Structural Health Monitoring by Accelerometric Data of a Continuously Monitored Structure with Induced Damages

The possibility of determining the integrity of a real structure subjected to non-invasive and non-destructive monitoring,such as that carried out by a series of accelerometers placed on the structure,is certainly a goal of extreme and current interest.In the present work,the results obtained from the processing of experimental data of a real structure are shown.The analyzed structure is a lattice structure approximately 9 m high,monitored with 18 uniaxial accelerometers positioned in pairs on 9 different levels.The data used refer to continuous monitoring that lasted for a total of 1 year,during which minor damage was caused to the structure by alternatively removing some bracings and repositioning them in the structure.Two methodologies detecting damage based on decomposition techniques of the acquired data were used and tested,as well as a methodology combining the two techniques.The results obtained are extremely interesting,as all the minor damage caused to the structure was identified by the processing methods used,based solely on the monitored data and without any knowledge of the real structure being analyzed.The results use 15 acquisitions in environmental conditions lasting 10 min each,a reasonable amount of time to get immediate feedback on possible damage to the structure.

Combined fascia iliaca compartment block and monitored anesthesia care for geriatric patients with hip fracture: Two case reports

BACKGROUND Major hip surgery usually requires neuraxial or general anesthesia with tracheal intubation and may be supplemented with a nerve block to provide intraoperative and postoperative pain relief.CASE SUMMARY This report established that hip surgical procedures can be performed with a fascia iliaca compartment block(FICB)and monitored anesthesia care(MAC)while avoiding neuraxial or general anesthesia.This was a preliminary experience with two geriatric patients with hip fracture,American Society of Anesthesiologists status III,and with many comorbidities.Neither patient could be operated on within 48 h after admission.Both general anesthesia and neuraxial anesthesia were high-risk procedures and had contraindications.Hence,we chose nerve block combined with a small amount of sedation.Intraoperative analgesia was provided by single-injection ultrasound-guided FICB.Light intravenous sedation was added.Surgical exposure was satisfactory,and neither patient complained of any symptoms during the procedure.CONCLUSION This report showed that hip surgery for geriatric patients can be performed with FICB and MAC,although complications and contraindications are common.The anesthetic program was accompanied by stable respiratory and circulatory system responses and satisfactory analgesia while avoiding the adverse effects and problems associated with either neuraxial or general anesthesia.

Applications of Monitored Natural Attenuation in Contaminated Soil and Groundwater

Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being＇s health risks by active remediation, while the second phase aims at eliminating ecological risks by natural attenuation （NA）. Because of cost-effective and sustainable cleanup, monitored natural attenuation （MNA） and enhanced natural attenuation （ENA） have been gaining more attention recently, especially in the respects of ecological risk-oriented contaminated land management and a follow-up measure after active remediation. The uses and procedures of MNA for contaminated site cleanup and remediation in USA and EU were introduced firstly, and then possible applications of MNA in China were suggested. More developments and practices of MNA and ENA for managing contaminated sites in China are expected.

针刺联合Monitored Rehab Systems下肢智能运动训练系统对卒中偏瘫患者平衡及步行功能的影响

脑卒中是常见脑血管疾病,具有发病率高、致残率高等特点[1-2]。随着社会进步,医疗水平提升,脑卒中患者存活率增加,但大约有80%脑卒中患者会伴随运动功能障碍,其中以偏瘫为主,伴随步行能力下降、平衡协调功能障碍、运动能力下降等,严重影响患者日常生活,增加患者家庭及社会负担[3-4]。Monitored Rehab Systems为闭链训练方式,可训练患者肢体控制、肌肉协同及关节匹配度,常用于下肢功能训练。针刺是中医外治疗法。本研究旨在观察观察针刺联合Monitored Rehab Systems下肢智能运动训练系统对卒中偏瘫患者平衡及步行功能影响,报道如下。

Clopidogrel Anergy and Monitored

Clopidogrel Anergy2003 Germany Müller et at 105 patients with stable coronary artery disease using clopidogrel for PCI,about5%of patients showed no response to the drug,which is defined as platelets in the 20μmol/L ADP under the action of its aggregation only on the basis of the inhibition rate of 10%or less.These people postoperative thrombosis,showing the drug has resisters,and postoperative thrombosis related.2004 SchrPat the current

METAL ION SUBSTIUTION OF Cd_5Zn_2－METALLOTHIONEINEIN WITR CUPROUS ION MONITORED BY￣1HNMR

Rat Liver Cd5Zn2-metallothionein isoforms were titrated with cuprous ion and monitored by 1H NMR Initial replacement occurred in β-domain followed by α-domain.MT exhibited well-defined structure under 10 mole equivalents cuprous ion.

