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As the number, severity, and frequency of events for which evacuations are viewed as a protective action continue to evolve and increase, there is a need to explore new methods and techniques to increase the effectiveness of mass population movements. This paper summarizes a recent United States Department of Transportation research study to evaluate the application of emerging advanced traffic communication technologies to facilitate evacuations. Specifically, the project involved the examined risk reduction impacts of EVAC, which is an application of the Response, Emergency Staging and Communications, Uniform Management, and Evacuation (R.E.S.C.U.M.E.) bundle based on connected-vehicle technology. Using a simulation model of the Greater New Orleans region to represent the mass evacuation that occurred during Hurricane Katrina, the analysis assessed EVAC using seven simulation scenarios including one baseline scenario and six strategy scenarios in which an EVAC functionality or a combination of functionalities were modeled. Each scenario was evaluated with three levels of EVAC penetration and compliance rates. The strategy scenarios were compared to the baseline scenario to determine the risk-reduction benefit of the applied EVAC functionality. Based on the results of the modeling efforts, the EVAC functionalities that were evaluated showed positive impacts for several key aspects of hurricane evacuation including congestion reduction, improved mobility, and shorter travel times to resources.

Field pupal weight, development time, and survival of gypsy moth, Lymantria dispar (L.), larvae on three defoliated (50%) and undefoliated tree species that are common to the forest of the Great Lakes basin were compared for one season in 1988. Host species and defoliation affected female pupal weight; male pupal weight was affected only by host species. The smallest and largest pupae of both sexes, from both defoliated and undefoliated trees, came from larvae that fed on red oak, Quercus rubra L., and trembling aspen, Populus tremuloides Michx., respectively; pupal weight of larvae that fed on white birch, Betula papyrifera Marsh., were intermediate. Development time was affected only by tree species; the shortest and longest development occurred on trembling aspen and red oak, respectively; development time on white birch was medial. Gypsy moth survival was not affected by defoliation or host species. Superficially, these data obviously suggest that both defoliated and undefoliated trembling aspen and white birch are more nutritious, and will support higher gypsy moth fitness than its traditional hosts like red oak. However, we argue that outbreaks of gypsy moth will not occur in aspen and birch stands because its tri-trophic fitness is lower there due in part to the higher efficacy of certain gypsy moth natural enemies. We hypothesize that outbreaks on these two tree species will be limited by the nuclear polyhedrosis virus, Entomophagus maimaiga, and key physical features (e.g. light trunk color) of the host that deter larval host-seeking/accepting behavior. More than 20 years of gypsy moth outbreak records in North America support this hypothesis.

This paper examines the impact of a regional simulation model on estimating vehicle emissions. The TRANSIMS software was used to simulate traffic for the Portland, Oregon, metropolitan area. Network and trip table data from the Portland METRO regional model were converted to TRANSIMS and calibrated against traffic counts. The TRANSIMS microsimulator was then used to generate detailed speed and volume information for 30-m link segments at 15-min intervals throughout the day. Second-by-second vehicle speeds were summarized with six speed bins (0, 16.8, 33.5, 50.3, 67.1, and 83.8 mph). The detailed simulation results were aggregated in various ways to produce the input data required by the MOBILE6 emission inventory software. MOBILE6 was also applied with specific parameters to test the impacts of various assumptions with regard to analysis year, seasons, vehicle types, facility types, and inspection and maintenance programs. The total emissions from each aggregation method were compared with the emissions estimated with the use of MOBILE6 with METRO's EMME/2 volumes and speeds. The analysis indicates that the emission estimates generated with simulation data are significantly different from the emission estimates produced by traditional modeling techniques. If simulation data are aggregated to levels that are more consistent with traditional regional outputs, the magnitude of the difference is minimized. In general, using the more detailed information produced by TRANSIMS or other simulation models will result in higher emissions than are currently estimated by using aggregate methods.

By means of high-resolution transmission electron microscopy and electron diffraction we show that samples of Bi-2212 high-temperature superconductors which exhibit the Wohlleben effect have an extremely polydomain microstructure on a μm length scale. In directions perpendicular to the c-axis small crystallites are separated by well-defined atomically sharp (1 nm) interfaces which provide good contacts between the domains in the ab-planes. The observed microstructure strongly favors the explanation of the Wohlleben effect due to spontaneous currents flowing in the closed paths between differently oriented unconventional (d-wave) superconductors.

