bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Optical Interactions in Optical Fibers
Authors: Boyd Robert W. , Buckland Eric L.
Published: July 2003

We report on our research program aimed at clarifying the physical processes leading to the nonlinear optical response of silica optical fibers and at studying the implications of optical nonlinearities on optical pulse propagation and optical switching devices. The dominant physical processes leading to the nonlinear optical response of an optical fiber are nonresonant electronic polarization, with essentially instantaneous response, the Raman interaction, with sub-picosecond response, and electrostriction, with nanosecond response. We present experimental results that show the consequence of each of these processes on the propagation of a light pulse through an optical fiber. We have also performed one of the first direct measurements of the electrostrictive contribution to the nonlinear refractive index of optical fibers. We measure values ranging from 1.5 × 10-16 to 5.8 × 10-16 cm2/W , depending on fiber type. These values are comparable to that of the fast, Kerr nonlinearity (i.e., sum of electronic and Raman contributions) of 2.5 × 10-16 cm2/W . The measured electrostrictive nonlinearities are significantly larger than those predicted by simple models, and the possible explanations of this difference are discussed.
Novel Organometallic Compounds for Nonlinear Optics
Authors: Houbrechts Stephan , Boutton Carlo , Clays Koen , Persoons André , Whittall Ian R. , Naulty Raina H. , Cifuentes Marie P. , Humphrey Mark G.
Published: July 2003

Hyper-Rayleigh scattering is used to investigate the nonlinear optical properties of novel metal (ruthenium, nickel and gold) σ-arylacetylide complexes. The influence of the organometallic donor group and conjugating bridge on the quadratic hyperpolarizability is studied. For all organic ligands, the addition of the metal (donor) group is shown to increase the static hyperpolarizability by a factor of 2, 4 and 7 for gold, nickel and ruthenium complexes, respectively. Moreover, replacement of phenyl with a heterocyclic ring is demonstrated to enlarge the hyperpolarizability in the case of gold and ruthenium compounds.
Quantum Light Generation and Superradiance Effects in the Active Microcavity
Authors: de Martini F. , Jedrkiewicz O. , Mataloni P.
Published: July 2003

The process of generation of non-classical radiation in an active Fabry-Perot dye microcavity, under femtosecond excitation, has been investigated. Single photon states, with a non-classical sub-Poissonian distribution have been generated after the excitation of a small number of active molecules, located between the two mirrors. By multiple excitation of the active medium, collective emission phenomena are expected because of the strong superradiant coupling occurring within the transverse coherence area of the microcavity. In particular, we have experimentally verified the principle of relativistic causality within the process of two-dipole superradiance by transverse interaction, in condition of strong microcavity confinement.
3-Dimensional Photonic Crystals at Optical Wavelengths
Authors: Romanov S. G.
Published: July 2003

Different experimental strategies towards the 3-dimensional photonic crystals operating at optical wavelength are classified. The detailed discussion is devoted to the recent progress in photonic crystals fabricated by template method — the photonic band gap materials on the base of opal. The control of photonic properties of opal-based gratings is achieved through impregnating the opal with high refractive index semiconductors and dielectrics. Experimental study demonstrated the dependence of the stop band behaviour upon the type of impregnation (complete or partial) and showed a way for approaching complete photonic band gap. The photoluminescence from opal- semiconductor gratings revealed suppression of spontaneous emission in the gap region with following enhancement of the emission efficiency at the low-energy edge of the gap.
Spatial Structures in Semiconductor Devices
Authors: Firth W. J. , Lord A.
Published: July 2003

The basic physics of nonlinear optics in semiconductors is reviewed. Optical bistability due to increasing absorption and in a Kerr cavity is discussed, as are spatial solitons in a Kerr medium. These introduce recent research on spontaneous pattern formation and soliton-like structures in semiconductor cavity models. Applications to optical information processing are discussed, and simulations of a soliton array memory presented.
Simulation Study of Plasma Wave Generation and Nonlinearity in InSb Semiconductor
Authors: Rajendran K.
Published: July 2003

It is shown that the large amplitude plasma were driven by two collinear laser beams in InSb semiconductor exhibit bistability and hysteresis studied by computer simulation. The influence of collision, laser parameter and frequency mismatch were considered for the large amplitude plasma wave and transition to chaos and leading to plasma wave breakdown. It is confirmed by bifurcation diagram and poincare map. The laser pump strength parameter rather greater than critical value leading to the occurrence of bistability (instability) region. The results may be relevant to beat-wave current drive in Tokamak devices and to beat-wave particle accelerator in semiconductor plasma.
Ultrafast Nonlinear Optical Properties of Charge-Transfer Polymers
Authors: McBranch Duncan W. , Maniloff Eric S. , Vacar Dan , Heeger Alan J.
Published: July 2003

