Substantial Additional Reduction Research Articles

Tirzepatide after intensive lifestyle intervention in adults with overweight or obesity: the SURMOUNT-3 phase 3 trial

The effects of tirzepatide, a glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, on weight reduction after successful intensive lifestyle intervention are unknown. This double-blind, placebo-controlled trial randomized (1:1) adults with body mass index ≥30 or ≥27 kg/m2 and at least one obesity-related complication (excluding diabetes), who achieved ≥5.0% weight reduction after a 12-week intensive lifestyle intervention, to tirzepatide maximum tolerated dose (10 or 15 mg) or placebo once weekly for 72 weeks (n = 579). The treatment regimen estimand assessed effects regardless of treatment adherence in the intention-to-treat population. The coprimary endpoint of additional mean per cent weight change from randomization to week 72 was met with changes of −18.4% (standard error (s.e.) 0.7) with tirzepatide and 2.5% (s.e. 1.0) with placebo (estimated treatment difference −20.8 percentage points (95% confidence interval (CI) −23.2%, −18.5%; P < 0.001). The coprimary endpoint of the percentage of participants achieving additional weight reduction ≥5% was met with 87.5% (s.e. 2.2) with tirzepatide and 16.5% (s.e. 3.0) with placebo achieving this threshold (odds ratio 34.6%; 95% CI 19.2%, 62.6%; P < 0.001). The most common adverse events with tirzepatide were gastrointestinal, with most being mild to moderate in severity. Tirzepatide provided substantial additional reduction in body weight in participants who had achieved ≥5.0% weight reduction with intensive lifestyle intervention. ClinicalTrials.gov registration: NCT04657016.

Declining, seasonal-varying emissions of sulfur hexafluoride from the United States

Abstract. Sulfur hexafluoride (SF6) is the most potent greenhouse gas (GHG), and its atmospheric abundance, albeit small, has been increasing rapidly. Although SF6 is used to assess atmospheric transport modeling and its emissions influence the climate for millennia, SF6 emission magnitudes and distributions have substantial uncertainties. In this study, we used NOAA's ground-based and airborne measurements of SF6 to estimate SF6 emissions from the United States between 2007 and 2018. Our results suggest a substantial decline of US SF6 emissions, a trend also reported in the US Environmental Protection Agency's (EPA) national inventory submitted under the United Nations Framework Convention on Climate Change (UNFCCC), implying that US mitigation efforts have had some success. However, the magnitudes of annual emissions derived from atmospheric observations are 40 %–250 % higher than the EPA's national inventory and substantially lower than the Emissions Database for Global Atmospheric Research (EDGAR) inventory. The regional discrepancies between the atmosphere-based estimate and EPA's inventory suggest that emissions from electric power transmission and distribution (ETD) facilities and an SF6 production plant that did not or does not report to the EPA may be underestimated in the national inventory. Furthermore, the atmosphere-based estimates show higher emissions of SF6 in winter than in summer. These enhanced wintertime emissions may result from increased maintenance of ETD equipment in southern states and increased leakage through aging brittle seals in ETD in northern states during winter. The results of this study demonstrate the success of past US SF6 emission mitigations and suggest that substantial additional emission reductions might be achieved through efforts to minimize emissions during servicing or through improving sealing materials in ETD.

Reduction of CO2 Emission in Concrete

‘Urbanization is the new life nowdays. We cannot change or reverse it. That’s why going green is the only option. As a responsible citizen, it is our duty to the next generation we know cement is one of the most crucial element so try to replace whereas possible because Concrete is the second most-used substance on Earth after water and it's responsible for eight percent of the world's carbon footprint, Ekkomaxx cement, magnesium oxychloride cement, geopolymer cement, ferrocrete, calcium sulfoaluminate cement, and sequestrated carbon cement these are some examples of green cement. some products already commercialized and used in some projects but a number of these cements have not been utilized broadly in construction projects but possess great potential to be used’. The scope of the study is to product-based approaches can deliver substantial additional reductions in their global CO2 emissions, reducing the need for costly investment in carbon capture and storage (CCS) over the next 20–30 years: Increased use of low-CO2 supplements (SCMs) as partial replacements for Portland cement clinker.

