Bullet Shape Research Articles

Fabrication of hydrothermal PPKTP and its spontaneous parametric down-conversion characteristics

High-voltage electric field polarization, selective corrosion, current monitoring, and other methods are used to develop hydrothermal PPKTP. It is found that the reversal domain nucleation of hydrothermal-grown KTP crystals has four kinds of microscopic morphology, namely, strip shape, spindle shape, bullet shape and irregular shape, in the process of high voltage electric field polarization. Compared with the leakage current in the process of polarization of flux-grown KTP crystals, the hydrothermal-grown KTP crystals only exist when the applied electric field is much larger than the coercive field. The leakage current can be suppressed by multiple loading of short pulses, and the PPKTP with a poled period of 10 μm and 46 μm were fabricated, respectively. Subsequently, based on the fabricated PPKTP, the SPDC characteristics are studied. To the PPKTP with a poled period of 10 μm, the quantum entanglement source whose brightness exceeds 2.1 kHz @ 810 nm is prepared by the SPDC technique. Otherwise, the PPKTP with a poled period of 46 μm is used for SPDC, and the brightness of entangled photon pairs in channel 1 and channel 2 are 3.21 kHz @ 1560 nm and 5.31 kHz @ 1560 nm, respectively.

Prostate volume: does it predict patient outcomes following prostate artery embolisation? A retrospective cohort study

Prostate artery embolisation (PAE) is a minimally invasive procedure commonly performed to treat lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia. International Prostate Symptom Score (IPSS) is a validated patient questionnaire quantifying LUTS and is used for patient selection for PAE, but it is largely subjective. Prostate volume is an easily estimated objective parameter across multiple imaging modalities. No strict threshold of prostate volume is established as a selection criterion for PAE, but it is generally accepted that prostate volume should be over 40 to 50 mL.We looked at a sample of 65 cases performed at a large teaching hospital between 2017 and 2019 with a minimum of four years follow up. Embospheres between 100 to 500 microns were injected into the prostatic arteries bilaterally (if technically feasible). A ‘bullet shape’ model was used to estimate prostatic volume from initial CT. N = 13 had an estimated volume < 51 mL (range 31-50 mL). IPSS before and at 3 months post-procedure were collected.80% of patients indicated a beneficial response to PAE (IPSS improvement > 5). 23% of patients required further PAE procedure or surgery. No major complications were recorded. The mean change in IPSS under 51 mL compared to over 51 mL cohort was 10.2 versus 11 (standard deviation 7.5 versus 7.3) (p = 0.44, 2 tailed Student’s T-test).There was no statistically significant difference in the IPSS improvement or outcome of small volume prostates under 51 mL compared to large volume. Our results suggest that prostate volume should not be used to exclude patients for PAE.

Spatial distribution of void fraction in the liquid slug in vertical Gas-Liquid slug flow

Vertical slug flow is characterized by the intermittent passage of two structures, the Taylor bubble and the liquid slug. The Taylor bubble is an elongated gas bubble with a bullet shape that flows upward and fills most of the radial cross-section, leaving room for an annular downward flow of a liquid film. The liquid slug is composed of the liquid phase carrying small, scattered bubbles and flowing upwards. The liquid slug presents three main regions: the wake, the development and the fully developed one. The liquid slug has a high concentration of dispersed bubbles in the wake region because of the entrainment mechanism. The detachment point (Dt) is a stagnation point with almost no dispersed bubbles around it, occurring close to the wall in the wake region end. Experimental data for the gas fraction in three different pipe diameters (26, 40.8 and 50 mm) were gathered in the 14-meter-high vertical flow experimental facility of the NUEM/UTFPR MULTILAB. The gas fraction along the liquid slug was evaluated by using a capacitive wire-mesh sensor (WMS) for quantitative results and a high-speed camera was used to analyze qualitative results. A new correlation to predict the average volumetric gas fraction along the unit cell is proposed. Radial and axial gas fraction distribution were analyzed and the detachment point was identified. The Reynolds and Froude number influence on the Dt point was evaluated and a new correlation to predict the Dt location (LDt) is proposed.

