SCR Method Research Articles

Genetic Diversity and Construction of Core Collection of Sterculia Germplasm

Amplification of 107 Sterculia accessions with 12 ISSR primers resulted in 235 bands, the percentage of polymorphic sites was 100%, with the average number of effective alleles (Ne) of 1.2464, the average Nei’s gene diversity index (H) of 0.1556, the average Shannon's information index (I) of 0.2563, and the average polymorphism information content (PIC) of 0.8594, indicating that the collected 107 accessions had high genetic diversity. The genetic diversity was unevenly distributed among Sterculia samples collected from different provinces, and the highest value was observed in samples from Guangdong Province, followed by those from Yunnan Province, and the lowest was from Guangxi Province. The core collection construction of the 107 Sterculia accessions was carried out by using the SCR and LDSS methods, respectively, and the results showed that the LDSS method was more suitable for Sterculia germplasm. Different core collections were constructed based on sampling proportions of 35, 30, 25, 20 and 15%, respectively, the t-test and principal coordinates analysis results showed that the genetic diversity of the original germplasm can be fully represented at a sampling proportion of 30%. Bangladesh J. Bot. 53(2): 319-325, 2024 (June)

Temperature and salinity in the Bohai Sea landfast ice: Observations and modelling

Temperature and salinity are essential thermodynamic properties of sea ice. A 40-day long field campaign was carried out in winter 2020/2021 in the northern Bohai Sea in the landfast sea ice to investigate the seasonal sea ice temperature and salinity evolution. Ice thickness was measured routinely. A thermistor string was used to measure the ice temperature. Ice samples were collected for salinity by coring (Sco) and crumbing (Scr) methods. The mean vertical values of Sco and Scr were 4.8–5.8 psu and 8.3–13.8 psu, respectively. In cold ice, Sco and Scr were very close to each other. When ice temperature increased to −5 °C, Sco and Scr tended to differ from each other, and the difference was at largest at ice bottom. The brine volume fraction (BVF) ranged between 0.03 and 0.21 for Sco and 0.03 and 0.32 for Scr. The growth of ice reached a maximum of 3.7 cm/day in very cold conditions, while the average growth rate was 0.8 cm/day comparable to other seasonally ice-covered seas. A numerical sea ice thermodynamic model was applied to simulate the ice thickness with particular attention to the effect of Sco and Scr on the ice mass balance. The modeled overall ice growth rate was 0.7 cm/day and agreed well with the observations but during cold periods the simulation was biased down (1.1 cm/day); a possible reason is underestimation of the thermal conductivity in the model. The modeled ice thickness differed by 3 cm when using Sco and Scr as the input salinity profiles indicating that salinity has a minor impact on sea ice mass balance during mid-winter.

Recovery of tungsten from spent selective catalytic reduction catalyst by sulfuric acid precipitation and evaporation crystallization method

AbstractBACKGROUNDSelective catalytic reduction (SCR) can effectively handle NOx from flue gas in coal‐fired power plants. However, as the core part of the SCR method, V2O5–WO3/TiO2 catalyst has a limited operational life in the complex flue gas environment. The recovery of rare metals from spent catalyst would not only bring economic benefits but also solve environmental problems. The process of reducing acid leaching and further roasting‐water leaching could realize the efficient recycling of vanadium, tungsten and titanium.RESULTSAfter reducing acid leaching and roasting‐water leaching to treat spent SCR catalyst, the obtained solution containing tungsten was used as the raw material in this study. The optimal pH value of solution for removal of silicon and aluminum impurities was 9.2–9.5. The best tungsten precipitation conditions were shown as follows: a tungsten concentration of 30 g L−1, a sulfuric acid concentration of 8 mol L−1, reaction temperature of 70 °C and reaction time of 2 h. Under the optimal tungsten precipitation conditions, the tungsten precipitation efficiency can reach 92.53%. Finally, in order to further improve the purity of the crude H2WO4, the crude H2WO4 was fully dissolved in ammonia, followed by filtration and evaporation crystallization to obtain 5(NH4)2O.12WO3.5H2O (APT) crystals with a purity of 93.05 wt%. The crystallization efficiency of APT was 73.37% at 60 °C for 2 h with a rotor speed of 400 rpm.CONCLUSIONThese results indicated that a higher purity of APT crystals can be obtained by the steps of removing silicon and aluminum, precipitation of tungsten by sulfuric acid, ammonia dissolution and evaporation crystallization. © 2023 Society of Chemical Industry (SCI).

Combined removal experiment of NOx, SO2 and PM from marine diesel exhaust gas with SCR-DryEGCS system

Pollutants such as nitrogen oxides (NOx), sulfur oxides (SO2), and particulate matter (PM) in ship exhaust have a great impact on human health, environment and climate conditions. Combined selective catalytic reduction technology and dry exhaust gas cleaning technology, a test rig (SCR-DryEGCS system) for WD10C195-15 marine four-stroke high speed diesel engine was established to analyse the removal effect of NOx, SO2, and PM from exhaust gas. The SCR-DryEGCS system removed 89.03%, 99%, and 96% of NOx, SO2, and PM respectively. And also compared with low sulfur oil combined SCR method to verify the feasibility of the SCR-DryEGCS method. It shows that the SCR-DryEGCS system has its own advantages and has a good effect on the removal of NOx, SOx, and PM at the same time.

Effect of serum creatinine difference between the Jaffe and the enzymatic method on kidney disease detection and staging.

Serum creatinine (SCr), mainly determined by the Jaffe or an enzymatic method, is the central marker to assess kidney function. Deviations between these two methods may affect the diagnosis and staging of acute kidney injury (AKI) and chronic kidney disease (CKD). The results of the first parallel SCr measurement (Jaffe and enzymatic method) of adult in- and outpatients in the same serum sample at the University Hospital Essen (Essen, Germany) between 2020-2022 were retrospectively evaluated. A Bland-Altman plot with 95% limits of agreement (LoAs) was used to assess the difference between the Jaffe and the enzymatic SCr (eSCr) method. We used the 2009 Chronic Kidney Disease Epidemiology Collaboration equation for determination of estimated glomerular filtration rate (eGFR) according to the Kidney Disease: Improving Global Outcomes guidelines. A total of 41144 parallel SCr measurements were evaluated. On average, Jaffe SCr was 0.07mg/dl higher than eSCr (LoA -0.12; 0.25mg/dl). In 19% of all cases there was a different CKD stage when comparing eGFR between both SCr methods, of which 98% resulted in a more severe CKD stage determined with Jaffe SCr. In 1.6% of all cases Jaffe SCr was ≥0.3mg/dl higher than eSCr. The present study showed that methods of SCr measurement may affect both the diagnosis and staging of AKI and CKD. This must be taken into account when interpreting measurements of renal function in everyday clinical practice, but also when planning and comparing studies on renal diseases. One should therefore stay with one method for SCr measurement, preferably with the enzymatic method.

Robustness of fecal DNA spatial capture‐recapture to clustered space‐use by tule elk

AbstractSpatially explicit capture‐recapture (SCR) approaches using noninvasive fecal DNA (fDNA) are applied increasingly to obtain statistically robust abundance estimates for various wildlife species. But SCR has not been widely used for more gregarious species, such as elk (Cervus canadensis). Because of their heterogeneous use of the landscape and grouping behavior, elk present novel challenges to sampling efficiency and statistical assumptions. We employed fDNA SCR and a stratified random sampling approach to estimate abundance in 3 northern California tule elk (C. c. nannodes) populations concurrent with global positioning system (GPS)‐telemetry monitoring of 66 elk (32 male, 34 female) in Colusa and Lake counties, California, USA, during June–August 2017–2019. We collected 1,616 fecal pellet groups from the 3 populations, resulting in 1,002 fDNA genotypes (≥19 microsatellite loci, 1 sex marker) of 425 unique individuals. Based on SCR estimates from a model incorporating both sexes, elk density ranged from 0.31 (95% CI = 0.17–0.55) elk/km2to 1.7 (95% CI = 1.3–2.2) elk/km2, translating approximately to 650 individuals (evenly split between sexes) among the 3 populations. Independent telemetry data from concurrently tracked individuals indicated that activity centers of females, but not males, were clustered on the landscape. This finding was corroborated using fDNA to infer activity centers. Comparison of SCR estimates to non‐spatial estimates using physically captured individuals suggested that combined‐sex SCR models were robust to spatial clustering of females in all 3 populations. Additionally, single‐sex models were robust to female clustering in the 2 populations with multiple female groups, but not in Lake Pillsbury, where all females effectively shared a single activity center. In that case, the estimate of female abundance was deemed an overestimate. Thus, results indicate that SCR was robust to gregariousness in elk in all but the most extreme cases of clustering (single‐sex female estimation when all individuals share a single activity center), and that the inclusion of both sexes was sufficient to offset biases stemming from aggregation of females in all cases. Altogether, our findings suggest that SCR methods can be gainfully applied to socially gregarious ungulates such as elk.

