Azotobacter vinelandii (ATCC 12837) became competent to be transformed by exogenous deoxyribonucleic acid towards the end of exponential growth. Competence in wild-type and nitrogenase auxotrophic (nif-) strains was repressed by the addition of ammonium salts or urea to the transformation medium. Transformation of wild-type cells and nif- strains was optimal on nitrogen-free or nitrogen-limitin...

Three well studied progress conditions for implementing concurrent algorithms without locking are, obstruction-freedom, non-blocking and wait-freedom. Obstruction-freedom is weaker than non-blocking which, in turn, is weaker than wait-freedom. While obstruction-freedom and non-blocking have the potential to significantly improve the performance of concurrent applications, wait-freedom (although...

bainitic transformation at low transformation temperatures leads to a microstructure involving fine plates of bainitic ferrite and thin films of retained austenite. this microstructure has shown ultimate tensile strength of about 2.2 gpa, noticeable uniform elongation in the range of 5 to 30%, hardness values of about 600 to 670 hv and impact toughness in the range of 30 to 40 mpa m1/2. with ca...

The general variable coefficient cylindrical/spherical KdV equation has been investigated by using the simplified homogeneous balance method. It proven that if its coefficients satisfy certain constraint conditions, then a nonlinear transformation converts solution of quadratic form into equation. admits series solutions expressed exponential functions, therefore one soliton-like and multi can ...

Abstract: The exponential distribution is a popular model in applications to real data. We propose a new extension of this distribution, called the Lomax-exponential distribution, which presents greater flexibility to the model. Also there is a simple relation between the Lomax-exponential distribution and the Lomax distribution. Results for moment, limit behavior, hazard function, Shannon entr...