bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zn/HY-Zeolite as a Catalyst for Upgrading Iraqi Heavy Crude Oil Using Aquathermolysis Method
Authors: Saeed Amani Q. , Hamadi Adel S. , Sherhan Bashir Y. 
Published: August 2019

Abstract
Upgrading heavy crude oil from East of Baghdad oilfield using a high pressure reactor with steam supplied and toluene as hydrogen donor has been investigated through aquathermolysis process. Synthesized Zn/HY Zeolite, which is characterized by XRD, SEM, EDX, FT-IR, BET-surface area and pore volume has been employed as a bi-functional catalyst. Statistical design of experiment (DOE) is also applying in determine the optimum operating conditions of aquathermolysis reaction under different temperatures, time and weight percentage of catalyst with the targeted response being the viscosity after upgrading. The extent of upgrading might be established through various analyses of the initial unconventional oil and final produced crude oil. These were included the measurements of oil density, API gravity, oil viscosity, flash point, pour point, sulfur content and yield of light and intermediate fractions. The results show that the optimum operating conditions are found at 0.25 wt% of catalyst, 231.25°C and 30 h reaction time. The experimental data under these conditions has confirmed that the viscosity and sulfur are decreased by 67.25% and 55.58% respectively, whilst the API has increased up to 24.5. The response surface regression model equation in coded unit for viscosity reduction percentage has been established.
Effect of Ce-promotion on iron catalysts activity through the synthesis of liquid fuels by the Fischer-Tropsch process
Authors: AL-Zuhairi F K , Kadhim W A 
Published: August 2019

Abstract
The main objective of this work is studying the effect of cerium promotion and reaction temperature on the catalysts activity and product selectivity, the iron-based catalysts utilized in this study were prepared by impregnation methods and characterized via temperature programmed reduction (TPR) and N2 adsorption-desorption isotherms. Reaction experiments were accomplished in a stainless steel fixed bed reactor. The reaction experiments for unpromoted and promoted catalysts were done at pressure 20 bar, space velocity 1400 h−1, H2/CO=2 and different reaction temperature (250, 275, 300 and 325 ºC). The results have shown the addition of promoter to iron-based catalyst enhanced the reducibility of Fe2O3 through a shift down in reduction temperature, furthermore, for both catalysts, conversion of carbon monoxide (CO) and selectivities of undesired products (CO2, CH4, and C2-C4) were found to be increased whereas the selectivity of desired products (C5+) was decreased with increasing in a reaction temperature from 55.87 to 35.65% and from 73.03 to 61.59 % for unpromoted and Ce-promoted catalysts respectively. A higher selectivity for high molecules weight hydrocarbons was about 73.03% detected at lower reaction temperature (250 ˚C) when a promotion catalyst was used.
Tracking boil off gas generation into liquefied natural gas supply chain using HYSYS simulator
Authors: Naji S Z , Abd A A , Hashim A S 
Published: August 2019

Abstract
Liquefied natural gas (LNG) is becoming one of the prominent clean energy sources with its abundance, high potential energy, and low emission and price. Unavoidable reality is that boil off gas (BOG) generates, because of low temperature of LNG, about -162.5 °C at 101.3 kPa for storage and transportation of liquefied natural gas. As natural gas productions increasing globally, BOG and handling problems become serious critical subject in both economic and environment regulations. In this work, liquefied natural gas storage facilities and loading facilities are simulated to investigate the generated BOG by calculating the heat leaks through cargo tank, pipelines, storage tank, and the generated heat by equipment’s. Later, boil off gas rates are estimated for each sector into LNG supply chain with different operational conditions, parameters and voyage time. Factors that affect BOG such as operation temperatures and pressures, methane content, and nitrogen content are presented. Current study would help to properly store and transport LNG to minimize the venting of BOG into supply chain, and thus reducing greenhouse emissions, save energy, and reducing waste of natural gas.
Syngas formation by dry and steam reforming of methane using microwave plasma technology
Authors: Majd Alawi Nabil , Hung Pham Gia , Barifcani Ahmed , Hoang Nguyen Minh , Liu Shaomin 
Published: August 2019

Abstract
The combined dry and steam reforming of methane at atmospheric pressure was experimentally studied by using microwave plasma technology. The effect of the process parameters such as total feed gas flow rate, steam concentration and input microwave power on the synthesis gas H2/CO ratio was investigated using a commercial microwave reactor system. In order to minimise the carbon formation and plasma instability, the concentration of methane and carbon dioxide in nitrogen plasma were kept at a low level in this study. The long-term test results show that at the flow rate of 0.2 L min−1, 0.4 L min−1 and 1.5 L min−1 for CH4, CO2 and N2 respectively, the carbon formation was not detectable at the input power of 700 W. This reaction condition offers an opportunity to study the effect of adding water to the feed on the syngas ratio H2/CO. The test results show that a higher CH4 conversion (82.74%), H2 selectivity (98.79%) and yield (81.73%) were achieved compared with those of the dry reforming at the same operating conditions. With the steam addition, the desired H2/CO ratio for the Fischer-Tropsch synthesis process can be reached.
Application of Geophysical Logs to Estimate the Source Rock Quantity of Ratawi Formation, Southern Iraq: A Comparison Study
Authors: Idan Rami M. , Faisal Rasha Fawzi 
Published: August 2019

