Mass Storage Research Articles

A multi-period optimization model for the design of mass networks including conversion systems and gas storage models: Application for hydrogen generation, distribution and storage

A multi-period mixed-integer-linear-programming problem for the design of mass networks is proposed in this paper. Design of mass networks, conversion systems and storages is done so as to minimize the capital expenses and operating costs and fulfill demand in resources. This work provides a detailed model of compressed gas storage, considering pressure state inside gas tank, compression costs and compressor design, which have not been considered before in a linear model, with a discrete pressure scale. The performance of the model is assessed on a hydrogen network design problem, including renewable electricity, electrolyzer design and hydrogen storage. The share of renewable electricity use increases from 60% to 90% with hydrogen storage. Different compressed gas storage linearized models are compared with different pressure scales and the linearization error is assessed. The introduction of discrete intermediate pressures reduces the committed error on compressor power and operating costs, due to the linearization.

3D-Printed Topological MoS2/MoSe2 Heterostructures for Macroscale Superlubricity.

Superlubricity is a fascinating phenomenon which attracts people to continuously expand ultralow friction and wear from microscale to macroscale. Despite the impressive advances in this field, it is still limited to specific materials and extreme operating conditions. Introducing a heterostructure with intrinsic lattice mismatch into delicate topologies mimicked from nature provides a promising alternative toward macroscopic superlubricity. Herein, 3D-printed MoS2/MoSe2 heterostructures with bioinspired circular-cored square/hexagonal honeycomb topologies were developed. Compared to 3D-printed Al2O3, all topological structures with both high hardness and excellent flexural strength achieve more than 30% decrease in the friction coefficient. The circular-cored hexagonal honeycomb composite with 30% area density exhibits a stable ultralow friction coefficient of 0.09 and a low wear rate of 2.5 × 10-5 mm3·N-1 m-1 under 5 N. Even under 10 N, a highly desirable coefficient value of 0.08 can be maintained within 370 s. The extraordinary ultralow friction could be attributed to the small contact area, high lubricant mass loading, efficient collection and storage of both abrasive debris and lubricant, and the self-orientation in the lubricating film. This work provides new insights into developing high-efficiency lubrication devices and aids in the industrial application of macroscopic superlubricity in future life.

RELEVANT PRINCIPLES IN THE ECHR AND CJEU JURISPRUDENCE REGARDING NATIONAL SECURITY

The European system ensuring the protection of human rights is nowadays one of the most advanced in the world. However, there are also areas of activity where clarification and improvement are constant demands. Counter-terrorism measures considered or adopted in Europe, in particular those that increase mass surveillance, the collection and storage of electronic information or the protection of personal data are such areas. Some of these measures give more intrusive powers to the intelligence services to channel decisions in the direction of the executive branch, without the necessary judicial guarantees being established in a state governed by the rule of law.
 
 Keywords: community law; ECHR; CJUE; national security.

Techno-Economic Analysis of Candidate Oxide Materials for Thermochemical Storage in Concentrating Solar Power Systems

The thermal storage capability is an important asset of state-of-the-art concentrating solar power plants. The use of thermochemical materials, such as redox oxides, for hybrid sensible/thermochemical storage in solar power plants offers the potential for higher specific volume and mass storage capacity and as a consequence reduced levelized cost of electricity making such plants more competitive. For the techno-economic system analysis, three candidate redox materials were analyzed for their cost reduction potential: cobalt-based, manganese–iron–based, and perovskite-based oxide materials. As a reference process the use of inert commercial bauxite particles (sensible-only storage) was considered. A solar thermal power plant with a nominal power of 125 MWe and a storage capacity of 12 h was assumed for the analysis. For each storage material a plant layout was made, taking the specific thermophysical properties of the material into account. Based on this layout a particle break-even cost for the specific material was determined, at which levelized cost of electricity parity is achieved with the reference system. Cost factors mainly influenced by the material selection are storage cost and steam generator cost. The particle transport system cost has only a minor impact. The results show differences in the characteristics of the materials, for example, regarding the impact on storage size and cost and the steam generator cost. Regarding the economic potential of the candidate redox materials, the perovskite-based particles promise to have advantages, as they might be produced from inexpensive raw materials.

