No abstract

Corona virus (COVID-19) outbreaks have severely disrupted the economy, with devastating effects on global trade and it has simultaneously affected households, businesses, financial institution, industrial establishments and infrastructure companies. The economic crisis caused by the virus has hit many more organizations around the world. Similarly, construction and engineering projects around the world have been jeopardize in various way by the COVID-19 pandemic and many projects have closed. As a result, there has been a financial recession in the construction industry in almost all countries and has created unemployment. All in all, this situation has caused great concern, uncertainty and unrest in the construction industry. This paper observes in several countries and describes the global impact of the Corona virus on the construction industry. This paper also explains how it is possible to continue construction work in this situation. If construction work continues, the economic downturn will be reduced and unemployment will be reduced.

To establish an entangled state of optimal fidelity between two distant observers when the available quantum channel is noisy, is a central problem in quantum information theory. We consider an instance of this problem for two-qubit systems when only a single use of the channel and local post-processing by trace preserving operations are allowed. We show that the optimal fidelity is obtained only when part of an appropriate nonmaximally entangled state is transmitted through the channel. The entanglement of this state can be vanishingly small when the channel becomes very noisy. Moreover, in the optimal case no further local processing is required to enhance the fidelity. We further show that local post-processing can enhance fidelity if and only if the amount of noise is larger than a critical value and entanglement of the transmitted state is bounded from below. A notable consequence of these results is that the ordering of states under an entanglement monotone can be reversed even when the states undergo the same local interaction via a trace-preserving completely positive map.arXiv:1209.3494v1 [quant-ph]

The present study has been conducted to investigate the relative changes of carbonaceous aerosols (CA) over a high altitude Himalayan atmosphere with and without (very low) anthropogenic emissions. Measurements of atmospheric organic (OC) and elemental carbon (EC) were conducted during the lockdown period (April 2020) due to global COVID 19 outbreak and compared with the normal period (April 2019). The interesting, unexpected and surprising observation is that OC, EC and the total CA (TCA) during the lockdown (OC: 12.1 ± 5.5 μg m −3 ; EC: 2.2 ± 1.1 μg m −3 ; TCA: 21.5 ± 10 μg m −3 ) were higher than the normal period (OC: 7.04 ± 2.2 μg m −3 ; EC: 1.9 ± 0.7 μg m −3 ; TCA: 13.2 ± 4.1 μg m −3 ). The higher values for OC/EC ratio too was observed during the lockdown (5.7 ± 0.9) compared to the normal period (4.2 ± 1.1). Much higher surface O 3 during the lockdown (due to very low NO) could better promote the formation of secondary OC (SOC) through the photochemical oxidation of biogenic volatile organic compounds (BVOCs) emitted from Himalayan coniferous forest cover. SOC during the lockdown (7.6 ± 3.5 μg m −3 ) was double of that in normal period (3.8 ± 1.4 μg m −3 ). Regression analysis between SOC and O 3 showed that with the same amount of increase in O 3 , the SOC formation increased to a larger extent when anthropogenic emissions were very low and biogenic emissions dominate (lockdown) compared to when anthropogenic emissions were high (normal). Concentration weighted trajectory (CWT) analysis showed that the anthropogenic activities over Nepal and forest fire over north-east India were the major long-distant sources of the CA over Darjeeling during the normal period. On the other hand, during lockdown, the major source regions of CA over Darjeeling were regional/local. The findings of the study indicate the immense importance of Himalayan biosphere as a major source of organic carbon.