Orthogonal Array Testing Strategy Research Articles

Constructing Ultra-Strong SERS Tags in the Cellular Raman-Silent Region by Orthogonal Array Testing Strategy.

Surface-enhanced Raman spectroscopy (SERS) tags have the advantages of unique fingerprint vibration spectrum, ultranarrow spectral line widths, and weak photobleaching effect, showing great potential for bioimaging. However, SERS imaging is still hindered for further application due to its weak spontaneous Raman scattering, biomolecular signal interference, and long acquisition times. Here, we develop a novel SERS tag of the core (Au)-shell (N-doped graphene) structure (Au@NGs) with ultrastrong and stable Raman signal (2180 cm-1) in the cellular Raman-silent region (1800-2800 cm-1) through base-promoted oxidative decarboxylation of amino acids. Exploring the factors (metal salts, amino acids, catalysts, temperature, etc.) to obtain Au@NGs with the strongest Raman signal commonly requires more than 100,000 separate experiments, while that using an orthogonal array testing strategy is reduced to 56. The existence of deep charge transfer between the Au surface and C≡N-graphene is proved by theoretical calculations, which means the ultrastrong signal of Au@NGs is the joint effect of electromagnetic and chemical enhancement. The Au@NGs have a detection sensitivity down to a single-nanoparticle level, and high-speed and high-resolution cellular imaging (4453 pixels) is obtained within 10 s by global Raman imaging. The combination of Au@NGs-based tags with ultrastrong intrinsic Raman imaging capability and global imaging technology holds great promise for high-speed Raman imaging.

Antimicrobial finishing of cotton fabric by atmospheric pressure plasma

In order to synthesize the antimicrobial cotton fabrics, two antimicrobial agents, 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (TX-DF) and 3-(acrylamidopropyl) trimethylammonium chloride (APTAC), were grafted onto cotton fabrics by atmospheric pressure plasma treatment. Orthogonal array testing strategy (OATS) was applied to investigate the optimum treatment conditions of the atmospheric pressure plasma, including sputter-gas species, gas pressure, treatment power and time. The obtained cotton fabrics were characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDS). And the results revealed the successful grafting of two antimicrobial agents on cotton fabrics. The antimicrobial efficiency of the plasma treated cotton fabric were studied and found that the TX-DF-treated cotton fabric inactivated 99.85% S. aureus and 99.07% E. coli O157:H7 in 30 min contact time. The cotton sample grafted with APTAC inactivated 74.6% S. aureus and 92.3% E. coli O157:H7 in 30 min. The hand feeling of the plasma treated antimicrobial cotton fabrics ware measured by PhabrOmeter system, and the result showed that the plasma treatment has little effect on hand value. Thus, the antimicrobial property of cotton fabric finished with TX-DF by the argon/oxygen-plasma techniques achieved sound effects.

TBEM: Testing-Based GPU-Memory Consumption Estimation for Deep Learning

Deep Learning (DL) has been successfully implemented and deployed to various software service applications. During the training process of DL, a large amount of GPU computing resources is required, but it is difficult for developers to accurately calculate the GPU resources that the model may consume before running, which brings great inconvenience to the development of DL systems. Especially in today’s cloud-based model training. Therefore, it is very important to estimate the GPU memory resources that the DL model may use in a certain computing framework. Existing work has focused on static analysis methods to assess GPU memory consumption, highly coupled with the framework, and lack of research on low-coupled GPU memory consumption of the framework. In this article, we propose TBEM, which is a test-based method for estimating the memory usage of the DL model. First, TBEM generates enough DL models using an orthogonal array testing strategy and a classical neural network design pattern. Then, TBEM generates DL model tested in a real environment to obtain the real-time GPU memory usage values corresponding to the model. After obtaining the data of different models and corresponding GPU usage values, the data is analyzed by regression.

