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Introduction. Сases of ineffective activation of automatic sprinkler fire-fighting systems (AFFS), designed pursuant to current standards, have made it necessary to address the following three issues: a) identification of reasons for ineffective activation; b) examination of AFFS systems to ensure their successful activation in case of fire; c) making a list of recommendations for AFFS designers. These issues can be resolved with reference to Appendix B to new SP (Construction Regulations) 485.13130.2020.Maximal critical height of sprinkler placement. Models of fire development were used to design the roof height limit and the AFFS bulb heating time. If the ceiling height exceeds the limit value, sprinklers cannot be activated in a timely manner. This leads to delays in the AFFS activation, and, as a result, the fire area exceeds the one safeguarded by the sprinkler.Acceptable sprinkler height. The analysis of fire scenarios and bulb heating models allows to more accurately project the feasibility of timely AFFS activation. This, in turn, allows to solve the three above listed problems.Using a differential heat detector to activate sprinklers. If it is established that the use of the AFFS, activating sprinklers by means of thermal destruction of a bulb, is ineffective in a given room, the feasibility of forced AFFS activation using a differential heat detector responding to the temperature rise in a room may be considered. The ratios, thus obtained, are applied to identify the acceptable height of premises protected by the AFFS equipped with such detectors. Problem solutions, including the identification of the reason for the ineffective operation of the AFFS, examination of the AFFS in operation, and provision of recommendations to designers, are demonstrated using the exhibition hall as an example.Conclusions. The above-mentioned problems are resolvable with the help of Appendix B to new Construction Regulations 485.13130.2020 and the above models.

Background. The inverse problem of finding a multidimensional memory kernel of a time convolution integral depending on a time variable t and (n-1)-dimensional spatial variable. 2-dimensional heat equation with a time-dependent coefficient of thermal conductivity is studied. Methods. The article is used Cauchy problems for the heat equation, resolvent methods for Volterra type integral equation and contraction mapping prinsiple.

A remarkable number of scientific papers are available in the literature about the process of hydrothermal carbonization (HTC), also called wet or hydrous pyrolysis, applied to biomass substrates. However, the biggest share of it focuses on the characterization of HTC products obtained from different feedstocks. Only a few works are available on the process thermodynamics, particularly about the determination of the enthalpy change and the related heat release or absorption during HTC, which is a key parameter to understand the nature of the process and to evaluate the heat requirements for the design of industrial scale HTC plants. The present review summarizes the research carried out with the aim of assessing the process enthalpy for HTC. Two main approaches have been identified and described, and the research works are sorted into two categories: enthalpy calculation based on the direct application of the Hess’s law and enthalpy evaluation based on differential heat measurement. The hypotheses and results obtained by the different authors are critically analysed and discussed, and directions for further research are proposed.

Differential heat of absorption of CO2 in aqueous solutions of N,N-diethylethanolamine (DEEA) and activated DEEA solutions up to a total concentration of 2 mol·L−1 was measured as a function of CO2 loading at 313.15 K using a reaction calorimeter. In order to analyze the performance of N-methyl-1,3-propanediamine (MAPA) as an activator, DEEA blended solutions containing 0.05, 0.1 and 0.2 mol·L−1 MAPA were studied. The heat of CO2 absorption in single DEEA solutions was unaffected by changing the DEEA concentration in the range of (0.5–2) mol·L−1. On the other hand, increasing the concentration of MAPA in aqueous amine mixtures of (DEEA + MAPA) raised the heat of absorption.