Charge-transfer polymers are a new class of nonlinear optical materials which can be used for generating femtosecond holographic gratings. Using semiconducting polymers sensitized with varying concentrations of C 60, holographic gratings were recorded by individual ultrafast laser pulses; the diffraction efficiency and time decay of the gratings were measured using nondegenerate four-wave mixing. Using a figure of merit for dynamic data processing, the temporal diffraction efficiency, this new class of materials exhibits between two and 12 orders of magnitude higher response than previous reports. The charge-transfer range at polymer/ C 60 interfaces was further studied using transient absorption spectroscopy. The fact that charge transfer occurs in the picosecond-time scale in bilayer structures (thickness 200 Å) implies that diffusion of localized excitations to the interface is not the dominant mechanism; the charge-transfer range is a significant fraction of the film thickness. From analysis of the excited state decay curves, we estimate the charge-transfer range to be 80 Å and interpret that range as resulting from quantum delocalization of the photoexcitations.
Phase Grating Recording on Photosensitive Langmuir–Blodgett Films
Authors: Blinov Lev M. , Cipparrone Gabriella , Palto Sergei P.
Published: July 2003

Photosensitive Langmuir–Blodgett films composed of amphiphilic azo-compounds were used as medium for formation of erasable holographic gratings. The gratings were recorded and erased by Ar laser pump beams of different wavelengths, power and polarization and read out by a probe He-Ne laser beam. The process of the phase grating formation was modelled based on a simple three dimensional mechanism of the light induced reorientation of azo-chromophore axes outward of the exciting light electric vector.
Multipolar Symmetry Patterns in Molecular Nonlinear Optics
Authors: Zyss J. , Brasselet S.
Published: July 2003

Organic materials for quadratic nonlinear optics generally follow the basic pattern of strongly dipolar quasi one-dimensional intramolecular charge transfer molecules organized in macroscopic crystalline or statistical polar lattices. This restriction has been lifted by the introduction of the much broader class of multipolar materials whereby efficient two- and three-dimensional molecules can be fruitfully exploited in self assembled or externally engineered multipolar macroscopic structures. At the molecular level, polarized harmonic scattering permits to evaluate the invariant irreducible components of the molecular quadratic tensor. Its anisotropy and dispersion can be accounted for by a three-quantum model in agreement with linear spectroscopy on poled samples, whereas the validity of the two-level model is restricted to one-dimensional systems. Permanent macroscopic multipolar organization can be implemented by purely optical photoinduced processes. Adequate choice of the polarization of "write" beams permits to imprint any desired symmetry pattern onto the (non)linear material. Photonic engineering thus complements and considerably broadens the more traditional scope of molecular engineering.
Observation of Optical Bistability in χ(2) Polyarylates
Authors: Pura B. , Jeda W. , Noniewicz K. , Zagórski A.
Published: July 2003

Results of measurements of optical bistability in a guest — host polymer structure are presented. A new type of polymer has been elaborated and its optical properties are described. The Fabry–Perot system has been used and the bistabile behaviour has been observed. The second order cascaded χ(2)(ω): χ(2)(2ω) process, leading to intensity dependent phase shift, has been suggested as the mechanism leading to this effect. A satisfactory model of this phenomenon was formulated.
Two-Frequency Bright and Dark Solitons in a Three-Level Atomic System
Authors: Ansari Nadeem A. , Sammut Rowland A.
Published: July 2003

The intensity-dependent refractive index is calculated for a Kerr-like medium composed of a closed three-level atomic system in V-configuration and it is shown that two optical waves of different frequencies can be mutually-trapped in the form of bright and dark spatial solitons.
An Improved Laser Model based on the Nonlinear Coupling of Lightfield with Boson Elementary Excitation
Authors: Minggao He , Fa Ou
Published: July 2003

The dynamics of the laser model based on the nonlinear coupling of light-field with boson elementary excitation is improved. A rate equation of pumping system directly coupled with the boson matter is added to the original equations. The system as a whole, therefore, becomes a perfect self-organized one, but the character of mirrorless unchanges, which is a character essentially different from conventional lasers, and the laser threshold behavior of second-order-like transition also remains. There is some resemblance between the new revised laser model and Maxwell–Bloch two-level-atom laser model.
Effect of Fifth Order Nonlinearity in Nonlinear Fibre Directional Couplers
Authors: Manzoor K. , Kuriakose V. C.
Published: July 2003

The effect of fifth order nonlinearity in the interaction of solitary waves in Nonlinear fibre directional coupler (NLFDC) is studied. Hamiltonian of the system of solitary waves are analyzed and the bound state regions of the two envelope pulses are found. The possibility of phase-controlled Switching in NLFDC is discussed.
Two and Three Photon Absorption in Rhodamine 6G Methanol Solutions Using Pulsed Thermal Lens Technique
Authors: Bindhu C. V. , Harilal S. S. , Kurian Achamma , Nampoori V. P. N. , Vallabhan C. P. G.
Published: July 2003

Dual beam transient thermal lens studies were carried out in rhodamine 6G methanol solutions using 532 nm pulses from a frequency doubled Nd:YAG laser. Analysis of thermal lens signal shows the existence of different nonlinear processes like two photon absorption and three photon absorption phenomena along with one photon absorption. Concentration of the dye in the solution has been found to influence the occurrence of the different processes in a significant way.
Intravenous colistin in the treatment of sepsis from multiresistant Gram-negative bacilli in critically ill patients
Authors: Markou Nikolaos , Apostolakos Haralampos , Koumoudiou Christiana , Athanasiou Maria , Koutsoukou Alexandra , Alamanos Ioannis , Gregorakos Leonidas
Published: July 2003

Introduction

The increasing prevalence of multiresistant Gram-negative strains in intensive care units (ICUs) has recently rekindled interest in colistin, a bactericidal antibiotic that was used in the 1960s for treatment of infections caused by Gram-negative bacilli. We conducted the present observational study to evaluate the efficacy of intravenous colistin in the treatment of critically ill patients with sepsis caused by Gram-negative bacilli resistant to all other antibiotics.

Patients and method

Critically ill patients with sepsis caused by Gram-negative bacilli resistant to all antibiotics with the exception of colistin were treated in the six-bed ICU of a trauma hospital. Diagnosis of infection was based on clinical data and isolation of bacteria, and the bacteria were tested with respect to their susceptibility to colistin. Clinical response to colistin was evaluated.

Results

Twenty-four patients (mean age 44.3 years, mean Acute Physiology and Chronic Health Evaluation II score 20.6) received 26 courses of colistin. Clinical response was observed for 73% of the treatments. Survival at 30 days was 57.7%. Deterioration in renal function was observed in 14.3% of 21 patients who were not already receiving renal replacement therapy, but in only one case did this deterioration have serious clinical consequences.

Conclusion

The lack of a control group in the present study does not allow any definite conclusions to be drawn regarding the clinical effectiveness of colistin. On the other hand, this drug has an acceptable safety profile and its use should be considered in severe infections with multiresistant Gram-negative bacilli.
User and carer involvement in mental health services: From rhetoric to science
Authors: Simpson E. L. , House A. O.
Published: July 2003

The Department of Health has emphasised the need for a patient-centred National Health Service (NHS), and the involvement of users and carers in mental health services is often a policy recommendation (Mental Health Task Force User Group, 1995; NHS Health Advisory Service, 1997; Department of Health, 1999a,b, 2001). The Patients' Forum and Consumers in NHS Research are established national bodies concerned with stakeholder involvement. The Commission for Patient and Public Involvement in Health was established in 2003.
Droperidol dropped; consultants not consulted
Authors: Reid Gavin , Hughson Mark
Published: July 2003

Aims and Method

We conducted a postal questionnaire survey of the practice of rapid tranquillisation among 215 consultant psychiatrists in the West of Scotland, before and after the withdrawal of droperidol by the manufacturer.

Results

One hundred and eighty questionnaires (84% of those sent) were returned. Droperidol had been used extensively, often combined with lorazepam, for rapid tranquillisation. The main replacement suggested for droperidol was haloperidol. About half of the respondents to our survey chose to comment on the withdrawal of droperidol. More than half of the comments were unfavourable, including lack of an adequate replacement and lack of consultation with the psychiatric profession.

Clinical Implications

The abrupt withdrawal of droperidol, partly for commercial reasons, was regrettable. There was no time for an adequate evaluation of possible replacement medications and a lack of consultation with the profession regarding the impact on clinical care.
Design Guidelines for Base-Isolated Buildings with Energy Dissipators
Authors: Mayes Ronald L. , Jones Lindsay R. , Kelly Trevor E. , Button Martin R.
Published: July 2003

Base isolation is a design strategy founded on the premise that a structure can be substantially decoupled from damaging horizontal components of earthquake motions, significantly reducing levels of force and acceleration in the structure. This paper provides the basis of a practical base isolation system which includes energy dissipation in special purpose mechanical devices. Topics covered include basic elements of base isolation, feasibility, design philosophy and code considerations. Design procedures based on a series of design charts are presented and an example of their use on a 12-story structure is detailed.
Earthquakes and Human Behavior
Authors: Mileti Dennis S. , Nigg Joanne M.
Published: July 2003

Efforts by social scientists to investigate behavioral aspects of earthquakes are few when compared to other disasterinducing natural phenomena. Nevertheless, completed studies reveal patterns of findings similar to those found in other disaster investigations; and social scientific earthquake investigations promise to be more frequent in the future. This paper catalogues what the existing research record suggests as the major conclusions about human behavior in reference to earthquakes. Some of the conclusions reached in this paper are, first, action to mitigate future earthquake losses does not necessarilly follow from heightened risk perceptions in individuals; second, human response to earthquake disasters is better viewed as one in which the “thin-veneer-of-civilization” is strengthened rather than as a state of chaos or societal disorder, and the public is better described as a resource in disaster than as a problem; third, earthquake disaster economic impacts are not uniform in human populations despite comparable damage; forth, emergency response by organizations to earthquake disasters is both more effective and efficient if prefaced by sound planning; fifth, public information needs are rarely if ever adequately met in earthquake emergencies; and, finally the adoption of hazard mitigation strategies at all levels of government is most frequent in the aftermath of earthquake disaster than at any other time.
Simple Computation of Liquefaction Probability for Seismic Hazard Applications
Authors: Atkinson Gail M. , Finn W. D. Liam , Charlwood R. G.
Published: July 2003

A computer program has been written for the routine calculation of the probability of seismically induced liquefaction for level sand or silty sand sites. The method combines Seed's simplified method of assessing liquefaction potential with the Cornell method of assessing seismic hazard, by modifying the latter to consider the joint probability of magnitude and acceleration. The input data to the program are simple geotechnical data from SPT, CPT or laboratory tests, and readily obtainable regional seismicity data. The program is simple to use.
A History of Reinforced Masonry Construction Designed to Resist Earthquakes: 1755-1907
Authors: Tobriner Stephen
Published: July 2003

