The coronavirus disease 2019 (COVID-19) pandemic imposed arestructuring of global health systems by rethinking spaces used for the care of these patients and the additions of intensive care, infectious diseases and pneumology departments. This paper provides evidence on the presence of severe acute respiratory syndrome coronavirus 2 in hepatocytes and its direct cytopathic activity, as well as the degree of liver damage due to drug toxicity, inflammation and hypoxia in COVID-19. A review of clinical trials has quantified liver damage through both pathology and biochemistry studies. Additionally, we briefly present the results of a study conducted in our clinic on 849 patients admitted for COVID-19 treatment, of which 31 patients had pre-existing chronic liver disease and 388 patients had values above the normal limit for alanine aminotransferase, aspartate aminotransferase, and total bilirubin. It was observed that patients with abnormal liver tests were significantly statistically older, had more comorbidities and had a higher percentage of unfavourable evolution (death or transfer to intensive care). The conclusion of this paper is that the main causes of liver damage are direct viral aggression, coagulation dysfunction and endothelial damage, and patients with impaired liver function develop more severe forms of COVID-19 which requires special care by a multidisciplinary team that includes a hepatologist.

Purpose: The COVID-19 pandemic was noted for the high degree of contagion and the large number of cases, as well as for the various clinical forms, from asymptomatic towards rapid evolution to death. The hospitals limited care capacity imposed the need to identify some markers of unfavorable evolution. The purpose of our study is to identify the parameters correlated with COVID-19 unfavorable evolution and to draw the profile of the patient at risk of unfavorable evolution. This set of parameters will help the doctor in deciding whether to hospitalize a patient and in choosing the treatment. Patients and Methods: We performed a prospective, observational, actively controlled study on 849 patients with COVID-19, hospitalized in the Second Clinic of “Sf. Cuv. Parascheva” Infectious Diseases Clinical Hospital Galati, Romania, between 1.03.2020– 30.11.2020. Results: The parameters statistically significant modified at the admission of the patients with COVID-19 unfavorable evolution were age, oxygen saturation, D-dimers, creatine kinase (CK), troponin, erythrocytes sedimentation rate (ESR), leukocytes, lymphocytes, neutrophils, platelets, hemoglobin (Hb), aspartate transaminase (AST), total and direct bilirubin (TBIL, DBIL), urea, creatinine, serum glucose. Strong correlations were observed between the unfavorable evolution and the admission values of D-dimers, AST, TBIL and between D-dimers and AST, which suggests that D-dimers levels can be considered predictive for the alteration of liver function and for the negative prognosis of the patient. Conclusion: Coagulation disorders and acute respiratory failure are the prevailing causes of death from COVID-19. Together with other parameters that constitute the risk profile for severe COVID-19 evolution, the D-dimers dosing at admission proved to be extremely useful in the management of COVID-19.

The processing of the piece surfaces involves the transformation of the blank into a piece, the defining characteristics of the surfaces (the form, dimensions, deviations, etc.), depending to a large extent on the parameters of the generated processes of the surfaces. Generating surfaces by enveloping represents a complex problem, this mode of generating being a constant concern of researchers due to its advantages. A very important issue is the cutting edge profiling of the future tool, which will generate the wanted profile of the piece. Throughout time, researchers have studied the problems of enveloping surfaces and stated theorems related to them, based on which practical solutions have been conceive to determine the generating and generated surfaces form. The paper presents an overview on study methods for reciprocally enwrapping surfaces, as well as methods for profiling tools for generating helical surfaces by the kinematic method and by the method of decomposing the helical movement. This review can represent a basis for future research articles and projects.

Progressive cavity pumps are used in industry for the circulation of high viscosity fluids, such as crude oil and petroleum products, sewage sludge, oils, salt water, and wastewater. Also known as single screw pumps, these pumps are composed of a single rotor which has the shape of a rounded screw, which moves inside a rubber stator. The stator has an double helical internal surface which, together with the helical surface of the rotor, creates a cavity that moves along the rotor. The movement effect of the cavity inside the stator is the movement of the fluid with a constant flow and high pressure. In this paper, an algorithm for profiling the rollers for generating the helical surface of the pump rotor with progressive cavities is proposed. These rollers are constituted as tools for the plastic deformation of the blank (in case the pump rotor is obtained by volumetric deformation) or for its superficial hardening.

Duralumin 2024-T351 is an alloy characterized by a good mechanical strength, relatively high hardness and corrosion resistance frequently used in the aeronautical, automotive, defense etc. industries. In this paper, the variation of axial forces and torques when drilling aluminum alloy 2024-T351 was investigated, analyzing the measured values for different cutting regimes. Experimental data on the forces and moments generated during the drilling process were collected using specialized equipment, and these data were preprocessed and analyzed using MatLab R218a. The experimental plan included 27 combinations of the parameters of the cutting regime (cutting depth, cutting speed, and feed), for which energetic cutting parameters were measured, the axial force and the torsion moment, respectively Based on these data, a neural network was trained, using the Bayesian regularization algorithm, in order to predict the optimal values of the cutting energy parameters. The neural model proved to be efficient, providing predictions with a relative error below 10%, indicating a good agreement between measured and simulated values. In conclusion, neural networks offer an accurate alternative to classical analytical models, being more suitable for materials with complex behavior, such as aluminum alloys.

In most situations, for the proper design of a gerotor pump, numerous parameters must be taken into account: the pump geometry, the properties of the materials from which the pumps are made (Young’s modulus, Poisson’s coefficient, friction coefficients, etc.), the hydraulic characteristics of the circulated fluids (fluid density, kinematic viscosity, etc.), the working performance of the pump (speed ranges, pressure, flow rate, etc.), with greater or lesser influence on volumetric efficiency, work capacity, or energy consumption. The paper presents a study regarding the inspection of the reciprocally enwrapping surfaces of the gerotor pumps using a three-dimensional measurement technique specific to reverse engineering, which involves 3D scanning of the pump components in gearing movement. The components were measured by means of a specific software (GOM Inspect) and compared, by overlap, with the CAD models made with the help of CATIA software (CATIA V5R21). At the same time, an analytical calculation algorithm was developed for the complementarity of virtual representations. Finally, the advantages of the reverse engineering technique compared to the developed theoretical algorithm and traditional CAD design are presented.