Separation of Southern Pine Pulp into its Springwood and Summerwood Components by Centrifugal Means: Savings in Refining and Other Possible Economic Justifications

A study of Southern Pine pulp separation into its springwood and summerwood fiber components was undertaken. Separation was accomplished through the use of two Bird Triclean centrifugal cleaner devices. Separation occurred mainly because of different apparent pulp densities in the two fiber fractions. Springwood collapsed during pulping, creating a flattened fiber, forty-five to sixty-five microns in length and ten to twelve microns in width. The thicker walled summerwood fibers, on the other hand, maintained their twenty-five to thirty-five micron diameter tubular shape. The greater surface area present in springwood fibers allowed a greater hydraulic force to be exerted to this surface, and thus they were pushed towards the center and out the top of the cleaner. A greater centrifugal force to hydraulic drag ratio acting on the lower surfaced area summerwood fibers caused them to move to the walls and out the reject nozzle at the bottom of the cleaner. The major factor governing separation (consistency) was .07% in the final run. Separation efficiencies of 73% springwood in the accepts line and 64% summerwood in the rejects line were obtained. The main thrust of the thesis dealt with separate refining of the two fractions after separation. The pulp was then recombined in various configurations. Refining, which was done in a PFI mill, seemed to lower freeness in a similar fashion for both pulps. This is contrary to the literature on the subject. Handsheets were then made using the Noble & Wood procedure, and various tests were then run on these sheets. Springwood formed a more dense sheet with higher tensile, burst, and density, and lower porosity and tear. The two most important results were: springwood reached very high tensile and burst properties at very low refining levels and then dropped off as the individual fibers weakened, summerwood maintained high tear, tensile, and porosity simultaneously at medium to high refining levels. These results seem to indicate that the two fractions might be used to create paper with special properties. They also indicate that springwood is overrefined in almost all conventional refining processes. A simple cost analysis indicated energy savings alone to be insufficient to warrant cleaner installation, but added benefits may render the separation process viable in certain specialized cases

Interaction Of Electrons With Spin Waves In The Bulk And In Multilayers

The exchange interaction between electrons and magnetic spins is considerably enhanced near interfaces, in magnetic multilayers. As a result, a dc current can be used to generate spin oscillations. We review theory and experimental evidence. The s-d exchange interaction causes a rapid precession of itinerant conduction-electron spins s around the localized spins S of magnetic electrons. Because of the precession, the time-averaged interaction torque between s and S vanishes. An interface between a magnetic layer and a spacer causes a local coherence between the precession phases of differnt electrons, within 10 nm from the interface, and restores the torque. Also, a second magnetic layer with pinned S is used to prepare s in a specific direction. the current-induced drive torque of s on S in the active layer may be calculated from the spin current (Slonczewski) or from the spin imbalance Delta-mu (Berger). Spin current and Delta-mu are proportional to each other, and can arise from Fermi-surface translation, as well as from expansion/contraction.Comment: Invited paper at Seattle MMM01 Conference, Nov. 2001 (to appear in J. Appl. Phys.

A Preliminary List of the Dolichopidae of Iowa

The Dolichopidae are small flies not exceeding eight millimeters in length, and are almost always bright metallic green or blue in color. The adults are found especially ahundant on plants around sand and mud, as well as on rocks and plants in the water. They are predaceous flies living on small, soft bodied insects. The genera Laxina, Condylostylus and Sciapus may be found on leaves of shaded flowers in search of food. These flies may be readily distinguished from the members of other families by the absence of a cross vein between the discal and the second basal cell, these uniting to form a single cell

Health education: what influences teachers’ and future teachers’ conceptions from 16 countries of Europe, Africa and Middle East?

One of the major objectives of the European FP6 BIOHEAD-CITIZEN project on “Biology Health and Environmental education for better citizenship” (STREP, CIT2-CT2004-506015, Carvalho et al. 2004) is to analyse the potential differences between countries by associating teachers’ and future teachers’ conceptions to controlled parameters, such as level of training, religion, political view and the broad socio-cultural context. A questionnaire was constructed with the participation of all Biohead-Citizen project research teams. The original English version was translated into each national language and after validation of the translation it was pre-tested before implementation in each country. A total of 6379 teachers and future teachers responded to the questionnaire. They were from 16 countries (of the 19 composing the Biohead-Citizen consortium) from Europe (West to East: Portugal, France, Italy, Malta, Germany, Poland, Hungary, Romania, Lithuania, Estonia, Finland, Cyprus), from Africa (West to East: Senegal, Morocco, Tunisia) and from the Middle East (Lebanon). Statistical multivariate methods to investigate complex data featuring the conceptions of many individuals were used. Results showed that the countries, rather than religion, have great effect on teachers and future teachers’ views conceptions on biomedical model or the health promotion approach. Furthermore primary school teachers (P), both in-service (InP) and pre-service (PreP), are more associated to the health promotion view than all the secondary school teachers: in-service Biology (InB), in-service Language (inL), pre-service Language (PreL) and pre-service Biology (PreB) teachers. Pre-teachers consider that health education should be taught at school, not only by the families, and that teachers should be obliged to teach even if they do not feel confident in doing it whereas teachers with teaching experience are more defensive in this respect, assuming exactly the opposite. In addition, the co-inertia analysis allows highlighting the correlations between differences in health education conceptions and the differences on political views.European Project FP6 “Biohead-Citizen” CIT2-CT-2004-506015Fundação para a Ciência e a Tecnologia (FCT) - LIBEC/CIFPEC - unidade de investigação 16/64

Education à la sexualité: représentations sociales, conceptions des enseignants et futurs enseignants, quelle incidence en formation?

