scholarly journals Sampling in Testing Standards

2021 ◽  
Keyword(s):  
Testing Standards

scholarly journals Electret Filters—From the Influence of Discharging Methods to Optimization Potential

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
Maximilian Kerner ◽  
Kilian Schmidt ◽  
Stefan Schumacher ◽  
Christof Asbach ◽  
Sergiy Antonyuk
Keyword(s):  
Fine Particles ◽  
Operating Time ◽  
Filtration Efficiency ◽  
Long Term Stability ◽  
Aerosol Filtration ◽  
Charge Decay ◽  
The One ◽  
Testing Standards ◽  
Discharge Efficiency

Electret filters are electrostatically charged nonwovens which are commonly used in aerosol filtration to remove fine particles from gases. It is known that the charge and thus also the filtration efficiency can degrade over time. Thus, many testing standards require to remove the charge by treatment with liquid isopropanol (IPA) or IPA-saturated air. However, the parameters influencing this discharge have not been completely clarified yet. The aim of this work was, on the one hand, to experimentally investigate the influence of the IPA treatment on different electret filters and, on the other hand, to show the optimization potential of electret filters with respect to efficiency and long-term stability by numerical simulations. The experiments revealed that the air permeability is a central influencing parameter. Small pores lead to a reduced discharge efficiency using liquid IPA, while both treatment methods are suitable for larger pores. The simulations showed that a homogeneous charge distribution within the filter depth is advantageous for the initial performance. In contrast, charge penetrating deeper in the filter medium delays the charge decay and thus increases the operating time, with the trade-off of a lower initial performance.

scholarly journals Rotational Acceleration Measurements - Evaluating Helmet Protection

2004 ◽  
Vol 31 (4) ◽  
pp. 499-503 ◽  
Author(s):  
M. Kis ◽  
F. Saunders ◽  
M.W. ten Hove ◽  
J.R. Leslie
Keyword(s):  
Horizontal Plane ◽  
Rotational Acceleration ◽  
Testing Device ◽  
Cerebral Concussion ◽  
Impact Simulation ◽  
Head Protection ◽  
Rotational Components ◽  
Protection Devices ◽  
Testing Standards ◽  
Testing Paradigm

Purpose:Current helmet testing standards do not address the rotational components of an impact to the head. We describe a new testing paradigm used to measure the rotational acceleration of a headform and a protective helmet following an impact to the head in the horizontal plane. This impact simulation allows for the testing of currently available head protection devices in conditions thought to be important for the generation of cerebral concussion. The degree to which a particular helmet dampens rotational acceleration, and thus protects against concussion, can be assessed.Methods:Our testing device consists of a pneumatic piston that provides a measured impact to a standard headform. Four different helmets were tested using the described paradigm.Results:Acceleration curves for each helmet and the corresponding headform are presented.Conclusion:Clear differences in rotational acceleration were demonstrated. Possible avenues of further investigation are discussed.

What Hit and Miss in Indonesia CBM Project : Empirical Study Slowing Down Factors CBM Development and Propose Suitable Action for CBM Development in Indonesia by Using Analytical Hierarch Process.

2021 ◽  
Author(s):  
I.A. Firdaus
Keyword(s):  
Oil And Gas ◽  
Economic Value ◽  
Gas Production ◽  
Coal Bed ◽  
Production Sharing ◽  
High Investment ◽  
The Government ◽  
Exploration Period ◽  
Production Areas ◽  
Testing Standards

