scholarly journals Investigation of Combustion Properties and Soot Deposits of Various US Crude Oils

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2368 ◽  
Author(s):  
Gurjap Singh ◽  
Mehdi Esmaeilpour ◽  
Albert Ratner

The oil boom in the North Dakota oilfields has resulted in improved energy security for the US. Recent estimates of oil production rates indicate that even completion of the Keystone XL pipeline will only fractionally reduce the need to ship this oil by rail. Current levels of oil shipment have already caused significant strain on rail infrastructure and led to crude oil train derailments, resulting in loss of life and property. Treating crude oil as a multicomponent liquid fuel, this work aims to understand crude oil droplet burning and thereby lead to methods to improve train fire safety. Sub-millimeter sized droplets of Pennsylvania, Texas, Colorado, and Bakken crude were burned, and the process was recorded with charge-couple device (CCD) and complementary metal-oxide semiconductor (CMOS) high-speed cameras. The resulting images were post-processed to obtain various combustion parameters, such as burning rate, ignition delay, total combustion time, and microexplosion behavior. The soot left behind was analyzed using a Scanning Electron Microscope (SEM). This data is expected be used for validation of combustion models for complex multicomponent liquid fuels, and subsequently in the modification of combustion properties of crude oil using various additives to make it safer to transport.

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 551
Author(s):  
Zhongjian Bian ◽  
Xiaofeng Hong ◽  
Yanan Guo ◽  
Lirida Naviner ◽  
Wei Ge ◽  
...  

Spintronic based embedded magnetic random access memory (eMRAM) is becoming a foundry validated solution for the next-generation nonvolatile memory applications. The hybrid complementary metal-oxide-semiconductor (CMOS)/magnetic tunnel junction (MTJ) integration has been selected as a proper candidate for energy harvesting, area-constraint and energy-efficiency Internet of Things (IoT) systems-on-chips. Multi-VDD (low supply voltage) techniques were adopted to minimize energy dissipation in MRAM, at the cost of reduced writing/sensing speed and margin. Meanwhile, yield can be severely affected due to variations in process parameters. In this work, we conduct a thorough analysis of MRAM sensing margin and yield. We propose a current-mode sensing amplifier (CSA) named 1D high-sensing 1D margin, high 1D speed and 1D stability (HMSS-SA) with reconfigured reference path and pre-charge transistor. Process-voltage-temperature (PVT) aware analysis is performed based on an MTJ compact model and an industrial 28 nm CMOS technology, explicitly considering low-voltage (0.7 V), low tunneling magnetoresistance (TMR) (50%) and high temperature (85 °C) scenario as the worst sensing case. A case study takes a brief look at sensing circuits, which is applied to in-memory bit-wise computing. Simulation results indicate that the proposed high-sensing margin, high speed and stability sensing-sensing amplifier (HMSS-SA) achieves remarkable performance up to 2.5 GHz sensing frequency. At 0.65 V supply voltage, it can achieve 1 GHz operation frequency with only 0.3% failure rate.


Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 369 ◽  
Author(s):  
Padmanabhan Balasubramanian ◽  
Nikos Mastorakis

Addition is a fundamental operation in microprocessing and digital signal processing hardware, which is physically realized using an adder. The carry-lookahead adder (CLA) and the carry-select adder (CSLA) are two popular high-speed, low-power adder architectures. The speed performance of a CLA architecture can be improved by adopting a hybrid CLA architecture which employs a small-size ripple-carry adder (RCA) to replace a sub-CLA in the least significant bit positions. On the other hand, the power dissipation of a CSLA employing full adders and 2:1 multiplexers can be reduced by utilizing binary-to-excess-1 code (BEC) converters. In the literature, the designs of many CLAs and CSLAs were described separately. It would be useful to have a direct comparison of their performances based on the design metrics. Hence, we implemented homogeneous and hybrid CLAs, and CSLAs with and without the BEC converters by considering 32-bit accurate and approximate additions to facilitate a comparison. For the gate-level implementations, we considered a 32/28 nm complementary metal-oxide-semiconductor (CMOS) process targeting a typical-case process–voltage–temperature (PVT) specification. The results show that the hybrid CLA/RCA architecture is preferable among the CLA and CSLA architectures from the speed and power perspectives to perform accurate and approximate additions.


