State of the art and practice of pavement anti-icing and de-icing techniques

Pavement snow and icing are worldwide problems, but effective countermeasures are just beginning to be developed in China. The two most common snow and ice removal methods are mechanical clearance and chemical melting, and the advantages and disadvantages of each approach are discussed here, including environmental and structural damage caused by corrosive snow melting agents. New developments in chemical melting agents and mechanical equipment are discussed, and an overview of alternative thermal melting systems is presented, including the use of geothermy and non-geothermal heating systems utilizing solar energy, electricity, conductive pavement materials, and infrared/microwave applications. Strategic recommendations are made for continued enhancement of public safety in snow and ice conditions.

Robustα-Fe_(2)O_(3)/Epoxy Resin Superhydrophobic Coatings for Anti-icing Property

α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating was prepared withα-Fe_(2)O_(3) nanoparticles and epoxy resin by spin coating method.The coating without epoxy resin has higher contact angle(CA)and lower ice adhesion strength(IAS),but the mechanical properties are poor.Theα-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating exhibits good mechanical durability.In addition,compared with the bare aluminum substrate,the Ecorr of the composite coating is positive and the Jcorr is lower.The inhibition efficiency of the composite coating is as high as 99.98%in 3.5 wt%NaCl solution.The difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.

Study of Flow and Heat Transfer in an Ejector-Driven Swirl Anti-Icing Chamber

The formation of ice on the leading edge of aircraft engines is a serious issue,as it can have catastrophic consequences.The Swirl Anti-Icing(SAI)system,driven by ejection,circulates hot fluid within a 360°annular chamber to heat the engine inlet lip surface and prevent icing.This study employs a validated Computational Fluid Dynamics(CFD)approach to study the impact of key geometric parameters of this system on flow and heat transfer characteristics within the anti-icing chamber.Additionally,the entropy generation rate and exergy efficiency are analyzed to assess the energy utilization in the system.The research findings indicate that,within the considered flow range,reducing the nozzle specific areaφfrom 0.03061 to 0.01083 can enhance the ejection coefficient by over 60.7%.This enhancement increases the air circulating rate,thereby intensifying convective heat transfer within the SAI chamber.However,the reduction inφalso leads to a significant increase in the required bleed air pressure and a higher entropy generation rate,indicating lower exergy efficiency.The nozzle angleθnotably affects the distribution of hot and cold spots on the lip surface of the SAI chamber.Increasingθfrom 0°to 20°reduces the maximum temperature difference on the anti-icing chamber surface by 60 K.

Peridynamic modeling and simulation of thermo-mechanical de-icing process with modified ice failure criterion

De-icing technology has become an increasingly important subject in numerous applications in recent years.However,the direct numerical modeling and simulation the physical process of thermomechanical deicing is limited.This work is focusing on developing a numerical model and tool to direct simulate the de-icing process in the framework of the coupled thermo-mechanical peridynamics theory.Here,we adopted the fully coupled thermo-mechanical bond-based peridynamics(TM-BB-PD)method for modeling and simulation of de-icing.Within the framework of TM-BB-PD,the ice constitutive model is established by considering the influence of the temperature difference between two material points,and a modified failure criteria is proposed,which takes into account temperature effect to predict the damage of quasi-brittle ice material.Moreover,thermal boundary condition is used to simulate the thermal load in the de-icing process.By comparing with the experimental results and the previous reported finite element modeling,our numerical model shows good agreement with the previous predictions.Based on the numerical results,we find that the developed method can not only predict crack initiation and propagation in the ice,but also predict the temperature distribution and heat conduction during the de-icing process.Furthermore,the influence of the temperature for the ice crack growth pattern is discussed accordingly.In conclusion,the coupled thermal-mechanical peridynamics formulation with modified failure criterion is capable of providing a modeling tool for engineering applications of de-icing technology.

Investigation on Preparation and Anti-icing Performance of Superhydrophobic Surface on Aluminum Conductor

Aluminum is widely used in transmission lines, and the accumulation of ice on aluminum conductor may inflict serious damage such as tower collapse and power failure. In this study, super-hydrophobic surface （SHS） on alurninurn conductor with rnicro-nanostructure was fabricated using the preferential etching principle of crystal defects. The surface rnicrostructure and wettability were investigated by scanning electron microscope and contact angle measurement, respectively. The icing progress was observed with a self-made icing experiment platform at different environment temperature. The results showed that, due to jumping and rolling down of coalesced droplets from SHS of aluminum conductor at low temperature, the formation of icing on SHS could be delayed. Dynamic icing experiment indicated that SHS on aluminum conductor could restrain the formation of icing in certain temperature range, but could not exert influence on the accumulation of icing. This study offers new insight into understanding the anti-icing performance of actual aluminum conductor.