Effects of groundwater abstraction and desalination brine deep injection on a coastal aquifer

As a result of climate change, population increase and improvement of living standards, the water demand is annually growing drawing worldwide attention on seawater desalination to face water crisis. The total global desalination capacity is dominated by Reverse Osmosis (RO) and, often, this desalination process is fed with the brackish water extracted from coastal aquifers. After this process the desalted freshwater is obtained at a recovery factor of ca. 50%, while concentrate byproduct, named brine, is disposed back to coastal aquifers, seas, oceans or evaporative ponds, determining detrimental effects on the surrounding environment. A common approach to clean out the brine is the deep-well injection into coastal aquifers, exacerbating the seawater intrusion. The ultimate result is a reduction of the available water both in terms quantity and quality hampering the benefits of the desalination.The aim of this study is to investigate the effects of brine water injection in the Nile coastal aquifer, one of the largest underground freshwater reservoirs in the world, and to find a way to minimize and manage the environmental impact of the RO process. In order to simulate the effects of the brackish water extraction and the brine deep-injection on the Nile coastal aquifer, a combined seawater intrusion, numerical models for flow and salt transport model in aquifers and the solution-diffusion in RO practices were implemented. Different management scenarios were considered and their consequences on salt mass storage in the Nile coastal aquifer evaluated.According to the numerical results, the salinization of the coastal aquifer can be mitigated by reducing the concentration of the water feeding the reverse osmosis plant, i.e., mixing the extracted brackish water with a lower salinity water. Besides, low feed salinity leads to significant gains by decreasing the specific energy consumption of the desalination process.

Adolescent Pitcher Fatigue: Ulnar Collateral Ligament Stress, Flexor-Pronator Mass Energy Depletion, and Correlation to Pitch Count

Objectives:There has been a rise in elbow ulnar collateral ligament (UCL) injuries in youth pitchers over recent years. With forearm flexor-pronator mass fatigue, the dynamic stability provided could be diminished placing greater stress on the UCL. Pitch count limits have been instituted in an attempt to help curtail this rise in throwing injuries, especially in youth athletes. In order to provide more objective data regarding current pitch count limits for youth pitchers, the purpose of this pilot study was to evaluate for potential fatigue of the flexor-pronator mass by assessing changes in medial elbow laxity, noninvasively characterizing changes in muscle glycogen storage within the forearm flexor-pronator mass, and evaluating changes in subjective fatigue, strength, range of motion (ROM), pitching velocity, and accuracy with increasing number of pitches thrown by 10-year-old pitchers up to their recommended 75 pitch count limit.Methods:After appropriate power analysis, male pitchers 10 years of age were recruited for the study (n=22). Pitchers threw a total of 75 pitches divided into sets of 25 pitches, with standardized periods of rest in between throws and sets to best simulate a game. Bilateral medial elbow laxity was measured by applying 10 decanewtons of valgus force with a standardized stress device and utilizing ultrasound imaging (Figures 1A-B) prior to pitching and after each pitching set. The change in medial ulnohumeral joint distance (Figure 1C) after stress was applied was calculated from baseline without stress. Relative changes in muscle glycogen storage, detected as changes in echogenicity, within the flexor carpi radialis (FCR) and the flexor digitorum superficialis (FDS)/flexor carpi ulnaris (FCU) muscles were measured non-invasively with ultrasound-based software (Figures 1D-E) and recorded as fuel percentile. Repeated measures analysis of variance and post-hoc testing were used to determine statistical significance (alpha=0.05).Results:There were no significant differences in medial elbow laxity between arms or time points. There was a trend for similar decline in FCR fuel percentile values between each arm, indicating relative decreases in glycogen storage bilaterally. However, only the throwing arm demonstrated a statistically significant decline in fuel percentile from baseline to after 75 pitches (p=0.05). There were no statistically significant differences across time points for FDS/FCU fuel percentile values. Fatigue measurements for both arms were significantly higher at all time points compared to baseline (p≤0.03). Grip strength of the dominant arm after 75 pitches was significantly decreased compared to after 25 pitches (p=0.02). There were no statistically significant changes in other strength measurements, ROM, velocity, or accuracy between all time points.Conclusions:By the recommended 75 pitch count limit in 10-year-olds, subjective fatigue and a decrease in grip strength had occurred. Furthermore, relative glycogen storage of the flexor-pronator mass of the throwing arm decreased between pitching 50 to 75 pitches, but without an increase in medial elbow gapping. This study provides a foundation and raises questions for further objective testing of physiologic changes that occur throughout increasing pitching to better guide pitch count limits and ensure the safety of young athletes

