Test results of a Stirling engine utilizing heat exchanger modules with an integral heat pipe

The Heat Pipe Stirling Engine (HP-1000), a free-piston Stirling engine incorporating three heat exchanger modules, each having a sodium filled heat pipe, has been tested at the NASA-Lewis Research Center as part of the Civil Space Technology Initiative (CSTI). The heat exchanger modules were designed to reduce the number of potential flow leak paths in the heat exchanger assembly and incorporate a heat pipe as the link between the heat source and the engine. An existing RE-1000 free-piston Stirling engine was modified to operate using the heat exchanger modules. This paper describes heat exchanger module and engine performance during baseline testing. Condenser temperature profiles, brake power, and efficiency are presented and discussed

Extraperitoneal v Intraperitoneal Robotic Prostatectomy: Analysis of Operative Outcomes

Background and Purpose: Robotic prostatectomy can be performed either via an extra- or intraperitoneal approach. The extraperitoneal approach has advantages similar to those of an extraperitoneal open radical prostatectomy, but the potential disadvantages of a small working space. We report our experience using both approaches. Methods: From July 2003 to June 2004, 55 patients underwent a robot-assisted laparoscopic prostatectomy. During the first 6 months, 21 prostatectomies were performed using an intraperitoneal approach (group 1); 34 were performed using an extraperitoneal approach (group 2) during the next 6 months. Clinicopathologic parameters and perioperative complications were compared in both groups. All patients were categorized as intent-to-treat analysis. Results: Median surgery time was significantly shorter in the extraperitoneal compared with the intraperitoneal approach (3 hours and 34 minutes v 4 hours and 1 minute, respectively, P = 0.017). This was because of the shorter time interval between the skin incision and incision of the endopelvic fascia in the extraperitoneal v the intraperitoneal approach (55 minutes v 74 minutes, respectively, P < 0.0001). There was no significant difference in terms of patient age, clinical and pathologic stage, length of hospital stay, and perioperative complications between the two approaches. Conclusion: Extraperitoneal robot-assisted laparoscopic prostatectomy offers a similar clinical outcome as the intraperitoneal approach. However, the extraperitoneal approach avoids potential bowel injury or complications related to an intraperitoneal urine leak.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63120/1/end.2007.9872.pd

Gambaran Darah Ayam Petelur Fase Grower (7--10 Minggu) pada Kepadatan Kandang Berbeda

The research aimed to determine the hematological profile (erythrocytes, leukocytes, andhemoglobin) of grower laying hens with different cage density and the best cage density. Thisresearch has been conducted in April 2014 using 210 grower laying hens 7--10 weeks in Varia AgungJaya Farm and Balai Veteriner Lampung. The treatment is given based on completely randomizeddesign (CRD), consisting of four treatments and five replications. The data was analyzed usinganalysis of variance on 5% significance level.The result of the research shows that the density of the cage 6,9,12, and 15 hens m-2 have notsignificant (P>0,05) on hematological profile (erythrocytes 1,04--2,74 x 106 mm-3; leukocytes 27,96--52,52 x 103 mm-3; and hemoglobin 6,40--8,20 g/dl)

Influence de la morphologie tridimensionnelle sur le comportement mécanique de réfractaires électrofondus

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Exact results on spin dynamics and multiple quantum dynamics in alternating spin-1/2 chains with XY-Hamiltonian at high temperatures

We extend the picture of a transfer of nuclear spin-1/2 polarization along a homogeneous one-dimensional chain with the XY-Hamiltonian to the inhomogeneous chain with alternating nearest neighbour couplings and alternating Larmor frequencies. To this end, we calculate exactly the spectrum of the spin-1/2 XY-Hamiltonian of the alternating chain with an odd number of sites. The exact spectrum of the XY-Hamiltonian is also applied to study the multiple quantum (MQ) NMR dynamics of the alternating spin-1/2 chain. MQ NMR spectra are shown to have the MQ coherences of zero and $\pm$ second orders just as in the case of a homogeneous chain. The intensities of the MQ coherences are calculated.Comment: 10 pages, 4 figure

Molecular evidence that Heligmosomoides polygyrus from laboratory mice and wood mice are separate species

The gastro-intestinal (GI) nematode Heligmosomoides polygyrus is an important experimental model in laboratory mice and a well-studied parasite of wood mice in the field. Despite an extensive literature, the taxonomy of this parasite in different hosts is confused, and it is unclear whether laboratory and field systems represent the same or different Operational Taxonomic Units (OTUs). Molecular analyses reveal high sequence divergence between H. p. bakeri (laboratory) and H. p. polygyrus (field); 3% difference in the ribosomal DNA Internal Transcribed Spacers (ITS) and 8.6% variation in the more rapidly evolving mitochondrial cytochrome c oxidase I (COI) gene. The COI sequence of U.K. H. p. polygyrus is more similar to H. glareoli from voles than to H. p. bakeri, while a single isolate of H. p. polygyrus from Guernsey confirms the extent of genetic variation between H. p. polygyrus populations. Analysis of molecular variance demonstrated that mtCOI sequence variation is associated primarily with groups with distinct ITS2 sequences, and with host identity, but is not partitioned significantly with a single combined taxon H. polygyrus incorporating European and North American isolates. We conclude therefore that the laboratory OTUshould be raised to the level of a distinct species, as H. bakeri from the laboratory mouse Mus musculus, and we reject the hypothesis that H. bakeri has diverged from H. polygyrus in the recent past following introduction into America. However, we are unable to reject the hypothesis that H. polygyrus and H. bakeri are sister taxa, and it may be that H. polygyrus is polyphyletic or paraphyletic