Depolymerization of coal increases the tar yield in coal pyrolysis and enhances the thermoplasticity of the coal, which makes coal more favorable for producing coke and other value-added products ...like graphite electrodes, carbon fiber, aromatic chemicals, etc. In this study, the authors have proposed a novel coal depolymerization method that combines the oxidation reactions by molecular oxygen and the following reduction reactions by the coexisting gaseous formic acid to upgrade a bituminous coal at 90–150 °C under atmospheric pressure. The softening and melting performance of the treated coals was enhanced when oxygen and formic acid coexisted in gas phase at 90–130 °C. The amount of low-molecular-weight compounds in the coal treated at 90 °C in air containing formic acid vapor significantly increased by 29.0% of the amount of low-molecular-weight compounds in the raw coal measured by the solvent extraction method. Thus, the authors have succeeded in depolymerizing coal by the treatment under mild conditions, which is expected to contribute to coal’s efficient utilization such as increasing the coal extracts and tar yield in the extraction and pyrolysis process, upgrading coal to be more suitable for the raw materials of coke, etc.
Mineral components bonded to organic parts in some Indonesian and Chinese coals were characterized by solid-state
29Si and
27Al NMR, inductively coupled plasma emission spectroscopy, and X-ray ...fluorescence before and after high temperature solvent extraction and acid treatments. In lower ranking coals such as South Banko and Berau coals, it was found that organically bonded Si species existed as siloxane-type from the solid-state
29Si NMR analyses. It was also found that some of aluminosilicates species were extracted by mild acid treatments with 2
M CH
3COOH or HCl solution even at room temperature. Solvent extraction using
N-methylpyrrolidinone (NMP) at 350
°C or with 1-methylnaphthalene(1-MN) at 360
°C was very effective for the production of coal extract (so-called hyper-coal: HPC) with high yields of ca. 60% and extremely low ash contents of ca. 200
ppm. It is noted that some organically associated Si, Al, Ca and Fe species still remained in the coal extract, especially siloxane-type Si species were concentrated in the extracts obtained from the lower rank coals. The same tendency was also observed for the higher rank coals such as Enshu and Nantun coals, although the contents of such organically associated minerals were lower than those of the lower rank coals.
In microscopic testicular sperm extraction (mTESE) for nonobstructive azoospermia (NOA), sperm can be recovered relatively easily in some cases, and mTESE may be retrospectively considered excessive. ...However, mTESE is routinely performed in the majority of NOA patients because of the difficulty in predicting tissue status. A minimally invasive and comprehensive sperm retrieval method that allows on-the-spot tissue assessment is needed. We have developed and evaluated a novel sperm retrieval technique for NOA called micromapping testicular sperm extraction (MMTSE).
MMTSE involves dividing the testis into four sections and making multiple small needle holes in the tunica albuginea to extract seminiferous tubules and retrieve sperm. The sperm-positive group by MMTSE (Group I) underwent additional tissue collection (ATC) via a small incision, whereas the sperm-negative group by MMTSE (Group 0) underwent mTESE.
In total, 40 NOA participants underwent MMTSE. Group I included 15 patients and Group 0 included 25 patients. In Group 1, sperm were recovered from all patients by ATC. In Group 0, sperm were recovered in 4 of 25 cases using mTESE.
MMTSE shows promise as a simple method that comprehensively searches testicular tissue and retrieves sperm using an appropriate method while minimizing patient burden.
A novel process to produce ash-free coal, called Hyper-Coal (HPC), has been developed based on the coal liquefaction with organic solvent extraction. Seventy wt% of combustible contents can be ...extracted from raw coal via the dissolution in 1-methylnaphthalen at 633K, reducing the ash and alkali contents to less than 1000 and 0.5ppm, respectively. This process is also a promising approach to separate toxic trace elements from fuel constituent in coal before its combustion. Mercury is one of the toxic trace elements of growing concern, because mercury emission from a coal combustion process to the atmosphere has been becoming a serious problem in the coal use all over the world. Therefore, in this study, various intermediate products such as coal–organic solvent slurry were sampled from the HPC manufacturing process, and analyzed for mercury contents to investigate the mass balance and the distribution behavior of mercury in the process. As a result, it was found that a large portion of the mercury was separated from fuel constituents and recovered as a dissolved matter in the solvent. This dissolved mercury, however, built up in the total distribution behavior of mercury in the HPC manufacturing process again because the solvent was recycled for the coal extraction process without any cleanup treatment this time. Nevertheless, the mercury distributed into the HPC was lowered to be 20% or less of the total found in raw coal.
Abstract There have been 60 births after transplantation of cryopreserved ovarian tissue: 58 using the slow freezing method, and two using the vitrification method. DMSO and EG are widely used as ...cryoprotectants. However DMSO is a known epimutagen, and EG has been reported to be toxic in high concentrations. In this study, we measured residual DMSO and EG in ovarian tissue after vitrification and slow freezing. Cryoprotectants remained at a high concentration in the vitrified/warmed ovarian tissue just before transplantation (DMSO: 9.8mg/g, EG: 9.8mg/g). We must consider the impact of the cryoprotectants on the mother and the baby.
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