Hi all. I have the gta san andreas extreme edition on my pc. I am trying to complete the "just business" mission. When I kill all the enemies inside and on the roof, CJ and Big Smoke climb onto the bike, and they go down the staircase. My problem is that when they start going down, the game like freezes, but time still passes. Nothing happens, and I waited alot. Any idea what can I do? tkx in advance
We report experimentally on extreme events in the pulsating dynamics of an optical time-delayed system, i.e., a diode laser subject to a phase-conjugate feedback. We study the effect of the feedback strength on extreme events' properties. We show a transition to non-Gaussian statistics of the pulse intensity and an increased number of extreme events as the mirror reflectivity increases. The extreme event pulse is anticipated and followed by smaller pulses with time-delay periodicity.
An unprecedented library of single and double bay-substituted perylene-pentaphenylbenzenes (PPBs) is presented. An extreme core-distortion as well as successful elimination of aggregation interactions of perylenes was confirmed by X-ray analysis. The isomerically pure perylene-PPB hybrids show remarkable differences in their photophysical properties with respect to their regiochemistry as well as different peri-functionalization.
For a recent project in Australia, Portland cement was modified to withstand contact with temperatures above 800 C. This High Temperature (HT) cement system is applied to cement casing strings used as injection and production wells in a process known as Underground Coal Gasification (UCG). In its simplest form, this process involves drilling a production well and an injector well into an existing coal seam. Once drilling and cementing of the wells are complete the coal is ignited underground, and air and water are then introduced through an injector well. The air reforms with the combustion materials and forms a synthesis gas (syngas) containing carbon monoxide, hydrogen and methane (as a minor component), that moves under pressure through the coal seam to the production well, where it travels uphole to the downstream facility. Since coal typically resides at shallow depths, it was necessary to have cement that would set at relatively low bottomhole static temperatures of less than 39 C and have the ability to withstand the extreme temperatures of the advancing combustion front, which can exceed 800 C.
It was recently reported that the extreme thermophile Methanopyrus kandleri contains only a H2-forming N5, N10-methylenetetrahydromethanopterin dehydrogenase which uses protons as electron acceptor. We describe here the presence in this Archaeon of a second N5,N10-methylenetetrahydromethanopterin dehydrogenase which is coenzyme F420-dependent. This enzyme was purified and characterized. The enzyme was colourless, had an apparent molecular mass of 300 kDa, an isoelectric point of 3.70.2 and was composed of only one type of subunit of apparent molecular mass of 36 kDa. The enzyme activity increased to an optimum with increasing salt concentrations. Optimal salt concentrations were e.g. 2 M (NH4)2SO4, 2 M Na2HPO4, 1.5 M K2HPO4, and 2 M NaCl. In the absence of salts the enzyme exhibited almost no activity. The salts affected mainly the Vmax rather than the Km of the enzyme. The catalytic mechanism of the dehydrogenase was determined to be of the ternary complex type, in agreement with the finding that the enzyme lacked a chromophoric prosthetic group. In the presence of M (NH4)2SO4 the Vmax was 4000 U/mg (kcat=2400 s-1) and the Km for N5,N10-methylenetetrahydromethanopterin and for coenzyme F420 were 80 μM and 20 μM, respectively. The enzyme was relatively heat-stable and lost no activity when incubated anaerobically in 50 mM K2HPO4 at 90C for one hour. The N-terminal amino acid sequence was found to be similar to that of the F420-dependent N5, N10-methylenetetrahydromethanopterin dehydrogenase from Methanobacterium thermoautotrophicum, Methanosarcina barkeri, and Archaeoglobus fulgidus.
The past three years in a row marked the 50th anniversaries of three significant innovations in optics: the invention of the laser; the discovery of the nonlinear upconversion of laser light in a spectral region where laser light has not been available; and the outlining of phase matching of this upconvertion process - a recipe that makes the newly generated laser-like light bright and usable for applications. The same revolution that made it possible to create well directed beams in the visible region of the spectrum is only now happening for X-rays. Large-scale X-ray free electron lasers are promising to capture images of ultrafast dynamics in a single shot. An extreme version of nonlinear optics - high harmonic generation (HHG) - can also generate bright, coherent, beams of X-rays, with very short wavelengths 1.3 keV) that any light source, large or small scale, can generate to date. Such an ultrabroad spectral bandwidth can support X-ray pulses as short as 2.5 attoseconds and is scalable towards zeptosecond pulse durations.
