Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO3/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ∼3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron’s mobility ∼2 × 10−3 cm2V−1s−1, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10−5 cm2V−1s−1, and electron mobility of 8.7 × 10−4 cm2V−1s−1.

Analysis of one-pass block cipher based authenticated encryption schemes

This project analyses and evaluates the integrity assurance mechanisms used in four Authenticated Encryption schemes based on symmetric block ciphers. These schemes are all cross chaining block cipher modes that claim to provide both confidentiality and integrity assurance simultaneously, in one pass over the data. The investigations include assessing the validity of an existing forgery attack on certain schemes, applying the attack approach to other schemes and implementing the attacks to verify claimed probabilities of successful forgeries. For these schemes, the theoretical basis of the attack was developed, the attack algorithm implemented and computer simulations performed for experimental verification.

High threshold of β1 integrin inhibition required to block collagen I-induced membrane type-1 matrix metalloproteinase (MT1-MMP) activation of matrix metalloproteinase 2 (MMP-2)

Background Matrix metalloproteinase-2 (MMP-2) is an endopeptidase that facilitates extracellular matrix remodeling and molecular regulation, and is implicated in tumor metastasis. Type I collagen (Col I) regulates the activation of MMP-2 through both transcriptional and post-transcriptional means; however gaps remain in our understanding of the involvement of collagen-binding ?1 integrins in collagen-stimulated MMP-2 activation. Methods Three ?1 integrin siRNAs were used to elucidate the involvement of ?1 integrins in the Col I-induced MMP-2 activation mechanism. ?1 integrin knockdown was analyzed by quantitative RT-PCR, Western Blot and FACS analysis. Adhesion assay and collagen gel contraction were used to test the biological effects of ?1 integrin abrogation. MMP-2 activation levels were monitored by gelatin zymography. Results All three ?1 integrin siRNAs were efficient at ?1 integrin knockdown and FACS analysis revealed commensurate reductions of integrins ?2 and ?3, which are heterodimeric partners of ?1, but not ?V, which is not. All three ?1 integrin siRNAs inhibited adhesion and collagen gel contraction, however only the siRNA showing the greatest magnitude of ?1 knockdown inhibited Col I-induced MMP-2 activation and reduced the accompanying upregulation of MT1-MMP, suggesting a dose response threshold effect. Re-transfection with codon-swapped ?1 integrin overcame the reduction in MMP-2 activation induced by Col-1, confirming the ?1 integrin target specificity. MMP-2 activation induced by TPA or Concanavalin A (Con A) was not inhibited by ?1 integrin siRNA knockdown. Conclusion Together, the data reveals that strong abrogation of ?1 integrin is required to block MMP-2 activation induced by Col I, which may have implications for the therapeutic targeting of ?1 integrin.

Simulation of pesticide behavior in a paddy block by a pesticide fate and transport model

A simulation model (PCPF-B) was developed based on the PCPF-1 model to predict the runoff of pesticides from paddy plots to a drainage canal in a paddy block. The block-scale model now comprises three modules: (1) a module for pesticide application, (2) a module for pesticide behavior in paddy fields, and (3) a module for pesticide concentration in the drainage canal. The PCPF-B model was first evaluated by published data in a single plot and then was applied to predict the concentration of bensulfuron-methyl in one paddy block in the Sakura river basin, Ibaraki, Japan, where a detailed field survey was conducted. The PCPF-B model simulated well the behavior of bensulfuron-methyl in individual paddy plots. It also reflected the runoff pattern of bensulfuron-methyl at the block outlet, although overestimation of bensulfuronmethyl concentrations occurred due to uncertainty in water balance estimation. Application of water management practice such as water-holding period and seepage control also affected the performance of the model. A probabilistic approach may be necessary for a comprehensive risk assessment in large-scale paddy areas.

