Heat Stagnation Research Articles

Laminar flow and convective heat transfer characteristics of plain and wavy wall cross confined circular cylinder

An attempt is made to identify the convective heat transfer characteristics of the plain wall (Pw) and wavy wall (Ww) cross confined circular cylinder in the laminar flow regime (20 ≤ Re ≤ 100). The study has been extended to identify the wake heat transfer characteristics for various confinements (L = 0.5D, 1D, 1.5D and 2D), such that the weaker and stronger heat transfer region in the downstream of cross-confined cylinder has been investigated. CFD solver Ansys Fluent (Version 18.0) is used for assessing the field variables, the results are analyzed using streamline plots, λ 2-criterion vortex identification method, Nusselt number and field synergy method. The wall confinement is highly significant on heat transfer, the maximum Nusselt number is observed at high confinement (L = 0.5D) for all the Reynolds number studied. The changes in Nusselt number with respect to confinements is more significant at high confinements (L = 0.5D and L = 1D), become less significant at low confinements (L = 1.5D, 2D). It is found around 73% and 50% rise in Nusselt number for the confinement height, L = 0.5D as compared to L = 1D at Reynolds number 20 and100, respectively. Besides, in order to identify the heat stagnation region in the wake, contour of zero temperature gradient along the flow direction is observed. From the contour, it is identified that more heat stagnation region in the wake of Pw confined cylinder as compared to Ww confinement which is due to the three-dimensional behavior of flow in the wake.

Preliminary exploration of method for screening efficacy markers compatibility in TCM prescriptions based on Q-markers: Anti-inflammatory activity of Dachaihu decoction as an example

Ethnopharmacological relevanceDachaihu Decoction (DD), a classic Chinese herbal prescription, is composed of radix of Bupleurum chinense DC. (Chaihu), radix of Scutellaria baicalensis Georgi (Huangqin), radix of Paeonia lactiflora Pall. (Baishao), rhizoma of Pinellia ternata (Thunb.) Breit. (Banxia), fructus of Citrus aurantium L. (Zhishi), rhizoma of Zingiber officinale Rosc. (Shengjiang), fructus of Ziziphus jujuba Mill. (Dazao) and rhizoma of Rheum officinale Baill. (Dahuang). DD has the traditional effects of soothing the liver, relieving depression and clearing heat from the stomach, and is mainly used to treat heat stagnation in the liver and stomach. Aim of the studyDachaihu decoction (DD), a classic prescription commonly used in clinical practice for the treatment of pancreatitis and cholecystitis. Although its pharmacological effects are clear, the efficacy components and mechanism of action remain intricate and difficult to clarify. Materials and methodsThe action targets and components of the anti-inflammatory activity of DD were predicted by network pharmacology; the effective components and targets were verified by HPLC and qPCR; the efficacy markers of DD were further screened by in vitro experiments; the pharmacological value of DD and its components compatibility were evaluated by in vitro experiments. ResultsThe key targets MMP9, JAK2, MAP2K1 and NR3C1 were screened by network pharmacology; HPLC analysis showed that paeoniflorin, naringin, hesperidin, neohesperidin, baicalin, wogonoside, baicalein and saikosaponin B2 were identified as potential efficacy markers of DD; molecular docking combined with qPCR verification suggested that baicalin, naringin, neohesperidin, hesperidin and baicalein and wogonoside had certain ability to regulate above targets; in vitro studies revealed that paeoniflorin, naringin, hesperidin, neohesperidin, baicalin, wogonoside, baicalein and saikosaponin B2 could inhibit the release of NO, pancreatic lipase and α-glucosidase; after comprehensive comparison and analysis, naringin, hesperidin, neohesperidin, baicalin, wogonoside, baicalein and saikosaponin B2 were selected as the efficacy markers of DD; in vivo studies indicated that DD and its efficacy markers (components compatibility) had definite therapeutic effects on guinea pigs with cholecystitis. ConclusionsThe efficacy markers of DD including naringin, hesperidin, neohesperidin, baicalin, wogonoside, baicalein and saikosaponin B2 can be used as components compatibility to exert anti-inflammatory activity. In addition, a method for obtaining the compatibility of efficacy markers by simplifying the prescription is initially established.