Results obtained by high resolution EDX measurements which demonstrate that polycrystalline samples of the LaSrCuO-system prepared by means of a refined wet-chemical preparation method exhibit a much better homogeneity of the cation distribution than samples prepared by standard ceramic routes. Other characteristic properties like FC flux expulsion, phase purity and behaviour of resistivity are at least preserved. The proposed wet-chemical method is similar to several spray-drying techniques described in the literature but easier to handle and optimized for LSCO.

We report on the observation of the Wohlleben effect (WE) in powders of Bi-based high-temperature superconductors consisting of isolated grains with sizes of order 1 mu m In these small grains the Josephson contacts with negative critical current (pi-junctions) generally involved to explain the WE must be able to carry a current density of order j approximate to 10(5)-10(6) A/cm(2) even close to T-c. Such high spontaneous currents can be explained, if such contacts are not ordinary tunneling Josephson junctions but superconductor-normal-metal-superconductor junctions and if the superconducting order parameter has d-wave symmetry.

If travel time and speed are to be used as critical performance measures in congestion management systems and air quality analysis procedures, existing modeling techniques will need to be enhanced. Many of the simplifying assumptions that are built into traditional modeling techniques are described. Several relatively simple enhancements to existing models that can greatly improve the model's ability to estimate travel time and speeds are identified, and more advanced methods that could be considered as part of major model redevelopment efforts or detailed air quality studies are suggested. One of these methods involves simulation techniques. The problems and issues of integrating simulation models with travel demand forecasting techniques are outlined, and it is concluded that modeling speed is considerably more difficult than modeling volumes. The bottom-line criterion for any model enhancement is that the procedure supports decision makers in a timely and cost-effective way. This criterion is likely to limit the types of enhancements that are possible.

Single crystals of Pb2Sr2(Y1-xCax)Cu3O8+δ have been grown from PbO-NaCl and PbO-KCl flux. Different temperature runs were performed to optimize the growth. A temperature gradient in the crucible is necessary to get crystals of Pb2Sr2(Y1-xCax)Cu3O8+δ with reproducible sizes of more than 2X2X1 mm3. Crystal growth in air yields a lot of large crystals but with broad transitions in magnetic susceptibility. The best results were obtained in an atmosphere of 3% O2 in N2. The crystals can be extracted from the flux very effectively by a solution of acetic acid in methanol. Neutron diffraction experiments confirm a low mosaicity and well defined lattice constants. High resolution energy dispersive X-ray (EDX) measurements show a very good homogeneity of the cations with a lateral resolution of 15 nm to 1 μm. The Y-to-Ca ratio has a stable value of 2:1. In high resolution transmission electron microscopy no crystal defects could be detected.

A study of the structural and electronic phase diagram of Pr-doped ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_{4}$ is presented in order to investigate whether there is an influence of the high-temperature tetragonal-to-orthorhombic phase transition on the disappearance of superconductivity in the overdoped region. We find that Pr doping shifts the structural phase boundary to higher Sr concentrations, but that superconductivity occurs in the same Sr-concentration range as in ``pure'' ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_{4}$. Thus, the disappearance of superconductivity is not related to the high-temperature structural transition, but is determined predominantly by the hole concentration in the CuO planes.

We have studied the low-field Meissner effect of polycrystalline Bi high-temperature superconductors using a special superconducting-quantum-interference-device magnetometer. In certain samples a surprising feature was observed: Instead of the usual diamagnetic moment a paramagnetic moment develops in the field cooling mode below ${\mathit{T}}_{\mathit{c}}$ for fields H1 Oe. The data are consistent with orbital paramagnetic moments due to spontaneous currents. Such currents may originate in so-called \ensuremath{\pi} contacts in the weak-link network of polycrystalline material. In some of these samples also an anomaly in the low-field microwave absorption was observed, which is obviously correlated with the existence of spontaneous currents.

Based on laboratory observations and experiments, a larval behavior of gypsy moth, Lymantria dispar (L.), is documented that is used for climbing on a smooth vertical surface. Larvae on surfaces that do not provide structures that can be grasped by the crochets are able to climb vertically by spinning a “ladder of silk.” This use of silk apparently occurs more frequently in laboratory populations that are less fit (as measured by head capsule size, reduced pupal weight, and increased development time). It is suggested that the use of silk for climbing in the field may be associated with decreased larval fitness as a result of wound-induced plant defences.