School-based education programmes are particularly good at providing information and opportunities for skills development and attitude clarification in more formal ways, through lessons within a curriculum. To public health, school sex education is nowadays an important public health issue as it concerns not only youth AIDS prevention (and other sexually transmitted infections) and adolescent pregnancy prevention but also interpersonal relationships and psychosocial issues. So it’s very important to well know the obstacles to sexuality education’s implementation. Therefore school sex education contributes to promote better citizenship. Various researches show the importance of social representations on teachers’ individual conceptions and practices. In this communication we analyse teachers’ and future teachers’ conceptions about sex education by using a questionnaire from 12 countries of Europe, Africa and Middle East, focusing on differences in conceptions related to controlled parameters (e.g. social context, religion, gender). It was applied to 5189 teachers and future teachers and we used standard statistical multivariate methods to investigate the structure of this complex dataset. The results show that teachers’ conceptions and future teachers’ conceptions clearly correlate to social representations linked to the countries’ culture, to religion, and in individual conceptions, especially to the level of belief in God and the level of religious practices. It was also found that the level of teaching (primary versus secondary school) and the training level correlate to individual conceptions on sex education. Detailed results will be presented and discussed at the meeting and we will conclude on their incidence on teacher’s training program.European Project FP6 “Biohead-Citizen” CIT2-CT-2004-506015Fundação para a Ciência e a Tecnologia (FCT) - LIBEC/CIFPEC - unidade de investigação 16/64

Intricate visibility effects from resolved emission of young stellar objects: the case of MWC158 observed with the VLTI

In the course of our VLTI young stellar object PIONIER imaging program, we have identified a strong visibility chromatic dependency that appeared in certain sources. This effect, rising value of visibilities with decreasing wavelengths over one base, is also present in previous published and archival AMBER data. For Herbig AeBe stars, the H band is generally located at the transition between the star and the disk predominance in flux for Herbig AeBe stars. We believe that this phenomenon is responsible for the visibility rise effect. We present a method to correct the visibilities from this effect in order to allow "gray" image reconstruction software, like Mira, to be used. In parallel we probe the interest of carrying an image reconstruction in each spectral channel and then combine them to obtain the final broadband one. As an illustration we apply these imaging methods to MWC158, a (possibly Herbig) B[e] star intensively observed with PIONIER. Finally, we compare our result with a parametric model fitted onto the data.Comment: 14 pages, 7 figure

Une enquête international : représentations sociales, conceptions individuelles et pratiques d’enseignants de quinze pays

Le travail que nous présentons ici s’insère dans le cadre du projet européen « Biohead-Citizen : Biology, health and Environmental education for better Citizenship » (FP6, CT2-CT2004-506015, Carvalho et al., 2004). Nous présentons ici lest résultats, issus de quinze pays, sur deux thèmes – l’éducation à la santé et l’éducation à la sexualité – qui étroitement liés aux conceptions individuelles des enseignants. Notre objectif est d’identifier en quoi ces conceptions individuelles varient, d’un pays à un autre, mais aussi au sein de chaque pays. À quoi sont-elles liées : leurs croyances religieuses, leur sexe, leur options philosophiques ou politiques ? Sont-elles également liées à leurs connaissances dans les domaines de la santé et de la sexualité ? Ou encore aux représentations sociales dominantes dans chaque pays ?CIEC – Research Centre on Child Studies, UM (FCT R&D 317

Education à la sexualité : représentations sociales et conceptions d'enseignants et futurs enseignants, incidences sur les pratiques et la formation ?

