INTERACTION OF THE ABRASIVE MEDIUM WITH THE TREATED SURFACE AND THE PROCESS OF METAL REMOVAL DURING VIBRATION TREATMENT IN THE PRESENCE OF A CHEMICALLY ACTIVE SOLUTION

Interaction of working medium granules with the processed surface of the part is considered. It is noted that the processing methods are characterized by the dynamic interaction of the abrasive medium with the processed surface. It is indicated that during vibration treatment there is an impact contact of the abrasive granule with the surface of the part, which leads to the formation of characteristic traces during the formation of the surface relief. The types of impact of abrasive grains of working medium granules on the surface of the processed part are identified. It is indicated that the effect of abrasive grains depends on the geometric parameters of the tops of the grains and the working contour of the granule as a whole. The alternation of the operation of abrasive grains in the connection with the nature of the motion of the granule over the surface of the part is shown. The interaction of surfaces of bodies during vibration treatment is considered. The distinctive features of the vibration treatment method from other analogs are indicated. The conditions for the formation of the surface layer of the part during vibration processing are given. The analysis of the mechanical-physicochemical model of the micro-cutting process in the presence of a chemically active solution is carried out and a comparison of the intensity of technologies for vibration treatment of steel parts is given.

Cornea-PAMPA as an Orthogonal in Vitro Physicochemical Model of Corneal Permeability

The present study was aimed to investigate the relationships between permeability and membrane retention values (logPe and MR) of the in vitro non-cellular permeability assay, corneal-PAMPA in comparison with experimental Caco-2 permeability data and calculated physicochemical properties (MW, clogP, clogD7.4 , TPSA). For the investigation, 50 structurally and physicochemically diverse drugs were selected and measured in PAMPA model optimized for corneal permeability. The results showed corneal-PAMPA model's orthogonality in terms of passive diffusion to the FDA approved Caco-2 as a gastrointestinal absorption model, while the comparison with physicochemical properties revealed trends between logPe , MR and the lipophilicity descriptors and TPSA.

Comparative analysis of acid-base balance in patients with severe sepsis and septic shock: traditional approach vs. physicochemical approach

Introduction: The evaluation of metabolism and the diagnostic classification of acid-base disorders has generated great controversy. Acid-base balance (ABB) is approached by means of the physicochemical and Henderson’s models.Objective: To compare two diagnostic approaches to ABB in patients with severe sepsis.Materials and methods: Prospective, descriptive study conducted in patients with severe sepsis. ABB was analyzed within the first 24 hours. The diagnosis was compared according to each model and the causes of the disorders were compared according to the physicochemical model.Results: 38 patients were included in the study, of which 21 (55%) were women; the mean age was 49 years, the median APACHE II, 13.28, and the mortality at 28 days, 24.3%. The traditional approach identified 8 patients with normal ABB, 20 with metabolic acidosis, and 10 with other disorders. Based on the physicochemical model, all subjects had acidosis and metabolic alkalosis. Increased strong ion difference (SID) was the most frequently observed disorder.Conclusion: The physicochemical model was useful to diagnose more patients with acid-base disorders. According to these results, all cases presented with acidosis and metabolic alkalosis; the most frequent proposed mechanism of acidosis was elevated SID. The nature of these disorders and their clinical relevance is yet to be established.