Separation Characteristics Research Articles

Optimizing the Cost of Garbage Collection in F2FS Using Working Set Strategy

As an important part of the operating system, the file system has always received wide attention, and different types of file system architectures have been constantly proposed and practiced, this time, we mainly focus on the log structured file system (LFS) type flash friendly file system (F2FS) file system. The existing garbage collection algorithm has offered a interface for future improvement. Hence, we tried to improve existing garbage collection algorithms by implementing the working set strategy in victim select algorithm and analyze the existing deficiencies of the F2FS file system. Under the original strategy, when F2FS selects a segment, it will select the section with the fewest valid blocks. After we change it, we have completed the balance consideration of the change time, the number of valid blocks, and the proportion of changes. It is expected that the Flash device will have the longer life. By using the proposed technique, the cost of garbage collection has reduced by 10%. At the same time, based on the cold and hot data separation characteristics of the F2FS file system, we propose optimization suggestions for the cold and hot data separation strategy.

Experimental study on the medium-pressure separation characteristics of coal seam gas hydrate

Experimental study on the medium-pressure separation characteristics of coal seam gas hydrate

COMPARATIVE EVALUATION OF MIDAZOLAM AND KETAMINE WITH MIDAZOLAM ALONE AS ORAL PREMEDICATION IN CHILDREN”

Introduction: The main aims of preanesthetic medication in children are to reduce anxiety associated with the unfamiliar environment, facilitate the separation of the child from their parent and allow smooth induction of an-esthesia. Both oral midazolam and oral ketamine fulfil many of these char-acteristics and are useful. Method: As 48 patients of ASA grade 1 and 2, aged between 2-10 years un-dergoing elective surgery were allocated to one of two study groups using random numbers: Group 1 received midazolam 0.5mg/kg and group 2 re-ceived midazolam 0.25 mg/kg with ketamine 3 mg/kg. The medications were prepared and mixed with 25% dextrose up to a maximum volume of 0.3 ml/kg. Result: Uniform and acceptable sedation scores were seen in both the groups, without any serious side effects. However, the combination offered significantly more children in an awake, calm and quiet state, who were eas-ily separated from their parents. The induction scores, Recovery room characteristics and time to achieve satisfactory Aldrete score were also comparable between the two groups. Conclusion: Oral midazolam alone and a combination of midazolam with ketamine provide equally effective anxiolysis and separation characteristics. However, the combination provided more Benefits.

Modern technologies of strengthening working bodies of soil processing machines

During the operation of soil tillage machines, their working bodies, which are in direct contact with the soil, are exposed to abrasive wear, high contact and dynamic loads, as well as the corrosive effect of the soil. Heavy operating conditions cause intensive wear of such parts. Therefore, works related to increasing the wear resistance of materials intended for the manufacture of working bodies of tillage machines (ploughshares, cultivator paws, disks, chisels, etc.) are relevant. The main strengthening technologies presented on the market for the working bodies of tillage machines are considered. Data on the percentage ratio of the market volume by certain types of strengthening were collected and analyzed. Separate characteristics of the considered methods of strengthening tillage bodies are shown in comparison. To ensure wear resistance and technical resource at the same level as the best foreign analogues, it is recommended that tillage bodies be made by casting from high-strength cast iron, heat treated, reaching its bainite metal base, saturated with carbides, in particular on the surface. It is advisable that one surface layer of the metal be of increased hardness, which will meet the condition of self-sharpening of the working organs during wear. Two methods of hardening are considered to fulfill this condition, in which water is used as a cooling medium for heat treatment of the plow blade. At the same time, a new feature of the isothermal tempering of ploughshares developed by us is the use of heated metal equipment, in the given examples of the quality of which ploughshare casting was used repeatedly. The features and advantages of cooling castings in a fluidized bed of sand are also considered. Replacing expensive materials, alloys and technologies with the use of unalloyed high-strength cast iron with a wear-resistant structure, as well as the use of low-cost casting methods together with thermal strengthening will lead to a significant reduction in the cost of the working bodies of tillage machines. Keywords: technologies of strengthening, quenching, wear, working bodies of soil tillage machines, plow, high -strength cast iron.

Modeling comparison and theoretical study of mass transfer characteristics for desiccant coated air channel under isothermal dehumidification

Coupled heat and mass transfer phenomena are encountered in desiccant coated dehumidifier, and their numerical modeling is becoming indispensable. In this study, three conjugate heat and mass transfer models were compared to clarify the effects of interparticle mass transfer and local kinetic non-equilibrium on modeling accuracy, and the models were validated by experiment results of silica gel and FAM Z01 coated dehumidifiers with single one air channel. Furthermore, a parametric study on the separate mass transfer characteristics of the dehumidifier under isothermal dehumidification was conducted based on one of the improved models. Results demonstrated that the effect of interparticle mass transfer should be involved, while the local kinetic non-equilibrium tends to be considered for desiccants with steep isotherm shape. Parametric study revealed that as air velocity increases, both air- and solid-side mass transfer change significantly, while desiccant layer thickness, interparticle porosity and isotherm shape mainly affect solid-side mass transfer. The average mass transfer Biot numbers Bim of desiccant layer with relative low thickness of 0.1 mm under various parameters are in the same order of magnitude as 1, indicating that the mass transfer resistance on solid side cannot be ignored generally.

