Hasil untuk "Oils, fats, and waxes"

杨世明1,刘克瑾2,姚辉江2,黄硕硕2,杜春来1,章敬波1 YANG Shiming1, LIU Kejin2, YAO Huijiang2, HUANG Shuoshuo2, DU Chunlai1, ZHANG Jingbo1

旨在为筒仓的设计和优化提供参考，基于自主设计的半圆柱形有机玻璃平底筒仓模型，进行了平均粒径分别为15、3.5 mm和5.5 mm陶球颗粒的室内筒仓中心卸料试验和离散元数值模拟。采用流态观察、速度分析、颗粒位移追踪3种方法探究了3组粒径颗粒的流态演变过程，分析了仓壁压力分布及变化规律，通过PFC 2D得到孔隙率、力链等细观变量分布并联合宏观层次的物理试验探讨了粒径大小对流态及仓壁压力的影响。结果表明：粒径对颗粒流态的整体演化过程无显著影响，不同粒径颗粒的流态均由整体流经漏斗流过渡为管状流；大粒径颗粒完成卸料过程耗时更久，卸料速率更慢；粒径对颗粒的流动轨迹无显著影响；边界区并不是一成不变的，在卸料过程中随着粒径的增大而逐渐上移；不同粒径颗粒组的峰值卸料压力最大值均位于距离仓底约1/3的位置；粒径越大，仓壁的压力波动越剧烈，峰值卸料压力也越大。综上，粒径对平底筒仓中心卸料的流态无显著影响，不同粒径的颗粒流态演化过程和颗粒流动轨迹具有相似性，粒径越大产生的仓壁卸料压力也越大。在实际工程中，需考虑粒径对筒仓结构安全性的影响。 To provide a reference for the design and optimization of silos, based on a self-designed semi-cylindrical plexiglass flat-bottom silo model, indoor silo center discharge tests and discrete element numerical simulations were conducted using ceramic ball particles with average particle size of 15, 3.5 mm and 5.5 mm. Three methods of flow pattern observation, velocity analysis, and particle displacement tracking were used to explore the flow pattern evolution of the three groups of particles with different particle sizes. The pressure distribution and variation of the silo wall were analyzed, and the distribution of microscopic variables such as porosity and force chain obtained from PFC 2D, along with macroscopic physical tests, were used to investigate the effect of particle size on flow pattern and silo wall pressure. The results showed that particle size had no significant effect on the overall evolution of particle flow pattern, and the flow pattern of particles with different particle size shifted from mass flow through funnel flow to tubular flow. Larger particle sizes of particles resulted in a longer discharge process with slower discharge rates. Particle size had no significant effect on the particle flow trajectories. The boundary zone was not fixed and gradually moved upwards with the increase of particle size during the discharge process. The peak of discharge pressure for different particle size groups was located approximately one-third of the way from the silo bottom. The larger the particle size, the more severe the pressure fluctuations on the silo wall, and the higher the peak of discharge pressure. In summary, particle size has no significant effect on the flow pattern of the silo center discharge. The flow pattern evolution and particle flow trajectories of particles with different particle sizes are similar. Larger particles generate higher discharge pressure on the silo wall. In practical engineering, the impact of particle size on silo structure safety should be considered.

吴娟娟1，田佳宁1，陈奕蒙1，王成成1，王玉明1,2 , 姜晓明1, 薛长湖1, 张恬恬1 WU Juanjuan1, TIAN Jianing1, CHEN Yimeng1, WANG Chengcheng1, WANG Yuming1,2, JIANG Xiaoming1, XUE Changhu1, ZHANG Tiantian1

