Extra Trace Research Articles

Noise suppression using a near-source wavelet

Denoising becomes a nontrivial task when the noise and signal overlap in multiple domains, such as time, frequency, and velocity. Fortunately, signal and noise waveforms, in general, tend to remain morphologically different and such differences can be used to separate body-wave signals from other waveforms such as ground roll and cultural noise. The key in denoising using a near-source wavelet is to find a wavelet that is a close approximation of the true source signature and remains uncontaminated by the Green’s function in any significant manner. An inverse filter designed using such a wavelet selectively compresses the body waves that can be extracted using median and low-pass filters. The overall phenomenon is explained with a synthetic example. The idea is also tested on a land data set generated using a large weight-drop source in which the wavelet recorded approximately 3 m from the source location fulfills the criteria set in our method. The results suggest that the incremental effort of recording an extra trace close to the source location during acquisition may provide previously unavailable denoising opportunities during processing, although the trace itself may be redundant for imaging.

Enhancing electrical properties of Cu2ZnSn(S,Se)4 thin films via trace Co incorporation

Substitution of Zn2+ ionic by Co2+ ionic is known to suppress the cation disorder of Cu2ZnSn(S,Se)4 thin films, which is helpful to obtain the excellent Cu2ZnSn(S,Se)4 solar cell devices. In our work, the extra trace Co incorporation was added in the solution without affecting the compositions of other elements (i.e. Cu, Zn, and Sn) to enhance the electrical properties of Cu2ZnSn(S,Se)4 thin films. And Co incorporation does not enter into the lattice nor be found in the selenized films after taking effect, but increases the crystallinity, compactness, carrier concentration, and electrical properties of Cu2ZnSn(S,Se)4 thin films samples. By tuning the doping ratios of Co2+ ionic, the surface roughness of the selenized films can be decreased from 110.2 nm (0 mol %) to 68.90 nm (5 mol %). As 1 mol % of Co2+ ionic is doped, the carrier concentration of films can be also improved to 4.35 × 1017 cm−3 from 2.63 × 1016 cm−3, and average surface current of films applied 1 V AC voltage can be increased from 2.426 nA to 4.454 nA. The enhanced properties of Co-incorporated films brings hope for the excellent performance of Cu2ZnSn(S,Se)4 solar cells.

Influence of extra trace Mn-doping on the properties of Cu2ZnSn(S,Se)4 absorber layer

Abstract Cations substitutions are known to make much significant contribution on achieving the high-quality kesterite Cu2ZnSn(S,Se)4 thin films. And the optimal ratios of Mn, Ni and Co substitutions are reported to be ~0.05, belong to the low doping to reduce their defect density, which looks like to some extent the effect of Na doping. In this study, learning the research experience of alkali metal doping, we introduced the extra trace Mn2+ ion into the precursor solution without affecting the compositions of other elements (i.e. Cu, Zn, and Sn), and the effect of trace addition on properties of the absorber layer was also studied. It was discovered that crystalline, electrical properties, and hole carrier concentration of Cu2ZnSn(S,Se)4 thin films increased with an increase of Mn incorporation, and the best doping ratio of Mn/(Cu + Zn + Sn) was considered to be 0.03. In addition, the effect of extra trace Mn-doping on the film thickness and elemental compositions of Cu2ZnSn(S,Se)4 absorber layer were studied in detail.

Ion Transfer-Resolved Fusion Impacts of Single Droplets Probed at the Liquid/Liquid Interface.

An ion transfer-resolved configuration has been introduced to study the fusion impact of a tiny (femtoliter) water-in-oil droplet probed at the micro liquid/liquid (L/L) interface. A periodic linear potential signal with a high frequency is applied in this configuration, and typical (facilitated) ion transfer voltammograms and capacitive voltammograms of single fusion events have been obtained. The responses with voltammetric characteristics allow us to identify ion transfer potentials and elucidate the mechanism in single fusion events. The aqueous droplets encapsulating femtomoles of different quaternary ammonium ions are successfully tracked by fusing with the L/L interface and are identified by their ion transfer potentials. In addition, a capacitive fusion impact is recorded in the obtained current response when no biphasic ion translocation event occurs during a single fusion process, revealing a new mechanism of charge exchange between the electrode surface and polarized interface in the alternating electric field. In addition, a single fusion impact revealed by the facilitating ion transfer is reported, and the obvious discrepancy of fusion event voltammograms with and without ionophore participation is established. By providing new physiochemical insights, this study enables extra trace analysis at the femtomole scale and provides a possible method to electrochemically characterize micro-/nanoscale heterogeneous media.

Studies on the effect of ochratoxicosis on extra renal pathology, hematology and trace elements status in broiler birds and response to powdered rhizome of Curcuma longa

Studies on the effect of ochratoxicosis on extra renal pathology, hematology and trace elements status in broiler birds and response to powdered rhizome of Curcuma longa

Output feedback stabilization of the linearized Korteweg–de Vries equation with right endpoint controllers

In this paper, we prove the output feedback stabilization for the linearized Korteweg–de Vries (KdV) equation posed on a finite domain in the case the full state of the system cannot be measured. We assume that there is a sensor at the left end point of the domain capable of measuring the first and second order boundary traces of the solution. This allows us to design a suitable observer system whose states can be used for constructing boundary feedbacks acting at the right endpoint so that both the observer and the original plant become exponentially stable. Stabilization of the original system is proved in the L2-sense, while the convergence of the observer system to the original plant is also proved in higher order Sobolev norms. The standard backstepping approach used to construct a left endpoint controller fails and presents mathematical challenges when building right endpoint controllers due to the overdetermined nature of the related kernel models. In order to deal with this difficulty we use the method of Özsarı and Batal, (2019) which is based on using modified target systems involving extra trace terms. In addition, we show that the number of controllers and boundary measurements can be reduced to one, with the cost of a slightly lower exponential rate of decay. We provide numerical simulations illustrating the efficacy of our controllers.

Do carnitine and extra trace elements change stability of paediatric parenteral nutrition admixtures?

High concentrations of trace elements (TE), in particular zinc and selenium, along with carnitine, are often added to parenteral admixtures in paediatric patients on long-term Parenteral Nutrition (PN). We aim to evaluate whether lipid droplet diameters of these admixtures maintain the recommended range of 0.4-1.0μm. Stability studies were carried out on six parenteral admixtures with carnitine, trace elements and electrolytes added in different amounts. Each admixture was formulated with five different lipid emulsions with or without fish oil. Analyses were performed at time 0 (t=0) and 24, 48, 72, 96 (t=96) hours after compounding. Droplet diameters were determined by Light Scattering-Reverse Fourier Optics Technique. Samples, stored at 4°C, were triple tested for a total of 450 analyses. Regression analyses were performed using panel-data techniques. During the 4 days, lipid droplet diameters were in the expected range of 0.4-1.0μm regardless of trace element and carnitine amounts in all admixtures apart from those containing fish-oil based emulsions and calcium concentrations equal to 4.5mmol/L. In these latter admixtures, 12% of droplet diameters were larger than 1.0μm and 2% exceeded 5.0μm immediately after compounding. Carnitine and high concentrations of trace elements do not affect PN admixtures stability and can be safely infused in long-term home-PN paediatric patients and prematures. Only high calcium concentrations in compresence with fish oil based lipid emulsions seem to change PN stability.

