7,106 research outputs found
The economics of direct-seeded rice in eastern India
No full textThe private costs and benefits of dry-seeded rice (DSR) were investigated using data from on-station trials at Pantnagar, Uttaranchal, for 2002 and 2003. Results showed that DSR was profitable for farmers, giving net returns of Rs. 13,350 per ha for dry-seeded rice and Rs. 11,592 per ha for wet-seeded rice compared with Rs. 10,343 per ha for transplanted rice. Net labor savings with DSR averaged 27 days per ha. A provisional cost-benefit analysis suggests that DSR was also profitable nationally. Transplanted rice was as socially profitable as DSR only if (1) labor was assumed to have zero opportunity cost, (2) yields were halved, or (3) environmental and health-related costs were twice as high as private costs. DSR was also profitable according to the compensation principle of welfare economics. However, these analyses did not take into account equity issues. DSR reduces equity because it transfers income from labor to farmers without a compensating increase in output. Gender segmentation in the labor market and the absence of
alternative employment at the local level impose additional social costs
ORR Catalysts Derived from Biopolymers
No full textDue to the limited reaction rate of the oxygen reduction reaction (ORR), it is considered as a limiting factor in the performance of fuel cells and metal-air batteries. Platinum is considered the benchmark catalyst for ORR; however, the scarcity of platinum, its high price, the drift phenomenon, its insufficient durability, and its susceptibility to gas poisoning are the reasons for the constant search for new ORR catalysts. Carbon-based catalysts show exceptional promise in this respect considering economic profitability and activity, and, in addition, they have favorable conductivity and often a large specific surface area. The use of chitin, cellulose, lignin, coconut shell particles, shrimp shells, and even hair for this purpose was reported, as they had similar electrochemical activity regarding Pt. Alginate, a natural polymer and a constituent of brown algae, can be successfully used to obtain carbon materials that catalyze ORR. In addition, metal atomic-level catalysts and metal N-doped porous carbon materials, obtained from sodium alginate as a precursor, have been proposed as efficient electrocatalysts for ORR. Except for alginate, other biopolymers have been reported to play an important role in the preparation of ORR catalysts. In this review, recent advances regarding biopolymer-derived ORR catalysts are summarized, with a focus on alginate as a source
Porous cerium-zeolite bifunctional ORR/OER electrocatalysts in alkaline media
No full textZeolite ZSM-5 and zeolite β were modified by aqueous ion exchange with cerium and then calcined (cal) to obtain Ce-ZSM-5, Ce-ZSM-5 cal, Ce-β, and Ce-β cal electrocatalysts. X-ray powder diffraction analysis, Fourier Ttransform infrared spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, fluorescence spectroscopy, and Brunauer-Emmett-Teller method revealed changes in the structure and porosity of zeolites upon calcination. Voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were used for testing four zeolites for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in alkaline media. OER starts the earliest at Ce-β cal with onset overpotential 50, 70, and 110 mV lower than Ce-ZSM-5 cal, Ce-ZSM-5, and Ce-β. Ce-β cal further showed the lowest OER Tafel slope (114 mV dec− 1 ). Consequently, the highest OER current density was recorded in the case of Ce-β cal, followed by Ce-β, Ce-ZSM-5 cal, and Ce-ZSM-5. Regarding ORR, Ce-ZSM-5 cal showed the lowest Tafel slope (70 mV dec− 1 ) with the highest current densities that remained constant during the chronoamperometry test with a negligible decrease of 4%. It could be concluded that calcined forms exhibit better performance for OER and OER than their parent, non-calcined forms due to more active sites available for OER/ORR and decreased charge-transfer resistance
Hazard ratios, <i>P</i> value, and heterogeneity for ORR and DCR in the stratified analyses.
No full text<p>HR, hazard ratio; <i>P</i><sub>H</sub>, heterogeneity <i>P</i>; GC, gastric cancer; CRC, colorectal cancer; ORR, objective response rate; DCR, disease control rate; RCT, randomized controlled trial; RS, Retrospective study.</p
astromatt42/digb_sfgs: Release for 10.21203/rs.3.rs-106679/v1
No full textThis release was used to compute the results in https://doi.org/10.21203/rs.3.rs-106679/v1
For any queries please contact the corresponding author
#nowplaying-rs
No full text<p>The nowplaying-rs dataset features context- and content features of listening events. It contains 11.6 million music listening events of 139K users and 346K tracks collected from Twitter. The dataset comes with a rich set of item content features and user context features, as well as timestamps of the listening events. Moreover, some of the user context features imply the cultural origin of the users, and some others - like hashtags - give clues to the emotional state of a user underlying a listening event.</p>
<p>The dataset contains three files:</p>
<ul>
<li>user_track_hashtag_timestamp.csv contains basic information about each listening event. For each listening event, we provide an id, the user_id, track_id, hashtag, created_at </li>
<li>context_content_features.csv: contains all context and content features. For each listening event, we provide the id of the event, user_id, track_id, artist_id, content features regarding the track mentioned in the event (instrumentalness, liveness, speechiness, danceability, valence, loudness, tempo, acousticness, energy, mode, key) and context features regarding the listening event (coordinates (as geoJSON), place (as geoJSON), geo (as geoJSON), tweet_language, created_at, user_lang, time_zone, entities contained in the tweet).</li>
<li>sentiment_values.csv contains sentiment information for hashtags. It contains the hashtag itself and the sentiment values gathered via four different sentiment dictionaries: AFINN, Opinion Lexicon, Sentistrength Lexicon and vader. For each of these dictionaries we list the minimum, maximum, sum and average of all sentiments of the tokens of the hashtag (if available, else we list empty values). However, as most hashtags only consist of a single token, these values are equal in most cases. Please note that the lexica are rather diverse and therefore, are able to resolve very different terms against a score. Hence, the resulting csv is rather sparse. The file contains the following comma-separated values: <hashtag, vader_min, vader_max, vader_sum,vader_avg, afinn_min, afinn_max, afinn_sum, afinn_avg, ol_min, ol_max, ol_sum, ol_avg, ss_min, ss_max, ss_sum, ss_avg >, where we abbreviate all scores gathered over the Opinion Lexicon with the prefix 'ol'. Similarly, 'ss' stands for SentiStrength. </li>
</ul>
<p>Please note that user_track_hashtag_timestamp.csv and context_content_features.csv partly provide the same features. We deliberately chose to do so to be able to provide useable files that do not have to be matched and joined with each other to perform e.g., simple recommendation tasks.</p>
<p>Please also find the training and test-splits for the dataset in this repo. Also, Asmita provides prototypical implementations of a context-aware recommender system based on the dataset at https://github.com/asmitapoddar/nowplaying-RS-Music-Reco-FM.</p>
<p><br>
If you make use of this dataset, please cite the following paper where we describe and experiment with the dataset:</p>
<p>@inproceedings{smc18,<br>
title = {#nowplaying-RS: A New Benchmark Dataset for Building Context-Aware Music Recommender Systems},<br>
author = {Asmita Poddar and Eva Zangerle and Yi-Hsuan Yang},<br>
url = {http://mac.citi.sinica.edu.tw/~yang/pub/poddar18smc.pdf},<br>
year = {2018},<br>
date = {2018-07-04},<br>
booktitle = {Proceedings of the 15th Sound & Music Computing Conference},<br>
address = {Limassol, Cyprus},<br>
note = {code at https://github.com/asmitapoddar/nowplaying-RS-Music-Reco-FM},<br>
tppubtype = {inproceedings}<br>
}</p>
Converter USB/RS 485
No full textThis thesis is describing problematic of realisation of converter from USB type media into the universal RS-485 bus which is mainly used for the industrial applications (author is using frequently as a device in order to enable communication between server and RFID devices). This thesis contains theoretical information, realisation of the device itself and assesment of reached targets
Converter USB/RS 485
No full textThis thesis is describing problematic of realisation of converter from USB type media into the universal RS-485 bus which is mainly used for the industrial applications (author is using frequently as a device in order to enable communication between server and RFID devices). This thesis contains theoretical information, realisation of the device itself and assesment of reached targets
Characterization of Defined Pt Particles Prepared by Ultrasonic Spray Pyrolysis for One-Step Synthesis of Supported ORR Composite Catalysts
No full textPolygonal Pt nanoparticles were synthesized using ultrasonic spray pyrolysis (USP) at different precursor concentrations. Physicochemical analysis of the synthesized Pt particles involved thermogravimetric, microscopic, electron diffractive, and light absorptive/refractive characteristics. Electrochemical properties and activity in the oxygen reduction reaction (ORR) of the prepared material were compared to commercial Pt black. Registered electrochemical behavior is correlated to the structural properties of synthesized powders by impedance characteristics in ORR. The reported results confirmed that Pt nanoparticles of a characteristic and uniform size and shape, suitable for incorporation on the surfaces of interactive hosts as catalyst supports, were synthesized. It is found that USP-synthesized Pt involves larger particles than Pt black, with the size being slightly dependent on precursor concentration. Among ORR-active planes, the least active (111) structurally defined the synthesized particles. These two morphological and structural characteristics caused the USP-Pt to be made of lower Pt-intrinsic capacitive and redox currents, as well as of lower ORR activity. Although being of lower activity, USP-Pt is less sensitive to the rate of ORR current perturbations at higher overpotentials. This issue is assigned to less-compact catalyst layers and uniform particle size distribution, and consequently, of activity throughout the catalyst layer with respect to Pt black. These features are considered to positively affect catalyst stability and thus promote USP synthesis for improved properties of host-supported Pt catalysts
Fiery Cores: Bursty and Smooth Star Formation Distributions across Galaxy Centers in Cosmological Zoom-in Simulations
No full textWe present an analysis of the R less than or similar to 1.5 kpc core regions of seven simulated Milky Way-mass galaxies, from the FIRE-2 (Feedback in Realistic Environments) cosmological zoom-in simulation suite, for a finely sampled period (Delta t = 2.2 Myr) of 22 Myr at z 0, and compare them with star formation rate (SFR) and gas surface density observations of the Milky Way's Central Molecular Zone (CMZ). Despite not being tuned to reproduce the detailed structure of the CMZ, we find that four of these galaxies are consistent with CMZ observations at some point during this 22 Myr period. The galaxies presented here are not homogeneous in their central structures, roughly dividing into two morphological classes; (a) several of the galaxies have very asymmetric gas and SFR distributions, with intense (compact) starbursts occurring over a period of roughly 10 Myr, and structures on highly eccentric orbits through the CMZ, whereas (b) others have smoother gas and SFR distributions, with only slowly varying SFRs over the period analyzed. In class (a) centers, the orbital motion of gas and star-forming complexes across small apertures (R less than or similar to 150 pc, analogously divide l divide < 1 degrees in the CMZ observations) contributes as much to tracers of star formation/dense gas appearing in those apertures, as the internal evolution of those structures does. These asymmetric/bursty galactic centers can simultaneously match CMZ gas and SFR observations, demonstrating that time-varying star formation can explain the CMZ's low star formation efficiency
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