Validation of low-dose lung cancer PET-CT protocol and PET image improvement using machine learning.

To conduct a simplified lesion-detection task of a low-dose (LD) PET-CT protocol for frequent lung screening using 30% of the effective PETCT dose and to investigate the feasibility of increasing clinical value of low-statistics scans using machine learning. We acquired 33 SD PET images, of which 13 had actual LD (ALD) PET, and simulated LD (SLD) PET images at seven different count levels from the SD PET scans. We employed image quality transfer (IQT), a machine learning algorithm that performs patch-regression to map parameters from low-quality to high-quality images. At each count level, patches extracted from 23 pairs of SD/SLD PET images were used to train three IQT models - global linear, single tree, and random forest regressions with cubic patch sizes of 3 and 5 voxels. The models were then used to estimate SD images from LD images at each count level for 10 unseen subjects. Lesion-detection task was carried out on matched lesion-present and lesion-absent images. LD PET-CT protocol yielded lesion detectability with sensitivity of 0.98 and specificity of 1. Random forest algorithm with cubic patch size of 5 allowed further 11.7% reduction in the effective PETCT dose without compromising lesion detectability, but underestimated SUV by 30%. LD PET-CT protocol was validated for lesion detection using ALD PET scans. Substantial image quality improvement or additional dose reduction while preserving clinical values can be achieved using machine learning methods though SUV quantification may be biased and adjustment of our research protocol is required for clinical use.

Assessing the epidemiological impact on cervical cancer of switching from 4-valent to 9-valent HPV vaccine within a gender-neutral vaccination programme in Switzerland

BackgroundAn infection with high-risk human papillomavirus (HPV) is the obligatory aetiological factor for the development of cervical cancer. In Switzerland, the prevention strategy for cervical cancer is based on primary prevention via HPV vaccination and secondary prevention with an opportunistic screening programme for precancerous lesions. Vaccination is recommended to 11–26 years old male and female persons. The objective of the study was to assess the epidemiological impact on cervical cancer of switching from the currently implemented programme with the 4-valent vaccine to the 9-valent vaccine, in an 11–26 years old gender-neutral vaccination programme in Switzerland.MethodsA previously validated dynamic transmission model of HPV infections was adapted and calibrated to the Swiss setting assuming an 80% coverage rate in HPV-vaccination and lifelong vaccine type-specific protection. A gender-neutral vaccination programme (males and females) for 11–26 years old with a 9-valent HPV vaccine was compared with the current 11–26 years old gender-neutral 4-valent vaccination programme. Sensitivity analyses were conducted in order to test the impact of lower vaccination coverage rates and a shorter duration of protection on the model outcomes.ResultsIn Switzerland, a 9-valent gender-neutral vaccination programme would result in an additional prevention of 2979 cervical cancer cases, 13,862 CIN3 and 15,000 CIN2 cases, compared with the 4-valent gender-neutral vaccination programme over 100 years. These additional disease cases avoided would correspond to a 24, 36 and 48% cumulative incidence decrease in cervical cancer, CIN3 and CIN2 cases, respectively. It would also prevent additional 741 cervical cancer-related deaths over 100 years. A substantial additional reduction in cervical cancer and precancerous lesions burden is still observed when varying the vaccination coverage rate from 30 to 60% or reducing the duration of protection from lifelong to 20 years.ConclusionsThe switch to the 9-valent vaccine in Switzerland to prevent cervical diseases showed an important contribution in terms of public health impact compared with the 4-valent vaccine in an 11–26 years old gender-neutral population, even with very conservative assumptions such as low coverage rates or low duration of protection and limiting analysis to only cervical disease.

