Cent Drop Research Articles

The cosmic baryon partition between the IGM and CGM in the SIMBA simulations

ABSTRACT We use the simba suite of cosmological hydrodynamical simulations to investigate the importance of various stellar and active galactic nuclei (AGN) feedback mechanisms in partitioning the cosmic baryons between the intergalactic (IGM) and circumgalactic (CGM) media in the z ≤ 1 Universe. We identify the AGN jets as the most prominent mechanism for the redistribution of baryons between the IGM and CGM. In contrast to the full feedback models, deactivating AGN jets results in ≈20 per cent drop in fraction of baryons residing in the IGM and a consequent increase of CGM baryon fraction by ≈50 per cent. We find that stellar feedback modifies the partition of baryons on a 10 per cent level. We further examine the physical properties of simulated haloes in different mass bins, and their response to various feedback models. On average, a sixfold decrease in the CGM mass fraction due to the inclusion of feedback from AGN jets is detected in $10^{12}\, {\rm M}_{\odot } \le M_{\rm 200} \le 10^{14}\, {\rm M}_{\odot }$ haloes. Examination of the average radial gas density profiles of $M_{200} \gt 10^{12}\, {\rm M}_{\odot }$ haloes reveals up to an order of magnitude decrease in gas densities due to the AGN jet feedback. We compare gas density profiles from simba simulations to the predictions of the modified Navarro–Frenk–White model, and show that the latter provides a reasonable approximation within the virial radii of the full range of halo masses, but only when rescaled by the appropriate mass-dependent CGM fraction of the halo. The relative partitioning of cosmic baryons and, subsequently, the feedback models can be constrained observationally with fast radio bursts in upcoming surveys.

COVID 19 RAMIFICATIONS ON TOURISTIC RESULTS IN 2020

The number of COVID 19 infections worldwide by the end of September 2020 rose to more than 34 million cases. At the same time number of fatalities caused by the same virus exceeds one million. In the year 2020 about ten per cent drop of economic growth was experienced compared to the previous year due to COVID 19 crisis and with probably the biggest impact on tourism industry. The results of global tourist international arrivals in April, May and June 2020 with drop of 95-98 per cent are self-explanatory. Thus, stabile and continuing growth from the beginning of 21st century has been suddenly brutally interrupted returning the tourism industry on level of at least 30-40 years back, maybe even more. The consequences of COVID 19 on touristic results have been analysed in the paper. The analysis is based on four different geographical areas – global, European, Southeast European and Croatian, based on the last 20 years of tourism results. Since similar dramatic situation has also affected air transport industry, the correlation between the tourism and air carriers’ results in the last two decades is also considered in this paper. Different scenarios of the future recovery of tourism industry are considered in the paper.

Total number of births shrinking faster than fertility rates: fertility quantum decline and shrinking generation size in South Korea

ABSTRACT South Korea’s total fertility rate reached 1.3 in 2001 and hit a record low (0.92) in 2019. The total number of births shrank even faster, recording a 45.9 per cent drop between 2001 and 2019. To understand the declining births and the contributing demographic factors, I decompose the change in the birth rate into mean generation size, fertility quantum, and tempo distortions, and evaluate their relative contributions to the decline. The remarkable birth decline since 2001 is largely explained by fertility quantum decline, especially for second births, and shrinking generation size caused by the decline in female population size. Tempo distortions were strong, but given the marginal change since 2001, they contributed less and only in recent years. This study highlights unique features of East Asia’s low fertility, such as continued fertility decline and the long-term negative effects of reproducing generations’ low fertility. Findings might have implications for developing countries experiencing rapid fertility decline.

Gasoline price reforms and household consumption behaviour: Evidence from household‐level survey data in Saudi Arabia

AbstractIn January 2016, as a measure of energy price reform, the government of Saudi Arabia implemented a 50 per cent nationwide increase in gasoline prices of both higher (octane 95) and lower (octane 91) grades. We utilised more than 1800 responses from a nationwide survey designed to study gasoline consumption preferences among residents of Saudi Arabia to investigate the impact of this price reform. Our analysis shows that the January 2016 price hike was responsible for more than 20 per cent drop, on average, in gasoline consumption among residents of the country who used the lower grade, octane 91‐type gasoline. However, users of octane 95 surveyed in the post‐price‐adjustment period consumed 15 per cent more gasoline than those who were surveyed in the pre‐adjustment period. Moreover, the estimated demand elasticity decreases with the level of education, while income level tends to be positively associated with higher consumption in the higher‐price period than in the lower‐price period.

