High Temperature Humidity Research Articles

Optimization of DNA extraction protocol using skeletal remains found in Sri Lanka

IntroductionThe preservation of DNA in old skeletal remains is reported to be very low in a tropical country like Sri Lanka due to prevailing climatic and environmental conditions such as high temperature, high rainfall and high humidity, etc. In this study, extraction of DNA from old skeletal remains dated back to 15 – 40 years was attempted by using previously published extraction protocols. Materials and MethodsA 15-years-old humerus (15Y) excavated from Kuliyapitiya area in Kurunegala district and the 40-yearsold tibia (40Y) received from Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura were used to extract old DNA. Human mitochondrial HVS I region of extracted DNA was amplified in PCR using four overlapping first round primers and second round nested primers respectively. A second-round nested PCR was performed. PCR amplification success was verified upon electrophoresis in 2% agarose gels. Results and AnalysisDNA bands were obtained with correct size ranges for all systems in both first and second round PCR products of amplified DNA extract of old bones 15Y and 40Y from modified phenolchloroform method. DNA bands were obtained from all four systems for 40Y bone DNA extract from DNA investigation Kit; QIAGEN, Germany. ConclusionIn the present study, we have successfully extracted and amplified DNA from old skeletal remains by using modified phenol chloroform method and DNA investigation Kit – QIAGEN, Germany, nevertheless the preservation of DNA in skeletal remains in Sri Lanka is very low.

Characterization and Image-Based Performance Evaluation on the Longevity of LCDs Under High Temperature and Humid Environment

Quality inspection and long term reliability of liquid crystal displays (LCDs) are critical for product assurance. In this work, the degradation of LCDs under both high temperature (~90°C) and high humidity (~near 100%) are characterized as a reference for related product reliability test in accelerating manner. Traditionally, manually inspection is performed for finding display defects such as Mura. Such an approach could be biased easily by subjective opinions and a more objective evaluation should be sought. In this paper, a computer-based inspection approach is proposed for addressing this need through a systematic design of LCD durability test. By capturing standard LCD display images during operation and perform essential image processing, it is possible to evaluate defect quantitatively. After each heating period, the LCD images are taken and analyzed either by Otsu thresholding or by analyzing their statistical properties in the gray level histograms. The results indicate that these image-based methods are highly correlated and therefore can be adapted as the measures of display qualities. The mean time to failure is characterized as 1500 hours under the testing condition. Meanwhile, both the Young’s modulus and warpage testing of the polarizer and the diffuser membranes of the LCDs, as well as the essential finite element deformation analyses, are performed for correlating the display performance of the LCDs. It is found that the resulted warpage and the reported Mura are also highly correlated. This provides a rational approach for improving device longevity based on fundamental mechanics.

Pre-blended conductive agent to effectively improve the storage properties of LiNi0.6Co0.2Mn0.2O2 cathode materials

Nowadays, the high-nickel ternary cathode materials attract more and more attention because of their high capacity. However, compared with other cathode materials, the disadvantage of high-nickel ternary cathode materials in storage performance is very obvious. The obvious impurities on the surface of high-nickel ternary materials are generated after storage for a period of time, and its electrochemical performance produce a cliff-like decline. In this work, we use the pre-blending of conductive agent to simply and effectively improve the storage performance of LiNi0.6Co0.2Mn0.2O2 cathode materials under high temperature and high humidity conditions. Fine particles of conductive agent can be well filled in the gap between the primary particles of the material, suppressing the sites where impurities are most easily formed during storage. Compared with the pristine materials, when stored for the same time, the impurities generated on the surface of modified materials are significantly fewer, the increase of weight is smaller, and more excellent electrochemical performance is exhibited. It can be seen from the results that the pre-blending of the conductive agent can greatly improve the storage performance of the high-nickel ternary cathode materials.

