Front Nose Research Articles

Visualization and Estimation of Nasal Spray Delivery to Olfactory Mucosa in an Image-Based Transparent Nasal Model.

Background: Nose-to-brain (N2B) drug delivery offers unique advantages over intravenous methods; however, the delivery efficiency to the olfactory region using conventional nasal devices and protocols is low. This study proposes a new strategy to effectively deliver high doses to the olfactory region while minimizing dose variability and drug losses in other regions of the nasal cavity. Materials and Methods: The effects of delivery variables on the dosimetry of nasal sprays were systematically evaluated in a 3D-printed anatomical model that was generated from a magnetic resonance image of the nasal airway. The nasal model comprised four parts for regional dose quantification. A transparent nasal cast and fluorescent imaging were used for visualization, enabling detailed examination of the transient liquid film translocation, real-time feedback on input effect, and prompt adjustment to delivery variables, which included the head position, nozzle angle, applied dose, inhalation flow, and solution viscosity. Results: The results showed that the conventional vertex-to-floor head position was not optimal for olfactory delivery. Instead, a head position tilting 45-60° backward from the supine position gave a higher olfactory deposition and lower variability. A two-dose application (250 mg) was necessary to mobilize the liquid film that often accumulated in the front nose following the first dose administration. The presence of an inhalation flow reduced the olfactory deposition and redistributed the sprays to the middle meatus. The recommended olfactory delivery variables include a head position ranging 45-60°, a nozzle angle ranging 5-10°, two doses, and no inhalation flow. With these variables, an olfactory deposition fraction of 22.7 ± 3.7% was achieved in this study, with insignificant discrepancies in olfactory delivery between the right and left nasal passages. Conclusions: It is feasible to deliver clinically significant doses of nasal sprays to the olfactory region by leveraging an optimized combination of delivery variables.

High-speed penetration of ogive-nose projectiles into thick concrete targets: Tests and a projectile nose evolution model

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm. This study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic penetration. In the hypersonic penetration test, eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/s. Severe erosion of the projectiles was observed during high-speed penetration of heterogeneous targets, and apparent localized mushrooming occurred in the front nose of recovered projectiles. By examining the damage to projectiles, a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration tests. Furthermore, microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration, i.e., material spall erosion abrasion mechanism, material flow and redistribution abrasion mechanism and localized radial upsetting deformation mechanism. Finally, a model of high-speed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting; the model was validated by test data from the literature and the present study. Depending upon the impact velocity, v0, the projectile nose may behave as undistorted, radially distorted or hemispherical. Due to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration, the predicted DOP had an upper limit.

The Augmentation of a Flight Control Mechanism for a Hybrid Fixed-Wing VTOL Drone for Parcel Delivery

Several companies are experimenting with multicopters drones to deliver packages to customers. Although they are less aerodynamically efficient than fixed-wing aircraft, their ability to do the vertical take-off and landing (VTOL) makes them ideal for delivery services. In this study, two methodologies will be used to build the drone which is software simulation and experimental approach. Software such as SIMNET is used to simulate and design an electronic operation of the drone while Mission Planner is used to setup the flight controller. Electronics layout is done prior to ensure a clear sight of work, components and information through the software. The flight controller used is called Pixhawk which is an open hardware mainly used for drone. The radio control system is also setup to be used as the link to control the flight controller. Flight tests were also performed to study the behavior of the drone at various percentage of throttle. At 60 percent throttle, the drone yaws continously to the left at 63.43 degrees at 4.879 degrees per second during test flights. With a payload weight of 516g, it tilted to the front nose down, with support provided at the tip of the left wing. With more design and calibration advancements, experimental findings that are similar to theoretical outcomes might be attained. Flight data after each test flight is extracted from the software and analysed for further improvement. The fabrication of complete prototype could not be finished within the stipulated time due to a delay in acquiring new parts such as propeller due to a problem, as well as procuring the appropriate material for the wing. A test of the drone motions including roll, pitch, and yaw, is also carried out using flight charts to validate the suggested design parameter. The drone tends to fly better with the motor turning with the same orientation rather than turning with different orientation due to better stability.This flight chart allows users to choose the best design parameters by determining the length of the wingspan, motor RPM, and propeller diameter that are expected to meet the performance requirements in these three flying motions. The procedure for estimating the drone's battery usage has also been presented in the flight chart.

