High Intrinsic Mobility and Ultrafast Carrier Dynamics in Multilayer Metal Dichalcogenide MoS2

The ultimate limitations on carrier mobilities in metal dichalcogenides, and the dynamics associated with carrier relaxation, are unclear. We present measurements of the frequency-dependent conductivity of multilayer dichalcogenide MoS2 by optical-pump terahertz-probe spectroscopy. We find mobilities in this material approaching 4200 cm2/Vs at low temperatures. The temperature dependence of scattering indicates that the mobility, an order of magnitude larger than previously reported for MoS2, is intrinsically limited by acoustic phonon scattering at THz frequencies. Our measurements of carrier relaxation reveal picosecond cooling times followed by recombination lasting tens of nanoseconds and dominated by Auger scattering into defects. Our results provide a useful context in which to understand and evaluate the performance of MoS2-based electronic and optoelectronic devices.Comment: 13 pages, 8 figure

COMPASSION FATIGUE AND THE SENSE OF COHERENCE IN CAREGIVERS WORKING WITH SEXUALLY ABUSED CHILDREN IN SOWETO

Faculty of Humanities School of Human and Community Development 0206924r [email protected] aim of this study was to contribute to literature the effects of working with traumatized children in a continuous traumatic stress environment more specifically in a township which is historically known as characterised by criminal activities and political oppression, Soweto. The study investigates the levels of compassion fatigue and the sense of coherence of caregivers working in a continuous traumatic stress environment. Working with trauma victims especially children who are perceived as vulnerable and helpless may leave caregivers with feelings of helplessness and hopelessness, anger towards the perpetrators or anger toward the parents for being unable to protect the children. Caregivers may view the environment as unsafe for both their own children and the traumatized children that they treat. These emotions may lead to compassion fatigue, meaning that the caregiver’s relationships at home and work become affected due to trauma work. The caregiver’s ability to manage or cope with a stressful situation may also be affected causing their levels of the sense of coherence to be compromised. This study investigated the levels of compassion fatigue and the sense of coherence among caregivers who work with sexually abused children in Soweto. Compassion fatigue was assessed by using the Compassion Fatigue Scale (CFS) (Figley, 1995, Stamm, 1996). The sense of coherence was measured by the Orientation to Life Questionnaire (OLQ) Antonvosky (1987). The sample group consisted of 25 caregivers working in Soweto. These included nurses, teachers, counsellors and social workers from this area. 2 Results of the study indicated that the majority of the respondents manifested an extremely high risk of compassion fatigue based on the high scores they obtained on the Compassion Fatigue Scale. Interestingly the levels of the sense of coherence for the majority of the participants were also high, which contradicts previous findings. Findings from the qualitative data revealed positive and negative emotions related to the nature of their work. It also became apparent that caregivers with limited resources become frustrated and manifested feelings of inadequacy due to poor referral systems and there was no feedback from other organisation that deal with the children they worked with. Leaving caregivers with feelings of isolation. It also emerged that caregivers used a range of coping strategies in dealing with stressful situations

Environmental Regulations and the Structure of U.S. Hog Farms

The U.S hog production industry has been continually subjected to rapid structural changes since the early 1990s. The industry's move towards more concentrated large hog farms and geographical concentration of such farms, have triggered public concerns over the dangers such big animal feeding operations are likely to pose to the waters of the country. This study investigates the implications of state-level environmental regulations on the structure of hog farms. The results of this study suggest that environmental regulations will result in one of three possible scenarios: (1) a more competitive industry in which small hog operations are not adversely affected which will allow more small operations to enter rather than exit the industry; (2) a more concentrated hog production industry in which large operations survive while small operations exit the industry; (3) no change in the structure of the industry where both sizes of operations are not significantly affected by environmental stringency.Perfect competition, U.S. hog production industry, Environmental regulations, Environmental Economics and Policy, Livestock Production/Industries,

FOREIGN DIRECT INVESTMENT IN ALBANIA. A STUDY ON INVESTORS MOTIVATION

FDI are considered an important factor to the economic growth of Albania. Transition to market economy and the democratic changes in the Albanian society after the 90s paved the way to the establishment of a legal framework which encouraged the flow of foreign investment. This study shows the reasons for investor motivation in Albania, considering such factors as reasons related to the low labor cost, infrastructure quality, cost of services and stimulators packages. The study is trying to find out whether investments made from foreign investors have fulfilled their predictions and if they will continue to invest in the future