739 resultados para Effective permeability


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The effective diffusivity of clove essential oil in subcritical liquid CO2 was estimated. The experimental apparatus employed was a fixed-bed extractor. The fixed bed was formed with grounded (mesh -32 + 65) and compacted clove buds which were considered a solid element. The effective diffusion coefficient was evaluated by fitting the experimental concentration profile to the unsteady state mass balance equation for unidirectional diffusion in a finite solid medium. The diffusion coefficient was related to the concentration of oil in the solid by an exponential function. The estimated values of the effective diffusion coefficient varied from 3.64 to 5.22x10-10 m2/s. The average relative errors were lower than 3.1%.

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Mimic biological structures such as the cell wall of plant tissues may be an alternative to obtain biodegradable films with improved mechanical and water vapor barrier properties. This study aims to evaluate the mechanical properties and water vapor permeability (WVP) of films produced by using the solvent-casting technique from blended methylcellulose, glucomannan, pectin and gelatin. First, films from polysaccharides at pH 4 were produced. The film with the best mechanical performance (tensile strength = 72.63 MPa; elongation = 9.85%) was obtained from methylcellulose-glucomannan-pectin at ratio 1:4:1, respectively. Then, gelatin was added to this polysaccharide blend and the pH was adjusted to 4, 5 and 6. Results showed significant improvement in WVP when films were made at pH 5 and at polysaccharides/gelatin ratio of 90/10 and 10/90, reaching 0.094 and 0.118 g.mm/h.m².kPa as values, respectively. Films with the best mechanical properties were obtained from the blend of polysaccharides, whereas WVP was improved from the blend of polysaccharides and gelatin at pH 5.

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Celery (Apium graveolens L. var. secalinum Alef) leaves with 50±0.07 g weight and 91.75±0.15% humidity (~11.21 db) were dried using 8 different microwave power densities ranging between 1.8-20 W g-1, until the humidity fell down to 8.95±0.23% (~0.1 db). Microwave drying processes were completed between 5.5 and 77 min depending on the microwave power densities. In this study, measured values were compared with predicted values obtained from twenty thin layer drying theoretical, semi-empirical and empirical equations with a new thin layer drying equation. Within applied microwave power density; models whose coefficient and correlation (R²) values are highest were chosen as the best models. Weibull distribution model gave the most suitable predictions at all power density. At increasing microwave power densities, the effective moisture diffusivity values ranged from 1.595 10-10 to 6.377 10-12 m2 s-1. The activation energy was calculated using an exponential expression based on Arrhenius equation. The linear relationship between the drying rate constant and effective moisture diffusivity gave the best fit.

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Abstract Composite films of chitosan, fish gelatin and microbial transglutaminase (MTgase) were developed. Films were produced by the casting method and dried at room temperature for 30 h, conditioned for 7 days at 30 °C at a relative humidity (RH) from 11 to 90%, and characterized. Chitosan:fish gelatin films in different proportions (100:0, 75:25, 50:50) with MTgase, were subjected to tensile properties and water vapor transmission (WVT) testing. The results showed that tensile strength decreased with an increase in RH and with an increase in gelatin content. Percent of elongation also increased with increasing RH and gelatin concentration. Water vapor transmission showed an increase proportional to an increase in RH with the presence of gelatin being unfavorable for reducing WVT. Results in this work allowed studying the effect of relative humidity on tensile and water vapor properties of chitosan and fish gelatin films.

