scholarly journals A real-time multiplexed microbial growth intervalometer for capturing high resolution growth curves

2019 ◽  
Author(s):  
David C. Vuono ◽  
Bruce Lipp ◽  
Carl Staub ◽  
Evan Loney ◽  
Joseph J. Grzymski
Keyword(s):  
Microbial Growth ◽  
Low Cost ◽  
Growth Curves ◽  
High Gain ◽  
Luria Bertani ◽  
Low Noise ◽  
Growth Monitoring ◽  
Remote Visualization ◽  
Light Pattern ◽  
K 12

AbstractBatch cultures are a low maintenance and routine culturing method used in anaerobic microbiology. Automated tools that measure growth curves from anaerobic microorganisms grown in traditional laboratory glassware, such as Balch-type tubes, are not commercially available. Here we present a new MicrobiAl Growth Intervalometer (MAGI) that captures microbial growth curves through photo conductivity of the medium using a diffused light pattern of specified frequency, rather than photo-attenuation of collimated light used in traditional systems, and is configured with an offset photodetector/emitter to minimize direct impingement of light from the source to improve the resolution of the solution’s density. MAGI is operated by software-driven automation and offers investigators a low noise/high gain instrument with capabilities for remote visualization and data acquisition. MAGI is a low maintenance, low cost, and robust platform primarily for anaerobic cultivation and growth monitoring. We demonstrate the utility of this device by first showing that growth rates and generation times inEscherichia coliK-12 are reproducible to previously published results. We then tested MAGI to measure growth curves of an environmental organism,Intrasporangium calvum, under various media compositions. Our results demonstrate that MAGI is a versatile platform to measure growth curves in media under various redox conditions (microaerobic and anaerobic), complex mediums such as Luria-Bertani (LB) broth and minimal media, and for resolving diauxic growth curves whenI. calvumis grown on a disaccharide. Lastly, we demonstrate that the device can resolve growth curves for μM concentrations of resources that yield low biomass. This research advances the tools available to microbiologist aiming to monitor growth curves in a variety of disciplines, such as environmental microbiology, clinical microbiology, and food sciences.

scholarly journals Low-Cost Clamp-On Photometers (ClampOD) and Tube Photometers (TubeOD) for Online Cell Density Determination

2022 ◽  
Vol 12 ◽  
Author(s):  
Jörg S. Deutzmann ◽  
Grace Callander ◽  
Wenyu Gu ◽  
Albert L. Müller ◽  
Alexandra L. McCully ◽  
...  
Keyword(s):  
Cell Density ◽  
Microbial Growth ◽  
Low Cost ◽  
Growth Curves ◽  
Calibration Procedure ◽  
Heat Sensitivity ◽  
Sampling Point ◽  
Strictly Anaerobic ◽  
Voltage Range ◽  
Manual Sampling

Optical density (OD) measurement is the gold standard to estimate microbial cell density in aqueous systems. Recording microbial growth curves is essential to assess substrate utilization, gauge sensitivity to inhibitors or toxins, or determine the perfect sampling point. Manual sampling for cuvette-photometer-based measurements can cause disturbances and impact growth, especially for strictly anaerobic or thermophilic microbes. For slow growing microbes, manual sampling can cause data gaps that complicate analysis. Online OD measurement systems provide a solution, but are often expensive and ill-suited for applications such as monitoring microbial growth in custom or larger anaerobic vessels. Furthermore, growth measurements of thermophilic cultures are limited by the heat sensitivity of complex electronics. Here, we present two simple, low-cost, self-assembled photometers—a “TubeOD” for online measurement of anaerobic and thermophilic cultures in Hungate tubes and a “ClampOD” that can be attached to virtually any transparent growth vessel. Both OD-meters can be calibrated in minutes. We detail the manufacturing and calibration procedure and demonstrate continuous acquisition of high quality cell density data of a variety of microbes, including strict anaerobes, a thermophile, and gas-utilizing strains in various glassware. When calibrated and operated within their detection limits (ca. 0.3–90% of the photosensor voltage range), these self-build OD-meters can be used for continuous measurement of microbial growth in a variety of applications, thereby, simplifying and enhancing everyday lab operations.