Disappearance of the Fe K α emission line in ultracompact X-ray binaries 4U 1543−624 and Swift J1756.9−2508

ABSTRACT We investigate the long-term variability of the iron K α line in the spectra of two ultracompact X-ray sources (UCXBs) with C/O-rich donors. We revisit archival observations from five different X-ray telescopes, over an ∼20-yr period. Adopting physically motivated models for the spectral continuum, we probe the long-term evolution of the source emission in a self-consistent manner enabling physical interpretation of potential variability of the primary X-ray continuum emission and/or any emission lines from reflection off the accretion disc. We find that the spectral shape and flux of the source emission (for both objects) has remained almost constant throughout all the observations, displaying only minor variability in some spectral parameters and the source flux (largest variation is an ∼25 per cent drop in the flux of Swift J1756.9−2508). We note a striking variability of the Fe K α line that fluctuates from a notable equivalent width of ∼66–100 eV in 4U 1543−624 and ∼170 eV in Swift J1756.9−2508 , to non-detections with upper limits of 2–8 eV. We argue that the disappearance of the iron line is due to the screening of the Fe K α line by the overabundant oxygen in the C/O-rich UCXBs. This effect is cancelled when oxygen becomes fully ionized in the inner disc region, resulting in the variability of the Fe K α line in an otherwise unaltered spectral shape. This finding supports earlier predictions on the consequences of H-poor, C/O-rich accretion disc on reflection-induced fluorescent lines in the spectra of UCXBs.

Financial Constraints and Likelihood of Product Innovation: Firm-level Evidence from China

This paper investigates how financial constraints affect a firm’s decision on whether to conduct product innovation. Theoretically, we show that a firm's optimal decision on product innovation is a function of its past decision, financial constraints and a set of control variables. Through influencing investment, financial constraints increase a firm's marginal cost of production, which eventually reduces the firm's probability of conducting product innovation. The theoretical modelling implies a set of population moments, which we fit with firm-level data of China's manufacturing sector from 2005 to 2007. Our estimations find that the more financially constrained a firm is, the less likely it will conduct product innovation. For a firm that innovates previously, a one unit increase in financial constraints results in around 0.9 per cent drop in the probability of innovation. In contrast, it leads to around 0.14 per cent decrease in the probability if a firm does not innovate previously.

Industrial Relations Reform, Firm‐Level Bargaining and Nominal Wage Floors

We investigate the impact of the 2011 industrial relations reform in Greece that made firms with less than 50 employees eligible to participate to firm‐level bargaining. Matching administrative contractual data with longitudinal firm‐level data we identify firms affected and not affected by the reform. We find that during the first post‐reform year, affected firms with less than 50 employees experienced a 4.8 per cent increase in the probability of firm‐level contracting and a 12 per cent drop in wage floors relative to not affected firms. We also report estimates regarding the post‐reform employment effect of firm‐level bargaining.

Numerical study on evaporation heat transfer characteristics of water in inclined microchannels with varying inlet vapor quality

PurposeThe purpose of this paper is to investigate the effects of gravity on the heat transfer behavior of the two-phase flow of water undergoing phase change. Most of the earlier studies of convective boiling considered systems where the gravity is neglected. In contrast, the authors investigated systems where the gravity is considered. The heat transfer characteristics of water during its evaporation in microchannel heat sink are studied for different channel inclinations.Design/methodology/approachComputational fluid dynamics software ANSYS Fluent is used for the computational study. The volume of fluids multiphase method available in the package is used to capture the vapor–liquid interface. Heat transfer studies are carried out for a rectangular microchannel having a characteristic dimension of 825 µm at different inclinations, which varied from −90° (vertically downward) to 90° (vertically upward). During each simulation, the vapor quality is set at the inlet. Uniform heat flux of 250 kW/m2is applied at the bottom wall of the channel in all orientations of the channel, keeping the upper wall insulated.FindingsAs compared to horizontal configuration, a significant increase in the values of heat transfer coefficient during the fluid flow in inclined microchannels is noticed. It is observed that the Nusselt number for the vertically upward (+90°) and horizontal (0°) configuration are similar and that for the 45° upward configuration exceeds other configurations. It is also observed that the heat transfer performance becomes lower in downward configurations; nearly 40-50 per cent drop in average Nusselt number is observed for a mass flux of 250 kg m-2s-1with respect to 45° inclined microchannel. This behavior can be attributed to the gravitational effect on the two-phase flow because of which the vapor phase being less dense moves away from the heated wall, whereas the primary phase being heavier moves towards the heated wall of the channel. Also, the conductivity of the liquid being higher than the vapor phase, as well as the aperture of the liquid being small during this process, its velocity increases resulting in the augmentation of heat transfer.Originality/valueUser-defined-functions for the mass and energy source terms have been written in C code and hooked in ANSYS Fluent to incorporate the phase change mechanism during the evaporation of water.

People, performance and place : How using perceptive and cognitive data can create inspiring and collaborative workspaces that enable growth and innovation

AECOM is a leading global infrastructure services provider. A major acquisition in 2015 led to the company rationalising its real estate, bringing about the opportunity to transform its workplaces and drive cultural and behaviour change across its offices in and around London. This paper sets out AECOM’s approach to the formation of its new Greater London Campus, the drivers underpinning the project, key features of the campus and measures used to identify changes in employee performance, collaboration and wellbeing. It primarily focuses on how return on investment (ROI) was achieved, with a spotlight on the campus headquarters in Aldgate Tower, East London, and the process used to capture the underlying metrics. A key objective was to go beyond spatial metrics and people’s perception of changes in performance to direct business impact. AECOM partnered with professional services firm AON’s talent assessment team to create a bespoke method of assessing performance, building off existing world-leading psychometric tests and including leading-edge wellbeing surveys. The post-occupancy evaluation (POE) results demonstrated a significant improvement, as evidenced by a three-fold value increase in cross-disciplinary working, a 10 per cent increase in creativity measures and a 26 per cent drop in attrition rates in the central London location. The paper concludes with key messages and learning points for future workplace transformation projects. It is important to note that this paper focuses on research in practice. The working hypothesis was to seek measurable connections between behaviour, space and business performance in a live working environment. Detailed descriptions of psychometric tests and opinion-based assessment are provided along with findings from a POE study.

Factors Influencing Time to Decrease in Intraoperative Parathyroid Hormone (ioPTH) Levels in Patients Undergoing Focused Parathyroidectomy (FP)

The aim of this study was to evaluate potential factors affecting the time period in which a 50 per cent parathyroid hormone (PTH) drop is observed. Eight-seven patients undergoing focused parathyroidectomy between 2011 and 2015, whose PTH values dropped to within normal range, were grouped according to whether they required > or ≤15 minutes after gland excision to achieve a 50 per cent PTH. Groups were compared according to preoperative PTH, calcium, age, glomerular filtration rate, and adenoma weight. Lower preoperative and preincision PTH levels were associated with requiring >15 minutes to achieve a >50 per cent drop in ioPTH. Time to >50 per cent ioPTH drop did not affect cure rates at one year, though a >15 minutes requirement was associated with higher serum calcium levels (P = 0.015). Lower baseline PTH and preincision PTH levels are significantly associated with a >15 minutes postexcision time to achieve a >50 per cent drop in ioPTH. Future analyses are warranted to determine whether a longer postexcision time threshold before proceeding with four-gland exploration is warranted in patients with primary hyperparathyroidism and mildly elevated preoperative PTH.

Experimental study of EUV mirror radiation damage resistance under long-term free-electron laser exposures below the single-shot damage threshold.

