Metal forming

Red lava rock is available in nature and is formed from volcanic eruptions. Volcanic rocks are composed of oxides of diverse metals and have considerable porosity. In this study, lava rock powder was ground to a specific size and dried to test its ability to adsorb heavy metals in water. The morphology of the stone powder was observed to show crystals of 100–300 nm in size clumping into particles of a few μm.

6p vikwong 29-09-2024 3 1   Download

This finding raise doubt about the effectiveness of the traditional adsorption isotherms and kinetics models to describe trace metals removal using RM, contributing with new insights for future researches involving these hazardous materials.

10p thebadguys 15-01-2022 8 1   Download

Bài giảng Kỹ thuật điện tử: Bài 5 - Lưu Đức Trung cung cấp cho học viên các kiến thức về transistor trường, đặc điểm của tụ MOS, Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Junction Field Effect Transistor (JFET), cấu trúc tụ MOS trên silic kiểu p,... Mời các bạn cùng tham khảo chi tiết nội dung bài giảng!

102p bachkhinhdaluu 10-12-2021 27 5   Download

The coefficients of thermal expansion of thin metal film with face-centered cubic structure at zero pressure are investigated using the statistical moment method (SMM), including the anharmonic effects of thermal lattice vibration. The Helmholtz free energy, mean-square atomic displacement and linear thermal expansion coefficients are derived in closed analytic forms in terms of the power moments of the atomic displacement.

8p tamynhan8 04-11-2020 14 1   Download

In this study, the effect of angle and length of copper made slope plate on the microstructure of A360-Aluminum alloy is investigated. Microstructure study of metallographic samples in different conditions revealed that for 400mm slope length and 60° slope angle the optimum sphierized and homogenized microstructure is achieved.

6p tohitohi 19-05-2020 11 0   Download

In this paper, an extended forming limit stress diagram (EFLSD) was applied to predict neck initiation failure in tube hydroforming of metal bellows. The proposed EFLSD was used in conjunction with ABAQUS/ EXPLICIT finite element simulations to predict the onset of necking in tube hydroforming of metal bellows.

10p tohitohi 19-05-2020 17 1   Download

In our recent work, we have theoretically shown that a broad negative permeability band can be achieved by introducing hybridized meta-materials [N. T. Tung et al., Appl. Phys. Express 5, 112001 (2012)]. To step forward an experimental realization of the above proposal, evaluating the loss contribution at resonant frequencies is indispensable. In this report, we study the metallic and dielectric losses that directly influence the strength of permeability negativity at microwave regime. The results show that the dielectric loss plays a decisive role in forming the meta-material hybridization.

6p minhxaminhyeu4 15-07-2019 19 1   Download

The dependences of mol-fractions i of the formed complexes [Cu2+ Eni] and of the reaction rate W on concentration of ligand En were determinated. The obtained results showed that the forms and catalytic activity of complexes [Cu2+ Eni] were similar to that of metal-polymer AN-221.

4p uocvong04 24-09-2015 43 4   Download

Investigations of kinetics of p-xylene deep oxidation on CuO/ -Al2O3 and CuO/ZSM-5 have been carried out. Specific surface area and pore size of catalyst samples as well as metallic state characteristics and catalytic properties of copper have been established. Catalyst CuO/ZSM-5 has been found to be more active than the first one, but it expressed lower stability because of less stable active form of Cu2+ on zeolite surface.

6p uocvong03 24-09-2015 32 5   Download

La0.9Ce0.1Mn0.5Cu0.5O3 was prepared by the combustion method using polyvinyl alcohol (PVA) and corresponding metal nitrates. Samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), FT-IR spectra, transmission electron microscopy (TEM) and BET (Brunaure-Emmet-Teller) measurements. The results show that perovskite phase is formed at 600o C. Sample synthesized under optimal condition has nanostructure with large specific area.

6p uocvong01 24-09-2015 38 2   Download

Metal forming to make large parts, take large reductions, use high strength materials, work to net shape (precision flashless closed die forging), and use cold forming to obtain certain physical properties all require high forming forces. These forces may be larger than the capacity of existing machinery.