为了揭示雌、雄膨腹海马磷脂组成及其差异，用溶剂萃取法分别提取雌、雄膨腹海马脂质，冷丙酮提取其中的磷脂，进一步采用薄层色谱法和硅胶柱层析分离制备各磷脂组分，利用气相色谱技术分析比较雌、雄膨腹海马磷脂及其各组分的脂肪酸组成。结果表明：雌、雄膨腹海马的磷脂含量丰富，分别占总脂的18.11%和18.72%；膨腹海马磷脂包括磷脂酰乙醇胺、磷脂酰胆碱、溶血磷脂酰胆碱和鞘磷脂，其中磷脂酰胆碱含量最高；膨腹海马磷脂中共鉴定出20种脂肪酸，且不饱和脂肪酸含量高于饱和脂肪酸含量；雌、雄膨腹海马磷脂中海洋特征性n-3多不饱和脂肪酸DHA和EPA总含量分别为18.30%、19.61%；膨腹海马的磷脂酰乙醇胺、磷脂酰胆碱和溶血磷脂酰胆碱饱和脂肪酸都以C16∶ 0和C18∶ 0为主，而在鞘磷脂中以C14∶ 0和C16∶ 0为主；膨腹海马4种磷脂组分的单不饱和脂肪酸均以C18∶ 1为主，多不饱和脂肪酸均以EPA和DHA为主；除了雄性膨腹海马溶血磷脂酰胆碱外，其余磷脂组分DHA和EPA总含量均超过16%。综上，膨腹海马磷脂组成多样，海洋特征性n-3多不饱和脂肪酸含量丰富，具有较高的营养价值。 In order to reveal the phospholipids compositions and differences between male and female Hippocampus abdominalis, the lipids of female and male Hippocampus abdominalis were extracted by solvent extraction method, then phospholipids in the lipids were extracted by cold acetone. Moreover, the different phospholipids fractions were separated by thin-layer chromatography and silica gel column chromatography, then the fatty acid composition of phospholipids and the different phospholipids fractions from female and male Hippocampus abdominalis were analyzed by gas chromatography. The results showed that the female and male Hippocampus abdominalis were rich in phospholipids, accounting for 18.11% and 18.72% of the total lipids, respectively. The phospholipids of Hippocampus abdominalis included phosphatidylethanolamine, phosphatidylcholine, lysophosphatidylcholine and sphingomyelin, among which phosphatidylcholine was the most abundant. The phospholipids of Hippocampus abdominalis identified 20 kinds of fatty acids, and the content of unsaturated fatty acids was higher than that of saturated fatty acids. Furthermore, the total content of marine characteristic n-3 polyunsaturated fatty acids DHA and EPA in female and male Hippocampus abdominalis phospholipids were 18.30% and 19.61%, respectively. The saturated fatty acids of phosphatidylethanolamine, phosphatidylcholine and lysophosphatidylcholine in both male and female Hippocampus abdominalis were all dominated by C16∶ 0 and C18∶ 0, whereas those in sphingomyelin were dominated by C14∶ 0 and C16∶ 0. The monounsaturated fatty acids of the four phospholipid fractions of the male and female Hippocampus abdominalis were all dominated by C18∶ 1, and the polyunsaturated fatty acids were all dominated by EPA and DHA. The total contents of DHA and EPA were more than 16%, except for lysophosphatidylcholine in male Hippocampus abdominalis. In conclusion, phospholipids composition of Hippocampus abdominalis is diverse, with abundant marine characteristic n-3 polyunsaturated fatty acids and high nutritional value.

Shubham S. Ganar, Deepak J., Arindam Das

Droplet impact on solid liquid-infused surfaces (LIS) has been widely explored due to its significant scientific implications and industrial relevance. In most studies, the predominant impact behavior observed is complete droplet rebound. In This study we investigated the influence of octadecyltrichlorosilane (OTS) functionalization and oil coatings on the droplet impact dynamics of smooth polydimethylsiloxane (PDMS) surfaces. We conducted droplet impact experiments on smooth PDMS functionalized with OTS and subsequently coated or absorbed with two different oils, silicone oil (5cSt) and hexadecane, to create Van der Waals and non-Van der Waals SLIP surfaces. Contact angle measurements revealed that OTS functionalization reduced adhesion and increased water repellency, facilitating partial droplet rebound upon impact. Oil-coated surfaces exhibited reduced droplet spreading due to viscous resistance, while absorbed oils altered surface flexibility, influencing impact dynamics. PDMS samples absorbed with silicone oil demonstrated complete droplet rebound at all Weber numbers, whereas hexadecane-absorbed surfaces exhibited limited spreading and no rebound, highlighting the significance of oil-PDMS interactions. High-speed imaging and quantitative analysis confirmed that surface functionalization and oil interactions critically affect droplet spreading, recoil, and rebound behavior. These findings provide insights into optimizing liquid-repellent surfaces for applications such as self-cleaning coatings and droplet transport systems.

