62 research outputs found
Finite semifields and their applications
This thesis is concerned with finite semi fields. The objective of this thesis is to give a full description of Knuth orbits of known commutative semi fields. We also describe planar functions corresponding to commutative semi fields. Results are presented by tables. Nuclei of semi fields are studied. Finally we consider applications of semi fields, planar functions and spreads to construction of mutually unbiased bases
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Periodicity and Partition Congruences
In this note, we generalize recent work of Mizuhara, Sellers, and Swisher that gives a method for establishing restricted plane partition congruences based on a bounded number of calculations. Using periodicity for partition functions, our extended technique could be a useful tool to prove congruences for certain types of combinatorial functions based on a bounded number of calculations. As applications of our result, we establish new and existing restricted plane partition congruences and several examples of restricted partition congruences. Also, we define a restricted form of plane overpartitions called k rowed plane overpartitions as plane overpartitions with at most k rows. We derive the generating function for this type of partition and obtain a congruence modulo 4. Next, we engage a combinatorial technique to establish plane and restricted plane overpartition congruences modulo small powers of 2. For each even integer k, we prove a set of k-rowed plane overpartition congruences modulo 4. For odd integer k, we prove an equivalence relation modulo 4 between k-rowed plane overpartitions and unrestricted overpartitions. As a consequence, using a result of Hirschhorn and Sellers, we obtain an infinite family of k rowed plane overpartition congruences modulo 4 for each odd integer k ≥ 1. Also, we obtain a few unrestricted plane overpartition congruences modulo 4. We establish and prove several restricted plane overpartition congruences modulo 8. Some examples of equivalences modulo 4 and 8 between plane overpartitions and overpartitions are obtained. In addition, we find and prove an infinite family of 5-rowed plane overpartition congruences modulo 8.Keywords: Partitions, Plane Overpartitions, Plane Partitions, Periodicit
Apodization Defocused Optical Imaging System with Different Apertures using Hanning Amplitude Filter
The Optical system performance is characterized by the modulus and the phase of the amplitude impulse response (point spread function). An optical system with a nonuniform amplitude across its pupil called an apodized system. The motivation of apodizing a system is to increase the image quality of the system. In this paper, the influence of Hanning amplitude filters on the intensity of incoherent optical systems has been analyzed. A general expression for the PSF in the case of different square size pupil apertures (half diagonal=........
Effect of Soil Textural Classes on the Biological Nitrogen Fixation by Bradyrhizobium Measured by 15N Dilution Analysis
The current study was conductedas a pot experiment to determine the effect of soil texture on biological nitrogen fixation (BNF) of six most efficient local isolates, specified, of Bradyrhizobium. Cowpea (Vignaunguiculata L.), as a legume host crop, was used as a host crop and 15N dilution analysis was used for accurate determination of the amount of N biologically fixed under experimental parameters specified. Soils used are clay loam, sandy clay loam and sandy loam. Biological Nitrogen Fixation (BNF), in different soil textural classes, was as in the following order: medium texture soil > heavy texture soil > light textured soil. Statistical analysis showed that there is a significant variation in BNF % among six Iraqi isolates in the three soil textural classes. There is a significant variation in the number of the nodules of the six Isolates in one soil texture. However, nodules number does not agree with the BNF% in the same soil for any isolates. Statistical analysis of the data showed that there were significant differences in plant dry weight among the soil textural classes all over local isolates used in this study. Data also showed that there were significant differences in dry weight under different isolates
A Novel Technique For The Quantitative Determination Of Wettability Of A Severely Heterogeneous Tight Carbonate Reservoir
The objective of this study is to accurately measure the wettability contact angle of a cretaceous carbonate reservoir in a vertical well set-up known for as an unconventional tight carbonate oil reservoir. Also, to investigate the relative heterogeneity of these samples using digitally captured images; these images accurately capture natural pore-system in this carbonate rock samples and their wettability performance attributed towards building a vertical depth wettability/heterogeneity model. To capture, measure and model natural tight matrix static contact angle wettability in order to understand their new physics that will advance unconventional tight oil reservoir characterization. Entire vertical well depth reservoir core rock samples, in the form of rock fragments, are selected, then imaged, and