In 2016, many tropical corals worldwide were exposed to anomalously high temperatures due to one of the strongest El Nino events ever recorded. Bleaching impacts were reported on 23 islands within three archipelagos of French Polynesia (Tuamotu, Society and Marquesas archipelagos). A detailed study on the effects of elevated temperatures on corals was performed on five islands (Mo'orea, Makemo, Hikueru, Marutea and Katiu) and revealed contrasting patterns of coral bleaching responses between Mo'orea (Society Archipelago) and the four islands of the Tuamotu Archipelago. While some reefs from the Tuamotu lost more than half of their coral cover, in Mo'orea, less than 1% mortality was recorded 6 months after bleaching. During the 2016 bleaching event, certain reefs at 12 m depth in the outer reef habitats were not exposed to sufficiently long high-temperature periods (heat stress not exceeding 1.1 degrees C weeks in Mo'orea) to cause large-scale bleaching-related coral mortality. In contrast, other reefs in the Tuamotu Archipelago had DHW reaching up to 9.2 degrees C weeks and experienced severe mortality (up to 71%). Our study showed how differential heat stress exposure across reefs of French Polynesia led to different impacts on corals. Until now, Mo'orea reefs have been spared abnormally high temperatures leading to mortality and should be considered an important source of larvae to help maintain reefs on the surrounding islands.

We report H2 adsorption capacities reaching 0.05 wt % at 303 K and at 1 atm H2 pressure on solid-state CuCl-exchanged [Al]-SSZ-13 and [B]-SSZ-13 zeolites. Differential heat of H2 adsorption is found in the range between 16 and 48 kJ mol H2–1 on Cu(I)-SSZ-13 at 323 K and isosteric heat of adsorption is found between 20 and 55 kJ mol H2–1 on Cu(I)-[B]-SSZ-13 at temperatures between 293 and 323 K. Strong interactions between H2 and the copper cations in Cu(I)-SSZ-13 are evidenced using Rietveld refinements of neutron powder diffraction patterns revealing Cu–deuterium (D2) distances of 2.3(2) and 2.41(1) A. A temperature-dependent Cu(I) migration—away from the six-membered ring (6MR) and eight-membered ring (8MR)—is related to the high adsorption capacities of the samples at 303 K. At 10 K, access to Cu(I) at 6MR is sterically hindered by framework oxygen atoms (Cu–Oframework distance of 2.196(5) A), rationalizing the low H2 adsorption capacities of Cu(I)-SSZ-13 samples as compared to Na-SSZ-13 at 77 K.

Gingerols and their shogaol derivatives play an important role in determining the sensory and organoleptic properties of ginger. In this study, 6-gingerol, 8-gingerol, 10-gingerol and 6-shogaol were quantified in 98 samples of dried Australian processing-grade ginger using high performance liquid chromatography (HPLC). A significant level of variation was found in the gingerol and shogaol contents of ginger samples grown under different conditions. The level of variation found in 6-shogaol content was lower than that observed for 6-gingerol, 8-gingerol or 10-gingerol content. It is possible that zeroth-order reaction kinetics under mild dehydration conditions could be responsible for this observation. More detailed information on the kinetics of the gingerol-dehydration reaction could potentially be used to manipulate the gingerol and shogaol contents of ginger through differential heat treatments.

This paper presents a two-dimensional description of the temperature field in refractory lining of the hearth in the blast furnace. The mathematical model is based on Fourier differential heat conduction equation. Different solutions of this equation are presented and the optimal quantity and location of thermosensors in the hearth is proposed. This paper also presents a methodology to obtain the heat conductivity of refractory materials.

We present the critical analysis of the utilization of CO2 adsorption calorimetry/volumetry and TPD-CO2 for the determination of the Mg–Al mixed oxide basicity. The aim of work is the description and the evaluation of both methods with respect to the fact when the same types of CO2 adsorption complexes are involved. Critical parts of basic sites determination are originally discussed for both methods. In TPD-CO2, the process of the purging of non-specifically physisorbed CO2 is stressed. In CO2 adsorption calorimetry, the differential heat of CO2 distinguishing CO2 adsorption on weak basic sites and non-specific CO2 physisorption is stressed. Both methods are applied on series of selected Mg/Al mixed oxides varying in Mg/Al molar ratio and alkali co-cation. We show that the generally used TPD-CO2 does not provide complete information about basic sites since some weak sites form unstable CO2 species and these species could not be involved in TPD experiments. All our TPD-CO2 experiments reflect at 0–485 °C those CO2 adsorbed in the range of the differential heat of CO2 above 30–32 kJ mol−1.

