34 research outputs found

    ASSESSMENT OF THE QUADRUPLE INJECTION STRATEGY OVER TRIPLE INJECTIONS TO IMPROVE EMISSIONS, PERFORMANCE AND NOISE OF THE AUTOMOTIVE DIESEL ENGINE

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    The present study aims at investigating effectiveness of the quadruple (early-pilot-main-after [epMa]) injection strategy over three different triple [early-main-after (eMa), early-pilot-main (epM) and pilot-main-after (pMa)] injection scheduling in terms of emissions, performance [brake specific fuel consumption (BSFC), torque, brake thermal efficiency (BTE) and fuel economy] and noise. The experimentation was carried out on a heavy-duty BS-IV diesel engine with 45% EGR fraction and fixed main injection (Crank-angle) scheduling at eight different RPMs and three loads of engine (20%, 60% and 100%) using design of experiments(DOE).     This comprehensive study showed that the quadruple injection strategy provides optimum results in both performance and emissions compared to the promising three triple injection strategy. The quadruple injection strategy exhibits the best BTE at all operating conditions and best BSFC at medium to high-speed zone around 0.5–1% inline to reduce combustion noise (CN) level, especially at low speeds and low to medium load of 0.2–2.2 dBA. Among triple injections, the pMa shows the best performance in BSFC, BTE, smoke and THC emissions. The epM is the best in the CO emissions and torque performance in the low-speed zone. Smoke value is marginally higher for the epMa at low to medium speed than the pMa, although average smoke emissions were the best. Taken together, the overall PM emission level was marginally better than Triple Injections, due to the impact of double pilots in combination with post-injection. In addition, NOx emissions were improved (around 3–6%) significantly with quadruple than with triple injections. The epMa injection scheduling also showed improvement in constant speed fuel economy and in pass-by-noise at the vehicle

    EVALUATION OF ANTISTRESS ACTIVITY OF EXTRACT OF TINOSPORA CORDIFOLIA & ASPARAGUS RACEMOSUS IN RATS

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    Objectives: Present study was undertaken to evaluate the adaptogenic and antistress activity of T. cordifolia & A.racemosus we investigated the antistress activity of T. cordifolia and A. racemosus by Cold Water Swim Stress Model in rats. Materials and Methods: The anti-stress activity was evaluated on Cold Water Swim Stress induced biochemical changes. Extract of T.cordifolia and A.racemosus was administered orally 400 mg /kg.b.wt. Diazepam (5 mg/ kg.b.wt was used as a gold standard. Serum lipid, serum glucose, plasma cortisol, plasma glutathione total plasma NO and lipid peroxidation in terms of MDA were used as the stress indices. Results: The level of total plasma nitric oxide, (NO), MDA, a lipid peroxidation marker and cortisol were significantly higher in rats with chronic stress compared with healthy control group (p<0.005). Both extract of T.cordifolia and A.racemosus reduced Stress induced lipid peroxide, serum glucose, and serum triglyceride and significantly enhance the plasma glutathione level compared with stress control group (p <0.005). Conclusion: The present findings strongly suggested that oxidative stress plays a significant role in the pathophysiology of chronic stress. The findings of the present study indicate that the herbal agents T.cordifolia and A.racemosus has significant antistress and adaptogenic activity as shown by its mitigating effects on several chronic stress induced biochemical perturbations, comparable to that induced by the well known antistress agent Diazepam

    Inherent control of growth, morphology and defect formation in germanium nanowires

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    The use of bimetallic alloy seeds for growing one-dimensional nanostructures has recently gained momentum among researchers. The compositional flexibility of alloys provides the opportunity to manipulate the chemical environment, reaction kinetics, and thermodynamic behavior of nanowire growth, in both the eutectic and the subeutectic regimes. This Letter describes for the first time the role of AuxAg1–x alloy nanoparticles in defining the growth characteristics and crystal quality of solid-seeded Ge nanowires via a supercritical fluid growth process. The enhanced diffusivity of Ge in the alloy seeds, compared to pure Ag seeds, and slow interparticle diffusion of the alloy nanoparticles allows the realization of high-aspect ratio nanowires with diameters below 10 nm, via a seeded bottom-up approach. Also detailed is the influence the alloyed seeds have on the crystalline features of nanowires synthesized from them, that is, planar defects. The distinctive stacking fault energies, formation enthalpies, and diffusion chemistries of the nanocrystals result in different magnitudes of {111} stacking faults in the seed particles and the subsequent growth of ⟨112⟩-oriented nanowires with radial twins through a defect transfer mechanism, with the highest number twinned Ge nanowires obtained using Ag0.75Au0.25 growth seeds. Employing alloy nanocrystals for intrinsically dictating the growth behavior and crystallinity of nanowires could open up the possibility of engineering nanowires with tunable structural and physical properties

