Robotization and digitalisation in the construction industry

Abstract. Industry 4.0 has emerged as a famous concept in the last few years to describe the significance of digitisation and robotization in the smart manufacturing environment. The advancements in robotics, digital software, and smart technologies have allowed a new wave in the construction industry. The construction industry is the major economic pillar and provides a significant impact on the overall GDP of the country. Despite the predominant pillar, it is considered as the poor innovator and late adopter of new technologies, which ends up with delays and cost overruns in their construction projects. Considering this aspect, the research emphasises the importance of adopting the latest technologies in the construction industry in order to enhance the productivity and efficiency of various processes. This study seeks to examine existing robotization and digitalisation practices in the leading construction companies and intends to provide the required improvement ideas in this research domain. The empirical results revealed that the majority of the case companies lack basis to implement the latest technologies in their construction activities. They believe that effective use of the available technologies is an asset, but it is a long process to be achieved. Thus, the thesis is concluded by providing the critical information regarding the adoption of latest technologies and proposes a framework that can help to enhance the robotization and digitisation practices to improve the performance of the construction activities. The mentioned framework mainly focusses on elements that this research found as a potential need for companies to implement. This framework has a future scope for validation and also key elements of the framework can be utilised for further research

On the highly reddened members in 6 young galactic star clusters - a multiwavelength study

The spectral and reddening properties of 211 highly reddened proper motion members with $V < 15$ mag in 6 young galactic star clusters are investigated using low resolution spectroscopic, broad-band $UBVRIJHK$ and mid-IR data. We report emission features in CaII HK and HI lines for a sample of 29 stars including 11 stars reported for the first time and also provide either a new or more reliable spectral class for a sample of 24 stars. CaII triplet width measurements are used to indicate the presence of an accretion disk for a dozen stars and to hint luminosity for a couple of stars. On the basis of spectral features, near-IR excesses, dereddened color-color diagrams and mid-IR spectral indices we identify a group of 28 pre-main sequence cluster members including 5 highly probable Herbig Ae/Be and 6 classical T Tauri star. A total of 25 non-emission MS stars, amounting to $\sim$ 10 % early type MS members, appears to show Vega-like characteristics or are precursors to such a phenomenon. The various membership indicators suggest that $\sim$ 16% of the PM members are non-members. A significant fraction ($>$70%) of program stars in NGC 1976, NGC 2244, NGC 6530 and NGC 6611 show anomalous reddening with $R_{V}$ = $5.11\pm0.11$, $3.60\pm0.05$, $3.87\pm0.05$ and $3.56\pm 0.02$, respectively, indicating the presence of grain size dust larger than that typical to the diffuse medium. A small number of stars in NGC 1976, NGC 2244 and NGC 6611 also show normal behavior while the cluster NGC 6823 appears to have a normal reddening. Three highly luminous late type giants, one in NGC 2244 and two in NGC 6530, appears to be member and are in post-hydrogen-core-burning stages suggesting a prolonged duration ($\sim$ 25 Myrs) of star formation.Comment: 12 pages, 13 figures, submitted to MNRA

On mass and velocity distributions in members of star clusters : An analytical approach

Dynamical evolution of stellar mass distribution in star clusters is analysed by considering simultaneously the effects of dynamical friction, stochastic heating and the gravitational potential due to mass distribution in the clusters. A simple expression is suggested for the dynamical friction which adequately describes it in both high and low velocity ranges and the effect of mass distribution in the cluster on the dynamics of a test mass can be described by an anharmonic potential. With the help of energy considerations we describe the dispersions in position and in velocity for stars of different masses showing how the slowing down and mass segregation of stars evolve in the cluster. Results are presented with the parameters for the star clusters of our Galaxy.Comment: 21 pages, 6 figures, minor changes in Fig 4, corrected typos, BASI(in press

Broad Band Optical Polarimetric Study of IC 1805

We present the BVR broad band polarimetric observations of 51 stars belonging to the young open cluster IC 1805. Along with the photometric data from the literature we have modeled and subtracted the foreground dust contribution from the maximum polarization (P_{max}) and colour excess (E_{B-V}). The mean value of the P_max for intracluster medium and the foreground are found to be 5.008 +/-0.005 % and 4.865 +/-0.022 % respectively. Moreover, the mean value of the wavelength of maximum polarization (lambda_{max}) for intracluster medium is 0.541 +/- 0.003 micro m, which is quite similar as the general interstellar medium (ISM). The resulting intracluster dust component is found to have negligible polarization efficiency as compared to interstellar dust. Some of the observed stars in IC 1805 have shown the indication of intrinsic polarization in their measurements.Comment: 8 pages, 7 figures, Accepted for publication in MNRA