Combined NOx and NH3 Slip Reduction in a Stoker Boiler Equipped with the Hybrid SNCR + SCR System FJBS+

The application of secondary NOx control methods in medium to low-capacity furnaces is a relatively new topic on the energy market and thus requires further research. In this paper, the results of full-scale research of SNCR and hybrid SNCR + SCR methods applied into a 29 MWth solid fuel fired stoker boiler is presented. The tests were performed for a full range of boiler loads, from 33% (12 MWth) to 103% (30 MWth) of nominal load. A novel SNCR + SCR hybrid process was demonstrated based on an enhanced in-furnace SNCR installation coupled with TiO2-WO3-V2O5 catalyst, which provides extra NOx reduction and works as an excess NH3 “catcher” as well. The performance of a brand-new catalyst was evaluated in comparison to a recovered one. The emission of NOx was reduced below 180 mg NOx/Nm3 at 6% O2, with ammonia slip in flue gas below 10 mg/Nm3. Special attention was paid to the analysis of ammonia slip in combustion products: flue gas and fly ash. An innovative and cost-effective method of ammonia removal from fly ash was presented and tested. The main idea of this method is fly ash recirculation onto the grate. As a result, ammonia content in fly ash was reduced to a level below 6.1 mg/kg.

Consequences of ignoring variable and spatially autocorrelated detection probability in spatial capture-recapture

ContextSpatial capture-recapture (SCR) models are increasingly popular for analyzing wildlife monitoring data. SCR can account for spatial heterogeneity in detection that arises from individual space use (detection kernel), variation in the sampling process, and the distribution of individuals (density). However, unexplained and unmodeled spatial heterogeneity in detectability may remain due to cryptic factors, both intrinsic and extrinsic to the study system. This is the case, for example, when covariates coding for variable effort and detection probability in general are incomplete or entirely lacking.ObjectivesWe identify how the magnitude and configuration of unmodeled, spatially variable detection probability influence SCR parameter estimates.MethodsWe simulated SCR data with spatially variable and autocorrelated detection probability. We then fitted an SCR model ignoring this variation to the simulated data and assessed the impact of model misspecification on inferences.ResultsHighly-autocorrelated spatial heterogeneity in detection probability (Moran’s I = 0.85–0.96), modulated by the magnitude of the unmodeled heterogeneity, can lead to pronounced negative bias (up to 65%, or about 44-fold decrease compared to the reference scenario), reduction in precision (249% or 2.5-fold) and coverage probability of the 95% credible intervals associated with abundance estimates to 0. Conversely, at low levels of spatial autocorrelation (median Moran’s I = 0), even severe unmodeled heterogeneity in detection probability did not lead to pronounced bias and only caused slight reductions in precision and coverage of abundance estimates.ConclusionsUnknown and unmodeled variation in detection probability is liable to be the norm, rather than the exception, in SCR studies. We encourage practitioners to consider the impact that spatial autocorrelation in detectability has on their inferences and urge the development of SCR methods that can take structured, unknown or partially unknown spatial variability in detection probability into account.

