The impact of force, time, and rotation on the transfer of ammonium nitrate: a reductionist approach to understanding evidence dynamics

The reduction in ammonia (NH3) losses from volatilization has significant implications in forage production. The objective of this study was to evaluate the impact of N fertilizers (urea, ammonium nitrate, and ammonium sulfate) and four doses (0, 90, 180 and 270 kg N ha−1) on N losses by NH3 volatilization, accumulation, and forage chemical composition of Urochloa brizantha cv Marandu. Two field experiments were conducted to measure NH3 losses using semi-open chambers. The forage accumulation and chemical composition were evaluated in the third experiment; the response variables included forage accumulation, crude protein (CP), and neutral detergent fiber (NDF). Compared to urea, ammonium nitrate and ammonium sulfate reduced NH3 losses by 84% and 87% and increased total forage accumulation by 14% and 23%, respectively. Forage accumulation rate and CP increased linearly with the N levels, while NDF contents decreased linearly with the N levels. In both experiments, NH3 losses and forage characteristics were different according to the rainfall pattern and temperature variations. Our results indicate that the use of nitric and ammoniacal fertilizers and the application of fertilizer in the rainy season constitute an efficient fertilizer management strategy to increase forage yield and decrease losses from volatilization of NH3.

Download Full-text

Effect of Velocity on the Impact Resistance of Woven Jute Fiber Reinforced Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.465-466.1277 ◽

2013 ◽

Vol 465-466 ◽

pp. 1277-1281 ◽

Cited By ~ 8

Author(s):

Al Emran Ismail ◽

Muhd Hafeez Zainulabidin ◽

Mohd Nazrul Roslan ◽

Abdul Latif Mohd Tobi ◽

Nik Hisyamudin Muhd Nor

Keyword(s):

Failure Mechanisms ◽

Impact Resistance ◽

Fiber Reinforced Composites ◽

Jute Fiber ◽

Reinforced Composites ◽

Fiber Reinforced ◽

Wide Range ◽

Force Time ◽

Type Of Failure ◽

The Impact

is present project investigated the impact penetration response of woven jute fiber reinforced composites subjected to wide range of low impact velocities. Hand layout woven jute fibers are thermally compressed to ensure no internal defects formed in the composites. Six layers of woven jutes are stacked together using different fiber orientations [0/q/0]s. Low impact velocities are used ranging between 5 – 20 m/s. Force-time, force-displacement and energy-time curves are obtained automatically during the impact tests. The results are then discussed with considering the composite fragmentations and failure mechanisms. It is found that 00composite orientations capable to absorb sufficiently impact energy for 5 m/s but not for velocity greater than 10 m/s. When fiber orientations used between 15 – 450, the composite impact resistance increased indicating two significant peak forces. These peak forces represent different type of failure mechanisms occurred during the striker progresses.

Download Full-text

Biomechanical assessment of various punching techniques

International Journal of Legal Medicine ◽

10.1007/s00414-020-02440-8 ◽

2020 ◽

Author(s):

Jiri Adamec ◽

Peter Hofer ◽

Stefan Pittner ◽

Fabio Monticelli ◽

Matthias Graw ◽

...

Keyword(s):