scholarly journals Design and implementation of a broad-band high gain low noise amplifier for 3G/4G applications

2021 ◽  
Vol 23 (2) ◽  
pp. 725
Author(s):  
Ahmed M. Abdelmonem ◽  
Ahmed S. I. Amar ◽  
Amir Almslmany ◽  
Ibrahim L. Abdalla ◽  
Fathi A. Farag
Keyword(s):  
Noise Figure ◽  
Supply Voltage ◽  
Low Cost ◽  
Broad Band ◽  
High Gain ◽  
Low Noise ◽  
Low Noise Amplifier ◽  
Design System ◽  
Matching Network ◽  
Noise Amplifier

The main aim of the paper is designing and implementing a broadband low-noise-amplifier (LNA) based on compensated matching network techniquein order to get high stable gain, low noise figure, low cost and smaller sizefor 3G/4G communication system applications at 2 GHz with bandwidth 600MHz. The Advanced Design System simulates the proposed circuit (ADS).The implementation was done with a class A bias circuit and a low noise transistor BFU 730F with a lower Noise Figure (NFmin) 0.62 dB. Collectorcurrent is measured to be 5.8mA and base current is 19.1μA with a supply voltage of 2.25V. The new design proposed a (NFmin) of 0.62 dB with a 17.8dB high stable amplifier gain. The microstrip lines (MSL) and compensated matching network techniques were used to improve the LNA’s stability and achieve a good result. The LNA board is implemented and assembled on the FR4 botton layer material. The results are virtually non existence equivalent between the simulated and the measured results.

scholarly journals Design of a LNA in the frequency band 1.8-2.2GHz in 0.13μm CMOS Technology

2005 ◽  
Vol 3 ◽  
pp. 299-303
Author(s):  
E. Di Gioia ◽  
C. Hermann ◽  
H. Klar
Keyword(s):  
Noise Figure ◽  
Supply Voltage ◽  
Low Cost ◽  
Operating Mode ◽  
Cmos Technology ◽  
Digital Circuit ◽  
High Gain ◽  
Low Noise ◽  
Noise Amplifier ◽  
Low Supply Voltage

Abstract. The subject of this work is a low noise amplifier (LNA), operating in the frequency range 1.8-2.1GHz. The CMOS 0.13μm technology is used in respect to the low cost of the final device. Among the specifications, a variable gain and an adjustable working frequency are required. In particular, four different working modes are provided: 1.8, 1.9 and 2.1GHz high gain and 2.1GHz low gain. The amplifier is designed to be used as first stage of a receiver for mobile telephony. For this reason low power consumption is taken into consideration (low supply voltage and low drain currents). A simple digital circuit, integrated on-chip, is used to select the operating mode of the LNA by means of two input pins. A Noise figure of 1dB is obtained with a supply voltage of 0.8V.

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

A Low-Noise, High-Gain Quasi-Millimeter-Wave Receiver MMIC with a Very High Degree of Integration Using 3D-MMIC Technology

2011 ◽  
Vol E94-C (10) ◽  
pp. 1548-1556 ◽  
Author(s):  
Takana KAHO ◽  
Yo YAMAGUCHI ◽  
Kazuhiro UEHARA ◽  
Kiyomichi ARAKI
Keyword(s):  
Millimeter Wave ◽  
High Gain ◽  
Low Noise ◽  
High Degree ◽  
Very High ◽  
Millimeter Wave Receiver

scholarly journals A 300-GHz low-cost high-gain fully metallic Fabry–Perot cavity antenna for 6G terahertz wireless communications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Frequency Selective Surface ◽  
High Gain ◽  
Wireless Communication Systems ◽  
Beam Radiation ◽  
Compact Size ◽  
Fabry Perot ◽  
Operating Bandwidth ◽  
Polarization Level

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.