Anti-Icing Method Based on Reducing Voltage of Transmission Lines

The icing of transmission lines threatens the security of power system. This paper proposes a novel anti-icing method based on reducing voltage of the transmission lines. The line voltage can be reduced by regulating the ratio of the transformers which install the both ends of the transmission lines. The line current can be increased and the power loss of the transmission lines can also be increased, which means the heat generated by power loss increases and the icing process of the transmission lines can be restrained. When the icing may occur in the atrocious weather, the anti-icing transformers installed the both ends of transmission line are put into operation. The ratios of transformers are regulated to the appropriate value. The current of transmission line can be increased to the value that is a little greater than the critical current, which can realize the purpose of anti-icing. At the same time, the conditions of normal running in the load side are kept invariably, which can ensure the security of power system. This method can be applicable to a wide range. It's an effective measure to prevent the icing of the transmission lines.

Super-hydrophobic film deposition by an atmospheric-pressure plasma process and its anti-icing characteristics

In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.Plasma synthesized organosilicon(SiOxCyHz)thin films with water contact angle over 160°and sliding angle below 5°,were able to be achieved.FTIR and XPS analysis indicates a large number of hydrocarbon compositions were polymerized in the thin films enduing the latter very-low surface free energy.SEM shows the SH films display micro-nanostructure and with high degree of averaged surface roughness 190 nm evaluated by AFM analysis.From experiments under controlled low-temperature and moisture conditions,the prepared SH surface exhibits good anti-icing effects.Significantly prolonging freezing time was achievable on the SH thin films for both static and sliding water droplets.This investigation demonstrates the anti-icing potentials of SH surface prepared through low-cost simple atmospheric-pressure plasma polymerization process.

Fast Algorithm for Prediction of Airfoil Anti-icing Heat Load

Many flight and icing conditions should be considered in order to design an efficient ice protection system to prevent ice accretion on the aircraft surface. The anti-icing heat load is the basic knowledge for the design of a thermal anti-icing system. In order to help the design of the thermal anti-icing system and save the design time, a fast and efficiency method for prediction the anti-icing heat load is investigated. The computation fluid dynamics (CFD) solver and the Messinger model are applied to obtain the snapshots. Examples for the calculation of the anti-icing heat load using the proper orthogonal decomposition (POD) method are presented and compared with the CFD simulation results. It is shown that the heat loads predicted by POD method are in agreement with the CFD computation results. Moreover, it is obviously to see that the POD method is time-saving and can meet the requirement of real-time prediction.

Design and Development of Anti-Icing Aluminum Surface

An anti-icing surface has been designed and prepared with an aluminum panel by creating an artificial lotus leaf which is highly hydrophobic. The hydrophobicity of a solid surface can be generated by decreasing its surface tension and increasing the roughness of the surface. On a highly hydrophobic surface, water has a high contact angle and it can easily rolls off, carrying surface dirt and debris with it. Super-cooled water or freezing rain can also run off this highly hydrophobic surface instead of forming ice on the surface, due to the reduction of the liquid-solid adhesion. This property can also help a surface to get rid of the ice after the water becomes frozen. In this study, a Cassie-Baxter rough surface was modeled, and an aluminum panel was physically and chemically modified based on the modeled structure. Good agreement was found between predicted values and experimental results for the contact and roll-off angles of water. Most importantly, by creating this highly hydrophobic aluminum rough surface, the anti-icing and de-icing properties of the modified surface were drastically improved compared to the control aluminum surface, and the cost will be reduced.

Dose-effect correlation of chloride de-icing salt on Euonymus japonicus

In order to prevent severe pollution by de-icing salt on greenery along urban roads, a half lethal dose （LD_50）for a plant population was confirmed through stress simulation of chloride de-icing salt on Euonymus japonicus, with an ianalysis of physiological changes, statistics on mortality rate on plant populations and mathematic modeling during a 30- day subacute toxicity test. The results indicate that a significant positive correlation in the early stages and a significant negative correlation in the later stages were observed between the amount of chlorophyll a and b in plants and a cumulative dose of de-icing salt. The amounts of free proline in plants and the dose of de-icing salt were positively correlated Over the entire period. No significant correlation in the initial stage, but a significant negative correlation in later stages was observed between the soluble protein and the dose of de-icing salt. LDs0 of this chloride agent on E. japonicus is 5 kg.（L·m2）-1 over 30 days.