Short- and long-term effects of manganese, zinc and copper ions on nitrogen removal in nitritation-anammox process

This study provided a deep insight into the impacts of trace elements (Mn2+, Zn2+ and Cu2+) on nitritation-anammox process. For short-term exposure, all the three elements could improve the nitrogen removal rate (NRR) and the optimal concentrations were 2.0 mg/L, 2.0 mg/L and 0.5 mg/L for Mn2+, Zn2+ and Cu2+, respectively. Accordingly, the NRRs were enhanced 54.62%, 45.93% and 44.09%. The long-term experiments were carried out in lab-scale sequencing batch reactors. The surprising results showed that only Mn2+ addition could enhance the long-term nitritation-anammox process, and the NRR increased from 0.35 ± 0.01 kg N/m3/d (control, no extra trace element addition) to 0.49 ± 0.03 kg N/m3/d. Vice versa, the amendment of Zn2+ reduced the NRR to 0.28 ± 0.02 kg N/m3/d, and Cu2+ had no significant effect on the NRR (0.36 ± 0.01 kg N/m3/d). From the analysis of microbial community structure, it was explained by the increasing abundance of anaerobic ammonium oxidizing bacteria (AnAOB) only in Mn2+ treatment, whereas Zn2+ predominantly promoted ammonium oxidizing bacteria (AOB). Additionally, the majority of Mn2+ was identified inside AnAOB cells, and Zn2+ and Cu2+ were mainly located in AOB. Our results indicated the synergistic effects of trace elements on nitritation-anammox, both short-term encouraging activities of AnAOB and long-term altering microbial community structure. This work implies the importance of trace elements addition in nitritation-anammox process.

Recycled wastewater from anaerobic digestion of lipid extracted algae as a source of nutrients

Nutrient supply, especially nitrogen and phosphorus, is one of the key obstacles limiting industrialization of algal biofuel. To help enhance nutrient utilization efficiency, our research focused on recycling of nutrients from lipid extracted algae biomass by the method of anaerobic digestion. Two methods of lipid extraction were performed, nutrients were released during anaerobic digestion of the lipid extracted biomass, the recycled nutrients were collected for algae cultivation, and the cycle was repeated: cultivation-extraction-digestion-cultivation. The results show that anaerobic digestion released nitrogen and phosphorus, and methane as a gaseous by-product. The algae grew well on the recycled nutrients. Ammonia is the limiting macro element, and extra trace elements enhanced algae production as well. Ash free dry weight, lipid content and lipid components were monitored and did not vary when the cycle was repeated. This system for recycling nutrients with supplementary nutrients holds potential for producing biofuel from algae.

Region of permanent generation of large-scale irregularities in the daytime winter ionosphere of the Southern Hemisphere

With the use of data from topside sounding on board the Interkosmos-19 (IK-19) satellite, the region of permanent generation of large-scale irregularities in the daytime winter ionosphere of the Southern Hemisphere is differentiated. This region is characterized by low values of foF2 and hmF2 and occupies a rather large latitudinal band, from the equatorial anomaly ridge to ~70° S within the longitudinal range from 180° to 360°. Irregularities with a dimension of hundreds kilometers are regularly observed in the period from 0700–0800 to 1800–1900 LT, i.e., mainly in the daytime. In the IK-19 ionograms, they normally appear in the form of an extra trace with a critical frequency higher than that of the main trace reflected from the ionosphere with lower density. The electron density in the irregularity maximum sometimes exceeds the density of the background ionosphere by nearly a factor of 3. A model of the ionosphere with allowance for its irregular structure was created, and it was shown on the basis of trajectory calculations how the IK-19 ionograms related to these irregularities are formed. A possible mechanism of the generation of large-scale irregularities of the ionospheric plasma is discussed.

Matter Confinement Mechanism in de Sitter Brane

The geodesic equation in induced matter theory with de Sitter brane is described. It is shown that the extra forces do not change the four-impulse of massive particles. We also show that the variation of length of the 4-velocity of a test particle in de Sitter brane along the extra dimensions could remain finite resulting in a fluctuating component and hence keeping the particle inside the 4D spacetime and within the observable physics. In fact, the extra components trace closed orbits keep them finite in length. All of these are formulated in the framework of a dynamical system and we characterize the behaviour of the integral curves of this system.

The syntax of Dutch embedded fragment answers: on the PF-theory of islands and the wh/sluicing correlation

This paper presents new evidence in favour of Merchant’s (2004, 2008) PF-theory of islands, which states that island-sensitivity is due to the presence of PF-uninterpretable traces at PF. This new evidence is provided by two types of Dutch embedded fragment answers: whereas one type is island-sensitive, the other one is not. The former differs from the latter in that it involves an extra movement step, leaving an extra trace. Moreover, this paper argues that the wh/sluicing correlation (van Craenenbroeck and Liptak 2006, 2009) makes the correct predictions regarding the (non-)embeddability of fragment answers in Dutch and English. The wh/sluicing correlation states that there is a correlation between the type of wh-movement a language exhibits and the types of clausal ellipsis attested in that language. I show that it follows straightforwardly that, unlike in Dutch, embedded fragment answers are not attested in English.

Links between two different types of spectra of charged nanometer aerosol particles

We have, since 2007, continuously measured the electrical mobility distribution of small (< 1.5 nm in diameter) corona-generated one-second-aged air ions, using our Small Air Ion Spectrometer (KAIS), in urban area, in the center of the town of Tartu, Estonia. We have simultaneously measured the mobility distributions of natural air ions (0.42–7.4 nm in diameter) with the Balanced Scanning Mobility Analyzer (BSMA). In this work we employ these data to establish certain links between the concurrent spectra of two types, especially for days with new particle formation events. We elaborated and tested an automatic classification method, which selected the spectra according their shape. In the case of the BSMA negative ions, we obtained four classes of the spectra which are associated with the intermediate ion (1.6–7.4 nm in diameter) nucleation burst events and rain-type events. The spectra within these classes are characterized by special shapes and they are called “event-like spectra”. The first class demonstrates the strongest increase in the concentration of all ions with the mobilities below 0.8 cm 2V −1 s −1 (above 1.25 nm in diameter), it mainly contains spring and early summer spectra, recorded around midday. In the second class, the events are weaker; it contains a large number of late spring morning time spectra, when relative humidity (RH) tends to decrease. The third and the fourth classes contain many spectra, which resemble to short isolated events. These spectra are excluded from the further analysis. In the first class, the precipitation spectra make about 34% of all the event-like spectra, in the other classes about 10%. In the case of the BSMA positive ions, only the first and second classes were present. The precipitation spectra make about 20% of all event-like classes. About 45% of the event-like spectra are without precipitation, but with RH > 90%, and these spectra are excluded from the further analysis. The spectra with RH < 50% formed 12% of the respective classes. The established links with the concurrent KAIS classes imply that especially the BSMA positive ion burst events are often connected with some extra trace gases, which can override the dependence on the meteorological conditions. All the ions within the BSMA ion burst spectra are definitely older than about 1 s.

High cell density media for Escherichia coli are generally designed for aerobic cultivations – consequences for large-scale bioprocesses and shake flask cultures

