Drawing Temperature Research Articles

Realizing 0.7 dB/m gain in O + E band by promoting BACs-P formation in bismuth-doped phosphosilicate fiber with double-pass configuration.

The long fiber length required for the amplification of bismuth-doped fiber (BDF) has hindered its practical application. In this paper, we propose and demonstrate a feasible method to improve the active absorption of bismuth active centers (BACs) by optimizing the drawing conditions, achieving a high gain with a short fiber length. The bismuth-doped phosphosilicate fiber (BPSF) preform was fabricated by the modified chemical vapor deposition (MCVD) process and drawn into fiber under nine different conditions. The results indicate that the active absorption of BACs increases as the drawing temperature increases and the drawing speed decreases within these drawing parameters. Meanwhile, the corresponding gain per unit length is improved. Furthermore, a maximum gain of 31.6 dB at 1350 nm with the >20 dB gain wavelength range of 1311-1401 nm was achieved in a double-pass double-pump configuration, using only 45 m BPSF. Meanwhile, the -3 dB bandwidth was 1328-1370 nm. The gain per unit length is 0.7 dB/m, which, to the best of our knowledge, is the highest gain per unit length reported for the BPSF.

Overconfidence in climate overshoot

Global emission reduction efforts continue to be insufficient to meet the temperature goal of the Paris Agreement1. This makes the systematic exploration of so-called overshoot pathways that temporarily exceed a targeted global warming limit before drawing temperatures back down to safer levels a priority for science and policy2–5. Here we show that global and regional climate change and associated risks after an overshoot are different from a world that avoids it. We find that achieving declining global temperatures can limit long-term climate risks compared with a mere stabilization of global warming, including for sea-level rise and cryosphere changes. However, the possibility that global warming could be reversed many decades into the future might be of limited relevance for adaptation planning today. Temperature reversal could be undercut by strong Earth-system feedbacks resulting in high near-term and continuous long-term warming6,7. To hedge and protect against high-risk outcomes, we identify the geophysical need for a preventive carbon dioxide removal capacity of several hundred gigatonnes. Yet, technical, economic and sustainability considerations may limit the realization of carbon dioxide removal deployment at such scales8,9. Therefore, we cannot be confident that temperature decline after overshoot is achievable within the timescales expected today. Only rapid near-term emission reductions are effective in reducing climate risks.

Membrane fouling in integrated forward osmosis and membrane distillation systems – A review

With the increase in water consumption, especially by the industrial and agricultural sectors, more strategies capable of increasing the recovery and reuse of water resources have been sought. An example of technology that assists in this challenge is membrane separation processes. However, systems that use this type of separation may be limited by the phenomenon of fouling. Integrated systems such as forward osmosis (FO) with membrane distillation (MD) have several advantages, such as obtaining a high-quality permeate from raw wastewater, the constant regeneration of the draw solution, which assists in continuous operation, and the possibility of association with biological tanks that enable nutrients recovery. However, these systems face limitations related to low flux values caused by membrane fouling. Therefore, the present review seeks to study fouling in integrated FO-MD systems to understand the main challenges of applying this technology and achieving higher permeate flux values. From the most recent studies, many strategies are being evaluated, such as different membrane materials, deposition of antifouling materials on membrane surface, feed temperature, draw solution substances, concentration and temperature, use of spacers and new modules configurations. That way, the low flux from those systems may be bypassed, enabling FO-MD systems scale up.

Experimental Study on Preparation of Inorganic Fibers from Circulating Fluidized Bed Boilers Ash.

The ash generated by Circulating Fluidized Bed (CFB) boilers is featured by its looseness and porosity, low content of glassy substances, and high contents of calcium (Ca) and sulfur (S), thus resulting in a low comprehensive utilization rate. Currently, the predominant treatment approach for CFB ash and slag is stacking, which may give rise to issues like environmental pollution. In this paper, CFB ash (with a CaO content of 7.64% and an SO3 content of 1.77%) was used as the main raw material. The high-temperature melting characteristics, viscosity-temperature characteristics, and initial crystallization temperature of samples with different acidity coefficients were investigated. The final drawing temperature range of the samples was determined, and mechanical property tests were conducted on the prepared inorganic fibers. The results show that the addition of dolomite powder has a significant reducing effect on the complete liquid phase temperature. The final drawing temperatures of the samples with different acidity coefficients range as follows: 1270-1318 °C; 1272-1351 °C; 1250-1372 °C; 1280-1380 °C; 1300-1382 °C; and 1310-1384 °C. The drawing temperature of this system is slightly lower than that of basalt fibers. Based on the test results of the mechanical properties of inorganic fibers, the Young's modulus of the inorganic fibers prepared through the experiment lies between 55 GPa and 74 GPa, which basically meets the performance requirements of inorganic fibers. Consequently, the method of preparing inorganic fibers by using CFB ash and dolomite powder is entirely feasible.

