DM Distribution Research Articles

Evolution of the DM distribution function in the density spikes around PBHs

At the cosmological stage of radiation dominance, dark matter density spikes should form around primordial black holes. In the case when dark matter particles are able to annihilate, the density in the central regions of the spikes decreases due to the elimination of particles, which gives an upper bound on the central density. In this paper, the modification of the central density profile is investigated, taking into account the distribution of the particle orbits. The orbits in spike around a primordial black hole are very elongated, almost radial, and the angular momentum distribution has an exponential form. For such an initial distribution function, it is obtained that a cusp with the exponent ≈-0.7 is formed in the central region, instead of an annihilation plateau. The presence of the cusp provides some correction to the rate of dark matter annihilation around primordial black holes.

Neutrino masses and self-interacting dark matter with mass mixing Z − Z′ gauge portal

New light gauge bosons can affect several low-energy experiments, such as atomic parity violation or colliders. Here, we explore the possibility that a dark sector is charged under a new U(1) gauge symmetry, and the portal to the Standard Model is through a Z − Z′ mass mixing. In our approach, breaking the new gauge symmetry is crucial to generate neutrino masses. We investigate the parameter space to reproduce neutrino masses, the correct dark matter relic abundance, and to produce the observed core-like DM distribution in galactic centers.

Evaluation of the residual life of a pipeline under conditions of erosion-corrosion wear

The article is devoted to solving the problem of determining the residual resource of pipelines. Erosion and corrosion damage was selected as the main negative factor that is being investigat-ed and affects the service life. In particular, it is the erosion-corrosion damage of the “pitting corrosion” type which is one of the most serious and widespread types of corrosion that can cause a significant shortening of the service life of technical objects and an increase in the cost of their maintenance, repair, and replacement. The residual thickness of the pipeline wall was chosen as the defining parameter. In case there are no significant failure statistics, a probabilis-tic-physical approach is used to assess the objective technical condition and predict the residual resource of the specified structures. The approach to durability assessment is based on a proba-bilistic model and uses the DM failure distribution that is specially formalized on the basis of a Markov random process of the diffusion type with a constant rate. The DM distribution most accurately aligns statistical data on failures of mechanical objects, which are pipelines for vari-ous purposes. It is very valuable that the parameters of the used model are based on a physical interpretation, which allows for estimating the parameters of the model when there are no fail-ure statistics. The analysis is based on two key parameters: the average rate of change of the defining parameter change (the performance criterion) and the coefficient of variation of the generalized degradation process. The paper provides an example in which the residual resource of a pipeline section is determined with the help of the probabilistic-physical method. The re-sults obtained during the calculations are compared with the results obtained by another tradi-tional method. Refining the assessment of the residual resource of the pipeline section will al-low for optimizing the operating costs by reducing the intervals between repairs.

Modelling repetition in zDM: A single population of repeating fast radio bursts can explain CHIME data

AbstractRegardless of whether or not all fast radio bursts (FRBs) repeat, those that do form a population with a distribution of rates. This work considers a power-law model of this population, with rate distribution$\Phi_r \sim R^{{\gamma_r}}$between${R_{\rm min}}$and${R_{\rm max}}$. ThezDMcode is used to model the probability of detecting this population as either apparently once-off or repeat events as a function of redshift,z, and dispersion measure, DM. I demonstrate that in the nearby Universe, repeating sources can contribute significantly to the total burst rate. This causes an apparent deficit in the total number of observed sources (once-off and repeaters) relative to the distant Universe that will cause a bias in FRB population models. Thus instruments with long exposure times should explicitly take repetition into account when fitting the FRB population. I then fit data from The Canadian Hydrogen Intensity Mapping Experiment (CHIME). The relative number of repeat and apparently once-off FRBs, and their DM, declination, and burst rate distributions, can be well explained by 50–100% of CHIME single FRBs being due to repeaters, with${R_{\rm max}} > 0.75$d$^{-1}$above$10^{39}$erg, and${{\gamma_r}} = -2.2_{-0.8}^{+0.6}$. This result is surprisingly consistent with follow-up studies of FRBs detected by the Australian Square Kilometre Array Pathfinder (ASKAP). Thus the evidence suggests that CHIME and ASKAP view the same repeating FRB population, which is responsible not just for repeating FRBs, but the majority of apparently once-off bursts. For greater quantitative accuracy, non-Poissonian arrival times, second-order effects in the CHIME response, and a simultaneous fit to the total FRB population parameters, should be treated in more detail in future studies.