Characteristics of hydrogen separation and methane steam reforming in a Pd-based membrane reactor of shell and tube design

This work investigates numerically the characteristics of the two process, hydrogen separation and steam methane reforming (SMR), in a palladium-based (Inconel-supported Pd–Ag film) membrane reactor (MR) of porous reformer (30% Ni/Al2O3) shell and multi-tube design. Still parameters like reactor design and temperature, feed gas concentration and pressure, and flow configuration need more investigation to figure out their impact on hydrogen production rate at lower energy cost and minimum possible volume. This work targets optimization of reactor performance for higher hydrogen yield and coming up with a scalable optimized reactor design for industrial applications. First, an optimization study is performed under non-reforming (separation-only) conditions to optimize the MR design and operating parameters for higher hydrogen production. Then, the study is extended to consider hydrogen separation under SMR conditions to come up with a MR design for hydrogen production at the industrial scale. Hydrogen permeation is limited to small zone near the membrane surface with no effect of feed pressure, inlet gas temperature, and feed hydrogen concentration on widening such zone that necessitates reducing the pitch distance between membrane tubes below 22 mm. The results showed reduced hydrogen permeation rate under SMR conditions compared to the separation-only cases.

Research on Pulse Shaper Based on Trapezoidal Function

In order to improve the time resolution and spatial resolution of photon-counting imaging system, the pulse shaper based on trapezoidal function is studied. The signal with an exponential decay shape from charge sensitive amplifier is converted to digital discrete signal by ADC and then the discrete number sequence is filtered and shaped by digital signal processing technology. The amplitude linearity and time width of the trapezoidal shaper are simulated and verified using software-generated single exponential signals and double exponential signals. While the continuous pulses are applied to the trapezoidal shaper, the separation characteristics of the trapezoidal algorithm for pulses pile-up is verified, and the setting method of the rise edge and fall edge parameters of the trapezoidal shaper is proposed, which can realize the high counting capability of the system.

Development of a three-stage, cross-current air sparged mixer-settler for the purification of degraded PUREX solvent

ABSTRACT Tri-butyl phosphate (TBP) diluted with in n-dodecane (n-DD) is used as the solvent in PUREX process. Solvent degradation due to radiolysis and hydrolysis during the process is one of the major problems prevailing in reprocessing plants. This paper presents an overview of the design, fabrication, and performance evaluation of a three-stage, continuous, cross-current air sparged mixer-settler developed for purifying the degraded PUREX solvent using hydrazine carbonate. The developmental program consisted of various stages, starting with small-scale batch experiments to investigate the solvent treatment kinetics and phase separation characteristics, followed by design fabrication and performance evaluation of three-stage air sparged mixer-settler. The study on solvent treatment kinetics in a 1.6 L batch air sparged mixer using 1.5 M hydrazine carbonate showed that the concentration of di-butyl phosphate (DBP) in the simulated degraded solvent could be reduced from 8,000 mg L−1 to less than 40 mg L−1 within 180 seconds. Performance evaluation of the three-stage air sparged mixer settler had shown that the DBP concentration in the simulated degraded organic phase could be brought down from 8,000 mg L−1 to less than 15 mg L−1, and the equipment could process up to 60 L h−1 throughput with negligible phase entrainment.

Oil Separation of Lubricating Greases under Static Conditions: Analytical Photo-Centrifuge and DIN 51817

Lubricating greases enclose oil in porous structures of aggregated thickener particles. Their tendency to separate oil under static conditions is evaluated according to DIN 51817 or DIN ISO 22285 in tests of up to 168 h with the mass fraction of separated oil as result. With an analytical photo-centrifuge, separated oil mass fractions can be tracked in real time in the instrument operating temperature range from 4–60 °C. Due to the higher mechanical load compared to standard tests, the grease samples separate more and faster oil, significantly speeding up the analysis process. Fitting the measured data from both methods with the function wO = wO,∞ exp(−t/tc), the parameters maximum oil separation wO,∞ and characteristic time tc are obtained as measures of oil separation extent and rate. Both parameters help to compare the two methods and to interpret the oil separation characteristics of greases. Using four commercial greases of NLGI classes 0–2, the analytical photo-centrifuge measuring method is presented in detail and its results are discussed in reference to those of standard DIN 51817.

