On the Stiffness and Damping Coefficients of Constant Flow Valve Compensated Conical Hydrostatic Journal Bearing with Micropolar Lubricant

AbstractA theoretical analysis for performance characteristics of a conical multirecess hydrostatic journal bearing compensated with constant flow valve has been carried out considering micropolar lubricant. The numerical solution of the modified Reynolds equation for the conical bearing has been done using finite element method with necessary boundary conditions. The performance characteristics have been presented for various values of the restrictor design parameter, load, micropolar parameters, semi-cone angle and aspect ratio (L/D ratio) of the bearing at zero speed. It has been observed that the bearing develops large stiffness and damping coefficients with increase in restrictor design parameter, micropolar effect and semi-cone angle

Exploitation of combining ability and heterosis for development of maize hybrids for tarai region of Uttarakhand

The present investigation was carried out with fifty six genotypes involving 10 parents, their 45 F1s hybrids and one check hybrid in tarai region of Uttarakhand. The presence of more amount of variance due to SCA effects than GCA effects in our experimental material indicated that heterosis breeding is better choice. The good general combiners were P1, P3 and P4 for ear length; P8 for ear diameter; P5 and P8 for number of kernel rows per ear; P1 and P4 for number of kernels per row, P8 and P9 for100-kernel weight and P5 for grain yield, which can be utilized directly or indirectly in breeding programme. The best eight specific combiners for grain yield were P1xP8, P4xP10, P7xP8, P5xP8, P5xP9, P4xP9, P1xP2 and P5xP10 involving average x average, good x average, good x poor and average x poor parental combinations of generalcombining ability indicating the presence of non-additive gene action. The nine crosses, P1xP2, P1 xP5, P1xP8, P4xP9, P4xP10, P5 xP8, P5xP9, P5xP10 and P7xP8 had positive significant per cent heterosis for grain yield, and crosses namely P1xP4, P1xP5 and P1xP8 for ear length; P1xP3 and P1xP5 for number of kernels per row and P1xP8 and P9x P10 for 100-kernel weight were having positive significant per cent heterosis at 1% and/or 5% level of significance for respective traits. The crosses, P1xP2, P1xP8, P4xP9 andP7xP8 manifested high SCA effects along with excellent standard heterosis and per se performance for grain yield and also for most of the studied characters, therefore, classified as potential hybrids

Evaluation of 976 nm Multimode Single Emitter Laser Diodes for Efficient Pumping of 100 W+ Yb-doped Fiber Laser

Experimental evaluation of spectral and power-current (P-I) characteristics of fiber coupled single emitter multimode laser diodes used for development of efficient pumping assembly is reported. Fiber coupled laser diodes emitting around 976 nm are best suited for pumping Yb-doped fiber lasers because of excellent coupling efficiency and reduced thermal load. We have experimentally investigated emission spectrum of fiber coupled multimode laser diodes at different temperatures and drive currents. It is found that peak emission wavelength shifts towards the longer wavelength with increase in temperature and drive current. P-I characteristics of fiber coupled laser diodes have been obtained and presented for drive current from 0.4 A to 11.5 A. Based on experiment, we have constructed spectrally matched laser diode assembly for efficient pumping of 100 W fiber laser. It requires very precise control of temperature and drive current to maintain the emission spectrum. Total 162 W power is pumped in to the Yb-doped fiber laser cavity through multi-mode pump combiners and we have obtained 110 W fiber laser output power @1070 nm. The achieved optical-to-optical efficiency is 68 per cent

Extent of Rock mass Damage Induced by Blasting in Tunneling

Drilling and blasting is preferred method of rock excavation world-wide due to low initial investment cheap explosive energy, easy acceptability amongst the blasting engineers, possibility to deal with different shapes and sizes of openinings. Although drill andblast method has witnessed significant technological advancements, it has inherent disadvantage of deteriorating surrounding rock mass due to developemt of network of fine caracks in it leading to safety and stability problem. The damage in the peripheral rock mass culminates in the form of overbrak and damanged zone. Overbreak increases project cost by more than 15%. The damaged zone extends beyond overbreak. Although significant efforts have been made to assess damage to the surrounding rock mass using different methods, easier solution based on easily available site parameters is still lacking. Authors have carried out field investigations at five different tunnel construction project sites located in Himalaya, India to formulate an empirical correlation for prediction of blast induced damamge for wide range of Q values (0.04 – 17.8). The proposed correlation is based on specific charge, perimeter charge factor, maximum charge per delay, advancement and confinement factor and rock mass quality rating Q. All the parameters used in empirical correlations are readily available to the site engineers and does not require laboratory testing. Data sets of 113 experimental blasts are collected from te five tunnel sites. The proposed empirical correlation has been validated using ultrasonic tests on rock core samples obtained from one of the experimental location

Screening of efficient arbuscular mycorrhizal fungi for Azadirachta indica under nursery condition: a step towards afforestation of semi-arid region of western India

To optimize nursery practices for efficient plant production procedures and to keep up to the ever growing demand of seedlings, identification of the most suitable species of arbuscular mycorrhizal fungi (AMF), specific for a given tree species, is clearly a necessary task. Sixty days old seedlings of Neem (Azadirachta indica A. Juss) raised in root trainers were inoculated with six species of AMF and a mixed inoculum (consortia) and kept in green house. Performances of the treatments on this tree species were evaluated in terms of growth parameters like plant height shoot collar diameter, biomass and phosphorous uptake capabilities. Significant and varied increase in the growth parameters and phosphorous uptake was observed for most of the AMF species against control. Consortia culture was found to be the best suited AMF treatment for A.indica, while Glomus intraradices and Glomus mosseae were the best performing single species cultures. It is the first time in the state of Gujarat that a wide variety of AMF species, isolated from the typical semi-arid region of western India, were tested for the best growth performance with one of the most important tree species for the concerned region

Disposition kinetics and urinary excretion of ciprofloxacin in goats following single intravenous administration

We evaluated the pharmacokinetics of ciprofloxacin in serum (n = 6) and urine (n = 4) in goats following a single intravenous administration of 4 mg/kg body weight. The serum concentration-time curves of ciprofloxacin were best fitted by a two-compartment open model. The drug was detected in goat serum up to 12 h. The elimination rate constant (β) and elimination half-life (t1/2β) were 0.446 ± 0.04 h-1 and 1.630 ± 0.17 h, respectively. The apparent volume of distribution at steady state (Vdss) was 2.012 ± 0.37 l/kg and the total body clearance (ClB) was 16.27 ± 1.87 ml/min/kg. Urinary recovery of ciprofloxacin was 29.70% ± 10.34% of the administered dose within 36 h post administration. In vitro serum protein binding was 41% ± 13.10%. Thus, a single daily intravenous dose of 4 mg/kg is sufficient to maintain effective levels in serum and for 36 h in urine, allowing treatment of systemic, Gram-negative bacterial infections and urinary tract infections by most pathogens

Acoustic Diagnostics of Electrical Origin Fault Modes with Readily Available Consumer-Grade Sensors

Acoustic diagnostics, traditionally associated with mechanical fault modes, can potentially solve a wider range of monitoring applications. Typically, fault modes are induced purposefully by the researcher through physical component damage whilst the system is shutdown. This paper presents low-cost real-time fault diagnostics of a previously unreported acute electrical origin fault that manifests sporadically during system operation with no triggering intervention. A suitability study into acoustic measurements from readily available consumer-grade sensors for low-cost real-time diagnostics of audible faults, and a brief overview of the theory and configuration of the wavelet packet transform (including optimal wavelet selection methods) and empirical mode decomposition processing algorithms is also included. The example electrical origin fault studied here is an unpredictable current instability arising with the PWM-controller of a BrushLess DC motor. Experimental trials positively detect 99.9 % of the 1160 resultant high-bandwidth torque transients using acoustic measurements from a USB microphone and a smartphone. While the use of acoustic techniques for detecting emerging electrical origin faults remains largely unexplored, the techniques demonstrated here can be readily adopted for the prevention of catastrophic failure of drive and power electronic components

Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe