Food additives in chemistry lessons

Els additius alimentaris són components comuns en els aliments i un bon context d'estudi per a les classes de química. En aquest treball, es descriu una sessió de laboratori per a estudiants de secundària (17-18 anys). Els alumnes van determinar algunes propietats físiques i químiques de quatre additius «desconeguts». Utilitzant els resultats de les proves, els estudiants havien d'esbrinar, entre els deu possibles additius d'una determinada llista, quins eren els quatre additius analitzats. Els estudiants van treballar en petits grups. Un 26 % dels estudiants (grups) va identificar correctament els quatre additius, un 29 % en va identificar tres i el 45 % en va identificar dos.Food additives are common food components and they should be studied in chemistry classes. This paper describes a lab lesson for high school seniors (17-18 years old). They tested some physical and chemical properties of four unknown additives. Using the test results the students had to figure out which four of the ten additives from a list given had been tested. The students worked in small groups. All four correct additives were chosen by 26 % of students (groups), three correct additives by 29 % and two correct additives by 45 % of students

Initial results of investigator initiated international database on catheter directed therapy of acute pulmonary embolism

Background: Catheter directed therapies (CDT) are widely used in the treatment of acute pulmonary embolism (PE). A multicenter registry was organized to evaluate their application in real life and to determine efficacy and safety of these procedures. Local experience of participating centers in percutaneous techniques for PE treatment was assessed. Methods: An internet-based registry was designed to collect clinical, echocardiographic and laboratory data of consecutive PE patients treated with CDT in participating centers between 2017 and 2022. Results: Under analysis were 145 consecutive patients with acute PE, aged 61 ± 15 years, treated with CDT in 7 centers: 50 (34.5%) patients with high-risk PE (HRPE), and 95 (65.5%) patients with intermediate-high risk PE (IHRPE). 100 (69%) patients were treated with dedicated devices, in 45 (31%) subjects a pigtail catheter was used. Total PE or CDT related in-hospital mortality in HRPE reached 14% (7 patients), while in IHRPE 3.2% (3 patients) (p = 0.032). 50% of PE or CDT related deaths occurred in patients treated with a pigtail catheter. All-cause mortality in 145 patients was 9.7%, and it was higher in HRPE than in IHRPE (18% vs. 5.3%, p = 0.019). The use of pigtail catheters compared to dedicated systems was associated with higher mortality (20% vs. 5%, p = 0.01). Conclusions: Catheter directed therapies is a real option of treating PE. It was used as primary therapy also in patients without contraindication for thrombolysis suggesting that clinical practice does not always follow current PE guidelines. Patients treated with dedicated CDT systems had a higher survival rate than subjects treated with pigtail catheters

Multi-Product Dividing Wall Columns: A Simple and Effective Assessment and Conceptual Design Procedure

The objective of this paper is to further exploit and demonstrate the potential benefits of a V-min diagram based analysis, using a fifteen component feed mixture as base case. Detailed explanations are given on how to interpret properly a V-min diagram and use it for DWC assessment. Emphasis is on how to set the component or fraction splits to maximize potential gains as well as how to handle some variations in the feed with the same purpose. Interestingly, it appeared that depending on the choice and specification of interesting products (components or fractions), a simplified four-product DWC and even five-product DWC could be an interesting option for aromatics processing plants

Translation of P = kT into a pictorial external representation by high school seniors

This paper describes the results achieved by high school seniors on an item which involves translation of the equation P = kT into a corresponding pictorial external representation. The majority of students (the classes of 2011, 2012 and 2013) did not give the correct answer to the multiple choice part of the translation item. They chose pictorial representations of the other gas laws (P = k/V, or V = kT) instead. Failure to choose the correct answer was surprising considering that the symbol for volume was absent which should have been the key clue. Through the analysis of students' explanations (the classes of 2011 and 2012) and interviews (the class of 2013) we considered the reasoning applied by students who chose the correct answer or distractors for the multiple choice part of the item. Among the students who answered correctly there were explanations which contained misconceptions. Several factors that lead to the unsuccessful translation between external representations have been discovered. Students interpreted the change in one quantity based on the notation for the change in another one because of deep rooted cognitive schemas about changing two quantities (volume and pressure, pressure and temperature, temperature and volume), without consideration that for such changes to be valid for gases all three quantities need to be considered for a certain amount of substance. Those cognitive schemas interfered with mathematical reasoning, i.e. students possessed limited understanding of the equations

Food additives in chemistry lessons

Els additius alimentaris són components comuns en els aliments i un bon context d'estudi per a les classes de química. En aquest treball, es descriu una sessió de laboratori per a estudiants de secundària (17-18 anys). Els alumnes van determinar algunes propietats físiques i químiques de quatre additius «desconeguts». Utilitzant els resultats de les proves, els estudiants havien d'esbrinar, entre els deu possibles additius d'una determinada llista, quins eren els quatre additius analitzats. Els estudiants van treballar en petits grups. Un 26 % dels estudiants (grups) va identificar correctament els quatre additius, un 29 % en va identificar tres i el 45 % en va identificar dos.Food additives are common food components and they should be studied in chemistry classes. This paper describes a lab lesson for high school seniors (17-18 years old). They tested some physical and chemical properties of four unknown additives. Using the test results the students had to figure out which four of the ten additives from a list given had been tested. The students worked in small groups. All four correct additives were chosen by 26 % of students (groups), three correct additives by 29 % and two correct additives by 45 % of students

Personalized Avatars for Mobile Entertainment

With evolution in computer and mobile networking technologies comes the challenge of offering novel and complex multimedia applications and end-user services in heterogeneous environments for both developers and service providers. This paper describes one novel service, called LiveMail that explores the potential of existing face animation technologies for innovative and attractive services intended for the mobile market. This prototype service allows mobile subscribers to communicate using personalized 3D face models created from images taken by their phone cameras. The user can take a snapshot of someone's face – a friend, famous person, themselves, even a pet – using the mobile phone's camera. After a quick manipulation on the phone, a 3D model of that face is created and can be animated simply by typing in some text. Speech and appropriate animation of the face are created automatically by speech synthesis. Furthermore, these highly personalized animations can be sent to others as real 3D animated messages or as short videos in MMS. The clients were implemented on different platforms, and different network and face animation techniques, and connected into one complex system. This paper presents the architecture and experience gained in building such a system