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Serial synchrotron crystallography (SSX) is an emerging technique for static and time‐resolved protein structure determination. Using specifically patterned silicon chips for sample delivery, the `hit‐and‐return' (HARE) protocol allows for efficient time‐resolved data collection. The specific pattern of the crystal wells in the HARE chip provides direct access to many discrete time points. HARE chips allow for optical excitation as well as on‐chip mixing for reaction initiation, making a large number of protein systems amenable to time‐resolved studies. Loading of protein microcrystals onto the HARE chip is streamlined by a novel vacuum loading platform that allows fine‐tuning of suction strength while maintaining a humid environment to prevent crystal dehydration. To enable the widespread use of time‐resolved serial synchrotron crystallography (TR‐SSX), detailed technical descriptions of a set of accessories that facilitate TR‐SSX workflows are provided.

Titanium was treated by pulsed Nd:YAG laser irradiation in nitrogen atmosphere, which led to nitrogen in-diffusion and TiN coating formation. The thickness of the TiN films was about 1.2 lm and the coatings had a universal hardness of about 11 GPa. The layers were investigated by X-ray diffraction at grazing incidence and resonant nuclear reaction analysis for nitrogen depth profiling. Fitting of the experimental depth profiles gave information about the physical processes (diffusion time and depth) with respect to the achieved hardness. The microscopic properties like lattice constants and the variation of the nitrogen content were evaluated. A relationship between laser scan parameters and coating properties could be revealed. Thus, it was possible to determine the physical limits such as film thickness, nitrogen content, and hardness of this direct laser synthesis.

Pure titanium was irradiated by pulsed Nd:YAG laser irradiation in nitrogen atmosphere. As a result, nitrogen uptake and diffusion occurred and a TiN layer was synthesized at the titanium surface. These TiN coatings were analyzed by X-ray diffraction and the diffraction patterns were investigated in detail, in order to obtain more information about the physical processes during the coating formation. The diffraction peaks were fitted by Pearson VII profiles and the grain size and the microstrain were determined by the analysis of line broadening and peak shifts, using the Williamson-Hall and the Warren-Averbach formalisms. Additional single-line analyses were performed by means of the method of Langford and Keijser to obtain information about the preferred grain orientation and the texture development. The maximum grain size was about 100 nm and a corresponding average lattice strain of 0.002 was found. A relation between the treatment parameters and the coating properties, such as grain size and microstrain, can be shown. Thus, it was possible to determine optimal scan parameters for material processing and to establish the physical limits of the coating properties.PACS 81.65.Lp; 81.15.Fg; 61.10.Nz; 68.55.Jk IntroductionNitriding and carburizing of metals are well known techniques to improve the tribological properties like hardness and wear resistance of technical surfaces [1]. As an example, plasma-and gas nitriding are established methods for surface treatment [2,3]. Alternatively, it is possible to treat the surface with laser radiation and to directly synthesize hard coatings [4][5][6][7][8]. Previous works have shown the successful synthesis of titanium nitride with laser irradiation [9][10][11]. Here, a Q-switched Nd:YAG laser was used for the nitriding treatment. The main advantages of this method are a reduction of the processing time and the negligible heat load for the workpiece. Stress, microstrain and inhomogeneity remain the main problems. Also the texture of cubic titanium nitride is a decisive factor for the technical quality of the coatings, as the u Fax: +49-551-39-4493, E-mail: pschaaf@uni-goettingen.de texture influences strain development and finally crack formation and propagation. Some investigations on texture and strain development in relation to the process parameters have been reported in the literature [12][13][14].This work resolves the resulting grain size and strain development and relates them to laser treatment parameters like scan parameters. In this way, one can try to predict optimum treatment parameters for optimum coating properties, i.e. find parameters that minimize the lattice strain in order to reduce crack formation and propagation. Experiments 2.1 Sample treatmentConventional α-titanium (purity > 99.98%) was used for the treatments. Titanium sheets of 1 mm thickness were cut into pieces of 15 × 15 mm 2 and used in the asreceived state without any further treatment.For laser nitriding, the samples were placed in a chamber which was first evacuated and then fil...

For the two proteins myoglobin (MB) and fluoroacetate dehalogenase (FAcD), we present a systematic comparison of crystallographic diffraction data collected by serial femtosecond (SFX) and serial synchrotron crystallography (SSX). To maximize comparability, we used the same batch of crystals, the same sample delivery device, as well as the same data analysis software. Overall figures of merit indicate that the data of both radiation sources are of equivalent quality. For both proteins reasonable data statistics can be obtained with approximately 5000 room temperature diffraction images irrespective of the radiation source. The direct comparability of SSX and SFX data indicates that diffraction quality is rather linked to the properties of the crystals than to the radiation source. Time-resolved experiments can therefore be conducted at the source that best matches the desired time-resolution.