scholarly journals Dropped Object Impact Analysis Considering Frequency and Consequence for LNG-FPSO Topside Module

2021 ◽  
Vol 11 (16) ◽  
pp. 7753
Author(s):  
Kwangkook Lee ◽  
Hyunsu Ryu
Keyword(s):  
Impact Energy ◽  
Impact Analysis ◽  
Quantitative Risk Assessment ◽  
Production Area ◽  
The Difference ◽  
Offshore Industry ◽  
Impact Energies ◽  
The Impact ◽  
External Loads ◽  
Specific Orientation

Recently, quantitative risk assessment (QRA) has been widely used as a decision-making tool in the offshore industry. This study focused on analyzing dropped objects in the design of a modern offshore platform. A modified QRA procedure was developed for assessing production module protection against accidental external loads. Frequency and consequence analyses were performed using the developed QRA procedure. An exceedance curve was plotted, and a high-risk management item was derived through this process. In particular, simulations and experiments were used to verify the difference between the potential and impact energies according to drop orientation. When the object dropped in a specific orientation, the impact energy was confirmed to be up to 4.7 times greater than the potential energy. To reflect the QRA results in structural design, the proposed procedure should be used to calculate the maximum impact energy. The proposed procedure provides a step-by-step guide to assess the damage capacity of a production area as well as the damage frequency and consequences.

scholarly journals Breakage Susceptibility of Wheat and Triticale Seeds Related to Moisture Content and Impact Energy

2012 ◽  
Vol 45 (3) ◽  
pp. 5-13
Author(s):  
F. Shahbazi ◽  
A Dowlatshah ◽  
S. Valizadeh
Keyword(s):  
Moisture Content ◽  
Impact Energy ◽  
Mechanical Damage ◽  
Moisture Contents ◽  
Seed Damage ◽  
Significant Difference ◽  
Impact Energies ◽  
The Impact ◽  
Content Range ◽  
Wheat Seeds

Abstract Mechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quantity of seeds. Seed damage result in lower grain value, storability problem, and reduced seed germination and seedling vigor and subsequent yield of crops. The objective of this research was to determine the effects of moisture content and impact energy on the breakage susceptibility of wheat and triticale seeds. The experiments were conducted at five moisture contents of 7.5, 12, 17, 22 and 27% w.b. and at the impact energies of 0.05 and 0.1 J. The percentage of breakage of both wheat and triticale seeds increased as impact energy increased. The analysis of variance showed that there was a significant difference between breakage susceptibility of wheat and triticale seeds at the 1% probability level. Triticale seeds had more breakage than wheat seeds. For both wheat and triticale seeds as the moisture content of the seeds increased, the amount of the percentage breakage of seeds decreased as a polynomial. The average values of percentage breakage of wheat seeds decreased from 43.81 to 19.88% as the moisture content increased from 7.5 to 27%. Over this same moisture content range the percentage breakage of triticale seeds varied from 81.34 to 37.77%. Below the moisture contents of 17% for the wheat and 22% for the triticale the percentage breakage of seeds increased dramatically.

scholarly journals IMPACT OF DEFORMABLE STAMP WITH A MULTILAYERED WALL

2020 ◽  
Vol 72 (4) ◽  
pp. 7-16
Author(s):  
М.M. Bukenov ◽  
◽  
Ye.M. Mukhametov ◽  
M.T. Iskakova ◽  
◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Contact Resistance ◽  
Contact Interaction ◽  
Impact Analysis ◽  
Numerical Work ◽  
The Difference ◽  
Complete Detachment ◽  
Deformable System ◽  
Separation Zones ◽  
The Impact