Thermal Performance Prediction of Indoor Swimming Pool Solar Heating System Using Different Types of Flat-Plate Solar Collectors

The current study includes a theoretical study of the enfluence of different types of flat-plate solar collector on the solar fraction factor (ƒ) of a proposed solar heating system used for heating "alShaab Olympic Indoor Swimming Pool" located in Baghdad (Iraq) at a latitude of 33.32˚N. The swimming pool building has external dimensions of 95 m length, 51 m width, and 16.5 m height, it contains two pools, the first is for swimming with dimensions of (50 m * 21 m) with fixed depth of 1.8 m, the second is for diving with an irregular surface area of (351) m2 and with depth of 5 m. The Total thermal losses from the two pools to the pool hall and from the pool hall to the outdoor environment were calculated for four months of winter season (November, December, January and February) and a computer program was built using the MATLAB (R2008a) environment to solve the mathematical model equations in order to calculate the solar fraction facor (ƒ) of the proposed solar heating system at different solar collecting areas which are (2000,2500,3000,3500,4000,4500,5000,6000,7000,8000,9000,10000) m2 and at five different types of flat-plate solar collector which are (A: one cover black solar collector, B: one cover selective absorber solar collector, C: two cover black solar collector, D: two cover selective absorber solar collector, and E: pool absorber (PVC) solar collector). The results obtained showed that the highest values of solar fraction factor were obtained when using the solar collector type D, and the lowest values obtained when using the solar collector type E. The values of solar fraction factor (ƒ) of the proposed solar heating system, at solar collecting area of 10000m2 and at mass storage of water in the storage tank of 25 kg/m2 collecting area, for type D are 84.27 % for November, 72.74% for December, 69.4% for January, and 82.91% for February, and for type E are 56.14% for November, 41.15% for December, 37.17% for January, and 50.6% for February.

Highly rechargeable lithium oxygen batteries cathode based on boron and nitrogen co-doped holey graphene

Heteroatoms doped carbon based materials with enhanced catalytic properties hold great potential in energy storage applications, including rechargeable lithium oxygen batteries (LOBs). However, large-scale production of heteroatoms co-doped carbon with high-level dopants as well as the precise control of uniformly distributed dopant location remain challenges. Holey graphene as an emerging carbon based material has attracted increased attention as cathode for LOBs due to its nanoholes through the graphene nanosheet basal plane. Apart from the given rapid diffusion channels for mass (e.g., O2 and Li+ ), the nanoholes also provide rich egdes for the mass adsorption and storage as well as the heteroatoms doping. Herein, we report an environment-friendly and simple approach to mass production of hG with abundant in-plane nanoholes via direct oxidation of reduced graphene oxides (rG) by a controlled flow gas of H2O. Based on the obtained hG, 3.0 at.% B and 2.1 at.% N atoms are further co-doped into the hG to form B, N-hG. Benefiting from its holey structures and the synergistic effect of B and N, the B, N-hG as cathode for LOBs displays promising properties with a maximum discharge capacity of 15340 mAh g−1 and long cycling stability over 117 cycles.

A Scalable Bidimensional Randomization Scheme for TLC 3D NAND Flash Memories.

