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Open-pit mining production process has many hazard factors.
Analysis of Risk Factors The common characteristics of large-scale open-pit mine are large scale equipment, high specialized production degree and high automaticity.
Establishment set of evaluation factors Set is the composition of each factor which mainly affects the judgment object
The weight set is a fuzzy subset of the factors set .
In such a way, all factors in appraisal collection U are built matrix R

Despite its unique properties, PLA took about 12 weeks to biodegrade which is slow degradation leads to an increased rate of plastic pollution in the environment.
The chemical, mechanical and physical properties of the PLA before and after the biodegradation process were investigated and analyzed using Fourier Transform Infrared (FTIR), light microscope, and physical observation of the PLA structure, respectively.
The influence of biotic and abiotic factors on the rate of degradation of poly(lactic) acid (PLA) coupons buried in compost and soil.
A review on the thermomechanical properties and biodegradation behaviour of polyesters.
A Comprehensive Evaluation of Mechanical, Thermal, and Antibacterial Properties of PLA/ZnO Nanoflower Biocomposite Filaments for 3D Printing Application.

However, products processed by extrusion, forging and rolling have higher strength, better ductility and various mechanical property compared to cast alloys, which meet the demands of more structures, and have excellent performance that can not be replaced by cast alloys [2].
Many factors affect the sheet quality during semi-solid roll strip-casting process, for instance, the flow behavior in molten pool, heat transfer phenomena between rolls and cast sheet, and the control of position of solidification final point.[7, 8].
Table 1 Equipment parameters and simulation conditions Roll size, mm Φ210×280 Roll gap, mm 6 Roll speed, m/min 2,3,4 Height of molten pool, mm 40 Rolling temperature, °C 545 Step, s 0.02 The material used in the study was AZ91D magnesium alloy, the physical properties of which are shown in Table 2.
We also assume that these properties keep constant during the rolling process.
Table 2 Physical properties of AZ91D magnesium alloy Physical properties Values Solidus temperature, °C 470 Liquidus temperature, °C 595 Thermal-conductivity , N·°C/S 72 Heat capacity, N°C/mm2 1.9 2.1 Establishment of geometric model.

Because PET has outstanding chemical and mechanical properties, such as strength, thermal stability and chemical resistance, and is inexpensive.
However, this recycling method results in worsening mechanical properties of the polymer, due to molecular chains being cut by hydrolysis degradation during extrusion recycling process.
The long chain with branching structure of the modified-rPET with low gels will improve the process-ability and mechanical properties of many rPET products, such as foam, film, sheet, and so on.
This work investigated structural change, viscosity change, thermal properties and thermal stability.
Tan, Unraveling the driving factors of the plastic waste trade network formation and dynamics, Journal of environmental Management 384 (2023)

Combined, these factors have shown that there would be a great advantage in forming at a lower temperature.
AMS-T9046) that does not specify SPF properties.
Several factors restrict regular Ti-6Al-4V alloy from being formed at a lower temperature.
Using the properties at 900°C above, target SPF properties for a new material were set at 35MPa for 3x10 4 strain rate.
NKK released data for incorporation into Mil Handbook 5 specifying the same mechanical properties as Ti-6Al-4V.

Due to the fact that the bridge structures experience a service period lasting for several decades or even hundreds of years, under the circumstances of load change, material variation, natural disasters, human factors, etc, it’s inevitable that the damage accumulation or even accidents would happen to the bridges, causing enormous economic loss[1][2].
The development of advanced testing technology requires such properties for the sensors like the small and thin size, which would not affect the structure appearance; the nice connection with the original structure material, on which has slighter effects; the wide coverage of sensing and the wide range of frequency response; the compatibility of the sensors and the other electrical equipments in engineering; the strong anti-interference from the outside; the proper functioning in the temperature range of structure performing[15][16].
Usually the selection of sensors mainly takes the following factors into consideration: the type, precision, resolution, frequency response and dynamic range; the distribution positions, the influence degree of the surrounding dynamic environment and measurement noise.
At now there’re many forms of the data acquisition and communication network, the selection of which should be based on the comprehensive consideration of the factors like the spot condition of bridge, the type, number and sampling rate of sensor.
Because of the wide range and multiple factors involved in condition evaluation of bridge, the understanding of its connotation always gets unbalanced.