Three dimensional architected thermoelectric devices with high toughness and power conversion efficiency

For decades, the widespread application of thermoelectric generators has been plagued by two major limitations: heat stagnation in its legs, which limits power conversion efficiency, and inherent brittleness of its constituents, which accelerates thermoelectric generator failure. While notable progress has been made to overcome these quintessential flaws, the state-of-the-art suffers from an apparent mismatch between thermoelectric performance and mechanical toughness. Here, we demonstrate an approach to potentially enhance the power conversion efficiency while suppressing the brittle failure in thermoelectric materials. By harnessing the enhanced thermal impedance induced by the cellular architecture of microlattices with the exceptional strength and ductility (>50% compressive strain) derived from partial carbonization, we fabricate three-dimensional (3D) architected thermoelectric generators that exhibit a specific energy absorption of ~30 J g−1 and power conversion efficiency of ~10%. We hope our work will improve future thermoelectric generator fabrication design through additive manufacturing with excellent thermoelectric properties and mechanical robustness.

Use of Danzhi Xiaoyao Powder in the Treatment of Diseases by Chief Physician Wang Defen: Case Examples

Danzhi Xiaoyao powder was first introduced by Xue Ji, a Ming Dynasty physician, in the “Summary of Internal Medicine.” It is primarily used for treating the syndrome of liver depression transforming into heat and is widely used in the treatment of dermatology, internal medicine, gynecology, and other multi-system diseases. This medical prescription is aptly dispensed, its detoxification effect is strong, and it is a representative medical prescription for soothing the liver, strengthening the spleen and stomach, as well as eliminating heat stagnation. Chief Physician Wang Defen inherited the academic experience of the fifth batch of nationally known Chinese medicine experts, under the guidance of Professor Ji Haiwang, a notable Chinese medicine practitioner in Shaanxi Province and Professor Shi Bingyin, a renowned endocrinologist. Through follow-up studies, the various methods and empirical prescriptions of Danzhi Xiaoyao powder applied by Chief Physician Wang Defen in the treatment of common clinical diseases are summarized. They have been proven to have conclusive efficacy, thus providing guidance and reference for the dialectical treatment using traditional Chinese medicine.

Influence of heat input on bead profile and microstructure characteristics in laser and laser-hybrid welding of Inconel 617 alloy

Bead profile and microstructure analysis are greatly influenced by heat input in any welding process. The present work provides a comprehensive comparative investigation on these aspects during Autogenous Laser welding (ALW) and Laser-MIG Hybrid welding (LHW) processes in Inconel 617 superalloy. In case of LHW, weld bead profile formed was a typical wine-cup shaped one, whereas, in case of ALW, bead profile observed was Y-type shape on account of differences in number of heat sources and intensity profiles. Weld bead width and penetration depth were found to increase with heat input in both ALW and LHW processes. The fusion zone (FZ) area of LHW was found to increase by 3 times as compared to ALW as a result of high heat input in LHW than ALW. Indeed, the addition of MIG source to laser in LHW produced wide upper bead width (trebled) as compared to ALW. Radius of curvature (ROC) at neck zone, an important bead profile characteristic for assessing liquation cracking susceptibility, was found to increase with heat input and was significantly higher in LHW than ALW due to heat stagnation at neck zone. In comparison with ALW, LHW showed a coarser columnar/cellular dendritic microstructure in FZ with segregation of inter-dendritic carbides relatively richer in Mo and Cr. Secondary dendritic arm spacing (SDAS), cooling rates and microhardness will also be discussed.

