An integrated charge amplifier for a pyroelectric sensor

This paper presents an integrated charge amplifier that measures a small charge. This charge is generated by a pyroelectric detector. The charge amplifier consists of a single-stage c-annon source configuration with a passive feedback network. The charge amplifier has a bandwidth of 700 kHz and an output noise voltage of 20 nV Hz 1/2 at 1 kHz. A 2×2 integrated pyroelectric sensor based on VDF/TrFE copolymer has been realized. The voltage response of this sensor-amplifier is reported

Correlated ab-initio calculations for ground-state properties of II-VI semiconductors

Correlated ab-initio ground-state calculations, using relativistic energy-consistent pseudopotentials, are performed for six II-VI semiconductors. Valence ($ns,np$) correlations are evaluated using the coupled cluster approach with single and double excitations. An incremental scheme is applied based on correlation contributions of localized bond orbitals and of pairs and triples of such bonds. In view of the high polarity of the bonds in II-VI compounds, we examine both, ionic and covalent embedding schemes for the calculation of individual bond increments. Also, a partitioning of the correlation energy according to local ionic increments is tested. Core-valence ($nsp,(n-1)d$) correlation effects are taken into account via a core-polarization potential. Combining the results at the correlated level with corresponding Hartree-Fock data we recover about 94% of the experimental cohesive energies; lattice constants are accurate to \sim 1%; bulk moduli are on average 10% too large compared with experiment.Comment: 10 pages, twocolumn, RevTex, 3 figures, accepted Phys. Rev.

Coherent control at its most fundamental: CEP-dependent electron localization in photodissoziation of a H2+ molecular ion beam target

Measurements and calculations of the absolute carrier-envelope phase (CEP) effects in the photodissociation of the simplest molecule, H2+, with a 4.5-fs Ti:Sapphire laser pulse at intensities up to (4 +- 2)x10^14 Watt/cm^2 are presented. Localization of the electron with respect to the two nuclei (during the dissociation process) is controlled via the CEP of the ultra-short laser pulses. In contrast to previous CEP-dependent experiments with neutral molecules, the dissociation of the molecular ions is not preceded by a photoionization process, which strongly influences the CEP dependence. Kinematically complete data is obtained by time- and position-resolved coincidence detection. The phase dependence is determined by a single-shot phase measurement correlated to the detection of the dissoziation fragments. The experimental results show quantitative agreement with ab inito 3D-TDSE calculations that include nuclear vibration and rotation.Comment: new version includes minore changes and adding the supp_material.pd

CEP-stable Tunable THz-Emission Originating from Laser-Waveform-Controlled Sub-Cycle Plasma-Electron Bursts

We study THz-emission from a plasma driven by an incommensurate-frequency two-colour laser field. A semi-classical transient electron current model is derived from a fully quantum-mechanical description of the emission process in terms of sub-cycle field-ionization followed by continuum-continuum electron transitions. For the experiment, a CEP-locked laser and a near-degenerate optical parametric amplifier are used to produce two-colour pulses that consist of the fundamental and its near-half frequency. By choosing two incommensurate frequencies, the frequency of the CEP-stable THz-emission can be continuously tuned into the mid-IR range. This measured frequency dependence of the THz-emission is found to be consistent with the semi-classical transient electron current model, similar to the Brunel mechanism of harmonic generation

Impurity Ion Complexation Enhances Carbon Dioxide Reduction Catalysis

Herein, we show that group 11 CO[subscript 2] reduction catalysts are rapidly poisoned by progressive deposition of trace metal ion impurities present in high purity electrolytes. Metal impurity deposition was characterized by XPS and in situ stripping voltammetry and is coincident with loss of catalytic activity and selectivity for CO[subscript 2] reduction, favoring hydrogen evolution on poisoned surfaces. Metal deposition can be suppressed by complexing trace metal ion impurities with ethylenediaminetetraacetic acid or solid-supported iminodiacetate resins. Metal ion complexation allows for reproducible, sustained catalytic activity and selectivity for CO[subscript 2] reduction on Au, Ag, and Cu electrodes. Together, this study establishes the principal mode by which group 11 CO[subscript 2] reduction catalysts are poisoned and lays out a general approach for extending the lifetime of electrocatalysts subject to impurity metal deposition.MIT Energy Initiative (Saudi Aramco, research agreement)United States. Air Force Office of Scientific Research (Award FA9550-15-1-0135)Massachusetts Institute of Technology. Department of Chemistry (Junior Faculty Funds)National Science Foundation (U.S.) (Predoctoral Fellowship)National Science Foundation (U.S.) (MIT MRSEC Program, award number DMR-0819762

Pengaruh Keadilan, Self Assessment System, Diskriminasi, dan Kemungkinan Terdeteksinya Kecurangan terhadap Persepsi Wajib Pajak dalam Tindakan Penggelapan Pajak (Studi Empiris pada Wajib Pajak Badan yang Terdaftar di Kpp Pratama Tampan Pekanbaru)

The research aims to examine the influence of fairness, self assessment system, discriminant and the probability of cheat detact to taxpayer perceptions about tax evasion. Object of this research taxpayer were registered in KPP Pratama Pekanbaru. There are one hundred questionnaires were sent, but only fourty four questionnaires were returned. That data are analyzed by multiple regression method and SPSS program version 19. The variables were examined are influence of fairness, self assessment system, discriminant and the probability of cheat detact to taxpayer perceptions about tax evasion. The results of this research showed that fairness has an effect on taxpayer perceptions about ta evasion with 0,000 significance, the self assessment system has an effect on taxpayer perceptions about tax evasion with 0,000 significance, discriminant has no effect on taxpayer perceptions about tax evasion with 0,427 significance and the probability of cheat detact has an effect on taxpayer perceptions about tax evasion with 0,006 significance. The results of this research also showed that coefficient determinant is 89,1%. Each independent variables, gives the strong influence to dependent variable, it means independents variables could explain dependent variable well. While the remaining influenced by other variables not included in the regression models were not included in this study. All variables also have strong relation with variable dependents in this research

Comparison of Number of Diffusion Gradient Direction in Brain Imaging Diffusion Tensor; Case Study of Tumor Brain

Background : Diffusion Tensor Imaging (DTI), namely MRI sequence which is the diffusion of water analysis that shows the complex structure of brain tissue. The weakness of this sequence is scanning time. Number of Diffusion Gradient Direction (NDGD) is one of parameter that effect scanning time. Purpose: This study has aim to compare between NDGD 25 and NDGD 15 in brain tumor. Methods: This study used observational analytic study with prospective approach. Five patients were examined using DTI sequence with NDGD 25 and NDGD 15. The parameter for evaluating the quality image is of Fractional Anisotropy (FA) and Fiber Tracking (FT). Result: Image with NDGD 25 was better than NDGD 15, but the difference was not significantly. Conclusion: It can be concluded that NDGD 15 can be solution to get informative image with short scan time when DTI sequence is used to examine brain tumor