A continuous Leontief dynamic input-output model

This paper extends the Leontief dynamic input-output model by incorporating continuous lags, capacity constraints, excess capacity and limits on disinvestment in each sector. These extensions result in phase changes, where sectors discretely change from one set of conditions to another. The resulting system of equations is solved by numerical methods and applied to the U.S. economy. Projections for the 1952 to 1962 period are compared with actual levels.     

Smoke Control in Hospitals

Full scale fire tests have been carried out in order to study the influence of different ventilating principles on the time point of fire detection and the smoke filling of a four-bed room. Using conventional mechanical ventilating systems as smoke exhaust systems the time difference left for evacuation of the fire room can be positively influenced. With the conventional ventilating system operating there is a significant difference between time points of detection of the ionization and optical smoke detectors, for both flaming and smoldering fire. Using the low momentum displacement ventilation this difference is reduced, resulting in possibilities for the ionization smoke detector to be optimized for both flaming and smoldering fires. Reference: Øystein Meland and Eimund Skåret, Smoke Control in Hospitals,Fire Technology, Vol. 22, No. 1, February 1986, p. 33.     

Dynamic forecasting of travel demand,residential location and land development

TheChicago Area Transportation/Land-Use Analysis System (CATLAS) is a large scale urban simulation model which synthesizes location rent analysis from urban economics with travel demand analysis from transportation planning. This paper describes the theoretical formulation, empirical estimation and policy application of CATLAS to the evaluation of CBD-oriented rapid transit projects in Chicago.     

Methods to calculate the response time of heat and smoke detectors installed below large unobstructed ceilings

Recently developed methods to calculate the time required for ceiling mounted heat and smoke detectors to respond to growing fires are reviewed. A computer program that calculates activation times for both fixed temperature and rate of rise heat detectors in response to fires that increase in heat release rate proportionally with the square of time from ignition is given. This program produces nearly equivalent results to the tables published in Appendix C, Guide for Automatic Fire Detector Spacing (NFPA 72E, 1984). A separate method and corresponding program are provided to calculate response time for fires having arbitrary heat release rate histories. This method is based on quasi-steady ceiling layer gas flow assumptions. Assuming a constant proportionality between smoke and heat released from burning materials, a method is described to calculate smoke detector response time, modeling the smoke detector as a low temperature heat detector in either of the two response time models.Nomenclature A g/(c _p T ) - c _p specific heat capacity of ambient air - C _s smoke mass concentration - D effective binary diffusion coefficient - g acceleration of gravity - H vertical distance from fuel to ceiling - I light intensity - I_o initial light intensity - L light beam length - _s smoke gas mass production rate per unit volume - OD optical density per unit length (see Equation 8) - fire energy release rate - energy release rate per unit volume - r radial distance from fire axis to the detector - RTI response time index, the product of the detector thermal time constant and the square root of the gas speed used in the test to measure the time constant.⁹ - t time - t ₂ ^* dimensionless time t/[A^{–1/5 –1/5} H^4/5) - (t ₂ ^* ) _f dimensionless time for time delay for gas front travel - T ambient temperature - T gas temperature at detector location - T _s temperature of detector sensing elements - T T — T - T ₂ ^* dimensionless temperature differences T/[A^2/5(T _f /g) ^2/5 H^–3/5] - U gas speed at the detector location - U ₂ ^* dimensionless gas speed U/[A H]^1/5 - Y _s local ratio of smoke mass to total mass in flow - proportionality constant for t²-fire growth = Q/t² - ambient air density Reference: David D. Evans and David W. Stroup, Methods to Calculate the Response Time of Heat and Smoke Detectors Installed Below Large Unobstructed Ceilings,Fire Technology, Vol. 22, No. 1, February 1985, p. 54. Note: This paper is a contribution of the National Bureau of Standards and is not subject to copyright.     

