scholarly journals Air Pressure-Assisted Centrifugal Dewatering of Concentrated Fine Sulfide Particles

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
R. Asmatulu
Keyword(s):  
Centrifugal Force ◽  
Fine Particles ◽  
Applied Pressure ◽  
Air Pressure ◽  
The Novel ◽  
Test Results ◽  
Filtration Method ◽  
Cake Moisture ◽  
The Cost ◽  
Filter Cakes

An air pressure-assisted centrifugal dewatering method was developed and used for the dewatering of concentrated finesulfide particles, such as sphalerite, galena, and chalcopyrite. This filtration method was mainly designed to increase the filtration rate during the drainage cycle and, hence, produce drier filter cakes, which in turn could reduce the cost and emission problems/concerns of thermal dryers in the preparation plants. Several dewatering parameters, including applied pressure, centrifugal force (G-force), spin time, cake thickness, and surface hydrophobization, were tested to optimize the processing conditions. Test results showed that, at higher air pressure and centrifugal force, the cake moisture reduction was more than 70%, depending on the testing conditions. As a result, it can be-concluded that the novel filtration method effectively works on the dewatering of fine particles (–150 μm).

Design of an Air Pressure-Assisted Centrifugal Dewatering Method for Fine Particle Suspensions

2011 ◽  
Author(s):  
R. Asmatulu
Keyword(s):  
Centrifugal Force ◽  
Fine Particles ◽  
Applied Pressure ◽  
Air Pressure ◽  
The Novel ◽  
Experimental Conditions ◽  
Cake Moisture ◽  
Filtration Unit ◽  
The Cost ◽  
Filter Cakes

An air pressure-assisted centrifugal dewatering unit was designed and fabricated for the dewatering of fine particles (−150 μm), such as clay, silica, and talc. The aim of this filtration unit is to increase the filtration rate during the drainage cycle and, hence produce drier filter cakes, which in turn could reduce the cost and emission problems of thermal dryers in the preparation plants. Several dewatering parameters, including applied pressure, centrifugal force (G-force), spin time, and cake thickness were tested to optimize the processing conditions. Test results showed that at higher air pressure and centrifugal force, the cake moisture reduction was more than 60% depending on the experimental conditions. As a result, it can be concluded that the novel filtration unit effectively works on the dewatering of fine particles and can open up new opportunities in the field.

scholarly journals Test Study on Airtight Capability of Filter Cakes for Slurry Shield and Its Application in a Case

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Fanlu Min ◽  
Wei Zhu ◽  
Shengquan Xia ◽  
Rui Wang ◽  
Daiwei Wei ◽  
...  
Keyword(s):  
Yangtze River ◽  
Filter Cake ◽  
Water Pressure ◽  
Air Pressure ◽  
Test Results ◽  
Test Study ◽  
Capillary Bundle ◽  
Slurry Shield ◽  
Filter Cakes ◽  
The Relationship

To learn the airproof capacity of filter cakes as opening chambers under air pressure, a series of tests were carried out. The variations of discharged water with air pressure and time were observed, and the relationship between airproof capacity of filter cakes and surrounding air pressure was analysed. The test results indicated that there were three stages as compressed air acting on filter cakes: completely not infiltration, a very small amount of infiltration, and penetration leakage. The certain air pressure between the first and second stages was called the airproofing value of filter cake. And a capillary bundle model was used to explain the mechanism of air tightness of filter cakes. In Nanjing Yangtze River Tunnel, a 5 cm thickness filter cake was formed in gravel sand, and its airproofing value was a little lower than 0.12 MPa. The air pressure used as opening chamber should be equal to the summation of water pressure in sand and airproofing value of filter cake. While the air pressure is larger than the summation, the filter cake would be gas permeable. The slurry formulation and airproofing value of filter cakes obtained in the tests were applied successfully in Nanjing Yangtze River Tunnel.

Insights into Transdermal Drug Delivery: Approaches for Redressal of a Burgeoning Issue of Osteoporosis

2020 ◽  
Vol 20 (10) ◽  
pp. 1682-1695
Author(s):  
Foziyah Zakir ◽  
Kanchan Kohli ◽  
Farhan J. Ahmad ◽  
Zeenat Iqbal ◽  
Adil Ahmad
Keyword(s):  
Drug Delivery ◽  
Transdermal Delivery ◽  
Oral Delivery ◽  
Calcium Absorption ◽  
Early Stage ◽  
Osteoporotic Fractures ◽  
The Novel ◽  
Systemic Delivery ◽  
Primary Focus ◽  
The Cost

