96 research outputs found

    HOW TO TALK TO AN ANGRY CUSTOMER

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    In the work presented the potential of a pyrometric process control during laser beam soldering will be enhanced. Primarily we have developed a processing head with an integrated up-to-date pyrometric sensor conditioned for the temperature range of soft soldering. Using high speed photography we have analysed the detected secondary emissions during laser beam soldering and correlated the acquired pyrometric signals of process emissions with processes sequencing. Finally we named different strategies and control methods to achieve reliable high quality solder joints implementing a pyrometric process control

    The \u3cem\u3edapE\u3c/em\u3e-encoded \u3cem\u3eN\u3c/em\u3e-succinyl-l,l-diaminopimelic Acid Desuccinylase from \u3cem\u3eHaemophilus influenzae\u3c/em\u3e Contains Two Active-site Histidine Residues

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    The catalytic and structural properties of the H67A and H349A dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae were investigated. On the basis of sequence alignment with the carboxypeptidase from Pseudomonas sp. strain RS-16, both H67 and H349 were predicted to be Zn(II) ligands. The H67A DapE enzyme exhibited a decreased catalytic efficiency (180-fold) compared with wild-type (WT) DapE towards N-succinyldiaminopimelic acid. No catalytic activity was observed for H349A under the experimental conditions used. The electronic paramagnetic resonance (EPR) and electronic absorption data indicate that the Co(II) ion bound to H349A-DapE is analogous to that of WT DapE after the addition of a single Co(II) ion. The addition of 1 equiv of Co(II) to H67A DapE provides spectra that are very different from those of the first Co(II) binding site of the WT enzyme, but that are similar to those of the second binding site. The EPR and electronic absorption data, in conjunction with the kinetic data, are consistent with the assignment of H67 and H349 as active-site metal ligands for the DapE from H. influenzae. Furthermore, the data suggest that H67 is a ligand in the first metal binding site, while H349 resides in the second metal binding site. A three-dimensional homology structure of the DapE from H. influenzae was generated using the X-ray crystal structure of the DapE from Neisseria meningitidis as a template and superimposed on the structure of the aminopeptidase from Aeromonas proteolytica (AAP). This homology structure confirms the assignment of H67 and H349 as active-site ligands. The superimposition of the homology model of DapE with the dizinc(II) structure of AAP indicates that within 4.0 Å of the Zn(II) binding sites of AAP all of the amino acid residues of DapE are nearly identical

    Inhibition of the \u3cem\u3edapE\u3c/em\u3e-Encoded \u3cem\u3eN\u3c/em\u3e-Succinyl- ʟ, ʟ-diaminopimelic Acid Desuccinylase from \u3cem\u3eNeisseria meningitidis\u3c/em\u3e by ʟ-Captopril

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    Binding of the competitive inhibitor ʟ-captopril to the dapE-encoded N-succinyl-ʟ, ʟ-diaminopimelic acid desuccinylase from Neisseria meningitidis (NmDapE) was examined by kinetic, spectroscopic, and crystallographic methods. ʟ-Captopril, an angiotensin-converting enzyme (ACE) inhibitor, was previously shown to be a potent inhibitor of the DapE from Haemophilus influenzae (HiDapE) with an IC50 of 3.3 μM and a measured Ki of 1.8 μM and displayed a dose-responsive antibiotic activity toward Escherichia coli. ʟ-Captopril is also a competitive inhibitor of NmDapE with a Ki of 2.8 μM. To examine the nature of the interaction of ʟ-captopril with the dinuclear active site of DapE, we have obtained electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) data for the enzymatically hyperactive Co(II)-substituted forms of both HiDapE and NmDapE. EPR and MCD data indicate that the two Co(II) ions in DapE are antiferromagnetically coupled, yielding an S = 0 ground state, and suggest a thiolate bridge between the two metal ions. Verification of a thiolate-bridged dinuclear complex was obtained by determining the three-dimensional X-ray crystal structure of NmDapE in complex with ʟ-captopril at 1.8 Å resolution. Combination of these data provides new insights into binding of ʟ-captopril to the active site of DapE enzymes as well as important inhibitor–active site residue interaction’s. Such information is critical for the design of new, potent inhibitors of DapE enzymes

    Micro-manufacturing : research, technology outcomes and development issues

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    Besides continuing effort in developing MEMS-based manufacturing techniques, latest effort in Micro-manufacturing is also in Non-MEMS-based manufacturing. Research and technological development (RTD) in this field is encouraged by the increased demand on micro-components as well as promised development in the scaling down of the traditional macro-manufacturing processes for micro-length-scale manufacturing. This paper highlights some EU funded research activities in micro/nano-manufacturing, and gives examples of the latest development in micro-manufacturing methods/techniques, process chains, hybrid-processes, manufacturing equipment and supporting technologies/device, etc., which is followed by a summary of the achievements of the EU MASMICRO project. Finally, concluding remarks are given, which raise several issues concerning further development in micro-manufacturing

