Electrochemical Polishing of Selective Laser Melted Inconel 718

Additive manufacturing (AM) has gained prominence in the field of manufacturing and is becoming a strong competition to conventional manufacturing technologies such as casting, forming etc. It is used for manufacturing of critical metallic parts for aerospace and automotive industries. Inconel 718, a Ni-Cr-Fe based superalloy, has been extensively used in extreme environments such as nuclear, oil/gas, aircraft applications. Inconel powder can be consolidated by using selective laser melting (SLM) process, which helps in preserving material properties and allows more design freedom. However, one of the drawbacks of additive manufacturing is the rough surface of the produced parts. This study aims to improve the surface finish of Inconel parts manufactured by SLM using electrochemical polishing (ECP) process. This study also compares the SLM parts with the extruded parts of the same metal polished by ECP. The parts are first hand-ground and then polished by ECP process. Inconel 718 is used as workpiece material, titanium rod is used as a tool, and a commercial acid-based electrolyte is used for running experiments. SEM studies are performed on the parts for analysis of results. Pulsed direct currents with varying duty cycles are used to study the effect of off-time during polishing process. Results show that the higher current values are desirable for extruded Inconel parts resulting in shinier surfaces, whereas for SLM manufactured Inconel parts, a very high current can lead to deterioration in surface properties due to presence of non-conductive particles. Successful polishing reduces surface roughness to a sub-micron value (<1 μm)

Antepartum posterior encephalopathy syndrome: a case study

Posterior reversible encephalopathy syndrome (PRES) is increasingly being recognised as a clinic-neuro-radiological complication of eclampsia, with the availability of better imaging techniques. Preeclampsia and eclampsia continues to be one of the leading cause of both maternal and foetal morbidity and mortality worldwide. PRES is a diagnostic and therapeutic challenge when it develops in a case of preeclampsia. Reported here a case of 21 years old primi gravida, presenting in emergency OPD with 30 weeks pregnancy, history of seizures and in unconscious state. She was diagnosed to have PRES by imaging. PRES is associated with various clinical conditions i.e. hypertensive encephalopathy, renal failure, auto immune disorders and treatment with cytotoxic medication and presence with headache, encephalopathy, seizures, cortical visual disturbances or blindness. Early recognition of the condition with prompt management can prevent permanent neurological damage antihypertensive, control of seizures and anti-oedema measures are the main stay of the treatment as prompt control of BP will cause reversal of the syndrome. Clinical improvement with prompt resolution of the neurological deficit in the reported case highlights the importance of early suspicion, diagnosis and management of PRES in order to prevent short and long term neurological damage.

Investigating the seasonal variability in source contribution to PM(2.5)and PM(10)using different receptor models during 2013-2016 in Delhi, India

The present work deals with the seasonal variations in the contribution of sources to PM(2.5)and PM(10)in Delhi, India. Samples of PM(2.5)and PM(10)were collected from January 2013 to December 2016 at an urban site of Delhi, India, and analyzed to evaluate their chemical components [organic carbon (OC), elemental carbon (EC), water-soluble inorganic components (WSICs), and major and trace elements]. The average concentrations of PM(2.5)and PM(10)were 131 +/- 79 mu g m(-3)and 238 +/- 106 mu g m(-3), respectively during the entire sampling period. The analyzed and seasonally segregated data sets of both PM(2.5)and PM(10)were used as input in the three different receptor models, i.e., principal component analysis-absolute principal component score (PCA-APCS), UNMIX, and positive matrix factorization (PMF), to achieve conjointly corroborated results. The present study deals with the implementation and comparison of results of three different multivariate receptor models (PCA-APCS, UNMIX, and PMF) on the same data sets that allowed a better understanding of the probable sources of PM(2.5)and PM(10)as well as the comportment of these sources with respect to different seasons. PCA-APCS, UNMIX, and PMF extracted similar sources but in different contributions to PM(2.5)and PM10. All the three models extracted 7 similar sources while mutually confirmed the 4 major sources over Delhi, i.e., secondary aerosols, vehicular emissions, biomass burning, and soil dust, although the contribution of these sources varies seasonally. PCA-APCS and UNMIX analysis identified a less number of sources (besides mixed type) as compared to the PMF, which may cause erroneous interpretation of seasonal implications on source contribution to the PM mass concentration

Magnetic resonance imaging in pelvic endometriosis with surgical correlation: a pictorial review

