A cohort of 452 rural children was followed longitudinally for 13 mo to ascertain the role HEp-2 cell adherent Escherichia coli and other pathogens in causing acute (≤14 d) persistent (>14 diarrhea. Aeromonas, Campylobacter jejuni, E. manifesting localized adherence cells enterotoxigenic were significantly associated with strains that exhibit aggregative adherence, so-called enteroaggregative coli, a newly-described category diarrheagenic distinct from enterotoxigenic, enteroinvasive,...

Data obtained in a thunderstorm with vertically pointing Doppler radar are analyzed to find the size distribution of raindrops at heights below 0C level. Drop-size distributions were computed using updraft UR deduced by Rogers' method and two other updrafts, namely, − 1 + m sec−1. It is found that drop-size data all may be well represented exponential equation, N (D) = N0 exp(− ΛD), which (D)ΔD concentration drops diameter range D ΔD, 0.07 R0.37 [cm−4], Λ 38R−0.14 [cm−1], R being rainfall...

The evolution of raindrop size distribution by coalescence, collisional breakup, and evaporation is studied using the Low List parameterization for collisions. authors consider two models development distribution; model 1 a spatially homogeneous, time-dependent model, 2 ID (vertical) model. present governing equations drop distribution, balance rainwater content rainfall rate, scaling relationships. demonstrate that are intimately related. For 1, find under action coalescence breakup attains...

A high-yield route to the new complexes OsBr2(dppe)2 and trans-OsHBr(dppe)2 starting from (NH4)2[OsBr6] is described. The 5-coordinate [OsX(dppe)2]PF6 (X = Cl (8Os) X Br (9Os)) are prepared by reaction of cis-OsX2(dppe)2 with NaPF6. Complexes 8Os 9Os consist distorted trigonal bipyramidal cations "Y"-shaped equatorial planes. They react in CH2Cl2 H2 or HD (1 atm) give trans-[Os(H··H)X(dppe)2]PF6 (1OsPF6), (2OsPF6)) trans-[Os(H··D)X(dppe)2]PF6, respectively. last have J(H,D) 13.9 13.7 Hz,...

Abstract A ono-dimensioral time-dependent model of a downdraft driven by the melting and evaporation precipitation loading is formulated. Equations for particle melting, evaporation, concentration, content, thermodynamic energy, vertical air velocity are formulated solved numerically. In environment, lapse rate temperature relative humidity prescribed. At top column, temperature, humidity, velocity, phase size distribution particles Two types considered: consisting single exponential...

Some computations of the evolution raindrop-size distributions under operation processes drop breakup and coalescence are presented. It is found that size distribution approaches a stationary state. The for different rainfall rates roughly parallel to each other when logf(r) plotted against r, f(r) being concentration density drops radius r. A comparison with observations shows computed flatter than observed ones. suggested besides raindrops shape their size.

An improved synthesis of (π-C5H5)2HfCl2 and new method for preparing Group IVA metallocene fluorides, bromides, iodides from either boron halides or C6F5CN, are reported. Vibrational (4000–600 cm.–1), 1H n.m.r., mass spectra presented. The mixed (π-C5H5)2MClBr have been identified by n.m.r. spectroscopy; in tetrahydrofuran solutions, redistribution equilibria (π-C5H5)2MCl2+(π-C5H5)2MBr2⇌ 2(π-C5H5)2MClBr at 38° approximately statistical.

Insertion reactions of amides LM–(NR2)n with the dipoles AB to give adducts LM(NR2)n – x(A–B–NR2)x are described. The included Group IVA [M(NMe2)4(M = Ti, Zr, or Hf)] and IVB [Me3M·NMe2(M Si, Ge, Sn)] compounds o-C6H4O2B·NEt2, while were PhNCO, PhNCS, MeNCS, p-MeC6H4·N:C:N·C6H4Me-p, C6H11·N:C:N·C6H11, MeO2C·C:C·CO2Me, CO2, CS2, CH2:CH·CN, PhCN, p-MeC6H4·CN, CH2:CCl(CN), C6F5·CN, CCl3·CN, [graphic omitted] MeCH:CH·CHO. problems discussed stoicheiometry reaction, structure adducts, relative...

In the present work, structural, morphological, magnetic and optical properties of nickel ferrite thin films having different thickness are reported. All were deposited on Si (100) substrate by pulsed laser deposition technique. Thicknesses determined x-ray reflectivity vary from 62 to 176nm as time varies 16 min 40 min. The characterised diffractogram, Fourier transform infrared (FTIR) Raman spectroscopy for structural phase confirmation. FTIR spectra confirm mixed spinel nature ferrite....

We have studied the role of Dy 3+ doping on XRD, TEM, FTIR, and dielectric electrical properties CoFe 2 O 4 at room temperature. Cubic spinel phase 2− x (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:math> = 0.00, 0.05, 0.10, 0.15) was synthesized by using different sintering temperatures (300, 500, 700, 900°C). The two absorption bands ν 1 are observed in Fourier transform infrared spectroscopy (FTIR) spectra corresponding to...

We are developing a procedure for the quick identification of structural phases in thin film composition spread experiments which map large fractions compositional phase diagrams ternary metallic alloy systems. An in-house scanning x-ray microdiffractometer is used to obtain spectra from 273 different compositions on single library. A cluster analysis software then sort into groups order rapidly discover distribution diagram. The most representative pattern each group compared database known...

Abstract Zinc ferrite nanoparticles of different sizes ranging from 12 to 62 nm were synthesized by using the nitrate route. These irradiated a 100 MeV oxygen beam at two fluences: 1 × 10 13 and 5 ions/cm 2 . It was observed that modes corresponding cubic spinel phase retained after irradiation in all systems. The variation parameters various follows phonon confinement, while this effect seems violate specimen. found irradiation‐induced changes F 2g (2) (3) depend on whether crystallite size...

The effect of precipitation on the properties a one-dimensional non-entraining cumulus is studied by numerically integrating equation motion and conservation water substance. initial state taken to be steady-state solution equations in absence precipitation. Two models development are considered. In first model, cloud considered change into rainwater at prescribed rate, whenever content exceeds given critical value. raindrops assumed have an exponential size distribution grow coalescing with...

The kinematic structure and reflectivity distribution within a region of widespread precipitation associated with summertime midlatitude (Illinois) squall line, as revealed by an analysis Doppler radar data, are presented discussed. line moved in southeasterly direction while active convection forming on its leading edge northeasterly direction. Decaying thunderstorms their anvils merged to form the extensive stratiform which trailed line. An extension VAD (Velocity Azimuth Display) method,...

The theory of the electron spin resonance dipolar coupled copper(II)–copper(II) pairs has been critically assessed and extended to take into account ΔM= 2 transitions that are observed experimentally. Computational procedures have evolved determine copper(II)–copper(III) separation in dimeric species. existence such species shown both aqueous non-aqueous solutions copper(II) chelates citric, malic, tartronic, mandelic, 5-sulphosalicyclic acids. computational applied calculating comparing...