12 research outputs found
An Analysis of the Sources of Wheat Output Growth in the Barani Area of the Punjab
A time-varying efficiency effects approach using district level data of wheat in barani Punjab is used to disintegrate wheat output growth into different sources. The results show that wheat output grew at an annual rate of 2.71 percent under barani conditions, during the period of study. Technological change was the main driving force, sharing about 107 percent of this growth, while the changing inputs contributed negatively by about 10 percent and the efficiency contribution was less than 4 percent. On the other hand, irrigated output increased by about 4.7 percent per annum in the region; of which 65 percent, 1.3 percent, and 34 percent were attributable to technological change, change in efficiency, and increase in inputs. As regards the overall wheat output in the barani region of the Punjab, it grew at an annual rate of 2.97 percent—84 percent of which was shared by the barani lands and the remaining 16 percent was contributed by irrigated lands in the region. One common result which was observed under both barani and irrigated conditions was that the productivity growth (the sum of technological and efficiency change) showed declining trends exclusively due to negative trends in technical efficiency. Low relative profitability as compared to growing vegetables and raising livestock might be the main cause of this trend in the barani area: the same reason could also be a source of decline in efficiency. Rapid technological advancements require that farmers and administrators improve their management skills even to keep the productive efficiency at the same level. This is not possible without education and training along with a more effective flow of information [Lall (1993)]. Under these circumstances, the agricultural extension system has to play a greater role in assisting the farming community in the barani areas so as to adopt and use new technologies more rationally.
An Analysis of the Sources of Wheat Output Growth in the Barani Area of the Punjab
A time-varying efficiency effects approach using district
level data of wheat in barani Punjab is used to disintegrate wheat
output growth into different sources. The results show that wheat output
grew at an annual rate of 2.71 percent under barani conditions, during
the period of study. Technological change was the main driving force,
sharing about 107 percent of this growth, while the changing inputs
contributed negatively by about 10 percent and the efficiency
contribution was less than 4 percent. On the other hand, irrigated
output increased by about 4.7 percent per annum in the region; of which
65 percent, 1.3 percent, and 34 percent were attributable to
technological change, change in efficiency, and increase in inputs. As
regards the overall wheat output in the barani region of the Punjab, it
grew at an annual rate of 2.97 percent—84 percent of which was shared by
the barani lands and the remaining 16 percent was contributed by
irrigated lands in the region. One common result which was observed
under both barani and irrigated conditions was that the productivity
growth (the sum of technological and efficiency change) showed declining
trends exclusively due to negative trends in technical efficiency. Low
relative profitability as compared to growing vegetables and raising
livestock might be the main cause of this trend in the barani area: the
same reason could also be a source of decline in efficiency. Rapid
technological advancements require that farmers and administrators
improve their management skills even to keep the productive efficiency
at the same level. This is not possible without education and training
along with a more effective flow of information [Lall (1993)]. Under
these circumstances, the agricultural extension system has to play a
greater role in assisting the farming community in the barani areas so
as to adopt and use new technologies more rationally
An Analysis of the Sources of Wheat Output Growth in the Barani Area of the Punjab
A time-varying efficiency effects approach using district level data of wheat in barani Punjab is used to disintegrate wheat output growth into different sources. The results show that wheat output grew at an annual rate of 2.71 percent under barani conditions, during the period of study. Technological change was the main driving force, sharing about 107 percent of this growth, while the changing inputs contributed negatively by about 10 percent and the efficiency contribution was less than 4 percent. On the other hand, irrigated output increased by about 4.7 percent per annum in the region; of which 65 percent, 1.3 percent, and 34 percent were attributable to technological change, change in efficiency, and increase in inputs. As regards the overall wheat output in the barani region of the Punjab, it grew at an annual rate of 2.97 percent-84 percent of which was shared by the barani lands and the remaining 16 percent was contributed by irrigated lands in the region. One common result which was observed under both barani and irrigated conditions was that the productivity growth (the sum of technological and efficiency change) showed declining trends exclusively due to negative trends in technical efficiency. Low relative profitability as compared to growing vegetables and raising livestock might be the main cause of this trend in the barani area: the same reason could also be a source of decline in efficiency. Rapid technological advancements require that farmers and administrators improve their management skills even to keep the productive efficiency at the same level. This is not possible without education and training along with a more effective flow of informatio
Behavior of Disordered Materials under Extreme Conditions
A joint experimental and theoretical study on the behaviors of disorderedchalcogenides (i.e., amorphous As2Se3 and amorphous AsSe) under high-pressure,behaviors of chemically disordered high entropy alloys (HEAs) under high-pressure andhigh-temperature, and low temperature dynamics of Zr-based metallic glasses (MGs) ispresented. A brief introduction, experimental methods and behavior of the studiedmaterials under extreme conditions of temperature and pressure are documented.A reversible breakdown of intermediate range ordering (IRO) and associated networktransition is observed under pressure in amorphous As2Se3. Such a networktransformation is found to be gradual without any sudden jump in density.A reversible pressure-induced crystallization is observed in amorphous As2Se3. Thehigh pressure FCC phase is found to be metastable due to possessing excess amount offree energy, and upon decompression the amorphous phase is found to be retrieved.Surprisingly, the as-prepared amorphous phase and the amorphous phase recovered fromthe complete decompression of the high-pressure crystalline phase are found to beidentical within the theoretical and experimental uncertainty. This is first time that anamorphous material, after going through pressure-induced crystallization, is seen torecover its virgin local structure upon complete decompression, which is the exactnovelty in the current thesis.Similar to amorphous As2Se3, a reversible breakdown of intermediate range ordering(IRO) and associated network transition is observed under pressure in amorphous AsSe.Such a network transformation is found to be gradual without any sudden jump indensity.Behaviors of chemically disordered high entropy alloys (HEAs) under high-pressureand high-temperature have been studied. For the studied HEAs, equations of state aredeveloped under high-pressure, and linear and volumetric thermal expansions aredocumented under high-temperature. The HEAs are found to be stable under both thehigh-pressure and high-temperature, and no phase transition is seen to occur up to thehighest pressure and temperature achieved in the current study.The low temperature dynamics and the possible origin of boson peak in the Zr-basedmetallic glasses have also been described in the current thesis. A universal correlationbetween the local structure and boson peak is established for the Zr-based metallicglasses. The boson peak is found to be originated from the vibrations caused in thedensity fluctuation regions in the metallic glasses
Out-migration in Rural Pakistan: Does Household Poverty Status Matter?
