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Prevelar raising/fronting has been documented as a “defining feature” of Pacific Northwest English, yet its status in nearby California remains unclear. This study investigates prevelar raising/fronting across four Californian field sites. Examining word list data from 276 White speakers and sociolinguistic interview data from 64 White speakers, we complicate assumptions of prevelar conditioning in the West in two ways. First, the authors show that the prevelar pattern is not confined to the Pacific Northwest but is extensive throughout California. Results suggest that, in line with previous work in Washington and Oregon, this prevelar pattern is also on the decline among younger Californians, although the trajectory of change appears to differ from that observed in Washington. As this is yet more evidence that the West is broadly participating in similar vocalic patterns, this article tentatively explores historical migration events as one possible source for the contemporary Western vowel system. Second, the authors also complicate phonetic notions of prevelar “tensing,” showing that F1 and F2 are not always operating in tandem: speakers who raise bag, for example, do not always front bag to the same degree, and vice versa. All of this points to an increasingly complex view of the prevelar pattern and one that warrants continued investigations for theories of sound change.

The dynamic general nesting spatial econometric model for spatial panels with common factors is the most advanced model currently available. It accounts for local spatial dependence by means of an endogenous spatial lag, exogenous spatial lags, and a spatial lag in the error term. It accounts for dynamic effects by means of the dependent variable lagged in time, and the dependent variable lagged in both space and time. Finally, it accounts for global cross-sectional dependence by means of cross-sectional averages or principal components with heterogeneous coefficients, which generalizes the traditional controls for time-invariant and spatial-invariant variables by unit-specific and time-specific effects. This paper provides an overview of the main arguments in favor of each of these model components, as well as some potential pitfalls.

Within the scope of the study, pre-softening, raising and final softening processes were applied to 2 selected fabrics under different conditions. The raising fastness, air permeability and bursting strength tests were performed on the samples obtained after the processes, and the effect of the process conditions on the researched performance values was examined. This paper is also detailed by statistical analysis. When the results were examined, it was seen that the best result in terms of raising fastness was the fabric with 50% waste + 50% PES back yarn. As a process, it was determined that the best result was obtained after a single passage with micro silicon pre-softening and raising at a speed of 15m / min, and then a low concentration softening process with a polyvinyl acetate-based binder and softener mixture.

Rechargeable aqueous zinc–manganese oxide batteries have attracted extensive attention in energy-storage systems owing to their high safety and low cost but still suffer from the lack of advanced c...

Изучена эффективность выращивания телок молочных пород при различных технологиях. В качестве объекта исследований выступали 14 племенных хозяйств Центрального Федерального округа, разводящих высококровную по голштинам черно-пеструю и голштинскую породы крупного рогатого скота при использовании разных способов содержания и технологических схем выращивания телок до 6-месячного возраста. Содержание молодняка молочного периода на открытом воздухе, относительно помещений, способствует увеличению его сохранности до 12 мес. на 5,2%, а также более высокой энергии прироста и соответственно живой массы как в первый и шестой (на 11,8 кг и 38,1 кг, или 26,6% и 26,0%, Р≤0,01—0,001), так и десятый и двенадцатый месяцы жизни (на 46,1 кг и 52,3 кг, или 19,5% и 18,6%; Р≤0,05). В онтогенезе условия содержания и кормления телят раннего возраста оказывают наиболее существенное влияние на формирование продуктивных качеств скота. Так, в первые 2 мес жизни телки, когда основными кормами являлись цельное молоко и концентраты, коэффициент корреляции между среднесуточным приростом и надоем молока был наиболее высоким, достигая значений: r=0,34—0,42; с содержанием жира и белка на порядок ниже — r=0,19—0,22 и r=0,11—0,13 соответственно. В последующих возрастных периодах выращивания телок, с 4- до 10—12-месячного возраста корреляционная зависимость между этими признаками снижалась до минимальных значений. Studies have been carried out to evaluate the efficiency of raising dairy heifer breeding using various technologies. The object of research were 14 breeding farms of the Central Federal District, breeding high-blooded Black-and-White and Holstein cattle breeds using different methods of housing and technological schemes for raising heifers up to 6 months of age. Housing young calves outdoors compared to building increases their survival rate up to 12 months by 5.2% and increased energy gain and live weight respectively in both the first and sixth months (by 11.8 kg and 38.1 kg, or 26.6% and 26.0%; P≤0.01-0.001) and the tenth and twelfth months (by 46.1 kg and 52.3 kg, or 19.5% and 18.6%; P≤0.05). During ontogeny, the conditions of housing and feeding of young calves have the most significant influence on the formation of productive qualities of livestock. Thus, in the first 2 months of the heifer's life, when the basic fodder was whole milk and concentrates, the correlation coefficient between an average daily gain in body weight and milk production was the highest, reaching the values: r=0.34-—0.42; with fat and protein content an order of magnitude lower - r=0.19-—0.22 and r=0.11—0.13, respectively. During the following age periods of heifer rearing, from 4 to 10—12 months of age, the correlation relationship between these traits decreased to minimum value.