33p vcuong222 13-05-2015 55 4   Download

Bioremediation presents a potentially low cost and environmentally agreeable alternative to current physico-chemical remediation strategies. However, heavy metals such as mercury cannot be converted into non-toxic forms by naturally occurring bacteria. Annual global emissions estimates for mercury released into the environment are in the thousands of tons per year [1,2] while the remediation cost is in the thousands of dollars per pound. Finding new bioremediation technologies is an urgent need.

8p zingzing09 24-04-2013 44 3   Download

The structure of peptidase T, or tripeptidase, was deter-mined by multiple wavelength anomalous dispersion (MAD) methodology and re®ned to 2.4 A Ê resolution. Pep-tidase T comprises two domains; a catalytic domainwith an active site containing two metal ions, and a smaller domain formed through a long insertion into the catalytic domain. The twometal ions, presumablyzinc, are separatedby3.3 AÊ , and are coordinated by ®ve carboxylate and histidine ligands.

8p research12 23-04-2013 30 4   Download

We studied the interaction of several metal ions with the copper chaperone fromEnterococcus hirae(EhCopZ). We show that the stoichiometry of the protein–metal complex varies with the experimental conditions used. At high con-centration of the protein in a noncoordinatingbuffer, a dimer, (EhCopZ)2–metal, was formed. The presence of a potentially coordinatingmolecule L in the solution leads to the formation of a monomeric ternary complex, EhCopZ– Cu–L, where L can be a buffer or a coordinatingmole-cule (glutathione, tris(2-carboxyethyl)phosphine). ...

11p dell39 03-04-2013 52 6   Download

H2 -forming methylenetetrahydromethanopterin dehydro-genase (Hmd) is an unusual hydrogenase present in many methanogenic archaea. The homodimeric enzyme dubbed
metal-free hydrogenase does not contain iron–sulfur clus-ters or nickel and thus differs from [Ni-Fe] and [Fe-Fe] hydrogenases, which are all iron–sulfur proteins. Hmd preparations were found to contain up to 1 mol iron per 40 kDa subunit, but the iron was considered to be a con-taminant as none of the catalytic and spectroscopic pro-perties of the enzyme indicated that it was an essential component....

10p dell39 03-04-2013 52 4   Download

Metal binding to the amyloidb-peptide is suggested to be involved in the pathogenesis of Alzheimer’s disease. We used high-resolution NMR to study zinc binding to amyloid b-peptide 1–40 at physiologic pH. Metal binding induces a structural change in the peptide, which is in chemical exchange on an intermediate rate, between the apo-form and the holo-form, with respect to the NMR timescale.

14p inspiron33 23-03-2013 50 6   Download

Vertebrate metallothioneins are found to contain Zn(II) and variable amounts of Cu(I),in vivo, and are believed to be important for d 10 -metal control. To date, structural information is available for the Zn(II) and Cd(II) forms, but not for the Cu(I) or mixed metal forms. Cu(I) binding to metallothionein-1 has been investigated by circular dichroism, luminescence and 1 H NMR using two synthetic fragments representing thea- and the b-domain.

14p galaxyss3 19-03-2013 34 5   Download

TheLactococcus lactisNRRL B-1821 prolidase gene was cloned and over-expressed in Escherichia coli. Under suboptimum growth conditions, recombinant soluble and active prolidase was produced; in contrast, inclu-sion bodies were formed under conditions preferred for cell growth.

10p media19 05-03-2013 42 2   Download

Molybdenum insertion into the dithiolene group on the 6-alkyl side-chain of molybdopterin is a highly specific process that is catalysed by the MoeA and MogA proteins in Escherichia coli. Ligation of molybdate to molybdopterin generates the molybdenum cofactor, which can be inserted directly into molybdoenzymes binding the molybdopterin form of the molybdenum cofactor,

12p vinaphone15 28-02-2013 33 1   Download

Alzheimer’s disease, a neurodegenerative disorder causing synaptic impair-ment and neuronal cell death, is strongly correlated with aggregation of the amyloid-bpeptide (Ab). Divalent metal ions such as Cu 2+ and Zn 2+ are known to significantly affect the rate of aggregation and morphology of Abassembliesin vitro and are also found at elevated levels within cerebral plaquesin vivo.

10p vinaphone15 25-02-2013 44 4   Download