107 ICU patients; 40 with sepsis, 43 with systemic inflammatory response syndrome, and 24 as control group. Serum soluble urokinase plasminogen activator receptor, ESR, white blood cell (WBC), and CRP levels were measured on the day of admission. Results: The group with sepsis had higher suPAR, ESR, and CRP levels compared with the group with noninfectious systemic inflammatory response syndrome (SIRS) (P = 0.01, 0.00 and 0.00, respectively). CRP concentrations and ESR were higher in the sepsis group than in the non-SIRS group (P = 0.00 and 0.00, respectively). In a receiver-operating characteristic curve analysis, ESR, CRP and suPAR had an area under the curve larger than 0.65 (P = 0.00) in distinguishing between septic and noninfectious SIRS patients. CRP, ESR and suPAR had a sensitivity of 87, 71 and 66 and a specificity of 59, 76 and 74 respectively in diagnosing infection in SIRS. Conclusions: The diagnostic values of CRP and ESR were better than suPAR and WBC count in patients with sepsis. © 2015, Infectious Diseases and Tropical Medicine Research Center