A Practical Analysis of Wire Drawing Operation Effects on the Die and Product Behaviors

This study analyse the effects of different wire drawing experimental tests on the die and product properties. Drawing load, temperature, and wear rate are main die factors, that concerned with the interaction effects of drawing speed variation, wire angle alignment and lubrication. For the product, two factors; tensile strength and hardness are taken. A copper wire is drawing from (4.3 mm) into (3.5 mm) diameter with an area reduction of 1.65, 34% ratio.Six dies were employed in various alignments at three different angles (0°, 1°, and 2°), each has two different drawing speeds of (20 mm/min and 40 mm/min). Results show, the highest drawing load and temperature values in die no.5. The effect of using grease on the die wear rate found that the die wear decreases compared to without. But, when using mixed gradients under the same working conditions, the wear rate changed into coating layer on the die surface. The interaction effect of wire alignment on the product strength showing very small when dealing with low or higher speed, but elongation and ductility are significantly reduced with increasing the angle. The wire produced from die no.1, gives the highest micro hardness.

Clinical Application of ISO and CEN/TS Standards for Liquid Biopsies-Information Everybody Wants but Nobody Wants to Pay For.

Liquid biopsies are emerging as valuable clinical biomarkers for cancer monitoring. Although International Organization for Standards (ISO) and Technical Specifications from the European Committee for Standardization (CEN/TS) standardized workflows exist, their implementation in clinical practice is underdeveloped. We aimed to assess the applicability of ISO and CEN/TS standards in a real-world clinical setting, with a particular focus on evaluating the impact of preanalytical parameters and hemolysis on liquid biopsy analysis. We evaluated 659 peripheral blood samples from advanced prostate cancer patients against ISO and CEN/TS standards and documented all essential criteria, including tube draw order, filling level, temperature, and time tracking from blood draw to storage. We assessed hemolysis and its effect on circulating tumor DNA (ctDNA) and circulating tumor cell (CTC) analysis. Our results demonstrated a high compliance rate, with 96.2% (634/659) of samples meeting essential ISO and CEN/TS criteria. We did not observe a significant impact on ctDNA or CTC detection rates between hemolytic and nonhemolytic samples. Hemolysis was identified in 12.9% (40/311) of plasma samples from our advanced prostate cancer cohort, and within the draw order of 5 blood collection tubes, hemolysis did not significantly increase from tube 1 to 5. In total, 83.8% (552/659) of blood collection tubes had high fill levels above 80% of nominal filling level. Our study demonstrates the feasibility and benefits of adhering to ISO and CEN/TS standards in a clinical liquid biopsy study. The standards revealed that hemolysis occurred frequently but did not impair downstream ctDNA and CTC analysis in our cohort of advanced prostate cancer patients.

Superior strength-ductility synergy of Mg-Nd-Zn-Zr alloy rod achieved by drawing at elevated temperatures

Mg alloys with superior strength-ductility synergy is highly desired for applications. In this study, the as-extruded Mg-Nd-Zn-Zr (JDBM) alloy rod was subjected to single-pass drawing over a range of temperature 200 ∼ 600 °C to enhance the properties. After drawing, a more homogeneous and refined microstructure developed because of dynamic recrystallization (DRX) and dynamic precipitation (DP). With the increase of drawing temperature, grain sizes increased first and then decreased due to the competition of grain nucleation and growth, while the sizes of the secondary phase particles varied in the same way. And a nearly basal texture evolved from a rare earth texture of the as-extruded sample. The yield strength of the as-drawn samples increased by ∼2.2 times with a sacrifice of elongation to fracture at different level. The high yield strength mainly originats from grain boundary and dislocation strengthening. An optimal combination of high yield strength (∼301 MPa) and good ductility (elongation to fracture of ∼19 % and improved strain hardening capacity) was obtained after drawing at 500 °C. The yield strength enhancement is mainly derived from texture and dislocation strengthening. Grain and secondary phase particle refinement, large volume fraction of low angle grain boundaries and reduced geometrically necessary dislocations are considered to be beneficial to the good ductility. In addition, a novel method has been proposed to fabricate materials with superior strength-ductility synergy by deformation with large strain at high temperatures to activate severe DP.

