scholarly journals Parallel Storage Devices Profiling with SeRRa

Author(s):  
Vinicius Machado ◽  
Francieli Boito ◽  
Rodrigo Kassick ◽  
Jean Luca Bez ◽  
Philippe Navaux ◽  
...  

This work presents the parallel storage device profiling tool SeRRa. Our tool obtains the sequential to random throughput ratio for reads and writes of different sizes on storage devices. In order to provide this information efficiently, SeRRa employs benchmarks to obtain the values for only a subset of the parameter space and estimates the remaining values through linear models. The MPI parallelization of SeRRa presented in this paper allows for faster profiling. Our results show that our parallel SeRRa provides profiles up to 8:7 times faster than the sequential implementation, up to 895 times faster than the originally required time (without SeRRa).

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4000
Author(s):  
Eunhwan Kim ◽  
Juyeon Han ◽  
Seokgyu Ryu ◽  
Youngkyu Choi ◽  
Jeeyoung Yoo

For decades, improvements in electrolytes and electrodes have driven the development of electrochemical energy storage devices. Generally, electrodes and electrolytes should not be developed separately due to the importance of the interaction at their interface. The energy storage ability and safety of energy storage devices are in fact determined by the arrangement of ions and electrons between the electrode and the electrolyte. In this paper, the physicochemical and electrochemical properties of lithium-ion batteries and supercapacitors using ionic liquids (ILs) as an electrolyte are reviewed. Additionally, the energy storage device ILs developed over the last decade are introduced.


2020 ◽  
Vol 10 (3) ◽  
pp. 999
Author(s):  
Hyokyung Bahn ◽  
Kyungwoon Cho

Recently, non-volatile memory (NVM) has advanced as a fast storage medium, and legacy memory subsystems optimized for DRAM (dynamic random access memory) and HDD (hard disk drive) hierarchies need to be revisited. In this article, we explore the memory subsystems that use NVM as an underlying storage device and discuss the challenges and implications of such systems. As storage performance becomes close to DRAM performance, existing memory configurations and I/O (input/output) mechanisms should be reassessed. This article explores the performance of systems with NVM based storage emulated by the RAMDisk under various configurations. Through our measurement study, we make the following findings. (1) We can decrease the main memory size without performance penalties when NVM storage is adopted instead of HDD. (2) For buffer caching to be effective, judicious management techniques like admission control are necessary. (3) Prefetching is not effective in NVM storage. (4) The effect of synchronous I/O and direct I/O in NVM storage is less significant than that in HDD storage. (5) Performance degradation due to the contention of multi-threads is less severe in NVM based storage than in HDD. Based on these observations, we discuss a new PC configuration consisting of small memory and fast storage in comparison with a traditional PC consisting of large memory and slow storage. We show that this new memory-storage configuration can be an alternative solution for ever-growing memory demands and the limited density of DRAM memory. We anticipate that our results will provide directions in system software development in the presence of ever-faster storage devices.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Hu ◽  
Xiaomin Tang ◽  
Qing Dai ◽  
Zhiqiang Liu ◽  
Huamin Zhang ◽  
...  

AbstractMembranes with fast and selective ions transport are highly demanded for energy storage devices. Layered double hydroxides (LDHs), bearing uniform interlayer galleries and abundant hydroxyl groups covalently bonded within two-dimensional (2D) host layers, make them superb candidates for high-performance membranes. However, related research on LDHs for ions separation is quite rare, especially the deep-going study on ions transport behavior in LDHs. Here, we report a LDHs-based composite membrane with fast and selective ions transport for flow battery application. The hydroxide ions transport through LDHs via vehicular (standard diffusion) & Grotthuss (proton hopping) mechanisms is uncovered. The LDHs-based membrane enables an alkaline zinc-based flow battery to operate at 200 mA cm−2, along with an energy efficiency of 82.36% for 400 cycles. This study offers an in-depth understanding of ions transport in LDHs and further inspires their applications in other energy-related devices.


2020 ◽  
Author(s):  
Jing Hu ◽  
Xiaomin Tang ◽  
Qing Dai ◽  
Zhiqiang Liu ◽  
Huamin Zhang ◽  
...  

Abstract Membranes with fast and selective ions transport are highly demanded for energy storage devices. Layered double hydroxides (LDHs), bearing uniform interlayer galleries and abundant hydroxyl groups covalently bonded within two-dimensional (2D) host layers, make them superb candidates for high-performance membranes. However, related research on LDHs for ions separation is quite rare, especially the deep-going study on ions transport behavior in LDHs. Here, we report a LDHs-based composite membrane with fast and selective ions transport for flow battery application. The hydroxide ions transport through LDHs via vehicular (standard diffusion) & Grotthuss (proton hopping) mechanisms is uncovered. The LDHs-based membrane enables an alkaline zinc-based flow battery to operate at 200 mA cm− 2, along with an energy efficiency of 82.36% for 400 cycles, which is among the highest efficiencies for zinc-based flow batteries. This study offers an in-depth understanding of ions transport in LDHs and further inspires their applications in other energy-related devices.


