Shock Temperature of Stainless Steel and a High Pressure - High Temperature Constraint on Thermal Diffusivity of Al_2O_3

Time dependent shock temperatures were measured for stainless steel (SS) films in contact with transparent anvils. The anvil/window material was the same as the driver material so that there would be symmetric heat flow from the sample. Inferred Hugoniot temperatures, T_h , of 5800–7500 K at 232–321 GPa are consistent with previous measurements in SS. Temperatures at the film‐anvil interface (T_i ), which are more directly measured than T_h , indicate that T_i did not decrease measurably during the approximately 250 ns that the shock wave was in Al_2O_3 or LiF anvils. Thus an upper bound is obtained for the thermal diffusivity of Al_2O_3 at the metal/anvil interface at 230 GPa and 6000K of κ≤0.00096 cm_2/s. This is a factor of 17 lower than previously calculated values, resulting in a decrease of the inferred T_h by 730 k. The observed shock temperatures are combined with temperatures calculated from measured Hugoniots and are used to calculate thermal conductivities of Al_2O_3. Also we note that since there was no measurable intensity decrease during the time when the shock wave propagated through the window, we infer from this that Al_2O_3 remained transparent while in the shocked state. Thus sapphire is a good window material to at least 250 GPa for shock temperature measurements for metals

Electronic structure and excited state dynamics in a dicyanovinyl-substituted oligothiophene on Au(111)

Dicyanovinyl (DCV)-substituted oligothiophenes are promising donor materials in vacuum-processed small-molecule organic solar cells. Here, we studied the structural and the electronic properties of DCV-dimethyl-pentathiophene (DCV5T-Me2) adsorbed on Au(111) from submonolayer to multilayer coverages. Using a multi-technique experimental approach (low-temperature scanning tunneling microscopy/spectroscopy (STM/STS), atomic force microscopy (AFM), and two-photon photoemission (2PPE) spectroscopy), we determined the energetic position of several affinity levels as well as ionization potentials originating from the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbitals (HOMO), evidencing a transport gap of 1.4 eV. Proof of an excitonic state was found to be a spectroscopic feature located at 0.6 eV below the LUMO affinity level. With increasing coverage photoemission from excitonic states gains importance. We were able to track the dynamics of several electronically excited states of multilayers by means of femtosecond time-resolved 2PPE. We resolved an intriguing relaxation dynamics involving four processes, ranging from sub-picosecond (ps) to several hundred ps time spans. These show a tendency to increase with increasing coverage. The present study provides important parameters such as energetic positions of transport levels as well as lifetimes of electronically excited states, which are essential for designing organic-molecule-based optoelectronic devices

Ice is born in low-mobility regions of supercooled liquid water

When an ice crystal is born from liquid water, two key changes occur: (i) The molecules order and (ii) the mobility of the molecules drops as they adopt their lattice positions. Most research on ice nucleation (and crystallization in general) has focused on understanding the former with less attention paid to the latter. However, supercooled water exhibits fascinating and complex dynamical behavior, most notably dynamical heterogeneity (DH), a phenomenon where spatially separated domains of relatively mobile and immobile particles coexist. Strikingly, the microscopic connection between the DH of water and the nucleation of ice has yet to be unraveled directly at the molecular level. Here we tackle this issue via computer simulations which reveal that (i) ice nucleation occurs in low-mobility regions of the liquid, (ii) there is a dynamical incubation period in which the mobility of the molecules drops before any ice-like ordering, and (iii) ice-like clusters cause arrested dynamics in surrounding water molecules. With this we establish a clear connection between dynamics and nucleation. We anticipate that our findings will pave the way for the examination of the role of dynamical heterogeneities in heterogeneous and solution-based nucleation

Composite materials for innovative urban farming of alternative food sources (macroalgae and crickets)