To improve the efficiency of harvesting energy, a cut-corner prism piezoelectric energy harvester based on galloping enhancement is designed in this study. Galloping is caused by the pressure difference between the upper and lower surfaces of the prism. Numerical simulations indicate that the cut-corner can reduce the occurrence of the shear layer reattachment phenomenon and also increase the strength of the secondary backflow between the shear layer and the lateral side of the prism, thereby raising the pressure difference between the upper and lower surfaces of the prism. The effect of cut-corner size on the performance of cut-corner prism energy harvesters is investigated experimentally. The results show that the optimal range for the prism is when the lengths of the cut-corner windward side and parallel side are 0.2B–0.4B (B is the length of the prism side) and 0.5B–0.6B, respectively. At a wind speed of 6.24 m/s and a resistance of 1 × 105 Ω , the maximum output power of the cut-corner prism energy harvester with a windward side length of 0.4B and a parallel side length of 0.6B can reach 47.5 mW, which is 261% higher than that of the reference square prism, effectively raising the performance of the piezoelectric energy harvester.

Background and objective This study was carried out to develop an effective technique for raising seedlings of Veronica pyrethrina Nakai, a native plant species in the Korean Peninsula, in plug trays. Methods To investigate the optimum plug cell size and sowing media, we sowed seed in to plug trays with 34, 21, and 10 mL cells and filled with a commercial horticultural substrate and mixtures of peatmoss and perlite in 1:1, 3:1, and 4:1 ratios. Fertilization levels were set at 0, 500, 1000 and 2000 mg • L−1. Results Plug cell size did not significantly influence the seedling growth of V. pyrethrina. By substrate type, the growth rate was highest in the horticultural substrate, followed by 4:1, 3:1, and 1:1. Growth by fertilization level was higher in all fertilized treatment groups than in the control group, and there was no difference among 500, 1000, and 2000 mg • L−1. Conclusion The results of this study proved that it is most suitable for raising seedlings of V. pyrethrina to sow the seeds in a 10 mL cell plug tray filled with horticultural substrates, and apply fertilizers with less than 500 mg • L−1 concentration.

Response surface methodology was adopted to establish the mathematical model between the parameters (overlap ratio, Y-axis lift, and X-axis offset) and responses (non-fusion area, flatness ratio, and width of clad). The results indicated that the non-fusion area reduced at first and increased afterwards as overlap ratio decreased and Y-axis lift increased, while gradually reduced when overlap ratio increased and X-axis offset decreased. The flatness ratio gradually decreased by lowering the overlap ratio and raising the X-axis offset but gradually increased as Y-axis lift and X-axis offset lowered simultaneously. The clad width gradually reduced when overlap ratio or X-axis offset increased. A validation experiment was carried out with the target of minimizing the non-fusion area and maximizing the flatness ratio. The error rate for both responses was 7.7% and 3.6%, respectively. This article provides a theoretical basis for the forming control and prediction of double-layer and multi-track coatings by laser cladding.

