金剛石鉆進能量與花崗巖地層風化程度的關系

Based on experimental data from a drilling process monitoring system instrumented with a hydraulic rotary drill rig in fill-weathered granite formation, the diamond penetrating energy was analyzed. The result shows that the distribution of the penetrating energy in fill-weathered granite formation agrees with that in common weathered granite formation. A negative correlation between the viscous energy, kinetic energy, total penetrating energy and the weathered degree of granite existed, and a positive correlation between the thrust force energy and the weathered degree was presented, which indicates that there is a well response between the penetrating energy and the weathered degree of rock. However, the kinetic energy, thrust force energy and viscous energy are limited in identification of formation because of different effects in various drilling modes. The specific energy of diamond drilling (SEDD) increased with the weathered degree of rock and the values of SEDD can be classified into corresponding range according to the weathered degree of rock. It is shown that the SEDD in rotary drilling is apparently less than the specific energy of percussive drilling (SEPD) in both fill soil and very strongly weathered granite formation. Reversely, the SEDD is much more than the SEPD in lightly weathered hard rock.link_to_subscribed_fulltex

Interface identification in weathered granite strata based on a instrumented drilling system

A hydraulic rotary drill instrumented with a drilling process monitoring system (DPM) was used for site investigation in Hong Kong weathered granite foundation engineering. The penetrating parameters such as effective thrust force, rotational speed, flushing pressure, penetrating rate and displacement of the bit were monitored in real time. A varied slope was defined as a significant index for identification of dominative and subsidiary interfaces in the granite site. The result from t-test shows that the confidence of the DPM in identification of the geotechnical interfaces is 99%. Besides, the analysis of variation of the penetrating parameters at the interfaces indicates that there are different fluctuations at the interfaces in the curves of the parameters with borehole depth. The response degree of effective thrust force and penetrating rate to the variation of rock strength at the interfaces is 81.82% alone.link_to_subscribed_fulltex

Theory and approach of identification of ground interfaces based on rock drillability index

Rock drillability index is a very key parameter in selection of drill bit type and determination of productivity in petroleum, mining and geology. Unfortunately, there are many limits in the current definition as well as experimental methods. Drillability is redefined and a new concept of drillability index is brought out from analysis. Under the new concept, the drillability index is defined as penetration rate under specific energy. Based on the coupling relationship among effective thrust, rotation speed, penetration rate and drillability index, a calculation formula is established. Besides, the sensitivity of the drillability index in identification of ground layer is analyzed and its physical signification is expatiated also. The result shows that the new index overcomes the blind area in the traditional concept and can be used in continuous identification of ground layer along borehole profile.link_to_subscribed_fulltex

A comparison of intrauterine haemopoietic cell transplantation and lentiviral gene transfer for the correction of severe β-thalassaemia in a HbbTh3/+ murine model

Major haemoglobinopathies place tremendous strain on global resources. Intrauterine haemopoietic cell (IUHCT) and gene (IUGT) therapies can potentially reduce perinatal morbidities with greater efficacy than postnatal therapy alone. We performed both procedures in the thalassaemic HbbTh3/+ murine model. Intraperitoneal delivery of coisogenic cells at E13-14 produced dose-dependent chimerism. High-dose adult bone marrow (BM) cells maintained 0.2-3.1% chimerism over ~24 weeks and treated heterozygotes demonstrated higher chimerism than wild-type pups (1.6 vs. 0.7%). Fetal liver cells produced higher chimerism compared to adult BM when transplanted at the same doses, maintaining 1.8-2.4% chimerism over ~32 weeks. We boosted transplanted mice postnatally with adult BM cells following busulfan conditioning. Engraftment was maintained at >1% only in recipients which were chimeric prior to boosting. IUHCT-treated non-chimeras and non-IUHCT mice showed micro- or no chimerism. Additional fludarabine treatment produced higher chimerism than busulfan alone. Engraftment was more effective following higher starting chimerism prior to boosting and in heterozygotes. Chimeric heterozygotes expressed 2.2-15.1% donor cells with eventual decline at 24 weeks (vs. <1% in non-chimeras) and demonstrated improved haematological indices and smaller spleens compared to untreated heterozygotes. Intravenous delivery of GLOBE lentiviral-vector expressing HBB (human β-globin) resulted in vector concentration of 0.001-0.6 copies/cell. Most haematological indices were higher in treated than untreated heterozygotes including haemoglobin and mean corpuscular volume, though still lower than in wild-types. Thus both direct IUGT and IUHCT strategies can be used to achieve haematological improvement but require further dose optimisation. IUHCT will be useful combined with postnatal transplantation to further enhance engraftment

Clinical and physiological effects of transcranial electrical stimulation position on motor evoked potentials in scoliosis surgery

<p>Abstract</p> <p>Background</p> <p>During intraoperative monitoring for scoliosis surgery, we have previously elicited ipsilateral and contralateral motor evoked potentials (MEP) with cross scalp stimulation. Ipsilateral MEPs, which may have comprised summation of early ipsilaterally conducted components and transcallosally or deep white matter stimulated components, can show larger amplitudes than those derived purely from contralateral motor cortex stimulation. We tested this hypothesis using two stimulating positions. We compared intraoperative MEPs in 14 neurologically normal subjects undergoing scoliosis surgery using total intravenous anesthetic regimens.</p> <p>Methods</p> <p>Trancranial electrical stimulation was applied with both cross scalp (C3C4 or C4C3) or midline (C3Cz or C4Cz) positions. The latter was assumed to be more focal and result in little transcallosal/deep white matter stimulation. A train of 5 square wave stimuli 0.5 ms in duration at up to 200 mA was delivered with 4 ms (250 Hz) interstimulus intervals. Averaged supramaximal MEPs were obtained from the tibialis anterior bilaterally.</p> <p>Results</p> <p>The cross scalp stimulating position resulted in supramaximal MEPs that were of significantly higher amplitude, shorter latency and required lower stimulating intensity to elicit overall (Wilcoxon Signed Rank test, p < 0.05 for all), as compared to the midline stimulating position. However, no significant differences were found for all 3 parameters comparing ipsilaterally and contralaterally recorded MEPs (p > 0.05 for all), seen for both stimulating positions individually.</p> <p>Conclusions</p> <p>Our findings suggest that cross scalp stimulation resulted in MEPs obtained ipsilaterally and contralaterally which may be contributed to by summation of ipsilateral and simultaneous transcallosally or deep white matter conducted stimulation of the opposite motor cortex. Use of this stimulating position is advocated to elicit MEPs under operative circumstances where anesthetic agents may cause suppression of cortical and spinal excitability. Although less focal in nature, cross scalp stimulation would be most suitable for infratentorial or spinal surgery, in contrast to supratentorial neurosurgical procedures.</p

Intraoperative monitoring study of ipsilateral motor evoked potentials in scoliosis surgery

Ipsilateral motor evoked potentials (MEPs) in spinal cord surgery intraoperative monitoring is not well studied. We show that ipsilateral MEPs have significantly larger amplitudes and were elicited with lower stimulation intensities than contralateral MEPs. The possible underlying mechanisms are discussed based on current knowledge of corticospinal pathways. Ipsilateral MEPs may provide additional information on the integrity of descending motor tracts during spinal surgery monitoring

Sleep-Disordered Breathing in Alcoholics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66229/1/j.1530-0277.1999.tb04034.x.pd

Multicore implementation of a fixed-complexity tree-search detector for MIMO communications

[EN] Multicore systems allow the efficient implementation of signal processing algorithms for communication systems due to their high parallel processing capabilities. In this paper, we present a high-throughput multicore implementation of a fixed-complexity tree-search-based detector interesting for MIMO wireless communication systems. Experimental results confirm that this implementation allows to accelerate the data detection stage for different constellation sizes and number of subcarriers.This work was supported by the TEC2009-13741 project of the Spanish Ministry of Science, by the PROMETEO/2009/013 project and ACOMP/2012/076 of the Generalitat Valenciana, and the Vicerrectorado de Investigacion de la UPV through Programa de Apoyo a la Investigacion y desarrollo (PAID-05-11-2898).Ramiro Sánchez, C.; Roger Varea, S.; Gonzalez, A.; Almenar Terré, V.; Vidal Maciá, AM. (2013). Multicore implementation of a fixed-complexity tree-search detector for MIMO communications. The Journal of Supercomputing (Online). 65(3):1010-1019. https://doi.org/10.1007/s11227-012-0839-xS10101019653Paulraj AJ, Gore DA, Nabar RU, Bölcskei H (2004) An overview of MIMO communications—a key to gigabit wireless. Proc IEEE 92(2):198–218Jiang M, Hanzo L (2007) Multiuser MIMO-OFDM for next-generation wireless systems. Proc IEEE 95(7):1430–14693GPP TS 36.201, V10.0.0, Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer—general description, December 2010Lin Y, Lee H, Woh M, Harel Y, Mahlke S, Mudge T, Chakrabarti C, Flautner K (2007) SODA: a high-performance DSP architecture for software-defined radio. IEEE MICRO 27(1):114–123Yang C-H, Markovic D (2008) A multi-core sphere decoder VLSI architecture for MIMO communications. In: Global telecommunications conference, November, pp 1–6Wu D, Eilert J, Liu D (2011) Implementation of a high-speed MIMO soft-output symbol detector for software defined radio. J Signal Process Syst 63(1):27–37Tan K, Liu H, Zhang J, Zhang Y, Fang J, Voelker GM (2011) Sora: high-performance software radio using general-purpose multi-core processors. Communun ACM 54(1):99–107Roger S, Ramiro C, Gonzalez A, Almenar V, Vidal AM (2012) An efficient GPU implementation of fixed-complexity sphere decoders for MIMO wireless systems. Integr Comput-Aided Eng 19(4):341–350Chen Y-K et al (2009) Signal processing on platforms with multiple cores: Part 1-Overview and methodologies. IEEE Signal Proc Mag 6:24–25Karam LJ, AlKamal I, Gatherer A, Frantz GA, Anderson DV, Evans BL (2009) Trends in multicore DSP platforms. IEEE Signal Process Mag 26(6):38–49Barbero LG, Thompson JS (2008) Fixing the complexity of the sphere decoder for MIMO detection. IEEE Trans Wirel Commun 7(6):2131–2142Hassibi B, Vikalo H (2005) On sphere decoding algorithm. Part I, The expected complexity. IEEE Trans Signal Process 54(5):2806–2818Agrell E, Eriksson T, Vardy A, Zeger K (2002) Closest point search in lattices. IEEE Trans Inf Theory 48(8):2201–2214OpenMP v3.0, http://www.openmp.org/mp-documents/spec30.pdf , May 200