Claudiu Popa - Academia.edu (original) (raw)

Papers by Claudiu Popa

Proceedings of the International Conference on Economics and Social Sciences

The current paper aims to identify the role of digitalisation in business development and busines... more The current paper aims to identify the role of digitalisation in business development and business communication, as the use of digital technologies is important in the daily activities of both companies and individuals. Digitalisation is defined as the use of technology in business processes and operations, which stands as a key element in developing new business models and achieving high efficiency on the market while helping businesses to stay connected with consumers' needs and demands. As follows, the paper highlights the importance of digitalisation by overviewing previous studies and connecting them to the current business environment and the new consumers' behaviour, reshaped by the current social situation. The paper also exposes several points of view on how digitalisation has been used for business development and how digital technologies can be implemented in marketing strategies and business communication. Meanwhile, since the current economic environment has been strongly impacted by the COVID-19 pandemic, the usage of digital technologies represented an important strategic step for businesses to continue their activity and overcome the output of the crisis, keeping both companies and individuals connected. Therefore, the paper shows the necessity to integrate digitalisation in business development and business communication, as the main key to implement new business models and to benefit from the advantages determined by using digital platforms as instruments for building and maintaining a good relationship with consumers and the target audience.

Abstract: This article aims to evoke some aspects of the fatigue cracks that have the consequence... more Abstract: This article aims to evoke some aspects of the fatigue cracks that have the consequence of pitting wear appearance on the spur gears. Different factors acting on the already propagated cracks and opened to the surface of the gear tooth will be considered. The result is the appearance of a pit. The stresses field corresponding to the contact between two cylinders that shape the contact between the teeth flanks was presented. A possible way of forming the cracks that start from the surface of the flanks is also presented. Key words: pitting, fatigue crack, pits, gear, stresses field, rollers, lubricant, voids, inclusions.

The Business & Management Collection, 2020

Open Journal of Modern Neurosurgery, 2019

The authors present the case of a 48-year-old man admitted for acute onset of paraplegia in a pat... more The authors present the case of a 48-year-old man admitted for acute onset of paraplegia in a patient suffering from backaches for 1 week. The rapidly progressive motor disturbances had been evolving for approximately 12 hours. The entire spinal MRI showed an epidural mass at T4-T6 associated with extensive lesions of spondylodiscitis and a T7-T8 vertebral body loss of height. A large six-level laminectomy was performed. A tumoral etiology couldn't be entirely excluded intraoperatively so that no fusion has been done at that time. The pathological exam revealed acute inflammatory lesions with no argument in favor of a tumoral process. Bacteriological exam of the pathological specimen and stools cultures were positive for Salmonella brandenburg. An episode of gastroenteritis after the ingestion of a pizza has been evoked. The antibiotic medication was prescribed for 12 weeks. Postoperative evolution was favorable with a possible march between bars 6 weeks after. The authors emphasize the pseudo-tumoral presentation in an immunocompetent patient, the lack of complications and the post-ingestion mechanism.

Key Engineering Materials, 2016

Injected plastic parts with internal threads (round, trapezoidal or saw) can increase products fu... more Injected plastic parts with internal threads (round, trapezoidal or saw) can increase products functionality but if not carefully designed can add unforeseen costs into the manufacturing process. In this paper the authors presents a computation methodology of the demolding moment for two cases of plastic injected parts with internal saw thread. This key parameter of the injection process directly influences the design solution of the ejector system. As further work the author will try to validate this method through a set of practical experiments.

Applied Mechanics and Materials, 2016

The values of the stress intensity factor (SIF) KI are almost always negative in the substrate of... more The values of the stress intensity factor (SIF) KI are almost always negative in the substrate of the gear teeth, due to the compressive stresses field. The more negative values are higher, respectively, the positive values are lower, the crack faces are more compressed, so the probability of crack propagation after the mode I is lower. Thus, the analysis of the factors leading to the minimum KI values may reveal the conditions that favor the fatigue crack propagation by opening mode. Instead, SIF KII is determinant in the growth rate of the fatigue crack by mode II, in terms of compressive stresses field. Thus, the more KII is higher, the propagation speed is higher, so an analysis of the factors that lead to its maximum value is very useful. The equivalent stress intensity factor Keq corresponds to a mixed-mode of loading and take into account the simultaneous influence of both stress intensity factors KI and KII. The variation of this factor can be used as a parameter of the modi...