For some severe applications, pieces are made in composite materials with woven fabrics reinforcements: interlock. High yarn density and specific weaving pattern can slow the production speed because of yarn damages. The purpose of this study is to identify conditions causing warp yarn damages during dense weaving in terms of weaving sequence, interlacing and yarn structure and morphology. Two approaches are followed in-situ on the weaving machine and in-lab on a tribometer designed for this study. An instrumented 3D interlock machine is used in order to measure yarn tension and contact force during weaving. A specific sequence with different kinds of yarn intercrossings is applied and the more aggressive cases in terms of yarn tension and contact force are identified. From the data acquired on the weaving machine, a specific tribometer reproducing the intercrossing between two yarns with different yarn tension and contact force has been developed. The results obtained from weaving and friction tests show the source of aggressive conditions: i) the Jacquard mechanics: higher tension and contact force are obtained while yarn has a raising movement in comparison to a lowering movement, ii) the intercrossing sequence: a single yarn in movement with its neighbours having an opposite movement, iii) yarn structure and morphology: a coarse yarn and/or with twist, because it is bulky however it also have a better cohesion, therefore a compromise has to be found, iv) normal load increases yarn damage, and decreases the coefficient of friction, however the effect of yarn tension is not determined.

Treating subgingival deep carious defects can be clinically challenging owing to the difficulty in obtaining sufficient restorative access and a moisture-free field for bonding. Traditional restorative and surgical approaches are aggressive. In keeping with modern restorative materials and techniques, the deep margin elevation procedure has evolved as a simple and convenient means to manage hitherto difficult cases. Clinical cases detailing the step wise procedure for deep margin elevation have been described with emphasis on magnification and isolation as the key to success

The effect of nano-modification and high-energy mechanical treatment in a magnetic mill on the process of spark plasma sintering of iron micropowders is studied. Iron nanopowders with a mean particle size of 94 nm are obtained by the method of chemical metallurgy. The nanopowders are introduced into the original blend with the help of a turbulent stirrer and a magnetic mill. The processes occurring during the high-energy mechanical treatment and subsequent sintering are considered, and their effect on the properties and the structure of the sintered specimens is assessed. Optimum variants for fabricating the material are suggested. The results may be used in the production of high-quality permanent magnets.

The purposeful impact of feeding and keeping dairy cattle on the formation of productive and other qualities is based on the laws of animal development. In the dairy period, calves, regardless of breed characteristics, must be fed on the basis of an optimal diet, which ensures high gains in live weight. The goal is to justify the effectiveness of a balanced feeding system using targeted feed additives of a new generation, contributing to the genetic manifestation of productivity of young animals during the rearing period. Methods – 2 experimental groups were formed according to the principle of pairs of analogs, taking into account gender, age, body condition, body weight and origin. The research was carried out on heifers of the Holstein breed in three farms in Almaty region. Results – the calves after the optimization of nutritional components at 12 months of age had a higher live weight compared to the heifers who received farm rations. So, in LLP “Agrofirma “Dinara-Ranch” it was higher by 3.14%, PF “ Aydarbayev”by 4.06, JSC “APC “Adal” by 4.52%. The average daily gain in live weight increased by 9.11%, 7.62 and 7.59%, respectively. Conclusions – during the experiments, it was found that optimization of feed rations for young animals in JSC "APC "Adal " increased profitability by 46.3%, total economic effect was 7,618 tenge, farm "Aydarbayev": 46.3% and 9,312 tenge, LLP “Agrofirm “Dinara-Ranch”: 31.1% and 4,588 tenge. The solution of these issues is important both for large industrial complexes and farms. A special role is given to the search for ways of the most rational use of feed, the use of biologically active substances, and creation of comfortable conditions for keeping animals.

The Southern Rocky Mountains of Colorado, United States, have the highest regional elevation in North America, but present-day crustal thickness (∼42–47 km) is no greater than for the adjacent, topographically lower High Plains and Colorado Plateau. The chemistry of continental-arc rocks of the mid-Cenozoic Southern Rocky Mountain volcanic field, calibrated to compositions and Moho depths at young arcs, suggests that paleocrustal thickness may have been 20%–35% greater than at present and elevations accordingly higher. Thick mid-Cenozoic Rocky Mountain crust and high paleo-elevations, comparable to those inferred for the Nevadaplano farther west in the United States from analogous volcanic chemistry, could be consistent with otherwise-perplexing evidence for widespread rapid erosion during volcanism. Variable mid-Cenozoic crustal thickening and uplift could have resulted from composite batholith growth during volcanism, superimposed on prior crustal thickening during early Cenozoic (Laramide) compression. Alternatively, the arc–crustal thickness calibration may be inappropriate for high-potassium continental arcs, in which case other published interpretations using similar methods may also be unreliable.

