RF energy harvesters for wireless sensors, state of the art, future prospects and challenges: a review

The power consumption of portable gadgets, implantable medical devices (IMDs) and wireless sensor nodes (WSNs) has reduced significantly with the ongoing progression in low-power electronics and the swift advancement in nano and microfabrication. Energy harvesting techniques that extract and convert ambient energy into electrical power have been favored to operate such low-power devices as an alternative to batteries. Due to the expanded availability of radio frequency (RF) energy residue in the surroundings, radio frequency energy harvesters (RFEHs) for low-power devices have garnered notable attention in recent times. This work establishes a review study of RFEHs developed for the utilization of low-power devices. From the modest single band to the complex multiband circuitry, the work reviews state of the art of required circuitry for RFEH that contains a receiving antenna, impedance matching circuit, and an AC-DC rectifier. Furthermore, the advantages and disadvantages associated with various circuit architectures are comprehensively discussed. Moreover, the reported receiving antenna, impedance matching circuit, and an AC-DC rectifier are also compared to draw conclusions towards their implementations in RFEHs for sensors and biomedical devices applications

CORPORATE GOVERNANCE AND EARNINGS MANAGEMENT: THE ROLE OF THE BOARD OF DIRECTOR

This study investigates the association between earnings management and corporate governance characteristics in the Chinese context. Chinese corporate governance system is improved in past two decades after deciding to move away from planned economy to market-oriented one. The data is collected from the Chinese A-listed firms for the period of 2008 to 2016 to investigate the impact of Board characteristics on Earnings management. Additionally, this study demonstrates if earnings management is still an issue in the Non-SOE or not?. This study finds that board size mitigates the earnings management, and board independence is not playing there due role in monitoring the top management. The board meetings are not so effective and therefore not contributing to mitigating the earnings management. CEO duality is not a big issue just like in developed countries. Furthermore, When segrgating the sample on the basis of ownership type, we find that, a board meeting is affective in SOE as compare to Non-SOE.Furthermore, board size substitutes the weak external governance mechanism and constrains Earnings management. Board meeting plays a complementary effect when external governance mechanism is strong. The findings of this study are significant for all stakeholders to analyze and to improve the board effectiveness and the financial reporting quality before making any decision

CORPORATE GOVERNANCE AND EARNINGS MANAGEMENT: THE ROLE OF THE BOARD OF DIRECTOR

This study investigates the association between earnings management and corporate governance characteristics in the Chinese context. Chinese corporate governance system is improved in past two decades after deciding to move away from planned economy to market-oriented one. The data is collected from the Chinese A-listed firms for the period of 2008 to 2016 to investigate the impact of Board characteristics on Earnings management. Additionally, this study demonstrates if earnings management is still an issue in the Non-SOE or not?. This study finds that board size mitigates the earnings management, and board independence is not playing there due role in monitoring the top management. The board meetings are not so effective and therefore not contributing to mitigating the earnings management. CEO duality is not a big issue just like in developed countries. Furthermore, When segrgating the sample on the basis of ownership type, we find that, a board meeting is affective in SOE as compare to Non-SOE.Furthermore, board size substitutes the weak external governance mechanism and constrains Earnings management. Board meeting plays a complementary effect when external governance mechanism is strong. The findings of this study are significant for all stakeholders to analyze and to improve the board effectiveness and the financial reporting quality before making any decision

Assessment of key determinants for economic growth in Pakistan

This study actually attempts to investigate economic growth determinants in case of Pakistan for the period of 1980 to 2009. The autoregressive distributed lag (ARDL) and error correction model (ECM) have employed to investigate the long run and short run parameters between economic growth and its major determinants. Prior the stated approaches has confirmed through ADF test that all of the variables are integrated first order i.e. I (1). The results from ARDL show that there is co-integration between economic growth and explanatory variables that are real domestic investment, foreign investment, export, remittances and literacy rate. The estimated long run elasticities of economic growth with respect to domestic investment, foreign investment, exports, remittances and literacy rate were found as, 0.121, 0.026, 0.020, 0.065 and 0.224. Further, results depict that the error coefficient term is -0.67 and significant, suggest 67 percent adjustment in a year

