Abstract Environmental testing of spacecraft flight hardware is performed to detect design and workmanship defects and verify mission requirements prior to launch. At the space vehicle level of assembly, the thermal vacuum test simulates an environment particularly well-suited for verifying mission performance requirements. In this paper, the test objectives of the space vehicle thermal vacuum test are reviewed and an assessment is made of the effectiveness and value of the test. Recent thermal vacuum test data is used to determine how the uniqueness of the thermal vacuum test environment achieves test purposes and how the test ensures mission assurance for space vehicles.

Selecting a non-cleanroom-approved vacuum cleaner may satisfy your budget, but the shortsighted choice brings substantial risk

Abstract Severe yet common product environmental tests are 1000 hours at 85 °C/85% RH or 95 °C/95% RH for products, circuit card assemblies, and electronic components. Such environments never occur naturally; however, they attempt to simulate the corrosion damage that could be expected in service. To what natural environment do these tests correlate? Further, how do tests based on MIL-HDBK-310, MIL-STD-810, and STANAG 2895 B3 daily environments compare to these standard test environments? The analysis employs the Physics-of-Failure (POF) Peck power law temperature-humidity model with common conservative values for the Arrhenius activation energy and the relative humidity exponent, based on aluminum corrosion, coupled with climatological data from 49 United States weather stations and 19 international locations. The monthly average temperature and humidity extremes were transformed into an hourly diurnal cycle assumed to occur every day of each month. Using the power law model the equivalent time at the test condition was calculated for each day, and summed for each month and location. The 85 °C/85% RH test can be correlated with about 10 years in a hot and moist natural environment, such as Singapore, with 1000 hours of 95 °C/95% RH exposure equivalent to 25 years. Long-term tests based on the worst-case diurnal temperature and humidity cycles in military standards are on the order of 1 in 1,000,000 probability of occurrence in nature.

Sabanci University Nanotechnology Research and Application Center (SUNUM) became operational in January 2012. SUNUM is a trendsetting example of a green and flexible research facility that is a test bed for the cost-effective operation of a Centralized Demand-Controlled Ventilation (CDCV) system, a state-of-the-art cleanroom, and world-class high technology equipment. The total investment in the facility was US$35 million.

Efficiently running a major nanofabrication research user facility within the framework of a university is a daunting task. Operational costs, staffing, training, safety, and the diversity of the research, faculty, and users are but a few of the challenges facing the management team. This article reports on a subset of metrics used to characterize such user facilities, based on an extensive survey of 12 major university laboratories. Data relating to such factors as laboratory staffing, operating costs, subsidies, cost recovery, tuition, comparative tool rates, hours of use, and populations are summarized and reported on in the context of determining a reasonable measure of an efficient laboratory operation.

This article describes some of the safety considerations for the design and construction of micro/nano facilities and applicable building code provisions. The two key elements required for safe operation in micro and nanotechnology facilities are: (1) engineered features incorporated into building construction, and (2) administrative features that deal with how people work within the facility.

The acoustic field generated during a Direct Field Acoustic Test (DFAT) has been analytically modeled in two space dimensions using a properly phased distribution of propagating plane waves. Both the pure-tone and broadband acoustic field were qualitatively and quantitatively compared to a diffuse acoustic field. The modeling indicates significant non-uniformity of sound pressure level for an empty (no test article) DFAT, specifically a center peak and concentric maxima/minima rings. This spatial variation is due to the equivalent phase among all propagating plane waves at each frequency. The excitation of a simply supported slender beam immersed within the acoustic fields was also analytically modeled. Results indicate that mid-span response is dependent upon location and orientation of the beam relative to the center of the DFAT acoustic field. For a diffuse acoustic field, due to its spatial uniformity, mid-span response sensitivity to location and orientation is nonexistent.

This paper evaluates a laboratory process for extracting, isolating, and identifying rubisco, an essential protein found in plant cells and an important catalyst during photosynthesis. Isolating rubisco from other proteins also found in plants requires a carefully planned series of laboratory procedures to separate the proteins on the basis of physical characteristics including solubility, electrical charge, and molecular size. In this study, ammonium sulfate precipitation was used to extract proteins from a sample of spinach leaves and to separate the proteins into two samples with different solubility characteristics. These samples were then subjected to ion exchange column chromatography using buffers with a range of salt concentrations to produce fractions with varying electrical charge characteristics. The resultant fractions were then analyzed via protein electrophoresis to determine the molecular weight of the isolated proteins, which were compared against the known molecular weight of rubisco. Finally, the experimental results were analyzed to determine which parameters for the ammonium sulfate saturation procedure and the ion exchange column chromatography procedure were most effective at isolating rubisco for future scientific study.

Transient vibration environments are an important consideration in qualification of aircraft store components — particularly for aircraft with internal storage bays. Generally, these transient vibration environments provide high stimulus input to a store via aerodynamic forces for up to 15 seconds on numerous occasions during training. With the recent introduction of the technique of Time Waveform Replication (TWR) to laboratory testing (MIL-STD-810G Method 525), store components can be readily tested to replications of field-measured transient vibration environments. This paper demonstrates the use of the Generalized Linear Mixed Model (GLMM) on a collection of measured field responses for specification of transient vibration environments. The paper establishes a basis for moving from (1) transient vibration measured field response to (2) transient vibration stochastic specification of the measured field response to (3) laboratory simulation of transient vibration environments.