Hydrolysis kinetic study of CaAlSiN3:Eu2+ red phosphor with both water immersion test and first-principles calculation

At present, most high-power white Light-emitting diode and laser diode (LED&LD) package is usually constructed by a blue LED&LD chip with a Cerium doped Yttrium Aluminum Garnet (YAG:Ce3+) yellow phosphor, but its color rendering performance is severely challenged due to the lack of red light emission spectrum. The CaAlSiN3:Eu2+ red phosphor can effectively improve the color quality of traditional yellow phosphor converted white LED&LDs(pc-wLED&LDs), however, it is often susceptible to degradation under high temperature and high humidity environments, which will directly affect the color quality of pc-wLED&LDs. In this study, a series of water immersion tests on CaAlSiN3:Eu2+ red phosphor are used to quantitatively study its hydrolysis reaction kinetics. Then, the degradations of its photoluminescence and photothermal performances are evaluated by characterizing the crystal structure, micromorphology and chemical element composition. Finally, an atomic level hydrolysis reaction mechanism of CaAlSiN3:Eu2+ red phosphor is investigated by using the first-principles density functional theory (DFT) calculation. The results show that: (1) By modelling the in-situ monitored electrical conductivity of CaAlSiN3:Eu2+ red phosphor water solution with a first-order reaction function, the calculated hydrolysis reaction rate satisfies the Arrhenius relationship and the reaction activation energy is estimated as 49.19 kJ/mol; (2) The increased self-heating effect of CaAlSiN3:Eu2+ red phosphor after water immersion test attribute to its drastic drop of light emission efficiency; (3) The hydrolysis reaction mechanism of CaAlSiN3:Eu2+ red phosphor is confirmed, which sequentially results in the dissolution of Ca2+ and OH−, the crash of host lattice and the accumulation of reaction residues.

Tuning residual metal in partially etched carbide-derived carbons for enhanced acid gas adsorption

Abstract An in-depth study on post-synthetic modification of residual metal in carbide-derived carbons (CDCs) from an Al4C3 starting material has been performed. Ambient temperature high humidity studies reveal the conversion of residual parent nanoparticles to poly(aluminum chloride) (PAC). Alkaline modification was employed resulting in the formation of amorphous Al(OH)3 nanoparticles within 24 h of reaction. After aging for up to 11 days, amorphous nanoparticles convert to well-crystallized α-Al(OH)3 (bayerite). Al4C3-CDCs with amorphous Al(OH)3 display significantly-enhanced interactions with SO2 and CO2 while X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance infrared (ATR-IR) spectroscopy indicated no significant change in the surface chemistry of the carbon. SO2 breakthrough results at 1000 ppm SO2 exhibit uptakes near 2 mmol g−1, displaying viability for these adsorbents in flue gas remediation applications. The results of this work provide detailed modification strategies for tuning the extent and type of residual metal embedded in the final CDC structure, along with further insights into the ramifications of oxygen functionalities and pore size distribution of CDCs for SO2 adsorption.

About ecology around industrial areas of Mariupol

The oxygen content in the atmospheric air of cities, as well as in residential, office and industrial premises is the most important factor in the health and well-being of citizens. With high temperature and high absolute humidity of the surface air, the oxygen content in ambient air is minimal, and people may experience signs of hypoxia. In the industrial southern cities to which the city of Mariupol (Ukraine) belongs, there are additional factors that impede human breathing: higher (relative to the territory surrounding the city) air temperature and pollution of the atmosphere, including carbon monoxide and suspended particles. This results in conditions of abnormal heat and industrial emissions to an increase in the morbidity and mortality of the urban population. Accurate measurements of partial pressure and partial density of oxygen require special equipment and techniques, since the percentage of oxygen in ambient air is large enough, and its changes are relatively small. Most modern instruments used by urban atmospheric monitoring services are focused on measuring significant deviations of oxygen content from the norm. Air quality monitoring services do not usually measure the density of oxygen, apparently due to the implicit assumption of the negligible effect of changes in weather conditions on its content. In addition, the measurement of small changes in the oxygen content in the surface air is a rather complicated technical task. The paper presents an attempt to analytically determine the distribution of oxygen concentrations in the surface layers of the atmosphere around the places of oxygen runoff from the atmosphere at metallurgical enterprises of Mariupol, provides an analytical model based on the theory of "reverse flow" in a one-dimensional formulation of oxygen flow from the surface layer. The corresponding concentration contour lines were obtained at various distances from the oxygen sink sites. At the same time, the oxygen concentration decreases inversely with the distance from the drain, which makes it quite easy to estimate the distribution of concentrations in the surface layer of the atmosphere around the metallurgical enterprises at known coordinates of its drain points in calm weather. The spatial variability and episodes of anomalous oxygen content in the surface air are analyzed in the context of their possible effect on people's well-being.

Fungal assessment on storerooms indoor environment in the National Museum of Fine Arts, Cuba

The artworks that are preserved in museums can be damaged by fungi when the conditions of temperature and humidity are adequate to accelerate their growth. This is increased in Cuba by the climatic conditions of the country, characterized by high temperature and relative humidity during the all year. These fungi do not only cause the artworks biodeterioration but also affectations in the personnel’s health. The aims of this work were to characterize the mycobiota in two microenvironments of the National Museum of Fine Arts, Cuba (1: three interior environments of repositories or storerooms and 2: six surfaces of artworks) and analyze its relationship with the conservation of artworks. Environmental samples were taken using a SAS Super 100 biocolector, while samples from the artworks surfaces were taken using sterile cotton swabs. Appropriate selective culture media were used to isolate fungi. The concentrations obtained in the indoor environments indicate that one storeroom was contaminated, while the other two were not. Fourteen filamentous genera, one genus of yeast, and two fungal mycelia were detected in the air of the storerooms, while four filamentous genera and one genus of yeast were obtained from the artworks studied. Aspergillus spp. was the predominant genus in the two microenvironments. Six species of the Aspergillus genus (A. glaucus, A. flavipes, A. niveus, A. proliferans, A. conjunctus, A. restrictus, A. janus) and three genera (Botryoderma, Hansfordia, Nodulisporium) detected in the repositories air as well as four isolated genera of artworks (Olpitrichum, Verticillium, Engyodontium, Tritirachium) are new findings for Cuban museums.

On the ecological state of the atmosphere around the industrial areas of Mariupol

The oxygen content in the atmospheric air of cities, as well as in residential, office and industrial premises is the most important factor in the health and well-being of citizens. With high temperature and high absolute humidity of the surface air, the oxygen content in ambient air is minimal, and people may suffer hypoxia. In the industrial southern cities to which the city of Mariupol (Ukraine) belongs, there are additional factors that impede human breathing: higher (relative to the territory surrounding the city) air temperature and pollution of the atmosphere, including carbon monoxide and suspended particles. This results in an increase in the morbidity and mortality of the urban population under the conditions of abnormal heat and industrial emissions. Accurate measurements of partial pressure and partial density of oxygen require special equipment and techniques, since the percentage of oxygen in ambient air is large enough, and its changes are relatively small. Most modern instruments used by urban atmospheric monitoring services are focused on measuring significant deviations of oxygen content from the norm. Air quality monitoring services do not usually measure the density of oxygen, apparently due to the implicit assumption of the negligible effect of weather conditions changes on its content. In addition, the measurement of small changes in the oxygen content in the surface air is a rather complicated technical task. The paper presents an attempt to analytically determine the distribution of oxygen concentrations in the surface layers of the atmosphere around the places of oxygen runoff from the atmosphere at metallurgical enterprises of Mariupol, provides an analytical model based on the theory of «reverse flow» in a one-dimensional formulation of oxygen flow from the surface layer. The corresponding concentration contour lines were obtained at various distances from the oxygen sink sites. In doing so, the oxygen concentration decreases inversely with the distance from the drain, which makes it quite easy to estimate the distribution of concentrations in the surface layer of the atmosphere around the metallurgical enterprises at known coordinates of its drain points in calm weather. The spatial variability and episodes of anomalous oxygen content in the surface air have been analyzed from considerations of their possible effect on people’s well-being

Chemical durability of thin pore-filling membrane in open-circuit voltage hold test

Long-term chemical stability of proton exchange membranes in polymer electrolyte fuel cells (PEFCs) is an important issue for widespread commercialization. Here, we report on the chemical stability of a membrane-electrode assembly with a 7 μm thick pore-filling membrane (porous substrate filled with high ion exchange capacity perfluorosulfonic acid (PFSA) polymer) using an open-circuit voltage hold test. The very thin pore-filling membrane shows comparable chemical durability to Nafion 211. Interestingly, the pore-filling membrane shows a different degradation behavior from Nafion 211 due to the use of chemically and mechanically stable porous substrate, with no thickness change and little amounts of fluorine leakages are observed in the pore-filling membrane compared to membrane thinning and large amounts of fluorine leakage in Nafion 211. The thin pore-filling membrane shows promise for application in PEFCs, as it balances high fuel cell performance at high temperature and low relative humidity with high chemical durability.