Microsurgerical treatment of PCA aneurysms via subtemporal approach monitored by microvascular Doppler(10 cases report)

Objective To summarize the clinical features of intracranial aneurysms of posterior cerebral artery (PCA) ,and the surgical approaches and operative skills to treat them . Methods The aneurysms arose from the P1 segment in 3 patients,the P2 segment in 5 patients and the P3 segment in 2 patients.

Analysis of monitored ground support and rock mass response in a longwall tailgate entry

A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia.Monitoring was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the entry.Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation,stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring site.During the passage of the first longwall, stress measurements in the rock and coal detected minor changes in loading while minor changes were detected in roof deformation.As a result of the relatively favorable stress and geological conditions, the support systems did not experience severe loading or rock deformation until the second panel approached within 10–15 m of the instrumented locations.After reaching the peak loading at about 50–75 mm of roof sag, the cable bolts started to unload, and load was transferred to the standing supports.The standing support system was able to maintain an adequate opening inby the shields to provide ventilation to the first crosscut inby the face, as designed.The results were used to calibrate modeled cable bolt response to field data, and to validate numerical modeling procedures that have been developed to evaluate entry support systems.It is concluded that the support system was more than adequate to control the roof of the tailgate up to the longwall face location.The monitoring results have provided valuable data for the development and validation of support design strategies for longwall tailgate entries.

Features of long-term health monitored strains of a bridge with wavelet analysis

This paper analyses the five years’ monitored strains collected from a long-term health monitoring system installed on a bridge with wavelet transform.In the analysis,the monitored strains are pre-processed,features of the monitored data are summarized briefly.The influences of the base functions on the results of wavelet analysis are studied simultaneously.The results show that the db wavelet is a good mother wavelet function in the analysis,and the order N should be larger than 20,but less than 46 in decomposing the monitored strains of the bridge.According to the strain variation features of concrete bridge,the proper decomposition level is 4 in the wavelet multi-resolution analysis.With the present method,the strains caused by random loads and daily sunlight can be accurately extracted from the monitored strains.The decomposed components of the monitored strains show that the amplitudes of the strains caused by random loads,daily sunlight,and annual temperature effect,are about 5 με,25 με,and 50 με respectively.The structural response under random load is smaller than the other parts.

Distribution changes of woody plants in Western Iran as monitored by remote sensing and geographical information system:a case study of Zagros forest

The status of woody plants in dry-land systems is a fundamental determinant of key ecosystem processes. Monitoring of this status plays an important role in understanding the dynamics of woody plants in arid and semi-arid ecosystems. The present study determined the dynamism of the Zagros forests in Iran using Remote Sensing and Geographic Information System techniques and statistical science. The results show that the density of trees varied from 10 to 53 % according to the physio- graphic and climatic conditions of semi-arid regions. The best and lowest correlation between vegetation indices and forest density were obtained for the global environmental monitoring index （GEMI; R2 = 0.94） and soil adjust vegetation index （R2 = 0.81）, respectively. GEMI is used to monitor land use changes over a 10-year period. Results show that 2720 ha2 of forest have been destroyed by human interference and tillage on steep slopes during this period which also resulted in the loss of the fertile soil layer. GEMI determined the areas with a biomass of trees and could normally separate border regions with low bio- mass density of trees from regions without canopy cover. The results revealed that assessment of forest and vegetation cover in arid and semi-arid arduous forest regions using satellite digital numbers and ordinary sampling is subject to uncertainty. A stratified grouping procedure should be established to increase the accuracy of assessment.

Natural and artificial landscape change in a Dutch Estuary: Partially monitored with low budget method (a study in the fourth dimension)

This study includes some aspects of the shift in the Dutch attitude in relation to water during the past millennia from defense to attack to keeping the balance(“co-evolution'). It has a special focus on the freshwater tidal part, which embraces the largest seaport of the world: Rotterdam, as well as the largest national park of the Netherlands. It reports especially about a young mans endeavor in half a century real time monitoring of some land(scape) units with simple means.

Time-varying Reliability Analysis of Long-span Continuous Rigid Frame bridge under Cantilever Construction Stage based on the Monitored Strain Data

In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state when the bridge is in construction.Among them,how to assess the safety is one of the challenges.As the continuous monitoring over a long-term period can increase the reliability of the assessment,so,based on a large number of monitored strain data collected from the structural health monitoring system(SHMS)during construction,a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory.At the same time,the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed.This method can provide basis and direction for the internal force control of this type bridge in construction process.So,it can reduce the bridge safety and quality accidents in construction stages.