Numerical simulations of the effects furrow surface conditions and fertilizer locations have on plant nitrogen and water use in furrow irrigated systems

The HYDRUS model can be used to evaluate the effects of different soil surface treatments at the bottom of the furrow, different initial nitrogen fertilizer locations, and different furrow irrigation rates on deep drainage and solute leaching in furrow irrigated systems. This paper extends our 2012 study, in which we considered only one irrigation cycle and ignored the effects of plants. As a result of considering only one irrigation cycle, a large amount of water was used to change the water storage in the transport domain and only limited deep drainage of water and leaching of fertilizer at the bottom of the domain occurred in most scenarios investigated. To obtain a more realistic and complete picture, we have in this study considered multiple irrigation cycles to reflect actual field practices better and accounted for root water and nitrogen uptake and plant transpiration. As in our previous study, soil surface treatments at the bottom of the furrow include untreated, compacted and an impermeable membrane, and fertilizer is initially placed at one of five different locations in the furrow or the ridge. We have also evaluated (1) the effectiveness of triggering irrigation based on a pre-set soil water pressure head at a specific location in the ridge compared with prescribed irrigation at a regular time interval to supply water and nitrogen, and (2) the effects of plant water and nitrogen uptake on the furrow water balance, infiltration, soil evaporation, deep drainage, transpiration and nitrogen leaching. Our simulations show that deep drainage and nitrogen leaching can be substantially reduced by using an impermeable membrane on the bottom of the furrow and that a substantial additional reduction in leaching can be achieved by triggering irrigation rather than using a fixed time schedule. We also show that the initial location of fertilizer has a substantial effect on nitrogen uptake and leaching.

Can Intraoperative Magnetic Resonance Imaging Be Helpful in the Surgical Resection of Parasellar Meningiomas? A Case Series

The surgery of parasellar meningiomas is crucial. There are only a few reports of the use of intraoperative magnetic resonance imaging (iMRI) for resection of these lesions. We discuss the safety and usefulness of this technique in achieving the planned surgical goal and analyze patients' outcomes. Nineteen cases of parasellar meningioma were treated in our institution using iMRI. We classified the tumors according to their primary location: tuberculum sellae, clinoidal, and cavernous sinus meningiomas. We evaluated the history of previous surgery, outcome, residual (if present) tumor volume, degree of resection, achievement of the surgical goal, and number of iMRI scans. The preoperative surgical goal was achieved in all patients. In 7 of 19 patients, (37%) further tumor resection was performed after the first iMRI scan. Regarding the cavernous sinus group, the surgical resection was continued after the first iMRI in 56% of patients, obtaining substantial additional volume reduction. No complications were found related to the use of iMRI scan. iMRI has been effective in safely increasing the extent of parasellar meningioma resection mainly for recurrent and invasive tumors. Its usefulness has been seen mostly in cavernous sinus lesions, in which it allowed the further safe resection in 56% of cases. Moreover, this tool was particularly useful in recurrent or residual meningiomas with extension in extracranial compartments.

Projected Population Benefit of Increased Effectiveness and Coverage of Influenza Vaccination on Influenza Burden in the United States.

Vaccination is the best way to prevent influenza; however, greater benefits could be achieved. To help guide research and policy agendas, we aimed to quantify the magnitude of influenza disease that would be prevented through targeted increases in vaccine effectiveness (VE) or vaccine coverage (VC). For 3 influenza seasons (2011-12, 2015-16, and 2017-18), we used a mathematical model to estimate the number of prevented influenza-associated illnesses, medically attended illnesses, and hospitalizations across 5 age groups. Compared with estimates of prevented illness during each season, given observed VE and VC, we explored the number of additional outcomes that would have been prevented from a 5% absolute increase in VE or VC or from achieving 60% VE or 70% VC. During the 2017-18 season, compared with the burden already prevented by influenza vaccination, a 5% absolute VE increase would have prevented an additional 1 050 000 illnesses and 25 000 hospitalizations (76% among those aged ≥65 years), while achieving 60% VE would have prevented an additional 190 000 hospitalizations. A 5% VC increase would have resulted in 785 000 fewer illnesses (56% among those aged 18-64 years) and 11 000 fewer hospitalizations; reaching 70% would have prevented an additional 39 000 hospitalizations. Small, attainable improvements in effectiveness or VC of the influenza vaccine could lead to substantial additional reductions in the influenza burden in the United States. Improvements in VE would have the greatest impact in reducing hospitalizations in adults aged ≥65 years, and VC improvements would have the largest benefit in reducing illnesses in adults aged 18-49 years.