Thirty years with spatial and intertemporal economics

In this paper the practical origin and development of the spatial and intertemporal price equilibrium (SIPE) models are chronologically followed around the personal life of the author. The fact that both the Marshallian (quantity) formulation and the Walrasian (price) formulation have been with the Takayama-Judge models in the primal-dual (purified-duality) relationship from the outset is pointed out. Historical use and abuse of large scale models in the past two decades, closely related to the SIPE models, are discussed. The author acknowledges recent developments of methodologies by younger generation researchers in this field and concludes that along with the recent development of high-powered computers and softwares, there will be a number of interesting and relevant SIPE model applications in the near future.This paper was first read at an international conference on Trade, Knowledge and the Network Economy, in Mallacoota, Victoria, Australia, and was revised to present for the workshop entitled Advances in Spatial Equilibrium Modeling held at the new Tinbergen Institute in Amsterdam, Netherlands on January 24–25, 1994.The author would like to express his gratitude to Professors Martin Beckmann, Peter Nijkamp, Dr. John R. Roy and an anonymous referee for their numerous comments and advice in revising this paper. Any remaining omissions and commissions are my own.This paper was presented in draft form at an International Workshop on Trade, Knowledge and the Network Economy, held in December 1992 in Mallacoota, Australia.     

Engineering geological and geophysical investigations of a slope failure at Edinburgh Castle, Scotland

Edinburgh Castle is one of Scotlands most important heritage sites. It was built on a classic crag and tail structure where the crag consists of columnar jointed basalt and the tail of sediments protected from glacial erosion by the crag.In 1997 apparent instability was observed on the southern side of the tail. A shallow slope failure was proved to have taken place within saturated, layered, cohesive to non-cohesive, loose to dense heterogeneous fill on a slope of 44°. The date of the initial failure is not known, but is likely to have taken place over a period of many years, since at least the 1950s.Remediation works were subsequently undertaken to stabilise the slope, consisting mainly of the installation of soil nails, a bi-axial geo-grid and minor filling to mitigate the effects of the ground movements and to facilitate repair of the retaining wall.     

Bestandsaufnahme Grundwasser nach der EU-Wasserrahmenrichtlinie im Koordinierungsraum Mulde-Elbe-Schwarze Elster

Kurzfassung Die Wasserrahmenrichtlinie regelt den Schutz von Grund- und Oberflächengewässern und fordert eine nachhaltige Wassernutzung. Sie legt einen Zeitplan fest, um bis zum Jahr 2015 für alle Gewässer einen guten Zustand zu erreichen. Der erste Schritt ist eine Bestandsaufnahme der Gewässer. Für das Grundwasser besteht diese aus einer erstmaligen Beschreibung, einer weitergehenden Beschreibung und der Prüfung der Auswirkungen menschlicher Tätigkeit auf das Grundwasser. Die Wasserrahmenrichtlinie wird unabhängig von administrativen Grenzen innerhalb von hydrologischen Einzugsgebieten umgesetzt. Im deutschen Teil des Flusseinzugsgebietes der Elbe wurden 5 Koordinierungsräume gegründet. Der Koordinierungsraum Mulde-Elbe-Schwarze Elster (MES) wird vorgestellt. Beispielhaft für die angewandten Methoden wird die Beurteilung diffuser Stoffeinträge in das Grundwasser bei der erstmaligen Beschreibung erläutert. Die Ergebnisse der Bestandsaufnahme Grundwasser im Koordinierungsraum MES werden präsentiert. Von 54 Grundwasserkörpern ist für 25 Körper aufgrund der Belastungen durch Punktquellen und diffuse Quellen, wegen des mengenmäßigen Zustands oder sonstiger anthropogener Einwirkungen die Zielerreichung nach der Wasserrahmenrichtlinie unklar/unwahrscheinlich.