International audienceThis paper presents the results of a questionnaire about teachers' and pre-teachers' representations coming from 17 countries (Europe, Africa, Middle-East) include in the European FP6 Biohead-Citizen research project which aims to understand how health and sex education can contribute to improving citizenship. School Sex Education is nowadays an important public health issue as it concerns not only youth AIDS prevention (and other sexually transmitted infections) and adolescent pregnancy prevention but also interpersonal relationships and psychosocial issues. Therefore school appears the best place to improve sex education and contributes to promote better citizenship. Questionnaire analyses the social representations and practices of teachers in several countries, focusing on their differences and associating them to controlled parameters (e.g. social context, religion, gender). In this communication we analyze data concerning teachers' and future teachers' conceptions on the topic of sex education derived from a questionnaire that was constructed and tested during the first year of the project. The questionnaire was completed by 5189 teachers and future teachers. We used statistical multivariate analyses, a method that has become standard for investigating complex data derived from many individuals that needs to be analyzed according to many variables (here we have used the responses to the questions as variables). The results show that the factors that correlate most closely with the teachers' and future teachers' conceptions are religion, the level of belief in God and the level of religious practices. It was also found that the level of teaching (primary versus secondary school) is also correlated with different conceptions on sex education. Detailed results will be presented and discussed.Cette communication présente les résultats de questionnaires recueillis auprès d'enseignants et futurs enseignants de 17 pays (Europe, Afrique et moyen-orient) dans le cadre du projet Biohead Citizen. Il s'agit d'identifier les différences de conception des enseignants sur l'éducation à la sexualité et de mettre en exergue les facteurs les influençant. L'éducation à la sexualité fait partie des missions confiées aux institutions scolaires. Elle concerne non seulement la santé publique à travers la prévention des infections sexuellement transmissibles, la prévention des grossesses précoces mais également la question de l'égalité de genre, des violences sexuelles, des rapports interpersonnels, du développement psychoaffectif et a des implications sociales conséquentes. L'école apparaît comme le lieu privilégié d'accès aux informations et aux connaissances scientifiques qui permettent de connaître et de comprendre les différentes dimensions de la sexualité. L'éducation à la sexualité vise aussi à susciter la réflexion des élèves et à les aider à développer des attitudes de responsabilité individuelle, familiale et sociale en partant de leurs conceptions et de leurs connaissances. Elle s'inscrit dans la construction du sujet, de l'élève et du citoyen et contribue à favoriser une meilleure citoyenneté. Le questionnaire a été renseigné par 5189 enseignants et futurs enseignants. Nous avons procédé par analyses en composantes principales qui ont montré l'importance des variables personnelles (genre, niveau de formation, niveau d'enseignement, discipline et statut) et l'incidence des variables sociales (pays, religion, niveau de croyance et de pratique religieuse) qui conduisent à des postions parfois très opposées sur l'enseignement et les contenus de l'éducation à la sexualité, sur l'égalité des sexes, sur les droits des personnes et sur la prévention. Certaines conceptions apparaissent comme des obstacles importants à la mise en place d'éducation à la sexualité et à la promotion de la santé. Les conceptions diffèrent significativement d'un pays à un autre mais également en fonction des convictions religieuses et du niveau de croyance des enseignants. Se pose alors la question des pratiques d'enseignement et de la formation des enseignants que nous discuterons

L’éducation à la sexualité: conceptions d’enseignants et futurs enseignants de douze pays

School Sex Education is nowadays an important public health issue as it concerns not only youth AIDS prevention (and other sexually transmitted infections – STI) and adolescent pregnancy prevention but also interpersonal relationships and psychosocial issues. Therefore school sex education contributes to promote better citizenship. The European FP6 Biohead-Citizen research project aims to understand how biology, health and environmental education can contribute to improving citizenship. It analyses the social representations and practices of teachers in several countries, focusing on their differences and associating them to controlled parameters (e.g. social context, religion, gender). In this communication we analyse data concerning teachers’ and future teachers’ conceptions on the topic of sex education derived from a questionnaire that was constructed and tested during the first year of the project. The questionnaire was completed by 5189 teachers and future teachers from 12 countries. We used statistical multivariate analyses, a method that has become standard for investigating complex data derived from many individuals that needs to be analysed according to many variables (here we have used the responses to the questions as variables). The results show that the factors that correlate most closely with the teachers’ and future teachers’ conceptions are religion, the level of belief in God and the level of religious practices. It was also found that the level of teaching (primary versus secondary school) is also correlated with different conceptions on sex education. Detailed results will be presented and discussed.LIBEC/CIFPEC - unidade de investigação 16/644 da FCT.European project FP6 Biohead-Citizen CIT2-CT-2004-506015

Health education: analysis of teachers’ and future teachers’ conceptions from 16 countries (Europe, Africa and Middle East)

School is an important setting for health education and health promotion, and it has been recognised that teachers’ conceptions play a crucial role for the effective implementation of school health education. With the European FP6 Biohead-Citizen project on “Biology Health and Environmental education for better citizenship” we analysed the potential differences between several countries by associating teachers’ and future teachers’ conceptions to controlled parameters, such as level of training, religion, political view. A questionnaire was constructed during the first year of the project, and following a pilot test, the final questionnaire was applied to 6379 teachers and future teachers. We then used well-suited statistical multivariate methods to investigate complex data featuring the conceptions of many individuals, according to many topics. We show that a prominent source of variation in teachers’ conceptions is related to countries, and further suggest that there are differences in two kinds of conceptions: a) individual health responsibilities and abilities; b) social policies. Religion, academic level or training had also an impact in teachers’ conceptions of health education. Another important feature is the gap between what teachers and future teachers say about their own health and what they say it should be taught in school. Results are then discussed.LIBEC/CIFPEC - unidade de investigação 16/644 da FCT.European project FP6 Biohead-Citizen CIT2-CT-2004-506015