Spatially differentiated regulation: Can it save the Baltic Sea from excessive N-loads?

The Baltic Sea Action Plan and the EU Water Framework Directive both require substantial additional reductions of nutrient loads (N and P) to the marine environment. Focusing on nitrogen, we present a widely applicable concept for spatially differentiated regulation, exploiting the large spatial variations in the natural removal of nitrate in groundwater and surface water. By targeting mitigation measures towards areas where nature's own capacity for removal is low, spatially differentiated regulation can be more cost-effective than the traditional uniform regulation. We present a methodology for upscaling local modelling results on targeted measures at field scale to Baltic Sea drainage basin scale. The paper assesses the potential gain and discusses key challenges related to implementation of spatially differentiated regulation, including the need for more scientific knowledge, handling of uncertainties, practical constraints related to agricultural practice and introduction of co-governance regimes.

Eco-efficient cements: Potential economically viable solutions for a low-CO2 cement-based materials industry

The main conclusions of an analysis of low-CO2, eco-efficient cement-based materials, carried out by a multi-stakeholder working group initiated by the United Nations Environment Program Sustainable Building and Climate Initiative (UNEP-SBCI) are presented, based on the white papers published in this special issue.We believe that Portland-based cement approaches will dominate in the near future due to economies of scale, levels of process optimisation, availability of raw materials and market confidence. Two product-based approaches can deliver substantial additional reductions in their global CO2 emissions, reducing the need for costly investment in carbon capture and storage (CCS) over the next 20–30 years:1.Increased use of low-CO2 supplements (SCMs) as partial replacements for Portland cement clinker.2.More efficient use of Portland cement clinker in mortars and concretes.However, other emerging technologies could also play an important role in emissions mitigation in the longer term, and thus merit further investigation.

Triple-combination therapy in the treatment of hypertension: a review of the evidence.

Hypertension is a serious public health concern with inadequate control of blood pressure (BP) worldwide. Contributing factors include low efficacy of drugs, underuse of combination therapies, irrational combinations, physicians' therapeutic inertia and poor adherence to treatment. Current guidelines recommend the use of initial (dual) combination therapy in high-risk patients for immediate BP response, better short- and long-term BP control, and continued/improved patient adherence. This article aims to review the existing evidence of triple-combination therapies with respect to efficacy, safety and adherence to treatment. It is estimated that three drugs are required to achieve BP control in approximately one-fourth to one-third of patients. Randomised controlled trials (RCTs) have shown that triple combinations of amlodipine/valsartan/hydrochlorothiazide, amlodipine/olmesartan/hydrochlorothiazide and amlodipine/telmisartan/hydrochlorothiazide produce greater BP reductions, with greater proportions of patients achieving BP control compared with dual therapies. Further evidence also demonstrates that triple-combination therapy is efficacious for moderate to severe hypertension, with substantial additional BP reduction over dual regimens. Both RCTs and post-marketing observational studies have shown consistent and comparable efficacy in both the general population and high-risk hypertensive subgroups. Triple therapies are generally well tolerated with adverse event profiles similar to dual regimens. In addition, fixed-dose combinations used as single pill improve patient adherence leading to better long-term BP control. Depending on regional circumstances, they may also be cost effective. Thus, single-pill triple combinations of different classes of drugs with complementary mechanisms of action help to treat patients to goal with improved efficacy and better adherence to treatment.

The Impact of Pharmaceutical Innovation on Cancer Mortality in Belgium, 2004-2012.