A spatial capture–recapture model to estimate call rate and population density from passive acoustic surveys

Abstract Spatial capture–recapture (SCR) models are commonly used to estimate animal population density from detections and subsequent redetections of individuals across space. In particular, acoustic SCR models deal with detections of animal vocalisations across an array of acoustic detectors. Previously published acoustic SCR methods either estimate call density (calls per unit space per unit time) rather than animal density itself, require an independently estimated call rate to estimate animal density, or discard data from all but one detected call from each individual. In this manuscript, we develop a new spatial capture–recapture model that estimates both call rate and animal density from the acoustic survey alone, without requiring an independently estimated call rate. Our approach therefore alleviates the need for the additional fieldwork of physically locating and monitoring individual animals. We illustrate our method and compare it to an existing approach using a simulation study and an application to data collected on an acoustic survey of the visually cryptic Cape peninsula moss frog Arthroleptella lightfooti. In the context of our acoustic survey, our calling animal density estimator has low bias, good precision and confidence intervals with appropriate coverage, yielding results that are consistent with previous studies of the same species. Our method can obtain accurate and precise estimates of animal density while eliminating the fieldwork burden associated with separately estimating call rate. We discuss how the development of our model's likelihood reveals a clear path to further extensions, which may incorporate features such as animal movement processes and uncertain individual identification.

An inherently kidney-targeting near-infrared fluorophore based probe for early detection of acute kidney injury

Acute kidney injury (AKI) is common in hospital patients. Delayed diagnosis and treatment of AKI due to the lack of efficient early diagnosis is an important cause of its high mortality. While fluorescence imaging seems promising to non-intrusively interrogate AKI-related biomarkers, the low kidney contrast of many fluorophores conferred by their relatively low abundance of distribution in the kidney limits their application for AKI detection. Herein, we discovered a near-infrared fluorophore with inherent kidney-targeting ability. Based on this fluorophore, a fluorogenic probe (KNP-1) was developed by targeting peroxynitrite (ONOO−), which is upregulated at the early onset of AKI. KNP-1 exhibits desirable kidney distribution after intravenous administration and is fluorescent only after activation by ONOO−. These properties lead to excellent kidney contrast imaging results. KNP-1 is capable of detecting both nephrotoxin-induced and ischemia-reperfusion injury-induced AKI in live mice. Temporally resolved imaging of AKI-disease model mice with KNP-1 suggests a gradual increase in renal ONOO− levels with disease progression. Notably, the upregulation of ONOO− can be observed at least 24 h earlier than the clinically popular sCr and BUN methods. Blocking ONOO− generation also proves beneficial. These results highlight the applicability of this inherently tissue targeting-based strategy for designing probes with desirable imaging contrast; potentiate ONOO− as a biomarker and target for AKI early diagnosis and medical intervention; and imply the clinical relevance of KNP-1 for AKI early detection.

SUN-049 A NEAR-INFRARED PROBE FOR EARLY DIAGNOSIS OF ACUTE KIDNEY INJURY WITH DESIRABLE RENAL ABSORPTION

Acute kidney injury (AKI) is common in patients. Delayed diagnosis and treatment of AKI due to the lack of efficient early diagnosis is an important cause for its high mortality. Numerous studies have shown that OONO- plays an important role in the pathological process of acute kidney injury. However, due to the extremely short lifetime (~10 ms) of ONOO- in physiological environment, it is impossible to separate the tissue and measure the species with conventional biology assays. In vivo near-infrared fluorescence imaging can realize the in situ and real-time analysis of elusive metabolites with high sensitivity. However, the noninasive fluorescence imaging of ONOO- in kidney has long been a challenge owing to the slow accumulation of conventional organic fluorophores in kidney but rapid accumulation in the skin which confers low signal-to-noise imaging contrast. we designed our renal absorption-based probe KNP-1, for high contrast fluorogenic imaging of ONOO− in kidney for early diagnosis of AKI. KNP-1 comprise two key building blocks : an ONOO− recognition functionality and a renal-absoption infrared-emission fluorophore. It is fluorescence-dark in the absence of ONOO− but can respond rapidly with ONOO− to produce strong fluorescences. KNP-1 exhibits excellent specificity, fast response, and high sensitivity toward ONOO− both in vitro and in vivo. In vivo fluorescent imaging of mice with probe KNP-1 realized the early diagnosis of AKI earlier than the clinically popular sCr and BUN methods. These results highlight ONOO- as a prodromal biomarker of AKI, and highlight the clinical promise of KNP-1 for early diagnosis of AKI.

