Timber Losses during Harvesting in Managed Shorea robusta Forests of Nepal

Logging and sawing of timber using conventional tools by unskilled workers causes enormous damage to the valuable timber, residual stand, regeneration, and forest soil in Nepal. The purpose of this study was to find out the volume reduction factor and identify major strategies to reduce timber losses in the tree harvesting process in the Terai Shorea robusta forest of Nepal. Field measurements and product flow analysis of 51 felled trees from felling coupes and randomly selected 167 sawed logs were examined to study harvesting losses. Responses from 116 forest experts were analyzed to explore strategies for reducing harvesting and processing losses. The results showed that timber losses in the felling and bucking stage with and without stem rot were 23% and 22%, respectively. Similarly, timber losses in the sawing stage with and without stem rot were 31% and 30%, respectively. Paired t-test at 5% level of significance revealed that there was significant loss in both tree felling and log sawing stages with present harvesting practice. The most leading factor contributing to timber loss in all of the three stages was the use of inappropriate equipment during tree harvesting. Use of synthetic ropes for directional felling and skidding as well as flexible and portable sawing machine with size adjustment options during sawing were mainly recommended as strategies to reduce timber losses. This study serves as a baseline study to identify and quantify timber losses in different stages of tree conversion and also formulate their reduction strategies in Nepal.

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Prediction of floor responses to crowd bouncing loads by response reduction factor and spectrum method

Advances in Structural Engineering ◽

10.1177/1369433220975567 ◽

2020 ◽

pp. 136943322097556

Author(s):

Jun Chen ◽

Jingya Ren ◽

Vitomir Racic

Keyword(s):

Structural Damage ◽

Response Spectrum ◽

Field Measurements ◽

Reduction Factor ◽

Response Reduction Factor ◽

Long Span ◽

Single Person ◽

Vibration Serviceability ◽

Concert Halls ◽

Structural Responses

Bouncing is a typical rhythmic crowd activity in entertaining venues, such as concert halls and stadia. When the activity’s frequency is close to the natural frequency of the occupied structure, the corresponding bouncing loads can cause intense structural vibrations resulting in vibration serviceability problems, even structural damage. This study suggests a method for prediction of vibration response due to crowd bouncing by a response reduction factor (RRF) in conjunction with a previously established response spectrum approach pertinent to a single person bouncing. The RRF is defined as a ratio between structural responses with and without taking into account synchronization of body movements of individuals in a bouncing crowd. The variations of RRF with number of persons, structural frequency, bouncing frequency and structural damping ratios have been studied using experimental records of crowd bouncing loads. Based on the findings a practical design curve for RRF has been proposed. Application of the proposed method has been validated on numerical simulations and field measurements of a long-span floor subjected to crowd bouncing loads.

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Erratum: Labelle, A., et al. Agent-Based Model for End-of-Life Product Flow Analysis, Resources 2018, 7, 42

Resources ◽

10.3390/resources8010023 ◽

2019 ◽

Vol 8 (1) ◽

pp. 23

Author(s):

Alexandre Labelle ◽

Jean-Marc Frayret

Keyword(s):

End Of Life ◽

Flow Analysis ◽

Agent Based Model ◽

Agent Based ◽

Product Flow

The authors wish to make the following corrections to this paper [...]

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BASICS: From Assess—Product-Flow Analysis (TIPS)

Implementing Lean ◽

10.4324/9781315118857-12 ◽

2018 ◽

pp. 117-136

Author(s):

Protzman Charles ◽

Whiton Fred ◽

Protzman Dan

Keyword(s):

Flow Analysis ◽

Product Flow

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Experimental Investigation of the Effect of Polymers on Residual Oil Saturation

SPE Journal ◽

10.2118/179683-pa ◽

2017 ◽

Vol 23 (01) ◽

pp. 1-17 ◽

Cited By ~ 14

Author(s):

Heesong Koh ◽

Vincent B. Lee ◽

Gary A. Pope

Keyword(s):

Low Cost ◽

Flow Analysis ◽

Reduction Factor ◽

Residual Oil ◽

Fractional Flow ◽

Oil Saturation ◽

Residual Oil Saturation ◽

And Performance ◽

Water Cut ◽

Core Permeability

Summary Polymer flooding is a widely used commercial process with a low cost per barrel of produced oil, and hydrolyzed polyacrylamide (HPAM) polymers are the most widely used type of polymer. The objective of this research was to better understand and predict the behavior of HPAM polymers and their effect on residual oil saturation (ROS), to improve the capability of optimizing field design and performance. The corefloods were performed under typical field conditions of low pressure gradients and low capillary numbers. The polymer floods of the viscous oils recovered much more oil than the waterfloods, with up to 24% lower oil saturation after the polymer flood than after the waterflood. The experimental data are in good agreement with the fractional-flow analysis by use of the assumptions that the true ROSs and endpoint relative permeabilities are the same for both water and polymer. This suggests that, for more-viscous oils, the oil saturation at the end of a waterflood (i.e., at greater than 99% water cut) is better described as “remaining” oil saturation rather than the true “residual” oil saturation. This was true for all the corefloods, regardless of the core permeability and without the need for assuming a permeability-reduction factor in the fractional-flow analysis.

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Novel Erosion Control Technology for Production Debottlenecking

Volume 5: Pipelines, Risers, and Subsea Systems ◽

10.1115/omae2018-78033 ◽

2018 ◽

Author(s):

Prasad Laxman Kane ◽

Dominic Pliszka

Keyword(s):

Substantial Reduction ◽

Erosion Control ◽

Significant Loss ◽

Mitigation Measures ◽

Control Technology ◽

Product Flow ◽

Sand Erosion ◽

Piping Systems ◽

Global And Local ◽

The Impact

Erosion of piping systems is a significant issue for many operators of Hydrocarbon infrastructure. Until now mitigation measures have been limited to detection / measurement and reducing production. For many operators this can be a significant loss in revenue and an increase in IMR costs. A novel Erosion Control Technology (ECT) is being developed that can significantly reduce the impact of erosion on piping infrastructure. This technology has the potential of adding immense value when it is used to debottleneck and optimize flow rates. The patented ECT has been designed to control sand erosion in real-time by deflecting and redistributing sand in the product flow stream. Preliminary laboratory testing of the ECT has been very successful. The ECT inserts designed for the ambient test conditions have shown substantial reduction in erosion (both global and local). Computational Fluid Dynamics (CFD) has been the key enabling factor allowing the critical breakthrough in this technology. Experimental results have shown very good correlation with the CFD sand erosion model results. A roadmap in line with industry practices and standards has been developed for project implementation of the ECT solution in the near future.

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Agent-Based Model for End-of-Life Product Flow Analysis

Resources ◽

10.3390/resources7030042 ◽

2018 ◽

Vol 7 (3) ◽

pp. 42 ◽

Cited By ~ 2

Author(s):

Alexandre Labelle ◽

Jean-Marc Frayret

Keyword(s):

Simulation Model ◽

End Of Life ◽

Flow Analysis ◽

Supply Networks ◽

Policy Makers ◽

Agent Based ◽

Product Flow ◽

Efficient Resource ◽

Series Of Experiments ◽

Behavior Models

This paper presents an agent-based simulation model for end-of-life product flow analysis in recuperation and recycling supply networks that focuses on individual consumer behaviors. The simulation model is applied to a deposit-return program on wine bottles that could be developed in the province of Quebec. Canadian data was used to calibrate and validate the model. A series of experiments was then conducted with three artificial populations to analyse how they would react to several implementation scenarios of this end-of-life product flow strategy. The results suggest that the distance to the nearest depot is an important decision factor, but less predominant than the ownership of a private vehicle and the deposit value. The results also indicate that the use of agent-based modeling combined with the theory of planned behavior (TPB) can produce modular behavior models, that are intuitive and simple, to better understand consumer-behavior-driven supply chains. Such models can be used to give insights to decision-makers and policy-makers about the potential performance of end-of-life product flows strategies and further facilitate efficient resource management.

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Multiple Anchor Behavior of Steel-to-Concrete Connections under Reversed Cyclic Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.669 ◽

2011 ◽

Vol 255-260 ◽

pp. 669-673 ◽

Cited By ~ 1

Author(s):

Qun Xie ◽

Qin Zhu Sheng ◽

Hao Xue Ju

Keyword(s):

Cyclic Loading ◽

Significant Loss ◽

Reduction Factor ◽

Shear Capacity ◽

Hysteresis Curve ◽

Embedment Depth ◽

Reversed Cyclic Loading ◽

Reversed Cyclic ◽

Small Shell ◽

Peak Value

Four steel-to-concrete connections with adhesive anchor groups under reversed cyclic loading have been tested. The results showed that anchor steel could reach yield strength before connection failure, generating small shell-shaped concrete cone in the surface of block and the ultimate capacity was governed by strength of anchor. Seismic characteristics of hysteresis curve, rigidity regression, ductility and energy-dissipation were used to draw conclusions that the connections would behave in a ductile manner without significant loss of loading capacity after peak value and visible deformation could develop until failure occurred. Increased embedment depth and added amount of anchors were helpful to improve seismic performance of connections. Only the outer row of most stressed anchors in the tension zone were needed to meet the elliptical interaction of tension and shear capacity requirement during the design process of anchor groups under combined shear and moment loading. In seismic design of steel-to-concrete connections, the predicted capacity by a reduction factor of 0.8 was advised and the comparison of calculated versus observed capacity presented limited variance.

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