2021 ◽  
Author(s):  
Muhammad Irfan ◽  
Xianhua Liu ◽  
Suraya Mushtaq ◽  
Jonnathan Cabrera ◽  
Pingping Zhang

Abstract Development of sustainable electrochemical energy storage devices faces great challenge in exploring highly efficient and low cost electrode materials. Biomass waste derived carbonaceous materials can be used as an alternative to expensive metals in supercapacitor. However, their application limited by low performance. In this study, the combination use of persimmon waste derived carbon and transition metal nitride demonstrated strong potential for supercapacitor application. Persimmon based carbonaceous gel decorated with bimetallic-nitride (N-NiCo/PC) was firstly synthesized through a green hydrothermal method. Electrochemical properties of N-NiCo/PC as electrode in 6 M KOH electrolyte solution were evaluated by using cyclic voltammetry (CV) and charge-discharge measurements. The N-NiCo/PC exhibited 895.5 F/g specific capacitance at 1 A/g current density and maintained 91.5% capacitance retention after 900 cycles. Hence, the bimetallic nitride-based-composite catalyst is a potentially suitable material for high-performance energy storage devices. In addition, this work demonstrated a promising pathway for transforming environmental waste into sustainable energy conversion materials.


2022 ◽  
Vol 9 ◽  
Author(s):  
Adriana M. Navarro-Suárez ◽  
Milo S. P. Shaffer

Structural energy storage devices (SESDs), designed to simultaneously store electrical energy and withstand mechanical loads, offer great potential to reduce the overall system weight in applications such as automotive, aircraft, spacecraft, marine and sports equipment. The greatest improvements will come from systems that implement true multifunctional materials as fully as possible. The realization of electrochemical SESDs therefore requires the identification and development of suitable multifunctional structural electrodes, separators, and electrolytes. Different strategies are available depending on the class of electrochemical energy storage device and the specific chemistries selected. Here, we review existing attempts to build SESDs around carbon fiber (CF) composite electrodes, including the use of both organic and inorganic compounds to increase electrochemical performance. We consider some of the key challenges and discuss the implications for the selection of device chemistries.


2021 ◽  
Vol 1 (3) ◽  
pp. 49-56
Author(s):  
S.M. Zuyev ◽  
◽  
R.A. Maleyev ◽  
YU.M. Shmatkov ◽  
M.YU. Khandzhalov ◽  
...  

This article provides a comparative analysis of various energy storage devices. A detailed review and analysis of molecular energy storage units is carried out, their main characteristics and parame-ters, as well as their application areas, are determined. The main types of molecular energy storage are determined: electric double layer capacitors, pseudo capacitors, hybrid capacitors. Comparison of the characteristics of various batteries is given. The parameters of various energy storage devices are presented. The analysis of molecular energy storage devices and accumulators is carried out. Ttheir advantages and disadvantages are revealed. It has been shown that molecular energy storage or double layer electrochemical capacitors are ideal energy storage systems due to their high specific energy, fast charging and long life compared to conventional capacitors. The article presents oscillograms of a lithium-ion battery with a voltage of 10.8 V at a pulsed load current of 2A of a laptop with and without a molecular energy storage device, as well as oscil-lograms of a laptop with DVD lithium-ion battery with a voltage of 10.8 V with a parallel shutdown of a molecular energy storage device with a capacity of 7 F and without it. The comparative analysis shows that when the molecular energy storage unit with a 7 F capacity is switched on and off, transient processes are significantly improved and there are no supply voltage dips. The dependenc-es of the operating time of a 3.6 V 600 mAh lithium-ion battery at a load of 2 A for powering mo-bile cellular devices with and without a molecular energy storage are given. It is shown that when the molecular energy storage device is switched on, the battery operation time increases by almost 20%.


2010 ◽  
Vol 04 (02) ◽  
pp. 181-202
Author(s):  
SHAYA POTTER ◽  
OREN LAADAN ◽  
RICARDO BARATTO ◽  
LEONARD KIM ◽  
JASON NIEH

We present MediaPod, a portable system that allows mobile users to maintain the same persistent, personalized multimedia desktop environment on any available computer. Regardless of which computer is being used, MediaPod provides a consistent multimedia desktop session, maintaining all of a user's applications, documents and configuration settings. This is achieved by leveraging rapid improvements in capacity, cost, and size of portable storage devices. MediaPod provides a virtualization and checkpoint-restart mechanism that decouples a desktop environment and its applications from the host, enabling multimedia desktop sessions to be suspended to portable storage, carried around, and resumed from the storage device on another computer. MediaPod virtualization also isolates desktop sessions from the host, protecting the privacy of the user and preventing malicious applications from damaging the host. We have implemented a Linux MediaPod prototype and demonstrate its ability to quickly suspend and resume multimedia desktop sessions, enabling a seamless computing experience for mobile users as they move among computers.


2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Lei Wang ◽  
Sidi Gong ◽  
Cihui Yang ◽  
Jing Wen

AbstractToday, the total amount of global data has been increasing at a phenomenal rate, and this necessitates the requirement for significant improvement in the storage capacity of current storage devices. Compared with other conventional storage devices, electrical probe memory exhibits several storage superiorities and is considered as the candidate for the next-generation mainstreaming storage device. In this case, to further mitigate the performances of the electrical probe memory, its architecture was previously optimized by simulation while lacking adequate experimental support. Therefore, we measured the electrical resistivities of the diamond-like carbon (DLC) capping and bottom layers by varying the film thickness, sputter power, and sputter pressure to thus establish the physically realistic property values of the DLC film. According to experiments, a 10 nm DLC capping layer with a resistivity of 0.1 Ω·m, and a 30 nm DLC bottom layer with a resistivity of 0.01 Ω·m, which most closely matches the theoretical prediction, are introduced into the originally designed electrical probe memory, and the subsequent recording experiment demonstrated the ability to achieve ultra-high density, large data rate, and ultra-low energy consumption using the redesigned architecture.


The chapter is focused on modelling of performance of adsorptive heat storage devices and estimation of performance of heat storage devices. Two groups of models of adsorptive heat storage units suggested previous researchers are analyzed. The first one is focused on predicting the heat energy storage density, it being based on Dubinin-Polanyi theory. The second one is devoted to analyzing the kinetic of adsorption processes and performance of the adsorber or adsorptive-desorptive reactor filled with traditional adsorbent or salt which forms crystalline hydrates. The key drawback of both groups of models concerns with considering only one stage of exploitation of adsorptive heat storage device in spite of its operating in two-stage mode, that is, alternating discharge (adsorption) and charge (regeneration). It inhibits estimation of efficiency of adsorptive heat storage device basing on full operating cycle and its involving in heat supply system. Two algorithms for estimation of operating parameters are proposed by authors for closed-type and open-type heat storage devices. The algorithm for calculation of operating parameters of closed type adsorptive heat storage device is proposed: calculation of the mass transfer coefficient, adsorption, useful heat, that is, heat of adsorption, determination of the heat input, it being calculated as heat inputs for heating the adsorbent, device housing, water in the tank, evaporation of water in the tank, heating of the adsorbed water and desorption. Then efficiency factor is calculated. The operating characteristics of a closed-type heat energy storage device were studied when the composite adsorbent ‘silica gel – sodium sulphate' used. The effect of the humid airflow velocity on the efficiency factor is taken into account by introducing a coefficient equal to the value of the adsorption. An increase in the efficiency coefficient was stated when the velocity and relative humidity of the airflow. It is shown that the humid air flow temperature practically does not affect its value. Having been used the suggested algorithm, the optimal operating characteristics of an adsorptive heat storage device of a closed type based on a composite adsorbent ‘silica gel – sodium sulphate' for a private house heating system are revealed to be humid air velocities of 0.6 – 0.8 m/s and relative humidity 40 – 60%. When these operational data applied, the efficiency coefficient is shown to reach the maximum values (about 55%). Algorithm of calculation of operating parameter of open-type heat storage device includes computation of mass transfer coefficient, adsorption, useful heat (heat of adsorption), heat input for heating the adsorbent, device casing, water in the humidifier, evaporation of water, heating the adsorbed water, desorption, and calculating efficiency coefficient. Performance of open-type heat storage device based on the composite adsorbent ‘silica gel – sodium sulphate' is estimated. The optimal operating conditions of the heat accumulating device which allow operating with maximal magnitudes of efficiency coefficients 53 – 57% are stated to be humid airflow speed of 0.6 – 0.8 m/s and relative humidity of 40 – 60%. Correlation between efficiency factors obtained by experiments and calculated with suggested algorithm is confirmed. The possibility of reducing the power consumption when heat storage devices applied in 2,4 – 90 times versus decentralized heating systems on basis of solid fuel boiler, gas boiler and electric boiler is stated when open-type sorptive heat storage device used. Results of the study can be used to develop adsorptive storage devices in decentralized heat supply and ventilation systems and adsorption units for utilization of low-temperature waste heat.


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