Modeling and optimization of EDM machined AZ-91 Mg alloy using ANFIS-VIKOR method

In this paper, machining of AZ-91 magnesium alloy was performed in EDM using different tool electrode (Cu, CuW and graphite). To perform experiments, Taguchi L18 design of experiments was used to reduce experimental runs. EDM process parameters viz. polarity, current (Ip), pulse-on-time (Ton), pulse-off-time (Toff), and tool electrode material were considered in experimental design to measure the responses (MRR, Ra). Multi-input-single-output adaptive neuro fuzzy inference system (ANFIS) model was developed to predict responses, and predicted results were found in good agreement with the experimental results. Maximum MRR (0.089 g/min) was found at positive polarity, Ip-5 A, Ton-50 μs, Toff - 30 μs, and Cu tool, and minimum Ra (0.08 μm) was at parameters positive polarity, Ip-4 A, Ton-30 μs, Toff -20 μs, and Cu tool. Relative errors between experiential results and ANFIS predicted results were 1.17 % for MRR, and 2.20 % for Ra. Multi response optimization ANFIS-VIKOR method was successfully developed and gave compromise solution for MRR and Ra corresponding to minimum ANFIS-VIKOR index (Qi). A factor level analysis was performed to evaluate optimal factor combination for ANFIS-VIKOR index, and it shows that current (Ip) have a significant effect.

Ionization wave propagation in a long capillary tube in the presence of a low-current glow discharge in low-pressure helium

The experimental results on the study of the positive ionization wave propagating along a long capillary tube are presented. The ionization wave was initiated by eigther high-voltage pulse of positive polarity applied over a long capillary tube with helium or high-voltage pulse applied over the same tube but in presence of low-current glow discharge. The spreading of this wave is accompanied by the surface charge deposition. The usage of the fine-sectioned outer electrode allows one to find out the features of the positive ionization wave in both cases (with or without low-current discharge).

Akt Phosphorylation of Hepatitis C Virus NS5B Regulates Polymerase Activity and Hepatitis C Virus Infection

Hepatitis C virus (HCV) is a single-stranded RNA virus of positive polarity [ssRNA(+)] that replicates its genome through the activity of one of its proteins, called NS5B. This viral protein is responsible for copying the positive-polarity RNA genome into a negative-polarity RNA strand, which will be the template for new positive-polarity RNA genomes. The NS5B protein is phosphorylated by cellular kinases, including Akt. In this work, we have identified several amino acids of NS5B that are phosphorylated by Akt, with positions S27, T53, T267, and S282 giving the most robust results. Site-directed mutagenesis of these residues to mimic (Glu mutants) or prevent (Ala mutants) their phosphorylation resulted in a reduced NS5B in vitro RNA polymerase activity, except for the T267E mutant, the only non-conserved position of all those that are phosphorylated. In addition, in vitro transcribed RNAs derived from HCV complete infectious clones carrying mutations T53E/A and S282E/A were transfected in Huh-7.5 permissive cells, and supernatant viral titers were measured at 6 and 15 days post-transfection. No virus was rescued from the mutants except for T53A at 15 days post-transfection whose viral titer was statistically lower as compared to the wild type. Therefore, phosphorylation of NS5B by cellular kinases is a mechanism of viral polymerase inactivation. Whether this inactivation is a consequence of interaction with cellular kinases or a way to generate inactive NS5B that may have other functions are questions that need further experimental work.

Impacts of Antarctic Sea Ice, AMV and IPO on Extratropical Southern Hemisphere Climate: A Modeling Study

Some studies have discussed potential influences of Antarctic sea ice anomalies, Atlantic Multi-decadal Variability (AMV), and Interdecadal Pacific Oscillation (IPO) on the Southern Hemisphere (SH) climate, individually. However, it is not clear how different combinations of them influence the extratropical SH climate. Here we select three different combinations of strong anomalies in Antarctic sea ice (SI), AMV and/or IPO identified from observations, and investigate their influence on the winter extratropical SH climate using the Community Atmosphere Model. The model results show that atmospheric responses vary with different combinations. When both SI and AMV are in strong positive polarity (SI + AMV), the polar jet shifts equatorward while the subtropical jet shifts poleward, the amplitude of zonal wave number 1 is reduced in high-latitudes with minimal changes in wave number 2, and a north-south circulation dipole occurs in both the Atlantic and Pacific. Different from SI + AMV, when SI is in strong positive polarity and IPO is in strong negative polarity (SI-IPO), the reduction of wave number 1 is dramatically increased, accompanied by remarkably increased wave number 2. The north-south circulation dipole only occurs in the Pacific and is confined to the central and eastern Pacific, whereas the Atlantic is dominated by anomalously anticyclonic circulation. Together, SI + AMV-IPO leads to the largest reduction of wave number 1 in high-latitudes and subtropics, the strongest north-south circulation dipole in the Pacific as well as the Amundsen Sea Low. As a result, the three combinations produce different patterns of surface temperature and precipitation anomalies over Antarctica, Australia and South America.

