Characterisation

The Iliad is the story of Achilles’ journey through anger. Over the epic, Achilles undergoes a continual process of transformation, and as he does, the world changes around him. His anger unleashes the fiery beast of war and creates a spectacle of destruction. However, as Achilles awakens to the immense personal and social cost of his anger, the spectacle begins to transform. In place of rage, compassion and humanity come forth and the fires of war are replaced by the cathartic flames of the hearth and the funeral pyre. In this thesis I chart this journey by analysing Achilles’ communicative acts: his use of speech and action, across the epic. Through examining his communication and the ways in which others communicate with him, subtle but important changes are revealed. These changes in communication reflect the transformation that takes place within Achilles and are instrumental in generating change in the world around him. My interpretation of Achilles’ use of speech draws on insights from contemporary cognitive psychology, especially the work of Martin Seligman. My work on communication is also influenced by a range of contemporary strategic studies theorists who consider a wide range of non-verbal acts that have an important communicative function, including gestural and performative acts of violence. In charting Achilles’ transformation, we also gain a glimpse into the poet’s view of the elemental and personal dynamics that lie behind the creation of war and peace. Whilst a necessary part of the mortal condition, conflict, suffering and death are shown to hold within them the vital forces of change, and to reveal the nature of humanity itself.

In view of the increasing littering of the river banks by shells of crustaceans, a study was carried out to investigate the extraction and characterization of chitin and chitosan from mussel shell. Chitin and chitosan was extracted and characterized from mussel shell found in banks of the Gubi Dam in Bauchi, Nigeria using the conventional methods of pretreatment, demineralization, deprotienization and deacetylation. The results obtained revealed that carbon nitrogen ratio of the chitosan extracted was 5.9 with a degree of deacetylation of 60.69% and 60.66% calculated from the elemental analysis and the FTIR spectra of chitosan respectively. The FTIR spectra for chitosan gave a characteristic-NH 2 band of 3447 cm-1 and a carbonyl group band of 1477 cm-1. The mussel shell was discovered to contain a mineral content of 51.62% and a chitin composition was found to be 21.32%.

The exceptional progress made in orthopaedic and dental applications have increased the demand of calcium phosphate bioceramics due to their chemical similarities to the inorganic component of hard tissues. Low cost production of calcium phosphate bioceramics could be achieved by using pure natural biogenic materials by relatively simple methods. In this study calcium phosphate powders were produced from ostrich (Struthio camelus) eggshell powder at a moderate temperature of 80oC by relatively simple process of low temperature heating by hot plate (HP) and hot platting while agitation with ultrasonication (HPUS) hence introducing mechanical activation. The product structure and compositions were studied with FTIR, SEM, DTA/TCA, XRD and ICP techniques. The results showed that calcium deficient hydroxyapatite and dicalcium phosphate were obtained from HP and HPUS methods. Poorly crystalline calcium deficient hydroxyapatite was converted into whilockite after calcining at 800oC. The re...

Dynamic properties of materials such as aramid and polyethylene fiber reinforced composites are rarely found in the literature, in spite of their significance in ballistic design. It is also difficult to find detailed descriptions of the testing techniques and procedures to characterize these materials. This paper describes a dynamic tensile testing technique for these composite materials, and discusses problems such as the specimen size and the clamping system. A full numerical simulation is performed in Autodyn-2D to elucidate what is happening during the experiment. Finally this testing technique is applied to show that reliable data can be obtained from the Hopkinson bar for aramid and polyethylene fiber reinforced composites. Stress-strain, stress versus rate of strain and strain versus rate of strain curves are included. The results indicate that for these materials the tensile strength rises with the strain rate while the maximum strain diminishes in the range studied.