The presence of thermally altered and broken flint artifacts is common at archaeological sites. Most studies focus their attention on the effects of heat treatment on flint to improve knapping qualities, disregarding the effects of fire over flint under uncontrolled conditions. This paper aims to show how under uncontrolled heating processes flint artifacts develop different heat alterations (such as levels of breakage, presence of scales, etc.) as a result of vertical distribution, volume or raw material and to establish a gradient of rock changes and behavior. Artifacts where macroscopically analyzed and a series of uncontrolled heating experiments through the distribution of flint blanks under two hearths were carried out, allowing a comparison of the before and after of the blanks. Preliminary results show how levels of breakage, surface alteration or development of heat alteration features can be differentiated according to artifact volume, vertical distribution and level of surface alteration. Results also show how two different raw materials react differently to similar thermal impact, and how surface alteration reacts at different rhythm in the case of recycled artifacts. We conclude that levels of thermal alteration can be differentiated through macroscopic analysis of flint surface.

The objective of this study was to differentiate the heat tolerance in ten varieties of barley (Hordeum vulgare L.) originating from Morocco. Five modern varieties and five landraces (local varieties) collected at five different geographical localities in the south of Morocco were investigated in the present study. After two weeks of growth, detached leaves were short term exposure to various temperatures (25, 30, 35, 40, and 45 °C) for 10 min in the dark. Two chlorophyll a fluorescence parameters derived from chlorophyll a fluorescence transient (OKJIP) (performance index (PIABS) and relative variable fluorescence at the K-step (VK)) were analysed. Heat treatment had a significant effect on the PIABS and VK at 45 °C treatment and the analysis of variance for PIABS and VK is highly significant between all varieties. The slope of the relationship between logPIABS and VK named heat sensitivity index (HSI) was used to evaluate the thermotolerance of photosystem II (PSII) between the studied barley varieties. According to this approach, barley varieties were screened and ranked for improving heat tolerance. HSI was found to be a new indicator with regard to distinguishing heat tolerance of different barley cultivars.

Background: The variation of the radon progeny concentration in outdoor environment and meteorological parameters at fine resolution were studied for one year at a continental location, National Atmospheric Research Laboratory, Gadanki, India.Materials and Methods: The concentrations were measured using Alpha Progeny Meter by collecting air samples at a height of 1 m above the Earth’s surface at a known flow rate. Results: Radon progeny concentration shows temporal variations on diurnal and monthly scales, and is due to mixing in the atmosphere. Peak in the early morning hours and low values during afternoon compared to nighttime are due to differential heat contrast between earth’s surface and its atmosphere. However, the activity during February shows maximum compared to June/July months.The diurnal variation of radon progeny shows positive correlation with the relative humidity and negative correlation with ambient temperature.The monthly mean activity of radon progeny for the year 2012 was found to be 4.76 ± 0.73 mWL. Conclusion: The mean concentration of radon progeny in the study region is relatively high compared to the other locations in India and may be due to the rocky terrains and trapping of air-masses near the observation site due to its topography.

The results of numerical simulation of heat and mass transfer in an ejection apparatus during condensation of vapor–gas mixture components on cold brine droplets are presented. The local parameters of working flows were determined by solving a system of differential heat transfer equations with account for the hydrodynamic pattern. Calculations were carried out on the assumption that the liquid spray is directed horizontally. The Stefan formula has been derived with reference to a spherical coordinate system. The results of calculation of heat and mass transfer rates with and without regard for steam condensation jointly with hydrocarbon vapors are compared and analyzed. Estimation of the effect exerted by the apparatus and drip pan walls on the general process of heat and mass transfer was carried out. The results of simulation made it possible to quantitatively estimate the influence of the adopted thickness of the diffusional boundary layer on the vapor–air mixture cooling effect.

