DRDO, PSU and Private Defence Sector News

[Bajirao]

so,finaly missile testing has started after a long gap...very very good news indeed.

 

[fire starter]

look likes it is having jet vanes a biggest upgrade.

 

[Holy Triad]

To investigate how aerosols are generated during routine eye surgeries, doctors at Narayana Nethralaya and IISc researchers have used high-speed imaging & aerodynamic models to visualise droplet generation, and calculate size, speed and distance travelled

Tracking aerosols during eye surgeries



There is growing evidence that the novel coronavirus, SARS-CoV-2, could spread through aerosols ‒ tiny droplets that can remain suspended in the air for hours in closed spaces. Aerosols generated during surgeries and out-patient procedures can be risky to healthcare workers.
To investigate how aerosols are generated during routine eye procedures, doctors at Narayana Nethralaya, an eye hospital in Bengaluru, have collaborated with researchers at the Indian Institute of Science (IISc). They used high-speed imaging and aerodynamic models to visualise the generation of droplets during procedures such as cataract and LASIK surgeries.

High speed imaging setup. (IMAGE CREDITS: Narayana Nethralaya Foundation)
“We identified the size of the droplets, and also calculated the speed and distance to which they travel,” says Saptarshi Basu, Professor at the Department of Mechanical Engineering, IISc, and co-author of two papers published in the Journal of Cataract and Refractive Surgery. The studies showed that during most procedures, aerosols are not generated, he adds.
The first study focused on phacoemulsification, a type of cataract surgery where an ultrasonic needle is used to break up the cataract. The fluids are then suctioned out and the eye is rehydrated with a balanced salt solution. The needle and a sleeve carrying the salt solution are usually combined into a single disposable probe. In the study ‒ conducted during surgeries on humans and animal eyes in a closed chamber ‒ the researchers employed a technique called shadowgraphy, which uses a light source such as pulsed laser or LED to cast shadows of fast-moving droplets onto the sensor of a high speed camera.

phacoemulsification.( IMAGE CREDITS: Narayana Nethralaya Foundation)
As long as the probe was restricted to the inner layer of the eye called anterior chamber – a protocol normally followed – no aerosols were generated. Aerosols were formed only when the probe was exposed to the salt solution on the eye’s outer surface called cornea. Therefore, replacing the salt solution with more gelatinous or viscous materials can prevent fluid spurting and aerosol generation, the researchers say.
The second study investigated aerosol generation during LASIK surgery, performed to correct near- or far-sightedness. It uses an oscillating blade to cut and lift a thin flap from the cornea’s top layer to reshape the inner layer called stroma. The researchers found that, as the blade cut through to the stroma, some droplets were generated, likely due to the balanced salt solution used as a lubricant prior to the procedure. However, most of the droplets were found to be large in size (>90 micrometers) and therefore likely to settle down fast, reducing the risk that they will become aerosolised. Because the droplets were found to travel up to 1.8 m in a simulated surgery setting, adequate precautions and protective equipment should be adopted by doctors, the researchers suggest.

microkeratome for LASIK. (IMAGE CREDITS: Narayana Nethralaya Foundation)
Studies on other eye procedures such as glaucoma screening have also been carried out, and will be published shortly, says Basu.
Based on these findings, the hospital has identified and implemented specific safety protocols, says corresponding author Abhijit Sinha Roy, Chief Scientist at Narayana Nethralaya Foundation. It has also put together videos to educate patients, medical staff and the general public, to make them feel more at ease about resuming routine procedures.
“Because of COVID-19, a lot of other surgical procedures are getting delayed. Our concern is that patients should not end up compromising their vision just because they delayed getting the appropriate healthcare they needed. They should feel at ease after seeing these robust studies and safety measures implemented in our eye clinics,” he says.
Similar studies are also planned for orthopaedic and heart surgeries, says Basu.

Indian Institute of Science

IISc is the premier institute for advanced scientific and technological research and education in India.

www.iisc.ac.in

 

[Bleh]

Since morning every Keen Kumar posing as Scientist was trying to project a few things :

* That MMW seekers can not be applicable for ground launched system which is wrong.
* You have been singing about Fire and Forget capability as if it a magic. Fire and forget only relates to command to a missile which is final at the time of firing and there is no need to track the missiles like in MACLOS or some SACLOS or call wire guide or call it second generation.
* That LOAL is is not applicable to ground launched systems... which is also not correct... after all Nag is being launched from a BMP and not a ground launcher..
* That Fire and Forget as also Top attack can not be defeated - that is also incorrect.

*I discussed the shortcomings with F&F all of the last 3 posts.
* "hardest to counter" & "can't be defeated" are different things.

Those are what I said & I think it's pretty safe to assume the others didn't say any of those things either... Go back & keep rereading their posts until you understand.

Amd this part is wrong too.

And Finally that such missile system may be good in offensive ops but not so good in defenses as IR devices of tank will definitely discover the launcher at the first go. BMP will be taken on just after first launch of missile. Imagine what will happen to Bhoop Singh who fires 84mm Carl Gustav.

This is not 1980... During defense the ATGM launcher should ideally be miles behind the line of contact, well out of tank range & keep falling back in case the enemy manages to keep advancing.

To IA higher officers Bhoop Singh is merely gun-fodder... Or else he shouldn't be firing Carl Gustav at tanks but at the remaining APCs with mech. infantry after ATGMs have taken out the heavies.

