Program readability: procedures versus comments

A 3×2 factorial experiment was performed to compare the effects of procedure format (none, internal, or external) with those of comments (absent or present) on the readability of a PL/1 program. The readability of six editions of the program, each having a different combination of these factors, was inferred from the accuracy with which students could answer questions about the program after reading it. Both extremes in readability occurred in the program editions having no procedures: without comments the procedureless program was the least readable and with comments it was the most readable     

A generalized reduced fluid dynamic model for flow fields and electrodes in redox flow batteries

High-dimensional models typically require a large computational overhead for multiphysics applications, which hamper their use for broad-sweeping domain interrogation. Herein, we develop a modeling framework to capture the through-plane fluid dynamic response of electrodes and flow fields in a redox flow cell, generating a computationally inexpensive two-dimensional (2D) model. We leverage a depth-averaging approach that also accounts for variations in out-of-plane fluid motion and departures from Darcy's law that arise from averaging across three-dimensions (3D). Our resulting depth-averaged 2D model successfully predicts the fluid dynamic response of arbitrary in-plane flow field geometries, with discrepancies of <5% for both maximum velocity and pressure drop. This corresponds to reduced computational expense, as compared to 3D representations (<1% of duration and 10% of RAM usage), providing a platform to screen and optimize a diverse set of cell geometries.     

Dyes for synthetic-polymer fibres: I72 I72 V 2 14H-naphtho[2,3-a]phenothiazine-8,13-diones I72 I72 V 3 and 1H-2,3-dihydroanthra[2,1-b][1,4]-thiazine-7,12-diones I72 I72 V 3

Condensation of 1-amino- or 1-hydroxy-2-bromoanthraquinones with 2-amino-benzenethiol, I72 I72 V 2 or of 1-amino-2-bromoanthraquinones with 2-nitrobenzenethiol I72 I72 V 3 gives 14H-naphtho[2,3-a]-phenothiazine-8,13-diones. The related 1H-2,3- I72 I72 V 3 dihydroanthra[2,1-b][1,4]thiazine-7,12-diones result from interaction of 1- I72 I72 V 3 amino-2-mercaptoanthraquinones with 1,2-dibromoethane or of 1-hydroxy-2- I72 I72 V 3 bromoanthraquinones with 2-aminoethanethiol. The colour, dyeing and fastness I72 I72 V 3 properties of these compounds on synthetic-polymer fibres are described. I72 I72 V 3     

The synthesis of tritium labeled 9, 10-oleic acid

Tritium labeled 9,10-oleic acid was prepared from stearolic acid by reduction with tritium gas, in the presence of 5% Palladium on Charcoal catalyst, at room temperature and under partial vacuum. No stearic or elaidic acids were formed. Unreacted stearolic acid was removed by low temperature erystallization from Skellysolve F. The tritium labeledcis 9,10-oleic acid was prepared with a specificity of greater than 90% of the activity at the 9 and 10 positions. Specific radio-activity of the oleic acid was 1000 me of Tritium/g. Tritium labeled stearic acid with a specific activity of 927 me of Tritium/g was also prepared. Supported by Research Grant No. H-3063 from the National Institute of Health, U. S. Public Health Service, Department of Health, Education, and Welfare, and the American Dairy Association. Presented in part at the Federation of American Societies meeting for Experimental Biology, 1961.     

Additive mixing modulation for public key encryption based on distributed dynamics

We introduce a public key encryption scheme that is based on additive mixing of a message with chaotic nonlinear dynamics. A high-dimensional dissipative nonlinear dynamical system is distributed between transmitter and receiver. The transmitter dynamics is public (known to all) and the receiver dynamics is private (known only to the authorized receiver). Bidirectional signals that couple transmitter and receiver are transmitted over a public channel. Once the chaotic dynamics which is initialized with a random state converges to the attractor, a message is mixed with the chaotic dynamics at the transmitter. The authorized receiver who knows the entire dynamics can use a simple algorithm to decode the message. An unauthorized receiver does not know the receiver dynamics and needs to use computationally unfeasible algorithms in order to decode the message. Security is maintained by altering the private receiver dynamics during transmission. We show that using additive mixing modulation is more efficient than the attractor position modulation distributed dynamics encryption scheme. We demonstrate the concept of this new scheme by simulating a simple coupled map lattice.     

Dyes for synthetic-polymer fibres: 14H-naphtho[2,3-a]phenothiazine-8,13-diones I72 I72 V 3 and 1H-2,3-dihydroanthra[2,1-b][1,4]-thiazine-7,12-diones I72 I72 V 3

Condensation of 1-amino- or 1-hydroxy-2-bromoanthraquinones with 2-amino-benzenethiol, or of 1-amino-2-bromoanthraquinones with 2-nitrobenzenethiol I72 I72 V 3 gives 14H-naphtho[2,3-a]-phenothiazine-8,13-diones. The related 1H-2,3- I72 I72 V 3 dihydroanthra[2,1-b][1,4]thiazine-7,12-diones result from interaction of 1- I72 I72 V 3 amino-2-mercaptoanthraquinones with 1,2-dibromoethane or of 1-hydroxy-2- I72 I72 V 3 bromoanthraquinones with 2-aminoethanethiol. The colour, dyeing and fastness I72 I72 V 3 properties of these compounds on synthetic-polymer fibres are described. I72 I72 V 3