scholarly journals A line laser detection screen design and projectile echo power calculation in detection screen area

2021 ◽  
Author(s):  
Han-shan Li ◽  
Xiao-qian Zhang ◽  
Xue-wei Zhang ◽  
Quan-min Guo
Keyword(s):  
Power Calculation ◽  
Screen Design ◽  
Laser Detection

Stopping-power determination for compound by EELS

1994 ◽  
Vol 52 ◽  
pp. 948-949 ◽  
Author(s):  
David C. Joy ◽  
Suichu Luo ◽  
John R. Dunlap ◽  
Dick Williams ◽  
Siqi Cao
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Average Energy ◽  
Stopping Power ◽  
Accurate Information ◽  
Power Calculation ◽  
Coulomb Collisions ◽  
Electron Energy Loss

In Physics, Chemistry, Materials Science, Biology and Medicine, it is very important to have accurate information about the stopping power of various media for electrons, that is the average energy loss per unit pathlength due to inelastic Coulomb collisions with atomic electrons of the specimen along their trajectories. Techniques such as photoemission spectroscopy, Auger electron spectroscopy, and electron energy loss spectroscopy have been used in the measurements of electron-solid interaction. In this paper we present a comprehensive technique which combines experimental and theoretical work to determine the electron stopping power for various materials by electron energy loss spectroscopy (EELS ). As an example, we measured stopping power for Si, C, and their compound SiC. The method, results and discussion are described briefly as below.The stopping power calculation is based on the modified Bethe formula at low energy:where Neff and Ieff are the effective values of the mean ionization potential, and the number of electrons participating in the process respectively. Neff and Ieff can be obtained from the sum rule relations as we discussed before3 using the energy loss function Im(−1/ε).

Comparison of iol optic power calculation refractive results using fourth-generation formulas after radial keratotomy

Reflection ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 45-49
Author(s):  
O. V. Shilovskih ◽  
◽  
A. N. Ulyanov ◽  
M. V. Kremeshkov ◽  
E. M. Titarenko ◽  
...  
Keyword(s):  
Fourth Generation ◽  
Power Calculation ◽  
Radial Keratotomy

Sand Free Production Success Through Proven Technology Enabler from An Untapped Heterogeneous Reservoir Zone Utilizing Gravel Pack Replacement Methodology

2020 ◽  
Author(s):  
Y. Anggoro
Keyword(s):  
Oil And Gas ◽  
Erosion Resistance ◽  
Cost Effective ◽  
High Rate ◽  
Screen Design ◽  
Sand Control ◽  
Rules Of Thumb ◽  
Production Success ◽  
Control Technologies ◽  
Gravel Pack

The Belida field is an offshore field located in Block B of Indonesia’s South Natuna Sea. This field was discovered in 1989. Both oil and gas bearing reservoirs are present in the Belida field in the Miocene Arang, Udang and Intra Barat Formations. Within the middle Arang Formation, there are three gas pay zones informally referred to as Beta, Gamma and Delta. These sand zones are thin pay zones which need to be carefully planned and economically exploited. Due to the nature of the reservoir, sand production is a challenge and requires downhole sand control. A key challenge for sand control equipment in this application is erosion resistance without inhibiting productivity as high gas rates and associated high flow velocity is expected from the zones, which is known to have caused sand control failure. To help achieve a cost-effective and easily planned deployment solution to produce hydrocarbons, a rigless deployment is the preferred method to deploy downhole sand control. PSD analysis from the reservoir zone suggested from ‘Industry Rules of Thumb’ a conventional gravel pack deployment as a means of downhole sand control. However, based on review of newer globally proven sand control technologies since adoption of these ‘Industry Rules of Thumb’, a cost-effective solution could be considered and implemented utilizing Ceramic Sand Screen technology. This paper will discuss the successful application at Block B, Natuna Sea using Ceramic Sand Screens as a rigless intervention solution addressing the erosion / hot spotting challenges in these high rate production zones. The erosion resistance of the Ceramic Sand Screen design allows a deployment methodology directly adjacent to the perforated interval to resist against premature loss of sand control. The robust ceramic screen design gave the flexibility required to develop a cost-effective lower completion deployment methodology both from a challenging make up in the well due to a restrictive lubricator length to the tractor conveyancing in the well to land out at the desired set depth covering the producing zone. The paper will overview the success of multi-service and product supply co-operation adopting technology enablers to challenge ‘Industry Rules of Thumb’ replaced by rigless reasoning as a standard well intervention downhole sand control solution where Medco E&P Natuna Ltd. (Medco E&P) faces sand control challenges in their high deviation, sidetracked well stock. The paper draws final attention to the hydrocarbon performance gain resulting due to the ability for choke free production to allow drawing down the well at higher rates than initially expected from this zone.

