Combating viral contaminants in CHO cells by engineering innate immunity

Viral contamination in biopharmaceutical manufacturing can lead to shortages in the supply of critical therapeutics. To facilitate the protection of bioprocesses, we explored the basis for the susceptibility of CHO cells to RNA virus infection. Upon infection with certain ssRNA and dsRNA viruses, CHO cells fail to generate a significant interferon (IFN) response. Nonetheless, the downstream machinery for generating IFN responses and its antiviral activity is intact in these cells: treatment of cells with exogenously-added type I IFN or poly I:C prior to infection limited the cytopathic effect from Vesicular stomatitis virus (VSV), Encephalomyocarditis virus (EMCV), and Reovirus-3 virus (Reo-3) in a STAT1-dependent manner. To harness the intrinsic antiviral mechanism, we used RNA-Seq to identify two upstream repressors of STAT1: Gfi1 and Trim24. By knocking out these genes, the engineered CHO cells exhibited activation of cellular immune responses and increased resistance to the RNA viruses tested. Thus, omics-guided engineering of mammalian cell culture can be deployed to increase safety in biotherapeutic protein production among many other biomedical applications

Utilization of High Ash, Low Volatile Coking Coals of Jharia Coalfield, India for Coke Making

India is having limited resources of coking coal, an essential input for production of iron and steel especially through blast furnace route. The coking coal sources are presently from the lower seams of Jharia coalfield, which are high in ash content and low in volatile matter and difficult to wash. This paper describes the washability characteristics of a typical coking coal from the Eastern and Western Jharia coalfields aiming at 18% ash level in the clean coal mainly to meet the specifications of coke making for blast furnace use. Conventional float-and-sink testing was used to determine the yield of clean coal for the coarser fraction, while the coal fines was subjected to flotation. The theoretical recovery of clean coal for the coal tested from Eastern and Western Jharia coalfields are 27% and 19.7% at the stipulated ash content. The coking propensities and the petrographic analysis of the clean coal strongly support its use for coke making either directly or as a blend with imported coal

Application of Response Surface Methodology in Effective Recovery of Settling Pond Coal Fines by Froth Flotation

In this study, response surface methodology was successfully applied to investigate the operating conditions of the froth flotation process used to recover coking coal fines obtained from a settling pond. A quadratic model was developed to evaluate the variation of yield and the grade of clean-coal product with different test conditions. Thirteen experiments were carried out based on a central composite design technique. The analysis of variance was performed using design expert software to confirm the developed second-order model was statistically significant and adequate to represent the experimental observations. Using this technique, model coefficients, R2, , and F values, were determined to analyze the developed models. Surface plots showing the relationship between the responses, namely, wt % and ash %, with process parameters, and also plots between experimental versus the predicted responses from the models are presented

Studies on the Segregation of Minerals in Different Size and Gravity Fractions While Treating Indian Coal

Gondwana coal makes up to 98 per cent of the total reserves and 99 per cent of the production of coal in India. These coals are intimately mixed with mineral matter, causing a high level of impurities in the run-of –mine (ROM) coal. Beneficiation of high – ash non-coking coals of India has become the prerequisite for improving the overall economics and efficiency for downstream utilization industries. The association between specific mineral and organic constituents in a typical non-coking coal sample form the Eastern Coalfields, India was studied. For this, raw coals were fractionated by size and density and the variation of major minerals with respect to size and density was examined. Mineral species were identified by X-ray diffraction. The results showed that the concentration of quartz and kaolinite increases with increase of gravity of the coal while concentration of siderite is much lower size fractions of the coal

Effect of Washing High-Ash Indian Noncoking Coals on Combustion

Indian thermal coals are usually high-moisture, high-ash, and high-volatile subbituminous type coal and are difficult to wash. Beneficiation of high-ash thermal coals of India has become the prerequisite for improving the overall economics and efficiency of power generation. The article highlights the studies carried out on the cleaning potentialities of thermal coal samples collected from three major coalfields through washability investigations followed by the identification of the level of cleaning by linking with the burning behavior. Conventional float-sink testing was used to determine the washability characteristics, and based on the washability data, clean coal was generated at three different ash levels. Combustion studies of the raw and clean coal have been conducted in a Drop Tube Furnace basically to observe the change in the burning behavior with the level of cleaning. From the combustion behavior of the washed fraction, it was found that, for two coal samples, Burnout Efficiency (BE) has improved compared to that of the raw coal, while for another sample, a reverse trend was observed. The studies concluded that it is better to fix the level of washing a particular coal based on combustion properties of the clean coal rather than taking an arbitrary value

Laboratory and pilot plant flotation studies on settling pond coking coal fines and its utilization for metallurgical purposes

Most of the Indian coking coal washeries were installed during the period 1960-1980 where the design of the washery was based on relatively easy or moderately difficult washing coking coals, mined in the eastern and western part of Jharia coalfields. The coal fines below 0.5 mm were not processed and though enriched in vitrinite content, nowadays the fines cannot be mixed directly with clean coal due to their high ash content (more than 25%) and of high percentage of silica content. Due to an increase in opencast mechanized mining of coals, quality of the coal fines deteriorated and they need to be beneficiated before blending with the coarse coals. Some of the washeries installed fine coal treatment plants, but due to varied reasons these circuits were not operated as a result, huge quantity of unwashed coal fines is left as such and discharged to nearby ponds or lagoons, and in the process they had been accumulated in adjoining settling ponds causing environmental pollution and are being sold to domestic market for use in non-metallurgical purposes. The coking coal fines constitute vitrinite content, which is a vital ingredient for metallurgical purpose. Hence, if these coal fines are beneficiated, they may add to the overall quality of the clean coal. In this paper attempt has been made to beneficiate the accumulated coal fines through laboratory flotation tests vis-à-vis pilot plant studies to generate maximum amount of cleans from settling pond coal fines suitable as blend for metallurgical coke making

A Modified Godbert Apparatus for Determining Optimum Level of Beneficiation for Indian Non-Coking Coal for Power Generation

The characteristics of coal depends on different parameters like rank, moisture, mineral matter content, macerals composition, etc. The combined effect of these characteristics governs the combustion behavior of coal in the furnace. The Indian ROM coals contain higher inherent mineral matter and a majority of these coals are used for power generation without any beneficiation; even though the environmental gazette notification of the Govt. of India requires all coal suppliers to install coal washeries. Combustion behavior of coal is evaluated by one of the following techniques: i.e., TGA, drop tube furnace, fuel efficiency test rigs, etc.; however, all these following techniques are costly and time consuming. The Godbert apparatus, which is low-cost simple equipment, can be used to evaluate the combustion behavior of coals. The minimum ignition temperature (the lowest temperature at which an ignition/explosion is observed as a flame) was determined for the ROM coal and density separated/various ash-content fractions up to 700°C. The results indicated that the coal containing up to 58% ash showed good flame/burning behavior. This study should provide guidance to coal washery operators to determine at what ash level the coal should be washed so that it can give better combustion rather than taking the ash value of 34% set up by the Indian Government