Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHYPHARM > RHEOLOGY > Flashcards

RHEOLOGY Flashcards

1
Q

RHEOLOGY

came from the greek word

A

rheo & logos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

RHEOLOGY

rheo means

A

to flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

RHEOLOGY

logos means

A

science

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the study of deformation and flow properties of matter

A

rheology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

RHEOLOGY

deformation is for

A

solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

RHEOLOGY

flow properties is for

A

liquids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

RHEOLOGY

main components

A

viscosity
elasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

RHEOLOGY | MAIN COMPONENTS

  • resistance to flow
  • property of liquids
A

viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

RHEOLOGY | MAIN COMPONENTS

  • stickiness or structure
  • property of solids
A

elasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

PROPONENTS OF RHEOLOGY

coined/suggested the term rheology

A

bingham & crawford

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

PROPONENTS OF RHEOLOGY

true theory of elasticity

A

robert hooke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

PROPONENTS OF RHEOLOGY

Robert hooke true theory of elasticity

A

Hooke’s Law of Solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

PROPONENTS OF RHEOLOGY

the resistance which arises lack of slipperiness of the parts of liquid is proportional to the velocity with which parts of the liquid are separated from one another

A

principia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

PROPONENTS OF RHEOLOGY

principia

A

Isaac Newton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

PROPONENTS OF RHEOLOGY

Isaac Newton’s Law

A

Law of liquids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

PROPONENTS OF RHEOLOGY

liquids automatically flow

A

Newton’s law of liquids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

CONCEPTS IN RHEOLOGY

the ____ of the material dictates the observed physical response

A

chemical nature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

CONCEPTS IN RHEOLOGY

the chemical nature of the material dictates the observed ____

A

physical response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

CONCEPTS IN RHEOLOGY

the ____ after applying force is linked to the timescale of the microstructural motion from thermal or mechanical energy

A

material’s structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

CONCEPTS IN RHEOLOGY

the material’s structure after applying force is linked to the ____ from thermal or mechanical energy

A

timescale of the microstructural motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  • the higher the viscosity of the liquid, the **greater the force per unit area (shearing stress**) required to produce a specific shear rate
  • viscosity is independent on the rate of shear (G)
  • ex: simple liquids, either pure chemicals or solutions, water
A

NEWTON’S LAW OF FLOW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

NEWTON’S LAW OF FLOW

relationship of viscosity and force per unit area (shearing stress) required to produce a specific shear rate

A

directly proportional

higher viscosity, greater shearing stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

NEWTON’S LAW OF FLOW

viscosity is ____ on the rate of shear (G)

A

independent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

NEWTON’S LAW OF FLOW

the higher the viscosity of the liquid, the greater the force per unit area (shearing stress) required to produce a ____

A

specific shear rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  • absolute viscosity divided by the density of the liquid at a specific temperature
  • units: stokes (s) or centistokes (cs)
  • arbitrary scales: Saybolt, Redwood, Engler, etc.
A

kinematic viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

KINEMATIC VISCOSITY

graphical presentation of rheology

A

rheogram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

KINEMATIC VISCOSITY

relationship between rate of shear and shear stress

A

directly proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

KINEMATIC VISCOSITY

units

A

stokes (s)
centistokes (cs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

TEMPERATURE DEPENDENCE OF VISCOSITY

for liquids

A

high temp, low viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

TEMPERATURE DEPENDENCE OF VISCOSITY

for gases

A

high temp, high viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

TEMPERATURE DEPENDENCE OF VISCOSITY

reciprocal of viscosity

A

fluidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

TEMPERATURE DEPENDENCE OF VISCOSITY

the fluidity ____ with temperature

A

increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q
  • majority of fluid pharmaceutical products do not follow Newton’s law of flow (without shear stress)
  • generally exhibited by:
    - colloids
    - emulsions
    - suspensions
    - ointments
A

non-newtonian systems

34
Q

NON-NEWTONIAN SYSTEMS

majority of fluid pharmaceutical products ____ Newton’s law of flow

A

do not follow

35
Q

NON-NEWTONIAN SYSTEMS

generally exhibited by

A

colloids
emulsions
suspensions
ointments

36
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS

  • does not begin to flow until a shearing stress corresponding to the yield value is exceeded
  • Bingham bodies
  • exhibited by concentrated flocculated suspension, and semisolid dosage forms

e.g. TOOTHPASTE

A

PLASTIC FLOW

37
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | PLASTIC FLOW

does not begin to flow until a shearing stress corresponding to the ____ is exceeded

A

yield value

38
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | PLASTIC FLOW

also known as

A

BINGHAM BODIES

39
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | PLASTIC FLOW

exhibited by concentrated ____ and ____

A

flocculates suspensions & semisolid dosage forms

40
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS

  • the viscosity of a susbtance decreases with increasing rate of shear
  • shear thinning system
  • exhibited by many pharmaceutical products, e.g. liquid dispersions of natural & synthetic gums

e.g. PAINT

A

PSEUDOPLASTIC FLOW

41
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | PSEUDOPLASTIC FLOW

the viscosity of a substance ____ with increasing rate of shear

A

decreases

42
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | PSEUDOPLASTIC FLOW

also known as

A

shear thinning system

43
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | PSEUDOPLASTIC FLOW

exhibited by many pharmaceutical products like liquid dispersions of ____ and ____

A

natural and synthetic gums

44
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS

  • the viscosity of a substance increases with increasing rate of shear
  • as shear stress is increased, the bulk of the system expands
  • shear thickening system
  • exhibited by highly concentrated deflocculated suspensions

e.g. CORNSTARCH (OBLEEK)