Our previous study showed the effect of pre-tension onto oscillation at the top of a ladder in raising and lowering processes on turntable ladders when steel wire ropes are added to ladder handrails. However, the oscillation was not switched off quickly. To quickly extinguish oscillation, we use steel ropes and a hydraulic system that is available on the truck to control the vibration. Based on the available multibody dynamic system and motion equation of the ladder, the group minimizes the number of variables in the motion equation and linearizes it. Thereafter, the vibration of the system is controlled and simulated by Matlab-Simulink software. This study presents a new method to control the ladder vibration on the turntable ladder.

Objective This experiment provides a first-of-its-kind driving-simulator study to investigate the feasibility of camera-monitor systems (CMS) with displaced side-mounted cameras in sedans. Background Among the increasing number of studies investigating the replacement of side-mounted rearview mirrors with CMS, the placement of side-mounted cameras has been largely neglected. Moreover, user preferences with respect to camera placement have not been validated in a driving simulator. Past research merely has shown that the vertical camera position can affect distance perception. Method In a driving simulator experiment, we investigated the effects of rearward camera placement on driver acceptance and performance. Thirty-six participants performed multiple lane changes in a last safe-gap paradigm. The camera position, ego-velocity, and velocity of the approaching vehicle varied across the experiment. Results The results suggest a clear preference for a high rearward perspective, whereas participants disliked the lower viewpoint. However, these stark differences were only marginally mirrored in lane change performance. Average safety margins tended to decrease and their variation tended to increase for the low camera position. Conclusion Even if the impact of the camera position on driving behavior seems to be small in sedans, driver expectations show clear-cut preferences. When designing CMS, this should be taken into account, as these preferences could promote the use of CMS and thus their positive impact on safety. Application Designers should place side-mounted cameras as high as possible to increase acceptance of CMS. Low camera positions are not recommended, as they might decrease safety margins and are not appreciated by drivers.

A comparative analysis of the main types of air coolers (ACs) is presented. Their advantages and disadvantages are indicated along with the main approaches for increasing heat removal efficiency. In order to intensify heat transfer without substantially raising equipment costs or significantly altering production processes, the authors propose a technological solution based on a calculation that ensures a theoretically optimal counter-flow phase interaction scheme by equipping a horizontal AC with segmental baffles. This technological solution is shown to increase the heat transfer coefficient, leading to a reduction in energy consumption, the area of the required heat transfer surface, as well as the overall weight and size of ACs.

Greenhouse systems in the form of glazed balconies may be accomplished both in the newly designed buildings and in the existing ones, raising their energy standard in a quick and inexpensive way. However, basic parameters influencing the efficiency of the systems are often chosen intuitively, not allowing to fully benefit from the sunspaces or causing overheating of the rooms and discomfort for the users. These issues are common drawbacks of passive systems and may become especially important in the aspect of anthropogenic climate changes, including temperature rise and summer heatwaves. The paper presents results of a long-term summer temperature monitoring in flats with glazed balconies of different construction. They were located in prefabricated multi-family buildings, in residential districts of Lublin and Zamość. The cities are situated in the south-eastern part of Poland, belonging to the warm-summer humid continental climate area. The monitoring enabled overheating assessment according to the concept of adaptive comfort and connecting it with the sunspace construction and the inhabitants’ behaviour. These issues are new aspects in the research area, and the work is a part of extensive studies including monitoring and dynamic simulations of dwellings with passive greenhouse systems in Poland. Practical application: Glazed balconies raise the energy standard of buildings in a quick and inexpensive way, but it is important to consider their function not only during the heating season but also in the summer. Recording of temperatures enabled the monitoring of thermal conditions in the flats and the overheating assessment. It is possible to keep the internal temperature in the rooms within the desired range thanks to the sunspace ventilation and occupants’ behaviour.

