This paper addresses the problem of finding the state of switching devices (open or closed) in primary distribution networks so that the total loss is minimum. Radiality and capacity constraints are ...taken into account. This optimization problem is a mixed-integer nonlinear optimization problem, in which the integer variables represent the state of the switches, and the continuous variables represent the current flowing through the branches. The standard Newton method (with second derivatives) is used to compute branch currents at each stage within the integer search, which, in turn, is implemented as a simple best-first search. Although a best-first search cannot normally guarantee the optimality of the solution, the high quality of the suboptimal solutions found, together with the high processing speed, make this approach very attractive for real-size distribution systems. Results from the application of the proposed methodology to a 1128-branch, 129-switch, real-world distribution system are presented and discussed.
We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel VCSEL (Vertical ...Cavity Surface Emitting Laser) array driver capable of operating up to 5Gb/s per channel. The ASIC is designed using a 130nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has also been implemented to allow bypassing of a broken VCSEL. The ASIC also contains a power-on reset circuit that sets the ASIC to a default configuration with no signal steering. In addition, the bias and modulation currents of the individual channels are programmable. The performance of the first prototype ASIC up to 5Gb/s is satisfactory. Furthermore, we are able to program the bias and modulation currents and to bypass a broken VCSEL channel. We are currently upgrading our design to allow operation at 10Gb/s per channel yielding an aggregated bandwidth of 120Gb/s. Some preliminary results of the design will be presented.
We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel Vertical Cavity ...Surface Emitting Laser (VCSEL) array driver capable of operating up to 5Gb/s per channel. The ASIC is designed using a 130nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has also been implemented to allow bypassing of a broken VCSEL. The ASIC also contains a power-on reset circuit that sets the ASIC to a default configuration with no signal steering. In addition, the bias and modulation currents of the individual channels are programmable. We have tested the ASIC and the performance up to 5Gb/s is satisfactory. Furthermore, we are able to program the bias and modulation currents and to bypass a broken VCSEL channel. We are currently upgrading our design to allow operation at 10Gb/s per channel yielding an aggregated bandwidth of 120Gb/s. Preliminary results of the design will be presented.
Radiation-hard/high-speed parallel optical links Gan, K.K.; Buchholz, P.; Heidbrink, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2016, Letnik:
831, Številka:
C
Journal Article
Recenzirano
Odprti dostop
We have designed and fabricated a compact parallel optical engine for transmitting data at 5Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) ...array in an optical package. The ASIC is designed using only core transistors in a 65nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5Gb/s is satisfactory.
Optical link ASICs for LHC upgrades Gan, K.K.; Kagan, H.P.; Kass, R.D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Letnik:
633
Journal Article
Recenzirano
Odprti dostop
We have designed three ASICs for possible applications in a new pixel layer (insertable B-layer or IBL) for the ATLAS detector for the first phase of the LHC luminosity upgrade. The ASICs are a ...high-speed driver for the vertical-cavity surface-emitting laser (VCSEL), a receiver/decoder to decode the signal received at the PIN diode to extract the data and clock, and a clock multiplier to produce a higher frequency clock to serialize the data for transmission. These ASICs were designed using a 130
nm CMOS process to enhance the radiation-hardness. We have characterized the ASICs and the submission has been mostly successful. We irradiated the ASICs with 24
GeV/c protons at CERN to a dosage of 70
Mrad. We observed no significant degradation except the driver circuit in the VCSEL driver fabricated using the thick oxide process in order to provide sufficient voltage to drive a VCSEL. The degradation is due to the radiation induced large threshold shifts in the PMOS transistors used.
High fidelity and effective adaptive changes of the cell and tissue metabolism to changing environments require strict coordination of numerous biological processes. Multicellular organisms developed ...sophisticated signaling systems of monitoring and responding to these different contexts. Among these systems, oxygenated lipids play a significant role realized via a variety of re-programming mechanisms. Some of them are enacted as a part of pro-survival pathways that eliminate harmful or unnecessary molecules or organelles by a variety of degradation/hydrolytic reactions or specialized autophageal processes. When these “partial” intracellular measures are insufficient, the programs of cells death are triggered with the aim to remove irreparably damaged members of the multicellular community. These regulated cell death mechanisms are believed to heavily rely on signaling by a highly diversified group of molecules, oxygenated phospholipids (PLox). Out of thousands of detectable individual PLox species, redox phospholipidomics deciphered several specific molecules that seem to be diagnostic of specialized death programs. Oxygenated cardiolipins (CLs) and phosphatidylethanolamines (PEs) have been identified as predictive biomarkers of apoptosis and ferroptosis, respectively. This has led to decoding of the enzymatic mechanisms of their formation involving mitochondrial oxidation of CLs by cytochrome c and endoplasmic reticulum-associated oxidation of PE by lipoxygenases. Understanding of the specific biochemical radical-mediated mechanisms of these oxidative reactions opens new avenues for the design and search of highly specific regulators of cell death programs. This review emphasizes the usefulness of such selective lipid peroxidation mechanisms in contrast to the concept of random poorly controlled free radical reactions as instruments of non-specific damage of cells and their membranes. Detailed analysis of two specific examples of phospholipid oxidative signaling in apoptosis and ferroptosis along with their molecular mechanisms and roles in reprogramming has been presented.
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•Enzymatic phospholipid peroxidation generates death signals.•Redox lipidomics establishes cardiolipin peroxidation in apoptosis.•Cytochrome c/cardiolipin acts as a peroxidase complex.•Hydroperoxy-phosphatidylethanolamines as biomarkers of ferroptosis.•Lipoxygenases peroxidize phosphatidylethanolamines in ferroptosis.
Radiation-hard ASICs for LHC optical data transmission Gan, K.K.; Kagan, H.P.; Kass, R.D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
We have designed several ASICs for possible applications in a new ATLAS pixel layer for the first phase of the LHC luminosity upgrade. The ASICs include a high-speed driver for the VCSEL, a ...receiver/decoder to decode the signal received at the PIN diode to extract the data and clock, and a clock multiplier to produce a higher frequency clock to serialize the data for transmission. These chips were designed using a 130nm CMOS process to enhance the radiation-hardness. We have characterized the fabricated chips and the submission has been mostly successful. We irradiated the chips with 24GeV/c protons at CERN to a dosage of 70Mrad. We observed no significant degradation except the driver circuit in the VCSEL driver fabricated using the thick oxide process in order to provide sufficient voltage to drive a VCSEL. The degradation is due to the radiation induced large threshold shifts in the PMOS transistors used.
Multiple roles of reactive oxygen species (ROS) and their consequences for health and disease are emerging throughout biological sciences. This development has led researchers unfamiliar with the ...complexities of ROS and their reactions to employ commercial kits and probes to measure ROS and oxidative damage inappropriately, treating ROS (a generic abbreviation) as if it were a discrete molecular entity. Unfortunately, the application and interpretation of these measurements are fraught with challenges and limitations. This can lead to misleading claims entering the literature and impeding progress, despite a well-established body of knowledge on how best to assess individual ROS, their reactions, role as signalling molecules and the oxidative damage that they can cause. In this consensus statement we illuminate problems that can arise with many commonly used approaches for measurement of ROS and oxidative damage, and propose guidelines for best practice. We hope that these strategies will be useful to those who find their research requiring assessment of ROS, oxidative damage and redox signalling in cells and in vivo.
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