Agglomeration in counter-current spray drying towers. Part A: Particle growth and the effect of nozzle height

Agglomeration of particles and droplets is critical to the operation of spray dryers, however it remains relatively unexplored. This paper studies the effect of the nozzle height on product properties, wall deposits and dryer conditions in a counter-current spray drying tower of detergent with a swirling air flow. The process efficiency is driven by changes in particle agglomeration. To interpret the results and facilitate the study of swirl towers, it is useful to subdivide these units according to the sources of growth in (a) spray region(s), (b) concentrated near-wall region(s) and (c) wall deposits. The particles formed are very heterogeneous and show a size-dependent composition. In this case, particle properties are driven by the separation of solid and liquid phases during atomization and the formation of a heterogeneous set of droplets. Agglomeration serves to homogenise the product and create a distinct source of porosity. The capacity and energy consumption of the dryer are also determined by the evolution of the particle size, as fine powder is elutriated from the tower top and coarse particles are removed from the product. When the nozzle is moved to lower positions in the tower the increased temperature near the spray suppresses agglomeration, however the residence time is shortened and ultimately it leads to creation of wet, coarse granules. An optimum location is found high enough to maintain the drying efficiency but sufficiently far from the top exit to minimise the loss of fine particles. In this way, a capacity ratio (i.e. product vs spray dried powder) C > 90% can be obtained and energy efficiency maximised

The endoscopic treatment of fourth ventricle outlet obstruction: Report of two children and systematic review

Key Clinical Message Fourth ventricle outlet obstruction (FVOO) is a rare cause of hydrocephalus. In the last century, the standard treatment was the suboccipital craniotomy with magendieplasty or ventriculoperitoneal shunt (VP shunt). Since the beginning of the 21st century, the endoscopic third ventriculostomy (ETV) has been considered a less invasive alternative. The medical literature lacks sufficient reports of FVOO cases and strong evidence about ETV's efficacy in treating this condition. We report two cases of FVOO treated with ETV and review published similar cases. Clinical and radiological findings of two FVOO cases with outcomes after ETV were presented. Moreover, we conducted a systematic review after protocol registration in PROSPERO (CRD42021281474). MEDLINE, Embase, Scopus, and Web of Science were searched from inception till December 31, 2022. Studies were included if they reported cases of FVOO treated initially with ETV. Cases with Chiari malformation, Dandy‐Walker malformation, tuberous sclerosis, trapped fourth ventricle, or space‐occupying lesions were excluded. Two reviewers independently examined title/abstract records in the first stage and full‐text publications in the second for eligibility. The primary outcome was the recurrence rate, defined by the need for re‐ETV or other invasive treatments (e.g., VP shunt or magendieplasty). Other outcomes included clinical state at follow‐up and mortality. Two cases, a 3‐year‐old male and 3.5‐year‐old female, with FVOO, were treated with ETV in our department by the same neurosurgeon (SH) in 2013 and 2021. Both cases improved significantly after ETV, and there was no recurrence through the follow‐up. Besides the present cases, we found 57 other cases of FVOO treated with ETV reported in 17 studies between 2001 and 2021. The median age was 26 years, with an IQR from 2.4 to 59 years, and 56% of cases were females. The recurrence rate was 32% in the sample (19 out of 59), with a 95% CI from 21% to 46%. The median time to recure was 2 months with IQR from 1.25 to 26. A VP shunt was the treatment for recurrence in 68% and a re‐ETV in 32%. At the follow‐up (41 ± 29 months), only one case died, and one deteriorated clinically. FVOO is a rare cause of hydrocephalus encountered mainly in the first or sixth decades of life. ETV provides the first reasonable treatment. Despite the moderate recurrence rate, the outcomes are favorable

Integration of Spatial Relationships in Visual Language Model for Scene Retrieval

International audienceno abstrac

Apprentissage automatique pour l'annotation d'images

Chapitre 11National audienc

WP2 Livrable 1 : Etat de l'Art sur lannotation automatique des images et sur les modèles de correspondnace texte et images

no abstrac

Comparison of Various AVEIR Visual Concept Detectors with an Index of Carefulness