A

DILATANT FLOW

45
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | DILATANT FLOW

the viscosity of a substance ____ with increasing rates of shear

A

increases

46
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | DILATANT FLOW

as shear stress is increased, the bulk of the system ____

A

expands

47
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | DILATANT FLOW

also known as

A

shear thickening system

48
Q

TIME-INDEPENDENT NON-NEWTONIAN FLUIDS | DILATANT FLOW

exhbited by highly concentrated ____

A

deflocculated suspensions

49
Q
  • with shear thinning systems, the structure breakdown does not reform immediatley when stress is reduced or removed
  • applicable only to shear thinning systems
  • thixotropy
A

time dependent non-newtonian fluids

50
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

with shear thinning systems, the structure breakdown ____ when stress is reduced or removed

A

does not reform immediately

51
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

an isothermal and comparatively slow recovery on standing of a material of a consistency lost through shearing

A

thixotropy

52
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

is applicable only to

A

shear thinning systems

53
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

Gel-Sol-Gel
slow process

A

thixotropy

54
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

thixotropy is a ____ process

A

slow

55
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

Gel-Sol-Gel
fast process, mild turbulence

A

rheopexy

56
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

rheopexy is a ____ process

A

fast

57
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

Sol-Gel-Sol
slow process

A

negative thixotropy

58
Q

TIME DEPENDENT NON-NEWTONIAN FLUIDS

Sol-Gel-Sol
fast process, mild turbulence

A

negative rheopexy

59
Q

DETERMINATION OF RHEOLOGIC PROPERTIES

Newtonian liquids (single shear rate)

A

Capillary viscometer
Falling sphere viscometer

60
Q

DETERMINATION OF RHEOLOGIC PROPERTIES

Newtonian & Non-Newtonian liquids (multipoint, rotational)

A

Cup & Bob viscometer
Cone & Plate viscometer

61
Q

DETERMINATION OF RHEOLOGIC PROPERTIES

  • aka Ostwald viscometer
  • the viscosity of a newtonian liquid can be determined by measuring the time required for the liquid to pass between two marks as it flows by gravity through a vertical capillary tube
  • principle is time-dependent
A

CAPILLARY VISCOMETER

62
Q

DETERMINATION OF RHEOLOGIC PROPERTIES

Capillary viscometer is also called as

A

Ostwald viscometer

63
Q

DETERMINATION OF RHEOLOGIC PROPERTIES

  • aka Hoeppler viscometer
  • a glass or steel ball rolls down an almost vertical glass tube containing the test liquid at a known constant temperature
  • the rate at which a ball of a particular density and diameter falls is an inverse function of the viscosity of the sample
  • time-dependent
A

FALLING SPHERE VISCOMETER

64
Q

DETERMINATION OF RHEOLOGIC PROPERTIES

Falling Sphere viscometer is also called as

A

Hoeppler viscometer

65
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | FALLING SPHERE VISCOMETER

a glass or steel ball rolls down an ____ containing the test liquid at a known constant temperature

A

almost vertical glass tube

66
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | FALLING SPHERE VISCOMETER

the rate at which a ball of a particular density and diameter falls is an ____ of the viscosity of the sample

A

inverse function

67
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN

  • the sample is sheared in the space between the outer wall of a bob and the inner wall of a cup into which the bob fits
  • Couette type - MacMichael Viscometer
  • Searle type - Brookfield and Stormer Viscometer
A

Cup and Bob Viscometer

68
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | CUP & BOB

the sample is **sheared **in the space between the ____ of a bob and the ____ of a cup nto which the bob fits

A

outer wall of a bob
inner wall of a cup

69
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | CUP & BOB

  • Couette type
  • Rotating cup
A

MacMichael viscometer

70
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | CUP & BOB

  • Searle type
  • Rotating bob
A

Brookfield & Stormer Viscometer

71
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | BROOKEFIELD

in the Brookefield viscometer, the generally acceptable %torque is

A

≥ 10%

72
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN

  • aka Ferranti-Shirley viscometer
  • the sample is placed at the center of the plate, which is then raised into position under the cone
  • a variable-speed motor drives the cone, and the sample is sheared in the narrow gap between the stationary plate and the rotating cone
  • plate is mobile
A

CONE & PLATE VISCOMETER

73
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | CONE & PLATE

Cone & Plate viscometer is also called as

A

Ferranti-Shirley viscometer

74
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | CONE & PLATE

the sample is placed at the ____

A

center of the plate

75
Q

DETERMINATION OF RHEOLOGIC PROPERTIES | NON-NEWTONIAN | CONE & PLATE

a ____ drives the cone

A

variable-speed motor

76
Q
  • based on mechanical properties of the material that exhibit both viscous properties of liquids and elastic properties of solids
  • can behave predominantly as viscous or predominantly as elastic, or equal, depending on the magnitude and the time scale of the applied shear stress
  • examples: creams, lotions, ointments, suppositories, suspensions, colloids
  • example: blood, sputum, cervical fluid
A

VISCOELASTICITY

77
Q

VISCOELASTICITY

based on mechanical properties of material that exhibit ____

A

both viscous & elastic properties

78
Q

VISCOELASTICITY

can behave ____

A

predominantly viscous or elastic

79
Q
  • study of how we perceive the textural characteristics of materials
  • relationship between instrumental data and sensory data
    - mouth-feel warmness and richness for food
    - smoothness, slimyness, stickiness or stinginess for cosmetics
A

PSYCHORHEOLOGY

80
Q

PSYCHORHEOLOGY

study of how we perceive the ____ of materials

A

textural characetristics

81
Q

PSYCHORHEOLOGY

relationship between ____ and ____

A

instrumental & sensory data

PHYPHARM (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions