Report Summary 1. Report Industry Investment Rating No relevant information provided. 2. Core View of the Report - The market was affected by news such as the US increasing military threats against Venezuela and the suspension of reciprocal tariffs after the China - US leaders' meeting, causing short - term increases in crude oil and asphalt prices. Concerns about asphalt raw material supply emerged due to Venezuela's importance as an oil source for Chinese asphalt refineries. However, short - term Venezuelan crude oil shipments were not substantially affected according to Kpler data. Demand has entered the off - season, winter storage is unpromising, and some Shandong refineries have复产 expectations. The price is expected to move downward, and short - term traders should pay attention to the rhythm and take profits in time [3]. 3. Summary by Related Catalogs 3.1. Asphalt Price and Volatility - The predicted monthly price range of the asphalt main contract is 3000 - 3450 yuan/ton, with a current 20 - day rolling volatility of 16.06% and a 3 - year historical percentile of 20.68% [2]. 3.2. Asphalt Risk Management Strategy - **Inventory Management**: For enterprises with high finished - product inventory worried about price drops, they can short asphalt futures (bu2512) with a 25% hedging ratio at an entry range of 3650 - 3750 yuan/ton to lock in profits and cover production costs. They can also sell call options (bu2512C3500) with a 20% ratio at an entry range of 30 - 40 to reduce capital costs and lock in the spot selling price if prices rise [2]. - **Procurement Management**: For enterprises with low procurement inventory and aiming to purchase based on orders, they can buy asphalt futures (bu2512) with a 50% hedging ratio at an entry range of 3300 - 3400 yuan/ton to lock in procurement costs. They can also sell put options (bu2512C3500) with a 20% ratio at an entry range of 25 - 35 to collect premiums and reduce procurement costs, and lock in the spot purchase price if prices fall [2]. 3.3. Price and Basis Information - **Spot Prices**: On November 7, 2025, the Shandong spot price was 3050 yuan/ton (down 50 yuan from the previous day and 180 yuan week - on - week), the Yangtze River Delta was 3390 yuan/ton (down 40 yuan and 80 yuan week - on - week), the North China was 3100 yuan/ton (down 50 yuan and 150 yuan week - on - week), and the South China was 3350 yuan/ton (down 10 yuan and 100 yuan week - on - week) [9]. - **Basis**: The Shandong spot 12 - contract basis was - 2 yuan/ton (down 16 yuan and 43 yuan week - on - week), the Yangtze River Delta was 338 yuan/ton (down 6 yuan and up 57 yuan week - on - week), the North China was 48 yuan/ton (down 16 yuan and 13 yuan week - on - week), and the South China was 298 yuan/ton (up 24 yuan and 37 yuan week - on - week) [9]. - **Crack Spread**: The Shandong spot crack spread against Brent was 75.7456 yuan/barrel (down 8.6645 yuan and 24.0369 yuan week - on - week), and the futures main contract crack spread against Brent was 75.3991 yuan/barrel (down 10.5705 yuan and 26.8094 yuan week - on - week) [9]. 3.4. Seasonal Data - The report also includes seasonal charts of asphalt 12 - contract basis in Shandong, North China, the Yangtze River Delta, and Northeast regions, asphalt futures month - spreads (03 - 06, 06 - 09, 09 - 12), domestic asphalt plant - warehouse total inventory rate, and asphalt warehouse and plant - warehouse receipt quantities [10][15][20].

纯苯-苯乙烯风险管理日报 2025/11/7 戴一帆（投资咨询证号：Z0015428） 投资咨询业务资格：证监许可【2011】1290号 苯乙烯价格区间预测 | | 价格区间预测（月度） | 当前波动率（20日滚动） | 当前波动率历史百分位（3年） | | --- | --- | --- | --- | | 纯苯 | 5200-5800 | / | / | | 苯乙烯 | 6200-6800 | 16.41% | 85.8% | source： 南华研究,同花顺 苯乙烯套保策略表 | 行为导 | 情景分析 | 现货敞 | 策略推荐 | 套保工具 买卖方 | 套保比例 | 建议入场 | | --- | --- | --- | --- | --- | --- | --- | | 向 | | 口 | | 向 | (%) | 区间 | | 库存管 理 | 产成品库存偏高，担心苯乙烯价格下 | | 为了防止存货跌价损失，可以根据企业的库存情况，做空苯乙烯期货来锁定利 EB2512 润，弥补企业的生产成本 | 卖出 | 25% | 6500-655 0 | | | 跌 | 多 | | | | | | | | | 卖出看 ...

1. Report Industry Investment Rating No relevant content provided. 2. Core Views of the Report - Short - term macro - driving forces have weakened, steel mill profits are fragile, and production cuts are insufficient, especially the high supply - demand contradiction in the plate segment, which exerts pressure on iron ore demand. With supply remaining high, continuous port inventory accumulation, and the squeeze from the coking coal end, it is expected that the overall iron ore price will continue to show a weak - running trend [3][4][7]. - There are some positive factors, such as the rising basis and the long - term loose overseas monetary and fiscal policies. However, the negative factors dominate the current market situation [4]. 3. Summary According to Relevant Catalogs 3.1 Core Contradictions and Strategy Recommendations 3.1.1 Core Contradictions - **Macro - level**: The PMI of both China and the US in October showed a month - on - month decline, indicating fluctuations in the global trade environment and a marginal slowdown in internal demand. Short - term market driving forces are on hold due to factors like Powell's hawkish stance and the risk of a US government shutdown, and risk appetite has declined [4]. - **Supply and inventory**: Port inventory has continued to accumulate to 15,624 tons, a month - on - month increase of 351 tons. The shipment volume remains at a high level, while the molten iron output is gradually decreasing, putting pressure on prices. The current high - price level encourages mainstream mines to maintain strong shipment willingness, and the port inventory accumulation pattern may continue [4][6]. - **Demand side**: The daily average molten iron output has decreased by 20,000 tons to 2.34 million tons. Some high - cost and severely loss - making steel mills have implemented marginal production cuts, and steel mill profits have slightly recovered but are still fragile. Further production cuts are needed to ease industrial chain contradictions [6]. - **Valuation level**: Coking coal remains strong, with a tight supply and low - inventory structure. The price difference between coking coal and iron ore in the 01 contract has continued to widen, squeezing steel mill profits and suppressing iron ore prices [7]. 3.1.2 Trading - type Strategy Recommendations Perform range - bound operations on the Iron Ore 2601 contract, with the range being [760, 810] [7]. 3.1.3 Industrial Customer Operation Recommendations Provide risk management strategy recommendations for iron ore in November, including different scenarios, risk exposures, strategy recommendations, hedging tools, trading directions, hedging ratios, and recommended entry intervals [8]. 3.1.4 Core Data - **Black产业链成本利润表**: Data such as molten iron cost, blast furnace hot - rolled coil profit, blast furnace rebar profit, etc., show weekly and monthly changes [9]. - **Iron ore weekly shipment data**: Global, Australian, Brazilian, and other regions' shipment volumes show different degrees of changes [10][11]. - **Iron ore demand weekly data**: Indicators such as daily average port clearance volume, daily average molten iron output, blast furnace operating rate, etc., have corresponding changes [12]. - **Iron ore inventory weekly data**: Port inventory, trade ore proportion, and steel mill inventory data show changes in inventory status [13]. 3.2 Supply 3.2.1 Global Shipment Analysis Analyze the seasonality, year - on - year changes, and over - seasonality of global iron ore shipments through various charts [14][15][16]. 3.2.2 Four Major Mines Shipment Analysis Analyze the seasonality, year - on - year changes, and over - seasonality of shipments from the four major iron ore mines [17][18][19]. 3.2.3 Non - mainstream Ore Shipment Analysis Examine the seasonality, year - on - year changes, and over - seasonality of non - mainstream ore shipments, and note that the Platts iron ore index leads non - mainstream shipments by about 5 weeks [23][24][26]. 