Investigating Unipolar Switching in Niobium Oxide Resistive Switches: Correlating Quantized Conductance and Mechanism

Memory devices based on resistive switching (RS) have not been fully realised due to lack of understanding of the underlying switching mechanisms. Nature of ion transport responsible for switching and growth of conducting filament in transition metal oxide based RS devices is still in debate. Here, we investigated the mechanism in Niobium oxide based RS devices, which shows unipolar switching with high ON/OFF ratio, good endurance cycles and high retention times. We controlled the boundary conditions between low-conductance insulating and a high-conductance metallic state where conducting filament (CF) can form atomic point contact and exhibit quantized conductance behaviour. Based on the statistics generated from quantized steps data, we demonstrated that the CF is growing atom by atom with the applied voltage sweeps. We also observed stable quantized states, which can be utilized in multistate switching

Evaluation of nasal mucociliary clearance in rheumatoid arthritis: a comparative analysis using saccharin test

Background: Rheumatoid arthritis (RA) is a chronic multisystem disease of unknown etiology characterized by persistent inflammatory synovitis, usually involving peripheral joints in a symmetric distribution. RA is a systemic disease often associated with cutaneous and organ-specific extra-articular manifestations the mucociliary clearance system protects the lower respiratory system by trapping and removing inhaled pathogenic viruses and bacteria, in addition to nontoxic and toxic particulates (e.g., pollen, ash, mineral dust, mold spores, and organic particles), from the lungs. Effective clearance requires both ciliary activity and the appropriate balance of periciliary fluid and mucus.Methods: This was a case control study conducted in the Department of Physiology, Pt. B.D. Sharma PGIMS, Rohtak in 50 females of age group 30-50 years. Control group comprised of 25 healthy volunteer females while study group comprised of 25 rheumatoid arthritis female patients with disease duration of more than five years. Proven cases of RA (as per 1987 ACR criteria) were taken with disease duration of more than five years from Rheumatology clinic of Pt. B.D. Sharma PGIMS, Rohtak. Nasal mucociliary clearance time was evaluated by saccharin method.Results: The results of our study showed abnormal mucociliary clearance in rheumatoid arthritis patients.Conclusions: The study shows an abnormal mucociliary clearance in rheumatoid arthritis patients. Impairment of mucociliary clearance seems to be the result of qualitative and quantitative alterations in respiratory secretions

Models of T cell antigen receptor activation: the puzzle still remained

T cell antigen receptor (TCR) is a protein-complex expressed on all T cells of the immune system and is responsible for the activation of T cells when infectious agent is presented by an antigen presenting cell (APC) in the form of peptides bound to the major histocompatibility complex (pMHC). Despite numerous studies it is not clear what biochemical changes upon binding of antigen ligand to the extracellular domains of TCR leads to activation of intracellular signaling (a process known as TCR triggering). This review summarizes possible biochemical mechanisms for TCR triggering and discusses their comparative limitations and advantages in explaining various experimental observations.Keywords: T cell antigen receptor; activation; modelDOI: http://dx.doi.org/10.3126/njb.v2i1.5684Nepal Journal of Biotechnology Jan.2012, Vol.2(1): 62-7

Controlled inter-state switching between quantized conductance states in resistive devices for multilevel memory

A detailed understanding of quantization conductance (QC), their correlation with resistive switching phenomena and controlled manipulation of quantized states is crucial for realizing atomic-scale multilevel memory elements. Here, we demonstrate highly stable and reproducible quantized conductance states (QC-states) in Al/Niobium oxide/Pt resistive switching devices. Three levels of control over the QC-states, required for multilevel quantized state memories, like, switching ON to different quantized states, switching OFF from quantized states, and controlled inter-state switching among one QC states to another has been demonstrated by imposing limiting conditions of stop-voltage and current compliance. The well defined multiple QC-states along with a working principle for switching among various states show promise for implementation of multilevel memory devices

Effect of paddy residue management techniques on yield of wheat crop and its attributes

The research study deals with the results of the yield and yield attributing characters of the wheat crop corresponding to the nine different treatments (T-1 to T-9) of paddy residue management. The wheat yield accounts for the grain yield and straw yield while the wheat yield attributing characters include the spike length, grains per spike, grain test weight, etc. The results of these pertains to the data collected and analysed from the two consecutive years of field experimentation employing various treatments and replications of paddy stubble management. The resultant data of different parameters (yield and its attributing characters) from various treatments carried out through the two years of field experiments is tabulated in the Table 1 and Table 2 for effective discussion of results. The results suggested that the combined use of SMS (straw management system) mounted combine harvester, happy seeder and decomposer provides the best way to manage paddy residue, thereby yielding good yields of succeeding wheat crop to the farmers

A Vertical Handover Algorithm in Integrated Macrocell Femtocell Networks

The explosion in wireless telecommunication technologies has lead to a huge increase in the number of mobile users. The greater dependency on the mobile devices has raised the user’s expectations to always remain best connected. In the process, the user is always desiring good signal strength even at certain black spots and indoors. Moreover, the exponential growth of the number of mobile devices has overloaded macrocells. Femtocells have emerged out as a good promising solution for complete coverage indoors and for offloading macrocell. Therefore, a new handover strategy between femtocells and macrocell is proposed in this paper. The proposed handover algorithm is mainly based on calculating equivalent received signal strength along with dynamic margin for performing handover. The simulation results of proposed algorithm are compared with the traditional algorithm. The proposed strategy shows improvement in two major performance parameters namely reduction in unnecessary handovers and Packet Loss Ratio. The quantitative analysis further shows 55.27% and 23.03% reduction in packet loss ratio and 61.85% and 36.78% reduction in unnecessary handovers at a speed of 120kmph and 30kmph respectively. Moreover, the proposed algorithm proves to be an efficient solution for both slow and fast moving vehicles

