Highly accelerated temperature and humidity stress test technique (HAST)

1982 ◽  
Vol 22 (6) ◽  
pp. 1186
Author(s):  
Abdul Cholid ◽  
Her Gumiwang Ariswati ◽  
Syaifudin Syaifudin

Calibration is a technical activity which consists of the determination, the determination of one or more properties or characteristics of a product, process or service in accordance with a special procedure has been set. The purpose of which is to ensure the calibration measurement results in accordance with national and international standards. The tools used for the calibration of pressure Digital Pressure Meter. This tool is used to measure the pressure and suction pump spygnomanometer or other devices that use parameters for measuring pressure. This module manufacturing system using Arduino system as a controller and as processing analog data into digital data of the sensor MPX5100GP and MPXV4115V using analog signal conditioning circuit and displayed on the LCD Touchscreen with 2 modes of measurement that is positive pressure and vacuum pressure with pressures ranging from 0-300 mmHg for positive pressure and 0 –(-400)  mmHg to vacuum pressure. There are also  DHT22 sensor, As a detector for temperature and humidity for use in the work method in the calibration process. Based on a stress test generated and using comparators Digital Pressure Meter 2 plus brand fluke, this tool has an error value of 0 to 0.58% and has a value increment or correction value of 0 - 3. It can be concluded that the DPM DUA MODE this deserves to be used.


2021 ◽  
pp. 548-562
Author(s):  
Muchtaridi Muchtaridi ◽  
Rini Yulianita ◽  
Iyan Sopyan ◽  
Amirah Mohd Gazzali

Drug stability is one of the most important criteria for producing safe, excellent and effective products. Some environmental factors that influence drug stability are light, temperature, and humidity. Simvastatin is a cholesterol-lowering drug that is known to be sensitive to high temperature and humidity. The purpose of this study is to analyze the effect of 6 months of real-time storage conditions on the stability of generic simvastatin tablets in public pharmacy facilities. This study used simulation method with 4 brands of simvastatin generic tablets with two different strengths (10 mg and 20 mg). In the process, the sample was conditioned in 6 different regions for 6 months. The results of temperature and humidity monitoring showed 2 locations at ≤ 25 ° C, 4 locations had a temperature of ≥ 25 °C and all locations had humidity > 65 %. The drug was evaluated for physical and chemical quality parameters at months 0, 3, and 6. After being stored for 6 months, the tablets showed a decrease in disintegration time and an increase in the friability, showing lack of durability. Similarly, there was a decrease in the content concentration in the tablets but fortunately the level was still within the accepted specification range (90 – 110 %). However, there was one tablet that did not meet the dissolution test requirements after the storage duration (Q ≤ 75 % at 30 minutes). The results of the stress test showed that simvastatin degraded in all conditions. This stress test confirmed the extreme instability of simvastatin.  Poor storage conditions can reduce the quality of generic simvastatin tablets, thus a well-controlled environment is vital in pharmacy facilities.


2021 ◽  
Vol 19 (4) ◽  
pp. 49-54
Author(s):  
P. L. Kuznetsov ◽  
V. A. Kuznetsova ◽  
V. V. Muravyev

The paper discusses the possibility of conducting accelerated tests to assess the quality of tantalum bulk-porous capacitors according to the developed STRESS TEST technique instead of outdated methods that require costly resources for testing and do not provide proper rejection of capacitors (detection of defects in the oxide layer). It is known that the grown amorphous pentoxide is able to form a uniform layer on the surface of tantalum, but due to various factors (due to surface roughness, porosity, uneven distribution of the electrolyte during the oxidation process and the electric contact of the carrier-anode), a surface is created with "problem areas", "incomplete formation", or, in other words, a "weak spot", the rejection of which is most important for modern tantalum capacitors. A comparative analysis of the application of the standard method and the STRESS TEST technique for accelerated evaluation of the quality of tantalum bulk-porous capacitors will prove the effectiveness of the developed technique. The developed STRESS TEST technique is based on cyclic (10 cycles) application of an increased voltage to the capacitor (corresponding to the voltage during the formation of an oxide layer on a tantalum anode) for the duration of each cycle for 5 minutes, which is proved by calculating this process based on the Zhurkov reliability acceleration model. The technique makes it possible to identify low-quality capacitors in advance with defects in the structure of the oxide layer. The technique makes it possible to evaluate the quality of capacitors in an accelerated time, which is confirmed by the obtained regression model of equivalent series resistance in comparison with the regression model of the standard type of tests for long-term reliability for 24,000 hours. The application of the STRESS TEST technique for tantalum volumetrically porous capacitors will reduce the testing time by approximately two and a half years.


2020 ◽  
Vol 13 (8) ◽  
pp. 174
Author(s):  
Giuseppe Montesi ◽  
Giovanni Papiro ◽  
Massimiliano Fazzini ◽  
Alessandro Ronga

The recent evolution of prudential regulation establishes a new requirement for banks and supervisors to perform reverse stress test exercises in their risk assessment processes, aimed at detecting default or near-default scenarios. We propose a reverse stress test methodology based on a stochastic simulation optimization system. This methodology enables users to derive the critical combination of risk factors that, by triggering a preset key capital indicator threshold, causes the bank’s default, thus detecting the set of assumptions that defines the reverse stress test scenario. This article presents a theoretical presentation of the approach, providing a general description of the stochastic framework and, for illustrative purposes, an example of the application of the proposed methodology to the Italian banking sector, in order to illustrate the possible advantages of the approach in a simplified framework, which highlights the basic functioning of the model. In the paper, we also show how to take into account some relevant risk factor interactions and second round effects such as liquidity–solvency interlinkage and modeling of Pillar 2 risks including interest rate risk, sovereign risk, and reputational risk. The reverse stress test technique presented is a practical and manageable risk assessment approach, suitable for both micro- and macro-prudential analysis.


Author(s):  
Yeshayahu Talmon

To achieve complete microstructural characterization of self-aggregating systems, one needs direct images in addition to quantitative information from non-imaging, e.g., scattering or Theological measurements, techniques. Cryo-TEM enables us to image fluid microstructures at better than one nanometer resolution, with minimal specimen preparation artifacts. Direct images are used to determine the “building blocks” of the fluid microstructure; these are used to build reliable physical models with which quantitative information from techniques such as small-angle x-ray or neutron scattering can be analyzed.To prepare vitrified specimens of microstructured fluids, we have developed the Controlled Environment Vitrification System (CEVS), that enables us to prepare samples under controlled temperature and humidity conditions, thus minimizing microstructural rearrangement due to volatile evaporation or temperature changes. The CEVS may be used to trigger on-the-grid processes to induce formation of new phases, or to study intermediate, transient structures during change of phase (“time-resolved cryo-TEM”). Recently we have developed a new CEVS, where temperature and humidity are controlled by continuous flow of a mixture of humidified and dry air streams.


Sign in / Sign up

Export Citation Format

Share Document