61 research outputs found
Application of modified least squares method for order reduction of commensurate higher order fractional systems
The paper related to the reduction and investigation of family of commensurate fractional order systems. The fractional order system is first transformed to integer order and then a hybrid method is applied as a model reduction scheme. In this scheme the reduced denominator is acquired by least square method and the numerator is achieved by time moment matching. This formulated reduced integer model is reconverted to reduced fractional model. Three examples are conferred to authenticate and emphasize the efficacy of the proposed approach. The proposed method is verified by MATLAB simulation, and shows better performance in the estimation process
EVALUATION OF IN VITRO ANTIUROLITHIATIC ACTIVITY OF CHLORIS BARBATA
Objective: The present study was undertaken to evaluate the in vitro antiurolithiatic activity of the medicinal plant Chloris barbata.Methods: The crude plant extract was prepared by Soxhlet extraction method.Results: Both Ethanolic and Aqueous extracts showed their maximum efficiencies in the dissolution of calcium oxalate crystals. Ethanolic extract was even more efficient than Aqueous extract in the dissolution of calcium oxalate crystals. Our results have clearly indicated that the Aqueous and Ethanolic leaf extracts of Chlorisbarbata were quite promising for further studies in this regard. In this study, Neeri was used as standard drug.Conclusion: This study has given primary evidence for Chloris barbata as the plant which possess antiurolithiatic property
Control of exhaust emissions using piston coating on two-stroke SI engines with gasoline blends
An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the
fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a
comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental
investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as
thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4
ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine
characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were
measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by
2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 %
of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and
gasoline blends can improve engine performance and reduce exhaust emissions
Instrumentation-related uncertainty of reflectance and transmittance measurements with a two-channel spectrophotometer
Spectrophotometers are operated in numerous fields of science and industry for a variety of applications. In order to provide confidence for the measured data, analyzing the associated uncertainty is valuable. However, the uncertainty of the measurement results is often unknown or reduced to sample-related contributions. In this paper, we describe our approach for the systematic determination of the measurement uncertainty of the commercially available two-channel spectrophotometer Agilent Cary 5000 in accordance with the Guide to the expression of uncertainty in measurements. We focus on the instrumentation-related uncertainty contributions rather than the specific application and thus outline a general procedure which can be adapted for other instruments. Moreover, we discover a systematic signal deviation due to the inertia of the measurement amplifier and develop and apply a correction procedure. Thereby we increase the usable dynamic range of the instrument by more than one order of magnitude. We present methods for the quantification of the uncertainty contributions and combine them into an uncertainty budget for the device. © 2017 Author(s)
Toll-Like Receptor Signaling and SIGIRR in Renal Fibrosis upon Unilateral Ureteral Obstruction
Innate immune activation via IL-1R or Toll-like receptors (TLR) contibutes to acute kidney injury but its role in tissue remodeling during chronic kidney disease is unclear. SIGIRR is an inhibitor of TLR-induced cytokine and chemokine expression in intrarenal immune cells, therefore, we hypothesized that Sigirr-deficiency would aggravate postobstructive renal fibrosis. The expression of TLRs as well as endogenous TLR agonists increased within six days after UUO in obstructed compared to unobstructed kidneys while SIGIRR itself was downregulated by day 10. However, lack of SIGIRR did not affect the intrarenal mRNA expression of proinflammatory and profibrotic mediators as well as the numbers of intrarenal macrophages and T cells or morphometric markers of tubular atrophy and interstitial fibrosis. Because SIGIRR is known to block TLR/IL-1R signaling at the level of the intracellular adaptor molecule MyD88 UUO experiments were also performed in mice deficient for either MyD88, TLR2 or TLR9. After UUO there was no significant change of tubular interstitial damage and interstitial fibrosis in neither of these mice compared to wildtype counterparts. Additional in-vitro studies with CD90+ renal fibroblasts revealed that TLR agonists induce the expression of IL-6 and MCP-1/CCL2 but not of TGF-β, collagen-1α or smooth muscle actin. Together, postobstructive renal interstitial fibrosis and tubular atrophy develop independent of SIGIRR, TLR2, TLR9, and MyD88. These data argue against a significant role of these molecules in renal fibrosis
