Développement d’un mur capteur-stockeur solaire pour le chauffage des bâtiments à très basse consommation d’énergie

Use of renewable energy is a necessary way to fight global warming and to anticipate scarcity of raw materials. The solar/storage wall used in buildings with lower energy consumption meets this evolution to renewable energy sources. In this thesis, solar energy is stored in a phase charge material (PCM), which provides latent storage. The latent storage is higher than sensible storage in usual building materials. This energy is restored to indoor air, by circulation and heating of inlet air through the wall storage element. In this thesis work, the solar storage wall was developed, based on previous published works dealing with similar systems. An experiment has been carried out with the solar storage integrated in a small wood building with a high insulation. The solar energy recovered by the wall reaches 2 kWh.m-2.day-1 and 1,5 kWh.day-1 was restored to air. In a second experiment, a prototype was developed to be used in controlled laboratory conditions. Special attention was given to PCM temperature measures to analyze the PCM thermal behavior. Two phenomena were observed: (i) liquid phase recovering solid phase, (ii) temperature homogenization in liquid phase. The PCM thermal behavior depends on interactions between three energetic flows: the charge flow (solar energy recovered), the restored flow (energy restored to the inlet air) and a vertical flow created by the liquid phase recovering. Furthermore, a numerical dynamic model for the solar storage wall was developed. It is based on a finite volume approach. This model simulates: (i) the ground effect in a solar wall, (ii) the thermal energy storage and phase changes, and (iii) heat recovery energy to air inlet. Numerical results were compared to experimental values. The model was validated for air temperature for daily cycle defined with a charge period (during sunning) and a continue air heating. The difference between numerical values and experimental values are lower than 0.6°C in mean temperature, and 10% in energy. This difference is lower than measurement uncertainties and energy calculation error margins. So the model is valeted and can be coupled with the dynamic thermal simulation code: TRNSYS.L’exploitation des énergies renouvelables est une voie nécessaire afin de lutter contre le réchauffement climatique, et afin d’anticiper la raréfaction des matières premières. Le mur capteur/stockeur solaire appliqué aux bâtiments à très basses consommations d’énergie s’inscrit dans cette volonté d’une transition vers les énergies renouvelables. Dans le cadre de ces travaux de thèse, l’énergie solaire est stockée dans des matériaux à changement de phase qui permettent un stockage de chaleur latente plus dense que le stockage sensible des matériaux de construction traditionnels. Cette énergie est restituée à l’ambiance intérieure par la circulation d’air neuf à travers l’élément de stockage. Un mur capteur/stockeur solaire a été développé en s’appuyant sur une revue bibliographique préalable des différents travaux scientifiques menés pour des problématiques similaires. Le dispositif a été expérimenté en environnement réel dans un premier temps, intégré à l’enveloppe d’un petit bâtiment en bois fortement isolé. La quantité de chaleur captée par le mur peut atteindre 2 kWh.m-2.jour-1, pour une quantité de chaleur restituée à l’air de 1,5 kWh.jour-1. Le dispositif a été testé en conditions maîtrisées de laboratoire. Une attention particulière a été portée à la mesure de température au sein même du MCP, afin d’analyser le comportement thermique de ce dernier. Deux phénomènes ont été observés : le recouvrement de la phase liquide sur la phase solide et l’homogénéisation des températures en phase liquide. Le comportement thermique du MCP dépend des interactions entre trois flux : le flux de charge (apport solaire), le flux de décharge (énergie restituée à l’air) et un flux vertical induit par le recouvrement de la phase liquide sur la phase solide. Par ailleurs, un modèle numérique dynamique du mur capteur a été développé en volumes finis. Ce modèle permet de simuler l’effet de serre du mur capteur, le stockage de chaleur et les phases de solidification et de fusion du MCP, et la restitution de chaleur à l’air entrant dans le bâtiment. Les résultats numériques alors obtenus ont été confrontés aux données expérimentales. Le modèle a été validé pour la température d’air soufflée (en sortie du mur capteur). L’écart entre valeurs expérimentales, sur des périodes journalières, est en moyenne de 0,6°C pour la température d’air soufflé et est inférieur à 10 % pour l’énergie fournie à l’air préchauffé. Ces différences sont inférieures aux incertitudes de mesures et à l’incertitude du calcul énergétique. Le modèle ainsi validé peut être couplé au code de simulation thermique dynamique du bâtiment TRNSYS

Vacuum stability and the Cholesky decomposition

We discuss how the Cholesky decomposition may be used to ascertain whether a critical point of the field theory scalar potential provides a stable vacuum configuration. We then use this method to derive the stability conditions in a specific example.Comment: 7 page

Constraints on left-right symmetric models from the process b→sγb \rightarrow s \gamma

In left-right symmetric models, large contributions to the decay amplitude $b \rightarrow s+ \gamma$ can arise from the mixing of the $W_L$ and $W_R$ gauge bosons as well as from the charged Higgs boson. These amplitudes are enhanced by the factor \mt/\mb compared to the contributions in the standard model. We use the recent CLEO results on the radiative $B$ decay to place constraints on the $W_L-W_R$ mixing angle $\zeta$ and the mass of the charged Higgs boson $m_{H^\pm}$. Significant departures from the standard model predictions occur when $|\zeta| > 0.003$ and/or when $m_{H^\pm} <$ a few TeV.Comment: in LaTeX, 12 pages + 4 figures (available on request), BA-93-69, UT-66

Anatomy of Mixing-Induced CP Asymmetries in Left-Right-Symmetric Models with Spontaneous CP Violation

