Humidity In Terms Research Articles

Distance-Based Analysis of Early Fire Indicators on a New Indoor Laboratory Dataset with Distributed Multi-Sensor Nodes

This work analyzes a new indoor laboratory dataset looking at early fire indicators in controlled and realistic experiments representing different incipient fire scenarios. The experiments were performed within the constraints of an indoor laboratory setting using multiple distributed sensor nodes in different room positions. Each sensor node collected data of particulate matter (PM), volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H2), ultraviolet radiation (UV), air temperature, and humidity in terms of a multivariate time series. These data hold immense value for researchers within the machine learning and data science communities who are keen to explore innovative and advanced statistical and machine learning techniques. They serve as a valuable resource for the development of early fire detection systems. The analysis of the collected data was carried out depending on the Manhattan distance between the fire source and the sensor node. We found that especially larger particles (>0.5 μm) and VOCs show a significant dependency with respect to the intensity as a function of the Manhattan distance to the source. Moreover, we observed differences in the propagation behavior of VOCs, PM, and CO, which are particularly relevant in incipient fire scenarios due to the presence of strand propagation effects.

QCM Measurements of RH with Nanostructured Carbon-Based Materials: Part 2-Experimental Characterization

In this series of two papers, the humidity sensing of a carbon nanotube (CNT) network-based material is transduced and studied through quartz crystal microbalance (QCM) measurements. To this aim, quartzes functionalized with different amounts of sensing material were realized, exposed to different humidity levels, and characterized. In this second paper, the experimental results are presented and discussed. The sensing mechanisms are elucidated exploiting the theory presented in the first paper of this series. The presented results show that the investigated material functionalization induces a large response of QCM to humidity in terms of resonant frequency even at low RH levels, with a sensitivity of about 12 Hz/%RH (at RH < 30% and room temperature and 10 ug of deposited SWCNT solution) and an increase in sensitivity in the high RH range typical of nanostructured film. Regarding the response in terms of motional resistance, a large response is obtained only at intermediate and high humidity levels, confirming that condensation of water in the film plays an important role in the sensing mechanism of nanostructured materials.

Defining relative humidity in terms of water activity: III. Relations to dew-point and frost-point temperatures

Relative humidity (RH) is a fundamental quantity used in many fields of engineering and science, and in particular in meteorology and climate research. Relative fugacity (RF) and, equivalently, relative activity of water vapour in humid air have recently been proposed as a physically well-founded, unambiguous common metrological reference quantity for several conventional but mutually inconsistent definitions of RH. The RF definition is valid is valid under real-gas conditions and above boiling and sublimation temperatures. While differences between RH and RF mostly remain within uncertainties of typical present-day RH measurements, such systematic discrepancies are expected to be of substantial climatological relevance. Consequently, interdisciplinary harmonisation of RH definitions is overdue within the SI framework. Dew-point and frost-point temperatures are preferred measurands in humidity metrology using, for example, chilled-mirror hygrometers. Here, relations are presented for estimating RF from those temperatures, based on equations of state of the 2011 IUGG 5IUGG: International Union of Geodesy and Geophysics, https://iugg.org/. standard TEOS-10, the ‘international thermodynamic equation of seawater—2010’. Recommendations are given for numerically computing RF using the open-source TEOS-10 SIA library 6 6SIA Library: Sea-Ice-Air Library of TEOS-10, http://teos-10.org.. The asymptotic limiting laws of RF for nearly saturated humid air exhibit the familiar form of Clausius–Clapeyron-like equations, despite departing from ideal-gas assumptions. Under various practical conditions, these simple equations may cover the full humidity range with only minor residuals compared to the full numerical TEOS-10 solution for RF.