Although the reinforcement of masonry buildings against earthquake damage was known as early as 1755, it only came of age in the United States in the late 1930s. This survey, which includes antiseismic construction systems dating from 1755, 1783, 1784, 1854, 1870, 1872, 1906 and 1907 illustrates how common sense solutions for the reinforcement of masonry buildings had already been invented and used long before the Long Beach earthquake in 1933 which stimulated modern reinforcement research.
Cyclic Behavior of Large Beam-Column Assemblies
Authors: Popov Egor P. , Amin Navin R. , Louie Jason J. C. , Stephen Roy M.
Published: July 2003

A series of experiments were conducted in order to verify the design criteria for beam-column joints under extreme seismic conditions for a 47-story building in San Francisco. The half-scale cruciform specimens were exceptionally large requiring 18 in. deep sections. The overall size of the specimens was the largest ever tested in the U.S. for this kind of application. The data on the behavior of such large moment-resisting joints under severe cyclic loading are very limited. The experimental evidence clearly supports the use of stiffeners and doubler plates at the joints for the cross-sectional geometries tested. The results are of direct relevance to seismic design of many steel buildings.
Earthquake Ground Motions: Implications for Designing Structures and Reconciling Structural Damage
Authors: Singh Jogeshwar P.
Published: July 2003

Until recently, characteristics of strong ground motion resulting from different soil conditions were considered the dominant factor in developing design ground motions and reconciling observed damage. Interpretation of recent recordings of earthquakes by strong motion instrument arrays installed in California and Taiwan show that basic characteristics of strong motion are greatly influenced by the seismological and geological conditions. For a given soil condition, the characteristics of strong ground motion (peak ground acceleration, peak ground velocity, peak ground displacement, duration, spectral content, and time histories) can vary significantly whether the site is near or far from the seismic source. As local soil conditions only modify the ground motions produced by a given source, variability in ground motion due to seismologic and geologic conditions (for a given soil condition) must be considered in estimating earthquake ground motions for structural design or for estimating structural vulnerabilities to reconcile earthquake-related damage.
Behavior of Building Occupants in Earthquakes
Authors: Durkin Michael E.
Published: July 2003

To be truly effective, earthquake hazard reduction measures must be based on a realistic appraisal of occupants' capabilities and actions during earthquakes. Studies suggest that many overly general beliefs about appropriate response can endanger rather than protect building occupants. We need to analyze occupant actions with respect to hazards posed by the seismic performance of specific building types. This paper will review the findings of recent U.S. studies, discuss the applicability of research from abroad, and summarize requirements for continued progress in this vital research area.
Industrial Earthquake Preparedness in Shizouka and the Role of the Prefectural Government
Authors: Selvaduray Guna S.
Published: July 2003

The Shizuoka Prefectural Office in Japan plays an important role in promoting earthquake emergency preparedness among its industries. In addition to implementing regulatory requirements and enacting new regulations as necessary, the Prefectural Office also provides significant guidance to industry. This includes making publications available and periodic surveys of the status of industrial emergency preparedness. A pharmaceutical company in the prefecture has developed an impressive earthquake preparedness program and hazard reduction techniques. This program addresses both primary and secondary effects of earthquakes.
The Morgan Hill Earthquake of April 24, 1984—Seismological Aspects
Authors: Bolt Bruce A. , Uhrhammer Robert A. , Darragh Robert B.
Published: July 2003

On April 24, 1984, at 21:15 UTC, a moderate earthquake occurred on the Calaveras fault in the vicinity of Halls Valley, California (epicenter 37° 19.2'N, 121° 41.9'W). The earthquake had a mean local magnitude of 6.2 ± 0.20 and a maximum Modified Mercalli Intensity of VIII. It is probably a repeat of the 1911 Coyote earthquake.

The rate of seismicity from historical catalogs, compiled at the U. C. Seismographic Stations yields an average recurrence time of 160±60 years for an ML≥6.2 event occurring in a 30 km segment of the Calaveras fault. Other evidence from the repeat times of earthquakes suggests a recurrence period of 75 years for a total magnitude of 6.0 or larger.. These estimates are in reasonable agreement.

A seismic moment of 1.1×1025 dyne-cm for the mainshock was estimated from broadband displacement seismograms recorded at Berkeley (Δ ≈ 79 km). The moment and the rupture area inferred from the aftershocks suggest a mean fault displacement of 30 cm. The aftershock sequence through December 31, 1984, contained four earthquakes of magnitude 4.0 or greater and the sequence b-value was 0.81 ± 0.03.
The Morgan Hill Earthquake of April 24, 1984—The 1.29g Acceleration at Coyote Lake Dam: Due to Directivity, a Double Event, or Both?
Authors: Abrahamson Norman A. , Darragh Robert B.
Published: July 2003