Facing an inexorable growth of the human population along with substantial environmental changes, the assurance of food security is a major challenge of the present century. To ensure responsible food consumption and production (SDG 12), new approaches in the food system are required. Thus, environmentally controlled, sustainable production of alternative food sources are of key interest for both urban agriculture and food research. To face the current challenge of integrating food production systems within existing structures, multidisciplinary discourses are required. Here, we bring together novel technologies and indoor farming techniques with the aim of supporting the development of sustainable food production systems. For this purpose, we investigated the feasibility of 10 composite materials for their innovative use as structural support in macroalgal cultivation (settlement substrates) and cricket rearing (housing). Considering material resistance, rigidity, and direct material-organism interactions, the bio-based composite polylactic acid (PLA) was identified as a suitable material for joint farming. For macroalgae cultivation, PLA sustained the corrosive cultivation conditions and provided a suitable substrate without affecting the macroalgal physiology or nutritional composition (carotenoids and chlorophylls). For cricket rearing, PLA provided a suitable and recyclable shelter, which was quickly accepted by the animals without any observed harm. In contrast, other common composite components like phenolic resin or aramid were found to be unsuitable due to being harmful for the cultivated organisms or instable toward the applied sterilization procedure. This multidisciplinary study not only provides profound insights in the developing field of urban indoor food production from a new perspective, but also bridges material science and farming approaches to develop new sustainable and resilient food production systems

Micro droplet formation towards continuous nanoparticles synthesis

In this paper, micro droplets are generated in a microfluidic focusing contactor and then they move sequentially in a free-flowing mode (no wall contact). For this purpose, two different micro-flow glass devices (hydrophobic and hydrophilic) were used. During the study, the influence of the flow rate of the water phase and the oil phase on the droplet size and size distribution was investigated. Moreover, the influence of the oil phase viscosity on the droplet size was analyzed. It was found that the size and size distribution of the droplets can be controlled simply by the aqueous phase flow rate. Additionally, 2D simulations to determine the droplet size were performed and compared with the experiment.Marek Wojnicki, Magdalena Luty-Błocho, Volker Hessel, Edit Csapó, Ditta Ungor and Krzysztof Fitzne

ДО ПИТАННЯ ПРО ЄДНІСТЬ ДВОРЯНСЬКОЇ ВЕРСТВИ (НА ПРИКЛАДІ КАТЕРИНОСЛАВСЬКОГО ДВОРЯНСТВА)

Встатті аналізуються внутрішньокорпоративні відносинидворянської верстви на прикладі Катеринославської губерніїCorporate Relationships ofNobility inKaterinoslavRegion are analyzed in this articl

Preliminary survey of polychlorinated biphenyls (PCBs) in aquatic habitats and Great Blue Herons on the Hanford Site. [Ardea herodias]

Polychlorinated biphenyls (PCBs), constituents of insulating fluids used in electrical transformers and capacitors, were identified during a preliminary survey of waters, sediments, and fish from five locations on the Hanford Site in southeastern Washington State: Gable Mountain Pond, B Pond, West Pond, White Bluffs Slough on the Columbia River, and a pond on the Wahluke Slope. These aquatic areas are all within the foraging range of great blue herons (Ardea herodias) that nest on the Hanford Site. Of those waters that contained PCBs, concentrations were found to be somewhat over 1 ng/L, but less than 20 ng/L, and equal to or less than concentrations reported for other freshwater regions of the United States. The PCBs in sediments and fish closely resembled the chromatographic profile of Aroclor 1260, a commercial PCB mixture produced in the United States by the Monsanto Company. Concentrations of PCBs detected in the sediments were 10 to 100 times lower than those found in soils and sediments from other areas of the nation. Concentrations of PCBs in fat from Hanford great blue herons ranged from 3.6 to 10.6 ppM, while PCB concentrations in herons from other areas of the Pacific Northwest ranged from 0.6 to 15.6 ppM. Great blue herons at Hanford contained PCB isomer distributions closely matching that of Aroclor 1260; great blue herons from other locations contained isomer distributions indicating the presence of a mixture of aroclors. 21 refs., 13 figs., 8 tabs