Liquid desiccant systems for cooling applications in broilers farms in humid subtropical climates

This paper intends to numerically analyse the performance of liquid desiccant systems on the supply air conditions for closed poultry barns. A commercially available evaporative cooler for poultry barns was modified into a desiccant dehumidifier by circulating desiccant solutions of LiCl-H2O and CaCl2-H2O instead of water. Ambient air conditions for one of humid and subtropical climates were simulated based on an ∊-NTU effectiveness model for an externally cooled liquid desiccant dehumidifier. Also, a distinctive temperature-humidity index (THI) was implemented to study the environmental thermal conditions that the poultry were subjected to. Concerning the thermal comfort for broilers, the results show that conventional direct evaporative cooling systems are not feasible when the ambient air is near saturation. The THI values for ambient and direct evaporative cooler were positioned mainly in the severe heat stress region, with THI value in the range of 80 to 82, and most air outlet conditions were near saturation. The numerical results for the liquid desiccant systems show a consistent reduction in humidity ratio and air dry-bulb temperature. The assessment of air outlet temperature and humidity in terms of THI values was shifted out of the emergency and danger zone with a preference for LiCl solution.

Michael addition curable coatings from renewable resources with enhanced adhesion performance

Novel malonate-functional polyesters from biobased and potentially biobased monomers were developed and cured through the base-catalyzed carbon-Michael addition reaction with acryloyl-functional oligomers. Both drop-in monomers, such as fully biobased diethyl malonate, and alternative raw materials, such as isosorbide and vegetable oil, were introduced. Isosorbide-based polyesters show improved performance to humidity in terms of adhesion on epoxy-amine primer, while vegetable oil-containing resins lead to improved coating appearance due to better flow and levelling. This study demonstrates that biobased malonate resins, having renewable contents up to 53%, offer attractive performance benefits in 2K RMA paints. It is anticipated that, with the development of additional fully biobased polyols, renewable contents in excess of 80% can be achieved.

Defining relative humidity in terms of water activity. Part 2: relations to osmotic pressures

Relative fugacity (RF), or relative activity, of water in humid air has recently been suggested as a real-gas generalisation for relative humidity, the latter being conventionally defined as a ratio of partial pressures of water vapour. The RF definition covers the entire temperature-pressure region below the critical point of water, where humid air remains a gas, in an unambiguous and continuous manner. However, while thermodynamically rigorous, the theoretical definition of RF does not provide experimental methods of measuring RF of given samples of humid air, nor of preparing reference materials of specified RF, such as for humidity-sensor calibration purposes. In this paper, the osmotic pressure of humid air with respect to pure water in different phases, mutually separated by a semi-permeable membrane, is proposed as an SI-traceable measurand for the calculation of RF over the full range of sub-saturated states. The method of osmotic pressures offers a theoretical option for the experimental determination of the RF of humid-air samples without use or knowledge required on their actual or saturation composition, without exploiting an empirical equation for the fugacity, or an equation of state of humid air.

Porous CeO2 nanospheres for a room temperature triethylamine sensor under high humidity conditions

The porous CeO2 nanospheres showed an enhanced triethylamine sensing performance at 98% of relative humidity in terms of sensitivity, selectivity, repeatability, and response time.

Defining relative humidity in terms of water activity. Part 1: definition

Relative humidity (RH) is a quantity widely used in various fields such as metrology, meteorology, climatology or engineering. However, RH is neither uniformly defined, nor do some definitions properly account for deviations from ideal-gas properties, nor is the application range of interest fully covered. In this paper, a new full-range definition of RH is proposed that is based on the thermodynamics of activities in order to include deviations from ideal-gas behaviour. Below the critical point of pure water, at pressures p < 22.064 MPa and temperatures T < 647.096 K, RH is rigorously defined as the relative activity (or relative fugacity) of water in humid air. For this purpose, reference states of the relative activity are specified appropriately. Asymptotically, the ideal-gas limit of the new definition is consistent with de-facto standard RH definitions published previously and recommended internationally. Virial approximations are reported for estimating small corrections to the ideal-gas equations.

