20 research outputs found
Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction
The central Altiplano is inferred to have experienced ∼2.5±1km surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene–Pliocene deposits of the Descanso–Yauri basin (14–15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Δ_(47) values), carbonate δ^(18)O_c, leaf wax δD_(wax) and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Δ_(47)) and meteoric water isotope values (δ^(18)O_c, δD_(wax)). Our results show that the northernmost plateau remained at low elevation (0.9±0.8 to 2.1±0.9km) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of 23±4°C, 2σ), low elevation vegetation and precipitation signature with reconstructed □ δ^(18)O_(mw) (VSMOW) of −8.3±2.0‰(2σ) from carbonate (δ^(18)O_c) and −8.6±1.8‰(2σ) from leaf wax (δD_(wax)). Modern elevations of 4 km were not reached until 5.4±1.0Ma, as indicated by a negative shift in δD_(wax) (VSMOW) from −143.4±12.8‰(2σ) to −209.2±21.1‰(2σ) between 9.1±0.7 and 5.4±1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16–19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern–central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19–22°S) between ∼16 and 9 Ma. These results are consistent with piecemeal removal of the lower dense lithosphere, combined with possible lower/middle crustal flow from south to north in the plateau acting as the main mechanisms for the formation of the Altiplano plateau
Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction
The central Altiplano is inferred to have experienced ∼2.5±1km surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene–Pliocene deposits of the Descanso–Yauri basin (14–15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Δ_(47) values), carbonate δ^(18)O_c, leaf wax δD_(wax) and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Δ_(47)) and meteoric water isotope values (δ^(18)O_c, δD_(wax)). Our results show that the northernmost plateau remained at low elevation (0.9±0.8 to 2.1±0.9km) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of 23±4°C, 2σ), low elevation vegetation and precipitation signature with reconstructed □ δ^(18)O_(mw) (VSMOW) of −8.3±2.0‰(2σ) from carbonate (δ^(18)O_c) and −8.6±1.8‰(2σ) from leaf wax (δD_(wax)). Modern elevations of 4 km were not reached until 5.4±1.0Ma, as indicated by a negative shift in δD_(wax) (VSMOW) from −143.4±12.8‰(2σ) to −209.2±21.1‰(2σ) between 9.1±0.7 and 5.4±1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16–19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern–central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19–22°S) between ∼16 and 9 Ma. These results are consistent with piecemeal removal of the lower dense lithosphere, combined with possible lower/middle crustal flow from south to north in the plateau acting as the main mechanisms for the formation of the Altiplano plateau
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
An investigation on performance of onion price and market arrivals in major Indian markets
Onion is a significant and essential commodity used in all the Indian delicacies either in raw form or dehydrated form to add flavour and taste to cuisine. India is the 2nd largest producer of onion next to china and it is also 2nd highest yielded vegetable in India. Though it shares a considerable amount of area and production among all the vegetables along with high marketable surplus, it fails to approve steady price throughout the year. Instability in market arrival contributing to the price fluctuations is mainly caused by substantial dependence on meteorological conditions and perishable nature of the crop. Often this high price fluctuation and variation in price causes suffering to the farmers by affecting their income level. It impacts the consumers adversely and also causes inefficiency in the functioning of the market. Realising the importance of the situation, through this paper it has been investigated. The trends in market arrival were positive in three markets except Azadpur. Trend in nominal price is found positive and for real price it was found negative in all the markets. Seasonal index showed that the arrival in different markets remained on the higher side during the peak harvesting season of the particular region and it collides with the low seasonal price index. Variability index revealed the existence of high variability for both of price and arrivals of onion. However, because of presence of significant seasonality in prices there is scope for increasing the income of farmers by concentrating on marketing during lean periods
Synthesis, characterization and corrosion performance evaluation of DDR membrane for H-2 separation from HI decomposition reaction
An all silica DDR (deca dodecasil rhombohedral) zeolite membrane with dense, interlocked structure has been developed for separation of H-2 from HI/I-2 mixture of HI decomposition reaction. In this work, the DDR zeolite membrane was synthesized on the seeded clay-alumina substrate within 5 days. The seeds were synthesized by sonication mediated hydrothermal process within short crystallization time which enhanced the nucleation for the membrane growth. The synthesized membranes along with seed crystals were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDAX). The selectivity of hydrogen with respect to CO2 and Ar was evaluated by single gas permeation studies at room temperature. The tests for corrosion resistance were carried out upto 120 h with both support and DDR membrane at 130 degrees C which confirmed the stability of membrane under the harsh HI/I-2 environment. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved
DDR zeolite membrane reactor for enhanced HI decomposition in IS thermochemical process
The third section of closed loop Iodine Sulphur (IS) thermochemical cycle, dealing with HI. processing, suffers from low equilibrium decomposition of HI to hydrogen with a conversion value of only similar to 22% at 700 K. Here, we report a significant enhancement in conversion of HI into hydrogen (up to similar to 95%) using a zeolite membrane reactor for the first time. The all silica DDR (deca dodecasil rhombohedral) zeolite membrane with dense, interlocked structure was synthesized on the seeded clay alumina substrate by sonication mediated hydrothermal process. The synthesized membranes along with seed crystals were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDX). Corrosion studies were carried out by exposing the membrane samples to simulated HI decomposition reaction environment (at 450 degrees C) for different durations of time upto 200 h. The FESEM, EDX and XRD analyses indicated that no significant changes occurred in the morphology, composition and structure of the membranes. Iodine adsorption on to the membrane surface was observed which got increased with the exposure duration as confirmed by secondary ion mass spectrometry studies. A packed bed membrane reactor (PBMR) assembly was fabricated with integration of in-house synthesized zeolite membrane and Pt-alumina catalyst for carrying out HI decomposition studies. The tube side was chosen as reaction zone and the shell side as the permeation zone. The HI decomposition experiments were carried out for different values of temperature and feed flow rates. DDR zeolite based PBMR was found to enhance the single-pass conversion of HI up to similar to 95%. The results indicate that for achieving optimal performance of PBMR, it should be operated with space velocities of 0.2 -0.3 s(-1) and temperature in the range of 650 K-700 K with permeate side vacuum of 0.12 kg/cm(2). It is believed that the in-house developed zeolite PBMR shall be a potential technology augmentation in making the IS thermochemical cycle energy efficient. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved