A constraint Jacobian based approach for static analysis of pantograph masts

This paper presents a constraint Jacobian matrix based approach to obtain the stiffness matrix of widely used deployable pantograph masts with scissor-like elements (SLE). The stiffness matrix is obtained in symbolic form and the results obtained agree with those obtained with the force and displacement methods available in literature. Additional advantages of this approach are that the mobility of a mast can be evaluated, redundant links and joints in the mast can be identified and practical masts with revolute joints can be analysed. Simulations for a hexagonal mast and an assembly with four hexagonal masts is presented as illustrations.

Modelling heterogeneity of concrete using 2D lattice network for concrete fracture and comparison with AE study

In this paper, numerical modelling of fracture in concrete using two-dimensional lattice model is presented and also a few issues related to lattice modelling technique applicable to concrete fracture are reviewed. A comparison is made with acoustic emission (AE) events with the number of fractured elements. To implement the heterogeneity of the plain concrete, two methods namely, by generating grain structure of the concrete using Fuller's distribution and the concrete material properties are randomly distributed following Gaussian distribution are used. In the first method, the modelling of the concrete at meso level is carried out following the existing methods available in literature. The shape of the aggregates present in the concrete are assumed as perfect spheres and shape of the same in two-dimensional lattice network is circular. A three-point bend (TPB) specimen is tested in the experiment under crack mouth opening displacement (CMOD) control at a rate of 0.0004 mm/sec and the fracture process in the same TPB specimen is modelled using regular triangular 2D lattice network. Load versus crack mouth opening isplacement (CMOD) plots thus obtained by using both the methods are compared with experimental results. It was observed that the number of fractured elements increases near the peak load and beyond the peak load. That is once the crack starts to propagate. AE hits also increase rapidly beyond the peak load. It is compulsory here to mention that although the lattice modelling of concrete fracture used in this present study is very similar to those already available in literature, the present work brings out certain finer details which are not available explicitly in the earlier works.

Testing and Modeling of MR Damper and Its Application to SDOF Systems Using Integral Backstepping Technique

Magnetorheological dampers are intrinsically nonlinear devices, which make the modeling and design of a suitable control algorithm an interesting and challenging task. To evaluate the potential of magnetorheological (MR) dampers in control applications and to take full advantages of its unique features, a mathematical model to accurately reproduce its dynamic behavior has to be developed and then a proper control strategy has to be taken that is implementable and can fully utilize their capabilities as a semi-active control device. The present paper focuses on both the aspects. First, the paper reports the testing of a magnetorheological damper with an universal testing machine, for a set of frequency, amplitude, and current. A modified Bouc-Wen model considering the amplitude and input current dependence of the damper parameters has been proposed. It has been shown that the damper response can be satisfactorily predicted with this model. Second, a backstepping based nonlinear current monitoring of magnetorheological dampers for semi-active control of structures under earthquakes has been developed. It provides a stable nonlinear magnetorheological damper current monitoring directly based on system feedback such that current change in magnetorheological damper is gradual. Unlike other MR damper control techniques available in literature, the main advantage of the proposed technique lies in its current input prediction directly based on system feedback and smooth update of input current. Furthermore, while developing the proposed semi-active algorithm, the dynamics of the supplied and commanded current to the damper has been considered. The efficiency of the proposed technique has been shown taking a base isolated three story building under a set of seismic excitation. Comparison with widely used clipped-optimal strategy has also been shown.

The grumpy stump - ultrasound and stump appendicitis

BACKGROUND: Stump appendicitis, the inflammation of an incompletely removed appendix, is a rare clinical presentation. Sonography can be useful in the diagnosis of the condition; by either directly visualising the inflamed stump, or by identifying signs of peri-caecal inflammation that can raise suspicion of the condition. SUMMARY OF WORK: A potential case of stump appendicitis was identified. This prompted a review of literature focused on the incidence of stump appendicitis, utility of ultrasound to identify an inflamed appendiceal stump, and surgical techniques used in appendectomy. SUMMARY OF RESULTS: Stump appendicitis is rare, with as few as 61 cases identified in literature during the last 60 years1. Of the two common techniques of appendectomy, which are ligation and invagination, the former can sometimes leave a residual stump that acts as a potential lumen for the pathophysiological process of appendicitis to recur. Established sonographic criteria for appendicitis also apply to the residual stump. Sonographic secondary signs that suggest the presence of acute appendicitis2 have also been demonstrated in cases of stump appendicitis3, even in the absence of an identifiable stump. DISCUSSION AND CONCLUSIONS: Appendicitis is usually dismissed in patients with a history of appendectomy. Though uncommon, sonographers should be aware of stump appendicitis in post-appendectomy patients that present with right iliac fossa pain from months to decades later. REFERENCE(S) 1. Subramanian A, Liang MK. A 60-year literature review of stump appendicitis: The need for a critical view. Am J Surg; 2012;203(4):503–7. 2. Reddan T, Corness J, Mengersen K, Harden F. Ultrasound of paediatric appendicitis and its secondary sonographic signs: providing a more meaningful finding. J Med Radiat Sci. 2015;DOI: 10.1002/jmrs.154 3. Martínez Chamorro E, Merina Castilla A, Muñoz Fraile B, Koren Fernández L, Borruel Nacenta S. Stump appendicitis: Preoperative imaging findings in four cases. Abdom Imaging. 2013;38(6):1214–9.

