SCR - Science topic

ANSYS FLUENT Software has a page dedicated to the formation and reduction of NOx. In the particular website below, the SNCR model is discussed and the Arrhenius constants are shown.

Emotional intelligence (EQ) can play a significant role in mediating the relationship between self-care regimens and engagement in health-promoting behaviors among patients with Chronic Kidney Disease (CKD). EQ refers to the ability to recognize, understand, manage, and effectively use emotions in oneself and others. Here's how EQ can mediate the relationship between self-care regimens and health-promoting behaviors in CKD patients:

1. **Self-Awareness:** High EQ individuals are more likely to be self-aware, understanding their own emotions and recognizing how they influence their behaviors. In the context of CKD, this self-awareness can lead patients to recognize the importance of adhering to self-care regimens and health-promoting behaviors.

2. **Motivation:** EQ is linked to intrinsic motivation and the ability to set meaningful goals. CKD patients with high EQ might be more motivated to engage in health-promoting behaviors because they understand the long-term benefits for their well-being, which could include improved kidney function and overall health.

3. **Emotion Regulation:** EQ helps individuals manage their emotions effectively. For CKD patients, who may face emotional challenges due to the demands of their condition, high EQ can lead to better stress management. This, in turn, reduces the likelihood of engaging in unhealthy behaviors as coping mechanisms and increases the commitment to self-care.

4. **Empathy:** Patients with high EQ are more likely to empathize with their own experiences and the experiences of others. This can help CKD patients understand the impact of their health-promoting behaviors on their own lives and the lives of their loved ones, reinforcing their commitment to self-care.

5. **Social Skills:** High EQ individuals tend to have better interpersonal skills, which can lead to better communication with healthcare professionals, peers, and support networks. Improved communication can lead to a better understanding of self-care regimens and promote adherence to health-promoting behaviors.

6. **Relationships:** EQ contributes to the quality of relationships. CKD patients with strong emotional intelligence may be better equipped to establish supportive relationships with healthcare providers, leading to clearer guidance on self-care and health-promoting behaviors.

7. **Positive Outlook:** EQ is associated with a positive outlook on life. CKD patients with a positive attitude might be more inclined to engage in health-promoting behaviors as they see these actions as opportunities to improve their quality of life.

8. **Problem-Solving:** EQ supports effective problem-solving and decision-making. CKD patients who can critically assess the benefits of self-care regimens and health-promoting behaviors are more likely to adopt and maintain these practices.

In summary, EQ can act as a mediator between self-care regimens and engagement in health-promoting behaviors among CKD patients. By enhancing self-awareness, motivation, emotion regulation, empathy, social skills, relationships, positivity, and problem-solving abilities, EQ can help CKD patients better understand the importance of self-care and improve their adherence to health-promoting behaviors, ultimately leading to better management of their condition and overall well-being.

You can check the paper below for more information:

Regards,

K

Your diminished SCL responses -- my first guess -- is, as you considered, the sensor placement. Using the dorsal forearm may be convenient, but what counts is the density of sweat glands: greater on the palms and fingers. All the research on GSR that I've read uses those placements. (The forehead is another good site, but not so good for ambulatory monitoring and subject to facial expression artifact). Toes can be used also -- fairly equivalent to the fingers, as long as your subjects don't walk away.

I have never used stainless steel sensors. Probably if the site is well-chosen and free of calluses and scars, they would work well enough. But silver-silver chloride electrodes are more standard.

Also check https://www.advancedenergy.com/globalassets/resources-root/white-papers/top-advantages-scrs-white-paper.pdf

You are right that NS-SCRs have to be taken into account when computing SCL. Two methods are available in the biopac's acknowledge for that.

One passes the raw data through a median value smoothing filter and the SCL can be obtained by subtracting the filtered waveform from the original data.

Another method passes the data through a high pass filter of 0.05 Hz. Since tonic is a "slow" component, cut-off frequency of 0.05 Hz should do the job of separating the two components.

If you are looking into a tool to process your EDA data, you can check out the NeuroKit package https://github.com/neuropsychology/NeuroKit . It has great functions and tutorials to process physiological data.

Hi,

Getting a research position in IC engine or in any specific field is completely dependent on the hiring professor at a particular institute. If he is having funding and project, then he would probably hire a candidate at any level (graduate or postgraduate). However, there are still lots of scope in engine and fuel research and it is not possible for the electric vehicle to replace it completely considering the economy, reliability and other factors. In India, almost all old IITs and IISc are having very good engine research labs. You can contact individual faculty through email. I hope this will help you.

Thanks!

-Arnab

IIT Madras.

If your AVE is less than 0.5 but your CR is more than the acceptable level of 0.6, I recommend you to refer to the paper:

Lam, L. W. (2012). Impact of competitiveness on salespeople's commitment and performance. Journal of Business Research, 65(9), 1328-1334.

We tried this in our camera trapping effort in the Sahara, however you do need an estimate of camera trapping rate in order to take this approach. I have the excel files that generated the graphs if you want to adapt them.

Hello Mahmoud Omar Amer , if I understand correctly you want to control the AC voltage (220 V) which powers the whole microwave oven.

With this approach, I see at least two problems:

- Common dimmers are not meant to drive transformers or generally inductive loads, so the manufacturer does not guarantee that both halfwaves of the AC voltage at the output enclose exactly the same area in the voltage over time diagram. But different areas mean a DC voltage component, and a DC voltage might cause high current in inductive loads, damaging the load. You could avoid this problem by using a dimmer especially designed for inductive loads. I guess the dimmer of your thermostat is not of this kind because it is designed to control heating equipment, i. e. resistance with negligible inductance.

- In the 50 .. 100% range of the dimmer (full amplitude), the supply voltage of the magnetron will remain at maximum (peak rectification) but the heating of the cathode will be reduced. I never tried to operate a magnetron this way but I guess if the result were satisfactory then some microwave ovens would reduce the power by reducing the temperature of the cathode. But I don't think they do.

I understand that controlling by a PWM signal can have disadvantages at low frequencies but the MOSFET I suggested in my first reply can be switched with frequencies in the kHz domain.

Diesel engines are one of the largest contributors to environmental pollution caused by exhaust emissions. The four main pollutant emissions from diesel engines are carbon monoxide-CO, hydrocarbons-HC, particulate matter-PM and nitrogen oxides-NOx. For perect thermodynamic equilibrium, the complete combustion of diesel fuel generates only CO2 and H2O. Bur for many reasons as: the air– fuel ratio, ignition timing, turbulence in the combustion chamber, combustion form, air–fuel concentration, combustion temperature, etc. a number of harmful products are also generated during combustion. Usually, in the diesel engine combustion process, the nitrogen in the air does not react with oxygen in the combustion chamber and it is emitted identically out of the engine. However, high temperatures above 1,600 oC in the cylinders cause the nitrogen to react with oxygen and generate NOx emissions. So the major influences of the formation of NOx are the temperature and concentration of oxygen in the combustion. The amount of produced NOx is a function of the maximum temperature in the cylinder, oxygen concentrations, and residence time. Most of the emitted NOx is formed early in the combustion process, when the piston is still near the top of its stroke. This is when the flame temperature is the highest. Increasing the temperature of combustion increases the amount of NOx as much as triple for almost every 100 oC increase. NOx are referred as nitrogen oxide (NO) and nitrogen dioxide (NO2). NO constitutes 85–95 % of NOx. It is progressively converted to NO2 in atmospheric air. NO is a colorless and odorless gas, while NO2 is a reddish brown gas with pungent odor. Road transport is the most important cause of urban NOx emissions worldwide contributing to more than 50 % of the NOx. Engine out NOx levels are lower for diesel engines than their stoichiometric gasoline counterparts reflecting the somewhat lower combustion temperatures in the diesel engine. However, tailpipe-out NOx emissions are higher from diesels reflecting difficulties in reducing NOx to N2 in the highly oxidizing environment of diesel exhaust, which typically contains approximately 8% O2.

