ELECTRICAL DRIVE AND CONTROL OF AN ELECTRIC MOTOR STEP BY STEP BY STEP BIPOLAR

"PWM, (Pulse Width Modulation) is the most effective way to control analog circuits using numerical outputs by changing the duration and frequency of the signal. The duration of each state t1 and t2, so the filling factor, where T = t1 + t2 = constant. If only one of the times (t1 or t2) varies, then the Tt period of a cycle varies, so the f = 1 / T frequency varies. The PWM signal is actually a modulated rectangular signal over the duration by modifying the duration of each period t1, t2 of the cycle as well as the change in frequency. The maximum benefit of a stepper motor can only be obtained if it is ordered correctly, this requiring a direct current source, an electronic switch and a controlled pulse generator (numerical information). The frequency of the CLOCK cycle is measured in Hz and the filling factor is measured in percentage (%). The amplitude of the output signal is constant even if the amplitude of signals producing the fill factor varies. "

Deciphering the triad of infection, immunity and pathology

The factors which drive and control disease progression can be inferred from mathematical models that integrate measures of immune responses, data from tissue sampling and markers of infection dynamics.

Daily and Non-daily Smokers: A Profile of Drive and Cognitive Control Mechanisms

Historically, smokers were considered a single homogeneous group, but over the past two decades research has increasingly focused on differentiating daily and non-daily smokers. Despite fundamentally different smoking habits and motives, daily and non-daily smokers have similar cessation rates. In order to understand why both groups may experience a similar difficulty quitting smoking, this thesis explored neurocognitive mechanisms associated with addictive behaviour. In order to profile these mechanisms, a systematic review was conducted, highlighting there was a gap to address in two areas of research relating to drive and control. Study One (N = 60) and Study Two (N = 166) investigated attentional bias towards smoking cues using the visual probe task, finding there was no meaningful difference between daily and non-daily smokers in trait-level attentional bias. Study Three (N = 28) measured ERP components associated with inhibitory control (Go/NoGo task) and error processing (Eriksen Flanker task). There were no significant effects of interest, but the sample size was smaller than planned. This thesis made three contributions to the study of addictive behaviour. First, the systematic review highlighted that research investigating lighter and heavier smokers has a problematic level of heterogeneity in the definitions used to define the groups. Second, there was no meaningful difference in attentional bias between daily and non-daily smokers, supporting contemporary theories that attentional bias may be best conceptualised as a state-level construct. Finally, internal consistency estimates of the ERP measures of inhibitory control and error processing supported previous research reporting good psychometric properties. Overall, this thesis presented a focused profile of measures relating to drive and control neurocognitive mechanisms, but there were no meaningful differences between daily and non-daily smokers. If these mechanisms are important to addictive behaviour, future research will have to investigate their role using alternative designs.

Sustainable mechanochemical synthesis of β-cyclodextrin polymers by twin screw extrusion

Cyclodextrin nanosponges (CD-NS) are cross-linked cyclodextrin polymers characterized by a nanostructured three-dimensional network. CD-NSs in the last years found many different applications in the pharmaceutical field for the controlled release of drugs and for the absorption of undesired substances from physiological media, food, and wastewater. Most of CD-NS syntheses involve the solubilization of the chosen CD in closed batch, using a suitable organic polar aprotic liquid, which may affect potential environmental or biomedical applications. Since the research is now moving towards more sustainable approaches, new and greener syntheses of CD-NS are now being developed. Here, it is reported a new eco-friendly and efficient synthesis of nanosponges through mechanochemistry. Mechanochemistry involves the application of mechanical forces to drive and control chemical reactions by transferring energy to chemical bonds. The mechanochemical approach involves the use of a twin-screw extruder (TSE) as a chemical reactor: TSE are capable of fine temperature control and, furthermore, TS Extrusion is a continuous process and not a batch process. Among the many available CD-NS syntheses, we tested our solvent-free approach on a β-CD/citric acid (CA) system. Moreover, using TSE, the same polymer was obtained in a considerably shorter time. The so obtained NSs were used for the adsorption and removal of probe molecules, in comparison with NSs prepared by cross-linking β-CD with CA in batch. Graphical Abstract

