Engineering

C will blur the boundaries between traditional manual and automated manufacturing processes. However, to achieve full potential of new technology, human operators need confidence in robotic co-worker technologies and their capacities. In this experiment, we investigate the impact of screen based dynamic instructional signage on 39 participants from a manufacturing assembly line. The results provide evidence that dynamic signage helps to improve response time for the experimental group with taskrelevant signage compared to control group with no signage. Furthermore, the significantly with increasing accuracy on the task after interaction with the robot.

As robots become more ubiquitous, and their capabilities extend, novice users will require intuitive instructional information related to their use. This is particularly important in the manufacturing sector, which is set to be transformed under Industry 4.0 by the deployment of collaborative robots in support of traditionally low-skilled, manual roles. In the first study of its kind, this paper reports how static graphical signage can improve performance and reduce anxiety in participants physically collaborating with a semi-autonomous robot. Three groups of 30 participants collaborated with a robot to perform a manufacturing-type process using graphical information that was relevant to the task, irrelevant, or absent. The results reveal that the group exposed to relevant signage was significantly more accurate in undertaking the task. Furthermore, their anxiety towards robots significantly decreased as a function of increasing accuracy. Finally, participants exposed to graphical signage showed positive emotional valence in response to successful trials. At a time when workers are concerned about the threat posed by robots to jobs, and with advances in technology requiring upskilling of the workforce, it is important to provide intuitive and supportive information to users. Whilst increasingly sophisticated technical solutions are being sought to improve communication and confidence in human-robot co-working, our findings demonstrate how simple signage can still be used as an effective tool to reduce user anxiety and increase task performance.

A Symbiotic relationship between robots is theoretically developed. It is characterised by sharing sensory information and tightly coordinating operational logic by taking care of each other's needs during missions. The system is characterised by an intertwined reasoning system while having separate conditioning and execution of plans to achieve subgoals to support each other. The results are illustrated on strong operational inter-dependence of a rover and a drone through shared logical inference. The drone uses the rover as a landing pad and the rover uses the drone to complements its sensor system by information gathering. There is a GitHub library provided in association with the demonstration for generic use of adding cameras and cooperation logic to a AR.Drone 2.0 and a KUKA youBot system. The benefits of symbiotic relationship are quantitatively evaluated on the demonstration example.

Background: Within the structural and grammatical bounds of a common language, all authors develop their own distinctive writing styles. Whether the relative occurrence of common words can be measured to produce accurate models of authorship is of particular interest. This work introduces a new score that helps to highlight such variations in word occurrence, and is applied to produce models of authorship of a large group of plays from the Shakespearean era. Methodology: A text corpus containing 55,055 unique words was generated from 168 plays from the Shakespearean era (16th and 17th centuries) of undisputed authorship. A new score, CM1, is introduced to measure variation patterns based on the frequency of occurrence of each word for the authors John Fletcher, Ben Jonson, Thomas Middleton and William Shakespeare, compared to the rest of the authors in the study (which provides a reference of relative word usage at that time). A total of 50 WEKA methods were applied for Fletcher, Jonson and Middleton, to identify those which were able to produce models yielding over 90% classification accuracy. This ensemble of WEKA methods was then applied to model Shakespearean authorship across all 168 plays, yielding a Matthews' correlation coefficient (MCC) performance of over 90%. Furthermore, the best model yielded an MCC of 99%. Our results suggest that different authors, while adhering to the structural and grammatical bounds of a common language, develop measurably distinct styles by the tendency to over-utilise or avoid particular common words and phrasings. Considering language and the potential of words as an abstract chaotic system with a high entropy, similarities can be drawn to the Maxwell's Demon thought experiment; authors subconsciously favour or filter certain words, modifying the probability profile in ways that could reflect their individuality and style.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

The Baryon Mapping eXperiment (BMX) is an interferometric array designed as a pathfinder for a future postreionization 21 cm intensity mapping survey. It consists of four 4-meter parabolic reflectors each having offset pyramidal horn feed, quad-ridge orthomode transducer, temperature-stabilized RF amplification and filtering, and pulsed noise injection diode. An undersampling readout scheme uses 8-bit digitizers running at 1.1 Gsamples/sec to provide access to signals from 1.1 -1.55 GHz (third Nyquist zone), corresponding to HI emission from sources at redshift 0 < z < 0.3. An FX correlator is implemented in GPU and generates 28 GB/day of time-ordered visibility data. About 7,000 hours of data were collected from Jan. 2019 -May 2020, and we will present results on system performance including sensitivity, beam mapping studies, observations of bright celestial targets, and system electronics upgrades. BMX is a pathfinder for the proposed PUMA intensity mapping survey in the 2030s.