Applied Mechanics and Materials, 2016

The most outstanding parameter that governs the fatigue crack growth under tensile stresses field... more The most outstanding parameter that governs the fatigue crack growth under tensile stresses field is the stress intensity factor, mode I, KI. This is a sufficient parameter to describe the whole stress field at the crack tip. An accurate stress intensity factor KI evolution was worked out taking into account the position of the crack centre depth, and also, the residual stresses that act on the surface of the tooth, tensions that are linearly decreasing with the depth in the contact zone. On the other hand, the parameter that governs the crack fatigue growth in the case of compression stresses field is the stress intensity factor mode II, KII. This paper also presents the KII variation along pitch line with respect to the Hertzian contact stresses, the residual stresses and the crack centre depth of an initial crack in the sub-surface of the pinion tooth, having different inclination angle α. As result of this study, some particular factors favorable to the propagation of the fatigu...

Oncology Letters, 2013

Ethmoid adenocarcinoma is the most frequent ethmoid tumor. To date, only a single case of spinal ... more Ethmoid adenocarcinoma is the most frequent ethmoid tumor. To date, only a single case of spinal cord compression resulting from ethmoid adenocarcinoma has been reported. The current case study presents a recent case of vertebroepidural metastasis of an ethmoid adenocarcinoma leading to spinal cord compression. Modern imaging studies, including magnetic resonance imaging (MRI) and 18 fludeoxyglucose positron emission tomography (FDG PET), as well as histological and immunohistochemical analyses, have led to diagnoses of a metastasis of an ethmoid adenocarcinoma, which is a mucinous variant, dedifferentiated when compared to the primary tumor. The present case discusses current diagnostic and treatment protocols of this condition. Since survival rates associated with the primary tumor are improving, the incidence of spinal metastasis of ethmoid carcinomas is likely to increase in the future, therefore requiring appropriate diagnostic and therapeutic management.

Proceedings of the International Conference on Economics and Social Sciences

The current paper aims to identify the role of digitalisation in business development and busines... more The current paper aims to identify the role of digitalisation in business development and business communication, as the use of digital technologies is important in the daily activities of both companies and individuals. Digitalisation is defined as the use of technology in business processes and operations, which stands as a key element in developing new business models and achieving high efficiency on the market while helping businesses to stay connected with consumers' needs and demands. As follows, the paper highlights the importance of digitalisation by overviewing previous studies and connecting them to the current business environment and the new consumers' behaviour, reshaped by the current social situation. The paper also exposes several points of view on how digitalisation has been used for business development and how digital technologies can be implemented in marketing strategies and business communication. Meanwhile, since the current economic environment has been strongly impacted by the COVID-19 pandemic, the usage of digital technologies represented an important strategic step for businesses to continue their activity and overcome the output of the crisis, keeping both companies and individuals connected. Therefore, the paper shows the necessity to integrate digitalisation in business development and business communication, as the main key to implement new business models and to benefit from the advantages determined by using digital platforms as instruments for building and maintaining a good relationship with consumers and the target audience.

Abstract: This article aims to evoke some aspects of the fatigue cracks that have the consequence... more Abstract: This article aims to evoke some aspects of the fatigue cracks that have the consequence of pitting wear appearance on the spur gears. Different factors acting on the already propagated cracks and opened to the surface of the gear tooth will be considered. The result is the appearance of a pit. The stresses field corresponding to the contact between two cylinders that shape the contact between the teeth flanks was presented. A possible way of forming the cracks that start from the surface of the flanks is also presented. Key words: pitting, fatigue crack, pits, gear, stresses field, rollers, lubricant, voids, inclusions.