BI Caixia

The research and application of risk analysis and evaluation for underground gas storage facilities are critical due to their diverse equipment, complex process flows, and numerous risk factors. In particular, corrosion failure accidents in ground process pipelines at these facilities have become increasingly common in recent years. Effective and accurate analysis of the causes of these corrosion failures is essential for ensuring the safe operation of underground gas storage facilities. This article presents a risk assessment methodology that leverages data and knowledge fusion. The process begins with a statistical analysis of the corrosion failure data from ground process pipelines in underground gas storage facilities, from which a Bayesian corrosion prediction model is developed. This model serves as the foundation for analyzing the basic events that lead to corrosion failure in these pipelines. Subsequently, a knowledge model of corrosion failure is established, and a detailed analysis of corrosion causes is conducted using the fault tree specific to corrosion failure in ground process pipelines. The importance of each basic event within the fault tree is quantified through the structural importance coefficient assigned to each event. The analysis categorizes the influencing factors of corrosion failure into four main groups. A judgment matrix is then created to determine the relative weight values of these different influencing factors. This matrix is crucial for setting the weight factors in the fuzzy comprehensive evaluation, which ultimately determines the risk level of corrosion failure in ground process pipelines at underground gas storage facilities. By applying examples of corrosion risk assessments for ground process pipelines, this study provides a scientific basis for enhancing safety management and operational practices at underground gas storage facilities.

Farouk I. Metwalli, Amir Ismail, M.S. Metwally et al.

The present study aims to integrate a large set of geological and geophysical data into a comprehensive model describing the depositional features of the Abu Madi/El Qar'a/Khilala gas fields. The model is based on the sequence stratigraphic framework of the Abu Madi Formation defined using cores, well logs, and time-migrated seismic data. Seismic trace attribute sections and relative acoustic impedance sections are also used. A possible depositional pattern for the main Level III is established, based on the lithological and petrophysical information derived from the seismic data analysis. The Abu Madi Formation can be regarded as a depositional sequence recording the progressive drowning of the incised valley. The sequence is bounded at the base by an erosional unconformity, created by a drop in the level of the Late Messinian Sea, and at the top by a drowning unconformity related to the Early Pliocene transgression. The bottom of Level II divides the Abu Madi sequence into two smaller sequences. In both sequences, gas-bearing traps can be found in the Lowstand Systems Tracts, represented by the fluvial Level III and fluvial-deltaic Level II, respectively.

HOU Dali, HAN Xin, TANG Hongming, GUO Jianchun, GONG Fengming, SUN Lei, QIANG Xianyu

Adsorbed gas represents a primary mode of shale gas occurrence and is a major source of shale gas production in the later stages of development. It primarily resides within the organic kerogen and clay minerals of shale formations, with organic kerogen being the dominant host. Consequently, the study of organic kerogen characteristics and its adsorption mechanisms is crucial for understanding shale gas development. In this paper, the kerogen of Longmaxi Shale in the Sichuan Basin is taken as the research object. The microstructure of kerogen is expressed by combining methods through the solid-state NMR experiment, Fourier transform infrared spectroscopy experiment, X-ray photoelectron spectroscopy experiment, and the molecular structure model of kerogen is constructed. The adsorption mechanism and characteristics of CH4 in kerogen of Longmaxi Shale are analyzed by magnetic levitation weight experiment, molecular simulation methods of the Grand Canonical Monte Carlo（GCMC）, and Molecular Dynamics（MD）. The results show that the molecular formula of the kerogen of shale experimental sample of Longmaxi Formation is C237H219O21N5S4. The excess adsorption gas volume of CH4 in kerogen increase first and then decreased with the increase of pressure. Under the same pore size and pressure, the excess adsorption gas volume and total gas volume of CH4 decrease with the increase in temperature. The C and S atoms in kerogen are the main cause of CH4 adsorption. The CH4 near the kerogen pore wall presents an adsorption state, while the CH4 far from the kerogen pore wall presents a free state. As the pore size increase, the distance between the two peaks of CH4 density gradually increases, and the peak value decreases gradually.

