Current developments in microprocessor design favor increased core counts over frequency scaling to improve processor performance and energy efficiency. Coupling this architectural trend with a message-passing protocol helps realize a data-center-on-a-die. The prototype chip (Figs. 5.7.1 and 5.7.7) described in this paper integrates 48 Pentium ™ class IA-32 cores [1] on a 6×4 2D-mesh network of tiled core clusters with high-speed I/Os on the periphery. The chip contains 1.3B transistors. Each core has a private 256KB L2 cache (12MB total on-die) and is optimized to support a message-passing-programming model whereby cores communicate through shared memory. A 16KB message-passing buffer (MPB) is present in every tile, giving a total of 384KB on-die shared memory, for increased performance. Power is kept at a minimum by transmitting dynamic, fine-grained voltage-change commands over the network to an on-die voltage-regulator controller (VRC). Further power savings are achieved through active frequency scaling at the tile granularity. Memory accesses are distributed over four on-die DDR3 controllers for an aggregate peak memory bandwidth of 21GB/s at 4× burst. Additionally, an 8-byte bidirectional system interface (SIF) provides 6.4GB/s of I/O bandwidth. The die area is 567mm 2 and is implemented in 45nm high-κ metal-gate CMOS [2].The design is organized in a 6×4 2D-array of tiles [3] to increase scalability. Each tile is a cluster of two enhanced IA-32 cores sharing a router for inter-tile communication. Cores operate in-order and are two-way superscalar. A 256 entry lookup table (LUT) extension of the 64-entry TLB translates 32-bit virtual addresses to 36-bit physical addresses. The separate L1 instruction and data caches are upsized to 16KB and support both write-through and write-back. Each L1 cache is reinforced by a unified 256KB 4-way write-back L2 cache. The L2 uses a 32-byte line size, matching the cache line size internal to the core, and has a 10-cycle hit latency. The L2 also uses in-line double-error-detection and single-error-correction for improved performance and several programmable sleep modes for power reduction. The L2 cache controller features a time-outand-retry mechanism for increased system reliability.Shared memory coherency is maintained through software protocols, such as MPI and OpenMP [4], in an effort to eliminate the communication and hardware overhead required for a memory coherent 2D-mesh. A new message-passing memory type (MPMT) is introduced as an architectural enhancement to optimize data sharing using these software procedures. A single bit in a core's TLB designates MPMT cache lines. The MPMT retains all the performance benefits of a conventional cache line, but distinguishes itself by addressing non-coherent shared memory. All MPMT cache lines are invalidated before reads/writes to the shared memory to prevent a core from working on stale data. A new instruction, MBINV, is added to the core to invalidate all MPMT cache entries in a single cycle. Subsequent reads/writes to inval...

One of the most important functions of the nose is heating the inspiratory air. The aim of the present study was to measure nasal mucosal temperature at defined intranasal sites during respiration, without interruption of nasal breathing. A total of 15 healthy volunteers was included in the study. A miniaturized thermocouple was used for continuous detection of the septal mucosal temperature in the nasal vestibule, the nasal valve area, the anterior turbinate area and the nasopharynx during respiration. The highest temperature values were measured at the end of expiration, the lowest values at the end of inspiration with a statistically significant difference (P < 0.005). Mean mucosal temperature ranged from 30.2 +/- 1.7 degrees C to 34.4 +/- 1.1 degrees C. Statistically there were significant differences between the detection sites during inspiration and expiration (P < 0.05). In our study, the temperature values of the nasal mucosa depend on the intranasal detection site and the respiratory cycle. We therefore conclude that whenever data of nasal mucosal temperature are published, it is absolutely essential to describe the precise site of detection and to give information about the time of detection in the respiratory cycle.

The anterior nasal segment is the most effective part of the nose in heating of the ambient air. The findings demonstrated the complexity of the relationship between airflow patterns and heating of inspired air. A numerical simulation of the temperature distribution using CFD is practicable.

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Radical sinus surgery with resection of the turbinates by means of midfacial degloving seems to disturb the climatization of the inspiratory air in the nasal cavity. Reduced absolute humidity and temperature may contribute to crusting, bleeding, and nasal dryness as frequent complaints of patients after aggressive sinus surgery with resection of the turbinates.

The numerical simulation demonstrates the interaction between airflow patterns and heating of respiratory air. The disturbed airflow causes reduced air conditioning. This fact may contribute to crusting and recurrent nosebleed.

Common complaints of patients with a nasal septal perforation are crusting, dryness and bleeding. As shown previously, intranasal humidity values are significantly lower in patients with a septal perforation compared with healthy volunteers. The aim of this study was to determine the influence of surgical closure of septal perforations on intranasal temperature and humidity, and to evaluate changes in clinical symptoms after surgery. Ten patients with septal perforations were included in the study. Intranasal temperature and humidity were measured at the nasal valve and anterior turbinate areas before and after surgical closure. Clinical symptoms were assessed using a nasal symptom score. The end-inspiratory humidity values were significantly (P < or = 0.05) higher postoperatively than preoperatively. The increase in temperature at the anterior turbinate area was significantly higher postoperatively. The temperature values at the nasal valve area were not significantly different. Recurrent epistaxis and nasal dryness were reduced after surgery. Nasal septal perforations disturb the intranasal temperature and humidity profile. After surgical closure, heating and humidification is improved. This may be responsible for the reduction of frequent complaints such as bleeding and dryness.

Nasal complaints in elderly patients are a consequence of lower intranasal air temperature and humidity values combined with relatively enlarged nasal cavities due to involution atrophy of the nasal mucosa.