Natural convection with variable fluid properties of couple stress fluid with Cattaneo-Christov model and enthalpy process

The geometry under consideration for this flow problem, namely paraboloid surface is similar to aircraft and car bonnet, bullet shape, front shape of submarine, rockets and these types of are useful in manufacturing of formula F1 cars and airplanes. The flow of fluid over paraboloid surface has several applications in space science, industries, mechanical works and architecture. The aim of this study is to explore the Cattaneo-Christov heat and mass flux model in steady 2D couple stress fluid flow with variable thermo-physical characteristics near the parabolic surface. The effects of enthalpy and activation energy are also taken into consideration. The stretching in the layers of fluid is assumed at the surface of body. The problem is amended by using the law of conservation of momentum, energy and mass transfer. The non-linear governing partial differential equations are converted into ordinary differential equations by using self-similar form with similarity transformation. The resulting ODE's are numerically solved by bvp4c method. The conclusion indicates that the fluid moves quickly due to higher inputs of couples stress parameter and buoyancy parameter while the viscosity coefficient creates restriction in the fluid motion. The transference analysis of temperature and concentration enhances for higher impacts of thermal conduction and mass diffusivity coefficient. The thermal concentration relaxation parameters are the source of decline in the concentration and temperature of fluid. The heat transmission rate is maximum and mass transfer is minimum due to raising values of Dramkholer number. The impression of all parameters on different fields is listed in discussion section.

Detection and discrimination of nanoparticles using bullet shape nanopores coated with PEG

The use of single track-etched nanopores to distinguish molecules is limited by the difficulty in comparing independent experiments. This is mainly because the properties (size, surface state) among various equivalent nanopores are not strictly identical. In this work, we propose a way to discriminate different sized gold nanoparticles coated with PEG from 38 to 90 nm using bullet-like shape nanopores with tip diameters of 100 and 130 ± 30 nm, functionalized with polyethylene glycol (PEG) chains of different lengths (5 and 20 kDa). We show that the two classical parameters of current perturbations (the relative blockade amplitude and the dwell time) caused by the interaction of the nanoparticles with the nanopore allow the discrimination of the nanoparticles using each nanopore independently. Indeed, both the nanopore diameter and the PEG length influence the current blockade parameter, showing that it is possible to distinguish nanoparticles from independent experiments despite the inherent variability of the track-etched nanopores.

Isolation and identification of a new strain Micropterus salmoides rhabdovirus (MSRV) from largemouth bass Micropterus salmoides in China

As an important farmed fish worldwide, largemouth bass (Micropterus salmoides) is suffering a severely disease caused by rhabdovirus, which has resulted to a massive economic loss. In the present study, a new Micropterus salmoides rhabdovirus (MSRV) strain named MSRV-NY01 was isolated from largemouth bass juvenile from a fish farm in Nanyang, Henan province, China. Cell culture, histopathological examination, reverse transcription-polymerase chain reaction (RT-PCR), plaque purification, phylogenetic analysis, transmission electron micrograph (TEM) observation, experimental infection, real-time quantitative polymerase chain reaction (RT-qPCR) were used for virus isolation and identification. The diseased fish exhibited abnormal symptoms with anorexia, exophthalmia, bloated abdomen, spiral swimming, hemorrhage on body surfaces, and fluid accumulation in the abdominal cavity. Histopathological examination showed obvious hemorrhage, inflammatory cell infiltration, and widespread cell degeneration and necrosis were presented in the liver, spleen, intestine and stomach of diseased fish. Obvious cytopathic effects (CPE) were induced in epithelioma papillosum cyprini (EPC), grouper spleen (GS) and grouper fin (GF-1) cell lines after inoculation of mixed liver and kidney homogenates from disease fish. RT-PCR, DNA sequencing and phylogenetic tree analysis showed that the virus belongs to rhabdovirus with the highest similar to the MSRV-FJ985 strain. Through five sequential rounds of plaque purification assay, a MSRV plaque isolate was derived and was confirmed by RT-PCR and DNA sequencing. TEM observation showed that numerous virions with typical bullet shape (100–150 nm in length and 70–90 nm in diameter) were present in infected GS cells. Thus, this newly isolated virus from diseased Micropterus salmoides was tentatively named as MSRV-NY01. Regression infection experiment indicated that MSRV-NY01 was highly pathogenic to Micropterus salmoides juvenile and the cumulative mortality of fish injected with 5 × 104, 104, 2 × 103, 4 × 102, 2 × 102, 102 and 50 PFU of virus were 100%, 100%, 100%, 96.7%, 96.7%, 93.3% and 90%, respectively. Moreover, RT-qPCR showed that MSRV was present in all 9 tested tissues of infected fish, and the virus loads of the spleen and heart were significantly higher than that in other tissues tested. In conclusion, we isolated and identified a new MSRV strain from diseased largemouth bass, and our results will provide new material and information for the prevention and control strategy for MSRV.