Endometriosis is a common gynaecological problem, primarily affecting women of reproductive age. Most common site of endometriosis is ovaries. Extra ovarian sites include uterine ligaments, fallopian tubes, rectosigmoid, laparotomy or C-section scars and urinary bladder. There can be formation of ovarian endometriotic cysts or deep infiltrating endometriosis. The role of MRI is in the evaluation of deep or more complex disease as it enables a large field of view, superior contrast resolution and multiplanar capabilities as compared to ultrasound. In this article, we are describing MRI imaging appearances of endometriomas and deep pelvic endometriosis in the form of a pictorial essay

Prevalence of hypertension and its association with anthropometric parameters in adult population of Raipur city, Chhattisgarh, India

Background: Obesity is now an important emerging public health problem in India. It is one of the major risk factor for hypertension. Overweight persons have two to six fold increase in the risk of developing hypertension. This study was carried out with objective to find out prevalence of Hypertension and assess its association with four obesity-related indices- body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR).Methods: A cross-sectional community-based study was done among 640 study subjects of age group 25-59 years during July 2015 to June 2016. Multi stage random sampling method was used. Data collection was done using WHO STEPS instrument V 3.1. Privacy and confidentiality of data was maintained. Data was entered in the Microsoft excel, collected data was checked for its completeness and correctness before data analysis with the help of PSPP software.Results: Prevalence of hypertension among study subjects was found to be 22.19% (142 out of 640).With respect to body mass index, waist circumference, waist hip ratio and waist height ratio, 4.38%, 64.35%, 85.33%, 76.2% were found to be obese respectively. Hypertension was strongly associated with BMI (p<0.001), waist circumference (p<0.001), waist hip ratio (p<0.05), waist height ratio (p<0.05). Out of the four anthropometric variables waist hip ratio (WHR) was most strongly associated with hypertension (β=420.236, p=0.007).Conclusions: The study shows a rising burden of hypertension among study population. As WHR is the best indicator for measuring obesity, so measurement of WHR should be made compulsory in healthy life style clinics along with other parameters

Cultural Differences between Indian & US College Students on Attitudes toward Celebrities & the Love Attitudes Scale

We administered the Celebrity Attitude Scale (CAS) and the Love Attitudes Scale (LAS) to 59 university students in the United States and 61university students in India. Students from both countries who scored as dependent, needy lovers tended to also score high on all three subscales of the CAS, suggesting that some persons with failed personal relationships may become attracted to parasocial relationships with celebrities as a safe alternative.  Students from the U.S. who tended to view love as a game, as measured by the LAS game-playing subscale, also tended to strongly admire their favorite celebrity in an intense personal way. Differences and similarities between the Indian and American samples on the CAS and LAS were discussed. The study provides additional evidence that the two problematic levels of the CAS are associated with undesirable attitudes and behaviors

BLOOM: A 176B-Parameter Open-Access Multilingual Language Model

Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License

Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass $M>70$ $M_\odot$) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities $0 < e \leq 0.3$ at $0.33$ Gpc$^{-3}$ yr$^{-1}$ at 90\% confidence level.Comment: 24 pages, 5 figure

Open data from the third observing run of LIGO, Virgo, KAGRA and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in April of 2019 and lasting six months, O3b starting in November of 2019 and lasting five months, and O3GK starting in April of 2020 and lasting 2 weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main dataset, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages.Comment: 27 pages, 3 figure

Search for continuous gravitational wave emission from the Milky Way center in O3 LIGO--Virgo data

We present a directed search for continuous gravitational wave (CW) signals emitted by spinning neutron stars located in the inner parsecs of the Galactic Center (GC). Compelling evidence for the presence of a numerous population of neutron stars has been reported in the literature, turning this region into a very interesting place to look for CWs. In this search, data from the full O3 LIGO--Virgo run in the detector frequency band $[10,2000]\rm~Hz$ have been used. No significant detection was found and 95$\%$ confidence level upper limits on the signal strain amplitude were computed, over the full search band, with the deepest limit of about $7.6\times 10^{-26}$ at $\simeq 142\rm~Hz$. These results are significantly more constraining than those reported in previous searches. We use these limits to put constraints on the fiducial neutron star ellipticity and r-mode amplitude. These limits can be also translated into constraints in the black hole mass -- boson mass plane for a hypothetical population of boson clouds around spinning black holes located in the GC.Comment: 25 pages, 5 figure