then characterized for porosity, permeability, tortuosity/heterogeneity, and pore/grain-wettability contact angle in 2D format utilizing SEM-BSE imaging techniques. The generated big data images will be quantified using pre-defined logic for tortuosity/heterogeneity and wettability contact angle measurement. Each rock sample will process several images captured at X40 (mm), X400 (μm), and X4000 (nm) magnifications and will investigate wettability/heterogeneity relationships for unconventional tight pore system from the entire vertical depth. From measured data and computed logics, the major portions of captured rock investigated show water wet tendency. The wettability distribution in the vertical 250 feet shows strong to medium and even weak water-wet system variation (θ = 10° - θ = 90°). The dominant wettability is medium-water-wet (θ = 30° - θ = 60°), and it is found in the middle section of the vertical column. Medium-water-wet indicates a good candidate for secondary recovery water injection development programs. This study includes tortuosity/heterogeneity quantifications from imaging 2D technology which is valuable in understanding vertical/horizontal fluid movements. The authors feel that this study will narrow the gap in understanding contact angle wettability, heterogeneity characterizations from static conditions viewpoint and hence, the reservoir crude oil recovery vertical profile history from vertical rock samples
Kuwaiti Carbonate Reservoir Oil Recovery Prediction Through Static Wettability Contact Angle Using Machine Learning Modeling
The objective of this study is to predict EOR efficiencies through static wettability contact angle measurement by Machine Learning (ML) modeling. Unlike conventional methods of measuring static wettability contact angle, the unconventional digital static wettability contact angle is captured and measured, then (ML) modeled in order to forecast the recovery based on wettability distribution phenomenon. Due to success in big data collection from reservoir imaging samples, this study applies data science lifecycle logic and utilizes Machine Learning (ML) models that can predict the recovery through wettability contact angles and thus identify the treatment of oil recovery for a candidate reservoir. Using developed morphological driven pixel-data and transformed numerical wettability contact angle data are acquired from Scanning Electron Microscope Backscattered Electron (SEM-BSE) for 27 fresh core samples from top to bottom of the reservoir. These samples are properly sequenced and then images are selected. Big data from imaging technology have been processed in a manner to train, and test the model accuracy. Applied Data Science Lifecycle technique, such as data mining, is utilized. Data Exploration Analysis (DEA) is implemented to understand and review data distribution as well as relationships among input features. Different supervised ML models to predict recovery are utilized and an optimal model is identified with an acceptable accuracy. The selected prediction model is applied to model the optimal recovery practice. Extreme Gradient Boosting (XGBoost) algorithm is utilized and found as a best-fit model for this Kuwaiti reservoir case practice. Moreover, decision tree and Artificial Neural Network (ANN) models could provide acceptable accuracy. Other supervised learning models were attempted and were not promising to provide feasible accuracy for this carbonate reservoir. The novel of this unique solution of the data-driven ML model is to predict recovery based on static wettability contact angles (?°). The static wettability contact angles (?°) and pore morphological features introduce an insights method to support reservoir engineers in making value-added decisions on production mechanisms and hydrocarbon recovery for their reservoirs. Hence, it improves the field development strategy
Preparation and in vitro evaluation of synthetic high-density lipoproteins as parenteral drug delivery system for tamoxifen citrate
The aim of this study was to develop a bioinspired drug delivery system for tamoxifen citrate (TC) based on synthetic high density lipoproteins (sHDL). For this purpose, sHDL nanoparticles were prepared from a mimetic peptide (5A peptide) and different lipids using thin film hydration method followed by sonication and thermal cycling. Various formulation parameters including lipid composition, lipid to peptide ratio, and drug to carrier ratio had a remarkable impact on the properties and the release pattern of the nanoparticles. The optimized formula (F14) displayed a spherical morphology, average diameter of (35.7±12.4) nm, and a zeta potential (ζ) equals to (-48.4± 0.5) mV. The encapsulation efficiency and drug loading of F14 were (96.5±0.7%) and (9.65±0.1%), respectively. Besides, F14 showed a good stability in human plasma for 24 hours. The encapsulation of the lipophilic drug within the hydrophobic core of the nanocarrier enabled a slow drug release from nanoparticles which follows a near zero order controlled mechanism. The promising results of this study opens an avenue for using sHDL as a delivery system for administration of TC intravenously. Therefore, the optimized formula is suggested to be subject for future analyses in terms of in vitro cytotoxicity against breast cancer cells and in vivo evaluation in tumor bearing animals