The Vassiliev conjecture states that the Vassiliev invariants are dense in the space of all numerical link invariants in the sense that any link invariant is a pointwise limit of Vassiliev invariants. In this article, we prove that the Vassiliev conjecture holds in the case of the coefficients of the HOMFLY and the Kauffman polynomials. Contents 1 Reducing the problem: the weak Vassiliev conjecture 2 2 Approximation of the coefficients of the HOMFLYPT polynomial by Vassiliev invariants 3 2.1 Notations .

From Schkuhria pinnata (Lam.) O. Ktze. var. pinnata we isolated two flavonoids, identified as 5, 7, 3', 4' -tetrahydroxi-6-methoxy flavonol and 5, 7, 3', 4'tetrahydroxi-3-methoxy flavone. Resides these we found ~-sitosterol, a-amirina lupeol and a mixture of lineal hydrocarbon. De la Schkuhria pinnata (Lam.) O. Ktze. var. pinnata, reportamos el aislamiento de dos flavonoides, caracterizando a uno de ellos como el 5, 7, 3'; 4' -tetrahidroxi-6-metoxiflavonol y proponiendo tentativamente al otro como 5, 7, 3', 4'-tetrahidroxi-3-metoxiflavona, además de los ya reportados ~-sitosterol, a-amirina, lupeol y una mezcla de hidrocarburos lineales C-27 a C-33. • La Schkhuria pinnata (Lam.) O. Ktze. var. pinnata, conocida comúnmente como "canchalagua" o "canchalahua", es una planta silvestre que crece en

Vanadium redox flow batteries have, in previous studies, shown to have great potential for large-scale energy storage applications. Due to their beneficial characteristics, such as long lifetime, safety and flexible sizing the technology could be used for several different applications. In this study, the economic and technological feasibility of integrating a vanadium redox flow battery with a 100 MW wind farm is assessed. Different applications and operating schedules were tested. Simulating models have been built using conditional statements or linear optimisation and solved in MATLAB. Results suggested that a model which stacked power levelling with frequency regulation had the highest profitability. For this model the payback time was shown to be 10 years and the net present value was around 1.2 M€ for a 5 MW/10 MWh battery. However, the battery had around 820 annual charge/discharge cycles, which could be a limiting factor of the battery's lifetime. A sustainability assessment was carried out which concluded that the battery can be seen as sustainable, given that the battery is manufactured and operated under safe conditions. iv Vanadin redox-flödesbatterier har visat stor potential för storskaliga energilagringsapplikationer i tidigare studier. På grund av deras fördelaktiga egenskaper, såsom lång livstid, säkerhet och skalningsflexibilitet har teknologin många användningsområden. I denna studie utreds den ekonomiska och teknologiska möjligheten att integrera ett vanadium redox-flödesbatteri med en 100 MW vindpark. Olika applikationer och driftsstrategier testades. Simuleringsmodeller har byggts där linjäroptimering eller villkorssatser har tillämpats och dessa har lösts i MATLAB. Den mest ekonomiskt gynnsamma modellen var en modell där kraftbalansering och primär frekvensreglering kombinerades. Denna modell visade en återbetalningstid på 10 år och ett nuvärde på 1.2 M€ för en batteristorlek på 5 MW/10 MWh. Däremot hade batteriet 820 laddning/urladdnings cykler på år, vilket kan vara en begränsade faktorn för batteriets livstid. En hållbarhetsbedömning gjordes där slutsatsen kunde dras att batteriet kan anses hållbart, förutsatt att batteritillverkningen och driften görs under säkra förutsättningar. This M.Sc. thesis has been carried out during the spring of 2018 at KTH Royal Institute of Technology and is the final examination part in the M.Sc. program "Sustainable Energy Engineering". The thesis was commissioned by ÅF -Renewables and Energy Strategy, which have provided support and information throughout the study. The supervision of this thesis was partly funded by the STandUP for Energy project. First, we would like to express special thanks to Janine af Klintberg and Jakob Dotevall, for helping us throughout the project and supporting us when necessary. Thank you for giving us the chance to work together with ÅF. We would also like to thank our supervisor, Anders Malmqvist for providing excellent support and reviews of the report. Lastly, we would like to thank Erik Bergström at Statkraft and Maria Eriksson at Svenska kraftnät. Thanks for your patience with our questions about the power market. Without your help this thesis would not have been possible.

