Peters described modifications of the Jores' solution (Peters, 1956). These immersion fluids are generally free of formaldehyde and phenol, which are replaced by choralhydrate (Supporting Information, Table S5); nevertheless, Peters adds 2% phenol for the preservation of pancreas, stomach and intestines.
FREE LICENCE FOR S7 CAN OPENER 1 316
In 1975, Tutsch (1975) published an embalming fluid formula replaced phenol with Lysoformin (Lysoform, Berlin, Germany). According to the maufacturer's product sheet, Lysoformin contains 6.0 g of formaldehyde and 1.8 g of glutaraldehyde per 100 g (Lysoform Dr. Hans Rosemann GmbH, Berlin, Germany); thus, this embalming fluid is completely free of aromatic substances (Supporting Information, Table S8).
Although formaldehyde is an excellent tissue fixative, its use is generally associated with extreme rigidity. It is possible, however, to modify this effect by adding 0.025 m sodium pyrophosphate, with or without additional 0.001 m magnesium chloride. The muscles remain pliable and the joints freely movable (Richins et al. 1963).
Highly regular laser-induced periodic surface structures (HR-LIPSS) have been fabricated on surfaces of Mo, steel alloy and Ti at a record processing speed on large areas and with a record regularity in the obtained sub-wavelength structures. The physical mechanisms governing LIPSS regularity are identified and linked with the decay length (i.e. the mean free path) of the excited surface electromagnetic waves (SEWs). The dispersion of the LIPSS orientation angle well correlates with the SEWs decay length: the shorter this length, the more regular are the LIPSS. A material dependent criterion for obtaining HR-LIPSS is proposed for a large variety of metallic materials. It has been found that decreasing the spot size close to the SEW decay length is a key for covering several cm2 of material surface by HR-LIPSS in a few seconds. Theoretical predictions suggest that reducing the laser wavelength can provide the possibility of HR-LIPSS production on principally any metal. This new achievement in the unprecedented level of control over the laser-induced periodic structure formation makes this laser-writing technology to be flexible, robust and, hence, highly competitive for advanced industrial applications based on surface nanostructuring.
It must be admitted that LIPSS formation is an intricate process which involves material ablation/relocation happening well after the laser pulse action. However, it is widely accepted that formation mechanism of LSFL is initiated by transient excitation of Surface Electromagnetic Waves (SEW), which, via interference with the incident laser wave, form a periodic pattern of laser energy absorption on the irradiated surface8, 33, 34, 41,42,43, thus creating a modulated temperature distribution44. Assuming that LIPSS are formed via the excitation of Surface Plasmon Polaritons (SPPs)34, 41, the 1/e2-decay length of SPPs (i.e. their mean free path, denoted by L SPP) can be calculated and associated with the regularity of the obtained periodic structures for several metals. The properties of this particular type of SEW are given by their dispersion relation, which at an air-material interface is expressed as45, 46
where ω is the laser frequency and c is the speed of light. Under the assumption that optical properties of metals do not considerably vary during the laser irradiation, the mean free path of SPPs, L SPP, can be calculated from the SPP wave number as
DLOA δθ as a function of the calculated mean free path L SPP of SEW. SEM images obtained with the same magnification are shown for metals studied in this paper (irradiation conditions are given in Table 1) with the corresponding 2D-FT images. Note that the angular sizes displayed on the 2D-FT are comparable to but not as precise as the DLOA used here. Asterisks stand for DLOA δθ data for Cr and Ni, estimated from the images of refs 15 and 26 respectively. Vertical error bars were evaluated from the convergence of the DLOA δθ (see Materials and Methods). The LIPSS fabricated in this work, which exhibit high and low regularities, are marked respectively by blue and pink. Materials located in the blue-colored area (respectively in pink-colored area) are suitable (respectively non-suitable) for the HR-LIPSS formation.
The following explanation for the preservation of coherence of SEWs (SPP) generated by the laser pulse can be proposed. The SEWs can be initiated by any sub-wavelength scattering centers39, 51 such as point defects, dipole-like nanohumps forming the sample roughness, nanoparticles or even scratches present on the surface52,53,54. When propagating to a large distance and experiencing interactions with numerous scattering centers, SEWs are loosing their initial coherence properties. Contrary to ref. 18, we hypothesize that the excited SEWs remain more independent (when their mean free path is small) within the irradiation spot, thus preserving their initial coherence with incoming laser light for forming a periodic absorption pattern. This is also in line with our observations that metals with short SPP decay lengths allow for better periodicity compared to metals with long SPP decay lengths. Interaction between rapidly decaying SEWs is reduced that enables to support their coherence with the incoming light even within relatively large irradiation spots15.