Amelioration, inclusion, and legal recognition: On sex, gender, and the UK's Gender Recognition Act

Amelioration, inclusion, and legal recognition: On sex, gender, and the <scp>UK</scp>'s Gender Recognition Act

AUTOMATIC 2D AND 3D SEGMENTATION OF GLIOBLASTOMA BRAIN TUMOR

The brain tumor is the most common destructive and deadly disease. In general, various imaging modalities such as CT, MRI and PET are used to evaluate the brain tumor. Magnetic resonance imaging (MRI) is a prominent diagnostic method for evaluating these tumors. Gliomas, due to their malignant nature and rapid development, are the most common and aggressive form of brain tumors. In the clinical routine, the method of identifying tumor borders from healthy cells is still a difficult task. Manual segmentation takes time, so we use a deep convolutional neural network to improve efficiency. We present a combined DNN architecture using U-net and MobilenetV2. It exploits both local characteristics and more global contextual characteristics from the 2D MRI FLAIR images. The proposed network has encoder and decoder architecture. The performance metrices such as dice loss, dice coefficient, accuracy and IOU have been calculated. Automated segmentation of 3D MRI is essential for the identification, assessment, and treatment of brain tumors although there is significant interest in machine-learning algorithms for computerized segmentation of brain tumors. The goal of this work is to perform 3D volumetric segmentation using BraTumIA. It is a widely available software application used to separate tumor characteristics on 3D brain MR volumes. BraTumIA has lately been used in a number of clinical trials. In this work, we have segmented 2D slices and 3D volumes of MRI brain tumor images.

Immobilization and property of penicillin G acylase on amino functionalized magnetic Ni0.3Mg0.4Zn0.3Fe2O4 nanoparticles prepared via the rapid combustion process.

Penicillin G acylase plays an important role in the biocatalytic process of semi-synthetic penicillin. In order to overcome the disadvantages of free enzymes and improve the catalytic performance of enzymes, it is a new method to immobilize enzymes on carrier materials. And magnetic materials have the characteristics of easy separation. In the present study, the Magnetic Ni0.3Mg0.4Zn0.3Fe2O4 nanoparticles were successfully prepared by a rapid-combustion method and calcined at 400°C for 2h. The surface of the nanoparticles was modified with sodium silicate hydrate, and the PGA was covalently bound to the carrier particles through the cross-linking of glutaraldehyde. The results showed that the activity of immobilized PGA reached 7121.00U/g. The optimum pH for immobilized PGA was 8 and the optimum temperature was 45°C, the immobilized PGA exhibited higher stability against changes in pH and temperature. The Michaelis-Menten constant (Km) values of the free and immobilized PGA were 0.00387 and 0.0101mol/L and the maximum rate (Vmax) values were 0.387 and 0.129μmol/min. Besides, the immobilized PGA revealed excellent cycling performance. The immobilization strategy presented PGA had the advantages of reuse, good stability, cost saving and had considerable practical significance for the commercial application of PGA.

How Rail Transit Makes a Difference in People’s Multimodal Travel Behaviours: An Analysis with the XGBoost Method

The rail transit system was developed in Chinese large cities to achieve more efficient and sustainable transport development. However, the extent to which the newly built rail transit system can facilitate people’s multimodality still lacks evidence, and limited research examines the interrelationship between trip stages within a single trip. This study aims to explore the interrelations between trip stage characteristics, socio-demographic attributes, and the built environment. It examines how rail transit is integrated as part of multimodal trips after it is introduced. The data are extracted from the Chongqing Urban Resident Travel Survey from 2014, three years after the new rail transit network was established. It applies an XGBoost model to examine the non-linear effect. As a result, the separate trip stage characteristics have more of an impact than the general trip characteristics. The non-linear effects revealed by the machine learning model show changing effects and thresholds of impact by trip stage characteristics on people’s main mode choice of rail transit. An optimal radius of facility distribution along the transit lines is suggested accordingly. Synergistic effects between variables are identified, including by groups of people and land use characteristics.

Experimental and numerical research on flow characteristics of inlet particle separator for aero-engine under the influence of water film

An aero-engine must be able to operate in all-weather conditions, which requires the aircraft to be safe throughout the flight even in bad weather. Excessive intake of rainwater can induce stall and surge of compressor and flameout of combustion chamber, which will lead to the loss of power of the engine. In rainy weather, water come into the engine inlet protection device, which directly determines the compressor inlet conditions and will further affect the compressor working condition and the matching features. In this paper, special attention was paid to the experimental characteristics of aero turbo-shaft engine inlet particle separator (IPS) and the numerical study employing ANSYS-CFX under water spraying condition. Based on the phenomenon of water film forming on the wall surface of the IPS and the experimental data under different water spraying conditions, combined with the predictions from CFD study, an empirical model of water film flow on the wall surface has been developed. The results indicate that in the case of high water ingestion, droplets will inevitably form water film on the wall after entering the IPS. Due to the viscous resistance of wall water film and its influence on the airflow boundary layer, the flow state inside the IPS will change. By establishing a wet wall water film model, the flow characteristics near the wall are closer to the experimental state. The total pressure loss prediction error was reduced from 24.8% to 5.2% and 26.4% to 5.7% under the uniform water spraying rate of 2.93% and 4.84%, respectively.