---

Status review groundwater for the Water Framework Directive in the coordination zone Mulde-Elbe-Schwarze Elster

Abstract The Water Framework Directive (WFD) governs the protection of groundwater and surface water and promotes sustainable water use. It sets up a timetable to ensure that a good status of all waters will be achieved by 2015. The first step is a status review of the waters. For groundwater, this procedure is divided into an initial characterisation, a further characterisation and a review of the impacts of human activity on groundwater. The WFD is to be implemented independently of administrative boundaries within hydrological river basins. In the German part of the Elbe river basin district five coordination zones have been established. The Mulde-Elbe-Schwarze Elster (MES) coordination zone is introduced. As an example for the applied methods, the assessment of the pressures of groundwater by diffuse sources (initial characterisation) will be explained. Then the outcome of the status review groundwater in the coordination zone MES will be presented: From the 54 individual bodies of groundwater 25 bodies will probably not achieve the environmental objectives of the WFD because of the pressures point sources, diffuse sources, quantitative status or other anthropogenic impacts.

     

Economic impact of potential new industries in a four-state area

This note applies an input-output multiplier technique developed by Burford and Katz to analyzing the impact of potential high technology industries in a rural, four-state, thirteen county Midwestern region. By using the 1972 national input-output table coefficients and the Burford-Katz multiplier estimation formula, the estimated output impacts for fifty-one individual industries were calculated. The results indicate that within the four-state region, conventional industries would produce greater economic impacts than designated high-tech ones. This analysis could be performed rather easily for any other region in the U.S.     

Geotechnical Solutions for Construction of the “Business Center” in Moscow

An example of a complex geotechnical solution is cited for the construction of buildings housing the Business Center in Moscow, which includes the analysis, design, and construction of a trench enclosure for the building complex, including an architectural monument with an underground level, and a newly constructed building with from two to three underground levels, as well as the church of Saint Peter and Paul on Yauze, which abuts the buildings under construction.     

Regional labor force participation and the discouraged worker hypothesis: Some empirical evidence

The purpose of this paper is to clarify the economic determination of the regional labor supply. In explaining the regional level of labor force participation two models are compared: the unemployment model based on the discouraged worker hypothesis and the neoclassical model of labor force participation. It is shown that a migration model complements the neoclassical model and provides an alternative interpretation of the discouraged worker hypothesis, this reinterpretation provides an explanation for the failure of the unemployment model at the regional level when it is quite successful at the national level.     

Postflashover fires — an overview of the research at the national research council of Canada (NRCC), 1970–1985

The NRCC model of fully developed compartment fires is discussed. Although the mathematics involved is quite simple, it allows a rather comprehensive simulation of the fire process. The model offers an explanation for the findings that ventilation control is related to the pyrolysis mechanism and is not a result of scarcity of air in the fire compartment, and that thermal feedback is of secondary importance in the burning (pyrolysis) of cellulosic fuels. Another feature of the model is the introduction of the normalized heat load concept. The normalized heat load is a scalar quantity that depends on the total heat absorbed by the compartment boundaries during the fire incident, and is practically independent of the temperature history of the fire. A simple explicit formula has been proposed and proved experimentally to describe the normalized heat load for real-world fires with fair accuracy. The normalized heat load concept offers a simple means for converting fire severities into fire resistance requirements, and makes it possible to design buildings for prescribed levels of structural fire safety. The potential of fires to spread by convection and the expected characteristics of fires of noncharring plastics are also discussed. Reference: T. Z. Harmathy, Postflashover Fires—An Overview of the Research at the National Research Council of Canada (NRCC), 1970–1985,Fire Technology, Vol. 22, No. 3, August 1986, p. 210.     

New directions in migration research

This paper takes several surveys of the literature concerning migration research as its starting point and directs the reader toward a number of potentially fruitful lines for future research. Major sections include one on modeling migrant choice in which the pros and cons of using gross versus net migration measures are discussed. A second introduces and discusses the concept of a spatial choice set, which has the potential to be implemented with laboratory experimental techniques. The third involves a wide-ranging discussion of new directions in modeling the interrelationships between employment and migration.This paper was prepared in connection with the Western Regional Science Association's President's Panel, Molokai, Hawaii, February 1990.     

