Mechanical and self-sensing properties of concrete reinforced with carbon nanofibres

Concrete is extensively used in the construction industry, but the formation and development of cracks undermines the integrity of concrete structures. Improving the mechanical properties of concrete and developing efficient health monitoring of structures are thus essential tasks to be tackled. The research described in this paper was concerned with the effect of nanofibres on the mechanical properties of concrete as the use of nanofibres such as carbon nanofibres (CNFs) within cementitious materials has been found to be effective in enhancing the mechanical properties of concrete as well as its sensing ability. Most previous works have focused on evaluating the microstructure and mechanical behaviour of nano-reinforced mortar. Only a few studies have attempted to evaluate the mechanical and sensing properties of nano-reinforced concrete made with coarse aggregates. The objective of this work was to fill this gap in the literature by evaluating the mechanical and self-sensing properties of CNF-reinforced concrete (CNFRC). Material tests were conducted on CNFRC cylinders and beams in order to determine the full compressive, tensile and flexural constitutive behaviour, including the post-peak response, as well evaluating the self-sensing capability. The results obtained are valuable for analysis and design of large critical infrastructures employing CNFRC

Determination of LC50 of copper in Litopenaeus vannamei

We determined the LC50 of copper (as CUSO_4) and it's Maximum Allowable Concentration (MAC) for Litopenaeus vannamei. The study was performed in 2003 for which bioassays were used for acute toxicity tests in a period of 96 hours during which water parameters such as water temperature, pH, dissolved oxygen, hardness, alkalinity were also measured. Ten treatments and three replicates for each treatment were used. A LC50 of 86.71, 27.28, 7.98 and 3.90mg/1 and also Maximum Allowable Concentration of 8.671, 2.728, 0.798 and 0.390mg/1 were determined at 24, 48, 72 and 96 hours post exposure. Results showed that L. vannamei is relatively resistant to copper. Hence, short period application of copper to white shrimp farms for controlling algal bloom is judged harmless to the fish

Structural performance of nano concrete-steel sandwich wall

Concrete is extensively used in the construction of infrastructures, however formation and development of cracks undermines the integrity of the structure. Thus, both improving the mechanical properties of this construction material as well as structural health monitoring of structures are essential tasks to be tackled. The research covered in this thesis is concerned with mechanical properties of carbon nanofiber reinforced concrete and the effect of this type of concrete on structural performance of the composite steel-concrete sandwich (SC) system. The use of nanofibers such as Carbon Nanofiber (CNF) within cementitious materials is found to be effective in enhancing the mechanical properties of the cementitious material as well as enhancing the sensing ability of the cementitious composites. Despite the abundant experimental work on nanofiber reinforced cementitious composites by researchers, their use within concrete has not been fully addressed. Therefore, the significance of this research is to assess mechanical properties of nanoreinforced concrete along with its sensing capability. The steel-concrete sandwich system consists of thick concrete core with exterior steel faceplates acting as reinforcement. The steel faceplates are anchored to the concrete core with shear connectors. This study presents the structural performance of the SC element with fiber reinforced concrete (FRC) core using both single fiber and hybrid fiber (i.e. consisting of two types of fibers) in the core. For this study carbon nanofiber and steel fiber, which is conventionally used in practice, are used for the FRC. Static tests were conducted on eight SC beams with different concrete types. In addition to studying the structural performance of the SC element with fiber reinforced concrete, the self-sensing capability of beams with CNF reinforced concrete core were assessed. Furthermore, finite element analysis was conducted to evaluate the effect of some design parameters on the behaviour of SC element. The outcome of this thesis enhances the current knowledge on the use of nanofibers in civil engineering industry as nano reinforcement and nanofilaments within cementitious materials, typically concrete and it will contribute to the understanding of the effect of CNF on concrete mechanical properties. This research laid the groundwork for additional in-depth study on using carbon nanofiber reinforced concrete within structural members and determination of their effect as nanofilaments on the self-sensing capability of the structural element

Differential gene-expression of metallothionein 1M and 1G in response to zinc in sertoli TM4 cells