BackgroundFor the cultivation of Escherichia coli in bioreactors trace element solutions are generally designed for optimal growth under aerobic conditions. They do normally not contain selenium and nickel. Molybdenum is only contained in few of them. These elements are part of the formate hydrogen lyase (FHL) complex which is induced under anaerobic conditions. As it is generally known that oxygen limitation appears in shake flask cultures and locally in large-scale bioreactors, function of the FHL complex may influence the process behaviour. Formate has been described to accumulate in large-scale cultures and may have toxic effects on E. coli.Although the anaerobic metabolism of E. coli is well studied, reference data which estimate the impact of the FHL complex on bioprocesses of E. coli with oxygen limitation have so far not been published, but are important for a better process understanding.ResultsTwo sets of fed-batch cultures with conditions triggering oxygen limitation and formate accumulation were performed. Permanent oxygen limitation which is typical for shake flask cultures was caused in a bioreactor by reduction of the agitation rate. Transient oxygen limitation, which has been described to eventually occur in the feed-zone of large-scale bioreactors, was mimicked in a two-compartment scale-down bioreactor consisting of a stirred tank reactor and a plug flow reactor (PFR) with continuous glucose feeding into the PFR.In both models formate accumulated up to about 20 mM in the culture medium without addition of selenium, molybdenum and nickel. By addition of these trace elements the formate accumulation decreased below the level observed in well-mixed laboratory-scale cultures. Interestingly, addition of the extra trace elements caused accumulation of large amounts of lactate and reduced biomass yield in the simulator with permanent oxygen limitation, but not in the scale-down two-compartment bioreactor.ConclusionThe accumulation of formate in oxygen limited cultivations of E. coli can be fully prevented by addition of the trace elements selenium, nickel and molybdenum, necessary for the function of FHL complex. For large-scale cultivations, if glucose gradients are likely, the results from the two-compartment scale-down bioreactor indicate that the addition of the extra trace elements is beneficial. No negative effects on the biomass yield or on any other bioprocess parameters could be observed in cultures with the extra trace elements if the cells were repeatedly exposed to transient oxygen limitation.

Operators with Singular Trace Conditions on a Manifold with Edges

We establish a new calculus of pseudodifferential operators on a manifold with smooth edges and study ellipticity with extra trace and potential conditions (as well as Green operators) at the edge. In contrast to the known scenario with conditions of that kind in integral form we admit in this paper ‘singular’ trace and Green operators. In contrast to standard conditions in the theory of elliptic boundary value problems (like Dirichlet or Neumann conditions) our singular trace conditions, in general, do not act on functions that are smooth up to the boundary, but admit a more general asymptotic structure. Their action is now associated with the Laurent coefficients of the meromorphic Mellin transforms of functions with respect to the half-axis variable, the distance to the edge.

(f, x) Migration — Some Side Issues

Conventional methods of treating boundaries in finite difference (f, x) migration, namely padding in both space and time, have the disadvantage of increasing the data volume. This increase, whilst acceptable for 2-D processing, becomes uneconomical in the 3-D arena. Dipping events move up-dip during the migration process. Dips close to the sides of the data that move outside the data range can be reflected back if the boundary conditions are poorly set. This results in misleading events appearing in the migrated data. The addition of extra zero trace padding allows these events to move out of the data and so avoids these artefacts. The alternative to padding with zero traces is to use absorbing side boundary conditions. Absorbing sides have been proposed by several authors. A method developed by Clayton and Engquist is reviewed in detail, and implementation issues are discussed. Although this method is exact for only one propagation angle, it is found to attenuate significantly the reflections of other dipping events. Time padding is used to avoid the wraparound that causes shallow data to reappear as noise at later times in the migrated result. Wraparound is inherent in (f, x) finite difference migration, because of the cyclic nature of the fast Fourier transform. The time padding increases the run time of both the fast Fourier transform and the migration. Clearly, it is desirable to find a technique to remove the wraparound and so avoid the need for costly time padding. Kjartansson showed a method for wraparound removal for the case when the sampling interval is equal to the migration time step or depth interval. In practice, however, a coarser time step is usually employed. A new generalised method has been developed for wraparound removal under these conditions of coarse time step. The technique is applied at each time step extrapolation. Although this obviously involves more computation, the method is more efficient than using extra time padding. Both these techniques, the absorbing side boundaries and the wraparound removal, can be used in 2-D and one-pass 3-D implementations. Without the need for extra padding, migration run times and hence costs are reduced. The methods are demonstrated on synthetic data. The results compare well with those obtained using conventional padding, with a considerable reduction in run time.

