The present disclosure relates to a field programmable gate array (FPGA)-based multi-channel dynamic light scattering (DLS) autocorrelation system and method. The system includes a DLS generation apparatus, a photon correlator, and a host computer, where the photon correlator includes an FPGA and a universal serial bus (USB) communication module; the DLS generation apparatus is connected to the FPGA; the FPGA is configured to count and perform correlation calculation on photon pulses generated by the DLS generation apparatus; the USB communication module is connected to the host computer; the FPGA includes a dual counter module and a correlation calculation module; the dual counter module is connected to the DLS generation apparatus and the correlation calculation module; the correlation calculation module is connected to the USB communication module; the dual counter module includes a plurality of dual counters; and the correlation calculation module includes a plurality of correlators.

The disclosed subject matter compensates or corrects for errors that otherwise would be present when a measurement is made on a condensation particle counting system with the only difference causing the errors being absolute pressure. The difference in absolute pressure may be due to, for example, a change in altitude in which the condensation particle counting system is located. Techniques and mechanisms are disclosed to compensate for changes in particle count, at a given particle diameter, for changes in sampled absolute pressure at which measurements are taken. Other methods and apparatuses are disclosed.

An optical particle detector is configured to simultaneously detect at least two particles within a useful detection volume. The detector includes a retina capable of receiving light rays scattered by the particles and a dark reticle interposed between the useful detection volume and the retina. The dark reticle includes at least one optical aperture allowing a passage towards the retina of a part of first scattered light rays and of a part of second scattered light rays, and an opaque surface on a periphery of the at least one aperture, preventing a passage towards the retina of another part of the first and second scattered light rays so as to project onto the retina first and second scattering diagrams separated from each other.

A method for synthesis of nanoparticles are described. The method includes dispersing metal oxide powder in a mixture of a base liquid and a surfactant to form a primary mixture, grinding the primary mixture using a grinding media by periodically adding a surfactant solution to form a slurry, extracting a predetermined amount of sample from the slurry at periodic time intervals to obtain a testing solution to assess particle size of in the slurry using a particle size analyzer; and systematically adding the surfactant solution and the grinding media to the slurry based on the assessed particle size in the testing solution until a mean particle size of the nanoparticles is achieved.

A high-efficiency particle analysis method includes the following steps: taking representative air-dried samples and measuring a moisture content; boiling, sieving, weighing and adding a dispersant; conducting a particle analysis test; reading four readings of 1.sup.st to 59.sup.th and 60.sup.th to 90.sup.th samples; and drawing a particle size distribution curve showing the relationship between the particle size and the percentage of below a certain diameter. According to the method, a time difference is used to change the measurement mode, and the four readings of the 59.sup.th and 90.sup.th samples are read in a cycling manner; and a novel test method is provided on the premise of ensuring quality, thus greatly improving the efficiency of a particle analysis test and meeting production requirements.

Various embodiments described herein relate to apparatuses and methods for detecting fluid particles and their characteristics. In various embodiments, a device for detecting fluid particles and their characteristics may comprise a fluid composition sensor configured to receive a volume of fluid. The fluid composition sensor has a collection media housing configured to receive a portion of a collection media, a pump for moving a volume of fluid over the collection media housing, an imaging device configured to capture an image of particles on the collection media, and a particle matter mass concentration calculation circuitry configured to calculate a total particle matter mass. The particle matter mass concentration calculation circuitry is connected with the imaging device and the pump. The particle matter mass concentration calculation circuitry is configured to adjust the volume of fluid over the collection media housing.

Provided is a medium evaluation method for evaluating the suitability of a medium in which cell aggregates are cultured in a suspended state, by which an evaluation of whether a medium is adequate for both the cell retention performance and the cell recovery efficiency, the medium evaluation method including dispersing a plurality of particles in a medium, measuring a sedimentation velocity by which the particles settle in the medium, and using the sedimentation velocity thus measured as an index value indicating the suitability of the medium; and also provided are a medium and a culture method.

Method and control system are provided for controlling values of process parameters of a pretreatment process of wood particles. A sampler is used to obtain a sample of a product flow of said pretreatment process after said wood particles have undergone steam explosion in a hemihydrolysis reactor. A particle measurement device is used to measure one or more characteristics of particles in said sample and to produce one or more pieces of measurement information indicative of the measured characteristics. Said one or more pieces of measurement information are used to select one or more values of one or more of said process parameters.

The invention describes a laser sensor module (100) for detecting ultra-fine particles (10) with a particle size of 300 nm or less, more preferably 200 nm or less, most preferably 100 nm or less, the laser sensor module (100) comprising: —at least one laser (110) being adapted to emit laser light to at least one focus region in reaction to signals provided by at least one electrical driver (130), —at least one detector (120) being adapted to determine a self-mixing interference signal of an optical wave within a laser cavity of the at least one laser (110), wherein the self-mixing interference signal is caused by reflected laser light reentering the laser cavity, the reflected laser light being reflected by a particle receiving at least a part of the laser light, —the laser sensor module (100) being arranged to perform at least one self-mixing interference measurement, —the laser sensor module (100) being adapted to determine a first particle size distribution function with a first sensitivity by means of at least one measurement result determined based on the at least one self-mixing interference measurement, the laser sensor module being further adapted to determine a second particle size distribution function with the second sensitivity, the second sensitivity being different from the first sensitivity, —the at least one evaluator (140) being adapted to determine a particle measure of the particle size of 300 nm or less by subtracting the second particle size distribution function multiplied with a calibration factor q from the first particle size distribution function. The invention further describes a corresponding method and computer program product. The invention enables a simple and low-cost particle detection module or particle detector based on laser self-mixing interference which can detect particles with a size of 100 nm or even less.

This disclosure relates generally to methods and systems for designing an optimal dual-band metamaterial polarization converter for refractive index sensing applications. Most of the existing techniques for designing the metamaterial-based polarization converters operating at very high frequency range limits the sensing performance and increases fabrication complexity. In the design of the optimal dual-band metamaterial polarization converter, first a circular split-ring resonator (SRR) as a unit cell is designed. Secondly, the two capacitive gaps of the top layer, are aligned at 180 degrees with respect to each other and at 45 degrees with respect to X-axis and Y-axis. Lastly, step-by-step tuning the one or more key design parameters of the SRR, is performed until an optimum frequency response is obtained, to obtain the optimal dual-band metamaterial polarization converter.