Strip Size Research Articles

Mechanical Behavior of Masonry Mortars Reinforced with Disposable Face Mask Strips.

This research presents an experimental analysis of the mechanical behavior of masonry mortars incorporating disposable face masks (FMs) cut into two different sizes. The objective is to provide experimental data contributing to the consolidation of recycling FMs in mortar mixtures. To achieve this, two types of mixtures were prepared: one with strips of 3 × 3 mm and another with strips of 3 × 10 mm. These FM strips were added in different proportions by the volume of mortar (0%, 0.2%, 0.5%, 0.8%, 1.0%, and 1.5%). In all mortars, the dry bulk density, volume of permeable voids, and water absorption, as well as compressive, flexural, and tensile strengths, were evaluated after a 28-day water immersion curing period. Additionally, two essential properties in masonry mortars were analyzed: air content and shear bond strength. The results indicated that, for both strip sizes, adding FMs up to 0.2% positively affected the flexural and tensile strengths; concerning control mortar, increases of 6% and 1.4%, were recorded, respectively, for the longer strips. At this percentage, the density, air content, and compressive and shear bond strengths are not significantly affected. The results demonstrated that incorporating FMs into mortar mixtures is a promising avenue for sustainable recycling and helps reduce microplastic environmental contamination.

Thermal Power and the Structural Parameters of a Wind Turbine Permanent Magnet Eddy Current Heater

Permanent magnet eddy current heating as a new type of wind energy utilization method, which is energy-saving, is zero-emission, and involves no pollution and a high utilization of wind energy, has attracted more and more attention. This paper deals with the simulation and optimal design of a permanent magnet eddy current heater (PMECH) driven by wind. Solid steel, closed-slot, and open-slot PMECH are proposed, and corresponding 2D finite element method (FEM) models are established. Using the skin depth concept, numerical analyses are conducted on the influence of the number, size, and position of copper strips on the thermal power of closed-slot and open-slot PMECHs, and the thermal power growth compared to solid steel PMECH. The results showed that there is an optimal value for stator wall thickness. When the air-gap length is 0.5 mm and the rotation speed is 200 and 1000 rpm, the optimal stator wall thickness is 16 and 9 mm, respectively. Compared to the influence of conductivity on thermal power, the influence of permeability is more significant. Compared with solid steel PMECH, both closed-slot and open-slot PMECH in a low-speed region can effectively improve thermal power, and the open slot has more obvious advantages. The maximum values of the thermal power growth (TPG) and thermal power growth rate (TPGR) of the closed-slot PMECH are 1.57 kW and 120.15%, respectively. The maximums of TPG and TPGR of the open-slot PMECH are 2.58 kW and 175.08%, respectively. The experimental results prove the validity of the analytical calculation.

PSO-FDM (Particle Swarm Optimization-Finite Difference Method)-Based Simulation Model of Temperature and Velocity of Full-Scale Continuous Annealing Furnace

Improving the accuracy of the temperature field prediction model for continuous annealing line strips and enhancing the model’s adaptability to full-size strips are key technical challenges in continuous annealing lines. This paper developed a continuous annealing temperature prediction model based on a variable step-size strategy for the heating section, even-heat section, slow-cooling section, and fast-cooling section of the continuous annealing line. To improve the prediction accuracy for different strip sizes, the PSO optimization algorithm was employed to determine the optimal heat transfer coefficient for each strip size. Additionally, due to the limited production of certain strip gauges, providing insufficient data for optimization, this study introduces a combined file approach to address gauge vacancies. The experimental results indicate that the optimized model with variable step size can control the absolute prediction error to less than 4 °C, improving prediction accuracy by 61.9% and prediction speed by 26.8% compared to the traditional equal-step prediction model. This study verified that the merger method is effective for addressing side gauge vacancies, while the proposed method is suitable for resolving middle gauge vacancies. The main technical contribution of this study is the establishment of a high-precision prediction model for continuous annealing temperature of variable step length strips, ensuring high temperature control accuracy for full-gauge strips when passing through the continuous annealing production line.

Optimized graphene metamaterial for dual plasmon-induced transparency in terahertz band with multifunctional applications

Abstract This paper proposes a patterned graphene periodic metamaterial structure, optimized using an improved genetic algorithm to adjust the position and size of each graphene strip, thereby achieving dual plasmon-induced transparency (PIT) effects in the terahertz band, resulting in extraordinary multifunctionality. The finite difference time domain method is employed to obtain the transmission spectrum, and coupled mode theory is used for theoretical analysis and verification of the dual-PIT effect. The structure exhibits multifunctionality: when used as a photoelectric switch, it achieves a modulation depth of up to 99.04% with an insertion loss as low as 0.16 dB by tuning the Fermi level. Additionally, the structure demonstrates excellent sensing performance, with a maximum sensitivity and figure of merit reaching 0.84 THz/RIU and 88.55, respectively. Furthermore, the slow light performance of the structure is investigated, showing a group delay of up to 0.5 picoseconds.

Using pulse current to tailor hydride networks while improving the strength and plasticity of pure titanium

Interstitial hydrogen atoms in titanium usually deteriorate the mechanical properties of titanium by brittle hydride phase or hydrogen-enhanced localized plasticity. In this study, hydride was used as the second phase to improve the tensile strength and elongation of TA1 pure titanium. The continuous coarse hydride network is precipitated in TA1 pure titanium after the hydrogen-charged. Then pulse current treatment is used to decompose the original coarse hydride network and reduce the size and number of hydride strips. Finally, a small uniform hydride network is formed in TA1 pure titanium. The results of tensile experiments indicate that the tensile strength of hydrogen-charged TA1 pure titanium treated by pulse current increases from the 286.4 MPa to 316.1 MPa and the elongation increases from the 47.6 % to 56.8 %. The improvement of mechanical properties demonstrate that the small and uniform hydrides can significantly improve the mechanical properties of TA1 pure titanium. In hydrogen-charged TA1 pure titanium treated by pulse current, the increment of strength is mainly caused by hard phase hydrides, and the increase in plasticity is attributed to the role of twins in coordinating deformation during plastic deformation. This study manifests that in addition to being used as a temporary alloying element to optimize the microstructure of titanium, hydrogen can also be directly act as a second phase in titanium to improve the mechanical properties.

Multi-directional strain sensor based on carbon nanotube array for human motion monitoring and gesture recognition

Flexible strain sensors have enormous application demands in health monitoring, soft robotics, and artificial skin. Traditional flexible strain sensors mainly focus on identifying strain amplitude. However, to determine complex movements, it is necessary for sensors to recognize not only the amplitude but also the direction of strain. Here, we propose a multi-directional strain sensor constructed from three flexible strain sensor units, which are based on a carbon nanotube (CNT) array, and configured in a right-angled triangle arrangement. Each strain sensor unit exhibited a strain detection range of over 90%, durability of over 5000 cycles, and fast response time (<150 ms). The multi-directional strain sensor can accurately identify the amplitude and direction (up to 180°) of the strain simultaneously. By optimizing the height and the size of the CNT array strips within the strain sensor unit, the preferred parameters for the sensor unit were determined. Further, by incorporating a neural network algorithm, the multi-directional strain sensor achieved synchronous detection of strain amplitude and direction with an accuracy rate exceeding 98%. Therefore, this work provides a new strategy for the design and construction of multi-directional strain sensors, underscoring their broad application potential in the fields of human motion monitoring and gesture recognition.

Industrial Big Data‐Driven Modeling and Prediction for Hot‐Rolled Strip Crown with Multigrade and Multispecification Data

In the field of hot rolling big data, the presence of different steel types, specifications, and data heterogeneity poses significant challenges to the accuracy and stability of using single machine learning regression technology for prediction. Therefore, this study proposes a hot‐rolled strip crown prediction method that combines data clustering and fusion modeling. First, this article introduces a relevant mechanism for designing cluster strategies. The optimal clustering strategy is determined through comparative experiments using rolling process parameters, strip size, and main material components as the clustering features. Subsequently, the K‐Means++ algorithm is used to effectively cluster the training and testing datasets based on this strategy, generating multiple clusters for both datasets. Finally, this study establishes seven different training models to match the most suitable regression prediction model for each cluster, and matching between each cluster and the model is determined through rigorous testing. The evaluation of the fusion model shows an R2 value of 0.829 and a root mean square error value of 3.974. The experimental results show that the proposed method outperforms traditional methods in solving the challenges of multiclass classification and data heterogeneity, providing strong data support for the intelligent control of the hot‐rolled strip crown in the future.

Plastic as a Soil Stabilizer

Soil stabilization is any process which improves the physical properties of soil, such as increasing shear strength, bearing capacity etc. which can be done by use of controlled compaction or addition of suitable admixtures like cement, lime and waste materials like fly ash, phosphogypsum etc. The cost of introducing these additives has also increased in recent years which opened the door widely for the development of other kinds of soil additives such as plastics, bamboo etc. This new technique of soil stabilization can be effectively used to meet the challenges of society, to reduce the quantities of waste, producing useful material from non-useful waste materials. Use of plastic products such as polythene bags, bottles etc. is increasing day by day leading to various environmental concerns.Therefore the disposal of the plastic wastes without causing any ecological hazards has become a real challenge. Thus using plastic bottles as a soil stabilizer is an economical utilization since there is scarcity of good quality soil for embankments. This project involves the detailed study on the possible use of waste plastic bottles for soil stabilization. The analysis was done by conducting plate load tests on soil reinforced with layers of plastic bottles filled with sand and bottles cut to halves placed at middle and one-third positions of tank.The comparison of test results showed that cut bottles placed at middle position were the most efficient in increasing strength of soil. The optimum percentage of plastic strips in soil was found out by California Bearing Ratio Test and using this percentage of plastic, plate load test was also performed. The size and content of strips of waste plastic bottles have significant effect on the enhancement of strength of the soil].

Multi-Objective Optimization of Low-Alloy Hot-Rolled Strip Cooling Process Based on Gray Correlation Analysis

The residual stress in low-alloy hot-rolled strips seriously affects the use and processing of products. Reducing residual stress is important for improving the product quality of hot-rolled strips. In this paper, the changes in grain size and residual stress of hot-rolled strips under different cooling processes were investigated via thermal simulation experiments and electron backscatter diffraction. It was found that the optimum cooling process solution for single-objective optimization of grain size was a final rolling temperature of 875 °C, a laminar cooling speed of 50 °C/s, and a coiling temperature of 550 °C. When single-objective optimization of residual stress was carried out, the optimal cooling process scheme was 900 °C for final rolling temperature, 20 °C/s for laminar cooling speed, and 625 °C for coiling temperature. The significance of the effect of cooling processes on grain size and residual stress was analyzed based on the extreme deviation of the effect of each cooling process on grain size and residual stress in orthogonal experiments. The results show that the coiling temperature was the most influential factor on grain size and residual stress among the cooling process parameters. The difference was that grain size increased with increasing coiling temperature, and residual stress decreased with increasing coiling temperature. Using both grain size and residual stress as evaluation indicators, a multi-objective optimization of the cooling process for hot-rolled strips was carried out via the gray correlation analysis method. The optimized solution was 875 °C final rolling temperature, 30 °C/s laminar cooling speed, and 625 °C coiling temperature. At this time, the grain size was 4.8 μm, and the KAM (Kernel Average Misorientation) was 0.40°. The grain size under the actual production process scheme was 4.4 μm with a KAM of 0.78°. Compared to the actual production process solution, the multi-objective optimization solution showed little change in grain size, with only a 9% increase and a 49% reduction in KAM. The optimization scheme in this paper could significantly reduce the level of residual stresses while ensuring the fine grain size of hot-rolled strips, thus improving the overall quality of hot-rolled strips.

First Report on Mesophyll Protoplast Isolation and Regeneration System for the Duboisia Species.