Solid fuel block as an alternate fuel for cooking and barbecuing: Preliminary result

A large part of the rural people of developing countries use traditional biomass stoves to meet their cooking and heating energy demands. These stoves possess very low thermal efficiency; besides, most of them cannot handle agricultural wastes. Thus, there is a need to develop an alternate cooking contrivance which is simple, efficient and can handle a range of biomass including agricultural wastes. In this reported work, a highly densified solid fuel block using a range of low cost agro residues has been developed to meet the cooking and heating needs. A strategy was adopted to determine the best suitable raw materials, which was optimized in terms of cost and performance. Several experiments were conducted using solid fuel block which was manufactured using various raw materials in different proportions; it was found that fuel block composed of 40% biomass, 40% charcoal powder, 15% binder and 5% oxidizer fulfilled the requirement. Based on this finding, fuel blocks of two different configurations viz. cylindrical shape with single and multi-holes (3, 6, 9 and 13) were constructed and its performance was evaluated. For instance, the 13 hole solid fuel block met the requirement of domestic cooking; the mean thermal power was 1.6 kWth with a burn time of 1.5 h. Furthermore, the maximum thermal efficiency recorded for this particular design was 58%. Whereas, the power level of single hole solid fuel block was found to be lower but adequate for barbecue cooking application.

“We live in in a house of blo- in a block of flats.” – Self-repair in EFL Spoken Language

Tämä tutkielma on osa Helsingin yliopiston rahoittamaa HY-talk -tutkimusprojektia, jonka tavoite on vankentaa puheviestinnän, erityisesti vieraiden kielten suullisen taidon opetusta ja arviointia yleissivistävässä koulutuksessa ja korkeakouluasteella. Tämän tutkielman tavoite on selvittää millaisia korjauksia englantia vieraana kielenä puhuvat ihmiset tekevät puheeseensa ja tutkia itsekorjauksen ja sujuvuuden välistä suhdetta. Korjausjäsennystä ja itsekorjausta on aiemmin tutkittu sekä keskustelunanalyysin että psykolingvistiikan aloilla, ja vaikka tämä tutkielma onkin lähempänä aiempaa keskustelunanalyyttistä kuin psykolingvististä tutkimusta, siinä hyödynnetään molempia suuntauksia. Itsekorjausta on yleisesti pidetty merkkinä erityisesti ei-natiivien kielenpuhujien sujuvuuden puutteesta. Tämän tutkielman tarkoitus on selvittää, kuinka läheisesti itsekorjaus todella liittyy sujuvuuteen tai sen puutteeseen. Tutkielman materiaali koostuu HY-talk -projektia varten kerätyistä puhenäytteistä ja niiden pohjalta tehdyistä taitotasoarvioinneista. Puhenäytteet kerättiin vuonna 2007 projektia varten järjestettyjen puhekielen testaustilanteiden yhteydessä kolmessa eteläsuomalaisessa koulussa. Koska projektin tavoitteena on tutkia ja parantaa kielten suullisen taidon arviointia, projektissa mukana olleet kieliammattilaiset arvioivat puhujien taitotasot projektia varten (Eurooppalaisen Viitekehyksen taitotasokuvainten pohjalta) koottujen arviointiasteikoiden perusteella, ja nämä arvioinnit tallennettiin osaksi projektin materiaalia. Tutkielmassa analysoidaan itsekorjauksia aiemman psykolingvistisen tutkimuksen pohjalta kootun korjaustyyppiluokituksen sekä tätä tutkielmaa varten luodun korjausten oikeellisuutta vertailevan luokituksen avulla. Lisäksi siinä vertaillaan kahden korkeamman ja kahden matalamman taitotasoarvioinnin saaneen puhujan itsekorjauksia. Tulokset osoittavat, että ei-natiivien puheessa esiintyy monenlaisia eri korjaustyyppejä, ja että yleisimpiä korjauksia ovat alkuperäisen lausuman toistot. Yleisiä ovat myös korjaukset, joissa puhuja korjaa virheen tai keskeyttää puheensa ja aloittaa kokonaan uuden lausuman. Lisäksi tuloksista käy ilmi, ettei suurin osa korjauksista todennäköisesti johdu puhujien sujuvuuden puutteesta. Yleisimmät korjaustyypit voivat johtua suurimmaksi osaksi yksilön puhetyylistä, siitä, että puhuja hakee jotain tiettyä sanaa tai ilmausta mielessään tai siitä, että puhuja korjaa puheessaan huomaamansa kieliopillisen, sanastollisen tai äänteellisen virheen. Vertailu korkeammalle ja matalammalle taitotasolle arvioitujen puhujien välillä osoittaa selkeimmin, ettei suurin osa itsekorjauksista ole yhteydessä puhujan sujuvuuteen. Vertailusta käy ilmi, ettei pelkkä itsekorjausten määrä kerro kuinka sujuvasti puhuja käyttää kieltä, sillä toinen korkeammalle taitotasolle arvioiduista puhujista korjaa puhettaan lähes yhtä monesti kuin matalammalle tasolle arvioidut puhujat. Lisäksi korjausten oikeellisuutta vertailevan luokituksen tulokset viittaavat siihen, etteivät niin korkeammalle kuin matalammallekaan tasolle arvioidut puhujat useimmiten korjaa puhettaan siksi, etteivät pystyisi ilmaisemaan viestiään oikein ja ymmärrettävästi.