The 1984 Halls Valley (Morgan Hill, California) earthquake had a complex seismic source. Velocities of the major seismic phases measured from continuous broadband seismograms at Berkeley Seismographic Station (BKS) and Richmond Field Station (RFS) show unambiguously that the earthquake is predominantly a double event with the second source hypocenter located approximately 17 km southeast of the mainshock hypocenter given by Bolt, Uhrhammer and Darragh (1985). The southeasterly fault rupture of the first source and the location of the focus of the second source have critical implications for the observed spatial variation of the recorded accelerograms. Of particular engineering interest, the high frequency 1.29g pulse of horizontal ground acceleration measured at Coyote Lake dam can be explained primarily as due to the second source and constructive interference of the principal S waves from the two sources.
The Morgan Hill Earthquake of April 24, 1984—Effects on Industrial Facilities, Buildings, and Other Facilities
Authors: Swan Sam W. , Miller David D. , Yanev Peter I.
Published: July 2003

The response of the equipment commonly found in power plants and industrial facilities to the Morgan Hill earthquake of April 24, 1984 is reviewed. Brief descriptions of the general effects of the earthquake are given, including strong ground motion recordings and impacts on commerical and residential structures and their contents. Four sites near San Jose and seven sites near Morgan Hill are examined in detail. These include two wineries, a community college, an industrial park, a software development laboratory, a chemical manufacturing complex, and an electrical substation. Both damaged and undamaged equipment is examined. Generally equipment performed quite well in this moderate earthquake. Seismic damage to well-engineered systems and structures was minimal to non-existent.
The Morgan Hill Earthquake of April 24, 1984—Effects on Mobile Homes
Authors: Kensler Charles D.
Published: July 2003

The greater Morgan Hill area has seven mobile home parks. Of the seven, there are three large parks and four small ones. For the most part, damage occurred at three parks: Windmill Mobile Estates, Woodland Mobile Home Park, and Madrone Manor Mobile Estates.
The Morgan Hill Earthquake of April 24, 1984—Investigation of Lifelines
Authors: Schiff Anshel J.
Published: July 2003

The overall response of all lifelines was good although there was some significant damage. In the power system there was significant damage to 500 kV circuit breakers at two substations, some other minor substation damage, and some damage to feeders in the distribution system. The substation damage did put a segment of one of the AC Pacific Interties out of service for a couple of days but the remaining intertie was able to carry the load. The loss of feeder lines caused local disruption of power for up to 5 hours. In water and sewage systems two 8 inch transit water lines broke in Morgan Hill and a break in an 8 inch pipe to a 350,000 gallon tank caused a large water loss. Five 6 inch water line couplings disengaged. There were numerous water service connection failures in the high damage area. There was no significant damage to communication systems but there was a significant downgrade in the quality of service due to system overload. Calls from outside the area were limited by AT&T. Damage to highway systems was limited to that caused by a rock slide which blocked E. Dunne Avenue near the Anderson Reservoir and damaged a nearby bridge over the reservoir. One bridge span moved one foot near an abutment and caused the adjacent pier to move out of plumb by almost one foot. The road surface on the crest of the Anderson Dam was cracked but there was no damage to the dam. In the natural gas system there was no damage to the utilities part of the system. A large fire in San Jose was caused by a gas leak in piping to a gas fired industrial heater. There was an explosion and fire in a mobile home and numerous leaks associated with toppled water heaters. There were numerous leaks beyond service connections to homes in the high damage area.
The Morgan Hill Earthquake of April 24, 1984—Effects on Facilities of the Santa Clara Valley Water District
Authors: Tepel Robert E.
Published: July 2003

The Santa Clara Valley Water District (the District) is a public agency with flood control and water supply management authority in Santa Clara County, California. The District operates ten dams and reservoirs, two water treatment plants which supply potable water, 74 miles of large-diameter water distribution pipelines and 34 miles of small canals. Flood control facilities include 45 miles of streams channeled by levees and 17 miles of bayfront levees. Immediately after the earthquake, the District's Emergency Operations Center was activated. Major dams were inspected immediately by operations staff in accordance with standing instructions. The fundamental operations of the District were not interrupted by the earthquake in any significant way. Both water treatment plants operated continuously during and after the earthquake. Damage was limited to minor (functionally insignificant) surficial cracking at two embankment dams. Electronic distance measuring surveys indicated that a large existing landslide, on which one of the water treatment plants is located, moved as much as 13 mm as a result of the earthquake.
The Morgan Hill Earthquake of April 24, 1984—Emergency Preparedness and Response
Authors: Eisner Richard K.
Published: July 2003

The Morgan Hill earthquake of April 24, 1984 tested the response structure of Santa Clara County and several cities within the County. While there was no damage to the communications and command infrastructure, the response was seriously disrupted by overloading of the telephone system, and the lack of accurate damage intelligence. Analysis of the response to the earthquake has served to emphasize the need for improved preparedness activities at the local and regional level, the involvement of individuals, businesses, and schools in preparedness planning, and for improvements in communication systems and procedures.
The Morgan Hill Earthquake of April 24, 1984—Fire-Related Aspects
Authors: Scawthorn Charles , Bureau Gilles , Jessup Craig , Delgado Robert
Published: July 2003

