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This paper begins with a historical review of the 1918 influenza pandemic as it affected military populations and operations. Our review then serves as a point of departure for the analytical reconstruction of certain influenza epidemics in stateside training camps and overseas units of the American Expeditionary Forces (AEF) in World War I. The main quantitative thrusts are to (a) derive time-varying rates of influenza transmission in unstructured and structured historical military populations and (b) assess potential natural or unnatural influenza effects on modern military populations. The explosiveness and severity of 1918 influenza epidemics in military populations obstructed the implementation of even rudimentary medical countermeasures (patient isolation, supportive care and quarantine). Neither a vaccine nor drugs were available then to prevent influenza, alter its natural course and deal with sequelae., The original document contains color images.

This investigation focuses on the spread of a contagious disease subsequent to the military employment of a biological weapon or an act of bioterrorism. Of particular interest are expected or average time histories of four cohorts: (I) Susceptible individuals; (2) Exposed and infected (incubating) individuals; (3) Infectious (contagious) individuals and (4) Removed (noncontagious, alive, or dead) individuals. The objective SEIR curves characterize health care and mortuary service needs as functions of time for a known disease, for given initial conditions, and for an average time-varying rate of disease transmission. Such a disease transmission rate is a key predictive tool, and it is obtainable from a Monte Carlo analysis of historical outbreak data. Recently published epidemiological data for the 1995 Ebola hemorrhagic fever outbreak in Kikwit, Democratic Republic of the Congo, serves as an excellent vehicle to demonstrate the overall semi-empirical SEIR model.

This report discusses technical progress made under the Tactical Environment Multiple Systems Evaluation Program (TEMSEP). The long and short range goals of the program are presented with particular emphasis on the topics of instrumentation in an ionizing radiation environment, basic phenomena associated with the electromagnetic pulse (EMP) generation within the nuclear source region, and laboratory simulation of the electromagnetic environment associated with the nearby (endoatmospheric) detonation of a nuclear weapon. Experiments used the AURORA Flash X-Ray Facility as a radiation source. Notable milestones accomplished were the experimental verification of the existence of the boundary layer phenomenon and verification of electromagnetic coupling models for simple structures.

Electromagnetic effects on ground-based military systems involved in tactical nuclear warfare will be engendered by ionizing radiation, a current density of Compton-recoil electrons in the air, and a nonlinear air conductivity. Many of these systems contain conducting enclosures of one form or another that may house susceptible electronic subsystems. Consequently, the electromagnetic responses of such enclosures to tactical nuclear threats could be significant in vulnerability assessments of critical equipment. The objective of the work discussed in this report was to develop physical intuition and analytical approximations that would be useful in these assessments. Emphasis is placed on the analytical description of the salient physical phenomena that may dominate the electromagnetic response of an ideal gamma-thin obstacle subjected to a tactical nuclear threat. The charge and current on a gamma-thin conducting sphere over a ground plane were determined via the following analyses: (a) an early-time analysis wherein the ground plane is ignored and the transient air conductivity is replaced by an average value over an interval, and (b) a late-time analysis wherein the ground plane is accounted for and conduction current is assumed to dominate displacement current in the air. In both analyses, the Compton-current density and the transient air conductivity were taken to be independent of the obstacle.

In studies related to protection against the Electromagnetic Pulse (EMP) resulting from nuclear explosions, electromagnetic shielding theory is applied to military electrical systems. Many complex boundary value problems must be solved in order to estimate the EMP effects on such a system. The complexity of these 'real world' problems is such that rigor must be sacrificed for engineering judgment if any estimates of EMP effects are to be obtained in a reasonable time frame. For instance, apertures that appear in equipment enclosures, cabinets, missiles, etc., are examples of such 'real world' problems. Transmission through circular apertures in long hollow cylindrical enclosures is frequently of interest in dealing with such systems. We consider the determination of interior fields for a hollow cylinder of infinite length with a circular aperture, which is uniformly immersed in a time varying axial magnetic field. (Author)

The authors present the formal derivation of two sets of pairs of coupled integral equations. These arise in the scattering of an incident plane wave by a perfectly conducting sphere with an annular slot defined by means of two angles. The incident radiation is assumed for simplicity to be along the symmetry axis of the slotted sphere. Simple but quite remarkable relations between the sets of coupled equations are indicated. The formal solution for the complementary geometry-namely the perfectly conducting spherical ribbon is also presented. (Author)