Pulse shaping in mode-locked ring-cavity fibre lasers

By means of extensive numerical modelling we have demonstrated the possibility of nonlinear pulse shaping in a mode-locked fibre laser using control of the intra-cavity propagation dynamics by adjustment of the normal net dispersion and integrated gain. Beside self-similar mode-locking, the existence of a novel type of pulse shaping regime that produces pulses with a triangular temporal intensity profile and a linear frequency chirp has been observed.

1220km propagation of 40Gbit/s single channel RZ data over dispersion managed standard (non-dispersion shifted) fibre

Error free propagation of a single polarisation optical time division multiplexed 40 Gbit/s dispersion managed pulsed data stream over dispersion (non-shifted) fibre. This distance is twice the previous record at this data rate.

16,000 km, 10 Gbits-1 soliton transmission over standard fibre by reduction of interactions through optimum amplifier positioning

We show that by optimizing the amplifier position in a two-stage dispersion map, the (dispersion-managed) soliton-soliton interaction can be reduced, enabling transmission of 10-Gbits-1 solitons over standard fiber over 16,000 km

Design of Raman-based NOLM for optical 2R regeneration of RZ-DPSK transmission

We present a concept for all-optical differential phase-shift keying (DPSK) signal regeneration, based on a new design of Raman amplified nonlinear loop mirror (RA-NOLM). We demonstrate simultaneous amplitude-shape regeneration and phase noise reduction in high-speed DPSK systems by use of the RA-NOLM combined with spectral filtering.

Highly birefringent long period gratings fabricated with femtosecond laser

Long Period Gratings (LPG) in standard fiber have been manufactured with a sharply focused near infrared (NIR) femtosecond laser beam. Polarization splitting of the attenuation bands is strongly dependent upon the inscription power.

Quantitative optical coherence tomography for characterization of microscopic structures with varying refractive index

In this paper we have done back to back comparison of quantitive phase and refractive index from a microscopic image of waveguide previously obtained by Allsop et al. Paper also shows microscopic image of the first 3 waveguides from the sample. Tomlins et al. have demonstrated use of femtosecond fabricated artefacts as OCT calibration samples. Here we present the use of femtosecond waveguides, inscribed with optimized parameters, to test and calibrate the sensitivity of the OCT systems.

Impression of the global climate change on the ornamental plant usage in Hungary

The climate modeling, which has adequate spatial and temporal resolution, shows that the future climate of the Carpathian Basin will be much more arid and hot than nowadays. The currently used and taught assortment of the ligneous ornamental plants should be urgently revised. It is aimed in my research to collect the species which will probably be introduced in the future. They can be gathered from the Hungarian botanical gardens and research centers and from the spatially analogous territories. The collected taxa should be examined with GIS software if they will really suffer our future climate.

Blue Development: Analyzing the Role of the State in the Rise of Aquaculture in India

In this paper, I analyze the processes that transformed aquaculture into a major export industry in India, in order to understand the role aquaculture has as a social and economic development strategy of the Indian state. The discussion employs a political ecology approach as I explore the complex relations between access and control of India’s coastal resources, society, and economy. I argue that many of the forces that initiated the development of aquaculture in India, namely the involvement of the Indian state, continue to shape the industry today. I also discuss how despite widespread social conflict, the shrimp farming industry, in particular, continues to thrive and grow in rural India. My analysis utilizes ethnographic and archival data collected over the course of 9 months of fieldwork in Tamil Nadu, India. Keywords: rural development, aquaculture, India, State, ethnography

The Anthropocene as an Accumulation Strategy

TBA

Desenvolvimento e calibração de fotômetro solar para medições da profundidade óptica por aerossóis e coluna de água precipitável

Instrumentation is a tool of fundamental importance for research in several areas of human knowledge. Research projects are often unfeasible when data cannot be obtained due to lack of instruments, especially due to impor ting difficulties and the high costs there associated. Thus, in order to collaborate with the enhancement of a national technology, a multiband hand - held sun p hotometer (FSM - 4) was developed to operate in the 500 nm, 670 nm, 870 nm and 940 nm bands. In the 500 nm, 670 nm and 870 nm bands aerosols are monitored for evaluation of the AOD (Aerosol Optical Depth), and the PWC (Precipitable Water Column) is evaluated in the 940 nm band. For the development of the mech anical and electronic parts for the FSM - 4, th e materials and componen ts should combine low cost and quality of the data collected. The calibration process utilized the Langley method (ML) and Modified Langley Method (MLM). These methods are usually applied at high altitudes in order to provide atmosp heric optical stability. This condition however can be found in low height sites as shown in the research by Liu et al. (2010). Thus, for calibration of the FSM - 4, we investigated the atmospher ic optical stability utilizing the ML and MLM at a site in the cit y of Caicó / RN, located in the s emiarid region in northeastern Brazil. This site lies in a region far aw ay from large urban centers and activities generating anthropogenic atmospheric pollution. Data for calibration of the prototype were collected usin g the FSM - 4 in two separate operations during the dry season, one in December 2012 and another in September 2013. The methodologies showed optical atmospheric instability in the studied region through the dispersion of the values obtained for the calibrati on constant. This dispersion is affected by the variability of AOD and PWC during the appl ication of the above mentioned methods . As an alternative to the descr ibed sun photometer calibration , a short study was performed using the sun photometer worldwide network AERONET/NASA (AERsol RObotic NETwork – US Space Agency), installed in Petrolina / PE in Brazil. Data were collected for three days utilizing the AERONET instruments and the FSM - 4, operating simultaneously on the same site. By way of the ML and MLM techniques, convergent test values were obtained for the calibration constants, despite the low amount of data collected. This calibration transfer methodology proved to be a viable alternative to the FSM - 4 calibration .

Ícones urbanos na cidade de Natal: arquitetura e desenvolvimento urbano na cidade do sol e mar

Natal has come through major changes in the last 150 years, since the actions of city beautification, in the 19th century, until the present day, when such transformations start to have the objective of including the city in the competition for the attraction of the capital flows and consumption, domestically and in a foreign sense. It is thought that the first initiatives aimed at increasing tourism in Natal occurred in the 1960s, however, it became apparent that only from the 1980s was there a significant increase in tourist activities in Natal and the Metropolitan Region, especially on the east coast of the state of Rio Grande do Norte, leading to an expansion of the labour market, the significant increase of foreign investment, territorial changes of great impact and the production of buildings primarily intended for the hotel industry and second residence for European tourists. Since then, the incentives for tourist activity in the state have been maintained and even increased, based on tourism aimed at natural beauties, local cuisine and events, which transformed the tourist activity in one of the main sources of foreign exchange for the city of Natal. In the early 21st century, the construction of high-rise condominiums, monuments (including the designer ones), such as the Parque da Cidade, designed by Oscar Niemeyer, were already established. Also, shopping centers and, in order to host the World Cup, the new football stadium, the Arena das Dunas, among others, which were aimed at local and foreign consumers, especially European, stood out in the city. It is understood that these new buildings, monuments and also renovations and restorations that were deployed in the city of Natal aimed at constructing a new identity for the city, within the process of capitalist development and urban spectacle. It is considered that the monuments and the iconic buildings are attributes of the cities aimed at selling locations as goods, establishing a new urban environment, a new role as cities, which aimed at seeking greater autonomy from the nation-state. In this research, it was sought to analyze the architectural object, that is, buildings and monuments built or restored in Natal and its relevance to the city marketing promoted by the city itself. It was found that, indeed, such buildings and monuments are inserted in contemporary architectural production as a basis for increasing the competitive nature of Natal. In addition, they reveal a capitalist mode of production, supported by public resources, operating in the production of urban space with a view to repeating the hegemonic model of a competitive city

Otimização do controle do diagrama de radiação de radares de varredura para rastreio de foguetes usando o método GAMMC para o Caso Planar (GAMMC-P)

Launching centers are designed for scientific and commercial activities with aerospace vehicles. Rockets Tracking Systems (RTS) are part of the infrastructure of these centers and they are responsible for collecting and processing the data trajectory of vehicles. Generally, Parabolic Reflector Radars (PRRs) are used in RTS. However, it is possible to use radars with antenna arrays, or Phased Arrays (PAs), so called Phased Arrays Radars (PARs). Thus, the excitation signal of each radiating element of the array can be adjusted to perform electronic control of the radiation pattern in order to improve functionality and maintenance of the system. Therefore, in the implementation and reuse projects of PARs, modeling is subject to various combinations of excitation signals, producing a complex optimization problem due to the large number of available solutions. In this case, it is possible to use offline optimization methods, such as Genetic Algorithms (GAs), to calculate the problem solutions, which are stored for online applications. Hence, the Genetic Algorithm with Maximum-Minimum Crossover (GAMMC) optimization method was used to develop the GAMMC-P algorithm that optimizes the modeling step of radiation pattern control from planar PAs. Compared with a conventional crossover GA, the GAMMC has a different approach from the conventional one, because it performs the crossover of the fittest individuals with the least fit individuals in order to enhance the genetic diversity. Thus, the GAMMC prevents premature convergence, increases population fitness and reduces the processing time. Therefore, the GAMMC-P uses a reconfigurable algorithm with multiple objectives, different coding and genetic operator MMC. The test results show that GAMMC-P reached the proposed requirements for different operating conditions of a planar RAV.

Análise da atuação do Ministério Público Estadual na assistência materno infantil do Rio Grande do Norte

Maternal and infant mortality have become a serious public health problem in Brazil, especially in northeasternand northern regions.In RioGrande do Norte, the high rates ofdeathsofmothersandbabies haveconcerned not onlythehealthauthorities andjusticeagenciessuch as the prosecution service. In 2011, State Public Ministry (MPE) has developed a proposition which was called “Nascer com Dignidade”, focused on the monitoring ofcare givenin prenatal, childbirth andpost childbirthin the cities. The aim of thisstudy was toinvestigate how the intervention of MPE works in maternal and child care. The method adopted to survey data was the case study by analyzing the skills of the reports which were carried out in four of the eight Public Health Regional Units (URSAP).A total of 26municipalities were chosenand the results showfragilityparticularly inprenatal care which can result in complicationsin childbirthand postpartumlike:incomplete health family teams(in05cities), lack of access orinaccessibility to laboratory tests(16 cities) and lack of the pregnant woman'sattachment to thebirthing place(in26 cities). Based on this reality, MPE has adopted relevant attitudes as filing public civil suits, compliance of Conduct Adjustment Declaration in the municipal management and performing interventions in heath care centers and maternity clinics of the state. Thereforeit is known thatPublic Ministryis of paramount importanceto indicatethe necessaryadjustmentsto addressinfant and maternalmortalityin the state (mean of 65/100,000 and16/100,000respectively) and give the city hall the responsibility for the health care quality provided to their citizens. These factors demand theprinciples ofuniversality and integrality to be performed in order to reduce social inequities.

Empirical expression of tool wear when face milling 416 SS

During a machining process, cutting parameters must be taken into account, since depending on them the cutting edge starts to wear out to the point that tool can fail and needs to be change, which increases the cost and time of production. Since wear is a negative phenomenon on the cutting tool, due to the fact that tool life is reduced, it is important to optimize the cutting variables to be used during the machining process, in order to increase tool life. This research is focused on the influence of cutting parameters such as cutting speed, feed per tooth and axial depth of cut on tool wear during a face milling operation. The Taguchi method is applied in this study, since it uses a special design of orthogonal array to study the entire parameters space, with only few numbers of experiments. Also a relationship between tool wear and the cutting parameters is presented. For the studies, a martensitic 416 stainless steel was selected, due to the importance of this material in the machining of valve parts and pump shafts. Copyright © 2009 by ASME.