91,893 research outputs found
Ab Initio Study of Ionic Liquids by KS-DFT/3D-RISM-KH Theory
No full textProperties of molecules solvated in ionic liquids (ILs) are strongly affected by solvent environment. For this reason, to give reliable results, ab initio calculations on solutes in ILs, including ions constituting ionic liquid itself, have to self-consistently account for the change of both electronic and classical solvation structure in ILs. Here, we study the electronic structure of the methyl-methylimidazolium ion in the bulk liquid of [mmim][CI] by using the self-consistent field coupling of Kohn-Sham density functional theory and three-dimensional molecular theory of solvation (aka 3D-RISM) with the closure approximation of Kovalenko and Hirata. The KS-DFT/3D-RISM-KH method yields the 3D distribution of the IL solvent species around the [mmim] solute, underlying the most important peculiarities of this kind of systems such as the stacking interaction between neighboring cations, and reproduces the enhancement of the dipole moment resulting from the polarization of the cation by the solvent in a very good agreement with the results of an ab initio MD calculation. The KS-DFT/3D-RISM-KH method offers an accurate and computationally efficient procedure to perform ab initio calculations on species solvated in ionic liquids
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Підхід до автоматичного створення анотованого датасету для виявлення, локалізації та класифікації клітин крові на зображенні
No full textKovalenko S. M. Approach to the automatic creation of an annotated dataset for the detection, localization and classification of blood cells in an image / S. M. Kovalenko, O. S. Kutsenko, S. V. Kovalenko, A. S. Kovalenko // Радіоелектроніка, інформатика, управління. – 2024. – № 1 (68). – C. 128-139.EN: Context. The paper considers the problem of automating the creation of an annotated dataset for further use in a system for detecting, localizing and classifying blood cells in an image using deep learning. The subject of the research is the processes of digital image processing for object detection and localization.
Objective. The aim of this study is to create a pipeline of digital image processing methods that can automatically generate an annotated set of blood smear images. This set will then be used to train and validate deep learning models, significantly reducing the time required by machine learning specialists.
Method. The proposed approach for object detection and localization is based on digital image processing methods such as filtering, thresholding, binarization, contour detection, and filling. The pipeline for detection and localization includes the following steps: The given fragment of text describes a process that involves noise reduction, conversion to the HSV color model, defining a mask for white blood cells and platelets, detecting the contours of white blood cells and platelets, determining the coordinates of the upper left and lower right corners of white blood cells and platelets, calculating the area of the region inside the bounding box, saving the obtained data, and determining the most common color in the image; filling the contours of leukocytes and platelets with said color; defining a mask for red blood cells; defining the contours of red blood cells; determining the coordinates of the upper left and lower right corners of red blood cells; calculating the area of the region within the bounding box; entering data about the found objects into the dataframe; saving to a .csv file for future use. With an unlabeled image dataset and a generated .csv file using image processing libraries, any researcher should be able to recreate a labeled dataset.
Results. The developed approach was implemented in software for creating an annotated dataset of blood smear images
Conclusions. The study proposes and justifies an approach to automatically create a set of annotated data. The pipeline is tested on a set of unlabelled data and a set of labelled data is obtained, consisting of cell images and a .csv file with the attributes “file name”, “type”, “xmin”, “ymin”, “xmax”, “ymax”, “area”, which are the coordinates of the bounding box for each object. The number of correctly, incorrectly, and unrecognised objects is calculated manually, and metrics are calculated to assess the accuracy and quality of object detection and localisation.
UK: Актуальність. Розглянуто проблему автоматизації створення анотованого набору даних для його подальшого використання в системі виявлення, локалізації та класифікації клітин крові на зображенні з використанням глибокого навчання. Об’єктом дослідження є процеси обробки цифрових зображень для виявлення та локалізації об’єктів.
Мета роботи – розробка пайплайну із послідовності методів обробки цифрових зображень для автоматичного створення анотованого набору зображень мазків крові з подальшим використанням для навчання та валідації моделей глибокого навчання, що має суттєво скоротити час спеціалістів з машинного навчання.
