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Nigeria has an estimated TB prevalence of 219 per 100,000 population. In 2019, Nigeria diagnosed and notified 27% of the WHO-estimated cases of all forms of TB and contributed 11% of the missing TB cases globally.To assess TB underreporting by type and level of health facility (HF), and associated factors in Lagos State, Nigeria.Quantitative secondary data analysis of TB cases was conducted in 2015. χOverall, 2,064 persons with bacteriologically confirmed TB (15.5%) were not matched to patients in sampled TB registers. Treatment status was unknown for 86 cases (IQR 55-97) per LGA. LGAs with higher case-loads had higher proportions of cases with unknown TB status. Discrepant reporting of treated TB was also common (60% HFs). Primary-level TB treatment facilities and unengaged private facilities were less likely to notify.There was TB under-reporting across all types and levels of HFs and LGAs. There is a need to revise or strengthen the process of supervision and data quality assurance system at all levels.Le Nigeria a une prévalence de la TB estimée à 219 pour 100 000 habitants. En 2019, le Nigéria a diagnostiqué et notifié 27% des cas estimés par l’OMS de toutes les formes de TB et a contribué à 11% des cas de TB manquants dans le monde.Évaluer la sous-déclaration de la TB par type et niveau d’établissement de santé (HF), et les facteurs associés dans l’État de Lagos, au Nigeria.Une analyse quantitative des données secondaires des cas de TB a été réalisée en 2015. Le test χDans l’ensemble, 2 064 personnes ayant une TB confirmée par épreuve bactériologique (15,5%) n’ont pas été appariées à des patients dans les registres de TB échantillonnés. Le statut de traitement était inconnu pour 86 cas (IQR 55–97) par LGA. Les LGA ayant un plus grand nombre de cas avaient une plus grande proportion de cas dont le statut de traitement était inconnu. La déclaration discrète de la TB traitée était également fréquente (60% des HF). Les établissements de traitement de la TB de premier niveau et les établissements privés non engagés étaient moins susceptibles de faire des déclarations.Il y avait une sous-déclaration de la TB dans tous les types et niveaux d’HF et de LGA. Il est nécessaire de réviser ou de renforcer le processus de supervision et le système d’assurance qualité des données à tous les niveaux.

Objective The carbon, titanium, and oxygen levels on titanium implant surfaces with or without ultraviolet (UV) pretreatment were evaluated at different wavelengths through X-ray photoelectron spectroscopy (XPS). Materials and Methods This interventional experimental study was conducted on nine Dio UFII implants with hybrid sandblasted and acid-etched (SLA) surface treatments, divided equally into three groups. Control group A samples were not given UV irradiation, while groups B and C samples were given UVA (382 nm, 25 mWcm2) and UVC (260 nm, 15 mWcm2) irradiation, respectively. The atomic ratio of carbon, titanium, and oxygen was compared through XPS. Results Mean carbon-to-titanium ratio and C1 peaks considerably increased in Group A compared to those in experimental Groups B and C. The intensity of Ti2p and O1s peaks was more pronounced for group C compared to that for groups A and B. Conclusions Although the decrease in surface hydrocarbons was the same in both UV-treated groups, the peak intensity of oxygen increased in the UVC-treated group. Thus, it can be concluded that compared with UVA irradiation, UVC irradiation has the potential to induce more hydrophilicity on SLA-coated implants.

Structural failure can be prevented if the damage in the structure is detected at its onset and appropriate retrofitting carried out. Towards this end, this paper presents a vibration-based technique, using only the first vibration mode, for predicting damage and its location and severity in steel beams that are important structural components in buildings and bridges. For single damage scenarios, the modal strain energy based damage index β was capable of detecting, locating and quantifying damage. For multiple damage scenarios, Artificial Neural Network incorporating β as the input layer was used. This research used computer simulations supported by limited experiments. Damage intensity was specified as a percentage reduction in stiffness compared to that at first yield. The procedure is illustrated through several numerical examples and the results confirm the feasibility of the method and its application in preventing structural failure. Keywords: Damage prediction, Failure prevention, Vibration based technique, Modal strain energy, Artificial Neural Network, Damage location, Damage severity, Damage index, Damage scenarios.

