Value Of Correction Factor Research Articles

LCC-based approach for design and requirement specification for railway track system

AbstractLife cycle cost (LCC) analysis is an important tool for effective infrastructure management. It is an essential decision support methodology for selection, design, development, construction, maintenance and renewal of railway infrastructure system. Effective implementation of LCC analysis will assure cost-effective operation of railways from both investment and life-cycle perspectives. A major setback in the successful implementation of LCC analysis by infrastructure managers is the availability of relevant, reliable, and structured data. Different cost estimation methods and prediction models have been developed to deal with this challenge. However, there is a need to include condition degradation models as an integral part of LCC model to account for possible changes in the model variables. This article presents an approach for integrating degradation models with LCC model to study the impact of change in design speed on key decision criteria such as track possession time, service life of track system, and LCC. The methodology is applied to an ongoing railway investment project in Sweden to investigate and quantify the impact of design speed change from 250 to 320 km/h. The results of the studied degradation models show that the intended change in speed corresponds to correction factor values between 0.79 and 0.96. Using this correction factor to compensate for changes in design speed, the service life of ballasted track system is estimated to decrease by an average of 15%. Further, the expected value of LCC for the route under consideration will increase by 30%. The outcome of this study will be used to support the design and requirement specification of railway track system for the project under consideration.

Verification of correction factors for determining mean annual levels of radon in underground facilities

The first verification of a tool developed to improve the work of controlling bodies, managers and employees of underground facilities subject to radiation protection requirements was conducted. The recommended values of correction factors were verified using archival results of measurements conducted for the Institute of Occupational Medicine in Łódź in seven underground workplaces in Poland over exposure periods of a month (10,8678 data) and a quarter of a year (53,688 data). In a cave two groups of monthly factors, produced estimates with almost 70% to 99% consistency with the measured values. Along tourist routes located in mines, a similar fit was obtained using three groups of correction factors for measurement results from March, June and July. In the extraction areas of active underground mines, the best fit was produced by factors calculated as averages for spaces varying in the degree of insulation and ventilation method, while in other departments of mining plants, by correction factors recommended for facilities equipped with mechanical ventilation systems. All the quarterly correction factors produced the best fit between estimated mean annual concentrations and measurement results obtained in the second quarter of the calendar year. A wide variation in result consistency (from 20–30 to 65–80%) obtained for two underground tourist routes in the fourth quarter of the year demonstrates that it is best not to adopt results from this measurement period (October-December) for estimating mean annual radon concentration using the set of quarterly correction factors.

An Improved Low-Density Parity-Check Decoder and Its Field-Programmable Fate Array Implementation

Based on the IEEE 802.16e standard’s (672,336) LDPC code and the normalized Min-Sum decoding algorithm, this paper designs and implements an LDPC decoder that optimizes the channel information. The correction factor for check nodes is converted into a correction factor for the initial channel information, replacing the optimization of check node information with that of initial channel information. This achieves decoding performance equivalent to the traditional normalized Min-Sum decoding algorithm. Different correction factor values vary in complexity during FPGA implementation, as they involve different amounts of shift-add operations. For NMS decoding requiring a high number of shift-add operations to achieve optimal correction values, this can be converted into an LDPC decoding algorithm optimized for channel information, reducing computational overhead without sacrificing performance. A partially parallel improved decoder was designed and implemented on an FPGA, and its feasibility was verified using the Vivado simulation platform.

Determination of the characteristic values of the undrained shear strength of organic soils according to Eurocode 7

The paper presents the methods of determining the characteristic value on the basis of the standards: PN-B-03020:1981, PN-EN 1997-1:2008, prEN 1997-1:2022-09 and Schneider formula. Determination of the characteristic value of the undrained shear strength τfu was carried out using statistical method on the basis of the prEN 1997-1:2022-09 standard and Schneider formula. The statistical calculations were based on the results of field vane tests carried out in organic subsoil of test embankment in Antoniny test site before loading and after the 2nd embankment stage. In order to determine the undrained shear strength τfu of organic soils from field vane tests, the measured values of shear strength τf v were corrected using the average values of correction factors μ = μ(lab) determined on the basis of triaxial compression, simple shear and triaxial extension tests. The analysis of the calculation results shows that with relatively numerous data sets, large values of the coefficient of variation Vx result in significantly lower characteristic values of τfu obtained according to prEN 1997-1:2022-09, compared to the values obtained according to the Schneider formula. In the case of few data sets, for which high values of the coefficient kn are obtained, with high values of the coefficient of variation Vx , the comparison of the values according to prEN 1997-1:2022-09 with the values obtained according to the Schneider formula shows the greatest differences.

Compensation of Accuracy Error for Time Interval Measurements

Abstract A method of accuracy error compensation for the time interval is examined, allowing to decrease the dependence of accuracy error on the duration of measured intervals and minimising the influence of destabilising factors – ambient temperature changes and the initial deviation of the meter clock generator frequency from the nominal value. The compensation method is based on a calibration procedure that measures precise time intervals under conditions of changing ambient temperature. Then the dependence of the accuracy error on temperature for a particular meter is recorded. Based on these data, a correction table is compiled containing correction factors and temperature values at which these factors were determined. Under real measurement conditions, the correction factor corresponding to the current temperature is determined from the table for measured result correction. The table with correction factor values could be stored in the memory of the meter or processing computer. Experimental verification of the method showed that applying a correction for a meter with a standard XO class clock generator (certificated instability of ±50 ppm) could obtain an equivalent clock generator instability of ±0.15 ppm. The application of the method is efficient in cases where the use of high-end clocking to ensure the required measurement accuracy is not economically feasible.

Tourism Carrying Capacity (TCC) of Tongkonan Lempe Tourism Attraction, North Toraja Regency

Tongkonan Lempe is one of tourist attraction in Lolai Tourist Area in Kapala Pitu Subdistrict, North Toraja Regency. Based on North Toraja Regional Spatial Plan 2012-2023, Kapala Pitu Subdistrict was set as a landslide-prone area. However, in the Lolai tourist area, there was a large-scaling land clearing for tourist objects without regard to environmental impact. The purpose of this study is to determine the Ecological Carrying Capacity and Economic Carrying Capacity of Tongkonan Lempe Tourism Object. The method used in this research is the Cifuentes Method to determine ecological carrying capacity which consists of Physical Carrying Capacity (PCC), Real Carrying Capacity (RCC), Management Carrying Capacity (MCC), and Effective Carrying Capacity (ECC). Meanwhile, to determine Economic Carrying Capacity use Cost Benefit Analysis. Existing tourist visits have exceeded the value of the environmental carrying capacity. The Tongkonan Lempe tourist attraction can only accommodate a maximum of 31 tourists per day, while the average number of visits in 2022 is expected to be 122 visitors per day.According to the cost-benefit analysis, the Tongkonan Lempe tourist attraction's management will have to spend IDR 50,596,000 to preserve environmental quality with the current number of visitors of 122. If the number of visitors is lowered to an environmentally ideal level of 31, the net economic profit value is IDR 17,236,000 because the environmental conditions are still maintained. Several recommendations can be made based on several literature sources to raise the ecological carrying capacity including: replanting by adding types of vegetation to increase the value of the flora diversity correction factor, increasing the number of officers to improve services, especially during holidays, and limiting the number of tourists.

Evaluation of ion chamber response for applications in electron FLASH radiotherapy.

Ion chambers are required for calibration and reference dosimetry applications in radiation therapy (RT). However, exposure of ion chambers in ultra-high dose rate (UHDR) conditions pertinent to FLASH-RT leads to severe saturation and ion recombination, which limits their performance and usability. The purpose of this study was to comprehensively evaluate a set of commonly used commercially available ion chambers in RT, all with different design characteristics, and use this information to produce a prototype ion chamber with improved performance in UHDR conditions as a first step toward ion chambers specific for FLASH-RT. The Advanced Markus and Exradin A10, A26, and A20 ion chambers were evaluated. The chambers were placed in a water tank, at a depth of 2cm, and exposed to an UHDR electron beam at different pulse repetition frequency (PRF), pulse width (PW), and pulse amplitude settings on an IntraOp Mobetron. Ion chamber responses were investigated for the various beam parameter settings to isolate their dependence on integrated dose, mean dose rate and instantaneous dose rate, dose-per-pulse (DPP), and their design features such as chamber type, bias voltage, and collection volume. Furthermore, a thin parallel-plate (TPP) prototype ion chamber with reduced collector plate separation and volume was constructed and equally evaluated as the other chambers. The charge collection efficiency of the investigated ion chambers decreased with increasing DPP, whereas the mean dose rate did not affect the response of the chambers (±1%). The dependence of the chamber response on DPP was found to be solely related to the total dose within the pulse, and not on mean dose rate, PW, or instantaneous dose rate within the ranges investigated. The polarity correction factor (Ppol ) values of the TPP prototype, A10, and Advanced Markus chambers were found to be independent of DPP and dose rate (±2%), while the A20 and A26 chambers yielded significantly larger variations and dependencies under the same conditions. Ion chamber performance evaluated under different irradiation conditions of an UHDR electron beam revealed a strong dependence on DPP and a negligible dependence on the mean and instantaneous dose rates. These results suggest that modifications to ion chambers design to improve their usability in UHDR beamlines should focus on minimizing DPP effects, with emphasis on optimizing the electric field strength, through the construction of smaller electrode separation and larger bias voltages. This was confirmed through the production and evaluation of a prototype ion chamber specifically designed with these characteristics.

Considerations on the methane correction factor and fraction of methane parameters in the IPCC first-order decay model for active aeration landfills

Understanding the behavior of organic carbon in municipal solid waste landfills is a major challenge for estimating methane (CH4) emissions using the Intergovernmental Panel on Climate Change (IPCC) first-order decay (FOD) model. According to the IPCC guidelines, the default values of CH4 correction factor (MCF) and fraction of CH4 (F) for active aeration landfills are set as 0.4 and 0.5, respectively. However, whether it is reasonable to apply the default values of MCF and F to active aeration landfills is questionable. This study aims to estimate the MCF and develop a method to determine the F value for active aeration landfills. In this investigation, three landfill sites were operated as active aeration landfills to estimate the MCF and the F. The study results indicate that MCF values were lower than the default value of 0.4 provided in the IPCC guidelines under aerobic conditions with a CH4 concentration of less than 5%. According to the carbon balance analyses, there was a mismatch between the theoretical CH4/CO2 ratio based on the F default value of 0.5 and the measured CH4/CO2 ratio. Using the F calculation method proposed in this study, the theoretical CH4/CO2 ratio and the measured CH4/CO2 ratio was calculated equally. The F values during air injection ranged from 0.25 to 0.93 at three landfill sites, suggesting that adapting the F default value of 0.5 for active aeration landfills may lead to significant errors in the estimation of CH4 emissions using the IPCC FOD model.

Comparison of derived correction factors for effects of ion recombination and photon beam quality index following TG-51 and TRS-398 dosimetry protocols

In this study, ion recombination correction factor (kS) and beam quality conversion factor (kQ,Q0) values were extracted following the recommendations of the TRS-398 and TG-51 dosimetry protocols for widely used cylindrical ionization chambers for high energy photon beam dosimetry to quantify the agreement between the instructions for these two protocols for absolute dosimetry inside water. Four different types of cylindrical ionization chambers comprising Farmer (TM30013), Semiflex 0.125 cm3 (TM31010), Semiflex 0.3 cm3 (TM31013), and PinPoint (TM31016) were considered, and kS and kQ,Q0 values were determined at photon energies of 6 MV and 15 MV. The maximum difference between the measured kS values according to the instructions in the TRS-398 and TG-51 protocols was 0.03%. The kS data measured with both protocols agreed well with those measured by using the Jaffe-plot approach, where the maximum difference was about 0.33%. The observed differences between the kQ,Q0 factors measured by using the TRS-398 and TG-51 dosimetry protocols at photon energies of 6 MV and 15 MV were 0.37% and 0.55%, respectively. The kQ,Q0 values measured using the TG-51 dosimetry protocols were slightly closer to those measured by a reference ionization chamber dosimeter. We conclude that the maximum differences were about 0.4% and 0.6% in the absorbed dose measurements according to the TRS-398 and TG-51 instructions at photon energies of 6 MV and 15 MV, respectively. The type of ionization chamber employed also affected the differences, where the maximum and minimum dose differences were found using the Farmer and PinPoint chambers, respectively.