Osteoporosis is a progressive bone disease that remains unnoticed until a fracture occurs. It is more predominant in the older age population, particularly in females due to reduced estrogen levels and ultimately limited calcium absorption. The cost burden of treating osteoporotic fractures is too high, therefore, primary focus should be treatment at an early stage. Most of the marketed drugs are available as oral delivery dosage forms. The complications, as well as patient non-compliance, limit the use of oral therapy for prolonged drug delivery. Transdermal delivery systems seem to be a promising approach for the delivery of anti-osteoporotic active moieties. One of the confronting barriers is the passage of drugs through the SC layers followed by penetration to deeper dermal layers. The review focuses on how anti-osteoporotic drugs can be molded through different approaches so that they can be exploited for the skin to systemic delivery. Insights into the various challenges in transdermal delivery and how the novel delivery system can be used to overcome these have also been detailed.

scholarly journals Prehospital identification of Covid-19: an observational study

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Douglas Spangler ◽  
Hans Blomberg ◽  
David Smekal
Keyword(s):  
Predictive Value ◽  
Prehospital Care ◽  
The Novel ◽  
Test Results ◽  
Care Providers ◽  
Care Systems ◽  
Primary Hospital ◽  
Novel Coronavirus ◽  
Rule Out ◽  
Descriptive Statistical Analysis

Abstract Background The novel coronavirus disease 2019 (Covid-19) pandemic has affected prehospital care systems across the world, but the prehospital presentation of affected patients and the extent to which prehospital care providers are able to identify them is not well characterized. In this study, we describe the presentation of Covid-19 patients in a Swedish prehospital care system, and asses the predictive value of Covid-19 suspicion as documented by dispatch and ambulance nurses. Methods Data for all patients with dispatch, ambulance, and hospital records between January 1–August 31, 2020 were extracted. A descriptive statistical analysis of patients with and without hospital-confirmed Covid-19 was performed. In a subset of records beginning from April 14, we assessed the sensitivity and specificity of documented Covid-19 suspicion in dispatch and ambulance patient care records. Results A total of 11,894 prehospital records were included, of which 481 had a primary hospital diagnosis code related to-, or positive test results for Covid-19. Covid-19-positive patients had considerably worse outcomes than patients with negative test results, with 30-day mortality rates of 24% vs 11%, but lower levels of prehospital acuity (e.g. emergent transport rates of 14% vs 22%). About half (46%) of Covid-19-positive patients presented to dispatchers with primary complaints typically associated with Covid-19. Six thousand seven hundred seventy-six records were included in the assessment of predictive value. Sensitivity was 76% (95% CI 71–80) and 82% (78–86) for dispatch and ambulance suspicion respectively, while specificities were 86% (85–87) and 78% (77–79). Conclusions While prehospital suspicion was strongly indicative of hospital-confirmed Covid-19, based on the sensitivity identified in this study, prehospital suspicion should not be relied upon as a single factor to rule out the need for isolation precautions. The data provided may be used to develop improved guidelines for identifying Covid-19 patients in the prehospital setting.

Mechanical Behavior of Ti-6Al-4V Manufactured by Electron Beam Additive Fabrication

2013 ◽  
Author(s):  
Leila Ladani ◽  
Lalit Roy
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Lead Time ◽  
Aerospace Industry ◽  
Tensile Tests ◽  
Test Results ◽  
Great Resistance ◽  
Additive Fabrication ◽  
Anisotropy Effect ◽  
The Cost

Additive Layer Fabrication, in particular Electron Beam Additive Fabrication (EBAF), has recently drawn much attention for its special usability to fabricate intricately designed parts as a whole. It not only increases the production rate which reduces the production lead time but also reduces the cost by minimizing the amount of waste material to a great extent. Ti6Al4V is the most common type of material that is currently being fabricated using EBAF technique. This material has been used in aerospace industry for several reasons such as excellent mechanical properties, low density, great resistance to corrosion, and non-magnetism. The effects of build direction of layers (namely, addition of layers along one of the x, y & z directions with respect to the build table) and the anisotropy effect caused by it has not been explored vigorously. This anisotropy effect has been investigated in this work. Different mechanical properties such as Yield Strength (YS), Ultimate Tensile Strength (UTS), and Modulus of Elasticity (E) of these three types of Ti6Al4V are determined using tensile tests and are compared with literature. The tensile test results show that YS and UTS for flat-build samples have distinguishably higher values than those of the side-build and top-build samples.