So, diesel engines are responsible for about 85 % of all the NOx emissions from movable sources, primarily in the form of NO. NO and NO2 are considered as toxic; but NO2 has a level of toxicity five times greater than that of NO and it is also a direct concern of human lung disease. NO2 can irritate the lungs and lower resistance to respiratory infection. NOx emissions contribute to acidification, formation of ozone, nutrient enrichment, and smog formation, which have become considerable problems in most major cities worldwide. In the atmospheric air, NOx emissions react chemically with other pollutants to form tropospheric ozone (the primary component of photochemical smog) and other toxic pollutants. According to Euro standards (I to VI), NOx ranged between 8 to 0.4 g/kW hr. So far, exhaust gas recirculation,EGR, (exhaust gas is recirculated back into the combustion chamber and mixed with fresh air at intake stroke), lean NOx trap, LNT, (NOx-storage-reduction (NSR) or NOx absorber catalyst (NAC)), diesel oxidation catalyst (DOC), and SCR catalysts (SCR is used to minimize NOx emissions in the exhaust gas to utilize ammonia (NH3) as the reductant. Water and N2 are released as a result of catalytically conversion of NOx in the exhaust gas. Due to the toxic effects of NH3 and to prevent burning of NH3 in the warm atmosphere before the reaction, NH3 is provided in the from of an aqueous solution of urea, or DOC with SCR. DOCs may also be used in conjunction with SCR catalysts to oxidize NO into NO2 and increase the NO2 ,are the most focused technologies to substantially eliminate the NOx emissions. As EGR technology, LNT technologies are imperfect to provide desired NOx emissions reduction. You can possible meet the current emissions standards by using SCR technology.

A fundamental aspect of Diesel combustion is the emission from the engine of oxides of nitrogen and particulate matter, both very difficult to eliminate together in the combustion chamber.

Diesel fuel contains neither nitrogen nor oxygen and so NOx creation results from chemical changes to combustion air due to the high cylinder pressures and temperatures experienced during the combustion process. In cylinder NOx reduction techniques involve measures to reduce maximum cylinder temperatures and pressures that, paradoxically, increase the creation of particulate matter and reduce combustion efficiency resulting in increased fuel consumption. Once the need for exhaust after-treatment is accepted, it is clearly necessary to make the system work as hard as possible in order to not compromise the engine combustion process.

The choice can be made to reduce particulate matter to the absolute minimum, allowing engine-out NOx emissions to increase due to the improved combustion efficiency resulting from this measure.

The “SCR Only” technology in the exhaust system allows the NOx reduction to be made. The modest engine-out PM emissions can be brought to the necessary levels using a full-flow Diesel Particulate filter that will achieve continuous regeneration due to the high exhaust NOx levels and the high gas temperature. Forced filter regeneration may not be necessary under normal circumstances.

A new generation Zeolite based compact SCR after-treatment system with all integrated components can be designed to optimise layout and minimise weight impact, resulting in a single, simple box shaped system that includes DOC (Diesel Oxidant Catalyst), DPF (Diesel Particulate Filter), SCR (Selective Catalytic Reduction) and CUC (Clean-Up Catalyst).

All these components can be installed with extreme compactness, achieving superior conversion efficiencies for all pollutants. In the very same box the AdBlue injection/mixing devices, as well as all exhaust gas sensors needed for the after-treatment management, are required to be carefully integrated.

This allows the entire exhaust after-treatment to be contained in a compact, fully enclosed structure thereby not impeding body building or chassis equipment mounting activities.

More in detail tailpipe emission reduction levels can potentially be achieved with a robust engineering margin by means of innovative design and accurate testing and modelling activities.

The result could be a perfect tuning of DOC, DPF, SCR and CUC coatings to grant maximum conversion efficiency without significant ageing for the full vehicle life. A clear-cut design of inlet and outlet substrate areas allows for the complete exploitation of the catalyst installation in its confined volume, including the AdBlue injection area with controlled turbulence and optimised thermal insulation. This guarantees perfect AdBlue aerosol mixing and urea hydrolysis prior to reaching the SCR. With precise positioning of exhaust gas sensors, a rapid and precise monitoring of all catalytic substrates and on-going chemical reactions is thus possible to achieve.

Selective catalytic reduction ( SCR ) is an advance active emissions control technology system that injects a liquid - reductant agent through a special catalyst into the exhaust stream of a diesel engine......it is called " selective " because it reduces levels of NOx using ammonia as a reductant within a catalyst system.

Shihab try this, using Lefebvre [21] or Wang and Lefebvre [22]

μ_L= dyn viscosity of liq, dyn/cm²

ν^_L= kin viscosity of liq, cm²/s

ρ^_L= liq density, g/cm3

σ_L = sur tension, dyn/cm

ΔP = Inj Pressure, Pa

lo =orifice length, m

Ls= length of swirl chamber, m

do = orifice dia, m

Ds = dia of swirl chamber, m

Ap = total inlet port area, m²

ṁ_L = flow rate, Flow Number, FN = ṁ_L / √ (ΔP * ρ^_L)

For example, the discharge coefficient is not available unless the actual mass flow rate is measured, and it can somewhat depend on the Reynolds number (and therefore, injection pressure). But, as a rough estimation, you can assume a constant discharge coefficient for your specific injection pressure.