The contribution to global CO2 emissions from concrete production is increasing. In this paper, the effect of concrete mix constituents on the properties of concrete and CO2 emissions was investigated. The tested materials used 47 mixtures, consisting of ordinary Portland cement (OPC) type I, coarse aggregate, river sand and chemical admixtures. Response surface methodology (RSM) and particle swarm optimisation (PSO) algorithms were employed to evaluate the mix constituents at different levels simultaneously. Quadratic and line models were produced to fit the experimental results. Based on these models, the concrete mixture necessary to achieve optimum engineering properties was found using RSM and PSO. The resulting mixture required to obtain the desired mechanical properties for concrete was 1.10-2.00 fine aggregate/cement, 1.90-2.90 coarse aggregate/cement, 0.30-0.4 water/cement, and 0.01-0.013 chemical admixtures/cement. Both methods had over 94% accuracy, compared to the experimental results. Finally, by employing RSM and PSO methods, the number of experimental mixtures tested could be reduced, saving time and money, as well as decreasing CO2 emissions. La contribución a las emisiones globales de CO2 debidas a la producción de hormigón está aumentando. En este trabajo, se investigó el efecto de los componentes de la mezcla de hormigón en las propiedades del mismo y las emisiones de CO2. Los materiales estudiados fueron 47 mezclas, que consistieron en cemento Portland ordinario (OPC) tipo I, árido grueso, arena de río y aditivos químicos. Se utilizaron algoritmos de metodología de respuesta de superficie (RSM) y optimización de nube de partículas (PSO) para evaluar los componentes de la mezcla a diferentes niveles simultáneamente. Se elaboraron modelos cuadráticos y lineales para ajustar los resultados experimentales. Basándose en estos modelos, utilizando RSM y PSO, la mezcla de hormigón logró propiedades óptimas de ingeniería. La mezcla resultante requerida para obtener las propiedades mecánicas deseadas para el hormigón fue de 1.10-2.00 árido fino / cemento, 1.90-2.90 árido grueso / cemento, 0.30-0.4 agua / cemento y 0.01-0.013 aditivos químicos / cemento. Ambos métodos tuvieron más del 94% de precisión, en comparación con los resultados experimentales. Finalmente, al emplear los métodos RSM y PSO, el número de mezclas experimentales probadas podría reducirse, ahorrando tiempo y dinero, así como disminuyendo las emisiones de CO2.

This paper proposes an optimized damage identification method in beam-like structures using genetic algorithm (GA) without baseline data. For this purpose, a vibration-based damage identification algorithm using a damage indicator called ‘Relative Wavelet Packet Entropy’ (RWPE) was implemented to determine the location and extent of damage. The procedure does not require vibration signals from an undamaged structure because the method of comparing signals from different locations in the existing state was found to be effective. To ameliorate the algorithm, GA was utilized to identify the best choice for “mother wavelet function” and “decomposition level” of the signals by means of the fundamental fitness function to optimize the algorithm. This resulted in the high accuracy of the damage identification algorithm. In addition, this method has eliminated the difficulties in selecting the type of mother wavelet function for damage identification purposes. To investigate the robustness and accuracy of the proposed method, numerical examples and experimental cases with different damage depths were considered and conducted. The results demonstrated that the proposed method has great potential in the identification of damage location and depth of cut in beam-like structures since it does not require the recorded data from an undamaged beam as a baseline for damage detection. Moreover, the relationship between damage location and depth of damage has been evaluated and results showed that the algorithm can be applied to actual structures.

