(a) What is the best coefficient of performance for a heat pump that has a hot reservoir temperature of 50.0C and a cold reservoir temperature of 20.0C ? (b) How much heat transfer occurs into the warm environment if 3.60107 J of work ( 10.0kW h ) is put into it? (c) If the cost of this work input is 10.0 cents/kW h , how does its cost compare with the direct heat transfer achieved by burning natural gas at a cost of 85.0 cents per therm. (A therm is a common unit of energy for natural gas and equals 1.055108 J .)
Block 4 lecture 1 - Visual system 1. Name 5 structures outside the visual globe that contribute to vision Eyelids and eyelashes - protection Lacrimal gland - produce tears Frontal eye fields and eye muscles - three cranial nerves control eye movement - 3,4, and 6 Conjunctiva - membrane that covers the inner surface of the eyelids and the sclera highly vascular Conjunctivitis “pink eye” nfection resulting in blood vessel inflammation 2. List the 3 major layers of the visual globe and the structures contained within each layer Outer -----> inner Fibrous layer - sclera and cornea -----> Vascular layer - choroid - iris - ciliary bodies -----> Neural tunic - retina 3. Discuss how each of the following structures contributes to vision and Name one visual disorder associated with each visual structure a. Conjunctiva - membrane that covers the inner surface of the eyelids and the sclera h ighly vascular C onjunctivitis “pink eye” infection resulting in blood vessel inflammation b. Cornea - provides most (75%) focusing of the eye avascular Astigmatism m isshapen cornea resulting in blurry vision c. Sclera - white of the eye, gives eye shape d. Iris - colored part of the eye, muscle that regulates pupil size 1. Pupillary dilator muscles - enlarge pupil sympathetic division 2. Pupillary constrictor muscles - decrease diameter of pupil - parasympathetic division