We investigate the pattern of CP violation in K, B_d and B_s mixing in a symmetrical SU(2)_R x SU(2)_L x U(1) model with spontaneous CP violation. We calculate the phases of the left and right quark mixing matrices beyond the small phase approximation and perform a careful analysis of all relevant restrictions on the model's parameters from Delta m_K, Delta m_B, epsilon, epsilon'/epsilon and the CP asymmetry in B->J/psi K_S. We find that, with current experimental data, the mass of the right-handed charged gauge boson, M2, is restricted to be in the range 2.75 to 13 TeV and the mass of the flavour-changing neutral Higgs boson, MH, in 10.2 to 14.6 TeV. This means in particular that the decoupling limit M2, MH -> infinity is already excluded by experiment. We also find that the model favours opposite signs of epsilon and sin 2beta and is excluded if sin 2beta > 0.1.Comment: 33 pages Latex with 11 Postscript-Figures (included

Low-scale Quantum Gravity and Double Nucleon Decay

In models with a low quantum gravity scale, one might expect sizable effects from nonrenormalizable interactions that violate the global symmetries of the standard model. While some mechanism must be invoked in such theories to suppress higher-dimension operators that contribute to proton decay, operators that change baryon number by two units are less dangerous and may be present at phenomenologically interesting levels. Here we focus on Delta B=2 operators that also change strangeness. We demonstrate how to compute explicitly a typical nucleon-nucleon decay amplitude, assuming a nonvanishing six-quark cluster probability and MIT bag model wave functions. We then use our results to estimate the rate for other possible modes. We find that such baryon-number-violating decays may be experimentally accessible if the operators in question are present and the Planck scale is less than ~ 400 TeV.Comment: 7 pages, RevTeX, reference adde

The Minimal Left-Right Symmetric Model and Radiative Corrections to the Muon Decay

A self-consistent version of the left-right (LR) symmetric model is used to examine tree- as well as one-loop level radiative corrections to the muon decay. It is shown that constraints on the heavy sector of the model parameters are different when going beyond tree-level physics. In fact, in our case, the only useful constraints on the model can be obtained from the one-loop level calculation. Furthermore, corrections coming from the subset of SM particles within the LR model have a different structure from their SM equivalent, e.g. the top quark leading term contribution to $\Delta \rho$ within the LR model is different from its SM counterpart. As a consequence, care must be taken in fitting procedures of models beyond the SM, where usually, only tree-level couplings modified by the SM radiative corrections are considered. This procedure is not always correct.Comment: small corrections, final version for proceeding

General CP Violation in Minimal Left-Right Symmetric Model and Constraints on the Right-Handed Scale

In minimal left-right symmetric theories, the requirement of parity invariance allows only one complex phase in the Higgs potential and one in the Yukawa couplings, leading to a two-phase theory with both spontaneous and explicit CP violations. We present a systematic way to solve the right-handed quark mixing matrix analytically in this model and find that the leading order solution has the same hierarchical structure as the left-handed CKM matrix with one more CP-violating phase coming from the complex Higgs vev. Armed with this explicit right-handed mixing matrix, we explore its implications for flavor changing and conserving processes in detail, low-energy CP-violating observables in particular. We report an improved lower bound on the $W_R$ mass of 2.5 TeV from $\Delta M_K$ and $\Delta M_{B}$, and a somewhat higher bound (4 TeV) from kaon decay parameters $\epsilon$, $\epsilon'$, and neutron electric dipole moment. The new bound on the flavor-changing neutral Higgs mass is 25 TeV.Comment: 35 pages, 14 figure

Complex CKM from Spontaneous CP Violation Without Flavor Changing Neutral Current

We analyse the general constraints on unified gauge models with spontaneous CP breaking that satisfy the conditions that (i) CP violation in the quark sector is described by a realistic complex CKM matrix, and (ii) there is no significant flavor changing neutral current effects in the quark sector. We show that the crucial requirement in order to conform to the above conditions is that spontaneous CP breaking occurs at a very high scale by complex vevs of standard model singlet Higgs fields. Two classes of models are found, one consisting of pure Higgs extensions and the other one involving fermionic extensions of the standard model. We give examples of each class and discuss their possible embeddings into higher unified theories. One of the models has the interesting property that spontaneous CP violation is triggered by spontaneous P violation, thereby linking the scale of CP violation to the seesaw scale for neutrino masses.Comment: Latex file ; 18 pages; No figures; some typos correcte

Muon Decay to One Loop Order in the Left-Right Symmetric Model

One loop corrections to the muon decay are studied in a popular and self-consistent version of the Left-Right symmetric model. It is shown quantitatively, that the corrections do not split into those that come from the Standard Model sector and some decoupling terms. For a heavy Spontaneous Symmetry Breaking (SSB) scale of the order of a least 1 TeV, the contributions from the top quark have a logarithmic behaviour and there is a strong quadratic dependence on the heavy Higgs scalar masses. The dependence on the light Higgs boson mass is small. The heavy neutrinos are shown to play an important role, although secondary in comparison with the heavy scalar particles as long as the heavy neutrinos' Majorana Yukawa coupling matrix $h_M$ obeys unitarity bounds.Comment: 20 pages, 7 figure

On Neutrino Masses and a Low Breaking Scale of Left-Right Symmetry

In left-right symmetric models (LRSM) the light neutrino masses arise from two sources: the seesaw mechanism and a VEV of an SU(2)$_L$ triplet. If the left-right symmetry breaking, $v_R$, is low, v_R\lsim15\TeV, the contributions to the light neutrino masses from both the seesaw mechanism and the triplet Yukawa couplings are expected to be well above the experimental bounds. We present a minimal LRSM with an additional U(1) symmetry in which the masses induced by the two sources are below the eV scale and the two-fold problem is solved. We further show that, if the U(1) symmetry is also responsible for the lepton flavor structure, the model yields a small mixing angle within the first two lepton generations.Comment: 18 pages references added published versio