Block works

A retail precinct along James Street in Brisbane is made more permeable by Richards and Spence.

Using children's picture books and process drama to develop students' critical literacy responses

This workshop introduces a range of process drama activities to develop students' critical literacy responses. Whilst children's picture books and process drama strategies have not traditionally been seen as sophisticated resources and strategies for developing students' critical literacy responses, this workshop shows teaching strategies that can be used in language instruction in primary classrooms with diverse student groups. The teaching activities include ‘attribute lists’, ‘sculptures’ and ‘freeze frames’.

Using children's picture books to develop students' critical literacy responses

This lecture introduces a range of children's picture books from around the world and teaching strategies that develop students' critical literacy responses. Whilst children's picture books have not traditionally been seen as sophisticated resources for developing students' critical literacy responses, this lecture presents research that shows young children as code breakers, text participants, text users and text analysts (Luke & Freebody, 1999) of written, visual, oral and gestural texts. This lecture also outlines the teaching strategies as they have been used in language instruction in primary classrooms with diverse student groups.

On a Two-Dimensional Problem in the End-Block Design of Post-Tensioned Prestressed Concrete Beams

Abstract is not available.

Halftone printing block portrait of Werner Cahnman Portraits

This block was used in the printing of "Who's Who in American Education"

Halftone printing block portrait of Gisella Levi Cahnman Portraits

This block was used in the printing of "Who's Who in American Education"

Evaluation of exclusion netting for insect pest control and fruit quality enhancement in tree crops

This work evaluated the following aspects of the use of exclusion netting in low chill stone fruit: the efficacy of protection from fruit fly for this highly susceptible crop; the effects on environmental factors; and the effects on crop development. Concurrently, an economic viability study on the use of exclusion netting was undertaken. The trial site was a 0.6-ha block of low chill stone fruit at Nambour, south-east Queensland, Australia. In this area, populations of Queensland fruit fly (Bactrocera tryoni) are known to be substantial, particularly in spring and summer. The trial block contained healthy 4-year-old trees as follows: 96 peach trees (Prunus persica cv. Flordaprince) and 80 nectarine trees (40 P. persica var. nucipersica cv. White Satin and 40 P. persica var. nucipersica cv. Sunwright). Exclusion netting was installed over approximately half of the block in february 2001. The net was a UV-stabilized structural knitted fabric made from high-density polyethylene yarn with a 10-year prorated UV degradation warranty. The results demonstrated the efficacy of exclusion netting in the control of fruit flies. Exclusion netting increased maximum temperatures by 4.4 deg C and decreased minimum temperatures by 0.5 deg C. Although exclusion netting reduced irradiance by approximately 20%, it enhanced fruit development by 7-10 days and improved fruit quality by increasing sugar concentration by 20-30% and colour intensity by 20%.