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Kaikkien kansalaisten ja yritysten, jotka kärsivät vahinkoa Euroopan Unionin kilpailusääntöjen (SEUT 101 ja 102 artiklan) rikkomisen vuoksi, on voitava vaatia korvauksia vahingon aiheuttaneelta osapuolelta. Euroopan unionin tuomioistuin on ratkaisuillaan Courage ja Manfredi vahvistanut vahinkoa kärsineen oikeuden saada korvausta kärsimästään vahingosta. Suomessa kilpailuoikeudellista vahingonkorvausta koskeva oikeuskäytäntö on ollut vähäistä, vaikkakin viime aikoina on annettu muutama merkittävä vahingonkorvausratkaisu, näistä kenties tunnetuimpana asvalttikartelliratkaisu. Kilpailuoikeuden rikkomisesta vahinkoa kärsineet saavat kuitenkin vain harvoin korvausta kärsimästään vahingosta, mikä on ollut seurausta erilaisista lainsäädännöllisistä ja menettelyistä johtuvista esteistä jäsenvaltioiden säännöissä. Komission pitkään kestänyt lainsäädäntöhanke EU:n kilpailuoikeuden täytäntöönpanojärjestelmän selkeyttämiseksi päättyi marraskuussa 2014, kun Euroopan parlamentin ja neuvoston direktiivi tietyistä säännöistä, joita sovelletaan jäsenvaltioiden ja Euroopan unionin kilpailuoikeuden rikkomisen johdosta kansallisen lainsäädännön nojalla nostettuihin vahingonkorvauskanteisiin (2014/104/ EU) hyväksyttiin. Direktiivi julkaistiin Euroopan unionin virallisessa lehdessä 5. joulukuuta 2014, ja jäsenvaltioilla on 27.12.2016 asti aikaa implementoida direktiivi osaksi kansallista lainsäädäntöä. Direktiivin tavoitteena on EU:n kilpailusääntöjen tehokas täytäntöönpano sekä kilpailuoikeuden julkisoikeudellisen ja yksityisoikeudellisen täytäntöönpanon selkeyttäminen. Lisäksi direktiivi pyrkii varmistamaan, että vahingonkärsijät voivat saada täyden korvauksen kärsimästään vahingosta, sekä poistamaan esteitä ja pienentämään kustannuksia vahingon todistamisessa, samalla harmonisoiden eri jäsenmaissa toimivien yritysten oikeussuojan tasoa. Tarkastelen pro gradu –tutkielmassani kilpailuoikeudellisen vahingonkorvauksen kehitystä sekä uuden EU:n vahingonkorvausdirektiivin vaikutuksia erityisesti vahingonkärsijän näkökulmasta, eli sitä kuinka direktiivi vaikuttaa vahingonkärsijän mahdollisuuteen saada korvausta kärsimästään vahingosta, joka johtuu EU:n kilpailusääntöjen rikkomisesta. Lisäksi tarkastelen lyhyesti direktiivin tuomia muutoksia Suomen lainsäädäntöön. Tutkielmani loppupäätelmä on, että vaikka vahingonkorvausdirektiivi ei täydellisesti paranna vahingonkärsijän asemaa, se selkeyttää monella tavalla kilpailuoikeudellisten vahingonkorvauskanteiden nykyistä tilaa, ja saattaa tietyssä määrin rohkaista vahingonkärsijiä hakemaan korvausta kärsimästään vahingosta.

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Hankintojen johtamisen kirjallisuus korostaa tehokkaan hankinnan olevan käypä keino tehostaa organisaation tulosta kokonaisvaltaisesti. Myös kasvava tietoisuus erityisesti epäsuorista hankintamenetelmistä ja työkaluista toimivat kannustimina tälle tutkimukselle. Tämän Pro Gradu -tutkimuksen päätarkoituksena on rakentaa kokonaisvaltainen ymmärrys epäsuorasta hankinnasta sekä löytää keinoja sen tehostamiseksi. Tutkimuksen tavoitteena on selvittää, miten globaali, monikansal- linen organisaatio voi parantaa kannattavuuttaan epäsuorissa hankinnoissa, sekä mitkä tekijät hankintastrategiassa vaikuttavat siihen. Tutkimus toteutettiin yksittäisenä tapaustutkimuksena suuren globaalin, monikan- sallisen yrityksen työntekijän näkökulmasta, Pääosa datasta pohjautuu vuonna 2015 toteutettuun Opportunity -analyysi projektiin, joka toteutettiin yhteistyössä ulkoisen konsulttifirman kanssa. Osa datasta pohjautuu puolistrukturoituihin haas- tatteluihin organisaation hankintajohtajan kanssa. Datan keruussa hyödynnettiin lisäksi henkilökohtaista havainnointia ja sekundääristä aineistoa organisaatiosta. Tämä Pro Gradu tutkimus on toteutettu kvalitatiivisella otteella, sisältäen joitakin kvantitatiivisia metodin piirteitä.

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This study examined the effects of providing students with explicit instruction in how to use a repertoire of reading comprehension strategies and test taking skills when reading and responding to three types of questions (direct, inferential, critical). Specifically, the study examined whether providing students with a "model" of how to read and respond to the text and to the comprehension questions improved their reading comprehension relative to providing them with implicit instruction on reading comprehension strategies and test taking skills. Students' reading comprehension and test taking performance scores were compared as a function of instructional condition. Students from 2 grade 8 classes participated in this study. The reading component of the Canadian Achievement Tests, Third Edition (CAT/3) was used to identify students' level of reading comprehension prior to the formal instructional sessions. Students received either explicit instruction, which involved modelling, or implicit instruction, which consisted of review and discussion of the strategies to be used. Comprehension was measured through the administration of formative tests after each instructional session. The formative tests consisted of reading comprehension questions pertaining to a specific form of text (narrative, informational, graphic). In addition, students completed 3 summative tests and a delayed comprehension test which consisted of the alternative version of the CAT/3 standardized reading assessment. These data served as a posttest measure to determine whether students had shown an improvement in their reading comprehension skills as a result of the program delivery. There were significant differences in students' Canadian Achievement Test performance scores prior to the onset of the study. Students in the implicit group attained significantly higher comprehension scores than did students in the explicit group. The results from the program sessions indicated no significant differences in reading comprehension between the implicit and explicit conditions, with the exception of the 6th session involving the reading and interpreting of graphic text. Students in the explicit group performed significantly better when reading and interpreting graphic text than those in the implicit group. No significant differences were evident between the two study conditions across the three summative tests. Upon completion of the study, the results from the Canadian Achievement Test indicated no significant differences in performance between the two study conditions. The findings from this study reveal the effectiveness of providing students with explicit strategy instruction when reading and responding to various forms of text. Modelling the appropriate reading comprehension strategies and test taking skills enabled students to apply the same thought processes to their own independent work. This form of instruction enabled students in the explicit group to improve in their abilities to comprehend and respond to text and therefore should be incorporated as an effective form of classroom teaching.