We report on the systhesis of (La,RE) 2- x Sr x CuO 4 for various RE=Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er as a function of the RE and Sr concentrations. The sample characterization by means of powder X-ray diffraction and EDX is described. We present our results on the solubility limit of the various RE in the T structure of La 2- x Sr x CuO 4 and discuss the systematic influence of RE and Sr doping on the structural properties. We furthermore show that doping with RE does not influence the charge carrier concentration of the samples.

In caged choice experiments, Lymantria dispar (L.) larvae strongly preferred Acer saccharum Marsh. and Fraxinus pennsylvanica Marsh. trunks (44.3 and 43.3% of larvae, respectively) to Betula papyrifera Marsh. trunks (5.7%). When larvae were allowed to choose among the foliage of live seedlings of the same species, they preferred B. papyrifera (71.0%) over A. saccharum (14.3%) and F. pennsylvanica (0.7%). Trunk sections of A. saccharum and B. papyrifera were wrapped around live seedlings of the same trees and F. pennsylvanica in six possible combinations of trunk and foliage species to evaluate the impact of trunk characteristics on host selection in the presence of foliage. The most preferred trunk-foliage combinations, in descending order of percentage larvae found on each, were as follows: A. saccharum-B. papyrifera (41.0%), B. papyrifera-B. papyrifera (19.0%), A. saccharum-A. saccharum (14.8%), B. papyrifera-A. saccharum (12.2%), A. saccharum-F. pennsylvanica (2.2%), and B. papyrifera-F. pennsylvanica (1.0%). Both trunk species and foliage species Significantly influenced larval choice. The effect of tree canopy size, as measured by leaf surface area, on the distribution of larvae was measured in a forest clearing where five replications of 17 tree species and cultivars were planted. The tree species ranged from highly susceptible ( Malus sp.) to highly resistant ( Gleditsia triacanthos L.). The number of larvae per tree was explained well by the size of the leaf canopy for the six most preferred tree species and cultivars. This relationship did not exist for the remaining 11 species and cultivars of less preferred trees. Apparently, the size of preferred trees influences the distribution of gypsy moth larvae among them.

We report the temperature and field dependence of the DC Meissner effect of sintered pellets of YBa 2 ( Cu 1− x Fe x ) 3 O 7− y with 0⪕ x ⪕0.08. In all samples the spontaneous flux expulsion remains incomplete ( −4πχ≈ 1 3 ) down to fields, which are much smaller than H cl , but at H ⪕ H m ≈2 Oe, they all exhibit a full Meissner effect and are therefore fully superconducting. The expulsion in 2 Oe decreases to near 30% by aging of the defect surfaces and goes back to near 100% after their reoxidation, all at a fixed and sharp T c of 93 K. The data are interpreted in terms of equilibrium properties of granular high temperature superconductors on the basis of an analysis worked out in the next paper [1]. From the temperature and field dependence of the spontaneous flux expulsion, an average cross-section of 4μm 2 is extracted for the superconducting blocks bordered by defect surfaces within the much larger grains. The superconducting loops around these surfaces are responsible for the final flux expulsion in H T c ⪕1 K in the orthorhombic phase ( x ⪕0.02). In the quasitetragonal phase, Δ T c increases from 1 to 16 K for 0.02 x ⪕0.08.

We identify the preparation procedures to obtain polycrystalline pellets of Bi-2212 and of Bi-2223 high-temperature superconductors, which slow only the superconducting properties and the X-ray diffraction pattern of one or the other phase (“single-phase” pellets). These procedures were found by systematic variation of the preparation, with substitution of PbO for Bi2O3 as well as with addition of PbO to the stoichiometric mixture of starting powders. Bi-2223 in single-phase form has a TZR of 107.5 ± 0.5 K, whereas single-phase pellets of “Bi-2212” can have sharp transitions with TZR's between 55–95 K, depending on the oxygen partial pressure of the atmosphere in the final annealing step.

