Electrostatic tweezer for droplet manipulation

Various physical tweezers for manipulating liquid droplets based on optical, electrical, magnetic, acoustic, or other external fields have emerged and revolutionized research and application in medical, biological, and environmental fields. Despite notable progress, the existing modalities for droplet control and manipulation are still limited by the extra responsive additives and relatively poor controllability in terms of droplet motion behaviors, such as distance, velocity, and direction. Herein, we report a versatile droplet electrostatic tweezer (DEST) for remotely and programmatically trapping or guiding the liquid droplets under diverse conditions, such as in open and closed spaces and on flat and tilted surfaces as well as in oil medium. DEST, leveraging on the coulomb attraction force resulting from its electrostatic induction to a droplet, could manipulate droplets of various compositions, volumes, and arrays on various substrates, offering a potential platform for a series of applications, such as high-throughput surface-enhanced Raman spectroscopy detection with single measuring time less than 20 s.

Evaluation of Feasibility of Gamma-Spectrometer NaI PAK-01 and SAS Na M3 Software Application for Regular Radionuclide Analysis of NPP Permissible Wastes

The feasibility of correct NaI gamma-spectrometry activity measurement for each nuclide in 131I, 132I, 133I, 134I, 135I, 133Xe, 135mXe, 135Xe and 222Rn composition is presented. To get this result the special matrix method M3 and SAS Na M3 software were used for spectra processing. SAS Na M3 software was developed for complex NaI gamma-spectra processing. Special algorithms and auxiliary software are used to overcome the problems of the classic spectra processing matrix method. Being used for spectrum processing SAS Na M3 software determines the nuclide composition of the sample, activity of nuclides identified and activities uncertainties. The activity values estimation is made for nuclides not identified in the sample measured but included in SAS Na M3 software nuclides library. The values of minimal detectable activities for NaI ∅3''× 3'' gamma-spectrometer and 1 hour measuring time are ~ 0.6 Bq for 131I, 132I, 133I, 134I and ~ 2 Bq for 135I.

A Quick-response and High-precision Dynamic Measuring Method with the Application on Small Angle Measurement

Small angle measuring tools with pendulum mechanical structure has two major challenges. One is that it takes long time to wait for the pendulum structure to completely stop swinging, and the other is that the instrument has poor anti-interference ability. Inspired by the two challenges, this paper proposes a dynamical measuring method to achieve a fast and accurate measurement synchronously. Specially, a damped oscillation modeling of the pendulum with nonlinear least squares fitting is presented to estimate the model parameters which includes the angle of the oblique plane. Besides, it is proved that the minimum sample size required for data fitting is decided by one oscillation period, which guarantees the shortest measuring time within high precision. Moreover, this paper also presents the precision criterion of fitting parameters to judge whether the fitting results meet the requirements. This proposed method is applied to a developed small angle measuring tool. The error of the proposed measurement system is better than 3.25 '' and the uncertainty is 4.8 '' within the measurement angle of 2000 '', and the settling time is 0.45 s. The experimental results confirm that this method can not only greatly shorten the measuring time, but also enhance the anti-interference ability and realize high-precision measurement.

Research on the Conversion Coefficient for Measuring Radon Concentration in Water Based on Bubbling Method

Radon is soluble in water, and the radon in drinking water is one of the sources of indoor radon. The China national standard for drinking water (GB5749-2006) indicates that the radon concentration in drinking water cannot be higher than 300pCi/L. The widely used method for measuring radon concentration in water is to use the RAD7 and the H2O accessory which provided by the Durridge Company for bubbling measurement. There are two kind sample bottles: 40ml and 250ml; the measurement steps: bubbling for 5 minutes, and measuring for 20 minutes. For the 40ml sample volume the conversion coefficient is around 25. For the 250ml sample volume the conversion coefficient is around 4. Since the price of the accessory is more than one thousand dollars, and the drying tube of the accessory is small, it needs to be replaced after each measurement which makes the operation is troublesome. We used a big drying tube to perform the radon concentration in water measurement. A new model for description the radon concentration in the gas circuit is proposed, and the conversion coefficient in any measurement condition is obtained. Any volume of sample bottle and drying tube can be used, selecting the suitable bubbling time and measuring time, the radon concentration in water can be obtained.

On the nature of the sustainability of the process in time

Introduction. Why do the ideas about time in ‘The Iliad’ and in the conditions of modern transmission speeds of large flows of information unexpectedly converge, and the key point is the study of the forms of stability of the process in time? What do we really mean by ingrained thinking and sustainable development, and how do they relate to the evolutionary nature of sustainable processes? The purpose of this paper is to present the form of a sustainable process, its constructive deployment in time by means of a natural science analysis. Materials and Methods. Based on the materials and methods of measuring time-varying quantities, as well as set-theoretic prerequisites for branching the process, it is proposed to look for natural scientific grounds for analyzing the sustainable development of trends in culture in general, in information processes and the education system, in particular. Here we will also try to take a well-known point of view (K. Lorentz, I. Prigozhin), when time, irreversibility, randomness in some constructive process relate to inanimate matter, to life, and to human. Results. Based on the analysis carried out by the author, the answer to the question of whether there are natural conditions for the sustainability of the object-process, in what aspect we can discuss the constructiveness of time, the evolutionary rooting of sustainable processes, branching points and the ‘stretching’ of a sustainable educational process into the future is presented. Conclusions. Our ideas about the processes in time and the conditions of their sustainability in the broadest cultural aspect, including the education system, need to be clarified. The constructive deployment of the process in time has its own structure that ensures the evolutionary rooting of the process and, in particular, the educational process.

METHOD OF MEASURING FRICTIONAL RESISTANCE IN PENDULAR MOTION

This paper presents a methodology for conducting tribological sliding tests based on decaying vibrations in pendular motion. The proposed method of determining the (averaged) coefficient of friction in pendular motion is based on measuring the potential kinetic energy. The method is characterized by a short measuring time and enables a quick comparison of the friction coefficients of different materials.

Evaluation of a sensitive, reasonable, and fast detection method for 55Fe in steel

A pilot study to quantify 55Fe in steel from a reactor vessel of a nuclear power plant by accelerator mass spectrometry (AMS) without any chemical sample preparation was validated by liquid scintillation counting (LSC) and AMS after radiochemical separation. AMS reaches an uncertainty < 10% at the 1 kBq gFe−1 level within less than 10 min measuring time. The background was < 3 Bq gFe−1, presently limited by the short measurement time. The new instrumental AMS method for analysing 55Fe from neutron capture production is reasonable and fast compared to other analytical methods.

A Compact Raster Lensless Microscope Based on a Microdisplay

Lensless microscopy requires the simplest possible configuration, as it uses only a light source, the sample and an image sensor. The smallest practical microscope is demonstrated here. In contrast to standard lensless microscopy, the object is located near the lighting source. Raster optical microscopy is applied by using a single-pixel detector and a microdisplay. Maximum resolution relies on reduced LED size and the position of the sample respect the microdisplay. Contrarily to other sort of digital lensless holographic microscopes, light backpropagation is not required to reconstruct the images of the sample. In a mm-high microscope, resolutions down to 800 nm have been demonstrated even when measuring with detectors as large as 138 μm × 138 μm, with field of view given by the display size. Dedicated technology would shorten measuring time.