|
Showing 1 - 25 of
212 matches in All Departments
A review is presented of the state of the art of smoke production
measurement, prediction of smoke impact as part of computer-based
fire modeling, and measurement and prediction of the impact of
smoke through deposition of soot on and corrosion of electrical
equipment. The literature review on smoke corrosivity testing and
damage due to smoke deposition emphasizes (despite extensive
research on smoke corrositity) the lack of validated and widely
applicable prescriptive or performance based methods to assure
electrical equipment survivability given exposure to fire smoke.
Circuit bridging via current leakage through deposited smoke was
identified as an important mechanism of electronic and electrical
equipment failure during NPP fires. In the near term, assessment of
potential damage can reasonably be based on the airborne smoke
exposure concentration and, perhaps, the exposure duration. Hence,
models that can predict the airborne smoke concentration would be
sufficient to suit short-term analysis needs. In the longer term,
it would be desirable to develop models that could estimate the
deposition behavior of smoke, as well and specifically correlate
the combination of deposited and airborne smoke to component
damage.
Bulk oxide determinations from a pair of portland cements provides
the basis for calculation precision and accuracy values for X-ray
fluorescence (XRF) analysis for both the fused glass bead and the
pressed powder sample preparation. Approximately 45 laboratories
provided six replicates analyzed in duplicate for two separate
portland cements covering eleven analytes, CaO, SiO2, Al2O3, Fe2O3,
SO3, MgO, Na2O, K2O, TiO2, P2O5, and Cl, with the laboratories
roughly split between the two different sample preparations.
Chemical data using traditional chemical analyses (the Reference
Methods) from the Cement and Concrete Reference Laboratory (CCRL)
proficiency test program were included for comparison to the XRF
results.
Research funded under the Fire Safe Cigarette Act of 1990 (P.L.
101-352) has led to the development of two test methods for
measuring the ignition propensity of cigarettes. The Mock-Up
Ignition Test Method uses substrated physically similar to
upholstered furniture and mattresses: a layer of fabric over
padding. The measure of cigarette performance is ignition or
non-ignition of the substrate. The Cigarette Extinction Test Method
replaces the fabric/padding assembly with multiple layers of common
filter paper. The measure of performance is full-length burning or
self-extinguishment of the cigarette. Routine measurement of the
relative ignition propensity of cigarettes is feasible using either
of the two methods. Improved cigarette performance under both
methods has been linked with reduced real-world ignition behavior;
and it is reasonable to assume that this, in turn, implies a
significant real-world benefit. Both methods have been subjected to
interlaboratory study. The resulting reproducibilities were
comparable to each other and comparable to those in other fire test
methods currently being used to regulate materials which may be
involved in unwanted fires. Using the two methods, some current
commercial cigarettes are shown to have reduced ignition
propensities relative to the current best-selling cigarettes. *]
This is one of six volumes in the Final Report, Fire Safe Cigarette
Act of 1990. VOLUME 1. Overview: Practicability of Developing a
Performance Standard to Reduce Cigarette Ignition Propensity by
Jones-Smith, J., et al. VOLUME 3. Modeling the Ignition of Soft
Furnishings by a Cigarette by Mitler, H. E., et al. VOLUME 4.
Cigarette Fire Incident Study by Harwood, B., et al. VOLUME 5.
Toxicity Testing Plan by Lee, B. C., et al. VOLUME 6. Societal
Costs of Cigarette Fires by Ray, D. R., et al.
FAST is a collection of fire modeling tools which uses the
underlying fire model CFAST and adds the routines of FIREFORM to
provide engineering calculations of fire phenomena in compartmented
structures. This manual provides documentation and examples for
using FAST. It describes how to install the software on a computer
and provides a guide for the use of FAST using examples.