This dissertation aims to offer an analysis of the linguistic construction of the
television character Piper Chapman, the protagonist of the running series Orange is the new black (Netflix, 2013-). Such a study will explore the way in which dialogue, the
main means of characterisation in television discourse, projects particular social
identities falling back on shared stereotypes with the audience. Explicit and implicit
cues will be examined in Piper's and others' dialogue to verify how Piper's character is
extracted from the stereotypes of WASP/yuppie in order to ease the audience's
recognition. The approach to this character will be carried out through a computer
analysis of dialogue (using concordances and keyword analysis) in the first season of
Orange is the new black. Furthermore, this will be complemented with a scene-based
analysis drawing on (im)politeness theory, which provides implicit cues to Piper's
identity. Such an analysis will explain how Piper is designed in contrast to other social
identities in the series relying on race and social class. Finally, this research has
implications for the study of television characters as part of a constructed text and,
therefore, as the carriers of the ideological content. Taking the case of Piper as an
example, this dissertation will speculate about the importance of her role as protagonist, relying on her creator's description of her as a “Trojan Horse”, an excuse to make the spectator aware of the stories of marginalised women in the media.

Thomas appears four times within the narrative framework of the Fourth Gospel (11:16; 14:5; 20:24-28; 21:2). His presence in the Gospel introduces some of the strategic transitions within the macro-narrative structure. The following are some of the crucial moments that are introduced through the entry of Thomas: first, Thomas’ character is brought to the foreground toward the end of Jesus’ public ministry, where a transition is underway through Lazarus’ death and raising to Jesus’ death and resurrection (11:16); second, he appears as a significant interlocutor engaged in dialogue so that Jesus’ identity as “the way, the truth, and the life” may be revealed to the disciples during his private ministry (14:5-6); third, Thomas’ character appears toward the climax of the Book of Glory as he is instrumental in revealing the identity of Jesus as “Lord” and “God” (20:24-29); and fourth, he appears as one of the seven disciples during the post-resurrection context in Galilee (21:2). The unique placement of Thomas communicates something significant about the character and his development within the narrative.

This paper reviews the utilization of acid tars with the overall aim of reducing or eradicating the environmental problems associated with acid tar landfill disposal at a local crude benzol refinery in Zimbabwe .The review focused on disposal, characterization, composition and utilization of acid tars. Peer reviewed journal and conference papers from 1980 to the current year were considered. The papers reviewed were mainly from petroleum processing since the acidic nature of the tar can be assumed to be similar to that of crude benzol processing and the databases used were Science direct, Hinari and Agora .The effects of the disposal of acid tar in lagoon were reviewed. The utilisation of acid tar waste is dependent on the chemical composition hence work on the characterization of acid tars was reviewed. The use G.C-MS was common in the characterization of acid tars as compared to other analytical techniques. Some of the utilization processes which were reviewed included among others the conversion of acid tar to asphaltenes, production of pavement binders, energy utilisation, acid tar co-processing, membrane technology, ion exchangers and carbon adsorbents technique. The utilization of acid tar waste hinges on effective treatment methods owing to its complex chemical composition.

Gyermekkép és oktatás Japánban konferencia


A konferencia időpontja: 2017. október 13. péntek 9.00 – 14. 00
A konferencia helyszíne: 1126 Budapest, Kiss János altábornagy utca 40.

A konferencia fővédnöke: Őexellenciája Kosuge Junichi Japán nagykövet



ABSZTRAKT

CÍM:
NARUTO -ナルト-: A magas- és a populáris kultúra örvénye

* [Tekintettel a japánul nem beszélőkre:] A naruto örvényt (is) jelent japánul.