 

[porky_kicker]

HELINA - army version ( flexible nozzle TVC )

DHRUVASTRA - airforce version ( jet van control JVC )

 

[Akula]

View attachment 53791

Small Turbofan & its components of Kalyani

There are two private companies in India who showed their engines in Defexpo.
Kalyani and PBS India (Subsidiary of Czech company)

PBS India - Supplier of propulsion systems

www.pbsindia.com

 

[porky_kicker]

India's dhruvastra ATGM testfired

So with 2 way data link now Dhruvastra has LOAL capability .

Actually it now has both LOBL and LOAL capability .

 

[LurkerBaba]

Lets keep the criticism to a separate thread and not divert this thread https://defenceforumindia.com/threads/constructive-criticism-of-defence-psus-and-ofb.81890/

@Bhadra

 

[fire starter]

View attachment 53874

HELINA - army version ( flexible nozzle TVC )

DHRUVASTRA - airforce version ( jet van control JVC )

what advantage does jet vanes offer wrt to flexible nozzle.

 

[porky_kicker]

Yeah. Best for container based system.

I hope you realise the one in the pic is for an ICBM

I once posted a similar pic , at that time I thought it was part of assembly jig

It's far fetched , what if someday we have ship launched, maybe even from cargo/container ships . Navy operated Dhanush so they might be open to the idea.

 

[porky_kicker]

what advantage does jet vanes offer wrt to flexible nozzle.

Well I have very little knowledge regarding all this , so cannot answer your question specifically. Actually zero knowledge.

All I know jet vanes are more popular and common

Flex nozzles are generally seen in modern long range ballistic missiles

There are different types of thrust control like gimbal nozzle , flexible nozzle , jet vanes , jet tabs , ventricle nozzles etc

Difference can be in terms of complexity of design due to constraints presented by the type of missile in question ( ICBM , ATGM , SAM etc ) , or the type of fuels , or the range of lateral thrust required etc etc

 

[fire starter]

Well I have very little knowledge regarding all this , so cannot answer your question specifically. Actually zero knowledge.

All I know jet vanes are more popular and common

Flex nozzles are generally seen in modern long range ballistic missiles

There are different types of thrust control like gimbal nozzle , flexible nozzle , jet vanes , jet tabs , ventricle nozzles etc

Difference can be in terms of complexity of design due to constraints presented by the type of missile in question ( ICBM , ATGM , SAM etc ) , or the type of fuels , or the range of lateral thrust required etc etc

bro I think army version is still having side thrusters .

 

[Bajirao]

View attachment 53874

HELINA - army version ( flexible nozzle TVC )

DHRUVASTRA - airforce version ( jet van control JVC )

is mpatgm also equiped with jet vane?

 

[Bajirao]

bro I think army version is still having side thrusters .
View attachment 53895

Yeah,it will remain..

 

[Bajirao]

what advantage does jet vanes offer wrt to flexible nozzle.

maybe,in terms of manuvering.

 

[porky_kicker]

bro I think army version is still having side thrusters .
View attachment 53895

My speculation

Possibly both helina and dhruvastra has lateral thrusters

I think the flex nozzle / JVC is required during the initial stage to maneuver the helina / dhruvastra into the required lofted trajectory for top attack mode.

After that the lateral thrusters maintains the required momentum and trajectory control .

Even for direct attack mode , it helps to nose up the missile initially so that the seeker can capture the target .

Watch the video of both top attack and direct attack mode . Lofted trajectory is more prominent for top attack mode and less prominent yet visible even for direct attack mode.

Also why we have 8 km range increase for both of them because it acts as a booster , flex nozzle / JVC is part of it.

 

[porky_kicker]

is mpatgm also equiped with jet vane?

Yes , it is visible on mpatgm

 

[ezsasa]

My speculation

Possibly both helina and dhruvastra has lateral thrusters

I think the flex nozzle / JVC is required during the initial stage to maneuver the helina / dhruvastra into the required lofted trajectory for top attack mode.

After that the lateral thrusters maintains the required momentum and trajectory control .

Even for direct attack mode , it helps to nose up the missile initially so that the seeker can capture the target .

Watch the video of both top attack and direct attack mode . Lofted trajectory is more prominent for top attack mode and less prominent yet visible even for direct attack mode.

Also why we have 8 km range increase for both of them .

Nag's angle of attack near the target in top attack mode seems to more prominent compared to Dhruvastra, isn't it?

 

[porky_kicker]

Nag's angle of attack near the target in top attack mode seems to more prominent compared to Dhruvastra, isn't it?

For me

Will need more videos of dhruvastra to confirm

Too far away and without a target, it is difficult to confirm

You could be right too , let's see

 

[HariPrasad-1]

Lol what kind of logic is that. Our ASAT destroy a satellite first only much later it appeared in parade. If you look at parade to see our progress you are an idiot.

Our slbm developing is moving along quietly.
Anyway there is no rush. Neither china nor Pakistan has any capability to take out Indian Land arsenal . And both of them don't have any uselful BMD either.

With such primitive adversaries we can perfect slbm slowly rather than rushing like Chinese only to end up with extremely noisy submarines which are all time tracked by enemies. Lmao.

Ignore him. It is my humble advice. You said it right. He pop ups with strange logic every time. He is in my ignore list.