Classificação fisiológica de sementes florestais quanto a tolerância à dessecação e armazenamento

Objetivou-se neste estudo classificar as sementes de aguano (Swietenia macrophylla King) e matamatá (Eschweilera juruensis R. Knuth) quanto à tolerância a dessecação pelo método SCR (Seed Coat Ratio), teste de 100 sementes, e pelo protocolo convencional. O experimento foi conduzido no Laboratório de Análises de Sementes Florestais da Universidade Federal do Acre. Para condução dos experimentos pelo método SCR foram utilizadas 40 sementes dissecadas em envoltório e eixo embrionário. Para o teste de 100 sementes foram utilizados dois ambientes, controle seco e controle úmido. Para o método convencional, as sementes de S. macrophylla foram submetidas à secagem a 6 e 5% e E. juruensis à secagem a 12 e 5%, ambas as espécies armazenadas por 90 dias com 5% do grau de umidade. Para avaliar o vigor foi utilizado o teste de emergência. O método SCR para as sementes de S. macrophylla foi de P=0,0046, classificadas como ortodoxas e as sementes de E. juruensis classificadas como recalcitrantes com P=0,96. No teste de 100 sementes a secagem a 15% ocasionou uma germinação de 76% para S. macrophylla e a perca do vigor das sementes de E. juruensis, após a secagem. Quando submetidas a secagem a 5% e armazenadas por 90 dias, as sementes de S. macrophylla apresentaram emergência de 93%, já as sementes de E. juruensis não mantiveram o vigor. A classificação fisiológica das espécies florestais quanto a tolerância a dessecação e ao armazenamento para Swietenia macrophylla classificada ortodoxa e Eschweilera juruensis como recalcitrante.

Binary copper-manganese based catalysts with urea for low-temperature selective catalytic reduction of NO: Performance, characterization and mechanism

The NO emission reduction for low-temperature flue gas is still a serious challenge, low-temperature selective catalytic reduction with urea (LTU-SCR) is a new and promising approach for removing NO at low temperatures (50–100 °C), which can avert the ammonia escape of the conventional SCR method. In this work, a series of binary catalysts were prepared and used for LTU-SCR, the carrier and catalysts were characterized in detail by EA, BET, FESEM, EDS, XRD, XPS, AAS, TPD, FT-IR and TGA. The results of catalytic activity tests showed that the binary catalysts exhibited better performance than the unary catalysts. When the calcination temperature is 500 °C and the mass ratio of CuOx to MnOx is 5:5, the binary Cu-Mn/NUAC catalyst had the highest catalytic activity. Moreover, the performance of the binary catalyst increased with the increasing reaction temperature, and the binary Cu0.5Mn0.5/NUAC catalyst could achieve 100% NO conversion at 100 °C. Finally, based on the results of NO transient responses, characterization experiments and thermodynamic analyses, the NO conversion mechanism on the binary Cu0.5Mn0.5/NUAC catalyst was proposed and discussed systematically; the synergetic effect between copper and manganese on the binary catalyst was attributed to the electron transfer of Cu2+ + Mn2+ ⇌ Cu0 + Mn4+.

PS1352 DISSECTING THE BONE MARROW IMMUNE MICROENVIRONMENT IN THE COMPLETE SPECTRUM OF MONOCLONAL GAMMOPATHIES: POTENTIAL IMPLICATIONS IN DISEASE PATHOGENESIS