3.2.4 Arrival and Berthing Analysis Analyze the seasonality and year - on - year changes of the arrival volume at 47 ports, the number of ships in port, berthing days, and actual arrival volume [29][30][31]. 3.2.5 Capsize Shipping Analysis Examine the seasonality of freight prices for capsize ships on different routes, the proportion of iron ore freight, ship speed, and global weekly floating inventory [34][35][40]. 3.2.6 Domestic Ore Supply Analysis Analyze the seasonality and year - on - year changes of the daily average output of iron concentrate powder from domestic mines [41][42][45]. 3.3 Demand Analysis 3.3.1 Molten Iron Analysis Analyze the seasonality, over - seasonality, and year - on - year changes of the daily average molten iron output of 247 steel enterprises, and make predictions on blast furnace maintenance [46][47][49]. 3.3.2 Steel Mill Profit Analysis Analyze the relationship between molten iron output and iron ore prices, and the seasonality of various steel product profits and their leading effects on production [50][52][53]. 3.3.3 Downstream Steel Analysis - **Rebar**: Analyze the production, consumption, inventory, and cost of rebar [65][66][67]. - **Hot - rolled coil**: Examine the production, consumption, inventory, and price difference of hot - rolled coils [72][73][74]. - **Medium - thick plate**: Analyze the production, consumption, inventory, and inventory - to - sales ratio of medium - thick plates [75][77][78]. - **Other steel products**: Analyze the production, inventory, and apparent demand of various other steel products such as H - beams, angle steels, galvanized coils, etc. [81][82][85]. 3.3.4 Export Analysis Analyze the monthly export volume of steel products, port departure volume, export orders, and export profits [100][101][103]. 3.4 Inventory Analysis 3.4.1 Port Inventory Analysis Analyze the seasonality, structure, and over - seasonality of iron ore port inventory, as well as the relationship between inventory and prices [104][105][106]. 3.4.2 Other Inventory Analysis Examine the seasonality of trade ore inventory, steel mill inventory, and inventory turnover days [121][122][127]. 3.5 Valuation Analysis 3.5.1 Basis and Term Structure - Provide the iron ore warehouse receipt price table, showing the basis and delivery profit of different iron ore varieties [128]. - Analyze the seasonality of the basis of different iron ore contracts [129][130]. 3.5.2 Rebar - Iron Ore Ratio and Hot - rolled Coil - Iron Ore Ratio Analyze the seasonality of the rebar - iron ore ratio and hot - rolled coil - iron ore ratio of different contracts [131][132][135]. 3.5.3 Coking Coal Ratio Analysis Analyze the seasonality of the price difference between coking coal and iron ore of different contracts and the cost - sharing relationship between coking coal and iron ore [138][139][144]. 3.5.4 Scrap Steel Cost - effectiveness Analysis Analyze the iron - scrap price difference, scrap steel cost - effectiveness, and the relationship between scrap steel consumption ratio and iron - scrap price difference [145][146][147].

南华期货棉花棉纱周报 ——新棉采收进入尾声，郑棉窄幅震荡波动 陈嘉宁（投资咨询证号：Z0020097 ） 投资咨询业务资格：证监许可【2011】1290号 第一章 核心矛盾及策略建议 1.1 核心矛盾 目前全疆棉花整体采收进度已进入尾声，近日南疆机采棉收购价多集中在6.30-6.40元/公斤，北疆多集中在 6.15-6.30元/公斤，新棉成本基本固化在14600-15000元/吨左右，截至2025年11月6日，全国新年度棉花公证 检验量累计225.44万吨，日度公检量维持在约8万吨上下，随着新棉加工公检量加速增长，新季供应将持续放 量，对棉价形成压力。目前下游纱布厂负荷整体基本持稳，整体需求温吞，但纱厂棉花库存不高，存在刚性 补库需求，下游库存尚未表现出明显矛盾。近日昨日郑商所对棉花替代交割品升贴水进行了调整，新规自 26/27年度开始实施，本次调整有利于提高仓单与纺企实际需求的匹配度，并在空间上合理配置棉花资源供 应。 新疆机采籽棉3128B收购价季节性 元/斤 2021 2022 2023 2024 2025 5 6 中国棉花累计检验量季节性 万吨 2021 2022 2023 2024 2025 600 ...

聚酯产业风险管理日报 ——动力煤走势偏强，前期空单考虑止盈 2025/11/07 戴一帆（投资咨询证号：Z0015428） 研究助理：周嘉伟（期货从业证号：F03133676） 投资咨询业务资格：证监许可【2011】1290号 聚酯价格区间预测 | | 价格区间预测（月度） | 当前波动率（20日滚动） | 当前波动率历史百分位（3年） | | --- | --- | --- | --- | | 乙二醇 | 3750-4250 | 15.81% | 30.0% | | PX | 6000-6800 | 17.16% | 56.6% | | PTA | 4250-4750 | 16.06% | 35.4% | | 瓶片 | 5300-5900 | 12.77% | 47.0% | source： 南华研究,同花顺 聚酯套保策略表 | 行为导向 | 情景分析 | 现货敞口 | 策略推荐 | 套保工具 | 买卖方向 | 套保比例（%） | 建议入场区间 | | --- | --- | --- | --- | --- | --- | --- | --- | | 库存管理 | 产成品库存偏高， 担心乙二醇价格下 | 多 ...