Pitting Stochastic Study in Airframe Aluminium Alloy using Non-linear Ultrasonic

Pitting corrosion is considered to be one of the principal degradation mechanisms for high-strength aluminum alloys. The aircraft airframe has been the most demanding application for aluminum alloys. The combined effects of corrosion and cyclic loading have been shown to produce cracks from corrosion pits and pits have frequently been the source of cracks on aircraft components operating in fleets. Once the pit or group of pits form, the rate of pit growth is dependent mainly on the material, environmental conditions and type and state of stress. Therefore, to estimate the total corrosion fatigue life of a component, it is of great importance to develop realistic models to establish the component life in these situations and to formulate methods by which designers and operators know likely sources of pitting early in the design and fleet operation. There are certain gaps in knowledge with regards to life prediction for pitting initiated fatigue. The need is to gauge the extent of pitting damage of a component or material non-destructively and predict the remaining life through superimposition of the pertinent operational, environmental and material parameters. However, a foolproof non-destructive means to characterize and three-dimensionally map pits is not available. The pitting phenomenon has to be analyzed statistically and the kinetics of pitting assessed through a change in the statistical distribution parameter of pits rather than deterministic equations relating pit dimensions to time. In this work we have applied high frequency ultrasonic and non-linear ultrasonic to assess the damage due to pitting and attempt has been made to establish correlations between this non-destructive tools and pit stochastic

Bulk Utilization of Red Mud in Geopolymer Based Products

Red Mud is the solid residue generated from Alumina refinery during the process of bauxite ore processing through Bayer’s process. Typical generation of red mud is 1.5 tons of red mud per ton of alumina produced. The disposal and storage of red mud has been a concern for the alumina industry since its inception, more than a hundred years ago. With the increase in alumina production, the magnitude of the problem is getting multiplied. Its alkaline nature (Na2O ~ 3-7%) and fine size make red mud unsuitable for many applications; a limited utilization is reported in cement industries as one of the raw mix components for cement. The present work deals with the utilization of red mud in geopolymer based paving blocks. Alumina, silica and alkali are the essential items required for geopolymer preparation. Having all these in red mud, the current study attempted to use the same in geopolymer based products. The focus has been on bulk utilization of red mud; target strength of 20 MPa after 28 days of curing (M20 grade) has been the goal as this strength is sufficient for many applications. The study focused on optimizing the red mud content, alkali concentration, fly ash content, etc. The samples are tested for its compressive strength and leachability. The study reveals that significant amount of red mud incorporation is possible with products conforming to USEPA 1311 norms

Banded leaf and sheath blight: A menacing disease of maize (Zea mays L.) and its management

Maize (Zea mays L.) crop is attacked by number of fungal, bacterial and viral diseases, out of which banded leaf and sheath blight (BLSB) caused by anastomosis group 1-IA of Rhizoctonia solani f. sp. sasakii Exner. is one of the most widespread and destructive disease of maize in Southeast Asian countries. The occurrence of this disease has also been reported from other parts of the world, which causes significant yield loss up to 100%. R. solani can survive in the soil for several years and able to infect plants belonging to more than 32 families, including many economically important monocots and dicots plants. The severity of the disease favoured by humid weather with temperature around 28°C, poses challenge to maize growers due to its soil borne nature and lack of resistance cultivars. It is indicated that none of the disease management approaches are effective against BLSB. Banded leaf and sheath blight is difficult to control through either fungicide or crop rotation alone. A number of quantitative trait loci (QTLs) controlling BLSB have been identified that would help the development of maize hybrids resistance to this disease. Management of BLSB requires an integrated approach based on the knowledge of each stage of the disease and molecular aspect of maize defence responses against R. solani. Mention conclusion statement and novelty of the work. The present review summarizes consolidated information on distribution, yield loss, symptoms, pathogen life cycle, epidemiology, genetic structure of the pathogen population, molecular aspect of pathogenicity and its integrated management through cultural, biological, chemical and genetic means. The consolidated knowledge presented in this review should help better disease management and reduce crop yield loss due to banded leaf and sheath blight pathogen