Reference: Lefebvre, Arthur H., and Vincent G. McDonell. Atomization and sprays. CRC press, 2017. ( Page No 145)

I like this discussion

Actually i am looking for circuit implementation of PID controller . This book explains analysis of closed loop control by using simulink model, but not explains the transfer function of single phase rectifer. I want to know transfer function of closed loop rectifier current control and then circuit realisation of PI controller for this.

Urea and the commercial solution is Adblue. The idea is to use the reaction between NH3 and NOx to minimize the formation of by product during the NOx reduction.

I could follow your schematic when i download it.

It is okay and it will suction properly from the basic point of view. But i have only one question why do you not connect 220 ohm in series with the gate of the right transistor to make the circuit symmetrical for the the positive and negative half cycles of the damped oscillations.

Connecting the two gates together is not allowed in your circuit as the two gates must have different potentials. From the beginning it is rejected.

Could you show me the current in the circuit during the discharge process?

In summary this circuit can work well from the conceptual point of view.

Best wishes

Thanks Dr.Sanket

Both diode and SCR (Silicon Controlled Rectifier) are semiconductor devices with P type and N type semiconductor layers. They are used in many electronic switching applications. Both devices have terminals called ‘anode’ and ‘cathode’ but SCR has an additional terminal called ‘gate’. Both these devices have application dependant advantages.

Diode is the simplest semiconductor device and it consists of two semiconductor layers (one P-type and one N-type) connected to each other. Therefore diode is a PN junction. Diode has two terminals known as the anode (the P-type layer) and cathode (the N-type layer).

Diode allows current flows through it only in one direction that is anode to cathode. This direction of current is marked on its symbol as an arrow head. Since diode restricts the current to only one direction, it can be used as a rectifier. The full bridge rectifier circuit which is made of four diodes can rectify an alternative current (AC) to a direct current (DC).

The diode starts acting as a conductor when a small voltage is applied in the direction of anode to cathode. This voltage drop (known as the forward voltage drop) is always there when a current flow happens. This voltage is usually about 0.7V for normal silicon diodes.

SCR is a type of thyristor and widely used in current rectification applications. SCR is made of four alternating semiconductor layers (in the form of P-N-P-N) and therefore consists of three PN junctions. In analysis, this is considered as a tightly coupled pair of BJTs (one PNP and other in NPN configuration). The outermost P and N type semiconductor layers are called anode and cathode respectively. Electrode connected to inner P type semiconductor layer is known as the ‘gate’.

In operation, SCR acts conducting when a pulse is provided to the gate. It operates at in either ‘on’ or ‘off’ state. Once the gate is triggered with the pulse, SCR goes to the ‘on’ state and keep conducting until the forward current become less than a threshold known as ‘holding current’.

SCR is a power device and most of the times it is used in applications where high currents and voltages are involved. The most used SCR application is controlling (rectifying) alternating currents.

1. The larger the SCR,  the smaller is Xd, the smaller is Ld, it is result of Larger air gaps in design ( As in Hydro generators or Salient Pole Machines), It results in to the Machine is loosely coupled to grid and its response will be slow, this increases the machines stability while operating on grid, but simultaneously will increase the short circuit current delivery capability of the machine (higher short ckt current) and higher size and higher cost subsequently. ( Typical values of SCR for Hydro alternators may be in the  range of 1 to 1.5)  .  A power system or Grid having having more numbers of such machines are less vulnerable to voltage stability issues and hence such grid or system is called strong grid or weak system

2. Conversely, The smaller  the SCR, the larger is Xd, the larger is Ld,  it is result of small air gaps in design ( As in Turbo generators or Cylindrical rotor Machines), It results in to the Machine is tightly coupled to grid and its response will be fast, this reduces the machines stability while operating on grid, but simultaneously will reduce the short circuit current delivery capability of the machine (lower short ckt current) and smaller size and lower cost subsequently. ( Typical values of SCR for turbo alternators may be in the range of 0.45 to 0.9) . A power system or Grid having having more numbers of such machines are more vulnerable to voltage stability issues and hence such grid or system is called weak grid or weak system

Hope this will give you in depth idea

Best wishes,

Dr. Vivek Pandya

Thanks Prof. Gadzhiev for kindly offering me an answer.