** „NARUTO -ナルト-” a hivatalos termékmegnevezés; ezért a stilizálás.

KULCSSZAVAK:
populáris kultúra; kiterjesztett kommunikáció; karakterizáció
 


KIVONAT: [300 SZÓ]
Manapság egyre nagyobb igény jelentkezik az alternatívákra; így van ez az oktatásban és a kutatásokban is. Nem meglepő ez a tény, hiszen az utóbbi évtizedekben a technika és a kommunikáció nagyobb léptékben változott, mint ahogyan azt követni tudnánk.
Ettől függetlenül a digitális és az információs kor szülöttei és neveltjei számára továbbra is szükséges releváns témákat és adekvát módszertant nyújtani. A megvalósítást nehezítő körülmény, hogy máig a konvencionális megközelítések és témák vannak fölényben, s csak elvétve találni olyan kezdeményezést, amely ezen kereteken kívül merészkedik. Olyan mintha a ma problémáira a tegnap megoldásait igyekeznénk ráerőltetni.
Jelen kutatás egy páratlan, új paradigmát képvisel: A kiterjesztett kommunikáció rendszerében, egy popkulturális produktumon, a NARUTO franchise-on (manga, anime, videójáték) keresztül bizonyítjuk be, hogy a tömegkultúra is lehet magas, mi több, hasznos forrás lehet az oktatás és a tudomány területén is.
Az elemzés fókusza az érték- és kultúra-reprezentáció (művészet, vallás, folklór, történelem és jelenkor, társadalom és politika, erkölcs, emberi viszonyok, nyelvi sztereotípiák); járulékos tényezők a kommunikáció (alap- és meta-dimenzió), a nyelvhasználat (szerepnyelvezet 役割語, genderjelölők, zárópartikulák) és a lokalizáció (fordítás, marketing).
A tárgyalt produktum világviszonylatban tekintve is egyedülálló, mert a „ma” pénz-orientált világában megkövetelt magas (globális) eladási ráták, és a médiumból fakadó „kötelező” szórakoztatás mellett, értékeket mutat fel — nemcsak a japánok számára, hanem minden emberre nézve.
A tézisünk, hogy (i.) a mindennapokban használt médiumok is képesek értéket képviselni, valamint (inter)kulturális élményt nyújtani; (ii.) a készítők az integrált tartalmakat a karakterizáció révén teszik fogyaszthatóvá.
Jelen kutatás olyan egyedi témákat (virtuális kultúraközi kommunikáció), teóriákat (kiterjesztett kommunikáció, kommunikáció-attribútumok, szerepnyelvezet) és eredményeket (karakterizáció, marketing) mutat fel, amelyekkel általában sem az oktatás során, sem a tudományban nem találkozni.
A kutatásban bemutatott paradigma gyakorlat-orientált, komplex összefüggésrendszert és módszertant nyújt korunk kihívásaira, ugyanakkor a valóságra reflektált, mélyebb megértést kínál a (populáris) kultúra, a kommunikáció és a nyelv terén — bárki által értelmezhető módon.




*** Helyesírási probléma vetődhet fel a ’meta-dimenzió’ kapcsán: Ennek oka, hogy nem a hagyományos értelemben vett ’metakommunikáció’-t értek a terminuson, hanem a saját teóriámban értelmezett ’meta-kommunikációt’ — ezért szükséges a megkülönböztetés.

**** Ezen megjegyzések nem az absztrakt részei, csupán a bírálóknak/szerkesztőknek készültek.

This study exploited the computation accuracy of governing equations of linearly or periodically behaves dynamic system with fourth and fifth order Runge-Kutta algorithms to develop chaos diagrams of harmonically excited Duffing oscillator. The study adopt the fall to tolerance of absolute deviation between two independently sought solutions of governing equation to characterise excitation frequencies and amplitude parameter point of Duffing oscillator as either chaotic or not. Displacement and Velocity time history, Phase plot and Poincare were used to validate FORTRAN coded programmes used for this study and chaos diagrams developed at two different damping coefficients. The validation results agreed perfectly with those obtained in the literature. The chaos diagrams predicted by computation at two different damp coefficient levels conforms generally in trend to literature results by and qualitatively the same for three different combination of constant time based Runge-Kutta algorithms. The chances of chaotic behaviour of Duffing oscillator under the combined driven force of parameters becomes more than double at 0.0168 damping coefficient when compared with corresponding results at 0.168 damping coefficient. The probability that selected excitation frequencies and amplitudes will drive Duffing oscillator chaotically at 0.168 damp coefficients is 29.4%, 27.8% and 29.4% respectively. This study demonstrated the significant utility of numerical techniques in dealing with real-world problems that are dominantly nonlinear and shows that in addition to being sensitive to initial conditions, chaos is equally sensitivity to appropriate simulation time steps. In addition, the present chaos diagram generating numerical tool is uniquely characterised by being faster and predicting reliably than that earlier reported by the authors.