南华纸浆产业周报 —— 相对偏强运行，但需注意高位回落风险 俞俊臣（投资咨询证号：Z0021065 ） 投资咨询业务资格：证监许可【2011】1290号 2025年11月7日 第一章 核心矛盾及策略建议 1.1 核心矛盾 本周的核心影响因素在于宏观情绪与纸企挺价落地情况。纸浆对美进口关税延续，本周进口木浆现货均价也 多数上涨，利好纸浆期价走势。而纸企挺价结果也部分落地，带来一定利好，但实际落地效果相对有限，限 制期价涨幅。 从基本面来看，中国港口库存下降5.3万吨，降幅相对明显，需注意其跌至200万吨以下后给期价带来的利多 影响。而就供应端来看，个别企业恢复生产，竹浆、阔叶浆、化机浆开工负荷率均较上周有所增长，在供应 端仍带来一定的压力。 在终端需求方面，略有好转。下游造纸开工率普遍上涨，下游需求有所恢复。 综合来看，下周纸浆期价走势将震荡偏强，但上方仍存一定限制。 *近端交易逻辑 短期受需求与进口浆价影响，仍存一定上涨空间。但下游需求并未真正改善，需注意追高风险。 * 远端交易预期 远端上，布针仓单的影响将有一定程度的下降，但26年仍然有今年注册的布针仓单可以交割。美联储持续降 息预期加强，宏观上利多整个大 ...

Group 1: Report Industry Investment Rating - The report gives a "Shock Weak" rating for the market [8] Group 2: Core Views of the Report - The market has become dull after the sharp profit correction last week, and the weakening fundamentals have been fully reflected in the market [3] - The 01 contract has been in a weak shock due to the collapse of previous expectations and the weak fundamentals of the spot market [4] - The probability that the traditional seasonal peak season for the 03 contract cannot be realized is also relatively high [5] - Import profits have been repaired to a certain extent. Reducing the proportion of imported timber and increasing the proportion of integrated timber will increase the import profit of the whole ship [26] Group 3: Summary According to the Table of Contents Chapter 1: Core Contradictions and Strategy Recommendations - **Core Contradictions**: The market center has moved down this week, and the volatility has returned to normal. The weakening fundamentals have been fully reflected in the market. The national port inventory increased by 40,000 cubic meters as of October 31, and the daily average outbound volume decreased slightly. The spot prices of 3.9m medium A, 3.9m small A, and 5.9m medium A in Lanshan area have all been lowered by 10 yuan per cubic meter. The 01 - 03 spread center has risen slightly, and attention should be paid to the opportunity to shrink the spread in the medium and long term [3] - **Trading Strategy Recommendations**: The market is in a "Shock Weak" state. Industrial customers can consider buying the basis, and short the 01 - 03 spread when it is high [8][11] - **Industrial Customer Operation Recommendations**: For inventory management, when the log import volume is high and the inventory is at a high level, enterprises can short log futures to lock in profits and make up for production costs. For procurement management, when the procurement of regular inventory is low, enterprises can buy log futures to lock in procurement costs in advance [9] Chapter 2: This Week's Important Information and Next Week's Concerns - **This Week's Important Information**: There is no positive information. Negative information includes low willingness of buyers to take delivery, high delivery costs for sellers, expected decline in shipping costs, short - term increase in supply, weakening downstream consumption, and reduction in spot prices [9][12] - **Next Week's Concerns**: Not mentioned in the report Chapter 3: Market Interpretation - **Price - Volume and Capital Interpretation**: The 01 contract has been in a weak shock this week, and the weekly position has increased by 2,000 lots [14] - **Basis and Spread Structure**: The 11 - 01 spread reached - 50 before the delivery of the 11 contract. Currently, the 01 - 03 spread is around - 10, and there is downward space in the long term [16] Chapter 4: Valuation and Profit Analysis - **Valuation**: The warehouse receipt cost in the Yangtze River Delta region is around 822, and that in Shandong region is around 814. The willingness of buyers to take delivery is around 771. When the price approaches the warehouse receipt cost, it is considered overvalued [25] - **Import Profit**: Import profits have been repaired to a certain extent. Adjusting the material ratio can increase the import profit of the whole ship [26] Chapter 5: Supply - Demand and Inventory Projection - **Supply**: From November 8 to 17, it is expected that 14 ships will arrive at the port, with a total cargo volume of 505,000 cubic meters, and the inventory is expected to change little [34] - **Demand**: As of October 31, the daily average outbound volume was 628,000 cubic meters, a decrease of 16,000 cubic meters compared with the previous period [34]

Report Investment Rating - No information provided on the industry investment rating Core View - The report suggests paying attention to central bank policy operations, maintaining a mid - term optimistic view on the bond market, advising mid - term long positions to be held and empty positions to buy in batches on pullbacks [1][3] Summary by Related Catalogs 1. Disk Review - On Friday, Treasury bond futures oscillated downward and closed down across the board. The funding situation was loose, with DR001 around 1.33%. Open - market reverse repurchase was 14.17 billion yuan, with a net withdrawal of 91.34 billion yuan, of which 70 billion yuan of outright reverse repurchase had been renewed previously [1] 2. Important Information - China's exports denominated in US dollars decreased by 1.1% year - on - year in October, while imports increased by 1.0% year - on - year. China's foreign exchange reserves in October were 3.34334 trillion US dollars, a month - on - month increase of 468 million US dollars; the gold reserves were 74.09 million ounces, a month - on - month increase of 30,000 ounces [2] 3. Market Judgment - The decline of Treasury bond futures intensified in the late trading today, possibly related to the rumor of the announcement of the public - offering fee new regulations over the weekend. If the new regulations lead to accelerated selling by institutions, the central bank can conduct bond purchases to hedge, and the impact on the market is expected to be less than that in September. In October, the export growth rate turned negative, and the export growth rates of South Korea and Vietnam also declined. It is necessary to observe whether external demand is trending weaker [3] 4. Treasury Bond Futures Daily Data - For TS2512, the price was 102.472 on 2025 - 11 - 07, down 0.022 from the previous day, and the contract position increased by 344 hands. For TF2512, the price was 105.92, down 0.04, and the contract position decreased by 1984 hands. For T2512, the price was 108.475, down 0.07, and the contract position decreased by 837 hands. For TL2512, the price was 116.03, down 0.1, and the contract position decreased by 593 hands. There were also corresponding changes in the basis and trading volume of each contract [4]

Report Industry Investment Rating - No relevant content provided Core View - Today, the stock index fluctuated throughout the day, with multiple switches between large - and small - cap indexes during the session. The trading volume of the two markets dropped below 2 trillion yuan again, and the dividend index led the gain, indicating that market sentiment is becoming more cautious. Currently, the news is relatively calm, and the market is in a stage of game between the expectation of policy benefits and the increasing willingness of funds to take profits. On the one hand, November is a policy - free window period, and the signal of subsequent additional favorable policies has weakened, so the upward driving force of the stock index is limited. On the other hand, under continuous high - level fluctuations, the demand for funds to take profits has increased, and the index is under callback pressure. However, the expectation of policy benefits still strongly supports the stock index, as can be seen from the multiple intraday rebounds of the stock index this week. The recommended strategy is to hold positions and wait and see [5] Market Review - Today, the stock index fluctuated throughout the day and closed slightly lower collectively. For example, the CSI 300 index closed down 0.31%. In terms of capital, the trading volume of the two markets decreased by 56.194 billion yuan. In the futures index market, IM rose with increasing volume, while other varieties declined with decreasing volume [3] Important Information - President Xi Jinping emphasized when listening to the report on the construction of the Hainan Free Trade Port that the construction goals of the Hainan Free Trade Port should be fully achieved. It is necessary to steadily expand institutional opening - up, further improve the level of trade and investment liberalization and facilitation, and promote the cross - border flow of production factors. The opening - up rhythm and progress should be scientifically and orderly arranged, and risk identification and prevention should be strengthened [4] - Private data provider Revelio Labs reported that the number of non - farm payrolls in the United States decreased by 9,100 in October, compared with an increase of 33,000 in the previous month. In addition, the number of Challenger job cuts in the United