Effects of Feeding Increasing Levels of HP 300 on Nursery Pig Performance

A total of 1,215 pigs (PIC 337 × 1050; initial BW 11.3 lb) were used in a 43-d growth trial evaluating the effects of feeding increasing HP 300 (Hamlet Protein, Findlay, OH) on nursery pig performance. Pigs were weaned at 16 to 19 d of age and placed in pens, with each pen containing a mix of barrows and gilts. Pens of pigs were weighed and allotted by BW to 1 of 5 dietary treatments in a randomized complete block design with 27 pigs per pen and 9 pens per treatment. The control diet was a standard cornsoybean meal-based diet with 7.5 and 5.63% fish meal (FM) included in phases 1 and 2, respectively. First, the diet with the highest inclusion of HP 300 (phase 1 – 20%; phase 2 – 15%) was formulated and 2 intermediate diets (low and medium HP 300) were then created to have an equal stepwise increase in HP 300 with the HP 300 included at the expense of soybean meal and fish meal. A fifth treatment was then formulated to have the same amount of soybean meal as the control diet, with HP 300 replacing fish meal. From d 22 to 43, a common phase 3 diet was fed to all pigs. Phase 1 diets were fed in pellet form, while phases 2 and 3 were fed in meal form. From d 0 to 7 (phase 1), increasing HP 300 at the expense of soybean meal and fish meal decreased ADFI (quadratic, P = 0.001) in pigs fed the low HP 300 diet, but then increased as HP 300 was increased. No differences were observed for ADG or F/G. Furthermore, performance did not differ between pigs fed the fish meal control diet and pigs fed the diet with HP 300 replacing fish meal. During phase 2 (d 7 to 22), ADG and ADFI decreased (linear, P \u3c 0.05) as HP 300 increased at the expense of soybean meal and fish meal resulting in a tendency for poorer F/G (quadratic, P = 0.073). However, no differences were observed between pigs fed the fish meal control diet and pigs fed HP 300 replacing fish meal. For the entire period when the specialty protein sources were fed (d 0 to 22), pigs fed increasing HP 300 had poorer ADG, ADFI, and final BW (linear, P \u3c 0.05) as HP 300 increased, but there were no differences observed for F/G. In addition, there were no differences observed between pigs fed the fish meal control diet and pigs fed the HP 300 diet replacing fish meal. From d 22 to 43 (phase 3) when a common diet was fed, F/G tended (quadratic, P = 0.075) to improve as HP 300 increased in the previous diets with pigs previously fed the diet with the low inclusion of HP 300 having the best F/G. Overall (d 0 to 43), pigs fed increasing HP 300 had a tendency for poorer ADFI (linear, P = 0.071) resulting in a decreased final BW (linear, P = 0.043). However, no differences were observed for growth performance between pigs fed the fish meal control diet and pigs fed HP 300 replacing fish meal. For the economic analysis, feed cost per pig and cost per pound of gain decreased (linear, P \u3c 0.05) for pigs fed increasing HP 300. However, there were no differences detected for revenue per pig and income over feed cost. In conclusion, increasing HP 300 up to 15 to 20% of the diet for the first 22 d post-weaning at the expense of soybean meal and fish meal resulted in a decrease in final BW at the end of the nursery period

Universal finite-size scaling for percolation theory in high dimensions

We present a unifying, consistent, finite-size-scaling picture for percolation theory bringing it into the framework of a general, renormalization-group-based, scaling scheme for systems above their upper critical dimensions $d_c$. Behaviour at the critical point is non-universal in $d>d_c=6$ dimensions. Proliferation of the largest clusters, with fractal dimension $4$, is associated with the breakdown of hyperscaling there when free boundary conditions are used. But when the boundary conditions are periodic, the maximal clusters have dimension $D=2d/3$, and obey random-graph asymptotics. Universality is instead manifest at the pseudocritical point, where the failure of hyperscaling in its traditional form is universally associated with random-graph-type asymptotics for critical cluster sizes, independent of boundary conditions.Comment: Revised version, 26 pages, no figure