Kivonat:
A jelen írásban tárgyalt popkulturális produktumok, illetőleg
médiumok megjelenése a digitális korszak paradigmaváltásának
természetes hozadéka, amelyeket nemcsak érdekes vizsgálni, hanem
egyenest a kutatási palettára szükséges venni, hiszen a populáció
túlnyomó részének meghatározzák a mindennapjait – egyelőre
reflektálatlanul, ugyanis sem a tudománynak, sem az oktatásnak nem
fókusza a popkultúra, a virtuális kommunikáció kutatása,
implementálása. Jelen kutatás célja, hogy kiderítse, hogyan
kommunikál egy fiktív kommunikátorcsoport, esetünkben a
Pokemonok. A feldolgozás módszertana a szerző
kiterjesztettkommunikáció-elméletén és a karakterteóriáján alapul,
annak okán, hogy a tudomány hagyományos módszerei nem adekvátak.
A több mint húszéves Pokemon-franchise sikerét többnyire a
karakterizáció jelenségében látjuk: valamennyi Pokemon karakteres a
vizuális, az auditív, a nyelvi és a nem nyelvi reprezentációjában is. A
vizsgálat elsősorban az anime hagyományos kommunikációjára
fókuszál, lévén ez a leggazdagabb – szemben a videojátékokkal és a
mangával. Az elemzésből kiderül, hogy a Pokemon és a
Pokemon-nyelv, azaz a Pokemon-karakterlektus esszenciája a karakter,
ugyanis prototipikus karakterjelölők útján kommunikálnak.

TAG: Kaba Ariel Pokemon

Tepetate formations are generally found in regions where climate presents a very well-defined dry season. The original materials are basically pyroclastic projections under rain or flood shapes. Tepetates are indurated earthy materials from Mexico that have been reported with different names in different countries. These materials have been subject of investigation by very different areas such as geology and edaphology related to their origin, constitution, minerals and location, and also to the agronomy focusing in its improvement and incorporation as a fertile soil. This material has also been used as an earthen structure like embankments for pavements and residential flooring and as a substitution material for problematic soil such as the expansive clays without serious studies that validate its behaviour. In this article, there appears a research work of the behaviour of the tepetates as earthen structures. We concluded that those methodologies in this study create a new material completely different from the original (indurated). Moreover, the types of cement in the tepetates have different behaviours. The lack of tepetate characterisation in the mentioned applications is contributing to create an image of a relatively homogeneous material, which can occasionally be the case but is not a generality.

Jelen előadás célja, hogy elméletet és eszköztárat adjon a ma kommunikációjának teljeskörű vizsgálatára. A digitális korszak paradigmaváltása nemcsak a digitális kommunikációt és az „újmédiát” hozta el a mának, hanem a virtuális kommunikáció (vk) térnyerését is.
A vk (reklám, zene, film, TV-show, YouTube, social media, videójáték, manga, anime) meghatározza a hétköznapjainkat, valamint új kihívások elé állítja az oktatást és a tudományt egyaránt.
Kiterjesztett kommunikáció néven egy új kommunikáció-paradigmát vezetünk be, amely a kommunikáció egészét képes értelmezni. A vizsgálat (i.) a kommunikáció meta-dimenziójára, a kommunikáció-attribútumokra fókuszál; (ii.) a Nyugat és a Kelet popkulturális produktumait egyaránt felöleli.
A kutatás hozzájárul a kiterjesztett kommunikatív kompetencia fejlesztéséhez: mély megértést kínál, s tudatosságot ad.

The study was conducted in 2011 at Hamamavhaire and Mhende irrigation schemes in Chirumanzu district in Zimbabwe to determine the typology of the farmers using different irrigation technologies. A structured household survey was carried out on a sample of 79 respondents drawn from farmers using the sprinkler (n=32), flood (n=39) and drip (n=8) irrigation systems. The information gathered was analysed and interpreted using descriptive statistics and inferential statistics in the form of the chi-square test and Analysis of Variance (ANOVA). The main findings showed that there are significant differences (P < 0.05) in yield per hectare (for green maize, maize-grain, wheat and sugar-beans) across the three irrigation systems. Farmers using sprinkler irrigation were found to be better-off in terms of livestock ownership and household assets compared to those using drip and flood irrigation. The study recommended that there is need to provide agricultural training to farmers in irrigat...

