Strength and Durability of Styrene Butadiene Latex Modified Concrete with Silica Fume

This paper discussed the properties of styrene butadiene rubber (SBR) latex modified concrete. The latex modified concrete using SBR latex were prepared with various polymer-binderratios and tested for compressive strength, flexure strength, elastic modulus and rapid chloride penetration test. Latex contents were varied as 5, 10 and 15 percentages by mass of binder (cement and silica fume). The effect of the polymer-binder ratio on the properties of latex modified concrete was examined. It was concluded from the test results that the compressive strength and elastic modulus decrease with polymer binder ratio and flexural strength increasing with polymer binder ratio. Addition of latex reduces the chloride ion penetration due to latex film formation..</jats:p

Factors Influencing Cost Overrun and Delay with Their Risks in Construction Management

Cost overrun and delay are the most important factors which affect the rate of progress in construction industries. There are numerous Risks are involved in cost and schedule overrun which leads to unprofitable situation or dropping the project. Previous literature studies are mainly focused only on cost overrun and delay but they do not deal with their risks which is important to study. This study is to assess the factors influencing time and cost overruns on construction projects and their risks also. The objectives of the study were achieved through valid questionnaire. The questionnaires are collected over 40 construction companies. From this survey, identify and ranking the various elements which are responsible for the inflation of cost and schedule overrun using analytical software like SPSS. And discuss about the significant values obtained from the collecting data and recommendation and mitigation ideas from the ranking of overrun factors. The significant value should be more than 0.05 and from our analysis most of the factors are above that value. The study clarified that incorrect estimates and low productivity level of labors highly contributes to overrun in construction management. It will leads to unprofitable situation, so proper scheduling and better management will rectify these problems.</jats:p

Memristor Based Planar Tunable RF Circuits

Memristors have been recently proposed as an alternative to incorporate switching along with traditional CMOS circuits. Adaptive impedance and frequency tuning are an essential and challenging aspect in communication system design. To enable both, a matching network based on switchable capacitors with fixed inductors is proposed in this paper where the switching is done by memristive switches. This paper analyzes the operation of memristors as a switch and a matching network based on memristors which adaptively tunes with impedance and frequency. With three capacitor banks of each 0.5 pF resolution and two fixed inductors, matching for antenna impedance ranging from 20 to 200Ohms and for frequencies ranging from 0.9 to 3.2GHz is reported. Thereafter, an adaptive planar band-pass filter is implemented on CMOS technology with two metal layers. This adaptive frequency tunable band-pass filter uses a π network with resonator tanks in both arms that operates at 2.45 GHz. It is tunable from 2.8GHz to 7.625GHz range. This tunability is achieved using tunable spiral inductor based on memristive switches. The proposed filter layout is implemented and simulated in ANSYS Designer. The initialization and the programming circuitry to enable adaptive switching of the memristive devices has to be addressed. Since RF memristive devices are not commercially available, circuit level simulations are done as a proof of concept to validate the expected results