Cancer mortality declined in Belgium during the period 2004-2012, but there was considerable variation in the rate of decline across cancer sites (breast, lung, etc.). I analyze the effect that pharmaceutical innovation had on cancer mortality in Belgium, by investigating whether the cancer sites that experienced more pharmaceutical innovation had larger subsequent declines in mortality, controlling for changes in cancer incidence. The measures of mortality analyzed - premature (before ages 75 and 65) mortality rates and mean age at death - are not subject to lead-time bias. Premature cancer mortality rates are significantly inversely related to the cumulative number of drugs registered 15-23 years earlier. Since mean utilization of drugs that have been marketed for less than 10 years is less than one fourth as great as mean utilization of drugs that have been marketed for at least a decade, it is not surprising that premature mortality is strongly inversely related only to the cumulative number of drugs that had been registered at least 10 years earlier. Drugs registered during the period 1987-1995 are estimated to have reduced the premature cancer mortality rate in 2012 by 20%. Mean age at death from cancer increased by 1.17 years between 2004 and 2012. The estimates indicate that drugs registered during the period 1987-1995 increased mean age at death from cancer in 2012 by 1.52 years. The estimates also suggest that drugs (chemical substances) within the same class (chemical subgroup) are not "therapeutically equivalent," i.e. they do not have essentially the same effect in the treatment of a disease or condition. The estimates imply that the drugs registered during 1987-1995 reduced the number of life-years lost to cancer at all ages in 2012 by 41,207. The estimated cost per-life-year gained in 2012 from cancer drugs registered in Belgium during the period 1987-1995 was €1311. This estimate is well below even the lowest estimates from other studies of the value of a life-year saved. The largest reductions in premature mortality occur 15-23 years after drugs are registered, when their utilization increases significantly. This suggests that, if Belgium is to obtain substantial additional reductions in premature cancer mortality in the future (15 or more years from now) at a modest cost, pharmaceutical innovation (registration of new drugs) is needed today.

High-Fidelity Flexibility-Based Component Mode Synthesis Method with Interface Degrees of Freedom Reduction

The partitioned structural equations of motion via the method of localized Lagrange multipliers (PALM) consist of internal and interface variables. The model reduction achieved based on PALM is called flexibility-based component mode synthesis (F-CMS), and it thus far has concentrated on reducing the internal degrees of freedom (DOFs) or reducing the internal and interface DOFs at once. In this work, well-defined three-level reduction formulations of the F-CMS method are proposed for better precision: internal DOFs, the localized Lagrange multipliers, and the interface boundary displacement. The proposed formulations include three different reduction techniques for the interface boundary displacement for better computational efficiency. Numerical experiments indicate that the proposed formulations can substantially reduce the overall reduced-order models further without compromising the accuracy, thus achieving a substantial additional reduction of computational cost compared with the previous works. In addition, the performance of a novel error estimator in the overall reduction levels is tested.

Negative Interest Rate Policy (NIRP): Implications for Monetary Transmission and Bank Profitability in the Euro Area

More than two years ago the European Central Bank (ECB) adopted a negative interest rate policy (NIRP) to achieve its price stability objective. Negative interest rates have so far supported easier financial conditions and contributed to a modest expansion in credit, demonstrating that the zero lower bound is less binding than previously thought. However, interest rate cuts also weigh on bank profitability. Substantial rate cuts may at some point outweigh the benefits from higher asset values and stronger aggregate demand. Further monetary accommodation may need to rely more on credit easing and an expansion of the ECB's balance sheet rather than substantial additional reductions in the policy rate.

Negative Interest Rate Policy (NIRP): Implications for Monetary Transmission and Bank Profitability in the Euro Area

More than two years ago the European Central Bank (ECB) adopted a negative interest rate policy (NIRP) to achieve its price stability objective. Negative interest rates have so far supported easier financial conditions and contributed to a modest expansion in credit, demonstrating that the zero lower bound is less binding than previously thought. However, interest rate cuts also weigh on bank profitability. Substantial rate cuts may at some point outweigh the benefits from higher asset values and stronger aggregate demand. Further monetary accommodation may need to rely more on credit easing and an expansion of the ECB’s balance sheet rather than substantial additional reductions in the policy rate.

Next Generation Automotive DeNOx Catalysts: Ceria What Else?

AbstractTemporal analysis of products (TAP) was used to study NO reduction to N2 over H2 and C3H6‐reduced La‐Zr doped ceria at 560 °C. (La‐Zr doped) ceria is found to be capable of fuel oxidation and NO reduction. NO dissociates on oxygen anion defects, thereby refilling these vacancies with oxygen anions and forming N2. The carbonaceous deposits, in case the catalyst was reduced by C3H6, are oxidized by oxygen species originating from lattice oxygen. This recreates oxygen anion defects, which enables substantial additional NO reduction. These findings may open a new perspective on the understanding of DeNOx by hydrocarbons.