Dual-layered polarization and frequency reconfigurable microstrip antenna by rotating breach-truncated circular radiator

2017 ◽  
Vol 9 (8) ◽  
pp. 1705-1712
Author(s):  
Haixiong Li ◽  
Yunlong Gong ◽  
Jiakai Zhang ◽  
Jun Ding ◽  
Chenjiang Guo
Keyword(s):  
Reflection Coefficient ◽  
Circular Polarization ◽  
Microstrip Antenna ◽  
Axial Ratio ◽  
Axial Rotation ◽  
Polarization Characteristic ◽  
The Novel ◽  
Test Results ◽  
Left Handed ◽  
Mechanical Rotation

In this study, a dual-layered polarization and frequency reconfigurable microstrip antenna is proposed based on sequential mechanical axial rotation of the circular metal radiator. The antenna can be reconfigured among three different polarized modes, including the linear polarization (LP), left-handed circular polarization and right-handed circular polarization in the band from 4.68 to 4.80 GHz (2.53%). The resonance frequency of the proposed antenna with the same LP mode could also be tuned in the range from 4.70 to 5.03 GHz by mechanical rotation of the breach-truncated circular metal radiator as well as the circular substrate. Furthermore, the polarization characteristic and frequency can be reconfigured, respectively, as the circular radiator is taken an axial rotation with an angle of 360°. The presented antenna in the four different states has been numerically simulated and fabricated for the experimental measurement, the investigated characteristics includes the port reflection coefficient, axial ratio, radiation pattern, gain, and the radiation efficiency. The simulated and test results agreed well with each other. This antenna enriches the novel mechanical reconfigurable method except for the popular electrical approach.

Design of the Automatic Guided Vehicle Control System Applied to Automotive Logistics

2014 ◽  
Vol 644-650 ◽  
pp. 381-384
Author(s):  
Xin Zhang ◽  
Hao Zhou ◽  
Guo Song Liu
Keyword(s):  
Control System ◽  
Absolute Error ◽  
Vehicle Control ◽  
Test Results ◽  
Circuit Performance ◽  
Automatic Driving ◽  
Automatic Guided Vehicle ◽  
Distribution Logistics ◽  
Auto Parts ◽  
The Cost

In order to improve the efficiency of auto parts distribution logistics, to lower the cost of auto production in transportation logistics, and to reduce accidents, in this paper it is designed that an automatic guided vehicle control system to replace the manned tractors in the distribution sites. The system is equipped with an infrared homing device that can ensure the automated guided vehicle (AGV) along a predetermined route automatic driving at a given distribution information, without the needs to manually guided. Test results show that the circuit performance of AGV control system is stable to ensure the accuracy of the tracking in the practical application, and the mean absolute error of the tracking is less than 0.04m.

scholarly journals Dynamic Analysis and Control of an Automatic Transmission for Start-Stop Function and Efficiency Improvement

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Yang Liu ◽  
Shuhan Wang ◽  
Peng Dong ◽  
Xiangyang Xu
Keyword(s):  
Control Strategies ◽  
Automatic Transmission ◽  
Simulation Method ◽  
Transmission Efficiency ◽  
The Novel ◽  
Test Results ◽  
Test Environment ◽  
Pump System ◽  
Oil Pump ◽  
And Control

An electric oil pump (EOP) was integrated into the hydraulic system and an automatic transmission (AT) mechanical oil pump (MOP) was downsized. These processes were performed to combine a start-stop function with the AT and further improve the transmission efficiency. Furthermore, this study established a dynamics model of power loss and leakage of an 8-speed AT; a flow-based control algorithm of the EOP was then developed to realize the start-stop function and support the MOP to meet the flow requirement of the system. Based on a driving simulation method, sizes of the MOP and EOP that ensured optimal fuel economy were selected. A control strategy for the starting clutch was also developed to minimize the starting delay of the test vehicle. A test environment on a rig and prototype vehicle was established to verify the feasibility of the proposed control strategies. The test results indicated that the transmission functioned favorably with the novel two-pump system presented, and a quick and smooth starting performance was achieved when the engine was restarted. The findings in this study are extremely valuable for forward designs of an AT for realizing start-stop function and improving efficiency.

FROUDE’S LAW OF SIMILITUDE – CONTEMPORARY AND FUTURE SEAKEEPING TESTING

2021 ◽  
Vol 153 (A2) ◽  
Author(s):  
R P Dallinga ◽  
R H M Huijsmans
Keyword(s):  
Model Test ◽  
Scale Effects ◽  
Higher Order ◽  
Air Pressure ◽  
Test Results ◽  
Viscous Effects ◽  
Two Phase ◽  
Scale Models ◽  
Non Linear

Historically “scale effects” in the interpretation of tests with scale models in waves using Froude’s Law of Similitude are mostly associated with viscous effects. Nowadays, with a much more complete modelling of reality and a focus on higher order non-linear phenomena, scaling of model test results implies a wider range of assumptions than the validity of Froude’s Law. Our contribution to the conference is a visionary review of contemporary and future problems in the interpretation of these tests. In this context we will discuss the developments in test techniques, including the development of a new Two-Phase Laboratory facilitating seakeeping and sloshing tests at reduced air pressure.

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