Deng Han, Wang Yao, Meng Zhaolan et al.

The main sand-control layer of the porous metal screen is made of metal with excellent high temperature resistance and corrosion resistance.Due to its special three-dimensional pore structure,the screen has strong permeability and flow capacity.It has good applicability in conventional cold production and development in oil and gas fields.In order to further evaluate the adaptability of the screen under the conditions of heavy oil thermal development,multi-round of steam huff and puff simulation experiments were carried out to simulate the change of sand control effect of the screen in the process of multi-round of steam huff and puff stimulation,and analyze the pressure,temperature,sand production and sand particle size of the screen during the injection and production process.The experimental results show that after 16 rounds of steam huff and puff experiments(the maximum steam temperature is 350 ℃,and the maximum injection pressure is 17 MPa),the sand concentration of the screen ranges from 1.86×10^-7% to 6.63×10^-6%,the median particle size of the sand is slightly smaller than the sand control accuracy of the screen,and the permeability retention capacity is about 85.7%.The overall flow capacity and anti-plugging performance retention rate of the screen is good.The experimental conclusion fully proves that the screen has an excellent adaptability in the development of heavy oil thermal recovery reservoirs.

Elena Candellone, Alberto Aleta, Henrique Ferraz de Arruda et al.

The global production and consumption of vegetable oils have sparked several discussions on sustainable development. This study analyzes over 20 million tweets related to vegetable oils to explore the key factors shaping public opinion. We found that coconut, olive, and palm oils dominate social media discourse despite their lower contribution to overall global vegetable production. The discussion about olive and palm oils remarkably correlates with Twitter's growth, while coconut increases more significantly with bursts of activity. Discussions around coconut and olive oils primarily focus on health, beauty, and food, while palm draws attention to pressing environmental concerns. Overall, virality is related to environmental issues and negative connotations. In the context of Sustainable Development Goals, this study highlights the multifaceted nature of the vegetable oil debate and its disconnection from scientific discussions. Our research sheds light on the power of social media in shaping public perception, providing insights into sustainable development strategies.

Francesca Venturini, Michela Sperti, Umberto Michelucci et al.

This dataset encompasses fluorescence spectra and chemical parameters of 24 olive oil samples from the 2019-2020 harvest provided by the producer Conde de Benalua, Granada, Spain. The oils are characterized by different qualities: 10 extra virgin olive oil (EVOO), 8 virgin olive oil (VOO), and 6 lampante olive oil (LOO) samples. For each sample, the dataset includes fluorescence spectra obtained with two excitation wavelengths, oil quality, and five chemical parameters necessary for the quality assessment of olive oil. The fluorescence spectra were obtained by exciting the samples at 365 nm and 395 nm under identical conditions. The dataset includes the values of the following chemical parameters for each olive oil sample: acidity, peroxide value, K270, K232, ethyl esters, and the quality of the samples (EVOO, VOO, or LOO). The dataset offers a unique possibility for researchers in food technology to develop machine learning models based on fluorescence data for the quality assessment of olive oil due to the availability of both spectroscopic and chemical data. The dataset can be used, for example, to predict one or multiple chemical parameters or to classify samples based on their quality from fluorescence spectra.

Jeremy W. Levitan, Jun Lu, Brent Jarvis et al.

