Multi-stage hydrogel rockets with stage dropping-off by thermal/light stimulation

2018 ◽  
Vol 6 (35) ◽  
pp. 16838-16843 ◽  
Author(s):  
Yuling Liang ◽  
Yibin Xu ◽  
Wei Ye ◽  
Dahua Yao ◽  
Yunhua Chen ◽  
...  
Keyword(s):  
Light Stimulation ◽  
Precise Control ◽  
Multi Stage ◽  
Thermal Light

A multi-stage hydrogel rocket with precise control of the step-by-step detachment of the hydrogel stage and tunable cargo release ability was fabricated.

scholarly journals Modeling the Electro-chemical Properties of Microbial Opsin ChrimsonR for Application to Optogenetics-based Vision Restoration

2018 ◽  
Author(s):  
Quentin Sabatier ◽  
Corentin Joffrois ◽  
Grégory Gauvain ◽  
Joël Chavas ◽  
Didier Pruneau ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Chemical Properties ◽  
Light Stimulation ◽  
Adaptation Mechanism ◽  
Detailed Model ◽  
Precise Control ◽  
Computer Interfaces ◽  
Slow Adaptation ◽  
Response Onset ◽  
Steady State Amplitude

AbstractOptogenetic activation of neurons [1] have greatly contributed to our understanding of how neural circuits operate, and holds huge promise in the field of neural prosthetics, particularly in sensory restoration. The discovery of new channelrhodopsins, Chrimson — which is 45 nm more red-shifted than any previously discovered or engineered channelrhodopsin — and its mutant ChrimsonR with faster kinetics [2] made this technology available for medical applications. However, a detailed model that would be able to accurately reproduce the membrane potential dynamics in cells transfected with ChrimsonR under light stimulation is missing. We address this issue by developing the first model for the electrochemical behavior of ChrimsonR that predicts its conductance in response to arbitrary light stimulation. Our model captures ON and OFF dynamics of the protein for stimuli with frequencies up to 100 Hz and their relationship with the brightness, as well as its activation curve, the steady-state amplitude of the response as a function of light intensity. Additionally, we capture a slow adaptation mechanism at a timescale at the order of minutes. Our model holds for light intensities covering the whole dynamic range of the channel (from response onset to saturation) and for timescales in the order of up to several minutes. This model is a new step towards modeling the spiking activity of ChrimsonR-expressing neurons, required for the precise control of information transmission in optogenetics-based Brain-Computer Interfaces, and will inform future applications of ChrimsonR based optogenetics.

CO2 Compression Using an Eight Stage, Integrally Geared, Centrifulgal Compressor

2004 ◽  
Author(s):  
Bill Olson ◽  
David Ammerman ◽  
Harmut Hage
Keyword(s):  
North America ◽  
Heat Exchangers ◽  
Inlet Temperature ◽  
Precise Control ◽  
Multi Stage ◽  
Critical Phase ◽  
Temperature And Pressure ◽  
Cross Country ◽  
Response To Temperature ◽  
Pressure Changes

This paper discusses the design, specification, and installation of an integrally geared, 8-stage centrifugal compressor for CO2 pipeline service in North America. To the authors’ knowledge, this was the first, and remains the only, such application of this compression technology in a cross-country pipeline in North America. The facilities were installed in 1999 and became operational in 2000. Design considerations included compressing process CO2 from near atmospheric pressure to the super critical phase that allows for efficient transport of large volumes over long distances in a pipeline. In this phase, the CO2 behaves much like a liquid, but its physical properties (e.g. density and viscosity) vary much like a gas in response to temperature and pressure changes. In order to function properly in this application, the compressor must be flexible enough to compress the CO2 under varying inlet temperature and pressure conditions. Inlet guide vanes were used to regulate flow to the suction of alternating stages. The controls system for these vanes was required to closely monitor interstage conditions in order to make sure that no stage entered surge. Furthermore, the interstage coolers also required precise control to prevent overheating in summer or liquid formation in winter. Ambient design temperatures ranged from −50°F (−45°C) to +104°F (+40°C). A simplified system diagram is shown in Fig. 1. If the air-cooled heat exchangers remove too much heat, liquids will form and the subsequent compressor stage could be severely damaged. If the compressor unit, or any stage, enters surge (stalls), the machine can also be damaged. Consequently, bypass and recirculation schemes (see Fig. 1) were used to enhance safe operations. Ambient airflow to the coolers was controlled by louvers, which in turn were regulated by the compressor control system. These heat exchangers also employed recirculation plenums to permit recirculation of warm air during low ambient temperature conditions. The problem solved by the application of this technology was to efficiently compress large volumes of very low pressure CO2 into the super critical phase for pipeline transportation. The overall compression ratio across these units exceeded 180. In the past, CO2 compression for pipeline service has been accomplished by using numerous, multi-stage reciprocating compressors, over much narrower compression ratios (typically < 15).

