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This work thoroughly investigates chemical solvent-particles interactions during the formation of composite particles by pulsed laser melting of α-Fe

This work thoroughly investigates chemical solvent-particles interactions during the formation of composite particles by pulsed laser melting of α-Fe2O3. Two solvents, with different dielectric constants, such as ethyl acetate (εr = 6) and ethanol (εr = 24.6), were examined in terms of their effect on the morphology, size, and phase composition of iron oxide composites. We calculated the laser fluence curves using the heating-melting-evaporation approach to identify the critical particle size that undergoes the phase changes first. We assessed the temperature of the particles irradiated with 390 mJ/pulse.cm2 in both solvents, including the heat dissipation between the particles and the liquid. The phase diagram of the Fe–O–C–H system was calculated to determine the temperature–pressure relationship of the system in equilibrium. We also employed an in situ GC–MS analysis to identify the volatile products during irradiation. Based on our experimental results, we concluded that the final diameter of the composites increases from 400 to 600 nm, along with the decreasing dielectric constant of the solvent, which is related to the different polarization of the organic liquid and the degree of particle agglomeration. The reduction of hematite in ethanol proceeded much faster, ending up with Fe/FeCx, while in ethyl acetate, it ended up with Fe3O4. Among all the particles, those with a diameter of 200 nm have the highest temperature and undergo the phase transition first. The temperature of a 200 nm composite particle in ethanol is slightly lower than in ethyl acetate, i.e. 1870 K as compared to 1902 K. Phase equilibrium diagrams proved the existence of Fe, FeO, and Fe3O4 as the preferred phases at about 1900 K. Our research provides a new insight into the process of submicron particle formation during pulsed laser irradiation and allows proposing a mechanism for the growth of particles of different size and phase composition depending on the solvent.

This study investigated the possibility to use thermophilic anaerobic high solid digestion of dewatered digested sewage sludge (DDS) at a wastewater treatment plant (WWTP) as a measure to increase total methane yield, achieve pasteurization and reduce risk for methane emissions during storage of the digestate. A pilot-scale plug-flow reactor was used to mimic thermophilic post-treatment of DDS from a WWTP in Linkoping, Sweden. Process operation was evaluated with respect to biogas process performance, using both chemical and microbiological parameters. Initially, the process showed disturbance, with low methane yields and high volatile fatty acid (VFA) accumulation. However, after initiation of digestate recirculation performance improved and the specific methane production reached 46 mL CH4/g VS. Plug flow conditions were assessed with lithium chloride and the hydraulic retention time (HRT) was determined to be 19-29 days, sufficient to reach successful pasteurization. Degradation rate of raw protein was high and resulted in ammonia-nitrogen levels of up to 2.0 g/L and a 30% lower protein content in the digestate as compared to DDS. Microbial analysis suggested a shift in the methane producing pathway, with dominance of syntrophic acetate oxidation and the candidate methanogen family WSA2 by the end of the experiment. Energy balance calculations based on annual DDS production of 10 000 ton/year showed that introduction of high-solid digestion as a post-treatment and pasteurization method would result in a positive energy output of 340 MWh/year. Post-digestion of DDS also decreased residual methane potential (RMP) by >96% compared with fresh DDS. (C) 2020 The Authors. Published by Elsevier Ltd.

The XENON1T collaboration recently reported the excess of events from recoil electrons, possibly giving an insight into new area beyond the Standard Model (SM) of particle physics. We try to explain this excess by considering effective interactions between the sterile neutrinos and the SM particles. In this paper, we present an effective model based on one-particle-irreducible interaction vertices at low energies that are induced from the SM gauge symmetric four-fermion operators at high energies. The effective interaction strength is constrained by the SM precision measurements, astrophysical and cosmological observations. We introduce a novel effective electromagnetic interaction between sterile neutrinos and SM neutrinos, which can successfully explain the XENON1T event rate through inelastic scattering of the sterile neutrino dark matter from Xenon electrons. We find that sterile neutrinos with masses around $90$ keV and specific effective coupling can fit well with the XENON1T data where the best fit points preserving DM constraints and possibly describe the anomalies in other experiments., Comment: 31 pages, 6 figures, matches the accepted version for publication in JHEP

In this work we study a role of baryon load and interstellarmediumdensity to explain the nature of peaks in the ultra-relativistic prompt emission (UPE) phase of Gamma-ray Bursts (GRBs). We study the behavior of their Γ Lorenz factor fromthe moment of transparency all the way up to interstellarmedium. We finally study the characteristic of equitemporal surfaces in the UPE phase.

