Enhancing wood efficiency through comprehensive wood flow analysis:Methodology and strategic insights

Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.

Two Approaches of Substance Flow Analysis—An Inspiration from Fluid Mechanics

That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper. Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concepts of the chain and the chain group of product life cycles, which are essential for understanding the specific features of substance flow, were advanced. Taking the specific feature of substance flow into consideration, on the analogy of the two approaches in fluid mechanics, two approaches of substance flow analysis, i.e. L method and E model, were formulated. Illustrative models of steady and unsteady substance flow were sketched by both methods, and comparison between them was made in general.

Copper and arsenic substance flow analysis of pyrometallurgical process for copper production

The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.

POWER FLOW ANALYSIS AND APPLICATION SIMULATION OF ELECTROMAGNETIC CONTINUOUSLY VARIABLE TRANSMISSION

With the structure of two air gaps and two rotors, the electromagnetic continuously variable transmission（EMCVT） is a novel power-split continuously variable transmission（CVT）. There are two kinds of power flowing through the EMCVT, one is mechanical power and the other is electric power. In the mean time, there are three power ports in the EMCVT, one is the outer rotor named mechanical power port and the other two are the inner rotor and the stator named electric power ports. The mechanical power port is connected to the driving wheels through the final gear and the electric ports are connected to the batteries through the transducers. The two kinds of power are coupled on the outer rotor of the EMCVT. The EMCVT can be equipped on the conventional vehicle being regarded as the CVT and it also can be equipped on the hybrid electric vehicle（HEV） as the multi-energy sources assembly. The power flows of these two kinds of applications are analysed. The back electromotive force（EMF） equations are illatively studied and so the dynamic mathematic model is theorized. In order to certify the feasibility of the above theories, three simulations are carried out in allusion to the above two kinds of mentioned applications of the EMCVT and a five speed automatic transmission（AT） vehicle. The simulation results illustrate that the efficiency of the EMCVT vehicles is higher than that of the AT vehicle owed to the optimized operation area of the engine. Hence the fuel consumption of the EMCVT vehicles is knock-down.

Continuous flow analysis of dissolved total phosphorus in seawater by UVK_(2)S_(2)O_(8) online digestion method

Several methods for analysis of dissolved total phosphorus in seawater were reviewed. Discussions were focused on UVirradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determinationmethods presently. The compounds used for the phosphorus recovery test were categorized into three groups accordingto their chemical structure. It was found that low power UV irradiation can decompose POC or PC bonds efficientlybut may be inefficient for POP bonds. Heating-bath in acid condition is useful for decomposing POP bonds. Usingthe continuous flow analysis system (Auto-analyzer II), UV digestion and heating-bath, series experiments were carriedout based on the above analysis. Eleven model compounds were employed for the phosphorus recovery test and thefactors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified. Finally,the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flowanalysis system was presented. For the organic mono-phosphate, the recovery is more than 90% and a recovery of33%~51% was obtained for inorganic or organic polyphosphates. Up to now, this is the highest decompositionefficiency for dissolved phosphorus based on the continuous flow analysis system.

Study on regional material flow analysis of Chengyang District in Qingdao

Base on the framework of material flow analsis （MFA） proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Material Input（DMI）, Direct Material Consumption （DMC） and Exports are calculated or estimated for the period of year 1995 through 2004. Several derivable iudicators defining direct material productivity and material intenstiy are also evaluated and some valuable conclusions were drawn. DMI in absolute number increased from about 1645.9 kilotons in 1995to about 8052.5 kilotons in 2004. Imports contribute to about 47 to 69% of DMI, and the biggest component of imports is fossil fuel that approximatley accounts far 50% of imnports. DMI per capita of Chengyang District increased rapidly and reached 17. 4 tons in 2004. Compared with other five economies studied by WRI, material consumption intensity of Chengyang District is significantly lower than developed countries, which indicates that Chengyang District is still in a development stage The direct material productivity （actual GDP per DMI） increased 59.1% from 1995 to 2004 and has been higher than either of stadies in China, which indicates efficiency of resources utilization has improved obviously in Chengyang District. But there was significant increase in material input in the last decade, which shows that rapid increase of economy is highly dependent on requirement and consumption of natural resources. Therefore, in order to promote the sustainahility, it is essential to develop circular economy and improve utilization efficiency of resources.