The National Institute of Standards and Technology hosted a twoday
workshop focusing on needed research on occupant behavior and
movement during building emergencies. This workshop was motivated
by a renewed interest in how buildings should be evacuated during
fire emergencies and by the desire to provide a forum for the
exchange of experiences among the fire and non-fire communities
working on emergency egress. The workshop was organized into
several sessions with specific topics areas, including codes and
standards requirements for building evacuation, building egress
strategies, and data needs for predictive models. Several
presentations were included in each session, with an extended
period for discussion at the end of each session. For each
presentation, visuals used for the presentation are included, along
with any additional information provided by the author on the
topic. For each workshop session, the session moderator prepared a
summary of key points of research interest from the presentations
and discussion.
New technologies and research are redefining the state-of-the-art
in building evacuation. The time is right to rethink the entire
infrastructure of egress from buildings in light new opportunities
to address the economic and life-safety issues. Approximately 40
experts from a variety of disciplinary background assembled in
Warrenton, VA from April 1-3, 2008 in order to consider building
evacuation, starting with a blank sheet of paper. Structured around
the principles of Value-Focused Thinking (a text authored by
workshop moderator Ralph Keeney), the participants were encouraged
to consider values, objectives, alternatives, and metrics. This
process combined the benefits of free-thinking brainstorming with a
formalism which encouraged evaluation of the potential for new
ideas. By the conclusion of the third day, over 400 ideas had been
developed, along with metrics for future evaluation of the ideas.
Fire protection measures are needed to maintain the safety and
integrity of the Nation s building stock and to limit loss of life
and property when building fires do occur. Statistics published by
the National Fire Protection Association demonstrate that fire
protection is a major investment cost in building construction.
Therefore, ways to reduce these costs while ensuring safety are of
interest to building owners, fire protection engineers, and other
construction industry stakeholders. Although all fire protection
measures have important economic implications, the focus of this
report is on egress-related requirements in new building
construction. Recent changes in the International Building Code
have set the stage for analyzing the costs of several key
egress-related requirements. The U.S. General Services
Administration commissioned this study to conduct an economic
analysis of the use of elevators and exit stairs for occupant
evacuation and fire service access. The goal of this study is to
produce analyses of cost data suitable for evaluating improved
egress system designs that promote efficient and timely egress of
occupants, including those with disabilities, and that facilitate
more efficient fire department operations. This report tabulates
cost data for selected egress-related requirements in five
prototypical buildings. The five prototypical buildings range in
height from a 5-floor, mid-rise building to a 75- floor, high-rise
building. Cost data are tabulated in a format that facilitates
lifecycle cost analyses of selected egress-related requirements.
Incremental costs are also tabulated to help assess the
implications of changing one or more design parameters. The results
of the economic analysis for four prototypical buildings over 120
ft (37 m), with two over 420 ft (128 m) high, demonstrate that: (1)
an additional exit stair is a cost-effective alternative to the
installation of occupant evacuation elevators on a first-cost
basis; and (
There is a general concern that the US manufacturing industry has
lost competitiveness with other nations. Additive manufacturing may
provide an important opportunity for advancing US manufacturing
while maintaining and advancing US innovation. Additive
manufacturing is a relatively new process where material is joined
together layer by layer to make objects from 3D models as opposed
to conventional methods where material is removed. The US is
currently the primary user of additive manufacturing technology and
the primary producer of additive manufacturing systems. Globally,
an estimated $642.6 million in revenue was collected for additive
manufactured goods with the US accounting for an estimated $468.9
million or 72.9% of global production in 2011. Change agents for
the additive manufacturing industry can focus their efforts on
three primary areas to advance this technology: cost reduction,
accelerating the realization of benefits, and increasing the
benefits of additive manufacturing. Significant impact on these
areas may be achieved through the reduction in the cost of additive
manufacturing system utilization, material costs, and facilitating
the production of large products. There is also a need for a
standardized model for cost categorization and product quality and
reliability testing.
Whole-building airflow and contaminant transport modeling has a
potentially important role in the development of contaminant
sampling strategies in response to the airborne release of chemical
or biological agents . The effectiveness of these strategies relies
on the ability of the selected sampling locations to adequately
characterize the levels of contamination throughout an exposed
facility to a desired level of confidence in the sampled results.