DNA markers were identified for the molecular detection of the Asian long-horned beetle (ALB), Anoplophora glabripennis (Mot.), based on sequence characterized amplified regions (SCARs) derived from random amplified polymorphic DNA (RAPD) fragments. A 2,740-bp DNA fragment that was present only in ALB and not in other Cerambycids was identified after screening 230 random primers in a PCR-based assay system. Three pairs of nested 22-mer oligonucleotide primers were designed on the basis of the sequence of this fragment and were used to perform diagnostic PCR. The first pair of primers (SCAR1) amplified a single 745-bp fragment of ALB DNA, but this did not differentiate ALB from other species. The other two pairs of SCAR primers (SCAR2 and SCAR3) amplified bands of 1,237- and 2,720-bp, respectively, that were capable of differentiating ALB from other closely related non-native and native Cerambycids, such as A. chinensis (Forster), A. malasiaca (Thomson), A. nobilis (Ganglbauer), Monochamus scutellatus (Say), Plectrodera scalator (Fab), Saperda tridentata (Olivier), and Graphisurus fasciatus (Degeer). The latter two SCAR markers could be amplified using DNA extracted from body parts of ALB such as the wing, the leg, and the antennae as well as tissues from all the developmental stages including the egg, larva, pupa, and adult. These markers were also capable of identifying ALB using the DNA extracted from frass. Our results demonstrate that the SCAR markers we have identified can be used for unambiguously identifying ALB from other closely related Cerambycids using a simple PCR procedure.

Survival, development time, and pupal weights of larvae were determined for gypsy moth reared on foliage of red oak, sugar maple, white birch, trembling aspen, white spruce, black spruce, jack pine, and balsam fir. Mortality was >50% on sugar maple and balsam fir, 35% on jack pine, and ≤15% on the other species. Female larvae developed significantly faster on trembling aspen foliage (29 days at 21°C) than on that of other species. Larvae reared on foliage of trembling aspen, white birch, or a mixture of foliage of either species and that of other species produced larger pupae than did other foliage combinations. North. J. Appl. For. 8(3):126-128.

The role of p21c-ras in the activation of DNA synthesis in quiescent Swiss 3T3 fibroblasts was examined by scrape loading or microinjecting the neutralizing monoclonal antibody Y13-259 into the cells. Y13-259 delayed but did not block both the serum-stimulated entry of the cells into S phase and the accumulation of cdc2 mRNA and protein at the G1-S boundary. Introduction of Y13-259 also stimulated expression of sufficient p21c-ras to neutralize the loaded antibody; this finding suggests that the delay of S phase is attributable to the time taken to synthesize an excess of p21c-ras over the antibody and implies autoregulation of c-ras expression. Y13-259 had no effect upon phosphoinositide-mediated responses ([Ca2+]i increase and activation of protein kinase C) to platelet-derived growth factor or bombesin, demonstrating that p21c-ras is not required for mitogen activation of protein kinase C. Y13-259 inhibited 5-bromo-2'-deoxyuridine incorporation in response to all of the combinations of mitogens used to stimulate quiescent cells (fetal calf serum, platelet-derived growth factor, and the combination of insulin with 12-O-tetradecanoylphorbol-13-acetate, bombesin, epidermal growth factor, or prostaglandin E1), indicating that p21c-ras functions on pathways common to all of the effective combinations of mitogens examined.

For certain ceramic samples of the Bi-based high-temperture superconductors, the dc-field-cooling signal becomes paramagnetic in fields below a few 100 mOe. This effect correlates with an anomaly in the low-field microwave absorption. The data are consistent with orbital paramagnetic moments due to the appearance of spontaneous supercurrents in fields smaller than the lower critical field ${\mathit{H}}_{\mathit{c}1\mathit{a}}$ parallel to the CuO planes.

2090 Background: GEM and DOC have demonstrated single-agent antitumor activity against a variety of malignancies. Pharmacological studies of GEM have demonstrated that the intracellular concentration of its active triphosphate metabolite is maximized at a dose rate of approximately 10 mg/m2/minute. The major purposes of this study were to determine the maximally tolerated dose (MTD), dose-limiting toxicity (DLT), and toxicity profile for GEM and DOC when administered to patients with advanced solid tumors on a weekly schedule. Methods: Both GEM and DOC were administered on days 1 and 8 of each 21-day course, with GEM administered at a rate of 10 mg/m2/minute and DOC over 60 minutes (after GEM). The initial dose levels were 600 mg/m2 and 25 mg/m2 for GEM and DOC, respectively. Results: Eight patients (5 men, 3 women, median age 60 years old) with advanced solid tumors have been treated with 25+ courses at 2 dose levels. Three patients were treated at dose-level 1 without DLT. Five patients have now been tr...