Microbial Growth Response to Hydrogel Encapsulated Quantum Dot Nanospheres

2007 ◽  
Vol 1064 ◽  
Author(s):  
Somesree GhoshMitra ◽  
Tong Cai ◽  
Santaneel Ghosh ◽  
Arup Neogi ◽  
Zhibing Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Growth Response ◽  
Microbial Growth ◽  
Biological Effects ◽  
Growth Curves ◽  
Swelling Properties ◽  
Growth Environment ◽  
E Coli ◽  
Cdte Qds ◽  
Biological Compatibility

ABSTRACTQuantum dots (QDs) are now used extensively for labeling in biomedical research due to their unique photoluminescence behavior, involving size-tunable emission color, a narrow and symmetric emission profile and a broad excitation range [1]. Uncoated QDs made of CdTe core are toxic to cells because of release of Cd2+ ions into the cellular environment. This problem can be partially solved by encapsulating QDs with polymers, like poly(N-isopropylacrylamide) (PNIPAM) or poly(ethylene glycol) (PEG). Based on biological compatibility, fast response as well as pH, temperature and magnetic field dependent swelling properties, hydrogel nanospheres has become carriers of drugs, fluorescence labels, magnetic particles for hyperthermia applications and particles that have strong optical absorption profiles for optical excitation. The toxicity of uncoated QDs are known; however, there have been a very limited number of studies specially designed to assess thoroughly the toxicity of nanosphere encapsulated QDs against QD density and dosing level.In this work, we present preliminary studies of biological effects of a novel QD based nanomaterial system on Escherichia coli (E. coli) bacteria. Cadmium chalcogenide QDs provide the most attractive fluorescence labels in comparison with routine dyes or metal complexes. Nanospheres on the other hand are the most commonly used carriers of fluorescence labels for fluorescence detection. The integration of fluorescent QDs in nanospheres therefore provides a new generation of fluorescence markers for biological assays. Hydrogels based on PNIPAM is a well known thermoresponsive polymer that undergoes a volume phase transition across the low critical solution (LCST) [2]. Therefore, the inherent temperature-sensitive swelling properties of PNIPAM offer the potentiality to control QD density within the nanospheres. In the present work, E. coli growth was monitored as E. coli served as a representation of how cells might respond in the presence of hydrogel encapsulated QDs in their growth environment. The present work describes the successful encapsulation of CdTe QDs in PNIPAM gel network. Microgel encapsulated QDs were synthesized by first preparing PNIPAM microspheres with cystaminebisacrylamide as a crosslinker and CdTe QDs capped with a stabilizer. The CdTe QDs were bonded into PNIPAM microgels through the replacement of CdTe's stabilizer inside PNIPAM microspheres. Growth curves were generated for E. coli growing in 20 mL of LB media containing hydrogel encapsulated QD nanospheres (400 nm diameter) at relatively higher (0.5mg/mL) and lower (0.01mg/mL) concentration of solution. From the growth curves, there was no evidence at lower concentration (0.01mg/mL) that the hydrogel encapsulated QDs prevent the microbial cells from growing but at higher concentration (0.5mg/mL), microbial growth was inhibited. Transmission Electron Microscopy (TEM) was used to characterize QD size and density inside the hydrogel nanospheres. Scanning Electron Microscopy (SEM) was used to observe size and morphology of the hydrogel particles. Further investigation is going on cell growth response at different QD density and to evaluate the limiting hydrogel concentration for different QD densities.

scholarly journals A 5.7GHz low noise figure ultra high gain CMOS LNA with inter stage technique

2010 ◽  
Vol 7 (23) ◽  
pp. 1686-1693 ◽  
Author(s):  
Ehsan Kargaran ◽  
Hojat Khosrowjerdi ◽  
Karim Ghaffarzadegan ◽  
Hooman Nabovati
Keyword(s):  
Noise Figure ◽  
High Gain ◽  
Low Noise ◽  
Cmos Lna
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