Sentiment Analysis of Imran Khan’s Tweets

In the recent past, sentiment analysis has been an area of interests of psychologists, sociologists, neurologists, computer scientists, and linguists including corpus linguists and computational linguists. Interdisciplinary approaches to researching various issues especially the analysis of social media websites such as Facebook, Twitter, and Instagram are becoming popular nowadays. The availability of data on social media has made it easier to analyse the opinion or sentiments of its users. Analysis of these sentiments could reveal the face of users and it could help in various decision-making processes. Sentiment analysis is a system of knowing polarity (positive, negative, and neutral) in discourse. Moreover, sentiments can enable and disable certain functions of discourse and can divert the attention of the audience from important to a less important issue or otherwise, hence, there is a need to analyse the sentiments. In this research, sentiments (Polarity) of Imran Khan’s tweets are analysed with the help of R studio. Data for this study is collected from Imran Khan’s one-year’s tweets, tweeted from 1st January 2018 to 20th November 2018. Later we saved the data in. csv files. The results of the polarity check revealed that he has used all three types of sentiments that is positive, negative, and neutral. However, he mostly used neutral or free polarity items (FPIs) that is 67.41% in his tweets. Among positive and negative polarity items the number of negative polarity items (NPIs) is higher that is 23.21% as compared to positive polarity items (PPIs) which are only 9.40%. The manual analysis of results revealed that only software is not enough and there is a need to check the accuracy of the results manually. The use of negative polarity/negative face reveals that he tries to be independent and autonomous in his decisions (Goffman, 1967). The use of positive polarity items shows he tries to show his positive face to others. Moreover, sentiment analysis demonstrates the presence of themes propagated through the use of various lexical items.

The Interpersonal Meaning on the Covid-19 Vaccination News in Indonesia: A Systemic Functional Linguistics Study

Some media use interesting titles in their news. Like the online media m.republika.co.id which uses the verbs "meminta (ask)" and "diminta (requested)" in its reporting. This study will reveal the interpersonal meaning of m.republika.co.id entitled "Jokowi Minta Daerah Kawal Vaksinasi Covid-19". This research is descriptive-qualitative research that will describe the findings and describe the status, affect, and contacts that are part of the focus of this research. The methods and techniques used in this study are data analysis methods proposed by Spradley (1980) namely domain, taxonomy, and componential analysis. The results of the study indicate that m.republika.co.id positions itself as a party that provides information and places readers as members of the academic community who are expected to also have an interest in the information. This is evidenced by the dominance of the proposition of the proposal, the dominance of positive polarity, the dominance of congruent lexis rather than incongruent, and also the use of a complex clause system that describes the closeness of the distance between the writer and the reader.

On the Acquisition of Polarity Items: 11- to 12-Year-Olds' Comprehension of German NPIs and PPIs

Existing work on the acquisition of polarity-sensitive expressions (PSIs) suggests that children show an early sensitivity to the restricted distribution of negative polarity items (NPIs), but may be delayed in the acquisition of positive polarity items (PPIs). However, past studies primarily targeted PSIs that are highly frequent in children’s language input. In this paper, we report an experimental investigation on children’s comprehension of two NPIs and two PPIs in German. Based on corpus data indicating that the four tested PSIs are present in child-directed speech but rare in young children’s utterances, we conducted an auditory rating task with adults and 11- to 12-year-old children. The results demonstrate that, even at 11–12 years of age, children do not yet show a completely target-like comprehension of the investigated PSIs. While they are adult-like in their responses to one of the tested NPIs, their responses did not demonstrate a categorical distinction between licensed and unlicensed PSI uses for the other tested expressions. The effect was led by a higher acceptance of sentences containing unlicensed PSIs, indicating a lack of awareness for their distributional restrictions. The results of our study pose new questions for the developmental time scale of the acquisition of polarity items.

The interpretation of disjunction in VP ellipsis: The case of Mandarin Chinese

It has long been noted that verb phrase (VP) ellipsis cancels the polarity sensitivity of the English Positive Polarity Items (PPIs). In recent work, it has been proposed that words for disjunction are governed by a parameter. On one value of the parameter, disjunction is a PPI for adult speakers of many languages including Mandarin Chinese. On the other value, disjunction is interpreted in situ. It has also been proposed that child language learners, across languages, initially interpret disjunction in situ, not as a PPI. Taken together, these proposals predict that child and adult speakers of Mandarin will assign the same interpretation to disjunction in sentences with VP ellipsis, but will assign a different interpretation in sentences without VP ellipsis. This study assessed these predictions. In sentences with a full VP, the adult participants analyzed disjunction as a PPI, but they interpreted disjunction in situ in sentences with VP ellipsis. The child participants interpreted disjunction in situ in sentences of both kinds. Together, the findings support the recent proposal that disjunction is governed by a lexical parameter, with a default setting.