Advances on no-insulation REBCO coil technology has made understanding and controlling contact resistivity increasingly im-portant. Praffin (wax) impregnation is a process that has been used for improving mechanical stability of insulated and no-insulation REBCO coils. Wax impregnation is beneficial in both no-insulation coils and insulated coils with additional copper sta-bilizer or multiple conductors. In the latter scenario, contact re-sistance between conductor and additional stabilizer is also im-portant. It is crucial to understand the effects of wax impregna-tion on contact resistivity (Rct). We designed and built an appa-ratus to use short REBCO samples which simulates the behavior of Rct in a pancake coil during the wax impregnation process. Rct was measured at 77 K before and after the wax impregnation. In addition, a single pancake coil was wound to test the effect of wax impregnation. This coil simulates the NHMFL 32 T magnet Coil A in winding stresses. Rct was measured at 77 K and 4.2 K before and after wax impregnation. We found that wax impregnation does not significantly change contact resistivity. This means that wax impregnation can be used in coils without compromising the current sharing ability between turns. The experimental process and results are discussed.

O. Aerts, Jeroen Pyl, E. Mangodt et al.

A 32-year-old atopic female patient was referred because of a severe cheilitis lasting a few months, together with a longer standing, yet mild, facial and hand dermatitis. Initially, she had suffered from dry cracked lips, diagnosed as atopic cheilitis, for which she had tried multiple (n= 6) lip balms (Table 1). Clinical examination showed a pronounced lip dermatitis complicated by bacterial superinfection (Staphylococcus aureus, Pseudomonas aeruginosa; Figure 1). Peroral ciprofloxacine, topical acetic acid 1% aq. compresses and betamethasone-17-valerate 0.1% ointment were prescribed, and she was advised to use unscented toothpaste (oraNurse, Welwyn, UK), and petrolatum jelly as lip balm. Patch tests were performed with a baseline, cosmetic, fragrance and bakery series (Chemotechnique Diagnostics, Vellinge, Sweden), together with four of six suspected lip balms (two not available for patch testing). The tests, mounted on AllergEAZE chambers (SmartPractice, Calgary, Canada), were applied on the upper back for 2 days and readings were performed on Day (D)2, D4 and D7 (Table 1). These showed + to ++ reactions to the four lip balms, and to several haptens (all +): fragrances (Myroxylon pereirae, propolis, fragrance mix I [FM-I], limonene and linalool hydroperoxides), colophonium, octylisothiazolinone (OIT), 2-hydroxyethyl methacrylate (HEMA), and sorbitan sesquioleate (SSO). Although SSO positivity potentially explained the positive patch tests to M. pereirae, FM-I and HEMA, the patient also reacted to limonene hydroperoxides, whichwas considered relevant for the cheilitis, facial and hand dermatitis as limonene was declared in several of her cosmetics, including her toothpaste. No relevance was found for SSO, HEMA, colophonium nor OIT. As only one of four tested lip balms was effectively scented, additional patch tests were performed with (non-commercialized) patch test preparations obtained from cosmetic manufacturers. On that occasion+ reactions were observed to four oils, fats and waxes: cera alba (beeswax) 30% pet., candelilla cera (Euphorbia cerifera) 41% pet., butyrospermum parkii (shea butter) 30% pet. and helianthus annuus seed oil 10% pet., present in 5/6, 1/6, 4/6 and 1/6 of previously used lip balms, respectively (Table 1). All four haptens tested negatively in 20 control patients. The abovementioned treatment, together with the use of cosmetics free from all demonstrated allergens, lead to complete resolution of the cheilitis, and significant amelioration of the hand and face dermatitis.

Karidewa Nyeinga, Denis Okello, Benard Tabu et al.

The thermal performance of locally available oils in Uganda have been experimentally investigated to determine their suitability for heat transfer and solar thermal energy storage. Sunflower oil and palm oil, both local vegetable vegetable oils and Shell thermia B, commonly used in the local industries as a heat transfer fluid were used in the study. The oils were heated in an insulated tank until temperatures close to their smoke points were attained and then heating was stopped; the tank temperature was recorded for 24 hours during the cooling. The second experiement involved charging the oil in a self-circulating system without the aid of a pump. It was observed that the vegetable oils gained heat faster than thermia B. Sunflower oil retained heat for a longer period compared to palm oil and thermia B. The total amount energy stored by sunflower was equally higher than palm oil while thermia B had the least energy stored. The results show that sunflower oil is the most suitable oil for solar thermal storage and heat transfer.

