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3 years ago

What's the difference between inplicit and explicit solvent?

1 answer:

7 0

Hi

Explicit- and implicit-solvent molecular dynamics simulations are performed to study complexation in two polyelectrolyte systems: poly(styrene sulfonate)/poly(allylamine hydrochloride) (PSS/PAH) and poly(acrylic acid)/poly(allylamine hydrochloride) (PAA/PAH). Both these systems have been used in layer-by-layer assembly of polyelectrolyte films, with the first of these typically yielding linear growth in film thickness with increasing numbers of layers and the second yielding exponential growth. In both the systems, the polyelectrolytes have the same number of monomers and are present in stoichiometric proportion, and water is used as solvent. Simulations give important insights into the structure and composition of the complexes. We found that the PSS/PAH complex is more compact and has a smaller fraction of water than the PAA/PAH complex due to the presence of phenyl rings in the PSS chain and the hydrophilic nature of the charged group in the PAA chain. Either an increase in salt concentration or a decrease in partial charge fraction increases swelling and the water content in the complex. To overcome the computational limitations associated with the explicit-solvent simulation, a simple strategy to develop the force field for an implicit-solvent simulation is proposed. In the absence of salt and for fully charged polyelectrolytes, the radius-of-gyration and the various radial distribution functions predicted by the implicit-solvent simulation match well with those predicted by the explicit-solvent simulation, while reasonable agreement is obtained in the other cases. The implicit-solvent simulation was performed for bigger system sizes, and we observed trends similar to those observed for smaller system sizes, suggesting that the simulation results are independent of system size.

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Mr. Phillips' car iso parked on a steep hill

Wewaii [24]

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4 years ago

Apparent magnitude depends mainly upon _________. our sun has a large apparent magnitude.

Ksenya-84 [330]

Apparent magnitude depends mainly on the brightness of the object as seen from an observer on Earth. This is taken into account without the effects of the atmosphere.

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3 years ago

An object is moving at a constant speed along a straight line. Which of the following statements is not true? A. There must be a

Svetradugi [14.3K]

Answer:

False statement = There must be a non-zero net force acting on the object.

Explanation:

An object is moving at a constant speed along a straight line. If the speed is constant then its velocity must be constant. We know that the rate of change of velocity is called acceleration of the object i.e.

$a=\dfrac{dv}{dt}$

a = 0

⇒ The acceleration of the object is zero.

The product of force and acceleration gives the magnitude of force acting on the object i.e.

F = m a = 0

⇒ The net force acting on the object must be zero.

So, the option (a) is not true. This is because the force acting on the object is zero. First option contradicts the fact.

6 0

3 years ago

Two astronauts are playing catch in a zero gravitational field. Astronaut 1 of mass m1 is initially moving to the right with spe

Ede4ka [16]

The final velocity ( $v_1_f$ ) of the first astronaut will be greater than the final velocity of the second astronaut ( $v_2_f$ ) to ensure that the total initial momentum of both astronauts is equal to the total final momentum of both astronauts after throwing the ball.

The given parameters;

Mass of the first astronaut, = m₁
Mass of the second astronaut, = m₂
Initial velocity of the first astronaut, = v₁
Initial velocity of the second astronaut, = v₂ > v₁
Mass of the ball, = m
Speed of the ball, = u
Final velocity of the first astronaut, = $v_f_1$
Final velocity of the second astronaut, = $v_f_2$

The final velocity of the first astronaut relative to the second astronaut after throwing the ball is determined by applying the principle of conservation of linear momentum.

$m_1v_1 + m_2v_2 = m_2v_2_f + m_1v_1_f$

if v₂ > v₁, then $v_1_f > v_2_f$ , to conserve the linear momentum.

Thus, the final velocity ( $v_1_f$ ) of the first astronaut will be greater than the final velocity of the second astronaut ( $v_2_f$ ) to ensure that the total initial momentum of both astronauts is equal to the total final momentum of both astronauts after throwing the ball.

Learn more here: brainly.com/question/24424291

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3 years ago

In the simplified version of Kepler's third law, P 2 = a3, the units of the orbital period P and the semimajor axis a of the ell

Orlov [11]

Answer:

The units of the orbital period P is years and the units of the semimajor axis a is astronomical units.

Explanation:

P² = a³ is the simplified version of Kepler's third law which governs the orbital motion of large bodies that orbit around a star. The orbit of each planet is an ellipse with the star at the focal point.

Therefore, if you square the year of each planet and divide it by the distance that it is from the star, you will get the same number for all the other planets.

Thus, the units of the orbital period P is years and the units of the semimajor axis a is astronomical units.

8 0

3 years ago