This work presents a design for a pressure swing adsorption process (PSA) to separate oxygen from air with approximately 95% purity, suitable for different numbers of columns and arrangements. The product refill PSA process was found to perform 33% better (weight of zeolite required or productivity) than the pressure equalization process. The design is based on the adsorption equilibrium of a binary mixture of O2 and N2 for two of the most commonly used adsorbents, 5A & 13X, and extension from a single column approach. Zeolite 13X was found to perform 6% better than zeolite 5A. The most effective variables were determined to be the adsorption step time and the operational pressure. Increasing the adsorption step time from 1 to 5 minutes decreased the performance by approximately 5 times. Increasing the pressure from 2 to 6 bars increased the performance by approximately 3 times.
Because of its importance in the world, Middle East area is one of the competition areas between the major and great powers. Among those powers are Russia and United states of America. The competition between these two powers to control Syria is greatly clear since 2011. It is also one of the most important subject in the international politics. This importance comes from the importance of Russia and the United States of America besides importance of the Middle East. At the end of the cold war, United States of America maintained its role in the international system and became the only pole that dominated the international affairs while Russia tried to overcome the challenges inherited from the former Soviet Union, and it succeeded in th
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The influence of an aortic aneurysm on blood flow waveforms is well established, but how to exploit this link for diagnostic purposes still remains challenging. This work uses a combination of experimental and computational modelling to study how aneurysms of various size affect the waveforms. Experimental studies are carried out on fusiform-type aneurysm models, and a comparison of results with those from a one-dimensional fluid–structure interaction model shows close agreement. Further mathematical analysis of these results allows the definition of several indicators that characterize the impact of an aneurysm on waveforms. These indicators are then further studied in a computational model of a systemic blood flow network. This demonstr
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In this research, titanium dioxide nanoparticles (TiO2 NPs) were prepared through the sol-gel process at an acidic medium (pH3).TiO2 nanoparticles were prepared from titanium trichloride (TiCl3) as a precursor with Ammonium hydroxide (NH4OH) with 1:3 ratio at 50 °C. The resulting gel was dried at 70 °C to obtain the Nanocrystalline powder. The powder from the drying process was treated thermally at temperatures 500 °C and 700 °C. The crystalline structure, surface morphology, and particle size were studied by using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), and Scanning Electron Microscope (SEM). The results showed (anatase) phase of titanium dioxide with the average grain size
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A twisted-fin array as an innovative structure for intensifying the charging response of a phase-change material (PCM) within a shell-and-tube storage system is introduced in this work. A three-dimensional model describing the thermal management with charging phase change process in PCM was developed and numerically analyzed by the enthalpy-porosity method using commercial CFD software. Efficacy of the proposed structure of fins for performing better heat communication between the active heating surface and the adjacent layers of PCM was verified via comparing with conventional longitudinal fins within the same design limitations of fin material and volume usage. Optimization of the fin geometric parameters including the pitch, numb
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Communication between unmanned aerial vehicle (UAV) swarms and flying ad-hoc networks is critical and challenging since it is over open radio networks and energy, memory and processing budgets are severely constrained. Lightweight cryptography is the solution and ASCON — the NIST standard for lightweight authenticated encryption — has become a popular option for securing UAV links at a fraction of the energy cost of AES. The security of ASCON relies on one nonlinear device — 5-bit substitution box (S-box). However, this S-box is fixed and publicly known, and allows an adversary to precompute the cryptographic properties one time and then reuse them against all the protected traffic, and moreover, it does not meet the strict av
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phenomenon in the Arab women's contemporary literature, but it is rare in Iraqi women's
literature and falls short to the level of the phenomenon until now. Perhaps this is one of the
main reasons that caused the reluctance of researchers to study it, and this is probably the first
academic research in this field.
This research followed the discourse of Autobiography of women in Iraq, depending on the
two factors of charter and reference of the elements of Philippe Lejeune’s definition of the
genre of Autobiography, without focusing on narrative method, so it handled notes,
memories, diaries and biography of the other and counted all under the genre of the
Biography.
It came in three sections, the first follo
the association between celiac disease and viral infection
Background: Stroke is an acute neurologic injury and represents the 2nd leading cause of mortality worldwide, and also the most leading cause of acquired disability and morbidity in adults.
Objective: Effect and association between stroke and risk factors.
Type of the study: A retrospective study.
Methods: The study conducted on 312 patients in 2016, all data were collected from patients’ files from the emergency unit, which included basic demographic and disease characteristic, co morbid diseases, risk factors, final diagnosis.
Results: both previous stroke, ischemic heart disease was strong predictor of new
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Background: Characterization of the ovarian masses preoperatively is important to inform the surgeon about the possible management strategies. MRI may be of great help in identifying malignant lesion before surgery. Diffusion Weighted Imaging (DWI) is a sensitive method for changes in proton of water mobility caused by pathological alteration of tissue cellularity, cellular membrane integrity, extracellular space perfusion, and fluid viscosity.
Objective: to study the diagnostic accuracy of DWI in differentiation between benign and malignant ovarian masses.
Type of the study:Cross-sectional study.
Methods: this study included 53with complex
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To decrease the impact on the environment of building waste, the recycled aggregate may be used in various sustainable engineering applications, such as roller compacted concrete pavement (RCCP). This research examined how using recycled aggregate as a partial replacement for natural aggregate as coarse or fine affected the mechanical properties of roller-compacted concrete pavement. The recycled aggregate was crushed and sieved to coarse and fine aggregate before being used in the roller-compacted concrete pavement. Compressive strength, splitting tensile strength, and flexural strength were all evaluated after the samples were prepared at 28 and 90 days of curing. According to the study's findings, the partial replacem
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