Data randomization has been a widely adopted Flash Signal Processing technique for reducing or suppressing errors since the inception of mass storage platforms based on planar NAND Flash technology. However, the paradigm change represented by the 3D memory integration concept has complicated the randomization task due to the increased dimensions of the memory array, especially along the bitlines. In this work, we propose an easy to implement, cost effective, and fully scalable with memory dimensions, randomization scheme that guarantees optimal randomization along the wordline and the bitline dimensions. At the same time, we guarantee an upper bound on the maximum length of consecutive ones and zeros along the bitline to improve the memory reliability. Our method has been validated on commercial off-the-shelf TLC 3D NAND Flash memory with respect to the Raw Bit Error Rate metric extracted in different memory working conditions.

Assessing the Role of Program Suspend Operation in 3D NAND Flash Based Solid State Drives

3D NAND Flash is the preferred storage medium for dense mass storage applications, including Solid State Drives and multimedia cards. Improving the latency of these systems is a mandatory task to narrow the gap between computing elements, such as CPUs and GPUs, and the storage environment. To this extent, relatively time-consuming operations in the storage media, such as data programming and data erasing, need to be prioritized and be potentially suspendable by shorter operations, like data reading, in order to improve the overall system quality of service. However, such benefits are strongly dependent on the storage characteristics and on the timing of the single operations. In this work, we investigate, through an extensive characterization, the impacts of suspending the data programming operation in a 3D NAND Flash device. System-level simulations proved that such operations must be carefully characterized before exercising them on Solid State Drives to eventually understand the performance benefits introduced and to disclose all the potential shortcomings.

(Invited) Mass Transport and Storage in Li-Ion Electrodes: Bulk and Interfaces

The subject of batteries is the interconversion of compositional changes and outer electrical potential changes. In solids all compositional changes refer explicitly to defect chemistry. Point defects such as interstitial and vacancies enable ion transport, mass transport and represent the species affected by storage [1].The contribution discusses the modes of storage (bulk and interfacial storage) [2], derives the respective theoretical charge/discharge curves and discusses transport kinetics. The latter follow from the defect chemical picture, too. As for storage (chemical capacitance) also for transport (chemical resistance) one may distinguish between bulk and boundary phenomena [3]. The defect-chemical description is shown not only to be the adequate description (superior to, e.g. lattice gas models), it also leads to a generalized picture of electrode and supercapacitive storage.

Compact cold atom gravimeters and precise gravity measurement

Atomic gravimetry measures the gravitional acceleration of an ensemble of identical neutral atoms through the atom interferometry based on Raman two-photon transition, where the Raman lasers are used as “optical ruler" and the identical neutral atoms play the role of test mass and quantum storage of gravity field information. As the novel gravimetry system suffers no mechanical wear and works at a higher repetition rate, atom gravimetry can reach a much better short-term sensitivity than the classical falling-corner-cube counterpart, and the accuracy is reasonably well. Since the very first in-laboratory device built over 30 years ago, atomic gravimetry has matured to a versatile tool that offers both precise and accurate absolute gravity measurement to fundamental research and metrology, such as testing the weak equivalence principle or linking the mass and weight of the test mass in Watt (Kibble) balance. As the current rapid development of compact cold-atom gravimeters, atomic gravimetry is moving out of the laboratory to be used as a quantum enhancement of classical devices in dynamical measurement, such as geophysics survey, inertial navigation and space mission. We review the roadmap for the development of cold-atom absolute gravimetry, highlight recent advances in the dynamical measurement using compact cold atom gravimeters and discuss the associated technological challenges. In the future, with the maturity of its application in dynamical measurement or civil engineering and the innovation in atom interferometry theory, atomic gravimetry could play a more and more important role in our life.

The Mu3e Data Acquisition

The Mu3e experiment aims to find or exclude the lepton flavor violating decay μ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> → e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> e <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> with a sensitivity of one in 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16</sup> muon decays. The first phase of the experiment is currently under construction at the Paul Scherrer Institute (PSI, Switzerland), where beams with up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> muons per second are available. The detector will consist of an ultra-thin pixel tracker made from High-Voltage Monolithic Active Pixel Sensors (HV-MAPS), complemented by scintillating tiles and fibers for precise timing measurements. The experiment produces about 100Gbit/s of zero-suppressed data, which are transported to a filter farm using a network of field programmable gate arrays (FPGAs) and fast optical links. On the filter farm, tracks and three-particle vertices are reconstructed using highly parallel algorithms running on graphics processing units, leading to a reduction of the data to 100 Mbyte/s for mass storage and offline analysis. This article introduces the system design and hardware implementation of the Mu3e data acquisition and filter farm.