There are several issues that present in conventional sensor including its accuracy, safety, durability and RF effect. These issues could be minimized with the implementation of fiber optic sensor. This project is to design and implement optical sensor using FBG for various temperature and liquid density sensing. The FBG sensor was submerged in liquid substances to determine the sensing conditions. The available pigtail was connected to the circulator, 1550nm laser source and optical spectrum analyzer (OSA). The data regarding temperature and density sensing captured from OSA were observed and analyzed. It is found that the relationship between the change in temperature and the change in wavelength is virtually linear in both environments making FBG a good candidate for sensing temperature.

Nearly 280 kilotons of polystyrene (PS) waste being discarded yearly in Malaysia. Banning usage of PS food packaging aims to minimize this “white pollution”. However, the existing PS waste volume remains the same despite the termination of PS production. Therefore, this study has investigated the optimization of biodegradation of PS using isolated strain Bacillus aryabhattai as an alternative solution to the biodegradation of recalcitrant plastic. The effect of pH and temperature as independent variables were studied at three levels each (pH: 6, 7.5 and 9, temperature: 25 °C, 35 °C and 45 °C) under the designation by three level-factorial and analysed using response surface methodology (RSM) by Design Expert Version 10.0. The biodegradation activity of Bacillus aryabhattai was quantified using simple colorimetric method. Bacillus aryabhattai was inoculated on the dye PS-film and incubated under designed conditions. As a result of biodegradation, the entrapped methylene blue dye was released and measured photometrically. Optimum conditions for the highest reading of blue dye absorbance were obtained at pH 9 and temperature of 25ºC with the desirability of 75.9%. This study provides significant information on the biodegradation activity of Bacillus aryabhattai for future research that can be applied in waste management.

This work examined sonocatalytic degradation of caffeine in the presence of CeO2 prepared by hydrothermal method. Several characterization techniques were used to study the CeO2 including TEM, XRD and BET method. Effects of various parameters such as pH, initial concentration of caffeine and dosage of CeO2 were investigated. This study also examined the reusability of CeO2. Results showed that the CeO2 had mixed shapes of crystallites consisting of rods and cubes with the specific surface area (Sbet) and pore volume of 126.63 m2/g and 0.4898 cm3/g, respectively. About 95.5% of caffeine degradation was achieved under the best parameter conditions i.e. at pH of 7.5, 5.0 mg/L of initial concentration of caffeine and 1.0 g/L of CeO2 dosage within 150 min. It was also revealed that the operating parameters played major roles in caffeine degradation efficiency. In addition, the CeO2 were quite stable since the efficiency of caffeine degradation achieved in the third cycle was 81.4%.

Galvanic coupling method is one of the methods introduced in intra-body communication (IBC). IBC uses human body to as the communication medium for data transmission. In this paper, the investigation focuses on signal attenuation performance across knee joint using the galvanic coupling analysis. The signal attenuation was determined by implementing the galvanic coupling analysis at specific knee flexion angle. The galvanic analysis initiated by deciding the operating frequency in between 40 to 60 MHz in order to analyze the signal attenuation between the knee flexion angles. This paper found that the lowest signal attenuation at the operating frequency was 47.25dB, while the highest one was 52.63dB where the knee flexion angle is 0o and 155o respectively. It was concluded that the signal attenuation decrease with the increasing of knee joint existence at the specific flexion angle. However, a wider experiment must be conducted for various data that will correspond to signal attenuation for various influenced human data characteristics.

Damage in a structure is defined as changes to its geometric and material properties, leading to a reduction in the structural stiffness which negatively affects the performance of the structure. Reduction in the structural stiffness produces changes in the modal parameters such as the natural frequencies and mode shapes. Artificial neural networks (ANNs) have been applied extensively in recent years due to their excellent pattern recognition ability that is useful for structural damage identification purposes. In this paper, ANNs based damage identification techniques were developed and applied for damage localization and severity identification in I-beam structures using dynamic parameters. Experimental modal analysis and numerical simulations were applied to generate dynamic parameters of the first five flexural modes of structures. In damage identification using ANNs, five individual networks corresponding to mode 1 to mode 5 were trained, and then a method based on neural network ensemble was proposed to combine the outcomes of the individual neural networks into a single network. The ensemble network has the advantages of all the individual networks from different vibrational modes. The results showed that ensemble neural networks have a strong potential for structural damage identification.

Watershed Conditions (DAS) Limboto has faced seriously problems of highly rates of erosion, sedimentation, spread of critical land, shift functions of forests and rarity quality water of river as a resutt of floods that always happen, water scarcity and the silting up of Lake Limboto. Therefore, the research has conducted as an integral part ofan effort to develop a model ofintegrated watershed management through mechanisms of payments for environment services (PES) and identify institutional forms. Through Valuation Method and Dynamic System ver.2.5 with 84 people of sample is found that preserving watershed area of Limboto will manage by integrated watershed management through the mechanisms of Payments for Environmental Services (PES) has potential to do in light of community participation and willingness to maintain the forest while maintaining the sustainability of the future of Environment and to proven society of social-and economic matters as has showed by analysis ofdynamic systems.

This study presents and reviews the technical literature and previous studies for the past three decades on structural damage identification using ANNs and measured FRFs as inputs. Much of the previous studies have used modal parameters to ascertain the success of damage identification. However, significant information may not be properly represented through the application of modal parameters. With this in mind, the direct use of frequency domain data in terms of the Frequency Response Functions (FRFs) seems more appropriate. Recent studies indicate that ANNs can be trained on measured FRFs of healthy and damaged models of structure to assess the condition of the structure. According to this review, it is clear that there have been numerous studies which have gone on to apply the ANNs on FRF data of structures in the field of damage identification and it has been shown that ANNs using FRFs can provide several advantages over the modal parameters and damage identification has subsequently become much improved.

This study deals with a proposed mix design method for SCC utilizing different properties of coarse aggregate. The work was conducted in three phases, i.e. paste, mortar and concrete to facilitate the mix design process. Initial investigation on cement paste determined the basis for water cement ratio and superplasticizer dosage for the concrete. For the study on mortar, metakaolin (MK) as pozzolan was used at replacement levels of 5%, 10%, 15%, and 20% by weight of cement. Self compactability of mortars was obtained by adding suitable materials such as mineral admixtures and superplasticizer which provided a sufficient balance between flowability and viscosity of the mix. The optimum MK replacement level for cement was 10% from the viewpoint of workability and strength. Flowability of mortar decreased with the use of metakaolin. Moreover, strength of mortar increased when the optimum replacement level of pozzolan was used. Different fresh concrete tests were adopted. The results obtained for fresh concrete properties showed that flowability of concrete increased with increase flowability of mortar. The mixes which contained coarse aggregate with lower volume, small size, and continuous grading affected positively the fresh properties of SCC. Finally, the mix design method used was successful in producing SCC with different coarse aggregate properties.

In this paper, fly ash and metakaolin as pozzolan while limestone powder and kaolin as filler material were used at replacement levels of 5%, 10%, 15%, and 20% by weight of cement and sand, respectively. The effects of these powders on the fresh property of mortar mixes were studied and reported. Superplasticizer dosages were determined from flow test on cement paste and mortar with different powder content. A total of 33 mixes were prepared, mixed, and tested. The mini slump cone and mini V-funnel box tests were used to assess the flowability of the fresh mortar. In addition, the effect of mineral admixture on setting time of the mixes was also evaluated. In this study, the optimum dosage of superplasticizer was determined based on the desired flowability for self compactability. Superplasticizer at higher dosages than optimum reduced the stability due to bleeding. The results confirmed the role of the mineral powders in determining the desired stability and the flowability of mortar mixes which is crucial for self compacting concrete.