The Business & Management Collection, 2020

Open Journal of Modern Neurosurgery, 2019

The authors present the case of a 48-year-old man admitted for acute onset of paraplegia in a pat... more The authors present the case of a 48-year-old man admitted for acute onset of paraplegia in a patient suffering from backaches for 1 week. The rapidly progressive motor disturbances had been evolving for approximately 12 hours. The entire spinal MRI showed an epidural mass at T4-T6 associated with extensive lesions of spondylodiscitis and a T7-T8 vertebral body loss of height. A large six-level laminectomy was performed. A tumoral etiology couldn't be entirely excluded intraoperatively so that no fusion has been done at that time. The pathological exam revealed acute inflammatory lesions with no argument in favor of a tumoral process. Bacteriological exam of the pathological specimen and stools cultures were positive for Salmonella brandenburg. An episode of gastroenteritis after the ingestion of a pizza has been evoked. The antibiotic medication was prescribed for 12 weeks. Postoperative evolution was favorable with a possible march between bars 6 weeks after. The authors emphasize the pseudo-tumoral presentation in an immunocompetent patient, the lack of complications and the post-ingestion mechanism.

Key Engineering Materials, 2016

Injected plastic parts with internal threads (round, trapezoidal or saw) can increase products fu... more Injected plastic parts with internal threads (round, trapezoidal or saw) can increase products functionality but if not carefully designed can add unforeseen costs into the manufacturing process. In this paper the authors presents a computation methodology of the demolding moment for two cases of plastic injected parts with internal saw thread. This key parameter of the injection process directly influences the design solution of the ejector system. As further work the author will try to validate this method through a set of practical experiments.

Applied Mechanics and Materials, 2016

The values of the stress intensity factor (SIF) KI are almost always negative in the substrate of... more The values of the stress intensity factor (SIF) KI are almost always negative in the substrate of the gear teeth, due to the compressive stresses field. The more negative values are higher, respectively, the positive values are lower, the crack faces are more compressed, so the probability of crack propagation after the mode I is lower. Thus, the analysis of the factors leading to the minimum KI values may reveal the conditions that favor the fatigue crack propagation by opening mode. Instead, SIF KII is determinant in the growth rate of the fatigue crack by mode II, in terms of compressive stresses field. Thus, the more KII is higher, the propagation speed is higher, so an analysis of the factors that lead to its maximum value is very useful. The equivalent stress intensity factor Keq corresponds to a mixed-mode of loading and take into account the simultaneous influence of both stress intensity factors KI and KII. The variation of this factor can be used as a parameter of the modi...

Applied Mechanics and Materials, 2016

The most outstanding parameter that governs the fatigue crack growth under tensile stresses field... more The most outstanding parameter that governs the fatigue crack growth under tensile stresses field is the stress intensity factor, mode I, KI. This is a sufficient parameter to describe the whole stress field at the crack tip. An accurate stress intensity factor KI evolution was worked out taking into account the position of the crack centre depth, and also, the residual stresses that act on the surface of the tooth, tensions that are linearly decreasing with the depth in the contact zone. On the other hand, the parameter that governs the crack fatigue growth in the case of compression stresses field is the stress intensity factor mode II, KII. This paper also presents the KII variation along pitch line with respect to the Hertzian contact stresses, the residual stresses and the crack centre depth of an initial crack in the sub-surface of the pinion tooth, having different inclination angle α. As result of this study, some particular factors favorable to the propagation of the fatigu...

Oncology Letters, 2013

Ethmoid adenocarcinoma is the most frequent ethmoid tumor. To date, only a single case of spinal ... more Ethmoid adenocarcinoma is the most frequent ethmoid tumor. To date, only a single case of spinal cord compression resulting from ethmoid adenocarcinoma has been reported. The current case study presents a recent case of vertebroepidural metastasis of an ethmoid adenocarcinoma leading to spinal cord compression. Modern imaging studies, including magnetic resonance imaging (MRI) and 18 fludeoxyglucose positron emission tomography (FDG PET), as well as histological and immunohistochemical analyses, have led to diagnoses of a metastasis of an ethmoid adenocarcinoma, which is a mucinous variant, dedifferentiated when compared to the primary tumor. The present case discusses current diagnostic and treatment protocols of this condition. Since survival rates associated with the primary tumor are improving, the incidence of spinal metastasis of ethmoid carcinomas is likely to increase in the future, therefore requiring appropriate diagnostic and therapeutic management.