910 resultados para Order-disorder effects


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The purpose of this study was to investigate the effects of information and communication technology (ICT) on school from teachers’ and students’ perspectives. The focus was on three main subject matters: on ICT use and competence, on teacher and school community, and on learning environment and teaching practices. The study is closely connected to the national educational policy which has aimed strongly at supporting the implementation of ICT in pedagogical practices at all institutional levels. The phenomena were investigated using a mixed methods approach. The qualitative data from three cases studies and the quantitative data from three statistical studies were combined. In this study, mixed methods were used to investigate the complex phenomena from various stakeholders’ points of view, and to support validation by combining different perspectives in order to give a fuller and more complete picture of the phenomena. The data were used in a complementary manner. The results indicate that the technical resources for using ICT both at school and at homes are very good. In general, students are capable and motivated users of new technology; these skills and attitudes are mainly based on home resources and leisuretime use. Students have the skills to use new kinds of applications and new forms of technology, and their ICT skills are wide, although not necessarily adequate; the working habits might be ineffective and even wrong. Some students have a special kind of ICT-related adaptive expertise which develops in a beneficial interaction between school guidance and challenges, and individual interest and activity. Teachers’ skills are more heterogeneous. The large majority of teachers have sufficient skills for everyday and routine working practices, but many of them still have difficulties in finding a meaningful pedagogical use for technology. The intensive case study indicated that for the majority of teachers the intensive ICT projects offer a possibility for learning new skills and competences intertwined in the work, often also supported by external experts and a collaborative teacher community; a possibility that “ordinary” teachers usually do not have. Further, teachers’ good ICT competence help them to adopt new pedagogical practices and integrate ICT in a meaningful way. The genders differ in their use of and skills in ICT: males show better skills especially in purely technical issues also in schools and classrooms, whereas female students and younger female teachers use ICT in their ordinary practices quite naturally. With time, the technology has become less technical and its communication and creation affordances have become stronger, easier to use, more popular and motivating, all of which has increased female interest in the technology. There is a generation gap in ICT use and competence between teachers and students. This is apparent especially in the ICT-related pedagogical practices in the majority of schools. The new digital affordances not only replace some previous practices; the new functionalities change many of our existing conceptions, values, attitudes and practices. The very different conceptions that generations have about technology leads, in the worst case, to a digital gap in education; the technology used in school is boring and ineffective compared to the ICT use outside school, and it does not provide the competence needed for using advanced technology in learning. The results indicate that in schools which have special ICT projects (“ICT pilot schools”) for improving pedagogy, these have led to true changes in teaching practices. Many teachers adopted student-centred and collaborative, inquiry-oriented teaching practices as well as practices that supported students' authentic activities, independent work, knowledge building, and students' responsibility. This is, indeed, strongly dependent on the ICT-related pedagogical competence of the teacher. However, the daily practices of some teachers still reflected a rather traditional teacher-centred approach. As a matter of fact, very few teachers ever represented solely, e.g. the knowledge building approach; teachers used various approaches or mixed them, based on the situation, teaching and learning goals, and on their pedagogical and technical competence. In general, changes towards pedagogical improvements even in wellorganised developmental projects are slow. As a result, there are two kinds of ICT stories: successful “ICT pilot schools” with pedagogical innovations related to ICT and with school community level agreement about the visions and aims, and “ordinary schools”, which have no particular interest in or external support for using ICT for improvement, and in which ICT is used in a more routine way, and as a tool for individual teachers, not for the school community.

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The main purpose of this thesis is to investigate winner-loser performance when financial markets are facing crisis. This is examined through the idea that does the prior loser portfolios outperform the prior winner portfolios during the three major crises: The depression of the 1990s, the IT-Bubble and the Subprime -crisis. Firstly, the winner and loser portfolios superiority is counted by using the cumulative excess returns from the examination period. The portfolios were formed by counting the excess returns and locating them in to the order of superiority. The excess returns are counted by using one year pre-data before the actual examination period. The results of this part did not support the results of De Bondt & Thaler’s (1985) paper. Secondly, it is investigated how the Finnish and the US macroeconomic factors are seen to be affecting the stock market valuation in Finnish Stock Markets during economic crises. This is done to explain better the changes in the successes of the winner-loser performance. The crises included different amount of selected macro factors. Two latest crises involved as well few selected US macro factors. Exclusively the IT-Bubble -crisis had the most statistically significant results with the US factors. Two other crises did not receive statistically significant results. An extra research was produced to study do the US macro factors impact more significantly on Finnish stock exchange after lags. The selected lags were three, six, nine and twelve months. Three and six month lagged US macro factors during the IT-Bubble -crisis improved the results. The extra research did not improve the results of the Subprime -crisis.

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Al2O3 is the most abundantly produced nanomaterial and has been used in diverse fields, including the medical, military and industrial sectors. As there are concerns about the health effects of nanoparticles, it is important to understand how they interact with cells, and specifically with red blood cells. The hemolysis induced by three commercial nano-sized aluminum oxide particles (nanopowder 13 nm, nanopowder <50 nm and nanowire 2-6 nm × 200-400 nm) was compared to aluminum oxide and has been studied on erythrocytes from humans, rats and rabbits, in order to elucidate the mechanism of action and the influence of size and shape on hemolytic behavior. The concentrations inducing 50% hemolysis (HC50) were calculated for each compound studied. The most hemolytic aluminum oxide particles were of nanopowder 13, followed by nanowire and nanopowder 50. The addition of albumin to PBS induced a protective effect on hemolysis in all the nano-forms of Al2O3, but not on Al2O3. The drop in HC50 correlated to a decrease in nanomaterial size, which was induced by a reduction of aggregation Aluminum oxide nanoparticles are less hemolytic than other oxide nanoparticles, and behave differently depending on the size and shape of the nanoparticles. The hemolytic behavior of aluminum oxide nanoparticles differs from that of aluminum oxide.

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Rockfish species are considered important to the ecology of rocky-reef communities which constitute a key habitat in many coastal marine protected areas (MPAs). These species, which are commercially valuable for artisanal fisheries in the Mediterranean, display particular biological traits that could render them vulnerable to fishing. In this study we monitored the artisanal fisheries of scorpaenids (Scorpaena spp.) in the MPA of Cap de Creus (northwestern Mediterranean) in order to estimate the status of their populations, to link captures with the reproduction of these species, and to evaluate the potential impact that artisanal fishing may have on them. Data from onboard sampling with artisanal fishermen and from fisheries statistics (total landings) were used. Total landings and catch per unit of effort (CPUE) follow a clearly seasonal cycle, with a prominent peak during the summer months coinciding with their spawning season, which may be due to mating behavior prior to fertilization. Although maximum sizes are bigger inside the MPA than in non-protected areas situated close by, a significant percentage of individuals caught inside the MPA are below their size at sexual maturity. Although rockfish seem to be favored by the partial protection of the MPA, the allowed artisanal fisheries are probably impacting the reproduction of these species

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Al2O3 is the most abundantly produced nanomaterial and has been used in diverse fields, including the medical, military and industrial sectors. As there are concerns about the health effects of nanoparticles, it is important to understand how they interact with cells, and specifically with red blood cells. The hemolysis induced by three commercial nano-sized aluminum oxide particles (nanopowder 13 nm, nanopowder <50 nm and nanowire 2-6 nm × 200-400 nm) was compared to aluminum oxide and has been studied on erythrocytes from humans, rats and rabbits, in order to elucidate the mechanism of action and the influence of size and shape on hemolytic behavior. The concentrations inducing 50% hemolysis (HC50) were calculated for each compound studied. The most hemolytic aluminum oxide particles were of nanopowder 13, followed by nanowire and nanopowder 50. The addition of albumin to PBS induced a protective effect on hemolysis in all the nano-forms of Al2O3, but not on Al2O3. The drop in HC50 correlated to a decrease in nanomaterial size, which was induced by a reduction of aggregation Aluminum oxide nanoparticles are less hemolytic than other oxide nanoparticles, and behave differently depending on the size and shape of the nanoparticles. The hemolytic behavior of aluminum oxide nanoparticles differs from that of aluminum oxide.