The durability of grazing- and normal-incidence optical coatings has been experimentally assessed under free-electron laser irradiation at various numbers of pulses up to 16 million shots and various fluence levels below 10% of the single-shot damage threshold. The experiment was performed at FLASH, the Free-electron LASer in Hamburg, using 13.5 nm extreme UV (EUV) radiation with 100 fs pulse duration. Polycrystalline ruthenium and amorphous carbon 50 nm thin films on silicon substrates were tested at total external reflection angles of 20° and 10° grazing incidence, respectively. Mo/Si periodical multilayer structures were tested in the Bragg reflection condition at 16° off-normal angle of incidence. The exposed areas were analysed post-mortem using differential contrast visible light microscopy, EUV reflectivity mapping and scanning X-ray photoelectron spectroscopy. The analysis revealed that Ru and Mo/Si coatings exposed to the highest dose and fluence level show a few per cent drop in their EUV reflectivity, which is explained by EUV-induced oxidation of the surface.

Intra-dialytic hypotension: Identifying patients most at risk.

Intra-dialytic hypotension (IDH) remains a frequent but serious complication of haemodialysis. We performed a retrospective observational analysis of our prevalent dialysis population extracting data from an online database. Four hundred and thirty-two patients underwent 21 consecutive outpatient dialysis sessions during the study period: Of the 9,072 dialysis sessions studied, 438 were complicated by episodes of IDH (4.8%). 266/432 patients were asymptomatic whilst 166/432 experienced at least one episode of IDH. Symptomatic patients had significantly lower pre-dialysis systolic blood pressures (137 mmHg compared with 146 mmHg p < 0.0001) and demonstrated a greater per cent drop in their systolic blood pressure (delta systolic) before and after dialysis (9.7% vs. 4.1% p < 0.0001). Patients taking either a single or no anti-hypertensive agents had a significantly higher delta systolic than those on two or more anti-hypertensive agents (7.6% vs. 2.2% p < 0.01) and were almost 50% more likely to suffer from IDH (RR = 1.48, p = 0.017). Using logistical regression we identified pre-dialysis systolic blood pressure and delta systolic blood pressure as strong predictor variables for IDH (p < 0.0001). We constructed a model able to calculate the risk of an individual patient suffering with IDH using delta systolic and pre-dialysis systolic blood pressure. A ROC analysis suggests this to be an accurate model (AUC = 0.79). Delta systolic blood pressure is clinically useful in identifying patients most at risk of IDH. Anti-hypertensive medication use is associated with a lower delta systolic and a lower risk of IDH.

Management of foot and mouth disease in a dairy farm: By ethnoveterinary practice

Gruel feeding remitted in rapid recovery of foot and mouth disease (FMD) affected dairy cows. The gruel was prepared by cooking equal proportion of whole rice, wheat flour and finger millet flour in adequate quantity of water, jaggery (10%) and mineral mixture. Four organized dairy cattle farms, affected with FMD were selected, where animals at first and second dairy farms were fed gruel @ 2 kg/day for 20 days, at the third dairy farm 2 kg/ day/animal for 10 days and in the fourth farm no gruel was given. Wounds were sprayed with 1% KMnO4 solution and then applied with paste of honey (50%, v/v) and finger millet flour. Topical application of honey- finger millet flour paste, remitted in observation of pain relief in cows having tongue lesions and healing of the tongue/mouth wounds in 3 days thereby enabling the cows to resume eating. The per cent drop in milk yield in FMD affected cows in the first, second, third and fourth dairy farms was 85, 67, 45 and 81 respectively, regain by 80– 100 % in the treatment group after 16 to 20 days post infection, while in untreated animals, only 50% milk yield could be achieved at day 30–35 post infection. Therefore, gruel being low cost, locally available and easy to apply at farm level for rapid relief to the affected cows and faster improvement in daily milk yield helps in improving economic status of small, marginal farmers or livestock holders.

Gender Bias in Education During Conflict: Evidence from Assam

Using a large-scale novel panel dataset (2005–14) on schools from the Indian state of Assam, we test for the impact of violent conflict on female students' enrollment rates. We find that a doubling of average killings in a district-year leads to a 13 per cent drop in girls' enrollment rate with school fixed effects. Additionally, results remain similar when using an alternative definition of conflict from a different dataset. Gender differential responses are more negative for lower grades, rural schools, poorer districts, and for schools run by local and private unaided bodies.