Abstract
Quantitative detection of the parameters of source rock that targeted Ratawi Formation in the south of Iraq is achieved via the Geophysical log data, precisely the resistivity, porosity, and gamma-ray log of the well X in the northern part of Mesopotamian basin, which is so called Euphrates subzone. Total organic carbon and source rock productivity is detected by mathematically interpreting of the log parameters and that lead to assigning and identification of the content of organic matter and source rock intervals. The responses of log curvatures are relevant to the rise of total organic carbon, which can be identified via logs indicators. Thereby, the organic carbon can be expected with a surge in values of sonic log, gamma-ray values, neutron or total porosity log, and resistivity as well as a decrease in the density log. The adoption of sonic/resistivity overlay technique for the determination of total organic carbon content has indicated the likely lithology of the intervals of interest where the logs initially could indicate the lithology. As such, high organic carbon content is significant to environments that have relatively low energy.
Low salinity water flooding in carbonate reservoirs – dissolution effect
Authors: Hadi Y A , Hussain F , Othman F 
Published: August 2019

Abstract
One of the most significant research subjects in the industry of oil is the low salinity water injection techniques (LSWI). This is because there are possible benefits of raising recovery in oil as opposed to the conventional injection of seawater. Recent research has been done to find out the causes of less salinity with the injection of water in carbonated rocks presented significant findings. The primary mechanisms that are thought to lower salinity water injection are carbonate rocks dissolution, fines migration and alteration of wettability to more water wet. However, many researchers have elected to oppose the mechanism of dissolution and instead attributed high recovery of oil to be the primary wettability modification mechanism. Additionally, previous researchers provided no evidence characterizing about the rock and fluids produced in a detailed manner. This research work provides a detailed description of the underlying mechanisms, the core flood laboratory and the spontaneous imbibition in carbonate rocks. In the experiment, we carried out a series of steps using a limestone core with low permeability. This core was obtained from a nearby oilfield in Iraq and used it to study how dissolution and fines migration mechanisms take place. Moreover, in the process of carrying out the experiment and before its starting, SEM imaging analysis was used. In this case, as we carried out the experiment, we had to inject two-phase flow of sea water (SW), de-ionized water (DW) as well as soltrol-130. This was done in a sequential manner at 50 °C as well as 0.02 ml per minute. As the experiment progressed, the concentration of ions and pH value of the extracted water were measured in a continuous manner. The results obtained indicate that the rate of change in concentration of Ca2+ ions is directly proportional to the effluent pH value. By just balancing the mass, we were able to easily see the rate at which limestone dissolved as the experiment progressed. The maximum increase in pH was registered when fresh water was injected (pH=9.2). An increase in pH value can have a positive effect on altering wettability in that it can increase the alkalinity of flood water. To notice fines migration, the Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) are used to scan the images of the inlet and outlet of the core plugs after completion the experiment. This method can indicate that dissolution can induce fines dislodgement for the surface of the rock. The two mechanisms of fine migration and carbonate rock dissolution can significantly increase recovery of oil and at the same time inject water low in salinity.
Application of streamlines for improved waterflood management of iraqi’s reservoir
Authors: al-musawi S , keshavarz moraveji M , Adnan M , Jawad M 
Published: August 2019

Abstract
In this paper, Using the unique advantages of streamline based (SL) flow simulation, for the first time, we have attempted to simulate waterflood strategies in Buzrgan oil field in southern Iraq and to optimize it. Therefore, in this paper the streamlines are really significant that:
• The numerical calculation of the produced and injection fluid at any given time is possible for each pair of wells.
• Fux pattern maps represent the significant information of the streamlines.
• The runtime in the simulation of the (SL) is much less than finite-difference (FD).
Using this (WAF’s), it is possible to calculate the efficiency of injected wells as the proportion of injected water to the oil delivered at balance wells. With injectedefficiencies (IE) known over the field for every injector, water can be reallocated from low-efficiency to high-efficiency wells, in this way computing the assemblyfor each barrel of water injected, resulting in more sweeping and significant optimization. In addition to this, the IE chart has been given obvious visual of the reservoir management such as (eg, the changes of the wells with low IE to the injection wells.
3D geological model of Nahr Umr/Ratawi oil field in Basra
Authors: Rashad Jemeel Mohammed , Lazim Samahr A. , Sameera  , Hamdullah M. 
Published: August 2019

Abstract
The study includes building a 3-D geological model, which involves get the Petrophysical properties as (porosity, permeability and water saturation). Effective Porosity, water saturation results from log interpretation process and permeability from special correlation using core data and log data. Clay volume can be calculated by six ways using IP software v3.5 the best way was by using gamma Ray. Also, Water Resistivity, flushed zone saturation and bulk volume analysis determined through geological study. Lithology determined in several ways using M-N matrix Identification, Density-Neutron and Sonic-Neutron cross plots. The cut off values are determined by Using EHC (Equivalent Hydraulic Unit) method. The full grid of the model was 454308 cells. Layering of units depend on the importance of these units and scale up had done using several methods depend on property (Arithmetic for porosity and water saturation and geometric for permeability). Petrophysical properties distributed using Gaussian statistical approach. Original oil in place calculated for Nahr Umr which equal to 460 m3.
Skin and Reservoir Pressure Profiling Utilizing Production Logging
Authors: Baker H A , Salih I S 
Published: August 2019

Abstract
Production Log is a key log that directly define the facies and layers behavior. The PLT measures the inflow zone thickness and the flow rate of each phase which is directly function of facies properties in terms of deliverability. On the basis of pseudo steady state flow regime (which is the dominant phase of production during PLT log operations) a mathematical relationship developed to determine skin and reservoir pressure per each inflow zone with reasonable error.
Study of multi-stage centrifugal pump guide vanes in a package of hydrodynamic simulating STAR CCM+
Authors: Abramov K 
Published: August 2019

Abstract
For multistage centrifugal pumps, one of the main components is the guide vane. A rather important task for the guide vane is compliance with the requirements of the technical specification. It is equally important technologically correct to produce a guide vane. The manufacture of such parts is a time consuming process. To avoid a number of difficulties, this article explores the two most frequently used guide vanes of hydrodynamic simulating tools.
The evaluation of the effect of gas content on the characteristics of a Centrifugal Pump
Authors: Saprykina M , Lomakin V 
Published: August 2019

Abstract
The effect of gas content on the changing ofhead of a centrifugal pump isresearched. The method of numerical hydrodynamic modeling is used for solving this problem. The using mathematical model is described. The results of the simulation of fluid flow,which are depended on the air content, are presented. The data on the changingof head and the termination of its work are obtained.
Mathematical representation of pressure regulator with variable characteristic
Authors: Kolodin I , Ryabinin M 
Published: August 2019

Abstract
One of major pressure regulator features is its static characteristic. It is necessary to choose parameters fulfilling static characteristic requirements while designing a regulator. The article observes possible requirements imposed on static characteristic and shows mathematical description of balance of pressure regulator with variable characteristic. Static characteristics are plotted for some of parameters being varied and others fixed. Influence of parameters is analyzed on the base of obtained data and recommendations for its choosing are given.
Definition of positive displacement pump output regulation mechanism parameters with providing of constant flow capacity in output
Authors: Barmin S , Nikitin O 
Published: August 2019

Abstract
This paper surveys mechanism of supply regulation for axial-piston pump with adjustable-angle swash plate operating with constant power. The mechanism includes a piston, whose working space is connected to delivery port, regulation unit and two springs. Least square method and successive approximations method are used to calculate parameters of the mechanism: cut-in pressure level for the second spring and springs stiffness. Regulation effectiveness is estimated by calculation of relative error of power delivered.
The multifaceted role of material production in society
Authors: Mukhin A , Ganina G , Mozgin S , Ostrovskiy Yu , Yakovleva A 
Published: August 2019

Abstract
The paper considers a new approach to substantiating the role and place of material production in a person’s life. It is shown that material production performs not only the function of satisfying the material needs of a person but is also the source for the development of spiritual production. The evidence base of such allegations is given. The paper may be useful to specialists in the field of production management and development, as well as to employees of educational institutions in the field of technology, production organization, economics, and sociology.
Comparative analysis of the use of the spiral and bladed stators in a compact high-speed centrifugal pump with hydrodynamic modeling methods
Authors: Martynyuk A , Petrov A , Kuleshova M 
Published: August 2019

Abstract
The relevance of improving pumps used in thermal stabilization systems and increasing their service life by reducing the radial forces on the rotor of the impeller is considered. The influence of the guide vane on the characteristics of a compact high-speed centrifugal pump is investigated. With the help of hydrodynamic modeling in STAR CCM + software package, the values of head, efficiency, radial force and power for two pumps were obtained. A comparison of the obtained characteristics of a pump with a spiral and a bladed stator was carried. The advantages and disadvantages of the guide vane are determined and recommendations for improving its characteristics are given.
Investigation of hermetic low-speed pumps performance when operating on highly viscous liquids
Authors: Petrov A , Morozov A , Kuleshova M 
Published: August 2019

