Patents Assigned to University of Southwestern Louisiana
  • Patent number: 4897353
    Abstract: A method of protecting soluble proteins such that their biological activity is preserved after freezing by exposing the protein to an amino acid or trimethylamine-N-oxide and transition metal ion prior to freezing. The protected protein can then be thawed without denaturation or impairment of the protein's biological activity. The protein is preferably exposed to the amino acid or trimethylamine-N-oxide by placing it in a 25-100 mM aqueous solution of organic solute and 1 mM Zn.sup.+2. This method is especially effective in preserving the biological activity of fragile proteins such as the enzyme phosphofructokinase. The present method can be used to preserve pharmaceutically useful proteins in a frozen form for storage and distribution. The treated protein can be thawed and administered directly to a user without removing the cryoprotectant since the amino acid or oxide and trace amounts of many transition metal ions are nontoxic.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: January 30, 1990
    Assignee: University of Southwestern Louisiana
    Inventors: John F. Carpenter, Steven C. Hand, Lois M. Crowe, John H. Crowe
  • Patent number: 4809791
    Abstract: A system is provided for the optimization of particle separation in a shaker system of a well drilling system. A well bore is drilled with a rotary drilling system. A stream of drilling fluid is circulated through the rotary drilling system to carry rock particles away from the bottom of the well bore as the well bore is formed. This stream of drilling fluid with the rock particles being carried therein is passed through a shaker system for separating the rock particles from the drilling fluid. A value of at least one, and preferably a plurality of operating parameters of the rotary drilling system are monitored, which parameters correlate to an average size of the rock particles being generated. The shaker system is adjusted in response to these monitored values, and more particularly in response to control signals computed based upon these monitored values, to increase separation of the rock particles by the shaker system.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: March 7, 1989
    Assignee: The University of Southwestern Louisiana
    Inventor: Asadollah Hayatdavoudi
  • Patent number: 4806343
    Abstract: A method of protecting soluble proteins such that their biological activity is preserved after freezing by exposing the protein to a carbohydrate and transition metal ion prior to freezing. The protected protein can then be thawed or lyophilized and rehydrated without denaturation of impairment of the protein's biological activity. The protein is preferably exposed to the carbohydrate by placing it in a 25-100 mM aqueous solution of carbohydrate and 2 mM Z.sup.+2. This method is especially effective in preserving the biological activity of fragile proteins such as the enzyme phosphofructokinase. The present method can be used to preserve pharmaceutically useful proteins in a frozen or freeze-dried form for storage and distribution. The treated protein can be thawed or rehydrated and administered directly to a user without removing the cryoprotectant since the carbohydrates and trace amounts of many transition metal ions are nontoxic.
    Type: Grant
    Filed: March 13, 1986
    Date of Patent: February 21, 1989
    Assignee: University of Southwestern Louisiana
    Inventors: John F. Carpenter, Steven C. Hand, John H. Crowe, Lois M. Crowe
  • Patent number: 4571736
    Abstract: Speech bit rate reduction by robbing, e.g. periodically not transmitting, a percentage of speech data samples in a communication system employing differential pulse code modulation (DPCM) or adaptive differential pulse code modulation (ADPCM). To overcome feedback interference introduced in the code by sample robbing, a robbed sample is replaced by its estimate so that the coding process continues in a normal manner. The estimate is established on the basis of autocorrelation statistics of the speech data samples. At the receiving end of the communication system, the robbed sample is estimated by the same process and re-estimated again using delayed interpolation after one period of delay. The technique is particularly useful where graceful degradation is desired under heavy traffic loading on the data channel, and is found most beneficial when the bit rate is about 24kb/s or lower where a relatively larger quantizing noise masks the interpolation noise introduced by sample robbing.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: February 18, 1986
    Assignee: University of Southwestern Louisiana
    Inventors: Jagannath P. Agrawal, Subramaniam S. Iyer