Liquefaction evaluation method of coral sand: Case study on the ports in Indonesia

While the liquefaction evaluation methods of siliceous sand have undergone extensive studies, few research efforts were conducted to establish standard for the liquefaction susceptibility of coral sand. The current study develops an innovative method to evaluate the liquefaction potential of coral sand. Specifically, the method integrates the grain-size distribution of coral sand, effective overburden stress and equivalent seismic acceleration. Scanning electron microscopy image of coral sand was processed to reveal the microstructural characteristics of coral sand. The correction equation for standard penetration resistance of coral sand in Indonesian ports was given based on geotechnical investigations, and the recommended values of correction factors were proposed for the regions lacking relevant data in the previous period. The process for liquefaction evaluation method of coral sand was described and applied to evaluate the liquefaction potential of coral sand in Indonesian port projects. This study demonstrates the feasibility of integrating standard penetration test and grain-size distribution for liquefaction evaluation of coral sand.

Effects of E-Cigarette Liquid Ratios on the Gravimetric Filter Correction Factors and Real-Time Measurements.

Electronic cigarettes (ECIGs) generate high concentrations of particulate matter (PM), impacting the air quality inhaled by humans through secondhand exposure. ECIG liquids are available commercially and some users create their own "do-it-yourself" liquids, and these liquids often vary in the amounts of their chemical ingredients, including propylene glycol (PG) and vegetable glycerin (VG). Previous studies have quantified PM concentrations in ECIG aerosol generated from liquids containing different PG/VG ratios. However, the effects of these ratios on aerosol instrument filter correction factors needed to measure PM concentrations accurately have not been assessed. Thus, ECIG aerosol filter correction factors for multiple aerosol instruments (SMPS + APS, MiniWRAS, pDR, and SidePak) were determined for five different PG/VG ratios 1) 0PG/100VG, 2) 15PG/85VG, 3) 50PG/50VG, 4) 72PG/28VG, and 5) 90PG/10VG and two different PM sizes, PM1 (1 μm and smaller) and PM2.5 (2.5 μm and smaller). ECIG aerosols were generated inside a controlled exposure chamber using a diaphragm pump and a refillable ECIG device for all the ratios. In addition, the aerosol size distribution and mass median diameter were measured for all five ECIG ratios. PM2.5 correction factors (5-7.6) for ratios 1, 2, 3, and 4 were similar for the SMPS + APS combined data, and ratios 1, 2, 3 were similar for the MiniWRAS (~2), pDR (~0.5), and SidePak (~0.24). These data suggest different correction factors may need to be developed for aerosol generated from ECIGs with high PG content. The higher correction factor values for the 90PG/10VG ratio may have resulted from greater PG volatility relative to VG and sensor losses. The correction factors (ratios 1-4) for PM2.5 were SMPS + APS data (4.96-7.62), MiniWRAS (2.02-3.64), pDR (0.50-1.07), and SidePak (0.22-0.40). These data can help improve ECIG aerosol measurement accuracy for different ECIG mixture ratios.

A comprehensive quality control evaluation for standard decoction of Smilax glabra Roxb based on HPLC-MS-UV/CAD methods combined with chemometrics analysis and network pharmacology

An effective, sensitive, and rapid method was developed for the quality control evaluation of the standard decoction of Smilax glabra Roxb (SGR). SGR is a primary ingredient of the traditional functional foods of turtle jelly and SGR tea. Chemometrics, Network Pharmacology, and molecular docking were used to screen for six quality markers. Multiple extraction parameters were optimized. HPLC-UV/CAD-QAMS was used to rapidly quantify the six quality markers (neoastilbin, astilbin, neoisoastilbin, isoastilbin, quercitrin, and isoengeletin) in 10 batches of the standard decoction of SGR samples. The relative correction factor (RCF) values of the five compounds were close to 1, demonstrating that the charged aerosol detection (CAD) showed a consistent response to compounds with similar parent nucleus structures. This method can serve as a guide for rapid quantitative analysis of the multi-components of the SGR standard decoction and all the traditional functional foods of turtle jelly with the homology of medicine.

