Could Alfa fibers substitute glass fibers in composite materials?

In the present work polyester resin composites with Alfa fibers in the form of pulp were prepared and their properties were compared with those of polyester resin reinforced with glass fibers, the latter composites being widely used for structural applications. The composites were prepared using two manufacturing processes, namely hand lay-up and vacuum molding, to assess the influence of the process on the composites properties. Firstly, the tensile properties for the two composites were evaluated. The composites thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis. Finally, the morphology of a glass fiber composite (GFC) and Alfa pulp composite (APC) was analyzed by scanning electron microscopy, to characterize the composites surface and cross-sections.The authors would like to thank CTC (Centre technique de la Chimie) for their valuable help during mechanical testing. The company Solutions Composites, especially Mr.Adel Hammami is gratefully acknowledged for financial and material support. The authors also wish to thank the members of the Department of Polymer Engineering University of Minho, Guimarães, Portugal for their valuable cooperation. This research work is carried out as part of a mobidocPhD, a program financed by the European Union within Pasri Projet. M.C Paiva acknowledges the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/COMPETE for the financial support through project PEst-C/CTM/ LA0025/2013 (LA 25-2015-2017)

Revue sur l'enlèvement des métaux des effluents par adsorption sur la sciure et les écorces de bois

Les résidus de transformation du bois tels les écorces et la sciure de bois ont été largement étudiés depuis quelques années pour leur propriété d'adsorption et d'enlèvement des métaux toxiques contenus dans les effluents contaminés. En ce qui concerne la sciure de bois, les recherches répertoriées ont porté principalement sur l'utilisation du sapin rouge, du manga, du tilleul, de l'épinette, du pin, du cèdre, du teck, de l'akamatsu et du buna. Pour ce qui est des écorces de bois, plusieurs espèces ont été étudiées, notamment les écorces de pin, de chêne et d'épinette. La présente revue fait le point sur les performances de ces différents adsorbants peu coûteux pour l'adsorption des principaux métaux contaminants (Cd, Cr, Cu, Hg, Ni, Pb et Zn). Les points discutés portent sur les méthodes de préparation (lavage, séchage et tamisage) et de traitement chimique de l'adsorbant (traitement acide ou basique, traitement à la formaldéhyde, phosphatation, carboxylation, sulfoéthylation, carboxyméthylation, etc.), les conditions opératoires utilisées lors de l'adsorption, les modèles thermodynamiques, cinétiques et autres applicables au couple adsorbant-adsorbat, l'effet des principaux paramètres opératoires (temps de contact, pH de traitement, température, concentration d'adsorbant, taille des particules, etc.), les principes et les mécanismes impliqués dans l'élimination des contaminants métalliques par les adsorbants présentés.Wood industry by-products such as barks and sawdusts have been widely studied in recent years for their property of metal adsorption and metal removal from contaminated effluents. Concerning the utilization of sawdusts, many researchers have studied metal adsorption on material from species such as red fir, mango, lime, pine, cedar, teak, Japanese red pine and Japanese beech. As regards wood barks, several species were studied, in particular pine, oak and spruce. The present review gives a progress report on the efficiency of these various inexpensive materials for the adsorption of different metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn). The points discussed relate to the preparation methods (washing, drying, screening) and the chemical treatments of the adsorbents (acid or base treatment, formaldehyde treatment, phosphatation, carboxylation, sulfoethylation, carboxymethylation, etc.). We also consider the operating conditions used during adsorption, the thermodynamic, kinetic and other models applicable to the adsorbent-adsorbate couple, the effect of the operational parameters (time of contact, pH, temperature, adsorbent concentration, particle size, etc.), as well as the principles and mechanisms involved in metal removal by the adsorbents.The accumulation of organic or inorganic matter at the solid-liquid interface is the basis of almost all surface reactions. Adsorption is often a process described in terms of isotherms, which represent the relationship between the concentration of a solute in solution and the quantity adsorbed at the surface at constant temperature. The isotherms are often used to establish the maximum adsorption capacity of a given adsorbent for metals. Langmuir and Freundlich isotherms are the most frequently used and their models are presented in this review.Knowledge of adsorption parameters is essential for understanding the adsorption mechanisms involved. Usually, the maximum adsorption capacity for sawdusts and barks is reached after one hour. The pH of the ambient water is a very important parameter because it affects the metal adsorption capacities. For most of the metals studied, the adsorption capacity increases when the pH increases. The opposite effect is observed for metals involved in an anionic complex (Cr, Se, Pt, Au). Metal adsorption efficiency also improves with increases in substrate concentration because there are more available adsorption sites. Metal adsorption is affected by an another important factor, the particle size. In effect, a smaller size particle increases the specific surface and improves the adsorption capacity. The presence of anions in the effluent doesn't appear to have a great effect on adsorption results with sawdusts. However, some anions were reported to have an influence on the metal adsorption capacities of barks. In the case of a metal mixture, the presence of one metal may influence, compete or exclude the recovery of another metal from the solution.Sawdusts contain lignin, cellulose, tannin and protein. Wood tannin likely serves as a primary adsorption site for divalent cations. The application of chemical treatments on sawdusts could modify the lignin functional groups. Other studies regarding the participation of major components of barks (lignin, carbohydrate and protein) in the adsorption process revealed the involvement of amine and carboxyl functional groups. The proposed mechanism involves an ion-exchange process. This phenomenon suggests that cationic exchange is the active mechanism for some wood species, in agreement with the work of some researchers.Currently, only a few industries use plant biomass to eliminate metals in wastewater. To encourage industries to use this biotechnology, research has to be oriented towards the cheapest and most competitive process rather than the current and conventional process. Forest waste products are produced in large quantities in several countries. They constitute easily-available resources of low cost. Future research in this field should be focused on cheap new chemical treatments to apply to by-products to improve their adsorption capacities