Dielectrophoresis (DEP) has been used for many years for the analysis of the electrophysiological properties of cells. However, such analyses have in the past been timeconsuming, such that it can take 30 min or more to collect sufficient data to make valid interpretations from a single DEP spectrum. This has limited the application of the technology to a rapid tool for non-invasive, label-free research in areas from drug discovery to diagnostics. In this paper we present the development of a programmable, multi-channel DEP system for rapid biophysical assessment of populations of biological cells. A new assay format has been developed for continuous near-real-time monitoring, using simultaneous application of up to eight alternating current electrical signals to independently addressable dot microelectrodes in an array format, allowing a DEP spectrum to be measured in 20 s, with a total cycle time between measurements of 90 s. To demonstrate the system, human leukaemic K562 cells were monitored after exposure to staurosporine and valinomycin. The DEP response curves showed the timing and manner in which the membrane properties changed for the actions of these two drugs at the early phase of induction. This technology shows the great potential for increasing our understanding of the role of electrophysiology in drug action, by observing the changes in electrical characteristics as they occur.

Using a semiempirical rule based on a range of existing hard materials, Liu and Cohen predicted that some of the crystalline forms of C3N4 might have values of bulk modulus close to, or even greater than, that of diamond. Subsequent theoretical work has supported this result, although modifying which of the crystal structures had the most extreme properties. Based on the assumption that hardness is primarily determined by the bulk modulus, a large number of groups initiated research to try to make this ‘harder-than-diamond’ material. Although today there are doubts as to the validity of this assumption, the ability to synthesise materials with such a large bulk modulus is of great interest because such substances can be expected to have extreme properties, such as thermal conductivity, compression strength, acoustic velocity, etc. A review is presented of the methods used, and the results obtained, by a variety of groups in their attempts to prepare carbon nitride films. The preparation techniques have been somewhat arbitrarily divided into the following sections: (1) atmospheric-pressure chemical processes, including pyrolysis and explosive shock; (2) ion-beam deposition, including cathode arc; (3) laser techniques; (4) chemical vapour deposition processes, including direct-current (DC) arc, hot-filament chemical vapour deposition (HFCVD) and plasma-enhanced chemical vapour deposition (PECVD); and (5) reactive sputtering, with and without deliberate substrate biasing. We have also included a section describing some of the problems associated with the analysis of carbon nitride films. A brief description of the techniques is provided and we discuss some of the problems associated with the characterisation methods that have been used in the analysis of the deposited material. A somewhat speculative set of conclusions is presented which we hope will be of assistance to colleagues working in this field.

Using a semiempirical rule based on a range of existing hard materials, Liu and Cohen predicted that some of the crystalline forms of C 3 N 4 might have values of bulk modulus close to, or even greater than, that of diamond. Subsequent theoretical work has supported this result, although modifying which of the crystal structures had the most extreme properties. Based on the assumption that hardness is primarily determined by the bulk modulus, a large number of groups initiated research to try to make this 'harder-than-diamond' material. Although today there are doubts as to the validity of this assumption, the ability to synthesise materials with such a large bulk modulus is of great interest because such substances can be expected to have extreme properties, such as thermal conductivity, compression strength, acoustic velocity, etc. A review is presented of the methods used, and the results obtained, by a variety of groups in their attempts to prepare carbon nitride films. The preparation techniques have been somewhat arbitrarily divided into the following sections: (1) atmospheric-pressure chemical processes, including pyrolysis and explosive shock; (2) ion-beam deposition, including cathode arc; (3) laser techniques; (4) chemical vapour deposition processes, including direct-current (DC ) arc, hot-filament chemical vapour deposition (HFCVD) and plasma-enhanced chemical vapour deposition (PECVD); and (5) reactive sputtering, with and without deliberate substrate biasing. We have also included a section describing some of the problems associated with the analysis of carbon nitride films. A brief description of the techniques is provided and we discuss some of the problems associated with the characterisation methods that have been used in the analysis of the deposited material. A somewhat speculative set of conclusions is presented which we hope will be of assistance to colleagues working in this field.