Prefailure of Rock Soils under Dynamic Loading

The effect of loading and unloading regimes on the threshold of the appearance and number of cracks, which precede their avalanche propagation that accompanies complete failure of the soil, is established. It is demonstrated that the appearance of pioneer cracks contributes to an increase in ultimate deformations of the soil, corresponding to its failure and energy consumption of the deformation process.     

Experimental infrared-radiometric investigations of stress variations on a borehole face in a model of the soil mass

A procedure for, and results of experimental investigations performed to substantiate the effectiveness of the method of infrared (IR) radiation in diagnosing changes in the stress state of soils over time are presented. The construction of a large-scale bench is described for the alternating loading of a relatively large (of the order of 0.35 m³) volume of soil. Variations in the stress state over time in the near-face zone of a borehole, which is arranged in a model of the soil mass, are recorded using synchronous recordings of signals from an IR radiometer and load-cell strain gages. The elastic nature of stress variations on the face of the borehole in an unsaturated sandy soil is revealed during alternating-sign stress variations at infinity. It is indicated that data derived from noncontact IR measurements will make it possible to record accurately moments of jumpwise stress variations in the soil mass, and evaluate their intensity.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 8–11, November–December, 2004.     

The effect of aggregation on the output multipliers in input-output models

This paper compares the output multipliers of the 1967 National input output model (367 industries) with the multipliers of the aggregated version (81 industries). The results show that, generally, the set of industries in the full model that were aggregated together for the reduced model, display a wide range of output multiplier values. Therefore, the output multiplier of an aggregated industry may not be truly representative of any of the industries that were joined together. Finally we show how information for a particular firm or disaggregated industry can be incorporated in an aggregated input-output model to obtain a close estimate of the actual output multiplier for that firm or industry.     

The impact of Alaskan oil development on the Washington-Alaska trade

Washington State serves as a marketing and transportation center for Alaska trade. This study estimates, via a Location Quotient Input-Output model for Alaska, the impact Alaskan oil development will have on various economic sectors in both states. A From-To table and the existing Washington Input-Output table quantified the impacts on Washington.The Alaska oil development impact will result in a tripling of the Alaskan economy's output from 1972 to 1980. The largest impact in Alaska will be on the Service, Finance, Agriculture, Trade, and State and Local Government sectors. The impact on Washington will be felt in sectors of Transportation, Finance, Trade, and Agriculture resulting in an aggregate increase in the Washington economy of 10.6 percent if 50 percent of Alaska's import requirements are provided by Washington, and 5.3 percent if the import movement is 25 percent.Work was done under Regional project 0191, An Economic Analysis of present and potencial Trade Between Alaska Washington.     

Ways to increase the economical effectiveness of foundations for agricultural buildings with three-hinged bents

Conclusions 1. The failure of a sandy foundation bed under a rigid embedded reinforced-concrete foundation (h/b0.5) with a flat, rough lower surface is three-dimensional in nature when the loads are inclined at =20–40° to the vertical.2. Plane shear is not observed when the load is inclined at an angle = and the eccentricity e0 ( is the angle of the soil's internal friction as determined on a shear apparatus in accordance with GOST 12248–66).3. The settlements and lateral displacements of an embedded foundation (h/b>0.5) in the limiting state are 2–3 times larger than those of the nonembedded foundation; lateral displacements exceed the limiting values established for farm buildings [2], or approach them.4. For angles =20–40°, eccentricity of the inclined load in the direction opposite to the horizontal component, but not less than r_C (r_C is the core radius of the section) effects an increase in the ultimate load as compared to a central positioning of the resultant. Additional experiments and theoretical studies are required to investigate the role of positive and negative eccentricity on the bearing capacity of the foundation bed.5. For loads inclined at angles =35–40° and a relative foundation embedment 0.5h/b1, computation in accordance with SNiP II-15-74 yields considerably lower bearing capacity than computation from experimental data.6. The studies that we conducted are used to develop a more economical method of computing and designing foundations for farm buildings under an inclined loading, which is employed in practice [2].B. E. Vedeneev All-Union Scientific-Research Institute of Hydraulic Engineering. Central Scientific-Research Institute of Experimental Design and Planning for Rural Construction. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 3–6, July–August, 1979.     