Chromatographic separation, fractionation and oxidation of selected beta-lactoglobulin peptides

The literature review elucidates the mechanism of oxidation in proteins and amino acids and gives an overview of the detection and analysis of protein oxidation products as well as information about ?-lactoglobulin and studies carried out on modifications of this protein under certain conditions. The experimental research included the fractionation of the tryptic peptides of ?-lactoglobulin using preparative-HPLC-MS and monitoring the oxidation process of these peptides via reverse phase-HPLC-UV. Peptides chosen to be oxidized were selected with respect to their amino acid content which were susceptible to oxidation and fractionated according to their m/z values. These peptides were: IPAVFK (m/z 674), ALPMHIR (m/z 838), LIVTQTMK (m/z 934) and VLVLDTDYK (m/z 1066). Even though it was not possible to solely isolate the target peptides due to co-elution of various fractions, the percentages of target peptides in the samples were satisfactory to carry out the oxidation procedure. IPAVFK and VLVLDTDYK fractions were found to yield the oxidation products reviewed in literature, however, unoxidized peptides were still present in high amounts after 21 days of oxidation. The UV data at 260 and 280 nm enabled to monitor both the main peptides and the oxidation products due to the absorbance of aromatic side-chains these peptides possess. ALPMHIR and LIVTQTMK fractions were oxidatively consumed rapidly and oxidation products of these peptides were observed even on day 0. High rates of depletion of these peptides were acredited to the presence of His (H) and sulfur-containing side-chains of Met (M). In conclusion, selected peptides hold the potential to be utilized as marker peptides in ?-lactoglobulin oxidation.

Effect of relative density and confining pressure on Poisson ratio from bender and extender elements tests

By using the bender and extender elements tests, together with measurements of the travel times of shear (S) and primary (P) waves, the variation of Poisson ratio (nu) was determined for dry sands with respect to changes in relative densities and effective confining pressures (sigma(3)). The tests were performed for three different ranges of particle sizes. The magnitude of the Poisson ratio decreases invariably with an increase in both the relative density and the effective confining pressure. The effect of the confining pressure on the Poisson ratio was found to become relatively more significant for fine-grained sand as compared with the coarse-grained sand. For a given material, at a particular value of sigma(3), the magnitude of the Poisson ratio decreases, almost in a linear fashion, with an increase in the value of maximum shear modulus (G(max)). The two widely used correlations in literature, providing the relationships among G(max), void ratio (e) and effective confining pressure (sigma(3)), applicable for angular granular materials, were found to compare reasonably well with the present experimental data for the fine- and medium-grained sands. However, for the coarse-grained sand, these correlations tend to overestimate the values of G(max).

CREMOFAC- a database of chromatin remodeling factors

Motivation: Chromatin-remodeling is an important event in the eukaryotic nucleus rendering nucleosomal DNA accessible for various transaction processes. Remodeling Factors facilitate the dynamic nature of chromatin through participation of the collective action of (i) ATP and (ii) Non-ATP dependent factors. Considering the importance of these factors in eukaryotes, we have developed, CREMOFAC, a dedicated and frequently updated web-database for chromatin-remodeling factors.Results: The database harbors factors from 49 different organisms reported in literature and facilitates a comprehensive search for them. In addition, it also provides in-depth information for the factors reported in the three widely studied mammals namely, human, mouse and rat. Further, information on literature, pathways and phylogenetic relationships has also been covered. The development of CREMOFAC as a central repository for chromatin-remodeling factors and the absence of such a pre-existing database heighten its utility thus making its presence indispensable.