Sparse Crowd Flow Analysis of Tawaaf of Kaaba During the COVID-19 Pandemic

The advent of the COVID-19 pandemic has adversely affected the entire world and has put forth high demand for techniques that remotely manage crowd-related tasks.Video surveillance and crowd management using video analysis techniques have significantly impacted today’s research,and numerous applications have been developed in this domain.This research proposed an anomaly detection technique applied to Umrah videos in Kaaba during the COVID-19 pandemic through sparse crowd analysis.Managing theKaaba rituals is crucial since the crowd gathers from around the world and requires proper analysis during these days of the pandemic.The Umrah videos are analyzed,and a system is devised that can track and monitor the crowd flow in Kaaba.The crowd in these videos is sparse due to the pandemic,and we have developed a technique to track the maximum crowd flow and detect any object(person)moving in the direction unlikely of the major flow.We have detected abnormal movement by creating the histograms for the vertical and horizontal flows and applying thresholds to identify the non-majority flow.Our algorithm aims to analyze the crowd through video surveillance and timely detect any abnormal activity tomaintain a smooth crowd flowinKaaba during the pandemic.

Preliminary Research on Regional Material Flow Analysis:A Case Study of Chengyang District in Qingdao

The method ＂Material Flow Analysis （MFA）＂ is one of the effective tools to study law and quantification of material flow between economic system and ecological system. On the national level, economy-wide material flow analysis has been published for a number of countries. However, published studies on the regional or local level are still very limited and a standardized method does not exist yet. On the basis of framework of Material Flow Analysis proposed by Eurostat, the paper collected related data and analyzed material input and output for the Chengyang district in Qingdao. The results showed that DMI （Direct Material Input） and TMR （Total Material Requirement） in absolute number increased about 3.6 and 3.9 times, respectively from 1995 to 2004. Fossil fuel and mineral contributed to about 50.3%-76.3% of DMI. Imports of material increased about 5.0 times and became the most important Contributor to DMI, which showed that local economic growth was highly dependent on resources from other regions and countries. DPO （Domestic Processed Output） and TDO （Total Domestic Output） represent slow increasing trend, and DPO contributed to 22.2%-58.1% of TDO, suggesting local hidden flows were of obvious effect on TDO. The biggest component of DPO is CO2, approximately accounting for 90% of DPO. The material productivity increased 57.7% in last decade, reflecting improvement of efficiency of resources utilization in some extent. However, compared to developed countries and regions, material productivity of Chengyang district was relatively low. Therefore, in order to promote the sustainability, it is essential to develop circular economy and enhance materials productivity.

Current status and future trends for material flow analysis applications at CSC

Material Flow Analysis(MFA) is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or substances.The results of MFA studies could support the strategies or decisions making for energy, resource,and waste management,especially achieving sustainable resource management.At CSC,the dynamic simulating software,STELLA,is used to develop a MFA model for scenario analysis.CSC also uses the freeware STAN 2.0 as a tool for visualizing and simulating material flows and stocks.Case studies of greenhouse gases MFA for integrated steel works are conducted.The results showed that the carbon content of hot-metal is an important hidden flow for balance analysis,and the different GHG emission scenarios and mitigation action scenarios are assessed.In addition,the Iron-making GHG I/O MFA Model,based on worldsteel Global Steel Sector Approach(GSSA),is developed for calculating the CO_2 and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO_2 reduction potential for iron-making process.The cases conducted for MFA applications at CSC were such as greenhouse gas,zinc,etc.In the future,CSC is going to develop a 'CSC Environment Management and Decision Supporting System' which combine MFA,LCA(life cycle assessment),and environment risk assessment.This supporting system expects to promoting energy efficiency and best resource use,supporting environment policymaking,creating environmental information value,etc.

