Simulation of rubber grommets and correlation with test at low frequencies

Residential air conditioning units include several sources which can lead to vibrational and noise issues. The most important structure-borne source is the compressor which controls the noise and vibration in certain frequency ranges. Compressors are mounted on four relatively stiff rubber grommets which partially isolate the basepan from the compressor motion while also ensuring that the compressor does not move too much. In this work, the grommets are simulated using the finite element method and results are correlated with measurement results with good agreement. It is demonstrated that the hyperelastic properties of the grommets should be increased due to the Payne effect to improve correlation.

ELECTRONIC COMPASS FOR UNMANNED SHIPS

Principle of action of semiconductor two-collector magnetic transistors and possibility of creation on their basis of electronic compass is covered in the article. Level of automation of marine ships navigation, appearance of the autonomous fully automated ships without a crew, requires presences aboard the ship of device giving out a not visual, but electronic signal about direction of motion. An electronic compass on the basis of magnetic sensor semiconductor elements can decide this task. There is of most interest an electronic compass, a consisting of semiconductor magnetic sensor element, electric signal on the output of which is proportional to the level of the external magnetic field, and electronic chip processing a signal. In this article the example of laboratory construction of such electronic compass is described and his descriptions over are brought. Important, that this electronic device does not have mobile mechanical parts and mechanisms. For the increase of sensitiveness of electronic sensor of the magnetic field application of reflector-absorbers of the magnetic field is offered. Ferrite bars are used in this case. Bars are disposed both-side sensor, parallell to optimum direction of the magnetic field. In the experiments it was succeeded to get the increase of sensitiveness of sensors in 400 times. The reflector-absorbers of the magnetic field also allow to improve correlation signal to noise in 100 times. An electronic compass on the basis of magnetic transistors can be also used and as an element to control the course of marine ship. If a magnetic transistors is set to direction of motion, the change of loading resistances sets the zero of tension between the collectors of magnetic transistor. At deviation of axis from the set direction, tension of one polarity appears between collectors, and in other - opposite. This tension through the system of autopilot can directly control a steering gear and automatically to maintain the set direction of motion of marine ship. Experimental descriptions over of pre-productions models of magnetic transistors and flows diagrams of compasses are brought. An experiments show that on the basis of two-collector magnetic transistors can be created electronic compass not containing mechanically moving details, that sharply promotes his reliability and durability. An electronic compass will become the obligatory attribute of future autonomous ships without a crew. He will be able not only to replace a classic magnetic compass but also to allow to realize the span-new functions of ships control.

HUBUNGAN ANTARA LIKUIDITAS, PENDANAAN DENGAN MANAJEMEN PERKREDITAN KSP DANATAMA JAKARTA

Research have been done based on KSP management and KSP performance. Problem loan increased in some KSP. The study proposed to further explore why this condition happened by analysis relationship between performance loan management, liquidity and funding. Research result presents liquidity rate of entity 68,81% as expected, funding rate 64,23% as expected and Loan management rate of the entity is 65,05% as expected. Result of result also present that the rate of three variables still under value as expected (more than 80%) thatswhy still need to be improve. Correlation rate between liquidity and loan management is 0,212, determination coefficient is 0,0449 or giving impact more or less than 4,49%. There is no correlation between Funding and loan management (rate is -0,0276). T-calculate is less than T-table. Correlation rate between liquidity, funding and loan management simultaneously is 0,093. This shows that liquidity factor together with funding factor giving impact to loan management more significant than partially. Impact of the two variables is 9,3%. As a result, to increase loan management rate will be more effective if increasing liquidity rate and funding rate to be implemented together other than partially instead.

Imaging features of bilateral vestibular neuritis

Introduction. The magnetic resonance imaging (MRI) was found to be insensitive diagnostic modality in detecting the abnormalities in patients with vestibular neuritis. Case report. A 32-year-old man was admitted to hospital with clinical signs of acute vestibular neuritis. The conventional MRI was inconclusive, including 3 mm slice-thickness postcontrast study, while the postcontrast high resolution study with 1 mm slice-thikness, detected bilateral enhancement of the vestibulocochlear nerve?s vestibular branch, consistent with inflammation. Conclusion. High-resolution 1 mm or submilimeter slices should be perfomed to evaluate patients with vestibular neuritis in order to increase the MRI sensitivity and improve correlation with clinical findings.

3D-Var versus Optimal Interpolation for Aerosol Assimilation: a Case Study over the Contiguous United States

This study applies the Gridpoint Statistical Interpolation (GSI) 3D-Var assimilation tool originally developed by the National Centers for Environmental Prediction (NCEP), to improve surface PM2.5 predictions over the contiguous United States (CONUS) by assimilating aerosol optical depth (AOD) and surface PM2.5 in version 5.1 of the Community Multi-scale Air Quality (CMAQ) modeling system. GSI results are compared with those obtained using the optimal interpolation (OI) method (Tang et al., 2015) for July, 2011 over CONUS. Both GSI and OI assimilate surface PM2.5 observations at 00, 06, 12, and 18 UTC, and MODIS AOD at 18 UTC. In the GSI experiments, assimilation of surface PM2.5 leads to stronger increments in surface PM2.5 compared to the MODIS AOD assimilation. In contrast, we find a stronger impact of MODIS AOD on surface aerosols at 18 UTC compared to the surface PM2.5 OI assimilation. The increments resulting from the OI assimilation are spread in 11×11 horizontal grid cells (12 km horizontal resolution) while the spatial distribution of GSI increments is controlled by its background error covariances, and the horizontal/vertical length scales. The assimilations of observations using both GSI and OI generally help reduce the prediction biases, and improve correlation between model predictions and observations. GSI produces smoother result and yields overall better correlation coefficient and root mean squared error (RMSE). In this study, OI uses the relatively big model uncertainties, which helps yield better mean biases, but sometimes causes the RMSE increase. We also examine and discuss the sensitivity of the assimilation experiments results to the AOD forward operators

New species of the conodontNeogondolellafrom the Anisian (Middle Triassic) of northeastern British Columbia, Canada, and their importance for regional correlation

Eight new species of the conodontNeogondolellaare described from the Anisian (Middle Triassic) of northeastern British Columbia. The subtlety of morphological variation in this conodont genus has hampered biostratigraphical correlation, but large, often independently dated collections have enabled the description ofN.cuneiforme,N.curva,N.hastata,N.dilacerata,N.indicta,N.panlaurentia,N.tenera, andN.vellicatan. spp. Several of these species are widespread, as specimens ofN.curva,N.hastata,N.indicta,N.panlaurentia,N.tenera, andN.vellicataare found in contemporary collections from Nevada, whereasN.panlaurentiahas also been recovered from the Canadian Arctic. This distribution promises to significantly improve correlation among Anisian sections in North America.