Fluometuron Removal from Agricultural Wastewater in Porous Media Filters

In the present study, six gravity filters were constructed and evaluated for the treatment of agricultural wastewater contaminated with herbicide fluometuron. Two filter types in terms of feeding strategy (i.e., batch and continuous feeding strategies), three porous media (i.e., coarse gravel, coarse zeolite and fine zeolite) and three hydraulic residence times (i.e., 1 day, 2 days and 4 days) were evaluated to find the best design and operation parameter in fluometuron removal by adsorption on porous media. Batch experiments were also conducted and the experimental data were fitted to adsorption kinetic and isotherm models. Results showed that the experimental data fitted better to the pseudo-first order model and to the Freundlich model, and the highest fluometuron adsorption was recorded for fine zeolite. The results of filter operation indicated that the most important parameter affecting fluometuron removal is the hydraulic residence time.

Application of nano-metric synthetic materials in medical imaging diagnosis

This paper investigates the application of nanometer synthetic materials in medical imaging diagnosis. The main synthesis methods of nanomaterials are described, and nanomaterials are applied to X-ray CT imaging, magnetic resonance imaging, PAT imaging, fluorescence imaging, photoacoustic imaging and PET imaging. The diagnostic results can be obtained by applying spatial filtering to filter operation, medical imaging and the filtering processing of image segmentation. By extracting the medical image texture feature using gray level cooccurrence matrix, studying shallow network features and combining the characteristics of the learning result, a more comprehensive medical imaging diagnosis can be obtained. The experimental results show that the method can reduce the error rate of medical imaging diagnosis and accelerate the efficiency of medical imaging diagnosis.

Energy and Water Savings during Backwashing of Rapid Filter Plants

This paper describes an analysis of the effects of adjusting the intensity of filter backwash to the water temperature. The consequences of the lack of such adjustment for the life of filter beds, the amount of water used for backwashing, the amount of energy used for backwashing and the quality of the first filtrate are presented. In order to determine the losses and profits resulting from controlling the intensity of backwash water depending on its temperature, an analysis was carried out at a water treatment plant in southern Poland. Laboratory measurements were used to determine the granulation and specific gravity of sand grains filling the filtration beds. On the basis of measurements on a semi-technical scale, the magnitudes of filter bed expansion were determined for average monthly wash water temperatures. They were first calculated from the Richardson–Zaki equation, using different formulae for the value of the exponent of the power in this equation. Due to significant differences in the density and shape of grains covered with a permanent deposit after several years of filter operation, a satisfactory match between the formulae known from the literature and the results of expansion measurements was not obtained. Therefore, an new formula for the bed expansion was developed based on the Richardson–Zaki equation. A good fit of this formula to the experimental results was obtained. Monthly average values of water temperature were compiled, and on this basis the required amount of backwash water and energy was computed. The computations were made for 25% of fluidized bed expansion. Possible energy and water savings were estimated, as well as further gains from keeping the required expansion of the porous bed constant regardless of the wash water temperature.

PECULIARITIES OF ELECTROMAGNETIC FILTER OPERATION IN PENNING SOURCE WITH METAL HYDRIDE CATHODE

The paper describes a method of negative hydrogen ions separation from axial flow of charged particles extracted from Penning discharge with a metal hydride cathode. For this purpose, an electromagnetic filter has been designed basing on numerical solution of motion equations of charged particles in the filter. The optimal parameters of the filter operation were determined for the effective registration of negative hydrogen ions extracted in axial direction. Performed calculations together with experimental verification shows that there are not more than 10% electrons in the registered H– current. This model could be applied for the interpretation of any experiments with H– ions separation from an axial flow of charged particles extracted from a source with cylindrical geometry.

Research On The Operation Of Bag Filters For Dust And Gas Cleaning In Cement Production (On The Example Of Factories In The Ferghana Region Of The Republic Of Uzbekistan)

Cement production is one of the most common man-made air pollutants. In this regard, the need for dust collection in this process is obvious. The article presents an analysis of the used designs of dust collection devices in the cement production of the Fergana region of the Republic of Uzbekistan. Methods of tissue filter regeneration are analyzed. The results of experimental studies on the state of synthetic fabric bag filters installed on air purifiers from dust and gas flows are presented. The choice of the standard size, design and the required number of fabric bag filters was made. For technical and economic reasons, there is a method and mode of filter regeneration that does not cause severe wear of the fabric, due to which the duration of filter operation without expensive stops for current repairs is significantly increased.