The impact of pharmaceutical innovation on premature cancer mortality in Switzerland, 1995-2012.

The premature cancer mortality rate has been declining in Switzerland, but there has been considerable variation in the rate of decline across cancer sites (e.g., breast or digestive organs). I analyze the effect that pharmaceutical innovation had on premature cancer mortality in Switzerland during the period 1995-2012 by investigating whether the cancer sites that experienced more pharmaceutical innovation had larger declines in premature mortality, controlling for the number of people diagnosed and mean age at diagnosis. Premature cancer mortality before ages 75 and 65 is significantly inversely related to the cumulative number of drugs registered 5, 10, and 15 years earlier. The number of drugs registered during 1980-1997 explains 63% of the variation across cancer sites in the 1995-2012 log change in the premature (before age 75) mortality rate. Controlling for the cumulative number of drugs, the cumulative number of chemical subgroups does not have a statistically significant effect on premature mortality. This suggests that drugs (chemical substances) within the same class (chemical subgroup) are not "therapeutically equivalent". Over 17,000 life-years before age 75 were gained in 2012 due to drugs registered during 1990-2007. The number of life-years before age 75 gained in 2012 from drugs registered during two earlier periods (1985-2002 and 1980-1997) were more than twice as great. Since mean utilization of new drugs is much lower than mean utilization of older drugs, more recent drug registrations may have a smaller effect on premature mortality than earlier drug registrations even if the average quality of newer drugs is higher. Estimates of the cost per life-year gained before ages 75 and 65 in 2012 from drugs registered during 1990-2007 are $21,228 and $28,673, respectively. These figures are below even the lowest estimates from the value-of-life literature of the value of a quality-adjusted life-year. The estimates indicate that the cost per life-year before age 75 gained from drugs registered during earlier periods (1985-2002 and 1980-1997) were considerably lower: $5299 and $3218, respectively. The largest reductions in premature mortality occur at least a decade after drugs are registered, when their utilization increases significantly. This suggests that if Switzerland is to obtain substantial additional reductions in premature cancer mortality in the future (a decade or more from now) at a modest cost, pharmaceutical innovation (registration of new drugs) is needed today.

The impact of pharmaceutical innovation on premature cancer mortality in Canada, 2000-2011.

The premature cancer mortality rate has been declining in Canada, but there has been considerable variation in the rate of decline across cancer sites. I analyze the effect that pharmaceutical innovation had on premature cancer mortality in Canada during the period 2000–2011, by investigating whether the cancer sites that experienced more pharmaceutical innovation had larger declines in the premature mortality rate, controlling for changes in the incidence rate. Premature mortality before age 75 is significantly inversely related to the cumulative number of drugs registered at least 10 years earlier. Since mean utilization of drugs that have been marketed for less than 10 years is only one-sixth as great as mean utilization of drugs that have been marketed for at least a decade, it is not surprising that premature mortality is strongly inversely related only to the cumulative number of drugs that had been registered at least ten years earlier. Premature mortality before age 65 and 55 is also strongly inversely related to the cumulative number of drugs that had been registered at least ten years earlier. None of the estimates of the effect of incidence on mortality are statistically significant. Controlling for the cumulative number of drugs, the cumulative number of chemical subgroups does not have a statistically significant effect on premature mortality. This suggests that drugs (chemical substances) within the same class (chemical subgroup) are not therapeutically equivalent. During the period 2000–2011, the premature (before age 75) cancer mortality rate declined by about 9 %. The estimates imply that, in the absence of pharmaceutical innovation during the period 1985–1996, the premature cancer mortality rate would have increased about 12 % during the period 2000–2011. A substantial decline in the “competing risk” of death from cardiovascular disease could account for this. The estimates imply that pharmaceutical innovation during the period 1985–1996 reduced the number of years of potential life lost to cancer before age 75 in 2011 by 105,366. The cost per life-year before age 75 gained from previous pharmaceutical innovation is estimated to have been 2730 USD. Most of the previously-registered drugs were off-patent by 2011, but evidence suggests that, even if these drugs had been sold at branded rather than generic prices, the cost per life-year gained would have been below 11,000 USD, a figure well below even the lowest estimates of the value of a life-year gained. The largest reductions in premature mortality occur at least a decade after drugs are registered, when their utilization increases significantly. This suggests that, if Canada is to obtain substantial additional reductions in premature cancer mortality in the future (a decade or more from now) at a modest cost, pharmaceutical innovation (registration of new drugs) is needed today.Electronic supplementary materialThe online version of this article (doi:10.1007/s10754-015-9172-2) contains supplementary material, which is available to authorized users.