The adsorption of CO2 coupled to calorimetry is a state-of-the-art technique for characterizing the basic properties of solids. In this paper, we show that the differential heat and entropy curves measured upon CO2 adsorption on a basic solid can be reasonably estimated from a single CO2 isotherm with no need for any independent heat (calorimetric) measurement. Our method relies on two important observations: (1) formulation of generalized F-H-TS thermodynamic isotherms, the former (F) being directly generated from the raw CO2 isotherms, and (2) the presence of unexpected enthalpy-entropy compensation effects upon CO2 adsorption linking the integral enthalpy and entropy of adsorption until saturation for different solids. Our thermodynamic method has been validated using a broad library of basic solids with variable site strength and heterogeneity. Finally, a new scale of basicity is proposed using the parameters fitted from the thermodynamic isotherm (free energy basis) as descriptors of basic strength. This method opens an avenue to the inference of site strength of basic solids without the need for expensive calorimeters.

The microbial community within the rumen can be changed and shaped by heat stress. Accumulating data have suggested that different breeds of dairy cows have differential heat stress resistance, however, the underlying mechanism by which nonanimal factors contribute to heat stress are yet to be understood. This study is designed to determine changes in the rumen microbiome of Holstein and Jersey cows to normal and heat stress conditions. Under heat stress conditions, Holstein cows had a significantly higher respiration rate than Jersey cows. Heat stress increased the rectal temperature of Holstein but not Jersey cows. In the Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, Jersey cows had a significantly higher proportion of genes associated with energy metabolism in the normal condition than that with other treatments. Linear discriminant analysis effect size (LEfSe) results identified six taxa as distinguishing taxa between normal and heat stress conditions in Holstein cows, in Jersey cows, 29 such taxa were identified. Changes in the rumen bacterial taxa were more sensitive to heat stress in Jersey cows than in Holstein cows, suggesting that the rumen mechanism is different in both breeds in adapting to heat stress. Collectively, distinct changes in rumen bacterial taxa and functional gene abundance in Jersey cows may be associated with better adaptation ability to heat stress.

Bioenergetics modeling is a popular tool used by waterfowl biologists to estimate carrying capacity based on food energy availability and daily energy expenditure (DEE). For wintering waterfowl, estimates of DEE may incorporate a cost of thermoregulation (CT) component, which accounts for metabolic heat production when ambient temperatures fall below a species-specific Lower Critical Temperature (LCT). Typically, DEE estimates have utilized either a fixed CT component or a simple CT model based solely on the magnitude of the difference between ambient temperature and LCT. Using a more complex CT model that accounts for differential heat loss from individual body regions due to temperature, wind speed, and contact with air or water may provide more detailed estimates of CT and, in turn, carrying capacity. However, such models required detailed morphometrics as model inputs in addition to environmental data. We present morphometrics for 8 dabbling duck species for use in thermoregulation models, as...

It has been shown that the differential heat conduction equation together with the boundary conditions can be recast as a sequence consisting of integral identities for the weighted temperature. Weight functions take into account the properties of the heat conduction equation and the boundary conditions. The sequence of identities was constructed on the basis of multiple differentiation or integration operators. Using the search for eigenvalues of the boundary value problem as an example, we have demonstrated the high efficiency of such systems.

Heat of adsorption is a basic thermodynamic property extensively used not only for understanding thermal effects and heat management in industrial gas storage and separation processes but also for development and validation of adsorption models and materials force fields. Despite a long history of theoretical studies and a vast experimental literature, controversies often arise in the thermodynamic analysis of heat effects due to various assumptions used to describe gas adsorption and inconsistencies between direct calorimetric measurements and isosteric heat obtained from various adsorption isotherms. Here we present a rigorous theoretical procedure for predicting isosteric heat without any assumption about the geometry of porous adsorbents or operating conditions. Quantitative relations between the differential heat and various isosteres have been established with the grand-canonical Monte Carlo simulation for gas adsorption in amorphous as well as crystalline porous materials. The inconsistencies and practical issues with conventional methods for the analysis of the heat effect have been clarified in the context of the exact results for model systems. Via the resolution of a number of controversies about heat analysis, we hope that the new theoretical procedure will be adopted for both fundamental research and industrial applications of gas adsorption processes.