Bearing capacity of interfering multiple strip footings by using lower bound finite elements limit analysis

The ultimate bearing capacity of a number of multiple strip footings, identically spaced and equally loaded to failure at the same time,is computed by using the lower bound limit analysis in combination with finite elements. The efficiency factor due to the component of soil unit weight, is computed with respect to changes in the clear spacing (xi(gamma)) between the footings. It is noted that the failure load for a footing in the group becomes always greater than that of a single isolated footing. The values of xi(gamma) for the smooth footings are found to be always lower than the rough footings. The values ofxi(gamma) are found to increase continuously with a decrease in the spacing between footings. As compared to the available theoretical and experimental results reported in literature, the present analysis provides generally a little lower values of xi(gamma). (C) 2010 Elsevier Ltd. All rights reserved.

Jauheiden erottuminen

Partikkelisysteemien segregaatio eli erottuminen on ilmiö, jossa tasalaatuisen jauheseoksen komponenteilla on taipumus erota toisistaan. Jauheen erottumistaipumus riippuu partikkelien ominaisuuksista, ympäröivistä olosuhteista ja partikkelien välisistä vuorovaikutuksista. Segregaatiomekanismeja on esitetty kirjallisuudessa valtava määrä ja pienetkin erot partikkelien välisissä ominaisuuksissa ja vuorovaikutuksissa voivat johtaa täysin eri segregaatiomekanismeihin. Segregaatioilmiö on lääketeollisuuden näkökulmasta hyvin keskeinen, eikä sitä tunneta vielä riittävän hyvin, jotta siltä osattaisiin systemaattisesti välttyä. Nykyinen segregaatiotutkimus perustuu suurelta osin yrityksen ja erehdyksen kautta tapahtuvaan oppimiseen. Todellisen segregaatioilmiön ymmärtämiseen tarvittaisiin innovatiivisia tutkimusmenetelmiä. Kokeellisen osan tarkoituksena oli kehittää ja perustestata menetelmä, jolla voidaan tutkia erilaisten partikkelisysteemien erottumiskäyttäytymistä, ja käyttää tätä menetelmää farmaseuttisten rae- ja pellettiseosten segregaation tutkimiseen. Tavoitteena oli todistaa kehitetyn Babel-laitteen toimintaperiaatteen soveltuvuus partikkelisysteemien erottumiskäyttäytymisen tutkimiseen, mutta suoritetut kokeet olivat lähinnä menetelmän ja laitteen testausta. Ongelmiksi muodostuivat Babel-laitteen asettamat rajoitukset, partikkelien sähköistyminen ja partikkelien väliset vuorovaikutukset. Käytetyt suoraviivaiset lähestymistavat eivät riittäneet segregaation aiheuttamiseen Babel-laitteella. Vertikaalisen ravistelun seurauksena syntynyt konvektiopyörre esti segregaation syntymisen. Johtopäätöksenä voidaan sanoa, että Babel-laite mittaa hyvin ja toistettavasti sekä se kykenee erottamaan erikokoiset partikkelit ja erilaiset kokojakaumat toisistaan. Laitteen kehittämistavoitteena olisi saada segregaatio paremmin näkyviin jauheseoksissa ravistelun seurauksena. Tällöin voitaisiin tehdä päätelmiä jauheseoksen erottumistaipumuksesta ja systeemissä vallitsevista erottumismekanismeista. Laitteen ja menetelmän jatkokehittäminen voisi tuottaa hyödyllistä lisätietoa, mikä edesauttaisi segregaation ymmärtämistä ilmiönä entistä paremmin

Redundancy resolution using tractrix -- Simulations and Experiments

Hyper-redundant robots are characterized by the presence of a large number of actuated joints, many more than the number required to perform a given task. These robots have been proposed and used for many applications involving avoiding obstacles or, in general, to provide enhanced dexterity in performing tasks. Making effective use of the extra degrees of freedom or resolution of redundancy has been an extensive topic of research and several methods have been proposed in literature. In this paper, we compare three known methods and show that an algorithm based on a classical curve called the tractrix leads to a more 'natural' motion of the hyper-redundant robot, with the displacements diminishing from the end-effector to the fixed base. In addition, since the actuators nearer the base 'see' a greater inertia due to the links farther away, smaller motion of the actuators nearer the base results in better motion of the end-effector as compared to other two approaches. We present simulation and experimental results performed on a prototype eight link planar hyper-redundant manipulator.

Kohdennetut nanopartikkelit ja isotooppikuvantaminen syövän hoidossa

Syövän diagnostiikassa ja hoidossa nanopartikkelit voivat toimia kuljetinaineina lääke- ja diagnostisille aineille tai nukleiinihappojaksoille. Kantaja-aineeseen voidaan liittää kohdennusmolekyylejä partikkelien passiivista tai aktiivista kohdennusta varten tai radioleima kuvantamista tai radioterapiaa varten. Kantaja-aineiden avulla voidaan parantaa lääkeaineen fysikaalis-kemiallisia ominaisuuksia ja biologista hyötyosuutta, vähentää systeemisiä sivuvaikutuksia, pidentää lääkeaineen puoliintumisaikaa ja siten harventaa annosteluväliä, sekä parantaa lääkeaineen pääsyä kohdekudokseen. Näin voidaan parantaa kemo- ja radioterapian tehoa ja hoidon onnistumisen todennäköisyyttä. Kirjallisuuskatsauksessa perehdytään nanokantajien rooliin syövän hoidossa. Vuosikymmeniä jatkuneesta tutkimuksesta huolimatta vain kaksi (Eurooppa) tai kolme (Yhdysvallat) nanopartikkeliformulaatiota on hyväksytty markkinoille syövän hoidossa. Ongelmina ovat riittämätön hakeutuminen kohdekudokseen, immunogeenisyys ja nanopartikkelien labiilius. Kokeellisessa osassa tutkitaan in vitro ja hiirillä in vivo 99mTc-leimattujen, PEG-verhoiltujen biotiiniliposomien kaksivaiheista kohdennusta ihmisen munasarjan adenokarsinoomasoluihin. Kohdentamiseen käytetään biotinyloitua setuksimabi-(Erbitux®) vasta-ainetta, joka sitoutuu solujen yli-ilmentämiin EGF-reseptoreihin. Kaksivaiheista kohdennusta verrataan suoraan ja/tai passiiviseen kohdennukseen. Tehokkaampien kuvantamismenetelmien kehitys on vauhdittanut kohdennettujen nanopartikkelien tutkimusta. Isotooppikuvantamista käyttäen pystytään seuraamaan radioleiman jakautumista elimistössä ja kuvantamaan solutasolla tapahtuvia ilmiöitä. Kirjallisuuskatsauksessa perehdytään SPECT- ja PET-kuvantamiseen syövän hoidossa, sekä niiden hyödyntämiseen lääkekehityksessä nanopartikkelien kuvantamisessa. Kyseiset kuvantamismenetelmät erottuvat muista menetelmistä korkean erotuskyvyn, herkkyyden ja helppokäyttöisyyden suhteen. Kokeellisessa osassa 99mTc-leimattujen liposomien distribuutiota hiirissä tutkittiin SPECT-CT-laitteen avulla. Aktiivisuus kasvaimessa, pernassa ja maksassa kvantifioitiin InVivoScope-ohjelman ja gammalaskijan avulla. Tuloksia verrattiin keskenään. In vitro-kokeessa saavutettiin kaksivaiheisella kohdennuksella 2,7- 3,5-kertainen (solulinjasta riippuen) hakeutuminen soluihin kontrolliliposomeihin verrattuna. Kuitenkin suora kohdennus toimi kaksivaiheista kohdennusta paremmin in vitro. In vivo –kokeissa liposomit jakautuivat kasvaimeen tehokkaammin i.p.-annosteltuna kuin i.v.-annosteltuna. Kaksivaiheisella kohdennuksella saavutettiin 1,24-kertainen jakautuminen kasvaimeen (% ID/g kudosta) passiivisesti kohdennettuihin liposomeihin verrattuna. %ID/elin oli kohdennetuilla liposomeilla 5,9 % ja passiivisesti kohdennetuilla 5,4%. Todellinen ero oli siis pieni. InVivoScope:n ja gammalaskijan tulokset eivät korreloineet keskenään. Lisätutkimuksia ja menetelmän optimointia vaaditaan liposomien kohdennuksessa kasvaimeen.

Energy efficient asymmetric binary search switching technique for SAR ADC

An asymmetric binary search switching technique for a successive approximation register (SAR) ADC is presented, and trade-off between switching energy and conversion cycles is discussed. Without using any additional switches, the proposed technique consumes 46% less switching energy, for a small input swing (0.5 V-ref (P-P)), as compared to the last reported efficient switching technique in literature for an 8-bit SAR ADC. For a full input swing (2 V-ref (P-P)), the proposed technique consumes 16.5% less switching energy.

Valokuvallistettu luonto : I. K. Inhan tuotanto luonnon merkityksellistäjänä

Photographized nature I. K. Inha s work as a signification of nature The dissertation examines, through the work of the Finnish photographer and writer I. K. Inha (formerly Konrad Into Nyström) (1865 1930), the different ways in which the signification of nature is achieved. The principal material consists of Inha s work from 1890 to 1925, from which a number of photographs and texts are considered and upon which the photographization of nature is contemplated. The dissertation addresses the issue of how nature is conceived and how the act of photographizing it can be defined. The methodical context of the study is composed of three thematic baskets that structure the material and which consist of narrations on Finnish national perception, nature conservation and understanding the world. In the first case nature is seen as the natural environment encompassing lakes, seashores, forests, and hills, which at the time were often perceived from a utilitarian viewpoint. By the photographization they generated a pictorial narrative that could be shared. The natural environment was thus turned into landscape by means of photography, following the global pictorial concepts picturesque and sublime, as well as the national canons that had been developed in literature and the visual arts. In the narrations concerning nature conservation, the photographization did not merely occur within the limits of presuppositions, but rather nature was given the opportunity to unfold itself. While the photograph was being established as a basis for supporting nature conservation or to highlight the destruction of nature at the hand of Man, an attempt was made to represent subjects that were difficult to convey in photographs, such as nature s power or the miracle of growth. The thesis suggests, that in the third case the concept of nature broke away from its strict interconnection with the natural environment and led to a contemplation of nature that is perceivable in a person. In this context the photograph and the photographization are interpreted as an attempt to understand a person and his or her very existence in the world, while this same existential wonder is seen as being embodied in Inha s portrait of a rune singer and in his photographs of forest interior and water. Further, the thesis asks whether photographing nature could be interpreted as an action similar to the idea of the phenomenological reduction as a means of bypassing the photographer s prevailing way of being.

Arvoja näkyvissä : Kaunokirjallisuuden etiikka Ludwig Wittgensteinin filosofian valossa

The goal of this dissertation was to study whether it is possible and meaningful to apply Ludwig Wittgenstein s distinction between saying (Sagen) and showing (Zeigen) to ethically oriented literary criticism. The following questions were used as the primary guidelines: 1. Is it possible, in the context of literary criticism, to put in practice Wittgenstein s ethical conceptions, which are quite theoretical and metaphysical by nature? 2. If so, what practical literary devices do authors use if they want to demonstrate their ethical values within the frame of a fictional work? 3. Does philosophy offer useful ethical consepts that open us new and interesting readings in fiction? The philosophical background of Wittgenstein s distinction is clarified in chapter I. This clarification is based on his main works, Tractatus logico-philosophicus and Philosophishe Untersuchungen, the published correspondence between Wittgenstein and Paul Engelmann, and selected Wittgenstein research and papers. Analyzing ethics and it s expression in Georg Trakl s poetry further elucidates Wittgenstein s concept of showing. The concept that a literary work is an act of an author was used as a starting point. The presumption was that analyzing this act of an author will reveal how ethical values can be demonstrated in literature. Categorizing an author s act at different levels of literary expression provides the structure of this study. In chapters IV - XIII literary devices useful for demonstrating ethics are examined and explained using examples from the works of Joseph Conrad, Charles Dickens, Nikolay Leskov, Ludwig Uhland, Eino Leino, Pentti Haanpää and Maria Jotuni. The concepts and views of researchers and writers such as Mihail Bahtin, Peter Juhl, E. D. Hirsch, Peter Lamarque and Stein Haugom Olsen are used. The concepts outlined in previous chapters are then applied in three case studies: Aeschylus s Oresteia trilogy, J-L. Runeberg s poem Sven Dufva and Sofi Oksanen s novel Puhdistus (Purge). On the whole, Wittgenstein s idea that ethical values can be demonstrated (shown) by means of literature is revealed as a fruitful point of departure for a more exact ethical reading, offering a new perspective on literary works.

Sonochemical reaction engineering

Ultrasound has been widely used by chemists to enhance yields as well as rates of homogeneous as well as heterogeneous chemical reactions. The effect of ultrasound on the course of chemical reactions is mediated through cavitation bubbles it generates. High temperatures and pressures are attained inside the cavitating bubbles when they collapse. The extreme conditions so generated lead to the formation of reactive intermediates, e.g., free radiacls, inside the bubbles, which cause chemical reactions to occur when they enter the surrounding liquid. This is the mechanism through which ultrasound influences the path of homogeneous reactions. The cavitation bubbles collapse asymmetrically in the vicinity of solids, e.g., catalyst particles. Asymmetric collapse lead to formation of high speed microjets. The microjets can enhance transport rates, the increase surface area through pitting as well as particle fragmentation through collisions. Both can alter the rates of heterogeneous reaction rates. It however appears that these effects do not exhaust the scope of the influence of ultrasound on heterogeneous reactions. Modelling and quantitative prediction of the effect of ultrasound on chemical reactions is however at a stage of infancy as the phenomena are complex. Only a few examples of modelling exist in literature. Apart from this, reactor design and scaleup pose significant problems. Thus sonochemical reaction engineering offers large scope for research and development efforts.