Метод. Запропонований підхід для виявлення та локалізації об’єктів базується на методах обробки цифрових зображень: методах фільтрації, порогової фільтрації, бінаризації, знаходження та заливки контурів тощо. Пайлайн по виявленню та локалізації складається з наступних кроків: приглушення шумів; перетворення в HVS кольорову модель; визначення маски для лейкоцитів та тромбоцитів; визначення контурів лейкоцитів та тромбоцитів; визначення координат верхнього лівого та правого нижнього кутів лейкоцитів та тромбоцитів; обчислення площі області всередині обмежувальної рамки; збереження отриманих даних; визначення найпоширенішого кольору на зображенні; заливка цим кольором контурів лейкоцитів та тромбоцитів; визначення маски для еритроцитів; визначення контурів еритроцитів; визначення координат верхнього лівого та правого нижнього кутів еритроцитів; обчислення площі області всередині обмежувальної рамки; занесення до датафрейму даних про знайдені об’єкти; збереження в файлі .csv для подальшого використання.
Результати. Розроблений підхід був впроваджений у програмне забезпечення для створення анотованого набору даних зображень мазків крові.
Висновки. В дослідженні запропоновано та обґрунтовано підхід для автоматичного створення набору анотованих даних. Пайплайн протестовано на наборі нерозмічених даних та отримано набір розмічених даних, що складається з зображень клітин та файлу в форматі .csv, що має ознаки «назва файлу», «тип клітини», «xmin», «ymin», «xmax», «ymax», що є координатами обмежувальної рамки для кожного об’єкту. Підраховано кількість правильно, неправильно та нерозпізнаних об’єктів та розраховано метрики для оцінки точності та якості виявлення та локалізації об’єктів
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Investigation of characteristics of binary Ni–Co oxy-hydroxides for supercapacitor application
No full textInvestigation of characteristics of binary Ni–Co oxy-hydroxides for supercapacitor applicationv. /V. Kovalenko , V. Kotok, A. Sykchin, I. Kovalenko, O. Berzenina, V. Stoliarenko, I. Plaksiienko, P. Pysarenko, M. Samojlik // Eastern-European Journal of Enterprise Technologies. 2020. 1/12 (103). Р. 15-23
C3H7NO2S effect on concrete steel-rebar corrosion in 0.5 M H2SO4 simulating industrial/microbial environment
No full textThis paper investigates C3H7NO2S (Cysteine) effect on the inhibition of reinforcing steel corrosion in concrete immersed in 0.5 M H2SO4, for simulating industrial/microbial environment. Different C3H7NO2S concentrations were admixed, in duplicates, in steel-reinforced concrete samples that were partially immersed in the acidic sulphate environment. Electrochemical monitoring techniques of open circuit potential, as per ASTM C876-91 R99, and corrosion rate, by linear polarization resistance, were then employed for studying anticorrosion effect in steel-reinforced concrete samples by the organic hydrocarbon admixture. Analyses of electrochemical test-data followed ASTM G16-95 R04 prescriptions including probability distribution modeling with significant testing by Kolmogorov-Smirnov and student's t-tests statistics. Results established that all datasets of corrosion potential distributed like the Normal, the Gumbel and the Weibull distributions but that only the Weibull model described all the corrosion rate datasets in the study, as per the Kolmogorov-Smirnov test-statistics. Results of the student's t-test showed that differences of corrosion test-data between duplicated samples with the same C3H7NO2S concentrations were not statistically significant. These results indicated that 0.06878 M C3H7NO2S exhibited optimal inhibition efficiency η = 90.52±1.29% on reinforcing steel corrosion in the concrete samples immersed in 0.5 M H2SO4, simulating industrial/microbial service-environment
Mellicta aurelia subsp. distans Higgins 1955
No full textM. aurelia distans Higgins, 1955 15 ♂ (7 ♂ dissected), 11 ♀ (5 ♀ dissected), Tian-Shan, E, edge of Terskei Alatau, Bajankol r., 1800 m, 25.06.2012, S. Toropov leg. (DEMSU); 11 ♂, 5 ♀, Kazakhstan, Terskei Mt. R., the Bayankol River, h. 1800 m; 26.06.2012. Mellicta aurelia distans Higgins, 1955 (female for breeding), imago hatched 20.05.2013 (coll. S. V. Churkin)Published as part of Kovalenko, Margarita G., Kolesnichenko, Kirill A. & Kudryavtseva, Anna A., 2020, Revealing the specific status of Mellicta distans Higgins, 1955, stat. n. (Lepidoptera Nymphalidae) with morphological and molecular characters, pp. 353-368 in Zootaxa 4853 (3) on page 368, DOI: 10.11646/zootaxa.4853.3.2, http://zenodo.org/record/441080