The Department of Homeland Security has sponsored a series of
multi-agency exercises, during which contamination experiments were
performed to gauge the confidence that could be obtained by various
sampling strategies as well as the effectiveness of various
sampling methods in a real-world setting. These experiments are
very resource intensive and time-consuming, limiting the number of
experiments that can be reasonably performed. Building simulation
can be used to perform virtual experiments that would allow more
tests to be performed under a much larger set of building
operational and environmental configurations. However, in order for
the simulations to be useful, the building models need to provide
realistic results with a high level of confidence. The purpose of
this report is to describe a simulation validation effort based on
measurements of contaminant levels performed during the
aforementioned exercises.
This report presents a computational assessment of the performance
of steel gravity framing systems with single-plate shear (, shear
tab ) connections and composite floor slabs under column loss
scenarios. The computational assessment uses a reduced modeling
approach, while comparisons with detailed model results and
available experimental data are presented to establish confidence
in the reduced models. The reduced modeling approach enables large
multi-bay systems to be analyzed much more efficiently than the
detailed modeling approaches used in previous studies. Both
quasi-static and sudden column loss scenarios are considered, and
an energy-based approximate procedure for analysis of sudden column
loss is adopted, after verification through comparisons with direct
dynamic analyses, further enhancing the efficiency of the reduced
modeling approach. Reduced models are used to investigate the
influence of factors such as bay spacing, slab continuity, and the
mode of connection failure on the collapse resistance of gravity
frame systems. Simple equations for the rotational capacities of
the connections are derived as a function of a few parameters
including the span length and the connection depth. These equations
yield good agreement with computed rotational capacities of
connections both in bare steel assemblies (i.e., no slab) and in
composite floor systems, where composite action leads to reduced
rotational capacities. The reduced models are used to assess the
adequacy of current structural integrity requirements, and based on
the computational results, a new relationship is proposed between
the uniform load intensity and the tie forces required for collapse
prevention
A standard procedure is needed for obtaining smoke toxic potency
data for use in fire hazard and risk analyses. Room fire testing of
finished products is impractical, directing attention to the use of
apparatus that can obtain the needed data quickly and at affordable
cost. This report examines the first of a series bench-scale fire
tests to produce data on the yields of toxic products in both
pre-flashover and post-flashover flaming fires. The apparatus is
the radiant furnace in NFPA 269 and ASTM E 1678. Test specimens
were cut from finished products that were also burned in room-scale
tests: a sofa made of upholstered cushions on a steel frame,
particleboard bookcases with a laminated finish, and household
electric power cable. Initially, the standard test procedure was
followed, with a variation to reduce the contribution to the
effluent of post- flaming pyrolysis. Subsequent variations in the
procedure included cutting the test specimen into small pieces and
performing the tests at a reduced oxygen volume fraction of 0.17.
The yields of CO2 CO, HCl, and HCN were determined. The yields of
other toxicants (NO, NO2, formaldehyde, and acrolein) were below
the detection limits, but volume fractions at the detection limits
were shown to be of limited toxicological importance relative to
the detected toxicants. In general, dicing the test specimen and
performing the tests at the reduced oxygen volume fraction had
little effect on the toxic gas yields, within the experimental
uncertainties. The exceptions were an increase in the CO yield for
diced specimens at reduced oxygen, a decrease in the HCN yield from
the intact sofa and cable specimens at reduced oxygen, and an
increase in the HCN yield from dicing the cable specimens. In none
of the procedure variations did the CO yield approach the value of
0.2 found in real-scale post flashover fire tests.
This study examines the energy consumption of automatic ice makers
installed in domestic refrigerators. This study builds upon the
findings of a previous study and examines two refrigerator-freezers
of different configurations, one French-door units with bottom
freezers and one bottom mount unit that uses a twist tray mechanism
to free frozen ice from the icemaker. Ice maker energy consumption
is difficult to measure because they operate on a periodic cycle
which is independent of the compressor cycle used to maintain the
cold temperatures in the domestic refrigerator where it is
installed; therefore methods proposed prior to this study have been
subject to significant truncation error due to partial ice maker or
compressor cycling. The purpose of this study is to define a method
of measuring the energy consumption of automatic ice makers that
will generate a repeatable and reproducible result. Several sets of
test data from these units were analyzed and used to decipher the
energy consumption of automatic ice makers. Through this effort, we
developed a method of test to characterize ice maker energy
consumption which circumvents the inherent problem with its
measurement, truncation error due to incomplete cycling. The
truncation error is avoided by measuring specific parameters with
different sections of data from the same data set. This method was
found to rapidly approach steady state values for the ice maker
energy consumption. We then analyzed data sets from a prior study
and found similar results for the stability of the ice making
energy consumption; that continuous data over only 6 or 7 ice
making cycles are typically sufficient to accurately characterize
the energy consumption.
A standard procedure is needed for obtaining smoke toxic potency
data for use in fire hazard and risk analyses. Room fire testing of
finished products is impractical, directing attention to the use of
apparatus that can obtain the needed data quickly and at affordable
cost. This report presents examination of the second of a series
bench-scale fire tests to produce data on the yields of toxic
products in both pre-flashover and post-flashover flaming fires.
The apparatus is the ISO/TS 19700 controlled equivalence ratio tube
furnace. This apparatus uses a mechanical feed mechanism to supply
solid fuel into a tube furnace at a pre-determined rate, so that
the global equivalence ratio can be adjusted. The test specimens
were cut from finished products that were also burned in room-scale
tests: a sofa made of upholstered cushions on a steel frame,
particleboard bookcases with a laminated finish, and household
electric cable. Initially, the standard test procedure was followed
for two fire stages, well ventilated flaming and post- flashover.
Subsequent variation in the procedure included dicing the specimen,
further decreasing the equivalence ratio (well ventilated flaming)
or increasing it (post-flashover), increasing the mass loading
while maintaining the equivalence ratio, and increasing the fuel
feed rate while maintaining the equivalence ratio. The yields of
CO2 CO, HCl, and HCN were determined. The yields of other toxicants
(NO, NO2, formaldehyde, and acrolein) were below the detection
limits, but volume fractions at the detection limits were shown to
be of limited toxicological importance relative to the detected
toxicants. In general, the largest effects were seen between the
two fire stages. The other variations within the fire stage had
minor effects on gas yields. Under post-flashover conditions, the
sum of the CO2 and CO yields frequently accounted for half or less
of the carbon originally in the specimen. As a result, the gaseous
combustion products cannot be used to estimate the mass burning
rate. Under post flashover conditions, the CO yield for the sofa
approached the value of 0.2 found in real-scale postflashover fire
tests. However, for the bookcase and cable it did not. Yields of
HCl from the cables generally approached their notional yields
under well- ventilated conditions, and HCN was most readily
detected from the sofa under post-flashover conditions at
toxicologically significant concentrations.
We analyze data from NIST field tests in which radio-propagation
channel path loss values were measured at approximately the same
physical locations where the performance of various RF-based
firefighter distress beacons were tested. These side-by-side tests
were made in two key representative emergency responder
environments, a New York subway station and the Empire State
Building. These environments contain propagation features that may
impair radio communications, including stairwells, tunnels, and
rooms deep within buildings, among others. The goal of this work is
to determine appropriate performance metrics for use in the
development of laboratory-based test methods for RF-based
electronic safety equipment. The analysis supports the
classification of structures into categories of attenuation values
that can be used in laboratory-based test methods to verify the
performance of the RF-based alarm systems. The environments, tests,
and measured data are discussed in detail. The RF
propagation-channel data also provide insight into the expected
attenuation in high-rise buildings and below-ground structures.