Co-milled API-lactose systems for inhalation therapy: impact of magnesium stearate on physico-chemical stability and aerosolization performance

Context: Particle micronization for inhalation can impart surface disorder (amorphism) of crystalline structures. This can lead to stability issues upon storage at elevated humidity from recrystallization of the amorphous state, which can subsequently affect the aerosol performance of the dry powder formulation.Objective: The aim of this study was to investigate the impact of an additive, magnesium stearate (MGST), on the stability and aerosol performance of co-milled active pharmaceutical ingredient (API) with lactose.Methods: Blends of API-lactose with/without MGST were prepared and co-milled by the jet-mill apparatus. Samples were stored at 50% relative humidity (RH) and 75% RH for 1, 5, and 15 d. Analysis of changes in particle size, agglomerate structure/strength, moisture sorption, and aerosol performance were analyzed by laser diffraction, scanning electron microscopy (SEM), dynamic vapor sorption (DVS), and in-vitro aerodynamic size assessment by impaction.Results: Co-milled formulation with MGST (5% w/w) led to a reduction in agglomerate size and strength after storage at elevated humidity compared with co-milled formulation without MGST, as observed from SEM and laser diffraction. Hysteresis in the sorption/desorption isotherm was observed in the co-milled sample without MGST, which was likely due to the recrystallization of the amorphous regions of micronized lactose. Deterioration in aerosol performance after storage at elevated humidity was greater for the co-milled samples without MGST, compared with co-milled with MGST.Conclusion: MGST has been shown to have a significant impact on co-milled dry powder stability after storage at elevated humidity in terms of physico-chemical properties and aerosol performance.

Climate Characteristics of Safranbolu (Karabuk) and Saffron Cultivation

Saffron (Crocus sativus) has been one of the most important spices in the world since ancient times. Though there is a variety of information about its origin, it is believed to have emerged in Iran, Turkey, or Greece and have spread across the world. Saffron, which is commonly produced in the Mediterranean and Southwest Asian countries, is used in many different fields such as painting, medicine, perfumery, and food. Climate and soil conditions also play an important role in saffron production. Saffron, which shows a flexible characteristic in terms of temperature demand, shows resistance to cold temperatures down to -18 degrees and to summer temperatures up to 45 degrees. The type of soil suggested for the development of the plant is clay loam soil. Although saffron growing in Turkey has lost its former significance today, it is still carried out on a small scale in Safranbolu city. This study intends to show the positive effects of climatic elements prevailing in the region on the production of saffron, the world's most expensive plant, and to reestablish its former importance in the region. The climate data used in the present study were taken from the General Directorate of Meteorology of Turkey. The climatic conditions required by the Thornthwaite climate classification method. Systematic approach was used as a research method. The maps used in the study were prepared on ArcGIS 10.3 GIS (Geography Information System) package. According to the Thornthwaite method, Safranbolu is arid-low humidity in terms of rainfall activity, has a 2nd level mesothermal climate, has no water excess, and is closed to sea effect. Considering the climate demands of saffron, it can be said that the climate of Safranbolu city is suitable for saffron growing. In Safranbolu, saffron plants are currently cultivated only in few villages. However, more effort should be made to enhance the production of saffron, which is as precious as gold.

Molecular formula composition of β-caryophyllene ozonolysis SOA formed in humid and dry conditions

We studied the molecular formula composition of six β-caryophyllene SOA samples using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry under various reaction conditions. The SOA samples were generated in dry or low relative humidity (RH) chamber conditions with or without cyclohexane. All of the studied SOA mass spectra have three distinct clusters of hundreds of negative ions referred to as Group I (100 < m/z < 400), Group II (400 < m/z < 700) and Group III (700 < m/z < 1 000) compounds. C14-16H22-28O2-11, C28-29H42-48O6-16 and C42-43H68-70O14-16 were observed as highly abundant organic compounds in the compound class of Group I, II and III, respectively. The relative intensities of most analytes were higher in humid conditions compared to those in dry conditions, indicating the importance of water-dependent reactions and the catalytic role of water both in the presence and absence of cyclohexane. In addition, molecular formulas with higher average carbon numbers were observed in humid SOA than in dry SOA in the absence of cyclohexane, suggesting a decrease of cleavage reactions in humid condition. This study characterizes β-caryophyllene ozonolysis SOA based on ultrahigh mass resolution and demonstrates the significance of humidity in terms of the molecular distributions and relative abundances of the analytes. We also discuss the possible mechanism for the formation of Group I-III compounds based on the current understanding of SOA formation in the atmosphere.