Assessing Raindrop Breakup Parameterizations Using Disdrometer Observations

Abstract An intercomparison of raindrop mean diameter frequency distribution (RDFD) is performed for numerical simulations of precipitating cloud systems using an array of models and microphysics schemes. This includes results from the Regional Atmospheric Modeling System (RAMS) double-moment microphysics, the Hebrew University Cloud Model bin microphysics (HUCM) interfaced to the RAMS parent model, and the Weather Research and Forecasting (WRF) Model with the Thompson, Morrison, double-moment 6-class (WDM6), and National Severe Storms Laboratory (NSSL) double-moment schemes. Simulations are examined with respect to the raindrop size distribution (DSD) volume-number mean diameter (Dm) and intercept parameter (Nw). When compared to a suite of disdrometer observations, the RDFD resulting from each microphysics scheme exhibits varying degrees of mean drop size constraints and peaks in the frequency distribution of Dm. A more detailed investigation of the peaked RDFD from the RAMS simulations suggests that the parameterization of raindrop collisional breakup can impose strong limitations on the evolution of simulated drop growth. As such, a summary and comparison of the drop breakup parameterizations among the aforementioned microphysics schemes is presented. While some drop breakup parameterizations are adjusted toward the observations by modifying the threshold diameter for the onset of breakup, this study explores the use of a modified maximum breakup efficiency. This method permits the parameterization to retain its threshold breakup diameter, while limiting the strength of drop breakup and permitting a broader range of drop sizes. As a result, the simulated mean drop sizes are in better agreement with observations.

The Characteristics of Raindrop Size Distributions in Different Climatological Regions in South Korea

To understand the microphysical characteristics of rainfall in four different climatological regions (called BOS, BUS, CPO, and JIN) in South Korea, DSDs and their variables, including the mass-weighted mean diameter (Dm) and normalized number concentration (logNw), were examined. To examine the characteristics of DSDs at four sites with different climatology and topography, data measured from Parsivel disdrometer and wind direction from Automatic Weather System (AWS) during rainy seasons from June to August for three years (2018 to 2020) were analyzed. The DSDs variables were calculated using Gamma distribution model. In the coastal area, larger raindrops with a lower number concentration occurred, whereas smaller raindrops with a higher number concentration dominated in the middle land and mountain region. The mountain area of CPO and middle land area of JIN had a larger contribution to the rain rate than that of the coastal area of BOS and JIN in the range of the smallest diameter. The contribution of the drop size to the total number concentration at the CPO and JIN sites was larger (smaller) than that at BOS and BUS in the smallest (larger) diameter. The average shape and slope parameter of gamma model were higher values at the mountain area than at other sites for both rain types, Z-R relation and polarimetric variables were also shown different values at the four studied sites. The intercept coefficient of Z-R relation showed higher values in the mountain area and middle land area than the coastal area. The slope values of Z-R relation were the smallest in the mountain area. The polarimetric variables of ZH and ZDR were shown highest (lowest) value at the coastal region of BOS (mountain area of CPO) site for both rain types. The Dm-rose, which shows the Dm distributions with the wind direction, was used in this study. In the coastal area (mountain and middle land area), the dominant wind was east–southeast (east) direction. The ratio of the smaller diameter to the middle size at BOS was much smaller than that at CPO. In the analysis of the hourly distribution of the Dm and logNw, there were two and four peaks of Dm at BUS and BOS, respectively. There was one peak of the Dm at the CPO and JIN sites. The time variation of the Dm was much higher than that of the logNw.