The recent economic climate, impact of government regulation, and new market trends has impacted the catalyst designers to improve the performance of catalyst. To achieve this goal, a series of experiments were conducted to focus on the influence of Ga and Re addition on the catalytic activity of Pt–Re/Al2O3 naphtha reforming catalysts. To supported γ-Al2O3 the Ga-Re-Pt prepare by using incipient wetness impregnation method. Many characterization tests are used such as scanning electron microscopy, temperature programmed desorption, X-ray diffraction and BET surface area. The liquid product yield tested by PONA method. In this study the benzene content is used as main performance criteria throughout many experiments performed at different liquid hourly space velocity, hydrogen/ hydrocarbon ratios and different operating temperature. According to the catalyst characterization tests the coimpregnation method showed good result in term of performance and properties. The catalyst exhibited good liquid product distribution and significant minimization of benzene content.

The strengthened effectiveness and the performance capacity of repaired Reinforced Concrete (RC) structures with Carbon Fibre Reinforced Polymer (CFRP) sheets is dependent on the properties of the adhesive interface layer. Adhesive material requires a specific setting time to achieve the maximum design capacity. Adhesive producer provides technical data which demonstrates the increase with time of the capacity, up to the maximum. The aim of this study is to investigate the effect of the adhesive setting time on the modal parameters as an indication of the effectiveness of CFRP on repaired RC beams. Firstly, datum modal parameters were determined on the undamaged beam and subsequently the parameters were obtained when damaged was induced on the RC beam by application of load until the appearance of the first crack. Finally, the RC beam is repaired with externally bonded CFRP sheets, and modal parameters are once again applied after 0.5, 1, 2, 3, 5, 8, 11, 15 and 18 days. The comparison is made with the data based on half day results in order to monitor the change in the modal parameters corresponding to the adhesive setting time. The modal parameters where used as indicators for the effectiveness of CFRP are affected by the adhesive time as shown in this study. Results are compared with the adhesive technical data provided by the adhesive producer.

The performance of structures such as bridges, machine foundations and base isolated buildings are very much affected by the condition of their elastic bearing supports, which eventually deteriorate due to wear and tear or which can be damaged during the service life of the structure. In this study, the dynamic parameters, namely natural frequencies and mode shapes are used to detect the deterioration of the elastic bearing supports of a simply supported bridge girder. For this purpose, force vibration testing was conducted on a reinforced concrete bridge girder supported at the ends by rubber bearings to simulate the actual conditions in a bridge deck. Three different levels of deteriorations were investigated namely that of no deterioration, partial deterioration, and full deterioration, whereby rubber with different stiffness was used to simulate the different deterioration levels. Vibration data were obtained for two cases i.e. an undamaged girder and a damaged girder after being subjected to a load exceeding its service limit for flexure. A direct relationship was observed between the dynamic parameters and the elastic bearing stiffness. Based on the results obtained in this study, the natural frequency of mode 3 is a good indicator of the deterioration in elastic bearing support conditions while mode 1 is the most sensitive to changes in support conditions. The Modal Assurance Criteria (MAC) index can be a useful indicator to identify different causes of deterioration in the structural system. In order to confirm and verify the observations, further tests were conducted on a different beam with more deterioration levels in the elastic bearing stiffness. The results support the deductions made regarding MAC and bending frequencies.

This study presents the potential energy saving, life cycle cost analysis and payback period of the lighting system in campus buildings of the University of Malaya, Malaysia. The survey results indicate that almost 90% of the lighting system at the University Malaya campus consists of fluorescent lamp. Cost benefit analysis of retrofitting with more efficient lighting system in terms of potential energy saving, life cycle cost analysis and payback period have been conducted. Comparison of existing and retrofitting of lighting system based on the energy consumption is presented. From the analysis, it can be concluded that by using energy efficient lighting system will save a significant amounts of energy and cost, and also indirectly reducing emission.