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Female sexual dysfunctions, including desire, arousal, orgasm and pain problems, have been shown to be highly prevalent among women around the world. The etiology of these dysfunctions is unclear but associations with health, age, psychological problems, and relationship factors have been identified. Genetic effects explain individual variation in orgasm function to some extent but until now quantitative behavior genetic analyses have not been applied to other sexual functions. In addition, behavior genetics can be applied to exploring the cause of any observed comorbidity between the dysfunctions. Discovering more about the etiology of the dysfunctions may further improve the classification systems which are currently under intense debate. The aims of the present thesis were to evaluate the psychometric properties of a Finnish-language version of a commonly used questionnaire for measuring female sexual function, the Female Sexual Function Index (FSFI), in order to investigate prevalence, comorbidity, and classification, and to explore the balance of genetic and environmental factors in the etiology as well as the associations of a number of biopsychosocial factors with female sexual functions. Female sexual functions were studied through survey methods in a population based sample of Finnish twins and their female siblings. There were two waves of data collection. The first data collection targeted 5,000 female twins aged 33–43 years and the second 7,680 female twins aged 18–33 and their over 18–year-old female siblings (n = 3,983). There was no overlap between the data collections. The combined overall response rate for both data collections was 53% (n = 8,868), with a better response rate in the second (57%) compared to the first (45%). In order to measure female sexual function, the FSFI was used. It includes 19 items which measure female sexual function during the previous four weeks in six subdomains; desire, subjective arousal, lubrication, orgasm, sexual satisfaction, and pain. In line with earlier research in clinical populations, a six factor solution of the Finnish-language version of the FSFI received supported. The internal consistencies of the scales were good to excellent. Some questions about how to avoid overestimating the prevalence of extreme dysfunctions due to women being allocated the score of zero if they had had no sexual activity during the preceding four weeks were raised. The prevalence of female sexual dysfunctions per se ranged from 11% for lubrication dysfunction to 55% for desire dysfunction. The prevalence rates for sexual dysfunction with concomitant sexual distress, in other words, sexual disorders were notably lower ranging from 7% for lubrication disorder to 23% for desire disorder. The comorbidity between the dysfunctions was substantial most notably between arousal and lubrication dysfunction even if these two dysfunctions showed distinct patterns of associations with the other dysfunctions. Genetic influences on individual variation in the six subdomains of FSFI were modest but significant ranging from 3–11% for additive genetic effects and 5–18% for nonadditive genetic effects. The rest of the variation in sexual functions was explained by nonshared environmental influences. A correlated factor model, including additive and nonadditive genetic effects and nonshared environmental effects had the best fit. All in all, every correlation between the genetic factors was significant except between lubrication and pain. All correlations between the nonshared environment factors were significant showing that there is a substantial overlap in genetic and nonshared environmental influences between the dysfunctions. In general, psychological problems, poor satisfaction with the relationship, sexual distress, and poor partner compatibility were associated with more sexual dysfunctions. Age was confounded with relationship length but had over and above relationship length a negative effect on desire and sexual satisfaction and a positive effect on orgasm and pain functions. Alcohol consumption in general was associated with better desire, arousal, lubrication, and orgasm function. Women pregnant with their first child had fewer pain problems than nulliparous nonpregnant women. Multiparous pregnant women had more orgasm problems compared to multiparous nonpregnant women. Having children was associated with less orgasm and pain problems. The conclusions were that desire, subjective arousal, lubrication, orgasm, sexual satisfaction, and pain are separate entities that have distinct associations with a number of different biopsychosocial factors. However, there is also considerable comorbidity between the dysfunctions which are explained by overlap in additive genetic, nonadditive genetic and nonshared environmental influences. Sexual dysfunctions are highly prevalent and are not always associated with sexual distress and this relationship might be moderated by a good relationship and compatibility with partner. Regarding classification, the results supports separate diagnoses for subjective arousal and genital arousal as well as the inclusion of pain under sexual dysfunctions.