Effect of Clinical Ketosis on Milk Yield in Mehsana Buffaloes

A study was conducted to assess the factors influencing the economic losses due to ketosis by gathering data from samples of eighteen ketotic Mehsana buffaloes. The study outlines the effect of ketosis in eighteen buffaloes. Three (16.67%) of 18 ketotic buffaloes showed 20-30 percent drop in milk yield, whereas 40-50 per cent drop in production was exhibited by 7 (38.89%) buffaloes. The average drop in daily milk yield was recorded to be 3.40+0.27 liters (34.24%) and the recovery after treatment could restore only 22.52 per cent (3.24+026 liters) milk per day. Decline in milk yield from 25.92 percent in 0 to 1 month of lactation to 40.72 percent at 3-4 month postpartum with an increasing trend.

Distance and utilisation of out-of-hours services in a Norwegian urban/rural district: an ecological study

BackgroundLong travel distances limit the utilisation of health services. We wanted to examine the relationship between the utilisation of a Norwegian out-of-hours service and the distance from the municipality population centroid to the associated casualty clinic.MethodsAll first contacts from ten municipalities in Arendal out-of-hours district were registered from 2007 through 2011. The main outcomes were contact and consultation rates for each municipality for each year. The associations between main outcomes and distance from the population centroid of the participating municipalities to the casualty clinic and were examined by linear regression. Demographic and socioeconomic factors were included in multivariate linear regression. Secondary endpoints include association between distance and rates of different first actions taken and priority grades assessed by triage nurses. Age and gender specific subgroup analyses were performed.Results141 342 contacts were included in the analyses. Increasing distance was associated with marked lower rates of all contact types except telephone consultations by doctor. Moving 43 kilometres away from the casualty clinic led to a 50 per cent drop in the rate of face-to-face consultations with a doctor. Availability of primary care doctors and education level contributed to a limited extent to the variance in consultation rate. The rates of all priority grades decreased significantly with increasing distance. The rate of acute events was reduced by 22 per cent when moving 50 kilometres away. The proportion of patients above 66 years increased with increasing distance, while the proportion of 13- to 19 year olds decreased. The proportion of female patients decreased with increasing distance.ConclusionsThe results confirm that increasing distance is associated with lower utilisation of out-of-hours services, even for the most acute cases. Extremely long distances might compromise patient safety. This must be taken into consideration when organising future out-of-hours districts.

Characterisation of poly(acrylamide‐co‐acrylic acid) mixed with anthocyanin pigment from hibiscus sabdariffa l.

PurposeThe purpose of this paper is to develop a new water based coating system composed of poly(acrylamide‐co‐acrylic acid) and anthocyanin colourant extracted from Hibiscus sabdariffa L. and characterise the system.Design/methodology/approachAnthocyanin from Hibiscus sabdariffa L. (roselle) calyxes was extracted using optimised water extraction method with ratio of calyxes to water being 1:2. UV‐Vis absorption spectroscopy was conducted on the anthocyanin extract to monitor its degradation. Poly(acrylamide‐co‐acrylic acid) was mixed with the extracted anthocyanin solution in two different weight ratios. The mixtures were coated on glass substrate and let to cure for approximately one day. FTIR spectroscopy was conducted on the samples to determine their functional groups and identify the compounds in the samples. Cross hatch test was performed on the samples to determine the adhesion properties. Thermal degradation of the samples was determined through thermogravimetric analysis. Surface roughness of the samples was studied by atomic force microscopy. Colour stability was determined before and after UV irradiation.FindingsAnthocyanin pigment from roselle extracted with water was found to be stable with 6.0 per cent drop in absorbance value over the 15 day period. The reaction rate was found to be 0.000181 h−1, and the half life was calculated to be 3,850 hours. Better adhesion of the samples to the glass substrate was due to the higher concentration of poly(acrylamide‐co‐acrylic acid). Thermogravimetric analysis revealed similar thermal stability of the samples. Surface roughness study revealed that sample with higher anthocyanin content has higher surface roughness. Colour stability of the 20PBR was found to be better than 10PBR.Research limitations/implicationsUsage of poly(acrylamide‐co‐acrylic acid) as coating is limited by its weak water resistance property. Improvement could be made in this direction for future applications.Practical implicationsMixture of water‐based polymer and anthocyanin colourant from roselle has been developed into coating for the first time. Commercialisation is possible if more research is conducted towards water resistance property of poly(acrylamide‐co‐acrylic acid), storage condition for the pigment and coating, and mass production of the pigment.Originality/valueIncorporation of anthocyanin pigment into water based coating is the first of its kind.

