cis-L-4-Hydroxyproline methyl ester hydrochloride

A hydrometallurgical process for recovering the total metal values from waste monolithic ceramic capacitors was investigated. The process parameters such as time, temperature, acid concentration, hydrogen peroxide concentration and other reagents (amount of zinc dust and sodium formate) were optimized. Base metals such as Ba, Ti, Sn, Cu and Ni are leached out in two stages using HCl in stage 1 and HCl with H2O2 in stage 2. More than 99% of leaching efficiency for base metals (Cu, Ni, Ba, Ti and Sn) was achieved. Precious metals such as Au and Pd are leached out using aquaregia and nitric acid was used for the leaching of Ag. Base metals (Ba, Ti, Sn, Cu and Ni) are recovered by selective precipitation using H2SO4 and NaOH solution. In case of precious metals, Au and Pd from the leach solution were precipitated out using sodium metabisulphite and sodium formate, respectively. Sodium chloride was used for the precipitation of Ag from leach solution.

Multiple adsorption and desorption cycles are required to achieve the reliable operation of copper removal and recovery. A green sorption media mixture composed of recycled tire chunk, expanded clay aggregate, and coconut coir was evaluated in this study for its desorptive characteristics as a companion study of the corresponding adsorption process in an earlier publication. We conducted a screening of potential desorbing agents, batch desorption equilibrium and kinetic studies, and batch tests through 3 adsorption/desorption cycles. The desorbing agent screening revealed that hydrochloric acid has good potential for copper desorption. Equilibrium data fit the Freundlich isotherm, whereas kinetic data had high correlation with the Lagergren pseudo second-order model and revealed a rapid desorption reaction. Batch equilibrium data over 3 adsorption/desorption cycles showed that the coconut coir and media mixture were the most resilient, demonstrating they could be used through 3 or more adsorption/desorption cycles.

BACKGROUND AND OBJECTIVE: Metformin hydrochloride (MTF-HCl) is extensively recommended by physicians for the treatment of polycystic ovary syndrome (PCOS). Mechanistically, MTF-HCl activates AMP-dependent kinase-α (AMPK-α) pathway to decrease the glucose production, enhances fatty acid oxidation and elevates the uptake of glucose in tissues. However, despite favourable physicochemical properties, oral administration of MTF-HCl is associated with impaired bioavailability (50-60%), lactic-acidosis and frequent dosing (500mg 2-3 times a day) in PCOS that ultimately influence the patient compliance. Therefore, in present investigation, MTF-HCl loaded unmodified and cationic small unilamellar niosomes were separately amalgamated with thermosensitive gel (MTF-HCl-SUNs-Gel and MTF-HCl-C-SUNs-Gel) for the treatment of PCOS through vaginal route of administration.

To investigate the mechanism of Hg0 adsorption on α-Fe2O3 (001) surface in the presence of HCl, which was considered to be beneficial for Hg0 removal, theoretical calculations based on density functional theory as well as corresponding experiments were carried out. HCl adsorption was firstly performed on α-Fe2O3(001) surface, and the Hg0 adsorption on HCl-adsorbed α-Fe2O3(001) surface was subsequently researched, demonstrating that HCl dissociates on the surface of α-Fe2O3, improving the Hg0 adsorption reactivity. With further chlorination of α-Fe2O3(001) surface, the FeCl3 could be achieved and the adsorption energy of Hg0 on FeCl3 surface reaches -104.2 kJ/mol, belonging to strong chemisorption. Meanwhile, a group of designed experiments, including the Hg0 adsorption on HCl pre-adsorbed α-Fe2O3 as well as the co-adsorption of both gaseous components, were respectively performed to explore the pathways of Hg0 transformation. Combining computational and experimental results together, the Eley-Rideal mechanism with HCl pre-adsorption can be determined.