Interior Egg Quality: Improvement by Distillers Feeds and Trace Elements

The effect of including distillers dried grains with solubles (DDG/S), additional trace minerals, and other supplements in a corn-soy ration for laying hens on changes in interior egg quality as measured by Haugh units was investigated. In the first experiment, both 10% DDG/S and 10% brewers dried grains significantly increased Haugh units. In the second experiment Haugh units were again significantly increased by 10% DDG/S but this supplement did not counteract a marked depression in Haugh units caused by adding 20 mg/kg vanadium to the diet. Feeding different levels of DDG/S in a third experiment showed that a level of 2.5% significantly increased Haugh units but a level of 10% was needed for a maximum response. Adding extra trace elements, but not doubling the vitamin premix, significandy increased Haugh units. In a fourth experiment, adding extra Fe, Cu, Zn, Mn, and Se significantly increased Haugh units, but V, Sn, Ni, and Mo did not. Neither DDG/S nor distillers dried solubles significantly affected Haugh units in a fifth experiment. The results of these experiments show that feed ingredients such as DDG/S and brewers dried grains contain a factor that generally improves interior egg quality and suggest that the factor may be a trace element(s).

Effects of Diet and Light During the Pre-Breeder Period, and of Diet During the Breeder Period on Turkey Breeder Performance

Based on two experiments each involving 150 Beltsville or Medium White female turkeys in the pre-breeder period and reduced to 144 in the breeder period, the following results were obtained. When a low energy diet containing 44 percent oat mill feed instead of a currently used high energy diet was fed from 20 to 32 weeks of age, average feed consumption increased 49 percent with only a small decrease in body weight gain. A small reduction in body weight gain was also achieved by feeding the high energy diet on a restricted intake basis saving 10 percent in feed consumption. Fortification of the pre-breeder diet with extra vitamins, and added bacitracin and ethoxyquin failed to influence the results of these measurements, but did tend to increase subsequent egg production (.10 > P > .05). By restricting the amount of light to 6 hours per day during most of the 12-week pre-breeder period of turkey females hatched on October 17, body weights at 32 weeks of age were increased 5.1 percent, feed consumption decreased 12.2 percent, and subsequent egg production was delayed and tended to be increased only slightly (.10 > P > .05). The addition of 6 and 12 percent menhaden fish meal to breeder turkey diets increased hatchability of fertile eggs from 72.4 to 78.7 percent (P < .05) and hatchability of all eggs incubated from 57.3 to 64.6 percent (P < .01); and the addition of extra trace minerals increased fertility of eggs incubated from 78.7 to 83.6 percent (P < .05). Egg production, fertility and hatchability from these hens during the 20-week production periods were not significantly influenced by the energy content of the pre-breeder diets or by adding extra vitamins to the breeder diets in these two experiments.

Trichomonads from poikilotherms: nutritional and physiological notes.

SYNOPSIS. Several trichomonads from poikilotherms (Hypotrichomonas acosta, Monocercomonas colubrorum and M. sp., Trichomonas batrachorum, and Tritrichomonas augusta) grew in a nearly‐defined medium to a level of 10–40% that permitted with media containing casein digests; T. augusta (4 strains) grew best. The defined medium contained TEM‐4T (a semisynthetic fat based on beef‐tallow fatty acids) and ascorbyl “palmitate” as sources of fatty acids. Besides ascorbyl palmitate, thiomalic and ascorbic acids, and tocopherol served as reducers and antiöxidants. High concentrations of nucleotides (adenylic, cytidylic, guanylic, and uridylic acids) seemed necessary. Indigo carmine was a useful redox indicator; the flagellates never grew in the oxidized zone. Extra trace elements and amino acids or rich natural media permitted better growth at about 34.5°C—the upper temperature limit for these trichomonads, raising the issue of a biochemical basis of a thermal barrier to the invasion of warmblooded hosts. Except for the limited carbohydrate in the nucleotides, carbohydrate could be omitted, the main substrates being a combination of glycerol, acetate, and gylcero‐phosphate, posing the question of the identity of the anaerobic, presumably non‐glycolytic, energy‐yielding pathway.