Historical Scientific Racism and Psychiatric Publications: A Necessary International Anti-racist Code of Ethics

Ethical aspects of publishing in scientific journals are an important issue addressed since the late 1970s by the International Committee of Medical Journal Editors (1978). Today, medical journals also benefit from other international organizations’ recommendations such as the Committee on Publication Ethics, World Association of Medical Editors, and World Health Organization (WHO). These international best practices guidelines cover various ethical issues related to integrity in research, authorship, conflicts of interest, and so on

Projet « cabinets de groupe » : collaboration entre médecine de premier recours et psychiatrie [« Group medical practices » project : collaboration between primary care medicine and institutional public psychiatry]

Collaboration between primary care medicine and psychiatry is a well-known challenge. In order to improve access to psychological care for patients undergoing primary care, the « group medical practices » project proposes a collaborative care model in which a psychiatrist employed by a public psychiatric institution integrates group medical practices in order to provide assistance to primary care physicians. It is thus able to evaluate patients directly in the practices and to offer supervision and consilium spaces to primary care physicians

Micrometastasis Detection Guidance by Whole-Slide Image Texture Analysis in Colorectal Lymph Nodes

Introduction/ Background Cancer is a disease that affects millions worldwide and accurate determination of whether lymph nodes (LNs) near the primary tumor contain metastatic foci is of critical importance for proper patient management. Histopathological evaluation is the only accepted method to make that determination. However, the current standard of care only examines a single central histological section per LN and yields an unacceptable false-negative rate. Aims To help pathologists in their examination we propose a method that extracts textural features from histopathological LN whole slide images (WSI) and then applies support vector machines (SVMs) to automatically identify regions suspicious for metastatic foci. Methods The database consisted of WSI from 44 LNs. Sections were stained with hematoxylin-eosin and examined at 20x (0.45μm resolution). Twenty-eight of the LNs were identified by an expert pathologist as positive for cancer (P), and the remaining sixteen were negative (N). This database was divided into two groups. Group 1 (15P and 5N) was used for training and Group 2 (13P and 11N) was used for testing the classification technique. For all analysis each WSI was divided into non-overlapping 1000 x 1000 pixel sub-images that will be referred to as high-power fields (HPFs). For each LN in Group 1, at least one WSI was annotated by a pathologist to identify rectangular, HPF-scale regions as locally cancerous or locally non-cancerous. From these annotated slides, 924 HPFs (462 P and 462 N) were obtained. For each of these HPFs, statistical features based on gray-level co-occurrence matrices [1] and Law’s texture energy measures [2, 3] were extracted from 9 derived images [4]. The extracted features were submitted to a sequential forward selection (SFS) method [5] to select few non-redundant features providing best class separation (cancerous vs. non-cancerous region). Combinations of the selected features were tested on the 924 HPFs using k-fold cross-validation to find those that produced the best results and consequently to train our SVM-based classifier. In Group 2, WSI were not annotated for cancerous and non-cancerous zones on a HPF scale. Each LN, however, had been labeled by a pathologist as positive or negative for cancer. For each WSI, each section was divided into contiguous HPFs, and those which mainly contain fatty tissue, background, and tears were automatically excluded. Each selected HPFs was classified as cancerous or non-cancerous using the previously trained classifier to obtain the total number of cancer-classified per LN. A receiver operating characteristics (ROC) curve was traced by changing the discriminator threshold (T) used to label the LN as P for cancer as a function of the total number of cancer-classified HPFs. Results During training, 5 Laws features were selected by SFS. Highly satisfactory k-fold cross-validation with a F-score of 0.996 ± 0.005 was obtained using only 2 statistical features computed at different scales. The ROC curve obtained by applying the SVM-classifier to the test set is shown in the next figure. Two valuable operating points can be identified which both guaranteed no false-negative. At T=11 we got 2 false-positives and an optimal F-score of 0.917, and with a more conservative approach, T=1, we got 7 false-positives and a F-score of 0.759. The top-left part of the slide displayed in next figure would have been proposed to the pathologist as the most suspicious region of the cancerous LN