scholarly journals Renewal of Middle Wave Transmitters in Slovak Republic

2021 ◽  
Vol 24 (4) ◽  
pp. 65-72
Author(s):  
Rene Hartansky ◽  
Jozef Hallon ◽  
Jakub Krchnak ◽  
Michal Dzuris
Keyword(s):  
Slovak Republic ◽  
Impedance Matching ◽  
Lightning Strike ◽  
Characteristic Parameters ◽  
Group Company ◽  
New Class ◽  
Class D ◽  
Power Inputs ◽  
Class C ◽  
Surge Protection

This paper deals with the replacement of middle wave transmitters in Slovak Republic. The original transmitters were based on class C vacuum tube fundamentals and were produced by the Czechoslovakian group company Tesla. Class C transmitters were transmitting reliably to this day, however, the lifespan of these transmitters was nearing its end, moreover the need for a better quality analog modulated signal has pushed for its replacement and therefore they were replaced by modern, highly efficient class D transmitters, while utilizing the original infrastructure consisting of antennas and power inputs. Due to differences in characteristic parameters, however minor, this caused some significant problems, with impedance matching. To resolve these problems, it was necessary to implement a newly designed IMU (Impedance Matching Unit), while also securing a lightning strike protection. This paper has proposed a possibility of lightning surge protection of middle wave transmitters. The original protection implemented with the installations of class C transmitters was consisted only of multiple spark gaps. This kind of protection may prove inefficient using new class D transmitters. The device described in this paper has been designed and successfully implemented on a middle wave transmitter in Čižatice. This transmitter is transmitting with 5 kW power on the antenna with the carrier frequency of 702 kHz. Since the implementation of our device, the transmitter reports no failures and continues to transmit safely.

The Effect of Deformation on Mechanical Properties and Shakedown on Railroad Wheels

2014 ◽  
Author(s):  
Steven L. Dedmon ◽  
Takashi Fujimura ◽  
Daniel Stone
Keyword(s):  
Mechanical Properties ◽  
Rolling Contact ◽  
Effect Of Temperature ◽  
Plastic Deformations ◽  
Rail Head ◽  
Class D ◽  
Shakedown Theory ◽  
Freight Car ◽  
Class C ◽  
Railroad Wheels

Plastic deformations alter the mechanical properties of many metals and alloys. Class C and Class D wheel steels such as are used in North American freight car service are particularly affected by plastic deformations occurring during rolling contact between the wheel tread and rail head. This investigation determines the effect plastic deformations have on the mechanical properties of Class C and D wheel steels and how those changes could relate to shakedown theory. The effect of temperature is also discussed.

scholarly journals Earth-termination system for onshore wind Turbines.

2020 ◽  
Vol 11 (7-2020) ◽  
pp. 66-72
Author(s):  
Liubov A. Belova ◽  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Lightning Strike ◽  
Lightning Protection ◽  
Protection Measures ◽  
Lightning Strikes ◽  
Grounding System ◽  
Initial Stage ◽  
Wind Turbine Towers ◽  
Surge Protection

The earth-termination system for towers of ground-based wind turbines in addition to protective and functional grounding provides lightning protection grounding, which is especially important since the wind turbine is susceptible to lightning strikes. If insufficient protective measures are taken, the risk of damage to a wind turbine due to a lightning strike increases. Therefore, a well-thought-out built-in grounding system for wind turbine towers is needed, which would function as necessary and guarantee long-term mechanical strength and corrosion resistance. The configuration of grounding systems for wind turbines is discussed in IEC 61400-24, which deals with the topic of lightning protection for wind turbines, including detailed information on the choice of lightning protection measures and surge protection. It is advisable to create a lightning protection concept at the initial stage of planning a wind turbine in order to avoid later costly repairs and retrofitting.

Voltage-dependent facilitation of calcium channels in rat neostriatal neurons

1996 ◽  
Vol 76 (4) ◽  
pp. 2290-2306 ◽  
Author(s):  
W. J. Song ◽  
D. J. Surmeier
Keyword(s):  
Polymerase Chain Reaction Amplification ◽  
Modal Shift ◽  
Whole Cell ◽  
Adult Rat ◽  
Class D ◽  
Current Voltage ◽  
Cell Recording ◽  
Voltage Dependent ◽  
Reaction Amplification ◽  
Class C

