Characterization and monitoring of vacuum pressure of tank containers with multilayer insulation for cryogenic clean fuels storage and transportation

2021 ◽  
Vol 187 ◽  
pp. 116569
Author(s):  
Bo Wang ◽  
Ruoyin Luo ◽  
Hong Chen ◽  
Chen Zheng ◽  
Yunfei Gao ◽  
...  
Keyword(s):  
Vacuum Pressure ◽  
Clean Fuels ◽  
Multilayer Insulation

Method and results of experimental researches of modes of work of the adaptive milking equipment on the basis of the portion meter of the weight type

2020 ◽  
pp. 140-146
Author(s):  
I. A. Afanasiev ◽  
V. V. Tkach
Keyword(s):  
Regression Analysis ◽  
Vacuum Pressure ◽  
Limit Values ◽  
Operating Modes ◽  
Machine Milking ◽  
Milk Output ◽  
Mode Of Operation ◽  
Milking Machine ◽  
Experimental Researches

Annotation Purpose. Improving the efficiency of machine milking due to the improvement of milking equipment on the basis of the portion meter of the weight type. Methods. Studies have been conducted on the basis of the planned experiment. The data obtained were processed using the methods of regression analysis. Results. The technique of laboratory researches is developed, a prototype of a membrane regulator of vacuum is made and experimental researches of operating modes of the adaptive milking equipment on the basis of the portion meter of the weight type. According to the results of the research, the dependence between the parameters and the mode of operation of the membrane vacuum regulator was obtained. Conclusions. The dependence is obtained, between the vacuum pressure in the milk collection chamber of the collector, milk expense, the diameters of the milk pipe and the diameters of a throttle opening. The limit values of the intensity of milk output (0.2 m3/s) at which there is a critical drop in the working vacuum pressure in the milk collection chamber of the collector and the corresponding choke parameters (diameter of the throttle opening 0,001 m) are defined. This eliminates this negative phenomenon. Keywords: adaptive milking equipment, milking machine, machine milking, milk expense.

Optimization of the operational parameters of a picking-type pneumatic planter using response surface methodology

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
SK PATEL ◽  
JB BHIMANI ◽  
P GUPTA ◽  
BK YADUVANSHI
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Important Variable ◽  
Vacuum Pressure ◽  
Forward Speed ◽  
Operational Parameters ◽  
Seed Spacing ◽  
Lady’S Finger ◽  
Multiple Regression Technique ◽  
Seed Metering Device

Singulation of seeds has been investigated extensively by researchers all over the world and a large number of precision seeding systems with design variations have been developed for different crops. A picking type metering mechanism was developed at CAET, AAU, Godhra, Gujarat, India. The performance of the picking type seed-metering device of a pneumatic planter was investigated under laboratory conditions to optimize the operating parameters for lady's finger seed. The picking of single seed the three operational parameters i.e. hole diameters for the nozzle: 1.0, 1.5, 2.5 and 3.0 mm; forward speed: 0.37, 0.56, 0.83, 1.11 and 1.30 m/s and vacuum pressure: 19.33, 39.32, 43.98, 58.64 and 68.63 kPa were selected for the study. The metering system of the planter was set to place the seed to seed spacing at 300 mm. The response surface methodology (RSM) technique was used to optimize the operational parameters of a precision planter. For optimizing the forward speed, vacuum pressure and nozzle size for developed machine was evaluated by examining the miss index, multiple index, quality of feed index and precision. The data obtained in the experiments were used to develop functions in polynomial form using multiple regression technique. The optimum value was found to be around 0.96 m/s, 36.25 kPa and 2.0 mm of forward speed, vacuum pressure and the holes diameter of nozzle, respectively. The most important variable that governs planting phenomenon is the combination of hole diameter of nozzle and vacuum pressure accounts 89.18 per cent.

scholarly journals Numerical Simulation of the Water Vapor Separation of a Moisture-Selective Hollow-Fiber Membrane for the Application in Wood Drying Processes

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 593
Author(s):  
Nasim Alikhani ◽  
Douglas W. Bousfield ◽  
Jinwu Wang ◽  
Ling Li ◽  
Mehdi Tajvidi
Keyword(s):  
Water Vapor ◽  
Constant Temperature ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Vacuum Pressure ◽  
Vapor Concentration ◽  
Water Vapor Concentration ◽  
Fiber Membrane ◽  
Wood Drying ◽  
Air Velocity

In this study, a simplified two-dimensional axisymmetric finite element analysis (FEA) model was developed, using COMSOL Multiphysics® software, to simulate the water vapor separation in a moisture-selective hollow-fiber membrane for the application of air dehumidification in wood drying processes. The membrane material was dense polydimethylsiloxane (PDMS). A single hollow fiber membrane was modelled. The mass and momentum transfer equations were simultaneously solved to compute the water vapor concentration profile in the single hollow fiber membrane. A water vapor removal experiment was conducted by using a lab-scale PDMS hollow fiber membrane module operated at constant temperature of 35 °C. Three operation parameters of air flow rate, vacuum pressure, and initial relative humidity (RH) were set at different levels. The final RH of dehydrated air was collected and converted to water vapor concentration to validate simulated results. The simulated results were fairly consistent with the experimental data. Both experimental and simulated results revealed that the water vapor removal efficiency of the membrane system was affected by air velocity and vacuum pressure. A high water vapor removal performance was achieved at a slow air velocity and high vacuum pressure. Subsequently, the correlation of Sherwood (Sh)–Reynolds (Re)–Schmidt (Sc) numbers of the PDMS membrane was established using the validated model, which is applicable at a constant temperature of 35 °C and vacuum pressure of 77.9 kPa. This study delivers an insight into the mass transport in the moisture-selective dense PDMS hollow fiber membrane-based air dehumidification process, with the aims of providing a useful reference to the scale-up design, process optimization and module development using hollow fiber membrane materials.

scholarly journals Factors critical to implementation success of cleaner cooking interventions in low-income and middle-income countries: protocol for an umbrella review

BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e041821
Author(s):  
Esther A Boudewijns ◽  
Debbie Vermond ◽  
Rianne M J J van der Kleij ◽  
Niels H Chavannes ◽  
Onno C P van Schayck ◽  
...  
Keyword(s):  
Solid Fuel ◽  
Low Income ◽  
Ethical Review ◽  
Umbrella Review ◽  
Implementation Success ◽  
Middle Income ◽  
Middle Income Countries ◽  
Level Of Confidence ◽  
Study Results ◽  
Clean Fuels

IntroductionOver a third of the world’s population relies on solid fuels as their primary energy source. These fuels have damaging effects on health, air quality and forest resources. Interventions to promote access to cleaner solid fuel cookstoves and clean fuels have existed for decades. However, the adoption by local communities has largely failed, which led to a waste of resources and suboptimal outcomes. Therefore, the objective of this umbrella review is to identify factors that determine implementation success for cleaner cooking interventions in low-resource settings and weigh their level of confidence in the evidence.Methods and analysisWe identified systematic and narrative reviews examining factors that influence the acquisition, initial adoption or sustained use of cleaner solid fuel cookstoves and clean fuels at any scale by a literature search in PubMed, Embase, Global Health Database, Cochrane, PsycINFO, Emcare, Web of Science and CINAHL, without date or language restrictions. The search was conducted on 23 October 2017 and updated on 10 July 2019. Reviews based on qualitative, quantitative or mixed-methods studies were included and will be appraised using the Meta Quality Appraisal Tool combined with the Assessment of Multiple Systematic Reviews. Data will be extracted and factors affecting implementation will be coded using the Consolidated Framework for Implementation Research. The Grading of Recommendations Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative Research tool will be used to determine the level of confidence in the coded factors. Two researchers will independently conduct these steps.Ethics and disseminationThis umbrella review does not require the approval of an ethical review board. Study results will be published in an international peer-reviewed journal. The outcomes will be converted into two practical tools: one for cleaner solid fuel cookstoves and one for clean fuels. These tools can guide the development of evidence-based implementation strategies for cleaner cooking interventions in low-income and middle-income countries to improve implementation success. These tools should be pilot-tested and promoted among regional and global initiatives.PROSPERO registration numberCRD42018088687.

scholarly journals Vacuum Venting Enhances the Replication of Nano/Microfeatures in Micro-Injection Molding Process

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Seong Ying Choi ◽  
Nan Zhang ◽  
J. P. Toner ◽  
G. Dunne ◽  
Michael D. Gilchrist
Keyword(s):  
Injection Molding ◽  
Quantitative Study ◽  
Vacuum Pressure ◽  
Injection Molding Process ◽  
Anodized Aluminum ◽  
Molding Process ◽  
Micro Injection Molding ◽  
Sample Shape ◽  
Final Sample ◽  
Qualitative And Quantitative Study

Vacuum venting is a method proposed to improve feature replication in microparts that are fabricated using micro-injection molding (MIM). A qualitative and quantitative study has been carried out to investigate the effect of vacuum venting on the nano/microfeature replication in MIM. Anodized aluminum oxide (AAO) containing nanofeatures and a bulk metallic glass (BMG) tool mold containing microfeatures were used as mold inserts. The effect of vacuum pressure at constant vacuum time, and of vacuum time at constant vacuum pressure on the replication of these features is investigated. It is found that vacuum venting qualitatively enhances the nanoscale feature definition as well as increases the area of feature replication. In the quantitative study, higher aspect ratio (AR) features can be replicated more effectively using vacuum venting. Increasing both vacuum pressure and vacuum time are found to improve the depth of replication, with the vacuum pressure having more influence. Feature orientation and final sample shape could affect the absolute depth of replication of a particular feature within the sample.

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