Analysis manufacturing technology small parts in single and small batch productions revealed that practiced administered manual finishing operations and the use of several expensive thermal artificially oldness operations for predetermined items parameters. Such a path substantially increases the complexity of the processing required and does not guarantee product quality. Therefore, improvement operations artificially oldness group in manufacturing small parts technology is an important task of raising manufacturing efficiency and quality of engineering products. Improving the efficiency and productivity vibration treatment technology, which refers to a group artificially oldness operations improves operational properties small parts, partial or complete elimination of the fitting works, the possibilities for intensification of the cutting subsequent mechanical operations. This, in turn, reduces the complexity of the manufacture of parts and assembly machines, increasing their reliability. New methods have been developed for controlling the process of vibration treatment and diagnostics of the stress-strain state of the material during vibration treatment, taking into account changes in the values of natural frequencies in the first three modes of vibration, providing for the correction of the location of the points of application of the action and supports relative to the part, and also taking into account changes in the temperature field of the part during vibration. The quality of the vibration treatment process is judged by the change in the value of the parameter, which indirectly characterizes the distribution of residual stresses in the material of the part, which is used as the temperature field of the part, and the vibration treatment process is completed when the temperature constant over the entire length of the part is reached, close to the values measured in the antinodes of its own part forms. The factors of the vibration treatment process influencing the increase of its productivity are analyzed. To date, there is no consensus on the degree of influence of such factors as the mass of abrasive granules, the mass of parts, the amplitude and frequency of oscillations of the machine tool container.

Noncontact methods of imaging temperature fields, based on the registration of thermal radiation, are widely used in the study and control of thermal processes in different branches of human activities. To reduce uncertainty in measuring temperature with digital infrared imaging equipment, it is necessary to take into account a number of factors causing deviation of its readings from true values. In the paper, analysis is made of physical processes occurring in registration of thermal radiation by thermographs on the basis of microbolometric arrays and methods are proposed for correcting registered signals that make it possible to reduce uncertainty in measuring temperature using them. The first part of the paper is devoted to considering the design of LWIR-range microbolometric arrays and the required corrections of registered signals making it possible to correctly interpret the obtained thermal images in a broad range of measured temperatures. The second part of the paper is devoted to algorithms of processing produced thermal imaging signals, and also to methods of accounting for the coefficient of thermal radiation of controlled surfaces and for the environmental radiation reflected from them whose use makes it possible to improve the validity of temperature determination.

QD-based high-performance photodetectors (PDs) typically contain hazardous elements such as lead- and cadmium-based materials, raising toxicity and safety concerns for optoelectronic devices. Here,...

Mechanical forces influence the development and behavior of biological tissues. In many situations these forces are exerted or resisted by elastic compliant structures such as the own-tissue cellular matrix or other surrounding tissues. This kind of tissue-elastic body interactions are also at the core of many state-of-the-art {\it in situ} force measurement techniques employed in biophysics. This creates the need to model tissue interaction with the surrounding elastic bodies that exert these forces, raising the question: which are the minimum ingredients needed to describe such interactions? We conduct experiments where migrating cell monolayers push on carbon fibers as a model problem. Although the migrating tissue is able to bend the fiber for some time, it eventually recoils before coming to a stop. This stop occurs when cells have performed a fixed mechanical work on the fiber, regardless of its stiffness. Based on these observations we develop a minimal active-fluid model that reproduces the experiments and predicts quantitatively relevant features of the system. This minimal model points out the essential ingredients needed to describe tissue-elastic solid interactions: an effective inertia and viscous stresses., Comment: 15 pages, 8 figures, supplemental material included. L. Valencia and V. Lopez-Llorente contributed equally to the paper

The issue of alkali-pumping has emerged in recent years raising concerns on the quality of the newly constructed asphalt pavement. To understand alkali-pumping and its effects, we conducted two-yea...

Reducing the operating temperature of conventional molten sodium-sulfur batteries (∼350 °C) is critical to create safe and cost-effective large-scale storage devices. By raising the surface treatment temperature of lead acetate trihydrate, the sodium wettability on β''-Al2O3 improved significantly at 120 °C. The low temperature Na-S cell can reach a capacity as high as 520.2 mA h g-1 and stable cycling over 1000 cycles.

The Performance of the Shell and Tube heat exchanger is estimated by its effectiveness. The rate of Heat transfer differs by developing the temperature difference between the entity and the atmosphere, by raising the rate of heat transfer coefficient or the surface area of the entity. The initial two techniques are not monetarily attainable hence the addition of fins to the entity would improve the rate of heat transfer. Thereby, three various cases are taken into account for this study; it includes a base model (without fins) and two different profiles of fins attached to the hot fluid pipe. The surface area of the fins is the same and fitted to the hot fluid pipe so that the heat transfer increased with suitable boundary conditions, as they are examined for the best profile. Initially, the base model is analyzed with suitable boundary conditions, and the required results obtained. This process is repeated for the other two cases to define the optimum fin profile; then the optimum profile is analyzed for the better angle orientation of the fins and results collated for greater effectiveness.