scholarly journals Prediction accuracy of standard and total keratometry by swept-source optical biometer for multifocal intraocular lens power calculation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hun Lee ◽  
Jae Lim Chung ◽  
Young Jun Kim ◽  
Jae Yong Kim ◽  
Hungwon Tchah
Keyword(s):  
Cataract Surgery ◽  
Case Series ◽  
Intraocular Lenses ◽  
Power Calculation ◽  
Neutral Position ◽  
Swept Source ◽  
Refractive Outcomes ◽  
Case Series Study ◽  
Significant Difference ◽  
Optical Biometer

AbstractWe aimed to compare the refractive outcomes of cataract surgery with diffractive multifocal intraocular lenses (IOLs) using standard keratometry (K) and total keratometry (TK). In this retrospective observational case series study, a total of 302 patients who underwent cataract surgery with multifocal IOL implantation were included. Predicted refractive outcomes were calculated based on the current standard formulas and a new formula developed for TK using K and TK, which were obtained from a swept-source optical biometer. At 2-month postoperatively, median absolute prediction errors (MedAEs) and proportion of eyes within ± 0.50 diopters (D) of predicted postoperative spherical equivalent (SE) refraction were analyzed. There was no significant difference between MedAEs or proportion of eyes within ± 0.50D of predicted refraction from K and TK in each formula. In TFNT00 and 839MP IOL cases, there was no difference between MedAEs from K and TK using any formula. In 829MP IOL cases, MedAE from TK was significantly larger than that from K in Barrett Universal II/Barrett TK Universal II (P = 0.033). In 677MY IOL cases, MedAE from TK was significantly larger than that from K in Haigis (P = 0.020) and Holladay 2 (P = 0.006) formulas. In the subgroup analysis for IOL, there was no difference between the proportion of eyes within ± 0.50 D of predicted refraction from K and TK using any formula. TFNT00 and 839MP IOLs were favorable with TK, with 677MY IOL with K and 829MP IOL being in a neutral position, which necessitates the study that investigates the accuracy of the new TK technology.

scholarly journals Model for Predicting the Operating Temperature of Stratospheric Airship Solar Cells with a Support Vector Machine

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1228
Author(s):  
Xuwei Wang ◽  
Zhaojie Li ◽  
Yanlei Zhang
Keyword(s):  
Support Vector Machine ◽  
Solar Cell ◽  
Energy Balance ◽  
Output Power ◽  
Operating Temperature ◽  
Support Vector ◽  
Power Calculation ◽  
Pv System ◽  
Stratospheric Airship ◽  
Cell Modules

The stratospheric airship is a kind of aircraft that completely relies on the cycle of photovoltaic energy systems to achieve long duration flight. The accurate estimation of the operating temperature of solar cell modules on stratospheric airship is extremely important for the design of photovoltaics system (PV system), the output power calculation of PV system, and the calculation of energy balance. However, the related study has been rarely reported. A support vector machine prediction method based on particle swarm optimization algorithm (PSO-SVM) was established to predict the operating temperature of solar cell modules on stratospheric airship. The PSO algorithm was used to dynamically optimize the SVM’s parameters between the operating temperature of the solar cell modules and the measured data such as atmospheric pressure, solar radiation intensity, flight speed, and ambient temperature. The operating temperature data of the two sets of solar cell modules measured in the flight test were used to verify the accuracy of the temperature prediction model, and the prediction results were compared with a back propagation neural network (BPNN) method and the simulation results calculated by COMSOL Multiphysics of COMSOL, Inc., Columbus, MA, USA. The results shown that the PSO-SVM model realized the accurate prediction of the operating temperature of solar cell modules on stratospheric airship, which can guide the design of PV system, the output power calculation of PV system, and the calculation of energy balance.

scholarly journals Validating scoring systems for fracture healing in infants and young children: pilot study

2021 ◽  
Author(s):  
Samuel Crompton ◽  
Fabrizio Messina ◽  
Gillian Klafkowski ◽  
Christine Hall ◽  
Amaka C. Offiah
Keyword(s):  
Pilot Study ◽  
Young Children ◽  
Fracture Healing ◽  
Callus Formation ◽  
Femoral Fractures ◽  
Scoring Systems ◽  
Power Calculation ◽  
Small Pilot Study ◽  
Fractures In Children ◽  
Infants And Young Children

Abstract Background Recent studies have analysed birth-related clavicular fractures to propose time frames for healing that could be applied to dating of all fractures in cases of suspected child abuse. Objective To assess differences in healing rates between femoral fractures and birth-related clavicular fractures in infants and young children. Materials and methods A retrospective 5-year pilot study of femoral fractures in children younger than 3 years of age was performed. Anonymised radiographs were independently scored by two radiologists for stages of fracture healing. In cases of reader disagreement, radiographs were independently scored by a third radiologist. Results In total, 74 radiographs (30 children) met the inclusion criteria. Fracture healing evolved over time with subperiosteal new bone formation (SPNBF) appearing first, followed by callus then remodelling. A power calculation for a single proportion, with a level of confidence of 95% and a margin of error of 5%, showed that in a definitive study, 359 radiographs would be required. Conclusion Although the overall pattern of healing is similar, in this small pilot study, the earliest times for SPNBF and callus formation in femoral fractures appeared to lag behind healing of birth-related clavicular fractures. Remodelling appeared earlier than remodelling of clavicular fractures. A power calculation has determined numbers of femoral radiographs (359) required for a definitive study.

scholarly journals Efficacy of acupuncture for sciatica: study protocol for a randomized controlled pilot trial

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Fang-Ting Yu ◽  
Guang-Xia Ni ◽  
Guo-Wei Cai ◽  
Wen-Jun Wan ◽  
Xiao-Qing Zhou ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Lumbar Disc ◽  
Pilot Trial ◽  
Sham Acupuncture ◽  
Leg Pain ◽  
Power Calculation ◽  
Clinical Trial Registry ◽  
Randomized Controlled ◽  
Link Type

Abstract Background Acupuncture is widely used for pain diseases while evidence of its efficacy for sciatica is insufficient. We aim to explore the feasibility and efficacy of acupuncture with different acupoint selecting strategies for sciatica induced by lumbar disc herniation. Methods This is a multicenter, three-arm, patient-assessor-blinded randomized controlled pilot trial. Ninety patients will be assigned randomly into 3 groups including disease-affected meridians (DAM) group, non-affected meridians (NAM) group, and sham acupuncture (SA) group in a 1:1:1 ratio. The trial involves a 4-week treatment along with follow-up for 22 weeks. The primary outcome is the change of leg pain intensity measured by the visual analogue scale (VAS) from baseline to week 4 after randomization. Secondary outcomes include functional status, back pain intensity, and quality of life. Adverse events will also be recorded. Discussion The results will inspire the optimal acupuncture strategy for sciatica and help establish a better design as well as power calculation for a full-scale study. Trial registration ChiCTR2000030680 (Chinese Clinical Trial Registry, http://www.chictr.org.cn, registered on 9 March 2020).

Sign in / Sign up

Export Citation Format

Share Document