Local scour evolution around semi-circular end bridge abutment in quasi-unsteady condition

In this experimental study, the temporal development of local scour is studied around semi-circular end bridge abutments under quasi-unsteady clear-water flow conditions in a rectangular sediment channel. A step-wise hydrograph of 6 h duration is used in the experiments. Six different abutment lengths having constant width, with uniform sand as bed material, were tested for three different successive flows – each applied continuously for 2 h. Bathymetry of the bed level was measured around the abutment every 15 min with the help of a measurement device to observe temporal development of the local scour around the semi-circular end abutment. Effects of the abutment length, flow intensity and time on the scour depths around semi-circular end bridge abutments, along with those at the front, upstream and downstream faces of the abutment, are also investigated and discussed. It is shown that the maximum scour depth always occurs at the front noses of the abutments compared with those at the upstream and downstream noses. A dimensionless empirical formula is derived to predict the scour depth at the front nose of the abutment as a function of related parameters. The results reveal that flow intensity is the most critical parameter in scour development.

Scour Evolution Around Bridge Piers Under Hydrographs with High Unsteadiness

The temporal development of scour at both the side and the front of circular bridge piers is studied under clear-water conditions with artificially generated, linearly rising and falling, asymmetric triangular-shaped hydrographs categorized as highly unsteady with relatively short rising durations. The base flow conditions are kept well below the conditions for scour inception so as to investigate the hysteresis in initialization of the scour. A conceptual model consisting of an S-shaped time–depth relationship is generated, and actual and effective time of scour inception, duration and finalization parameters are defined. Both the effective and the actual time of scour inception decreased with increasing unsteadiness, either at the side or at the front nose of the piers; however, scour finalization does not depend on the hydrograph unsteadiness The effect of flow deceleration during the falling phase of the hydrograph on scouring was weaker than the effect of flow acceleration during the rising phase. A five-step procedure is proposed involving the calculation of (1) the densimetric Froude number corresponding to effective scour inception at piers side, (2) the final scour depth at piers side, (3) and at the front nose, (4) the exponent n and finally (5) the scour depth time evolution for both side and front nose of the piers. The method is verified both by experimental and literature data.

Investigating the feasibility of a new testing method for GFRP/polymer foam sandwich composites used in railway passenger vehicles

This paper investigates the feasibility and validity of a recently proposed testing method when applied to foam core sandwich composites to determine the impact resistance of train car body shells. The published method proved itself useful when applied to monolithic fibre reinforced plastic laminates, however, further analysis is required if sandwich composites are used due to the subtle differences compared to monolithic laminates. It is especially important for the front nose section of high-speed trains as these car body parts can be subjected to ballast flight at high impact velocities. Due to the aerodynamic design aspects, front nose sections generally incorporate complex 3D geometries, and sandwich composite materials are advantageous in this respect due to the ease of manufacturing of complex 3D shapes. Quasi-static punch tests (QSPT) were performed on E-glass fibre/epoxy resin/PET foam core sandwich plates. Numerical finite element model (FEM) was developed and validated with experiments in terms of penetration resistance and structural damage. Numerical model was used to investigate three railway impact related standards and high-velocity impact parameters (energy transfer, contact force, projectile velocity) were analysed for each case. Additionally, the foreseeable contribution of this work to the railway industry was given from multiple aspects.

Drag Reduction and Aerodynamic Shape Optimization for Spike-Tipped Supersonic Blunt Nose

A space vehicle in atmosphere travels mostly at supersonic speed and generates a very strong bow shock wave around its blunt nose. This causes a large high-pressure area at the front nose surface accompanied with high temperature. It suggests high-pressure drag and high risk of heat shield failure. Oblique shock and conical separated flow zone generated by a forward disk-tip spike significantly reduce the drag by reducing the high-pressure area on the blunt nose. In the present work, aerodynamics of the high-speed spike-tipped blunt nose is investigated here numerically with Mach number up to 4.5. It is highlighted here that there exists an optimal combination of spike length and disk-tip diameter giving rise to minimal drag at supersonic speed. The reason for drag reduction is analyzed in detail.

Analysis of the aerodynamic effects of different nose lengths on two trains intersecting in a tunnel at 350 km/h

The three-dimensional compressible Navier-Stokes equation and k-ε turbulence model are used to simulate the flow and pressure waves caused by two trains passing each other in a tunnel. The simulation results were verified by comparison with the results of a full-scale experiment. This simulation results indicate that the positive peak of the initial compression wave on the tunnel wall has a logarithmically decreasing trend with increasing nose length. This tendency is more obvious near the tunnel portal than in the tunnel, and the positive peak caused by a train with a nose length of 12m at a distance of 20m from the tunnel entrance is 10.26% less than that caused by a train with a nose length of 4m. Throughout the intersection process, the peak-to-peak amplitude of body surface pressure decreases with increasing longitudinal distance from the front nose tip. The influence of different nose lengths on the surface pressure on the train body is mainly concentrated at the front and rear of the train. The fluctuation amplitude of the surface pressure on the head car with a 4m nose is 1.63 times that of a head car with a 12m nose. The amplitudes of the lateral force and overturning moment are also influenced by the nose length, with the strongest effect on the head car and a stronger effect on the middle car than on the tail car. A shorter train nose results in a more significant influence on the train total drag. As the nose length changes from 4m to 7m, the maximum total drag decreases by 6.71%; however, as the nose length changes from 9m to 12m, the maximum total drag decreases by only 0.16%.

Shape of mole nose providing minimum axial resistance

Abstract Introduction As a carrier of different sensors, moles can penetrate into the regolith automatically and keep investigating the subsurface environment continuously. In this section, features of several moles with different applications are introduced to explain why we choose a hammer-driven mole to study. Mole driven by a hammer In this section, the penetrating principle of a hammer-driven mole is illustrated and a circular arc shape for the front nose is proposed. Moreover, applying the penetrating principle, experiments of the mole with an arc-shaped nose are performed to observe the penetration phenomena in a simulated lunar regolith. Mechanics analysis According to soil mechanics theory, regions of soil failure are divided and a mechanics model is established between soil and mole with an arc-shaped nose. The work is done to get approximate axial resistance equations which are analyzed with the defined geometric parameters caliber-radius-head. EDEM simulations EDEM is leading global software based on discrete element method, whose main function is to analyze and observe the movement of particles. Lunar soil simulacrum is established to simulate axial resistance. Eventually, the theoretical results are validated by simulation.

Clinical analysis of intractable epistaxis under nasal endoscope in the treatment of elderly people

Objective To summarize the clinical experience of intractable epistaxis under nasal endoscope in the treatment of elderly people .Methods 312 cases of endoscope of intractable epistaxis patients were retrospectively analyzed.Results Nasal septum and olfactory corresponding head of middle turbinate bleeding site was mainly the upper part of the nasal cavity and the split-plot,back-end middle turbinate at the back of the nose and nasal were fol-lowed,as well as inferior turbinate and the rear end of inferior nasal meatus ,the Littell nasal septum of the front nose were bleeding less .After nasal endoscopic radio hemostatic therapy or local packing treatment with expansive sponge , 310 cases were cured,2 cases were invalid.The total efficiency was up to 99.4%.During the following 3 months,there was no recurrence .Conclusion For the elderly intractable epistaxis hemostatic therapy ,under nasal endoscope oper-ation method,radio hemostatic therapy or local packing treatment with expansive sponge is simple and effective ,which is worthy of popularization and application . Key words: Natural Orifice Endoscopic Surgery; Epistaxis

Burning behavior of minivan passenger cars

Four full-scale fire experiments using minivan passenger cars were carried out to establish the burning behavior of minivan passenger cars. The cars were ignited with 80g of alcohol gel fuel placed at the splashguard of the right rear wheel, on the right side of the front bumper, or at the seat in the passenger compartment. We observed how the fire spread from the point of origin and investigated the effects of the location of the ignition on the burning behavior. The temperature inside the burning car and the mass loss rate were measured. The burning of a minivan was composed of three compartmental fires: the front compartment (front nose), the passenger compartment, and the rear part inclusive of the fuel. In the experiments where ignition was initiated outside the passenger compartment, depending on its location the flames spread to the compartments in the following order: rear or front (ignition point), passenger, and front or rear (opposite to the ignition point). The breaking of the window glass markedly affected the spread of fire into the passenger compartment. In the experiments where ignition was initiated at the seat of the passenger compartment, air supply from open windows was required to continue the combustion. When all the windows were closed, the combustion in the passenger compartment self-extinguished. The temperature of the passenger compartment peaked at 1094°C. The heat release rate (HRR) curves showed several peaks depending on the burning conditions in the three compartments. The HRR increased markedly when the fire spread to several different parts of the car at the same time. The HHR peaked at 4MW when the seat in the passenger compartment was ignited and a window was open by 20cm. We characterized the measured HRR curves as a function of time by the superposition of Boltzmann and Gaussian curves. The HRRs of the burning cars were described by the sum of the HRRs from each compartment.

Investigation of noise sources in high-speed trains

In this paper, the quantification of the external noise sources in high-speed trains is discussed. A thorough understanding of the underlying causes of noise generation in high-speed trains is needed to develop effective noise control measures. However, because high-speed trains produce a complex array of sounds, it is very difficult to determine each individual source of noise. In this study, the delay-and-sum beamforming method, which uses microphone arrays, was used to separate the noise sources and analyze the sound characteristics of high-speed trains. A new microphone array with 96 microphones was designed to measure the noise produced by high-speed trains. Performance verification tests were conducted to ensure the reliability of the results obtained from the array. Then, the system was used to measure the sounds produced by Korean high-speed trains traveling at speeds between 150 and 300 km/h. Sound maps were then produced using the beamforming technique. The study determined that the majority of the noise produced by the high-speed trains originated from the front nose, bogie, pantograph and inter-coach spacing. Finally, the beampower spectra of the aerodynamic noise sources originating in the front nose, pantograph and inter-coach spacing were deduced from frequency conversion. From these results, the aerodynamic noise characteristics of the major sources of noise in high-speed trains were determined.

Analysis of jacketed rod penetration

An analytical model for the cratering process in a metal target due to high-velocity penetration of a jacketed rod has been developed. The jacketed rod consists of a central high-density core surrounded by a low-density jacket. The analysis is based on the observation that two mechanisms are involved in the cavity growth by eroding rods: flow of rod erosion products, which exerts radial stress on the target and opens a cavity, and radial momentum of the target as it flows around the rod front nose. Hence, the mushrooming effects on the cavity growth are isolated. The model includes the centrifugal force exerted by the core and jacket, radial momentum of the target, and the strength of the target. A criterion for the onset of “bi-erosion”, where there exist two stagnation points such that the performance is different significantly from the homogeneous rods, is obtained from the model. Predicted results for the final cavity diameter are found to match well with the corresponding test values. Further numerical simulations are conducted and indicate that as long as “co-erosion” occurs the penetration performance of jacketed rods is governed by the aspect ratio not of the jacketed rod but of the high-density core rod.

121 先頭が球面の円筒体周りの流れとその発生音

The aerodynamic sound generated from the high speed train under progress of speed up program is now a great issue. This aerodynamic sound radiating from a half-cylindrical train model with a quarter spherical front nose and the behaviour of an air-flow created around this model are measured in a low-noise wind tunnel. This paper presents a study of an appearance of generated sound referring to the graphical flow pattern. The case that there is a quarter sphere at the tail part of model is compared the case that there is none. If the cylinder is long, the presence of the tail part or none will have a small influence on the generated sound. On the other hand, if the cylinder is short, the sound without the tail part is bigger than that with it.