Celtis mildbraedii sawdust (CMS) from Ghana was characterised to investigate its suitability with polyethylene terephthalate (PET) for syngas production via co-pyrolysis. The physical and chemical properties assessed include proximate and ultimate compositions, pH value, higher heating value (HHV), and lignocellulosic composition. Also, the thermal behaviour at different heating rates (5, 10, and 20 K/min) and qualitative prediction of organic compounds of CMS were examined using thermogravimetric analysis (TG/DTG) and NIR spectroscopy techniques, respectively. Results of proximate analysis (moisture = 17.15 ± 0.0 wt.%, ash = 1.13 ± 0.4 wt.%, volatile matter = 68.39 ± 0.4 wt.%, fixed carbon = 13.33 ± 0.8 wt.%); ultimate analysis (C = 48.51 wt.%, H = 6.66 wt.%, N = 0.51 wt.%, S = 0.02 wt.%, O = 44.30 wt.%); pH values (cold phase = 7.60, hot phase = 6.30); HHV (15.37-18.03 MJ/kg); and lignocellulosic composition (extractives = 13.80 ± 0.57 wt.%, hemicellulose = 21.95 ± 3.89 wt.%, lignin = 17.35 ± 0.35 wt.%, cellulose = 46.90 ± 2.97 wt.%) were obtained. The maximum mass loss was 83.48% at 289.8 °C at 5 K/min. It was concluded that CMS is a highly potential biomass resource for syngas production with an empirical formula of CH 1.64 O 0.69 N 0.009 S 0.0 0 01 .

The development of new reverse osmosis (RO) membranes with enhanced performance would benefit from a detailed knowledge of the membrane structures which participate in the filtration process. Here, we examined the hierarchical structures of the polyamide (PA) active layer of the SW30HR RO membrane. Scanning electron microscopy combined with focused ion beam milling (FIB-SEM) was used to obtain the 3-D reconstructions of membrane morphology with 5 nm cross-sectional resolution (comparable with the resolution of low magnification TEM imaging in 2D) and 30 nm slice thickness. The complex folding of the PA layer was examined in 3 dimensions, enabling the quantification of key structural properties of the PA layer, including the local thickness, volume, surface area and their derivatives. The PA layer was found to exhibit a much higher and convoluted surface area than that estimated via atomic force microscopy (AFM). Cross-sectional scanning transmission electron microscopy (STEM) was used to observe the distribution of a tracer stain under various conditions. The behaviour of stain in dry and wet PA indicated that the permeation pathways have a dynamic nature and are activated by water. High resolution STEM imaging of the stained PA nano-films revealed the presence of <1nm pore-like structures with a size compatible with free volume estimations by positron annihilation lifetime spectroscopy (PALS). This study presents a comprehensive map of the active PA layer across different length scales (from micro-to sub-nanometer) and mechanistic insight into their role in the permeation process.

In view of the increasing littering of the river banks by shells of crustaceans, a study was carried out to investigate the extraction and characterization of chitin and chitosan from mussel shell. Chitin and chitosan was extracted and characterized from mussel shell found in banks of the Gubi Dam in Bauchi, Nigeria using the conventional methods of pretreatment, demineralization, deprotienization and deacetylation. The results obtained revealed that carbon nitrogen ratio of the chitosan extracted was 5.9 with a degree of deacetylation of 60.69% and 60.66% calculated from the elemental analysis and the FTIR spectra of chitosan respectively. The FTIR spectra for chitosan gave a characteristic-NH 2 band of 3447 cm-1 and a carbonyl group band of 1477 cm-1. The mussel shell was discovered to contain a mineral content of 51.62% and a chitin composition was found to be 21.32%.