In modern day handheld cellular devices, low-profile is a key design target. In addition, with the introduction of 4G protocols, the number of cellular bands has increased significantly and the simultaneous transmission of multiple bands is more common than ever before. These requirements lead to challenges for designers as the close proximity of passive devices (e.g., antenna) to active devices (e.g., radio) can lead to additional distortions in the signal. Due to the overlapping nature of many frequency bands, harmonics/intermodulation distortion can seriously degrade the receiver sensitivity of coexisting radios. One way in which this can occur is that the antenna metal-to-metal contact can generate a metal-insulator/semiconductor junction due to surface roughness. If the gap between the layers is small enough, it can generate a tunnel current through the gap. This tunnel current has a non-linear I-V characteristic. For this reason, it is important to investigate the nonlinearity caused by passive sources in antenna structures. Non-linearity caused by passive sources can produce significant distortion for active devices with high transmit power or low receive sensitivity requirements. The aim of this research was to devise a measurement technique to study the unknown nonlinear behavior of radio frequency antenna metalto-metal contacts. Issues related to the measurement of low-level distortion were investigated. As part of this research, a measurement setup was developed to measure low-level distortion. Measurements made showed that intermodulation caused by metal-to-metal contact in the antenna structure can degrade receiver sensitivity significantly. This thesis also discusses an approach to modelling nonlinear relationships, based on the measurements made with the new test setup. provide valuable feedback. Working full time while doing this research as a part-time student, I had to steal lots of time from my family. I am grateful to my father for always trusting me, my mother for dedicating her life to me, my sister and brothers for being such wonderful beings and my supportive family for their patience. I owe great thanks to my wife for keeping patience, raising our two daughters with very little support from me. Without her help, I would not have been able to pull off my graduate studies. Finally, I would like to thank the Almighty God for giving me a wonderful family, and for allowing me to pursue my dream. v

In modern day handheld cellular devices, low-profile is a key design target. In addition, with the introduction of 4G protocols, the number of cellular bands has increased significantly and the simultaneous transmission of multiple bands is more common than ever before. These requirements lead to challenges for designers as the close proximity of passive devices (e.g., antenna) to active devices (e.g., radio) can lead to additional distortions in the signal. Due to the overlapping nature of many frequency bands, harmonics/intermodulation distortion can seriously degrade the receiver sensitivity of coexisting radios. One way in which this can occur is that the antenna metal-to-metal contact can generate a metal-insulator/semiconductor junction due to surface roughness. If the gap between the layers is small enough, it can generate a tunnel current through the gap. This tunnel current has a non-linear I-V characteristic. For this reason, it is important to investigate the nonlinearity caused by passive sources in antenna structures. Non-linearity caused by passive sources can produce significant distortion for active devices with high transmit power or low receive sensitivity requirements. The aim of this research was to devise a measurement technique to study the unknown nonlinear behavior of radio frequency antenna metalto-metal contacts. Issues related to the measurement of low-level distortion were investigated. As part of this research, a measurement setup was developed to measure low-level distortion. Measurements made showed that intermodulation caused by metal-to-metal contact in the antenna structure can degrade receiver sensitivity significantly. This thesis also discusses an approach to modelling nonlinear relationships, based on the measurements made with the new test setup. provide valuable feedback. Working full time while doing this research as a part-time student, I had to steal lots of time from my family. I am grateful to my father for always trusting me, my mother for dedicating her life to me, my sister and brothers for being such wonderful beings and my supportive family for their patience. I owe great thanks to my wife for keeping patience, raising our two daughters with very little support from me. Without her help, I would not have been able to pull off my graduate studies. Finally, I would like to thank the Almighty God for giving me a wonderful family, and for allowing me to pursue my dream. v

Submitted for the DFD13 Meeting of The American Physical Society von Neumann Stability Analysis of Pressure-Based Formulation of 1D and 2D Euler Equations SANTOSH KONANGI, URMILA GHIA, University of Cincinnati -The stability properties of a pressure-based scheme for the Euler equations are investigated, as such schemes are widely employed in commercial computational fluid dynamics codes. The published literature often focusses on model equations, and does not consider the solution scheme used in the parent code. The present study conducts a von Neumann stability analysis for a pressure-based, segregated scheme, SIMPLE (Semi-Implicit Method for Pressure-Linked Equations). The 1D and 2D Euler equations, closed by an "artificial" equation of state, are discretized using finite differences on a staggered grid, which permits equivalence to finite-volume discretization. As a first effort, first-order accurate spatial and temporal schemes are analyzed, to determine error amplification matrices, identify stable and unstable regimes, and predict practical stability limits in terms of the maximum allowable CFL number as a function of Mach number. The predictions are verified using the Riemann problem at several Mach numbers, and very good agreement is obtained between the predicted and the "numerically" observed CFL values. Hence, the present results should prove useful in guiding the stability of a simulation using the parent-code and the scheme tested here.