Onaiwu Oduwa David, Usiosefe Ikponmwosa, Okon Samuel

Generating pressure transient response for an interpretation model to describe essential features of a reservoir system accurately is often difficult. It is generally due to the inaccessibility of standard pressure transient analysis tools due to the cost, and even when accessible, they are constrained to its workflow and limitations. This study presents an alternative to standard industry tools to determine transient pressure response for a given rate history. A reservoir model for a single well with constant skin and wellbore storage producing a varying step rate in a semi-infinite acting reservoir with a sealing fault was used as a case study. The well is also assumed to be producing above saturation pressure from a reservoir saturated with slightly compressible fluid hence having constant fluid properties. The method discussed in this study can be applied to well-test interpretation models with an analytical constant terminal rate solution producing at variable step rates from a reservoir having constant rock and fluid properties. The results show conformance with that of standard industry software, and diagnostic plots of the simulated data set can help engineers plan well-test jobs and study the behavior of different reservoir models. Moreover, the program can be modified and used to regress observed pressure response with a selected model. The approach suggested by this study is a perfect alternative where time and cost are constraints.

Liang Zhang, Rong Feng, Songhe Geng et al.

Seepage-type gas hydrate accumulation in subsea shallow formations involves complicated thermo-hydro-solid coupling processes and matching problem between various accumulation elements. The formation physical properties control local natural gas migration pathway and thus the final reservoir characteristics of hydrates. In this paper, a novel mixed-flux model for gas hydrate accumulation is established and then used to simulate the process of methane gas migration into the shallow stratum to form a hydrate reservoir. The effects of reservoir heterogeneity and gas source conditions on the distribution of pore fluid and hydrate accumulation are examined. The simulation results show that reservoir heterogeneity is conducive to the retention and lateral migration of CH4 in a hydrate stability zone. CH4 can contact more pore water to form a large hydrate reserve, but the formed hydrate is often dispersed. Low-permeability layers enhance the trapping of CH4 and form a uniform and large hydrate saturation. Besides, gas source conditions have an important impact on the hydrate accumulation in reservoirs. Large gas flux, small pore water flux, continuous gas supply, high content of heavy components in natural gas, and numerous gas source points contribute to large amounts of hydrates generation in a certain time period. The presented work will deepen our understanding of the controls of natural gas hydrate systems in subea shallow formations.

Qian Deru, Zheng Junhua, Gao Runfeng et al.

The MWD tool for formation pressure is composed of mechanical, electronic and hydraulic components. The internal installation space is small, the structure is complex, and the integration is difficult. In order to reduce the research and development risk of the tool, the formation pressure simulation gauging nipple was developed firstly. The 3D visualization technology was used to establish the virtual digital prototype of the simulation gauging nipple. The hydraulic valve insertion technology was used to study the key modules such as the micro hydraulic system with an output pressure of 20 MPa. Meanwhile, a formation pressure simulation test apparatus was developed as a platform for indoor high-temperature and high-pressure test and test principle verification of simulation gauging nipple. Actual measurement shows that the simulation gauging nipple runs stably at 120 ℃ and 60 MPa. Cores with permeability of 1×10^-3 μm² and 320×10^-3 μm² were selected to investigate the gauging nipple test principle, obtaining the formation pressure test curve, with measurement accuracy reaching 96%. The laboratory test verified the correctness of the measurement principle of the simulation gauging nipple and the accuracy of the measurement data. The research results lay a solid foundation for the development of formation pressure MWD engineering prototype.

Sophie Lauren Mason, John Christopher Meyer, David John Needham

In this paper we develop and significantly extend the thermal phase change model, introduced in [12], describing the process of paraffinic wax layer formation on the interior wall of a circular pipe transporting heated oil, when subject to external cooling. In particular we allow for the natural dependence of the solidifying paraffinic wax conductivity on local temperature. We are able to develop a complete theory, and provide efficient numerical computations, for this extended model. Comparison with recent experimental observations is made, and this, together with recent reviews of the physical mechanisms associated with wax layer formation, provide significant support for the thermal model considered here.

