Shift in Management Strategy of Yak Herding in the South of Mustang District, Nepal, Himalaya

In the Himalayan regions of Nepal, people herd yaks (Bos grunniens) under transhumant pastoralism, seasonal migrations of herds between summer highlands and winter lowlands. For several decades, the number of yaks has decreased, and the management strategy of yak herding has been altered due to the influence of substantial changes in both the social environment and their livelihoods. We conducted field surveys on yak herding in the south of Mustang District from 2012 to 2016 to examine the recent shift in management strategy and practice. The surveys were focused on fifteen yak owners and their herdsmen who lived in southernmost three villages in the district and organized a yak owners’ cooperative group. The herd scale has been constant in recent years, although the owners had a willingness to increase the scale. The herding practices were traditional and extensive, which might not have led to an increase in herd size or productivity. Dairy production has shown an obvious declining trend, whereas sales of meat and the revenue from the yak blood drinking festival hosted by the cooperative group have become more important income sources for local yak herding in association with the development of local infrastructures and livelihoods. Because the economic incentives for yak herding remained strong in the study area, the herding scale will be maintained, or expanded if the management practices are improved in the future

Furnace System Improvements

This Final Design Review (FDR) documents the work done by the group to manufacture the system to deliver improvements to the furnace in the Cal Poly microfabrication laboratory (better known as the cleanroom). The document describes the material covered in the Scope of Work (SOW), including background research, customer needfinding, and the problem statement, material associated with concept development and selection for Preliminary Design Review (PDR), material detailing the design and manufacturing plan of the system for Critical Design Review (CDR), and new material detailing the manufacture of the system for FDR. Research done for the SOW resulted in a list of engineering and customer specifications. These in turn led to the development of the goal of the project: to make the furnace system more user- friendly to operate by simplifying the tubing layout, introducing digital control, and creating a consolidated user interface. Following the development of the problem statement, the problem was decomposed into its individual functions, and solutions developed for each function. These solutions were analyzed, and the best were combined into a final design. The solution is a system consisting of a tubing subsystem, a user interface, and a control subsystem to connect the two. A prototype system has been designed to test key functionalities of the control system, and design, manufacturing, and test plans have been created for the subsystems. The system was intended to allow the user to set up a temperature and gas program, start the run, and not interact further with the system until the end of the run. In the event of an unsafe condition detection, the system would raise an alert (it was assumed that users would remain in the room as a matter of safety during runs). The fluid lines were vastly simplified, and gas programming is performed on a touchscreen user interface connected to a Raspberry Pi board. It was originally intended to be able to perform temperature programming on the same interface, but this functionality has been removed from the project as a matter of safety, as requested by the sponsors. The new interface and all controlling functions run on software written by the team, which is publicly available and free for any subsequent project to modify and use. The openness of this setup allows further improvements to the electronics and software as necessary. The system was mostly built as designed, although several key functionalities are incomplete. As such, the system was not installed in the cleanroom. Therefore, finishing the remaining components and installing them in the cleanroom are tasks which are left to subsequent senior project teams. Next steps for subsequent projects include implementing bubbler refill, building a graphical user interface for the gas routing system, implementing communication with the thermocouples, installing the pressure monitoring system, and implementing automatic gas switching. After this, the system may be installed. Upon installation, the original gas programming interface will be retained, and the new system will be installed so that it will be possible to throw a switch to revert to the old interface in the event of system malfunction

An energy scale directly related to superconductivity in the high-TcT_c cuprate superconductors: Universality from the Fermi arc picture

We have performed a temperature dependent angle-resolved photoemission spectroscopy (ARPES) study of the tri-layer high-$T_c$ cuprate superconductor (HTSC) Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10+\delta}$ (Bi2223), and have shown that the \textquotedblleft effective\textquotedblright superconducting (SC) gap $\Delta_{\rm{sc}}$ defined at the end point of the Fermi arc and the $T_c$ (= 110 K) approximately satisfies the weak-coupling BCS-relationship 2$\Delta_{\rm{sc}}$ = 4.3$k_{\rm{B}}T_c$. Combining this result with previous ARPES results on single- and double-layer cuprates, we show that the relationship between 2$\Delta_{\rm{sc}}$ = 4.3$k_{\rm{B}}T_c$ holds for various HTSCs. Furthermore, at $T$ $\sim$ $T_c$, the quasi-patricle width at the end point of the Fermi arc is found to coincide with $\Delta_{\rm{sc}}$, consistent with the context of Planckian dissipation.Comment: 5 pages, 4 figure

