19 research outputs found
Gauge symmetry of the 3BF theory for a generic Lie 3-group
The higher category theory can be employed to generalize the BF action to the
so-called 3BF action, by passing from the notion of a gauge group to the notion
of a gauge 3-group. In this work we determine the full gauge symmetry of the
3BF action. To that end, the complete Hamiltonian analysis of the 3BF action
for a general Lie 3-group is performed, by using the Dirac procedure. This
analysis is the first step towards a canonical quantization of a 3BF theory.
This is an important stepping-stone for the quantization of the complete
Standard Model of elementary particles coupled to Einstein-Cartan gravity,
formulated as a 3BF action with suitable simplicity constraints. We show that
the resulting gauge symmetry group consists of the already familiar G-, H-, and
L-gauge transformations, as well as additional M- and N-gauge transformations,
which have not been discussed in the existing literature.Comment: v2: various typos corrected, some new comments added; 22+14 pages, 2
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Hamiltonian Analysis for the Scalar Electrodynamics as 3BF Theory
The higher category theory can be employed to generalize the BF action to the
so-called 3BF action, by passing from the notion of a gauge group to the notion
of a gauge 3-group. The theory of scalar electrodynamics coupled to
Einstein-Cartan gravity can be formulated as a constrained 3BF theory for a
specific choice of the gauge 3-group. The complete Hamiltonian analysis of the
3BF action for the choice of a Lie 3-group corresponding to scalar
electrodynamics is performed. This analysis is the first step towards a
canonical quantization of a 3BF theory, an important stepping stone for the
quantization of the complete scalar electrodynamics coupled to Einstein-Cartan
gravity formulated as a 3BF action with suitable simplicity constraints. It is
shown that the resulting dynamic constraints eliminate all propagating degrees
of freedom, i.e., the 3BF theory for this choice of a 3-group is a topological
field theory, as expected.Comment: published version, 21 page
THE INFLUENCE OF A TEN-WEEK TRAINING PROGRAM ON THE BIOMECHANICAL PARAMETERS OF MADE JUMP SHOTS IN YOUNG BASKETBALL PLAYERS
The aim of this study was to determine the influence of the specific training program on the kinematic parameters of made jump shots in basketball. Participants were 31 basketball players, aged 15.32±0.65. All participants trained according to a specific training program for 10 weeks. Data obtained at the initial and final measurements were processed by nonparametric statistics. Data processing was carried out in the direction of determining the difference in kinematic parameters within the group between the initial and final measurements. After that, the level of impact of a specific training program on the mentioned parameters was determined. The obtained results indicated that there are differences between initial and final measurements in eight out of 10 (80%) kinematic parameters and the influence of the specific training program existed in the same eight (80%) kinematic parameters
Comparative model analysis of two types of clamping elements in dynamic conditions
U radu se razmatra popustljivost sustava naprava-izradak. Razmatra se slučaj stezanja izratka s dva tipa elemenata za stezanje. Prvi tip elementa za stezanje je sa standardnim ravnim čelom. Drugi tip elementa za stezanje je specijalne izvedbe s čelom u obliku kružnog klina. Analiziran je slučaj stezanja malim vrijednostima sila stezanja pri čemu se deformacije u zonama kontakta između elemenata za stezanje i izratka pretežno odvijaju u zonama visine neravnina. Također je prikazana komparativna analiza, predhodno spomenuta, dva načina stezanja izradaka u uvjetima dinamičkih opterećenja. Specijalno dizajnirani element za stezanje s čelom oblika kružnog klina u odnosu na standardni element za stezanje s ravnim čelom ima izrazito veću steznu učinkovitost po pitanju tangencijalne nosivosti i popustljivosti.This paper studies the compliance of the fixture-workpiece system. Workpiece clamping case with two types of clamping elements is considered. The first type of clamping element is standard, with flat top, while the second one is specially designed, with round cutting insert. Analyzed was the case of workpiece clamping using small forces, whereby the deformations in the workpiece/clamping element interface are predominantly on the order of magnitude of roughness height. A comparative analysis of dynamic behaviour of both types of clamping elements is also presented. In comparison with its standard counterpart, the specially designed clamping element with round cutting insert has superior clamping performance regarding both tangential load capacity and compliance
