What is Hidden, in the Hidden Economy of Pakistan? Size, Causes, Issues and Implications

There is a worldwide contemporary debate about the role of the hidden economy in achieving the goal of sustained and inclusive economic growth and development, especially in the context of its spillover effects on the formal economy. For this purpose, policy makers and academicians have made concerted efforts to estimate the size of the hidden economy and to analyze its causes, issues and implications on key macroeconomic variables. However, there is a consensus among the policy makers that a better macroeconomic policy formulation and its true implementation are subject to the proper management of the associated issues of the hidden economy with suitable policy measures. In Pakistan, it is generally assumed that the hidden economy contributes about 30% to 50% to the overall GDP. The purpose of this paper is to estimate more precisely the size of the hidden economy with the determination of its potential causes and implications. Five statistical and structural modeling approaches namely; simple monetary approach, modified monetary approach using dynamic ordinary least square (DOLS), multiple-indicators multiple-causes (MIMIC) approach, electricity consumption approach and labor market survey based approach are used to estimate the size of the hidden economy and to analyze the characteristic nature of its growth over the period. The study also investigates the potential determinants of the hidden economy and various interrelated socio-economic issues in perspective of achieving national goal of inclusive growth and development. Finally, policy implications are provided consistent with pervading facts of the hidden economy in Pakistan especially in the context of the 18th Amendment and the 7th NFC Award.Hidden Economy, Size, Causes, Socio-Economic Implications, Inclusive Growth and Development, 18th Amendment and 7th NFC Award of Pakistan

What is Hidden, in the Hidden Economy of Pakistan? Size, Causes, Issues, and Implications

The informal economy is initially considered as the subsidiary sector in terms of its contribution to the overall economy. However, it received the focus of attention with the publication of Peter Guttmann’s estimates for sizing the informal economy (i.e. US $ 200 billion in 1976) for the US economy especially in the context of achieving the goal of inclusive growth and development. The informal economy is recognised with different names in different countries/regions throughout the world. For example, the Swedish and Russian term it as ―Hidden Economy‖, the English call it ―Fiddle‖, the Japanese recognise it as ―Hidden Incomes‖, the French identify it as ―Travail au noir‖, the Italian consider it as ―The Lavorno Nero‖, while in Pakistan it has been analysed as an ―Hidden Economy‖ or ―Informal Economy‖

Investigating Nanoindentation Creep Behavior of Pulsed-TIG Welded Inconel 718 and Commercially Pure Titanium Using a Vanadium Interlayer

In a dissimilar welded joint between Ni base alloys and titanium, creep failure is a potential concern as it could threaten to undermine the integrity of the joint. In this research, the mechanical heterogeneity of a Pulsed TIG welded joint between commercially pure titanium (CpTi) and Inconel 718 (IN718) with a vanadium (V) interlayer was studied through a nanoindentation technique with respect to hardness, elastic modulus, and ambient temperature creep deformation across all regions (fusion zones and interfaces, mainly composed of a dendritic morphology). According to the experimental results, a nanohardness of approximately 10 GPa was observed at the V/IN718 interface, which was almost 70% higher than that at the V/CpTi interface. This happened due to the formation of intermetallic compounds (IMCs) (e.g., Ti2Ni, NiV3, NiTi) and a (Ti, V) solid solution at the V/IN718 and V/CpTi interfaces, respectively. In addition, nanohardness at the V/IN718 interface was inhomogeneous as compared to that at the V/CpTi interface. Creep deformation behavior at the IN718 side was relatively higher than that at different regions on the CpTi side. The decreased plastic deformation or creep effect of the IMCs could be attributed to their higher hardness value. Compared to the base metals (CpTi and IN718), the IMCs exhibited a strain hardening effect. The calculated values of the creep stress exponent were found in the range of 1.51–3.52 and 2.52–4.15 in the V/CpTi and V/IN718 interfaces, respectively. Furthermore, the results indicated that the creep mechanism could have been due to diffusional creep and dislocation climb

Dissimilar P-TIG welding between Inconel 718 and commercially pure Titanium using niobium interlayer

