The age and origin of reservoir sandstones which underlie the lowermost Silurian “hot” shales of the Sahmah Formation in the west of Oman is controversial. Here we describe one such sandstone which ...was cored and interpreted based on geological well evidence, and which then had to be re‐interpreted when definitive palynological results became available. The findings are enhanced when interpreted along with other deep wells in the area which have consistent palynological data.
The western part of the Sultanate of Oman is a tectonically stable intra‐basinal high with low regional dips. In this area, the relief on the base‐Silurian unconformity of >250 m appears to be greater than that beneath the Permo‐Carboniferous unconformity which is well known for being highly erosive. The sandstones preserved beneath the base‐Silurian unconformity vary in depositional environment and reservoir quality from well to well, depending on their age, degree of erosion and differences in regional subsidence.
There has been little evidence for the presence of Hirnantian‐aged deposits in Oman to date. However, some of the erosion and deep incisions which affect deposits of the Upper Ordovician Hasirah Formation are almost certainly related to falling sea levels accompanying the Hirnantian glaciation, just as the presence of the “hot shale” source rocks in the overlying Sahmah Formation are likely to be related to rising sea‐levels and anoxic conditions during the later deglaciation. Deformed strata in the Upper Ordovician deposits may reflect the instability of valley‐sides cut into weakly‐consolidated strata exposed during changes in sea‐level.
The Sahmah oil play underlying the basal Silurian “hot” shales in Oman carries significant risks relating to the presence or absence of closures and reservoir, and the character, continuity and cementation of reservoir sandstones.
Objectives
To determine the prevalence and antimicrobial susceptibility of carbapenemase-producing Enterobacteriaceae among hospitalized patients and outpatients attending two military hospitals in ...Rawalpindi, Pakistan, and to compare the performance of two chromogenic culture media for the isolation of these organisms.
Methods
Stool samples from 200 distinct patients were cultured on MacConkey agar and subsequently on two chromogenic media-Colorex KPC and a prototype chromogenic medium, ID Carba-designed for the isolation of carbapenemase-producing Enterobacteriaceae. All Gram-negative isolates growing on either chromogenic medium were investigated for carbapenemases by phenotypic and molecular methods. Producers were subjected to susceptibility testing with 40 antimicrobials by VITEK 2 or agar dilution.
Results
In total, 64 NDM-1-positive isolates of Enterobacteriaceae, belonging to seven distinct species, were recovered from 37 (18.5%) of the stool samples. No other carbapenemase types were confirmed. Nineteen positive samples were identified among 70 from inpatients (prevalence 27.1%) and there were 18 positive samples among 130 from outpatients (prevalence 13.8%). Fifty-six isolates (87.5%) harbouring the NDM-1 enzyme were recovered on ID Carba compared with 41 isolates (64.1%) on Colorex KPC (P = 0.012). Multidrug resistance was prevalent, but no pan-resistant isolates were found, with most isolates susceptible in vitro to colistin (97%), mecillinam (95%), fosfomycin (94%), tigecycline (89%) and nitrofurantoin (78%).
Conclusions
This study shows a high prevalence of multidrug-resistant Enterobacteriaceae with the NDM-1 enzyme in Rawalpindi. The new chromogenic medium, ID Carba, was more sensitive than Colorex KPC and has potential as a screening medium for isolation of Enterobacteriaceae harbouring the NDM-1 enzyme.
The Albian Kharfot Formation is preserved in the eastern margin of the Jeza-Qamar Basin which straddles across the Oman–Yemen border. This study addresses the sedimentological attributes of the ...formation and deduces its depositional setting, cyclicity and relative sea level changes in local (within the basin) and regional (Arabian) contexts. The interaction among siliciclastic influxes, in-situ carbonate production and tectono-climatic controls on the stacking nature of the various lithofacies that build-up the formation is discussed. In the study area, the formation lies unconformably over Barremian–Aptian Qishn Formation and conformably under late Albian–?Turonian Dhalqut Formation. The Kharfot Formation thickens from ~140m in the eastern side of the study area to ~300m at the Oman–Yemen border. It consists of eight lithofacies: Orbitolina-rich marls, peloidal bioclastic packstone, bioclastic mudstone to wackestone, argillaceous, bioclastic floatstone to rudstone, bioclastic rudstone, sandy, peloidal, bioclastic mudstone to packstone, peloidal, bioclastic grainstone and dolostone. The vertical arrangement of these lithofacies defines recurring meter- to decameter-scale, shallowing-upward units deposited on a westward-deepening inner- to outer-ramp setting. Tectonic rejuvenation of the siliciclastic source area was accompanied by warm, humid climatic conditions as suggested by high kaolinitic marls of the Kharfot Fm. and coeval quartz-rich sandstone units (Harshiyat Fm.). The shallowing-upward rhythmic sedimentation of the formation has close resemblance with cycles of the Nahr Umr Formation in northern Oman and partially comparable with the global sea level changes. The Kharfot basin was an intrashelf depression that was part of the much larger Arabian epeiric platform. The latter is defined by a rimmed margin in northern Oman where Al-Hassanat Formation represents platform margin deposits and Nahr Umr Formation representing back-rim intrashelf depression which received fine-grained siliciclastic influx from the land (westward). In southern Oman where Kharfot Formation accumulated, the platform was unrimmed ramp type basin with high fine clastic influx along with elevated carbonate production.
•Lithofacies and depositional environment of the Albian Kharfot Formation, Oman.•Concurrent siliciclastic and carbonate deposition within regional (Arabian) context.•Cyclicity, tectono-eustatic fluctuations and their effect on basin-fill architecture.
High-pulse repetition rate lasers allow significant enhancement in the average power of the low-order harmonics generation in isotropic media. We report on the third (343-nm) and fifth (206-nm) ...harmonics generating in air and different nanoparticle-containing laser-produced plasmas by applying Yb-doped fiber laser delivering 37-fs, 100-kHz, 1030-nm, 0.5-mJ pulses. Different characteristics of these processes (power and density dependences, influence of impeding processes, role of synthesized nanoparticles, variations of the spectral modulation of driving pulses, etc.) are analyzed. We compare the formation of the plasmas on the surfaces of aluminum, carbon, manganese, and titanium bulk species, as well as quantum dots of metal sulfides as the media for low-order harmonics generation, using 250-fs (1030-nm) and 5-ns (1064-nm) heating pulses at different delays between the heating and driving pulses. Average power of about 20 mW was estimated for the third harmonic emission from metal plasmas, with 3 × 10
16
UV photons (343 nm) emitted per second.
Resistance among bacterial isolates is the leading cause of increased mortality and morbidity worldwide. Carbapenems once thought to be effective are becoming ineffective mostly due to the emergence ...of carbapenemase. This study was designed to determine in vitro efficacy of Modified Hodge test for detection of carbapenemase production in Gram negative rods.
The study was done in the Department of Microbiology, Armed Forces Institute of Pathology Rawalpindi Pakistan from January 2010 to December 2010. A total of 200 Gram negative rods from different clinical samples were taken. Those isolates which showed intermediate or susceptible zones i.e 16mm-21mm on disc diffusion were included in the study. These isolates were then subjected to Modified Hodge test.
Out of 200 isolates, 138 (69%) were positive for carbapenemase production by Modified Hodge test. Out of 138 MHT positive organisms, the frequency of E. coli was 38%, followed by Pseudomonas aeruginosa (30%), Klebsiella pneumoniae (17%), Acinetobacter baumannii (12%), Citrobacter diversus (2%) and Enterobacter agglomerans (1.4%).
Modified Hodge test is a simple test which can be performed in the routine lab for detection of carbapenemases in isolates showing intermediate or sensitive zone diameter on disc diffusion.
Design and assessment of THz communications systems, which will form an essential part of 6G, require an understanding of the propagation channels the systems will operate in. This paper presents ...investigations of the channel characteristics in various scenarios at 145 GHz, which is the band currently envisioned for the first round of deployments. In particular, we review several extensive measurement campaigns performed by the University of Southern California in both outdoor and indoor environments. We present the measurement and evaluation methodology and sample results that illustrate the dominant propagation effects in different environments. We then summarize the parameters of the statistical channel models for path loss, delay dispersion, and angular dispersion. Based on these results, we find that even in NLoS (non-line-of-sight) situations, Gbit/s communications can be sustained over a 100 m distance; that (for an antenna gain of 20 dB), there is considerable delay dispersion, requiring tens of equalizer taps, and that angular dispersion is significant in both LoS and NLoS situations. The channel parameters can be thus used as a basis for system design and evaluation under realistic operating conditions.
For sustainable development construction, recycle or reuse of waste materials is utilized. Many researchers conducted tried to create an innovative green concrete, utilizing waste materials. The aim ...of this research is to contribute and promote the use of plastic waste in concrete. The concrete’s flexural and workability were investigated by using different percentages of 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1% of plastic fibers in concrete. In this study, M15 grade concrete beams were casted and cured for 7 and 28 days to analyze the flexural performance and workability. The outcomes demonstrated that the workability was slightly reduced by the utilizing plastic fibers where flexural strength improved by 16.5% at 0.6% addition of plastic fibers in concrete.
•Oblique stagnation point flow over a stretching cylinder is considered.•Thermal and concentration slip conditions are imposed.•Runge-Kutta-Fehlberg method is used for the numerical solution.•The ...effects of thermal radiation and chemical reaction are presented.•Local Nusselt and Sherwood numbers are presented.
The oblique stagnation point flow of a viscoelastic nanofluid over a stretching cylinder is entertained in presence of non-linear thermal radiation and chemical reaction. Buongiorno's model is used to incorporate the significance of Brownian motion and thermophoresis diffusion. The governing partial differential equations in cylindrical polar coordinates are first transformed to system of ordinary differential equations using suitable transformations and dimensionless variables and then simulated numerically. Impact of interesting parameters on flow and heat transfer features is analyzed graphically and numerically. It is noticed that axial velocity increases with the retardation parameter while tangential velocity reduces. The magnitude of both axial and tangential velocities is large over stretching cylinder as compared to stretching sheet. Radiation parameter enhanced temperature profile and chemical reaction parameter rise the concentration profile.
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The goal of zero defects is pursued by many manufacturing and service companies. In this regard, statistical tools are being used for defect reduction leading to productivity improvement. In this ...work, seven traditional QC tools (flow chart, check sheet, histogram, Pareto chart, cause, and effect diagram, scatter diagram and control chart) have been developed and implemented in an automobile company to assess and improve the defect reduction level in the assembly line. Chassis and trim lined were selected for data collection to assess and improve the defect level for productivity improvement. It was found from the results that after the successful implementation of the QC tools, the defect level reduced by 90% (from 132 to 13 defects) at the chassis line. Similarly, the defect level was reduced by 80% (from 157 to 28 defects) at the trim line. The automobile company implemented only a few of the seven QC tools in their assembly line. It is suggested that the company may need to manage a mechanism for the implementation of all seven QC tools in every section of the company.
We evaluated the thin-layer agar (TLA) method for the recovery of Mycobacterium tuberculosis complex and compared the results with the BACTEC Mycobacteria Growth Indicator Tube (MGIT) 960 system. A ...total of 53 mycobacterial isolates were isolated on both media. The recovery rates of mycobacteria on TLA and BACTEC MGIT 960 system were respectively 90.6% and 96.2%. Mean time to detection of mycobacteria on TLA was 12.5 compared to 11.2 days on BACTEC MGIT 960. TLA is a simple technique and can be used as an alternative to the Löwenstein-Jensen medium and BACTEC MGIT 960 for the isolation of mycobacteria in resource-poor settings.
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