Thermomechanical and Flow Analysis of a Typical Truck Radiator Using PTC-Creo

In automobile engines,it is commonly known that the proper removal of the excess heat,resulting from internal combustion,is of high significance in the prevention of numerous negative consequences.In this regard,the radiator has a pivotal role as the main component of the engine’s cooling system.Hence,its design and analysis are highly important,requiring more comprehensive failure and flow investigations.In this work,a Scania radiator is examined under the thermal and mechanical loads,followed by its analysis under the combined thermomechanical loading.Then,the flow characteristics,including the velocity,pressure,and enthalpy,are studied.In this regard,PTC-Creo software is utilized.The results demonstrate that thermal stress causes seven times more displacement than a mechanical one.When they are combined,this value reaches 1.5 mm.Also,the max­imum failure index value of the Tresca theory is around 4.58,observed at the inlet side of the radiator.Besides,this paper indicates that the PTC-Creo can be considered a reliable and economical tool for the simulation of industrial applications,such as the considered radiator of a heavy-duty cooling system.

Full Cycle Cold Flow Analysis of the Effect of Twin Swirl Combustion Chamber Design in a Diesel Engine

New designs and adaptation methods are experimented to ensure compliance to ever increasing emissions and efficiency requirements of modern diesel engines. Piston head structure which influences the mixing rate and timing of the fuel within in the combustion chamber is known to enable increase in combustion efficiency and thus lower emission rates. In this paper, computation analysis of flow within a diesel engine cylinder with a twin swirl combustion chamber design throughout a full cycle is presented. The results obtained indicate that the effect of the twin swirl combustion chamber on the cold flow conditions is noteworthy and further analysis together with experiments may reveal information that may prove to be useful in further new designs.

Industrial Ecosystems and Food Webs＂ An Ecological-Based Mass Flow Analysis to Model the Progress of Steel Manufacturing in China

Materials and energy are transferred between natural and industrial systems, providing a standard that can be used to deduce the interactions between these systems, An examination of these flows is an essen- tial part of the conversation on how industry impacts the environment, We propose that biological sys- tems, which embody sustainability, provide methods and principles that can lead to more useful ways to organize industrial activity, Transposing these biological methods to steel manufacturing is manifested through an efficient use of available materials, waste reduction, and decreased energy demand with cur- rently available technology, In this paper, we use ecological metrics to examine the change in structure and flows of materials in the Chinese steel industry over time by means of a systems-based mass flow analysis, Utilizing available data, the results of our analysis indicate that the Chinese steel manufacturing industry has increased its efficiency and sustainable use of resources over time at the unit process level, However, the appropriate organization of the steel production ecosystem remains a work in progress, Our results suggest that through the intelligent placement of cooperative industries, which can utilize the waste generated from steel manufacturing, the future of the Chinese steel industry can better reflect ecosystem maturity and health while minimizing waste.

A Multi-slack Bus Model for Bi-directional Energy Flow Analysis of Integrated Power-gas Systems

The bi-directional energy conversion components such as gas-fired generators(GfG)and power-to-gas(P2G)have enhanced the interactions between power and gas systems.This paper focuses on the steady-state energy flow analysis of an integrated power-gas system(IPGS)with bi-directional energy conversion components.Considering the shortcomings of adjusting active power balance only by single GfG unit and the capacity limitation of slack bus,a multi-slack bus(MSB)model is proposed for integrated power-gas systems,by combining the advantages of bi-directional energy conversion components in adjusting active power.The components are modeled as participating units through iterative participation factors solved by the power sensitivity method,which embeds the effect of system conditions.On this basis,the impact of the mixed problem of multi-type gas supply sources(such as hydrogen and methane generated by P2G)on integrated system is considered,and the gas characteristics-specific gravity(SG)and gross calorific value(GCV)are modeled as state variables to obtain a more accurate operational results.Finally,a bi-directional energy flow solver with iterative SG,GCV and participation factors is developed to assess the steady-state equilibrium point of IPGS based on Newton-Raphson method.The applicability of proposed methodology is demonstrated by analyzing an integrated IEEE 14-bus power system and a Belgian 20-node gas system.