Characterization of Salinity and Sodicity Levels in Groundwater and Their Impact on the Yield of Banana (Musa Indicata) in District Lasbela

The study on characterization of different levels of salinity and sodicity was carried in district Lasbela during 2012-2013.The study area is situated between 24°-54 and 26°-37 north latitude and 64°-02 and 67°-28 east longitude. Lasbela’s geography and landscape is diverse and interesting. A total no 32 groundwater samples were collected from the study area. Water was characterized in accordance to the diagram for the classification of irrigation waters based on EC and SAR values. 94 % of the sites were falling in the high salinity class of C3 where as only 6% of the sites were falling in the C4 class. On the other hand, nearly 81% of the sites have SAR values below 10, which fall in the low category of sodicity S1. Hence only 19% of the sites have medium SAR. The percentage of the salts of the same site is higher when compared to its sodicity. The combined ECw-SAR classification of groundwater of 81% of the samples are in C3-S1 class followed by the respective classes of C4-S1 and C4-S2 at 13% and 6% of the groundwater analysed. Such water is classified as highly and very highly saline for irrigation. The average yield of banana in the whole area was 7447 kg/ha/year. ECw has no impact on yield of crops in the region. However a weak but general increase in salinity shows a bit increasing trend in yield while a minute increase in salinity shows a decreasing trend. Also SAR has no noimpact on yield of crops in the region. This might be because of use of such water that was entirely feasible particularly on light (sandy) soils. The present groundwater may be considerably better under many conditions that might be usable which be able to be successfully be applied to produce good yields of salt tolerant crops. Keywords: Lasbela, Groundwater Quality, Salinity, Sodicity, Yield, Banana, USDA

Assesment of Salinity and Alkalinity of Groundwater and It Relation to the Geochemical Propersties of Soil in a Specific Site of Lasbela Region

The study was conducted on assessment of salinity and alkalinity of groundwater and it relation to the geochemical properties of soil in a specific site of Lasbela region during 2013-14. Field data was collected through questionnaires. Water and soil samples were collected from 32 randomly selected sites. Both soil and water were analyzed for Electrical Conductivity and SAR by following standard procedures. The general trend line showed that soil salinity increased with an increase in water salinity. ECw has significantly affected the soil properties sites. The Alkanity levels both at water and soil differ significantly with each other. Alkanity of soil is increasing with the application of sodic water. Alkanity levels of groundwater used for irrigation of crops didn’t have a significant relation for soil Alkanity at different sites of the study area. There is an inverse relationship between Electrical conductivity and Sodium Adsorption Ratio. The saline groundwater quality from the irrigation to the whole region is although causing reduction in soil alkanity but it is causing lesser impact when compared to the individual sites in the study area. Keywords: Salinity, Alkanity, Sodium Absorption Ratio, Electrical Conductivity, Assessmen

Globalization and unemployment in Pakistan

This study analyzes the impact of globalization on unemployment in Pakistan, using annual data for the period 1980 to 2013. Using the ARDL econometric framework, we find that the economic, political and social aspects of globalisation differ in their effects. The data suggest that political and social integration, whilst beneficial in the short run, increase the long run expected unemployment rate. Economic integration appears to be only marginally beneficial in the short run; it is significantly beneficial in the long run but cointegration with the other aspects of globalisation means that it cannot fully counteract their undesirable long-run effect

Direct hyperspectral dual-comb imaging

Even though dual-comb-based systems are employed almost routinely nowadays in an ever-increasing number of applica-tions, an efficient combination of this effective technique withan imaging arrangement, which would undoubtedly revolu-tionize hyperspectral imaging, had not yet been demonstrated. Here we present, to our knowledge, the first hyperspectral dual-comb imaging system in which interferograms are directly detected by a video camera. The system, based on a dual-comb scheme capable of consistently generating interfer-ograms at a rate of 1 Hz and below, combines fast hyperspectral imaging with unprecedented optical resolution and fully multiplex operation. Various proof-of-principle experiments demonstrating hyperspectral imaging of molecular resonances have proved that the direct hyperspectral dual-comb imaging method presented here is capable of characterizing a scene with super-fine resolution in a narrow optical span within 1 s.European Commission (ATTRACT project Grant Agreement 777222