States in October reached 153,100, a year - on - year surge of 175.3%, the highest level in the same period since 2003 [4] Futures Index Market Observation | | IF | IH | IC | IM | | --- | --- | --- | --- | --- | | Main contract intraday change (%) | - 0.25 | - 0.13 | - 0.13 | 0.14 | | Trading volume (10,000 lots) | 8.645 | 3.7804 | 10.6961 | 18.7617 | | Trading volume change compared with the previous period (10,000 lots) | - 2.4963 | - 1.3677 | - 2.6527 | - 1.5813 | | Open interest (10,000 lots) | 25.7486 | 9.0943 | 24.0492 | 35.6424 | | Open interest change compared with the previous period (10,000 lots) | - 0.7165 | - 0.5291 | - 0.9003 | 0.6568 | [5] Spot Market Observation | Name | Value | | --- | --- | | Shanghai Composite Index change (%) | - 0.25 | | Shenzhen Component Index change (%) | - 0.36 | | Ratio of rising to falling stocks | 0.66 | | Trading volume of the two markets (100 million yuan) | 19990.53 | | Trading volume change compared with the previous period (100 million yuan) | - 561.94 | [7]

Report Summary 1. Report Industry Investment Rating No information provided. 2. Core Viewpoints - The current situation is weak, but the cost is relatively strong. The game for the 01 contract may continue until delivery. Without unexpected production cuts, a bearish view is maintained for the glass and soda ash 01 contracts [6]. - Structural contradictions still exist. The reduction in glass supply is insufficient to change the oversupply situation, and the high inventory in the middle - stream puts great pressure on the 01 contract. The expectation of glass cold - repair is rising again, which is negative for the rigid demand of soda ash, but the cost side is relatively firm [2]. 3. Summary by Related Content Price Forecast - The monthly price range forecast for glass is 1000 - 1300, with a current 20 - day rolling volatility of 28.31% and a 3 - year historical percentile of 75.4%. For soda ash, the monthly price range forecast is 1100 - 1400, with a current 20 - day rolling volatility of 17.69% and a 3 - year historical percentile of 9.8% [1]. Market Data - **Glass Futures**: On November 7, 2025, the prices of glass 05, 09, and 01 contracts were 1225, 1315, and 1091 respectively, with daily changes of - 2, - 4, and - 10, and daily change rates of - 0.16%, - 0.3%, and - 0.91% compared to the previous day [7]. - **Glass Spot**: Some glass spot prices in different regions showed little change on November 7, 2025. For example, the safety brand in the Shahe area remained at 1130, while the Great Wall brand increased by 5 to 1126 [8]. - **Soda Ash Futures**: On November 7, 2025, the prices of soda ash 05, 09, and 01 contracts were 1294, 1363, and 1210 respectively, with daily changes of 1, - 1, and 3, and daily change rates of 0.08%, - 0.07%, and 0.25% compared to the previous day [8]. - **Soda Ash Spot**: On November 7, 2025, the heavy - alkali market prices in some regions such as North China and South China remained unchanged, while the light - alkali market price in some regions had slight changes [9][10]. Hedging Strategies - For glass inventory management, when the finished - product inventory is high and worried about price drops, shorting glass futures (FG2601) and selling call options (FG601C1200) are recommended. When the procurement inventory is low and worried about price increases, buying glass futures (FG2601) and selling put options (FG601P1000) are recommended [1]. - For soda ash inventory management, when the finished - product inventory is high and worried about price drops, shorting soda ash futures (SA2601) and selling call options (SA601C1400) are recommended. When the procurement inventory is low and worried about price increases, buying soda ash futures (SA2601) and selling put options (SA601P1200) are recommended [1]. Factors Affecting the Market - **Positive Factors**: The cost of glass and soda ash (fuel & raw materials) still has an upward expectation, which affects the far - month pricing. The industrial policy expectation cannot be completely excluded and may be repeatedly traded [5]. - **Negative Factors**: The inventories of glass and soda ash in the upper and middle reaches are high, and the downstream's ability to absorb is questionable. The supply pressure remains, and the oversupply situation is difficult to change. After the glass spot price increases, the production and sales have weakened, and the sustainability needs to be observed [5][6].