A 2-year-old, egg-laying maroon-bellied conure (Pyrrhura frontalis) was referred for treatment of bilateral femoral fractures believed to be secondary to recent egg laying and nutritional and husbandry deficiencies. On radiographs, all skeletal components were diffusely osteopenic, precluding surgical fixation. A novel device to stabilize the bilateral femoral fractures was manufactured with polyvinyl chloride piping, which braced the bird's feet at the level of the perch and supported its upper body weight via a breast plate, thus maintaining the bird in a physiologically appropriate perching position. The conure was ambulatory and returned to normal function after 3 weeks of external coaptation with this device. After 6 weeks, callus formation was palpable over both fracture sites even though minimal bone remodeling was visible radiographically. This body splint device may present a viable alternative to euthanasia in select cases of bilateral femoral fractures in companion birds.

We revisit the efficiency of Schwinger mechanism in creating charged pairs during inflation. We consider a minimal setup of inflation in which the inflaton field is a complex scalar field charged under a $U(1)$ gauge field. There is a time dependent conformal coupling which pumps energy from the inflaton field to the gauge field to furnish a nearly constant background electric field energy density to drive the Schwinger mechanism. The coupling between the gauge field and the scalar field induces a time dependent effective mass for the inflaton field. The requirement of a long period of slow-roll inflation causes the Schwinger mechanism to be highly inefficient during inflation. The non-perturbative Schwinger mechanism can be relevant only towards the end of inflation and only on very small scales. This is in contrast to hypothetical models studied in literature in which the complex scalar field is a test field and a constant electric field is imposed on the dS background by hand. We calculate the number of pairs of charged particles created perturbatively during inflation. We show that it is proportional to the amplitude of the quadrupolar statistical anisotropy and it is very small. Consequently, the back-reactions of created particles on magnetogenesis on large scales are negligible., Comment: 23 pages, 3 figures, matches published version in PRD

In this article, we are interested in the existence of positive solutions for the following Kirchhoff type system  −M1 (∫ Ω |x| −ap|∇u|p dx ) div(|x|−ap|∇u|p−2∇u) = λ|x|−(a+1)p+c1 (f(v)− 1 uα ) in Ω, −M2 (∫ Ω |x| −bq |∇v|q dx ) div(|x|−bq |∇v|q−2∇v) = λ|x|−(b+1)q+c2 (g(u)− 1 vβ ) in Ω, u = v = 0 on ∂Ω, (1) where Ω is a bounded smooth domain of R with 0 ∈ Ω, 1 0, α, β ∈ (0, 1), λ is a parameter, f, g : (0,∞) → (0,∞) are C nondecreasing functions and M1,M2 : Ω → R satisfy the following condition

We consider the polarization characteristics of the electromagnetic (EM) counterpart of the gravitational wave (GW) created by coalescence of the binary sources. Here, we explore the impact of the photon-graviton interaction on the polarization evolution of X-ray emission of GammaRay Bursts (GRBs). We show that significant circular polarization can be generated due to the gravitational wave from the binary merger. The circular polarization besides photon energy depends on parameters of GW source such as the chirp mass of the binary, frequency of the GWs and radial distance from the source. Our predicted signal can be used as an indirect probe for GW events and also the nature of photon-graviton interaction. We argue that this polarization signal might be in sensitivity range of upcoming X-ray polarimetry missions., Comment: 9 pages, 2 figures, matches version to appear in JCAP