The formation of brittle intermetallics is a challenge for the direct joining of commercially pure titanium (CpTi) and Inconel 718 (IN718) alloy. In the present work, dissimilar weldments using the P-TIG (Pulsed-Tungsten Inert Gas) welding technique were produced, with elemental Niobium (Nb) as an interlayer. The insertion of Nb acted as a barrier and suppressed the interdiffusion of Ti and Ni across the interlayer resulting in no TixNiy intermetallic compounds (IMCs) at the CpTi/IN718 dissimilar joint. Titanium (Ti) and Nb on CpTi side joined by solid solution (Ti, Nb) strengthening mechanism. Nickel (Ni) joined with Nb at IN718 side via eutectic reaction, where a diffused layer comprising of NbNi3, and Nb7Ni6 IMCs was found. Owing to the formation of brittle IMCs (NbNi3, Nb7Ni6), the diffused layer at Nb/IN718 interface exhibited the microhardness of ~782 HV, which is ~64 % higher than the Nb/CpTi interface and considered highest in comparison to the other regions of the joint. The maximum tensile strength of the weldment was 150 MPa, which is significantly less than CpTi (360 MPa) and IN718 (850 MPa) base alloys possibly due to the presence of cracks in the diffused layer and the welded joint

Peutz-Jeghers Syndrome presenting as Intussusception in a young female: A Case Report

Peutz-jeghers syndrome is rare condition with autosomal dominant inheritance. It is due to the mutation in a tumor suppressor gene SK 11 at chromosome no 9. It has a very characteristic presentation. Patient usually presents at a young age with intestinal obstruction due to polyps leading to intussusception. Also there is melanosis at perioral, digits and perineal regions. There is very strong association of cervical and breast carcinoma in females and testicular tumors in males. GIT, pancreatic and lung malignancies occur in both sexes. Regular follow up and screening are necessary for early detection of malignancies. We present a case of young girl who presented with intestinal obstruction along with other signs and symptoms of peutz-jeghers syndrome. Exploratory laparotomy revealed jejunoileal intussusception and hamartomatous polyps. Patient and other family members were advised screening studies of associated malignancies and regular follow up

Response surface approach to minimize the residual stresses in full penetration pulsed TIG weldments of Ti-5Al-2.5Sn alloy

Pulsation of current in Tungsten Inert Gas (TIG) welding is employed to obtain good quality weldments. Peak current, background current, and welding speed in TIG welding are important parameters and their effects on the induced residual stresses are studied using Box–Behnken design methodology. The location of maximum residual stress was found to be close to the weld centerline. Longitudinal and transverse residual stresses at this location were found to be dependent on the pulsed TIG welding input parameters. However, using design of experiment approach, welding speed was found to have the most dominant influence on the stress values. In order to minimize the residual stresses, a reduction in heat input also led to reduction of weld pool penetration. The results of multiresponse optimization showed that in order to achieve a full penetration weldment, a minimum value of 235 MPa for longitudinal and 84 MPa for transverse residual stress will be attained. A weldment with these features can be obtained by using a high value of peak current and a high value of welding speed

Real time vision-based implementation of plant disease identification system on FPGA

Plant diseases have turned into a dilemma as it can cause significant reduction in both quality and quantity of agricultural products. To overcome that loss, we implemented a computer vision based real time system that can identify the type of plant diseases. Computer vision-based applications are computationally intensive and time consuming, so FPGA-based implementation is proposed to have a real time identification of plant diseases. In this paper an image processing algorithm is proposed for identifying two types of disease in Potato leaves. The proposed algorithm works well on images taken under different luminance conditions. The hardware/software-based implementation of the proposed algorithm is done on Xilinx ZYNQ SoC FPGA. Results show that our proposed algorithm achieves an accuracy of up to 90%, whereas the hardware implementation takes 0.095 seconds achieving a performance gain of 76.8 times as compared to the software implementation

A comparative study of pulsed laser and pulsed TIG welding of Ti-5Al-2.5Sn titanium alloy sheet

Pulsed Nd:YAG laser beam welding (P-LBW) and pulsed tungsten inert gas (P-TIG) welding were used to prepare full penetration bead-on-plate weldments of 1.6 mm thick Ti-5Al-2.5Sn alpha titanium alloy sheet. The influence of welding phenomenon on the microstructure, micro-hardness, tensile properties, surface and sub-surface residual stress distribution and deformation and distortion of both the weldments were studied. Higher cooling rate in P-LBW resulted in complete α’ martensitic transformation in fusion zone whereas in P-TIG weldment α’ and acicular α was formed within equiaxed β matrix due to lower cooling rate. Hardness in fusion zone of P-LBW was higher than that of the fusion zone of P-TIG weldment due to faster cooling rate in P-LBW. The welded zone in both the weldments showed higher hardness and strength than that of the parent metal since a ductile fracture occurred in the un-welded section during tensile testing. Residual stresses in both P-LBW and P-TIG weldments showed similar trend but the distribution was much narrower in P-LBW due to less width of heat affected zone. P-LBW resulted in more nonuniformity in through thickness stress profile because of greater top to bottom width ratio. Less residual stresses, deformation and distortion and superior mechanical properties in P-LBW made the process more feasible than P-TIG for the welding of Ti-5Al-2.5Sn alloy sheet