Interindividual Differences and Their Consistency in Grazing Cattle Behavior across Seasons

Interindividual differences and their consistency in behavior were investigated for cattle (Bos taurus) grazing a bahiagrass (Paspalum notatum) and centipedegrass (Eremochloa ophiuroides) dominated pasture as a herd of about 30 breeding cows with their calves. Behavior of the cows was monitored directly by observers and also using GPS and accelerometer data loggers attached to focal cows for a period of 1–5 days every month during the grazing seasons (from May to October) in 2018 and 2019. The data were converted into behavioral variables (e.g. time spent grazing, ruminating and resting, time spent in particular areas, and selectivity for grass species). Time budget of the maintenance behavior, spatial use pattern, preference for grass species on a daily basis were different among cows consistently across the seasons although the behavior varied daily and seasonally in accordance with sward and weather conditions, i.e. some individuals showed a particular tendency in some behavioral traits compared with others across various environmental situations. The consistent individual behavioral characteristics found in this study can be partly explained by age, body size and nutritional and physiological states; otherwise considered as personal traits of animals, which may affect their ecological fitness to the environment and production performances as livestock and be transmitted to their offspring. Further studies are warranted to reveal associations of behavioral traits with fitness or productivity and their transmissibility

Orbital Degeneracy and Peierls Instability in Triangular Lattice Superconductor Ir1−x_{1-x}Ptx_xTe2_2

We have studied electronic structure of triangular lattice Ir$_{1-x}$Pt$_x$Te$_2$ superconductor using photoemission spectroscopy and model calculations. Ir $4f$ core-level photoemission spectra show that Ir $5d$ $t_{2g}$ charge modulation established in the low temperature phase of IrTe$_2$ is suppressed by Pt doping. This observation indicates that the suppression of charge modulation is related to the emergence of superconductivity. Valence-band photoemission spectra of IrTe$_2$ suggest that the Ir $5d$ charge modulation is accompanied by Ir $5d$ orbital reconstruction. Based on the photoemission results and model calculations, we argue that the orbitally-induced Peierls effect governs the charge and orbital instability in the Ir$_{1-x}$Pt$_x$Te$_2$.Comment: 5 pages,4 figure

Effect of electron-phonon coupling in the ARPES spectra of the tri-layer cuprate Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta}

Angle-resolved photoemission spectroscopy using tunable low energy photons allows us to study the quasi-particle (QP) dispersions of the inner and outer CuO2 planes (IP and OP) separately in the tri-layer cuprate Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10+\delta}$ (Bi2223). The kink energy of the OP band is $\sim$ 70 meV, as observed in various high-$T_c$ cuprates, while that of the IP band is as large as 100 meV in the superconducting (SC) state. This large kink energy is attributed to the $\sim$ 35 meV buckling mode plus the large ($\sim$ 60 meV) SC gap of IP. The IP band also shows a weak kink feature at 70 meV in the SC state. The latter feature can be explained either by the 70 meV half-breathing mode or by the $\sim$ 35 meV buckling-phonon mode plus the $\sim$ 40 meV SC gap of OP if interlayer scattering of QP is involved.Comment: 5 pages, 2 figure

Spin-density-wave transition of (TMTSF)2_2PF6_6 at high magnetic fields

The transverse magnetoresistance of the Bechgaard salt (TMTSF)$_2$PF$_6$ has been measured for various pressures, with the field up to 24 T parallel to the lowest conductivity direction c$^{\ast}$. A quadratic behavior is observed in the magnetic field dependence of the spin-density-wave (SDW) transition temperature $T_{\rm {SDW}}$. With increasing pressure, $T_{\rm {SDW}}$ decreases and the coefficient of the quadratic term increases. These results are consistent with the prediction of the mean-field theory based on the nesting of the quasi one-dimensional Fermi surface. Using a mean field theory, $T_{\rm {SDW}}$ for the perfect nesting case is estimated as about 16 K. This means that even at ambient pressure where $T_{\rm {SDW}}$ is 12 K, the SDW phase of (TMTSF)$_2$PF$_6$ is substantially suppressed by the two-dimensionality of the system.Comment: 11pages,6figures(EPS), accepted for publication in PR