Modified Sieve Sampling: A Method for Single- and Multi-Stage Probability- Proportional-to-Size Sampling

2010 ◽  
Vol 29 (1) ◽  
pp. 125-148 ◽  
Author(s):  
Lucas A. Hoogduin ◽  
Thomas W. Hall ◽  
Jeffrey J. Tsay
Keyword(s):  
Sample Size ◽  
Single Stage ◽  
New Method ◽  
Systematic Sampling ◽  
Reliable Control ◽  
Selection Methods ◽  
Sample Sizes ◽  
Precise Control ◽  
Multi Stage ◽  
Efficiency Measures

SUMMARY: Widely used probability-proportional-to-size (PPS) selection methods are not well adapted to circumstances requiring sample augmentation. Limitations include: (1) an inability to augment selections while maintaining PPS properties, (2) a failure to recognize changes in census stratum membership which result from sample augmentation, and (3) imprecise control over line item sample size. This paper presents a new method of PPS selection, a modified version of sieve sampling which overcomes these limitations. Simulations indicate the new method effectively maintains sampling stratum PPS properties in single- and multi-stage samples, appropriately recognizes changes in census stratum membership which result from sample augmentation, and provides precise control over line item sample sizes. In single-stage applications the method provides reliable control of sampling risk over varied tainting levels and error bunching patterns. Tightness and efficiency measures are comparable to randomized systematic sampling and superior to sieve sampling.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Multiple-fracturing and viewing of the same frozen sample at different depths using a low temperature FESEM

1996 ◽  
Vol 54 ◽  
pp. 820-821
Author(s):  
M.V. Parthasarathy ◽  
C. Daugherty
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Multiple Fracture ◽  
Precise Control ◽  
Cold Stage ◽  
Different Depths ◽  
Transfer Device

The versatility of Low Temperature Field Emission SEM (LTFESEM) for viewing frozen-hydrated biological specimens, and the high resolutions that can be obtained with such instruments have been well documented. Studies done with LTFESEM have been usually limited to the viewing of small organisms, organs, cells, and organelles, or viewing such specimens after fracturing them.We use a Hitachi 4500 FESEM equipped with a recently developed BAL-TEC SCE 020 cryopreparation/transfer device for our LTFESEM studies. The SCE 020 is similar in design to the older SCU 020 except that instead of having a dedicated stage, the SCE 020 has a detachable cold stage that mounts on to the FESEM stage when needed. Since the SCE 020 has a precisely controlled lock manipulator for transferring the specimen table from the cryopreparation chamber to the cold stage in the FESEM, and also has a motor driven microtome for precise control of specimen fracture, we have explored the feasibility of using the LTFESEM for multiple-fracture studies of the same sample.

Planning and Search in Multi-Stage Risky Decision Making

2011 ◽  
Author(s):  
Jared Hotaling ◽  
Jerry Busemeyer ◽  
Richard Shiffrin
Keyword(s):  
Decision Making ◽  
Risky Decision Making ◽  
Risky Decision ◽  
Multi Stage

Pharmacokinetics and Haemostatic Status During Consecutive Infusions of Recom binant Tissue-Type Plasminogen Activator in Patients with Acute Myocardial Infarction

1989 ◽  
Vol 61 (03) ◽  
pp. 497-501 ◽  
Author(s):  
E Seifried ◽  
P Tanswell ◽  
D Ellbrück ◽  
W Haerer ◽  
A Schmidt
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Plasminogen Activator ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Precise Control ◽  
Type Plasminogen Activator