Self Compacting Concrete (SCC) is new type of concrete that posse's property of high flow ability, passing ability and stability. To achieve SCC, many factors must be investigated. Coarse aggregate is one of these factors that have a significant influence on SCC. This paper presents the coarse aggregate properties such as maximum size, texture and type of coarse aggregate that have a direct effect on achieving SCC. Three types of coarse aggregate are used, namely crush gravel, uncrushed gravel and crush limestone. To determine the workability, different test methods are adopted such as slump flow, V-funnel, L-box and U-box test. It was found that by increasing the maximum size of coarse aggregate, flowability and passing ability reduced. In addition it was observed that when uncrushed gravel was used in the concrete mixture, flow ability, passing ability and segregation resistance increased as compared to concrete with crushed gravel. Furthermore, the inclusion of 10% HRM as a partial replacement by weight of cement leads to reduce flow ability and increase viscosity. The compressive and flexural strengths and modulus of elasticity was measured. It was noticed that concrete mixes prepared with crushed limestone showed higher strengths and modulus of elasticity than concrete mixes prepared with crushed and uncrushed gravel. In addition, lower maximum size of coarse aggregate leads to higher strengths compared to higher maximum size of coarse aggregate in SCC mixes.

The effects of far distant earthquakes felt in regions with low and moderate seismicity has increased markedly over the last decade. Henceforth fragility curves in this study are to indicate whether buildings are safe to enter or not after an earthquake event occurring more than 300 km away. The probability of light, moderate and severe damage states occurring on two and four storey reinforced concrete buildings up to a peak ground acceleration of 0.2 g were predicted. The building models were constructed using finite element software based on eight node brick elements with three degrees of freedom at each node. The analysis was carried out using a dynamic response spectrum to calculate the peak inter-storey drift ratios. For the development of fragility curves, the results were collated following a log-normal mean distribution. The results showed that light damage is likely to occur with a probability of over 10% within a 50 year period, while the existing record is unlikely to cause structural damage. The fragility curves were comparable to those for RC moment resisting frames obtained by (Rossetto and Elnashai 2003) at a lower drift limit, with approximately 2% of inter-storey drift ratio.

Investigation of the influence of the differences in the support conditions on the dynamic parameters are presented in this study. Bridge girders are usually supported by elastic bearings and suffer deterioration during the service life of the bridge. Early stages of deterioration of the elastic bearing occur with decrease in its stiffness. Advance stages of deterioration causes total damage of the elastic bearing, whereby the bridge girder will be supported directly on the structural element below it. The deterioration can occur on one or both sides of the supports. In order to study the effect of this phenomenon, experiments were conducted on a simply supported beam supported on elastic rubber pads with different stiffness as well as on steel supports. The undamaged support condition was simulated by using new rubber pads with stiffness of 10MN/m. The damage support conditions were represented by using old rubber pads with stiffness of 3 MN/m and using steel supports to simulate the case of total deterioration of the rubber bearing pads. Natural frequencies and mode shapes were obtained from modal testing and compared using of Modal Assurance Criteria MAC. The results showed a direct relationship between the support stiffness and the natural frequencies and mode shape. The first bending mode was most sensitive to the changes in support stiffness followed by Mode 2. It was also observed that the other modes had similar but lower sensitivity to the state of deterioartion of the supports.

Sea level rise due to climate change have a profound impact on low lying coastal zones. The objective of this study is to identify the potential of coastal inundation area due to Sea Level Rise (SLR) along of Cherating to Pekan coast. The shoreline of Pahang has been undergoing severe erosion and inundated by sea water in some locations, hence affects the socio-economy and the livelihood of the coastal communities. Numerical modelling using the MIKE 21 FM software was done to predict coastal inundation for the years 2020 and 2080 along the Cherating to Pekan shoreline by using the condition for the year 2017 as the baseline. The results of the statistical analysis of this numerical model is congruous with the measured data, such as tide, current, and wave direction. The results show that about 17 to 22% of the Cherating to Pekan shoreline is at risk of being inundated due to the projected SLR for the years 2020 and 2080. The map for projected inundation shows that the infrastructure located in the 1km buffers zone from the shoreline will be affected by the sea level rise. This information could be of benefit to all parties involved in ensuring effective coastal management and making preparation and plan to and protect the coastal areas from the potential impacts of climate change and future disasters.