Influence of the volute on the flow in a centrifugal compressor of a high-pressure ratio turbocharger

The asymmetric influence of the volute on the flow in a transonic, high-pressure ratio centrifugal compressor at off-design conditions was investigated. Fully three-dimensional viscous steady-state computational fluid dynamics (CFD) was applied to simulate the flow in a 4.2:1 design pressure ratio compressor for automotive application. Computed performance characteristics are presented for low- and high-pressure ratio operating conditions, with and without an overhung volute. The volute was found to severely harm aerodynamic stability of the investigated compressor when operating at lower than design mass flow. The relative narrowing effect of the volute on compressor map width increases with pressure ratio up to a 42 per cent drop in stable flow range at design speed. The inter-passage variations in performance quantities and the influence of the volute tongue region are discussed in detail. The circumferential variations of incidence angle correlate with rotational speed, which, in combination with the higher sensitivity to incidence angle at transonic inflow conditions, seems to deteriorates stability when transonic inflow conditions are reached.

Measures of blood loss and red cell transfusion targets for caesarean delivery complicated by placenta praevia

The objective of this study was to assess the association between transfusion, per cent drop in haemoglobin (Hb), and estimated blood loss during the delivery and the first postoperative week following caesarean delivery for placenta praevia. Clinical data predictive of an objective laboratory test for risk of haemorrhage and the need for transfusion were investigated. Transfusions outside national Guidelines were noted. Retrospective observational study of patients with placenta praevia, who were delivered consecutively by caesarean section at Royal Brisbane and Women's Hospital from 1999 to 2005. University-affiliated tertiary hospital. All caesareans were performed by one or more consultant obstetricians, gynaecology oncology surgeons and registrar assistants. Seventy-one (28.9%) of 246 patients with placenta praevia were transfused, with 45 of these receiving three or more red cell units. The antenatal Hb fell by a mean of 20.2% (SD 13.5). The average operative haemorrhage was estimated as 1225 mL (SD 996). No patient or surgical factors were significantly associated with changes in Hb. There was a significant association between per cent fall in antenatal Hb and both transfusion P < 0.001 and estimated loss P = 0.002. After transfusion, the Hb of 19 patients was higher than that recommended by Guidelines. Whether transfusion is necessary, but not the number of red cell units, can be planned by the effect of haemorrhage on antenatal Hb during delivery by caesarean section complicated by placenta praevia.

Endoscopist-Administered Propofol: A Retrospective Safety Study

Propofol is an anesthetic agent that is commonly used for conscious sedation. Propofol has advantages as a sedative agent for endoscopic procedures including rapid onset, short half-life and rapid recovery time. However, concerns exist regarding the potential for respiratory depression, hypotension, perforation due to deep sedation and the need for monitoring by an anesthetist. Propofol has been used under endoscopist supervision at the Stanton Territorial Hospital in Yellowknife, Northwest Territories since 1996 (approximately 7000 cases). A retrospective chart review of endoscopic procedures conducted at the Stanton Territorial Hospital between January 1996 and May 2007 was performed. A random sample of 680 procedures was reviewed from a total of 6396 procedures. The mean (+/- SD) baseline systolic blood pressure (SBP) was 122.8+/-17.0 mmHg. The mean lowest SBP was 101.7+/-14.5 mmHg. The mean absolute drop in SBP was 21.1+/-16.7 mmHg, with a mean per cent drop of 16.3%+/-11.7%. Eighty-eight patients (12.9%) developed transient hypotension (SBP lower than 90 mmHg). All patients regained normal blood pressure spontaneously on repeated measurement. No patients required intravenous fluid resuscitation. The mean O2 saturation was 96.4%+/-2.1%. One patient (0.1%) transiently desaturated (O2 saturation 89%), but recovered spontaneously on repeat measurement with no intervention. No procedures were aborted for patient safety. There were no major complications, including perforation or death. There was one mucosal tear during nontherapeutic colonoscopy (0.1%). Propofol can be safely administered in a community hospital setting under endoscopist supervision, with no additional support or monitoring.