We analyze the early X-ray flares in the GRB "flare-plateau-afterglow" (FPA) phase observed by Swift-XRT. The FPA occurs only in one of the seven GRB subclasses: the binary-driven hypernovae (BdHNe). This subclass consists of long GRBs with a carbon-oxygen core and a neutron star (NS) binary companion as progenitors. The hypercritical accretion of the supernova (SN) ejecta onto the NS can lead to the gravitational collapse of the NS into a black hole. Consequently, one can observe a GRB emission with isotropic energy $E_{iso}\gtrsim10^{52}$~erg, as well as the associated GeV emission and the FPA phase. Previous work had shown that gamma-ray spikes in the prompt emission occur at $\sim 10^{15}$--$10^{17}$~cm with Lorentz gamma factor $\Gamma\sim10^{2}$--$10^{3}$. Using a novel data analysis we show that the time of occurrence, duration, luminosity and total energy of the X-ray flares correlate with $E_{iso}$. A crucial feature is the observation of thermal emission in the X-ray flares that we show occurs at radii $\sim10^{12}$~cm with $\Gamma\lesssim 4$. These model independent observations cannot be explained by the "fireball" model, which postulates synchrotron and inverse Compton radiation from a single ultra relativistic jetted emission extending from the prompt to the late afterglow and GeV emission phases. We show that in BdHNe a collision between the GRB and the SN ejecta occurs at $\simeq10^{10}$~cm reaching transparency at $\sim10^{12}$~cm with $\Gamma\lesssim4$. The agreement between the thermal emission observations and these theoretically derived values validates our model and opens the possibility of testing each BdHN episode with the corresponding Lorentz gamma factor., Comment: 57 pages, 40 figures, accepted for publication on ApJ

This paper is concerned with the existence of positive solutions for a class of quasilinear singular elliptic systems with Dirichlet boundary condition. By studying the competition between the Caffarelli–Kohn–Nirenberg exponents, the sign-changing potentials and the nonlinear terms, we establish an interval on the range of multiple parameters over which solutions exist in an appropriate weighted Sobolev space. The arguments rely on the method of weak sub- and super-solutions.

We review our recent results on the classification of long and short gamma-ray bursts (GRBs) in different subclasses. We provide observational evidences for the binary nature of GRB progenitors. For long bursts the induced gravitational collapse (IGC) paradigm proposes as progenitor a tight binary system composed of a carbon-oxygen core (COcore) and a neutron star (NS) companion; the supernova (SN) explosion of the COcore triggers a hypercritical accretion process onto the companion NS. For short bursts a NS–NS merger is traditionally adopted as the progenitor. We also indicate additional sub-classes originating from different progenitors: (COcore)–black hole (BH), BH–NS, and white dwarf–NS binaries. We also show how the outcomes of the further evolution of some of these sub-classes may become the progenitor systems of other sub-classes.

In the presence of strong magnetic fields near pulsars, the QED vacuum becomes a birefringent medium due to nonlinear QED interactions. Here, we explore the impact of the effective photon-photon interaction on the polarization evolution of photons propagating through the magnetized QED vacuum of a pulsar. We solve the quantum Boltzmann equation within the framework of the Euler-Heisenberg Lagrangian to find the evolution of the Stokes parameters. We find that linearly polarized X-ray photons propagating outward in the magnetosphere of a rotating neutron star can acquire high values for the circular polarization parameter. Meanwhile, it is shown that the polarization characteristics of photons besides photon energy depend strongly on parameters of the pulsars such as magnetic field strength, inclination angle and rotational period. Our results are clear predictions of QED vacuum polarization effects in the near vicinity of magnetic stars which can be tested with the upcoming X-ray polarimetric observations., 12 pages, 3 figures