Unveiling the potential of forward osmosis desalination: Multi-objective optimization for peak efficiency

Forward osmosis (FO) has emerged as a promising technology with diverse applications. While recent advancements in FO have primarily focused on developing efficient membranes and draw solutes, studies on process optimization remain scarce. This work aims at identifying optimal operating conditions to use FO in seawater and brackish water desalination. Central Composite Design was conducted to investigate the effects of draw solution concentration, temperature, and flow rate on water flux (Jw), reverse solute flux (RSF), and specific cost index (Isc) responses. Response Surface Methodology analysis was performed to identify factors influencing responses. The desirability function was used to determine the best-input variables. The optimum operating conditions for the FO process are found at a flow rate of 0.6 L/min, a temperature of 32.9 °C, and a concentration of 1.79 mol/l, with corresponding values for water flux, RSF and Isc of 18.16 L/m2h and 41.03 g/m2h and 0.274, respectively. These results were experimentally validated. Experiments were also performed using seawater and brackish water feed solutions.

Properties Optimization of Polypropylene/Montmorillonite Nanocomposite Drawn Fibers.

In this study, the mechanical properties and thermal stability of composite polypropylene (PP) drawn fibers with two different organically modified montmorillonites were experimentally investigated and optimized using a response surface methodology. Specifically, the Box-Behnken Design of Experiments method was used in order to investigate the effect of the filler content, the compatibilizer content, and the drawing temperature on the tensile strength and the onset decomposition temperature of the PP composite drawn fibers. The materials were characterized by tensile tests, thermogravimetry, and X-ray diffraction. Two types of composites were investigated with the only difference being the type of filler, namely, Cloisite® 10A or Cloisite® 15A. In both cases, statistically significant models were obtained regarding the effect of design variables on tensile strength, while poor significance was observed for the onset decomposition temperature. Nanocomposite fibers with tensile strength up to 540 MPa were obtained. Among the design variables, the drawing temperature exhibited the most notable effect on tensile strength, while the effect of both clays was not significant.

In Situ Crystallization of SiO Spherical Nanocrystals in Optical Fibers

Extreme synthesis conditions can lead to discover materials and phenomena that are unknown under standard synthesis laboratory conditions. The particularities of the optical fiber fabrication, such as extreme temperatures, quenching heat treatments and the pressure generated during fiber drawing, among others, can be leveraged to explore novel phenomena at the nanoscale when optical fibers are engineered by nanoparticle doping. In this work, we demonstrate that starting from tetragonal cubic-shaped YPO4 nanocrystals contained into a silica-based optical fiber core, with a silica-based glass composition slightly modified with Ge P, and Al, it is possible to nucleate isolated spherical-shaped SiO nanocrystals by controlling fiber drawing temperature. This work demonstrates the existence of crystalline SiO, discussing the possible formation mechanism in detail, which addes new knowledge to silicon oxide family. Moreover, we show the suitability of using SiO nanocrystals for fabricating Rayleigh scattering enhanced optical fibers that can be applied for distributed sensing applications.

Dependence of lithium‐ion battery separator porous structure and performance on synchronous bidirectional drawing process regulation of β‐crystal polypropylene

AbstractUneven separator porous construction inevitably raises lithium‐ion migration barriers within the separator and thus limits overall lithium‐ion battery (LIB) performance. In this research, serial LIB separators with various porous constructions were prepared precisely by adjusting the synchronous bidirectional drawing temperatures to confirm the bidirectional drawing mode‐determined porous constructions and subsequent mechanical properties, thermal stability and electrochemical properties of separators. Crystal structure analyses, porous construction diagnoses, mechanical property characterizations and electrochemical tests reveal the competitive relationship between lamella slip and separation during the synchronous bidirectional drawing process. Lamella slip weakens at lower drawing temperatures, enhancing lamella separation and molecular chain rupture within amorphous regions. Therefore, a separator with broken fibrils presents optimized permeability and smoothed ion migration channels, but inferior mechanical properties and thermal stability. Excessive temperature highlights lamella slip, which damages the pore‐forming process, worsens separator permeability and increases ion migration resistance. An appropriate drawing temperature of 100 °C maximally balances lamella slip and separation behaviors, retains intact fibrils and homogenized porous construction, which endows the separator with strengthened mechanical properties, isotropic thermal stability and optimized electrochemical performances. This study provides new insights for synchronous bidirectional drawing in practical separator fabrication and clarifies separator structure‐determined LIB performances. © 2023 Society of Industrial Chemistry.

Cold Drawing of AISI 321 Stainless Steel Thin-Walled Seamless Tubes on a Floating Plug.

The paper presents the results of an analysis of the process of drawing AISI 321 stainless steel thin-walled seamless tubes on a floating plug. The influence of the geometry of dies and plugs, drawing velocity, and lubricants on the possibility of carrying out the pipe drawing process without a loss of strength of the lubricating film and, consequently, disturbance of the forming process and tube cracking, and also on the temperature in the drawing process, the mechanical properties of the tubes drawn, and the microhardness and roughness of the inner and outer surface of the tubes was investigated. The parameters of the drawing tools used were as follows: angle of drawing dies α = 16° and floating plugs with angles of inclination of the conical part of the plug β = 11.5°, 13°, and 14°. The drawing dies and floating plugs were made of G10 sintered carbide. Drawing speed was varied over the range 1 to 10 m/min. The study used several lubricants. Tubes with dimensions (outer diameter D0, wall thickness g0 before drawing process) D0 = 19 mm, g0 = 1.2 mm and D0 = 18 mm, g0 = 1.2 mm were drawn to produce tubes with dimensions (outer diameter Dk, wall thickness gk after drawing process) Dk = 16 mm, gk = 1.06 mm on a drawbench with the same total elongation, while the diameter and wall thickness were changed. During the process, continuous measurements were made of the drawing force and temperature in the deformation zone and on the tube surface. It was found that the drawing process causes a decrease in the roughness parameters Ra and Rz of the inner surface of the tubes. Moreover, after drawing, an increase of 30-70% was observed in the microhardness of the tube material in relation to the microhardness of the charge material. Based on the test results, it can be concluded that the work of frictional forces is the main direction of optimization of tube drawing on a floating plug process of hard-deforming materials.

Study on formability and microstructure evolution of hot deep drawing manufactured 7005 aluminum alloy sheet metal

The hot deep drawing process with an in-die heating system was proposed on the forming of 7005 aluminum alloy to improve the formability due to the limitation of ductility during severe plastic deformation at room temperature. The feasibility of hot deep drawing AA7005 sheet (only 0.8 mm) was investigated and evaluated by Swift cup tests from RT to 450 °C. The priority of main process parameters, namely temperature, blank holder force, and stamping speed, on sheet metal forming limit were discussed by analysis of range and variance. Experimental results indicated that elevating the temperature could fundamentally improve the deep drawing performance of the alloy, which is manifested by the revolutionary change in sheet metal behavior — from the failure of deformation at lower temperatures (RT-200 °C) to achieving a limiting drawing ratio of 2.19 at 450 °C. The optimal process parameters under HDD conditions are given as drawing temperature of 400 °C∼450 °C, BHF of 3 kN, and punch speed of 15–20 %. The thickness variation increases with rising temperature corresponding to the formability enhancement during the process within acceptable limits. DRV and DRX are the flow softening mechanism under the high temperature and large strain in HDD process obtained from the analysis of microstructure and texture evolution. The elongation and rotation of grains further substantiated the interrelationship between drawing performance and microstructure evolution. Improving the deep drawing performance through HDD process can provide practical guidance for the application of AA7005 sheet metal.

Reduction of Concentrating Poisonous Metallic Radicals from Industrial Wastewater by Forward and Reverse Osmosis

The research aims to use a new technology for industrial water concentrating that contains poisonous metals and recovery quantities from pure water. Therefore, the technology investigated is the forward osmosis process (FO). It is a new process that use membranes available commercial and this process distinguishes by its low cost compared to other process. Sodium chloride (NaCl) was used as draw solution to extract water from poisonous metals solution. The driving force in the FO process is provided by a different in osmotic pressure (concentration) across the membrane between the draw and poisonous metals solution sides. Experimental work was divided into three parts. The first part includes operating the forward osmosis process using TFC membrane as flat sheet for NaCl. The operating parameters studied were: draw solutions concentration (10 – 95 g/l), draw solution flow rate (12-36 I/h), temperature of draw solution (30 and 40°C), feed solution concentration (10 -210 mg/l), feed solution flow rate (10 -50 l/h), temperature of feed solution (30 and 40°C) and Pressure (0.4 bar). The second part includes operating the forward osmosis process using CTA membrane as flat sheet for NaCl. The operating parameters studied were: draw solution concentration (15 – 95 g/l), feed solution concentration (10-210 mg/l). Constant temperature was maintained at 30°C. The last part includes operating the reverse osmosis process using TFC membrane as spiral wound module in order to separate NaCl salt from draw solution and obtain on pure water so as to usefully in different uses and also obtain on solution of NaCl concentrate which was recirculated to forward osmosis process. It is then used as draw solution. The operating parameter studied was: feed solution flow rate (15-55 l/h). The experimental results show that the water flux increases with increasing draw solution concentration, feed solution flow rate, temperature of draw solution and decreases with increasing feed solution concentration, draw solution flow rate and temperature of feed solution. The experiments also show that CTA membrane gives higher water flux than TFC membrane for forward osmosis operation.

Semi-distributed interferometers fiber-optic sensors for high-sensitivity refractive index detection: Design and sensitivity analysis

In this work, we present the design and analysis of fiber-optic refractive index (RI) sensors based on a simple semi-distributed interferometer (SDI). The SDI is a cavity formed between a cleaved fiber tip and the reflective interface between a single-mode fiber and a high-scattering fiber with core doped by Mg-silicate nanoparticles. The fabrication is rapid (∼1 min) and straightforward, as only a splice and cleave of the fibers are required; the resulting spectral fingerprint is an interferometer-shaped envelope, with a stochastic distribution due to the random scattering centers of the in-cavity fiber. We fabricated 18 sensors with 6 different enhanced-scattering fibers, having different drawing temperature and speed; by analyzing the RI sensitivity of each unit, we obtain sensitivity values up to 787.0 dB/RIU (refractive index units), whereas the optimal fiber allows achieving average sensitivity of 457.9 dB/RIU.

Machine learning and multilayer perceptron enhanced CFD approach for improving design on latent heat storage tank

Solid-liquid phase change heat storage is an important method to solve the mismatch of the generation and usage of waste heat, which is conducive to decarbonization and energy conservation. However, there always exists inhomogeneity for the melting and temperature of the phase change material (PCM) in solid–liquid phase change heat storage. Changing the shape of the heat storage tank will change the distance of heat transfer to the phase change material, thus changing the heat storage performance. Therefore, this paper designed ten shapes of trapezoidal tank with different proportions of upper and lower radius. And the heat storage performance of ten cases were investigated through the designed numerical model, whose accuracy is convinced through comparison with experimental results. Many indexes are proposed to evaluate the properties of the latent heat thermal energy storage (LHTES) from the view of whole region, uniformity among subregions, and the storage heat performance of integrity. Except for drawing mass fraction, temperature, and streamline contours, the temperature proportion and the average velocity are proposed to quantitatively evaluate the temperature distribution and convection intensity. The results showed that the cases with larger upper radius are shorter than cases with larger lower radius. In addition, the shortest melting time is 17210 s, which is about 39.2% shorter by 11080 s than that of basic case. The evaluation from the view of uniformity also indicated that properly increasing the PCM amount is beneficial for improving the melting uniformity. The most uniform temperature and mass fraction are case 5 and case 4, respectively, with 12.92% and 38.28% improvement. Finally, one multilayer perceptron (MLP) network model is built to predict the melting fraction and total heat storage. After training, one model with a deviation lower than 10% between simulation and prediction is set up.