Coastal zones are one of the major significant areas for human activities and infrastructure growth. As known as dynamic area, thus the important to do study comprehensively in order to avoid damage due to climate change and more on. The main tool to assess these system is numerical modelling of the coast to predict the coastal environment characteristics. Thus, this study simulates the hydrodynamic characteristics at Selangor coast by applying a numerical modelling of MIKE 21 software based on flexible mesh grids. The objective of this study is to stimulate and verify the best estimation of Manning values around the Selangor coast. This study was carried out to evaluate the accuracy of the simulation results, statistical analysis method namely Root Mean Square Error (RMSE) is calculated to compare the observed and simulated results. The device of Acoustic Wave and Current Profiler (AWAC) was installed and used to record the water level, current direction and current speed at two stations near shore at Carey Island. Most of the hydrodynamic parameter in this study between observed and simulated were achieved requirement standard error for hydraulic study by Department of Irrigation and Drainage (DID) guidelines on year the 2013. The outcome of this study recommend that the bed resistant is significant factor in the hydrodynamic simulation using MIKE 21 Hydrodynamic FM.

The rising cost of construction in developing countries like Malaysia has led concrete experts to explore alternative materials such as coconut shells which are renewable and possess high potential to be used as construction material. Coconut shell powder in varying percentages of1%, 3% and 5% was used as filler material in concrete grade 30 and evaluated after a curing period of 7 days and 28days respectively. Compressive strength, water absorption and carbonation tests were conducted to evaluate the strength and durability of CSP concrete in comparison with normal concrete. The test results revealed that 1%, 3% and 5% of CSP concrete achieved a compressive strength of 47.65MPa, 45.6MPa and 40.55% respectively. The rate of water absorption of CSP concrete was recorded as 3.21%, 2.47%, and 2.73% for 1%, 3% and 5% of CSP concrete respectively. Although CSP contained a carbon composition of 47%, the carbonation test showed that CSP no signs of carbon were detected inside the concrete. To conclude, CSP offers great prospects as it demonstrated relatively high durability as a construction material.

Plantar fascia is a ligament found in human foot structure located beneath the skin of human foot that functioning to stabilize longitudinal arch of human foot during standing and normal gait. To perform direct experiment on plantar fascia seems very difficult since the structure located underneath the soft tissue. The aim of this study is to develop a finite element (FE) model of foot with plantar fascia and investigate the effect of the surface hardness on biomechanical response of plantar fascia during running. The plantar fascia model was developed using Solidworks 2015 according to the bone structure of foot model that was obtained from Turbosquid database. Boundary conditions were set out based on the data obtained from experiment of ground reaction force response during running on different surface hardness. The finite element analysis was performed using Ansys 14. The results found that the peak of stress and strain distribution were occur on the insertion of plantar fascia to bone especially on calcaneal area. Plantar fascia became stiffer with increment of Young's modulus value and was able to resist more loads. Strain of plantar fascia was decreased when Young's modulus increased with the same amount of loading.

This paper describes the determination of the location of damage due to single cracks and due to honeycombs in RC beams using mode shape derivatives from modal testing. The cracks were induced by application of point loads at predetermined locations on the RC beams. The load was increased in stages to obtain different crack heights to simulate the extent and severity of damage. Experimental modal analysis was performed on the beams with cracks prior to and after each load cycle, on a control beam, and beams with honeycombs. The mode shapes and the eigenvectors were used to determine the location of damage. The indicator | λ 4 | was obtained by rearranging the equation for free transverse vibration of a uniform beam, and applying the fourth order centered finite-divided difference formula to the regressed mode shape data. The equation is an eigenvalue problem, and the value of | λ 4 | will be a constant. Differences in the values indicate stiffness change, and the affected region indicates the general area of damage. Analysis of results using | λ 4 | was able to indicate the general region of damage, the exact location being around the center of the region. Curve fitting with Chebyshev series rationals onto the mode shape also highlighted points of high residuals around the region of damage. The proposed algorithm on the mode shape can form the basis of a technique for structural health monitoring of damaged reinforced concrete structures.

