Effect of Mechanical Alloying and Sintering Environment on the Crystallographic Evolution, Microstructure, Mechanical and Corrosion Properties of Porous Ti4Al4Co Alloy

Pradeep Singh,Vikas Shrivastava,I. B. Singh,D. P. Mondal 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Three group of porous Ti4Al4Co samples made of (i) unmilled powder and vacuum sintered (S1), (ii) milled powder andvacuum sintered (S2), and (iii) milled powder sintered in open atmosphere (S3) were prepared. Phase change, crystallite sizeand lattice strain variations due to powder milling and sintering were examined by SEM and XRD. To evaluate mechanicalproperty, alloy samples were subjected to the uniaxial compression test. For corrosion analysis, Tafel plot was plotted usingelectrochemical corrosion system in simulated body fluid (SBF) as electrolytic medium. From the obtained results, it wasfound that significant microstructural transformation takes place due to milling and change in sintering atmosphere. SampleS1possessed 139 MPa compressive strength, which was about 48% and 76% higher than samples S2and S3respectively. Corrosion current density for S3was found as 5.5 ± 0.3 μA/cm2 which is 7 and 12 times lower than S2and S1samples.

The Form and Function of Conjunct Verb Construction in Hindi

Pradeep Kumar Das 한국외국어대학교 인도연구소 2009 남아시아연구 Vol.15 No.1

The present paper examines the form and function of one of the complex predicates that is known as Conjunct verb construction in Hindi. The conjunct verb is a kind of predicate that is formed with either a noun or an adjective and a verb (the light verb). The conjunct verbs that are formed with an adjective and a verb do not pose any problem for the theoreticians. However, the function of the conjunct verb that has a noun and verb is descriptively and theoretically puzzling. The nominal host which comes to form a complex predicate with the light verb has two functions. In one, it not only helps the verb to become complex, but also controls agreement when other noun phrases are overtly case marked, but in other case, it just remains passively in the verb phrase and even when it is the only noun phrase with no overt case marking, it does not show any agreement with the verb. The paper presents this puzzling behaviour of the conjunct verb and its nominal host in two sets A and B respectively and finally evokes the case theory of Chomsky and Panini to give a solution of the problem. The solution is of course a hypothesis but it seems to have explanatory power for the conjunct verb construction.

Potential impact of climate change on the species richness of subalpine plant species in the mountain national parks of South Korea

Pradeep Adhikari,신만석,전자영,김현우,홍승범,서창완 한국생태학회 2018 Journal of Ecology and Environment Vol.42 No.4

Background: Subalpine ecosystems at high altitudes and latitudes are particularly sensitive to climate change. In South Korea, the prediction of the species richness of subalpine plant species under future climate change is not well studied. Thus, this study aims to assess the potential impact of climate change on species richness of subalpine plant species (14 species) in the 17 mountain national parks (MNPs) of South Korea under climate change scenarios’ representative concentration pathways (RCP) 4.5 and RCP 8.5 using maximum entropy (MaxEnt) and Migclim for the years 2050 and 2070. Results: Altogether, 723 species occurrence points of 14 species and six selected variables were used in modeling. The models developed for all species showed excellent performance (AUC > 0.89 and TSS > 0.70). The results predicted a significant loss of species richness in all MNPs. Under RCP 4.5, the range of reduction was predicted to be 15.38–94.02% by 2050 and 21.42–96.64% by 2070. Similarly, under RCP 8.5, it will decline 15.38–97.9% by 2050 and 23.07–100% by 2070. The reduction was relatively high in the MNPs located in the central regions (Songnisan and Gyeryongsan), eastern region (Juwangsan), and southern regions (Mudeungsan, Wolchulsan, Hallasan, and Jirisan) compared to the northern and northeastern regions (Odaesan, Seoraksan, Chiaksan, and Taebaeksan). Conclusions: This result indicates that the MNPs at low altitudes and latitudes have a large effect on the climate change in subalpine plant species. This study suggested that subalpine species are highly threatened due to climate change and that immediate actions are required to conserve subalpine species and to minimize the effect of climate change.