Background: Zinc (Zn) as an important trace element is essential for testicular development and spermatogenesis. Molecular mechanism of Zn action in the reproductive system may be related to metal binding low-molecular weight proteins, metallothioneins (MT). Our objective was to determine the effect of Zn on two important isoforms of MT, MT1M and MT1G genes expression on testicular sertoli cells. Methods: Cultured sertoli TM4 cells were exposed to different concentrations of Zn at different time points. Cellular uptake of Zn was tested using flame atomic absorption spectrometry. The cellular viability and gene expression were assessed by MTT and real-time PCR methods, respectively. Results: The treated cells resulted in higher Zn concentration and cellular viability. The expression of MT1M and MT1G genes in the treated cells were greater than those of the untreated cells (P<0.05). In the high dosage treated group (100 and 500 μM), Zn concentration and expression of MT1M and MT1G genes increased three h after treatment; MT1G gene expression increased more at sixth h. At 18th h of treatment, the expression of both genes especially MT1G, increased dramatically while Zn concentration decreased. Conclusion: Since the increase of MT1G mRNA was coincident with cellular Zn level, it seems that MT1G has a more prominent role than MT1M in the homeostasis of Zn. In addition, Zn at dosage of 50 μM (pharmacologic concentration) may protect cells by increasing the expression of MT genes at longer periods

Seismic evaluation of reduced web section (RWS) moment connections

This paper presents a study of fully-fixed (welded) perforated beam-to-column connections, used as strengthening techniques to code-deficient steel frames. The effect of reduced web sections (RWS) using non-standard novel opening shapes on of variable depths and positions is investigated. The improvements on the structural behaviour foreshadow the enhancements gained using such perforated members. It is concluded that using large isolated perforations is an effective way of improving the behaviour of connections enhancing their ductility, rotational capacity and their energy dissipation capacity. Moreover, the connections with novel openings outperform the conventional ones; therefore they can be suitably used in the seismic-resistant design of steel frames

When does it pay off to use electricity demand data with rich information about households and their activities? A comparative machine learning approach to demand modelling

Energy demand modelling has been widely applied in various contexts, including power plant generation, building energy simulation and demand-side management. However, it is still an ongoing research topic in terms of the choice of modelling method, feature engineering for data-driven methods, the application contexts and the type of data used. In the residential sector, survey-based and meter-based approaches are categorised according to the type of input data used, i.e. the activity records from the time use survey and energy consumption from meters respectively. These two paradigms are not necessarily easy to combine, which warrants the questions of when one may be preferred over the other and whether they need to be combined despite the significant data requirements. Other details also have a huge impact on the data structure and performance of the energy demand model, including the choice of influential factors, the historical time window of factors selected, the split between training and test data, and the choice of machine learning (ML) algorithm. There is a lack of comparative research to guide researchers and practitioners in developing energy demand modelling capability, specifically as it pertains to these issues. This study analyses three groups of test scenarios in a multi-household residential context based in the UK. Six ML algorithms (LightGBM, Random forest, ANN, SVM, KNN and LSTM), with eight sets of various influential features, at four different historical time window widths and two train-test splits were compared. An appropriate methodology was designed to capture the temporal impact of activities on energy demand and represent the overlap and interaction of activities. The results show that the combination of meter-based and survey-based energy demand models performs better in terms of modelling accuracy and robustness against sudden load variation. Particularly, integrating energy tariffs, household and individual attributes, appliance usage and general activity features can improve the energy demand model. Among the ML algorithms, LightGBM and ANN perform better than other algorithms while LSTM and SVM may not be suitable in this multi-household short monitoring context

Synthesis of CdO nanoparticles using direct chemical precipitation method: Fabrication of novel voltammetric sensor for square wave voltammetry determination of chlorpromazine in pharmaceutical samples

A chemically modified electrode was constructed and applied to the electrooxidation of the chlorpromazine (CPZ). The oxidation peak potential of the CPZ at a surface of CdO/nanoparticles (NPs) ionic liquid carbon paste electrode (CdO/NPs/IL/CPE) appeared at 695 mV. The CdO/NPs were characterized with different methods such as transmission electron microscope and X-ray diffraction. Under optimized (pH 7.0), linear calibration curves were obtained in the range of 0.1–350 µM for CPZ, which shows adequate for the quantification in real samples. The proposed method was successfully applied to the determination of CPZ in both pharmaceutical and urine samples. © 2017 Taylor & Francis Group, LLC