This paper presents a new topology for multilevel current source converters. The new converter uses parallel connections of full-bridge cells. Four different methods have been presented for the calculation of the levels in each bridge. These methods provide more flexibility for designers and can generate a large number of levels (odd and even). Also by adding or removing the full-bridge cells, modularized circuit layout and packaging is possible, where the number of output current levels can also be easily adjusted. Using enough levels, the multilevel current converter generates approximately sinusoidal output current with very low harmonic distortion. Based on this converter a shunt active filter has been modeled. The simulation results of the proposed shunt active filter and the traditional shunt filters (which are based on PWM convectors) show that the suggested filter is better than the traditional filter in distribution systems.

In this paper, an inverse compensator based on the Bouc-Wen model is used to reduce the effect of hysteresis on a piezoelectric micro-actuator. This compensator is used as an open loop controller which partially eliminates the system hysteresis effect. In the last step, in order to increase the reliability of the system and to achieve the desired goals, a H∞ robust controller is proposed in the presence of a compensator, to detect in the presence of modeling error and compensator error. At the end, simulation results are provided by MATLAB to demonstrate the effectiveness of the proposed control scheme. These results indicate that the proposed scheme provides a robust system performance and the tracking error reaches zero with acceptable accuracy.

In this paper, an inverse compensator based on the Bouc-Wen model is used to reduce the effect of hysteresis on a piezoelectric micro-actuator. This compensator is used as an open loop controller which partially eliminates the system hysteresis effect. In the last step, in order to increase the reliability of the system and to achieve the desired goals, a H∞ robust controller is proposed in the presence of a compensator, to detect in the presence of modeling error and compensator error. At the end, simulation results are provided by MATLAB to demonstrate the effectiveness of the proposed control scheme. These results indicate that the proposed scheme provides a robust system performance and the tracking error reaches zero with acceptable accuracy.

Artificial intelligence (AI) is rapidly changing the world, and education is no exception. AI-powered technologies are being used to automate tasks, personalize learning, and create new educational experiences. This has led to a great deal of excitement about the potential of AI to transform education. However, there are also concerns about the ethical implications of AI in education. In this paper, we explore the potential benefits and risks of AI in education. We argue that AI has the potential to improve education in many ways, but that it is important to carefully consider the potential challenges before widespread adoption. By carefully planning for the future of AI in education, we can ensure that it is used to improve education for all students. The findings from this study contribute to the ongoing discussion on the role of AI in higher education institutions in the changing economic environment and provide insights into the effective integration of AI to enhance educational quality, relevance, and employability outcomes.

One of the world wide health care concerns in the last two decades has been the decrease in fertility rates. The problem is said to be more severe among the male population. Research has shown that environmental factors and life style habits have an impact on the quality of semen. Orthodox diagnosis of seminal quality employs a laboratory approach, involving expensive tests, which are also sometimes uncomfortable to the patient. Application of machine learning techniques has been on the rise and has demonstrated encouraging results in many fields, including health care. In this paper we propose Naïve Bayes and Artificial Neural Network classifiers for the characterization of seminal quality, based on environmental factors and life style habits Comparisons between the two classifier models show that their accuracy rate is the same and stands at 97%, on the training set.

Woody invading alien plants, many of which are nitrogen-fixing legumes (Fabaceae family), are currently cleared in South African catchments to reduce water loss and preserve streamflow, and for the restoration of the ecosystem. This study tested the hypothesis that clearing invasive alien vegetation may disturb the vegetation-micro-organism-soil N cycling system by producing a large once-off input of fresh tree litterfall rich in N and by eliminating a large N sink. Three experimental plots were established at the Riverlands Nature Reserve (Western Cape, South Africa): a site invaded by Acacia saligna to be used as control; a site cleared of Acacia saligna; and a site with natural vegetation to be used as background. Nitrogen concentrations in soil and groundwater, volumetric soil water contents, root density and weather conditions were measured during 2007. Oxidised forms of nitrogen, in particular NO 3 -, were dominant in the system. Recharge and leachate were simulated with the HYDRUS-2D model and used as inputs into Visual MODFLOW to predict the spatial distribution of nitrate plus nitrite (NOx) in groundwater. NOx levels in soil and groundwater were higher in alien-invaded areas compared to fynbos-covered land. A quick release of NOx into groundwater was observed due to high residual N reserves in the rooting zone, decreased evapotranspiration and increased recharge in the treatment cleared of alien vegetation. In the long run, high NOx concentrations in groundwater underlying cleared land will last only until all the excess nitrogen has been leached from the soil. A decrease in NOx concentration in groundwater can be expected thereafter. Clearing land of alien invasive legumes may therefore have a beneficial effect by reducing groundwater contamination from NOx and reducing water losses in catchments.