Comparative model analysis of two types of clamping elements in dynamic conditions
U radu se razmatra popustljivost sustava naprava-izradak. Razmatra se slučaj stezanja izratka s dva tipa elemenata za stezanje. Prvi tip elementa za stezanje je sa standardnim ravnim čelom. Drugi tip elementa za stezanje je specijalne izvedbe s čelom u obliku kružnog klina. Analiziran je slučaj stezanja malim vrijednostima sila stezanja pri čemu se deformacije u zonama kontakta između elemenata za stezanje i izratka pretežno odvijaju u zonama visine neravnina. Također je prikazana komparativna analiza, predhodno spomenuta, dva načina stezanja izradaka u uvjetima dinamičkih opterećenja. Specijalno dizajnirani element za stezanje s čelom oblika kružnog klina u odnosu na standardni element za stezanje s ravnim čelom ima izrazito veću steznu učinkovitost po pitanju tangencijalne nosivosti i popustljivosti.This paper studies the compliance of the fixture-workpiece system. Workpiece clamping case with two types of clamping elements is considered. The first type of clamping element is standard, with flat top, while the second one is specially designed, with round cutting insert. Analyzed was the case of workpiece clamping using small forces, whereby the deformations in the workpiece/clamping element interface are predominantly on the order of magnitude of roughness height. A comparative analysis of dynamic behaviour of both types of clamping elements is also presented. In comparison with its standard counterpart, the specially designed clamping element with round cutting insert has superior clamping performance regarding both tangential load capacity and compliance
The Amount of Weight Loss Six Months after Bariatric Surgery: It Makes a Difference
Background: Bariatric surgery, especially Roux-en-Y gastric bypass (RYGB), has become the most frequently used therapy for morbid obesity. Objectives: The aim of this study was to examine the effects of surgically induced weight loss on cardiopulmonary function 6 months after the procedure, as well as the effect of such an intervention on well-known risk factors for cardiovascular diseases. Methods: This is a cross-sectional study on 66 morbidly obese patients (BMI ≥40 or ≥35 kg/m2 with present comorbidities), comparing their cardiopulmonary function prior to and 6 months after RYGB surgery. Results: The substantial amount of weight loss (29.80 ± 13.27 kg) after RYGB surgery was associated with significant reduction of comorbidities, especially diabetes and sedentary lifestyle (p = 0.005 and p = 0.002, respectively). Regarding functional capacity, there was significant increase in peak oxygen uptake (VO2 peak, p = 0.003), duration of exercise testing, metabolic equivalents (exercise time and METs, p < 0.001), and in peak O2 pulse. These findings were particularly pronounced in a group of patients who had lost more than 18% of initial weight. Conclusions: Reduction of body weight after RYGB surgery is associated with significantly improved cardiorespiratory function 6 months after surgery, especially in patients who lost more than 18% of their initial body weight. In addition, substantial decreases in body weight were also associated with a reduction of cardiovascular risk factors such as diabetes, smoking, hypertriglyceridemia, and sedentary lifestyle
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Human Centered Approach for Reducing Household Food Waste by Tracking Fridge Inventory and the Use of Mobile Application
Increasing amounts of food waste is becoming a problem in developed countries. This research project is about how to reduce food waste by tracking fridge inventory and the best-before date of fridge stored food by a smartphone application. Food waste occurs in several different ways. It can be found in the household, retail stores and in the catering and events sector. Food waste can also be classified as avoidable waste, possibly avoidable waste and unavoidable waste. This project focuses on the household sector and the use of a mobile application to track fridge inventory and best-before date. The purpose of the application is to try to reduce household food waste. There is previous research about reducing household food waste using mobile applications and they all take different approaches. This study focuses on building upon these previous approaches together with data gathered from our own questionnaire with Sweden as primary focus. The combined data results in our own mobile application solution that has been tested by users in Swedish households. The study’s research question is addressed by the use of the application during a period of one-week observation. Our data collection consists of the participants being interviewed at the end of the observation period. The interviews gathered information related to whether the users successfully reduced food wastage in their households