Bioprocess optimization is a prime target to decrease the cost of functionalized medium-chain-length poly(3-hydroxyalkanoate) (mcl-PHA). We have already demonstrated at the laboratory scale that the ...pomace of white wine grapes is a promising growth substrate for the biosynthesis of mcl-PHA that is both cheap and does not compete with food and land use. Here, we report the scale-up of a 2-step, 100 L bioprocess with Pseudomonas putida KT2440 involving: (1) a batch growth phase on extract of Gewurztraminer grape pomace, and (2) a fed-batch polymer accumulation phase with a linear feed of 50 mol % octanoic acid and 50 mol % 10-undecenoic acid. With this approach, we achieved a cell dry weight of 14.2 ± 0.3 g L.sup.-1 containing 41.1 ± 1.3 wt % of poly(3- hydroxyoctanoate-co-3-hydroxy-10- undecenoate) with 53 mol % and 47 mol % of saturated and unsaturated monomers, respectively. The molecular weight (M.sub.w) was 139 000 Da (PDI = 1.97) and DSC analysis showed a T.sub.g of -45.5°C but no T.sub.m thus indicating a completely amorphous polymer. Key words: polyhydroxyalkanoate, mcl-PHA, scale-up, pomace, functionalized PHA
Conventional thermogravimetric analysis (TG) uses constant heating rates to determine decomposition rates of a material and compositional analysis. Often, the decomposition steps can not be separated ...clearly enough due to parallel or consecutive reactions. If the reaction rates and the respective activation energies are enough different the TG resolution can be much enhanced by lowering the heating rate during the decomposition steps. The automated discrete adjustment of the heating rate is controlled by a set of parameters, such as threshold values, waiting times and rate factors. This technique, called MaxRes, allows for faster compositional analysis without loss of resolution. The same technique is also applicable to thermomechanical analysis (TMA) if time/temperature dependent events such as softening are to be separated.
This study evaluated the efficacy of a range of commercially available fining agents and other interventions on reducing 2-isopropyl-3-methoxypyrazine (IPMP) concentration and taint characteristics ...of white and red wine affected by Harmonia axyridis (HA). Wines fermented in the presence of HA beetles were treated with bentonite, activated charcoal, oak chips, deodorized oak chips and either ultraviolet (red wine) or visible (white wine) light. IPMP concentrations were lowered by activated charcoal in white wine and deodorized oak in red wine. Treatment with oak chips reduced the intensity of HA-associated sensory attributes ('ladybug taint') in both white and red wines, while other applications generally had no effect on white wine and limited effect on red wines.
A Hybrid MPI Simulator Riesen, R.
2006 IEEE International Conference on Cluster Computing,
2006-Sept.
Conference Proceeding
Performance analysis of large scale applications and predicting the impact of architectural changes on the behavior of such applications is difficult. Traditional approaches to measuring applications ...usually change their behavior, require recompilation, and need specialized tools to extract performance information. Often the tools are programming language specific and not suitable for all applications. If instead, an application is to be modeled to gather the same kind of information, then in-depth knowledge of the application is required. Furthermore, parameters that control the behavior of the application on a specific machine have to be adjusted; often in ways that are more art than science. In this paper we describe an approach that is a hybrid between running a parallel application in stand-alone mode and simulating the network it uses for MPI data exchanges. The discrete event network simulator is execution-driven by the application. We explain how our early prototype works and how it can be used. We mention several experiments that we have already performed with this prototype and show its potential for future research
Own-rooted 'Seyval Blanc' vines were evaluated over 5 years in the following training systems: bilateral cordon, bilateral cordon sylvos (sylvos), upright cordon-spur pruned, and upright cordon-cane ...pruned. Vines in all systems were spaced 1.8 x 2.7 m and were shoot thinned to 40 shoots and cluster thinned to one cluster per shoot. Cumulative yields over 5 years of the upright cordon systems were higher than vines in the sylvos system. Average weight of cane prunings was higher in the upright cordon vines than in all other systems. Vines trained to the sylvos system had more canopy gaps, less Botrytis bunch rot, and higher juice soluble solids than other systems in some years. The chemical constituents of the must and wine or evaluation by tasting showed little influence of training system.
This study sought to further characterize the effects of Harmonia axyridis (HA) on white and red wine quality, including determining the influence of bottle aging on the composition and sensory ...attributes of HA‐affected wines and examining the hypothesis that methoxypyrazines are responsible for the characteristic sensory profiles of these wines. Vinification in the presence of HA beetles had little effect on basic physical and chemical attributes of white and red wine, either at bottling or after 10‐mo of aging. 2‐Isopropyl‐3‐methoxypyrazine (IPMP) was detected at relatively high concentrations and at levels above sensory threshold in wines fermented in the presence of HA. In addition, significant positive correlations were found between IPMP concentration in wines and sensory attributes that characterize HA“taint.” After aging, the aroma and flavor profiles of HA‐ treated wines were similar to those of newly bottled wines. White wines showed a trend, as beetle numbers increased, of higher intensities of peanut, bell pepper, asparagus, and bitterness attributes and lower scores for fruit and floral descriptors. Red wines showed a trend of higher scores for peanut and asparagus/bell pepper aroma intensity and lower scores for fruit attributes as the number of beetles increased.
Many of the modern networks used to interconnect nodes in cluster-based computing systems provide network-interface cards (NICs) that offer programmable processors. Substantial research has been done ...with the focus of offloading processing from the host to the NIC processor. However, the research has primarily focused on the static offload of specific features to the NIC, mainly to support the optimization of common collective and synchronization-based communications. We describe the design and implementation of a framework based on MP1CH-GM to support the dynamic NIC-based offload of user-defined modules for Myrinet clusters. We evaluate our implementation on a 16-node cluster using a NIC-based version of the common broadcast operation and we find a maximum factor of improvement of 1.2 with respect to total latency as well as a maximum factor of improvement of 2.2 with respect to average CPU utilization under conditions of process skew. In addition, we see that these improvements increase with system size, indicating that our NIC-based framework offers enhanced scalability when compared to a purely host-based approach.
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