Determination of dV/dt and dI/dt characteristics for high voltage 4H-SiC Schottky diodes with different types of metal-polymeric packages

Abstract Determination of metal bridging failures on plastic encapsulated devices is difficult due to the metal etching effects that occur while removing many of the plastic mold compounds. Typically, the acids used to remove the encapsulation are corrosive to the metals that are found within the device. Thus, decapsulation can result in removal of the failure mechanism. Mechanical techniques are often not successful due to damage that results in destruction of the die and failure mechanism. This paper discusses a novel approach to these types of failures using a silicon etch and a backside evaluation. The desirable characteristics of the technique would be to remove the silicon and leave typical device metals unaffected. It would also be preferable that the device passivation and oxides not be etched so that the failure location is not disturbed. The use of Tetramethylammonium Hydroxide (TMAH), was found to fit these prerequisites. The technique was tested on clip attached Schottky diodes that exhibited resistive shorting. The use of the TMAH technique was successful at exposing thin solder bridges that extruded over the edge of the die resulting in failure.

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Characterization of Different Types of Biomass Wastes Using Thermogravimetric and ICP-MS Analyses

Revista de Chimie ◽

10.37358/rc.19.12.7797 ◽

2020 ◽

Vol 70 (12) ◽

pp. 4594-4600

Keyword(s):

Thermogravimetric Analysis ◽

Food Industry ◽

Wood Waste ◽

Biomass Ash ◽

Minor Elements ◽

Ms Analysis ◽

Icp Ms ◽

Different Types

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG

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Studies on the Behavior Some Paints in Electro-insulating Fluid Based on Vegetable Esters

Revista de Chimie ◽

10.37358/rc.18.5.6276 ◽

2018 ◽

Vol 69 (5) ◽

pp. 1139-1144

Author(s):

Iosif Lingvay ◽

Adriana Mariana Bors ◽

Livia Carmen Ungureanu ◽

Valerica Stanoi ◽

Traian Rus

Keyword(s):

Structural Changes ◽

Oxidation Processes ◽

High Oleic ◽

Painting Materials ◽

Insulating Paper ◽

Different Types ◽

Mechanism And Kinetics ◽

Kinetics Of ◽

Natural Ester

For the purpose of using three different types of painting materials for the inner protection of the transformer vats, their behavior was studied under actual conditions of operation in the transformer (thermal stress in electro-insulating fluid based on the natural ester in contact with copper for electro-technical use and electro-insulating paper). By comparing determination of the content in furans products (HPLC technique) and gases formed (by gas-chromatography) in the electro-insulating fluid (natural ester with high oleic content) thermally aged at 130 �C to 1000 hours in closed glass vessels, it have been found that the presence the investigated painting materials lead to a change in the mechanism and kinetics of the thermo-oxidation processes. These changes are supported by oxygen dissolved in oil, what leads to decrease both to gases formation CO2, CO, H2, CH4, C2H4 and C2H6) and furans products (5-HMF, 2-FOL, 2 -FAL and 2-ACF). The painting materials investigated during the heat treatment applied did not suffer any remarkable structural changes affecting their functionality in the electro-insulating fluid based on vegetable esters.

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Determination of sterols by capillary column gas chromatography. Differentiation among different types of olive oil: Virgin, refined, and solvent-extracted

Journal of the American Oil Chemists Society ◽

10.1007/bf02517973 ◽

1996 ◽

Vol 73 (12) ◽

pp. 1685-1689 ◽

Cited By ~ 39

Author(s):

Oroncio Jiménez de Blas ◽

Amando del Valle González

Keyword(s):

Gas Chromatography ◽

Olive Oil ◽

Capillary Column ◽

Different Types ◽

Capillary Column Gas Chromatography

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The Importance of Diet in Predicting the Remission of Urticaria—Determination of Allergen-Specific IgE

Medicina ◽

10.3390/medicina57070679 ◽

2021 ◽

Vol 57 (7) ◽

pp. 679

Author(s):

Monica Iuliana Ungureanu ◽

Liliana Sachelarie ◽

Radu Ciorap ◽

Bogdan Aurelian Stana ◽

Irina Croitoru ◽

...