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examined in Choanephora cucurbita rum during the early stages of infection by Piptocephalis virginiana » There was a small but consistent increase in the leakage of electrolytes, amino acids and sugars as a result of infection. These low levels of differential leakage in infected tissues are explained on the basis of the nature of this obligate, biotrophic, mycoparasitic system. Quantitative analysis of the twenty six amino acids and amino compounds detected in the leacheates — showed similar profiles in infected and control host and no new species of amino acids or amino compounds were detected in either infected or control host leacheates. Comparatively high amounts of aspartic acid, glutamic acid and alanine were found in the leacheates of host and infected host . Analyses of the sugars comprising the leacheates of infected and control host showed the presence of eight sugars, among which glucose was found in significant amounts (50-53%) ' The nutritional implication of this preferential leakage is discussed. No significant difference was observed in the leacheates of infected host sugar profiles compared with that of the control host. Profiles of the internal pool sugars of infected and control host did not reflect that obtained from the leacheate data, perhaps owing to leakage of sugars in a selective manner . Membrane lipid analyses yielded higher levels of lipid in infected host compared with the control, both at the 24 h and 36 h analyses. In addition, preliminary investigations of phosphorous-32 incorporation and turnover in phospholipids showed higher levels of 32p incorporation and turnover in infected host compared with the control. No apparent difference was noted in the profiles of the neutral lipid classes and the polar lipid classes of the membrane lipids as determined by one and two dimensional thin-layer chromatography respectively. However, a small but consistently higher degree of unsaturation was detected in the fatty acids of infected tissue compared with the control. Also, '^''-^^''^^'-'-^'^^c acid, a polyunsaturated fatty acid previously reported to show a direct correlation during the early stages of infection and the degree of parasitism of P. virginiana on C. cucurbitarum , was found in higher amounts in infected host membrane lipids compared with that of the control host. The implications of these membrane lipid alterations are discussed with particular reference to the small but consistently higher leakage of electrolytes, amino acids and sugars observed during infection in this study.

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Abstract A noted benefit of Project Based Learning (PBL) as a teaching strategy is how it engages the student and enhances learning outcomes as a result of working through challenges intended to depict dilemmas outside the classroom. PBL has seldom been applied outside the parameters of the classroom curriculum. The current needs assessment carried out in this research project examined current practices of language instruction and International Administrative Professionals of both the private and public Language Industry. Participants responded to survey questions on their current administrative practices, strategies, and program characteristics. The study investigated the usefulness of a handbook on the procedure of assisting administrative service teams in language instruction settings to an engaged approach to PBL for student service issues. The diverse opinions, beliefs, and ideas, along with institutional policy, can provide beneficial framework ideas for future tools.

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The purpose of this major research project was to develop a practical tool in the form of a handbook that could facilitate educators’ effective use of technology in primary and junior classrooms. The main goal was to explore the use of iPad devices and applications in the literacy classroom. The study audited available free applications against set criteria and selected only those that promoted 21st-century learning. The researcher used such applications to develop literacy lessons that aligned with curriculum expectations and promoted 21st-century skills and traditional skills alike. The study also created assessment models to evaluate the use of iPads in student work and explored the benefits and limitations of technology usage in student learning.

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This project addressed the need for more insightful, current, and applicable resources for intermediate math teachers in Canadian classrooms. A need for a handbook in this division seemed warranted by a lack of government resource support. Throughout an extensive review of the literature, themes and topics for the handbook emerged. The handbook was designed to not only provide educators with examples of effective teaching strategies within the mathematics classroom but to also inform them about the ways in which their personal characteristics and personality type could affect their students and their own pedagogical practices. Three teaching professionals who had each taught in an intermediate math class within the past year evaluated the handbook. The feedback received from these educators was directly applied to the first draft of the handbook in order to make it more accessible and applicable to other math teachers. Although the handbook was written with teachers in mind, the language and format used throughout the manual also make it accessible to parents, tutors, preservice education students, and educational administrators. Essentially, any individual who is hoping to inspire and educate intermediate math students could make use of the content within the handbook.