Characteristics of the mechanical milling on the room temperature ferromagnetism and sensing properties of TiO2 nanoparticles

We report on the correlation between defect-related emissions, the magnetization and sensing of TiO2 nanoparticles (NPs) prepared by milling method. Surface morphology analyses showed that the size of the TiO2 NPs decreases with milling time. Raman and XRD studies demonstrated that the structural properties of the TiO2 transform to orthorhombic structure upon milling. Magnetization improved with an increase of a defect-related band originating from oxygen vacancies (VO), which can be ascribed to a decrease in the size of the NPs due to the milling time. Moreover, the longer-milled TiO2 exhibited enhanced gas-sensing properties to humidity in terms of sensor response, with about 12s response time at room temperature. A combination of photoluminescence, X-ray photoelectron spectroscopy, vibrating sample magnetometer and sensing analyses demonstrated that a direct relation exists between the magnetization, sensing and the relative occupancy of the VO present on the surface of TiO2 NPs.

Effect of Humidity on Carbon Monoxide Desorption Kinetics

The kinetics of carbon monoxide desorption on a platinum catalyst under humidified conditions were investigated with the steady state isotropic transient kinetic analysis (SSITKA) method. The effect of the humidity level on desorption kinetics was quantified. The carbon monoxide (CO) desorption kinetic constant was calculated regardless of the gas flow rate. The kinetic constant dropped up to 58% with the increasing relative humidity. The negative effect of humidity in terms of CO poisoning for PEM fuel cells was determined.

Clutch and egg size variation, and productivity of the House Sparrow (Passer domesticus): effects of temperature, rainfall, and humidity

This study was conducted on the campus of the regional department of the forestry service, encompassing 2.25 ha in Antalya city center. The area has gardens and is surrounded by trees, providing nesting and feeding opportunities for many songbird species. The study aimed to determine clutch and egg size variation, breeding success, and productivity of the House Sparrow (Passer domesticus), in terms of clutch size and breeding attempts, and to evaluate variation in temperature, rainfall, and humidity in terms of breeding attempts and years, and their possible effects on given parameters of the species. In total, 2016 eggs were laid in 393 clutches and clutch size varied from 1 to 11 eggs; the clutches most commonly contained 4-6 egg in the 3 consecutive years. Mean egg length, width, weight, volume, and sphericity index were 21.16 ± 0.03 mm, 14.99 ± 0.01 mm, 2.02 ± 0.01 g, 2.38 ± 0.01 cm^{3}, and 71.01 ± 0.09, respectively. Breeding attempts were affected by temperature (r = 0.97 P < 0.0001) and rainfall (r = -0.84 P < 0.001). Egg length was affected by rainfall (r = 0.60 P < 0.041), humidity (r = 0.59 P < 0.044), and temperature (r = -0.81 P < 0.002), and egg volume was affected by temperature (r = -0.68 P < 0.015). This study shows that the House Sparrow population in the study area exhibited important variation in clutch and egg size, which was affected by changes in temperature, rainfall, and humidity.

A scanning force microscope study of detachment of nanometer‐sized particles from glass surfaces

The nominal shear stress required to detach nanometer‐scale, single‐crystal salt particles from a soda lime glass substrate is a strong function of particle size and relative humidity. We use the tip of an atomic force microscope to detach these particles from a glass substrate under controlled atmospheres of known humidity. The peak lateral force at detachment was divided by the nominal particle area to yield an effective interfacial shear strength. We describe the variation of shear strength with particle area and humidity in terms of detachment by chemically assisted crack growth along the salt–glass interface.

Acute and Sublethal Activity of the Entomopathogenic Fungus Paecilomyces fumosoroseus (Deuteromycotina: Hyphomycetes) on Adult Aphelinus asychis (Hymenoptera: Aphelinidae)

