Experimental Study on Match for Indoor and Outdoor Heat Exchanger of Residential Air-conditioner

In this study, the effects of indoor unit heat transfer area and air flow rate and outdoor unit air flow rate on the system performance of residential air-conditioner were experimentally investigated under rated cooling and heating conditions. The experimental results showed that the system cooling capacity, EER, heating capacity and COP all had evident variation with indoor unit heat transfer area and air flow rate and out unit air flow rate, which predicated that there was a proper match range for indoor unit and outdoor unit to make the system overall performance best. The increase of indoor unit heat transfer area and air flow rate significantly improved system cooling and heating performances especially for the smaller heat transfer area indoor unit, and the improvement was more obvious for heating performance. The heat transfer area ratio of indoor unit and outdoor unit was smaller, the indoor unit air flow rate should be designed as higher air velocity, but that should not be higher than 1.2m/s. In addition, with the specified outdoor unit in this study, the matched heat transfer area of indoor unit should not be too high or too low, and the optimal heat transfer area ratio of indoor and outdoor unit was between 0.33 and 0.37, which was better to choose the smaller value for higher indoor unit air flow rate. The increase of outdoor unit air flow rate also was advantageous for improving system cooling and heating performances especially for system EER and COP, but excessive higher air flow rate can cause the degradation of the system performance. The proposed outdoor unit designed air velocity should not be higher than 1.6m/s

Contribution à la modélisation et à la simulation de la machine synchrone soumise à des défauts internes

Les défauts internes dans les enroulements statoriques de la machine synchrone sont considérés très sévères car ils génèrent des courants élevés dans la machine dont les effets peuvent endommager les enroulements et parfois même les parties mécaniques de la machine telles que l'arbre et les paliers. Les modèles de simulation des défauts internes offrent un moyen commode et efficace pour étudier les comportements de la machine synchrone soumise à des défauts internes permettant d'évaluer les systèmes de surveillance et de protection. Le présent travail propose des méthodes de modélisation et de simulation des défauts internes de la machine synchrone. Les défauts internes entraînent deux nouvelles problématiques. La première est liée au changement de la distribution d'enroulement et la seconde est le changement du nombre de phases (ou enroulements). Ces deux caractéristiques sont au centre de la modélisation des défauts internes et ne correspondent pas aux hypothèses simplificatrices de la théorie de Park. Partant de l'hypothèse que la saturation magnétique est négligée et que la machine est considérée comme un système linéaire, cette thèse propose des solutions aux problématiques exposées précédemment. En s'appuyant sur la théorie de la fonction de bobinage, une nouvelle approche de détermination des inductances des enroulements à distribution arbitraire est proposée. Les ondes complètes de la fonction de bobinage des enroulements sont utilisées dans le calcul des inductances de la machine. Donc, toutes les harmoniques d'espace peuvent être prises en compte d'une façon simple. Deux expressions des inductances sont proposées: l'une utilise les paramètres géométriques de la machine, tandis que l'autre utilise les paramètres électriques de la machine. Les représentations d'état pour tous les types de défauts internes statoriques, soit les défauts entre phases et la terre, les défauts entre deux phases et les défauts entre deux bobines d'une même phase, sont présentées dans cette thèse. En outre, un modèle simplifié de défauts internes de la machine synchrone utilisant uniquement les paramètres électriques est aussi présenté. La validation des modèles est effectuée par comparaison des résultats de simulation avec ceux obtenus par des essais sur une machine réelle

Experimental Investigation of the Refrigerant Flow Distribution Characteristic of Heat Exchangers on the Residential Heat Pump Air Conditioner System Performance