Multiobjective maintenance optimization of the continuously monitored deterioration system

With the development of the monitoring technology,it is more and more common that the system is continuously monitored.Therefore,the research on the maintenance optimization of the continuously monitored deterioration system is important.The deterioration process of the discussed system is described by a Gamma process.The predictive maintenance is considered to be imperfect and formulated.The expected interval of two continuous preventive maintenances is derived.Then,the maintenance optimization model of the continuously monitored deterioration system is presented.In the model,the minimization of the expected operational cost per unit time and the maximization of the system availability are the optimization objectives.The improved ideal point method with the normalized objective functions is employed to solve the proposed model.The validity and sensitivity of the proposed multiobjective maintenance optimization model are analyzed by a numerical example.

Maintenance Management Research of a Large-span Continuous Rigid Frame Bridge Based on Reliability Assessment by Using Strain Monitored Data

When the bridge components needing maintenance are the world problem at present,and the health monitoring system is considered to be a very help­ful tool for solving this problem.In this paper,a large number of strain data acquired from the structural health monitoring system(SHMS)installed on a continuous rigid frame bridge are adopted to do reliability assessment.Firstly,a calculation method of punctiform time-dependent reliability is proposed based on the basic reliability theory,and introduced how to cal­culate reliability of the bridge by using the stress data transformed from the strain data.Secondly,combined with“Three Sigma”principle and the basic pressure safety reserve requirement,the critical load effects distribu­tion function of the bridge is defined,and then the maintenance reliability threshold for controlling the unfavorable load state which appears in the early operation stage of this type bridge is suggested,and then the combi­nation of bridge maintenance management and health monitoring system is realized.Finally,the transformed stress distribution certifies that the load effects of concrete bridges practically have a normal distribution;as for the concrete continuous rigid frame bridge with C50 strength grade concrete,the retrofit reliability threshold should be valued at 6.13.The methodology suggested in this article can help bridge engineers do effective maintenance of bridges,which can effectively extend the service life of the bridge and bring better economic and social benefits.

Monitored anesthesia care and asleep-awake-asleep techniques combined with multiple monitoring for resection of gliomas in eloquent brain areas:a retrospective analysis of 225 patients

Background:Awake craniotomy(AC)has become gold standard in surgical resection of gliomas located in eloquent areas.The conscious sedation techniques in AC include both monitored anesthesia care(MAC)and asleep-awake-asleep(AAA).The choice of optimal anesthetic method depends on the preferences of the surgical team(mainly anesthesiologist and neurosurgeon).The aim of this study was to compare the difference in physiological and blood gas data,dosage of different drugs,the probability of switching to endotracheal intubation,and extent of tumor resection and dysfunction after operation between AAA and MAC anesthetic management for resection of gliomas in eloquent brain areas.Methods:Two-hundred and twenty-five patients with super-tentorial tumor located in eloquent areas underwent AC from 2009 to 2021 in Xijing Hospital.Forty-one patients underwent AAA technique,and the rest one-hundred eighty-four patients underwent MAC technique.Anesthetic management,dosage of different drugs,intraoperative complications,postoperative outcomes,adverse events,extent of resection and motor,and sensory and language dysfunction after operation were compared between MAC and AAA.Result:There was no significant difference in gender,KPS score,MMSE score,glioma grade,type,and growth site between the patients in the two groups,except the older age of patients in MAC group than that in AAA group.During the whole process of operation,there were greater pulse pressure difference(P=0.046),shorter operation time(P=0.039),less dosage of remifentanil(P=0.000),more dosage of dexmedetomidine(P=0.013),more use of antiemetics(81%,P=0.0067),lower use of vasoactive agent(45.1%,P=0.010),and lower probability of conversion to general anesthesia(GA,P=0.027)in MAC group than that in AAA group.Blood gas analysis showed that PetCO2(P=0.000),Glu concentration(P=0.000),and PaCO2(P=0.000)were higher,but SPO2(P=0.002)and PaO2(P=0.000)were lower in MAC group than that in AAA group.In the postoperative recovery stage,compared with that of AAA group,the probability of dysfunction in MAC group at 1,3,5,and 7 days after operation was lower,which were 27.8%vs 53.6%(P=0.003),31%vs 68.3%(P=0.000),28.8%vs 63.4%(P=0.000),and 25.6%vs 58.5%(P=0.000),respectively.Conclusion:Compared with AAA,it seems that MAC has more advantages in the management for resection of gliomas in eloquent brain areas,and MAC combined with multiple monitoring such as cerebral cortical mapping,neuronavigation,and ultrasonic detection is worthy of popularization for the resection of gliomas in eloquent brain areas.

