117 research outputs found
Using Large-Angle Beamstrahlung To Detect And Diagnose Colliding Beams For Luminosity Optimization
The large-angle-beamstrahlung is a very effective technique that can be used to monitor two crossing beams. Monitoring the beam helps in analyzing and studying the beams profiles, allowing beams adjustments, and eventually leading to a perfect beams collision. The perfect beam collision results in a higher luminosity; as a result, a high particles production rate and new physics can be discovered
Recent Trends in Plasmonic Nanowire Solar Cells
Light trapping is crucial for low-cost and highly efficient nanowire (NW) solar cells (SCs). In order to increase the light absorption through the NWSCs, plasmonic materials can be incorporated inside or above the NW design. In this regard, two novel designs of plasmonic NWSCs are reported and analyzed using 3D finite difference time domain method. The geometrical parameters of the reported designs are studied to improve their electrical and optical efficiencies. The ultimate and power conversion efficiencies (PCE) are used to quantify the conversion efficiency of the light into electricity. The first design relies on funnel shaped SiNWs with plasmonic core while the cylindrical NWs of the second design are decorated by Ag diamond shaped. The calculated ultimate efficiency and PCE of the plasmonic funnel design are equal to 44% and 18.9%, respectively with an enhancement of 43.3 % over its cylindrical NWs counterpart. This enhancement can be explained by the coupling between the three optical modes, supported by the upper cylinder, lower cone and plasmonic material. Moreover, the cylindrical SiNWs decorated by Ag diamond offer an ultimate efficiency and short-circuit current density of 25.7%, and 21.03 mA∕cm2, respectively with an improvement of 63% over the conventional cylindrical SiNWs
Wireless Sensor Network on Board Vessels
International audienceWireless Sensor Networks (WSNs) have been used recently in different applications such as environmental monitoring and target tracking. Few papers have investigated the viability of this technology on board ships. We study in this paper the possibility of replacing the wired shipboard monitoring system by a WSN. This environment has a specific metallic structure which makes the wireless communication more difficult than in other classical indoor and outdoor environments. Two types of experiments have been carried out on board a ferry-type boat during sailings and stopovers. The first experiment consists of point-to-point measurements using ZigBee-based equipments and the second one consists of deploying and testing a WSN on board the ferry. These tests have been conducted during realistic conditions on board the ferry, which give a high level of reliability to results with respect to the earlier experiments on board ships moored to the harbor. In spite of the harsh metallic structure and the dynamic environments on board the ferry, the obtained results have shown that the wireless solution may be a cost-effective alternative of the huge amount of cables used actually to connect sensors to central control units
Performance Analysis of a Hierarchical Shipboard Wireless Sensor Network
International audienceWireless Sensor Networks (WSN) have recently gained a great attention in several applications such as environmental monitoring and target tracking. Applying this technology to shipboard monitoring systems may be a cost-effective solution to reduce the cost of wires installation and maintenance. However, wireless communications on board ships may be severely obstructed by the metallic structure of bulkheads. In this paper, we analyze the efficiency of a shipboard WSN by measurement and simulation. A measurement campaign is conducted to study the radio wave propagation and to verify the feasibility of a WSN on board a ship. Based on the measurement results, a hierarchical group-based topology for a large-scale shipboard WSN is proposed. A realistic simulation model of the ship, taking into account the environment particularities, is then performed using OPNET network simulator. Performance of the WSN architecture is evaluated using the ZigBee model. Measurement results show the feasibility of WSN technology on board ships, while simulation results show significant performance of proposed architecture in terms of end-to-end delay and packet delivery ratio
Tapered Plasmonic Nanoantennas for Energy Harvesting Applications