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More and more innovations currently being commercialized exhibit network effects, in other words, the value of using the product increases as more and more people use the same or compatible products. Although this phenomenon has been the subject of much theoretical debate in economics, marketing researchers have been slow to respond to the growing importance of network effects in new product success. Despite an increase in interest in recent years, there is no comprehensive view on the phenomenon and, therefore, there is currently incomplete understanding of the dimensions it incorporates. Furthermore, there is wide dispersion in operationalization, in other words, the measurement of network effects, and currently available approaches have various shortcomings that limit their applicability, especially in marketing research. Consequently, little is known today about how these products fare on the marketplace and how they should be introduced in order to maximize their chances of success. Hence, the motivation for this study was driven by the need to increase our knowledge and understanding of the nature of network effects as a phenomenon, and of their role in the commercial success of new products. This thesis consists of two parts. The first part comprises a theoretical overview of the relevant literature, and presents the conclusions of the entire study. The second part comprises five complementary, empirical research publications. Quantitative research methods and two sets of quantitative data are utilized. The results of the study suggest that there is a need to update both the conceptualization and the operationalization of the phenomenon of network effects. Furthermore, there is a need for an augmented view on customers’ perceived value in the context of network effects, given that the nature of value composition has major implications for the viability of such products in the marketplace. The role of network effects in new product performance is not as straightforward as suggested in the existing theoretical literature. The overwhelming result of this study is that network effects do not directly influence product success, but rather enhance or suppress the influence of product introduction strategies. The major contribution of this study is in conceptualizing the phenomenon of network effects more comprehensively than has been attempted thus far. The study gives an augmented view of the nature of customer value in network markets, which helps in explaining why some products thrive on these markets whereas others never catch on. Second, the study discusses shortcomings in prior literature in the way it has operationalized network effects, suggesting that these limitations can be overcome in the research design. Third, the study provides some much-needed empirical evidence on how network effects, product introduction strategies, and new product performance are associated. In general terms, this thesis adds to our knowledge of how firms can successfully leverage network effects in product commercialization in order to improve market performance.

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ABSTRACT This work aimed to evaluate the consequences of the monthly extraction of immature leaves in survival, leaf production and reproductive performance ofCopernicia prunifera H. E. Moore palm, popularly known as carnaúba. One hundred sixty reproductive adult palms were monitored for 17 months in four extractive communities located at the coast of the state of Piauí. As a result, it was observed that leaves, flowers, fruits and seeds production were reduced in the palm submitted to 50% or 75% monthly extraction. Higher levels of extraction were followed by smaller levels in seed germination. No deaths were observed even in the group subjected to 75% monthly leaves exploration. In order not to produce damage to palm trees development it is suggested that leaf extraction rate should not exceed 25% monthly as well as pausing of extractive activity preferentially during fruit maturation.

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The objective of this study was to evaluate the effects of the nitrogen fertilization in the form of swine deep bed in the properties of a quartz-sand neosol. The organic compound used was the deep bed made with rice hulls, from a commercial swine finishing system farm. Deep bed samples have been collected at various points in the installation in order to obtain a representative composite sample which has been fractionated in a 2.0 mm sieve and submitted to a 50-day maturation period. Then, agronomic value analyses were done. The experimental design was completely randomized. The treatments consisted of 0; 75; 150 and 300 mg dm-3 of N doses of deep bed as well as an additional treatment with ammonium sulfate at a 150 mg dm-3 of N. The experimental period in the greenhouse was 45 days, where the soil was cultivated with maize. After the experiment completion, further soil properties analyses were done. From the results, it was noted that the organic fertilization with deep bed provided a significant increase in the levels of potassium, in the sum of the bases, in the effective CEC, in the CEC at pH 7.0 and in the percentage of saturation.

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The goal of this study was to evaluate the nitrogen fertilization as deep litter for pigs in order to produce biomass and accumulate nutrients by the corn. A deep litter made of rice husk as organic compound, from a commercial pig farm during finishing phase, was used. After three consecutive batches of pigs, the deep litter was subjected to a maturation period of 50 days, and samples of this material were taken for analysis of agronomic value. The experimental design was completely randomized with five replicates. The treatments consisted of doses of 0, 75, 150 and 300mg dm-3 of N of deep litter, as well as an additional treatment with ammonium sulfate, with a dosage of 150mg dm-3 of N. After 45 days, corn plants were harvested in order to evaluate the total dry weight and nutrient concentrations of their aerial parts. Dry matter increases were found with more application of deep litter. Regarding control fertilization, the use of increasing dosages of deep litter allowed accumulation of K, reduced the availability of P, Ca, Mg, Zn and B and did not alter the concentrations of N, Cu, Fe and Mn.