Self-assembling patchy colloidal particles form a promising platform to create designer soft materials. To dress such systems with mechanical functionality, one can take inspiration from biological structures such as the cell's cytoskeleton, which consists of semiflexible filaments, whose mechanical behavior give the cell its unique mechanical properties. Here we present mechanical experiments on analogs of biological fibers, semiflexible "colloidal polymers"made from bonded patchy colloidal particles. We use optical tweezers to probe their extreme mechanics under increasingly high compressions and we reveal a rich nonlinear mechanical response involving buckling, viscoelastic creep, and ultimately break-up. We characterize and model this response using elastic and viscoelastic models involving Euler buckling and stress relaxation. This allows us to identify the critical Euler buckling force, and relate the critical bending at break-up to the finite patch size of the colloids. These results demonstrate the crucial role of the patch-patch interactions in the mechanics of self-assembled colloidal materials, and they provide mechanical relationships that are essential to design functional colloidal architectures inspired by nature.
N2 - Self-assembling patchy colloidal particles form a promising platform to create designer soft materials. To dress such systems with mechanical functionality, one can take inspiration from biological structures such as the cell's cytoskeleton, which consists of semiflexible filaments, whose mechanical behavior give the cell its unique mechanical properties. Here we present mechanical experiments on analogs of biological fibers, semiflexible "colloidal polymers"made from bonded patchy colloidal particles. We use optical tweezers to probe their extreme mechanics under increasingly high compressions and we reveal a rich nonlinear mechanical response involving buckling, viscoelastic creep, and ultimately break-up. We characterize and model this response using elastic and viscoelastic models involving Euler buckling and stress relaxation. This allows us to identify the critical Euler buckling force, and relate the critical bending at break-up to the finite patch size of the colloids. These results demonstrate the crucial role of the patch-patch interactions in the mechanics of self-assembled colloidal materials, and they provide mechanical relationships that are essential to design functional colloidal architectures inspired by nature.
AB - Self-assembling patchy colloidal particles form a promising platform to create designer soft materials. To dress such systems with mechanical functionality, one can take inspiration from biological structures such as the cell's cytoskeleton, which consists of semiflexible filaments, whose mechanical behavior give the cell its unique mechanical properties. Here we present mechanical experiments on analogs of biological fibers, semiflexible "colloidal polymers"made from bonded patchy colloidal particles. We use optical tweezers to probe their extreme mechanics under increasingly high compressions and we reveal a rich nonlinear mechanical response involving buckling, viscoelastic creep, and ultimately break-up. We characterize and model this response using elastic and viscoelastic models involving Euler buckling and stress relaxation. This allows us to identify the critical Euler buckling force, and relate the critical bending at break-up to the finite patch size of the colloids. These results demonstrate the crucial role of the patch-patch interactions in the mechanics of self-assembled colloidal materials, and they provide mechanical relationships that are essential to design functional colloidal architectures inspired by nature.
Large parts of central Europe have been hit by very extreme floods over the last decade. In many river courses, observed water levels and flow rates have exceeded previously measured maximum values and design discharge. The issue of extraordinary, that is to say extraordinarily high or 'extreme', floods has to be faced both for the purpose of creating protected areas and for developing the early warning measures required.
Experience during and after very extreme discharges has taught us that construction and technical measures for protection against extraordinary events is only possible to a limited degree. It has also been shown that application of such measures to an event of a particular volume is still necessary and purposeful. However, corresponding residual risk must also be accounted for. The best cover for this remaining risk is offered by preventive measures such as object protection, application of danger zones, timely event prediction and early-warning systems. All countries concerned have been analyzing the potential for applying corresponding measures, and conversion of this research into practice has begun.
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