Using a semiempirical rule based on a range of existing hard materials, Liu and Cohen predicted that some of the crystalline forms of C 3 N 4 might have values of bulk modulus close to, or even greater than, that of diamond. Subsequent theoretical work has supported this result, although modifying which of the crystal structures had the most extreme properties. Based on the assumption that hardness is primarily determined by the bulk modulus, a large number of groups initiated research to try to make this 'harder-than-diamond' material. Although today there are doubts as to the validity of this assumption, the ability to synthesise materials with such a large bulk modulus is of great interest because such substances can be expected to have extreme properties, such as thermal conductivity, compression strength, acoustic velocity, etc. A review is presented of the methods used, and the results obtained, by a variety of groups in their attempts to prepare carbon nitride films. The preparation techniques have been somewhat arbitrarily divided into the following sections: (1) atmospheric-pressure chemical processes, including pyrolysis and explosive shock; (2) ion-beam deposition, including cathode arc; (3) laser techniques; (4) chemical vapour deposition processes, including direct-current (DC ) arc, hot-filament chemical vapour deposition (HFCVD) and plasma-enhanced chemical vapour deposition (PECVD); and (5) reactive sputtering, with and without deliberate substrate biasing. We have also included a section describing some of the problems associated with the analysis of carbon nitride films. A brief description of the techniques is provided and we discuss some of the problems associated with the characterisation methods that have been used in the analysis of the deposited material. A somewhat speculative set of conclusions is presented which we hope will be of assistance to colleagues working in this field.

Dielectrophoresis (DEP) has been used for many years for the analysis of the electrophysiological properties of cells. However, such analyses have in the past been timeconsuming, such that it can take 30 min or more to collect sufficient data to make valid interpretations from a single DEP spectrum. This has limited the application of the technology to a rapid tool for non-invasive, label-free research in areas from drug discovery to diagnostics. In this paper we present the development of a programmable, multi-channel DEP system for rapid biophysical assessment of populations of biological cells. A new assay format has been developed for continuous near-real-time monitoring, using simultaneous application of up to eight alternating current electrical signals to independently addressable dot microelectrodes in an array format, allowing a DEP spectrum to be measured in 20 s, with a total cycle time between measurements of 90 s. To demonstrate the system, human leukaemic K562 cells were monitored after exposure to staurosporine and valinomycin. The DEP response curves showed the timing and manner in which the membrane properties changed for the actions of these two drugs at the early phase of induction. This technology shows the great potential for increasing our understanding of the role of electrophysiology in drug action, by observing the changes in electrical characteristics as they occur.

This work investigates the thermal, mechanical and chemical characteristics of sorghum stalks rind. Sorghum stalks have been divided into three equal regions: bottom, middle, and top. The thermal degradation behaviour has been studied using static and dynamic thermogravimetric analysis. The results of this study show that it is not recommended to subject the fibres to elevated temperatures (>200°C) for time periods exceeding 10 min. The highest tensile strength of 280 MPa was found at the middle region of the sorghum stalk. However, based on practical and economic aspects, the use of the complete stalk is recommended, since variations are minor. Microscopic investigation has been done for the sorghum stalk using optical microscope to relate mechanical properties to structural appearance.

Faecal samples of two Mexican breast-fed infants were used to isolate a Bifidobacterium strain in a selective medium. This strain was characterised biochemically for carbohydrate fermentation patterns and the fructose-6-phosphate phosphoketolase assay; genetically it was identified by PCR using genus-specific primers. The isolated strain was named Bifidobacterium JCLA3 and was grown on four different carbon sources; the respective growth kinetics of glucose, lactose, inulin and sucrose were measured. The highest cellular yield was presented in the culture media containing sucrose, followed by inulin, while on glucose and lactose, the cellular yield was lowest; these results correlate with the characteristic that bifidobacteria prefer complex carbon sources. We also determined the expression of the ack and ldh genes. The ldh gene presented high levels of expression regarding the ack gene; nevertheless on sucrose, the expression was lower regarding the other three substrates. The highest expression level of the ack gene was from the culture media with glucose, followed by inulin, sucrose and lactose.