1. Voltage-dependent facilitation of Ca2+ channels was studied in acutely isolated adult rat neostriatal neurons. Particular attention was paid to the facilitation of L-type channels. 2. In the absence of neuromodulators, the current-voltage relationship for whole cell Ba2+ currents was enhanced by a prepulse to +100 mV. The median enhancement at -20 mV was nearly 60%. The voltage dependence and kinetics of the processes underlying the facilitation were similar to those reported in other neurons. N-, P-, Q-, and L-type currents contributed to the observed facilitation. 3. Voltage-dependent facilitation of L-type currents was studied by subtracting nifedipine-insensitive currents from control currents. Although the kinetics were similar to those of the whole cell currents, the half-activation voltage for facilitation of L-type currents [half-activation voltage (Vh) = -0.6 mV, slope factors (Vc) = 11.8 mV, [n = 5] was significantly less depolarized than that of the pooled currents (Vh = 47.3 mV, Vc = 12.3 mV, n = 7). 4. Repetitive depolarization with spikelike waveforms was also able to induce facilitation of L-type currents, suggesting that facilitation was not simply a consequence of a modal shift in gating like that induced by Bay K 8644. 6. Combined whole cell recording and single-cell reverse transcription-polymerase chain reaction amplification revealed that neostriatal medium spiny neurons expressed detectable levels of either class C or class D L-type channel alpha 1, subunit mRNA. Both neurons expressing class C L-type channels and neurons expressing class D L-type channels exhibited voltage-dependent facilitation.

Pre-Operational Business Planning: Program for Improving General Hospitals of Pademangan Class D be a Class C

IARJSET ◽  
2018 ◽  
Vol 5 (11) ◽  
pp. 1-5
Author(s):  
DR. Tantri Yanuar Rahmat Syah, SE., MSM ◽  
DR. Rokiah Kusumapradja, MHA ◽  
MM, Siti Rachmi
Keyword(s):  
Business Planning ◽  
Planning Program ◽  
General Hospitals ◽  
Class D ◽  
Class C

scholarly journals Structural and functional characterization of two new class D β-lactamases: OXA-46 and OXA-48

2006 ◽  
Vol 62 (a1) ◽  
pp. s161-s161
Author(s):  
V. Calderone ◽  
F. Giuliani ◽  
M. Benvenuti ◽  
J. D. Docquier ◽  
P. Nordmann ◽  
...  
Keyword(s):  
Functional Characterization ◽  
New Class ◽  
Class D

scholarly journals Characterization of OXA-29 from Legionella(Fluoribacter) gormanii: Molecular Class D β-Lactamase with Unusual Properties

2001 ◽  
Vol 45 (12) ◽  
pp. 3509-3516 ◽  
Author(s):  
Nicola Franceschini ◽  
Letizia Boschi ◽  
Simona Pollini ◽  
Raphaël Herman ◽  
Mariagrazia Perilli ◽  
...  
Keyword(s):  
Divalent Cations ◽  
Expression System ◽  
Amino Acid Identity ◽  
Exchange Chromatography ◽  
Chloride Ions ◽  
Penicillin G ◽  
New Class ◽  
Class D ◽  
Mature Enzyme ◽  
Isoelectric Ph

ABSTRACT A class D β-lactamase determinant was isolated from the genome ofLegionella (Fluoribacter) gormaniiATCC 33297T. The enzyme, named OXA-29, is quite divergent from other class D β-lactamases, being more similar (33 to 43% amino acid identity) to those of groups III (OXA-1) and IV (OXA-9, OXA-12, OXA-18, and OXA-22) than to other class D enzymes (21 to 24% sequence identity). Phylogenetic analysis confirmed the closer ancestry of OXA-29 with members of the former groups. The OXA-29 enzyme was purified from an Escherichia coli strain overexpressing the gene via a T7-based expression system by a single ion-exchange chromatography step on S-Sepharose. The mature enzyme consists of a 28.5-kDa polypeptide and exhibits an isoelectric pH of >9. Analysis of the kinetic parameters of OXA-29 revealed efficient activity (k cat/Km ratios of >105 M−1 · s−1) for several penam compounds (oxacillin, methicillin, penicillin G, ampicillin, carbenicillin, and piperacillin) and also for cefazolin and nitrocefin. Oxyimino cephalosporins and aztreonam were also hydrolyzed, although less efficiently (k cat/Km ratios of around 103 M−1 · s−1). Carbapenems were neither hydrolyzed nor inhibitory. OXA-29 was inhibited by BRL 42715 (50% inhibitory concentration [IC50], 0.44 μM) and by tazobactam (IC50, 3.2 μM), but not by clavulanate. It was also unusually resistant to chloride ions (IC50, >100 mM). Unlike OXA-10, OXA-29 was apparently found as a dimer both in diluted solutions and in the presence of EDTA. Its activity was either unaffected or inhibited by divalent cations. OXA-29 is a new class D β-lactamase that exhibits some unusual properties likely reflecting original structural and mechanistic features.

scholarly journals HSE MANAGEMENT SYSTEM AT HIGH ELEVATION IN SHIPBUILDING PROJECT

2020 ◽  
Vol 5 (11) ◽  
pp. 117-127
Author(s):  
Idris Othman ◽  
Hisham Mohamad ◽  
Nasiman Sapari ◽  
Nasir Shafiq ◽  
Fauzan Ibrahim ◽  
...  
Keyword(s):  
Management System ◽  
Safety Management ◽  
High Elevation ◽  
Peninsular Malaysia ◽  
Survey Method ◽  
Liquefied Petroleum Gas ◽  
Class D ◽  
Fall From Height ◽  
Class C ◽  
Almost All

The Shipyard industry is one of the growing industry in Malaysia. There is still a lot of room for improvement with regards to the safety aspects within the industry. This study presents the finding of a survey on the safety management in shipyard operation of class C and D in Peninsular Malaysia as registered with Ministry of Finance Malaysia. Shipyard operation is considered a hazardous job. Most of the cases were due to fall from height, fire and explosion. The accidents were due to crane collapsed and explosion during welding works inside a hull of a Liquefied Petroleum Gas (LPG) carrier. The research aims to study the Health, Safety and Environment Management System (HSEMS) of shipyard operations in Malaysia particularly in Class C and Class D. This study was conducted using a survey method following the Glenn D’s equation. The findings of this study shown that almost all the shipyards had HSEMS in placed but some were incomplete. Accidents still happen in the Malaysian shipyard industry from time to time. Nearly 10% of shipyards did not have clear HSE Policy due to low priority given to HSE matters.

scholarly journals In VitroandIn VivoProperties of BAL30376, a β-Lactam and Dual β-Lactamase Inhibitor Combination with Enhanced Activity against Gram-Negative Bacilli That Express Multiple β-Lactamases

2011 ◽  
Vol 55 (4) ◽  
pp. 1510-1519 ◽  
Author(s):  
Malcolm G. P. Page ◽  
Clothilde Dantier ◽  
Eric Desarbre ◽  
Bérangère Gaucher ◽  
Klaus Gebhardt ◽  
...  
Keyword(s):  
Clavulanic Acid ◽  
Stenotrophomonas Maltophilia ◽  
Multidrug Resistant ◽  
Triple Combination ◽  
Class A ◽  
Link Type ◽  
Class D ◽  
Class C ◽  
Inhibitor Combination ◽  
Lactamase Inhibitor

ABSTRACTBAL30376 is a triple combination comprising a siderophore monobactam,BAL19764; a novel bridged monobactam,BAL29880, which specifically inhibits class C β-lactamases; and clavulanic acid, which inhibits many class A and some class D β-lactamases. The MIC90was ≤4 μg/ml (expressed as the concentration ofBAL19764) for most species of theEnterobacteriaceaefamily, including strains that produced metallo-β-lactamases and were resistant to all of the other β-lactams tested. The MIC90forStenotrophomonas maltophiliawas 2 μg/ml, for multidrug-resistant (MDR)Pseudomonas aeruginosait was 8 μg/ml, and for MDRAcinetobacterandBurkholderiaspp. it was 16 μg/ml. The presence of the class C β-lactamase inhibitorBAL29880contributed significantly to the activity ofBAL30376against strains ofCitrobacter freundii,Enterobacterspecies,Serratia marcescens, andP. aeruginosa. The presence of clavulanic acid contributed significantly to the activity against many strains ofEscherichia coliandKlebsiella pneumoniaethat produced class A extended-spectrum β-lactamases. The activity ofBAL30376against strains with metallo-β-lactamases was largely attributable to the intrinsic stability of the monobactamBAL19764toward these enzymes. Considering its three components,BAL30376was unexpectedly refractory toward the development of stable resistance.

A VERY LOW NOISE WIDEBAND CLASS-C CMOS LC VCO

2012 ◽  
Vol 21 (04) ◽  
pp. 1250033 ◽  
Author(s):  
FATEMEH ATAEI ◽  
MOHAMMAD YAVARI
Keyword(s):  
Phase Noise ◽  
Tuning Range ◽  
Capacitor Bank ◽  
Cmos Technology ◽  
Low Noise ◽  
Voltage Controlled Oscillator ◽  
Switching Scheme ◽  
Wide Tuning Range ◽  
New Class ◽  
Class C

In this paper, a new class-C voltage-controlled oscillator (VCO) is presented. In the proposed VCO, the tail capacitor of the conventional class-C oscillator is dislocated from the source of the cross-coupled transistors to their gate to achieve a rail-to-rail output swing. This improves the phase noise by 2.9 dB compared to the conventional class-C one. Besides, a new switching scheme is presented in the switched capacitor bank used for coarse tuning of the proposed VCO to lower the on resistance of the switches as well as to reduce the parasitic capacitors. This wide tuning range class-C VCO is designed in a 0.18 μm CMOS technology. It achieves a -125.3 dBc/Hz phase noise at 1 MHz offset from a 2.2 GHz carrier frequency while covering a wide tuning range from 1.82 to 2.65 GHz and consuming 3.5 mW power from a single 0.9 V power supply.

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