Relationship of Vascular Access Flow with Impaired Right Ventricular Function in Chronic Hemodialysis Patients

Background: Cardiovascular events are the leading cause of morbidity and mortality in chronic hemodialysis patients. Impaired right ventricular function is often associated with poor survival in hemodialysis patients. Objective: To determine the effect of vascular access flow (AVFs) of right ventricular function. Methods: This cross-sectional study was done in Department of Nephrology, DMCH during the period January 2020 to July 2021. End stage renal disease patient underwent hemodialysis for ≥3 months were recruited in the study. Patients with chronic respiratory disease, severe valvar heart disease, AVFs flow<200ml/min were excluded. Right ventricular function was assessed by Tricuspid Annular Plane Systolic Excursion (TAPSE) through echocardiography and AVFs blood flow by color duplex study. History for diabetes mellitus, glomerulonephritis and hypertension were retrieved from medical records in addition to variable age and gender. Results of the biochemical variable also retrieved. TAPSE ≤16mm was taken as cut off to characterize subjects as Group I, impaired right ventricular function. Those with >16mm termed as Group II, normal right ventricular function. Data were expressed as mean±SD and number (present) as appropriate. Unpaired student t test, invariable and multivariable analysis were performed as applicable using statistical package for social science (SPSS). p<0.05% was taken as level of significant. Results: of the total 80 subject 26 constituted Group I and 54 in Group II. Distribution of male and female did not show any statistical association. Distribution of gender in two groups did not show any statistical association. Distribution of the subjects in age cluster was similar in the two groups. History of DM, GN, and HTN distribution in the two groups was also similar. Duration of hemodialysis (mean±SD) in Group I was 28.04 months and 26.39 months in Group II; two group did not show statistical difference (p=0.529). Systolic blood pressure was 163 mmHg and 160mmHg in Group I and Group II respectively and diastolic blood pressure (mean±SD, mmHg) was 92mmHg and 92mmHg in Group I and Group II respectively; did not statistical difference (p=0.283 and 0.960 respectively). AVFs blood flow 1603±382ml/min (mean±SD,ml/min) in group I was significantly higher compared to the counterpart group II 791±189ml/min. The trend was supported by the significant (p=0.001) inverse relationship between TAPSE and AVFs blood flow. In Group I radio cephalic and brachiocephalic AV fistula distribution was 12 vs 24 (46.2 vs 53.8%) which in the Group II was 51 vs 3(94.4 vs 5.6%). Conclusion: Data concluded that brachiocephalic AVFs lead to significantly higher blood flow than the radio cephalic fistula resulting impaired right ventricular function, which reconfirmed the usefulness of distal AVF as a vascular access in patient for hemodialysis.

The z–DM distribution of fast radio bursts

ABSTRACT We develop a sophisticated model of fast radio burst (FRB) observations, accounting for the intrinsic cosmological gas distribution and host galaxy contributions, and give the most detailed account yet of observational biases due to burst width, dispersion measure, and the exact telescope beamshape. Our results offer a significant increase in both accuracy and precision beyond those previously obtained. Using results from ASKAP and Parkes, we present our best-fitting FRB population parameters in a companion paper. Here, we consider in detail the expected and fitted distributions in redshift, dispersion measure, and signal to noise. We estimate that the unlocalized ASKAP FRBs arise from z < 0.5, with between a third and a half within z < 0.1. Our predicted source-counts (‘logN–logS’) distribution confirms previous indications of a steepening index near the Parkes detection threshold of 1 Jy ms. We find no evidence for a minimum FRB energy, and rule out Emin > 1039.0 erg at 90 per cent C.L. Importantly, we find that above a certain DM, observational biases cause the Macquart (DM–z) relation to become inverted, implying that the highest-DM events detected in the unlocalized Parkes and ASKAP samples are unlikely to be the most distant. More localized FRBs will be required to quantitatively estimate this effect, though its cause is a well-understood observational bias. Works assuming a 1–1 DM–z relation may therefore derive erroneous results. Our analysis of errors suggests that limiting factors in our analysis are understanding of FRB spectral behaviour, sensitivity response of search experiments, and the treatment of the repeating population and luminosity function.