Study on the controller factors associated with roof falling and ribs spalling in deep mine with great mining height and compound roof

To analyze the controllable factors associated with roof fall and rib spalling during the mining process in a deep well with a great mining height and compound roof, and to resolve such issues during the mining process, a mechanical model for describing the deflection of a compound roof was established based on the beam theory for an elastic foundation. The maximum deflection position of a compound roof and the associated depth of the rib spalling were further calculated and determined in this study. Based on the depth of the rib spalling, we determined the force distribution of spalling coal from the mine wall. By combining the force distribution with the safety margin, we established a critical failure equation of the coal wall and further calculated the height of the spalling coal. The human factors used to control the rib spalling issue were also analyzed based on these results. Furthermore, taking the mining conditions of the Pingdingshan No. 11 coal mine as the engineering background, we simulated the mining process on the working face (Ji16-17-24030) using FLAC3D numerical modeling software and an orthogonal array testing strategy. By conducting a range analysis on the simulation results, we determined the sensitivity of each main controllable factor to a roof fall and rib spalling in the working face. The results show that the comprehensive sensitivities of the main controllable factors to roof fall and rib spalling follow the order of cohesion > support strength > mining height > distance to face > lateral force. In addition, the maximum deformation of the coal wall decreases by 0.682 mm with every 1 MPa increase in the cohesion strength of the coal body.

Copper electroless plating of cotton fabrics after surface activation with deposition of silver and copper nanoparticles

In this work, surface metallization of cotton fabrics was performed by electroless plating using a shorter route than is conventional. The fabric surface was activated by deposition of silver and copper nanoparticles, and then a thin layer of copper was coated using electroless plating. The performance of coated fabrics was compared in terms of electrical conductivity, electromagnetic interference (EMI) shielding, Joule heating and antibacterial properties with another sample coated with conventional electroless plating. The orthogonal array testing strategy was adopted to optimize the various factors of the electroless plating bath. The samples prepared by electroless plating of copper showed greater performance for the fabric first deposited with silver particles than those first deposited with copper particles or conventionally treated. Samples of copper electroplating over silver had surface resistivity of 20 Ω, EMI shielding of 75.53 dB and Joule heating of 83.1 °C. Moreover, samples with modified electroless plating showed better attachment of the metal layer and therefore longer durability.

Preparation of an associative thickener for digital printing of nylon carpet

PurposeThis paper aims to prepare an associative thickener base on two polyacrylate-based copolymers, which can be used for digital printing of nylon carpet with enhanced performance.Design/methodology/approachAn associative thickener was prepared by compounding two polyacrylate-based copolymers, cationic starch and polyacrylic acid; and mediated by polyethylene glycol and polyacrylamide crosslinker. The formulation of the associative thickener was optimized by using the orthogonal array testing strategy. The stability of the associative thickener was investigated by measuring effects of temperature, electrolytes, storage time and auxiliaries on viscosity. The associative thickener was compared with a commercial thickener by evaluating their performance in digital printing of nylon carpet.FindingsThe associative thickener provided same color strength and fastness in the printing of nylon carpet as the commercial one, but was more easily washed off for a better hand feeling of the printed carpet.Practical implicationsThe prepared associative thickener can be applied for digital printing of nylon carpet.Originality/valueThe associative thickener can be facilely prepared from commercially available chemicals and suitable for digital printing of nylon carpet.

Study on chemical spray etching of stainless steel for printed circuit heat exchanger channels