Author(s):  
Widianto Widianto ◽  
Lailis Syafaah ◽  
Nurhadi Nurhadi

In this paper, effects of process variations in a HCMOS (High-Speed Complementary Metal Oxide Semiconductor) IC (Integrated Circuit) are examined using a Monte Carlo SPICE (Simulation Program with Integrated Circuit Emphasis) simulation. The variations of the IC are L and VTO variations. An evaluation method is used to evaluate the effects of the variations by modeling it using a normal (Gaussian) distribution. The simulation results show that the IC may be detected as a defective IC caused by the variations based on large supply currents flow to it. 


MRS Bulletin ◽  
1996 ◽  
Vol 21 (4) ◽  
pp. 38-44 ◽  
Author(s):  
F.K. LeGoues

Recently much interest has been devoted to Si-based heteroepitaxy, and in particular, to the SiGe/Si system. This is mostly for economical reasons: Si-based technology is much more advanced, is widely available, and is cheaper than GaAs-based technology. SiGe opens the door to the exciting (and lucrative) area of Si-based high-performance devices, although optical applications are still limited to GaAs-based technology. Strained SiGe layers form the base of heterojunction bipolar transistors (HBTs), which are currently used in commercial high-speed analogue applications. They promise to be low-cost compared to their GaAs counterparts and give comparable performance in the 2-20-GHz regime. More recently we have started to investigate the use of relaxed SiGe layers, which opens the door to a wider range of application and to the use of SiGe in complementary metal oxide semiconductor (CMOS) devices, which comprise strained Si and SiGe layers. Some recent successes include record-breaking low-temperature electron mobility in modulation-doped layers where the mobility was found to be up to 50 times better than standard Si-based metal-oxide-semiconductor field-effect transistors (MOSFETs). Even more recently, SiGe-basedp-type MOSFETS were built with oscillation frequency of up to 50 GHz, which is a new record, in anyp-type material for the same design rule.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2447 ◽  
Author(s):  
Michaela Hissa ◽  
Seppo Niemi ◽  
Katriina Sirviö ◽  
Antti Niemi ◽  
Teemu Ovaska

Sustainable liquid fuels will be needed for decades to fulfil the world’s growing energy demands. Combustion systems must be able to operate with a variety of renewable and sustainable fuels. This study focused on how the use of various alternative fuels affects combustion, especially in-cylinder combustion. The study investigated light fuel oil (LFO) and six alternative liquid fuels in a high-speed, compression-ignition (CI) engine to understand their combustion properties. The fuels were LFO (baseline), marine gas oil (MGO), kerosene, rapeseed methyl ester (RME), renewable diesel (HVO), renewable wood-based naphtha and its blend with LFO. The heat release rate (HRR), mass fraction burned (MFB) and combustion duration (CD) were determined at an intermediate speed at three loads. The combustion parameters seemed to be very similar with all studied fuels. The HRR curve was slightly delayed with RME at the highest load. The combustion duration of neat naphtha decreased compared to LFO as the engine load was reduced. The MFB values of 50% and 90% occurred earlier with neat renewable naphtha than with other fuels. It was concluded that with the exception of renewable naphtha, all investigated alternative fuels can be used in the non-road engine without modifications.


Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 305 ◽  
Author(s):  
Dong Wang ◽  
Xiaoge Zhu ◽  
Xuan Guo ◽  
Jian Luan ◽  
Lei Zhou ◽  
...  

This paper presents an eight-channel time-interleaved (TI) 2.6 GS/s 8-bit successive approximation register (SAR) analog-to-digital converter (ADC) prototype in a 55-nm complementary metal-oxide-semiconductor (CMOS) process. The channel-selection-embedded bootstrap switch is adopted to perform sampling times synchronization using the full-speed master clock to suppress the time skew between channels. Based on the segmented pre-quantization and bypass switching scheme, double alternate comparators clocked asynchronously with background offset calibration are utilized in sub-channel SAR ADC to achieve high speed and low power. Measurement results show that the signal-to-noise-and-distortion ratio (SNDR) of the ADC is above 38.2 dB up to 500 MHz input frequency and above 31.8 dB across the entire first Nyquist zone. The differential non-linearity (DNL) and integral non-linearity (INL) are +0.93/−0.85 LSB and +0.71/−0.91 LSB, respectively. The ADC consumes 60 mW from a 1.2 V supply, occupies an area of 400 μm × 550 μm, and exhibits a figure-of-merit (FoM) of 348 fJ/conversion-step.


