A STUDY ON SUDDEN EXPANSION HYDRODYNAMIC PHENOMENA OCCURRING IN CYLINDRICAL PIPES

Introduction: This paper studies the frequency with which hydrodynamic parameters change in the sudden expansion section of axisymmetric pressure flow, based on the boundary layer equations. Methods: The suggested method reveals the regularity of changes in the hydrodynamic parameters of the flow in the transitional area, making it possible to obtain a velocity profile in any cross-section under common initial and boundary conditions. Based on the general solutions, we studied the hydrodynamic processes occurring in the transitional area of the effective sudden cross-section expansion within the axisymmetric pressure movement, in the following cases: a) when the velocity is constant at any point of the inlet face; b) when the velocity is distributed along the inlet face according to the parabolic law. Our calculations were carried out for different values of the expansion factor. Results: Based on the results of the computer-aided experimental study, we obtained velocity diagrams along the length of the transitional area with constant and parabolic velocity distributions for fluid inflowing into the expanded section. We also determined the patterns of pressure distribution along the length of the relevant section.

Encoding Individual Source Sequences for the Wiretap Channel

We consider the problem of encoding a deterministic source sequence (i.e., individual sequence) for the degraded wiretap channel by means of an encoder and decoder that can both be implemented as finite-state machines. Our first main result is a necessary condition for both reliable and secure transmission in terms of the given source sequence, the bandwidth expansion factor, the secrecy capacity, the number of states of the encoder and the number of states of the decoder. Equivalently, this necessary condition can be presented as a converse bound (i.e., a lower bound) on the smallest achievable bandwidth expansion factor. The bound is asymptotically achievable by Lempel–Ziv compression followed by good channel coding for the wiretap channel. Given that the lower bound is saturated, we also derive a lower bound on the minimum necessary rate of purely random bits needed for local randomness at the encoder in order to meet the security constraint. This bound too is achieved by the same achievability scheme. Finally, we extend the main results to the case where the legitimate decoder has access to a side information sequence, which is another individual sequence that may be related to the source sequence, and a noisy version of the side information sequence leaks to the wiretapper.

Oral administration of bacterial Beta cell expansion factor A (BefA) alleviates diabetes in mice with Type 1 and Type 2 diabetes

Diabetes mellitus (DM) is a group of metabolic diseases, which is of urgent need to develop new therapeutic DM oral drugs with less side effects and sound therapeutic efficacy. In this study, a Beta cell expansion factor A (BefA) production strain of Escherichia Coli BL21-pet 28C-BefA was constructed, and the anti-diabetes effect of BefAwas evaluated using type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) mice models. The T1DM mice results indicated that BefA significantly reduced the blood glucose level, exerted protective function of islet β cell morphology, down-regulated the TLR-4, p-NFκB/NFκB, Bax/Bcl-2 expressions and the secretion level of IL-1β, TNF-α, increased the expression of PDX-1 protein and insulin secretion in a concentration-dependent manner, and restored the disturbed microbial diversity to normal level. Similar with the T1DM mice, BefA obviously increased islet β cells, reduced inflammatory reaction and apoptosis in T2DM mice, and also improved liver lipid metabolism by down-regulating the expression of CEBP-α, ACC, Fasn and inhibiting the synthesis of triglyceride and induce Cpt-1, Hmgcs2, Pparα in a concentration-dependent manner. In the present study, we verified therapeutic effect and potential mechanisms of BefA in mammal for the first time, providing basic data for its clinical application.

2D Electrical Resistivity Imaging of Bedrock Fissures in Ogbomoso, Southwestern Nigeria

2D electrical resistivity surveys were conducted around the site of the failed proposed Ogbomoso North Secretariat building with a view to examining the trend of suspected bedrock fissures and assessing the vulnerability of structures in the vicinity to potential failure. Electrical Resistivity Tomography data were acquired along ten traverses 80-200 m long each, using the dipole-dipole electrode configuration with station interval of 5 m and expansion factor, n, varied from 1 to 6. The data were processed by using 2D resistivity inversion technique in the DipproTM software package to generate 2D resistivity sections beneath the traverses. The 2D resistivity sections delineated 2-19 m thick typically clay overburden underlain by bedrock with resistivity ranging from 103 to 59767 Ωm, and anomalously low resistivity zones suspected to be fissures within the bedrock. The bedrock fissures are generally 5-20 m wide and occur at depths ranging from 5 m to ˃25 m beneath the traverses. The fissures trend southward toward the roundabout and front of the College of Health Sciences premises. The incessant road failures and groundwater seepages observed within the study area are attributable to the network of bedrock fissure.