Advanced material is required for modern science and technology. To fulfill these requirements of advanced technology, the scientist is involved in the invention of finite particles and structures in a very small size ~ 10–9 m (Nanometer Scale). Carbon nanotubes are one of the innovative substances of allotropic carbon. They have a production capacity of more than a thousand tons per year. In modern days, innovative products are produced by themselves by raising the properties of other materials. CNT powders are joined in other merchandise items running from rechargeable batteries, automobile parts, and objects to water swept frames and water channels. Advances in CNT blend, refinement, and compound adjustment are empowering reconciliation of CNTs in thin-film gadgets and expansive territory coatings. In this article, we have researched the current state of Carbon nanotubes, their properties and provide a future purpose of study and research in this area.

The article raises the problem of growing waterfowl on reservoirs of complex purpose. Methods of growing waterfowl ducks and geese on reservoirs of complex purpose are considered. The stocking density and species composition of the reared fish are specified, and the high reclamation effect of the joint rearing of fish, duck and geese is emphasized.

In Selective Laser Sintering and Melting it is necessary to protect metal powder deposited on the powder bed from contact with atmospheric air, which may lead to oxidation and downgrading of the properties of the powder in the presence of high temperature that is necessary for achieving full or partial melting. Thus, the building chamber of commercially available SLS/SLM machines is fully isolated and filled with inert shielding gas which may need to be replenished before each build session thereby raising both machine building and consumables costs. In this paper, it is examined using Computational Fluid Dynamics how protection of the powder area around the laser spot can be achieved by locally insulating it from air by gas circulation in a suitably designed box moving with the laser beam. Full coverage of the respective area and at the same time no disturbance of the powder particles within it are critical requirements. Two concept variants are studied and simulated with promising results.

High purity germanium detectors have important applications in many fields. Detector’s performance deteriorated significantly due to radiation of neutron. The annealing of damaged HPGe detector is expounded in this monograph. The experiment results indicate that raising the temperature to 70°C for five days, the restoration efficiency can reach 90%.

The possibility of raising the wear resistance and prolonging the service of forging die inserts is analyzed with the aim to elevate the efficiency of the production process and to reduce the cost of forgings. Three sets of inserts fabricated from the same grade of die steel and subjected to the same heat treatment are studied. Additional nitriding (gas or ion plasma one) is applied to two sets for comparison. It is shown that the inserts subjected to ion nitriding have the highest wear resistance and endurance.

The effect of the chemical composition and microstructural parameters on the corrosion resistance of low-alloy steels serving in oilfield pipelines is studied. The causes of lowering of the corrosion resistance of the steels are determined. Recommendations are given for raising this characteristic without lowering the strength of the steels.

The proliferation of smart mobile terminals has weakened the attention and reduced the learning efficiency of students, making them more likely to lower their heads. To quantify the classroom participation, it is helpful to detect the head raising rate (HRR) of students in classroom. To this end, this paper puts forward a novel method to recognize the HRR of students in classroom. Based on the map of predicted facial features, an extraction method was developed for the salient facial features of students, and used to realize model matching between facial contour and facial organ. Next, the face orientation of each student was determined by soft label coding. After that, a multi-task convolutional neural network (CNN) was constructed to detect the HRR of students. The authors also explained the regularization of the loss function, and the steps of target detection. The proposed method was proved effective through experiments. The research results provide a reference for the application of head posture recognition in other fields.

The main raising propose in material science is to modify the structural, electronic, optical and magnetic properties. Here, the effect of substituted VIB transition metals in In2O3 semiconductor i...

The authors have presented results of experiential investigations of the process of ultrasonic coagulation of dispersed particle in a swirling flow. The investigations were conducted using the proposed and developed test bed implementing a two-stage removal of fi ne particles. At the first stage (agglomeration), the formation of a swirling flow and the ultrasonic pre-coagulation of fi ne particles are ensured. At the second stage, high-efficiency trapping of particles preformed at the first stage is attained using a cyclone. As a result of the experimental investigations, the authors have established the prospects of using a two-stage removal of fi ne particles and have revealed the optimum conditions of ultrasonic action on a swirling gas-dispersed flow that ensure an enlargement of 4.5 times of particles in the range of RM2.5 particle sizes which is the most hazardous for humans.