Two Particle States and the SS-matrix Elements in Multi-channel Scattering

Using a quantum mechanical model, the exact energy eigenstates for two-particle two-channel scattering are studied in a cubic box with periodic boundary conditions in all three directions. A relation between the exact energy eigenvalue in the box and the two-channel $S$-matrix elements in the continuum is obtained. This result can be viewed as a generalization of the well-known L\"uscher's formula which establishes a similar relation in elastic scattering.Comment: 18 pages, no figures. minor changes compared with previous versio

Pozzolanic and mechanical properties of Date Palm Seed Ash (Dpsa) concrete

This paper presents the findings of a research work conducted on how to improve the mechanical properties of concrete using Date Palm Seed Ash (DPSA) as partial replacement of cement. The DPSA used was obtained by controlled burning of date palm seed in a kiln at a maximum temperature of 630oC for eight hours and air cooled afterwards. The ash obtained was sieved through 75μm sieve and its oxide composition analysed using X-ray fluorescence (XRF) procedures. DoE method of mix design was used to produce concrete ingredients for grade 30N/mm2 giving a water-cement ratio of 0.53. The effect of partial replacement of cement with DPSA on cement paste and concrete using 0, 2.5, 5, 7.5, 10, 15 and 20% DPSA was investigated through consistency and setting times tests, workability test, compressive strength test (at 7, 21, 28 and 56 days curing duration), pozzolanic activity index evaluation and water absorption test. Results show that DPSA has high silicon dioxide (45.50%), aluminum oxide (20.75%) and Iron oxide (7.25%). Findings indicate that the consistency and setting times of cement-DPSA paste increased with increase in the replacement of cement with DPSA. The workability of DPSA concrete decreased with increase in cement replacement. Compressive strength test results show that cement can be replaced with DPSA up to 10% as the compressive strength at 10% replacement is 31.5N/mm2 as against the 31N/mm2 of the normal concrete, at 56 days. The pozzolanic activity index result also show that DPSA concrete meets up the minimum requirement of 75% specified by ASTM C618-15. Also, the water absorption capacity of DPSA concrete at the highest replacement (20%) is 11% less than that at 0%. Keywords: Cement, Compressive strength, Concrete, Date palm seed ash, Partial replacement, Pozzolan

A Preliminary Study of the Effectiveness of Chinese Therapeutic Food on Regulating Female Reproductive Hormones

This study investigated the effectiveness of Chinese therapeutic food on female reproductive hormones in a double-blind, placebo-controlled clinical trial. Chinese kiwi fruit extract (Hong En No. 1) was provided for Australian peri-menopausal women for one month. Chinese medical assessment and urinary 2-hydroxyestrone (2-OHE) and 16alpha-hydroxyestrone (16alpha-OHE) tests were conducted. Twenty-six urinary samples (pre and post-trial) which met the requirement of testing were analysed, the ratio 2-OHE:16alpha-OHE of pre-trial (1.18 ± 0.34) and post-trial (0.97 ± 0.29) in the control group (n = 6) decreased but showed no significant change, this ratio of pre-trial (1.44 ± 0.16) and post-trial (1.65 ± 0.21) in the treatment group (n = 7) indicated an improvement (P = 0.066), which results in beneficial hormone regulation. The Chinese medicine assessment indicated that the patterns of disharmony mainly include Liver Qi stagnation and Liver-Kidney Yin deficiency patterns. No significant change observed in the control group, significant score reduction of the patterns of disharmony was achieved at post-trial in the treatment group, which indicates an improvement of general health condition

Analytical solution of the tooling/workpiece contact interface shape during a flow forming operation

Flow forming involves complicated tooling/workpiece interactions. Purely analytical models of the tool contact area are difficult to formulate, resulting in numerical approaches that are case-specific. Provided are the details of an analytical model that describes the steady-state tooling/workpiece contact area allowing for easy modification of the dominant geometric variables. The assumptions made in formulating this analytical model are validated with experimental results attained from physical modelling. The analysis procedure can be extended to other rotary forming operations such as metal spinning, shear forming, thread rolling and crankshaft fillet rolling.Comment: 28 pages, 11 figure

Pilot, Rollout and Monte Carlo Tree Search Methods for Job Shop Scheduling

Greedy heuristics may be attuned by looking ahead for each possible choice, in an approach called the rollout or Pilot method. These methods may be seen as meta-heuristics that can enhance (any) heuristic solution, by repetitively modifying a master solution: similarly to what is done in game tree search, better choices are identified using lookahead, based on solutions obtained by repeatedly using a greedy heuristic. This paper first illustrates how the Pilot method improves upon some simple well known dispatch heuristics for the job-shop scheduling problem. The Pilot method is then shown to be a special case of the more recent Monte Carlo Tree Search (MCTS) methods: Unlike the Pilot method, MCTS methods use random completion of partial solutions to identify promising branches of the tree. The Pilot method and a simple version of MCTS, using the $\varepsilon$-greedy exploration paradigms, are then compared within the same framework, consisting of 300 scheduling problems of varying sizes with fixed-budget of rollouts. Results demonstrate that MCTS reaches better or same results as the Pilot methods in this context.Comment: Learning and Intelligent OptimizatioN (LION'6) 7219 (2012

Ophiolites in the Xing’an-Inner Mongolia accretionary belt of the CAOB: Implications for two cycles of seafloor spreading and accretionary orogenic events