Application and testing of a windblown dust module for a bare riverbed

To accurately predict the occurrence of riverbed dust events, a high-grid resolution (1 km2) riverbed dust module was constructed for this study. Although the module used the built-in CMAQ (Community Multiscale Air Quality model) dust module, the critical parameter values in the module were adjusted according to the experimental data for Taiwan. The results showed that the riverbed dust module can accurately predict the occurrence time of riverbed dust and thus improve the prediction of CMAQ's for the PM10 concentrations of downwind riverbed dust. The mean fractional bias and mean fractional error improved from −77 and 84% to −5 and 57%, respectively. Seven sensitivity-case simulations were performed to understand which parameters and formulas were important. The results are summarized as follows. (1) Selecting an appropriate horizontal sand flux estimation formula/vertical-to-horizontal dust flux ratio estimation formula/surface roughness length value is important because it can significantly affect dust emissions estimation. A local experimental value for the surface roughness length value is preferred. (2) For bare river land, it was acceptable to use the default value (= 1) for the surface roughness correction factor value. (3) In environments with high soil moisture, special attention should be paid to setting the threshold soil moisture value. (4) Different river locations may require different parameter values to be set within the module, and the ideal threshold friction velocity is an important parameter. (5) The estimation and use of gusts can improve the prediction of intense dust emissions; however, the prediction of hourly gusts must be improved.

Calculation of Correction Factors for Vickers’ Hardness Measurements on a Non-Planar Surface

The exact determination of Vickers HV hardness is important for determining of the product material mechanical properties. An important aspect of measuring HV is to obtain its values on a non-planar surface. Regulatory documents contain table values of correction factors K which depend on the surface shape (convex or concave, spherical or cylindrical), its curvature (diameter D) and hardness (arithmetic mean d of indentation diagonal lengths) but this does not solved the problem. The K values for d/D ratios not given in the tables are determined by interpolation from the closest to the measured tabulated d/D values. The error in the representation of these tabulated d/D values is fully included in the error of determining the K coefficient for the measured d/D ratio. The aim of the work was to simplify the calculation of correction factors K for Vickers hardness measurements on non-planar surfaces and to reduce the calculation error compared to the methodology governed by the regulations.The method presented is based on a statistical analysis of K coefficients, presented in regulatory documents for cases considered in the form of tables. The sufficiency of using of a quadratic power function for approximating K(d/D) dependences and the necessity of fulfilling the physically justified condition K ≡ 1 at zero curvature of tested surface have been substantiated. Simplification of calculation of K coefficient and decrease of calculation error in comparison with the recommended in the regulatory documents obtaining of K value by linear interpolation relative to two adjacent table values are shown.The reduction of the calculation error in comparison with the calculation recommended in the regulatory documents occurred because of the reason that when calculating by the developed formulas, the error in the value of the calculated for a specific value of d/D coefficient K is averaged over all n values of d/D given in the table of GOST for a given surface. That is, the error is reduced by a factor of about √n 2 in comparison with the calculation according to the regulated procedure. This is illustrated by the above numerical data and an example of the use of the method.The obtained formulas for calculation of correction coefficients K when measuring hardness HV on spherical and cylindrical (concave and convex) surfaces are reasonable to use for automatic calculation of HV on items with a non-planar surface.

DYNAMIC BEHAVIOUR OF HIGHLY PRESTRESSED ORTHOTROPIC RECTANGULAR PLATE UNDER A CONCENTRATED MOVING MASS

In this paper the dynamic response to concentrated moving masses of highly prestressed orthotropic rectangular plate-structure is examined. When the ratio of the bending rigidity to the in-plane loading is small, a small parameter multiplies the highest derivatives in the equation governing the motion of the plate under the action of moving masses. Such vibrational problems defile conventional methods of solution. An approach suitable for the solution of this type of problem is the singular perturbation. To this end, a choice is made of the method of matched asymptotic expansions (MMAE) among others. The application of the singular perturbation scheme in conjunction with the finite Fourier sine transform produces two different but complementary approximations to the solution for small parameter - one being valid in the region where the other fails. One is valid away from the boundary called the outer solution while the other is valid near and at the boundary called the inner solution. Thereof, the Van Dyke asymptotic matching principle which produces the unknown integration constants in the outer and inner expansions is applied. Thereafter, the inverse Laplace transformation of the obtained results is carried out using the Cauchy residue theorem. This process produces the leading order solution, and the first order correction, to the uniformly valid solution of the plate dynamical problem. The addition of the two results above produces the sought uniformly valid solution in the entire domain of definition of the plate problem. Similarly, the resonant states and the corresponding critical speeds are obtained. The analysis of this result is then shown in plotted curves. Graphical interpretation of the results show that the critical speeds at the respective resonant states increase as the value of prestress increase thus the risk of resonance is remote as prestress is increased for any choice of value of rotatory inertia correction factor. Also, lower values of rotatory inertia show variation in the value of critical speed hence the possibility of resonance. Similarly, the critical speed increases with shear modulus for various values of prestress. However, as the value of shear modulus increases, critical speed approaches more or less constant value. Thus, a design incorporating high value of shear modulus is more stable and reliable. The critical speed increases with material orthotropy for lower values of rotatory inertia correction factor.

О МОДЕЛИРОВАНИИ ГЕОМЕХАНИЧЕСКОГО ПОВЕДЕНИЯ ПОДКРЕПЛЕННЫХ МАССИВОВ ГОРНЫХ ПОРОД В ОКРЕСТНОСТИ ПОДЗЕМНЫХ СООРУЖЕНИЙ

The paper presents a method of modelling the mechanical behavior of supported rock mass, in the vicinity of complex underground structures. The method is based on calculations of the effective mechanical properties of the bolted rock mass. The algorithm is based on the effective properties of a bolted rock unit that are obtained by conducting a series of numerical experiments. These experiments allow to define the values of correction factors, which, in turn, determine the difference in mechanical behavior of supported and non-supported rock mass. Such approach makes it possible to calculate the stress-strain state of complex space underground structures precisely without direct considering of the roof bolting elements. The application of the proposed method is demonstrated on the example of an applied problem of the strength assessment of geotechnical system “underground equipment chamber — enclosing potash rock mass”. The results of the research have a wide range of applications since they can significantly simplify and speed up the process of strength and stability calculations of bolted underground structures and make the results more accurate.

Damage integral and other predictive formulas for nonisothermal heating during laser exposure.

.Significance: Physics-based models supply simulated temperature rises to photothermal damage rate models and provide comprehensive risk assessments for laser-induced damage. As the physics-based models continue to be refined, the damage rate models have not advanced. This peculiar lack of improvement is counterintuitive considering the damage integral (), originally derived for isothermal heating events, and fails to accurately represent the nonisothermal heating from short laser exposures.Aim: Derive a nonisothermal form of the damage integral and predict more accurately the damage induced by short laser exposures, as well as identify the role of heating rate in laser damage.Approach: From first principles, we derived a version of the damage integral specific to the shape of thermal profiles rather than the square function provided by Arrhenius plots. We used previously published threshold thermal profiles, where all nonisothermal frequency factors () solved all values to unity. Nonisothermal correction factors correct isothermal values.Results: The values were identical for both the isothermal and nonisothermal conventions. Correction factor values for ranged from 0.0 (20-s exposures at thermal steady state) to (0.05-s exposures). Based on empirical results, we have derived a two-dimensional empirical formula that predicts the heating rate as a function of exposure duration and ambient temperature. Threshold peak temperatures () and threshold critical temperatures are mathematically determined without thermal profiles when appropriate and values are established.Conclusions: We have identified a modified damage integral that does not rely on the Arrhenius plot and provides a value for the frequency factor () that accounts for the nonisothermal nature of short laser exposures. The method, validated in our in vitro retinal model, requires thermal profiles recorded under threshold conditions, such as at minimum visible lesions or the boundary of cell death. The method is a new option for laser damage modelers.

Evaluation of Two-Voltage and Three-Voltage Linear Methods for Deriving Ion Recombination Correction Factors in Proton FLASH Irradiation

Ultrahigh dose-rate (FLASH) proton therapy is of great interest due to potential reduced normal tissue toxicities without compromising tumor-killing effect compared to current clinical proton practices. However, the ionization chamber response to proton beams under ultrahigh dose rates (&#x003E;40 Gy/s) has not been thoroughly investigated. In this study, four different ion chambers (PTW 34045 Advanced Markus, PPC-40, CC-04, and CC-13 from IBA Dosimetry) were irradiated with 230 MeV proton beams at 1.5, 63.7, and 127.6 Gy/s dose rates. Theoretical values of ion recombination correction factor (<inline-formula> <tex-math notation="LaTeX">${k}_{s}$ </tex-math></inline-formula>) were calculated from saturation curves using Niatel&#x2019;s model. The theoretical <inline-formula> <tex-math notation="LaTeX">${k}_{s}$ </tex-math></inline-formula> values were compared to the values using the two-voltage (2V) method from standard dosimetry protocols and the three-voltage linear (3VL) method proposed by Rossomme <i>et al.</i> Both parallel plate chambers and CC-04 demonstrated adequate ion collection efficiency at the highest dose rate. For these three chambers, there is no statistically significant difference between theoretical <inline-formula> <tex-math notation="LaTeX">${k}_{s}$ </tex-math></inline-formula> values and those calculated with 2V and 3VL methods. However, significant ion recombination correction was found in CC-13 (<inline-formula> <tex-math notation="LaTeX">${k}_{s}&gt;1.50$ </tex-math></inline-formula>) when dose rate reached 63.7 Gy/s. The assumption of insignificant initial recombination in standard dosimetry protocols also underestimated the ion recombination effect in this scenario.

Re-evaluation of shear strength design code provisions of RC beams with shear reinforcements

This paper provides a critical probabilistic evaluation of shear strength design code provisions for reinforced concrete (RC) beams with shear reinforcements under different strength combinations of steel reinforcements and concrete. Based on the modified compression field theory (MCFT), a probabilistic shear strength model for RC beams with shear reinforcements was proposed by taking into account the influences of contribution ratio for shear strength between concrete and stirrup, constitutive law of cracked concrete, and uncertainty in influencing coefficient of shear reinforcement. Then the accuracy and applicability of three typical shear strength design code provisions under different strength combinations of steel reinforcements and concrete were evaluated based on the confidence interval determined by the proposed probabilistic shear strength model. Meanwhile, the influences of material strength of steel reinforcements and concrete on confidence level of three typical shear strength design code provisions were also investigated. Finally, three typical shear strength design code provisions for RC beams were modified to improve the computational accuracy based on the characteristic values of correction factor under different strength combinations of steel reinforcements and concrete.

Karakteristik Jaringan Jalan dan Keterbukaan Tanah Hutan Akibat Kegiatan Pembukaan Wilayah Hutan (Studi Kasus di IUPHHK-HA PT Sindo Lumber Kalimantan Tengah)

The purpose of this study: a) to determine the characteristic parameters the forest roads network, such as: density forest roads, spacing forest roads, average distance skid trails, correction factor and quality forest opening area; (b) calculate the percent openness forest land due to activities making main roads network, branch roads, skid trail and TPn. The location research in block harvesting RKT 2018 at IUPHHK-HA PT Sindo Lumber Central Kalimantan. The results showed density the forest roads network ranged between 7.96 – 17.66 m/ha, 1256.28 m main road spacing, 1097.69 m branch road spacing, 566.25 m skid trail spacing, 146.5 m average distance skid theoritical (REo), 186.83 m REm and 252.30 m REt. The correction factor value of the roads network (Vcorr), Tcorr and the correction factor forest opening area (KG) respectively by 1.27, 1.35 and 1.71 with the quality forest opening area included in the category of “very good”. While the percent of the openness forest land due to making main roads network, branch roads, skid trail and TPn respectively by 0.87%, 0.73%, 3% and 0.53%.