Electric Field Controlled Strain Induced Switching of Magnetization of Galfenol Nanomagnets in Magneto-electrically Coupled Multiferroic Stack

The ability to control the bi-stable magnetization states of shape anisotropic single domain nanomagnets has enormous potential for spawning non-volatile and energy-efficient computing and signal processing systems. One of the most energy efficient switching methods is to adopt a system of a 2-phase multiferroic nanomagnet, where a voltage applied on the piezoelectric layer generates a strain in it and the strain is elastically transferred to the magnetostrictive nanomagnet which rotates the magnetization states of the nanomagnet at room temperature via the converse magnet-electric effect. Recently, it has been demonstrated that the magnetization of a Co nanomagnet can be switched between two stable orientations by this technique. The switching probability, however, is low due to the relatively small magnetostriction of Co. One possible way to improve the statistics is to use a better magnetostrictive material like Galfenol which has much higher magnetostriction and is therefore desirable, but it also presents unique material challenges owing to the existence of many phases. Nonetheless, there is a need to step beyond elemental ferromagnets and examine compound or alloyed ferromagnets with much higher magnetostriction to advance this field. There has not been much work in nanoscale FeGa magnets which are important for nanomagnetic logic and memory applications. Here, we have experimentally demonstrated switching of magnetization of Galfenol nanomagnets and proposed a core component of ultra-energy-efficient memory cell. We also demonstrated a bit writing scheme which completely reverses the magnetization with only strain, thus overcoming the fundamental obstacle of strain induced switching of magnetizations of nanomagnets

The Supply and Demand for Exports of Pakistan: The Polynomial Distributed Lag Model (PDL) Approach

In the global economy, the performance of any country will greatly depend on the performance of its exports. The trade performance determines the prospects of change. It helps countries win friends, and break the traditional mould of isolation and indifference. The performance of exports of countries depends on various price and non-price factors. In international trade transactions it is important to recognise that these transactions require some amount of time that occurs between the decision to buy and actual delivery of the product from foreign country. In the Econometric modelling lag occupies a central role. It is recognised that due to psychological, technical and institutional reasons, a dependent variable may respond to explanatory variables with lapse of time, in particular when dealing with time-series trade models. A number of studies have been conducted to examine the export performance of Pakistan. In the best of our knowledge, no study has been undertaken incorporating lags to examine the individual and cumulative impact of determinants of export performance of Pakistan. Thus, the ultimate purpose of this paper is to estimate consistent individual (short run) and cumulative (long run) elasticities of both export demand and supply determinants using annual data over the period 1972–2000 by applying Almon approach.

When it comes to academic libraries, which term is more appropriate: "social" or "communal?" The development of academic libraries and their future prospects

University libraries have extended their offerings to incorporate cafes, larger study spaces, and "information commons" in order to meet the social demands of students. This modification is a direct response to the prevailing notion that university libraries are seeing a decline in the number of visitors and the availability of their resources. This study offers a comprehensive examination of several social models in contrast to the traditional emphasis of academic libraries on the local community. Academic libraries are known to offer a unique type of community that regular visitors greatly appreciate. The current efforts of the academic library to promote a wider social agenda may lead to unexpected negative outcomes and a decline in community solidarity

The Causal Relationship between Foreign Direct Investment and Current Account: An Empirical Investigation for Pakistan Economy

This paper investigates relationship between FDI and current account (CA) in Pakistan using the Johansen-Juselius cointegration technique and the Granger causality test. The study results indicate that FDI and CA are cointegrated and thus exhibit a reliable long run relationship. The Granger causality test findings indicate that the causality between FDI and CA is uni-directional. However, there is no short run causality from FDI to CA and vice versa. Therefore, as a policy implication that FDI inflows may cause to the deterioration of the balance of payments in the long run should be taken into account when policy makers decide to implement policies to attract foreign investors.Asia; Pakistan; Cointegration; Granger; causality; FDI; Current Assount; error correction

Foreign Capital Inflows and Domestic Savings in Pakistan: Cointegration Techniques and Error Correction Modelling