The Duboisia species, a group of plants native to Australia, have been historically valued for their pharmacological properties and have played a significant role in traditional medicine and pharmaceutical research. Persistent efforts are underway to enhance the efficacy of the active ingredient scopolamine, employing both conventional breeding methods and advanced biotechnology tools. The primary objective of this research was to establish a highly efficient method for isolating mesophyll protoplasts and facilitating their regeneration, thereby laying a robust foundation for the application of various advanced plant biotechnology tools in the pursuit of genetic enhancement. The mesophyll protoplast isolation process was developed for hybrid D. myoporoides × D. hopwoodii with careful optimisation of the following parameters: leaf strip size; incubation conditions; physical treatment; and enzyme concentration. The optimal parameters were combined in each individual step; the best enzyme concentration was determined to be 2% (w/v) cellulysin and 0.5% (w/v) macerase. Protoplast yield was found to be greatly affected by the enzyme concentrations. The isolated protoplasts were cultured at a density of 0.5 × 105 to best sustain the highest cell division (33.2%) and a microcalli induction frequency of 17.9%. After 40 days of culture in a modified KM8P medium at 25 °C in darkness, visible microcalli were transferred to a solidified Murashige and Skoog (MS) medium with 1 mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) for callus induction under a 16 h photoperiod. After 30 days of culture, compact organogenic calli were transferred into a solid MS medium with 6-benzylaminopurine (BA) alone or thidiazuron (TDZ) alone or in combination with BA or naphthalene acetic acid (NAA) for shoot regeneration. The maximum shoot regeneration frequency (63.3%) was observed in the medium with 1.5 mg L-1 TDZ alone. For the first time, a reliable protoplast isolation and regeneration system from mesophyll cells was established for Duboisia with high protoplast viability, successful microcalli formation, and intact plant regeneration. This innovation will significantly contribute towards the genetic enhancement of the Duboisia species.

Dual-domain strip attention for image restoration

Image restoration aims to reconstruct a latent high-quality image from a degraded observation. Recently, the usage of Transformer has significantly advanced the state-of-the-art performance of various image restoration tasks due to its powerful ability to model long-range dependencies. However, the quadratic complexity of self-attention hinders practical applications. Moreover, sufficiently leveraging the huge spectral disparity between clean and degraded image pairs can also be conducive to image restoration. In this paper, we develop a dual-domain strip attention mechanism for image restoration by enhancing representation learning, which consists of spatial and frequency strip attention units. Specifically, the spatial strip attention unit harvests the contextual information for each pixel from its adjacent locations in the same row or column under the guidance of the learned weights via a simple convolutional branch. In addition, the frequency strip attention unit refines features in the spectral domain via frequency separation and modulation, which is implemented by simple pooling techniques. Furthermore, we apply different strip sizes for enhancing multi-scale learning, which is beneficial for handling degradations of various sizes. By employing the dual-domain attention units in different directions, each pixel can implicitly perceive information from an expanded region. Taken together, the proposed dual-domain strip attention network (DSANet) achieves state-of-the-art performance on 12 different datasets for four image restoration tasks, including image dehazing, image desnowing, image denoising, and image defocus deblurring. The code and models are available at https://github.com/c-yn/DSANet.

STUDY OF THE PERFORMANCE OF WASTE PLASTIC IN CLAY SOIL STABILIZATION

Every year, tons of plastic garbage is produced, damaging our environment. So, recycling these waste plastic has become a need of this time. Therefore, using such materials in technical applications like soil stabilization will be advantageous. Additionally, stabilization using waste plastic is a practical option that is also easily accessible around us. In this research, the soil was stabilized with Waste Plastic. Waste Plastic and Bottle Strips were collected and used as soil reinforcement in this study to improve the engineering performance of subgrade soil. The plastic strips were cut in two distinct aspect ratios (5 mm x 5 mm) and (5 mm x 10 mm) and were prepared to add at two different weight proportions (1% and 2%). Unconfined Compressive Strength testing was then carried out. The testing findings revealed that shear strength parameters improved significantly. The current analysis yielded the following Compressive Strength values: 27.68 psi and 32.73 psi when 1.0% and 2.0% of plastic bottle strips (5mm x 5mm) were used, and 17.32 psi and 21.99 psi when 1.0% and 2.0% of plastic bottle strips were used (5 mm x 10 mm). The results demonstrate that in the instance of bottle strips, mixing smaller strip sizes created an increase in shear strength on the soil. Any additional increase in strip size has resulted in a loss in compressive strength because increasing strip size generates un-compacted weak shear planes. So, this can be concluded that using waste plastic in clay soil for soil stabilization is recommended since it helps to both reduce the cost of stabilization and protects the environment.

Flower strip effectiveness for pollinating insects in agricultural landscapes depends on established contrast in habitat quality: A meta‐analysis

Abstract Flower strips have become a prevalent measure in agricultural landscapes to counteract biodiversity loss and especially promote pollinators. Although their benefits for pollinating insects have been frequently evaluated and reported, generalized conclusions about optimal settings for effective flower strips are still difficult. From the perspective of pollinators, flower strips vary distinctly in habitat quality, and the same applies for the control sites selected for scientific studies. In this study, we used a meta‐analytic approach based on a systematic review of recent studies (2009–2020) to analyze the relationship between flower strip effectiveness for pollinators and the contrast in habitat quality between flower strips and control sites. We extracted 350 data entries from 29 of 172 studies based on available data for richness or abundance of the pollinator taxa groups Apiformes, Lepidoptera and Syrphidae as response variables, for both flower strips and control treatments. All flower strips and control treatments were assigned a habitat quality score including information on spatial dimension, floral resources and management. Moreover, we included information on landscape complexity as measured by percent cover of seminatural habitats in the studied landscape. In general, our results of meta‐analytical models showed an increasing effect size of flower strips on pollinators for higher contrasts in habitat quality between flower strips and control treatments. This relationship was consistent across pollinator taxa and different levels of landscape complexity. Altogether, in terms of pollinator habitat quality, high‐quality flower strips were more attractive than low‐quality flower strips, and the reported effectiveness of flower strips decreased from low‐quality to high‐quality control treatments. We recommend that results of future studies evaluating flower strips for pollinators are always linked with the contrast in habitat quality between selected flower strips and control treatments.

Monitoring herbage mass and pasture growth rate of large grazing areas: a comparison of the correspondence, cost and reliability of indirect methods

AbstractTimely grazing decision-making requires routine information on the herbage mass (HM) and pasture growth rate (GR). The aim of this study was to compare the correspondence, cost and reliability of two indirect methods –the comparative yield method (COMPYLD) and the pasture-meter (CDAX)– to estimate HM and weekly GR of a 42 ha grazing area. Weekly assessments from April 2017 to October 2018 were made with both methods to estimate HM and GR of 13 individual paddocks. In addition, estimated GR were compared to aerial net primary productivity (ANPP) estimated using remote sensing (SAT). Estimated HM was 22% lower for COMPYLD than CDAX (HMCOMPYLD = 33 + 0.78*HMCDAX, R2 = 0.61, CV = 17%, RMSE = 291 kgDM/ha). The correspondence between methods of estimated weekly GR of individual paddocks was weak (GRCDAX = 0.18*GRCOMPYLD + 19.1, R2 = 0.05, CV = 73%, RMSE = 21.8 kgDM/ha/d). However, when integrated in three-week moving-averages, over the complete grazing area, COMPYLD and CDAX yielded similar GR up to 35 kg DM/ha/d. Accumulating GR of the grazing area over one year resulted similar to annual SAT-estimated ANPP. These results imply that, on one hand, decisions based on nominal HM, such as target HM and grazing strip size, would need to be adjusted depending on the method, but on the other hand, decisions based in temporal trends or GR, such as size and timing of set-aside areas for reserves, would be unaffected by method. Compared with COMPYLD, CDAX would be advantageous whenever high labour costs offset higher amortization, maintenance and fuel costs, provided there is an alternative in place to monitor during downtime periods.