A phase diagram of Pr-doped La 2-x Sr x CuO 4 including structural and superconducting properties is presented. We find that Pr-doping shifts the phase boundary of the high temperature tetragonal to orthorhombic phase transition to higher Sr-concentrations without inducing the low temperature structural phase transition as other RE do. As superconductivity occurs in the same Sr-concentration range as in “pure” La 2-x Sr x CuO 4 (LSCO), the disappearance of superconductivity is not related to the high temperature structural transition, but is determined predominantly by the hole-concentration in the CuO-planes. The decrease of T c of ≈ 5–10 K in the Pr-doped samples with respect to the undoped ones can mainly be attributed to the increase of the octahedra tilting angle.

Single crystals of Pb 2 Sr 2 (Y 1−x Ca x )Cu 3 O 8+ δ (PSYCCO) have been grown from PbO KCl flux in an atmosphere of 3% O 2 in N 2 . A temperature gradient in the crucible is necessary to get crystals of PSYCCO with reproducible sizes of more than 2 × 2 × 1 mm 3 . Neutron diffraction experiments, high resolution EDX and high resolution transmission electron microscopy confirm a low mosaicity without any crystal defects, well defined lattice constants and a good cation homogeneity.

For certain polycrystalline Bi-HTSC samples, a surprising feature was observed: instead of the usual diamagnetic response of the dc field-cooling (FC) signal, a paramagnetic moment develops below Tc for fields < 1 Oe. This effect correlates with an anomaly in the low-field microwave absorption. The data are consistent with spontaneous paramagnetic moments due to spontaneous orbital supercurrents. Such currents may originate in so called π-contacts in the weak link network of polycrystalline material.

The complete series of solid solutions Ce (Rh x Pt 1−x ) 2 (0 ≤ × ≤ 1) present a single cubic phase C15. The magnetic susceptibility and lattice parameters were measured, showing a big change in the temperature dependence of the susceptibility, which is explained as a change in the valence of the Ce ions, from 3+ (CePt 2 ) to 3.5+ (CeRh 2 ). This is supported by the lattice parameter study, which shows a non-linear relationship of the lattice parameter with the concentration x. We compare our results with previous works, and we also found a T 2 dependence for the susceptibility in the low temperature region for the compounds presenting intermediate valence. This can be explained in the light of the Fermi liquid theory.

The magnetic susceptibility of some Ce intermetallic compounds was measured up to 1200 K. Using the susceptibility and the valence from L III -X-ray absorption we calculate the fluctuation temperatures. For α-type Ce compounds we separate the volume anomaly into one part due to fractional valence and a rest which we find to scale with the fluctuation temperature.

Specific heat, field cooling Meissner effect, isothermal magnetization, AC susceptibility and resistance were measured on sintered pellets of the Bi and Tl high temperature superconductors with nominal compositions BiPb 0.3 SrCaCu 2 O 5.8 and Tl 2 Ba 2 CaCu 2 O 8 , and for comparison on some pellets of the REBa 2 Cu 3 O 6.9 system. With decreasing field, the field cooling Meissner signals of the Bi and Tl systems approach the same magnitude and transition width (Δ T ≈ 2–3 K) as in high quality pellets of the REBa 2 Cu 3 O 6.9 . The field and temperature dependence of the Meissner signals is analysed in detail. At the transition temperatures of five superconducting phases of the Bi and Tl pellets, the specific heat shows no jumps nor maxima, within the accuracy of the measurement (Δ( C/T ) 2 )). There are however sharp breaks of the slope of C/T at the T c values, which are intrinsically as large as in the REBa 2 Cu 3 O 6.9 . The transitions in the Bi and Tl systems look more like third order transitions rather than like the second order transitions of the REBa 2 Cu 3 O 6.9 .