High Speed ◽

Vertical Wall ◽

Force Plate ◽

Physical Parameters ◽

Time Curve ◽

Biomechanical Assessment ◽

Sports Science ◽

General Terms ◽

Force Time ◽

The Impact

Abstract Punches without the use of instruments/objects are a common type of body violence and as such a frequent subject of medicolegal analyses. The assessment of the injuries occurred as well as of the potential of the assault to produce severe body harm is based on objective traces (especially the documented injuries of both parties involved) as well as the—often divergent—descriptions of the event. Quantitative data regarding the punching characteristics that could be used for the assessment are rare and originate mostly in sports science. The aim of this study was to provide physical data enabling/facilitating the assessment of various punching techniques. A total of 50 volunteers took part in our study (29 males and 21 females) and performed severe punches with the fist, with the small finger edge of the hand (karate chop), and with the open hand with both the dominant and the non-dominant hands in randomized order. The strikes were performed on a boxing pad attached to a KISTLER force plate (sampling frequency 10,000 Hz) mounted on a vertical wall. The punching velocity was defined as the hand velocity over the last 10 cm prior to the contact to the pad and ascertained by using a high-speed camera (2000 Hz). Apart from the strike velocity, the maximum force, the impulse (the integral of the force-time curve), the impact duration, and the effective mass of the punch (the ratio between the impulse and the strike velocity) were measured/calculated. The results show a various degree of dependence of the physical parameters of the strikes on the punching technique, gender, hand used, body weight, and other factors. On the other hand, a high degree of variability was observed that is likely attributable to individual punching capabilities. In a follow-up study, we plan to compare the “ordinary” persons with highly trained (boxers etc.) individuals. Even though the results must be interpreted with great caution and a direct transfer of the quantitative parameters to real-world situations is in general terms not possible, the study offers valuable insights and a solid basis for a qualified forensic medical/biomechanical assessment.

Download Full-text

Development of Imaging Technique for Evaluating the RC Plate Containing Epoxy-Repaired Delamination

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.321-323.348 ◽

2006 ◽

Vol 321-323 ◽

pp. 348-351 ◽

Cited By ~ 1

Author(s):

Chia Chi Cheng ◽

Kuang Chih Pei ◽

Jiunn Hong Wu

Keyword(s):

Transfer Functions ◽

Imaging Technique ◽

Crack Depth ◽

Spectral Image ◽

Impact Echo ◽

Amplitude Spectra ◽

Before And After ◽

Force Time ◽

The Impact ◽

Crack Widths

The paper introduces a newly developed imaging technique for evaluating the integrity of concrete structures. The image of normalized amplitude spectra is obtained from B-scan of impact-echo tests. The normalizing process was carried out by obtaining the simulated transfer functions, in which the displacement of R-wave waveform of the impact-echo response multiplying a correcting factor is used as the simulated force-time function. Two specimens, one reinforced and the other unreinforced concrete plates, containing naturally delaminated cracks with crack widths 1 mm, 3 mm and 5 mm were constructed and repaired by injected epoxy into the delaminated cracks. The NDT method was performed on the specimens before and after the repairing work for comparison. The spectral image shows consistent high intensity at the crack-depth-frequency for specimens at crack stages and less in intensity for the ones at repaired stage.

Download Full-text

INELASTIC DYNAMIC ANALYSIS OF AN RC BUILDING IMPACTED BY A TSUNAMI WATER-BORNE SHIPPING CONTAINER

Journal of Earthquake and Tsunami ◽

10.1142/s1793431112500017 ◽

2012 ◽

Vol 06 (01) ◽

pp. 1250001 ◽

Cited By ~ 7

Author(s):

M. A. K. M. MADURAPPERUMA ◽

ANIL C. WIJEYEWICKREMA

Keyword(s):

Impact Analysis ◽

Failure Modes ◽

Indian Ocean Tsunami ◽

Shipping Container ◽

Axial Forces ◽

Rc Building ◽

Time Histories ◽

Force Time ◽

The Impact ◽

Water Borne

In the aftermath of the Indian Ocean tsunami of December 26, 2004, buildings without in-fill walls in the first story, which allow the unimpeded flow of tsunami waves, have been constructed in the regions of low seismic risk. However, columns in such buildings could be susceptible to impact of tsunami water-borne massive objects. In the present study, the impact of a tsunami water-borne shipping container on a reinforced concrete (RC) building is considered. The impact force-time histories are obtained from a high-fidelity finite element analysis, for a range of container velocities. These force-time histories are used in the impact analysis of the RC building and potential failure modes of the impacted column, changes in column axial forces, and floor displacements are studied. For the range of container velocities considered, it is found that although the axial load carrying capacity of the impacted column has significantly decreased, the building remains stable due to redistribution of internal forces to adjacent members.

Download Full-text

Numerical Simulation Analysis of Collision between Ship and Steel Sheet Pile Quay-Wall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.744-746.1175 ◽

2015 ◽

Vol 744-746 ◽

pp. 1175-1179 ◽

Cited By ~ 1

Author(s):

Peng Liu ◽

Hong Wang ◽

Chao Zhu

Keyword(s):

Numerical Simulation ◽

Steel Sheet ◽

Impact Force ◽

Simulation Analysis ◽

Sheet Pile ◽

Time Curve ◽

Finite Element Software ◽

Quay Wall ◽

Force Time ◽

The Impact

The impact process of 50000t ship and steel sheet pile bulkhead is simulated by finite element software ANSYS/LS-DYNA. This article acquires the impact force-time curve, equivalent force-time curve of steel sheet pile and the pressure-time curve of breast wall. Comparing the impact force of numerical simulation with the result of ship-bridge collision specifications, and general rules and characteristics are obtained. At the same time, put forward some measures to prevent the damage of wharf structure under the ship of large velocity impact, which provide theoretical references during the design, maintenance, and transformation of similar wharf.

Download Full-text

Determination of impact events on a plate-like composite structure

The Aeronautical Journal ◽

10.1017/aer.2016.36 ◽

2016 ◽

Vol 120 (1228) ◽

pp. 984-1004 ◽

Cited By ~ 4

Author(s):

L. Xu ◽

Y. Wang ◽

Y. Cai ◽

Z. Wu ◽

W. Peng

Keyword(s):

Composite Structures ◽

Transfer Functions ◽

Flat Glass ◽

Time History ◽

Identification Algorithm ◽

Impact Location ◽

Force Time ◽

The Impact ◽

The Relationship ◽

Impact Events

ABSTRACTComposite materials have been increasingly used in aircraft structures. However, these composite structures are susceptible to damage from external low-velocity impacts. In this paper, an impact identification algorithm is proposed to estimate the impact location and force time history simultaneously. A localisation method based on basis vectors is proposed, and the impact force time history is reconstructed by simplified transfer functions. The basis vector stands for the relationship between the impact location and the sensor signals, and the transfer function shows the relationship of the sensor signal and the force time history. An experiment is conducted on a flat glass fibre-epoxy matrix composite plate to verify the developed algorithm using only four sensors. The soft impactor and hard impactor are two typical impactors for impact events; therefore, the impact experiment is performed by the rubber and the steel impactors, respectively. The experimental results indicate that the proposed algorithm is feasible for the identification of impact events on plate-like composite structures.

Download Full-text

Factors that affect the impact sensitiveness of ammonium nitrate - fuel oil (ANFO) explosives containing aluminium

Journal of Energetic Materials ◽

10.1080/07370650008216119 ◽

2000 ◽

Vol 18 (2-3) ◽

pp. 177-205

Author(s):

R. K. Wharton ◽

H. J. Royle

Keyword(s):

Ammonium Nitrate ◽

Fuel Oil ◽

The Impact

Download Full-text

Study on the Uplift Force of Plunge Pool Slab

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.580-583.1897 ◽

2014 ◽

Vol 580-583 ◽

pp. 1897-1900

Author(s):

Chun Tao Wang ◽

Bang Hua Xie ◽

Wen Hui Zeng

Keyword(s):

Low Frequency ◽

Time History ◽

Uplift Force ◽

Plunge Pool ◽

Discharge Water ◽

Amplitude Vibration ◽

History Of ◽

Force Time ◽

The Impact ◽

Test Result

The impact of the flood discharge water flow from a high dam is rather great on the slab of a plunge pool, and may cause damages to the plunge pool and consequently endangers the dam body safety. Therefore, a reverse arch slab model was established on the base of a study on and a simulation of the rational scale of gaps between the plates of the plunge pool slab. The model was an arch ring containing 7 slabs. The uplift force time history of each slab was measured, and the uplift force power spectrum and probability density were analyzed. The test result shows that the uplift energy mainly centers in 0-15Hz frequency bandwidth, and mostly within 1Hz. It belongs to a low frequency and big amplitude vibration.

Download Full-text