Parametric study of retrofitted reinforced concrete columns with steel cages and predicting load distribution and compressive stress in columns using machine learning algorithms

Abstract Recently, the use of reinforced concrete (RC) structures is becoming very common worldwide. Because of earthquakes or poor design, some of these structures need to be retrofitted. Among different methods of retrofitting a structure, we have utilized a steel cage to support a column under axial load. The numerical modeling of a retrofitted column with a steel cage is carried out by the finite-element method in ABAQUS, and the effectiveness of the number of strips, size of strips, size of angles, RC head, the strips’ thickness, and the steel cage’s mechanical properties are studied on 15 different case studies by the single factorial method. These parameters proved to be very effective on the load distribution of the column because by choosing the optimum case, lower amounts of force are born by the column. By increasing the number of strips, the steel cage would reach 52% of the total load. This value for the size of strips and angles’ size is 48 and 50%, respectively. However, the thickness of the strips does not have a significant effect on the load bearing of the column. In order to fully predict the load distribution of the retrofitted columns, the data of the present study are utilized to propose a predictive model for N c/P FEM and N c/P FEM using artificial neural networks. The model had an error of 1.56 (MAE), and the coefficient of determination was 0.97. This model proved to be so accurate that it could replace time-consuming numerical modeling and tedious experiments.

Refinement mechanism and optimization for compact strip production process

To avoid the fracture of cold-rolled sheets, this study investigated the refinement mechanism for the compact strip production process and proposed an optimised method. The primary austenite grain size was 50–475 µm, and the grain size of the hot-rolled strips was 3.6–4.8 µm. The Gleeble-3500 simulator was applied to simulate the hot rolling process. Grain refinement was realised through dynamic recrystallization and the supply of more nucleation sites for transformation by sub-structures. Increasing the coiling temperature from 620 to 730 °C increased the ferrite fraction from 3.95 to 24.16%. The adjacent cementite distance changed from 0.33 to 0.84 µm, resulting in decreased yield and tensile strengths and increased elongation. Thus, the fracture of cold-rolled sheets was avoided.

Seismic Overturning Fragility Analysis for Rigid Blocks Subjected to Floor Motions

This paper investigates the seismic rocking-overturning fragility of freestanding rigid blocks subjected to one-sine acceleration pulses from a probabilistic perspective. An equivalent single-degree-of-freedom (SDOF) model with a bespoke discrete damper is used to simulate the responses of four blocks with varying geometries under excitation with various characteristics. The simulation results are used to perform an overturning fragility analysis and evaluate the performance of various intensity measures (IMs). An IM strip, referred to as a hybrid strip, can be observed in the analysis, within which both safe rocking and overturning occur. For IM values outside of the hybrid strip, there exists a clear distinction between these two states. In this study, we introduce the hybrid ratio, a parameter that can estimate the size of the hybrid strip of different IMs. The hybrid ratio is defined as the combination of two ratios of hybrid strip width and the two IM strip widths corresponding to safe rocking and overturning, respectively. The effect of the different analysis strip widths is also examined in the overturning fragility analysis. The results suggest that the IM determined by excitation magnitude, frequency, and block geometry parameters demonstrates its superiority compared with some well-known IMs by having the smallest hybrid ratio and coefficient of variation, as well as good robustness of the overturning fragility curves against the change of the analysis strip width.

Development of paper-immobilized molecularly imprinted polymers by laser pointer activation for methamphetamine extraction with analysis by ion mobility spectrometry

