Isothermal Tests Research Articles

Hot Deformation Behavior of a Hot-Isostatically Pressed Ti-6Al-4V Alloy from Recycled Powder.

In this work, a new use of mixed Ti-6Al-4V powder, consisting of the retained powder after screening for additive manufacturing and the recycled powder after multiple printing, has been exploited. The powder mixture has been hot-isostatically-pressed (HIPed) at 930 °C/120 MPa for 3 h to reach full density. The hot deformation behavior of the as-HIPed powder compacts were investigated through isothermal compression tests, kinetic analyses, and hot processing maps. Finally, the optimized hot working parameters were validated using upsetting tests. The results show that the as-HIPed Ti-6Al-4V alloy has a fine and homogeneous microstructure. The activation energies were calculated to be 359 kJ/mol in the α + β phase regime and 463 kJ/mol in the β phase regime, respectively. The optimal hot working parameters are a deformation temperature above 950 °C and strain rate higher than 0.1 s-1. The hot workability of as-HIPed powder compacts is better than the as-cast billets. The deformed microstructure can be finer than that of as-HIPed state, and the mechanical performance can be further improved by the optimal thermo-mechanical processing treatment.

Research on the Hot Deformation Process of A100 Steel Based on High-Temperature Rheological Behavior and Microstructure.

To obtain the optimal hot deformation process, the rheological and dynamic recrystallization behaviors of A100 steel were researched through isothermal compression tests. Firstly, a Hensel-Spittel constitutive model was established based on the stress-strain curves. Secondly, dynamic recrystallization percentage and grain size models were established to identify the necessary conditions for complete dynamic recrystallization. Finally, microstructural analysis was employed to validate the accuracy of the recrystallization model. The results indicate that the flow stress is highly sensitive to both the strain rate and the temperature, and the HS model demonstrates a high predictive accuracy, with a correlation coefficient of 0.9914. There exists a contradictory relationship between decreasing the average grain size and increasing the recrystallization percentage. The higher the percentage of dynamic recrystallization, the larger the average grain size tends to be. This situation should be avoided when devising the actual processing procedures. The optimal hot working processes for achieving complete dynamic recrystallization and a smaller average grain size are as follows: a strain equal to or greater than 0.6, a temperature between 1193 and 1353 K, and a strain rate between 0.1 and 1 s-1.

Effect of dry-wet alternation on the adsorption of dissolved organic matter by soil minerals

Dry-wet alternation has an essential effect on soil minerals' adsorption of dissolved organic matter. In this study, kaolin, illite, and hematite were subjected to 0, 1, 3, and 6 dry-wet alternation incubation tests, respectively, and the changes in the characterization of the three minerals were explored by using a BET specific surface area analyzer and an X-ray diffractometer. The effects of different dry-wet alternation treatments on the adsorption of tannic acid and glucose as the representatives of dissolved organic matter were investigated by isothermal and kinetic adsorption tests as well as by different model-fitting methods. The effects of different dry-wet alternation treatments on the adsorption of tannic acid and glucose by the three minerals were investigated by isothermal and kinetic adsorption tests and different model fitting methods. The results showed that alternating dry-wet treatment could change the three minerals' specific surface area and average pore diameter to different degrees. Still, the spacing of the crystal layers did not change significantly. The dry-wet alternation did not alter the adsorption process and tannic acid and glucose adsorption mode. Still, it affected the equilibrium adsorption amount to different degrees, which was illite>hematite>kaolin, and the intensity of the effect was mainly affected by the decrease of the specific surface area of the minerals, which was not related to the change of the average pore diameter and the spacing of the crystal layers.

Mass-time equivalence in dynamic equilibrium systems

The truth of time has been debated for more than two centuries. Scientists like Leibniz, Einstein, Rowley, Wheeler and DeWitt believe that it is the result of change in the world and is not original. According to our research, only Einstein introduced the law of space–time and showed that time is woven in space (general relativity), but no one (at least in classical physics) explained the relationship between time and changes in the world (mass and energy). has not provided In the rest of the references, only mathematical and theoretical topics are presented. In kinetic experiments (in various scientific fields), time is used as a variable to plot kinetic curves. This choice is neither scientific nor based on principled modeling. For this reason, kinetic models are presented experimentally. The aim of this research is (1) to introduce the "dynamic mass (∂Mout/∂Min)" equation as a platform for mass-based modeling in open systems. (2) Introducing the relationship between mass (m) and time (t) or mass-time equivalence in mass flows (mass conversion or mass transfer system). (3) Expansion of time relativity in mass-mass systems. To achieve the objectives of the study, the equation "dynamic mass (∂M/∂M)" based on the law of conservation of mass has been introduced for the first time. Then, using the dynamic mass equation, the absorption model was presented in two mass forms (mass-mass curve) and time (mass-time curve). Then, using Fe2+, Pb2+, Cr6+, Ni2+, Cd2+and As2+ elements and Jacobi activated carbon, Iranian activated carbon, and blowy sand adsorbents, routine kinetic and isotherm tests were performed separately. To evaluate the absorption model, three methods were used: (1) evaluation by evaluation indices (R2 and RMSE) and (2) comparison of the "temporal form of the model" with the kinetic models of absorption (Lagergren and Ho et al.) and (3) comparison of the "mass form of the model" with Shammahmadi adsorption isotherm model.

Utilization of oyster shell nano-hydroxyapatite modified red-brick waste as an environmentally friendly composite filler for Cd(II) and Cr(VI) adsorption: Preparation, property and mechanism

The ongoing process of urbanization in China has led to a growing concern regarding environmental contamination caused by the significant accumulation of construction demolition trash. This study employs the water thermal method to synthesize hydroxyapatite using natural waste oyster shells as the primary raw material. This study explores the use of synthesized hydroxyapatite (O-HA) on building waste red-brick fragments (RBF) for removing cadmium (Cd(II)) and chromium (Cr(VI)) from water. The RBF fillers, both before and after modification, underwent comprehensive characterization using various techniques, including automated analysis of specific surface area and porosity (BET), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). In the sixth cycle of purification experiments, the average removal rate of Cd(II) by O-HA-modified red-bricks (O-HA/RBF) could still reach 88.18 %, which was about 20.00 % higher than that of the RBF. However, the removal of Cr(VI) by O-HA/RBF was unsatisfactory at 5.33 %. The adsorption mechanisms of Cd(II) and Cr(VI) were explored by isothermal adsorption tests and adsorption kinetic tests. According to the mechanism analysis, physical adsorption and chemical adsorption were the main reasons for Cd(II) adsorption by O-HA/RBF. This involves ion exchange and surface complexation between calcium ions in O-HA and Cd(II), forming a low-solubility precipitate for effective removal. However, for Cr(VI), physisorption predominantly governs O-HA/RBF, elucidating the limited efficacy in Cr(VI) removal. The cost analysis showed that using O-HA/RBF as filler reduced overall expenses in wetland development, offering promising prospects for engineering applications.

Laboratory and field validation of the recombinase polymerase amplification assay targeting the Schistosoma mansoni mitochondrial minisatellite region (SmMIT-RPA) for snail xenomonitoring for schistosomiasis

