Power-saving method for wireless sensor network

A power saving method of the present invention is provide for a wireless sensor network including a plurality of sensor nodes each transiting between a power saving mode and a transmit/receive mode, determines whether or not there is no transmit or receive data, enters the power saving mode if there is no transmit or receive data, and controls power consumption on the basis of signal-to-noise ratios in the power saving mode. In the power saving method of the present invention, it is possible to minimize the power consumption regardless of nodes density and without an adverse effect on the connectivity of the network, since the sojourn times of the sleep and idle states are determined adaptive to the interference level from neighboring nodes.Board of Regents, University of Texas Syste

Performance Analysis On A Variable Capacity Swash Plate Compressor

A numerical study on the performance of a variable capacity swash plate compressor for an automotive air-conditioning system was carried out. The compressor under investigation had six cylinders and capacity regulation was made by changing the swash plate inclination angle. A numerical simulation program was made based on mathematical modelings on the swash plate dynamics, refrigerant states in various control volumes such as cylinders and crank room, and flows in the opening passages of electric control valve for crank room pressure control. The simulation results such as mass flow rate, compressor power consumption, cooling capacity and COP were compared with measurements within ±5% deviation over various operating conditions except at low operating speed such as idling condition. By using the simulation program, the effect of the crank room pressure on the swash plate inclination angle and the determination of the crank room pressure level by the electric control valve openings could be investigated

The Influence of Electron Beam Sterilization on In Vivo Degradation of β-TCP/PCL of Different Composite Ratios for Bone Tissue Engineering.

We evaluated the effect of electron beam (E-beam) sterilization (25 kGy, ISO 11137) on the degradation of β-tricalcium phosphate/polycaprolactone (β-TCP/PCL) composite filaments of various ratios (0:100, 20:80, 40:60, and 60:40 TCP:PCL by mass) in a rat subcutaneous model for 24 weeks. Volumes of the samples before implantation and after explantation were measured using micro-computed tomography (micro-CT). The filament volume changes before sacrifice were also measured using a live micro-CT. In our micro-CT analyses, there was no significant difference in volume change between the E-beam treated groups and non-E-beam treated groups of the same β-TCP to PCL ratios, except for the 0% β-TCP group. However, the average volume reduction differences between the E-beam and non-E-beam groups in the same-ratio samples were 0.76% (0% TCP), 3.30% (20% TCP), 4.65% (40% TCP), and 3.67% (60% TCP). The E-beam samples generally had more volume reduction in all experimental groups. Therefore, E-beam treatment may accelerate degradation. In our live micro-CT analyses, most volume reduction arose in the first four weeks after implantation and slowed between 4 and 20 weeks in all groups. E-beam groups showed greater volume reduction at every time point, which is consistent with the results by micro-CT analysis. Histology results suggest the biocompatibility of TCP/PCL composite filaments

Coprinus comatus Cap Inhibits Adipocyte Differentiation via Regulation of PPARγ and Akt Signaling Pathway

This study assessed the effects of Coprinus comatus cap (CCC) on adipogenesis in 3T3-L1 adipocytes and the effects of CCC on the development of diet-induced obesity in rats. Here, we showed that the CCC has an inhibitory effect on the adipocyte differentiation of 3T3-L1 cells, resulting in a significant decrease in lipid accumulation through the downregulation of several adipocyte specific-transcription factors, including CCAAT/enhancer binding protein β, C/EBPδ, and peroxisome proliferator-activated receptor gamma (PPARγ). Moreover, treatment with CCC during adipocyte differentiation induced a significant down-regulation of PPARγ and adipogenic target genes, including adipocyte protein 2, lipoprotein lipase, and adiponectin. Interestingly, the CCC treatment of the 3T3-L1 adipocytes suppressed the insulin-stimulated Akt and GSK3β phosphorylation, and these effects were stronger in the presence of an inhibitor of Akt phosphorylation, LY294002, suggesting that CCC inhibited adipocyte differentiation through the down-regulation of Akt signaling. In the animal study, CCC administration significantly reduced the body weight and adipose tissue weight of rats fed a high fat diet (HFD) and attenuated lipid accumulation in the adipose tissues of the HFD-induced obese rats. The size of the adipocyte in the epididymal fat of the CCC fed rats was significantly smaller than in the HFD rats. CCC treatment significantly reduced the total cholesterol and triglyceride levels in the serum of HFD rats. These results strongly indicated that the CCC-mediated decrease in body weight was due to a reduction in adipose tissue mass. The expression level of PPARγ and phospho-Akt was significantly lower in the CCC-treated HFD rats than that in the HFD obesity rats. These results suggested that CCC inhibited adipocyte differentiation by the down-regulation of major transcription factor involved in the adipogenesis pathway including PPARγ through the regulation of the Akt pathway in 3T3-L1 cells and HFD adipose tissue

Compact Penta-Band Dual ZOR Antenna for Mobile Applications

A compact penta-band dual zeroth order resonator (ZOR) antenna with band-stop filter is proposed for mobile applications. The ZOR antenna is designed with modified mushroom-like structures extended on nonground region to obtain good efficiency and broad bandwidth. This modified mushroom-like structure is confirmed as double negative (DNG) transmission line by full wave simulated dispersion relation. Moreover, a bended patch and a band-stop filter (BSF) are employed to increase efficiency and bandwidth, respectively. The length of each antenna is about λ0/10 at the resonant frequencies of 900 MHz and 1800 MHz, respectively. The overall dimension of the antenna is 54.4 mm (length) × 4 mm (width) × 5 mm (height). The total efficiencies in low and high bands are measured more than 40% and 70%, respectively

Optimizing Ship Speed to Minimize Total Fuel Consumption with Multiple Time Windows

We study the ship speed optimization problem with the objective of minimizing the total fuel consumption. We consider multiple time windows for each port call as constraints and formulate the problem as a nonlinear mixed integer program. We derive intrinsic properties of the problem and develop an exact algorithm based on the properties. Computational experiments show that the suggested algorithm is very efficient in finding an optimal solution

A New Approach to Predict the Thermal Conductivity of Composites with

An examination of the concept of a microgeometry proposed by Benveniste reveals that the thermal conductivity of the concentric sphere adopted by generalized self-consistent model (GSCM) is equal to that of the composite. It is also noted that the thermal conductivities of the composite with spherical fillers predicted by GSCM and modified Eshelby model (MEM) are the same. These equivalencies enable to propose a simple and alternative approach for determining the thermal conductivity of the composite with multiply coated spherical fillers by applying MEM repeatedly. The present result is compared and shows the exact agreement with the results from literatures

A multicenter, prospective, randomized, controlled trial evaluating the safety and efficacy of intracoronary cell infusion mobilized with granulocyte colony-stimulating factor and darbepoetin after acute myocardial infarction: study design and rationale of the 'MAGIC cell-5-combination cytokine trial'

<p>Abstract</p> <p>Background</p> <p>Bone marrow derived stem/progenitor cell transplantation after acute myocardial infarction is safe and effective for improving left ventricular systolic function. However, the improvement of left ventricular systolic function is limited. This study will evaluate novel stem/progenitor cell therapy with combination cytokine treatment of the long-acting erythropoietin analogue, darbepoetin, and granulocyte colony-stimulating factor (G-CSF) in patients with acute myocardial infarction.</p> <p>Methods</p> <p>The 'MAGIC Cell-5-Combination Cytokine Trial' is a multicenter, prospective, randomized, 3-arm, controlled trial with blind evaluation of the endpoints. A total of 116 patients will randomly receive one of the following three treatments: an intravenous darbepoetin infusion and intracoronary infusion of peripheral blood stem cells mobilized with G-CSF (n = 58), an intracoronary infusion of peripheral blood stem cells mobilized with G-CSF alone (n = 29), or conventional therapy (n = 29) at phase I. Patients with left ventricular ejection fraction < 45% at 6 months, in the patients who received stem cell therapy at phase I, will receive repeated cell therapy at phase II. The objectives of this study are to evaluate the safety and efficacy of combination cytokine therapy with erythropoietin and G-CSF (phase I) and repeated progenitor/stem cell treatment (phase II).</p> <p>Discussion</p> <p>This is the first study to evaluate the safety and efficacy of combination cytokine based progenitor/stem cell treatment.</p> <p>Trial registration</p> <p><url>http://www.ClinicalTrials.gov</url> identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00501917">NCT00501917</a>.</p