619 research outputs found
Lithofacies Architecture of the Gercus Formation in Jabal Haibat Sultan, NE Iraq; New Concept of Lithostratigraphy and Depositional Environmental
Lithostratigraphic analysis of the Gercus Formation reveals four associations based on lithofacies types, petrography and sedimentary structures. The identified lithotypes are shale/claystone, sandstone, carbonate, conglomerate and debrite. Lithofacies association reveals four types arranged from bottom to top; FA1 proximal turbidite (sand dominated), FA2 distal turbidite (clay dominated), FA3 slop-apron turbidite (sand dominated) and FA4 distal deep turbidite (clay dominated). Lithofacies and associated sedimentary structures suggest sedimentation in marine turbidite regime followed the deep marine turbidites of Tanjero and Kolosh Formations in Tethyian foreland basin. The Middle-Late Eocene Gercus Flysch sediments composed of predominant litharenitic sandstones and interbedded mudstones, of turbiditic origin and mostly derived from a NE Arabian Plate margins. The sediments are well exposed in the NE side of Haibat Sultan Mountain, and provide excellent examples of fan sands associated with turbidites and related facies. The examined section indicates that the sandstones were deposited in larger channel complexes, which fed a mud-dominated slope. The more proximal facies have proportion of pebble conglomerates, shale-clast conglomerates and thick-bedded structureless pebbly sandstones, deposited by high-density turbidity currents, debris flows and slump. Other facies, either more distal or with a more uniform sand-rich are dominated by thick-bedded and amalgamated structureless sandstones. The massive sands are thought to originate from the gradual aggradations of sediment beneath or near-steady flows. In this paper, new sedimentological and lithofacies evidences prove for the first time that the Gercus Formation was deposited in gravity-flow regime in marine environment. The identified sedimentary structures display alternative graded and fining upward cycles, load and flute casts, submarine channels, sand and clay balls and pillow structures, convolute and slump beddings, of turbidity origin, which is supported by index glauconite mineral in some sandstone horizons. Keywords: Turbidites, Sedimentary structures, Gravity flow, Flysch, Gercus, Eocene, NE Iraq
Symmetric encryption relying on chaotic henon system for secure hardware-friendly wireless communication of implantable medical systems
Healthcare remote devices are recognized as a promising technology for treating health related issues. Among them are the wireless Implantable Medical Devices (IMDs): These electronic devices are manufactured to treat, monitor, support or replace defected vital organs while being implanted in the human body. Thus, they play a critical role in healing and even saving lives. Current IMDs research trends concentrate on their medical reliability. However, deploying wireless technology in such applications without considering security measures may offer adversaries an easy way to compromise them. With the aim to secure these devices, we explore a new scheme that creates symmetric encryption keys to encrypt the wireless communication portion. We will rely on chaotic systems to obtain a synchronized Pseudo-Random key. The latter will be generated separately in the system in such a way that avoids a wireless key exchange, thus protecting patients from the key theft. Once the key is defined, a simple encryption system that we propose in this paper will be used. We analyze the performance of this system from a cryptographic point of view to ensure that it offers a better safety and protection for patients. 2018 by the authors.Acknowledgments: This publication was made possible by NPRP grant #8-408-2-172 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu
Effect of mulching and organic manure on growth and yield performance of wheat
An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh in Rabi season (dry season) of 2014 to study the effect of mulching and organic manure on growth and yield performance of wheat. Five mulching practices viz. M1=1 irrigation at 17-21 days after sowing (DAS), M2=2 irrigations at 17-21 and 55-60 DAS, M3=3 irrigations at 17-21, 55-60 and 75-80 DAS, M4=control, M5=straw mulch (6 t ha-1) and five organic manure managements viz. O1=recommended chemical fertilizer (NPKS @ 100-23-20-16 kg ha-1), O2=poultry manure @ 6 t ha-1 (100% PM), O3=vermicompost @ 8 t ha-1 (100% VC), O4=50% chemical fertilizer+50% VC and O5=50% chemical fertilizer+50% PM were used as experimental variables. The experiment was conducted in split-plot design with three replications. The results showed that mulching had significant influence on all attributes. The highest values of all attributes were found in straw mulch treatment. It was observed that organic manure had significant influences on all characters. The highest values of yield and yield attributes were found in O5 (50% chemical fertilizer+50% PM) treatment. It was observed that effective tillers hill-1, grain yield and straw yield were significantly affected by combined effect of mulching and organic manure. The highest values obtained from mulching and O5 (50% chemical fertilizer+50% PM) treatment. Therefore, it can be inferred from the results of the study that highest production could be obtained from mulching and O5 (50% chemical fertilizer+50% PM) treatment
Silica-based chelating resin bearing dual 8-Hydroxyquinoline moieties and its applications for solid phase extraction of trace metals from seawater prior to their analysis by ICP-MS
Solid phase extraction (SPE) using chelating resins has been established as a convenient technique for samples pretreatment prior to trace metal analysis from complex matrices. Oxine chelating agents (e.g., 8-Hydroxyquinoline (8-HQ)) are popular moieties in the synthesis of chelating resins, due to their characteristic coordination chemistry. So far most of the reported silica-oxine chelators encompasses a single oxine molecule per spacer arm. In this work, two 8-HQ ligands have been covalently attached onto silica surface throughout a single linkage. The synthesized resin characterized with FTIR, elemental analysis and SEM. The main parameters affecting SPE procedures, such as pH, and sorption kinetics, investigated using batch experiments. The capacity exchange of the produced resin under optimized conditions was 0.219 and 0.161 mmol g−1 for Cu(II) and Mn(II) respectively. The resin packed into 10 ml standard cartridges and used with a typical SPE manifold for matrix removal prior to an ICP-MS analysis of transition metals (i.e., Cu, Cd, Ni, Pb, Zn, and Co) in seawater certified reference material samples and real samples from high saline seawater near the discharge zone of Yanbu desalination plant. The obtained results confirm the usefulness of the method.The authors are grateful for the Scientific Research Deanship, Taibah University for the generous financial support, grant No. 766/432