In this study, the refrigerant flow distribution characteristic of fin-and-tube heat exchanger used as outdoor and indoor heat exchanger of a residential heat pump air-conditioner was experimentally studied and analyzed. The outdoor heat exchanger included “n shape†1 -circuit, 2-circuit and 3-circuit arrangements, and the indoor heat exchanger was only “n shape†2–ciucuit arrangement. It showed that the refrigerant flow distribution of both outdoor and indoor heat exchanger as evaporator would give much more system performance change of the residential heat pump air-conditioner than that as condenser. The refrigerant flow distribution characteristic can be expressed with the difference value of each circuit exit superheat as evaporator. The maximum difference value with little effect on system performance had been obtained both under cooling mode and heating mode. The maximum difference value was nearly the same at various test conditions and can be considered as 3℃. According to the experimental results, the system performance under heating mode especially for rated heating mode had more sensitive with refrigerant flow distribution characteristic than that under cooling mode, therefore the adjustment of refrigerant distribution characteristic of both the outdoor and indoor heat exchanger should mainly base on the rated heating mode

Study of R161 Refrigerant for Residential Air-conditioning Applications

In order to investigate the feasibility of R161 applied in residential air conditioner, the thermodynamic performance and comprehensive theoretical thermodynamic cycle of R161, R22 and R290 under various air-conditioner operating condition were carried out. Further more, the cooling and heating performance of R161 and R22 under various operating condition was investigated experimentally in a 3.5kW residential heat pump air conditioner. Property and thermodynamic cycle comparison showed that R161 has better thermodynamic performance than R290, the rated cooling and heating capacity is lower than R22 but higher than R290, the rated cooling and heating COP is higher than both R22 and R290. The experimental rated cooling capacity reduced 7.6% and rated cooling EER increased 6.1%, rated heating capacity reduced 6.8% and rated heating COP increased 4.7%, refrigerant optimized charge reduced 43% compared to R22 system, theoretical and experimental test revealed that R161 has lower discharge temperature than R22 system

Expansion and systematics redefinition of the most threatened freshwater mussel family, the Margaritiferidae.

Two Unionida (freshwater mussel) families are present in the Northern Hemisphere; the Margaritiferidae, representing the most threatened of unionid families, and the Unionidae, which include several genera of unresolved taxonomic placement. The recent reassignment of the poorly studied Lamprotula rochechouartii from the Unionidae to the Margaritiferidae motivated a new search for other potential species of margaritiferids from members of Gibbosula and Lamprotula. Based on molecular and morphological analyses conducted on newly collected specimens from Vietnam, we here assign Gibbosula crassa to the Margaritiferidae. Additionally, we reanalyzed all diagnostic characteristics of the Margaritiferidae and examined museum specimens of Lamprotula and Gibbosula. As a result, two additional species are also moved to the Margaritiferidae, i.e. Gibbosula confragosa and Gibbosula polysticta. We performed a robust five marker phylogeny with all available margaritiferid species and discuss the taxonomy within the family. The present phylogeny reveals the division of Margaritiferidae into four ancient clades with distinct morphological, biogeographical and ecological characteristics that justify the division of the Margaritiferidae into two subfamilies (Gibbosulinae and Margaritiferinae) and four genera (Gibbosula, Cumberlandia, Margaritifera, and Pseudunio). The systematics of the Margaritiferidae family is re-defined as well as their distribution, potential origin and main biogeographic patterns

Methodology and experiences of rapid advice guideline development for children with COVID-19: responding to the COVID-19 outbreak quickly and efficiently

BACKGROUND: Rapid Advice Guidelines (RAG) provide decision makers with guidance to respond to public health emergencies by developing evidence-based recommendations in a short period of time with a scientific and standardized approach. However, the experience from the development process of a RAG has so far not been systematically summarized. Therefore, our working group will take the experience of the development of the RAG for children with COVID-19 as an example to systematically explore the methodology, advantages, and challenges in the development of the RAG. We shall propose suggestions and reflections for future research, in order to provide a more detailed reference for future development of RAGs. RESULT: The development of the RAG by a group of 67 researchers from 11 countries took 50 days from the official commencement of the work (January 28, 2020) to submission (March 17, 2020). A total of 21 meetings were held with a total duration of 48 h (average 2.3 h per meeting) and an average of 16.5 participants attending. Only two of the ten recommendations were fully supported by direct evidence for COVID-19, three recommendations were supported by indirect evidence only, and the proportion of COVID-19 studies among the body of evidence in the remaining five recommendations ranged between 10 and 83%. Six of the ten recommendations used COVID-19 preprints as evidence support, and up to 50% of the studies with direct evidence on COVID-19 were preprints. CONCLUSIONS: In order to respond to public health emergencies, the development of RAG also requires a clear and transparent formulation process, usually using a large amount of indirect and non-peer-reviewed evidence to support the formation of recommendations. Strict following of the WHO RAG handbook does not only enhance the transparency and clarity of the guideline, but also can speed up the guideline development process, thereby saving time and labor costs

Methodology and experiences of rapid advice guideline development for children with COVID-19: responding to the COVID-19 outbreak quickly and efficiently.

BACKGROUND Rapid Advice Guidelines (RAG) provide decision makers with guidance to respond to public health emergencies by developing evidence-based recommendations in a short period of time with a scientific and standardized approach. However, the experience from the development process of a RAG has so far not been systematically summarized. Therefore, our working group will take the experience of the development of the RAG for children with COVID-19 as an example to systematically explore the methodology, advantages, and challenges in the development of the RAG. We shall propose suggestions and reflections for future research, in order to provide a more detailed reference for future development of RAGs. RESULT The development of the RAG by a group of 67 researchers from 11 countries took 50 days from the official commencement of the work (January 28, 2020) to submission (March 17, 2020). A total of 21 meetings were held with a total duration of 48 h (average 2.3 h per meeting) and an average of 16.5 participants attending. Only two of the ten recommendations were fully supported by direct evidence for COVID-19, three recommendations were supported by indirect evidence only, and the proportion of COVID-19 studies among the body of evidence in the remaining five recommendations ranged between 10 and 83%. Six of the ten recommendations used COVID-19 preprints as evidence support, and up to 50% of the studies with direct evidence on COVID-19 were preprints. CONCLUSIONS In order to respond to public health emergencies, the development of RAG also requires a clear and transparent formulation process, usually using a large amount of indirect and non-peer-reviewed evidence to support the formation of recommendations. Strict following of the WHO RAG handbook does not only enhance the transparency and clarity of the guideline, but also can speed up the guideline development process, thereby saving time and labor costs

Combining CD38 antibody with CD47 blockade is a promising strategy for treating hematologic malignancies expressing CD38

BackgroundCD38 and CD47 are expressed in many hematologic malignancies, including multiple myeloma (MM), B-cell non-Hodgkin lymphoma (NHL), B-cell acute lymphoblastic leukemia (ALL), and B-cell chronic lymphocytic leukemia (CLL). Here, we evaluated the antitumor activities of CD38/CD47 bispecific antibodies (BsAbs).MethodsFive suitable anti-CD38 antibodies for co-targeting CD47 and CD38 BsAb were developed using a 2 + 2 “mAb-trap” platform. The activity characteristics of the CD38/CD47 BsAbs were evaluated using in vitro and in vivo systems.ResultsUsing hybridoma screening technology, we obtained nine suitable anti-CD38 antibodies. All anti-CD38 antibodies bind to CD38+ tumor cells and kill tumor cells via antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Five anti-CD38 antibodies (4A8, 12C10, 26B4, 35G5, and 65A7) were selected for designing CD38/CD47 BsAbs (IMM5605) using a “mAb-trap” platform. BsAbs had higher affinity and binding activity to the CD38 target than those to the CD47 target, decreasing the potential on-target potential and off-tumor effects. The CD38/CD47 BsAbs did not bind to RBCs and did not induce RBC agglutination; thus, BsAbs had much lower blood toxicity. The CD38/CD47 BsAbs had a greater ability to block the CD47/SIRPα signal in CD38+/CD47+ tumor cells than IMM01 (SIRPα Fc fusion protein). Through Fc domain engineering, CD38/CD47 BsAbs were shown to kill tumors more effectively by inducing ADCC and ADCP. IMM5605–26B4 had the strongest inhibitory effect on cellular CD38 enzymatic activity. IMM5605–12C10 had the strongest ability to directly induce the apoptosis of tumor cells. The anti-CD38 antibody 26B4 combined with the SIRPα-Fc fusion proteins showed strong antitumor effects, which were better than any of the mono-therapeutic agents used alone in the NCI-H929 cell xenograft model. The CD38/CD47 BsAbs exhibited strong antitumor effects; specifically, IMM5605–12C10 efficiently eradicated all established tumors in all mice.ConclusionA panel of BsAbs targeting CD38 and CD47 developed based on the “mAb-tarp” platform showed potent tumor-killing ability in vitro and in vivo. As BsAbs had lower affinity for binding to CD47, higher affinity for binding to CD38, no affinity for binding to RBCs, and did not induce RBC agglutination, we concluded that CD38/CD47 BsAbs are safe and have a satisfactory tolerability profile