The Xing'an-Inner Mongolia accretionary belt in the southeastern segment of the Central Asian Orogenic Belt (CAOB) was produced by the long-lived subduction and eventual closure of the Paleo-Asian Ocean and by the convergence between the North China Craton and the Mongolian microcontinent. Two ophiolite belts have been recognized: the northern Erenhot-Hegenshan-Xi-Ujimqin ophiolite belt and the southern Solonker-Linxi ophiolite belt. Most basalts in the northern ophiolite belt exhibit characteristics of normal-type to enriched-type mid-ocean ridge basalt affinities with depleted Nd isotopic composition (εNd(t) > +5), comparable to modern Eastern Pacific mid-ocean ridge basalts. Most basaltic rocks in the southern belt show clear geochemical features of suprasubduction zone-type oceanic crust, probably formed in an arc/back-arc environment. The inferred back-arc extension along the Solonker-Linxi belt started at circa 280 Ma. Statistics of all the available age data for the ophiolites indicates two cycles of seafloor spreading/subduction, which gave rise to two main epochs of magmatic activity at 500–410 Ma and 360–220 Ma, respectively, with a gap of ~50 million years (Myr). The spatial and temporal distribution of the ophiolites and concurrent igneous rocks favor bilateral subduction toward the two continental margins in the convergence history, with final collision at ~230–220 Ma. In the whole belt, signals of continental collision and Himalayan-style mountain building are lacking. We thus conclude that the Xing'an-Inner Mongolia segment of the CAOB experienced two cycles of seafloor subduction, back-arc extension, and final “Appalachian-type” soft collision

Deglacial history of the Pensacola Mountains, Antarctica from glacial geomorphology and cosmogenic nuclide surface exposure dating

The retreat history of the Antarctic Ice Sheet is important for understanding rapid deglaciation, as well as to constrain numerical ice sheet models and ice loading models required for glacial isostatic adjustment modelling. There is particular debate about the extent of grounded ice in the Weddell Sea embayment at the Last Glacial Maximum, and its subsequent deglacial history. Here we provide a new dataset of geomorphological observations and cosmogenic nuclide surface exposure ages of erratic samples that constrain the deglacial history of the Pensacola Mountains, adjacent to the present day Foundation Ice Stream and Academy Glacier in the southern Weddell Sea embayment. We show there is evidence of at least two glaciations, the first of which was relatively old and warm-based, and a more recent cold-based glaciation. During the most recent glaciation ice thickened by at least 450 m in the Williams Hills and at least 380 m on Mt Bragg. Progressive thinning from these sites was well underway by 10 ka BP and ice reached present levels by 2.5 ka BP, and is broadly similar to the relatively modest thinning histories in the southern Ellsworth Mountains. The thinning history is consistent with, but does not mandate, a Late Holocene retreat of the grounding line to a smaller-than-present configuration, as has been recently hypothesized based on ice sheet and glacial isostatic modelling. The data also show that clasts with complex exposure histories are pervasive and that clast recycling is highly site-dependent. These new data provide constraints on a reconstruction of the retreat history of the formerly-expanded Foundation Ice Stream, derived using a numerical flowband model

Study on Fatigue Life of Plow Bit under Different Planning Parameters

In order to study the fatigue life of plow bit under different planning parameters, the process of plow bit cutting coal seam is simulated based on a solid model. The variation of the stress in the joint between the blade and carbide head is obtained by simulating the planning process with different planning parameters of the weak joint (cutting angle, plow thickness and plow spacing). The fatigue life of the plow bit is predicted using the improved rain-flow method and the Miner linear accumulated fatigue damage model. According to the experiment on plow bit life, the stress amplitude and accumulated damage in one stroke are the least at the cutting angle of 80C, with the number of working strokes and working hours of a damaged plow bit reaching the maximum. The thicker the plow bit is, the larger is the resistance and higher is the damage. In addition, a smaller plow spacing implies a better planning ability and a smaller damage. The experimental data are consistent with the results of the theoretical analysis.С целью исследования усталостной долговечности бурового долота с различными параметрами технологического проектирования проведено моделирование процесса подрезки угольного пласта с помощью долота на основе твердотельной модели. Изменение напряжения в соединении между лопаткой и твердосплавной головкой получили путем моделирования процесса проектирования при различных параметрах разработки слабого соединения (угол подрезки, толщина и шаг долота). Усталостную долговечность долота прогнозировали с помощью усовершенствованного метода дождевого потока и правила Майнера. Согласно данным испытаний на усталость значения амплитуды напряжений и накопления повреждений за один ход являются наименьшими при угле подрезки 80, при этом количество рабочих ходов и часов поврежденного долота достигает максимума. Чем толще долото, тем больше его сопротивление и тем значительнее повреждение. Кроме того, чем меньше шаг долота, тем проще его спроектировать и тем меньше повреждение. Результаты испытаний соответствуют данным теоретического анализа.Із метою дослідження довговічності від утомленості бурового долота з різними параметрами технологічного проектування проведено моделювання процесу підрізки вугільного пласта за допомогою долота на основі твердотільної моделі. Зміну напруження в з’єднанні між лопаткою і твердосплавною головкою отримали шляхом моделювання процесу проектування за різних параметрів розробки слабкого з’єднання (кут підрізки, товщина і крок долота). Довговічність від утомленості долота спрогнозували за допомогою удосконаленого методу дощового потоку і правила Майнера. Згідно з даними випробувань на утому значення амплітуди напружень і накопичення пошкоджень за один хід є найменшими при куті підрізки 80, при цьому кількість робочих ходів і годин пошкодженого долота сягає максимуму. Чим товще долото, тим більший його опір і тим значніше пошкодження. Окрім того, чим менший крок долота, тим простіше його спроектувати і тим менше пошкодження. Результати випробувань збігаються з даними теоретичного аналізу