    Probing thermal flux in twinned Ge nanowires through Raman spectroscopy

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    We report a noninvasive optical technique based on micro-Raman spectroscopy to study the temperature-dependent phonon behavior of normal (nondefective) and twinned germanium nanowires (Ge-NWs). We studied thermophysical properties of Ge-NWs from Raman spectra, measured by varying excitation laser power at ambient condition. We derived the laser-induced temperature rise during Raman measurements by analyzing the Raman peak position for both the NWs, and for a comparative study we performed the same for bulk Ge. The frequency of the Ge–Ge phonon mode softens for all the samples with the increase in temperature, and the first-order temperature coefficient (χT) for defected NWs is found to be higher than normal NWs and bulk. We demonstrated that apart from the size, the lamellar twinning and polytype phase drastically affect the heat transport properties of NWs

    Prevalencija i otpornost na lijekove šiga-toksigenih (STEC), enteropatogenih (EPEC) i enterotoksigenih (ETEC) izolata bakterije Escherichia coli u slobodno držanih jakova s proljevom i bez proljeva u pokrajini West Kameng, Arunachal Pradesh, Indija.

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    Food producing animals are the major reservoirs of Shiga-toxin producing (STEC) and enteropathogenic Escherichia coli (EPEC). The yak (Poephagus grunniens) is a unique multipurpose bovid, reared by highlanders in the Himalayan region. A total of 67 STEC, 5 EPEC and 22 ETEC strains were isolated from 256 rectal swabs of free ranging yaks from the West Kameng district of Arunachal Pradesh, India. Among the STEC isolates, shiga toxin producing genes stx2 was predominant, followed by stx1. Of all the stx variants, stx1c, stx2d, stx2c, stx2e and stx2f were detected in 23, 11, 2 and 1 isolates, respectively. Further, genes such as eaeA, ehxA, saa, iha and toxB were detected in 16, 35, 28, 10 and 2 isolates, respectively. One of the EPEC isolates possessed a bfpA gene and was categorized as typical EPEC. Among the ETEC isolates, genes such as LT, STa, STb, F41 and K99 were detected in 14, 5, 13, 2 and 2 isolates, respectively. The majority of the STEC, EPEC and ETEC isolates exhibited multi-drug resistance. The study revealed the presence of multi-drug resistant diarrhoea genic E. coli in free ranging yaks from the West Kameng district of Arunachal Pradesh. Moreover, the presence of STEC/EPEC can be a potential public health risk for tribal highlanders residing in close proximity of the reservoir yaks.Životinje koje služe za proizvodnju hrane mogu biti rezervoar šiga-toksigenih (STEC) i enteropatogenih (EPEC) sojeva bakterije Escherichia coli. Jak (Poephagus grunniens) je jedinstveni multipari bovid kojeg uzgajaju gorštaci na Himalaji. Ukupno je bilo izdvojeno 67 STEC sojeva, 5 EPEC sojeva i 22 ETEC soja iz 256 rektalnih obrisaka slobodno držanih jakova na području West Kameng, Arunachal Pradesh, Indija. Među izolatima STEC prevladavao je gen stx2 za prizvodnju šiga-toksina, a slijedio ga je gen stx1. Od svih varijanata gena stx, stx1c bio je dokazan u 23 izolata, stx2d u 11 izolata, stx2c u dva izolata, a stx2e i stx2f u jednog izolata. Nadalje gen eaeA dokazan je u 16 izolata, gen ehxA u 35, gen saa u 28, gen iha u 10 te gen toxBu dva izolata. Jedan od izolata EPEC posjedovao je gen bfpA i svrstan je u tipične EPEC izolate. Gen LT dokazan je u 14 ETEC izolata, gen Sta u pet, gen STb u 13, gen F41 u dva i K99 također u dva izolata. Većina izolata STEC, EPEC i ETEC pokazivala je otpornost na više lijekova. Istraživanje je pokazalo da postoji višestruka otpornost bakterije E. coli izdvojene iz slobodno držanih jakova s proljevom na području West Kameng, Arunachal Pradesh. Povrh toga, prisutnost STEC/EPEC može predstavljati rizik za javno zdravstvo za gorštačka plemena koja dolaze u bliski dodir s jakovima

    Diameter controlled germanium nanowires with lamellar twinning and polytypes

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    One-dimensional nanostructures with controllable morphologies and defects are appealing for use in nanowire devices. This paper details the influence of colloidal magnetite iron oxide nanoparticle seeds to regulate the radial dimension and twin boundary formation in Ge nanowires grown through a liquid-injection chemical vapor deposition process. Control over the mean nanowire diameter, even in the sub-10 nm regime, was achieved due to the minimal expansion and aggregation of iron oxide nanoparticles during the growth process. The uncommon occurrence of heterogeneously distributed multiple layer {111} twins, directed perpendicular to the nanowire growth axis, were also observed in 〈111〉-directed Ge nanowires, especially those synthesized from patterned hemispherical Fe3O4 nanodot catalysts. Consecutive twin planes along 〈111〉-oriented nanowires resulted in a local phase transformation from 3C diamond cubic to hexagonal 4H allotrope. Localized polytypic crystal phase heretostructures were formed along 〈111〉-oriented Ge nanowire using magnetite nanodot catalysts

    Prevalencija i otpornost na lijekove šiga-toksigenih (STEC), enteropatogenih (EPEC) i enterotoksigenih (ETEC) izolata bakterije Escherichia coli u slobodno držanih jakova s proljevom i bez proljeva u pokrajini West Kameng, Arunachal Pradesh, Indija.