Comparison of individual tree aboveground biomass estimation in community forests using allometric equation and expansion factor in Magetan, East Java, Indonesia

Setiahadi R. 2021. Comparison of individual tree aboveground biomass estimation in community forests using allometric equation and expansion factor in Magetan, East Java, Indonesia. Biodiversitas 22: 3899-3909. The use of allometric equation and biomass expansion factor can facilitate more efficient tree biomass estimation. This study evaluates the accuracy of the allometric equation and expansion factor for quantifying the individual tree aboveground biomass in community forest tree species. Destructive sampling n on 120 trees from four different species: Falcataria moluccana, Melia azedarach, Swietenia macrophylla, and Tectona grandis. For each tree sample, aboveground biomass measured at every tree component, i.e., stem, branches, and leaves. The allometric equation developed using regression analysis with several predictor variables, such as diameter at breast height (D), squared diameter at breast height combined with tree height (D2H), and D and H separately. On another side, the biomass expansion factor was calculated based on the total aboveground biomass and stem biomass ratio. The results found the highest mean aboveground biomass for all species are M. azedarach (326.36±88.40 kg tree-1), S. macrophylla (244.47±98.73 kg tree-1), T. grandis (173.31±80.97 kg tree-1), and F. moluccana (56.56±23.10 kg tree-1). The most significant average biomass expansion factor observed in M. azedarach (1.78±0.03), adhered by T. grandis (1.66±0.09), S. macrophylla (1.61±0.04), and F. moluccana (1.59±0.06). The equation ln? = lna + b x ln (D) was best for estimating aboveground biomass in each tree component and a total of four species with an accuracy of more than 90%.

Determining the Optimal Conditions for the Production by Supercritical CO2 of Biodegradable PLGA Foams for the Controlled Release of Rutin as a Medical Treatment

Poly(D,L,-lactide-co-glycolide) (PLGA) foam samples impregnated with rutin were successfully produced by supercritical foaming processes. A number of parameters such as pressure (80–200 bar), temperature (35–55 °C), depressurization rate (5–100 bar/min), ratio lactide:glycolide of the poly(D,L,-lactide-co-glycolide) (50:50 and 75:25) were studied to determine their effect on the expansion factor and on the glass transition temperature of the polymer foams and their consequences on the release profile of the rutin entrapped in them. The impregnated foams were characterized by scanning electron microscopy, differential scanning calorimetry, and mercury intrusion porosimetry. A greater impregnation of rutin into the polymer foam pores was observed as pressure was increased. The release of rutin in a phosphate buffer solution was investigated. The controlled release tests confirmed that the modification of certain variables would result in considerable differences in the drug release profiles. Thus, five-day drug release periods were achieved under high pressure and temperature while the depressurization rate remained low.

The expansion of the Universe may be an illusion created by Compton scattering of free electrons

The high-precision measurements of the Hubble parameter make the theory of cosmic expansion more and more confusing, which bolster the idea that new physics may be needed to explain the mismatch. The cosmological redshift may not only be related to distance but also to other factors. The expansion of the Universe may be just an illusion. The Compton effect of free electrons and low energy photons has been observed in the laboratory. This article proposes a theory: Free electron Compton scattering (FEC) produce the illusion of the Universe exponential expansion: FEC causes photons to redshift (FEC redshift), and the photon beam expands along the propagation direction, that is, the redshift factor is (1 + z); the beam length stretch factor (time dilation of the supernova curve) is (1 + z); the expansion factor of the beam volume is (1 + z)3, and FEC will not be blurred Distant galaxy. The reason for rejecting the “tired light” does not hold in FEC.