Analysis of the Flow Field and Impact Force in High-Pressure Water Descaling

This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications.

A dynamic analysis of environmental losses from anthropogenic lead flow and their accumulation in China

Substance flow analysis was applied to analyzing the lead emissions in 2010. It turns out that in 2010, for every 1 kg of lead consumed, 0.48 kg lead is lost into the environment. The emissions in 2010 were estimated to be 1.89×10^6 t, which were mainly from use （39.20%） and waste management＆recycling （33.13%）. The accumulative lead in 1960-2010 from the anthropogenic flow was estimated and the results show that the total accumulative lead in this period amounted to 19.54×10^6 t, which was equivalent to 14.26 kg and 2.04 g/m^2 at the present population and territory.

Sulfur Flow Analysis for New Generation Steel Manufacturing Process

Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis, and measures for SO2 emission reduction are put forward as assessment and target intervention of the results. The results of sulfur flow analysis indicate that 90 % of sulfur comes from fuels. Sulfur finally discharges from the steel manufacturing route in various steps, and the main point is BF and BOF slag desulfurization. In sintering process, the sulfur is removed by gasification, and sintering process is the main source of SO2 emission. The sulfur content of coke oven gas （COG） is an important factor affecting SO2 emission. Therefore, SO2 emission reduction should be started from the optimization and integration of steel manufacturing route, sulfur burden should be reduced through energy saving and consumption reduction, and the sulfur content of fuel should be controlled. At the same time, BF and BOF slag desulfurization should be optimized further and coke oven gas and sintering exhausted gas desulfurization should be adopted for SO2 emission reduction and reuse of resource, to achieve harmonic coordination of economic, social, and environmental effects for sustainable development.

The Building of Papermaking Enterprise's Recycling Economy Evaluation Index System Based on Value Flow Analysis

At present,the research on circular economy has made a lot of substantive results both at home and abroad.But for the papermaking enterprise,which is the representative of the light industry,few studies have analyzed the evaluation index system of circular economy.Since the current material flow analyses have limitations that the researchers cannot calculate materials with different units.The authors take advantage of the intrinsic correlation between the basic principle of value flow analysis and circular economy,and then analyze the dynamic changes of material flow and value flow through enterprises internal production process.Considering the resource output,the authors set up the layered structure of the evaluation index system,and then preliminarily determine the index form.Next,the authors use the frequency statistics analysis method to adjust indicators,forming a preliminary index system.After that,the principal component analysis and independent analysis are applied for screening.Finally,the authors build a circular economy evaluation index system for papermaking enterprise to provide scientific guidance for the process of circular economy.

Analysis of secondary flow in shell-side channel of trisection helix heat exchangers

The flow characteristics of shell-side fluid in the tube-and-shell heat exchangers with trisection helical baffles with 35° inclined angles are numerically analyzed. The secondary flow distribution of the fluid in the shell-side channel is focused on. The results on meridian planes indicate that in the shell-side channel, the center part of fluid has an outward tendency because of the centrifugal force, and the peripheral region fluid has an inward tendency under the centripetal force. So in a spiral cycle, the fluid is divided into the upper and lower beams of streamlines, at the same time the Dean vortices are formed near the left baffle, and then the fluid turns to centripetal flow near the right baffle. Finally the two beams of streamlines merge in the main flow. The results of a number of parallel slices between two parallel baffles with the same sector in a swirl cycle also show the existence of the secondary flow and some backward flows at the V-gaps of the adjacent baffles. The secondary flows have a positive effect on mixing fluid by promoting the momentum and mass exchange between fluid particles near the tube wall and in the main stream, and thus they will enhance the heat transfer of the helix heat exchanger.