In 2008, the first Coal Bed Methane (CBM) PSC was signed in Indonesia. To date, 54 CBM PSCs have been awarded to explore and develop CBM Block in Indonesia. Twelve years later, only one PSC has submitted a Plan of Development but has not yet produced gas commercially. Most CBM PSCs have been struggling during the 10 years’ exploration period and some may receive extensions for 3 years under specific conditions. The lack of integrated authorities’ approval in the overlay of coal mining and natural gas production areas has become a great obstacle for CBM Development. Besides that, the government regulations in CBM activities have defects in PSC contract terms that may lead marginal economic value for contractors, especially due to high investment during the early development (C. Irawan, 2017). On the other hand, drilling regulations, Pipe Classing standards and Testing Standards following the Oil and Gas standards are too expensive for CBM Investment. According to our observations, CBM Regulations in Indonesia should be modified starting from the Exploration period, Production Sharing Contract Terms and Standard Operating Procedures to suit Indonesian CBM characteristics. Good coordination within government departments is a must for the success of CBM Exploration and Development.

Domestic and international best practice in research and testing glass for load-bearing structures of buildings

2021 ◽  
Vol 31 (4) ◽  
pp. 5-19
Author(s):  
I. I. Vedyakov ◽  
D. V. Konin ◽  
A. A. Egorova ◽  
I. V. Rtishcheva
Keyword(s):  
Best Practice ◽  
Glass Structure ◽  
Deformation Modulus ◽  
Distinct Pattern ◽  
Design Standards ◽  
Load Bearing ◽  
Wide Range ◽  
Two Samples ◽  
Scientific Technical ◽  
Testing Standards

The present work provides an overview and analysis of scientific, technical, regulatory, and methodical Russian and foreign literature regarding using glass as a material for load-bearing structures of buildings. In the absence of design standards, an experimental study of usually one or two samples is necessary each time glass structure is used; however, this is insufficient to determine the distinct pattern of material performance. Since jointing the glass structures has been rarely studied, the number of tests is minimal, thus preventing establishing the unambiguous material operation and its calculated physical and mechanical characteristics. The article considers and evaluates the test results of glass structures obtained by various methods. The particular values of ultimate stresses and deformation modulus lie in a wide range. The technology, manufacturing process, and starting materials have a significant influence on the characteristics of glass, including multilayer glass. This article stresses the need for developing regulatory technical and methodical documents, the design and testing standards for glass structures and their jointing. It is necessary to classify load-bearing glass structures by various criteria.

FEM-BEM Modeling and Experimental Verification of the Vibro-Acoustic Behaviour of a Section of Aircraft Fuselage

2016 ◽  
Author(s):  
Viken N. Koukounian ◽  
Chris K. Mechefske
Keyword(s):  
Transmission Loss ◽  
Pressure Fluctuations ◽  
Experimental Methodology ◽  
Reverberation Chamber ◽  
Aircraft Fuselage ◽  
Ongoing Work ◽  
Damping Materials ◽  
Fuselage Skin ◽  
International Testing ◽  
Testing Standards

The aerodynamics of an aircraft in flight impose significant stresses upon the structure. Specifically, the mechanics of fluid flow are highly turbulent and, the layer around the aircraft, is referred to the turbulent boundary layer (TBL). The TBL incites a gradient of pressure fluctuations across the fuselage skin resulting in its vibration, and in turn, the generation of noise inside the passenger cabin. The investigation herein proposes a hybrid FEM-BEM modeling technique to predict the aforementioned vibro-acoustic response and an experimental methodology to verify the results (following ASTM and ANSI international testing standards). The described expectations required construction of an acoustic facility consisting of a reverberation chamber and a semi-anechoic room, the development of DAQ software using LabVIEW, an assembly of DAQ hardware using National Instruments products, and the post-processing of test data using Microsoft Excel. The principal quantity of interest is transmission loss (though insertion loss, absorption and other metrics are also calculated). Two panels (0.04in (40thou) and 0.09in (90thou) in thickness) were simulated and tested (0.01in = 1thou). The calculated error of the proposed methodology is within a maximum of 5dB, with an average of 1dB. Ongoing work is investigating complex constructions and the use of damping materials.

The Analysis and Assessment of Test Method for Flammability of an Automotive Headlining Fabric

2011 ◽  
Vol 332-334 ◽  
pp. 1162-1166
Author(s):  
Zhuo Zhang ◽  
Ying Qing Liu ◽  
Zhong Hai Ren ◽  
Jia Zhuang Ma ◽  
Hu Shui Ye
Keyword(s):  
Traffic Safety ◽  
Test Method ◽  
Highway Traffic ◽  
National Highway Traffic Safety ◽  
Test Standards ◽  
Foreign Countries ◽  
Mandatory Standard ◽  
Testing Standards ◽  
Interior Textile ◽  
Automotive Interior

The flammability is one of the most important features about safety for automotive interior material. This paper summarized the testing standards for flammability performed testing on a type of interior textile material made by one of domestic manufacturers, in accordance with the Chart 571.302 Standard No. 302 of the National Highway Traffic Safety Administration of U.S. The complete introduction of national mandatory standard of China in flammability of interior material was introduced and domestic test standards of flammability with those of foreign countries all over world were compared. Finally, this paper proposed possible and would-be necessary parameters based on comprehensiveness of this kind of test due to safer requirement in future.

scholarly journals Forensic Engineering Analysis Of Dot Verses Non-Dot Helmet Performance As A Function Of Velocities Exceeding Standardized Testing As A Function Of Velocities Exceeding Standardized Testing

2012 ◽  
Vol 29 (2) ◽  
Author(s):  
Laura L. Liptai
Keyword(s):  
Standardized Testing ◽  
The United States ◽  
Department Of Transportation ◽  
Impact Performance ◽  
Performance Improvements ◽  
Motorcycle Helmet ◽  
Road Surfaces ◽  
Hybrid Iii ◽  
Forensic Engineering ◽  
Testing Standards

Motorcyclists Suffer Serious Trauma More Often Than Automotive Occupants Tracing To Contact With Non-Yielding Road Surfaces And/Or Direct Impact From Other Vehicles. A Motorcycle Helmet Is The Principal Defense To Head Impact. If A Motorcycle Helmet Passes Dot, Department Of Transportation, Approval, What Performance Improvements Correlate? Dot And Non-Dot Helmets Were Tested To Determine Impact Performance At Velocities Exceeding Standardized Testing Velocities. Three Types Of Dot Approved And Three Types Of Non-Dot Approved Helmets Were Tested At Two Speeds Outside Of The Federal Testing Standards In The United States. The Analysis Was Performed Using An Inverted Pendulum Sub-System Experimental Device With A Hybrid-Iii Anthropometric Dummy Cranium And Neck. Results Quantify The Performance By Category, Model, And Experiment By Test Metric.

scholarly journals Air Pollution around Schools and Poorer Student Health and Academic Performance: A Case of Dhaka, Bangladesh

2020 ◽  
Vol 9 (1) ◽  
pp. 9-18
Author(s):  
Nusrat Jahan
Keyword(s):  
Air Pollution ◽  
Academic Success ◽  
Environmental Pollutants ◽  
Future Generation ◽  
Student Health ◽  
Attendance Rate ◽  
New School ◽  
The Times ◽  
A Site ◽  
Testing Standards

Dhaka is one of the most vulnerable cities of the world to the adverse effects of air pollution and variables. Children of Dhaka are the most affected group of people to any crucial change in any climatic change, i.e., air pollution. Exposing children to any environmental pollutants during the times of their growth can lead to long-lasting health problems, dysfunction, and disease. The location of the schools can increase their exposure. In such, a survey has been conducted on the extent of air pollution from industrial sources around different schools in Dhaka to find out whether air pollution threatens children’s health and academic success. We found that schools in the highest air polluted areas had the poorer attendance rate — indicates poor health—and the highest proportions of students who are not performing up to their potential in educational testing standards. However, Dhaka and some other cities do not require officials considering a site for a new school to analyze its air quality. The survey result shows that such requirements are needed. For schools already in existence, we recommend that their environmental quality should be examined and improved to save our future generation.     

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