Problematic cell phone use has alarmingly increased in industrialized countries in the past 10 years. For many perpetrators, it can turn into a behavioural addiction, although this is not a ...recognized medical condition. Although there are many tools for evaluating this use, one of the most widely used tools is the Mobile Phone Problematic Use Scale (MPPUS), which we test on a representative sample of the population in Spain to obtain an estimate of the prevalence of problematic cell phone use in our midst. The age range consists of 16-65 years, with 1,126 surveys conducted. In this population, we verify that the reliability and internal consistency of the MPPUS (α = 0.939) are maintained. Additionally, the construct validity, considering the derived factors (Abuse and Dependence, Craving and Loss of Control, and Dependence on the Social Environment) are aligned with other research and with diverse external criteria of addiction. We establish four categories of users (Casual, Regular, At Risk, and Problematic) and obtain a prevalence of 15.4% among At Risk Users and 5.1% among Problematic Users. This finding implies a total of 20.5% of Users with Problems. A binary logistic regression analysis shows that age, gender, level of education, and daily cell phone use predict problematic cell phone use. The results, based on multiple criteria, show that such problematic use shares features of recognized addictions, affecting large segments of the population and not only adolescents.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper, the geometric modeling and virtual reconstruction of the double-acting steam engine designed by Agustín de Betancourt in 1789 are shown. For this, the software Autodesk Inventor ...Professional is used, which has allowed us to obtain its geometric documentation. The material for the research is available on the website of the Betancourt Project of the Canary Orotava Foundation for the History of Science. Almost all parts of the steam engine are drawn on the sheets, but due to the absence of scale and space, it is insufficient to obtain an accurate and reliable 3D CAD (Computer-Aided Design) model. For this reason a graphic scale has been adopted so that the dimensions of the elements are coherent. Also, it has been necessary to make some dimensional and geometric hypotheses, as well as restrictions of movement (degrees of freedom). Geometric modeling has made it possible to know that the system is balanced with the geometric center of the rocker arm shaft, and presents an energetic symmetry whose axis is the support of the parallelogram where the shaft rests: calorific energy to the left and mechanical energy to the right, with the rocker arm acting as a transforming element from one to the other.
This article shows the geometric modeling and virtual reconstruction of the inclined plane of Coalbrookdale (Shropshire, England) that was in operation from 1792 to 1894. This historical invention, ...work of the Englishman William Reynolds, allowed the transportation of boats through channels located at different levels. Autodesk Inventor Professional software has been used to obtain the 3D CAD model of this historical invention and its geometric documentation. The material for the research is available on the website of the Betancourt Project of the Canary Orotava Foundation for the History of Science. Also, because the single sheet does not have a scale, it has been necessary to adopt a graphic scale so that the dimensions of the different elements are coherent. Furthermore, it has been necessary to establish some dimensional, geometric, and movement restrictions (degrees of freedom) so that the set will work properly. One of the main conclusions is that William Reynolds designed a mechanism seeking a longitudinal symmetry so that, from a single continuous movement, the mechanism allows two vessels to ascend and descend simultaneously. This engineering solution facilitated a doubling of the working capacity of the device, as well as a reduction of the energy needs of the system.
Cell-Phone Addiction: A Review De-Sola Gutiérrez, José; Rodríguez de Fonseca, Fernando; Rubio, Gabriel
Frontiers in psychiatry,
10/2016, Letnik:
7
Journal Article
Recenzirano
Odprti dostop
We present a review of the studies that have been published about addiction to cell phones. We analyze the concept of cell-phone addiction as well as its prevalence, study methodologies, ...psychological features, and associated psychiatric comorbidities. Research in this field has generally evolved from a global view of the cell phone as a device to its analysis
applications and contents. The diversity of criteria and methodological approaches that have been used is notable, as is a certain lack of conceptual delimitation that has resulted in a broad spread of prevalent data. There is a consensus about the existence of cell-phone addiction, but the delimitation and criteria used by various researchers vary. Cell-phone addiction shows a distinct user profile that differentiates it from Internet addiction. Without evidence pointing to the influence of cultural level and socioeconomic status, the pattern of abuse is greatest among young people, primarily females. Intercultural and geographical differences have not been sufficiently studied. The problematic use of cell phones has been associated with personality variables, such as extraversion, neuroticism, self-esteem, impulsivity, self-identity, and self-image. Similarly, sleep disturbance, anxiety, stress, and, to a lesser extent, depression, which are also associated with Internet abuse, have been associated with problematic cell-phone use. In addition, the present review reveals the coexistence relationship between problematic cell-phone use and substance use such as tobacco and alcohol.
This article analyses the double-acting steam engine designed by Agustín de Betancourt in 1789 and based on the steam engine of James Watt. Its novelty and scientific interest lies in the fact that ...from the point of view of industrial archaeology and the study of technical historical heritage there is no worldwide study on this invention, which marked a historic milestone in the design of the steam engines of the Industrial Revolution (1760–1840). This underscores the utility and originality of this research. To this end, a study of computer-aided engineering (CAE) was carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite-element method of the 3D CAD model of the invention under real operating conditions. The results have shown that the double-acting steam engine was correctly designed considering that the values of the maximum von Mises stress (188.4 MPa) obtained were taken away from the elastic limit of the material it was made of (cast iron), as well as to the maximum deformations (0.14% with respect to its length) obtained in the same element that presents the maximum stress (opening axle of the high pressure steam valve). Similarly, the maximum displacements (18.74 mm) are located in the mobile counterweights that transmit certain inertia to facilitate the opening and closing of the valves. Finally, if we look at the results of the safety coefficient, whose lowest value was 4.02, we could say that the invention was oversized, following constructive criteria of the time, as there were no resistance tests on materials that would help in the optimization of the design of the invention.