Hyaluronidase Promote Transdermal Diffusion of Small Sized Curcumin Nanocrystal by Dissolving Microneedles Delivery.

Hyaluronidase is clinically used in treating many skin diseases due to its good permeability-promoting effect, which may motivate the diffusion and absorption of drugs. To verify the penetration osmotic effect of hyaluronidase in microneedles, 55 nm-size curcumin nanocrystals were fabricated and loaded into microneedles containing hyaluronidase in the tip. Microneedles with bullet shape and backing layer of 20% PVA + 20% PVP K30 (w/v) showed excellent performance. The microneedles were able to pierce the skin effectively with a skin insert rate of 90% and demonstrated good mechanical strength. In the in vitro permeation assay, with the increase of hyaluronidase concentration at the tip of the needle, the cumulative release of curcumin increased, as well as the skin retention decreased. In addition, compared with the microneedles without hyaluronidase, the microneedles containing hyaluronidase in the tip exhibited a larger drug diffusion area and deeper diffusion depth. In conclusion, hyaluronidase could effectively promote the transdermal diffusion and absorption of the drug.

Texture shape optimization induced higher load carrying capacity of sealing ring based on improved PSO algorithm

An improved particle swarm optimization (PSO) algorithm is presented to optimize the texture shape of the sealing ring in order to enhance the load carrying capacity (LCC). The shape optimization uses the unrelated generation method of the texture curves, and two splines are applied to fit the boundary of the texture to improve the continuity. The inertia factor is adjusted through the differential strategy to enhance the local optimization capacity. The optimization model is verified by two optimization cases. The optimized texture is bullet-shaped. The increase of inlet oil pressure transforms the optimized texture from the bullet shape to the inner spiral shape. In addition, the increase of the texture depth leads to the gradual elongation of the texture shape. The increase in the number of textures flattens the seal texture. The results shows that the improved PSO algorithm has high global optimization ability of the texture shape for the sealing ring in the vehicle transmission through appropriate parameter settings.

Lead bullets of the Russian warrior host of 1582–1585 (based on the materials from the settle-ment of Isker)

The capital of the Siberian Khanate, the Isker hillfort, is located on the right bank of the Irtysh River, 17 km up from the mouth of the Tobol River. A large collection of bullets has been assembled on the monument, which were left by the soldiers who participated in the Yermak's campaign. For the first time, the data on 30 bullets from Isker were reviewed by A.P. Zykov in a joint monograph published in 2017, which included the bullets stored in Tobolsk Museum Reserve. However, some conclusions made by the researcher were not supported by the mu-seum's collections. In total, 23 bullets are stored in the museum, and there are no bullets less than 8 mm in di-ameter, no bullets with a lead funnel, and no cylindrical bullets produced by cutting a lead rod into pieces. In total, our work made use of the data on 139 bullets that are stored in Tobolsk Museum Reserve and bullets that we found during the field research and collection of artefactual remains from the Isker hillfort since 2007. The bullets can be divided into two groups: molded (137 items) and mechanically manufactured (2 items). For the bullets, 12 variants of the traits, which characterize some features of their manufacture, and traces of impact on the projec-tiles before expulsion and those that appeared afterwards, were identified. During the manufacture, the bullet shape was attempted to be made spherical; this was recorded for 37.4 % of the items. Twenty-three percent of the bullets feature a seam from the mold sections, 14.4 % of the bullets preserved areas from lead shrinkage when cooling in the mold, 1.4 % of the bullets preserved a lead funnel, and 27.3 % of the bullets have notches made to increase their lethality. Furthermore, 58.3 % of the bullets bear traces of shooting — striation caused by friction of the projectile against the smooth barrel and traces of deformation caused by hitting a hard surface; only 10.1 % of the bullets are significantly undermolded or cut in halves. Summarizing the data on the bullets from the Isker hillfort, it must be noted that the Russian warrior host of 1582–1585 were armed with Russian-made muskets of small calibers of 8–15 mm. At the same time, the vast majority of them had a caliber of 10–14 mm, of which almost 2/3 were of a 12–13 mm caliber. The warriors campaigning in Siberia did not feel a noticeable shortage of ammunition, conducting annual target practice shooting at hard targets. Ball bullets were used, without lead funnels, which were cast from a precisely meas-ured amount of lead. Notched bullets were quite widely used.

Joint Stiffness Leads to the Diagnosis of a Rare Disease

Introduction: A 6-year-old boy was referred to our hospital because of the stiffness of both knees, which had commenced two years ago and gradually progressed to both hips, ankles, elbows, fingers, and toes. He occasionally had arthralgia with no complaint of joint swelling. He had a long face, a prominent forehead and chin, and a short neck. There was a limitation in the range of motion in all appendicular joints with stiffness and deformity. Case Presentation: Skeletal survey images revealed central beaking and a bullet shape appearance in the cervical and lumbar vertebra, tapering of iliac wings, deformity of the femoral head, and short sacral length. A +3 glycosaminoglycan (GAG) excretion was detected in the urine test, but genetic analysis revealed Mucolipidosis type III. Conclusions: The diagnosis of metabolic diseases should be considered whenever there is joint stiffness without any evidence of inflammation. Mucopolysaccharidoses and Mucolipidoses are progressive storage disorders with many clinical and radiological characteristics.

Combining ionic diode, resistive pulse and membrane for detection and separation of anti-CD44 antibody

The need for antibody proteins is growing for both diagnosis and therapy. In this work, we combine two strategies based on single nanopore sensing and multipore membrane to separate, detect and identify antibodies. This proof of concept was done for the anti-CD44. In a first step, a single nanopore with a bullet shape were designed using track-etching of polymer film and functionalized, with a PEG spacer and CD44 antigen. The detection of anti-CD44 was evidenced by an inversion of the current rectification. After demonstrating the ability to specifically detect the antiCD44 in a single nanopore, a multipore membrane with cylindrical nanopore was designed following the same protocol and used to elute a solution of anti-CD44.In a second step, the elution product was analysed using a single SiN nanopore showing that the anti-CD44 and CD44 antigen are extracted from the membrane. The analysis of the amplitude of the current blockade shows that the complex is dissociated. • Multipore and single pore track-etched membrane was designed to detect and trap antiCD44. • The membranes are functionalized with CD44 antigen to ensure the selectivity to antiCD44. • SiN single nanopore membrane was use to confirms of the presence of antiCD44 and CD44 antigen in eluted solution. • The SiN single nanopore membrane reveals that the antiCD44 and CD44 antigen complex is dissociated after elution.

Experiment and simulation analysis on dynamic response of plane cable-membrane structure under impact load

This paper presents an experimental and simulation analysis investigation into the dynamic response of plane cable-membrane structure under impact load. Firstly, the impact tensile tests of the PVDF coated fabric were carried out, and the effect of strain rate on the mechanical properties was characterized. Then the experiment of a plane cable-membrane structure under impact load is carried out. The effects of prestress, impact velocity, and bullet shape on the vibration law of membrane surface are studied. Finally, the mechanical response of the plane cable-membrane structure under impact load is simulated by ABAQUS/Explicit, and the energy dissipation mechanism is characterized. The results show that the displacement of membrane surface increases with the increase of impactor velocity, and decreases with the increase of membrane prestress. The vibration frequency of the membrane surface is the inherent property of structure, which is affected by the prestress of the membrane surface and increases with the increase of prestress. The proportion of elastic strain energy in total energy consumption increases with the increase of prestress. The finite element (FE) models provide a reasonable prediction of the dynamic response of the plane cable-membrane structure under impact load.

Lattice Boltzmann simulation of drop splitting in a fractal tree-like microchannel

Fractal tree-like microchannel is advantageous to faster emulsification and droplet production in microchannels. Although computer simulation is becoming a powerful tool for design and optimization, precise treatment of a large number of walls in fractal tree-like microchannel is troublesome. The numerical roughness caused by traditional bounce-back boundary condition may accumulate and generate large errors in flow pattern recognization. In this paper, an approach integrating Immersed Boundary Method (IBM), Phase-Field Model (PFM) and Lattice Boltzmann Method (LBM) is developed, aiming to accurately simulate droplet splitting in fractal tree-like microchannel system involving surfactants and wetting boundary walls. Then the operating conditions including capillary number, flow rate ratio and wetting boundary conditions were optimized. We found that the capillary number in 0.02 ∼ 0.05 and flow rate ratio in 1/3.6 – 1/9 can accelerate emulsification. Hydrophobic-lipophilic walls generate a slug-like water drop of bullet shape and thin oil film between the drop and walls, facilitating drop movement in microchannel. The effects of surfactant, Marangoni stress and interfacial tension force on droplet splitting were investigated. The contact walls at the corner and forks resist the surfactant migration, and therefore enrich surfactant at the upstream end of drop interface, leading to uneven distribution of interfacial tension. The breaking interfaces and the interfaces contacting with wall or fork are subjected to opposite reaction of Marangoni stress and tend to be thinner and finally deform or break.

Instability of a liquid sheet with viscosity contrast in inertial microfluidics

Flows at moderate Reynolds numbers in inertial microfluidics enable high throughput and inertial focusing of particles and cells with relevance in biomedical applications. In the present work, we consider a viscosity-stratified three-layer flow in the inertial regime. We investigate the interfacial instability of a liquid sheet surrounded by a density-matched but more viscous fluid in a channel flow. We use linear stability analysis based on the Orr–Sommerfeld equation and direct numerical simulations with the lattice Boltzmann method (LBM) to perform an extensive parameter study. Our aim is to contribute to a controlled droplet production in inertial microfluidics. In the first part, on the linear stability analysis we show that the growth rate of the fastest growing mode xi ^{*} increases with the Reynolds number text {Re} and that its wavelength lambda ^{*} is always smaller than the channel width w for sufficiently small interfacial tension Gamma . For thin sheets we find the scaling relation xi ^{*} propto mt^{2.5}_{s}, where m is viscosity ratio and t_{s} the sheet thickness. In contrast, for thicker sheets xi ^{*} decreases with increasing t_s or m due to the nearby channel walls. Examining the eigenvalue spectra, we identify Yih modes at the interface. In the second part on the LBM simulations, the thin liquid sheet develops two distinct dynamic states: waves traveling along the interface and breakup into droplets with bullet shape. For smaller flow rates and larger sheet thicknesses, we also observe ligament formation and the sheet eventually evolves irregularly. Our work gives some indication how droplet formation can be controlled with a suitable parameter set {lambda ,t_{s},m,Gamma ,text {Re}}.Graphical

Investigation of shape effects and dead layer thicknesses of a coaxial HPGe crystal on detector efficiency by using PHITS Monte Carlo simulation

In gamma-ray spectrometry, the full energy peak efficiency can be determined by experimental, or by Monte Carlo (MC) simulation methods. In experimental methods, reference standard materials including a large number of gamma emitters or mixed gamma emitters in different geometries are requested to determine the efficiency curves. Besides, simulation by MC methods has advantages of modelling any geometries and energy range of interest. However, by simulation it is not easy to determine the efficiency curves due to the lack of information supplied from manufacturers. In this work, it is focused on the effect of dead layer thickness and other geometric parameters of detector crystal on the efficiency of the detector. The general-purpose MC code PHITS and specific-purpose MC code GESPECOR are used to simulate the detector. The experiments are performed by single gamma point sources at a 12.5 cm distance from the end cap of the detector. The results showed that the physical parameters of the detector are different from those provided by the manufacturer. After 15 years of operation of the detector, it is observed that the dead layer thickness increased from 0.7 mm to 1.29 mm. It causes a decrease in the efficiency by a reduction in the active volume of the detector. In addition, it is showed that the round shape of the front edge and bullet shape of the inner hole of the detector crystal have an undeniable effect on efficiency of detector especially for low energy photons. The study shows that the PHITS MC simulation program can be successfully used in obtaining efficiency calibration of HPGe detectors and determining the dead layer thickness.

Faster Taylor bubbles

Gas volumes with an equivalent spherical diameter greater than that of the tube in which they rise by buoyancy – so-called Taylor bubbles – assume a characteristic bullet shape and ascend with a velocity that is dependent primarily on the tube diameter, and also on the physical properties of the liquid, but, remarkably, is mostly independent of the gas volume. The requirement of liquid volume conservation suggests a plausible explanation of this paradoxical feature in that the space vacated under the rising bubble must be replenished by the liquid film falling along the bubble surface. It is demonstrated by numerical means that, by limiting the bubble diameter, a cylindrical ‘cage’ of thin vertical rods coaxial with the tube permits the flow rate of this film to increase, with the result that the bubble is able to ascend with a significantly higher velocity than in an empty tube with the same diameter.

Computational Fluid Dynamics(CFD) of Drag Force for Bullet’s Shape Design

The factors in bullet’s shape design which affect the drag force of bullets are important in aerodynamics, especially in ballistics. In this paper, based on traditional researches about different bullet shape designs, nose cone design of the bullet is mainly discussed, as well as the hollow tip and the rifling on the appearance of the bullet are also included. This paper adopts Fusion 360 and Ansys fluent to calculate and model. This research verifies the similarity of the drag coefficient of different bullet shape design at a low speed and figures out the best shape characteristic coefficient in Haack series design, while some problems still exists in the influence of hollow tips of the bullet to the drag force.

Trans-Domain Amphibious Unmanned Platform Based on Coaxial Counter-Propellers: Design and Experimental Validation

The rapid evolution of the Unmanned Aerial Vehicle (UAV) industry has significantly increased interest in UAV design with trans-domain capabilities. It is still a major challenge to achieve miniaturization and enhance the maneuverability and underwater reliability of trans-domain UAVs. In this paper, a novel bullet shape Trans-Domain Amphibious Vehicle (TDAV) is proposed which achieves free trans-domain motion and has the advantages of small size, high maneuverability and high reliability for both rotary-wing UAV and Autonomous Underwater Vehicle (AUV) operation. Compared with traditional amphibious machines, the TDAV design is streamlined and thus inherits the advantages of both the Bamboo Dragonfly and underwater AUVs. The proposed TDAV has a coaxial counter-propeller-tilting platform which satisfies the power and small diameter fuselage requirements, and the blades fold to reduce underwater drag and facilitate transportation. Further, a stable and efficient trans-domain attitude adjustment system is presented which effectively realizes trans-domain attitude switching. Based on the characteristics of the symmetric TDAV body, a rudder blade allocation algorithm is proposed to realize free movement in water. Finally, an improved particle swarm optimization algorithm is used to obtain suitable hierarchical fractional-order PID parameters. Both simulation and outdoor tests were performed and the results demonstrate that the proposed TDAV achieves outstanding performance in terms of lift altitude, trans-domain attitude switching time, and free trans-domain movement in both water and air.

Hydrodynamics of bubble coalescence in microchannels

AbstractGas‐liquid flow in microchannels is relevant to a number of microfluidic devices without moving parts for application in chemical micro‐processing, inkjet printing, and electronics cooling. Over a large range of gas and liquid flow rates, gas bubbles have the same size as that of the channel. Such bubbles are nearly spherical in shape until their radius is less than that of the channel. The bubbles with a larger volume expand along the axis taking a capsular or bullet shape and are commonly known as Taylor bubbles. For air‐water flow, the spherical bubble is observed to move with a velocity higher than that of the Taylor bubble. In this work, the flow of a Taylor bubble followed by a spherical one, initially separated by several channel diameters, has been studied numerically using the volume of fluid (VOF) method. The hydrodynamics during the bubble approach as well as the evolution of the doublet, that is, the merged bubble, has been investigated. To track the velocity of each bubble with time during the bubble approach stage, a novel methodology has been developed using k‐means clustering algorithm. The evolution of the interface of the doublet has been monitored. The neck radius of the doublet grows as τ0.5, τ being the time since the contact between the bubble interfaces, when the interface is away from the wall. In the near wall region, the radius grows more slowly and is proportional to τ0.1.

Исследование рассеивания и аэродинамического сопротивления модифицированных пуль при дозвуковых скоростях полета на баллистической трассе

The purpose of the work was to experimentally research and analyze the effect of the proposed modifications of a pneumatic bullet on the accuracy parameters of the shooting system with a subsonic initial speed. The study introduces variants of modernization of a bullet with a flat head part for pneumatic weapons, describes the external ballistic experiments carried out on the ballistic track of the Department of Dynamics and Flight Control of Rockets and Spacecraft of Bauman Moscow State Technical University, and theoretically substantiates the physics of the interaction between a bullet and the air, which became possible after analyzing the results of shooting. The obtained correlation between scattering characteristics of unguided aircraft and the type of modification of their aerodynamic shape is described. On the basis of the data obtained, modifications of the bullet shape were determined, leading not only to a decrease in aerodynamic drag, but also to a certain decrease in dispersion during shooting.