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Companies operating in today’s highly internationalized markets consider product differentiation the key priority in pursue to attain a constant competitive advantage in challenging global environment (Baker and Ballington 2002, 158). The main driver affecting companies’ differentiation actions was described as early as 1912 by one of the marketing pioneers A. W. Shaw (1912, 710) as meeting human wants more accurate than the competition, and thus increasing customers’ perceived value and satisfaction. Dickson and Ginter (1987, 2) point out in their study based on earlier research by Chamberlin (1965) and Porter (1976) that differentiation can be based on either tangible characteristics of a product such as design or intangible characteristics such as a brand name and country of origin (hereafter referred to as COO). The concept of COO and its impact on consumers’ evaluation of a product as an extrinsic product cue has been one of the most noteworthy topics in international marketing, having been voluminously examined by over 780 authors in more than 750 academic publications in the past 40 years (Papadopoulos and Heslop 2002, 294). Many of these studies accentuate the significant effect the COO has on consumers’ product attribute evaluations. People routinely associate country images with products and services in order to judge and categorize them based on perceived quality and risk levels; thereby COO can influence the likelihood of a purchase (Peterson and Jolibert 1995, 883-884; Verlegh and Steenkamp 1999, 523). Based on the vast research related to COO in the field of international business, it is widely recognized that the country associated with a product can act in a similar way as the name of a brand and even become a part of product’s total image. Thereby depending on customer’s values and perceptions, the product-country image can either increase or decrease perceived value.

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For the past two decades the music digitalization has been considered the most significant phenomenon in the music industry as the physical sales have been decreasing rapidly. The advancement of the digital technology and the internet have facilitated the digitalization in the music industry and affected all stages of the music value chain, namely music creation, distribution and consumption. The newly created consumer culture has led to the establishment of novel business models such as music subscriptions and à-la-carte downloads websites and live streaming. The dynamic digital environment has presented the music industry stakeholders with the challenge to adapt to the requirements of the constantly changing modern consumers’ needs and demands. The purpose of this study was to identify how music digitalization can influence change in the Finnish music industry value chain; i.e. how digitalization affects the music industry stakeholders, their functions and inter-relatedness and how the stakeholders are able to react to the changes in the industry. The study was conducted as a qualitative research based entirely on primary data in the form of semi-structured interviews with experts from different units of the Finnish music industry value chain. Since the study offers assessment of diverse viewpoints on the value chain, it further provides an integrated picture of the Finnish music industry current situation and its competitive environment. The results suggest that the music industry is currently in a turbulent stage of experimentation with new business models and digital innovations. However, at this point it is impossible to determine which business model will be approved by the consumers in the longer run. Nevertheless, the study confirmed the claim that consumption of music in its digital form is to become dominant over the traditional physical copies sales in the nearest future. As a result the music industry is becoming more user-oriented; that is the focus is shifting from music production towards artist branding and management and visibility to the audience. Furthermore, the music industry is undergoing the process of integration with other industries such as media, social networks, internet services providers and mobile phone manufacturers in order to better fulfill the consumers’ needs. The previously underrated live music and merchandising are also increasing their significance for the revenues in the stagnant music markets. Therefore, the music industry is developing at present towards becoming an integrated entertainment industry deeply penetrating every point of modern people’s leisure activities.

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In this Thesis various aspects of memory effects in the dynamics of open quantum systems are studied. We develop a general theoretical framework for open quantum systems beyond the Markov approximation which allows us to investigate different sources of memory effects and to develop methods for harnessing them in order to realise controllable open quantum systems. In the first part of the Thesis a characterisation of non-Markovian dynamics in terms of information flow is developed and applied to study different sources of memory effects. Namely, we study nonlocal memory effects which arise due to initial correlations between two local environments and further the memory effects induced by initial correlations between the open system and the environment. The last part focuses on describing two all-optical experiment in which through selective preparation of the initial environment states the information flow between the system and the environment can be controlled. In the first experiment the system is driven from the Markovian to the non- Markovian regime and the degree of non-Markovianity is determined. In the second experiment we observe the nonlocal nature of the memory effects and provide a novel method to experimentally quantify frequency correlations in photonic environments via polarisation measurements.