Movement of the people within the geographical and
administrative boundaries of a country is known as internal migration.
Researchers regard the movement to urban areas from both rural and
less-advanced urban areas as more important, yet studying the dimensions
of movement between rural areas is worth investigating. Scholars assert
economic incentives as the main motive behind the rural-urban movement;
various unforeseeable factors, however, may also stimulate the human
flows. In Pakistan, the phenomenon of internal migration is as old as
the inception of the country as Helbock (1975a) maintained, while
studying life-time migrants in 12 largest cities of the country in 1961,
that almost every 7th person residing in these cities had come from a
different distric
Breakdown of intermediate range order in AsSe chalcogenide glass
As-cast amorphous AsSe (a-AsSe) has been characterized by in-situ high pressure XRD and Raman spectroscopy up to the pressure of ∼30 GPa using diamond anvil cell together with ab-initio molecular dynamics simulations. A gradual densification has been observed under compression along with the breakdown of intermediate range ordering at ∼16 GPa. The whole transformation process can be divided into three relatively distinct pressure regimes from 1 bar to 7 GPa, from 7 to 16 GPa, and beyond 16 GPa. Our XRD results together with Raman spectroscopic studies confirm that in the a-AsSe pressure tuning results in network transformations only, without sudden jump in the density. The results obtained by high pressure ab-initio molecular dynamics simulations demonstrate the variations in the local structures associated with the experimentally observed transformations. The amorphous-to-amorphous network transformation is found to be reversible upon decompression
Temperature- and Pressure-Induced Polyamorphic Transitions in AuCuSi Alloy
Temperature-induced liquid–liquid phase transition (LLPT) and pressure-induced amorphous–amorphous phase transition (AAPT) have never been simultaneously reported in any single metallic system. In an AuCuSi alloy, however, we discovered a temperature-induced LLPT by detecting “reversible λ-anomalies” of the thermal expansion coefficient between two liquid states at ambient pressure, while a pressure-induced AAPT in AuCuSi metallic glass (MG) occurs upon compression at ambient temperature. Both LLPT and AAPT are reversible with a hysteresis in temperature and pressure, respectively. Using molecular dynamics simulations and synchrotron X-ray techniques, we elucidate structural differences in both low- and high-pressure AuCuSi MG phases and low- and high-temperature AuCuSi liquid phases. Electronic transfer between Si and Au or/and Cu atoms occurs in both temperature-induced LLPT and pressure-induced AAPT in the AuCuSi alloy
Isosymmetric phase transitions, ultrahigh ductility, and topological nodal lines in α- A g2 S
We report two reversible pressure-induced isosymmetric phase transitions in that are accompanied by two compressive anomalies at 7.5 and 16 GPa, respectively. The first transition arises from a sudden and drastic puckering of the wrinkled Ag-S layers, which leads to an anomalous structural softening at high pressure and gives rise to the ultrahigh compressive ductility in . The second transition stems from a pressure-driven electronic state crossover from a conventional semiconductor to a topological metal. The band-crossing points near the Fermi energy form a nodal-line structure due to the preservation of the time-reversal and space-inversion symmetries under pressure. Our findings not only reveal the underlying mechanism responsible for the ultrahigh ductility in this class of inorganic semiconductors, but also provide a distinctive member to the growing family of topological metals and semimetals
Structural stability of high entropy alloys under pressure and temperature
The stability of high-entropy alloys (HEAs) is a key issue before their selection for industrial appli-cations. In this study,in-situhigh-pressure and high-temperature synchrotron radiation X-raydiffraction experiments have been performed on three typical HEAs NiCoFeMnCr,HfNbZrTi, and ReRuCoFe(at. %), having face-centered cubic (fcc), body-centeredcubic (bcc), and hexagonal close-packed (hcp) crystal structures, respectively, up to the pressure of80 GPa and temperature of1262 K. Under the extreme conditions of the pressure and tempera-ture, all three studied HEAs remain stable up to the maximum pressure and temperatures achieved.For these three types of studied HEAs, the pressure-dependence of the volume can be welldescribed with the third order Birch-Murnaghan equation of state. The bulk modulus and itspressure derivative are found to be 88.3 GPa and 4 for bcc-HfNbZrTi, 193.9 GPa and5.9 for fcc-NiCoFeMnCr, and 304.6 GPa and 3.8 for hcp-Re25Ru25Co25Fe25HEAs,respectively. The thermal expansion coefficient for the three studied HEAs is found to be in theorder as follows: fcc-NiCoFeMnCr > bcc-HfNbZrTihcp-ReRuCoFe