514 research outputs found

    Mathematical modelling of ciliary propulsion of an electrically conducting Johnson-Segalman physiological fluid in a channel with slip

    Get PDF
    Bionic systems frequently feature electromagnetic pumping and offer significant advantages over conventional designs via intelligent bio-inspired properties. Complex wall features observed in nature also provide efficient mechanisms which can be utilized in biomimetic designs. The characteristics of biological fluids are frequently non-Newtonian in nature. In many natural systems super-hydrophobic slip is witnessed. Motivated by these phenomena, in the present article, we present a mathematical model for the cilia-generated propulsion of an electrically-conducting viscoelastic physiological fluid in a ciliated channel under the action of an externally applied static magnetic field. The rheological behavior of the fluid is simulated with the Johnson-Segalman constitutive model which allows internal wall slip. The regular or coordinated movement of the ciliated edges (which line the internal walls of the channel) is represented by a metachronal wave motion in the horizontal direction which generate a two-dimensional velocity profile with the parabolic profile in the vertical direction. This mechanism is imposed as a periodic moving velocity boundary condition which generates propulsion in the channel flow. Under the classical lubrication approximation (long wavelength and low Reynolds' number), the boundary value problem is rendered non-dimensional and solved analytically with a perturbation technique. The influence of the geometric, rheological (slip and Weissenberg number) and magnetic parameters on the velocity, pressure gradient and the pressure rise (evaluated via the stream function in symbolic software) are presented graphically and interpreted at length

    The co-creation of social ventures through bricolage, for the displaced, by the displaced

    Get PDF
    Purpose Although scholars have investigated how social entrepreneurs create and develop social enterprises in the penurious stable environment, how they are created in the penurious unstable environment has yet been overlooked. The purpose of this paper is to address this research gap by exploring how internally displaced individuals, despite the lack of resources, create and develop a social enterprise to serve the other displaced population in the war and conflict zones. Design/methodology/approach Underpinned by a biographical research design, in-depth interviews with internally displaced individuals who have created social enterprises in the war and conflict zones were undertaken. Three social entrepreneurs were chosen for this study from three different social enterprises that are created by internally displaced individuals to serve the other internally displaced people of three different countries, namely, Pakistan, Afghanistan and Syria. Findings The single and cross-case analysis found that internally displaced individuals deploy bricolage strategy, for example, reconfiguration of pre-existing resources and competencies (both internal and external), to start up a social venture in the war and conflict zones. They utilise pre-existing internal resources, mainly human capital, and external resources, through a frugal approach towards resources acquisitions. The authors also found that the displaced social entrepreneurs utilise resources of other displaced individuals, for example, networks, volunteers, local knowledge and financial supports mainly from older arrivals, and develop their own enterprise ecosystem within the host location to co-create and co-develop social enterprise and social values for all of them. Research limitations/implications The findings show that internally displaced individuals utilise bricolage strategies to create and develop socially entrepreneurial venture to serve other internally displaced individuals in the war and conflict zones. As the findings are based on three case studies, for confirmatory approach, a quantitative study with a large sample size is necessary. Furthermore, as the differences in economic, cultural and linguistic in between the home and host locations can have impact on the creation and the development of a social venture, they should be considered in the future studies. Originality/value This study contributes to the limited literature and studies on social entrepreneurship, specifically, to the context of unstable penurious environment. It also contributes to the literature on bricolage by extending its application from penurious stable environment to the penurious unstable environment. By exploring what and how internal and external resources are utilised to create and develop a socially entrepreneurial venture in a war and conflict zones, this study has added value to the literature on not only bricolage but also entrepreneurship in war and conflict zones

    SALES PROMOTION ACTIVITIES, REAL-ESTATE INDUSTRIES, BANGALORE

    Get PDF
    The sales marketing initiatives in Bangalore, India's real estate market are the main subject of this study. Bangalore's real estate market has grown quickly, drawing substantial capital inflows as well as interest from both local and foreign investors. Examining the various sales advertising tactics and initiatives used by Bangalore real estate companies to entice prospective buyers and investors is the goal of this study. The study intends to provide light on the efficacy of various promotional tactics within the Bangalore real estate market by examining these strategies. The research technique entails a thorough analysis of the body of knowledge regarding real estate industry sales promotion initiatives, in addition to primary data collecting via surveys and interviews with relevant parties such as customers, marketers, and real estate developers. Given the increasing prominence of digital platforms in the real estate market, the study will also examine how digital marketing and online promotions affect Bangalore's real estate market. The results of this study will help to clarify the dynamics of sales promotion in the real estate sector and offer insightful information to academics and practitioners alike. The goal of the study is to provide real estate firms in Bangalore with ideas and advice on how to improve their approaches to sales promotion and interact with potential customers in a cutthroat marke

    Nanotechnology Applications for Chemical and Biological Sensors

    Get PDF
    Recent discoveries indicate that when the materials are brought down to sizes in the range 1–100 nm, theseexhibit unique electrical, optical, magnetic, chemical, and mechanical properties. Methods have now beenestablished to obtain the monodisperse nanocrystals of various metallic and semiconducting materials, single-walled and multi-walled nanotubes of carbon and other metallic and non-metallic materials together withorganic nanomaterials such as supra-molecular nanostructures, dendrimers, hybrid composites with tailoredfunctionalities. The high surface-to-volume ratio with an added element of porosity makes these highly potentialcandidates for chemical and biological sensor applications with higher degree of sensitivity and selectivity ascompared to their bulk counterparts. The paper reviews the recent developments and applications of chemicaland biological sensors based on nanomaterials of various structural forms.Defence Science Journal, 2008, 58(5), pp.636-649, DOI:http://dx.doi.org/10.14429/dsj.58.168

    A Comparative Study of Customer Preferences for Telecommunication Technologies in Pakistan

    Get PDF
    The telecommunication industry is a huge and ever-growing industry and it is contributing dominantly to the economy in terms of revenue generation and being one of the biggest taxpayers to the government. Telecommunication is now considered to be a basic necessity. In this paper, a study has been conducted to know the customer preferences of telecommunication technologies in Lahore, Pakistan, and also to compare different customer preferences for telecommunication technologies. From the results of our study, we have concluded that there is a great variation among people in terms of their usage of mobile phones and internet services. Furthermore, results regarding the relationship between the socio-demographic characteristics and the preference towards specific telephony and internet service providers have also been analyzed. This work is unique when the scenario of Pakistan is considered. No such study has been conducted in Pakistan to know the customer preferences in Pakistan. Some recommendations for the telecommunication operators have also been discussed which can help to know their customer needs in a better fashion

    Detection and identification of ethanal-derived spin-trapped free radicals using headspace thermal desorption gas chromatography-mass spectrometry (TD-GC-MS)

    Get PDF
    In this study, we demonstrate a novel approach to the detection and identification of the products of spin-trapped free radicals. Hydroxyl free radicals were generated by Fenton-based chemistry in the presence of ethanal and the spin-trapping agent N-tert-butyl- -phenylnitrone (PBN). The resulting volatile compounds present in the reaction vial headspace were collected using thermal desorption (TD) and analysed by gas chromatography-mass spectrometry (GCMS). Eleven compounds were detected in the headspace, and their identification was aided by using either a fluorinated or deuterated analogue of PBN as an alternative spin trap and/or deuterated ethanal (CD 3CHO) as the secondary source of free radicals. The electron-ionisation (EI) mass spectra clearly demonstrate the “capture” of methyl radicals; two of the compounds detected were identified as containing one methyl group derived from ethanal, and four were shown to contain two methyl groups. This study demonstrates that sampling the reaction headspace using TD-GC-MS is a viable method for analysing products of free radical trapping, and potentially may be applied to a wide range of free radical systems

    Data Warehouse Model to Support Optimized Operation and Energy Savings in Buildings

    Get PDF
    corecore