Abstract Nuclear power is considered as the most promising energy for power generation due to low carbon emission, small fuel cost, high efficiency and reliability. As a new type of heat exchanger, printed circuit heat exchanger (PCHE) with high compactness and efficiency can be used for the supercritical carbon dioxide (SCO2) Brayton power cycle in the Gen IV nuclear reactor systems to transfer great amount of heat from nuclear reactors. The chemical etching technology plays an important role in production of heat transfer channels for PCHEs from micron level to millimeter level. In order to produce high-quality heat transfer channels, the chemical spray etching method is used in the manufacturing process. In this work, a chemical spray etching experiment was carried out to analyse the etching phenomenon on the PCHE channels. The influences of etching parameters, such as etching rate, lateral erosion, surface roughness, etc., are investigated. The results showed that the etching parameters significantly affected the etching quality, which provided comprehensive view of details for the etching process. Besides, an orthogonal array testing strategy (OATS) was adopted for chemical spray etching to synthetically study the influences of FeCl3 and H3PO4 concentrations, etching temperature, spray pressure on the etching rate, the lateral erosion and the surface roughness. The optimal combination of etching parameters in the setting level was investigated and obtained, which is in the condition with spray gage pressure of 0.15 MPa, etching temperature of 35 °C, FeCl3 concentration of 400 g·L−1 and H3PO4 concentration of 1.5 M. The present work is of significance to realize the low-cost, high-efficiency and controllable manufacturing process of PCHEs.

A Parameter Study of the Effect of a Plasma-Induced Ozone Colour-Fading Process on Sulphur-Dyed Cotton Fabric

A plasma-induced ozone colour-fading treatment was used for treating a blue sulphur-dyed knitted cotton fabric. Since the process parameters of plasma-induced ozone colour-fading treatment are inter-related with one other, the final colour-fading results are affected. An orthogonal array testing strategy (OATS) method was used for determining the optimum conditions of the plasma-induced ozone colour-fading treatment in this study. Three process parameters used in the plasma-induced ozone colour-fading treatment, i.e., oxygen gas concentration (%), water content in fabric (%), and treatment time (minutes), were used in the optimization process. Experimental results reveal the optimum conditions for fading the colour by plasma-induced ozone colour-fading treatment are: (1) oxygen gas concentration = 70%; (2) water content in fabric = 35%; and (3) treatment time = 30 min. The order of importance of these parameters is: oxygen gas concentration > water content in fabric > treatment time. In addition, the plasma-induced ozone colour-fading treatment can effectively remove the colour from the dyed fabric and the colour-fading effect is uniform and even.

Finite element simulation and process optimization for hot stretch bending of Ti-6Al-4V thin-walled extrusion

Ti-6Al-4V is widely utilized to manufacture airframe component structures with curvature, because of its excellent strength to weight ratio, outstanding resistance to corrosion, and inherent thermal and electrical compatibility with carbon fiber composite. Hot stretch bending (HSB) is an effective technology to manufacture these kinds of structures. When comparing the thin-walled extrusion with the thick-walled one, however, it is more difficult to form. The reason is that the local temperature of extrusion decreases more because of the heat transfer between extrusion and die. In this study, the material properties of Ti-6Al-4V were measured experimentally, such as the tensile property within the temperatures from 873 to 1023 K and the strain rates from 0.0005 to 0.005 s−1, the stress relaxation behavior in a wide range of temperatures (773–973 K) and prestrains (0.7–10%), as well as the heat transfer rule between Ti-6Al-4V (extrusion material) and asbestos cement (die material) under different pressures (8–25 MPa). The heat transfer coefficients (HTCs) were determined by an inverse analysis procedure, which was based on the comparison between measured and calculated temperature. Then, the coupled thermomechanical finite element (FE) model considering the effect of heat transfer was established. The influence of preheating temperature of die, initial temperature of extrusion, and dwell time on spring-back was researched based on orthogonal array testing strategy (OATS). The optimized parameters were verified by process test. It was showed that the established FE model could be used to predict spring-back within a relative deviation of 8.05%.

Regenerable Antibacterial Cotton Fabric by Plasma Treatment with Dimethylhydantoin: Antibacterial Activity against S. aureus

This study examined the influence of variables in a finishing process for making cotton fabric with regenerable antibacterial properties against Staphylococcus aureus (S. aureus). 5,5-dimethylhydantoin (DMH) was coated onto cotton fabric by a pad-dry-plasma-cure method. Sodium hypochlorite was used for chlorinating the DMH coated fabric in order to introduce antibacterial properties. An orthogonal array testing strategy (OATS) was used in the finishing process for finding the optimum treatment conditions. After finishing, UV-Visible spectroscopy, Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) were employed to characterise the properties of the treated cotton fabric, including the concentration of chlorine, morphological properties, and functional groups. The results show that cotton fabric coated with DMH followed by plasma treatment and chlorination can inhibit S. aureus and that the antibacterial property is regenerable.