In order to be most effective, components of integrated pest management programs should act in concert with minimal antagonistic interaction between natural enemy groups and other interventions. Entomopathogenic fungi and insect natural enemies have the potential to complement or interfere with one another, depending on environmental conditions. The acute and sublethal effects of the hyphomycete fungus, Paecilomyces fumosoroseus (Wize) Brown & Smith, on adult female Aphelinus asychis Walker, a common parasitoid of the Russian wheat aphid, Diuraphis noxia (Mordvilko), were studied under conditions of low (a55% RH) and high (≥95% RH) humidity at 24°C. Parasites exposed to dosages of P. fumosoroseus ranging from 3.75 to 3.75 × 103 conidia per square centimeter and incubated at 24°C in low or high relative humidity responded with mortality ranges of 20–33% and 33–88%, respectively. The effect of treatment with P. fumosoroseus at 5.2 × 104 spores per square centimeter (2× LC95 for D. noxia ) on foraging behavior of the parasitoid was studied with video image analysis 24–96 h after treatment with the fungus and incubation at low or high relative humidity. There was no significant difference between control and fungus-treated females that were incubated at the lower humidity in terms of percentage of time walking, turning, resting, and average walking speed. However, fungus-treated insects that were incubated at high relative humidity were significantly less active than their respective controls for percentage of time walking, walking speed, and distance covered. Also, average walking speed and distance walked by treated parasitoids incubated at low relative humidity for 96 h following treatment was significantly greater than treated insects incubated at the high relative humidity. Females treated with 2.6 × 104 spores per square centimeter and held in ≥95% RH for 24 h followed by incubation at 60% RH survived for an average of 5.7 d relative to 9 d for untreated females. The number of mummies produced per female per day was not significantly different between treated and untreated females, but more aphids were parasitized by the control insects due to longer survival. The limited untoward effect of P. fumosoroseus on adult A. asychis under conditions of lower humidity indicates good potential for their combined use for control of the Russian wheat aphid.

An attempt to interpret the humidity dependencies of the aerosol extinction and scattering coefficients

This paper shows that there exists a possibility of interpreting the variation of the aerosol scattering coefficient with relative humidity in terms of mean composition of the aerosol particles of all sizes (not the chemical compositions of specific size classes). Furthermore, the discussion of a specific example has demonstrated the most important requirements for such an analysis. These are: 1. (1) knowledge of the approximate shape of the size distribution, 2. (2) the approximate complex refractive index of the particles, and 3. (3) that the measurements are taken in one specific air mass.

Shear-dependent surface rheological measurements of foam stabilizers in nonaqueous liquids

Theoretical relations are discussed for the flow of a two-dimensional Bingham plastic in a viscous-traction canal viscometer. Furthermore, this relatively simple model has been found to correlate the observed shear dependency of the system studied over a wide range of experimental conditions and has made it possible to interpret complex effects of temperature and relative humidity in terms of their respective effects on the surface viscosity and surface yield value.

A New Relative Humidity Recorder

Recorder Mechanism.—A mechanism is described capable of automatically balancing any network of impedances where the balance point is attained by the motion of one or more sliders along slide wires, and where the balance point is determined by the absence of current in the recorder galvanometer.Relative Humidity Curves.—From the formula for relative humidity in terms of the wet and dry bulb temperatures, it is shown that for constant humidity the relation between wet and dry bulb temperatures is very nearly a linear one, and that the value of the humidity is uniquely defined by the ratio (wet bulb temp.—A)/(dry bulb temp.—B) where B is a constant and A is a function of the relative humidity but changes only slightly with it.Recorder Circuit.—By using a nickel resistance thermometer in a network which is essentially a split circuit potentiometer, it is possible to secure a potential difference across the ends of a slide wire which is directly proportional to (dry bulb temp.—B). In another very similar circuit a potential difference is gotten which is proportional to (wet bulb temp-A). This latter potential difference is automatically balanced against a portion of the former by the recorder mechanism mentioned above, and the position of balance is indicative of the ratio (wet bulb temp.—A)/(dry bulb temp.—B) so that the instrument reads directly in relative humidity.The results of a check on the finished instrument are given from which it appears that the approximations made in the design and any inaccuracies introduced in the actual construction are of no greater magnitude than the uncertainties in the humidity formula itself.Maintenance of Wet Bulb.—Two forms of wet bulb are described which are capable of continuous operation. In one the customary wick is replaced by a spray, and in the other a long wick is provided so that a clean portion can be substituted for the soiled part merely by turning a roller to wind the wick from one holder on to another.