Background: To discriminate different outcomes among patients in CR the IMWG introduced a more stringent CR (sCR) criteria by adding to the pre-existing CR criteria the requirement of a normal free-light chain ratio (sFLCr) plus the absence of clonal plasma cells (PCs) in bone marrow (BM) by immunohistochemistry (IHC). In 2011, the low-sensitivity cytometry was included as alternative methodology to IHC to define sCR. However, the prognostic significance of the kappa/lambda ratio values is not clear. Aims: To verify the conclusion of our previous study (Blood 2015. 126:858–62) regarding the lack of influence in the prognosis of abnormal serum free light chain ratios (sFLCr) in a more extensive series of newly diagnosed multiple myeloma (NDMM) patients in CR or sCR Methods: NDMM patients aged ≤65 years enrolled in GEM2012MENOS65 (NCT01916252). Of 458 patients, 8 discontinued early and were not evaluable. The definition of CR and sCR was made according to the IMWG criteria. SFLCr (FREELITE assay) was classified as normal (0.26–1.65) or abnormal (<0.26 if the patient was λ; >1.65 if the patient was κ). MRD was assessed using next-generation flow cytometry. The median limit of detection was of 3x10–6. All the CR with normal sFLCr and absence of clonal PCs by MFC with a sensitivity of 10–2 were considered sCR. Median follow-up was 47.5 months. Results: After induction, 425 patients were evaluable for response; 201 (47%) reached ≥CR. Data from sFLCr and MRD was available in 192 and 193 patients, respectively. In the CR evaluable patients for sCR assessment (n = 184), the rate of sCR was 64% (n = 117). In a landmark from the end of induction (median follow-up 39 months), sCR didn’t show significantly differences in PFS (2 years-PFS 89% vs 87%; P = .7) (fig 1a) neither in OS (2 years-OS 94% vs 94%; P = .9). Interestingly, patients with abnormal (n = 67) vs normal (n = 125) sFLCr showed superimposable PFS (2 years-PFS 88% vs 87%; P = .9) (fig 1b) and OS (2 years-OS 96% vs 94%; P = .8).By contrast, the few patients (n = 3) in whom BM clonality was detected by the low-sensitivity IHC-adapted MFC method had significantly worse PFS (2 years-PFS 89% vs 67%; P = .03) (fig 1c) and OS (2 years-OS 95% vs 67%; P = .8) than patients in whom BM clonality was undetectable or detected at levels below the threshold proposed for IHC assessment. On using our traditional MRD method, persistent MRD (>10–4) was detectable among 39 of the 193 (20%) patients who, compared with MRD-negative cases, had significantly inferior PFS (2-years PFS 91% vs 80%; P = .01) (fig 1b) and OS (2 years-OS 96% vs 87%; P = .01).As validation, we reproduced the analysis in the ASCT end-point. Of the 395 evaluable patients; 238 (60%) reached ≥CR. Once again, in the landmark analysis, sCR didn’t show significantly differences in PFS in respect to CR (P = .3) neither in OS (P = .6). Patients with abnormal (n = 51) vs normal (n = 173) sFLCr showed superimposable PFS (P = .9) and OS (P = .6). Patients with persistent MRD (>10–4), had significantly inferior PFS (P = .003) but similar OS (P = .2).Summary/Conclusion: These results confirm our previous analysis based on GEM05menos65/ GEM10mas65 clinical trials. For MM patients in CR, the stringent CR criteria does not predict a different outcome. If this essential criterion in the definition of sCR lacks for the prognosis connotations, it is not justified to maintain a response category whose real significance depends on the combination of the traditional CR criteria with a negative MRD status based on very low (IHC) or low resolution (<104) levels, today outdated.

Two-Staged Dielectric Barrier Discharge-Urea Configuration for the Removal of NO of NOx in a Simulated Coal-Combustion Flue Gas

NO is a deadly pollutant that makes up more than 90% NOx in a flue gas. NO is insoluble in water; thus, its removal is extremely difficult using the SCR method. This study investigates the feasibility of NO removal and energy efficiency from a coal-combustion flue gas connected to a DBD reactor merged with urea. The results showed that the combined effect of urea and the DBD reactor gave a significant increase in the removal of NO. Comparing the removal efficiencies of NO at different urea mass percentages (9%, 17%, 23%, 29%, and 33%), it was found that the optimum concentration of urea for efficient NO removal was 23% because there is enough NH3 produced at this concentration and less H2O species generated to consume N• free radicals by OH to produce more NO in the system. The removal efficiencies of the optimum 23% urea concentration with oxygen [(NO/N2/O2/CO(NH2)2:23% w/w system] and without oxygen [(NO/N2/CO(NH2)2:23% w/w system] were also compared. It was also found that the addition of urea solution showed a considerably good energy efficiency which implies that the cost of this technology will be effective. The study complements past studies on the efficient removal of NO from the environment.

A novel peak-to-average power ratio reduction scheme via tone reservation in OFDM systems

In this paper, a novel signal-to-clipping noise ratio and least squares approximation tone reservation scheme (SCR-LSA TR) is proposed to reduce the peak-to-average power ratio for orthogonal frequency division multiplexing systems. During the SCR procedure, only the element with the maximal amplitude is picked for processing, which not only decreases the algorithm complexity, but also helps to overcome the BER deterioration. With the LSA method, the amplitude of the peak-cancelling signals can approximate to that of the original clipping noise as much as possible. Through the combination of the optimization factor in the LSA method, the classic SCR method can achieve better PAPR reduction with faster convergence. Simulation results show that the proposed SCR-LSA TR scheme has less in-band distortion and smaller out-of-band spectral radiation. The BER of the proposed scheme shows a better performance especially under the 16-QAM over the additive white Gaussian noise channel.