Superelastic stability of nanocrystalline Ni47Ti50Fe3 shape memory alloy

NiTi shape memory alloys have been widely explored because of their superelasticity. However, the application of conventional coarsed NiTi SMAs is limited by low superelastic stress and poor superelastic stability due to their low yield strength. In this study, nanocrystalline (NC) Ni47Ti50Fe3 alloy with average size is ∼15 nm was obtained by large deformation cold drawing and low temperature annealing. After ten cycles of loading (up to 6%)-unloading, the NC Ni47Ti50Fe3 alloy exhibited a high superelastic stress (1170 MPa)，low areduction rate of superelastic stress (12%) and small residual strain (0.66%). This overall performance is better than that of previous NiTi-based SMAs. We have suggested that this mainly stems from the synergistic reinforcement combines Fe element doping and high-density grain boundary.

Effectively using heat to thermally enhance pressure retarded osmosis

Thermal energy from solar radiation and industrial waste heat is abundant and can be used to improve the performance of membrane processes for water treatment and power generation. In this study, we investigate the concept of using heat to thermally enhance pressure retarded osmosis for improved energy recovery from salt gradients. A laboratory apparatus is used to demonstrate performance at temperatures between 20 and 50 °C, and improvements in water flux and power density of up to 110 % are observed. Temperature of the feed solution is found to be more important than draw temperature. A finite element model is experimentally validated and used to identify what transport dynamics are responsible for the priority to heat feed. It is found that a hot feed solution produces a warmer membrane (thereby encouraging higher permeability and mitigated polarization), and this principally because the feed boundary offers little thermal resistance as it is typically well-mixed during pressure retarded osmosis. Finally, a new metric of effectiveness is introduced to evaluate power increases relative to the change in temperature. It is found that although operation at higher temperatures may yield higher power, operation at low temperatures of ~30 °C may represent a more effective use of thermal energy.

Bio‐based polyamide 56 fibers by one‐step melt‐spinning: Process, structure and properties

AbstractPolyamide 56 (PA56) fibers were prepared by one‐step melt spinning and drawing process. The effects of draw ratio and draw temperature on the structure and properties of PA56 fibers were investigated. Both α‐like‐ and γ‐crystalline phases were formed in PA56 fibers. An increase in the draw ratio at a given draw temperature leads to the significantly increase in crystallinity, chain orientation, and the content of the α‐like crystalline phase in the resultant PA56 fibers. The crystallinity and orientation parameters of the PA56 fibers increase with draw temperature in the range of 130–190°C. The PA56 α‐like crystalline phase is unfavorable at a higher draw temperature. The optimal process parameters for PA56 fibers with good mechanical properties are at draw ratio above 3 and with a draw temperature in the range of 150–190°C.

Cubic-Shaped and Rod-Shaped YPO4 Nanocrystal-Doped Optical Fibers: Implications for Next Generation of Fiber Lasers

Engineering silica optical fibers by nanoparticle doping is a promising technology that allows the introduction of new functionalities and extends their applicable fields. However, the knowledge gap about the impact of the extreme fabrication temperatures on the nanoparticle features prevents field progress. Herein, we demonstrate that the particularities of fiber fabrication, such as fast-heating rates and quenching heat treatments, can be leveraged to explore unlikely phenomena at the nanoscale under standard laboratory conditions. Tetragonal cubic-shaped and monoclinic rod-shaped YPO4 nanocrystals are in situ nucleated in a silica-based fiber core glass, slightly modified with Ge and P, which shows for the first time, the possibility of doping optical fibers with this type of nanostructures, in terms of shape, composition, and structure of the nanocrystals. Structural and anisotropic differences allow engineering differently their shape and composition in the fiber core by tailoring the drawing temperature, as revealed by a thorough study consisting of scanning electron microscopy (SEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), electron energy loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HRTEM). This work demonstrates, for the first time, the possibility of doping optical fibers fabricated by modified chemical vapor deposition (MCVD) with anisotropic nanostructures, as well as the stability of the monoclinic YPO4 phase. These findings open up new avenues to study shape-dependent properties of rare-earth orthophosphate (REPO4) nanostructures in optical fibers which will allow incorporating unprecedented functionalities and will have an impact in several fields of application, such as fiber lasers and optical fiber amplifiers, among others.