The various form of inflow of foreign capital (loans, FDI, grant and portfolio) was welcome in developing countries to bridge the gap between domestic saving and domestic investment and therefore, to accelerate growth [Chenery and Strout (1966)]. Some other have been challenged the traditional view that foreign aid impedes domestic savings growth and mobilisation and have economic growth.1 Much attention have been paid in past 30 years, relationship between foreign capital flows and domestic saving, the main purpose of these studies have been determined whether in less developed countries foreign capital inflow and domestic saving are complementary or substitute. However, there is a controversy at theoretical and empirical levels, over the effects of foreign capital on both economic growth and national saving. A number of studies in Pakistan have been conducted during the early 1990s to examine the relationship between saving and foreign capital inflow.2 All studies shows the inverse relationship between foreign capital inflows3 (aggregate level) and saving rate, but the impact of FCI at disaggregate levels (loans, grants, FDI) on saving rate show different magnitude and signs, similarly impact of FCI on decomposition of saving rate (Public, private, household, corporate) also have different magnitude and sign. However, the most important problem associated with previous studies is that these are based on the assumption that the time series data that are being used are stationary.

The Impact of FDI on Economic Growth under Foreign Trade Regimes: A Case Study of Pakistan

FDI has been one of the defining features of the world economy over the past two decades. It has grown at an unprecedented pace for more than a decade. Liberalisation of the foreign trade regime is an integral part of growth of FDI. This paper investigates the trade policy regime followed by Pakistan that has influenced significantly both the amount of inward FDI received and economic growth. Our findings maintain that the Bhagwati Hypothesis Emphasis on both export promotion policy and inward FDI on the part of the government can get the desired result of economic growth.Foreign Investment, Economic Growth, Trade, Pakistan

Foreign Direct Investment, Exports, and Domestic Output in Pakistan

The impact of the policy reform on economic performance has been one of the stifling issues in development economics in the recent years. Since the middle 1970s, there has been considerable progress in the trade reform in the most developing countries, turning from an import substitution strategy to export-oriented approach. Pakistan also follows export-oriented policies. Pakistan’s trade pattern and trade policy have been moving towards fewer and fewer controls, tariffs rates have come tumbling down. Export-led-growth hypothesis (ELG) suggests that due to positive correlation between export and growth, therefore, export-oriented policies contribute to economic growth. Thus, international trade and development theory suggests that export growth contributes positively to economic growth. On the basis of this framework, most empirical work on the effects of export promoting strategy followed in developing countries evaluated openness with trade. Empirical research about the effect of this liberalisation process has treated export as principal channel for growth. The relationship with exports and growth, grounded in endogenous growth theory, has been tested for Pakistan.

Experimental demonstration of complete 180 degree reversal of magnetization in isolated Co-nanomagnets on a PMN-PT substrate with voltage generated strain

Rotating the magnetization of a shape anisotropic magnetostrictive nanomagnet with voltage-generated stress/strain dissipates much less energy than most other magnetization rotation schemes, but its application to writing bits in non-volatile magnetic memory has been hindered by the fundamental inability of stress/strain to rotate magnetization by full 180 degrees. Normally, stress/strain can rotate the magnetization of a shape anisotropic elliptical nanomagnet by only up to 90 degrees, resulting in incomplete magnetization reversal. Recently, we predicted that applying uniaxial stress sequentially along two different axes that are not collinear with the major or minor axis of the elliptical nanomagnet will rotate the magnetization by full 180 degrees. Here, we demonstrate this complete 180 degree rotation in elliptical Co-nanomagnets (fabricated on a piezoelectric substrate) at room temperature. The two stresses are generated by sequentially applying voltages to two pairs of shorted electrodes placed on the substrate such that the line joining the centers of the electrodes in one pair intersects the major axis of a nanomagnet at ~+30 degrees and the line joining the centers of the electrodes in the other pair intersects at ~ -30 degrees. A finite element analysis has been performed to determine the stress distribution underneath the nanomagnets when one or both pairs of electrodes are activated, and this has been approximately incorporated into a micromagnetic simulation of magnetization dynamics to confirm that the generated stress can produce the observed magnetization rotations. This result portends an extremely energy-efficient non-volatile "straintronic" memory technology predicated on writing bits in nanomagnets with electrically generated stress