Land utilization and ecological aspects in the Sylhet-Mymensingh Haor Region of Bangladesh: An analysis of LANDSAT data

The use of remote sensing data from LANDSAT (ERTS) imageries in identifying, evaluating and mapping land use patterns of the Haor area in Bangladesh was investigated. Selected cloud free imageries of the area for the period 1972-75 were studied. Imageries in bands 4, 5 and 7 were mostly used. The method of analysis involved utilization of both human and computer services of information from ground, aerial photographs taken during this period and space imageries

Patterns of population structure and growth in East Pakistan

The aspects of population structure refer to the individually carried traits or attributes of a population group, and include such ascribed and non ascribed characteristics as age, sex, marital status, literacy and education, economic activities and related phenomena which are thought to be the principal associates of geodemographic conditions and socio-economic levels of a country. These observations are applied in this study of population of East Pakistan, The study attempts by means of a detailed and exclusive analysis of the available materials to evaluate and elaborate past and present patterns in the different ascribed and non-ascribed characteristics of the population and their growth in socio-economic, cultural and regional contexts, and in quantitative terms. For regional studies, the 17 rural districts and 37 selected urban centres have been taken into consideration in relation to different aspects of population structure. Further, the aspects of population structure are studied individually and regionalized quantitatively by using a multivariate technique, known as Factor Analysis, which incorporates geodemographic and socio-economic variables for the respective residential areas. The results of the quantification present some of the most significant spatial characteristics in this agrarian society with very high density, ethno-cultural and linguistic homogeneity, low urbanization, high and stable fertility, and unbalanced and un-favourable age-sex structures, which have far reaching geodemographic implications in the country. On the other hand, as indicated in the text, the patterns of the population characteristics are closely associated with the framework on which rests the institutional structure of the whole society, and the attitude and outlook of the people who live within it. Many elements of population composition are themselves functions of the form and the mode of operation of existing institutions, i.e. value systems, traditions and norms. The residential variations in this connection only reflect the mode of their institutional differentials. The uniformity in the aspects of population structure within a particular residential or regional unit signifies the institutional exclusiveness or distinctiveness within it, the intra-residential and spatial differences imply the degree of dynamism or change in this exclusiveness - which is more apparent in the urban centres than in the densely populated rural areas. The overall low variability in most elements of population structure, in turn, reflects the slow socio-economic change, and the traditionalism in the geodemographic set-up of East Bengal, Given no significant institutional and attitudinal changes any radical and favorable transformation in the patterns of population structure in the province seems to be rather remote. These aspects of East Pakistan's population are of particular importance in relation to her geodemographic development and planning strategy in relation to the overall socio-economic development of the country

Energy harvesting towards self-powered iot devices

The internet of things (IoT) manages a large infrastructure of web-enabled smart devices, small devices that use embedded systems, such as processors, sensors, and communication hardware to collect, send, and elaborate on data acquired from their environment. Thus, from a practical point of view, such devices are composed of power-efficient storage, scalable, and lightweight nodes needing power and batteries to operate. From the above reason, it appears clear that energy harvesting plays an important role in increasing the efficiency and lifetime of IoT devices. Moreover, from acquiring energy by the surrounding operational environment, energy harvesting is important to make the IoT device network more sustainable from the environmental point of view. Different state-of-the-art energy harvesters based on mechanical, aeroelastic, wind, solar, radiofrequency, and pyroelectric mechanisms are discussed in this review article. To reduce the power consumption of the batteries, a vital role is played by power management integrated circuits (PMICs), which help to enhance the system's life span. Moreover, PMICs from different manufacturers that provide power management to IoT devices have been discussed in this paper. Furthermore, the energy harvesting networks can expose themselves to prominent security issues putting the secrecy of the system to risk. These possible attacks are also discussed in this review article

Prediction of pulse-to-pulse intensity fluctuation characteristics of high power ultrafast fiber amplifiers

Cataloged from PDF version of article.We report on the experimental characterization and theoretical prediction of pulse-to-pulse intensity fluctuations, namely, intensity noise, for ultrafast fiber amplifiers. We present a theoretical model with which the intensity noise of a Yb-doped fiber amplifier can be predicted with high accuracy, taking into account seed and pump noise, as well as generation of amplified spontaneous emission. Transfer of pump and seed signal modulations to the amplified output during fiber amplification are investigated thoroughly. Practically, our model enables design and optimization of fiber amplifiers with regards to their intensity noise performance. As a route to reducing noise imparted by pump diodes in a double-clad amplifier, we show the use of multiple, low-power diodes is more beneficial compared to a single, high-power diode due to the largely uncorrelated nature of their individual noise contributions. (C) 2014 AIP Publishing LLC

Home Is Where You Hang Your Hat: Host Town Identity, But Not Hometown Identity, Protects Against Mental Health Symptoms Associated with Financial Stress

Debt and financial insecurity are associated with stress, low self-worth, and poor health. Joining and identifying with social groups (social identification) promotes better health and higher self-esteem. Here, we examined whether identifying with one's local neighborhood protected people from developing mental health symptoms associated with financial stress. We analyzed data from a general population survey (Study 1, N = 4319) and a student mental health survey (Study 2, N = 612) conducted in the North West of England. We administered measures of financial stress, self-esteem, neighborhood identity, and mental health, and conducted moderated mediation analyses to test our predictions. Study 1 (population survey) demonstrated that stronger identification with one's local neighborhood attenuated the adverse effects of financial stress on self-esteem and subsequent mental health. Study 2 (student survey) showed that strong host town identities buffered students from mental health symptoms related to financial stress. Strong hometown identities, however, showed no buffering effect. The findings suggest that one way financial stress impacts mental health is by eroding self-esteem. Identifying with one's current place of residence appears to disrupt this pathway, while identifying with one's previous place of residence does not provide the same psychological protection. Read More: https://guilfordjournals.com/doi/10.1521/jscp.2018.37.3.15