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Selected in-®eld physical, chemical and biological indicators were measured for the rapid assessment of soil quality changes in a Sorrento silty clay loam as a result of compost and ammonium nitrate application to a broccoli ®eld (San Benito County, CA). Plots were laid out in a randomized complete block design with four replications of 0, 22 and 44 Mg haÿ1(More)
The soil microbial biomass contains important labile pools of C, N, P, and S, and fluctuations in its size and activity can significantly influence crop productivity. In cropping systems where fertilizer use is reduced or eliminated and green-manure legumes are used, nutrient availability is more directly linked to C-cycle dynamics. We observed the(More)
Results are presented on the performance of a heterojunction interfacial workfunction internal photoemission ~HEIWIP! wavelength-tailorable detector. The detection mechanism is based on free-carrier absorption in the heavily doped emitter regions and internal emission across a workfunction barrier caused by the band gap offset at the heterojunction. The(More)
The recent development of p-GaAs homojunction interfacial workfunction internal photoemission (HIWIP) far-infrared (\40 mm) detectors is briefly reviewed. The emphasis is on the detector performance, which includes responsivity, quantum efficiency, bias effects, cut-off wavelength, uniformity, noise, and negative capacitance characteristics. Promising(More)
We have measured the frequency-dependent shear modulus of entangled solutions of wormlike micelles by high-frequency microrheology and have compared the results with those from macrorheology experiments done on the same samples. Using optical microrheology based on laser interferometry we have measured loss and storage moduli over six decades in frequency(More)
Metal corrugated surfaces have the potential of enhancing optical absorption through surface plasmon (SP) excitation facilitated by light-metal interactions. The successful utilization of metal corrugation induced optical absorption can improve the response of free carrier absorption (FCA), based HEterojunction Interfacial Workfunction Internal(More)
A large pixelless thermal imager based on the epitaxial integration of a GaAs–AlGaAs quantum-well infrared photodetector and a GaAs light-emitting diode is demonstrated. The device transforms a mid-infrared (9 m) scene to a near-infrared (0.82 m) emission image with a temperature resolution of 1 K, limited by the integration capacity of the near-visible(More)
A molecular beam epitaxy grown wavelength tunable GaAs p-i homojunction interfacial work-function internal photoemission far-infrared detector is developed. The multilayer (p-ip-i. . . ! detector structures consist of 2, 5, and 10 emitter layers. Experimental results are explained in terms of the number of emitter layers and the doping concentrations of the(More)
The temperature dependence of capacitance and ac conductance for GaAs/AlGaAs multiquantum well ~MQW! structures with 4, 8, 16, and 32 wells has been studied at different bias and frequency ranges. The dominant contribution to ac conductance depends on temperature and frequency, and changes from thermally assisted tunneling through the first excited state to(More)