Influence of Particle and Grain Size on Sand Filtration: Effect on Head Loss and Turbidity

Sand filtration is an eco-friendly method to treat either drinking water or wastewater ; it requires only natural granular media. It is also easy to use and to maintain ; the only problem they face is clogging that affects filter performance, that can be detected when head loss or turbidity increase. The purpose of this work is to see what are the factors that influence the performance of filter operation, for this, we used a pilot consisting on a circular column filled with sand (from South Algeria), where various parameters were tested; pressure, flow rate, sand granulometry, suspended matters and particle concentration of the water which is filtered. After eighteen weeks of operation, we have found that head loss increases by decreasing granulometry and increasing flow rate, pressure, particle size, and concentration. However, turbidity increases by decreasing particle size and increasing granulometry and particle concentration. Turbidity and head loss have different behaviour towards the same parameter; that is why it is necessary to take them into account in order to find a compromise between acceptable head loss / turbidity for a good functioning of the filter.

Lossless and Efficient Secret Image Sharing Based on Matrix Theory Modulo 256

Most of today’s secret image sharing (SIS) schemes are based on Shamir’s polynomial-based secret sharing (SS), which cannot recover pixels larger than 250. Many exiting methods of lossless recovery are not perfect, because several problems arise, such as large computational costs, pixel expansion and uneven pixel distribution of shadow image. In order to solve these problems and achieve perfect lossless recovery and efficiency, we propose a scheme based on matrix theory modulo 256, which satisfies ( k , k ) and ( k , k + 1 ) thresholds. Firstly, a sharing matrix is generated by the filter operation, which is used to encrypt the secret image into n shadow images, and then the secret image can be obtained by matrix inverse and matrix multiplication with k or more shadows in the recovery phase. Both theoretical analyses and experiments are conducted to demonstrate the effectiveness of the proposed scheme.

Особенности возникновения и предупреждение взрывоопасных режимов в системах аспирации с фильтрами-пылеуловителями

Обоснованы преимущества использования зернистых фильтров в системах аспирации производственных помещений, в которых образуется и обращается горючая пыль. Рассмотрены некоторые известные конструкции, имеющие достаточно узкое применение, однако перспективные для обработки взрывоопасных пылегазовых потоков. Дано описание лабораторного стенда и приведены результаты экспериментальных исследований процесса фильтрования зернистыми фильтрами, подтверждающие необходимость контроля взрывоопасных ситуаций в работе пылеуловителя. Предложен автоматизированный способ контроля аспирации для предупреждения взрывоопасных состояний фильтра.There is a large number of technological operations associated with the treatment of combustible dusts at production facilities. Such industries include food, pharmaceutical, woodworking, metalworking, textile and other industries, the main technological equipment of which is supplemented with aspiration systems. According to the requirements of ecology, labour protection and fire safety, this system must include a dust collector. When choosing a dust collector for such systems granular filters are found particularly effective. They allow to precipitate combustible dust. The article presents the known constructions of granular filters, the narrow application of which is associated with insufficient study of their operation with explosive flows. Therefore, the authors developed an experimental stand and analyzed the operation of different filters: with metal balls, screws, peas and pea mash, grain, which can be used as filter material. During the experiment it was found a state in which the filter operation is explosive. According to the results of the analysis, the criteria for the descriptions of normal and explosive operation are introduced - the criteria of geometric form, characterizes the filter and dust - K, and the rate of filtration - T. Numerical values of criteria are given for automated control of the filter operation. The automated control method of the filter allows to make the operation of the aspiration system more efficient and prevents explosive situations by timely regeneration and replacement of the layer, taking into account the calculated value of criteria K and T. In the scheme there are shown fire extinguishing modules, which are triggered by sensors when the temperature rises above normal.