Microcontroller-based phase-angle measurement and correctiontechnique
An intelligent system is presented, which monitors the phase angle continuously and in the event of the phase angle deviating beyond the allowable limits, a correction action is initialized to compensate for this difference by continuously changing a variable capacitor. Adjustment of the capacitance value is done automatically and the major advantage of the proposed system is its ability to continuously change the capacitance in a linear manner. Thus achieving high degree of accuracy in phase angle correction is feasible. The system has been implemented on an 8-bit microcontroller. Experimental results obtained show that the phase angle can be linearly varied over a wide range at different frequencies of the input signa
Microcontroller-based phase-angle measurement and correctiontechnique
An intelligent system is presented, which monitors the phase angle continuously and in the event of the phase angle deviating beyond the allowable limits, a correction action is initialized to compensate for this difference by continuously changing a variable capacitor. Adjustment of the capacitance value is done automatically and the major advantage of the proposed system is its ability to continuously change the capacitance in a linear manner. Thus achieving high degree of accuracy in phase angle correction is feasible. The system has been implemented on an 8-bit microcontroller. Experimental results obtained show that the phase angle can be linearly varied over a wide range at different frequencies of the input signa
Early clinical outcome after right anterolateral thoracotomy as an alternative for median sternotomy for mitral valve replacement
Background: The advantages of the right anterolateral thoracotomy (RALT) approach for mitral valve surgery over standard median sternotomy (MS) are still debatable. The objective of this study was to evaluate and compare the postoperative clinical outcome after RALT and MS for mitral valve replacement.
Methods: This prospective observational study included 40 patients who underwent mitral valve replacement between January 2016 and August 2018. Patients were assigned to two groups, the first group included 20 patients who had conventional median sternotomy approach and the second group included 20 patients who had right anterolateral thoracotomy with the complete cannulation and aortic cross-clamping conducted through the same incision.
Results: In comparison to MS, RALT had significantly higher cross-clamp time (77.7±16.1 vs 45.8±8.7 minutes, P < 0.01), total bypass time (105.2±12.7 vs 72.2±10.4 minutes, P < 0.01), and total operative time (287±41 vs 231±36 min, P < 0.01), in addition to significantly lower ventilation time (4.2±1.51 vs 6.1±1.84 hours, P < 0.01), blood loss (229±85 vs 335±137 ml), amount of blood transfusion (1.41±0.6 vs 2.19±1.1 units, P < 0.01), ICU stay duration (2.11±0.49 vs 2.78±0.82 days, P < 0.01), pain scores at 1st and 2nd postoperative days (5.67±0.79 vs 7.81±0.53, p < 0.01), and total hospital stay duration (7.2±1.3 vs 8.4±1.6 days, P = 0.01). Patients' satisfaction about their wound was significantly higher in RALT group compared to MS group (95% vs 30%, P < 0.01).
Conclusion: The RALT approach for mitral valve surgery could be a safe and effective approach when compared to median sternotomy. RALT could be associated with a reduction of blood loss, blood transfusion, wound infection, in addition to shorter ICU and hospital stay
Digitally programmable grounded capacitor oscillators usingoperational amplifier poles
New simple sinusoidal oscillator circuits are proposed. Each circuit uses an internally compensated operational amplifier, a resistor and a capacitor. The feasibility of obtaining digitally programmable sinusoidal oscillation is studied and a new digitally programmable capacitorless resistorless sinusoidal oscillator is develope
Digitally programmable grounded capacitor oscillators usingoperational amplifier poles
New simple sinusoidal oscillator circuits are proposed. Each circuit uses an internally compensated operational amplifier, a resistor and a capacitor. The feasibility of obtaining digitally programmable sinusoidal oscillation is studied and a new digitally programmable capacitorless resistorless sinusoidal oscillator is develope
Exploring the role of digital citizenship and digital empowerment to enhance academic performance of business students
In the changing educational environment brought about by the COVID-19 pandemic, this study investigates the dynamic interactions between digital citizenship, digital empowerment, and academic performance. Data is collected from a survey of students at the College of Business, Al-Ahliyya Amman University. The Partial Least Squares (PLS) method of structural equation Modeling (SEM) was used to analyze the collected data. The findings reveal how digital empowerment is directly impacted by digital education, respect and protection. It was also discovered that digital empowerment directly improves academic performance, highlighting the significance of promoting digital settings that are safe, respectful, and conducive to learning. With the changing educational landscape, this study adds to a better understanding of how digital citizenship influences students' academic performance and learning experiences. It provides educators, organizations, and legislators with useful information to help them better prepare students for success in a fast-evolving educational landscape by enhancing their digital skills and competences
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