We have measured the static magnetic susceptibility of CePb3 and LaPb3 between 0.5 and 1,000 K and 1.5 and 900 K, respectively and the specific heat of CePb3 between 1.5 and 40 K. The data show clearly an antiferromagnetic phase transition at 1.25 K. The order occurs in a doublet 4f groundstate whose entropy is removed only partially by long range order. There are strong indications for quadrupole-quadrupole interactions enhancing the ordering energy over that from spin spin interactions alone. The CEF splittings seem to depend on temperature. The 4f-instability in CePb3 is quite weak.

We report the measurement of the dynamic magnetic susceptibility of an intermediate-valence Eu compound in inelastic neutron scattering experiments, namely, on a sample of EuPd 2 Si 2 with enriched 153 Eu. The most remarkable feature is an increase of the quasielastic linewidth with decreasing temperature, which is apparently a consequence of the well-known temperature-driven valence change. Moreover, at low temperatures a strong inelastic line is observed, which is interpreted as a multiplet transition within the Eu 3+ configuration (J=0→J=1). To check the quality of the sample, additional Mossbauer and magnetization measurements were performed. From these we conclude a fraction of approximately 6% of the so-called "satellite" phase in our sample, which is ferromagnetic at low temperatures and whose effects can be separated consistently out of all of our data.

The pressure dependence of the susceptibility was measured up to 1.2 GPa at room temperature for the compounds YbAlCu, YbCu 2 Si 2 , YbInAu, YbNi 2 Ge 2 , YbInAu 2 and YbInPd. dln χ/d p shows a maximum at valence 2.5. Isobanic susceptibility curves are presented for YbInAu 2 and YbInPd at 1.2 GPa between 300 and 4 K and for YbInPd and YbInAu at atmospheric pressure below 1100 and 300 K respectively. Pressure shift the susceptibility maximum to lower temperatures.

The superconducting transition temperature of crystalline and amorphous cadmium doped with dilute Mn atoms was measured. In the first case the initial depression ofT c as function of concentration isdT c /dc=5.4 K/at % and in the second casedT c /dc=2.65 K/at %. Both systems show non linear behavior at higher concentrations, the one in the crystalline state much more than the one in the amorphous state. While the curve in the amorphous state fits the Abrikosov-Gor'kov theory to the experimental limit of 70 mK, i.e., to within 3% of the critical concentration, the curve in the crystalline state does not, but is interpretable with the Muller-Hartmann-Zittartz theory with a Kondo temperature of10 −6 K.

Measurements of specific heat (1.4–350 K), thermopower and thermal conducctivity (1.5–300 K), electrical resistivity (40 mK–300 K) and of the magnetic susceptibility (40 mK–300 K) on polycrystalline samples of CeInAu, CeInAu2 and of the reference compounds LaInAu and LuInAu2 are reported. The properties of the Ce-compounds are unusual due to phase transitions (magnetic ordering, martensitic) and crystalline electric field effects. There are only weak indications of a valence instability.

We have measured the specific heat, the electrical resistance and the magnetic susceptibility of YBa2Cu3O7−x in a superconducting (sc) and in a non-superconducting (nsc) version. The latter was obtained by inducing a small loss of oxygen. In the sc sample we find a jump of the specific heat with ΔC=3.6 J mole−1 K−1. Below the maximum nearTc the specific heat of the sc version drops too fast for an electronic effect alone: there is a cross-over from excess to deficiency already at 0.9Tc. The specific heat of the nsc version shows a change of slope in the temperature range between 70 and 80 K, which indicates the existence of a second specific heat anomaly, which apparently exists independently of that due to the onset of superconductivity and explains at least partially the premature crossover.