An Abrasion Resistant TPU/SH-SiO_(2) Superhydrophobic Coating for Anti-Icing and Anti-Corrosion Applications

As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pollution,high energy-consumption,high-cost and other undesirable issues.Besides,the durability of superhydrophobic coating also plagues its commercial application.In this paper,we introduced a facile and environment-friendly technique for fabricating abrasion-resistant superhydrophobic surfaces using thermoplastic polyurethane(TPU)and modified SiO_(2)particles(SH-SiO_(2)).Both materials are non-toxicity,low-cost,and commercial available.Our methodology has the following advantages:use of minimal amounts of formulation,take the most streamlined technical route,and no waste material.These advantages make it attractive for industrial applications,and its usage sustainability can be promised.In this study,the mechanical stability of the superhydrophobic surface was evaluated by linear wear test.It is found that the excellent wear resistance of the superhydrophobic coating benefits from the characteristics of raw materials,the preparation strategy,and the special structure.In anti-icing properties test,the TPU/SH-SiO_(2)coating exhibits the repellency to the cold droplets and the ability to extend the freezing time.The electrochemical corrosion measurement shows that the asprepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Q235 substrates.These results indicate that the TPU/SH-SiO_(2)coating possesses good abrasion resistance and has great potential in anti-corrosion and anti-icing applications.

Experimental investigation on de-icing by an array of impact rod-type plasma synthetic jets

Since flight accidents due to aircraft icing occur from time to time,this paper proposes an array of impact rod-type plasma synthetic jet de-icing methods for aircraft icing problems.The impact rod-type plasma synthetic jet actuator(PSJA)is based on the traditional PSJA with an additional impact rod structure for better de-icing in the flight environment.In this work,we first optimize the ice-breaking performance of a single-impact rod-type PSJA,and then conduct an array of impact rod-type plasma synthetic jet ice-breaking experiments to investigate the relationship between crack expansion and discharge energy,ice thickness and group spacing.The results show that the impact force and impulse of a single-impact rod-type PSJA are proportional to the discharge energy,and there exists a threshold energy Qmin for a single actuator to break the ice,which is proportional to the ice thickness.Only when the discharge energy reaches above Qmin can the ice layer produce cracks,and at the same time,the maximum radial crack length produced during the ice-breaking process is proportional to the discharge energy.When the ice is broken by an array of impact rod PSJAs,the discharge energy and group spacing together determine whether the crack can be extended to the middle region of the actuator.When the group spacing is certain,increasing the energy can increase the intersection of cracks in the middle region,and the ice-fragmentation degree is increased and the ice-breaking effect is better.At the same time,the energy estimation method of ice breaking by an array of impact rod-type PSJAs is proposed according to the law when a single actuator is breaking ice.

Self-Structured Organizing Single-Input CMAC Control for De-icing Robot Manipulator

This paper presents a self-structured organizing single-input control system based on differentiable cerebellar model articulation controller (CMAC) for an n-link robot manipulator to achieve the high-precision position tracking. In the proposed scheme, the single-input CMAC controller is solely used to control the plant, so the input space dimension of CMAC can be simplified and no conventional controller is needed. The structure of single-input CMAC will also be self-organized;that is, the layers of single-input CMAC will grow or prune systematically and their receptive functions can be automatically adjusted. The online tuning laws of single-input CMAC parameters are derived in gradient-descent learning method and the discrete-type Lyapunov function is applied to determine the learning rates of the proposed control system so that the stability of the system can be guaranteed. The simulation results of three-link De-icing robot manipulator are provided to verify the effectiveness of the proposed control methodology.