Plasma treatment applied in the pad-dry-cure process for making rechargeable antimicrobial cotton fabric that inhibits S. Aureus

In this paper, variables in an environmentally friendly rechargeable antimicrobial finishing process were studied. Cotton fabric was treated with nitrogen plasma after padding with 5,5-dimethylhydantoin (DMH) when fabric was treated through the pad-dry-cure method, that is, pad-plasma-dry-cure. After that, fabric was chlorinated with sodium hypochlorite to impart antimicrobial property and function. An orthogonal array testing strategy was used in the finishing process for finding the optimum treatment condition. Ultraviolet spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy were employed to evaluate the properties of treated cotton fabric, including concentration of chlorine on cotton fabric, morphological properties of the surface of cotton fabric and function groups on the cotton fabric. The results showed that cotton fabric finished with DMH with the help of plasma treatment followed by chlorination inhibits microorganisms effectively, the antimicrobial property against Staphylococcus (S.) aureus was rechargeable and durability of antimicrobial property was improved by plasma treatment.

Regenerable Antimicrobial Finishing of Cotton with Nitrogen Plasma Treatment

The effects of process variables on regenerable antimicrobial finishing of cotton fabric with nitrogen plasma treatment were investigated. Cotton fabric was treated with a mixture of nitrogen and helium plasma, and it was chlorinated with sodium hypochlorite to impart antimicrobial properties. An orthogonal array testing strategy (OATS) was used in the finishing process to determine the optimum treatment conditions. After finishing, the properties of cotton fabric, including concentration of chlorine, tearing strength, and presence of functional groups, were evaluated by ultraviolet spectroscopy (UV), tear testing, and Fourier transform infrared spectroscopy (FTIR). Cotton fabric treated with nitrogen plasma and chlorination effectively blocked microorganism growth. The resistance to Staphylococcus aureus bacteria was regenerable, and nitrogen plasma treatment showed no noticeable influence on the tearing strength of the cotton fabric.

Orthogonal analysis for rechargeable antimicrobial finishing of plasma pretreated cotton

This paper reports results of an investigation of the effects of different parameters used in the antimicrobial finishing process on rechargeable antimicrobial finishing of cotton fabric after plasma pretreatment. Cotton fabric was pretreated with a mixture of nitrogen and helium plasma before coating with 5, 5-dimethylhydantoin (DMH) (i.e. plasma-pad-dry-cure) and then chlorinated with sodium hypochlorite to impart antimicrobial property. An orthogonal array testing strategy was employed for identifying optimal conditions for the coating process. After coating and chlorination, properties of finished cotton fabrics were measured in terms of concentration of chlorine, morphological properties of the surface and functional groups on the cotton fabric by Ultraviolet spectroscopy, Scanning electron microscope and Fourier Transform Infrared Spectroscopy, respectively. The results show that coating of plasma pretreated fabric with DMH, followed by chlorination, inhibits microorganisms effectively and the antimicrobial property against S. aureus is rechargeable.

Optimizing rechargeable antimicrobial performance of cotton fabric coated with 5,5-dimethylhydantoin (DMH)

In this study cotton fabric was coated with 5,5-dimethylhydantoin (DMH), followed by chlorination with sodium hypochlorite to impart antimicrobial properties and functions. An orthogonal array testing strategy was employed for obtaining the optimum treatment condition. After coating and chlorination, cotton fabrics were characterized with different methods. Ultraviolet spectroscopy, Scanning Electron Microscope and Fourier Transform Infrared Spectroscopy were used to observe the properties of cotton fabric after finishing, such as concentration of chlorine on cotton fabric, morphological properties of the surface of cotton fabric and functional groups on the cotton fabric. The results showed that cotton fabric coated with DMH followed with chlorination has antimicrobial properties that are able to resist S. aureus and this property is rechargeable.

Upper bound limit analysis of support pressures of shallow tunnels in layered jointed rock strata

With more and more large-span shallow underground projects being built in layered jointed rock strata, there is an increasing interest in the study of stability problems of such projects. The upper bound theorem of limit analysis has been found to be a valid method for analyzing such problems and it is crucial to ensure the accuracy of the failure mode when applying this method. In the present paper, for tunnels in layered jointed rock strata, 8 factors including the thickness of the weathered overburden, the states of the rock joints, and the depth of the tunnel were considered by analyzing the failure mode. By using the orthogonal array testing strategy and the distinct element method, 64 different numerical simulation models based on an actual tunnel project were simulated. The test results showed that the range of the loose zone was determined by the stretch, slippage, and fracture area of the joints. Two kinds of loose zone were obtained, i.e. the arch collapse loose zone and the caving collapse loose zone. The loose zone boundary was analyzed and fitted with linear and non-linear models; such as parabola and power function curves, respectively. The rational failure mode was studied by analyzing the recognition method, the classification, and the failure mechanism of the caving collapse loose zone. By using the liner least squares method, an empirical formula of the boundary of the caving collapse loose zone was obtained, and its boundary were divided equally with identical angles, then a kinematically admissible velocity field was established. Based on the virtual power principle and virtual work principle, the upper bound theorem of limit analysis was adopted to study the support pressures and a limit analysis model was established. A real tunnel project case was studied as an example, and the results were compared with the Terzaghi theory and the Fraldi theory, so as to demonstrate the applicability of the proposed method.

Effect of atmospheric pressure plasma treatment on the desizing and subsequent colour fading process of cotton denim fabric

In this article, the performance of atmospheric pressure plasma treatment in the desizing of grey cotton denim fabric followed by an enzymatic colour fading process was studied. Four atmospheric pressure plasma processing parameters, namely, treatment time, ignition power, reactive gas (oxygen) concentration and jet distance were considered for desizing. In order to investigate the optimum conditions (based on weight change) for atmospheric pressure plasma treatment, an orthogonal array testing strategy was used. The optimum conditions for atmospheric pressure plasma treatment in this study were: treatment time, 5 s/mm; ignition power, 160 W; oxygen concentration, 1%; and jet distance, 3 mm. The level of importance of atmospheric pressure plasma processing parameters based on the orthogonal array testing strategy analysis was in the order: jet distance > ignition power > oxygen concentration > treatment time, and the effect of each processing factor is also discussed. In addition, the desizing effect induced by atmospheric pressure plasma treatment was compared with conventional enzyme desizing treatment. The resultant performance properties were also compared. After conducting desizing with atmospheric pressure plasma treatment, the cotton denim fabric was subjected to an enzymatic colour fading process. The colour fading effect was found to be more significant when compared with the conventional enzymatic colour fading process.

Research on the influences of point defects on the thermal conductivity of carbon nanotube by simulation with orthogonal array testing strategy

In the preparation process of carbon nanotubes, various point defects inevitably come into being in the lattice structures. The defects strongly affect the thermal transport properties of carbon nanotubes. Thermal conduction in carbon nanotube is simulated by using nonequilibrium molecular dynamics method with reactive bond order (REBO) potential. Thermal conductivities of carbon nanotubes with and without defects are calculated for comparison. An orthogonal array testing strategy is employed. In the calculation it greatly saves the experimental effort and identifies the degrees of influence of such structural factors as defect type, tube length, tube radius, etc. on thermal conductivity of tube. The effects of three types of point defects: vacancy, doping and adsorption are primarily studied, and the ambient temperature factor is also analyzed. Simulation results show that the thermal conductivity of carbon nanotubes with defects decreases significantly due to point defects compared with that of perfect carbon nanotubes. The defect type has the first greatest influence on the decrease of thermal conductivity, and hvae the second third greatest infuluences respeetively the radius and the length of carbon nanotubes. The degrees of influence of the above types of point defect are in the order of vacancydopingadsorption. Different types of point defects have different effects on tubes at different ambient temperatures.

