149 research outputs found

    A fully integrated autonomous power management system with high power capacity and novel MPPT for thermoelectric energy harvesters in IoT/wearable applications

    Get PDF
    This paper reports a fully integrated autonomous power management system for thermoelectric energy harvesting with application in batteryless IoT/Wearable devices. The novel maximum power point tracking (MPPT) algorithm does not require open circuit voltage measurement. The proposed system delivers 0.5 mA current with 1 V regulated output based on simulations, which is the highest output current for a fully integrated converter reported in the literature for ultra-low voltage applications, to the best knowledge of the authors. Regulated 1 V output can be achieved for load range >2 k Omega, and input voltage range >140 mV. The circuit has been implemented in UMC-180nm standard CMOS technology and simulated

    TiO2 21 nm nanoparticles as a photocatalytic antimicrobial agent against Escherichia coli, Candida albicans and Methicillin resistant Staphylococcus aureus: A comparison

    Get PDF
     Objectives: To determine and compare the antimicrobial activity of 21 nm TiO2 nanoparticles against Escherichia colii, Candida albicans and Methicillin resistant Staphylococcus aureus (MRSA).Methods: Titanium dioxide (TiO2) 21 nm anatase nanoparticles (13.9 g/l) were suspended in miliQ (MQ) water, sonicated (35 MHz for 1 hour) and autoclaved. Sterile glass petriplates were treated with TiO2 suspension or sterile MQ(control). Overnight cultures of E.coli MRSA and C. albicans were added to TiO2 coated plates and control plates and kept at room temperature.   Viable counts were obtained by spread plate method at 0 hours and 24 hours; before and after sunlight exposure for 30 minutes.  Colony forming units (CFU) / ml was calculated to determine percentage reduction of CFU in presence of TiO2. Experiments were done in triplicates.Results: TiO2 nanoparticles demonstrated antimicrobial activity against E.coli, MRSA and C. albicans. Estimated percentage CFU reduction in E.coli (13±8.4), MRSA (12±6.6) and C. albicans (36±4.9 ) was observed at 0 hours of contact in the supernatant. The bactericidal effect was enhanced on exposure of the plates to sunlight. Estimated percentage CFU reductions are E. coli (46±7.9), MRSA (99±0.2 ) and C. albicans (99±0.4). The results for 24 hours were (95±1 ), (35±2.1 ) and (83±4 ) reduction for E. coli, MRSA and C. albicans respectively. When the 24 hour plates were exposed to sunlight (99±0.6), (99±0.6) and (99±0.2) reduction was seen for E.coli, MRSA and C. albicans respectively. Conclusion: Anatase 21 nm TiO2 nanoparticles show enhanced antimicrobial activity against the tested microbial strains following photoactivation by sunlight.  Antimicrobial activity against three different types of microbial strains has varying effects

    Hyper-precarious lives : Migrants, work and forced labour in the Global North

    Get PDF
    This paper unpacks the contested inter-connections between neoliberal work and welfare regimes, asylum and immigration controls, and the exploitation of migrant workers. The concept of precarity is explored as a way of understanding intensifying and insecure post-Fordist work in late capitalism. Migrants are centrally implicated in highly precarious work experiences at the bottom end of labour markets in Global North countries, including becoming trapped in forced labour. Building on existing research on the working experiences of migrants in the Global North, the main part of the article considers three questions. First, what is precarity and how does the concept relate to working lives? Second, how might we understand the causes of extreme forms of migrant labour exploitation in precarious lifeworlds? Third, how can we adequately theorize these particular experiences using the conceptual tools of forced labour, slavery, unfreedom and precarity? We use the concept of ‘hyper-precarity’ alongside notions of a ‘continuum of unfreedom’ as a way of furthering human geographical inquiry into the intersections between various terrains of social action and conceptual debate concerning migrants’ precarious working experiences

    The Arabidopsis thaliana F-box gene HAWAIIAN SKIRT is a new player in the microRNA pathway

    Get PDF
    In Arabidopsis, the F-box HAWAIIAN SKIRT (HWS) protein is important for organ growth. Loss of function of HWS exhibits pleiotropic phenotypes including sepal fusion. To dissect the HWS role, we EMS-mutagenized hws-1 seeds and screened for mutations that suppress hws-1 associated phenotypes. We identified shs-2 and shs-3 (suppressor of hws-2 and 3) mutants in which the sepal fusion phenotype of hws-1 was suppressed. shs-2 and shs-3 (renamed hst-23/hws-1 and hst-24/hws-1) carry transition mutations that result in premature terminations in the plant homolog of Exportin-5 HASTY (HST), known to be important in miRNA biogenesis, function and transport. Genetic crosses between hws-1 and mutant lines for genes in the miRNA pathway, also suppress the phenotypes associated with HWS loss of function, corroborating epistatic relations between the miRNA pathway genes and HWS. In agreement with these data, accumulation of miRNA is modified in HWS loss or gain of function mutants. Our data propose HWS as a new player in the miRNA pathway, important for plant growth

    Week 48 resistance analyses of the once-daily, single-tablet regimen darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) in adults living with HIV-1 from the Phase III Randomized AMBER and EMERALD Trials

    Get PDF
    Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is being investigated in two Phase III trials, AMBER (NCT02431247; treatment-naive adults) and EMERALD (NCT02269917; treatment-experienced, virologically suppressed adults). Week 48 AMBER and EMERALD resistance analyses are presented. Postbaseline samples for genotyping/phenotyping were analyzed from protocol-defined virologic failures (PDVFs) with viral load (VL) >= 400 copies/mL at failure/later time points. Post hoc analyses were deep sequencing in AMBER, and HIV-1 proviral DNA from baseline samples (VL = 3 thymidine analog-associated mutations (24% not fully susceptible to tenofovir) detected at screening. All achieved VL <50 copies/mL at week 48 or prior discontinuation. D/C/F/TAF has a high genetic barrier to resistance; no darunavir, primary PI, or tenofovir RAMs were observed through 48 weeks in AMBER and EMERALD. Only one postbaseline M184I/V RAM was observed in HIV-1 of an AMBER participant. In EMERALD, baseline archived RAMs to darunavir, emtricitabine, and tenofovir in participants with prior VF did not preclude virologic response
    • 

    corecore