At relatively high laser fluences which are exploited in this work for generation of LIPSS on metal surfaces, free electrons can gain energies of several electron-Volts during the laser pulse action31, 57. As a consequence, their optical response can be dramatically changing, thus affecting the results of our predictions. Hence, it is important to investigate the possible changes in the SPP mean free path during laser irradiation.
was implemented in the numerical scheme of the TTM, with ν eff to be the temperature dependent effective collision frequency31, and ω and ω pe to be respectively the laser and plasma frequency. Details of the modeling can be found in the Supplementary Information, section S5. The calculations thus allow for self-consistent simulations of the temporal evolution of the electron and lattice temperatures and the dielectric permittivity. The latter enables to calculate the temporal variations of L SPP and provides the reflection and absorption coefficients, R(t) and \(\alpha _\textabs(z,t)=4\pi \,\rmI\rmm(\sqrt\varepsilon (z,t))/\lambda \) respectively (z is the distance from the sample surface to a point inside the bulk). The results of simulations for Ti and Mo are presented in Fig. 4(a) and (b) respectively, showing the evolution of the dielectric permittivity and the corresponding variations of the SPP mean free path during the laser pulse irradiation at fluences, which are typical for production of the HR-LIPSS reported here. Hence, an important conclusion can be made that L SPP is decreasing during the irradiation. This provides vital consequences for the HR-LIPSS direct writing. During the irradiation, materials with initially small L SPP processed with ultrashort laser pulses will continue to satisfy the condition for obtaining highly regular periodic structures, as indicated in Table 2. Furthermore, according to our prediction, the regularity can be even improving upon swift laser heating due to dynamically decreasing L SPP value. This can imply that some materials, which have relatively large L SPP under normal conditions, can exhibit a tendency of improved LIPSS regularity with increasing laser fluence, which calls for further studies.
We used the freely available OrientationJ plugin23 written for the ImageJ open-source software59 based on the tensor structure analysis of the image to be processed. The specific module Orientation Distribution with the Riesz Filters structure tensor was used. No Gaussian smearing was applied. For each analysis, the angle distribution was corrected from its offset (minimum value of the spectrum) and the half width at half maximum was extracted to obtain the DLOA, δθ.
The stiffness and torsional spring constants were calculated using the methods outlined in (Matsushita et al., 2010). Briefly, the variances in each relevant degree of freedom were computed directly from the simulation data followed by the use of the equipartition theorem to assign an effective spring constant to each mode of deformation. We calculated the stiffness spring constant by considering the distance di,j(t) between the center of mass (COM) of ARi to ARj (Fig. 3 A):
AHRI Liquid to Liquid Heat Exchanger (LLHE) Certification Program ensures that the product performs in accordance with manufacturers' published specifications, and is particularly useful in applications such as district cooling substations, ice-storage systems, data centers and free cooling systems.
At its core, the operating system is known as Android Open Source Project (AOSP)[4] and is free and open-source software (FOSS) primarily licensed under the Apache License. However most devices run on the proprietary Android version developed by Google, which ship with additional proprietary closed-source software pre-installed,[5] most notably Google Mobile Services (GMS)[6] which includes core apps such as Google Chrome, the digital distribution platform Google Play, and the associated Google Play Services development platform. While AOSP is free, the "Android" name and logo are trademarks of Google, which imposes standards to restrict the use of Android branding by "uncertified" devices outside their ecosystem.[7][8]
In 2010, Google launched its Nexus series of devices, a lineup in which Google partnered with different device manufacturers to produce new devices and introduce new Android versions. The series was described as having "played a pivotal role in Android's history by introducing new software iterations and hardware standards across the board", and became known for its "bloat-free" software with "timely ... updates".[37] At its developer conference in May 2013, Google announced a special version of the Samsung Galaxy S4, where, instead of using Samsung's own Android customization, the phone ran "stock Android" and was promised to receive new system updates fast.[38] The device would become the start of the Google Play edition program, and was followed by other devices, including the HTC One Google Play edition,[39] and Moto G Google Play edition.[40] In 2015, Ars Technica wrote that "Earlier this week, the last of the Google Play edition Android phones in Google's online storefront were listed as "no longer available for sale" and that "Now they're all gone, and it looks a whole lot like the program has wrapped up".[41][42] 2ff7e9595c
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