In this paper, we consider the system of differential equations $$\begin{aligned} \left\{ \begin{array}{l@{\quad }l@{\quad }l} -\Delta _{p(x)} u=\lambda ^{p(x)}[\lambda _{1}f(v)+\mu _{1}h(u)] &{} \mathrm{in }\, \Omega , \\ -\Delta _{p(x)} v=\lambda ^{p(x)}[\lambda _{2}g(u)+\mu _{2}\tau (v)] &{} \mathrm{in }\,\Omega , \\ u=v=0 &{} \mathrm{on }\,\partial \Omega ,\\ \end{array}\right. \end{aligned}$$ where $$\Omega \subset \mathbb R ^N$$ is a bounded domain with $$C^2$$ boundary $$\partial \Omega $$ and $$1 0, \end{aligned}$$ $$\begin{aligned} \lim _{u \rightarrow +\infty } \frac{h(u)}{u^{p^-- 1}} = 0, \quad \lim _{u \rightarrow +\infty } \frac{\tau (u)}{u^{p^- - 1}} = 0. \end{aligned}$$ In particular, we do not assume any symmetry condition, and we do not assume any sign condition on $$f(0), g(0), h(0)$$ or $$\tau (0)$$ .

International audience; Our concept of induced gravitational collapse (IGC paradigm) starting from a supernova occurring with a companion neutron star, has unlocked the understanding of seven different families of gamma ray bursts (GRBs), indicating a path for the formation of black holes in the universe. An authentic laboratory of relativistic astrophysics has been unveiled in which new paradigms have been introduced in order to advance knowledge of the most energetic, distant and complex systems in our universe. A novel cosmic matrix paradigm has been introduced at a relativistic cosmic level, which parallels the concept of an S-matrix introduced by Feynmann, Wheeler and Heisenberg in the quantum world of microphysics. Here the “in” states are represented by a neutron star and a supernova, while the “out” states, generated within less than a second, are a new neutron star and a black hole. This novel field of research needs very powerful technological observations in all wavelengths ranging from radio through optical, X-ray and gamma ray radiation all the way up to ultra-high-energy cosmic rays.

Short and long-duration gamma-ray bursts (GRBs) have been recently sub-classified into seven families according to the binary nature of their progenitors. For short GRBs, mergers of neutron star binaries (NS–NS) or neutron star-black hole binaries (NS-BH) are proposed. For long GRBs, the induced gravitational collapse (IGC) paradigm proposes a tight binary system composed of a carbon–oxygen core (CO[Formula: see text]) and a NS companion. The explosion of the CO[Formula: see text] as supernova (SN) triggers a hypercritical accretion process onto the NS companion which might reach the critical mass for the gravitational collapse to a BH. Thus, this process can lead either to a NS-BH or to NS–NS depending on whether or not the accretion is sufficient to induce the collapse of the NS into a BH. We shall discuss for the above compact object binaries: (1) the role of the NS structure and the equation-of-state on their final fate; (2) their occurrence rates as inferred from the X and gamma-ray observations; (3) the expected number of detections of their gravitational wave (GW) emission by the Advanced LIGO interferometer.

Nonlinear QED interactions induce different polarization properties on a given probe beam. We consider the polarization effects caused by the photon-photon interaction in laser experiments, when a laser beam propagates through a constant magnetic field or collides with another laser beam. We solve the quantum Boltzmann equation within the framework of the Euler-Heisenberg Lagrangian for both time-dependent and constant background field to explore the time evolution of the Stokes parameters Q, U, and V describing polarization. Assuming an initially linearly polarized probe laser beam, we also calculate the induced ellipticity and rotation of the polarization plane., Comment: 14 pages, 4 figures

In this work, we consider the positive solutions to the singular problem $$ \left\{\begin{array}{ll} -\Delta u = am(x)u-f(u) - \dfrac{c}{u^{\alpha}} & {\rm in}\;\Omega,\\ u=0 & {\rm on}\; \partial\Omega, \end{array} \right. $$ where 0 0 and c > 0 are constants, Ω is a bounded domain with smooth boundary $\partial\Omega$ , Δ is a Laplacian operator, and $f:[0,\infty] \longrightarrow{\mathbb R}$ is a continuous function. The weight functions m(x) satisfies m(x) ∈ C(Ω) and m(x) > m 0 > 0 for x ∈ Ω and also ||m|| ∞ = l 0, M > 0, p > 1 such that alu − M ≤ f(u) ≤ Au p for all u ∈ [0, ∞ ). We prove the existence of a positive solution via the method of sub-supersolutions when $m_{0}a>\frac{2\lambda_{1} }{1+\alpha}$ and c is small. Here λ 1 is the first eigenvalue of operator − Δ with Dirichlet boundary conditions.

In this paper we define complete fuzzy metric space and proved that a fuzzy topologically complete subset of a fuzzy metric space is a

In this paper we prove result for Jensen type mapping in the setting of intuitionistic fuzzy normed spaces. We generalize a Hyers-Ulam stability result in the framework of classical normed spaces.

In this paper, we consider complete menger probabilistic quasi- metric space and prove a common flxed point theorem for commuting maps in this space.

BACKGROUND: Bariatric procedures like gastric banding, vertically banded gastroplasty and Roux-en-Y gastric bypass have impacted on the postoperative eating behavior. Since laparoscopic sleeve gastrectomy (LSG) leads to decreased plasma ghrelin levels, a reduced sensation of hunger following surgery is expected. The aim of this study was to assess the impact of LSG on the eating behavior in correlation with plasma ghrelin levels. METHODS: This prospective study was carried out in 15 morbidly obese patients who underwent LSG. The German version of the self-report Three-Factor Eating Questionnaire (TFEQ) was applied preoperatively and at six months following surgery to assess the impact of LSG on the three dimensions of eating behavior: restraint, disinhibition and hunger. The correlation between plasma ghrelin levels and the sensation of hunger was assessed in a subset of seven patients. RESULTS: Following LSG, increased cognitive restraint and decreased disinhibition of eating were found. Furthermore, a significant decrease in hunger was observed with a significant correlation (r = 0.834, p = 0.01) between circulating plasma ghrelin levels and hunger scores. CONCLUSIONS: Following LSG, a high correlation between decreased ghrelin levels and the reduced sensation of hunger was found. This may contribute to the excellent weight loss observed following laparoscopic sleeve gastrectomy.

International audience; It has previously been discovered that there is a universal power-law behavior exhibited by the late X-ray emission (LXRE) of a “golden sample” of six long energetic GRBs, when observed in the rest frame of the source. This remarkable feature, independent of the different isotropic energy (E (iso)) of each GRB, has been used to estimate the cosmological redshift of some long GRBs. This analysis is extended here to a new class of 161 long GRBs, all with ${E}_{\mathrm{iso}}\gt {10}^{52}$ erg. These GRBs are indicated as binary-driven hypernovae (BdHNe) in view of their progenitors: a tight binary system composed of a carbon–oxygen core (CO(core)) and a neutron star undergoing an induced gravitational collapse (IGC) to a black hole triggered by the CO(core) explosion as a supernova (SN). We confirm the universal behavior of the LXRE for the “enlarged sample” (ES) of 161 BdHNe observed up to the end of 2015, assuming a double-cone emitting region. We obtain a distribution of half-opening angles peaking at $\theta =17.62^\circ $, with a mean value of $30.05^\circ $, and a standard deviation of $19.65^\circ $. This, in turn, leads to the possible establishment of a new cosmological candle. Within the IGC model, such universal LXRE behavior is only indirectly related to the GRB and originates from the SN ejecta, of a standard constant mass, being shocked by the GRB emission. The fulfillment of the universal relation in the LXRE and its independence of the prompt emission, further confirmed in this article, establishes a crucial test for any viable GRB model.

BACKGROUND: Bilateral vasectomy is the most effective method of male contraception but there are still some reports on its failure. This study was undertaken to determine the failure rate of the no-scalpel vasectomy in Shiraz Vasectomy Center, Southern Iran. METHODS: From 2001 to 2003, 3900 no-scalpel vasectomies were done in Nader Kazemi Health Center. The records were studied for any failure in the method. Presence of any live sperm 6 months after surgery or any report of pregnancy post-vasectomy were considered as vasectomy failure. RESULTS:Among 3900 cases, 2928 patients had a complete follow up file while failure in the method was visible among 109 (3.72%) cases. CONCLUSION: The low failure rate of no-scalpel method indicated its high efficacy to control the fertility in males but there is still need of performance by expert surgeons in well organized centers. KEYWORDS: Iran, no-scalpel vasectomy, failure rate.