Neurosyphilis complicated by anti-γ-aminobutyric acid-B receptor encephalitis: A case report

BACKGROUND Syphilis is an infectious disease caused by Treponema pallidum that can invade the central nervous system,causing encephalitis.Few cases of anti-N-methyl-Daspartate receptor autoimmune encephalitis(AE)secondary to neurosyphilis have been reported.We report a neurosyphilis patient with anti-γ-aminobutyric acid-B receptor(GABABR)AE.CASE SUMMARY A young man in his 30s who presented with acute epileptic status was admitted to a local hospital.He was diagnosed with neurosyphilis,according to serum and cerebrospinal fluid(CSF)tests for syphilis.After 14 d of antiepileptic treatment and anti-Treponema pallidum therapy with penicillin,epilepsy was controlled but serious cognitive impairment,behavioral,and serious psychiatric symptoms were observed.He was then transferred to our hospital.The Mini-Mental State Examination(MMSE)crude test results showed only 2 points.Cranial magnetic resonance imaging revealed significant cerebral atrophy and multiple fluidattenuated inversion recovery high signals in the white matter surrounding both lateral ventricles,left amygdala and bilateral thalami.Anti-GABABR antibodies were discovered in CSF(1:3.2)and serum(1:100).The patient was diagnosed with neurosyphilis complicated by anti-GABABR AE,and received methylprednisolone and penicillin.Following treatment,his mental symptoms were alleviated.Cognitive impairment was significantly improved,with a MMSE of 8 points.Serum anti-GABABR antibody titer decreased to 1:32.The patient received methylprednisolone and penicillin after discharge.Three months later,the patient’s condition was stable,but the serum anti-GABABR antibody titer was 1:100.CONCLUSION This patient with neurosyphilis combined with anti-GABABR encephalitis benefited from immunotherapy.

青枯病生防菌ANTI-8098A的微胶囊化技术

以明胶和阿拉伯胶为壁材,通过复凝聚法进行青枯病生防菌ANTI-8098A微胶囊的制备,研究壁材浓度、 生防菌ANTI-8098A发酵液添加浓度、搅拌速度、酸碱度和甲醛固化条件对微胶囊粒径、形状的影响。试验结果表 明.用2.5％明胶和2.5％阿拉伯胶为壁材制备青枯病生防菌ANTI-8098A微胶囊,条件为pH值4.0、生防菌发酵 液浓度10％～30％、搅拌速度400 r·min-1、固化时添加1％的甲醛溶液.生防菌的包被率可稳定在70％左右,微 胶囊为圆形.平均直径为30.8～57.3μm,生防菌微胶囊萌发率达93％以上。

MAPKs在anti-β_2 GPI/β_2 GPI刺激THP-1细胞表达TF过程中的作用探讨

目的:探讨丝裂原活化蛋白激酶(Mitogen-activated protein kinases,MAPKs)在anti-β2 GPI/β2 GPI复合物诱导单核细胞株THP-1表达组织因子(TF)中的活化及其作用。方法:利用荧光定量PCR(Real-time PCR)、TF活性试剂盒等分别检测anti-β2 GPI/β2 GPI复合物诱导THP-1细胞表达TF mRNA及TF活性,Western blot检测细胞表达p38、磷酸化-p38(p-p38)、ERK1/2、磷酸化-ERK1/2(p-ERK1/2)、JNK、磷酸化-JNK(p-JNK)的情况。进一步采用p38、ERK1/2、JNK抑制剂(SB203580、U0126、SP600125)观察是否能阻断anti-β2 GPI/β2 GPI复合物诱导THP-1细胞表达TF。结果:Anti-β2 GPI/β2 GPI复合物(100μg/ml)能够显著增强THP-1细胞表达TF,并使p-p38、p-ERK1/2、p-JNK水平显著升高(P<0.05 vs control);其引发的MAPKs磷酸化具有时间效应性,均在刺激30分钟时达到高峰;对应的特异抑制剂SB203580(10μmol/L)、U0126(5μmol/L)、SP600125(90 nmol/L)单独或合并处理THP-1细胞后,anti-β2 GPI/β2 GPI复合物诱导细胞TF mRNA表达及TF活性的效应明显被阻断(P<0.01 vs control)。结论:Anti-β2 GPI/β2 GPI复合物诱导THP-1细胞表达TF过程中,MAPKs被激活进而发挥重要作用。

TLR4在anti-β2GPⅠ/β2GPⅠ复合物诱导THP-1细胞表达TF中的作用探讨

目的:探讨TLR4及相关信号分子在anti-β2GPⅠ/β2GPⅠ复合物诱导单核细胞株THP-1表达组织因子(TF)中的作用。方法:利用荧光定量PCR(Real-timePCR)检测anti-β2GPⅠ/β2GPⅠ诱导THP-1细胞TFmRNA表达,采用试剂盒检测细胞TF活性;利用自制的β2GPⅠ胶联亲和层析柱(β2GPⅠ-Affi-Gel)分析β2GPⅠ与THP-1细胞表面相应受体结合情况;Real-timePCR及Western蛋白印迹检测anti-β2GPⅠ/β2GPⅠ复合物诱导细胞表达TLR4、MyD88、MD-2情况;观察TLR4途径抑制物——紫杉醇是否干预anti-β2GPⅠ/β2GPⅠ复合物对细胞的作用。结果:Anti-β2GPⅠ/β2GPⅠ复合物(100μg/ml)诱导THP-1细胞TF表达显著增加(P<0.05);THP-1细胞表面的TLR4能够结合于β2GPⅠ-Affi-Gel柱;Anti-β2GPⅠ/β2GPⅠ复合物(100μg/ml)刺激THP-1细胞表达TLR4、MyD88、MD-2显著升高(P<0.05);紫杉醇(1μmol/L)能够抑制anti-β2GPⅠ/β2GPⅠ复合物对细胞的刺激效应。结论:TLR4及相关信号分子在anti-β2GPⅠ/β2GPⅠ复合物诱导THP-1细胞表达TF中具有重要作用。

生防菌ANTI-8098A对青枯雷尔氏菌不同致病力菌株抑制作用的差异性

采用共培养法测定了生防菌ANTI-8098A对青枯雷尔氏菌强致病力菌株F-01-V和无致病力菌株F.1.3-010602-01-A的抑制作用,并以链霉素作参照。结果表明,生防菌ANTI-8098A对F-01-V的抑制作用较强,抑制率与生防菌培养液菌体数成正相关;对F.1.3-010602-01-A的抑制作用则较弱,菌体数为20.0×108cfu/ml的生防菌液对F.1.3-010602-01-A的抑制率为14.7%,而对F-01-V的抑制率高达99.5%。链霉素对F-01-V和F.1.3-010602-01-A都具有较强的抑制作用,抑制率与浓度成正相关,但是对F.1.3-010602-01-A的抑制作用更强:浓度为0.25U/ml的链霉素溶液,对F.1.3-010602-01-A的抑制率为50.0%,而对F-01-V的抑制率仅为3.3%。应用生防菌ANTI-8098制剂进行田间防治茄子青枯病的试验结果表明,生防菌制剂的防治效果达92.11%,显著地比农用链霉素的防效(72.81%)高。研究结果为阐述生防菌ANTI-8098对青枯雷尔氏菌的致弱现象提供了依据。

青枯病生防菌ANTI-8098A菌株发酵过程氨基酸变化动态的研究

青枯病生防菌ANTI- 80 98A发酵过程的氨基酸测定结果表明 :ANTI - 80 98A的氨基酸代谢消耗发生在 0～ 2 4h ,消耗了 87.0 7%的总氨基酸 ;代谢累积发生在 2 4～ 4 8h ,4 8h的总氨基酸为 0h的 1 .6 7倍。在 1 7种测定的氨基酸中 ,1 6种氨基酸都表现出与总氨基酸类似的变化趋势 ,丝氨酸在 32h有最大值 ;根据含量大小可分为 3类 ,根据变异系数大小也可分为 3类 ,其中谷氨酸含量 ,丝氨酸变异系数最大。氨基酸种类特性的聚类分析结果表明 :当λ =1 7.5 0时 ,氨基酸变化可分为 4大类。发酵时间的聚类分析结果表明 :当λ=2 5 .36时 ,可分为 3大类 。

生防菌ANTI-8098A对青枯雷尔氏菌致病力的影响

经生防菌蜡状芽孢杆菌Bacillus cereus菌株ANTI-8098A处理后,番茄青枯雷尔氏菌Ral-stoniasolanacearum强致病力菌株弱化为无致病力菌株,弱化指数由0.40转变为0.86,回接番茄苗发病率由100.0%转变为0。同时,生防菌处理后的无致病力菌株在培养24h以前菌体生长能力显著增加,其中在12h时生长速率增长最快,达到了5.6倍;紫外-可见光吸收值明显下降,OD450nm由0.5740降为0.2644;高效液相离子交换色谱的表征由前峰<后峰转变为前峰>后峰;对生防菌异源蛋白的吸附由2种蛋白质(97.4kD和116.0kD)转变为1种蛋白质(97.4kD)。结果表明:ANTI-8098A对青枯雷尔氏菌具有致弱作用,并使其生理生化特性产生显著的变化。