Dark Matter Sterile Neutrino from Scalar Decays

We place constraints on DM sterile neutrino scalar decay production (SDP) assuming that sterile neutrinos representa fraction from the total Cold Dark Matter energy density. For the cosmological analysis we complement the CMB anisotropy measurements with CMB lensing gravitational potential measurements, that are sensitive to the DM distribution to high redshifts and with the cosmic shear data that constrain the gravitational potential at lower redshifts than CMB. We also use the most recent low-redshift BAO measurements that are insensitive to the non-linear effects, providing robust geometrical tests. We show that our datasets have enough sensitivity to constrain the sterile neutrino mass mνs and the mass fraction fS inside the co-moving free-streaming horizon. We find that the best fit value mνs=7.88±0.73 keV (68% CL) is in the parameter space of interest for DM sterile neutrino decay interpretation of the 3.5 keV X-ray line and that fS=0.86±0.07 (68% CL) is in agreement with the upper limit constraint on fS from the X-ray non-detection and Ly-α forest measurements that rejects fS=1 at 3σ. However, we expect that the future BAO and weak lensing surveys, such as EUCLID, will provide much more robust constraints.

Self-interacting neutrino portal dark matter

We present a realistic, simple and natural model of strongly-interacting dark matter based on the neutrino-portal paradigm. The strong interactions at small velocities are generated by the exchange of dark photons, and produce the observed core-like DM distribution in galactic centers; this effect could be spoiled by the formation of DM bound states (also due to dark-photon effects), which we avoid by requiring the DM candidates to be light, with masses below O(10 GeV). The mixing of the dark photon with the Z and ordinary photon is strongly suppressed by introducing a softly-broken discrete symmetry similar to charge conjugation, which also ensures that the dark photon life-time is short enough to avoid restrictions derived form big-bang nucleosynthesis and large-scale structure formation. Other constraints are accommodated without the need of fine tuning, in particular nucleon scattering occurs only at one loop, so direct detection cross sections are naturally suppressed. Neutrino masses are generated through the inverse see saw.

SIMULATION MODEL OF THE ADAPTIVE MAINTENANCE PROCEDURE OF COMPLEX RADIOELECTRONIC FACILITIES

Context. The process of maintenance of modern radio-electronic facilities is aimed at supporting the serviceability or performance of the facilities during their technical operation. Specifications for achieving high reliability of operation are often contrary to other required characteristics, such as reducing the size of the product, obtaining high accuracy, reducing the cost of operation, etc. Therefore, the problem of the optimal choice of maintenance parameters to solve various tasks of operation using different criteria is relevant.Objective. The objective of this research is developing approaches to determine the optimal parameters of the process of adaptive maintenance.Method. Within the framework of the general simulation statistic model of the process of maintenance and repair of a complex facility (REF), we have developed a simulation model for parameter optimization of one of the maintenance strategies. The general simulation statistic model is intended to simulate the process of the TMR of the FEF in order to predict the reliability and value of the facility operation. Optimization of maintenance parameters improves both indicators of reliability of the facility and economic indicators of operation of the facility as a whole. The parameters are optimized on the basis of the criterion of a minimum specific cost of the REF operation or the criterion of the maximum ratio of technical use. In both cases, limitation means the required value of the mean time between failures of the facility, and as a method of optimization, we use the method of directed search within the scope of the maintenance parameters. An expert can participate in the process of finding an optimal solution, being involved in the analysis of intermediate data and making a decision on the completion of the search process.Results. The improved method of optimizing the maintenance parameters is a mathematical and algorithmic basis for the general software of the simulation statistic model of the maintenance and repair process. The method is programmed and tested in solving testing tasks. The results of the computational experiment are illustrated in the tabular form.Conclusions. In our work we have developed the simulation model of the process of adaptive maintenance of a complex radioelectronic facility. The model enables to substantially simplify and automate the process of research and optimization of the adaptive maintenance parameters of a complex radio-electronic facility. By adding the least reliable elements gradually to a plurality of items subject to servicing and modeling the random moments of the failure time, the simulation model calculates the optimal maintenance options with the adaptive time of condition monitoring. The simulation model is based on the algorithmic model and algorithmic optimization methods for adaptive maintenance, developed in our research, and works in the ISMPN software environment. As a method of optimization, we use the method of directed search within the scope of the maintenance parameters, with a DN distribution as a mathematical reliability model for electronic components and DM distribution for mechanical components.The practical value of the research lies in developing software which optimizes the maintenance parameters and predicts the reliability and value of operation for the given REF. The results obtained are to be used when determining the requirements for the parameters of operation of both new facilities and those of the available stock.