Electrical Spin Injection and Detection in Copper with Perpendicularly Magnetized [CoSiB/Pt] Multilayer Electrodes

Pradeep Raj Sharma,Young Gwang Kim,Tae Wan Kim,Hwayong Noh 한국자기학회 2018 한국자기학회 학술연구발표회 논문개요집 Vol.2018 No.11

Analytical and numerical studies on hollow core slabs strengthened with hybrid FRP and overlay techniques

Pradeep Kankeri,S. Suriya Prakash,Sameer Kumar Sarma Pachalla 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.5

The objective of this study is to understand the behaviour of hollow core slabs strengthened with FRP and hybrid techniques through numerical and analytical studies. Different strengthening techniques considered in this study are (i) External Bonding (EB) of Carbon Fiber Reinforced Polymer (CFRP) laminates, (ii) Near Surface Mounting (NSM) of CFRP laminates, (iii) Bonded Overlay (BO) using concrete layer, and (iv) hybrid strengthening which is a combination of bonded overlay and NSM or EB. In the numerical studies, three-dimensional Finite Element (FE) models of hollow core slabs were developed considering material and geometrical nonlinearities, and a phased nonlinear analysis was carried out. The analytical calculations were carried out using Response-2000 program which is based on Modified Compression Field Theory (MCFT). Both the numerical and analytical models predicted the behaviour in agreement with experimental results. Parametric studies indicated that increase in the bonded overlay thickness increases the peak load capacity without reducing the displacement ductility. The increase in FRP strengthening ratio increased the capacity but reduced the displacement ductility. The hybrid strengthening technique was found to increase the capacity of the hollow core slabs by more than 100% without compromise in ductility when compared to their individual strengthening schemes.

Geomorphic evidences of active faulting in the northwestern Ganga Plain, India: implications for the impact of basement structures

Pradeep K. Goswami 한국지질과학협의회 2012 Geosciences Journal Vol.16 No.3

Active faults of the densely forest covered northwestern part of the Ganga Plain have been identified and mapped on the basis of geomorphic signatures as observed in the Digital Terrain Models, remote sensing data and field. The structural limit between the Ganga Plain and Himalaya in the north is defined by the Himalayan Frontal thrust (HFT), which is a direct consequence of the compression resulting from collision of Indian and Eurasian plates and present day principal displacement zone between them. This HFT is offset by dip-slip, oblique-slip and strike-slip faults, extending transversely through the Ganga Basin. Analysis of these faults in conjunction with the available geological and subsurface geophysical data reveals that the development of some of these transverse faults is localized along basement highs of the basin. These faults tear asunder the Himalayan thrust sheets and may have developed during the collision either because of a rheological contrast between the basement highs and adjacent sedimentary fill, or a lateral change in cover thickness across the basement highs, or due to the reactivation of pre-existing basement faults. The continuous pressing and prodding by these basement highs have caused bending of the strata, leading to conspicuous bending of the mountain belt. One of the tear faults has formed as a result of the along-strike propagation of an oblique ramp of the Main Boundary thrust (MBT), along which the Lesser Himalayan succession is thrust over the Siwalik. In addition to these tear faults,some transverse faults of limited lateral extent, cutting through the mountain belt and basin, may have formed during the last event of deformation along the HFT zone. Active faults of the densely forest covered northwestern part of the Ganga Plain have been identified and mapped on the basis of geomorphic signatures as observed in the Digital Terrain Models, remote sensing data and field. The structural limit between the Ganga Plain and Himalaya in the north is defined by the Himalayan Frontal thrust (HFT), which is a direct consequence of the compression resulting from collision of Indian and Eurasian plates and present day principal displacement zone between them. This HFT is offset by dip-slip, oblique-slip and strike-slip faults, extending transversely through the Ganga Basin. Analysis of these faults in conjunction with the available geological and subsurface geophysical data reveals that the development of some of these transverse faults is localized along basement highs of the basin. These faults tear asunder the Himalayan thrust sheets and may have developed during the collision either because of a rheological contrast between the basement highs and adjacent sedimentary fill, or a lateral change in cover thickness across the basement highs, or due to the reactivation of pre-existing basement faults. The continuous pressing and prodding by these basement highs have caused bending of the strata, leading to conspicuous bending of the mountain belt. One of the tear faults has formed as a result of the along-strike propagation of an oblique ramp of the Main Boundary thrust (MBT), along which the Lesser Himalayan succession is thrust over the Siwalik. In addition to these tear faults,some transverse faults of limited lateral extent, cutting through the mountain belt and basin, may have formed during the last event of deformation along the HFT zone.

Buckwheat noodles: processing and quality enhancement

Pradeep Puligundla,임석원 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.12

In recent years, buckwheat noodles have gainedincreased importance because of their functional properties. These qualities are attributed to the abundance ofbioactive compounds (e.g., rutin, quercetin) and nutraceuticals(e.g., B vitamins, unsaturated fatty acids). Buckwheatnoodle consumption has been shown to be associated withimproved metabolic health. Buckwheat flour exhibitsproperties similar to those of common cereal flours in foodprocessing, but devoid of gluten. However, the maintenanceof good textural properties and high sensoryacceptability are key challenges in the development ofgluten-free products, and these limitations preventedwidespread application of buckwheat in the food industry. Nevertheless, continuous technological developmentsrelated to raw materials processing, noodle processing, andnoodle quality enhancement have contributed to thegrowing popularity and acceptability of buckwheat noodlesin recent times. These improvements could render buckwheatnoodles a healthy gluten-free alternative to wheatnoodles.

Recent advances in biotechnological valorization of brewers' spent grain

Pradeep Puligundla,목철균 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.3

Brewers’ spent grain (BSG) is the most abundantby-product of beer-brewing. BSG is rich in nutrients suchas protein, fiber, minerals, and vitamins, and therefore it isconventionally used as low-cost animal feed. On the otherhand, alternative utilization of BSG has gained increasedattention during recent years due to technological progressin its processing and the emergence of the concept of circulareconomy. The valorization of BSG through biotechnologicalapproaches is environmentally friendly andsustainable. This review was focused on recent advancementsin the conversion of BSG into value-added products,including bioenergy (ethanol, butanol, hydrogen, biodiesel,and biogas), organic acids, enzymes, xylitol, oligosaccharides,and single cell protein, via biotechnologicalapproaches. In addition, the potential applications of BSGas immobilization matrices in bioprocesses have beenreviewed.

Pulsed electric field (PEF) technology for microbial inactivation in low-alcohol red winePulsed electric field (PEF) technology for microbial inactivation in low-alcohol red wine

Pradeep Puligundla,변유량,목철균 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.6

The decontamination of spoilage-related microbes in low-alcohol red wine was performed using a serial multiple electrode pulsed electric field (PEF) treatment system. The system consisted of seven electrodes connected in series, and it has been designed to produce square-wave high-voltage pulses of 1 ls duration at various electric field strengths and frequencies for decontamination. The initial counts of aerobic bacteria, yeast and lactic acid bacteria (spoilage-associated microbes) in the wine were 5.56, 5.61 and 5.22 log CFU/mL, respectively. The pattern of decontamination of the spoilage microorganisms followed first-order kinetics and the decontamination effect increased as the field strength and frequency increases. DHz and DPEF values were inversely related to the electric field strength of the PEF treatment. The yeast exhibited relatively low DPEF-value than the aerobic and lactic acid bacteria. The lowest ZPEF-value was observed for the lactic acid bacteria (24.6 kV/cm) among the spoilage microbes.

Seasonal and altitudinal variation in roe deer (Capreolus pygargus tianschanicus) diet on Jeju Island, South Korea

Pradeep Adhikari,박선미,김태욱,이준원,김가람,한상현,오홍식 국립중앙과학관 2016 Journal of Asia-Pacific Biodiversity Vol.9 No.4

In order to understand the feeding ecology and dietary differences of roe deer (Capreolus pygargus tianschanicus) in different seasons and altitudes, this study was carried out at three altitudinal sites(Songdang 250-270 m above sea level (ASL), Aradong 330-370 m ASL, Mt. Hallasan 1100 m ASL) on Jeju Island, South Korea. Altogether, 205 plants taxa of six categories of foods (forbs-climbers, graminoids, trees, shrubs, conifers, and ferns) were identified using morphological and molecular analyses. The highest number of dietary plants was found in summer (93 taxa) and at Aradong (124 taxa) and lowest at Songdang (71 taxa) and in winter (51 taxa). Food categories were significantly different among the seasons (F ¼ 15.646, p < 0.05) and altitudinal sites (F ¼ 3.941, p < 0.05). This study revealed that dietary selectivity of roe deer shifted with seasonal and altitudinal variations and preferred to the nutritive and low fibers food.