Colloidal CdSe Quantum Wells with Graded Shell Composition for Low-Threshold Amplified Spontaneous Emission and Highly Efficient Electroluminescence
No full textSemiconductor nanoplatelets (NPLs) have emerged as a very promising class of colloidal nanocrystals for light-emitting devices owing to their quantum-well-like electronic and optical characteristics. However, their lower photoluminescence quantum yield (PLQY) and limited stability have hampered the realization of their outstanding luminescent properties in device applications. Here, to address these deficiencies, we present a two-step synthetic approach that enables the synthesis of core/shell NPLs with precisely controlled shell composition for engineering their excitonic properties. The proposed CdSe colloidal quantum wells possess a graded shell, which is composed of a CdS buffer layer and a CdxZn1-xS gradient layer, and exhibit bright emission (PLQY 75-89%) in the red spectral region (634-648 nm) with a narrow emission line width (21 nm). These enhanced optical properties allowed us to attain low thresholds for amplified spontaneous emission (down to ∼40 μJ/cm2) under nanosecond laser excitation. We also studied the electroluminescent performance of these NPLs by fabricating solution-processed light-emitting diodes (LEDs). In comparison to NPL-LEDs with CdSe/CdS core/shell NPLs, which exhibit an external quantum efficiency (EQE) value of only 1.80%, a significantly improved EQE value of 9.92% was obtained using graded-shell NPLs, the highest value for colloidal NPL-based-LEDs. In addition, the low efficiency roll-off characteristics of NPL-LEDs enabled a high brightness of up to ∼46 000 cd/m2 with an electroluminescence peak centered at 650 nm. These findings demonstrate the paramount role that heterostructure engineering occupies in enhancing the optoelectronic characteristics of semiconductor NPLs toward practically relevant levels
Author Correction: A global analysis of terrestrial plant litter dynamics in non-perennial waterways
No full text© 2018 The Author(s) In the version of this Article originally published, the affiliation for M. I. Arce was incorrect; it should have been:5Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany. This has now been corrected in the online versions of the Article
Studies on Thermal Reactions and Sintering Behaviour of Red Clays by Irreversible Dilatometry
No full textThermal behavior of clays strongly influences that of ceramic bodies made thereof and hence, its study is must for assessing its utility in ceramic products as well as to set the body composition. Irreversible dilatometry is an effective thermal analysis tool for evaluating thermal reactions as well as sintering behavior of clays or clay based ceramic bodies. In this study, irreversible dilatometry of four red clay samples (S, M, R and G) of Gujarat region, which vary in their chemical and mineralogical compositions was carried out using a Dilatometer and compared. Chemical analysis and XRD of red clays were carried out. XRD showed that major clay minerals in S, M and R clays are kaolinite. However, clay marked R and G showed presence of both kaolinite and illite and / muscovite. Presence of non-clay minerals such as hematite, quartz, anatase were also observed in all clays. XRD results were in agreement with chemical analyses results. Rational analyses showed variation in amount of clay and non-clay minerals in red clay samples. Evaluation of dilatometric curves showed that clay marked as S, M and R exhibit patterns typical for kaolinitic clays. Variation in linear expansion (up to 550 degrees C) and shrinkage (above 550 degrees C) between these three clays was found to be related to difference in amount of quartz and kaolinite respectively. However, dilatometric curve of G exhibit a pattern similar to that for an illitic clay. This study confirmed that sintering of investigated kaolinitic and illitic and / muscovitic red clays initiates at above 1060 degrees C and 860 degrees C respectively and this behaviour strongly depends upon type and amount of minerals and their chemical compositions
- …