Process intensification in manufacture of nitric acid: NOx absorption using enriched and pure oxygen

Absorption column occupies a dominant place in the manufacturing of nitric acid. A mathematical model has been developed for the absorption of NOx gases using air and enriched oxygen in packed columns. For the first time, this paper considers the kinetics of nitrous acid decomposition and oxidation in the liquid phase. Till date, the published literature considers the instantaneous decomposition of nitrous acid in the liquid phase. The same case has also been considered in this paper as the base case. In addition, three more cases have been considered: (1) decomposition and oxidation kinetics of nitrous acid with a typical concentration of oxygen which is usually employed in nitric acid plants (2) complete decomposition and oxidation with enriched oxygen (3) complete conversion of nitrous to nitric acid by liquid phase nitrous acid oxidation. Enriched oxygen results in substantial reduction in column volume and/or the operating pressure. The enriched oxygen enhances the rate of nitrous acid oxidation (to nitric acid) and hence the nitrous acid available for decomposition reduces throughout the column. This implies that lesser quantity of nitric oxide gets desorbed to the gas phase. This feature has crucial implication because the need for gas phase oxidation of NO reduces and hence the absorption column becomes compact due to reduction in oxidation volume. Thus, the enriched oxygen plays a significant role in process intensification and equipment miniaturization. Additionally, the liquid phase oxidation of nitrous acid carried out in a suitable oxidizer was found to give substantial additional reduction in the column volume.For packed column absorber, the effects of design parameters viz. column diameter, heights of packed and empty sections, and operating parameters such as pressure and temperature have been examined.

OSSE impact analysis of airborne ocean surveys for improving upper-ocean dynamical and thermodynamical forecasts in the Gulf of Mexico

A prototype, rigorously validated ocean Observing System Simulation Experiment (OSSE) system is used to evaluate the impact of different sampling strategies for rapid-response airborne ocean profile surveys in the eastern interior Gulf of Mexico. Impacts are assessed with respect to improving ocean analyses, and forecasts initialized from those analyses, for two applications: improving oil spill forecasts and improving the ocean model response to tropical cyclone (TC) forcing. Rapid model error growth in this region requires that repeat surveys be conducted frequently in time, with separation of less than 4 days required to approach maximum error reduction in model analyses. Substantial additional error reduction in model dynamical fields is achieved by deploying deep (1000m) AXCTDs instead of shallow (400m) AXBTs. Shallow AXBTs constrain the ocean thermal field over the upper 400m nearly as well as deep AXCTDs. However, in addition to constraining ocean fields over a greater depth range, AXCTDs also measure salinity profiles and more accurately constrain upper-ocean density than AXBTs, leading to a more accurate representation of upper ocean pressure and velocity fields. Sampling AXCTD profiles over a one-half degree array compared to one degree leads to substantial additional error reduction by constraining variability with horizontal scales too small to be corrected by satellite altimetry assimilation. A 2-day lag in availability of airborne profiles does not increase errors in dynamical ocean fields, but it does increase errors in upper-ocean thermal field including Tropical Cyclone Heat Potential (TCHP), demonstrating that these profiles must be rapidly made available for assimilation to improve TC forecasts. The additional error reduction in ocean analyses achieved by assimilation of airborne surveys translates into significantly improved forecasts persisting over time intervals ranging between 1 and 2 weeks for most model variables but several weeks for TCHP. In particular, upper-ocean temperature forecasts can be significantly improved for an extended interval of time by conducting airborne profile surveys.