In a previous paper M. S. Ben Hammouda and Akram Nemri derived criteria for the expansion of solutions u(x, t) from the generalized q-heat equation, in series of polynomial solutions \({p_{n}^{\alpha}}\), thus extending an analogous theory of the ordinary heat equation developed by P. C. Rosenbloom and D. V. Widder. It is the goal to carry out a parallel study for the q-Laguerre differential heat equation and establish the region of convergence of the series of q-Laguerre heat polynomials and their temperature transforms.

In this paper we present a new method for calculation of the thermal diffusivity of a rigid body. This method is based on contactless thermal treatment of the examined construction material by an infrared radiation source. Further we analytically find one-dimensional non-stationary temperature field of a rigid body during its heating using data from thermal elements. The calculation of the thermal diffusivity of a rigid body is made using differential heat equation.

The article discusses the development of a mathematical model of the thermodynamic system during winter concreting of bored piles. The processes of heat transfer based on the differential heat equation and the Stefan problem are described. A method for calculating the rationale for the parameters of the energy-saving and gentle thermal treatment of concrete using non-traditional sources of thermal energy is proposed. The solutions for using two-phase thermosyphons as heating elements are considered.

The dissolution enthalpy of Cisplatin and Etoposide in the appropriate solvent were measured by RD496-2000 microcalorimeter under the conditions of atmospheric pressure and 309.65 K. The differential heat and the integral heat of the process are obtained, thereby establishing the relationship between the heat and the amount of solute, knowing that the dissolution process is the pseudo-first order reaction. In turn, the half-life, △solHm, △solGm, △solSm are also can obtained.

The isotherms and differential heats of water vapor adsorption on Na- and Ca-saponite samples are measured. It is shown that the successive stages of hydration of the internal surface of this mineral appear as waves or inflections in the adsorption isotherms and maxima in the dependences of the differential heat on the adsorption value. The compositions of Na+ and Ca2+ aquacations in single- and double-layer saponite hydrates are determined. The heats of interaction between water molecules and interlayer Na+ cations in single-layer saponite hydrates and between Na+ cations and the ion exchanger matrix are estimated.

Thermal treatments of citrus juices to inactivate microorganisms and pectinmethylesterase (PME) must be as soft as possible to preserve fresh taste. PME, a cell wall enzyme associated with pulp, is more heat resistant than spoilage microorganisms. This paper analyzes fresh taste and storage stability of orange juices in which the pulp receives a heat treatment more intense than the rest of the juice. The products compared where: A) low pulp juice treated at 60 °C–15 s; B) aseptic blend of A and the corresponding pulpy fraction treated at 85 °C–15 s; C) non aseptic blend of non-treated low pulp fraction and the corresponding pulpy fraction treated at 85 °C–15 s. Product C was finally treated at 60 °C–15 s and packed under aseptic conditions. PME activity in A, B and C was around 10% of that in the original juice (1.30 nkat/ml). After 12 months at 3 °C, juices B and C retained the original fresh taste with minimal losses of color and cloudiness. Juice A maintained fresh taste but its color and cloud were not satisfactory. Industrial Relevance The procedures proposed in this paper can be applied to produce chilled orange juices without losses in fresh taste having in addition, higher stability than commercial juices. Other advantages when compared to non thermal emergent technologies are that can be carried out by regular equipments used in citrus industries with an important energy saving. These procedures imply energy savings of 22% to 38% when compared to thermal requirements of juice pasteurization at 85 °C.

An adsorption microcalorimeter was designed and built in our laboratory and used for the determination of differential adsorption heats in different samples of porous solids: activated carbon granules, activated carbon pellets, an activated carbon monolith and a zeolite sample. This work shows the relationship between adsorption heat and the pore size of different porous solids using adsorption of NH 3 , CO and N 2 O. The result shows that the thermal effect can be related with textural properties and superficial chemical groups of the studied porous solids. The values of differential heats of N 2 O adsorption in the investigated systems have shown that this interaction is weaker than that with CO. Small amounts of N 2 O are chemisorbed in the investigated systems. For the room temperature adsorption of N 2 O, the strongest active sites for the interaction with Brönsted acid groups in the ACM structure were identified. The values determined are between −60 kJ/mol and −110 kJ/mol for ZMOR and ACM, respectively, for the adsorption of N 2 O and −95 kJ/mol and −130 kJ/mol for the adsorption of CO.

