Pulverização eletrostática: principais processos utilizados para eletrificação de gotas.

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Pulverização eletrostática com bicos hidráulicos.

Sistema de indução por eletrificação direta para bicoshidráulicos foi testado em condições de laboratóriopara obtenção de parâmetros de voltagens, correntesde eletrificação e distâncias de pulverização maisadequados para o desenvolvimento de pulverizadorcostal eletrostático. Foram testados os bicos TXVS-2, TXVK-3 e TXVK-4 em associação com tensões de-40 kV, -32 kV e -25 kV. Resistor de 1 G? limitou apotência teórica máxima da fonte de alta tensão em1,6 watts para 40 kV. Foram utilizados 4 tubosmetálicos aterrados, radialmente dispostos emrelação ao bico, em distâncias de 25 cm, 30 cm,35 cm e 40 cm para coletar as gotas eletrificadas. Obico TXVK-3, alimentado com -40 kV, proporcionourecuperação média de 678 mL para cada litropulverizado numa distância de 25 cm dos tuboscoletores. A recuperação diminuiu com a redução datensão e com o aumento da distância dos alvos dapulverização. Todos os bicos testados recuperarammais de 30% dos volumes aplicados, com tensõesentre 32 e 40 kV e distância mínima de 30 cm dos alvos

Monolithic optoelectronic integration of a GaAlAs laser, a field-effect transistor, and a photodiode

A low threshold buried heterostructure laser, a metal-semiconductor field-effect transistor, and a p-i-n photodiode have been integrated on a semi-insulating GaAs substrate. The circuit was operated as a rudimentary optical repeater. The gain bandwidth product of the repeater was measured to be 178 MHz

High-speed GaAlAs/GaAs p-i-n photodiode on a semi-insulating GaAs substrate

A high-speed, high-responsivity GaAlAs/GaAs p-i-n photodiode has been fabricated on a GaAs semi-insulating substrate. The 75-µm-diam photodiode has a 3-dB bandwidth of 2.5 GHz and responsivity of 0.45 A/W at 8400 Å (external quantum efficiency of 65%). The diode is suitable for monolithic integration with other optoelectronic devices

Gallium Aluminum Arsenide/Gallium Arsenide Integrated Optical Repeater

A low threshold buried heterostructure laser, a metal-semiconductor field effect transistor (MESFET), and a photodiode, have for the first time, been monolithically integrated on a semi-insulating GaAs substrate. This integrated optoelectronic circuit (IOEC) was operated as a rudimentary optical repeater. The incident optical signal is detected by the photodiode, amplified by the MESFET, and converted back to light by the laser. The gain bandwidth product of the repeater was measured to be 178 MHz

The Agency Tax Costs of Mutual Funds

In the intermediated economy of the twenty-first century, retail mutual fund investors cede investment and voting decisions to institutional investors who manage the funds. As a result, actions undertaken uni-laterally by financial intermediaries dictate the tax liability of passive individual investors. This Article argues that the tax decisions of insti¬tutional investors are guided by their own tax considerations rather than by the tax considerations of those beneficiaries who own mutual funds through conventional taxable accounts. Because these beneficiaries, unlike the institutional investors, are tax-sensitive, the diverging incen¬tives give rise to agency tax costs. These agency tax costs arise from the institutional investors’ trading decisions and stewardship activities, as well as their voting behavior. Because these investors regularly vote on corporate mergers and acquisitions (M&A), voting outcomes on these transactions are dis¬torted. The structure of M&A deals, the method of payment used in such deals, and even premiums paid to sellers are skewed because the votes of passive tax-sensitive investors are cast by tax-insensitive insti¬tutional investors. As a result, institutional investors not only fail to rep¬licate the tax outcomes that tax-sensitive investors could have achieved had they owned stock directly, but they also fail to achieve the same cor¬porate voting outcomes. This Article proposes several options for mitigating agency tax costs. These options include mandatory separation of funds based on the tax profile of the beneficiaries, heightened tax disclosure by mutual funds, decentralization of votes in mutual fund sponsors and pass-through voting systems. These alternatives would reduce the agency tax costs of mutual funds without imposing new agency costs on tax-insensitive shareholders who also rely on institutional investors for port¬folio management

AlGaAs lasers with micro-cleaved mirrors suitable for monolithic integration

A technique has been developed for cleaving the mirrors of AlGaAs lasers without cleaving the substrate. Micro-cleaving involves cleaving a suspended heterostructure cantilever by ultrasonic vibrations. Lasers with microcleaved mirrors have threshold currents and quantum efficiencies identical to those of similar devices with conventionally cleaved mirrors

Direct amplitude modulation of short-cavity GaAs lasers up to X-band frequencies

Experimental and theoretical studies indicate that a high-frequency laser with bandwidths up to X-band frequencies (~> 10 GHz) should be one having a short cavity with a window structure, and preferably operating at low temperatures. These designs would accomplish the task of shortening the photon lifetime, increasing the intrinsic optical gain, and increasing the internal photon density without inflicting mirror damage. A modulation bandwidth of >8 GHz has been achieved using a 120-µm laser without any special window structure at room temperature

Superluminescent damping of relaxation resonance in the modulation response of GaAs lasers

It is demonstrated experimentally that the intrinsic modulation response of injection lasers can be modified by reducing mirror reflectivities, which leads to suppression of relaxation oscillation resonance and a reduction of nonlinear distortions up to multi-GHz frequencies. A totally flat response with a 3-dB bandwidth of 5 GHz was obtained using antireflection coated buried heterostructure lasers fabricated on a semi-insulating substrate. Harmonic distortions were below 40 dB within the entire 3-dB bandwidth. These results are in accord with theoretical predictions based on an analysis which include the effects of superluminescence in the laser cavity