16 research outputs found
Regulating the Coordination Environment of Single-Atom Catalysts Anchored on Thiophene Linked Porphyrin for an Efficient Nitrogen Reduction Reaction
No full textThe electrochemical nitrogen reduction reaction (NRR)
offers a
promising strategy to resolve high energy consumption in the nitrogen
industry. Recently, the regulation of the electronic structure of
single-atom catalysts (SACs) by adjusting their coordination environment
has emerged as a rather promising strategy to further enhance their
electrocatalytic activity. Herein, we design novel SACs supported
by thiophene-linked porphyrin (TM–N4/TP and TM–N4‑xBx/TP,
where TM = Sc to Au) as potential NRR catalysts using density functional
theory calculations. Among these catalysts, TM–N4/TP (TM = Ti, Nb, Mo, Ta, W, and Re) and TM–N4/TP
with a water bilayer (TM = Nb, Mo, W, and Re) show excellent activity
(low limiting potential) but low selectivity. Encouragingly, we find
that Mo–N3B/TP, Mo–N2B2-2/TP, W–N3B/TP, W–N2B2-2/TP, Re–N3B/TP, Re–N2B2-2/TP, and Re–N2B2-1/TP serve
as the most efficient NRR electrocatalysts, as they present stability,
superior activity, better selectivity with low limiting potentials
(−0.18 ∼ −0.90 V), and high Faradaic efficiencies
(>99.80%). Based on microkinetic modeling, kinetic analysis of
the
NRR is performed and shows that the Re–N2B2-1/TP catalyst is more efficient for NH3 formation. Additionally,
multiple-level descriptors provide insight into the origin of NRR
activity and enable fast prescreening among numerous candidates. This
work provides a new perspective to design highly efficient catalysts
for the NRR under ambient conditions
A Phantasmagoria of human relationships: Pursuit of Identity
No full textA series of events distorts in the human relationship, marriage life and search the real meaning of life in the modern culture. Anita Nair’s Lessons in Forgetting (2010) reflects the real side of human relationships between man and women after marriage and impact of culture understood by the words of the characters throughout novels. Searching the real meaning for life and happiness of the main two characters in the novel are portrayed in the way of factual image in the society. The author shows the impact of the common customs of the culture on the characters throughout the novel.  
Prenatal testosterone-induced fetal growth restriction is associated with down-regulation of rat placental amino acid transport
No full textAbstract Background Exposure of pregnant mothers to elevated concentrations of circulating testosterone levels is associated with fetal growth restriction and delivery of small-for-gestational-age babies. We examined whether maternal testosterone crosses the placenta to directly suppress fetal growth or if it modifies placental function to reduce the capacity for transport of nutrients to the fetus. Methods Pregnant rats were exposed to testosterone propionate (TP; 0.5 mg/kg) by daily subcutaneous injection from gestational days (GD) 15-19. Maternal and fetal testosterone levels, placental nutrient transport activity and expression of transporters and birth weight of pups and their anogenital distances were determined. Results This dose of TP doubled maternal testosterone levels but had no effect on fetal testosterone levels. Maternal daily weight gain was significantly lower only on GD 19 in TP treated dams compared to controls. Placental weight and birth weight of pups were significantly reduced, but the anogenital distance of pups were unaffected by TP treatment. Maternal plasma amino acids concentrations were altered following testosterone exposure, with decreases in glutamine, glycine, tyrosine, serine, proline, and hydroxyproline and increases in asparagine, isoleucine, leucine, lysine, histidine and arginine. In the TP dams, placental system A amino acid transport activity was significantly reduced while placental glucose transport capacity was unaffected. Decreased expression of mRNA and protein levels of slc38a2/Snat2, an amino acid transporter, suggests that reduced transporter proteins may be responsible for the decrease in amino acid transport activity. Conclusions Taken together, these data suggest that increased maternal testosterone concentrations do not cross the placenta to directly suppress fetal growth but affects amino acid nutrient delivery to the fetus by downregulating specific amino acid transporter activity.</p
The influence of fiber content and length on mechanical and water absorption properties of Calotropis Gigantea fiber reinforced epoxy composites
No full text This work deals with the investigation of mechanical properties and water absorption behavior of Calotropis Gigantea fiber reinforced epoxy composites prepared by using compression molding technique. The experiments were carried out by varying fiber length (10, 20, and 30 mm) and volume fraction (0, 5, 10, 15, 20, 25, and 30%). In addition to this, the water absorption behavior was analyzed at different climatic temperatures of 10℃, 40℃, and 70℃. The composites reinforced with 25% in volume of Calotropis Gigantea fiber showed better tensile, flexural, and impact properties. The hardness value and water absorption rate are higher for composites reinforced with 30% in volume of 30-mm Calotropis Gigantea fibers. Moreover, by increasing the bath temperature, the water absorption rate associated to this class of composite increases. </jats:p
Analysis of Shifts & trends of Organizations in Indonesia using Tweets & RSS feeds
No full textabstract: With the advent of social media (like Twitter, Facebook etc.,) people are easily sharing their opinions, sentiments and enforcing their ideologies on others like never before. Even people who are otherwise socially inactive would like to share their thoughts on current affairs by tweeting and sharing news feeds with their friends and acquaintances. In this thesis study, we chose Twitter as our main data platform to analyze shifts and movements of 27 political organizations in Indonesia. So far, we have collected over 30 million tweets and 150,000 news articles from RSS feeds of the corresponding organizations for our analysis. For Twitter data extraction, we developed a multi-threaded application which seamlessly extracts, cleans and stores millions of tweets matching our keywords from Twitter Streaming API. For keyword extraction, we used topics and perspectives which were extracted using n-grams techniques and later approved by our social scientists. After the data is extracted, we aggregate the tweet contents that belong to every user on a weekly basis. Finally, we applied linear and logistic regression using SLEP, an open source sparse learning package to compute weekly score for users and mapping them to one of the 27 organizations on a radical or counter radical scale. Since, we are mapping users to organizations on a weekly basis, we are able to track user's behavior and important new events that triggered shifts among users between organizations. This thesis study can further be extended to identify topics and organization specific influential users and new users from various social media platforms like Facebook, YouTube etc. can easily be mapped to existing organizations on a radical or counter-radical scale.Dissertation/ThesisM.S. Computer Science 201
Author Correction: The impact of socioeconomic and stimulus inequality on human brain physiology
No full textAnalysis of physico-chemical characteristics of seawater in Andaman and Nicobar Islands using multivariate statistical analysis
No full text271-280The current study was aimed to determine the physico-chemical characteristics from the seawaters of Andaman and Nicobar Islands, during one year seasonal (post-monsoon, summer, pre-monsoon and monsoon) survey from January to December 2016 at six different sampling stations viz. Carbines Cove beach (CC), Burmenalla beach (BB), Hadoo Wharf harbor (HW), Pigeon Island (PI), Bquarry beach (BQB) and Campbell Bay (CB). Surface water temperature, pH, salinity, dissolved oxygen, nitrite (NO2), nitrate (NO3), total nitrogen (TN), inorganic phosphate (IP), total phosphate (TP) and silicate (SiO3) were recorded. The physico-chemical parameters were tested by means of multivariate statistical methods including Pearson’s correlation, Principal Component Analysis (PCA), Cluster Analysis (CA) and Multidimensional Scaling (MDS). PCA revealed that 60.38% of variations in physico-chemical characteristics of all the six sampling stations. It showed a high degree of positive correlation with surface water temperature, salinity, DO, nitrite, nitrate and inorganic phosphate. A moderate degree of positive correlation with total phosphate in all the four seasons. CA produced a dendrogram assemblage of the study sites into four groups that exhibited maximum similarity of 99.3 % which has anthropogenic influence. The acquired results are significant to the mentioned conditions for virtual study with other parallel ecosystem in the area
Compact multiband microstrip patch antenna with slot-rings for wireless applications
No full textThis paper presents the design of compact
microstrip patch antenna operating at multiple frequency bands.
The antenna has traditional structure of microstrip patch
combined with two ring slots and two semicircular slots at the
edges. The antenna is designed with dimensions of 24.25 x 31.43 x
3.5 mm on a TD/Duroid 6002 substrate having a relative
permittivity of 2.94. The antenna has a good bandwidth of 90
MHz (3.17-3.26 GHz) at 3.2 GHz WiMAX technology, 80 MHz
(3.55.2.63 GHz) at 3.6 KHz for mobile broadband (MBB)
frequency and 465 MHz at range from 4.85-to-5.16 GHz for
Wireless Local Area Network (WLAN) (802.11a/h/j/n/ac). The
antenna meets the 2:1 VSWR at the selected center frequencies.
The designed antenna able to produce a maximum gain of 7.15dB
at 4.82 GHz. The antenna has good bandwidth and reasonable
efficiency for the wireless communication applications