Francesca Venturini, Michela Sperti, Umberto Michelucci et al.

Extra virgin olive oil (EVOO) is the highest quality of olive oil and is characterized by highly beneficial nutritional properties. The large increase in both consumption and fraud, for example through adulteration, creates new challenges and an increasing demand for developing new quality assessment methodologies that are easier and cheaper to perform. As of today, the determination of olive oil quality is performed by producers through chemical analysis and organoleptic evaluation. The chemical analysis requires the advanced equipment and chemical knowledge of certified laboratories, and has therefore a limited accessibility. In this work a minimalist, portable and low-cost sensor is presented, which can perform olive oil quality assessment using fluorescence spectroscopy. The potential of the proposed technology is explored by analyzing several olive oils of different quality levels, EVOO, virgin olive oil (VOO), and lampante olive oil (LOO). The spectral data were analyzed using a large number of machine learning methods, including artificial neural networks. The analysis performed in this work demonstrates the possibility of performing classification of olive oil in the three mentioned classes with an accuracy of 100$\%$. These results confirm that this minimalist low-cost sensor has the potential of substituting expensive and complex chemical analysis.

Érick Oliveira Rodrigues, FFC Morais, NAOS Morais et al.

The deposits of fat on the surroundings of the heart are correlated to several health risk factors such as atherosclerosis, carotid stiffness, coronary artery calcification, atrial fibrillation and many others. These deposits vary unrelated to obesity, which reinforces its direct segmentation for further quantification. However, manual segmentation of these fats has not been widely deployed in clinical practice due to the required human workload and consequential high cost of physicians and technicians. In this work, we propose a unified method for an autonomous segmentation and quantification of two types of cardiac fats. The segmented fats are termed epicardial and mediastinal, and stand apart from each other by the pericardium. Much effort was devoted to achieve minimal user intervention. The proposed methodology mainly comprises registration and classification algorithms to perform the desired segmentation. We compare the performance of several classification algorithms on this task, including neural networks, probabilistic models and decision tree algorithms. Experimental results of the proposed methodology have shown that the mean accuracy regarding both epicardial and mediastinal fats is 98.5% (99.5% if the features are normalized), with a mean true positive rate of 98.0%. In average, the Dice similarity index was equal to 97.6%.

Diana Cholakova, Desislava Glushkova, Slavka Tcholakova et al.

Preparation of nanoemulsions of triglyceride oils in water usually requires high mechanical energy and sophisticated equipment. Recently, we showed that alpha-to-beta (viz. gel-to-crystal) phase transition, observed with most lipid substances (triglycerides, diglycerides, phospholipids, alkanes, etc.), may cause spontaneous disintegration of micro-particles of these lipids, dispersed in aqueous solutions of appropriate surfactants, into nanometer particles/drops using a simple cooling/heating cycle of the lipid dispersion (Cholakova et al. ACS Nano 14 (2020) 8594). In the current study we show that this "cold-burst process" is observed also with natural oils of high practical interest, incl. coconut oil, palm kernel oil and cocoa butter. Mean drop diameters of ca. 50 to 100 nm were achieved with some of the studied oils. From the results of dedicated model experiments we conclude that intensive nano-fragmentation is observed when the following requirements are met: (1) The three phase contact angle at the air-water-solid lipid interface is below ca. 30 degrees; (2) The equilibrium surface tension of the surfactant solution is below ca. 30 mN/m and the dynamic surface tension decreases rapidly. (3) The surfactant solution contains non-spherical surfactant micelles. e.g. ellipsoidal micelles or bigger supramolecular aggregates; (4) The three phase contact angle measured at the contact line (frozen oil-melted oil-surfactant solution) is also relatively low. The mechanism(s) of the particle bursting process is revealed and, on this basis, the role of all these factors is clarified and discussed. We explain all main effects observed experimentally and define guiding principles for optimization of the cold-burst process in various, practically relevant lipid-surfactant systems.