    Get PDF
    Food producing animals are the major reservoirs of Shiga-toxin producing (STEC) and enteropathogenic Escherichia coli (EPEC). The yak (Poephagus grunniens) is a unique multipurpose bovid, reared by highlanders in the Himalayan region. A total of 67 STEC, 5 EPEC and 22 ETEC strains were isolated from 256 rectal swabs of free ranging yaks from the West Kameng district of Arunachal Pradesh, India. Among the STEC isolates, shiga toxin producing genes stx2 was predominant, followed by stx1. Of all the stx variants, stx1c, stx2d, stx2c, stx2e and stx2f were detected in 23, 11, 2 and 1 isolates, respectively. Further, genes such as eaeA, ehxA, saa, iha and toxB were detected in 16, 35, 28, 10 and 2 isolates, respectively. One of the EPEC isolates possessed a bfpA gene and was categorized as typical EPEC. Among the ETEC isolates, genes such as LT, STa, STb, F41 and K99 were detected in 14, 5, 13, 2 and 2 isolates, respectively. The majority of the STEC, EPEC and ETEC isolates exhibited multi-drug resistance. The study revealed the presence of multi-drug resistant diarrhoea genic E. coli in free ranging yaks from the West Kameng district of Arunachal Pradesh. Moreover, the presence of STEC/EPEC can be a potential public health risk for tribal highlanders residing in close proximity of the reservoir yaks.Životinje koje služe za proizvodnju hrane mogu biti rezervoar šiga-toksigenih (STEC) i enteropatogenih (EPEC) sojeva bakterije Escherichia coli. Jak (Poephagus grunniens) je jedinstveni multipari bovid kojeg uzgajaju gorštaci na Himalaji. Ukupno je bilo izdvojeno 67 STEC sojeva, 5 EPEC sojeva i 22 ETEC soja iz 256 rektalnih obrisaka slobodno držanih jakova na području West Kameng, Arunachal Pradesh, Indija. Među izolatima STEC prevladavao je gen stx2 za prizvodnju šiga-toksina, a slijedio ga je gen stx1. Od svih varijanata gena stx, stx1c bio je dokazan u 23 izolata, stx2d u 11 izolata, stx2c u dva izolata, a stx2e i stx2f u jednog izolata. Nadalje gen eaeA dokazan je u 16 izolata, gen ehxA u 35, gen saa u 28, gen iha u 10 te gen toxBu dva izolata. Jedan od izolata EPEC posjedovao je gen bfpA i svrstan je u tipične EPEC izolate. Gen LT dokazan je u 14 ETEC izolata, gen Sta u pet, gen STb u 13, gen F41 u dva i K99 također u dva izolata. Većina izolata STEC, EPEC i ETEC pokazivala je otpornost na više lijekova. Istraživanje je pokazalo da postoji višestruka otpornost bakterije E. coli izdvojene iz slobodno držanih jakova s proljevom na području West Kameng, Arunachal Pradesh. Povrh toga, prisutnost STEC/EPEC može predstavljati rizik za javno zdravstvo za gorštačka plemena koja dolaze u bliski dodir s jakovima

    Distinction of Fly Artifacts from Bloodstains in Crime Scenes: A Brief Literature Review

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    Insect artifacts produced by necrophagous adult flies over a variety of depositional surfaces are problematic in crime scene investigations. Assessment of bloodstains through morphological features combined with contextual and presumptive chemical analysis, as traditional practices, are often inconclusive. Absorbance of bloodstains and substantial wicking on fabrics due to underlying texture and repeated stitch loops in the fabric makes the diagnosis even more difficult than stain morphology. Literature related to the application of modern techniques in the diagnosis of fly artifacts was critically reviewed and presented along with working efficacies and challenges. Apart from the traditional morphological comparison of bloodstains, findings on immunoassay, scanning electron microscopy and DNA-based molecular discrimination have been considered more confirmatory differential diagnosis in crime scenes.  Scanning electron microscopic methods reveal distinctive features of small crystal-like deposits with fly artifacts absent in bloodstains. The immunodetection method tested positive with antiserum (anti-md3) against defecatory and regurgitate stains. Moreover, mitochondrial DNA cytochrome c oxidase I (CO1) gene-based molecular diagnosis hold promises in discrimination. However, these modern techniques may be applied along with traditional methods to overcome confusion as per suitability of sampling, following conservative and non-conservative approaches that may offer a real help to crime scene investigators
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