Microscopic investigation of modified hydration kinetics in tricalcium silicate paste and mortar strength caused by dicalcium silicate addition.

It was recently revealed that some processes of hydrating tricalcium silicate are altered by the addition of dicalcium silicate. Previous neutron scattering results revealed two critical tri/dicalcium silicate compositions. At one composition, changes in the early time hydration kinetics were observed that result in the formation of more products (reflected in increased 28 day strength), despite dicalcium silicate being essentially unreactive at early times. At the other composition, changes in the early-time hydration kinetics were observed that correspond to reduced strength. The current work uses scanning electron microscope analysis with backscattered electron imaging of 50 day hydrated tri- and dicalcium silicate mortars to reveal that at the former critical composition increased hydration of the tricalcium silicate phase occurs, and at the latter critical composition, the amount of dicalcium silicate reacted is decreased. © 2008, Materials Research Societ

Precision measurements of the nucleon strange form factors at Q(2)similar to 0.1 GeV2 RID A-2969-2011

We report new measurements of the parity-violating asymmetry APV in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with h-lab=6deg. The 4He result is APV=(+6.40+-0.23stat+0.04syst)x10**6. The hydrogen result is APV= (1.58+-0.12stat+-0.04syst)*10**6. These results significantly improve constraints on the electric and magnetic strange form factors GsE and GsM. We extract GsE=0.002+-0.014+-0.007 at Q**2=0.077 GeV2, and GsE+0.09GsM=0.007+-0.011+-0.006 at Q2=0.109 GeV2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions

Precision measurements of the nucleon strange form factors at Q(2)similar to 0.1 GeV2

We report new measurements of the parity-violating asymmetry A(PV) in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with approximately 6.0 degrees . The 4He result is A(PV)=(+6.40+/-0.23(stat)+/-0.12(syst))x10(-6). The hydrogen result is A(PV)=(-1.58+/-0.12(stat)+/-0.04(syst))x10(-6). These results significantly improve constraints on the electric and magnetic strange form factors G(E)(s) and G(M)(s). We extract G(E)(s)=0.002+/-0.014+/-0.007 at =0.077 GeV2, and G(E)(s)+0.09G(M)(s)=0.007+/-0.011+/-0.006 at =0.109 GeV2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions