Explicit design formulae for digital tan filters with low-pass,high-pass,band-pass,and band- stop characteristics

Explicit expressions of transfer functions for digital tan filters with low-pass, high-pass, band-pass, and band-stop characteristics approximating given design specifications are advanced. The higher order transfer function satisfying the design specification is expressed as the product of first-order and second-order filter sections of identical forms but with different coefficient values. All coefficients of these low-order filter sections are expressed in explicit forms related simply to the specification values. Thus, the result developed can be easily applied for the cascade or time-sharing realization. The low-order filter section developed here can be implemented with the fewest multipliers.The design formulae for Butterworth, Chebyshev, inverse Chebyshev and elliptic approximations are included. The transfer functions for all these filters are expressed in the same form of low-order filter section with different coefficient values.     

Study on the use of dielectrophoresis and electrothermal forces to produce on-chip micromixers and microconcentrators

The present study uses the dielectrophoresis (DEP) and electrothermal (ET) forces to develop on-chip micromixers and microconcentrators. A microchannel with rectangular array of microelectrodes, patterned either on its bottom surface only or on both the top and the bottom surfaces, is considered for the analysis. A mathematical model to compute electrical field, temperature field, the fluid velocity, and the concentration distributions is developed. Both analytical and numerical solutions of standing wave DEP (SWDEP), traveling wave DEP (TWDEP), standing wave ET (SWET), and traveling wave ET (TWET) forces along the length and the height of the channel are compared. The effects of electrode size and their placement in the microsystem on micromixing and microconcentrating performance are studied and compared to velocity and concentration profiles. SWDEP forces can be used to collect the particles at different locations in the microchannel. Under positive and negative DEP effect, the particles are collected at electrode edges and away from the electrodes, respectively, irrespective of the position, size, and number of electrodes. The location of the concentration region can be shifted by changing the electrode position. SWET and TWET forces are used for mixing and producing concentration regions by circulating the fluid at a given location. The effect of forces can be changed with the applied voltage. The TWDEP method is the better method for mixing along the length of the channels among the four options explored in the present work. If two layers of particle suspension are placed side by side in the channel, triangular electrode configuration can be used to mix the suspensions. Triangular and rectangular electrode configurations can efficiently mix two layers of particle suspension placed side-by-side and one-atop-the-other, respectively. Hence, SWDEP forces can be successfully used to create microconcentrators, whereas TWDEP, SWET, and TWET can be used to produce efficient micromixers in a microfluidic chip.     

Assessement of Blood Lead and Cadmium Levels in Occupationally Exposed Workers of Jodhpur,Rajasthan

In spite of the established knowledge regarding their toxicities, occupational exposure to heavy metals like lead and cadmium still continues because of their wide distribution in environment. Due to lack of awareness, most of the workers usually eat, smoke, drink at their workplace which may aggravate the metal exposure. The present study was planned to assess the blood levels of lead and cadmium in occupationally exposed workers of Jodhpur (India). A total of 110 individuals working in different industrial set ups (furniture, metal handicraft, welders) of Jodhpur district (exposed group), aged between 20 and 60 years and 97 apparently healthy people (controls) with no history of occupational heavy metal exposure aged between 25 and 60 were recruited. Details of personal habits and demographics were recorded by means of self-developed questionnaire. 5 ml of whole blood was drawn from every individual. Metal levels were measured by graphite furnace atomic absorption spectrophotometer. Statistical analysis was done using GraphPad Prism Software. Results showed that Blood Lead Level and Blood Cadmium Level (CdB) were significantly higher in the exposed group as compared to the non-exposed group. Significant age and gender-based differences were found in terms of blood cadmium levels but no such difference was observed in case of blood lead. The study also revealed that higher blood levels of these metals in workers are influenced by their occupational practices, lack of protection against workplace environment pollutants, thus increasing their susceptibility to metal toxicity.     

Prevalence of Vitamin D Deficiency in a Pediatric Hospital of Eastern India

Vitamin D deficiency is highly prevalent in Indian children of northern, western and southern states. Serum 25 hydroxy cholecalferol (ng/ml) was analyzed in 310 children and adolescents of pediatric hospital of Kolkata, India. Serum calcium (mg/dl), phosphorous (mg/dl) and alkaline phosphatase (IU/L) data was obtained. Median 25(OH)D was 19 ng/ml. 19.2 % of population had serum 25(OH)D < 10 ng/ml (severe deficiency), 52.9 % had <20 ng/ml (deficiency), 24.5 % had 20–29 ng/ml (insufficiency) and 22.6 % had >30 ng/ml (optimum). Deficiency was highest in adolescents (86.1 %), followed by school children (61.0 %), lowest in pre-school children (41.6 %). 25(OH)D concentrations was lowest in winters (P = 0.002) and spring (P = 0.03) compared to summer. There was no correlation with calcium (P = 0.99), phosphorous (P = 0.23) and ALP (P = 0.63). There is high prevalence of vitamin D deficiency in children and adolescents of eastern India. Prevalence was lower in younger subjects. 25(OH)D did not correlate with bone mineral markers.     

Student support services in open schooling: a case study of students' needs and satisfaction in India

This paper identifies the key factors that contribute to the Open School in India students' satisfaction, considering student support elements at pre‐entry, start up, learning, evaluation and certification and after certification phases. The study adapted Rekkedal and Eriksen's importance‐satisfaction model to recognise areas that are important to students as well as their degree of satisfaction with each attribute. It is found that the student group considered is generally satisfied with the support elements that they perceive to be important and there is a strong positive linear relationship (r =0.83) between importance and satisfaction. However, according to the group, priority needs to be given to personal contact programmes in the study centres, online tutorials and feedback on assignments, which are three prime support elements in the learning phase.     

The Feminisation of Iranian Higher Education

The number of women attending institutions of higher education in Iran has been steadily increasing since 1989. Growing enrollment rates for women in colleges and universities have sparked wide social and political debates in that country. The basic question of why young Iranian women might even choose to pursue tertiary education, however, has not been adequately addressed in the critical literature. This study gives voice to young women who explain for themselves why they are interested in higher education. It reveals that college or university studies represent for female students many things: a sphere of hope, a refuge, and a place to experience limited freedom beyond restrictive family environments; an asset that can increase a woman’s value in the marriage market; a right that may make possible financial independence; and a vehicle that can earn respect for women. On the whole, the desire for higher education illuminates the challenges facing women in Muslim nations and the ways in which Muslim women are using this institution to change their social status.     

Purpose-driven consultancies’ negotiation of organizational tensions

This article examines the negotiation of organizational tensions by purpose-driven consultancies, for-profit firms also motivated by social change agendas in their implementation of organizational development for corporate clients. Using two case studies – APCom training ethical corporate leaders, and GreenD communicating environmental sustainability programs – we trace how such consultancies negotiate these tensions, and how their underlying purpose might accordingly transform. Our multi-case study suggests two broad tensions related to purpose and impact that are experienced in context-specific ways by the consultancies. Although members sought to frame these tensions in positive ways, as complementary dialectics or contradicting the dominant capitalist system, they were also at risk of devolving into more paradoxical contradictions and even debilitating double binds, without sustained discussion to ‘repurpose’ the firms. We close by discussing theoretical and practical implications for purpose-driven consultancies, given that their pursuit of social change is often at odds with the status quo.     

A contextual perspective of performance assessment in eGovernment: A study of Indian Police Administration

There is considerable research work on the performance assessment of eGovernment projects, especially on performance assessment measures per se. The point that the authors in this paper make is that while a variety of performance assessment measures are important for evaluation of eGovernment projects, performance itself is intended to relate governance with eGovernment applications. Thus, while developing performance assessment measures, there is a need to be conscious of governance as the ultimate purpose. Taking the Indian Police Administration as its domain, this paper demonstrates how performance assessment can be so conceived as to help capture the impact of eGovernment in regard to implications for governance in the given domain.     

Balancing power in communities of practice: An examination of increasing student voice through school-based youth–adult partnerships

This article examines how power imbalances influence the formation of student voice initiatives, which are defined as school-based youth–adult partnerships that consist of youth and adults contributing to decision making processes, learning from one another, and promoting change. Using the concept of community of practice as a lens, the paper examines the ways in which power influences the mutual engagement, shared repertoire, and joint enterprise of youth–adult partnerships. Specifically, the study finds that the following strategies can strengthen student voice initiatives: building meaningful roles based upon mutual responsibility and respect among all members; developing shared language and norms, and developing joint enterprises aimed at fostering voices that have previously been silenced from decision making and knowledge-building processes.