A Study on Process Parameters for Plasma Pre-Treatment of Cotton Fiber Prior to Titanium Dioxide Wrinkle-Resistant Treatment

Titanium dioxide (TiO2) has been found feasible to improve wrinkle resistant property of cotton fiber. In this study, the performance of TiO2 wrinkle resistant treatment was further enhanced by plasma pre-treatment compared with the conventional wet treatment. Different plasma pre-treatment process parameters (treatment speed, i.e. treatment time; oxygen flow rate; and jet-to-substrate distance) were used for determining the optimum conditions (of plasma pre-treatment) for the subsequent wrinkle resistant treatment with TiO2. The optimum conditions for plasma pre-treatment of cotton fabrics before TiO2 treatment were obtained through the orthogonal array testing strategy (OATS): 10mm/s treatment speed, 0.3L/min oxygen flow rate and 6mm jet-to-substrate distance. This was found to be the most effective combination of plasma pre-treatment conditions for improving wrinkle resistant property of cotton fiber. After plasma, if the cotton fiber was treated with 0.1% TiO2, the wrinkle resistant property was further enhanced. Based on the OATS analysis, not only the optimum conditions for plasma pre-treatment could be obtained, but the level of relative importance of the three process parameters could also be obtained.

Orthogonal Array Approach for Optimization of Carrageenase Production by Solid State Fermentation of Pseudomonas aeruginosa ZSL-2

The optimization of solid-substrate medium and fermentation conditions for the production of enzyme carrageenase by a Pseudomonas aeruginosa ZSL-2 was achieved for the first time by employing an orthogonal array testing strategy (OATS). Of the four different substrates tested, wheat bran showed maximum production of carrageenase enzyme. The factors that influence the solid-substrate fermentation (SSF) conditions such as, moisture content, moistening agent, temperature, pH, inoculum size, additional carbon source and the fermentation period for the production of enzyme were studied by one-factor at a time and also by L9(34) an orthogonal array method. The maximal production of k-carragenase (7.44 U/g) dry bacterial bran was achieved at moisture level 1:2.5 (w/v; wheat bran to moisture level), moistening agent IV, inoculum size (10%), temperature 37°C and 48 h of fermentation. The effects of various parameters like medium, inoculum size, temperature, moistening agent, moisture level, incubation period, and supplementation of other carbon sources on the production of carrageenase by SSF using OATS is investigated and the results are presented and discussed.

Effect of plasma pretreatment on enhancing wrinkle resistant property of cotton fiber treated with BTCA and TiO2 System

Abstract1,2,3,4‐butanetetracarboxylic acid (BTCA) with titanium dioxide as a catalyst, was used to crosslink cotton fibers for the purpose of enhancing wrinkle recovery angle (WRA). To enhance the BTCA treatment with TiO2, surface modification of cotton fiber is required; atmospheric pressure plasma jet pretreatment was used in experiments reported in this article. In this study, optimum conditions for plasma pretreatment were analyzed using orthogonal array testing strategy (OATS) technique, on the basis of WRAs achieved after BTCA treatment with and without TiO2 as catalyst. It was found that (i) longer duration of plasma pretreatment provides enough time for the substrate to be impacted by the concentrated active species produced in plasma gas and therefore, modifies the material surface effectively and offers the best balance between enhancement of WRA and minimization of fiber damage, (ii) high oxygen flow rate producing a severe etching effect that alters the material's surface characteristics. However, when concentration of O2 increased during the plasma pretreatment, the active species might react with the oxygen also, besides the cotton surface, and (iii) when the distance between the plasma jet nozzle and the substrate surface is too large, plasma gas from the nozzle is unable to hit the fabric surface, which means no surface modification is achieved. As a result, plasma treatment with 2 mm/s treatment speed, 0.1 L/min oxygen flow rate, and 2 mm jet‐to‐substrate distance was the most effective plasma pretreatment. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012