T NHE following reflections are based upon the assumption that the Graduate Library School of the University of Chicago was brought into existence in response to a mandate, in part expressed but in much larger part implied, and that behind this mandate there lay a succession of events and developments which slowly but surely induced a frame or state of mind among librarians, and especially among public librarians, a sort of inward and spiritual state -not of grace but rather the opposite-of which the school is, for better or worse, the outward and visible form. The story of its corporate beginnings is familiar enough and has been duly recorded. The proximate steps which led the Carnegie Corporation out of its bounty to allocate a generous fund for the endowment of a "new type" of library school are less familiar and perhaps of enough interest and pertinence to be briefly reviewed. But, more remotely, it is germane to these reflections to point out that the state of mind above referred to was a gradual growth, having its roots somewhere within that period in library history that began with the organization of the American Library Association in 1876 and ended with the establishment of the Graduate Library School in I926, thrusting upward its first tentative and sporadic shoots somewhere toward the end of the period. Incidentally, it is of interest to note that this period embraced exactly fifty years and so qualifies, chronologically, as an era. Specifically, it was the romantic era in American librarianship. These fifty years merit much more attention than they have hitherto received-far more than the preceding twenty-five that some of our inquiring juniors have been exploring for the vestiges of a library philosophy in the deposits of muddy idealism, out of which the public library was raised before a bewildered generation. It was in the halfcentury forward from I876 that the American public library attained its maturity and set its feet definitely upon the path it has since followed-not the straight and narrow path marked out for it by the founders, but a much pleasanter road with picturesque windings and distracting detours and a much less definite end. It was an interesting

Experiments with vertical arrays of seismometers were conducted from 1963 to 1965. Data of exceptionally high quality were obtained through the use of special 1‐cps, deep‐well seismometers and direct digital recording techniques. Arrays studied experimentally contained up to 7 vertical‐component seismometers and extended to depths as great as 3.1 km. P‐wave signals observed at depth are generally distorted because of interference between incident and surface‐reflected waves. It is shown that the outputs of two or more deep‐well instruments can be combined to reconstruct signal waveforms. Small additional improvements were obtained through the application of optimum multichannel filtering to vertical array outputs, but the best signal‐to‐noise ratios obtained were never more than 6 db above those available from single deep‐well seismometers located at points of constructive signal interference. Results obtained from analysis of experimental data support the hypothesis that severe attenuation of seismic noise with depth is a characteristic only of sites where ambient noise is very intense at the surface. It is concluded that improvements in record quality which can be obtained through the application of vertical array processing at noisy sites are probably not greater than the improvements which would result from careful selection of a quiet site.

Summary. Theoretical calculations have been made for the idealized case in which an ocean is approximated by an infinitely long rectangular conducting sheet. The results indicate that even in the case of magnetic variations with periods as long as 24 hr one should expect a significant and easily observable enhancement in the vicinity of the edge of an ocean. When the inducing field is a function of local time only, it is found that the amplification of the variations is greater at the eastern edge of the ocean than at the western edge. Laboratory model studies have been used to investigate the effect of irregularities in the shape of a coastline. Results which have been obtained from a model of the Pacific Ocean in the neighbourhood of Japan indicate that it is reasonable to attribute at least a part of the anomalous diurnal variations observed in central Japan to electric currents induced in the ocean.

Summary The work of Bullard (1950) and Rochester (1960) on the geomagnetic westward drift and its effects on the Earth’s rotation is extended to investigate the effects of assuming various distributions of electrical conductivity in the mantle. By a proper choice of conductivities, one is able to increase the theoretical value for the tightness of the coupling by a factor of at least six over that afforded by Rochester’s model, without sacrificing agreement with observations on the rapidity with which changes in the secular variation are established at the Earth’s surface. It is shown that it is reasonable to attribute the observed random changes in the length of the day to perturbations in the electromagnetic coupling. I. Introduction . The most significant hypotheses brought forward to date for the explanation of the existence and maintenance of the terrestrial magnetic field have been reviewed by Jacobs (1956). Of these, only the electromagnetic dynamo theory is able to stand in the light of present information. Elsasser (1956) has reviewed the models suggested for a dynamo mechanism in the core capable of maintaining the dipole part of the field. The analytical details of dynamo operation in the core are irrelevant to the theoretical development in this paper. We need only assume, as did Rochester (1960), that toroidal fields of the correct character are produced in the deep interior and manifest themselves at the core boundary. Convective motion (more or less radial) in the fluid core is fundamental to the maintenance of dynamo action in all current theories. Where the velocity of the convective motion possesses a radial component, conservation of angular momentum requires that the inner fluid core rotate more rapidly than the outer layers. Evidence for this differential rate of rotation is given by observation of a westward drift of the non-dipole part of the field and of the centres of secular change (Bullard & others 1950). Since the high electrical conductivity of the core requires that the magnetic field lines be forced to move bodily with the fluid, the average value of the geomagnetic westward drift can be interpreted as the rate of rotation of the outer layers of the fluid core relative to an observer stationed on the mantle. The non-uniform rotation, together with the high electrical conductivity of the core, leads to the conclusion that a large toroidal field must be induced at the core boundary from the poloidal fields observed at the Earth’s surface. The toroidal fields leak into the conducting part of the mantle, vanishing at the boundary between the conducting and insulating parfs. The existence of a 361

