scholarly journals Molecularly Heterogeneous Structure of a Nonionic Deep Eutectic Solvent Composed of N-Methylacetamide and Lauric Acid

2019 ◽  
Vol 123 (18) ◽  
pp. 3984-3993 ◽  
Author(s):  
Yaowen Cui ◽  
Jeramie C. Rushing ◽  
Soenke Seifert ◽  
Nicholas M. Bedford ◽  
Daniel G. Kuroda
Keyword(s):  
Lauric Acid ◽  
Deep Eutectic Solvent ◽  
Heterogeneous Structure

scholarly journals Pemanfaatan Hidrofobik Deep Eutectic Solvents dalam Penyisihan Dimetoat, Klorpirifos, dan Profenofos pada Buah Tomat dan Sayur Brokoli

2020 ◽  
Vol 9 (1) ◽  
pp. 7-10
Author(s):  
Axel Try Iddo Daely ◽  
Renita Manurung
Keyword(s):  
Lauric Acid ◽  
Freezing Point ◽  
Deep Eutectic Solvent ◽  
Chemical Properties ◽  
Deep Eutectic Solvents ◽  
Extraction Process ◽  
Molar Ratio ◽  
Organophosphate Insecticide ◽  
Pesticide Removal ◽  
New Generation

Organophosphate insecticide is a type of pesticide that is commonly used, where this pesticide can be toxic to environmental organisms even to humans. Hydrophobic Deep Eutectic Solvent (DES) is a new generation nonpolar solvent of ionic liquids because it has better physical properties and chemical properties so that it can be used in the extraction process. DES was synthesized at 50 oC for 15 minutes with a stirring speed of 300 rpm and a molar ratio of Dl-menthol: lauric acid varied from 1: 1, 2: 1, and 3: 1. Pesticide removal is done by mixing 5 ml of DES with 200 ml of aquadest and then Tomatoes and Broccoli vegetables are washed with the solution. DES characteristics are done by analyzing the shape and measuring the freezing point, density and viscosity of DES. The concentration of pesticide residues was analyzed using Gas Chromatography-Mass Spectrometer (GC-MS). The highest elimination of pesticides obtained with DES hydrophobic which has a molar ratio of dl-menthol: lauric acid is 3: 1 where the highest elimination of pesticides in Tomatoe is 44.82% for Dimethoate pesticide, 84.1% for Chlorpyrifos pesticide, and 83.72% for Profenofos pesticide and Broccoli 35.19% for Dimetoat pesticide, 64.64% for Chlorpyrifos pesticide, and 55.28% for Profenofos pesticides.

Recovery of metabolites from natural deep eutectic solvent matrices by countercurrent separation

Planta Medica ◽  
2015 ◽  
Vol 81 (11) ◽  
Author(s):  
Y Liu ◽  
J Garzon ◽  
JB Friesen ◽  
DC Lankin ◽  
JB McAlpine ◽  
...  
Keyword(s):  
Deep Eutectic Solvent ◽  
Natural Deep Eutectic Solvent

Lauric Acid-Induced Thrombocytopenia and Thrombosis in Rabbits

1967 ◽  
Vol 18 (01/02) ◽  
pp. 057-065 ◽  
Author(s):  
G Zbinden
Keyword(s):  
Acid Solution ◽  
Intravenous Injection ◽  
Lauric Acid ◽  
Repeated Administration ◽  
Intravenous Dose ◽  
Acid Injection ◽  
Small Doses ◽  
High Doses

SummaryIntravenous injection of 0.5% lauric acid solution into rabbits caused moderate to marked thrombocytopenia. With small doses (2.5 mg/kg) this thrombocyte decrease was reversible and microscopically demonstrable thrombosis in the lungs was only seen or suspected in a small number of rabbits 10 to 30 min after lauric acid injection. High doses were followed by partly reversible thrombocytopenia and by moderate to marked, sometimes lethal, thrombosis in the lungs still demonstrable 24 hrs after injection. Repeated administration of small doses of lauric acid did not lead to a depletion of the circulating thrombocytes. Thrombocytopenic response, however, appeared to be less pronounced after the second and subsequent injections. Studies with Cr51-labeled platelets indicate that during the reversible thrombocytopenia following a small intravenous dose of lauric acid platelets are retained in various organs, particularly the lungs.

Расчетные методы оценки ударной вязкости сварных элементов с трещинами

2020 ◽  
Vol 44 (3) ◽  
pp. 22-36
Author(s):  
Keyword(s):  
Stress Intensity ◽  
Impact Strength ◽  
Welded Joints ◽  
Development Process ◽  
Welded Joint ◽  
Operating Temperature ◽  
Crack Development ◽  
Heterogeneous Structure ◽  
Critical Crack Length ◽  
The Impact

Практика показывает, что для сварных конструкций, эксплуатируемых в условиях Крайнего Севера необходимо уделять внимание работоспособности сварных соединений при низких температурах. Металл сварных соединений в процессе воздействия обработки изменяет свои свойства, снижается ударная вязкость, образуется гетерогенная структура с большой степенью разнозернистости. Чтобы оценивать и иметь возможность правильно контролировать термическое воздействие и последствия сварочного процесса, требуется решить задачу аналитического определения ударной вязкости для всех зон сварного соединения. В настоящей статье представлен инженерный метод оценки ударной вязкости, применимый для любой зоны сварного соединения, в которой имеется острый или особый концентратор напряжений – трещина. Разработанный аналитический метод расчета ударной вязкости отражает качественную и количественную картину взаимосвязи структурно-механических характеристик и работы развития трещины в диапазоне температур 77…300 К. Предложенная схематизация зависимости критического коэффициента интенсивности напряжений от температуры позволила найти коэффициенты, характеризующие свойства материала, и выполнить расчеты изменения предела текучести и предела прочности от температуры эксплуатации. Построены графики зависимости работы развития трещины от температуры эксплуатации для сталей 15ГС и 17ГС, сравнение которых с экспериментальными данными показывает удовлетворительное согласование. Найдено, что при напряжениях предела выносливости отношение работы развития трещины к критической длине трещины постоянно, не зависит от температуры и для сталей 15ГС и 17ГС равно около 10. Ключевые слова: ударная вязкость, работа разрушения, коэффициент интенсивности напряжений, трещина, феррито-перлитная сталь, зона термического влияния. For welded structures under operation in the Far North, attention must be paid to the performance of welded joints at low temperatures. The properties of metal of welded joints are changed in the process of treatment, its toughness decreases, and a heterogeneous structure with a large range of different grain sizes is formed. In order to evaluate and be able to correctly control the thermal effect and the consequences of the welding process, it is necessary to solve the problem of analytical determination of impact strength for all zones of the welded joint. The paper presents an engineering method for evaluation of the impact strength applicable to any area of the welded joint in which there is a sharp or super sharp stress concentrator – a crack. The developed analytical method for calculating the impact strength reflects a qualitative and quantitative codependency of structural and mechanical characteristics and the process of crack development in the temperature range of 77–300 K. The proposed schematization of dependence of the critical coefficient of stress intensity on the temperature made it possible to find coefficients characterizing the properties of the material and to perform calculations of changes in yield strength and tensile strength on operating temperature. Graphs of the crack development process dependency on the operating temperature for 15ГС and 17ГС steels were constructed, and their comparison with experimental data displays satisfactory agreement. It was found that at endurance limit stresses, the ratio of the crack development process to the critical crack length is constant, non-dependent on temperature, and is equal to 10 for 15ГС and 17ГС steels. Keywords: impact strength, fracture work, stress intensity factor, crack, ferrite-pearlite steel, heat affected zone, steel tempering.

Probabilistic multiscale modeling of fracture in heterogeneous materials and structures

2020 ◽  
Vol 86 (7) ◽  
pp. 45-54
Author(s):  
A. M. Lepikhin ◽  
N. A. Makhutov ◽  
Yu. I. Shokin
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Fracture Mechanics ◽  
Multiscale Modeling ◽  
Virtual Work ◽  
Numerical Models ◽  
Heterogeneous Materials ◽  
Heterogeneous Structure ◽  
Generalized Coordinates ◽  
Heterogeneous Structures

The probabilistic aspects of multiscale modeling of the fracture of heterogeneous structures are considered. An approach combining homogenization methods with phenomenological and numerical models of fracture mechanics is proposed to solve the problems of assessing the probabilities of destruction of structurally heterogeneous materials. A model of a generalized heterogeneous structure consisting of heterogeneous materials and regions of different scales containing cracks and crack-like defects is formulated. Linking of scales is carried out using kinematic conditions and multiscale principle of virtual forces. The probability of destruction is formulated as the conditional probability of successive nested fracture events of different scales. Cracks and crack-like defects are considered the main sources of fracture. The distribution of defects is represented in the form of Poisson ensembles. Critical stresses at the tops of cracks are described by the Weibull model. Analytical expressions for the fracture probabilities of multiscale heterogeneous structures with multilevel limit states are obtained. An approach based on a modified Monte Carlo method of statistical modeling is proposed to assess the fracture probabilities taking into account the real morphology of heterogeneous structures. A feature of the proposed method is the use of a three-level fracture scheme with numerical solution of the problems at the micro, meso and macro scales. The main variables are generalized forces of the crack propagation and crack growth resistance. Crack sizes are considered generalized coordinates. To reduce the dimensionality, the problem of fracture mechanics is reformulated into the problem of stability of a heterogeneous structure under load with variations of generalized coordinates and analysis of the virtual work of generalized forces. Expressions for estimating the fracture probabilities using a modified Monte Carlo method for multiscale heterogeneous structures are obtained. The prospects of using the developed approaches to assess the fracture probabilities and address the problems of risk analysis of heterogeneous structures are shown.

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