Fire following the April 24, 1984, Morgan Hill earthquake (M 6.2) was a primary cause of damage in the cities of Morgan Hill and San Jose, California. Delays in telephone dial tones, perceived as telephone outages, resulted in delayed reports of structural fires to fire departments. A fire at a shopping center in San Jose was the largest single loss in the earthquake, totaling approximately $1 million. Multiple non-fire specific incidents which fire departments were called upon to respond to, such as gas investigations, structural damage checks, downed power wires and medical aid, placed additional heavy demand on limited resources.
Costs and Benefits of Seismic Upgrading of Some Buildings in the Boston Area
Authors: Paté-Cornell M. Elisabeth
Published: July 2003

We examine here the costs and benefits of reinforcing some existing buildings in Boston at the time of remodelling with significant change of use. The buildings of interest are the unreinforced masonry warehouses and the reinforced concrete manufacturing buildings that are remodelled into apartment or office buildings. Given some estimates of the Boston seismicity and of the performance of these buildings in earthquakes with and without additional reinforcement, we evaluate three possible levels of reinforcement that the Masssachusetts Seismic Advisory Committee could recommend as part of the building codes. For the unreinforced masonry buildings, the first upgrading level is the addition of floor and roof diaphragms, and the two subsequent levels involve addition of internal walls and reinforcement of the existing ones. For the reinforced concrete buildings, the first level involves increase of the shear walls' size, and higher upgrading levels involve addition of shear walls and increase of the columns' size. We introduce in our study the market effects of the additional costs. We conclude that only the first levels of reinforcement that we considered could be adopted as regulations, and that higher standards should be left to the choice of the buildings' occupants.
The Distribution of Earthquake Damage to Underground Facilities during the 1976 Tang-Shan Earthquake
Authors: Jing-Ming Wang , Litehiser Joe J.
Published: July 2003

This paper, through description and analysis of the performance of underground facilities during the magnitude 7.8 Tang-Shan earthquake of 1976, indicates that, in the area of strong surface shaking, damage to underground facilities decreases exponentially with depth to 500 m (1640 ft). Below this depth, damage remains constant. In addition, the rate of reduction of earthquake shaking away from the source fault is greater in the subsurface than on the surface.
Strong Motion Attenuation Relations: A Ten-Year Perspective
Authors: Campbell Kenneth W.
Published: July 2003

Research on strong ground-motion characteristics conducted in the United States within the last 10 years (1974-1984) forms the basis for a detailed discussion of important factors to be considered when selecting or developing strong-motion attenuation relations for use in earthquake engineering and seismic hazard studies. While emphasis is placed on the empirical prediction of ground-motion amplitudes, a brief discussion of procedures is presented that can be used when insufficient strong-motion data are available to perform an adequate statistical analysis. The discussion is followed by a tabulated summary of selected strong-motion attenuation relations proposed and developed in the last 10 years (1974-1984) to acquaint the reader with the types of relationships currently available.
A Review of Earthquake Damage Estimation Methods
Authors: Reitherman Robert
Published: July 2003

A number of methods have been developed with the aim of estimating the damage or effects of future earthquakes. As this field continues to rapidly expand, it is valuable to gain some perspective by comparing a representative sample of methods to see in what respects they are similar or different. The most significant conclusion of this review is that the use to which a damage estimation may be put is the single most important factor and, while there is already an extensive array of methods, there has been relatively little in the way of practical application.
The Borah Peak, Idaho Earthquake of October 28, 1983—Isoseismal Map and Intensity Distribution
Authors: Stover Carl W.
Published: July 2003

The Borah Peak, Idaho, earthquake of October 28, 1983, caused two deaths in Challis and injured one person in Mackay. The most severe damage occurred in Mackay and Challis, where 11 businesses and 239 homes were damaged. Maximum Modified Mercalli intensity of VII was rated for both Challis and Mackay based on damage due to vibrational effects. Intensity IX was assigned to the area along the 34-kilometer-length of surface faulting. This event is comparable to the 1959 Hebgen Lake, Montana, earthquake, which was assigned an intensity X based on geologic effects and VII - VIII on vibrational effects (Steinbrugge and Cloud, 1962). The Borah Peak event was felt over 855,000 km2 of the United States and Canada.
The Borah Peak, Idaho Earthquake of October 28, 1983—Surface Faulting and Other Phenomena
Authors: Taylor Charles L. , Cline K. Michael , Page William D. , Schwartz David P.
Published: July 2003

The Borah Peak Earthquake of October 28, 1983 occurred near MacKay, Idaho with about 42 km (26 mi) of complex normal-oblique-slip faulting on the Lost River fault. Associated with the surface faulting was strong ground shaking and dramatic cold-water geysers and hydrologic changes related to regional ground subsidence. Faulting occurred on pre-existing Quaternary-Holocene scarps as both single and en echelon traces with net vertical displacement of 2 to 3 m (6.6 to 9.8 ft) and up to 1 m (3 ft) of left lateral displacement. Although no earthquakes prior to 1983 are known to have been associated with this fault, there is abundant geomorphic evidence of late Quaternary activity. Other normal-slip faults in the basin and range of Idaho, Montana, Utah, and Nevada show similar geomorphic evidence of activity.
The Borah Peak, Idaho Earthquake of October 28, 1983—Strong Ground Motion
Authors: Jackson Suzette M. , Boatwright John
Published: July 2003