A standard procedure is needed for obtaining smoke toxic potency
data for use in fire hazard and risk analyses. Room fire testing of
finished products is impractical, directing attention to the use of
apparatus that can obtain the needed data quickly and at affordable
cost. In this work we compare yields of toxic gases generated by
four bench scale apparatus to previously conducted room-scale
fires. The bench scale apparatus are the radiant apparatus in NFPA
269 and ASTM E 1678, the smoke density chamber in ISO 5659-2, a
controlled-atmosphere version of the cone calorimeter (ASTM E
1354), and the tube furnace in ISO/TS 19700. In the bench scale
experiments, the test specimens were cut from finished products
that were also burned in the room-scale tests: a sofa made of
upholstered cushions on a steel frame, particleboard bookcases with
a laminated finish, and household electric cable. The yields of CO2
CO, HCl, and HCN were determined. The yields of other toxicants
(NO, NO2, formaldehyde, and acrolein) were below the detection
limits, but volume fractions at the detection limits were shown to
be of limited toxicological importance relative to the detected
toxicants. The bench scale and room scale yields are compared, and
the bench scale apparatus are assessed for the degree to which they
accurately predict room scale yields. The results of this study
provide a better basis for obtaining toxic potency input data for
fire modeling than currently exists.
The National Institute of Standards and Technology's Manufacturing
Engineering Laboratory (MEL)strengthens the U.S. economy and
improves the quality of life by working with the U.S. manufacturing
industry to develop and apply infrastructural technology,
measurements, and standards to meet their needs. This report
contains summaries of MEL programs that support the needs of the
U.S. manufacturing industry. Each program summarizes the resources,
objectives, customer needs that are addressed, accomplishments,
current year plans, lifetime objectives, and related measurement
and standards work.
Economic tools are needed to help the owners, managers, and
designers of constructed facilities to select cost-effective
combinations of mitigation strategies that respond to natural and
man-made hazards. Economic tools include evaluation methods,
standards that support and guide the application of those methods,
and software for implementing the evaluation methods. Developing a
cost-effective risk mitigation plan involves assessing the risks
associated with natural and man-made hazards, formulating
combinations of mitigation strategies for constructed facilities
exposed to those hazards, and using economic tools to identify the
most cost-effective combination of strategies. Developing a risk
mitigation plan requires both guidance and data. Guidance is needed
to help owners and managers to assess the risks facing their
facility. Data about the frequency and consequences of natural and
man-made hazards are needed when assessing the risks that a
particular facility faces from these hazards. Estimates of the
costs of protection are needed to insure that safeguarding
personnel and physical assets and satisfying financial constraints
are kept in balance. Although there is a great deal of high-quality
information available on risk assessment and risk management,
natural and man-made hazards, and economic tools, there is no
central source of data and tools to which the owners and managers
of constructed facilities and other key decision makers can turn
for help in developing a cost-effective risk mitigation plan. This
document provides an annotated bibliography of printed and
electronic resources that serves as a central source of data and
tools to help the owners, managers, and designers of constructed
facilities develop a cost effective risk mitigation plan.
Due to concerns about potential airborne chemical and biological
(chembio) releases in or near buildings, building owners and
managers and other decision makers are considering retrofitting
buildings to provide some degree of protection against such events.
A wide range of technologies and approaches are being proposed with
varying levels of efficacy and cost, as well as varying degrees of
applicability to particular buildings and ventilation systems. This
document presents the results of an effort to evaluate chembio
retrofit options for buildings. A number of retrofit options are
identified, and their potential to protect building occupants from
a number of generic contaminant releases is evaluated using
building airflow and contaminant transport modeling. In addition, a
case study is presented in which specific retrofit options were
considered for two actual buildings and pre-installation designs
and cost estimates were developed. Based on the analyses performed,
the results of the case study and other available information,
guidance on the application and effectiveness of various retrofits
are presented. An economic analysis software tool employing life
cycle cost analysis techniques was developed as part of this
project, and its use is described in an appendix to this report.
The retrofit options considered fall into two categories, the first
being stand-alone technologies or devices such as enhanced
particulate filtration that are installed and implemented as
purchased. The second category includes retrofit approaches that
employ operational strategies or building modifications to increase
building protection, such as outdoor air purging or building
envelope tightening. The guidance section describes each retrofit
technology and approach in some detail, presenting relevant
performance data and the level of protection that might be expected
from the retrofit. Potential disadvantages and knowledge gaps are
also discussed for each technology. The retrofit technologies
considered include enhanced particle filtration, sorbent based
gaseous air cleaning, ultraviolet germicidal irradiation,
photocatalytic oxidative air cleaning, and work area air capture
and filtration equipment such as mail handling tables. The
approaches include ventilation system recommissioning, building
envelope tightening, building pressurization, relocation of outdoor
air intakes, shelter-in-place (SIP), isolation of vulnerable spaces
such as lobbies, system shutdown and purge cycles, and automated
HVAC operational changes in response to contaminant sensing. The
filtration and air cleaning options are noted to have an advantage
of always being operational, which is an advantage as long as the
systems are properly designed, installed and maintained. However,
the lack of standard test methods for sorbent-based gaseous air
cleaning and other air cleaning approaches is identified as a
critical impediment to the application of these technologies.