In this paper, was performed by numerical work according to the difference scheme. Analysis of the numerical results showed: one of the important issues of contact interaction is to determine the duration of the impact of the colliding bodies. Obviously, under the condition of a hard clutch, sticking of the striker from the barrier will not occur. To study the process of complete breakage of mechanical contact (appearance of separation zones), we will use boundary conditions that simulate a perfectly smooth impact. Analysis of the dynamics of contact resistance has shown that its magnitude and features of evolution over time substantially depend on the geometric and physicomechanical parameters of the deformable system, as well as on the type of boundary conditions. An increase in the acoustic rigidity of the impactor leads to an increase in the amplitude and duration of the impact. The impact of a less rigid punch or the presence in the barrier of a shielding layer of a polymeric material reduces the contact resistance of the plate, but the force interaction between the impacted bodies is longer. As the analysis of the results shows, the evolution of contact stresses is characterized by a number of specific features. For example, there is a direct correlation between the height of the cylinder and the time of its complete detachment from the obstacle, which corresponds to the vanishing of the function   tk  . An increase in the acoustic rigidity of the impactor leads to a sharp increase in the amplitude of the total resistance and an increase in the duration of the contact interaction. Thus, the contours of the isolines provide a visual representation of the configuration of the areas at which points the stresses develop, immediately preceding the appearance of elastoplastic deformations for spall fractures (for brittle materials).

scholarly journals The Effect of Sorbitol and Conservation Period on The in Vitro Evolution of Solanum Tuberosum L. Plantlets

2012 ◽  
Vol 45 (3) ◽  
pp. 79-86
Author(s):  
Iustina Brînduşa Ciobanu ◽  
Dana Constantinovici
Keyword(s):  
Moisture Content ◽  
Impact Energy ◽  
Solanum Tuberosum L ◽  
Mechanical Damage ◽  
Moisture Contents ◽  
Significant Difference ◽  
Impact Energies ◽  
The Impact ◽  
Wheat Seeds

Abstract Mechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quantity of seeds. Seed damage result in lower grain value, storability problem, and reduced seed germination and seedling vigor and subsequent yield of crops. The objective of this research was to determine the effects of moisture content and impact energy on the breakage susceptibility of wheat and triticale seeds. The experiments were conducted at five moisture contents of 7.5, 12, 17, 22 and 27% w.b. and at the impact energies of 0.05 and 0.1 J. The percentage of breakage of both wheat and triticale seeds increased as impact energy increased. The analysis of variance showed that there was a significant difference between breakage susceptibility of wheat and triticale seeds at the 1% probability level. Triticale seeds had more breakage than wheat seeds. For both wheat and triticale seeds as the moisture content of the seeds increased, the amount of the percentage breakage of seeds decreased as a polynomial. The average values of percentage breakage of wheat seeds decreased from 43.81 to 19.88% as the moisture content increased from 7.5 to 27%. Over this same moisture content range the percentage breakage of triticale seeds varied from 81.34 to 37.77%. Below the moisture contents of 17% for the wheat and 22% for the triticale the percentage breakage of seeds increased dramatically.

${\rm C}^+_{60}$ IONS IN COLLISIONS WITH CRYSTALLINE SURFACES: KINEMATICS AND DYNAMICS

1996 ◽  
Vol 10 (01) ◽  
pp. 11-57 ◽  
Author(s):  
TH. LILL ◽  
H.-G. BUSMANN ◽  
F. LACHER ◽  
I.V. HERTEL
Keyword(s):  
Molecular Dynamics ◽  
Kinetic Energy ◽  
Impact Energy ◽  
Tangential Component ◽  
Measured Velocity ◽  
Surface Molecules ◽  
Molecular Dynamics Calculations ◽  
Impact Energies ◽  
Impact Angles ◽  
The Impact

Collisions of [Formula: see text] ions with surfaces of highly oriented pyrolytic graphite (HOPG), diamond (111) and heteroepitaxial fullerite films on mica in the impact energy range between 100 and 1500 eV are studied by mass, energy, and angle resolved time-of-flight mass spectrometry. For the graphite and diamond surfaces, highly inelastic scattering has been observed. The analysis of the velocity dependence of the scattered ions reveals that the normal and tangential component of the ion velocity have different significance for the collision dynamics. The normal component of the velocity appears to determine the amount of energy transferred into vibrational and deformational energy of the projectile and target. The final kinetic energy is independent of the impact energy for impact angles of ≈20° and impact energies between 140 and 450 eV. This observation can be explained by the existence of an upper bound of the final kinetic energy that is defined by the amount of energy stored in the deformed molecule without being deposited or destroyed. The tangential component is partially transformed into rotational energy of the [Formula: see text] in the collision with the surface, as may be explained by a simple rolling ball model. In contrast, scattering from heteroepitaxial fullerite films is nearly elastic for impact energies up to 230 eV and impact angles of about 20°. Additionally, the velocity distributions reveal a low velocity component. Its relative intensity increases with increasing impact energy and remains the only feature in the velocity distribution for impact energies higher than 290 eV. This component is due to sputtering of surface molecules. The angular dependent intensities of the fast ions exhibit a rich structure. This can be attributed to rainbow scattering, as confirmed by classical trajectory and molecular dynamics calculations with different levels of sophistication. These calculations also show that linear collision sequences along the closed packed rows of the fullerite surface may be generated as the result of the [Formula: see text] impact. A detailed study of these collision sequences by molecular dynamics calculations reveals that rainbow effects might be possible when these sequences are defocused due to thermal motion of the surface molecules. The contribution of this process to the measured velocity and angular distributions is discussed.

scholarly journals The Impact of Farmland Transfer on Rural Households’ Income Structure in the Context of Household Differentiation: A Case Study of Heilongjiang Province, China

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 362
Author(s):  
Lili Chen ◽  
Hongsheng Chen ◽  
Chaohui Zou ◽  
Ye Liu
Keyword(s):  
Rural Areas ◽  
Rural Households ◽  
Heilongjiang Province ◽  
Agricultural Income ◽  
Agricultural Employment ◽  
Agricultural Households ◽  
Part Time ◽  
Production Area ◽  
The Difference ◽  
The Impact

Farmland transfer is an important factor affecting rural households’ income and sustainable development of rural areas in developing countries. However, recent studies have reached controversial conclusions on how farmland transfer affects rural households’ income because of ignoring the household differentiation and the difference in the impacts of farmland transfer-in and transfer-out on the income structure. Taking the Heilongjiang province, the major cereal production area in China, as the study area, the paper aims to estimate the impacts of farmland transfer-in or transfer-out of different rural households on income structure based on the Propensity Score Matching (PSM) model. Results showed that the total income of all rural households transferring-in farmland increased significantly while the income decreased after transferring-out farmland, and I part-time households have the largest increase, followed by pure-agricultural households and II part-time households, whereas I part-time households has the smallest reduction, followed by pure-agricultural households and II part-time households. Because the increase in the agricultural income and subsidies was greater than the decrease in the outworking income for I part-time households transferring-in farmland, while the outworking income not increasing but decreasing when II part-time households transferring-out farmland. We can conclude that (1) encouraging pure-agricultural and I part-time households to transfer farmland in and II part-time households to transfer out of farmland, and develop mutual assistance for the aged in rural areas should be strengthened. (2) Improving the farmland transfer market and promoting non-agricultural employment of surplus-labor need to be synchronized. (3) Agricultural subsidies should be provided to cultivators.

Abrasion regimes in fluvial bedrock incision

Geology ◽  
2021 ◽  
Author(s):  
Alexander R. Beer ◽  
Michael P. Lamb
Keyword(s):  
Impact Energy ◽  
Fragment Size ◽  
Bedrock Rivers ◽  
Rock Fragments ◽  
River Incision ◽  
Energy Scaling ◽  
Wide Range ◽  
Bedrock Erosion ◽  
Impact Energies ◽  
The Impact

River incision into bedrock drives landscape evolution and couples surface changes to climate and tectonics in uplands. Mechanistic bedrock erosion modeling has focused on plucking—the hydraulic removal of large loosened rock fragments—and on abrasion—the slower fracturing-driven removal of rock due to impacts of transported sediment—which produces sand- or silt-sized fragments at the mineral grain scale (i.e., wear). An abrasion subregime (macro-abrasion) has been hypothesized to exist under high impact energies typical of cobble or boulder transport in mountain rivers, in which larger bedrock fragments can be generated. We conducted dry impact abrasion experiments across a wide range of impact energies and found that gravel-sized fragments were generated when the impact energy divided by squared impactor diameter exceeded 1 kJ/m2. However, the total abraded volume followed the same kinetic-energy scaling regardless of fragment size, holding over 13 orders of magnitude in impact energy and supporting a general abrasion law. Application to natural bedrock rivers shows that many of them likely can generate large fragments, especially in steep mountain streams and during large floods, transporting boulders in excess of 0.6 m diameter. In this regime, even single impacts can cause changes in riverbed topography that may drive morphodynamic feedbacks.

The flexural behaviors of the impacted composite single-lap adhesive joints

2015 ◽  
Vol 22 (5) ◽  
Author(s):  
Emin Ergun ◽  
Hasan Çallioğlu
Keyword(s):  
Experimental Study ◽  
Impact Energy ◽  
Energy Levels ◽  
Composite Plates ◽  
Lap Joints ◽  
Adhesive Joints ◽  
Single Lap Joints ◽  
Impact Tests ◽  
Impact Energies ◽  
The Impact

AbstractThis experimental study deals with the flexural behaviors of composite single-lap adhesive joints after impact tests. Increasing impact energies are applied at the center of the composite plates having three different overlap lengths. It is shown that the overlap lengths and impact energy levels affect considerably the impact responses of the composite single-lap joints. It is also shown that the bending stiffness of the composite increases with increasing overlap length. For this reason, after the impact tests, how these effects influence the flexural behaviors of the impacted composite lap joints was also investigated. The flexural loads of the impacted and non-impacted composite single-lap joints were determined and compared with each other. It is shown that the residual flexural loads after impact increase with increasing overlap lengths but decrease with increasing impact energy.

Investigating the influence of Taekwondo body protectors size on shock absorption

2020 ◽  
pp. 1-9
Author(s):  
Hee Seong Jeong ◽  
Sae Yong Lee ◽  
Hyung Jun Noh ◽  
David Michael O’Sullivan ◽  
Young Rim Lee
Keyword(s):  
Impact Strength ◽  
Impact Force ◽  
Impact Load ◽  
The Body ◽  
Shock Absorption ◽  
Significance Level ◽  
The Difference ◽  
Maximum Impact Force ◽  
Impact Energies ◽  
The Impact

OBJECTIVE: This study aims to compare and analyze the difference of impact force attenuation according to size and impact location on a Taekwondo body protector. METHODS: Body protectors sized 1 to 5, were impact tested by equipment based on the specifications in the European standard manual (EN 13277-1, 3). The impactor release heights were set to match impact energies of 3 and 15 J. The impactor was made from a 2.5 kg cylindrically cut piece of aluminum. Each body protector was impacted 10 times at the two impact energies and two locations. The differences in performance for each body protector size were compared using a two-way analysis of variance with a significance level of p< 005. The effect sizes were investigated using a partial eta squared value (η2). RESULTS: The significant mean differences between the body protector size and impact area (p< 005) and the average impact time of impact strengths 3 and 15 J were 0.0017 and 0.0012 s, respectively In addition, when an impact strength of 15 J was applied, the maximum resulting impact force exceeded 2000 N for both locations on all sizes. Furthermore, at an impact strength of 3 J size 3 significantly reduced the impact force more than the other sizes; however, size 1 showed the greatest shock absorption at an impact of 15 J. CONCLUSION: The results of this study show that the shock absorption of body protectors does not increase according to size; i.e., a larger body protector does not reduce the impact load more effectively. To improve safety performance, we recommend a maximum impact force of 2000 N or less for all body protectors.

scholarly journals Budget impact analysis of dabigatran compared with rivaroxaban in the prevention of the thromboembolic risk in patients with non-valvular atrial fibrillation

2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Maria Grazia Celeste ◽  
Francesca De Marco ◽  
Claudio Fresco ◽  
Giuseppe Musumeci ◽  
Roberto Ravasio
Keyword(s):  
Atrial Fibrillation ◽  
Observational Study ◽  
Intracranial Hemorrhage ◽  
Impact Analysis ◽  
Budget Impact ◽  
Bleeding Event ◽  
Base Case ◽  
Cost Offset ◽  
The Difference ◽  
The Impact

BACKGROUND: Dabigatran 150 mg BID (D150) and rivaroxaban 20 mg (R20) are indicated for the prevention of thromboembolic events in patients with Non-Valvular Atrial Fibrillation (NVAF). Outcomes from observational study demonstrated that D150 and R20 reduced the rate of thromboembolic events.OBJECTIVE: This analysis estimated the budget impact of the use of D150 and R20 for the treatment of NAFV patients in Italy.METHODS: A budget-impact model (BIM) was developed to estimate the direct costs up to 12 months from an Italian NHS perspective. The resource utilization (drugs and intracranial hemorrhage or major extracranial bleeding event) was derived from an observational study. Only direct medical costs were considered. Ex-factory prices and National Tariffs were considered to estimate the costs of drugs and medical resource used, respectively. The BIM showed the difference of expenditure and clinical events (intracranial hemorrhage or major extracranial bleeding) generated by the base case calculated for current prescription volumes (D150 30%, R20 100%), and for different prescription volume scenarios (D150 at 70% and 100%). Key variables were tested in the sensitivity analysis.RESULTS: D150 was associated with a medical cost offset driven by fewer intracranial hemorrhage and major extracranial bleeding event, these offset the incremental drug cost and results in an annual saving per patient treated (D150: € 1,052.78; R20: € 1,161.23). The present scenario determines an annual cost of € 262,543,583. The impact of total annual costs for the Italian NHS would be lower if D150 prescription volumes would be higher. The total cost is predicted to decrease by 3.8% if the D150 prescription increase to 70% and it is predicted to decrease by 6.7% if the D150 prescription increase to 100%.CONCLUSION: The use of D150, as an alternative to R20 to prevent events in patients with NVAF, could represent a cost-saving option for the Italian NHS.

scholarly journals Performance of Composite Metal Foam Armors against Various Threat Sizes

2020 ◽  
Vol 4 (4) ◽  
pp. 176
Author(s):  
Jacob Marx ◽  
Marc Portanova ◽  
Afsaneh Rabiei
Keyword(s):  
Kinetic Energy ◽  
Impact Energy ◽  
Metal Foam ◽  
Efficient Design ◽  
Thin Aluminum ◽  
Impact Energies ◽  
The Impact ◽  
Hollow Metal

The ballistic capabilities of composite metal foam (CMF) armors were experimentally tested against a 14.5 × 114 mm B32 armor-piercing incendiary (API) and compared to various sizes of armor-piercing (AP) ballistic threats, ranging from a 7.62 to 12.7 mm. Three different arrangements of layered hard armors were designed and manufactured using ceramic faceplates (in one layer, two layers or multiple tiles), a combination of ceramic and steel face sheets, with a single-layered CMF core, and a thin aluminum backing. The performance of various CMF armor designs against the 14.5 mm rounds are compared to each other and to the performance of the rolled homogeneous armor standard to identify the most efficient design for further investigations. The percentage of kinetic energy absorbed by the CMF layer in various armor arrangements and in tests against various threat sizes was calculated and compared. It appears that the larger the threat size, the more efficient the CMF layer will be due to a greater number of hollow metal spheres that are engaged in absorbing the impact energy. The results from this study will help to model and predict the performance of CMF armors against various threat sizes and impact energies.

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