The concept of efficiency can be used for comparing the relative performance of various pozzolans when incorporated into concrete. In this paper, an alternative approach for the evaluation of efficiency factor k of a pozzolanic material has been introduced. The method, developed following Abrams strength-W/C ratio rule, calculates efficiency in terms of relative strength and cementitious materials content. The advantage of this method is that only two mixtures are required to determine the k factor of a specific mixture. A laboratory investigation on silica fume (SF) and metakaolin (MK) concrete found that the computed efficiency factors varied with pozzolan type, replacement level and age. At 28 days, the k values ranged from 1.6 to 2.3 for MK and 2.1 to 3.1 for SF mixtures, while at 180 days, the k values varied from 1.8 to 4.0 for MK and 2.4 to 3.3 for SF mixtures. Generally, the k factors increased with age but declined with higher pozzolanic content. It was also observed that change in W/CM ratio from 0.33 to 0.27 did not significantly affect the resultant efficiency factors. © 2004 Elsevier Ltd. All rights reserved.

A mathematical model is presented for estimating compressive strength of high-strength concrete incorporating pozzolanic materials, based on the strength of a control ordinary Portland cement (OPC) concrete made with similar mixture characteristics and curing history. In this study, metakaolin (MK) and silica fume (SF) were used as cement replacement materials at 5%, 10%, and 15% by mass. Water/cementitious materials (w/cm) ratios varied from 0.27 to 0.33, and strength testing was conducted up to an age of 180 days. It was found that the strength of a pozzolanic mixture could be related to the strength of its equivalent control by a linear function. Key parameters involved in the model are the pozzolanic and dilution factors, which can be correlated to the pozzolan content in the mixture. The study concludes that the accuracy of the model increases with concrete age. At ages 28 days and above, 97% of the estimated strengths are within ±5% of the actual value. © 2004 Elsevier Ltd. All rights reserved.

An experimental investigation to study the effect of general corrosion on the modal parameters of reinforced concrete beams was conducted. The full scale beams were subjected to reinforcement corrosion until an appreciable amount of steel corrosion damage was introduced. The states of damage in the test beams were assessed through measurement of crack width and spalling. Modal tests were performed on the test beams after corrosion damage and the modal parameters extracted were compared against that from a control beam. The results obtained showed changes in the modal parameters especially natural frequencies and damping ratio. The trend in the measured natural frequencies was sensitive to the deterioration state of the beams. Changes in modal damping ratio for the transfer function method and the normal mode method were also observed. However, the changes were inconsistent with the changes in natural frequencies, as concluded by previous researchers, but a trend was observed which was rather mode dependent. Furthermore, the load carrying capacity of the beams was determined through static load test and the results were correlated with the state of corrosion damage and changes in the modal parameters. This investigation provides further insight on the use of modal parameters to detect damage in structural concrete elements which can be useful for structural appraisal and assessment purposes when applied to full scale structures.

Structures are exposed to damage during their service life which can severely affect their safety and functionality. Thus, it is important to monitor structures for the occurrence, location and extent of damage. Artificial neural networks (ANNs) as a numerical technique have been applied increasingly for damage identification with varied success. ANNs are inspired by human biological neurons and have been used to model some specific problems in many areas of engineering and science to achieve reasonable results. ANNs have the ability to learn from examples and then adapt to changing situations when sufficient input-output data are available. This paper presents the application of ANNs for detection of damage in a steel girder bridge using natural frequencies as dynamic parameters. Dynamic parameters are easy to implement for damage assessment and can be directly linked to the topology of structure. In this study, the required data for the ANNs in the form of natural frequencies will be obtained from experimental modal analysis. This paper also highlights the concept of ANNs followed by the detail presentation of the experimental modal analysis for natural frequencies extraction. Key words: Artificial neural networks (ANNs), back propagation (BP), damage identification, natural frequency.