A model of teleseismic signal and surface‐mode noise is derived from wave‐propagation theory. Optimum Wiener multichannel frequency domain filters are designed to operate on the outputs of six seismometer arrays so as to pass signals and reject noise. The arrays studied include two 19‐element surface arrays, two 19‐element shallow‐buried arrays and two 6‐element vertical arrays where a 20‐db reduction in spatially uncorrelated noise is assumed to result from seismometer burial. It is found that there is very little difference among the outputs of the filter systems designed for the two surface arrays and the two vertical arrays. The performance of the systems designed for the shallow‐buried arrays found to be considerably better. For one particular array, the predicted signal‐to‐noise improvement resulting from the assumed effect of shallow burial varies from 5 to 15 db. The theoretical results are sensitive to the amount of uncorrelated noise assumed in the model. However, when the levels of incoherent noise are equal, it appears that a surface array will generally possess greater capability for rejection of coherent noise than will a vertical array with the same size and number of receivers. The performance of an array of either type appears to be quite insensitive to changes of geometry if the number of receivers and the maximum dimension are not changed very much. Although a vertical array will always be superior to a single deeply buried seismometer, the improvement in performance which may be obtained by increasing the number of receivers in a vertical array is much less than in the case of a surface array.

The use of seismometer arrays containing both horizontal‐ and vertical‐component instruments for attenuation of surface‐wave noise has been studied theoretically. If a process can be defined to estimate the vertical noise component by operating on the outputs of one or more horizontal‐component seismometers, the estimate may be subtracted from the vertical‐component record to improve signal‐to‐noise ratio. The exact waveforms of vertically‐incident signals must be preserved in an operation of this kind. Formulas are developed to describe the response of a system employing three components measured at a single point. This system is found to be useful only in cases where the noise is strongly directional. A physical separation between the vertical‐ and horizontal‐component instruments is necessary to resolve the difficulties caused by uncertainties in the sense of the propagation velocity vector and particle orbit vector. Formulas, derived for systems consisting of circular rings of radially‐oriented horizontals and a central vertical show, that useful noise rejection can be obtained even in the most unfavorable case of uniform azimuthal noise distribution. The performance of arrays of this kind is not affected very much by uncorrelated noise or Love‐wave noise. Comparisons with similar arrays containing only vertical‐component seismometers indicate that, for some of the noise models studied, the multicomponent array should provide useful noise rejection over a greater bandwidth and at longer wavelengths than an all‐vertical array with the same dimensions.

Results of the superconducting transition temperatureT c of amorphous and microcrystalline films of lead doped with manganese as magnetic impurity are reported in this work. The amorphous films show an Abrikosov-Gor'kov behaviour, whereas for the crystalline films there is a much smaller depression and a peak for higher Mn concentrations, which indicates a region of coexistence of superconductivity and magnetic ordering as a spinglass.

Measurements of magnetic susceptibility, specific heat, transport properties and L III -absorption edges are reported for (RE x ZR 1-x )B 12 , RE = Ce, Pr, Tb. The thermodynamic properties indicate an incipient valence instability of Pr and Ce, although the L III valence is very close to three. The experimental data for Pr can be understood by a fluctuation temperature, which changes from 18 K at 2 K to about 100 K at room temperature.

The magnetic susceptibility of eight Ce-intermetallic compounds and two concentrated alloys was measured together with that of isostructural reference compounds between 1.5 and 1200 K. The high temperature susceptibility gives a lower bound of 0.3 for the 4ƒ occupation number, supporting L III evidence that Ce is never tetravalent in intermetallics.

We have measured the specific heat of dilute Th 1− x Tb x alloys (0.44 x C / T ≈ 450 mJ/K 2 molTb followed by a Schottky anomaly with a maximum near 3.8 K. The high temperature Δ χ T product was found to be 4% lower than that of Tb 3+ . The resistivity shows no minimum at low temperatures. Discussion is made in terms of non-integral valence of Tb.