Investigating the energy flexibility of Dutch office buildings on single building level and building cluster level

Demand Response is used to reduce the mismatch between electricity generation by renewable energy sources and electricity demand. Buildings are large energy consumers and can play an important role in matching generation and demand. Energy flexibility is defined as the ability of a building to manage its generation and demand according to local climate conditions, user needs and grid requirements. This article focuses on the thermal mass of buildings as a source of energy flexibility.The investigation is based on a characterization assessment method on single building level and on aggregator level. On single building level, different building parameters such as the thermal capacity of the construction, window to wall ratio, façade insulation and glazing properties are investigated and their impact on the energy flexibility is assessed. The thermal capacity and window to wall ratio are considered the most influential in the studied buildings. The characterization assessment shows a minimum 0.14 and a maximum 0.34 kWh/m2 potential shiftable energy. The results of the characterization assessment method are compared with Demand Response events under more realistic conditions for specific case study buildings. The results show to be representative of the potential shiftable energy of a building envelope. The results show that in certain cases, the potential shiftable energy by the thermal mass of the building is comparable to the capacity of a commercial battery for utility buildings (232 kWh).Finally, the aggregated flexibility of clusters of Dutch office buildings is investigated and analogized to different electrical battery storage projects around the world. The results show that the thermal mass of 17 reference buildings show the potential of a storage capacity close to the biggest electrical battery projects in the Netherlands. The limitations of this study and advantages and disadvantages of electrical storage and thermal mass storage are discussed.

IoT Based Automated Hydroponics Greenhouse Monitoring

Hydroponics refers to the art of growing plants in water without soil (land). Nutrients for the plants are supplied to the roots in the form of solution that can be either in the form of static or flowing. Hydroponics can be cultivated both in green house and glass house environment. The limitation in green house environment is to maintain the temperature, pressure, humidity value at a particular level. In addition to that, monitoring on PH value and electrical conductivity in hydroponics is another challenge that has to be monitored and maintained. Manual monitoring is in practice which is a very trivial task else the plants may die out. This project, focuses on two tasks, the first one is to automate the greenhouse environment monitoring. The subsequent is automation of PH level, temperature, turbidity and electrical conductivity maintenance. IOT is used to transfer the retrieved data to the internet (mass storage) and mobile app is used to communicate the current status to the user through the use of internet to their mobile phones, so that monitoring &amp; maintenance will be easier. This Hydroponics system requires less manual intervention, water and space than traditional agricultural systems.

Successful Indoor Mass Storage of Honeybee Queens (Apis mellifera) during Winter

The production of young, mated honeybee queens (Apis mellifera) is essential to replace dead queens or to start new colonies after wintering. Mass storage of mated honeybee queens during winter and their use the following spring is an interesting strategy that could help fulfill this need. In this study, we investigated the survival, fertility, and fecundity of young, mated queens stored massively in queenless colonies from September to April (eight months). The queens were kept in environmentally controlled rooms at temperatures above and below cluster formation. The results show that indoor mass storage of mated queens can be achieved with success when queen banks are stored above cluster temperature. Significantly higher survival of queens was measured when wintering queen banks at 16 °C. Surviving queens wintered at different temperatures above or below cluster formation had similar fertility (sperm viability) and fecundity (egg laying and viable worker population). This study shows the potential of indoor overwintering of honeybee queen banks. The technique we describe could be applied on a commercial scale by beekeepers and queen breeders.