Characterization of PTZ-Induced Seizure Susceptibility in a Down Syndrome Mouse Model That Overexpresses CSTB
Down syndrome (DS) is a complex genetic syndrome characterized by intellectual disability, dysmorphism and variable additional physiological traits. Current research progress has begun to decipher the neural mechanisms underlying cognitive impairment, leading to new therapeutic perspectives. Pentylenetetrazol (PTZ) has recently been found to have positive effects on learning and memory capacities of a DS mouse model and is foreseen to treat DS patients. But PTZ is also known to be a convulsant drug at higher dose and DS persons are more prone to epileptic seizures than the general population. This raises concerns over what long-term effects of treatment might be in the DS population. The cause of increased propensity for epilepsy in the DS population and which Hsa21 gene(s) are implicated remain unknown. Among Hsa21 candidate genes in epilepsy, CSTB, coding for the cystein protease inhibitor cystatin B, is involved in progressive myoclonus epilepsy and ataxia in both mice and human. Thus we aim to evaluate the effect of an increase in Cstb gene dosage on spontaneous epileptic activity and susceptibility to PTZ-induced seizure. To this end we generated a new mouse model trisomic for Cstb by homologous recombination. We verified that increasing copy number of Cstb from Trisomy (Ts) to Tetrasomy (Tt) was driving overexpression of the gene in the brain, we checked transgenic animals for presence of locomotor activity and electroencephalogram (EEG) abnormalities characteristic of myoclonic epilepsy and we tested if those animals were prone to PTZ-induced seizure. Overall, the results of the analysis shows that an increase in Cstb does not induce any spontaneous epileptic activity and neither increase or decrease the propensity of Ts and Tt mice to myoclonic seizures suggesting that Ctsb dosage should not interfere with PTZ-treatment
Effect of Preheating on Microstructure and Tensile Properties of Friction Stir Welded AA7075 Aluminium Alloy Joints
Simulation Study of Topological Structures and Node Coordinations for Deterministic WSN with TSCH
Time-Slotted Channel hopping (TSCH) that was introduced in IEEE802.15.4e is a promising technique to offer deterministic data deliveries in Wireless Sensor Networks (WSN). Its main strength lies in using multiple channels for the transmissions, using frequency hopping method. However, it takes more time for initializing the network, as beacons have to be released on multiple frequencies and scanning needs to be carried out by the devices in all those frequencies for joining the network. In this work, a simulation study is carried out to investigate the effect of these delays for different types of multihop networks. The benefit of introducing multiple coordinators in reducing these time delays is also studied. It is found that the delays are increasing linearly with the number of hops in the network and adding an additional coordinator can bring down the initialization time by half
Blocking probability analysis of wireless sensors that employ opportunistic spectrum access
Opportunistic accessing of vacant channels of licensed spectrum by non-licensed wireless devices offers a convenient solution to the spectrum scarcity problems experienced by many wireless communication systems. Due to the fixed assignment policy of spectrum, some of the licensed frequencies are not in full utilization by their licensed users. On the other hand, there exists a severe scarcity of bandwidth for new wireless services. In this context, opportunistic access is found to be a boon, to overcome the spectrum scarcity problems. In this paper, opportunistic accessing of vacant channels by the wireless sensors is analysed. Finding the number of devices that can be supported for the available vacant bandwidth is the main focus of the work. Assessing the blocking probabilities experienced by the devices is found to offer an approximation of the number of devices that can be accommodated in a given scenario, for permissible blocking rates. This kind of analysis can help in proper planning of such wireless sensor networks, to deploy them in a way that they can make use of the white space bandwidths efficiently.
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