FREQUENCY, DISTRIBUTION AND DETERMINANTS OF DIABETES MELLITUS IN ADULT ACUTE CORONARY SYNDROME POPULATION OF D.I.KHAN DIVISION, PAKISTAN

Background: Global Health Estimates 2015 has shown IHD as second leading global cause of death and 3rd leading global cause for DALYs for 2015. The objectives of this study were to determine frequency, distribution and determinants of DM in adult acute coronary syndrome (ACS) population of D.I.Khan Division, Pakistan. Materials & Methods: This cross-sectional study was conducted in Departments of Ophthalmology & Community Medicine, Gomal Medical College, D.I.Khan, from February 1, 2017 to April 30, 2017. 331 cases were selected with margin of error 4.511%, 90%CL and 25% prevalence of DM in 73,438 adults assumed to have IHD. All indoor adult patients of ACS were eligible. Sex, age groups, and residence and presence of DM were variables. Frequency and distribution were analyzed by count and percentage. Hypotheses for distribution were substantiated by chi-square goodness-of-fit and of association by chi-square test of association. Results: Out of 331 patients with ACS, 225 (68.0%) were men and 106 (32.0%) women, 221 (66.8%) ≤60 years and 110 (33.2%) >60 years, and 210 (63.4%) urban and 121 (35.6%) rural. Frequency of DM was 79/331 (23.87%). Out of 79 patients with DM, men were 44 (13.29%), women 35 (10.57%), age group ≤60 years 57 (17.22%), >60 years 22 (6.65%), urban 53 (16.01%) and rural 60 (7.85%). Our prevalence of DM was lower than expected (p=.00214), our distribution by sex was similar to expected (p=.4993) while our distribution for age groups (p=.01209) and residence (p=.00005) were not similar to expected. Presence of DM was associated to sex (p=.011) but not to age groups (p=.0304) and residence (p=.5241). Conclusion: Prevalence of DM in adult ACS population of D.I.Khan Division, Pakistan was found lower than expected. The prevalence was more in men than women, more in younger age group (≤60 years) than older age group (>60 years) and more in urban than rural population. Our prevalence of DM was lower than expected, our distribution by sex was similar to expected while our distribution for age groups and residence were not similar to expected. The presence of DM was associated to sex but not to age groups and residence.

Two-dimensional spatial error distribution of key tensiomyographic parameters

Tensiomyography detects the contraction time (Tc) and amplitude (Dm) of muscle belly thickening during maximal isometric twitch contraction. The assessment of both parameters is highly reliable; however, it seems that their calculation depends on the measurement point. The aim of the study was to determine spatial relative error distribution of Tc and/or Dm within a two-dimensional array of 27 (3 × 9) measurement points in comparison to the reference point (RP) in 12 male participants (22.5 ± 3.1 years). The RPs were determined as follows: in the biceps brachii (BB) at 50% of the humerus length; in the erector spinae (ES) at the height of the iliac crest; in the vastus lateralis (VL), vastus medalis (VM), and rectus femoris (RF) at 30%, 20%, and 50% of femur length above the patella, respectively. The surface area under the 3% relative error in Dm (BB: 4.0; VL: 3.8; VM; 8.2; RF: 6.2; ES: 2.4 cm2) was lower than in Tc (BB: 6.9; VL: 3.8; VM; 4.6; RF: 9.5; ES: 3.7 cm2), yielding merged values (BB: 3.9; VL: 3.7; VM; 4.8; RF: 5.1; ES: 2.4 cm2). Dm show twice as steep relative error rate when moving away from the RP in comparison to Tc, which seems to be less sensitive to spatial sensor positioning.