Keyword(s):

Predictive Value ◽

Allergic Diseases ◽

Specific Ige ◽

Egg White ◽

Food Allergens ◽

Pediatric Hospital ◽

Disease Remission ◽

Specific Serum ◽

Different Types

Background and Objectives: Different types of food introduced gradually in the diet will expose children to different food allergens, increasing the chance of developing allergic diseases. The aim of our study was to determine if allergen-specific IgE values can influence, depending on the diet, the prediction of remission of urticaria in children. Materials and Methods: This prospective study was conducted in 132 patients diagnosed over two years with urticaria, admitted to “Sf. Maria” Clinical Pediatric Hospital Iaşi. Total IgE assay was performed by ELISA, and determination of specific serum IgE by the CLA System Quanti Scan method (Innogenetics, Heiden, Germany). Data were gathered and statistical analysis was performed using statistical software SPSS, using descriptive and inferential statistics. Results: The determination of specific IgE to food allergens was performed on a total of 132 cases. The values of specific IgE were positive for one or more food allergens in 84 patients (63.64%). The most common allergens involved were: cow’s milk in 33.3% cases, egg white in 22.6% cases, and hazelnuts in 11.9% cases. The specific IgE values for the different types of food included in our study had a predictive value for disease remission. Conclusions: The determination of specific IgE confirms the presence of a particular food allergen and may have predictive value for the future development of an allergic manifestation.

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Development of multi-residue extraction procedures using QuEChERS and liquid chromatography tandem mass spectrometry for the determination of different types of organic pollutants in mussel

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03363-y ◽

2021 ◽

Author(s):

Rodrigo Álvarez-Ruiz ◽

Yolanda Picó ◽

Daniele Sadutto ◽

Julián Campo

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Organic Pollutants ◽

Tandem Mass ◽

Extraction Procedures ◽

Chromatography Tandem Mass Spectrometry ◽

Different Types ◽

Liquid Chromatography Tandem Mass

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Parametric Analysis of Rotational Effects in Seismic Design of Tall Structures

Applied Sciences ◽

10.3390/app11020597 ◽

2021 ◽

Vol 11 (2) ◽

pp. 597

Author(s):

Milan Sokol ◽

Rudolf Ároch ◽

Katarína Lamperová ◽

Martin Marton ◽

Justo García-Sanz-Calcedo

Keyword(s):

Seismic Design ◽

Parametric Study ◽

Tall Buildings ◽

Soil Parameters ◽

Eurocode 8 ◽

Tall Structures ◽

Rotational Components ◽

Different Types ◽

Depth Study

This paper uses a parametric study to evaluate the significance of the rotational components of Earth’s motion in a seismic design. The parametric study is based on the procedures included in Eurocode 8, Part 6. Although the answer to the question of when the effects of rotational components are important is quite a complex one and requires a more in-depth study, our aim was to try to assess this question in a relatively quick manner and with acceptable accuracy. The first part of the paper is devoted to derivation of a simple formula that can be used for expressing the importance of rotational components in comparison with the classic seismic design without their usage. The quasi-static analysis, assuming inertial forces, is used. A crucial role plays the shape of the fundamental mode of the vibration. Due to simplicity reasons, well-known expression for estimation of the first eigenmode as an exponential function with different power coefficients that vary for different types of buildings is used. The possibility of changing the soil parameters is subsequently included into the formula for estimation of the fundamental frequency of tall buildings. In the next part, the overall seismic analyses of complex FEM models of 3D buildings and chimneys are performed. The results from those analyses are then compared with those from simplified calculations. The importance of the soil characteristics for determination of whether it is necessary to take into account the rotational effects is further discussed.

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