Opto-mechanical subsystem with temperature compensation through isothemal design

An opto-mechanical subsystem for supporting a laser structure which minimizes changes in the alignment of the laser optics in response to temperature variations is described. Both optical and mechanical structural components of the system are formed of the same material, preferably beryllium, which is selected for high mechanical strength and good thermal conducting qualities. All mechanical and optical components are mounted and assembled to provide thorough thermal coupling throughout the subsystem to prevent the development of temperature gradients

Small, efficient power supply for xenon lamps

Device, which operates from 28 V dc, has four sections, a preregulator, a dc-to-dc converter, a current regulator, and a high voltage starter. The unique characteristics of the individual sections are described

Temperature dependence of species concentrations near the substrate during diamond chemical vapor deposition

Measurements have been made of the temperature dependence of CH3, CH4, and C2H2 very near the substrate during filament-assisted diamond growth. CH3 was detected using (2+1) resonance-enhanced multiphoton ionization (REMPI), and CH4 and C2H2 concentrations were measured using sampling mass spectrometry. A strong dependence of the CH3 REMPI signal on substrate temperature was observed, which at low temperatures may be characterized as having an activation energy of approximately 4±1 kcal/mole. Methane and acetylene, on the other hand, are relatively independent of substrate temperature. These results are most likely due to recombination of methyl to methane or ethane in the cool gas layer near the substrate or on the surface at low substrate temperatures

Addressable time division multiplexer system /cable and connector study/ Final report

Reliability studies of single interrogation and single data cables used in prototype addressable time division multiplexer syste

Detection of Turbidity Dynamics in Tampa Bay, Florida Using Multispectral Imagery from ERTS-1

Detection of turbidity dynamics in Tampa Bay, Florida using multispectral imagery from ERTS-

Incommensurate chirality density wave transition in a hybrid molecular framework

Using single-crystal X-ray diffraction we characterise the 235\,K incommensurate phase transition in the hybrid molecular framework tetraethylammonium silver(I) dicyanoargentate, [NEt$_4$]Ag$_3$(CN)$_4$. We demonstrate the transition to involve spontaneous resolution of chiral [NEt$_4$]$^+$ conformations, giving rise to a state in which molecular chirality is incommensurately modulated throughout the crystal lattice. We refer to this state as an incommensurate chirality density wave (XDW) phase, which represents a fundamentally new type of chiral symmetry breaking in the solid state. Drawing on parallels to the incommensurate ferroelectric transition of NaNO$_2$ we suggest the XDW state arises through coupling between acoustic (shear) and molecular rotoinversion modes. Such coupling is symmetry-forbidden at the Brillouin zone centre but symmetry-allowed for small but finite modulation vectors $\mathbf q=[0,0,q_z]^\ast$. The importance of long-wavelength chirality modulations in the physics of this hybrid framework may have implications for the generation of mesoscale chiral textures, as required for advanced photonic materials.Comment: 5 pages, 3 figure

Mental health and spiritual well-being in humanitarian crises: the role of faith communities providing spiritual and psychosocial support during the COVID-19 pandemic

Across the globe, people’s reactions to the COVID-19 pandemic and its accompanying lockdowns highlighted, and continued to stress, the relevance of mental health and psychosocial support (MHPSS) in responding to crises, including in low-income and emergency settings. They also demonstrated the importance of faith practices and communities of faith as core needs and important coping mechanisms for many affected people in times of crisis. Drawing on data collected by World Vision International, the world’s largest child-focused humanitarian and development organisation, in the course of its response to COVID-19 in 70 different countries, this article explores the ways in which faith groups and faith leaders responded to the perceived needs of their communities. While keen to offer psychosocial support to people suffering anxiety and fear in the context of the crisis, this has often been integrated with spiritual support. Analysing their work from the framework of a rights-based approach to mental health, we conclude that they did contribute to psychosocial support through their MHPSS, in part through their provision of spiritual care. However, spiritual well-being should not be conflated with psychosocial well-being. While faith groups play an important role in MHPSS, their primary role is to offer spiritual care

Spatial Analysis of Market Linkages in North Carolina Using Threshold Autoregression Models with Variable Transaction Costs

In North Carolina, where soybeans and corn are the two primary crops, the recent increase in the demand for U.S. corn has triggered a shift of farm acreage from soybeans to corn, leading to a rapid rise in prices of both commodities. However, the rate of the price changes, as well as the price level, is significantly different in markets that are located in different parts of the state. This study extends the literature that examines linkages between spatially separated markets by using a threshold autoregressive model with a less restrictive assumption for estimating the transaction cost neutral band -- the band within which trade is not profitable. This generalization allows the neutral band of transactions costs to change according to various external factors, including fuel costs and seasonality. The estimation results indicate that for longer time series data, variable thresholds models statistically outperform the constant thresholds specification, and may provide a better representation of corn and soybean price data. Additionally, impulse response functions that use the asymmetric variable threshold model parameters indicate that the magnitude of the shock as well as the time-to-price-parity-equilibrium in the linked markets may be underestimated if a constant thresholds specification is implemented.threshold autoregression, spatially separated markets, impulse response, neutral band, Demand and Price Analysis, Marketing, Q11, Q13,