PubMed Health⌕ Search

Biomedical subjects

S P Das

Publications and source records attributed to S P Das.

At least 19 recordsLinked to original sources
PubMed2001

Structural relaxation and frequency-dependent specific heat in a supercooled liquid.

We have studied the relation between the structural relaxation and the frequency-dependent thermal response or the specific heat, c(p)(omega), in a supercooled liquid. The mode coupling theory (MCT) results are used to obtain c(p)(omega) corresponding to different wave vectors. Due to the two-step relaxation process present in the MCT, an extra peak, in addition to the low-frequency peak, is predicted in specific heat at high frequency.

Journal Article↗
PubMed2001

Heterogeneities in supercooled liquids: a density-functional study.

A metastable state, characterized by a low degree of mass localization, is identified using density-functional theory (DFT). This free energy minimum, located through the proper evaluation of competing terms in the free energy functional, is independent of the specific form of the DFT used. Computer simulation results on particle motion indicate that this heterogeneous state corresponds to the deeply supercooled state.

Journal Article↗
PubMed2000

Metastable state dynamics and power law relaxation in a supercooled liquid.

We consider glassy relaxation by using a model for supercooled liquid where the usual set of hydrodynamic variables is extended to include the presence of very slowly decaying defect densities. The long time limit of the density correlation function, the nonergodicity parameter, is studied in the vicinity of the dynamic transition point, and scaling exponents with respect to the distance from the critical point are obtained. In addition to the usual square root cusp, we also see a linear dependence on distance from transition with respect to the metastability parameters. We analyze the power law relaxation of the density correlation function at the initial stage of the dynamics, and obtain an exponent dependent on temperature. Results are compared with data obtained from light scattering experiments.

Journal Article↗
PubMed1977

[Surgical mangement of erectile impotence with special reference to Small-Carrion penil prosthesis (author's transl)].

Due to increasing number of radical surgeries for malignant tumors of the pelvis the incidence of iatrogenically caused erectile impotence rises. Available surgical management comprises implantation of rigid penile prothesis or inflatable device. The authors prefer a rigid implant (Small-Carrion penile prothesis) on account of its simplicity and have been impressed with the results.

Adult↗
PubMed1977

[Prosthetic management of urinary incontinence following prostatectomy with special reference to Kaufman's prosthesis].

Issuing from the pathophysiological fundaments of the incontinence after operative sanation of the outlet of the urinary bladder the principal surgico-prosthetic possibilities for the removal of this complication are describes: 1. artificial systems of the sphincter with arbitrary increase and decrease of the occlusion pressure of the proximal urethra, 2. permanent compression of the bulbar urethra. On the last mentioned principle is based the incontinence prosthesis after Kaufman, which in its rate of success corresponds to the artificial sphincter systems.

Humans↗
PubMed1976

[The Small-Carrion penile prosthesis for erectile impotence (author's transl)].

The insertion of two silicone rods into the penile corpora cavernosa (Small-Carrion penile prosthesis) is a considerable procedure for operative management of erectile impotence. Of 61 treated patients, 55 had a satisfactory anatomical and functional result, most of them regained the same sexual activity as prior to onset of impotence. Their partners were satisfied, too. Preoperative evaluation of causes of impotence is particularly important. Type and number of complications in this operative procedure are reported in detail.

Adult↗
PubMed1975

Aneurysm of a polar renal artery.

A patient with a saccular aneurysm arising from the left superior polar renal artery is presented together with a review of two further reports from the literature. The importance of selective arteriography and the interpretation of the "naked calyx" sign in the diagnosis of supernumerary renal arteries has been emphasized. We feel that this is the only report of an aneurysm of a polar artery successfully treated by excision and end-to-end arterial anastomosis.

Adult↗