Dark Matter: An Efficient Catalyst for Intermediate-mass-ratio-inspiral Events

Abstract Gravitational waves (GWs) can be produced if a stellar compact object, such as a black hole (BH) or neutron star, inspirals into an intermediate-massive black hole of . Such a system may be produced in the center of a globular cluster or a nuclear star cluster and is known as an intermediate- or extreme-mass-ratio inspiral (IMRI or EMRI). Motivated by the recent suggestions that dark matter minispikes could form around IMBHs, we study the effect of dynamical friction against DM on the merger rate of IMRIs/EMRIs. We find that the merger timescale of IMBHs with BHs and NSs would be shortened by two to three orders of magnitude. As a result, the event rate of IMRIs/EMRIs are enhanced by orders of magnitude relative to that in the case of no DM minispikes. In the most extreme case where IMBHs are small and the DM minispikes have a steep density profile, all the BH in GCs and NSCs might be exhausted so that the mergers with NSs would dominate the current IMRIs/EMRIs. Our results suggest that the mass function of the IMBHs below 104 M ⊙ would bear imprints of the distribution of DM minispikes because these low-mass IMBHs can grow efficiently in the presence of DM minispikes by merging with BHs and NSs. Future space-based GW detectors, like LISA, Taiji, and Tianqin, can measure the IMRI/EMRI rate and hence constrain the distribution of DM around IMBHs.

Novel constraints on fermionic dark matter from galactic observables II: Galaxy scaling relations

We have recently introduced in paper I an extension of the Ruffini–Argüelles–Rueda(RAR) model for the distribution of DM in galaxies, by including for escape of particle effects. Being built upon self-gravitating fermions at finite temperatures, the RAR solutions develop a characteristic dense quantum core-diluted halo morphology which, for fermion masses in the range mc2≈ 10–345 keV, was shown to provide good fits to the Milky Way rotation curve. We study here for the first time the applicability of the extended RAR model to other structures from dwarfs to ellipticals to galaxy clusters, pointing out the relevant case of mc2=48 keV. By making a full coverage of the remaining free parameters of the theory, and for each galactic structure, we present a complete family of astrophysical RAR profiles which satisfy realistic halo boundary conditions inferred from observations. Each family-set of RAR solutions predicts given windows of total halo masses and central quantum-core masses, the latter opening the interesting possibility to interpret them as alternatives either to intermediate-mass BHs (for dwarf galaxies), or to supermassive BHs (SMBHs, in the case of larger galaxy types). The model is shown to be in good agreement with different observationally inferred scaling relations such as: (1) the Ferrarese relation connecting DM halos with supermassive dark central objects; and (2) the nearly constant DM surface density of galaxies. Finally, the theory provides a natural mechanism for the formation of SMBHs of few 108M⊙ via the gravitational collapse of unstable DM quantum-cores.

Yield and dry matter dynamics of vegetative and reproductive organs in Japanese and US soybean cultivars

ABSTRACTRecently, US soybean cultivars have exhibited higher yields than Japanese soybean cultivars. To identify the determinants for this yield difference in reference to dry matter dynamics, recently developed US cultivars and Japanese commercial cultivars were cultivated in drained paddy fields in 2012 and 2013. The total dry matter (TDM) of each cultivar was measured at the initial seed-filling stage (R5), at 30 d after R5, and at maturity (R8). From R5 to R8, the DM of abscised leaves and petioles were measured. The actual HI (with abscised leaves and petioles) and apparent HI (without abscised leaves and petioles) were determined at R8. US soybean cultivars showed higher yields and apparent TDM (without abscised leaves and petioles) than did Japanese cultivars at R8. However, the difference in actual TDM (with abscised leaves and petioles) production was not significant between US and Japanese cultivars at R8. On the other hand, the actual HI was higher in US cultivars than in Japanese cultivars. US cultivars exhibited a higher TDM distribution to the pod before R5 and a higher pod growth rate from R5 to 30 d after R5. US cultivars tended to show greater crop growth rates (CGRs) from R5 to 30 d after R5. The higher yield in US cultivars was associated with the higher actual HI, which was considered attributable to a greater TDM productivity during the seed-filling period and higher DM distribution in the pod before R5.