The 1983 Borah Peak, Idaho Earthquake was the largest normal faulting event to occur in the last 20 years. There were no near-field recordings of ground motion during the main shock, however, thirteen accelerographs in a permanent array at the Idaho National Engineering Laboratory (INEL) recorded the event at epicentral distances of 90-110 km. Peak horizontal accelerations, or PGA, recorded at accelerographs above ground-floor level range from 0.037 to 0.187 g. Accelerographs at basement and free-field sites recorded as low as 0.022 g and as high as 0.078 g. Peak vertical accelerations range from 0.016 g at ground level to 0.059 g above ground-floor level. A temporary array of digital seismographs deployed by the U. S. Geological Survey (USGS) in the epicentral area recorded ground motion from six large aftershocks at epicentral distances of 4-45 km; the largest of these aftershocks also triggered four accelerographs in the INEL array. This paper presents our estimates of near-field ground motion derived from two separate analyses. The first analysis uses the attenuation of the aftershock PGA measurements to extrapolate the INEL main shock PGA measurements into the near-field. This estimates an upper limit of 0.8 g for near-field ground motion. In the second analysis, a set of main shock accelerograms were synthesized. Wave propagation effects were determined from aftershock recordings at one of the USGS portable stations and an INEL seismograph station. These effects were removed from one of the INEL main shock acceleration traces. The synthetic accelerograms were derived for a hypothetical station southwest of Mackay, Idaho. The PGA measured from the synthetic accelerograms were 0.08, 0.14, 0.15, 0.23 g. These estimates correlate well with ground motion expected for an area of intensity VII.
The Borah Peak, Idaho Earthquake of October 28, 1983—Liquefaction
Authors: Youd T. L. , Harp E. L. , Keefer D. K. , Wilson R. C.
Published: July 2003

The most pervasive and damaging effects of liquefaction generated by the 1983 Borah Peak, Idaho earthquake occurred in the Big Lost River and Thousand Springs Valleys above Mackay Reservoir. Less severe effects occurred in the Big Lost River Valley south of Mackay Reservoir and in the Pahsimeroi Valley. Nearly all of the liquefaction effects developed in floodplain alluvium of late Holocene age. However, the sediment that liquefied beneath the alluvial fans on the east side of the Thousand Springs Valley was deposited in late Pleistocene time. The distance from the fault to the farthest effect of liquefaction was unusually short for an MS = 7.2 event. The distribution of liquefaction effects were consistent, however, with the distribution of MMI intensity and estimated peak ground motion parameters, both of which attenuated more rapidly than is generally expected for an earthquake of this type and magnitude.
The Borah Peak, Idaho Earthquake of October 28, 1983—Hydrologic Effects
Authors: Wood Spencer H. , Wurts Caroline , Lane Ted , Ballenger Nick , Shaleen Mary , Totorica Dolores
Published: July 2003

Spectacular groundwater effects accompanied the October 28, 1983 Idaho earthquake (Ms = 7.3). Groundwater discharge increased from many springs and base flow of major rivers significantly increased over an 18,000 km2 region. In the epicentral area a 35-m surge in artesian pressure produced spectacular bursts of muddy water from carbonate bedrock hills at Chilly Buttes. This pressure surge was also manifested as a 1.4-km long zone of large sand boils erupted through the valley alluvium. At Smith's Fish Hatchery, sediment eroded by the surge of water clogged the fresh spring-water supply inlet pipes and led to suffocation of the entire crop of trout. North of the epicentral area a major warm springs dried up for 8 days and then recommenced flowing at an ever increasing rate until it stabilized at about 9 times the pre-earthquake flow. This flow of about 1400 l/s caused severe bank erosion of pastureland until diverted into an artificially excavated channel. At Clayton Silver Mine, 50 km north of the epicenter, increased seepage into the underground mine workings overwhelmed the mine-pump capacity and flooded the 330-meter level within 14 hrs. Thirty kms south of the epicenter a 200,000 m3 mudflow was apparently caused by increased spring flows. The valley fill failed two days after the earthquake and devastated a 3.5-km reach of Lupine Creek valley. Similar coseismic and post-seismic hydrologic effects were reported in studies of the 1952 Kern County, California earthquake, and the 1959 Hebgen Lake, Montana earthquake. Several mechanisms for these hydrologic phenomena are considered, but the most plausible cause is the sudden release of elastic strain in aquifer rocks. Sudden strain release of elastic rebound increases pore pressure in some confined aquifers thus leading to increase in discharge from springs that contribute to the base flow of major rivers.
The Borah Peak, Idaho Earthquake of October 28, 1983—Buildings and Schools
Authors: Adham Samy A. , Ballif Brent
Published: July 2003

At 8:07 AM MDT, October 28, 1983, a major earthquake (Ms = 7.3) rocked central Idaho. The earthquake source zone was near the base of Mt. Borah with an elevation of 12,662 ft (3859 m). This earthquake is the largest earthquake to occur in Idaho in recorded history, and is the strongest to occur in the continental United States since the magnitude 7.1 Hebgen Lake Montana earthquake of 1959. It was felt that a study of the effects of such a large magnitude earthquake on buildings and communities would enhance understanding of the response of buildings to different types of earthquakes. Therefore, an EERI reconnaissance team was dispatched to the earthquake area on the day following the event. Performance of buildings and other structures near the earthquake source zone is discussed.
The Borah Peak, Idaho Earthquake of October 28, 1983—Industrial Facilities and Equipment at INEL
Authors: Guenzler R. C. , Gorman V. W.
Published: July 2003

Reactors and facilities of the Idaho National Engineering Laboratory (INEL) are located 90 to 110 km from the epicenter of the October 28, 1983 earthquake. Several reactors were up and operating normally when the earthquake struck. These reactors were shut down in accordance with normal procedures. Plant inspections, functional tests and evaluations indicated no significant damage was experienced. Minor cosmetic damage was found in some auxiliary buildings, however.
The Borah Peak, Idaho Earthquake of October 28, 1983—Performance of Unreinforced Masonry Buildings in Mackay, Idaho
Authors: Reitherman Robert
Published: July 2003

Damage to buildings in Mackay, Idaho during the October 28, 1983 Borah Peak earthquake was largely limited to unreinforced masonry construction, including the unreinforced masonry chimneys of wood frame dwellings. Except for chimneys, which typically collapsed or were severely damaged, the level of damage was only slight to moderate, even though the earthquake resistance of the construction was very low, even for unreinforced masonry.
The Borah Peak, Idaho Earthquake of October 28, 1983—Lifelines
Authors: Eppich Earle S.
Published: July 2003

The Borah Peak earthquake of October 28, 1983 shook a rural area of central Idaho. The effects on engineered lifelines was small because the population centers were located some distance from the epicenter. The most visible damage observed was to the roads and highways. The MacKay Dam on the Lost River was examined for damage, but aside from temporary cloudy water from a spring at the base of the dam, no significant problems were discovered. Water distribution and sewer collection systems were not damaged, but people were alerted to take precautionary measures with the water they used for drinking. Electrical service was interrupted for an interval of 45 minutes in MacKay. There was a noticeable dimming of lights in Pocatello, Idaho. No significant damage was observed to electrical or telephone systems.
Small Amplitude Vibration Measurements of Buildings Undamaged, Damaged, and Repaired after Earthquakes
Authors: Carydis Panayotis , Mouzakis Harris P.
Published: July 2003

Ambient vibrations provided the means to measure dynamic properties of reinforced concrete undamaged buildings, damaged and repaired after the destructive earthquakes of February 24, 1981, in the major area of Athens and in Central Greece. Each fundamental period is given as function of the number of stories, the height of the building, the dimensions of its plan and the percentage of shear walls. The shape of the deformation of the vertical centerline and the associated percentage of critical damping resulted also from the measurements, which in addition proved that for the damaged buildings the vertical centerline presents a discontinuity at the level where the damages are concentrated. For the repaired buildings this line becomes smooth.
Bidirectional Loading of R.C. Beam-Column Joints
Authors: Leon Roberto , Jirsa James O.
Published: July 2003

Fourteen reinforced concrete beam-column joint subassemblages were tested to investigate the effects of load history, beam reinforcement size, beam geometry and floor slabs on joint behavior under cyclic bidirectional load reversals. The full-scale specimens were loaded biaxially to simulate the worst loading condition on the joints of a multi-story ductile moment-resisting frame. The tests showed that biaxial effects can have a significant impact on joint behavior due to the deterioration of column strength, that the beam and slab geometry can significantly affect the joint shear response, and that bond conditions and column-to-beam flexural capacity ratio control the design of such subassemblages.
Ductile Design Approach for Reinforced Concrete Frames
Authors: Park Robert
Published: July 2003

In the design of multistorey moment-resisting reinforced concrete frames to resist severe earthquakes the emphasis should be on good structural concepts and detailing of reinforcement. Poor structural concepts can lead to major damage or collapse due to column sidesway mechanisms or excessive twisting as a result of soft storeys or lack of structural symmetry or uniformity. Poor detailing of reinforcement can lead to brittle connections, inadequate anchorage of reinforcement, or insufficient transverse reinforcement to prevent shear failure, premature buckling of compressed bars or crushing of compressed concrete. In the seismic provisions of the New Zealand concrete design code special considerations are given to the ratio of column flexural strength to beam flexural strength necessary to reduce the likelihood of plastic hinges forming simultaneously in the top and bottom of columns, the ratio of shear strength to flexural strength necessary to avoid shear failures in beams and columns at large inelastic deformations, the detailing of beams and columns for adequate flexural strength and ductility, and the detailing of beams, columns and beam-column joints for adequate shear resistance and bar anchorage. Differences exist between current United States and New Zealand code provisions for detailing beams and columns for ductility and for the design of beam-column joints.
Domenico Campagnola and an Earthquake Fantasy
Authors: Oppenheim Irving J.
Published: July 2003

Domenico Campagnola was a sixteenth century artist who worked in Venice and Padua; it can be presumed that he experienced the Friuli earthquake of 1511. A drawing by him has recently surfaced, representing the collapse of a city in an earthquake. Examining the structural and seismological evidence it is identified here as an artist's fantasy. This is consistent with the artistic interest in landscape for its most tumultuous and tempestuous qualities.