If I understand correctly. State-averaged calculation must be done before spin-orbit coupling calculation. As Gaussian manual suggests, two  states for state-averaged calculation are, in my case, ground and excited states of which nroot= 1 and 2. So, I modify my input into:

ground state:

#p casscf(4,4,nroot=1,stateaverage)/sto-3g scfcon=4 scfcyc=900 nosym

test guess=read geom=check SP

excited state:

#p casscf(4,4,nroot=2,stateaverage)/sto-3g scfcon=4 scfcyc=900 nosym

test guess=read geom=check SP

Unfortunately, these calculation both end up with l510.exe error. I don't  know what step I go wrong. Therefore, I hope for more detail to solve this question.

Sincerely. 

 

No !

SCR is a measure of emotional arousal.

You need to use eyetracking with behavioural response.

Thank you Sanjay :)

Dear Albert,

Determination of the coefficient of thermal expansion, Determination of glass transition point, softening point, annealing studies, densification, kinetics and sintering studies are some of the results obtained from Dilatometry analysis.

In Diesel Enmgines especially for smaller cars you can meet Euro V also without SCR, even Euro 6 is possible without.

For larger cars and trucks you definitely need SCR. Up to 9% of the amount of fuel is necessary of Adblue.

Low cost is not always the cheapest over the lifetime of the engine. This is why many heavy-duty commercial engines use SCR - the added additional cost is worth the fuel savings in the long run.

One cheap method is to instruct the operators not to idle the engines when not necessary - you would be surprised how many diesel engines are idled without the need to have them running.

yes, you can use it

Hi Yaron,

Eye-tracking can provide some useful indicators about attention, either through the pattern of eye movements and duration of fixations (e.g. during reading - Foulsham, Farley and Kingstone, 2013), or through the diameter of the pupil, as an indicator of cognitive load or attention (e.g. where our attention is focused - Kang & Wheatley, 2015). In terms of other methods for measuring inattention, this paper may be useful - https://www.researchgate.net/profile/Murugappan_M/publication/236966223_Driver_inattention_detection_methods_A_review/links/0f31753c110f27059d000000.pdf

In addition, we have found a concurrent dual-task can indicate levels of attention / inattention. We used an ongoing reaction time task alongside eye-tracking, with reaction times indicating whether attention was focused on the dual task or, in instances when reaction times were significantly slower than average, if attention was focused elsewhere, potentially towards something in the visual environment (Fotios, Uttley, Cheal & Hara, 2015).

We are investigating whether Skin Conductance Response can be used as an indicator of visual attention. We don't have an answer yet, so if you find any relevant literature on this subject please post back on this thread.

Links to references are below.

Thanks,

Jim Uttley

My answer is just a guess, which is based on the final message before the Gaussian error.

You get the message: NTrRo=3 is not 5 or 6.

To my understanding, it means that for some reason Gaussian is considering that the number of translations + rotations of your system is 3 when it should 5 or 6 for linear or non-linear molecules, respectively. 

sorry I do not have the expertise to answer this question.

Hi Roy, we have used laser stimulation with fMRI to provide A-delta or C-fibre stimulation in a scanner. Obviously electrical stimulation has more complications with artifacts and safety issues, although perhaps these may be overcome with design or correction. Our laser (Nd−YAP laser stimulator Stim1324, El.En., Italy) has a handpiece and optical cable that are MR compatible, and a 10 meter cable so that the stimulator itself can be located in the researchers room. Obviously, it is an expensive piece of kit but it is quite difficult to find MR compatible pain stimulation with a high level of control. Good luck

The SCR should be rated at 1200v & the current rating of each SCR should be> atleast 0.707 of the rms load current.Pulse transformers could be used to trigger the SCR"s.    artee133@gmail.com

turn on of the SCR depends upon the load and source parameters but in the practical case it will need minimum angle above the 1-10 degree depend upon the load

With the short ISI the previous responses can (and will) still have effect due to the additive nature of the skin conductance signal. Ie if there's a previous response that has yet to be peaked, it will cause inflation of the current response and if there's one that is decaying from the peak it will cause deflation. Of course if there's proper randomization, this should just increase the error variance.

For short ISI settings the best way would be probably to remove/lessen the SCR overlaps via deconvolution. There are couple of open source packages for this: http://www.ledalab.de/ http://scralyze.sourceforge.net/