Clinical Effect Observation of Jieyu Decoction in the Treatment of Generalized Anxiety Disorder

Objective: To observe the clinical effect of Jieyu decoction in treating generalized anxiety disorder with stagnation-heat in liver meridian type. Methods: There were 72 cases of generalized anxiety disorders outpatient and inpatient patients, and 36 in the control and treatment group. The control group was given oral Deanxit; the treatment group was given Jieyu decoction granules, and necessary psychological counseling was given to patients in both groups. Changes in traditional Chinese medicine syndrome scoring scale, Hamilton scale (HAMA), dynamic electrocardiogram heart rate variability and other indicators were recorded and compared between the two groups. Results: The total effective rate of the control group was 76.5%, and the total effective rate of the treatment group was 80.0%. The curative effect of the treatment group and the control group was significantly higher than that before treatment (P < 0.05), and there was no significant difference in the overall curative effect between the two groups (P > 0.05). The HAMA scale score of the two groups was significantly lower than that before treatment (P < 0.05), and there was no significant difference in the reduction rate of HAMA score between the two groups (P > 0.05). The traditional Chinese medicine syndrome scores of the two groups were significantly decreased compared with that before treatment (P < 0.05). The traditional Chinese medicine syndrome scores of the treatment group were significantly different from that of the control group after 8 weeks of treatment (P < 0.05). Two groups of heart rate variability in 24 h period of standard deviation between the average normal R - R (SDNN), 24 h per 5 min normal R - R period between the standard deviation (SDANN), root mean square of phase difference between adjacent R - R (RMSSD) and the number of cardiac 50 ms accounted for the percentage of the total number of cardiac (PNN50) than before treatment significantly increased (P < 0.05), 8 weeks after treatment the SDNN, SDANN than the control group no significant difference (P > 0.05), RMSSD,PNN50 significantly difference compared with control group (P < 0.05). Conclusion: Jieyu decoction has good efficacy and high safety in the treatment of generalized anxiety disorder of the type of liver meridian and heat stagnation, which is suitable for clinical promotion and application.

Heat Stagnation of Dy-Doped La2/3Ca1/3MnO3 Manganese Oxides in the Measurement Process of Warming and Cooling.

(La1–xDyx)2/3Ca1/3MnO3 samples with the perovskite structure were prepared by the sol–gel method, and the R–T curves of the samples in 0–3000 Gs magnetic field during warming and cooling processes were compared. It is found that the transition temperature (Tc) of the samples decreases and peak resistance (RP) of the samples increases with the increase of Dy concentration in the same magnetic field. In addition, for the samples with the same Dy concentration, Tc of the samples increases and magnetoresistance (MR) of the samples decreases with the increase of the magnetic field, and the increase of Tc as well as the decrease of resistance is more obvious during the cooling process than those during the warming one. Besides, the variation of MR during the cooling process is also larger than that during the warming one.

Response of Silicon Nitride Ceramics under High-enthalpy Plasma Flows

Silicon nitride ceramics were prepared by means of a hot-press sintering method. The ablation behavior was studied by plasma wind tunnel tests. The data suggested that, under low heat flux and stagnation pressure conditions, the ablation process was controlled by the atomic oxidation of Si3N4, leading to the elimination of Si3N4. By contrast, the erosion was mainly produced by the decomposition of Si3N4 under high heat flux and stagnation pressure conditions. Under these conditions, a fraction of Si phase, formed upon decomposition of Si3N4, was volatilized. The remained Si had melted due to high temperatures and scoured away from stagnation point area, generating mushroom-shaped samples.

Clinical experience and academic thoughts of Professor LIU Feng-bin on case series of gastroesophageal reflux disease based on data mining