    Intensity noise of injection-locked lasers: Quantum theory using a linearized input-output method

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    We derive analytical expressions for the quantum-noise spectra of an atomic laser using a linearized input-output method. We generalize the method to the problem of injection-locked lasers. We identify three distinct spectral noise regimes in the solution, unifying previous results. The approach offers insights into the physical processes and is especially suited for comparison with experiment. The quantum spectral noise properties of the pump laser and the injected laser appear explicitly in the solution

    Perspective taking and systematic biases in object location memory.

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    The aim of the current study was to develop a novel task that allows for the quick assessment of spatial memory precision with minimal technical and training requirements. In this task, participants memorized the position of an object in a virtual room and then judged from a different perspective, whether the object has moved to the left or to the right. Results revealed that participants exhibited a systematic bias in their responses that we termed the reversed congruency effect. Specifically, they performed worse when the camera and the object moved in the same direction than when they moved in opposite directions. Notably, participants responded correctly in almost 100% of the incongruent trials, regardless of the distance by which the object was displaced. In Experiment 2, we showed that this effect cannot be explained by the movement of the object on the screen, but that it relates to the perspective shift and the movement of the object in the virtual world. We also showed that the presence of additional objects in the environment reduces the reversed congruency effect such that it no longer predicts performance. In Experiment 3, we showed that the reversed congruency effect is greater in older adults, suggesting that the quality of spatial memory and perspective-taking abilities are critical. Overall, our results suggest that this effect is driven by difficulties in the precise encoding of object locations in the environment and in understanding how perspective shifts affect the projected positions of the objects in the two-dimensional image

    High power parallel ultrashort pulse laser processing

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    The class of ultra-short-pulse (USP) laser sources are used, whenever high precession and high quality material processing is demanded. These laser sources deliver pulse duration in the range of ps to fs and are characterized with high peak intensities leading to a direct vaporization of the material with a minimum thermal damage. With the availability of industrial laser source with an average power of up to 1000W, the main challenge consist of the effective energy distribution and disposition. Using lasers with high repetition rates in the MHz region can cause thermal issues like overheating, melt production and low ablation quality. In this paper, we will discuss different approaches for multibeam processing for utilization of high pulse energies. The combination of diffractive optics and conventional galvometer scanner can be used for high throughput laser ablation, but are limited in the optical qualities. We will show which applications can benefit from this hybrid optic and which improvements in productivity are expected. In addition, the optical limitations of the system will be compiled, in order to evaluate the suitability of this approach for any given application

    Über die Verbreitung von Halophyten an Einem Salzstandort im Mitteleuropäischen Binnenland

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    On substantiation of selection of economic and mathematical methods for the assessment of energy efficiency of production facilities

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    Метою дослідження є обґрунтування вибору найбільш доцільних економіко-математичних методів забезпечення енергоефективного режиму роботи виробничих об’єктів. Розглянуті методи можуть бути використані для вибору найкраще працюючих технологічних ліній, агрегатів, насосних, компресорних, вентиляторних установок, або інших електроприймачів з декількох їм подібних за критеріями рівної та нерівної ваги. Описано спосіб контролю енергоефективності роботи виробничих об’єктів в трикутних координатах у випадку, коли електричне навантаження залежить від двох параметрів при наявності їх граничних обмежень. Наведено приклад порівняння ефективності роботи виробничих об’єктів хімічної промисловості методами апріорного ранжування та морфологічним (геометричним). Зроблений висновок про те, що тотожність поточного значення енергоспоживання з розрахованим методом Хольта прогнозованим значенням при визначених заздалегідь оптимальних сталих згладжування визначає стабільність роботи технологічного процесу. Доведена доцільність застосування коефіцієнту автокореляції першого порядку вибірок електроспоживання для перевірки технологічних процесів на стабільність роботи.Research purpose is generalization and further development of economic-mathematical methods for ensuring energy efficient operation mode of production facilities. The above methods can be used for selection of the most energy-efficient production lines, mechanisms; pumping, compression, ventilation installations or other electric receivers among several similar ones by using equal and unequal weight criteria. An example of comparing the efficiency of the production facilities of the chemical industry is showed by a priori ranking and morphological (geometric) methods. The method of control the correctness of the production facilities in the case when the electric load depends on two parameters in triangular coordinates in the presence of boundary restrictions is described. The identity of the current energy values calculated by Holt predicted value at a predetermined optimal smoothing constant determines the stability of the process. Expedience of application the autocorrelation coefficient for testing processes on the stability is proved
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