Feasibility of Face Surcharging during Deep Settlement-Free Tunneling in Dense Urban Settings

A procedure is proposed for the computational modeling of the driving of a deep tunnel by a tunnel-boring machine (TBM) with an active surcharge on the face, which is realized in the GEO-MIGG program. Basic factors affecting the stress-strain state (SSS) of the soil bed-TBM- buildings and structures of the urban setting system are demonstrated in a trial example. The feasibility of using the proposed procedure is confirmed by comparing results of computational modeling of a practical example of tunneling for the third transportation beltway around Moscow in the area of Lefortovo using a TBM manufactured by the German firm Herrenknecht with data derived from field observations.     

Aquatische Kolloide I: Eine Übersichtsarbeit zur Definition, zu Systemen und zur Relevanz

Kurzfassung Kolloide sind Bestandteile aller aquatischen Systeme. Sie umfassen Feststoffe, deren Größe in zumindest einer Dimension zwischen 1 und 1.000 nm liegt. Sie können anorganischer (z. B. Tonteilchen, Karbonate oder Silikate) oder organischer (z. B. Ruß oder höhermolekulare organische Verbindungen wie Huminstoffe) Natur sein. Auch Bakterien, Viren, Sporen und Algen in diesem Größenbereich können zu den Kolloiden gerechnet werden (häufig als Bio-Kolloide bezeichnet). Kolloide können den Transport von (Schad-)stoffen im Untergrund und in Oberflächengewässern beeinflussen, insbesondere von Spurenelementen und hydrophoben organischen Verbindungen, oder zu unerwünschten Effekten wie Porenraumreduktion (Clogging) führen. Für die Hygiene des Trinkwassers ist das Verhalten von Bakterien, Viren und Sporen (den Bio-Kolloiden) von besonderer Bedeutung. Bisher ist das Verhalten von Kolloiden nur unzureichend verstanden. Dieser Artikel soll einen Beitrag zu dem Verständnis des physikalischen Verhaltens der Kolloide, deren Vorkommen in der aquatischen Umwelt sowie Relevanz in Form einer Übersichtsarbeit leisten.

---

Aquatic Colloids: Definition and Relevance—a Review

Abstract Colloids are abundant in all natural aquatic environments. The size of colloids ranges between 1 and 1,000 nm, at least in one dimension. They can consist of inorganic material (e. g. clay, carbonates, silicates), organic material (e. g. soot or high-molecular-mass organic carbon), and bio-colloids (e. g. bacteria, viruses, spores, algae). Colloids may influence the transport and fate of contaminants, especially trace elements and hydrophobic organic substances. They may also cause a pore space reduction. In particular, drinking water quality can be adversely affected by the transport and relocation of bio-colloids; however, the behaviour of colloids is not fully understood. The aim of this paper is to contribute to the understanding of the physical properties of colloids, their occurrence in natural aquatic systems, and their relevance.

     

Intermediate goods and the location of productive activity

This paper assesses the impact of the production and use of an intermediate good upon the location of productive activity in an economy consisting of two asymmetrically sized regions. The Nash equilibria of locations of an upstream and two downstream firms are completely defined in the the space of parameters transport cost and intensity of vertical linkages. While the relationship between transport cost and agglomeration is usually regarded as a decreasing one, the inclusion of an intermediate good can make it nonmonotonic.Received: September 2003/Accepted:01 March 2004The author wishes to thank the Editor of The Annals of Regional Science and three anonymous referees for helpful comments. The usual disclaimer applies.