The part structure of concrete slab likely is crazed by the effect of tension and compression,and concrect ecclasis occurred.： 脱落，破碎；脱落, 破碎.According to the traffic situation at present in da-qin railway, part of its existing slab culvers can not meet the total needs of overloading,long-term operation will make the slabs of the culvert structure damage aggravate even fatigue damage, it will affect safety of train operation.
At present, the domestic and foreign research mainly aims at reinforced concrete beam component about reinforced concrete structure of the fatigue performance and prediction of fatigue service life, and it obtaines some achievements. [1]draws a reinforced concrete beam bridge will not aggravate fatigue damage with axle load 25 tons; [2]~[4]puts forward residual life prediction method based on the system reliability for existing reinforced concrete beam, and establishes corresponding mathematical model; [5]shows that the effect of heavy haul train is little to small span bridges ; [6] analyses the reinforced concrete beam fatigue damage for 8 meters span and evaluates the service life,it show that existing bridge cannot achieve fatigue damage in da-qin railway currently. the domestic and foreign little research aims at fatigue performance of reinforced concrete slab structure and the prediction of fatigue service life, but for recearch on roof and bridge panel, and the lesser fatigue properties
Then uninstall to zero,next for second crack test(second static load), it is used to determine crack well.numerical examples deformation property and stress conditions, stop loading until achieving unprotected ground reinforced concrete structure crack width allow value at general atmospheric conditions when loading until producing 0.2 millimetre crack in beam[6].
The fatigue strength analysis of tensile steel :The steel fatigue is the result of crack initiation and expansion for fatigue loads, the stress balance of crack tip is broken when the stress intensity factor reached critical value,and the crack expands until the new balance is reformed as the equilibrium process of continuous cycle until steel cannot make crack tip stress strength balanced then ruptured.There are many factors for fatigue strength, such as stress amplitude, the smallest stress level, reinforced appearance, diameter and strength, but stress amplitude impacted is the most important.
The calculated value of tensile steel fatigue life Strain amplitude of the tensile steel （με） Stress amplitude of the tensile steel （MPa） Calculating fatigue life times（million times） 344.24 68.85 183.10 345.34 69.07 180.28 297 59.40 374.71 The steel stress variation is very complex with fatigue loads,and it’s influencing factors is various.We carried fatigue test of reinforced concrete cover in order to study stress law of development of steel and reinforced concrete(the fatiguelife is more than 2 million times ) of reinforced concrete cover plate on fatigue- normal using state.

The activated carbon was finally stored in the reagent bag for the following tests. 1.3 Test methods 1.3.1 Orthogonal test The main factors affecting the ammonia modification is modifier concentration, soaking time, activation time, activation temperature and so on.
In this paper, in order to obtain the optimization conditions of modified activated carbon as soon as possible, the five-factors and four-levels orthogonal list was selected. 1.3.2 Adsorption experiment Some amounts of modified activated carbons were put into a series of 250mL conical flasks that contained a certain volume of 500mg/L phenol solution.
Results and discussion 2.1 The analysis of orthogonal experiment result The factors and the levels of this test were shown in the Table1.
Table 1 The factors and levels factor A the concentration of Na2CO3 solution（mol/l） B soaking time （h） C activation time（h） D activation temperature（℃） level 1 0.5 2 1 350 level 2 1.0 3 2 400 level 3 1.5 4 2.5 450 level 4 2.0 5 3 500 Table 2 The results of orthogonal test factor test number Athe concentration of Na2CO3 solution（mol/l） B soaking time （h） C activation time（h） D activation temperature（℃） F the rate of increasing（%） 1 1 1 1 1 48.15 2 1 2 2 2 33.80 3 1 3 3 3 48.10 4 1 4 4 4 54.10 5 2 1 2 3 44.73 6 2 2 1 4 44.68 7 2 3 4 1 51.26 8 2 4 3 2 49.23 9 3 1 3 4 63.27 10 3 2 4 3 59.03 11 3 3 1 2 40.38 12 3 4 2 1 52.34 13 4 1 4 2 45.37 14 4 2 3 1 39.85 15 4 3 2 4 34.27 16 4 4 1 3 41.04 K1 46.04 50.38 43.56 47.90 Exegesis:Kn and R respective are the average rate of F and range K2 47.47 44.34 41.28 42.19 K3 53.76 43.50 50.11 48.22 K4 40.13 49.17 52.44 49.08 R 13.62 6.88 11.16 6.89 The results of table 2 showed that: The means of different factors showed that
The Na2CO3-activated carbon of adsorption test were all from this process system. 2.2 The influence of activated carbon Surface modification for the chemical and physical properties 2.2.1 The changes of specific surface area and surface functional groups The Na2CO3-activated carbon was preparated by the optimum technological conditions.

The interface agent of SBR (styrene-butadiene rubber) latex modified cement paste has better tensile　bonding properties.
Intorduction Nowadays load of cement pavement is constantly growing, causing different levels of damage and functional defects in most of the road, which have already seriously affected service and vehicle security of highway [1,2].
And studies have shown that influencing factors of interlayer bonding performance as follows: cement concrete pavement roughness, the interface agent, power, age [3,4].
Figure 3 The influence of DB-1 polymer dosage on tensile bond strength The mix design of interface agent of RCC-PCC specimens The impact of pouring and interface agent mix on its interface bond performance was studied by studying bond splitting tensile properties of hybrid cubic specimens of the PCC and RCC.
Analysis of reasons: the bond surface is vertically when the lateral placement, and because of the bleeding and shrinkage effects of the new PCC, distribution of the adhesive mass is uneven, resulting in lower bond splitting tensile strength; the bond surface is horizontal when horizontal pouring, the aggregate sank and bubbles rose under the action of the weight and vibration, making the new PCC bond better with surface of RCC, it would form a better result of mechanical occlusion.

Their ceramic properties and results of the raw materials’ selection are given, including: screenings - 60-65%; siliceous clay - 20-30% coal sludge - 10-15%, on the basis of which it is possible to obtain the products with low cost and high strength for the load-bearing wall structures.
The main factors affecting the calcined samples’ properties are the degree of grinding screenings and the firing temperature.
The mechanical bending strength of the samples in the dry state reaches 2-2.5 MPa, which is also sufficient for trouble-free passage of all technological operations.
However, the ceramic material itself is characterized by the increased density (more than 1800 kg/m3), which significantly affects the thermal conductivity of the products themselves and the thermal conductivity of a masonry.
Teryokhina, Municipal waste management as an important factor in the sustainable development of the metropolis. 1 (2018) 115-118