Control of Precursor Maturation and Disposal Is an Early Regulative Mechanism in the Normal Insulin Production of Pancreatic β-Cells

The essential folding and maturation process of proinsulin in β-cells is largely uncharacterized. To analyze this process, we improved approaches to immunoblotting, metabolic labeling, and data analysis used to determine the proportion of monomers and non-monomers and changes in composition of proinsulin in cells. We found the natural occurrence of a large proportion of proinsulin in various non-monomer states, i.e., aggregates, in normal mouse and human β-cells and a striking increase in the proportion of proinsulin non-monomers in Ins2+/Akita mice in response to a mutation (C96Y) in the insulin 2 (Ins2) gene. Proinsulin emerges in monomer and abundant dual-fate non-monomer states during nascent protein synthesis and shows heavy and preferential ATP/redox-sensitive disposal among secretory proteins during early post-translational processes. These findings support the preservation of proinsulin's aggregation-prone nature and low relative folding rate that permits the plentiful production of non-monomer forms with incomplete folding. Thus, in normal mouse/human β-cells, proinsulin's integrated maturation and degradation processes maintain a balance of natively and non-natively folded states, i.e., proinsulin homeostasis (PIHO). Further analysis discovered the high susceptibility of PIHO to cellular energy and calcium changes, endoplasmic reticulum (ER) and reductive/oxidative stress, and insults by thiol reagent and cytokine. These results expose a direct correlation between various extra-/intracellular influences and (a)typical integrations of proinsulin maturation and disposal processes. Overall, our findings demonstrated that the control of precursor maturation and disposal acts as an early regulative mechanism in normal insulin production, and its disorder is crucially linked to β-cell failure and diabetes pathogenesis

Régularisation spatiale de représentations distribuées de mots

Stimulée par l’usage intensif des téléphones mobiles, l’exploitation conjointe des don-nées textuelles et des données spatiales présentes dans les objets spatio-textuels (p. ex. tweets)est devenue la pierre angulaire à de nombreuses applications comme la recherche de lieux d’attraction. Du point de vue scientifique, ces tâches reposent de façon critique sur la représentation d’objets spatiaux et la définition de fonctions d’appariement entre ces objets. Dans cet article,nous nous intéressons au problème de représentation de ces objets. Plus spécifiquement, confortés par le succès des représentations distribuées basées sur les approches neuronales, nous proposons de régulariser les représentations distribuées de mots (c.-à-d. plongements lexicaux ou word embeddings), pouvant être combinées pour construire des représentations d’objets,grâce à leurs répartitions spatiales. L’objectif sous-jacent est de révéler d’éventuelles relations sémantiques locales entre mots ainsi que la multiplicité des sens d’un même mot. Les expérimentations basées sur une tâche de recherche d’information qui consiste à retourner le lieu physique faisant l’objet (sujet) d’un géo-texte montrent que l’intégration notre méthode de régularisation spatiale de représentations distribuées de mots dans un modèle d’appariement de base permet d’obtenir des améliorations significatives par rapport aux modèles de référence