In this chapter, novel designs of tapered-dipole nanoantennas are investigated for energy harvesting applications. A full systematic analysis for the proposed structure is presented where the harvesting efficiency, return loss, radiation pattern, and near-field enhancement are calculated using a finite-element frequency domain solver. Simulation results show that the proposed nanoantennas can achieve a harvesting efficiency of 60% at a wavelength of 500 nm where the antenna input impedance is matched to that of fabricated rectifying devices. Additionally, the cross-tapered nanoantenna offers a near-field enhancement factor of 252 V/m, which is relatively high compared to previously reported nanoantennas. The spatial and spectral resonance modes are investigated, and the simulation results indicate the ability of the cross geometry to be utilized in color-sorting applications. Moreover, the particle swarm optimization technique is adapted to configure the proposed designs for maximum performance
Étude de la propagation des ondes électromagnétiques pour le déploiement des réseaux sans fil à bord d'un bateau
International audienceAfin de déployer des réseaux de communications sans fil (réseau local sans fil, réseau de capteurs, téléphone sans fil) à bord des navires, une étude de la propagation des ondes électromagnétiques (EM) est nécessaire dans cet environnement particulier. En effet, les communications sans fil à l'intérieur d'un bateau peuvent être sévèrement limitées par la structure métallique des ponts, des cloisons et des portes étanches. Cet article présente une étude expérimentale de la propagation des ondes EM à bord des navires. Ce travail fait partie du projet SAPHIR financé par la région Bretagne. Des mesures en porteuse pure, visant à déterminer la couverture radioélectrique pour des environnements typiques, ont été réalisées à bord d'un ferry. Ensuite, d'autres mesures, consistant en une caractérisation doublement directionnelle du canal de propagation en utilisant un sondeur MIMO (Multiple Input Multiple Output), ont été réalisées. Les mesures MIMO visent à déterminer les principales directions de propagation des ondes EM dans des scénarios typiques, tels que la communication entre des pièces adjacentes, les ponts adjacents, ou entre les cabines des passagers et les couloirs
Severe Cholestasis and Bile Cast Nephropathy Induced by Anabolic Steroids Successfully Treated with Plasma Exchange
We report a case of a bodybuilder who took a regimen of anabolic steroids containing stanozolol and testosterone propionate for 8 weeks which led to the development of jaundice and severe pruritus with serum total bilirubin reaching 41.22 mg/dL. Despite supportive care with fluid and albumin therapy, serum creatinine was progressively increasing. He underwent 6 successful sessions of plasma exchange (PE) with marked improvement at the end of the sessions. Three months after discharge, the patient’s creatinine and total bilirubin levels were 1.08 mg/dL and 1.2 mg/dL, respectively
Focused Ultrasound Stimulation of Microbubbles in Combination With Radiotherapy for Acute Damage of Breast Cancer Xenograft Model
Objective: Several studies have focused on the use of ultrasound-stimulated microbubbles (USMB) to induce vascular damage in order to enhance tumor response to radiation. Methods: In this study, power Doppler imaging was used along with immunohisto- chemistry to investigate the effects of combining radiation therapy (XRT) and USMB using an ultrasound-guided focused ultrasound (FUS) therapy system in a breast cancer xenograft model. Specifically, MDA-MB-231 breast cancer xenograft tumors were induced in severe combined immuno-deficient female mice. The mice were treated with FUS alone, ultrasound and microbubbles (FUS + MB) alone, 8 Gy XRT alone, or a combined treatment consisting of ultrasound, microbubbles, and XRT (FUS + MB + XRT). Power Doppler imaging was conducted before and 24 h after treatment, at which time mice were sacrificed and tumors assessed histolog- ically. The immunohistochemical analysis included terminal deoxynucleotidyl transferase dUTP nick end labeling, hematoxylin and eosin, cluster of differentiation-31 (CD31), Ki-67, carbonic anhydrase (CA-9), and ceramide labeling. Results: Tumors receiving treat- ment of FUS + MB combined with XRT demonstrated significant increase in cell death (p = 0.0006) compared to control group. Furthermore, CD31 and Power Doppler analysis revealed reduced tumor vascularization with combined treatment indicating (P \u3c .0001) and (P = .0001), respectively compared to the control group. Additionally, lesser number of proliferating cells with enhanced tumor hypoxia, and ceramide content were also reported in group receiving a treatment of FUS + MB + XRT. Conclusion: The study results demonstrate that the combination of USMB with XRT enhances treatment outcomes