Annotation
During the operation of hermetic low-speed vane pumps in a wide range of viscosities of the working fluid, their characteristics change significantly. Experimental dependencies of the effect of viscosity on these characteristics for hermetic vane pumps do not exist. To determine these changes, 3D-models of the flow parts for various pumps are designed. By means of hydrodynamic modeling characteristics for each model are calculated when operating on highly viscous liquids. The results obtained are summarized in the form of relative head ratio and relative efficiency, which determine the performance characteristics of a hermetic pump for various operating modes. A comparison of the results with existing ones is carried.
Left ventricular assist devices of a new generation
Authors: Grishakov V , Shein S , Lomakin V 
Published: August 2019

Abstract
The most competitive left ventricular assist devices (LVAD) in the world were identified in this article. 3D models of two samples were constructed for pumping blood based on existing pumps. The models were imported into the software package, where the flow of blood through these models was modeled. For this, a computational grid was constructed. According to the results of calculations, the main characteristics of the samples were obtained, as well as pictures of the distribution of velocities and pressures in the flow part. The calculation used a number of basic hydraulic equations that form a mathematical model.
Methods for Dealing With Missing Covariate Data in Epigenome-Wide Association Studies
Authors: Mills Harriet L , Heron Jon , Relton Caroline , Suderman Matt , Tilling Kate 
Published: August 2019

Abstract
Multiple imputation (MI) is a well-established method for dealing with missing data. MI is computationally intensive when imputing missing covariates with high-dimensional outcome data (e.g., DNA methylation data in epigenome-wide association studies (EWAS)), because every outcome variable must be included in the imputation model to avoid biasing associations towards the null. Instead, EWAS analyses are reduced to only complete cases, limiting statistical power and potentially causing bias. We used simulations to compare 5 MI methods for high-dimensional data under 2 missingness mechanisms. All imputation methods had increased power over complete-case (C-C) analyses. Imputing missing values separately for each variable was computationally inefficient, but dividing sites at random into evenly sized bins improved efficiency and gave low bias. Methods imputing solely using subsets of sites identified by the C-C analysis suffered from bias towards the null. However, if these subsets were added into random bins of sites, this bias was reduced. The optimal methods were applied to an EWAS with missingness in covariates. All methods identified additional sites over the C-C analysis, and many of these sites had been replicated in other studies. These methods are also applicable to other high-dimensional data sets, including the rapidly expanding area of “-omics” studies.
neoepiscopeimproves neoepitope prediction with multivariant phasing
Authors: Wood Mary A , Nguyen Austin , Struck Adam J , Ellrott Kyle , Nellore Abhinav , Thompson Reid F 
Published: August 2019

AbstractMotivationThe vast majority of tools for neoepitope prediction from DNA sequencing of complementary tumor and normal patient samples do not consider germline context or the potential for the co-occurrence of two or more somatic variants on the same mRNA transcript. Without consideration of these phenomena, existing approaches are likely to produce both false-positive and false-negative results, resulting in an inaccurate and incomplete picture of the cancer neoepitope landscape. We developed neoepiscope chiefly to address this issue for single nucleotide variants (SNVs) and insertions/deletions (indels).ResultsHerein, we illustrate how germline and somatic variant phasing affects neoepitope prediction across multiple datasets. We estimate that up to ∼5% of neoepitopes arising from SNVs and indels may require variant phasing for their accurate assessment. neoepiscope is performant, flexible and supports several major histocompatibility complex binding affinity prediction tools.Availability and implementationneoepiscope is available on GitHub at https://github.com/pdxgx/neoepiscope under the MIT license. Scripts for reproducing results described in the text are available at https://github.com/pdxgx/neoepiscope-paper under the MIT license. Additional data from this study, including summaries of variant phasing incidence and benchmarking wallclock times, are available in Supplementary Files 1, 2 and 3. Supplementary File 1 contains Supplementary Table 1, Supplementary Figures 1 and 2, and descriptions of Supplementary Tables 2–8. Supplementary File 2 contains Supplementary Tables 2–6 and 8. Supplementary File 3 contains Supplementary Table 7. Raw sequencing data used for the analyses in this manuscript are available from the Sequence Read Archive under accessions PRJNA278450, PRJNA312948, PRJNA307199, PRJNA343789, PRJNA357321, PRJNA293912, PRJNA369259, PRJNA305077, PRJNA306070, PRJNA82745 and PRJNA324705; from the European Genome-phenome Archive under accessions EGAD00001004352 and EGAD00001002731; and by direct request to the authors.Supplementary informationSupplementary data are available at Bioinformatics online.