Race/ethnicity and challenges for optimal insulin therapy

AimsWe aimed to review insulin dosing recommendations, insulin regulation and its determinants, glycaemic response to carbohydrates, and the efficacy and safety of insulin therapy in different races/ethnicities. MethodsWe searched for articles in PubMed and Google Scholar databases up to 31 March 2021, with the following keywords: “ethnicity”, “diabetes”, “insulin”, “history of insulin”, “insulin therapy”, “food/rice”, “carbohydrate intake”, “insulin resistance”, “BMI”, “insulin dosing”, “insulin sensitivity”, “insulin response”, “glycaemic index”, “glycaemic response”, “efficacy and safety”, with interposition of the Boolean operator “AND”.In addition, we reviewed the reference lists of the articles found. ResultsThe differential effect of race/ethnicity has not yet been considered in current insulin therapy guidelines. Nevertheless, body size and composition, body mass index, fat distribution, diet, storage, and energy expenditure vary significantly across populations. Further, insulin sensitivity, insulin response, and glycaemicresponse to carbohydrates differ by ethnicity. These disparities may lead to different insulin requirements, adversely impacting the efficacy and safety of insulin therapy among ethnic groups. ConclusionsRace/ethnicity affects glucose metabolism and insulin regulation.Until now, international guidelines addressing racial/ethnic-specific clinical recommendations are limited. Comprehensive updated insulin therapy guidelines by ethnicity are urgently needed.

Experimental investigation of internal air flow during slow piston compression into isothermal compressed air energy storage

Compressed air could be a solution for the future mass storage of renewable energies. The isothermal compression and expansion of air by liquid piston is a solution that offers good performance and significant power. Lengthening the compression chamber and slowing down piston displacement may be advantageous for quasi-isothermal development. Presented here is an analysis of the internal air flow during slow piston compression inside a compression chamber with a very low stroke-to-bore ratio. The existence of two consecutive flow regimes is produced repeatably by 2D PIV (particle image velocimetry) measurement. First, a highly-structured regime develops with air speeds significantly higher than the piston advance speed, and a general recirculation of the air. The symmetry of this structure is confirmed with a simple flow distribution model. A second, more disorderly, flow regime then takes over for the remainder of the compression. The transition between the two regimes observed is also described, highlighting instabilities in the high shear zones in the transition from the first regime to the second.

Processes of Heat and Mass Transfer During Grain Mass Storage in Metal Silos of Large Capacity

This study showed that there were some changes in the temperature and humidity parameters of wheat grains during the storage year. The grain moisture content in both the near-wall and central parts of the metal silo largely did not change, remaining at a level of 10-11%. Moisture values were recorded monthly, and grain temperature was recorded in accordance with seasonal changes, thus, the range of temperature changes was from 20 to 32°С at a minimum outdoor temperature of 5°С. The moisture content of the grain in the surface layer increased by 0.4-1.2% and the final moisture content of the grain was 11.6%. Experiments on grain temperature and humidity changes with active ventilation in large-capacity metal silos have shown that the rate of change (decrease) in temperature depends on the specific air flow rate, and the difference in air and grain temperature. Experimental storage showed that a grain with the moisture content up to 13.6% can be stored for up to nine months without deterioration in quality. A longer shelf life is possible for wheat grains with a moisture content of up to 12%. This article pays special attention to the processes occurring in the under-roof space of large-capacity metal silos and suggests methods for solving this problem.&#x0D; Keywords: long-term storage, active ventilation, metal silos, heat and mass transfer processes

Discrete transformation technique for video compression

A large composition of image, sound, motion, video and other signal sequences is always a rich source of useful and reliable information. With the proliferating cost and complexities of mass storage media, the need for redundancy and complex transmission-free signals is on the rise. Furthermore, the growing increase in the number of video-specific applications has heightened the need for digital multimedia technologies that emphasized bit compression. This paper presents a Discrete Transform Technique (DTT) that leveraged the integration of Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) for higher scale video compression. The experimental study of the new technique was based on some online videos with varying sizes, sources and formats. The analysis of the experimental values obtained for standard performance metrics such as maximum difference, mean square error and peak signal to noise ratio for the pre- and post-compression videos portrayed a very significant and encouraging impact of the new technique. Comparative analysis based on compression ratios derived using the new technique and some recent video compression techniques also established a very impressive performance of the new technique.