Electrical performance of efficient quad-crescent-shaped Si nanowire solar cell
The electrical characteristics of quad-crescent-shaped silicon nanowire (NW) solar cells (SCs) are numerically analyzed and as a result their performance optimized. The structure discussed consists of four crescents, forming a cavity that permits multiple light scattering with high trapping between the NWs. Additionally, new modes strongly coupled to the incident light are generated along the NWs. As a result, the optical absorption has been increased over a large portion of light wavelengths and hence the power conversion efficiency (PCE) has been improved. The electron–hole (e–h) generation rate in the design reported has been calculated using the 3D finite difference time domain method. Further, the electrical performance of the SC reported has been investigated through the finite element method, using the Lumerical charge software package. In this investigation, the axial and core–shell junctions were analyzed looking at the reported crescent and, as well, conventional NW designs. Additionally, the doping concentration and NW-junction position were studied in this design proposed, as well as the carrier-recombination-and-lifetime effects. This study has revealed that the high back surface field layer used improves the conversion efficiency by ∼ 80%. Moreover, conserving the NW radial shell as a low thickness layer can efficiently reduce the NW sidewall recombination effect. The PCE and short circuit current were determined to be equal to 18.5% and 33.8 mA/cm for the axial junction proposed. However, the core–shell junction shows figures of 19% and 34.9 mA/cm. The suggested crescent design offers an enhancement of 23% compared to the conventional NW, for both junctions. For a practical surface recombination velocity of 10 cm/s, the PCE of the proposed design, in the axial junction, has been reduced to 16.6%, with a reduction of 11%. However, the core–shell junction achieves PCE of 18.7%, with a slight reduction of 1.6%. Therefore, the optoelectronic performance of the core–shell junction was marginally affected by the NW surface recombination, compared to the axial junction
Assessment of diagnosis of inflammatory breast cancer cases at two cancer centers in E gypt and T unisia
The diagnosis of inflammatory breast cancer ( IBC ) is largely clinical and therefore inherently somewhat subjective. The objective of this study was to evaluate the diagnosis of IBC at two centers in N orth A frica where a higher proportion of breast cancer is diagnosed as IBC than in the U nited S tates ( U . S .). Physicians prospectively enrolled suspected IBC cases at the National Cancer Institute ( NCI ) – C airo, E gypt, and the I nstitut S alah A zaiz ( ISA ), T unisia, recorded extent and duration of signs/symptoms of IBC on standardized forms, and took digital photographs of the breast. After second‐level review at study hospitals, photographs and clinical information for confirmed IBC cases were reviewed by two U . S . oncologists. We calculated percent agreement between study hospital and U . S . oncologist diagnoses. Among cases confirmed by at least one U . S . oncologist, we calculated median extent and duration of signs and S pearman correlations. At least one U . S . oncologist confirmed the IBC diagnosis for 69% (39/50) of cases with photographs at the NCI ‐ C airo and 88% (21/24) of cases at the ISA . All confirmed cases had at least one sign of IBC (erythema, edema, peau d'orange) that covered at least one‐third of the breast. The median duration of signs ranged from 1 to 3 months; extent and duration of signs were not statistically significantly correlated. From the above‐mentioned outcomes, it can be concluded that the diagnosis of a substantial proportion of IBC cases is unambiguous, but a subset is difficult to distinguish from other types of locally advanced breast cancer. Among confirmed cases, the extent of signs was not related to delay in diagnosis. The diagnosis of inflammatory breast cancer ( IBC ) is largely clinical and therefore inherently somewhat subjective. The objective of this pilot study was to evaluate the diagnosis of IBC at two centers in N orth A frica, where a higher proportion of breast cancer is diagnosed as IBC than in the U nited S tates ( U.S. ). The diagnosis of a substantial proportion of IBC cases at the study centers was unambiguous, but a subset was difficult to distinguish from other types of locally advanced breast cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97479/1/cam448.pd
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