The problem of focal-segmental glomerulosclerosis in primary glomerulonephritis

The concept of focal segmental glomerulosclerosis in clinical practice is used to describe both a separate disease and morphological characteristics of secondary kidney damage. Most often, focal segmental glomerulosclerosis occurs as a result of the course of primary glomerulonephritis and is the cause of the development of nephrotic syndrome. A feature of the course of nephrotic syndrome in focal segmental glomerulosclerosis is a longer response to steroid therapy, or the formation of dependence/resistance to glucocorticosteroids. Despite the development of scientific progress, the problem of focal segmental glomerulosclerosis in primary glomerulonephritis is still relevant. Understanding the mechanisms of podocyte damage and disease progression is important not only for basic research, but also for everyday clinical practice.

Development Characteristics of Roof Separation of Coal Seam Based on UDEC

The formation, development and fracture of the separation space of the coal seam roof are accompanied by the formation of water hazard of the separation layer of the working face. Using UDEC numerical simulation method, taking a certain working face of a mine as the research object, the dynamic development process of the separation space of overburden of the coal seam roof during the mining process of the working face is analyzed, and the separation development position and three-zone height are determined, which provides theoretical basis for the formation mechanism of water hazard of the separation layer of the mine.

An innovative technology for utilization of oolitic hematite via microwave fluidization pretreatment: Separation characteristics and mechanism

An innovative technology for utilization of oolitic hematite via microwave fluidization pretreatment: Separation characteristics and mechanism

Stability evaluation and heavy metal quantification of lotions from caprine milk, yogurt, and kefir

Context: Caprine milk has beneficial antioxidant and anti-inflammatory properties, thus the potential to be developed as a topical formulation against the skin-aging process. However, the influence of temperature during topical formulation storage from caprine milk must be explored. Aims: To analyze the physical stability and heavy metal contents of skin lotion from caprine milk, yogurt, and kefir. Methods: All lotions were storage at different conditions, such as 4°C, 25°C without light exposure (LE), 25°C with light exposure, and 33°C for 12 months. The characteristics of color, aroma, separation, viscosity, pH level, and heavy metals were determined periodically. Results: Yogurt lotions showed more maintained color, aroma, and separation under different storage conditions than milk and kefir lotions. The viscosity of all samples was relatively stable, with a minor reduction at 33°C of temperature storage. The longer duration of storage reduced the pH level for all lotions. Heavy metals were slightly detected in safe range values. Conclusions: This study concludes that the physical characteristics of lotions made from caprine milk, yogurt, and kefir were relatively stable during the different storage conditions, and these lotions are proposed as a safe topical formulation for skin application.

Potential of closed contour analysis for species differentiation and holotype designation: a case study on lower Norian (Upper Triassic) conodonts

AbstractGeometric morphometric approaches become increasingly applied in the fields of biology and palaeontology. Taxonomy is a good example, where a long‐standing intention of scientists is to eliminate subjectivity as much as possible. In the case of biostratigraphically important conodont elements, the application of such methods is not widespread. Only a handful of studies attempted to deal with the morphological variance of conodont elements from this aspect. The detailed description of five lower Norian (Upper Triassic) taxa (Ancyrogondolella quadrata, A. rigoi, A. triangularis, A. uniformis and Metapolygnathus mazzai) is presented here based on landmarks and Fourier analysis of the P1 element and keel outlines. Both methods led to similar outcomes regarding taxonomic differentiation and exposing shape variability. Consensus shapes were generated to objectively reveal the typical contour shape of each taxon, which allowed their comparison with each other, and with the members of their respective sample population including the holotypes. The results demonstrated that the holotype of a taxon is generally not an average representative, but rather a peripheral form with well separable morphological characteristics. Ancyrogondolella quadrata and A. rigoi turned out to represent a morphological continuum with ample transitional forms between these two end‐members that may cause bias in their biostratigraphic applicability, however their combined shape variance seems to be too large for uniting them into a single species. Given the results that may be too subtle to realize based solely on qualitative observations, future taxonomic studies and type material designation could greatly benefit from the application of similar methodologies.

Numerical study of temperature separation characteristics of vortex tubes: Effects of structural parameters and modeling of cooling performance correlations

Numerical study of temperature separation characteristics of vortex tubes: Effects of structural parameters and modeling of cooling performance correlations