Improvements in diagnostics for schistosomiasis in both humans and snail hosts are priorities to be able to reach the World Health Organization (WHO) goal of eliminating the disease as a public health problem by 2030. In this context, molecular isothermal amplification tests, such as Recombinase Polymerase Amplification (RPA), are promising for use in endemic areas at the point-of-need for their accuracy, robustness, simplicity, and time-effectiveness. The developed recombinase polymerase amplification assay targeting the Schistosoma mansoni mitochondrial minisatellite region (SmMIT-RPA) was used to detect S. mansoni DNA from both laboratory and field Biomphalaria snails. Laboratory snails were experimentally infected and used at one, seven, and 28 days post-exposure (dpe) to 10 S. mansoni miracidia to provide samples in the early pre-patent infection stage. Field samples of Biomphalaria spp. were collected from the Mucuri Valley and Jequitinhonha Valley regions in the state of Minas Gerais, Brazil, which are endemic for S. mansoni. The sensitivity and specificity of the SmMIT-RPA assay were analysed and compared with existing loop-mediated isothermal amplification (LAMP), PCR-based methods, parasitological examination of the snails, and nucleotide sequencing. The SmMIT-RPA assay was able to detect S. mansoni DNA in the experimentally infected Biomphalaria glabrata as early as one dpe to 10 miracidia. It also detected S. mansoni infections (55.5% prevalence) in the field samples with the highest accuracy (100% sensitivity and specificity) compared with the other molecular tests used as the reference. Results from this study indicate that the SmMIT-RPA assay is a good alternative test to be used for snail xenomonitoring of S. mansoni due to its high sensitivity, accuracy, and the possibility of detecting early pre-patent infection. Its simplicity and portability also make it a suitable methodology in low-resource settings.

Effects of C and Al Alloying on Constitutive Model Parameters and Hot Deformation Behavior of Medium-Mn Steels.

Single-pass isothermal hot compression tests on four medium-Mn steels with different C and Al contents were conducted using a Gleeble-3500 thermal simulation machine at varying deformation temperatures (900-1150 °C) and strain rates (0.01-5 s-1). Based on friction correction theory, the friction of the test stress-strain data was corrected. On this basis, the Arrhenius constitutive model of experimental steels considering Al content and strain compensation and hot processing maps of different experimental steels at a strain of 0.9 were established. Moreover, the effects of C and Al contents on constitutive model parameters and hot processing performance were analyzed. The results revealed that the increase in C content changed the trend of the thermal deformation activation energy Q with the true strain. The Q value of 2C7Mn3Al increased by about 50 KJ/mol compared with 7Mn3Al at a true strain greater than 0.4. In contrast, increasing the Al content from 0 to 1.14 wt.% decreased the activation energy of thermal deformation in the true strain range of 0.4-0.9. Continuing to increase to 3.30 wt.% increased the Q of 7Mn3Al over 7Mn by about 65 KJ/mol over the full strain range. In comparison, 7Mn1Al exhibited the best hot processing performance under the deformation temperature of 975-1125 °C and strain rate of 0.2-5 s-1. This is due to the addition of C element reduces the δ-ferrite volume fraction, which leads to the precipitation of κ-carbides and causes the formation of microcracks; an increase in Al content from 0 to 1.14 wt.% reduces the austenite stability and improves the hot workability, but a continued increase in the content up to 3.30 wt.% results in the emergence of δ-ferrite in the microstructure, which slows down the austenite DRX and not conducive to the hot processing performance.

Oxide Scale Formation on Low-Carbon Steels in Future Reheating Conditions

The mitigation of CO2 emissions is one of the major areas of research in iron ore-based steelmaking. In this study, four simulated current and potential future reheating scenarios with different fuel and oxidizer gases were studied regarding the amount of oxide formation and the adhesion of the steel–oxide interface: (1) methane–air; (2) coke oven gas–air; (3) hydrogen–air; (4) and an oxyfuel scenario with 50:50 methane/hydrogen as fuel gases. Isothermal oxidation tests were conducted at temperatures of 1150, 1230 and 1300 °C. Four low-carbon steel grades were tested in the previously mentioned gas atmospheres. The structure and composition of the formed oxide scales was analyzed with FESEM-EDS microscopy. The amount of oxide formation correlated with the water vapor content of the gas atmosphere for all four steel grades; however, notable differences were found between individual steel grades regarding the degree of oxidation increase. No clear evidence was found of the gas atmospheres affecting the adhesion of oxide scales to the steel substrate. The adhesion of the interface was mainly determined by the content of silicon in the steel grade and the test temperature.

The Oxidation Behaviors of NiCoCrAlY Coatings After Pre-Oxidation Treatment During High-Temperature Oxidation at 800 ℃ and 900 ℃

Thermal barrier coatings (TBCs) are essential for protecting the high-temperature components in gas turbines. However, the durability of TBCs is limited, and new technologies to improve their lifetime are necessary. This study focuses on the pre-oxidation treatment of the NiCoCrAlY bond coat in TBCs to reduce the growth rate of the thermally grown oxide (TGO) and improve the TBC lifetime. The mechanism of the TGO growth rate reduction by the pre-oxidation treatment of NiCoCrAlY was investigated. Oxidation behaviors of the surface of NiCoCrAlY coating samples with or without pre-oxidation treatment were evaluated in air at 800 °C and 900 °C. In-situ X-ray diffraction (XRD) measurements and isothermal oxidation tests were performed. The obtained results revealed that the growth rate of TGO is significantly suppressed by α-Al2O3 layer formed by the pre-oxidation treatment. The generation of γ-Al2O3 and θ-Al2O3, which are typically formed below 900 °C, was significantly reduced by pre-oxidation. It is suggested that this reduction suppresses of the TGO growth.

Hot deformation behavior and hot working window of a solid solution strengthened Ni–Cr–Fe-based superalloy

The hot deformation behavior of Ni–Cr–Fe-based ChS57 alloy was investigated by isothermal compression tests in the temperature range of 1000–1200 °C with strain rates covering 0.001–10 s−1. Based upon the hyperbolic sine function and dynamic material model, the constitutive model and processing maps of the alloy were established, the microstructure evolution was systematically analyzed and the optimization of the hot working window was completed. The results indicate that the flow stress increases remarkably with increasing strain rate and decreasing deformation temperature, while the amount of strain required to reach peak stress also gradually increases. The hot deformation process of this alloy is the result of the competition between dynamic softening and work hardening, with a deformation activation energy of 451.34 kJ/mol; dynamic recrystallization (DRX) is the main softening mechanism, while both continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) exist; the low temperatures and medium strain rates (1000–1025 °C, 0.045–0.37s−1) are the instability zone parameters of the alloy when flow localization and deformation bands are the microstructural manifestations of unstable hot working. The optimum hot working window for ChS57 alloy is the medium-low temperatures and low strain rates（1050–1100 °C, 0.001–0.003s−1）and the medium-high temperatures and high rates（1125–1175 °C, 1-10s−1 or 1100 °C/10s−1）, where the microstructure appears as randomly oriented and uniformly distributed full DRX grains.

Investigation on the heat generation and heat sources of cylindrical NCM811 lithium-ion batteries

High temperature may cause the degradation of capacity and lifespan for the batteries, and even possibly triggers the thermal runaway. Therefore, in order to safe use of batteries, investigation on the heat generation characteristics of lithium-ion batteries is essential to guard the design of thermal management system (TMS). In this work, the heat generation rate (HGR) and heat sources of the 18650 NCM811 battery is investigated by both the isothermal calorimetry test and calculation using the modified Bernardi model, respectively. It is revealed that during charging or discharging, the irreversible heat increases rapidly at low SOC due to large internal resistance, while the reversible entropic heat becomes more important at about 40–60 % SOC due to high entropy coefficient therein. Moreover, the ratio between heat sources has been revealed. The irreversible heat is dominated among the heat sources during charging/discharging with a proportion of 76.33–96.65 %. Wherein, the ohmic heat contributes the most heat generation. Meanwhile, the reversible heat accounts for the smallest proportion of 3.25–23.67 %. It should be noted that current is the main influence factor to the HGR of the lithium-ion battery. With increasing the current, the irreversible HGR, especially ohmic heat, increases much faster than that of reversible heat, resulting in higher ratio. The calculation data are validated to be well consistent with experimental results, giving insights to the investigation of the heat generation of the lithium ion battery.

Rapid and reliable diagnosis of Moraxella catarrhalis infection using loop-mediated isothermal amplification-based testing.

Moraxella catarrhalis (M. catarrhalis) was an important pathogen closely associated with respiratory tract infections. We employed the loop-mediated isothermal amplification (LAMP) coupled with nanoparticle-based lateral flow biosensor (LFB) and fluorescence testing technique for formulating two diagnostic methods for M. catarrhalis detection, termed M. catarrhalis-LAMP-LFB assay and M. catarrhalis-LAMP-FRT, respectively. The M. catarrhalis-LAMP-LFB system incorporated the use of biotin-14-dCTP and a forward loop primer (LF) with a hapten at the 5' end. This design in LAMP reaction enabled the production of double-labeled products that could be effectively analyzed using the lateral flow biosensor (LFB). For the M. catarrhalis-LAMP-FRT assay, the LF was modified with a sequence at 5' end, and a fluorophore, as well as a black hole quencher, were strategically labeled at the 5' end and within the middle of the new LF. The restriction endonuclease Nb.BsrDI could accurately recognize and cleave the newly synthesized double-strand terminal sequences, resulting in the separation of the fluorophore from the black hole quencher and releasing fluorescence signals. Both assays have been proven to be highly sensitive and specific, capable of detecting genomic DNA of M. catarrhalis at concentrations as low as 70 fg, with no cross-reactivity observed with non-M. catarrhalis pathogens. Furthermore, both methods successfully identified M. catarrhalis in all clinical samples within 1h that were confirmed positive by real-time PCR, exhibiting superior sensitivity than conventional culture methods. Herein, the newly developed two LAMP-based assays were rapid and reliable for M. catarrhalis detection and hold significant promise for deployment in point-of-care (POC) settings.

Recrystallization behavior and kinetic analysis of an Al-Cu-Li alloy during hot deformation and subsequent heat treatment

Al-Cu-Li alloys exhibit enhanced performance when possessing a high substructure proportion and a low recrystallization proportion. To achieve this, it necessitates a thorough understanding of recrystallization behavior during its hot working and heat treatment. To this end, isothermal compression tests were conducted on an Al-Cu-Li alloy in the temperature range of 350–500 °C and strain rate range of 0.01–10 s−1. The deformed specimens underwent solution treatment at 530 °C/2 h followed by water quenching, and aging treatment at 155 °C/27 h. The microstructures of the deformed and heat-treated specimens were characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). During hot deformation, continuous dynamic recrystallization (CDRX) dominates when the natural logarithm of the Zener-Hollomon parameter (lnZ) >26 and discontinuous dynamic recrystallization (DDRX) predominates when lnZ ≤ 26. A low proportion kinetic model associated with lnZ was constructed to describe the DRX behavior, and the model parameters were optimized using genetic algorithm (GA) to improve accuracy. During heat treatment, substantial static recrystallization (SRX) occurs following deformation at lnZ > 30, while it is limited when lnZ < 27. The comparison of average geometrically necessary dislocations (GNDs) before and after heat treatment reveals that the consumption of dislocations increases with increasing lnZ. Statistical analysis indicates that the density of low/medium angle grain boundaries (L/MAGBs) can be increased and the recrystallization fraction can be decreased within the lnZ range of 24 to 27. Therefore, these specific hot deformation conditions are recommended as the optimal hot working window for the Al-Cu-Li alloy.

A phenomenological constitutive model of Novel Rheo Gravity Die Cast Al-15Mg2Si-4.5Si-0.01Sr-0.015B composite

The present study discusses the high temperature deformation behaviour as well as phenomenological constitutive model development of the novel Rheo gravity die cast (RGDC) Al-15Mg2Si-4.5Si-0.01 Sr-0.015B composite. Within the scope of the study, uniaxial isothermal compression tests are performed on the RGDC Al-15Mg2Si-4.5Si-0.01 Sr-0.015B composite, covering a range of strain rates from 10−3 to 10 s−1 and deformation temperatures spanning from 250 °C to 450 °C. Analysis using X-ray Diffraction (XRD), Energy dispersive spectroscopy (EDS) and Electron Probe Micro Analyzer (EPMA) revealed the presence of distinct phases within the material, including primary Al, Mg2Si, and elemental Si. The study employed three different constitutive models i.e., the Johnson-Cook (JC), modified Johnson-Cook (mJC), and sine hyperbolic Arrhenius (shA) types, to predict the flow stress of the material as a function of strain, strain rate, and deformation temperature. The results indicated that the sine hyperbolic Arrhenius type model and the modified Johnson Cook model effectively accounted the coupling effect of strain, strain rate, and deformation temperature, which affect the flow stress. Statistical analysis, specifically Pearson coefficient correlation (R), average absolute relative error (AARE) and standard deviations, established a reasonable agreement between the predicted flow stress values and the experimental flow stress data. Furthermore, it is observed that the sine hyperbolic Arrhenius type model exhibited superior accuracy compared to the modified Johnson Cook model, particularly at higher strain levels.

Pesticides’ low-cost removal from polluted groundwater using charcoal from “Salix mucronata” trees activated by gold nitrate

ABSTRACT Used pesticides result in soil pollution, which potentially seep into groundwater, posing risks to human and animal health. The current study examines the use of a new cheap material for removing four commonly used pesticides from polluted groundwater before use for drinking. These pesticides are Malathion, Methomyl, Abamectin, and Thiamethoxam. Activated charcoal obtained from the trunk of “Salix mucronata” trees is introduced for removing these pesticides by surface adsorption. Activation treatment using gold-nitrate solution is introduced to enhance the charcoal adsorption capacity, because removal of pesticides is difficult due to their large-sized molecules and lack of obvious surface electrostatic charges. Physical and chemical properties of the studied pesticides and the activated charcoal were determined. Batch experiments tested the effects of solution pH, contact time, dose of charcoal, and initial concentrations on the charcoal adsorption capacity. Langmuir adsorption linear isotherm test was done to use for the prediction of adsorption behavior. Fixed-bed column experiments tested clean-up of polluted water using charcoal filter under steady flow. Gold-nitrate activated charcoal adsorption capacities were almost three times higher than other charcoals for the same pesticides at the same initial concentrations. Maximum adsorption capacities achieved in the current study were 16.17, 14.59, 9.55, and 8.99 mg/g, respectively, at the initial concentrations of 50.0 mg/l. Meanwhile, treatment times in steady-flow fixed-bed columns were much lower compared to other studies. Preparation cost of gold-nitrate activated charcoal in the current study was lower than other adsorbents. The charcoal introduced in this study is recommended for use in low-cost removal of pesticides from polluted groundwater on the national scale, including small treatment units for rural communities with limited facilities.

High temperature oxidation behaviors of Al/Cr composite coating on Ti2AlNb alloy

The Al/Cr coatings were deposited on Ti2AlNb alloy by magnetron sputtering and double glow plasma alloying technology to improve the oxidation resistance. The morphology of the protective coating was investigated by scanning electron microcopy and the phase composition of the coating was analyzed using x-ray diffraction. The results suggested that the protective coating with multilayer structure was dense and homogeneous. The formation of Cr inner diffusion layer was beneficial to the bonding strength between the coating and substrate, which was attributable to the double glow technology. The oxidation behaviors of Al/Cr coating were investigated by the isothermal oxidation tests for 100 h at 700 °C, 800 °C and 900 °C, respectively. The results indicated that the protective coating showed a lower oxidation rate. At 700 °C, the Al2O3 oxidation products were formed on the surface of coating at high temperature, which were dense and homogeneous against oxygen diffusion. With the increase of oxidation temperature, the external diffusion of Cr element reacted with oxygen to form Cr2O3, which provided the further protection. As for 900 °C, the volatile CrO3 was formed by the reaction of the external diffusion of Cr and Cr2O3, and the oxidation products Al2O3 and Cr2O3 continued to provide protection for Ti2AlNb alloy.

An analysis comparing the mechanical properties of ASS 316L at high and low temperatures

Austenitic Stainless Steel 316L is one among most frequent ASS scores utilized in modern industry. It is more resistant to corrosion in normal atmospheric conditions in severe settings such as seawater with salt and situations that require protection against chloride corrosion and pitting. While operating effectively at high temperatures, it can also retain Because to its resilience and strength at low temperatures, it is a great option for use in the automotive, nuclear, water treatment, marine, and aerospace industries. The mechanical metrics yield quality (YS), percentage elongation, and ultimate tensile strength (UTS) were assessed and compared in this study using experimental data through uniaxial isothermal tensile testing.

A multiplexed, allele-specific recombinase polymerase amplification assay with lateral flow readout for sickle cell disease detection.

Isothermal nucleic acid amplification tests have the potential to improve disease diagnosis at the point of care, but it remains challenging to develop multiplexed tests that can detect ≥3 targets or to detect point mutations that may cause disease. These capabilities are critical to enabling informed clinical decision-making for many applications, such as sickle cell disease (SCD). To address this, we describe the development of a multiplexed allele-specific recombinase polymerase amplification (RPA) assay with lateral flow readout. We first characterize the specificity of RPA using primer design strategies employed in PCR to achieve point mutation detection, and demonstrate the utility of these strategies in achieving selective isothermal amplification and detection of genomic DNA encoding for the healthy βA globin allele, or genomic DNA containing point mutations encoding for pathologic βS and βC globin alleles, which are responsible for most sickle cell disorders. We then optimize reaction conditions to achieve multiplexed amplification and identification of the three alleles in a single reaction. Finally, we perform a small pilot study with 20 extracted genomic DNA samples from SCD patients and healthy volunteers - of the 13 samples with valid results, the assay demonstrated 100% sensitivity and 100% specificity for detecting pathologic alleles, and an overall accuracy of 92.3% for genotype prediction. This multiplexed assay is rapid, minimally instrumented, and when combined with point-of-care sample preparation, could enable DNA-based diagnosis of SCD in low-resource settings. The strategies reported here could be applied to other challenges, such as detection of mutations that confer drug resistance.

Vibration mixing for enhanced paper-based recombinase polymerase amplification.

Isothermal nucleic acid amplification tests (NAATs) are a vital tool for point-of-care (POC) diagnostics. These assays are well-suited for rapid, low-cost POC diagnostics for infectious diseases compared to traditional PCR tests conducted in central laboratories. There has been significant development of POC NAATs using paper-based diagnostic devices because they provide an affordable, user-friendly, and easy to store format; however, the difficulties in integrating separate liquid components, resuspending dried reagents, and achieving a low limit of detection hinder their use in commercial applications. Several studies report low assay efficiencies, poor detection output, and poorer limits of detection in porous membranes compared to traditional tube-based protocols. Recombinase polymerase amplification is a rapid, isothermal NAAT that is highly suited for POC applications, but requires viscous reaction conditions that has poor performance when amplifying in a porous paper membrane. In this work, we show that we can dramatically improve the performance of membrane-based recombinase polymerase amplification (RPA) of HIV-1 DNA and viral RNA by employing a coin cell-based vibration mixing platform. We achieve a limit of detection of 12 copies of DNA per reaction, nearly 50% reduction in time to threshold (from ∼10 minutes to ∼5 minutes), and an overall fluorescence output increase up to 16-fold when compared to unmixed experiments. This active mixing strategy enables reactions where the target and reaction cofactors are isolated from each other prior to the reaction. We also demonstrate amplification using a low-cost vibration motor for both temperature control and mixing, without the requirement of any additional heating components.

An analysis comparing the mechanical properties of ASS 316L at high and Sub-zero temperatures

Austenitic Stainless Steel 316L is one among most frequent ASS scores utilized in modern industry. It is more resistant to corrosion in normal atmospheric conditions in severe settings such as seawater with salt and situations that require protection against chloride corrosion and pitting.While operating effectively at high temperatures, it can also retain because to its resilience and strength at low temperatures, it is a great option for use in the automotive, nuclear, water treatment, marine, and aerospace industries.The mechanical metrics yield quality (YS), percentage elongation, and ultimate tensile strength (UTS) were assessed and compared in this studyusing experimental data through uniaxial isothermal tensile testing.