The aim of this study was to determine the effect of opium on hypothalamic pituitary gonad function. Fifty-six opium dependent (28 men and 28 women; mean age, 25±5 year) were enrolled for hypothalamic pituitary gonadal axis. The control group considered of 56 non-opium dependent subject (28 men and 28 women; mean age 25±5 year). Decreased libido or impotency was present in 26 of 28 opium dependent men. The serum testosterone level was below 9 nmol L-1 in 24 of 28 men and was significantly lower than that in the control group (p

We photographed molten tin droplets (2.2 mm diameter) landing off-center on a circular splat formed by the impact and solidification of another, identical drop. Final splat shapes were sensitive to the spacing between droplet centers, which was varied from 1.0 to 5.0 mm. We used a three-dimensional model of spreading and solidification to simulate interactions between droplets. The model applied a fixed-grid Eulerian control volume method to solve the fluid dynamics and energy conservation equations. A volume-of-fluid algorithm was used to track free surface deformation. Predictions of droplet shapes during impact from the model agreed well with photographs. By following temperature variations at different points on the surface of the first splat we could identify locations where remelting occurred and the splats fused together. Splat shapes observed in experiments with large tin droplets qualitatively resembled those obtained by plasma-spraying nickel powders on a steel surface.

Although Muslim patients with Type 2 diabetes may be exempt from fasting during Ramadan for medical reasons, a high proportion of them fast.To investigate the association between Ramadan fasting and glycemic control in patients with Type 2 diabetes.A prospective cohort clinical trial was designed. Eighty-eight patients with Type 2 diabetes (45 male, 43 female, age 51±10 yr) who opted to fast for at least 10 days during the month of Ramadan were recruited. Fasting blood samples were taken at the beginning and end of Ramadan, and 1 month after Ramadan, to assess fasting blood glucose (FBG), fasting insulin, full blood count, glycated hemoglobin (HbA(1c)) and fasting lipid profile. Insulin resistance was estimated using the homeostatic model assessment. Anthropometrics and blood pressure were also measured.There was a significant deterioration in FBG and HbA(1c) (p=0.002 and p≤0.001, respectively) and significant improvements in HDL and LDL cholesterol and body mass index after Ramadan (p0.001). Interestingly, HbA(1c) showed a reduction 1 month after Ramadan (9.4±2% at the end of Ramadan vs 8.4±2.5% 1 month after Ramadan; p0.001).Results from this study showed that fasting during Ramadan deteriorated the glycemic control in Type 2 diabetes patients. This was more evident in patients using oral hypoglycemic medication than diet- controlled patients. However, Ramadan fasting had small positive effects on lipid profile and body weight.

Aim To identify those agents reported as being associated with reactive airways dysfunction syndrome (RADS). Methods A systematic review was undertaken. Abstracts were screened and those selected reviewed against pre-determined diagnostic criteria for RADS. Results Significant information gaps were identified for all measures of interest. In some articles, even the causative agent was not reported. The most commonly reported agents were chlorine (nine subjects), toluene di-isocyanate (TDI) (n = 6) and oxides of nitrogen (n = 5). Most exposures occurred in the workplace (n = 51) and affected men (60%). Dyspnoea (71%) and cough (65%) were the commonest symptoms. Median symptom duration was 13 months (interquartile range = 6.5-43.5) for RADS. Conclusions Although the most commonly reported agent associated with RADS was chlorine, the main finding of a general lack of adequate information on exposure, investigation and outcome suggests that to better explore RADS a more structured approach to gathering information is required. A minimum data set for reporting RADS cases is proposed.

The spreading and solidification of a molten droplet is governed a number of factors such as fluid inertia, viscosity, surface tension, surface wettability, heat transfer between the droplet and substrate, and surface thermal properties. Most numerical and experimental studies of droplet impact have considered a single molten droplet landing on a flat, solid surface. This paper investigates the sequential deposition of tin droplets with their centers offset using a three-dimensional model of droplet impact and solidification. In this study, the successive deposition of two tin droplets on a stainless steel substrate is simulated and the results are compared with photographs of impacting droplets. Paper includes a German-language abstract.