EFEK LOKASI INJEKTOR TERHADAP INDEKS PENCAMPURAN AMMONIA UNTUK SCR DENGAN MIXER DINAMIK

Diesel engines many are used as transportation mode in the land and sea compared with gasoline engines due to their high efficiency and durability. However, diesel engine releases much more NOx and soot emissions than that of gasoline engine. NOx is formed from a reaction of Nitrogen and Oxygen at high temperature. If these emissions are breathed into human body resulting respiratory disorders such as emphysema and bronchitis as well as lungs tissue damage. Therefore, NOx emissions controll is required to reduce them reaching under a threshold level. An effective method for controlling NOx emissions produced by the diesel engines is by injecting ammonia obtained from urea into selective catalytic reduction (SCR method) system. Ammonia by means of catalyst reacts with NOx forming Nitrogen (N2) and Water (H2O). Therefore, a chance of each ammonia particle to react with each NOx particle is required to consider. A reaction quality between ammmonia and NOx particles can be increased by improving a mixing index. One of the methods to increase the mixing index is by using a dynamic mixer.There are several factors which influence the increase of mixing index. One of these factors is a location of ammonia injector. Since this work is focused on investigating the effect of ammonia injector location on the mixing index of ammonia to diesel engine exhaust gases which content of NOx emissions

Analyzing Behavioural Scenarios over Tabular Specifications Using Model Checking

Tabular notations, in particular SCR specifications, have proved to be a useful means for formally describing complex requirements. The SCR method offers a powerful family of analysis tools, known as the SCR Toolset, but its availability is restricted by the Naval Research Laboratory of the USA. This toolset applies different kinds of analysis considering the whole set of behaviours associated with a requirements specification. In this paper we present a tool for describing and analyzing SCR requirements descriptions, that complements the SCR Toolset in two aspects. First, its use is not limited by any institution, and resorts to a standard model checking tool for analysis; and second, it allows to concentrate the analysis to particular sets of behaviours (subsets of the whole specifications), that correspond to particular scenarios explicitly mentioned in the specification. We take an operational notation that allows the engineer to describe behavioural "scenarios" by means of programs, and provide a translation into Promela to perform the analysis via Spin, an efficient off-the-shelf model checker freely available. In addition, we apply the SCR method to a Pacemaker system and we use its tabular specification as a running example of this article.

Study on Molecular Sieve Catalyst for Selective Catalytic Reduction of Nox at Low Temperature

Low temperature SCR method has caused concern for the scholars in recent years. This SCR unit can be installed downstream of the desulfurization and particulate control devices, which is conducive to match the existing boiler system. It can relief the poisoning and blocking of SO2 and dust, so as to extend the life of catalyst. This paper summarizes the research progress of molecular sieve catalyst of low temperature SCR.

Development of DPF and DeNOx Combined for Rubber-Tired Gantry Crane (RTG)

Recently, the regulation of the diesel engine (DE) exhaust has become stricter due to environmental considerations. It is now required to take countermeasures against DE exhaust on the material handling of equipment in the container terminal. Mitsui Engineering & Ship Building Co., Ltd. (MES) has proposed to the market a solution for DE exhaust of Rubber Tired Gantry Crane (RTG) and has developed a combined system of Diesel Particulate Filter (DPF) and NOx Reduction System (DeNOx) . A Continuous Regenerating Trap method is newly applied for DPF. An Urea Injecting SCR method is used to improve the DeNOx performance of the system. With these new methods, a target reduction rate of 50% for PM, and 80% for NOx have been achieved. This confirmed by measurement and analyzing field data of the RTG in operation. The system was mounted on the RTG and its durability and reliability were verified through the pattern test for each operation mode, and throughout 1, 500 hour operations. In 2006 MES acquired the certification of DPF from the U. S. Environmental Protection Agency (USEPA) and the California Air Resource Board (CARE) . In 2007 orders were placed by the Port of Los Angeles (POLA) .