To analyze and summarize Professor LIU Feng-bin's clinical experience and academic thoughts on gastroesophageal reflux disease (GERD), the study group adopted the retrospective study for case series and expert interview, extracted the retrospective data, including the herbs, diseases, syndrome type, medical expense and quantity of herbs of GERD patients attended the First Affiliated Hospital of Guangzhou University of Chinese Medicine. Statistical description and binary Logistic regression were used for the identification and modification of syndrome type and initial core herbs. After expert interviews were performed for the syndrome type and herbs, the final scheme were formed. A total of 112 GERD patients ages（48.97±13.13）y; male: 35 (31.3%), female: 77(68.7%) were enrolled. The numbers of patients with liver and stomach incoordination syndrome, heat stagnation of liver and stomach syndrome, syndrome of dual deficiency of Qi and Yin, syndrome of spleen deficiency and dampness-heat, spleen-stomach disharmony syndrome were 40, 26, 19, 17 and 10, respectively. The patients used totally 80 herbs, and 26 of them had significant differences among different syndrome groups. According to the logistic regression analysis on the 23 herbs used by 112 patients, the herbs scheme was modified for the second time. After the expert interviews and modification, the final consensus was reached. The main causes for GERD were dietary irregularities, moodiness, and weak constitution. The basic mechanism of GERD was spleen deficiency with Qi adverseness. The spleen-stomach disharmony syndrome was deleted by expert interviews. The 10 core herbs for GERD treatment were Taizishen(Pseudostellariae Radix), Fuling(Poria), Baizhu(Atractylodismacrocephalae Rhizoma), Gancao(Glycyrrhizae Radix Et Rhizoma), Zhebeimu(Fritillariae Thunbergii Bulbus), Haipiaoxiao(Sepiae Endoconcha), Zhiqiao(Aurantii Fructus), Chenxiang(Alosewood), Pugongying(Taraxaci Herba), Zhizitan(Cape Jasmine Fruit). The modification and psychological and diet interventions were also identified. This study summarized Professor LIU Feng-bin's clinical experience and academic thoughts of chronic atrophic gastritis based on data mining of case series and expert interviews. The quality of methodologies and report were both well. The results provide a foundation and ideas for further study on the complex intervention for GERD, and can be directly applied in clinical practice.

Experimental study on two-way application of drugs with neutral property for promoting blood circulation and removing blood stasis on cold and heat blood stasis syndromes Ⅱ

To further study the characteristics of drugs with neutral property in two-way application and conditioned dominance by observing the action characteristic of 10 traditional Chinese medicines with neutral property in hemorheological indicators of heat stagnation and blood stasis syndrome and cold stagnation and blood stasis syndrome rats.The model of heat stagnation and blood stasis syndrome rats was established by injecting carrageenan and dry yeast, while the model of cold stagnation and blood stasis syndrome rats was established by body freezing. Subsequently, 10 traditional Chinese medicines with neutral property, 5 traditional Chinese medicines with heat property and 5 traditional Chinese medicines with cold property were selected for intervention to observe the changes in such indicators as whole blood viscosity, plasma viscosity and hematocrit and analyze the action characteristics of drugs with neutral property.ANOVA showed that among six of the 10 traditional Chinese medicines with neutral property, including Typhae Pollen, Sarcandrae Herba and Sappan lignum, could obviously increase the hemorheological indicators of both heat stagnation and blood stasis syndrome and cold stagnation and blood stasis syndrome rats; five traditional Chinese medicines with cold property, such as Salviae Miltiorrhizae Radix et Rhizoma, Leonuri Herba, Rhei Radix et Rhizoma, could significantly ameliorate the hemorheological indicators of heat stagnation and blood stasis syndrome rats (P < 0.01 or P < 0.05), and Salvia Miltiorrhiza Radix et Rhizoma alone could ameliorate the hemorheological indicators of cold stagnation and blood stasis syndrome rats (P < 0.05); all of the five traditional Chinese medicines with heat property could significantly ameliorate the hemorheological indicators of cold stagnation and blood stasis syndrome rats (P < 0.01), among which Carthami Flos and Notoginseng Radix et Rhizoma could significantly ameliorate the hemorheological indicators of cold stagnation and blood stasis syndrome rats. According to the average high-shear blood viscosity analysis, drugs with neutral property showed similar action characteristics to those with cold property in ameliorating hemorheology indicators of heat stagnation and blood stasis syndrome rat and better effect than those with heat property in reducing whole blood viscosity; and traditional Chinese medicines with neutral property have the similar action characteristics to those with heat property in improving the hemorheology indicators of cold stagnation and blood stasis syndrome rat and better effect than those with heat property in reducing whole blood viscosity.Under the condition of heat stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property show the similar action characteristics to those with cold property; but under the condition of cold stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property show the similar action characteristics to those with heat property. This indicates that traditional Chinese medicines with neutral property show both heat and cold properties under he conditions of heat stagnation and blood stasis syndrome and cold stagnation and blood stasis syndrome.

Experimental study on two-way application of traditional Chinese medicines capable of promoting blood circulation and removing blood stasis with neutral property in cold and hot blood stasis syndrome I

To study the action characteristics of "two-way application and conditioned dominance" of traditional Chinese medicines with neutral property by observing the action characteristic of 10 traditional Chinese medicines capable of promoting blood circulation and removing blood stasis with neutral property in the microcirculation in rats with heat stagnation and blood stasis syndrome. The rat model with heat stagnation and blood stasis syndrome was established by injecting carrageenan and dry yeast, and the rat model with cold stagnation and blood stasis syndrome was built by the body freezing method. Ten traditional Chinese medicines with neutral property, including 5 with hot property and 5 with cold property, were selected for intervention to observe blood flow rate and flow state indicators in rat auricles and make a comparative analysis on action characteristics of traditional Chinese medicines with neutral property. ANOVA showed that among the 10 traditional Chinese medicines with neutral property, 6 such as Typhae Pollen, Sappan Lignum and Vaccariae Semen can obviously increase the blood flow rate (P < 0.01 or P < 0.05) in the above two models; all of the 5 traditional Chinese medicines with cold property can increase the blood flow rate (P < 0.01 or P < 0.05) in the rat model with heat stagnation and blood stasis syndrome, but only Salvia miltiorrhiza can increase the blood flow rate (P < 0.01 or P < 0.05) in the rat models with cold stagnation and blood stasis syndrome, while other medicines showed no notable effect; among the 5 traditional Chinese medicines with hot property, Carthamus tinctorius and Ligusticum chuanxiong can increase the blood flow rate (P < 0.01 or P < 0.05) in the rat models with cold stagnation and blood stasis syndrome, but had no obvious effect to the blood flow rate in the rat models with heat stagnation and blood stasis syndrome. According to the analysis on average blood flow rate, traditional Chinese medicines with natural and cold properties showed similar effect on heat stagnation and blood stasis syndrome and better effect in increasing blood flow rate than those with hot property; those with natural and hot properties showed similar effect and better effect in increasing blood flow rate than those with cold property. Under the condition of heat stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property have the similar action characteristics with those with cold property; wile under the condition of cold stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property have the similar action characteristics with the Chinese medicinal herbs with hot property. This indicates the action characteristics of "two-way application and conditioned dominance" of traditional Chinese medicines with neutral property to some extent.

Discussion of the Clinical Research for Integrating Traditional Chinese Medicine and Western Medicine in the Treatment of HIV/AIDS Herpes Zoster

Abstract Herpes zoster in HIV/AIDS patients is characterized by high incidence, wide skin damage, intractability, long course, and high recurrence rate. It is an important opportunistic infection among HIV/AIDS patients. By summarizing clinical practice and the theories in ancient books and recent manuscripts, we argue that the key to pathogenesis is the exogenous pathogenic toxin and endoretention of damp heat, resulting in herpes in the skin. HIV/AIDS herpes zoster localizes in the liver and gallbladder, in addition to being closely related to the heart and the spleen, according to traditional Chinese medicine (TCM) theories. The syndrome types of HIV/AIDS herpes zoster include heat stagnation in the liver channel, spleen deficiency with dampness, qi-stagnation, and blood stasis. In this article, we discussed clinical research of HIV/AIDS herpes zoster in TCM with reference to its disease characteristics, etiology, pathogenesis, diagnosis, and syndrome differentiation, in addition to the treatment of HIV/AIDS herpes zoster patients.

