Lock-in thermography (LIT), which is a well established technique for non-destructive evaluation, can also be used to identify and locate thermal active electrically defects like shorts and resistive ...opens in microelectronic devices. Defect localization on the level of the integrated circuits (IC) requires a μm resolution. But LIT can also be applied to locate buried thermal active defects within fully packaged microelectronic devices by analysing the thermal signal detected at the surface of the device. In addition to the lateral localization of the hot spot, its depth can also be determined by analysing the phase shift of the thermal signal. This is especially valued for non destructive defect localization in complex 3D integrated system in package devices (3D SiP). In comparison to competitive thermal imaging techniques, like liquid crystal imaging or fluorescent micro thermal imaging, LIT is easier to apply since it does not need any foreign thermal sensitive layer at the surface of the device. Also, the sensitivity limit of this technique within μK range is significantly better. In addition the dynamic character of LIT reduces thermal blurring, and the problem of inhomogeneous IR emissivity can be overcome by using the phase image or the 0°/−90° image. The spatial resolution limit of the used microscopic thermal imaging setup performed in the mid-wavelength range is about 5μm, but can be improved to 1.5μm by applying solid immersion lenses. Within the paper, the principle theory of LIT and the practical use for both, single and multiple IC devices is presented.
The biliary anastomosis is still one of the major causes for morbidity after orthotopic liver transplantation. The optimal method of reconstruction remains controversial. The aim of the study was to ...assess biliary complications after liver transplantation using a choledochocholedochostomy with or without a temporary T-tube.
Several reports have suggested that biliary reconstruction without T-tube is a safer method with a lower rate of biliary complications compared with T-tube insertion.
A total of 194 recipients of deceased donor liver grafts were randomized. In group 1 the biliary reconstruction was performed by side-to-side choledochocholedochostomy with (n = 99) and in group 2 (n = 95) without a T-tube. The T-tube was removed after 6 weeks.
The overall biliary complication rate was significantly increased in group 2 (P < 0.0005). Biliary leaks occurred in 5 patients in group 1 and in 9 patients in group 2 (5.05% vs. 9.47%; P = 0.2756 ns). Anastomotic strictures of the bile duct were seen in 7 patients in group 1 and in 8 patients in group 2 (7.07% vs. 8.42%; P = 0.7923 ns). Two of the patients in group 1 and 5 patients in group 2 developed an ischemic type biliary lesion (2.02% vs. 5.26%; P = 0.2716 ns). The rate of reoperations was comparable in both groups. The rate of invasive interventions was higher in the group without T-tubes (9% vs. 18%, P = ns), as was the rate of cholangitis (5% vs. 11%. P = ns) and pancreatitis (4% vs. 14%, P = 0.0218). No complications after removal of the T-tube were observed.
This study is a large prospective randomized trial to assess biliary complications that occur following liver transplantation, after anatomizing the bile duct with or without T-tubes. A significant increased rate of complications in the group without T-tube insertion was observed. In summary, our results indicate that the usage of T-tubes is safe and an excellent tool for the quality control of biliary anastomoses.
On the basis of revisions of some of the systematic errors, we reanalyzed the electron-antineutrino angular correlation (a coefficient) in free neutron decay inferred from the recoil energy spectrum ...of the protons which are detected in 4π by the aSPECT spectrometer. With a=-0.104 02(82) the new value differs only marginally from the one published in 2020. The experiment also has sensitivity to b, the Fierz interference term. From a correlated (b,a) fit to the proton recoil spectrum, we derive a limit of b=-0.0098(193) which translates into a somewhat improved 90% confidence interval region of -0.041≤b≤0.022 on this hypothetical term. Tighter constraints on b can be set from a combined shown as superscript (c) analysis of the PERKEO III (β asymmetry) and aSPECT measurement which suggests a finite value of b with b^{(c)}=-0.0181±0.0065 deviating by 2.82σ from the standard model.