Fiber optic monitoring of an anti-slide pile in a retrogressive landslide

Anti-slide piles are one of the most important reinforcement structures against landslides,and evalu-ating the working conditions is of great significance for landslide mitigation.The widely adopted analytical methods of pile internal forces include cantilever beam method and elastic foundation beam method.However,due to many assumptions involved in calculation,the analytical models cannot be fully applicable to complex site situations,e.g.landslides with multi-sliding surfaces and pile-soil interface separation as discussed herein.In view of this,the combination of distributed fiber optic sensing(DFOS)and strain-internal force conversion methods was proposed to evaluate the working conditions of an anti-sliding pile in a typical retrogressive landslide in the Three Gorges reservoir area,China.Brillouin optical time domain reflectometry(BOTDR)was utilized to monitor the strain distri-bution along the pile.Next,by analyzing the relative deformation between the pile and its adjacent inclinometer,the pile-soil interface separation was profiled.Finally,the internal forces of the anti-slide pile were derived based on the strain-internal force conversion method.According to the ratio of calculated internal forces to the design values,the working conditions of the anti-slide pile could be evaluated.The results demonstrated that the proposed method could reveal the deformation pattern of the anti-slide pile system,and can quantitatively evaluate its working conditions.

Thermo-hydro-poro-mechanical responses of a reservoir-induced landslide tracked by high-resolution fiber optic sensing nerves

Thermo-poro-mechanical responses along sliding zone/surface have been extensively studied.However,it has not been recognized that the potential contribution of other crucial engineering geological interfaces beyond the slip surface to progressive failure.Here,we aim to investigate the subsurface multiphysics of reservoir landslides under two extreme hydrologic conditions(i.e.wet and dry),particularly within sliding masses.Based on ultra-weak fiber Bragg grating(UWFBG)technology,we employ specialpurpose fiber optic sensing cables that can be implanted into boreholes as“nerves of the Earth”to collect data on soil temperature,water content,pore water pressure,and strain.The Xinpu landslide in the middle reach of the Three Gorges Reservoir Area in China was selected as a case study to establish a paradigm for in situ thermo-hydro-poro-mechanical monitoring.These UWFBG-based sensing cables were vertically buried in a 31 m-deep borehole at the foot of the landslide,with a resolution of 1 m except for the pressure sensor.We reported field measurements covering the period 2021 and 2022 and produced the spatiotemporal profiles throughout the borehole.Results show that wet years are more likely to motivate landslide motions than dry years.The annual thermally active layer of the landslide has a critical depth of roughly 9 m and might move downward in warmer years.The dynamic groundwater table is located at depths of 9e15 m,where the peaked strain undergoes a periodical response of leap and withdrawal to annual hydrometeorological cycles.These interface behaviors may support the interpretation of the contribution of reservoir regulation to slope stability,allowing us to correlate them to local damage events and potential global destabilization.This paper also offers a natural framework for interpreting thermo-hydro-poro-mechanical signatures from creeping reservoir bank slopes,which may form the basis for a landslide monitoring and early warning system.

Coalbursts in China: Theory, practice and management

Coalburst is one of the most serious disasters that threaten the safe production of coal mines, and this disaster is particularly serious in China. This paper presents an overview of coalbursts in China since 1980s. From the "stress and energy" and "regional and local" perspectives, the achievements in the theory, practice and management of coalbursts in China are systematically summarized. A theoretical system of coalbursts has been formed to reveal the deformational behavior of coalbursts and explain the mechanism of coalbursts. The occurrence conditions of coalbursts are put forward and the critical stress is obtained. The stress index method for risk evaluation of coalbursts before mining is proposed, and the deformation localization prediction method of coalbursts is put forward. The relationship between energy release and absorption in the process of coalbursts is found, and the prevention and control methods of coalbursts, including the regional method, the local method and support, are presented. The safety evaluation index of coalburst prevention and control is put forward. The integrated prevention and control method for coal and gas outbursts is proposed. The prevention and control technology and equipment of coalbursts have also been developed. Amongst them, the distribution law of the critical stress in China coalburst mines is discovered. The technology and equipment for monitoring, prevention and control of coalbursts, as well as for integrated prevention and control of combined coalbursts and other disasters, have been developed. The energy-absorbing and coalburst-preventing support technology for roadways is invented, and key engineering parameters of coalburst prevention and control are pointed out. In China, coalburst prevention and control laws and standards have been developed. Technical standards for coalbursts are formulated, statute and regulations for coal mines are established, and regulatory documents are promoted.

Harness High-Temperature Thermal Energy via Elastic Thermoelectric Aerogels

Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great challenge.Herein,a highly elastic,flame-retardant and high-temperature-resistant TE aerogel,made of poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube(PEDOT:PSS/SWCNT)composites,has been fabricated,displaying attractive compression-induced power factor enhancement.The as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range monitoring.Subsequently,a flexible TE generator is assembled,consisting of 25 aerogels connected in series,capable of delivering a maximum output power of 400μW when subjected to a temperature difference of 300 K.This demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature pipelines.Moreover,the designed self-powered wearable sensing glove can realize precise wide-range temperature detection,high-temperature warning and accurate recognition of human hand gestures.The aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning capability.Benefitting from these desirable properties,the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring,industrial overheat warning,waste heat energy recycling and even wearable healthcare.