844 resultados para Frameworks
Resumo:
The starting point of this study is that the prevailing way to consider the Finnish IT industries and industry information often results in a limited and even skewed picture of the sector. The purpose of the study is to contribute and increase knowledge and understanding of the status, structure and evolution of the Finnish IT industries as well as the Finnish IT vendor field and competition. The focus is on software product and IT services industries which form a crucial part of all ICT industries. This study examines the Finnish IT sector from production (supply) as well as market (demand) perspective. The study is based on empirical information from multiple sources. Three research questions were formulated for the study. The first concerns the status of the Finnish IT industries considered by applying theoretical frameworks. The second research question targets at the basis for the future evolution of the Finnish IT industries and, finally, the third at the ability of the available definitions and indicators to describe the Finnish IT industries and IT markets. Major structural changes like technological changes and related innovations, globalization and new business models are drivers of the evolution of the IT industries. The findings of this study emphasize the significant role of IT services in the Finnish IT sector and in connection to that the ability to combine IT service skills, competences and practices with high level software skills also in the future. According to the study the Finnish IT enterprises and their customers have become increasingly dependent on global ecosystems and platforms, applications and IT services provided by global vendors. As a result, more IT decisions are made outside Finland. In addition, IT companies are facing new competition from other than IT industries bringing into market new substitutes. To respond to the new competition, IT firms seek growth by expanding beyond their traditional markets.. The changing global division of labor accentuates the need for accurate information of the IT sector but, at the same time, also makes it increasingly challenging to acquire the information needed. One of the main contributions of this study is to provide frameworks for describing the Finnish IT sector and its evolution. These frameworks help combine empirical information from various sources and make it easier to concretize the structures, volumes, relationships and interaction of both, the production and market side of the Finnish IT industry. Some frameworks provide tools to analyze the vendor field, competition and the basis for the future evolution of the IT industries. The observations of the study support the argument that static industry definitions and related classifications do not serve the information needs in dynamic industries, such as the IT industries. One of the main messages of this study is to emphasize the importance of understanding the definitions and starting points of different information sources. Simultaneously, in the structure and evolution of Finnish IT industries the number of employees has become a more valid and reliable measure than the revenue based indicators.
Model-View-Controller architectural pattern and its evolution in graphical user interface frameworks
Resumo:
Model-View-Controller (MVC) is an architectural pattern used in software development for graphical user interfaces. It was one of the first proposed solutions in the late 1970s to the Smart UI anti-pattern, which refers to the act of writing all domain logic into a user interface. The original MVC pattern has since evolved in multiple directions, with various names and may confuse many. The goal of this thesis is to present the origin of the MVC pattern and how it has changed over time. Software architecture in general and the MVC’s evolution within web applications are not the primary focus. Fundamen- tal designs are abstracted, and then used to examine the more recent versions. Prob- lems with the subject and its terminology are also presented.
Resumo:
Immobilized lipase B from Candida antarctica (Novozym® 435, N435) was utilized as part of a chemoenzymatic strategy for the synthesis of branched polyesters based on a cyclotetrasiloxane core in the absence of solvent. Nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were utilized to monitor the reactions between tetraester cyclotetrasiloxanes and aliphatic diols. The enzyme-mediated esterification reactions can achieve 65– 80% consumption of starting materials in 24–48 h. Longer reaction times, 72–96 h, resulted in the formation of cross-linked gel-like networks. Gel permeation chromatography of the polymers indicated that the masses were Mw ¼ 11 400, 13 100, and 19 400 g mol 1 for the substrate pairs of C7D4 ester/ octane-1,8-diol, C10D4 ester/pentane-1,5-diol and C10D4 ester/octane-1,8-diol respectively, after 48 h. Extending the polymerization for an additional 24 h with the C10D4 ester/octane-1,8-diol pair gave Mw ¼ 86 800 g mol 1. To the best of our knowledge this represents the first report using lipase catalysis to produce branched polymers that are built from a cyclotetrasiloxane core.
Resumo:
Photosynthesis is a process in which electromagnetic radiation is converted into chemical energy. Photosystems capture photons with chromophores and transfer their energy to reaction centers using chromophores as a medium. In the reaction center, the excitation energy is used to perform chemical reactions. Knowledge of chromophore site energies is crucial to the understanding of excitation energy transfer pathways in photosystems and the ability to compute the site energies in a fast and accurate manner is mandatory for investigating how protein dynamics ef-fect the site energies and ultimately energy pathways with time. In this work we developed two software frameworks designed to optimize the calculations of chro-mophore site energies within a protein environment. The first is for performing quantum mechanical energy optimizations on molecules and the second is for com-puting site energies of chromophores in a fast and accurate manner using the polar-izability embedding method. The two frameworks allow for the fast and accurate calculation of chromophore site energies within proteins, ultimately allowing for the effect of protein dynamics on energy pathways to be studied. We use these frame-works to compute the site energies of the eight chromophores in the reaction center of photosystem II (PSII) using a 1.9 Å resolution x-ray structure of photosystem II. We compare our results to conflicting experimental data obtained from both isolat-ed intact PSII core preparations and the minimal reaction center preparation of PSII, and find our work more supportive of the former.
Resumo:
Chemistry occupies a unique middle position in the scientific arena, between physics and mathematics on the one side and biology, ecology, sociology and economics on the other [1]. Chemistry is the science of matter and of its transformations, and life is its highest expression [2]. According to reductionist thinking biology is reducible into chemistry, chemistry into physics, and ultimately physics into mathematics. Reductionism implies the ease of understanding one level in terms of another.The work presented this thesis comprises synthesis and characterization of suitably substituted thiocarbohydrazone and carbohydrazone ligand building blocks, self-assembled metallosupramolecular square grid complexes as well as some di/multinuclear complexes. The primary aim was the deliberate syntheses of some novel transition metal framework complexes, mainly metallosupramolecular coordination square grids by self-assembly and their physico-chemical characterization. The work presented, however, also include synthesis and characterization of four mononuclear Ni(II) complexes of two thiosemicarbazones, which we carried out as a preliminary and supporting study. Based on the present work we would like to conclude that the carbohydrazones, thiocarbohydrazones and their coordination framework complexes of transition metals are promising systems for wide application in science and technology varied from physics to biotechnology. Novel classes of materials and biologically important potential compounds open up further scope of researches and we hopefully welcome any sort of related research to make this work more valuable.
Resumo:
A prerequisite for the enrichment of antibodies screened from phage display libraries is their stable expression on a phage during multiple selection rounds. Thus, if stringent panning procedures are employed, selection is simultaneously driven by antigen affinity, stability and solubility. To take advantage of robust pre-selected scaffolds of such molecules, we grafted single-chain Fv (scFv) antibodies, previously isolated from a human phage display library after multiple rounds of in vitro panning on tumor cells, with the specificity of the clinically established murine monoclonal anti-CD22 antibody RFB4. We show that a panel of grafted scFvs retained the specificity of the murine monoclonal antibody, bound to the target antigen with high affinity (6.4-9.6 nM), and exhibited exceptional biophysical stability with retention of 89-93% of the initial binding activity after 6 days of incubation in human serum at 37degreesC. Selection of stable human scaffolds with high sequence identity to both the human germline and the rodent frameworks required only a small number of murine residues to be retained within the human frameworks in order to maintain the structural integrity of the antigen binding site. We expect this approach may be applicable for the rapid generation of highly stable humanized antibodies with low immunogenic potential.
Resumo:
We report the use of transition-metal-exchanged zeolites as media for the catalytic formation and encapsulation of both polyethyne and polypropyne, and computer modeling studies on the composites so formed. Alkyne gas was absorbed into the pores of zeolite Y (Faujasite) exchanged with transition-metal cations [Fe(II), Co(II), Cu(II), Ni(II), and Zn(II)]. Ni(II) and Zn(II) were found to be the most efficient for the production of poly-ynes. These cations were also found to be effective in polymer generation when exchanged in zeolites mordenite and beta. The resulting powdered samples were characterized by FTIR, Raman, diffuse reflectance electronic spectroscopy, TEM, and elemental analysis, revealing, nearly complete loading of the zeolite channels for the majority of the samples. Based on the experimental carbon content, we have derived the percentage of channel filling, and the proportion of the channels containing a single polymer chain for mordenite. Experimentally, the channels for Y are close to complete filling for polyethyne (PE) and polypropyne (PP), and this is also true for polyethyne in mordenite. Computer modeling studies using Cerius2 show that the channels of mordenite can only accept a single polymer chain of PP, in which case these channels are also completely filled.