Ecological study in ponds of Litopenaeus vannamei

This study has carried out on five earth ponds of Litopenaeus vannamei shrimps investigation and Mahan Siraf farm s which located at Helleh site in the Bushehr province from may 2007. main objectives’ were: (1) Measurements of quality factors in water and sediment, Planktons and benthoses, (2) quality factors’ effects on growth and survival of Litopenaeus vannamei. With respect the time of shrimp stocking and harvesting, the frequencies of water and sediment sampling were done per 10 day and once per month, respectively. both sediment sampling of the pond beds have done before and after harvesting. The measured factors in the water ponds were: pH, salinity, dissolved oxygen, transparency, temperature (Twice a day in the morning and the afternoon), chlorophyll-a, nitrate, nitrite, orthophosphate, iron, biochemical oxygen demand, TSS, TDS, Planktons. The parameters (pH, total organic matter, iron) were measured in sediment. The measurement of grain size has done in two times (before and after harvesting). Independent variables including nitrate, Ammonia, orthophosphate, iron and chlorophyll-a had significant correlations with shrimp weights as dependent variable. Nitrate showed the highest correlation with the shrimp weights (r=0.921). overall correlation of fifth most important factors with the shrimp weights, namely nitrate, orthophosphate, Ammonia, iron and chlorophyll-a was estimated to r=0.999. The results show low concentration of the essential nutrient such as phosphate and nitrate, high concentration of ammonia, undesirable’s transparency, and a great amount of clay in pond beds. On the basis of above description, required to renewing management in fertilizing, feedings, liming qualities of the bed

Deconvolution of Serum Cortisol Levels by Using Compressed Sensing

The pulsatile release of cortisol from the adrenal glands is controlled by a hierarchical system that involves corticotropin releasing hormone (CRH) from the hypothalamus, adrenocorticotropin hormone (ACTH) from the pituitary, and cortisol from the adrenal glands. Determining the number, timing, and amplitude of the cortisol secretory events and recovering the infusion and clearance rates from serial measurements of serum cortisol levels is a challenging problem. Despite many years of work on this problem, a complete satisfactory solution has been elusive. We formulate this question as a non-convex optimization problem, and solve it using a coordinate descent algorithm that has a principled combination of (i) compressed sensing for recovering the amplitude and timing of the secretory events, and (ii) generalized cross validation for choosing the regularization parameter. Using only the observed serum cortisol levels, we model cortisol secretion from the adrenal glands using a second-order linear differential equation with pulsatile inputs that represent cortisol pulses released in response to pulses of ACTH. Using our algorithm and the assumption that the number of pulses is between 15 to 22 pulses over 24 hours, we successfully deconvolve both simulated datasets and actual 24-hr serum cortisol datasets sampled every 10 minutes from 10 healthy women. Assuming a one-minute resolution for the secretory events, we obtain physiologically plausible timings and amplitudes of each cortisol secretory event with R[superscript 2] above 0.92. Identification of the amplitude and timing of pulsatile hormone release allows (i) quantifying of normal and abnormal secretion patterns towards the goal of understanding pathological neuroendocrine states, and (ii) potentially designing optimal approaches for treating hormonal disorders.National Science Foundation (U.S.). Graduate Research Fellowship ProgramNational Institutes of Health (U.S.) (NIH DP1 OD003646)National Science Foundation (U.S.) (0836720)National Science Foundation (U.S.). Office of Emerging Frontiers in Research and Innovation (EFRI-0735956

Determination of biotechniqe and bionormative of breeding and culturing of Penaeus merguiensis de Man in Bushehr Area

To introduce the native commercial shrimp species to aquaculture industry, the Iranian Fisheries Research Organization conducted a project to investigate the possibility of reproduction and cultivation of the banana shrimp (Penaeus merguensis). The present work has been carried out from 21st March 2001 in two phase, reproduction and cultivation, in Iran Shrimp Research Center. The main objectives of this study was to find the possibility of reproduction and cultivation of banana shrimp with emphasis on its cost and benefit and to find if this species could be introduced to aquaculture industry in Iran. In this work, 42 brood stocks of banana shrimp caught in Jask waters and were transported to Bushehr. The shrimps were reproduced in aquaculture research station, and then cultivated in 0.4 ha ponds in Heleh region. Most of the broodstocks perished, due to long distance of Jask from Bushehr province, or had problem in hatching. Finally 8 of broodstock shrimps spawned. In 3 cases, the reared naplii larva suffered high mortality, but the other 5 spawner’s bread successfully. The post larvae were introduced to the shrimp ponds. The primary stocking was 360,000 larvae, introduced to each of two 4 m 3 tanks. The survival in both tanks for mysis stage was 83% but for PL stages, the survival was 5% for Tank 1 due to disease outbreak (until PL 24), and 62% for Tank 2. On 10 th June 2001 the PL 24 were stocked into the ponds but unfortunately due to adaptation problem, all of the shrimps perished. It seems that banana shrimp couldn’t to be adapted to the pond condition in Heleh region. On the basis of the results, the reproduction of the banana shrimps is achievable, but broodstocks needs to be transferred to reproduction areas as soon as possible to reduce stress on the shrimps. Our finding shows that the optimum conditions of salinity and temperature for growth of the reared banana shrimp in Heleh region is 33ppt and 30 °C, respectively