EFFECT OF SELECTED PHASE CHANGE MATERIALS CONCENTRATION AND MANUFACTURING PROCESS ON THE PROPERTIES OF PLASTER MIXTURE SYSTEMS

Phase change materials (PCM) are generally used in building construction materials for their ability to absorb and release large amounts of energy when their phase change happens at their specific melting temperature. This results in a significant increase in thermal mass of the building, a reduction in temperature fluctuations and therefore a reduction in heating and cooling loads. However, in order to properly select a PCM and optimize its integration in a specific building, the properties of building construction materials enhanced with PCM must be known. This research focuses on studying the effects of the concentration of a micro-encapsulated PCM on the physical, thermal, and mechanical properties of plaster mixtures. A series of gypsum wallboard samples with integrated Microtek 18D of varying concentration up to 40% in weight were prepared and analyzed using macro-scale analysis methods (i.e., thermal pile and flash method for measuring thermal conductivity, Thermogravimetric Analysis, Differential Scanning Calorimetry, and three-point bending test) and micro-scale analysis methods (i.e., Scanning Electron Microscopy, Energy Dispersive Spectroscopy) to evaluate the effect of PCM on the properties of gypsum wallboards, and the effect of the curing process on the properties of gypsum wallboards. The results suggest that the curing process has an impact on the effect of the PCM concentration on material properties

Beyond Newtonian Mechanics: An Exploration of Active Force in Complex Swing Motions

Life mechanics, an emerging field, focuses on the self-organizing forces and motions within living systems. This study introduces the novel concept of active force, generated by mind-body interactions, as an essential element in understanding self-organizing movements. We propose a new set of control equations to model the self-pumping swing motion by incorporating the active force into Newton's second law. With this new mechanical framework, we analyzed the child's complex swing motions with rapid standing and squatting movements. The results reveal a pulse-like pattern of the active force along the swing length, driving changes in the radial speed and swing length. This active force counteracts the resistance and propels the swing, which is not attainable by the stone. Thus, active force underlies self-organization in living systems, warranting further exploration of its mechanics in life movements.Comment: 22 pages, 7 figure

Land Policy and Systematic Transformation in Chinese Rural Areas（1950—1978）

Based on historical review of the Chinese rural land policy from 1950 to 1978, we looked back the devious journey undergone in Chinese rural areas during this period. At first, the landlord’s ownership was transferred into the peasant’s ownership; and then private ownership was transferred into public ownership. The radical transformation of property right and process of agricultural cooperation went against the economic law and the wills of the mass peasants, which led to laggard rural productive forces and long-term low peasants’ income level. During the policy transformation process, political and ideological factors played the predominant role, which led to harmful results. The experiences in this period demonstrated that the economic developmental model and systematic arrangement in Chinese rural areas should satisfy the peasants’ free wills and protect the peasants’ essential interests. Only in this way could the Chinese rural economy gain fast development. Key Words: Chinese Rural Areas, Land Policy, System Arrangement, Ideology, Interests Abstrait: Basés sur une révision historique de la politique de terre dans les régions rurales de Chine de 1950 à 1978, nous avons mené un examen rétrospectif sur le parcours détourné qu’avaient traversé ces régions pendant cette période. Au début, les terres des propriétaires fonciers avaient été transférées comme propriétés des paysans ; et puis, les propriétés privées avaient été transféré comme propriétés publiques. La transformation radicale du droit de propriété et le processus de la coopération agricole après la réforme de terre allaient à l’encontre de la loi économique et de la volonté des paysans, ce qui avait conduit à un retard des forces productives dans les régions rurales et à un niveau de revenu très inférieur pour les paysans chinois. Dans ce processus de transformation de politiques, les facteurs politiques et idéologiques avaient joué un rôle prédominant, d’où des résultats défavorables. Les expériences que nous avons tirées pendant cette période montrent bien que le modèle du développement économique et l’arrangement systématique dans les régions rurales de Chine doivent satisfaire la volonté des paysans et protéger leurs intérêts fondamentaux. C’est aussi le seul moyen qui permette aux régions rurales de Chine de réaliser un développement rapide. Mots Clés: Régions Rurales de Chine, Politique de Terre, Transformation Systématique, Idéologie,Intérêt

GeV Scale Asymmetric Dark Matter from Mirror Universe: Direct Detection and LHC Signatures

Mirror universe is a fundamental way to restore parity symmetry in weak interactions. It naturally provides the lightest mirror nucleon as a unique GeV-scale asymmetric dark matter particle candidate. We conjecture that the mirror parity is respected by the fundamental interaction Lagrangian, and its possible soft breaking arises only from non-interaction terms in the gauge-singlet sector. We realize the spontaneous mirror parity violation by minimizing the vacuum Higgs potential, and derive the corresponding Higgs spectrum. We demonstrate that the common origin of CP violation in the visible and mirror neutrino seesaws can generate the right amount of matter and mirror dark matter via leptogenesis. We analyze the direct detections of GeV-scale mirror dark matter by TEXONO and CDEX experiments. We further study the predicted distinctive Higgs signatures at the LHC.Comment: 16pp. Plenary talk presented by HJH at the International Symposium on Cosmology and Particle Astrophysics (CosPA2011). To appear in the conference proceedings of IJMP. Minor refinement

Atomic-resolution imaging of magnetism via ptychographic phase retrieval

Atomic-scale characterization of spin textures in solids is essential for understanding and tuning properties of magnetic materials and devices. While high-energy electrons are employed for atomic-scale imaging of materials, they are insensitive to the spin textures. In general, the magnetic contribution to the phase of high-energy electron wave is 1000 times weaker than the electrostatic potential. Via accurate phase retrieval through electron ptychography, here we show that the magnetic phase can be separated from the electrostatic one, opening the door to atomic-resolution characterization of spin textures in magnetic materials and spintronic devices.Comment: 20 pages, 9 figure