The radiation of any object in a homogeneous environment can be described by a set of equivalent sources. Different types of equivalent sources are feasible and all of them have their own benefits. ...Equivalent current methods are especially advantageous for irregular measurement grids of arbitrary shape and if a priori information about the object shall be used. Also, they can immediately provide diagnostic information about the object. In this paper, a very flexible equivalent current method is presented, which has been derived from a general purpose boundary integral equation solver. As such the method works with arbitrary triangular surface meshes and Rao-Wilton-Glisson basis functions, where electric and/or magnetic surface current densities can be assumed. High efficiency is achieved since the multilevel fast multipole method has been adapted to speed-up the inverse solution process. Results obtained from simulations and measurements are presented, where large-scale problems with dimensions up to 75 wavelengths are considered.
The excitation function and momentum distribution of η′ mesons have been measured in photon induced reactions on 12C in the energy range of 1250–2600 MeV. The experiment was performed with tagged ...photon beams from the ELSA electron accelerator using the Crystal Barrel and TAPS detectors. The data are compared to model calculations to extract information on the sign and magnitude of the real part of the η′-nucleus potential. Within the model, the comparison indicates an attractive potential of −(37±10(stat)±10(syst)) MeV depth at normal nuclear matter density. Since the modulus of this depth is larger than the modulus of the imaginary part of the η′-nucleus potential of −(10±2.5) MeV, determined by transparency ratio measurements, a search for resolved η′-bound states appears promising.
A recently presented fully probe-corrected near-field far-field transformation employing plane wave expansion and diagonal translation operators enables near-field far-field transformation for ...arbitrary measurement contours and arbitrary antennas. A multilevel extension, inspired by the multilevel fast multipole method, is presented that is suitable for the efficient transformation of electrically large antennas with a size of tens or even hundreds of wavelengths. The measurement points are grouped in a multilevel fashion and translations are carried out to the box centers on the highest level only. The plane waves are processed through the different levels to the measurement points using a disaggregation and anterpolation procedure resulting in a reduced overall complexity. In the second part of this paper, the influence of perfectly conducting ground planes and dielectric halfspaces, as an approximation for ground effects in a real measurement setup, is investigated. As such ground reflected waves are assumed, which propagate from the investigated antenna to the field probe and add to the direct wave contributions. The far-field conditions required for these assumptions are achieved by a source box grouping scheme. By this extension ground effects are directly considered within the near-field far-field transformation. Transformation results using simulated and measured near-field data are shown.
Near-field antenna measurements combined with a near-field far-field transformation are an established antenna characterization technique. The approach avoids far-field measurements and offers a wide ...area of post-processing possibilities including radiation pattern determination and diagnostic methods. In this paper, a near-field far-field transformation algorithm employing plane wave expansion is presented and applied to the case of spherical near-field measurements. Compared to existing algorithms, this approach exploits the benefits of diagonalized translation operators, known from fast multipole methods. Due to the plane wave based field representation, a probe correction, using directly the probe's far-field pattern can easily be integrated into the transformation. Hence, it is possible to perform a full probe correction for arbitrary field probes with almost no additional effort. In contrast to other plane wave techniques, like holographic projections, which are suitable for highly directive antennas, the presented approach is applicable for arbitrary radiating structures. Major advantages are low computational effort with respect to the coupling matrix elements owing to the use of diagonalized translation operators and the efficient correction of arbitrary field probes. Also, irregular measurement grids can be handled with little additional effort.
We determine the second order endpoint of the line of first order phase transitions, which occur in the light quark mass regime of 3-flavour QCD at finite temperature, and analyze universal ...properties of this chiral critical point. A detailed analysis of Binder cumulants and the joint probability distributions of energy like and ordering-field like observables confirms that the chiral critical point belongs to the universality class of the three-dimensional Ising model. From a calculation with improved gauge and staggered fermion actions we estimate that the transition is first order for pseudo-scalar meson masses less than about 200 MeV.
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