This article analyzes the ‘Hay inclined plane’ designed by the English engineer and entrepreneur William Reynolds and put into operation in 1792 to facilitate the transport of vessels between ...channels at different levels using an inclined plane. To this end, a study of computer-aided engineering (CAE) was carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite-element method (FEM) of the 3D model of the invention under real operating conditions. The results obtained after subjecting the mechanism to the two most unfavorable situations (blockage situation of the inertia flywheel and emergency braking situation) indicate that, with the exception of the braking bar, the rest of the assembly is perfectly designed and dimensioned. In particular, for the blockage situation, the point with the greatest stress is at the junction between the inertia flywheel and the axle to which it is attached, the maximum value of von Mises stress being at that point (186.9 MPa) lower than the elastic limit of the cast iron. Also, at this point the deformation is very low (0.13% of its length), as well as the maximum displacement that takes place in the inertia flywheel itself (22.98 mm), and the lowest safety factor has a value of 3.51 (located on the wooden shaft support), which indicates that the mechanism is clearly oversized. On the other hand, the emergency braking situation, which is technically impossible with a manual operation, indicates that the braking bar supports a maximum von Mises stress of 1025 MPa, above the elastic limit of the material, so it would break. However, other than that element, the rest of the elements have lower stresses, with a maximum value of 390.7 MPa, and with safety factors higher than 1.7, which indicates that the mechanism was well dimensioned.
This article analyzes the first self-propelled floating dredging machine designed and executed by Agustín de Betancourt in 1810 to dredge the port of Kronstadt (Russia). With this objective, a study ...of computer-aided engineering (CAE) has been carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite element method, of the 3D model which is reliable under operating conditions. The results have shown that the system of inertia drums proposed by Betancourt manages to dissipate the tensions between the different elements, locating the highest stresses in the links of the bucket rosary, specifically at the point of contact between links. Similarly, the maximum displacements and the greatest deformations (always associated with these points of greater stress), are far from reaching the limits of breakage of the material used in its construction, as well as the safety coefficient of the invention, confirming that the mechanism was oversized, as was generally the case at the time. This analysis highlights the talent of the Spanish engineer and his mastery of mechanics, in an invention, the first of its kind worldwide, which served the Russian Empire for many years.
Agustín de Betancourt was one of the most distinguished engineers of the 18th and 19th centuries with numerous contributions to various fields of engineering, including civil engineering. This ...research shows the process followed in documenting the cultural heritage of this engineer from the Canary Islands (Spain), especially in the geometric documentation of the Kronstadt harbour-dredging machine presented in 1808. The initial information was taken from the Canary Orotava Foundation, History of Science, which has been compiling information on the Betancourt Digital Project for years. In particular, there are only 8 colour illustrations without scale, as well as a small report on the description of the parts and the operation of a dredging machine previously designed for the Port of Venice (but never put into operation). This was the basis for the construction of the dredging machine for the Port of Kronstadt (Russia) that did go into operation in 1812 for more than 10 years. From this information, 3D reconstruction was made by means of Computer-Aided Design (CAD) techniques thanks to the use of the Autodesk Inventor Professional parametric software, which made it possible to build the 3D model and complete its geometric documentation as well as different detailed plans and exploded views. The results show a reliable approach to its modelling, a process in which several dimensional and operational hypotheses have had to be assumed due to the lack of existing information.
This article shows the geometric modeling and virtual reconstruction of the optical telegraph by Agustín de Betancourt and Abraham Louis Breguet developed at the end of the 18th century. Autodesk ...Inventor Professional software has been used to obtain the three-dimensional (3D) model of this historical invention and its geometric documentation. The material for the research is available on the website of the Betancourt Project of the Canary Orotava Foundation for the History of Science. Thanks to the three-dimensional modeling performed, it has been possible to explain in detail both its operation and the assembly system of this invention in a coherent way. After carrying out its 3D modeling and functional analysis, it was discovered that the transmissions in the telegraph were not performed by hemp ropes but rather by metal chains with flat links, considerably reducing possible error. Similarly, it has also been found that the use of the gimbal joint facilitated the adaptability of the invention to geographical areas where there was a physical impediment to the alignment of telegraph stations. In addition, it was not now necessary for the telescope frames to be located parallel to the mast frame (frame of the indicator arrow) and therefore they could work in different planes.
This article analyzes an olive oil mill formed of four conical stones used in the milling of the olive. To this end, a study of computer-aided engineering (CAE) was carried out using the parametric ...software Autodesk Inventor Professional, consisting of a static analysis using the finite-element method (FEM) of the three-dimensional (3D) model of the mill under real operating conditions. The results obtained revealed that the conical stones mill was a very robust machine. When studying the assembly in the most unfavorable situation (blockage of one of its millstones), we observed that the element with the highest von Mises stress was the bearing nut, reaching a value of 263.9 MPa, which was far from the elastic limit of cast iron (758 MPa). On the other hand, the machine hardly presented any equivalent deformations or displacements that could jeopardize the operation as a whole. The maximum displacement obtained was 2.494 mm in the inertia flywheel, and the equivalent deformations did not reach 0.1% of the part dimension. Similarly, the element with the lowest safety coefficient (2.87) was the same bearing nut with the highest von Mises stress, although the next element with the second lowest safety coefficient had a value of 8.69, which showed that the set was clearly oversized. These results demonstrate the convenience of redesigning the set in order to resize some of its elements, and that they could have lower safety coefficients of between 2 and 4. After an initial analysis, the resizable elements would fundamentally be those related to the movement transmission system and the frame structure.
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