2019 ◽  
Vol 28 (10) ◽  
pp. 1950165 ◽  
Author(s):  
Sandeep Garg ◽  
Tarun K. Gupta

In this paper, a fin field-effect transistor (FinFET)-based domino technique dynamic node-driven feedback transistor domino logic (DNDFTDL) is designed for low-power, high-speed and improved noise performance. In the proposed domino technique, the concept of current division is explored below the evaluation network for enhancement of performance parameters. Simulations are carried out for 32-nm complementary metal–oxide–semiconductor (CMOS) and FinFET node using HSPICE for 2-, 4-, 8- and 16-input OR gates with a DC supply voltage of 0.9[Formula: see text]V. Proposed technique shows a maximum power reduction of 73.93% in FinFET short-gate (SG) mode as compared to conditional stacked keeper domino logic (CSKDL) technique and a maximum power reduction of 72.12% as compared to modified high-speed clocked delay domino logic (M-HSCD) technique in FinFET low-power (LP) mode. The proposed technique shows a maximum delay reduction of 35.52% as compared to voltage comparison domino (VCD) technique in SG mode and a reduction of 25.01% as compared to current mirror footed domino logic (CMFD) technique in LP mode. The unity noise gain (UNG) of the proposed circuit is 1.72–[Formula: see text] higher compared to different existing techniques in FinFET SG mode and is 1.42–[Formula: see text] higher in FinFET LP mode. The Figure of Merit (FOM) of the proposed circuit is up to [Formula: see text] higher as compared to existing domino logic techniques because of lower values of power, delay and area and higher values of UNG of the proposed circuit. In addition, the proposed technique shows a maximum power reduction of up to 68.64% in FinFET technology as compared to its counterpart in CMOS technology.


2021 ◽  
Author(s):  
Mark Dong ◽  
Genevieve Clark ◽  
Andrew J. Leenheer ◽  
Matthew Zimmermann ◽  
Daniel Dominguez ◽  
...  

AbstractRecent advances in photonic integrated circuits have enabled a new generation of programmable Mach–Zehnder meshes (MZMs) realized by using cascaded Mach–Zehnder interferometers capable of universal linear-optical transformations on N input/output optical modes. MZMs serve critical functions in photonic quantum information processing, quantum-enhanced sensor networks, machine learning and other applications. However, MZM implementations reported to date rely on thermo-optic phase shifters, which limit applications due to slow response times and high power consumption. Here we introduce a large-scale MZM platform made in a 200 mm complementary metal–oxide–semiconductor foundry, which uses aluminium nitride piezo-optomechanical actuators coupled to silicon nitride waveguides, enabling low-loss propagation with phase modulation at greater than 100 MHz in the visible–near-infrared wavelengths. Moreover, the vanishingly low hold-power consumption of the piezo-actuators enables these photonic integrated circuits to operate at cryogenic temperatures, paving the way for a fully integrated device architecture for a range of quantum applications.


Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kalpana Kasilingam ◽  
Paulchamy Balaiah

Purpose The nano-router would be a mastery device for providing high-speed data delivery. Here nano-router with a space-efficient crossbar scheduler is used for making absolutely less consumption in power. Design/methodology/approach In the emerging modern technology, every one of us is expecting a delivery of data at a high speed. To achieve high-speed delivery the authors are using the router. The router used here is at nanoscale reading which provides a compact size. Findings This can be implemented using the modern tools called Quantum-dot Cellular Automata (QCA) which is operated without the use of a transistor. As conventional complementary metal oxide semiconductor (CMOS) designs have some limitations such as low density, high power consumption and requirement of a large area. Research limitations/implications To overcome these limitations the QCA is used. It characterizes capability is used to substituting CMOS technology. The round-robin fashion is used in a high-speed space-efficient crossbar scheduler. Practical implications The simulation of the planned circuit with notional information established the practical identity of the scheme. Social implications The proposed nano router can be stimulated in the QCA environment using the QCADesigner tool and the power of the router can be calculated with the QCADesigner–E tool. Originality/value The proposed nano router can be stimulated in the QCA environment using the QCADesigner tool and the power of the router can be calculated with the QCADesigner–E tool. In this work, the performance of the router can be done in both the QCA environment and CMOS technology.


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