105,903 research outputs found
Atefeh Khazeni, Peter H. Adler, Zakieh Telmadareiiy, Mohammad Ali Oshaghi1,*, Hasan Vatandoost, Seyed Mohammad Abtahi & Abolfazl Lotfi
No full textKhazeni, Atefeh, Adler, Peter H., Telmadareiiy, Zakieh, Oshaghi, Mohammad Ali, Vatandoost, Hasan, Abtahi, Seyed Mohammad, Lotfi, Abolfazl (2013): Atefeh Khazeni, Peter H. Adler, Zakieh Telmadareiiy, Mohammad Ali Oshaghi1,*, Hasan Vatandoost, Seyed Mohammad Abtahi & Abolfazl Lotfi. Zootaxa 3718 (6): 600-600, DOI: 10.11646/zootaxa.3718.6.
Chyloperitoneum: A Rare Complication after Abdominal Aortic Aneurysm Repair
No full textWe report a case of chylous ascites as a rare complication following elective aortic aneurysm repair in a 66-year-old male. After early development of this condition on the second postoperative day, relaparotomy was performed with ligation of fistulae as well as omentoplasty. After recurrence of chylous ascites, conservative treatment consisting of parenteral nutrition and a low-fat diet for 3 months along with continuous peritoneal drainage finally led to successful resolution of this complication. DOI: 10.1007/s100169910030
Ultrasonic Data of signals backscattered by mortar using the principal component analysis
No full textInvestigation of ultrasonic parameters of signals backscattered by mortar using the Principal Component Metho
Characterization of Data of ultrasonic parameters of signals backscattered by mortar using the principal component analysis
No full textIinvestigation of ultrasonic parameters of signals backscattered by mortar using the Principal Component Metho
Assessment of Ultrasonic Data of signals backscattered by mortar using the principal component analysis
No full textInvestigation of ultrasonic parameters of signals backscattered by mortar using the Principal Component Metho
Analysis and Design of D-Band Cascode SiGe BiCMOS Amplifiers with Gain-Bandwidth Product Enhanced by Load Reflection
No full textEmerging applications in D-band (110-170GHz) demand amplifiers with high gain-bandwidth (GBW) products. In this frequency range, the cascode stage offers superior available gain, thanks to the high output impedance, but the design of the output matching network entails a GBW tradeoff. The issue is deeply investigated in this work. Simple, closed-form equations for gain and bandwidth as a function of the load reflection coefficient are derived, leading to the following design insights: 1) for maximum gain and bandwidth, the output matching network should be implemented with positive (magnetic) reactances; 2) with lossy reactances, an optimal load reflection coefficient exists to maximize the power gain, Γ L-opt; and 3) by selecting Γ L < Γ L-opt, the bandwidth increases quickly with a marginal gain penalty, finally enhancing the GBW product. Leveraging the results of the analysis, single-stage and multistage stagger-tuned amplifiers are implemented in SiGe BiCMOS technology. Two-and three-stage amplifiers demonstrate more than 60GHz bandwidth with 20 and 28dB gain, respectively, corresponding to 700GHz and 1.7 THz GBW. Normalizing gain and bandwidth to the number of stages and technology f the resulting figure of merit is remarkably higher than previously reported silicon amplifiers in the same band
150 GHz Differential Amplifiers with Lumped-Elements Matching Networks in 55 nm SiGe BiCMOS
No full textThis paper presents compact D-band amplifiers in 55 nm SiGe BiCMOS technology. Device models and design tools are first validated with measurements on elementary components above 100 GHz. Then, amplifiers are designed leveraging lumped components in matching networks for minimum area occupation. A differential topology is developed for robustness against parasitic effects of the non-ideal ground, a key issue with lumped components at high frequency. Experimental results are in very good agreement with simulations. The 1-stage amplifier reaches 8 dB gain at 156 GHz and 17.8 GHz bandwidth in 0.026 mm2 silicon area. The 2-stage amplifier displays 17.4 dB gain at 157 GHz with 42.7 GHz bandwidth in 0.048 mm2. Compared to previously reported SiGe amplifiers in similar frequency range, more than 2x core area reduction is demonstrated at comparable gain-bandwidth product
Design of Compact D-Band Amplifiers with Accurate Modeling of Inductors and Current Return Paths in 55-nm SiGe BiCMOS
No full textThis letter presents 1-stage and 2-stage compact D-band amplifiers with lumped-element matching networks implemented in 55 nm SiGe BiCMOS. To correctly account for the effects of a nonideal ground plane, i.e., reactances in current return paths, and coupling of inductors with nearby layout structures, a shielded 2-port, 4-terminal simulation strategy for inductors is proposed. Validated by measurements, the approach allows very accurate design of compact amplifiers in D-band. The 1-stage design proves 11.8 dB gain at 152 GHz and 17.9 GHz bandwidth in 0.031 mm2. With the 2-stage amplifier, featuring 20.1 dB gain at 150 GHz with 24.5 GHz bandwidth in 0.058 mm2, from 2 imes to 5.7 imes area reduction is demonstrated against similar SiGe amplifiers in the same frequency band
Chyloperitoneum - A rare complication after abdominal aortic aneurysm repair
No full textWe report a case of chylous ascites as a rare complication following elective aortic aneurysm repair in a 66-year-old male. After its early development on the second postoperative day, re-laparotomy was performed with ligation of fistulas and omentumplasty. After recurrence of chylous ascites, conservative treatment for three months including parenteral nutrition and low-fat diet under continuous peritoneal drainage led finally to success
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