A fast, simple, cheap, and versatile strategy has been proposed for the synthesis of paper-immobilized molecularly imprinted polymers (MIPs) by photoactivated bulk polymerization over a piece of nitrocellulose using a 405 nm laser pointer. Polymerization was carried out using a mixture of methacrylic acid and ethylene glycol dimethacrylate, using methamphetamine as template molecule and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide as radical initiator. After investigation of different polymerization parameters, the following experimental conditions were found to give best results: size of nitrocellulose strip (13.5 × 4.0 × 0.8 mm), type of porogen (acetonitrile), polymerization mixture volume (75 µL), and irradiation times (10 min). Experimental conditions (such as sample pH, extraction and desorption time, and type and volume of desorption solvent) were also adjusted for the extraction of methamphetamine using the proposed paper-MIP. Methamphetamine determination was carried out by ion mobility spectrometry providing a limit of detection of 14 µg L−1 and quantitative recoveries from 81 to 95% using spiked urine and oral fluid samples. The proposed paper-immobilized MIP device allows a simple and selective sample extraction procedure for the determination of methamphetamine in oral fluids and urine with a high portability, minimal solvent consumption, and reduced costs compared to other conventional approaches.

Effect of NaOH Treated Polyethylene Terephthalate (PET) Plastic Bottle Strips on Stabilization of Soil

Plastics such as polyethene bags, bottles, and so on are growing increasingly common as science progresses. The disposal of discarded material is a significant issue because most plastic wastes are non-biodegradable and unsuitable for combustion due to the emission of hazardous gases. By just using controlled compaction, soil stabilization enhances the engineering capabilities of weak sub-soils or the addition of stabilizing agents such as cement, lime, fly ash, bitumen, tar etc. But these additions have also been quite costly in recent years. This research report gives a thorough examination of the performance and effectiveness of waste plastic bottle strips in soil improvement. This waste plastic bottle is made of Polyethylene Terephthalate (PET). The size of PET plastic strips used in this study is not more than 5 mm in length and 2 mm in width. These strips were treated with Sodium Hydroxide (NaOH) to perform the proper dispersion of PET bottle fibres in soil. Although sodium hydroxide is a noncombustible solution, it is a highly reactive substance. It interacts with PET strips to exhibit changes in its properties. This work comprises replacement of soil by NaOH treated PET bottle strips in the varying percentage of 0.75%, 1%, 1.5%, 2%, 3% and 4% by dry weight of soil sample and to find out the optimum percentage mix of PET strips. The strength and geotechnical property of soil mixed with NaOH treated PET strips was evaluated and compared with the strength of soil and non-treated PET strips mix. The result shows the benefit of adding NaOH treated PET strips over non-treated strips by improving the maximum dry density (MDD), unconfined compressive strength (UCS) and California bearing ratio (CBR) value appreciably at an optimum mix of 1.5%. This soil stabilizing approach may be utilized efficiently to fulfil social and environmental problems. This exploratory inquiry would lead to the ecologically friendly management of this waste material.

Electroplastic rolling of refractory metal strips: mathematical modelling of the process

In order to analyze the electroplastic deformation process, the authors developed a mathematical model that simulates strip rolling with high-density electric current going through the deformation zone. The model consists of two main parts: a model for determining the strip temperature beyond the deformation zone; and a model of the deformation zone. The paper describes temperature fields calculated for a tungsten strip rolled out of a 200 &mu;m thick and 200 &mu;m wide workpiece at the electric current power W equal to 0.2 and 0.4 kW and rolling speeds V equal to 8.5, 28 and 50 mm/s. It was established that the maximum temperature of the strip Tmax is reached inside the deformation zone, the length of which is taken equal to the length of the contact arc ld. In the section located at a distance of more than 3&middot;l d before the rolling stand, the temperature of the strip is equal to 25 оC, which corresponds to the ambient temperature. After the rolling stand, the strip cools down due to heat dissipation. How quickly the strip will cool down is dictated by the cooling conditions, rolling speed and strip size. Obviously, a thinner strip transfers heat more intensely. A drastic temperature increase was observed in the deformation zone of the rolling stand. After exiting from the deformation zone, the strip, heated to the deformation temperature, gradually cools down as a result of heat dissipation. The intensity of the lengthwise temperature decrease rises as the rolling speed and the heat transfer coefficient go down. The results obtained with the help of the mathematical model were used to revise the technical data of the electroplastic rolling mill (the spacing between its key components, roll design, rolling speed, electric current density, etc.) and to elaborate recommended thermomechanical rolling regimes for micron thin molybdenum and tungsten strips.