Building envelope air sealing and pressurization can be quite
effective in protecting against outdoor releases as long as
effective filtration against the contaminant of concern is also in
place. The protection provided by operational changes such as
system shutdown and purging are shown to be very dependent on the
timing of their implementation, with the possibility of increasing
occupant exposure if the timing is inappropriate. Isolating
vulnerable zones and other system related modifications are highly
dependent on the building layout and system design, and their
implementation must be well conceived to be effective under the
range of conditions that exist in buildings. Finally, many
retrofits are noted as also providing additional benefits of
increased energy efficiency and improved indoor air quality, which
need to be included in the life-cycle cost comparison of different
options to the degree possible.
The Homeland Security Presidential Directive HSPD-12 called for new
standards to be adopted governing the interoperable use of identity
credentials to allow physical and logical access to Federal
government locations and systems. The Personal Identity
Verification (PIV) for Federal Employees and Contractors, (Federal
Information Processing Standard 201 (FIPS 201)) was developed to
establish standards for identity credentials. This document,
Special Publication 800-87 (SP 800-87), provides the organizational
codes necessary to establish the PIV Federal Agency Smart
Credential Number (PIV FASC-N) that is required to be included in
the FIPS 201 Card Holder Unique Identifier (CHUID) and is a
companion document to FIPS 201.
The purpose of this workshop was to identify performance needs and
establish research priorities to address the thermal
characteristics of respiratory equipment used by emergency first
responders. The workshop provided a forum for representatives from
the first responder community, self contained breathing apparatus
(SCBA) and component manufacturers, and research and testing
experts to discuss issues, technologies, and research associated
with SCBA high temperature performance. The goals of the workshop
were defined in two parts: 1) Clarify baseline information,
including the current state-of-the-art, applicable fire service
events, and current related research, and 2) Research planning,
including identification of performance needs and short and long
term research priorities. Presentations were given to explain the
current SCBA and certification process, understand experience from
actual fire service incidents, and review the current state of
respirator research. After the presentations, the workshop divided
into three working group sessions to discuss performance needs and
research priorities in smaller groups. Suggested topics for
discussion included: a) Current Equipment, b) Current Practice and
Usage, c) Future Trends, d) Short Term Research Needs, e) Long Term
Research Needs, and f) other issues. The results of the three
smaller groups' deliberations were discussed when the full workshop
reconvened. The responses from each group were merged into a
combination of issues that related to the use and performance of
the lens of the SCBA. The primary concerns and research priorities
were the characterization of the fire fighter environment,
performance of current and new technology, development of
representative and realistic testing, and improvements to fire
fighter training on the limitations of protective equipment. A
significant amount of discussion concentrated on the testing for
NFPA certification, which currently contains limited thermal
testing.
This report contains the results of NIST s research into
technologies to improve the voting process for United States
citizens living overseas. It splits the overseas voting process
into three stages: voter registration and ballot request, blank
ballot delivery, and voted ballot return. For each stage, this
report describes how various transmission options could be used to
support overseas voting. The transmission options discussed in this
paper are postal mail, telephone, fax, electronic mail, and
web-based systems. This report documents a threat analysis based on
the methodology provided in NIST SP 800-30 for each method. As part
of the analysis, mitigating controls for each threat are provided
when possible. The mitigating controls for each threat provided in
this report provide the basis for an effort to develop best
practices for overseas voting systems.
|
You may like...
Loot
Nadine Gordimer
Paperback
(2)
R383
R310
Discovery Miles 3 100
|