Laws of syndrome element combination in stable angina pectoris: a study based on cluster analysis and corresponding-correlation analysis

To study the classification of common symptoms and the laws of syndrome element combination in 251 cases of stable angina pectoris (SAP) by using cluster analysis and corresponding-correlation analysis. A total of 251 SAP cases were selected and their information from four diagnosis in traditional Chinese medicine was recorded. The classification of common symptom and the laws of syndrome element combination were investigated by cluster analysis and corresponding-correlation analysis. Twenty-five symptoms found in 251 SAP cases were divided into four types by cluster analysis: deficiency of heart qi, deficiency of spleen qi, deficiency of qi and yin, and phlegm accumulation and blood stasis. The deficiency of heart qi had the closest relation to phlegm accumulation and blood stasis. By corresponding-correlation analysis, the deficiency of qi had the closest relation to blood stasis, next was turbid phlegm and heat stagnation, and then deficiency of qi and deficiency of yin. Blood stasis due to deficient qi is the key factor in pathogenesis of SAP. Deficiency of qi plus blood stasis, deficiency of qi plus deficiency of yin, blood stasis plus turbid phlegm, deficiency of heart qi plus blood stasis plus turbid phlegm are common syndrome element combinations of SAP. It is proved that cluster analysis and corresponding-correlation analysis are the proper methods for studying laws of syndrome element combination.

A PHENOMENOLOGICAL DISCUSSION ABOUT FERROELECTRIC PHASE TRANSITION

The irreversibility of ferroelectric phase transition has been studied by using irreversible thermodynamics.Heat stagnation of the first-order ferroelectric phase transition and polydomain configuration of ferroelectrics can be explained on the basis of the principle of minimum entropy production.A conclusion has been derived that the heat stagnation is not an intrinsic property of a system in which a first-order ferroelectric phase transition arises.The finiteness of the system's surface is connected with the heat stagnation.

Effects to Firefighters of Exercise in a Hot Environment when Wearing the Anti-fire Coat

To investigate the effects of heat and exercise on firefighters wearing anti-fire coat, following measurements were made using five healthy untrained male subjects at rest and during exercise in a hot environment. The physiological parameters were loss of weight, axillary temperature, respiratory rate, ventilation, oxygen consumtion, carbon dioxide output, blood pressure, heart rate. The hematological parameters were red blood cell counts, white blood cell counts, and their differential. The blood biochemical parameters were osmolarity, Na, K, Cl, total protein, total cholesterol, free fatty acids, glucose, lactate, pyruvate, CPK, CPK isozyme, LDH, GOT, aldolase, creatinine, creatine, myoglobin, and those for urine were osmolarity, Na, K, Cl, urea nitrogen, creatinine, creatine, myoglobin. Two separate experiments were conducted as follows: sitting for 30 minutes in climatic chamber at 25°C, 35°C, 45°C and 55°C respectively with the relative humidity at about 40% and during exercise in the chamber at 25°C and 50°C with the relative humidity at about 40% for 20 minutes, including 10 minutes exercise with a bicycle ergometer at 600kpm/min followed by 10 minutes rest. Serum and urinary myoglobin were assayed by the radioimmunoassay method.The degree of weight loss and increase in heart rate and serum enzyme activities were more significant when the subjects wore the anti-fire coat than when they were naked. GOT, LDH, CPK and serum myoglobin significantly increased after exercise at 50°C, but not after exercise at 25°C or at rest in 50°C temperatures. The results thus indicate that the effects of the combination of heat and exercise were greater than the sum of their individual effects.It was concluded that heat stagnation must be taken into consideration, given the work condition and anti-fire coat worn by firefighters.

Convective Heating at the Deflecting Surface of a Rocket Launch-Pad

Summary:When a large rocket or missile is fired, the hot exhaust gases must be allowed to escape without damaging structures or equipment in the vicinity of the firing area. Generally, the exhaust gases are directed harmlessly away from the launching installation by water-cooled deflecting surfaces fabricated in steel. In arid areas such as Woomera, where water is not available in large quantities, there is the possible danger that a steel efflux deflector will melt, and other materials such as refractories may be more suitable for the deflecting surface.To provide data for the design of uncooled efflux deflectors, a heating rate investigation of the Blue Streak installation at Woomera has been carried out theoretically and experimentally. The heat transfer coefficient and stagnation temperature at the efflux deflecting surface are calculated theoretically with the aid of model test results. Heat transfer coefficients derived from temperature measurements on steel plates embedded in the deflecting surface are compared with the theoretical results. It is concluded that simple aerodynamic heat transfer theory can provide an effective engineering estimate of the temperature rise of an efflux deflecting surface.

癩患者の体温及び物質代謝

The author conducted studies on the pattern of body temperature in leprosy and from the findings attempted to correlate this with body metabolism.The following results were obtained.1. There is no significant difference in axillary temperature according to type of leprosy but the temperature is higher in the summer than in the winter, cases suggesting heat stagnation being observed at times. A difference was observed according to time of day and month and there was a marked climatic fluctuation.2. A greater variation from the normal basal metabolism was found in lepromatous leprosy.3. Analysis of the diet of the patients in the leprosarium showed that it was higher in total calories, protein, carbohydrate, riboflavin, iron and hosphorus and somewhat lower in fat, vitamin A, and calcium compared to the standard of the general population.From these findings, it can be seen that the reactivity of the leprosy patient is extremely labile from the standpoint of body temperature and basal metabolism suggesting a general systemic dysfunction. It is believed that this will be influenced by diet.

The Influence of Weather Conditions on the Mortality from Bronchitis and Pneumonia in Children

In the preceding pages, an analysis has been made of the correlation coefficients found between the number of fatal cases from bronchitis, pneumonia and respiratory diseases, or the two summed together, in children under five years of age in London, Glasgow, Edinburgh, Aberdeen and Dundee, and the meteorological factors, mean and mean minimum temperature, mean relative humidity and mean rainfall, for a period of from 40 to 50 years; and between the death-rates from bronchitis, pneumonia and respiratory diseases amongst children at the same period of life in the registration counties of England and Wales in the decennia, 1901–10 and 1891–1900, and their mean annual temperature and mean annual rainfall and it seems warrantable to draw the following conclusions.1. The meteorological factor, amongst those investigated, that seems to exercise the greatest influence in predisposing to an increased mortality from, and presumably an increased incidence of, bronchitis in children in the cities, is the prevailing temperature. In accordance with the average duration of the disease, the mortality is most intimately related to the mean temperature of the preceding week and is, on the average, as closely related to the temperature of two weeks before as it is to that of the corresponding week. The relationship is inverse, the lower the mean temperature the greater the fatality from bronchitis. As suggested by Dr Leonard Hill, the cold weather probably compels children to remain indoors in stuffy, overheated rooms where infection is intensified and health weakened by heat stagnation, a lowered metabolism and want of sunlight.2. While there is a suggestion from some of the correlation coefficients found, that pneumonia in children may have some inverse relationship to mean temperature this association is not shown in the monthly or weekly data generally.3. There is a definite inverse relationship between the mortality from the respiratory diseases, or bronchitis and pneumonia summed together, and the mean temperature; and, as occurs with bronchitis, the relationship to the mean temperature of the preceding week is closer than to that of the corresponding week.4. The mortalities from bronchitis, pneumonia and respiratory diseases (bronchitis and pneumonia summed together), in children under five years in the registration counties of England and Wales, are inversely associated with the mean annual temperature in the corresponding counties. This association still persists after allowance is made for the proportion of each county which is urban, a proportion which has been taken as a rough index of industrial conditions therein.5. The mortalities from bronchitis and pneumonia in children in the cities examined and in the registration counties are not influenced in any consistent manner or degree by the amount of rainfall.6. While the coefficients of correlation between the corrected monthly deaths from bronchitis and respiratory diseases, respectively, and the corresponding mean monthly humidity in Glasgow seem to suggest the existence of a significant direct association between these variables, viz. the moister the atmosphere, the higher the death-rate from bronchitis; such a relationship is not definitely indicated in the coefficients found for the other cities. The magnitude of the coefficients for Glasgow is apparently determined, in some degree, by the periodicity in the mortality figures. It is probable, however, that the periodicity is not wholly responsible for the correlation found as the correlation coefficients between the mean temperature and the deviations in the same monthly data from the five-yearly moving average—the method adopted to eliminate the effect of the periodicity—are not very different from those found by using the actual figures. There would appear to be some evidence for the view that a high relative humidity, when associated with a low temperature, has some influence in predisposing to an increased mortality from the respiratory diseases.