Impact of whole-building hygrothermal modelling on the assessment of indoor climate in a library building

This paper focuses on the importance of accurately modelling the hygrothermal interaction between the building and its hygroscopic content for the assessment of the indoor climate. Libraries contain a large amount of stored books which require a stable relative humidity to guarantee their preservation. On the other hand, visitors and staff must be comfortable with the indoor climate.     

Time Petri nets as an evaluation tool for handling travel time uncertainty in vehicle routing solutions

Congestion on roads leads to uncertainty in travel times, which is important in delivery of goods, especially in a business environment where high levels of customer service are expected. Delivery periods to customers might be constrained by time windows, which makes the scheduling and routing of vehicles from the supplier’s side more difficult. Operations Research methods turn into heuristics for this type of application. But when, on top, uncertainty on travel times are the case, any hope of a simple and well-performing heuristic is lost. This study applies a methodology in which a heuristic is used to find a solution for scheduling and routing under deterministic travel times and, by means of simulation, though the use of Time Petri nets evaluates the sensitivity of the solution to uncertainties in travel times from one customer to the next in a route.     

The performance of cache-based error recovery in multiprocessors

Several variations of cache-based checkpointing for rollback error recovery from transient errors in shared-memory multiprocessors have been recently developed. By modifying the cache replacement policy, these techniques use the inherent redundancy in the memory hierarchy to periodically checkpoint the computation state. Three schemes, different in the manner in which they avoid rollback propagation, are evaluated in this paper. By simulation with address traces from parallel applications running on an Encore Multimax shared-memory multiprocessor, we evaluate the performance effect of integrating the recovery schemes in the cache coherence protocol. Our results indicate that the cache-based schemes can provide checkpointing capability with low performance overhead, but with uncontrollable high variability in the checkpoint interval     

Albumin exchange and polymorphonuclear vascular transit in hyperoxic pulmonary oedema in awake rats

Vascular inflammatory response to hyperoxia (FIO2 greater than 0.98) was studied in awake jugular and carotid catheterized rats. Simultaneous i.v. injection of 125I albumin (125I A), 99mTc polymorphonuclear cells (99mTc PMN) and 51Cr red blood cells (51Cr RBC) allowed to study both the macromolecule exchange through vascular endothelium and the leukocyte uptake by several organs (liver, lungs, spleen) with respect to radiolabelled red blood cells, as an intravascular reference. Rats were exposed to O2 for 24, 38 and 45 h. They were anesthetized and killed by exanguination 15 to 120 min following the tracer injection. After 45 h exposure, the plasmatic 125I A half-life decreased significantly (158 +/- 42 min for the control; 106 +/- 34 min for the exposed animals). The ratio 125I A/51Cr RBC varied significantly in the lung. The iodinated albumin exchange through lung vascular endothelium was altered at the 24th h, with a significant difference reached by the 45th h. At the same time, the pulmonary decreasing curve of 99mTc/51Cr RBC ratio versus time was not not modified. In our experimental conditions, there was no detectable variation in the lung uptake and vascular transit of PMN cells. The discussion of the results must be related with the technics used in the present work when the albumin exchange increased.