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The flow structure of cold and ignited jets issuing into a co-flowing air stream was experimentally studied using a laser Doppler velocimeter. Methane was employed as the jet fluid discharging from circular and elliptic nozzles with aspect ratios varying from 1.29 to 1.60. The diameter of the circular nozzle was 4.6 mm and the elliptic nozzles had approximately the same exit area as that of the circular nozzle. These non-circular nozzles were employed in order to increase the stability of attached jet diffusion flames. The time-averaged velocity and r.m.s. value of the velocity fluctuation in the streamwise and transverse directions were measured over the range of co-flowing stream velocities corresponding to different modes of flame blowout that are identified as either lifted or attached flames. On the basis of these measurements, attempts were made to explain the existence of an apparent optimum aspect ratio for the blowout of attached flames observed at higher values of co-flowing stream velocities. The insensitivity of the blowout limits of lifted flames to nozzle geometry observed in our previous work at low co-flowing stream velocities was also explained. Measurements of the fuel concentration at the jet centerline indicated that the mixing process was enhanced with the 1.38 aspect ratio jet compared with the 1.60 aspect ratio jet. On the basis of the obtained experimental data, it was suggested that the higher blowout limits of attached flames for an elliptic jet of 1.38 aspect ratio was due to higher entrainment rates.

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The superconducting gap is a basic character of a superconductor. While the cuprates and conventional phonon-mediated superconductors are characterized by distinct d- and s-wave pairing symmetries with nodal and nodeless gap distributions respectively, the superconducting gap distributions in iron-based superconductors are rather diversified. While nodeless gap distributions have been directly observed in Ba1–xKxFe2As2, BaFe2–xCoxAs2, LiFeAs, KxFe2–ySe2, and FeTe1–xSex, the signatures of a nodal superconducting gap have been reported in LaOFeP, LiFeP, FeSe, KFe2As2, BaFe2–xRuxAs2, and BaFe2(As1–xPx)2. Due to the multiplicity of the Fermi surface in these compounds s± and d pairing states can be both nodeless and nodal. A nontrivial orbital structure of the order parameter, in particular the presence of the gap nodes, leads to effects in which the disorder is much richer in dx2–y2-wave superconductors than in conventional materials. In contrast to the s-wave case, the Anderson theorem does not work, and nonmagnetic impurities exhibit a strong pair-breaking influence. In addition, a finite concentration of disorder produces a nonzero density of quasiparticle states at zero energy, which results in a considerable modification of the thermodynamic and transport properties at low temperatures. The influence of order parameter symmetry on the vortex core structure in iron-based pnictide and chalcogenide superconductors has been investigated in the framework of quasiclassical Eilenberger equations. The main results of the thesis are as follows. The vortex core characteristics, such as, cutoff parameter, ξh, and core size, ξ2, determined as the distance at which density of the vortex supercurrent reaches its maximum, are calculated in wide temperature, impurity scattering rate, and magnetic field ranges. The cutoff parameter, ξh(B; T; Г), determines the form factor of the flux-line lattice, which can be obtained in _SR, NMR, and SANS experiments. A comparison among the applied pairing symmetries is done. In contrast to s-wave systems, in dx2–y2-wave superconductors, ξh/ξc2 always increases with the scattering rate Г. Field dependence of the cutoff parameter affects strongly on the second moment of the magnetic field distributions, resulting in a significant difference with nonlocal London theory. It is found that normalized ξ2/ξc2(B/Bc2) dependence is increasing with pair-breaking impurity scattering (interband scattering for s±-wave and intraband impurity scattering for d-wave superconductors). Here, ξc2 is the Ginzburg-Landau coherence length determined from the upper critical field Bc2 = Φ0/2πξ2 c2, where Φ0 is a flux quantum. Two types of ξ2/ξc2 magnetic field dependences are obtained for s± superconductors. It has a minimum at low temperatures and small impurity scattering transforming in monotonously decreasing function at strong scattering and high temperatures. The second kind of this dependence has been also found for d-wave superconductors at intermediate and high temperatures. In contrast, impurity scattering results in decreasing of ξ2/ξc2(B/Bc2) dependence in s++ superconductors. A reasonable agreement between calculated ξh/ξc2 values and those obtained experimentally in nonstoichiometric BaFe2–xCoxAs2 (μSR) and stoichiometric LiFeAs (SANS) was found. The values of ξh/ξc2 are much less than one in case of the first compound and much more than one for the other compound. This is explained by different influence of two factors: the value of impurity scattering rate and pairing symmetry.