A Novel Driving Scheme for Three-Phase Bearingless Induction Machine with Split Winding

In order to reduce the costs of implementing the radial position control system of a three-phase bearingless machine with split winding, this article proposes a driving method that uses only two phases of the system instead of the three-phase traditional one. It reduces from six to four the number of inverter legs, drivers, sensors, and current controllers necessary to drive and control the system. To justify the proposal, this new power and control configuration was applied to a 250 W machine controlled by a digital signal processor (DSP). The results obtained demonstrated that it is possible to carry out the radial position control through two phases, without loss of performance in relation to the conventional three-phase drive and control system.

Research on Real Working Condition Simulation and Performance Test of Wind Power Main Bearing Based on Test Bench

As a renewable energy source, wind energy has received more and more attention, and the wind power industry has also been advocated and developed by countries all over the world. In the production and use of wind turbines, the design and manufacturing technology of wind turbine bearings is very important. In order to ensure the reliable operation of the wind power main bearing after installation and realize the longest life of it, this paper designs a bearing test bench that can test the performance of the wind power main bearing. It can analyze the temperature, displacement, load, and moment of the key parts of the 5 MW wind power main shaft bearing. The solid modeling of the experimental platform was carried out using the 3D modeling software SolidWorks. Hydraulic loading system and test monitoring system are designed to realize the drive and control of the test bench. Through the established mathematical model, the central load of the hub is converted into the axial cylinder load and the radial cylinder load of the test bench to simulate the actual working conditions of the tested bearing. The test results show that the test bench meets various loading requirements and can reliably complete the task of testing wind power main bearings.

DESIGN of SPEED CONTROL of HYDRAULIC MOTOR

-This study is about Hydraulic Power Pack in hydraulic system Hydraulic drives and controls have become more important due to automation and mechanization. A large number of the advanced and incredible machineries are controlled partly or totally by hydraulics. Hydraulic system is less convoluted and has less moving parts. Today drive and control framework designing is unfathomable without hydraulics. Hydraulic Power Pack gives energy to the activities of the water driven framework, likewise moves the liquid through the framework, gives a protected greatest framework working pressing factor, and furthermore helps with keeping up the liquid temperature and tidiness. Water driven Power Pack is chosen by Pressure range, ostensible force and Size of tank different boundaries.

Pathophysiological mechanisms of root resorption after dental trauma: a systematic scoping review

BackgroundThe objective of this scoping review was to systematically explore the current knowledge of cellular and molecular processes that drive and control trauma-associated root resorption, to identify research gaps and to provide a basis for improved prevention and therapy.MethodsFour major bibliographic databases were searched according to the research question up to February 2021 and supplemented manually. Reports on physiologic, histologic, anatomic and clinical aspects of root resorption following dental trauma were included. Duplicates were removed, the collected material was screened by title/abstract and assessed for eligibility based on the full text. Relevant aspects were extracted, organized and summarized.Results846 papers were identified as relevant for a qualitative summary. Consideration of pathophysiological mechanisms concerning trauma-related root resorption in the literature is sparse. Whereas some forms of resorption have been explored thoroughly, the etiology of others, particularly invasive cervical resorption, is still under debate, resulting in inadequate diagnostics and heterogeneous clinical recommendations. Effective therapies for progressive replacement resorptions have not been established. Whereas the discovery of the RANKL/RANK/OPG system is essential to our understanding of resorptive processes, many questions regarding the functional regulation of osteo-/odontoclasts remain unanswered.ConclusionsThis scoping review provides an overview of existing evidence, but also identifies knowledge gaps that need to be addressed by continued laboratory and clinical research.