The Atlantis Water Supply Scheme (AWSS, Western Cape, South Africa) has been in operation for about 40 years as a means to supply and augment drinking water to the town of Atlantis via managed aquifer recharge (MAR). In this study, the numerical model MODFLOW for groundwater flow and contaminant transport was used in support of the management of the AWSS. The aims were: (i) to calibrate the MODFLOW model for the MAR site at Atlantis; (ii) to run realistic scenarios that cannot be replicated through experiments; and (iii) to make recommendations in support of efficient and sustainable management of the aquifer. MODFLOW was calibrated through comparison of observed and simulated groundwater levels (R 2 between 0.663 and 0.995). Scenario simulations indicated possible drawdowns between < 5 m (low groundwater abstraction and low artificial recharge of groundwater through infiltration basins) and > 20 m (high abstraction and high artificial recharge) at localized areas of the Witzand wellfield. At Silwerstroom, large drawdown levels were not predicted to occur, so this wellfield could be exploited more without affecting the sustainability of the groundwater resource. Groundwater moves from the infiltration basins towards the Witzand wellfield at a rate of 120-150 m•a -1 . The modelling results supported recommendations for balancing groundwater abstraction and artificial recharge volumes, monitoring the water balance components of the system, the potential risks of groundwater contamination and the delineation of groundwater protection zones.

The primary aquifer at Atlantis (Western Cape, South Africa) is ideally suited for water supply and the indirect recycling of urban stormwater runoff and treated domestic wastewater for potable purposes. The relatively thin, sloping aquifer requires careful management of the artificial recharge and abstraction for balancing water levels. Water quality management is a further key issue at Atlantis for ensuring the highest quality potable water. Groundwater quality varies from point to point in the aquifer, while urban runoff and wastewater qualities vary greatly. The layout of the town allows for the separation of stormwater from the residential and industrial areas as well as separate treatment of domestic and industrial wastewater. This permits safe artificial recharge of the various water quality portions at different points in the aquifer, either for recycling or for preventing seawater intrusion. All of the management actions are dependent on detailed data collection and this paper describes the various parts of the system, describes the data collection activities, and provides results of the monitoring and aquifer responses over the past four decades. Challenges related to iron fouling of production boreholes are also described. The presence of emerging contaminants was studied in 2008 but requires follow-up research for establishing the extent of any possible threat to water recycling. In order to address the shortcomings of the system a risk management plan based on the Hazard Analysis and Critical Control Points approach was developed. Lessons learnt from the Atlantis experience can be transferred to other potential sites for establishment of similar systems in arid and semi-arid areas of South Africa and the African continent.

The adsorption of molecular acceptors is a viable method for tuning the work function of metal electrodes. This, in turn, enables adjusting charge injection barriers between the electrode and organic semiconductors. Here, we demonstrate the potential of pyrene-tetraone (PyT) and its derivatives dibromopyrene-tetraone (Br-PyT) and dinitropyrene-tetraone (NO 2 -PyT) for modifying the electronic properties of Au(111) and Ag(111) surfaces. The systems are investigated by complementary theoretical and experimental approaches, including photoelectron spectroscopy, the X-ray standing wave technique, and density functional theory simulations. For some of the investigated interfaces the trends expected for Fermi-level pinning are observed, i.e., an increase of the metal work function along with increasing molecular electron affinity and the same work function for Au and Ag with monolayer acceptor coverage. Substantial deviations are, however, found for Br-PyT/Ag(111) and NO 2 -PyT/Ag(111), where in the latter case an adsorption-induced work function increase of as much as 1.6 eV is observed. This behavior is explained as arising from a face-on to edge-on reorientation of molecules in the monolayer. Our calculations show that for an edge-on orientation much larger work-function changes can be expected despite the prevalence of Fermi-level pinning. This is primarily ascribed to a change of the electron affinity of the adsorbate layer that results from a change of the molecular orientation. This work provides a comprehensive understanding of how changing the molecular electron affinity as well as the adsorbate structure impacts the electronic properties of electrodes.

Controlling contact resistance in organic field‐effect transistors (OFETs) is one of the major hurdles to achieve transistor scaling and dimensional reduction. In particular in the context of ambipolar and/or light‐emitting OFETs it is a difficult challenge to obtain efficient injection of both electrons and holes from one injecting electrode such as gold since organic semiconductors have intrinsically large band gaps resulting in significant injection barrier heights for at least one type of carrier. Here, systematic control of electron and hole contact resistance in poly(9,9‐di‐n‐octylfluorene‐alt‐benzothiadiazole) ambipolar OFETs using thiol‐based self‐assembled monolayers (SAMs) is demonstrated. In contrast to common believe, it is found that for a certain SAM the injection of both electrons and holes can be improved. This simultaneous enhancement of electron and hole injection cannot be explained by SAM‐induced work‐function modifications because the surface dipole induced by t...

We report one of the first observations of lowfrequency noise of NiFe/Cu spin-valves. A ~t h o u g ~ the observed noise is very low in comparison to m ~~t ~~a y e r systems, it is typically concentrated in the linear region where such devices are expected to Increased noise is also associated with ~a r k h ~~s in the ~agnetores~stance trace. In devices one m i c ~o ~e t e r high, structures start to appear in the noise s perturbation to the simple llf-like noise observ devices. Although the large magnetoresistance of spin-valves make them attractive as magnetic read heads, this same sensitivity could also make them susceptible. to thermally activated noise. Due to processing effects, edge effects, and nonuniformities in the layer structure, there may be regions in a spinvalve that are weakly coupled to the main part of the device which could give rise to llf noise. These regions may be thought of as consisting of domains which are distinct from and in addition to the "single domain" of an ideal spin-valve. Additionally, due to strong magnetostatics, microdomains may also show llfnoise which is correlated with Barkhausen noise. In particular, as linear response is sought in sub-micrometer devices, either of two scenarios could result in increased noise. Domain sizes may be expected to decrease with a possible corresponding increase in their sensitivity to thermally driven noise. Alternatively, if domain sizes remain constant, unstable domains could come to dominate small device behavior. We have pursued observations of llj-type noise in NiFe/Cu spin valves. The noise we observe is typically concentrated near the low-field linear response region. The noise does not scale in an obvious manner with device height. We also find peaks in the noise near Barkhausen jumps in the magnetoresistance (MR) curve. These peaks may arise from thermally driven fluctuations of the large domain responsible for the Barkhausen resistance jump.

We report noise data for discontinuous Ni82Fe18/Ag multilayer test structures. Examination of the noise data for this material indicates that random telegraph fluchator (RTF) noise of the resistance is the predominant noise source. Analysis of the RTF noise in these structures presents an opportunity to estimate magnetic domain or magnetic cluster strengths and the domain-domain interactions.

We show that thin-film Ni82Fe18/Ag multilayer structures display multiple peaks in their magnetoresistance curves when biased at current densities above 106 A/cm2. These peaks appear for annealed and unannealed structures, and their number is correlated with the number of NiFe layers. At high bias currents, the peak positions shift linearly with the internal magnetic field created by the bias current. The peak positions extrapolate to nonzero fields at zero bias currents, providing an upper bound on the magnetic layer-layer coupling strength of J0≊10−20 J (kB×700 K). The peak positions do not shift with temperature over the range 200–375 K; their widths narrow with increasing temperature. The single-domain magnetic moment μ is estimated as 10−17 J/T (106 μB) from the peak widths of ∼0.8 kA/m.

Questo paper affronta un cambiamento paradigmatico nelle relazioni tra impresa e cliente di cui si osservano i primi effetti indotti soprattutto dalle comunicazioni via Web. Si tratta della sempre maggiore presenza e intervento nella vita aziendale da parte dei clienti, dapprima stimolati a un comportamento partecipativo da parte delle imprese che poi, timorose delle conseguenze non previste che questa invadenza crea, cercano di frenare l’ingresso e la loro partecipazione. L’invadenza dei clienti, infatti, cambia le regole di relazione del mercato e i sistemi di gestione degli asset di marketing delle imprese. A supporto di questa considerazione si e fatto riferimento a una ricerca sulla comunicazione Web 2.0 nelle societa di calcio italiane di serie A e B, dove e evidente l’invadenza dei supporter-clienti. This study copes with a paradigmatic change in the relationships between companies and customers that is strongly visible in web communication. This change concerns the growing p...

L’indagine, a carattere esplorativo, condotta su 30 imprese che investono almeno un milione di euro in comunicazione, si propone di identificare modelli e strumenti utilizzati dalle imprese per misurare l’efficacia della comunicazione. I risultati confermano che piu elevato e il budget maggiore e l’interesse a controllare l’efficacia della comunicazione utilizzando piu indici (il 56.7% delle imprese fa uso di misure di efficacia). Internet e le campagne di direct marketing risultano piu monitorati rispetto a sponsorizzazione e PR. Gli indici utilizzati sono legati a vendite e quote di mercato. The purpose of this study is to identify which models and tools companies use to measure communication effectiveness. An empirical investigation was carried out with exploratory purposes involving 30 companies which invest in communication activities at least one million euros. The survey results confirm that the more companies are investing, the more they need to evaluate the returns of activ...

is an Education Specialist and Curriculum Developer at the Tufts Center for Engineering Education and Outreach; she has a M.Ed. in Literacy Instruction K-12 and is a certified Reading Specialist. She has taught 1-4th grades and included engineering concepts and thinking in her curriculum. Her focus is to help teachers gain confidence and experience in STEM and enable them to inspire and teach engineering to budding engineers.

is an Education Specialist and Curriculum Developer at the Tufts Center for Engineering Education and Outreach; she has a M.Ed. in Literacy Instruction K-12 and is a certified Reading Specialist. She has taught 1-4th grades and included engineering concepts and thinking in her curriculum. Her focus is to help teachers gain confidence and experience in STEM and enable them to inspire and teach engineering to budding engineers.

The national efforts underway to include engineering in K-12 science education present a variety of new challenges, including how to prepare teachers to teach a new discipline. In this paper, we focus on elementary teachers and how they enter into responsive teaching, in which they closely attend and meaningfully respond to students' thinking. This pedagogical approach is particularly critical for teaching engineering design in ways that support students in developing original solutions to complex, dynamic problems. Drawing on 3 years of professional development that helped teachers incorporate engineering in literacy contexts, we investigated the knowledge and abilities teachers displayed for responsive teaching and how features of instructional design and classroom dynamics impacted their teaching. Throughout the project, we observed and videotaped professional development workshops and teachers' classrooms, and interviewed teachers about their classroom experiences. We then conducted a thematic analysis across these data sources, presenting common themes as conjectures for how teachers enter into responsive teaching in engineering. We discuss how these conjectures can inform teacher research and the design of teacher preparation programs in engineering.

Society is recognizing the need to improve STEM education and introduce engineering design concepts before college. In the recent National Academy of Engineers report, Engineering in K-12 Education: Understanding the Status and Improving the Prospects, the authors suggest that the STEM disciplines not be treated as―silos‖ and that engineering might serve as a motivating context to integrate the four STEM disciplines (Katehi, Pearson, & Feder, 2009). Recent research has suggested that integrated technology and ...

Sprawny proces zarządzania zasobami ludzkimi w przedsiebiorstwie stanowi o skuteczności dzialania oraz skutkuje optymalnym wykorzystaniem wszystkich niezbednych zasobow do osiągniecia celow organizacyjnych. Niezwykle istotnym faktem jest świadomośc znaczenia jakości pracy i jej wplywu na globalne zarzą dzanie firmą. Proces ten ma niebagatelne znaczenie w polityce personalnej, a czynniki ksztaltujące stają sie cennym narzedziem kadry kierowniczej kazdego szczebla do prowadzenia efektywnego zarządzania zasobami ludzkimi. W artykule poruszono zasadnicze kwestie dla zarządzania jakością pracy. Zaprezentowano rowniez wachlarz indywidualnych i organizacyjnych dzialan mogących przyczynic sie do usprawnienia, a w konsekwencji do podniesienia jakości pracy czlonkow organizacji 1 .

For the first time in Mexico, a comprehensive data gathering and analysis project on the seismic performance of school buildings in the aftermath of the 2017 earthquakes was developed. Aimed at supporting the planning and decision-making of the Mexican government's reconstruction program, school performance was observed and measured in the field. To further evaluate building performance, numerical modeling of archetypical buildings was carried out. Calculated performance was consistent with observed structural damage. Numerical analysis indicated that pre-1985 masonry and concrete buildings are more likely to exhibit damage that could compromise the structural stability. In contrast, recent structures are very likely to attain the immediate occupancy (IO) performance level that is implicitly assumed in school design. Studies indicated that rehabilitated school buildings through wall jacketing in masonry buildings and by adding new concrete shear walls and masonry infills to concrete structures are likely to comply with IO. From the lessons learned, policy, technical, implementation, and sustainability and outreach recommendations are proposed to implement a multiannual, systematic, incremental, and integral strategy for reducing earthquake risk of school buildings in Mexico.

For the first time in Mexico, a comprehensive data gathering and analysis project on the seismic performance of school buildings in the aftermath of the 2017 earthquakes was developed. Aimed at supporting the planning and decision-making of the Mexican government’s reconstruction program, school performance was observed and measured in the field. To further evaluate building performance, numerical modeling of archetypical buildings was carried out. Calculated performance was consistent with observed structural damage. Numerical analysis indicated that pre-1985 masonry and concrete buildings are more likely to exhibit damage that could compromise the structural stability. In contrast, recent structures are very likely to attain the immediate occupancy (IO) performance level that is implicitly assumed in school design. Studies indicated that rehabilitated school buildings through wall jacketing in masonry buildings and by adding new concrete shear walls and masonry infills to concrete...

This qualitative research advocates for prioritizing Critical and Creative Thinking in professional design over empathy. The study involved 74 undergraduate Product Design and Engineering students from Brazil, Portugal, and India to explore the relationship between these thinking skills and sustainability. The students' Critical and Creative Thinking levels were evaluated using rubrics developed by Shively et al. ( ) and a multi-level framework developed by Ceschin & Gaziulusoy (2019) was applied to identify sustainable innovation levels. The research highlights the need to enhance tertiary students' skills in addressing wicked problems, a concern recognized by the Organization for Economic Co-operation and Development for the 21st-century workplace. This research contributes to the ongoing debate on the significance of Critical and Creative Thinking in professional design practice and emphasizes the importance of integrating sustainability considerations into design education.

Archaeo-geophysics currently stands as a powerful discipline in European archaeological research to discover, study and record subsurface archaeological sites. Its importance lies in its capacity to reveal hidden archaeological assets in a non-destructive, rapid and detailed manner in comparison with traditional and more invasive archaeological methods such as excavation or test-trenching. In the last decade, a major technological development in archaeo-geophysics has been the introduction of multi-sensor and motorised instrumentation. This has revolutionised archaeological prospection by allowing extremely fast and high-resolution surveys to explore large areas.Whilst the discipline of archaeo-geophysics is going through an exciting phase of technological development, a major problem concerning researchers and practitioners is that our ability to interpret the full suite of information extractable from geophysical datasets has not kept pace with developments in technology and is st...

This paper discusses how to build a time scale with an intermittently-operated optical clock. In particular, it gives suggestions on how long and how often to run an optical clock. It also explores the benefits of having an optical clock in a time scale, by comparing with the current UTC(NIST) performance and the time scale with a continuously-operated Cs fountain.

In this paper, we apply the method of discrete simulation of power-law noise, developed by Timmer and König, Ashby, and Ashby and Patla, to the problem of simulating phase noise for a combination of power-law noises. We derive analytic expressions for the probability of observing a value of phase noise L(f) or of any of the one-sided spectral densities S(f), S(f) , or S(f) , for arbitrary superpositions of power-law noise.

This paper discusses the results of a simulation of a time scale based on continuously operating commercial hydrogen masers and an optical frequency standard that does not operate continuously as a clock. The simulation compares the performance of this time scale with one that is based on the same commercial devices but incorporates a continuously operating cesium fountain instead of the optical standard. The results are independent of the detailed characteristics of the optical frequency standard; the only requirement is that the optical device be much more stable than the masers in the ensemble. We discuss two methods for realizing the results of this simulation in an operational time scale.

A method for simulating power law noise in clocks and oscillators is presented based on modification of the spectrum of white phase noise, then Fourier transforming to the time domain. Symmetric real matrices are introduced whose traces-the sums of their eigenvalues-are equal to the Allan variances, in overlapping or non-overlapping forms, as well as for the corresponding forms of the modified Allan variance. We show that the standard expressions for spectral densities, and their relations to Allan variance, are obtained with this method. The matrix eigenvalues determine probability distributions for observing a variance at an arbitrary value of the sampling interval τ, and hence for estimating confidence in the measurements. Examples are presented for the common power-law noises. Extension to other variances such as the Hadamard variance, and variances with dead time, are discussed.

Karachi has experienced major surges in population due to the migration of people and urbanization. This growth in population has not been complemented with appropriate planning, which has been evident in the transportation sector as well. This paper discussed in detail the current situation of public transport in the city. The outcome of this research consists of identification of major problem areas and recommendations to be adapted for integrated improvement of the transportation system in light of various surveys and studies.

Artigo submetido em agosto/2012 e aceito em maio/2013 RESUMO A fixação biológica de N 2 , associada às plantas forrageiras é importante no ciclo do nitrogênio, pois bactérias podem atender no suprimento do nutriente necessário às plantas. Amostras de raízes foram coletadas de três gramíneas: Andropogon, Capim Tanzânia e Capim Buffel. Para bactérias isoladas em meio seletivo procederam-se: Quantificação, caracterização fenotípicas, eposteriormente purificadas com hipoclorito de sódio e armazenadas em sacos plásticos. A densidade de bactérias foi influenciada pelos nichos radiculares e gramíneas forrageiras, sendo o capim Andropogon e Buffel que apresentaram maiores densidades de microorganismos.