In this paper we present a mathematical model of a three-dimensional non-stationary temperature field for concrete that hardens in winter conditions. The developed mathematical model describes heat transfer processes basing on the differential heat equation. We also consider the classical boundary conditions of the I, II, III and IV kinds. We compiled a computer interpolation of the family of nomograms in the second order regression equation in order to calculate the relative theoretical strength of concrete after heat treatment.

An adsorption microcalorimeter for the determination of the differential heat of adsorption is designed and built, and some of the results are presented here. For this purpose, a Calvet heat-conducting microcalorimeter is developed and is connected to a gas volumetric unit built in stainless steel to record adsorption isotherms. The microcalorimeter is electrically calibrated to establish its sensitivity and reproducibility, obtaining K = 154.34 ± 0.23 W V −1 and, chemically, it is examined with a THAM–HCL system, obtaining Δ f = −30.49 ± 0.05 kJ mol −1 .The adsorption microcalorimeter is used here to obtain adsorption isotherms and the corresponding differentials heats, using as reference solid, a zeolite ZSM-5 type.

The high cost of sensitivity commercial calorimeters may represent an obstacle for many calorimetric research groups. This work describes the construction and calibration of a batch differential heat conduction calorimeter with sample cells volumes of about 400 μL. The calorimeter was built using two small high sensibility square Peltier thermoelectric sensors and the total cost was estimated to be about US$ 500. The calorimeter was used to study the excess enthalpy of solution of binary mixtures of liquids, as a function of composition, for the following binary systems of solvents: water + 1,4-dioxane or + dimethylsulfoxide at 298,2 ± 0,5 K.

KEYWORD: biomass; DSC analysis; combustion and pyrolysis; thermal decomposition ABSTRACT: Based on results of biomass combustion and pyrolysis using TG-DSC analyzer, biomass thermodynamics characteristics were studied. Integrated heat model and differential heat model were used to determined biomass thermal behavior, and the former fitted the actual better; the heat capacities with temperature can be empirically expressed in the linear form as: . Study results provided an insight of biomass thermal decomposition mechan- ism.

An extended dual kinetic model allows to fit the n-heptane cracking results working in a wide range of reaction conditions. The duality of the model is provided by the contribution of monomolecular and bimolecular cracking mechanisms. It takes into account the role played by the olefins formed on the global cracking or added within the feed. Furthermore by means of this model and the kinetic parameters obtained when cracking n-heptane on ZSM-5, it has been observed that, while some characterization techniques show a homogeneous zeolite surface from the point of view of the active sites, rigorous kinetic experiments point to the possibility that the reactant sees a heterogeneous surface with, at least, two groups of cracking active sites. Those differentiated active sites give different cracking rates and different activation energies for the process and, in the case of ZSM-5, could be assimilated to sites pointing to the 10R channels and sites pointing into the crossing of the 10R channels, mainly due to differences in kid site location and confinement effects. (C) 2015 Elsevier Inc. All rights reserved., Financial support by the Ministerio de Economia y Competitividad of Spain (MINECO) [Programa Estatal (Project MAT2012-31657) and Programa Consolider-Ingenio 2010 (Project MULTICAT)] is gratefully acknowledged.

The surface of amorphous solids cannot be usually represented by a regular lattice of adsorbing sites. One of the main characteristics of such surfaces is a variable connectivity for each site. A simple model consisting of a triangular lattice where a fraction of bonds (interactions) is suppressed at random is used here to find out, by using Monte Carlo simulations, how the adsorption thermodynamics of repulsively interacting monomers is modified with respect to the same process in the regular lattice. Adsorption isotherm, differential heat of adsorption and adsorbed phase entropy calculations are carried out showing and interpreting the effects of the variable connectivity. In particular, it is found that the order–disorder phase transition observed for the regular lattice survives, though with modifications, above a critical mean connectivity.