Resumo:
Three new polynuclear copper(II) complexes of 2-picolinic acid (Hpic), {[Cu-2(pic)(3)(H2O)]ClO4}(n) (1), {[Cu-2(pic)(3)(H2O)]BF4}(n) (2), and [Cu-2(pic)3(H2O)(2)(NO3)](n) (3), have been synthesized by reaction of the "metalloligand" [Cu-(pic)(2)] with the corresponding copper(II) salts. The compounds are characterized by single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. Compounds 1 and 2 are isomorphous and crystallize in the triclinic system with space group P (1) over bar, while 3 crystallizes in the monoclinic system with space group P2(1)/n. The structural analyses reveal that complexes 1 and 2 are constructed by "fish backbone" chains through syn-anti (equatorial-equatorial) carboxylate bridges, which are linked to one another by syn-anti (equatorial-axial) carboxylate bridges, giving rise to a rectangular grid-like two-dimensional net. Complex 3 is formed by alternating chains of syn-anti carboxylate-bridged copper(II) atoms, which are linked together by strong H bonds involving coordinated nitrate ions and water molecules and uncoordinated oxygen atoms from carboxylate groups. The different coordination ability of the anions along with their involvement in the H-bonding network seems to be responsible for the difference in the final polymeric structures. Variable-temperature (2-300 K) magnetic susceptibility measurement shows the presence of weak ferromagnetic coupling for all three complexes that have been fitted with a fish backbone model developed for 1 and 2 (J = 1.74 and 0.99 cm(-1); J' = 0.19 and 0.25 cm(-1), respectively) and an alternating chain model for 3 (J = 1.19 cm(-1) and J' = 1.19 cm(-1)).
Resumo:
The structural transformations between cesium silver-copper cyanides under modest conditions, both in solution and in the solid state, are described. Three new cesium silver(I) copper(I) cyanides with three-dimensional (3-D) framework structures were prepared as single crystals from a one-pot reaction initially heated under hydrothermal conditions. The first product to appear, Cs3Ag2Cu3(CN)(8) (I), when left in contact with the supernatant produced CsAgCu(CN)(3) (II) and CsAgCu(CN)(3)center dot 1/3H(2)O (III) over a few months via a series of thermodynamically controlled cascade reactions. Crystals of the hydrate (III) can be dehydrated to polycrystalline CsAgCu(CN)(3) (II) on heating at 100 degrees C in a remarkable solid-state transformation involving substantial breaking and reconnection of metal-cyanide linkages. Astonishingly, the conversion between the two known polymorphs of CsAg2Cu(CN)(4), which also involves a major change in connectivity and topology, occurs at 180 degrees C as a single-crystal to single-crystal transformation. Structural features of note in these materials include the presence of helical copper-cyanide chains in (I) and (II), which in the latter compound produce a chiral material. In (II) and (III), the silver-copper cyanide networks are both self- and interpenetrating, features also seen in the known polymorphs of CsAg2Cu(CN)(4).
Resumo:
A new family of antimony sulfides, incorporating the macrocyclic tetramine 1,4,8,11-tetraazacyclotetradecane ( cyclam), has been prepared by a hydrothermal method. [C10N4H26][Sb4S7] (1), [Ni(C10N4H24)][Sb4S7] (2), and [Co(C10N4H24)](x)[C10N4H26](1-x)[Sb4S7] (0.08 <= x <= 0.74) (3) have been characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetry, and analytical electron microscopy. All three materials possess the same novel three-dimensional Sb4S72- framework, constructed from layers of parallel arrays of Sb4S84- chains stacked at 90 to one another. In 1, doubly protonated macrocyclic cations reside in the channel structure of the antimonysulfide framework. In 2 and 3, the cyclam acts as a ligand, chelating the divalent transition- metal cation. Analytical and X-ray diffraction data indicate that the level of metal incorporation in 2 is effectively complete, whereas in 3, both metalated and nonmetalated forms of the macrocycle coexist within the structure.
Resumo:
Current mathematical models in building research have been limited in most studies to linear dynamics systems. A literature review of past studies investigating chaos theory approaches in building simulation models suggests that as a basis chaos model is valid and can handle the increasing complexity of building systems that have dynamic interactions among all the distributed and hierarchical systems on the one hand, and the environment and occupants on the other. The review also identifies the paucity of literature and the need for a suitable methodology of linking chaos theory to mathematical models in building design and management studies. This study is broadly divided into two parts and presented in two companion papers. Part (I), published in the previous issue, reviews the current state of the chaos theory models as a starting point for establishing theories that can be effectively applied to building simulation models. Part (II) develop conceptual frameworks that approach current model methodologies from the theoretical perspective provided by chaos theory, with a focus on the key concepts and their potential to help to better understand the nonlinear dynamic nature of built environment systems. Case studies are also presented which demonstrate the potential usefulness of chaos theory driven models in a wide variety of leading areas of building research. This study distills the fundamental properties and the most relevant characteristics of chaos theory essential to (1) building simulation scientists and designers (2) initiating a dialogue between scientists and engineers, and (3) stimulating future research on a wide range of issues involved in designing and managing building environmental systems.