SummaryPharmacokinetics and systemic effects of recombinant tissue type plasminogen activator (rt-PA) were determined during coronary thrombolysis in 12 acute myocardial infarction patients using a consecutive intravenous infusion regimen. Ten mg rt-PA were infused in 2 minutes resulting in a peak plasma concentration (mean ±SD) of 3310±950 ng/ml, followed by 50 mg in 1 h and 30 mg in 1.5 h yielding steady state plasma levels of. 2210±470 nglml and 930±200 ng/ml, respectively. All patients received intravenous heparin. Total clearance of rt-PA was 380±74 ml/min, t,½α was 3.6±0.9 min and t,½β was 16±5.4 min.After 90 min, in plasma samples containing anti-rt-PA-IgG to inhibit in vitro effects, fibrinogen was decreased to 54%, plasminogen to 52%, α2-antiplasmin to 25%, α2-macroglobulin to 90% and antithrombin III to 85% of initial values. Coagulation times were prolonged and fibrin D-dimer concentrations increased from 0.40 to 2.7 μg/ml. It is concluded that pharmacokinetics of rt-PA show low interpatient variability and that its short mean residence time in plasma allows precise control of therapy. Apart from its moderate effect on the haemostatic system, rt-PA appears to lyse a fibrin pool in addition to the coronary thrombus.

Effects of Cooking Oil Subsidy Removals on Related Markets in Malaysia: A Comparative Static, Multicommodity, Multi Stage Production Approach

2011 ◽  
Author(s):  
Jamal Othman ◽  
Yaghoob Jafari
Keyword(s):  
Equilibrium Model ◽  
Comparative Statics ◽  
Partial Equilibrium ◽  
Cooking Oil ◽  
Multi Stage ◽  
Supply Factor ◽  
Partial Equilibrium Model ◽  
Factor Markets ◽  
Input Markets ◽  
Production Approach

Malaysia is contemplating removal of most of her subsidy support measures including subsidies on cooking oil which is largely palm oil based. This paper aims to examine the effects of cooking oil subsidy removals on the competitiveness of the oil palm subsector and related markets. This is done by developing and applying a comparative static, multi-commodity, partial equilibrium model with multi-stages of production function for the Malaysian perennial crops subsector which explicitly links different stages of production, primary and intermediate input markets, trade, and policy linkages. Results partly suggest that export of cooking oil will increase by 0.2 per cent due to a 10 per cent cooking oil subsidy reduction, while domestic output of cooking oil may eventually see a net decline of 1.97 per cent. The results clearly point out that the effect of reducing cooking oil subsidies is relatively small at the upstream levels and therefore it only induces minute effects on factor markets. Consequently, the market for other agricultural crops is projected to change very marginally.   Keywords: Multicomodity, comparative statics, partial equilibrium model, output supply-factor markets linkages, effects of cooking oil subsidy removals.

IMPACT ASSESSMENT OF AGRICULTURAL TRANSFORMATION PROJECT ON PRODUCTIVITY AND POVERTY AMONG RICE FARMERS IN KANO STATE, NIGERIA.

2020 ◽  
Vol 4 (2) ◽  
pp. 392-400
Author(s):  
O. S. Balogun ◽  
M. A. Damisa ◽  
O. Yusuf ◽  
O. L. Balogun
Keyword(s):  
Sampling Method ◽  
Insect Pests ◽  
Study Data ◽  
Average Treatment Effect ◽  
Descriptive Statistics ◽  
Rice Farmers ◽  
Agricultural Transformation ◽  
Multi Stage ◽  
Significant Difference ◽  
Late Model

The study was carried out to examine the effect of agricultural transformation on the beneficiary’s productivity and poverty of rice farmers in Kano State Nigeria. A multi-stage sampling method was employed to select 571 respondents for the study. Data were collected through structured questionnaires on respondent’s income, input and output quantities as well as their expenditures. Data were analysis using descriptive statistics, Foster-Greer-Thorbecke (FGT), Propensity score matching and LATE model. Results from the study shows that respondents productivity revealed a significant difference of about 127 kg/ha in rice productivity between participants and non-participants. Also, the LATE estimates revealed an average treatment effect ATE0 of about 222.98kg/ha. Furthermore, the project had a significant effect N11, 321.4 on the participant’s consumption expenditure than the non-participants N9980.60. Moreover, participants were, able to increase their household total expenditures by N34780 per annum. Fluctuations of input/output prices insect pests and inadequate extension visits were all the major constraints faced by the farmers. It was recommended that farmers’ information and sensitization system should be overhauled and improved. Also, attention should be given to well organize extension visits for the farmers from stake holders

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