GIS based modeling using Analytic Hierarchy Process (AHP) for optimization of landfill site selection of Rohtak city, Haryana (India)

Landfills are the most common method for the disposal of municipal solid waste the world over, as well as in India due to their low technical and economic requirements. The selection of an appropriate site for the establishment of a landfill is a complex process because it must combine social, environmental and technical parameters. The scientific selection of landfill site is based on several diverse criteria (Land Use and Land Cover, ground water table depth, soil permeability, surface water, roads distance, slop etc) and regulations. The study presents the selection of a site for the establishment of a landfill based on several criteria using geographic information system (GIS) based site suitability modeling and analytical hierarchy process (AHP). Site suitability modeling was implemented using Boolean and Index overlay models. Each criterion and sub criteria was evaluated with the aid of AHP to assign a relative weightage in the index overlay model. Rules and criteria’s set by Central Pollution Control Board (CPCB) and Central Public Health and Environmental Engineering Organisation (CPHEEO) were implemented through Boolean model. The combination of the results of the two models generated a map with several suitable sites. Further selection was done on basis of the size requirement of the site, to handle Municipal solid waste (MSW) for next ten years. Two sites having the maximum suitability and also fulfilling the size requirement were shortlisted. Final selection from the two sites was done by a field survey of the sites. Finally the site B was selected on the basis of field survey which revealed it being better on account of certain factors discussed and social acceptability

Paddy Stubble Management: A Study on Farmers’ Opinions

The purpose of the study is to examine the paddy straw management practices by farmers amidst the various difficulties faced by them in terms of machinery, resources, etc. The study was conducted in Rohtak district of Haryana (India). A well-structured interview schedule was formulated and one hundred farmers were interviewed accordingly. Simple random sampling technique was adopted for the selection of twenty paddy growing farmers from each of the blocks viz. Rohtak, Sampla, Meham, Lakhan Majra and Kalanaur of the selected district. The data was analysed, tabulated and the results were drawn using the statistical tools of SPSS and MS Excel. The Chi-square test was used to establish the relation between the paddy straw management technologies and the reasons for non-adoption of these technologies. It is found that maximum number of farmers are marginal land holders. Many farmers are unaware of the conservation techniques to manage paddy stubble viz. use of decomposers, etc. The high cost and low availability of paddy stubble management machinery also plague the farmers. The results of the study help in understanding the behaviours of farmers towards tackling the paddy stubble. Also, useful inputs can be drawn to design, manufacture and adopt the agricultural implements for stubble management. The study is based on a sample of just hundred farmers and is limited to Rohtak district only. Nevertheless, the study is valuable for it comprehensively interrelates the myriad aspects of paddy stubble management in the stubble burning prone area of Rohtak

Comparing hypertonic saline and xylometazoline in allergic rhinitis

Background: Allergic rhinitis (AR) affects productivity, quality of life and performance at work. Pharmacological agents are widely used and nasal irrigation using hypertonic saline is underused.Methods: All consecutive patients presenting at the outpatient clinic with complaints of AR at Santosh Medical College Hospital from August 1, 2014 to August 31, 2015 were included in the study. Patients were randomly assigned to either xylometazoline nasal drops (0.1%, three times a day, brand Otrivin) or hypertonic seawater saline (2.2%, three times a day, brand Physiomer). They were followed for a period of 2 months. Symptom change was assessed at the start of the treatment and at the end using the Nasal Index Score (NIS), which comprised of grading blocked nose, runny nose, sneezing and eye itching on a 4-point severity scale.Results: 85 patients were included in the final analysis. On the NIS, patients receiving hypertonic nasal drops showed a decrease in mean score by 0.7, 0.5, 0.7 and 0.7 for blocked nose, runny nose, sneezing and eye irritation respectively, all of which were statistically significant. Additionally, more side effects like bloody nasal discharge, respiratory infections and headache were seen with xylometazoline nasal drops.Conclusion: Our findings suggest that using hypertonic nasal drops can reduce the dependence on pharmacological agents like xylometazoline, improve symptoms and quality of life with fewer adverse reactions

Water Quality Assessment of Brahma Sarovar: A Sacred Lake at Kurukshetra (India)

Brahama Sarovar, in Kurukshetra city (India), is an ancient sacred lake where devotees perform various religious activities/offerings on daily basis, and on special occasions of solar and lunar eclipses, millions of pilgrims all over the country have mass bathing (holy-dip) for internal and external purity. Along with religious importance, this artificial lake also acts as a sacred grove/wetland that serves as an important wintering and stopover site for migratory birds from the Palearctic region. The study was carried out with the objective to analyze the improvement in water quality status after the provision of a closed conduit for the supply of fresh water to the lake and additional measures required for public health safety. For this, the water quality of this sacred lake has been spatially analyzed and compared with Indian standards prescribed for ‘Designated Best Use Class-B: Outdoor Bathing (Organised)’ in the present study. Though the parameters – pH (7.94 within the limits of 6.5-8.5), turbidity (3.63 < 5 NTU), TDS (222.33 < 500 mg/L), TSS (100.25 mg/L) and MPN (239.25 ≤ 500 per 100 ml) were observed to be within the permissible limits, but DO (4.7 ≤ 5.0 mg/L) and BOD (3.54 ≥ 3.0 mg/L) of the lake water were found beyond the permissible limits. Thus, making the lake water unfit for human use for bathing. The comparison with the previous two studies revealed that the lake’s water quality has improved in the last couple of years through the provision of a closed conduit, in place of an open channel, for the supply of fresh canal water to the lake. A couple of additional measures have also been suggested to maintain the water quality standards in the lake so as to protect the human health of the devotees and pilgrims