scholarly journals A Study on Comparison and Shortening of Evacuation Time Required of University Library by Simulation

Author(s):  
Jeong-Pill An ◽  
Gwang-Hee Kim
Author(s):  
A.A. Ustsov ◽  
M.Yu. Kupriyanov

We performed the required theoretical computations to simulate the process of pumping saturated liquid nitrogen vapours, accounting for the assumptions adopted. The paper provides a schematic of the test bench and describes the sequence of experiment stages. We checked whether the storage Dewar and volumetric vacuum pump were selected correctly so as to ensure the required evacuation level above the liquid nitrogen surface. We built our test bench and conducted an experiment involving thermostatting in the 63 to 77 K temperature range, and achieved a phase transition in the nitrogen, it turning from liquid to solid. We computed the mass of the nitrogen evaporated required to reach its triple point temperature. We calculated the effective evacuation rate in the system, taking into account the conductivity of separate components. We determined the minimum vapour evacuation time required. We plotted system temperature and pressure as functions of time. The paper describes possible modernisation of the experimental installation, that is, introducing additional crystallisation centres and monitoring the liquid nitrogen mass using electronic scales


2020 ◽  
Vol 40 (02) ◽  
pp. 461-469
Author(s):  
Nidhi Niwant Rakshikar ◽  
Sushama Powdwal

Libraries often intimidate new or potential users through their size, complexity as well as unfamiliar tools and technology. Observing library users coping with the environment and perceiving their behavior, assists in planning and designing an ideal guidance system. The present article is based on an observation of university library users in Mumbai. The study provides narratives of variety of tasks completed by participants with average task completion time ATCT) and further explores users’ facial expressions and behavior and conducted cause analysis. Findings revealed that majority of participants in university libraries felt that wayfinding is complex and not self-oriented even after attending library orientation, due to the complexity of library buildings and lack of appropriate signage. The analysis of ATCT highlighted that maximum users of the university libraries in Mumbai require inordinate time to find their way and locate the required information source. Many participants experienced confusion, disorientation, indecisiveness and anxiousness while navigating and searching for information sources in libraries. It further revealed that major reasons behind prolonged time required in task completion were user specific such as user unawareness about library physical settings, classification schemes, floor-wise splits in stacking arrangement, availability of facilities, etc. The observational findings and recommendations lead to serve as a starting point in defining patron orientation needs.


2021 ◽  
Author(s):  
Mufeng XIAO ◽  
Xihua ZHOU ◽  
Xinxin PAN ◽  
Yanan WANG ◽  
Xianlin LI ◽  
...  

Abstract To ensure the safe construction of prefabricated buildings and improve the efficiency of the safe evacuation of construction personnel after a fire caused by improper operation during construction, this study used the PyroSim software to numerically simulate a fire situation based on the size and volume of a prefabricated building construction site. The variation rules of smoke visibility, CO concentration, and ambient temperature in the construction site of prefabricated buildings were analyzed and the available safe evacuation time was determined. Moreover, the Pathfinder software was used for simulation in combination with the physical attributes of personnel, evacuation speed, and personnel proportions. The time required for safe evacuation was determined and the factors influencing the evacuation time, such as the quantity and location of stacked prefabricated components, machinery, and appliances, and the number of on-site construction personnel, were analyzed. The results reveal that the original layout of the prefabricated building construction site cannot facilitate the safe evacuation of all construction personnel. The bottleneck area for the evacuation of construction personnel is the indoor corridor and evacuation stairway. The quantity and location of stacked items at the construction site greatly influence the evacuation time. When the number of construction personnel on each floor reaches a certain value, restrictions should be imposed. The results obtained by this study can provide the theoretical basis for the rational planning of evacuation routes and construction site management.


Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.


Author(s):  
O. E. Bradfute

Electron microscopy is frequently used in preliminary diagnosis of plant virus diseases by surveying negatively stained preparations of crude extracts of leaf samples. A major limitation of this method is the time required to survey grids when the concentration of virus particles (VPs) is low. A rapid survey of grids for VPs is reported here; the method employs a low magnification, out-of-focus Search Mode similar to that used for low dose electron microscopy of radiation sensitive specimens. A higher magnification, in-focus Confirm Mode is used to photograph or confirm the detection of VPs. Setting up the Search Mode by obtaining an out-of-focus image of the specimen in diffraction (K. H. Downing and W. Chiu, private communications) and pre-aligning the image in Search Mode with the image in Confirm Mode facilitates rapid switching between Modes.


Author(s):  
Anthony S-Y Leong ◽  
David W Gove

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.


1999 ◽  
Vol 4 (5) ◽  
pp. 4-7 ◽  
Author(s):  
Laura Welch

Abstract Functional capacity evaluations (FCEs) have become an important component of disability evaluation during the past 10 years to assess an individual's ability to perform the essential or specific functions of a job, both preplacement and during rehabilitation. Evaluating both job performance and physical ability is a complex assessment, and some practitioners are not yet certain that an FCE can achieve these goals. An FCE is useful only if it predicts job performance, and factors that should be assessed include overall performance; consistency of performance across similar areas of the FCE; consistency between observed behaviors during the FCE and limitations or abilities reported by the worker; objective changes (eg, blood pressure and pulse) that are appropriate relative to performance; external factors (illness, lack of sleep, or medication); and a coefficient of variation that can be measured and assessed. FCEs can identify specific movement patterns or weaknesses; measure improvement during rehabilitation; identify a specific limitation that is amenable to accommodation; and identify a worker who appears to be providing a submaximal effort. FCEs are less reliable at predicting injury risk; they cannot tell us much about endurance over a time period longer than the time required for the FCE; and the FCE may measure simple muscular functions when the job requires more complex ones.


2003 ◽  
Vol 42 (05) ◽  
pp. 215-219
Author(s):  
G. Platsch ◽  
A. Schwarz ◽  
K. Schmiedehausen ◽  
B. Tomandl ◽  
W. Huk ◽  
...  

Summary: Aim: Although the fusion of images from different modalities may improve diagnostic accuracy, it is rarely used in clinical routine work due to logistic problems. Therefore we evaluated performance and time needed for fusing MRI and SPECT images using a semiautomated dedicated software. Patients, material and Method: In 32 patients regional cerebral blood flow was measured using 99mTc ethylcystein dimer (ECD) and the three-headed SPECT camera MultiSPECT 3. MRI scans of the brain were performed using either a 0,2 T Open or a 1,5 T Sonata. Twelve of the MRI data sets were acquired using a 3D-T1w MPRAGE sequence, 20 with a 2D acquisition technique and different echo sequences. Image fusion was performed on a Syngo workstation using an entropy minimizing algorithm by an experienced user of the software. The fusion results were classified. We measured the time needed for the automated fusion procedure and in case of need that for manual realignment after automated, but insufficient fusion. Results: The mean time of the automated fusion procedure was 123 s. It was for the 2D significantly shorter than for the 3D MRI datasets. For four of the 2D data sets and two of the 3D data sets an optimal fit was reached using the automated approach. The remaining 26 data sets required manual correction. The sum of the time required for automated fusion and that needed for manual correction averaged 320 s (50-886 s). Conclusion: The fusion of 3D MRI data sets lasted significantly longer than that of the 2D MRI data. The automated fusion tool delivered in 20% an optimal fit, in 80% manual correction was necessary. Nevertheless, each of the 32 SPECT data sets could be merged in less than 15 min with the corresponding MRI data, which seems acceptable for clinical routine use.


Sign in / Sign up

Export Citation Format

Share Document