Practical Imaging Applications Of Wettability Contact Angles On Kuwaiti Tight Carbonate Reservoir With Different Rock Types
This study focuses on a tight carbonate reservoir which is located in Northern Kuwait and is classified as an unconventional reservoir. A practical imaging technique of wettability contact angle (θ°) presents big data as well as relative-permeability (Krw and Kro) measurements. Also, modeling, through rock image technology, the vast well-documented grain/pore boundary morphology available inside fresh rock fragments have achieved good results. Conventional laboratory relative-permeability experiments are expensive and time-consuming. This study introduces a novel method to measure/calculate relative permeability through fast, less expensive, non-destructive, and environmentally friendly techniques of imaging technology. One tight carbonate reservoir is selected, imaged, processed, analyzed, and then modeled using several pore diameter morphological models. The images are captured using a backscattered electron microscopy BSE-SEM technology analyses. In this study, two-dimensional images are used to characterize the morphology of selected samples grains and pores, using a two-step technique. In the first step, the image is captured using a backscattered electron detector (BSE), digital electron microscopy imaging, and pore-counting processing technology. All of the sample grain/pore features captured in the image are reported in micrometer units. In the second step, the pore area of such features is scanned using image analysis software that can accurately measure several morphological parameters of pore and grain spaces. A robust technique of visual estimate is used, which has the advantage of speeding the image analysis process. The visual analysis software tool counts different pores and counts grains and also measures their shapes and sizes which are crucial for relative permeability calculations. Several pore morphological models have been considered for optimum accuracy comparisons, including pore/grain relationships (area/perimeter), pore contact angle (θ), and pore count. Relative permeability is calculated based on the area of the pore/grain features measured from two-dimensional images. The study objectives are to accurately measure the wettability contact angle of huge pore geometries using 2D image technology to understand the nature of the pore network in the candidate reservoir. To study the relative permeability of internal influences of pore and grain morphology needed for enhanced oil recovery/improved oil recovery (EOR/IOR) future programs. And, finally, to measure relative permeability faster and more accurately
Optimum Median Filter Based on Crow Optimization Algorithm
يُقترح مرشح متوسط جديد يعتمد على خوارزميات تحسين الغراب (OMF) لتقليل ضوضاء الملح والفلفل العشوائية وتحسين جودة الصور ذات اللون الرمادي والملونة . الفكرة الرئيسية لهذا النهج هي أن أولاً ، تقوم خوارزمية تحسين الأداء بالكشف عن وحدات البكسل الخاصة بالضوضاء ، واستبدالها بقيمة وسيطة مثالية تبعًا لدالة الأداء. أخيرًا ، تم استخدام نسبة القياس القصوى لنسبة الإشارة إلى الضوضاء (PSNR) ، والتشابه الهيكلي والخطأ المربع المطلق والخطأ التربيعي المتوسط لاختبار أداء المرشحات المقترحة (المرشح الوسيط الأصلي والمحسّن) المستخدمة في الكشف عن الضوضاء وإزالتها من الصور. يحقق المحاكاة استنادًا إلى MATLAB R2019b والنتائج الحالية التي تفيد بأن المرشح المتوسط المحسّن مع خوارزمية تحسين الغراب أكثر فعالية من خوارزمية المرشح المتوسط الأصلية ومرشحات لطرق حديثة ؛ أنها تبين أن العملية المقترحة قوية للحد من مشكلة الخطأ وإزالة الضوضاء بسبب مرشح عامل التصفية المتوسط ؛ ستظهر النتائج عن طريق تقليل الخطأ التربيعي المتوسط إلى أدنى أو أقل من (1.5) ، والخطأ المطلق للتساوي (0.22) ,والتشابه الهيكلي اكثر من ( 95%) والحصول على PSNR أكثر من 45dB).) وبنسبة تحسين ( 25%) . A novel median filter based on crow optimization algorithms (OMF) is suggested to reduce the random salt and pepper noise and improve the quality of the RGB-colored and gray images. The fundamental idea of the approach is that first, the crow optimization algorithm detects noise pixels, and that replacing them with an optimum median value depending on a criterion of maximization fitness function. Finally, the standard measure peak signal-to-noise ratio (PSNR), Structural Similarity, absolute square error and mean square error have been used to test the performance of suggested filters (original and improved median filter) used to removed noise from images. It achieves the simulation based on MATLAB R2019b and the results present that the improved median filter with crow optimization algorithm is more effective than the original median filter algorithm and some recently methods; they show that the suggested process is robust to reduce the error problem and remove noise because of a candidate of the median filter; the results will show by the minimized mean square error to equal or less than (1.38), absolute error to equal or less than (0.22) ,Structural Similarity (SSIM) to equal (0.9856) and getting PSNR more than (46 dB). Thus, the percentage of improvement in work is (25%)
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