Sources of variation in corn silage and total mixed rations of commercial dairy farms

ABSTRACT Information on sources of variation in feed and diet characteristics is needed to develop appropriate strategies to reduce uncertainty and to separate true variation from that associated with measurements. The objectives were to determine sources of variation in DM content and particle size distribution in corn silage (CS) and TMR. Ten dairy farms in Argentina were visited on 3 consecutive days, samples of CS and TMR were taken, and an audit of feed management was conducted. Corn silage and TMR were sampled in duplicate each day. Variance components were calculated with the Mixed Linear Models of InfoStat for CS and Generalized Linear Mixed Models for TMR. For CS, the model included the effects of farm and day within farm, and for TMR, the model included farm, pen within farm, day within pen, and feed bunk site within pen. Residual effects accounted for sampling and analytical variation. Farm was the greatest source of variation for DM and particle size distribution of CS and TMR, explaining 40 to 92% of total variation. For CS, day within farm variation was greater compared with residual variation in DM (7 and 0.6%, respectively), meaning real changes occurred from one day to the other. For TMR, daily variation in DM content was high and possibly associated with feed management errors. For particle size distribution in TMR, sampling and assaying variation was greater than feed bunk site variation, indicating increased replication and averaging is needed to increase precision.

The astrophysical consequences of intervening galaxy gas on fast radio bursts

We adopt and analyze results on the incidence and physical properties of damped Ly$\alpha$ systems (DLAs) to predict the astrophysical impact of gas in galaxies on observations of Fast Radio Bursts (FRBs). Three DLA measures form the basis of this analysis: (i) the HI column density distribution, parameterized as a double power-law; (ii) the incidence of DLAs with redshift (derived here), $\ell(z)=A+B \arctan(z-C)$ with $A=0.236_{-0.021}^{+0.016}, B=0.168_{-0.017}^{+0.010}, C=2.87_{-0.13}^{+0.17}$ and (iii) the electron density, parameterized as a log-normal deviate with mean $10^{-2.6} cm^{-3}$ and dispersion 0.3dex. Synthesizing these results, we estimate that the average rest-frame dispersion measure from the neutral medium of a single, intersecting galaxy is DM$^{NM}_{DLA}=0.25$ pc/cm^3. Analysis of AlIII and CII* absorption limits the putative warm ionized medium to contribute DM$^{WIM}_{DLA}<20$pc/cm^3. Given the low incidence of DLAs, we find that a population of FRBs at z=2 will incur DM(z=2)=0.01 pc/cm^3 on average, with a 99% c.l. upper bound of 0.22 pc/cm^3. Assuming that turbulence of the ISM in external galaxies is qualitatively similar to our Galaxy, we estimate that the angular broadening of an FRB by intersecting galaxies is negligible ($\theta<0.1$mas). The temporal broadening is also predicted to be small, $\tau \approx 0.3$ms for a z=1 galaxy intersecting a z=2 FRB for an observing frequency of $\nu=1$GHz. Even with $\nu=600$MHz, the fraction of sightlines broadened beyond 25ms is only approximately 0.1%. We conclude that gas within the ISM of intervening galaxies has a minor effect on the detection of FRBs and their resultant DM distributions. Download the repository at https://github.com/FRBs/FRB to repeat and extend the calculations presented here.

The large-scale environment from cosmological simulations – I. The baryonic cosmic web

Using a series of cosmological simulations that includes one dark-matter-only (DM-only) run, one gas cooling-star formation-supernovae feedback (CSF) run and one that additionally includes feedback from active galactic nuclei (AGNs), we classify the large-scale structures with both a velocity-shear-tensor code (Vweb) and a tidal-tensor code (Pweb). We find that the baryonic processes have almost no impact on large-scale structures -- at least not when classified using aforementioned techniques. More importantly, our results confirm that the gas component alone can be used to infer the filamentary structure of the Universe practically un-biased, which could be applied to cosmology constrains. In addition, the gas filaments are classified with its velocity (Vweb) and density (Pweb) fields, which can theoretically connect to the radio observations, such as HI surveys. This will help us to bias-freely link the radio observations with DM distributions at large scale.

Effect of agitation time on nutrient distribution in full-scale CSTR biogas digesters

The aim of this work was to study the impact of reduced mixing time in a full-scale CSTR biogas reactor from 10 to 5 and to 2min in half an hour on the distribution of DM, acetic acid and FOS/TAC as a measure to cut electricity consumption. The parameters in the digestate were unevenly distributed with the highest concentration measured at the point of feeding. By reducing mixing time, the FOS/TAC value increases by 16.6%. A reduced mixing time of 2min lead to an accumulation of 15% biogas in the digestate.