International audienceVisual annotation is still an open issue. The Content Based community admits thata plurality of features and systems shall be considered. We present in this paper fourvery different strategies using not only visual information but also text, to implementImageCLEF2009 Photo Annotation Task. The visual features are various, such as HSV,Gabor, EDGE, SIFT, and some more recent. Then we study each model performances,and propose a new measure, the Carefulness Index (Q) computed on the histogram ofthe model?s outputs. Q seems to be correlated with the model performances

Comparison of Various AVEIR Visual Concept Detectors with an Index of Carefulness

International audienceVisual annotation is still an open issue. The Content Based community admits thata plurality of features and systems shall be considered. We present in this paper fourvery different strategies using not only visual information but also text, to implementImageCLEF2009 Photo Annotation Task. The visual features are various, such as HSV,Gabor, EDGE, SIFT, and some more recent. Then we study each model performances,and propose a new measure, the Carefulness Index (Q) computed on the histogram ofthe model?s outputs. Q seems to be correlated with the model performances

Consortium AVEIR at ImageCLEFphoto 2008: on the fusion of runs

International audienceIn this working note, we present the submission of the AVEIR consortium, composed of 4 French laboratories, to ImageCLEFphoto 2008. The submitted runs correspond to different fusion strategies applied to four individual ranks, each proposed by an AVEIR consortium partner. In particular, we study the complete, and partial, average of the ranking values, the minimum of these values, and a random based diversification. We first briefly describe the individual run of each partner, then we describe the fusion runs. The official results classed one of the runs, the MEAN fusion, as the third best in the automatic text-image run category. This run gives better results than the best partner run

Examining the Impact of Artificial Intelligence and Social and Computer Anxiety in E-Learning Settings: Students’ Perceptions at the University Level

The learning environment usually raises various types of anxiety based on the student’s abilities to use technology and their abilities to overcome the negative feelings of an individual being watched all the time and criticized. Hence, learners still feel anxious while using computers and socializing in an e-learning environment. Learners who are faced with computer and AI tools are confused and frustrated. The uneasiness stems from anxiety or uneasiness, which is highly evident in daily interaction with computers and artificial intelligence tools or devices in e-learning contexts. The uneasiness stems from anxiety or uneasiness, which is highly evident in the daily interaction with computers and artificial intelligence tools or devices in e-learning contexts. To investigate this phenomenon empirically, a questionnaire was distributed among a group of undergraduate students who are studying different majors. This study aims to investigate the role of social anxiety and computer anxiety in an e-learning environment at the university level. Universities in the Gulf area are among those implementing e-learning systems. In spite of this, recent studies have shown that most students at Gulf universities are still resistant to using online systems; hence, it is necessary to determine the type of anxiety that creates such resistance and their relationship with other external variables such as motivation, satisfaction and self-efficacy. Students would be more likely to use e-learning tools and participate more effectively in their courses using the accessible electronic channels when the degree of anxiety is low. In this study, we have proposed a theoretical framework to investigate the role of social anxiety and computer anxiety in e-learning environments in the Gulf region. We examined how different variables such as satisfaction, motivation and self-efficacy can negatively or positively affect these two types of anxiety

Factors Affecting the Adoption of Digital Information Technologies in Higher Education: An Empirical Study

In this study, we present the results of an assessment of an initiative that seeks to transcend the application of digital information in the higher education sector by recommending an integrative approach that quantifies both the flow of digital information and tutors’ quality impacts concerning technology acceptance model (TAM) constructs and the perceived experience of digital information in education (DIE). There is a mounting evidence that the educational institutions that prioritize the perceived experience and the quality of the tutors do not, generally, take into account the limited exposure to digital information and technologies. Data gathered from a survey of 485 college students were used to evaluate the model and hypotheses. The findings show that users’ perceptions of the value of DIE may depend on several extrinsic conditions that improve their experiences of learning and teaching. The user’s traits, such as technological preparedness, are vital in determining perceived ease of use. In some cultures, the superior quality of the tutor may further increase perceptions of the technology’s perceived usefulness. The intention to adopt technology may also be highly influenced by other variables such as information flow. Therefore, academic institutions must reevaluate the usefulness of digital information technology as a tool for improving educational sections. This research limited its focus to educational environments in which DIE has a significant impact on the teaching and learning setting. Future works may concentrate on health or monetary organizations