The rational design of enzymes is a challenging research field, which plays an important role in the optimization of a wide series of biotechnological processes. Computational approaches allow ...screening all possible amino acid substitutions in a target protein and to identify a subset likely to have the desired properties. They can thus be used to guide and restrict the huge, time-consuming search in sequence space to reach protein optimality. Here we present HoTMuSiC, a tool that predicts the impact of point mutations on the protein melting temperature, which uses the experimental or modeled protein structure as sole input and is available at the dezyme.com website. Its main advantages include accuracy and speed, which makes it a perfect instrument for thermal stability engineering projects aiming at designing new proteins that feature increased heat resistance or remain active and stable in nonphysiological conditions. We set up a HoTMuSiC-based pipeline, which uses additional information to avoid mutations of functionally important residues, identified as being too well conserved among homologous proteins or too close to annotated functional sites. The efficiency of this pipeline is successfully demonstrated on Rhizomucor miehei lipase.
The flame brazing of H62 brass using a novel, low-silver Cu-P brazing filler metal was investigated in this study. The effect of the addition of a trace amount of Sn on the microstructure and ...properties of Cu-7P-1Ag filler metals was analyzed by means of X-ray diffractometer, scanning electron microscopy and energy dispersive spectrometer. The addition of trace Sn led to a decrease in the solidus and liquidus temperatures of Cu-7P-1Ag filler metals. Meanwhile, the spreading performance of the filler metals on a H62 brass substrate was improved. The microstructure of the low-silver, Cu-P brazing filler metal was mainly composed of α-Ag solid solution, α-Cu solid solution and Cu3P; an increase of Sn content led to the transformation of the microstructure of the joints from a block to a lamellar structure. When the Sn content was 0.5 wt. %, the shear strength of the joint at room temperature reached 348 MPa, and the fracture morphologies changed from a cleavage to a quasi-cleavage structure.
In the present study, a device for measuring the viscosity and melting temperature of hot metal is designed based on the method of damped torsional oscillations. The effects of carbon, titanium, ...chromium, vanadium, and sulfur contents on the viscosity and melting temperature of hot metal are investigated. The results indicated that titanium is the most important element affecting the viscosity and melting temperature of hot metal. Carbides of titanium, chromium, and vanadium are precipitated when the hot metal cooled below the melting temperature. This is an important reason that titanium, chromium, and vanadium have great influence on the viscosity and melting temperature of hot metal. Furthermore, the influences of carbon and sulfur contents on the viscosity and melting temperature of hot metal are also analyzed.
This paper simplify a device for measuring the viscosity and melting temperature of hot metal. The effects of carbon, titanium, chromium, vanadium, and sulfur contents on the viscosity and melting temperature are investigated. It is expected to find out the influence of different elements, for providing theoretical reference for the refining of hot metal containing vanadium, titanium, and chromium.
The influence of Ga content on the melting temperature, wettability, microstructure, and mechanical properties of low-silver 12AgCuZnSn-2In-0.15Pr cadmium-free filler metal was investigated ...systematically by means of differential thermal analysis, X-ray diffractometer, scanning electron microscopy, energy-dispersive spectrometer, etc. The results showed that the addition of the Ga element reduced the solidus and liquidus temperatures of the novel low-silver filler metals, and effectively increased the spreading area of the filler metal on the copper and 304 stainless steel substrates. Furthermore, an appropriate amount of Ga element significantly optimized the interface morphology and improved the mechanical properties of the brazed joints. When the Ga content was 1wt.%, the shear strength of the brazed joints reached a peak value of 448 MPa, and the corresponding fracture morphology showed typical ductile characteristics with obvious dimples.
In this study, the isothermal crystallization process of poly(l-lactide) (PLLA) has been investigated using in situ XRD, differential scanning calorimetry (DSC), and polarized optical microscopy ...(POM). Linear and nonlinear extrapolation methods have been deployed to estimate the equilibrium melting temperature ( T m 0 ), which is used for analyzing the supercooling dependence of the PLLA spherulitic growth rate (
). A double-melting behavior observed for PLLA under crystallization
< 120 °C has been attributed to the formation of both α' and α crystals. The T m 0 values of both α' and α crystals have been evaluated using the linear method (172.8 °C) and nonlinear method (196.4 °C), with the nonlinear estimate being 23.6 °C higher. A discontinuity in the temperature dependence of spherulite growth rate is observed around 128.3 °C. Regime II⁻III transition is found to occur at 128.3 °C when T m 0 = 196.4 °C as estimated by the nonlinear extrapolation method.
The statistical moment method is used to study the melting of defective interstitial AB alloys, where A is the main element and B is an interstitial atom, with a body-centered-cubic (BCC) structure. ...The melting temperature of the AB alloy with defects is obtained from the temperature of absolute stability for the crystalline state and the equilibrium vacancy concentration. Numerical calculations are performed for the interstitial alloys TaSi and WSi. Our calculated results are in good agreement with other calculations.
•The thermal properties of Np- and Am-MOX solid solutions were investigated.•Np- and Am-MOX solid solutions exhibit the same linear thermal expansion.•The thermal conductivity of Am-MOX is about 10% ...higher than that of Np-MOX.•The melting temperatures of Np-MOX and Am-MOX are 3020±30K and 3005±30K, respectively.
The thermal properties of Np- and Am-MOX solid solution materials were investigated. Their linear thermal expansion, determined using high temperature X-ray diffraction from room temperature to 1973K showed no significant difference between the Np and the Am doped MOX. The thermal conductivity of the Am-MOX is about 10% higher than that of Np-MOX. The melting temperatures of Np-MOX and Am-MOX, measured using a laser heating self crucible arrangement were 3020±30K and 3005±30K, respectively.
Wildlife trading and the illegal hunting of wildlife are contributing factors to the biodiversity crisis that is presently unfolding across the world. The inability to control the trade of animal ...body parts or available biological materials is a major challenge for those who investigate wildlife crime. The effective management of this illegal trade is an important facet of wildlife forensic sciences and can be a key factor in the enforcement of effective legislation surrounding the illegal trade of protected and endangered species. However, the science of wildlife forensics is limited by the absence of a comprehensive database for wildlife investigations. Inter-simple sequence repeat markers (ISSR) coupled with high resolution melting analysis (HRM) have been effectively used for species identification of 38 mammalian species. Six primers of the ISSR markers were chosen for species identification analysis. From six ISSR primers resulting in a range of accuracy of 33.3%–100% and 100% in terms of precision in every primer. Furthermore, 161 mammalian samples were 100% distinguished to the correct species using these six ISSR primers. ISSR-HRM analysis was successfully employed in determining mammal identification among varying mammalian species, and thus could serve as an effective alternative tool or technique in the species identification process. This option would offer researchers a heightened level of convenience in terms of its performance and the ease with which researchers or field practice veterinarians would be able to interpret results in effectively identifying animal parts at wildlife investigation crime scenes.
En la presente investigación se estudiaron los efectos del contenido de fibra (20, 30 y 40 wt %) y el tratamiento térmico de recocido sobre las propiedades térmicas del material biocompuesto formado ...por una matriz polimérica de polipropileno isotáctico (iPP) reforzada con fibras cortas de bambú (PP/FB). El agente de acople fue iPP con injertos de moléculas de anhídrido maleico (MAPP). Se empleó la técnica de calorimetría diferencial de barrido (DSC) para determinar la temperatura de fusión (Tm), la temperatura de cristalización (Tc) y el grado de cristalinidad (Xc) de los biocompuestos. La temperatura de fusión del PP puro no se afectó de manera significativa por la presencia de las fibras de bambú; sin embargo, el grado de cristalinidad del PP aumentó con el contenido de fibra. El tratamiento térmico de recocido provocó un aumento de la Tm del PP puro y del PP/FB. El compuesto con 20 wt% de contenido de fibra (PP/20F) recocido alcanzó el mayor Xc (37,47 %). La Tc del polipropileno aumentó con la presencia de las fibras, y el compuesto PP/20F alcanzó el mayor valor (115 °C). También, se realizó el estudio de la Tm de los biocompuestos en estado amorfo, y se obtuvo que la muestra con un contenido de fibra de 30 wt% presentó un pico endotérmico a una temperatura aproximada de 168 °C.
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