Evaluation of carboxylic, phosphonic, and sulfonic acid protogenic moieties on tunable poly(meta‐phenylene oxide) ionomer scaffolds

A tunable, meta-linked aryl ether polymer scaffold enables the introduction of various acid groups for a fundamental comparison of their contributions to proton conduction. Sulfonic acid-functionalized polymers offer the best proton conduction at low temperature and high relative humidity, while phosphonic acid-functionalized polymers outperform sulfonic and carboxylic acid-derived polymers at high temperature or low humidity. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Research and Application of Screw Feeding Mechanism for Fiberboard Separation

The main function of the screw feeding mechanism is to force the cooked wood fiber material into the high pressure, high temperature and high humidity grinding chamber for fibrosis heat treatment, which is an important part of the fiberboard fiber separation feeding equipment. Through the analysis of typical screw feeding mechanism, combined with production performance requirements, the improvement measures are put forward and the structure of main functional components is determined, and the design scheme of screw feeding mechanism for fiberboard fiber separation is formulated, so as to effectively improve the feeding efficiency.

A novel MYB transcription factor CaPHL8 provide clues about evolution of pepper immunity againstsoil borne pathogen

MYB TFs in plants are of crucial importance not only for growth and development but also for plant defense against pathogens. CaPHL8, an MYB TF, was identified as a positive regulator of pepper defense against Ralstonia solanacerum inoculation (RSI). Phylogenetic evaluation and functional characterization of CaPHL8 revealed its role in pepper defense evolution. Analysis of the amino acid sequence of PHL8 demonstrates its maximum similarity with the MYB family transcription factor in other plants. Up-regulation of CaPHL8 was observed in pepper plants facing Ralstonia attack.. Consistently the GUS activity of pCaPHL8 showed significantly high activity under RSI as compared to mock-treated plants. The loss of function studies of CaPHL8 conducted through VIGS (virus-induced gene silencing) confirmed the reduced pepper immunity to R. solanacearum and impaired plant growth accompanied by high pathogen growth. Compromised pepper immunity in silenced plants was coupled with a reduction in transcription of defense linked marker genes. On the other hand, transiently overexpressing CaPHL8 (35S::CaPHL8-HA) in pepper caused a hypersensitive response, elevated H2O2 production and high expression of immunity associated marker genes. Stable expression of CaPHL8-HA protein was confirmed by Western blot. Additionally, unlike many other TFs, CaPHL8 is not involved in high-temperature stress tolerance as evident by phenotype and non-significant transcription of high temperature-tolerance related marker genes in pepper. So, all these findings confirm that CaPHL8 is induced by RSI, not by high temperature and high humidity (HTHH). It provides adaptive plasticity to pepper by activating defense to RSI by direct or indirect regulation of different immunity -associated genes.

Transcriptomic analysis reveals Apis mellifera adaptations to high temperature and high humidity

Temperature and humidity are the most important factors affecting the growth, reproduction, and survival of bees. Apis mellifera are important pollinating bees that are widely used in agricultural systems. However, the higher temperatures and humidity in greenhouses are not conducive to the survival of bees. Although previous research has revealed the behavioral responses and physiological mechanisms of honeybees to adapt to high temperature and humidity, there are few data on the exact molecular mechanisms involved. In our study, we investigated gene expression in A. mellifera under different temperature and humidity treatments, using transcriptomic analysis to identify differentially expressed genes (DEGs) and relevant biological processes. Based on the transcriptomic results, we selected several genes with significant differences in expression, and detected the expression patterns of these genes at different temperatures or humidity or different treatment times by q-RT PCR. In the high temperature treatments, 434 DEGs were identified; in the high humidity treatments, 86 DEGs were identified; in the combined high temperature and humidity treatments, 266 DEGs were identified. Analysis results showed that DEGs were enriched in pathways related to amino acid and fatty acid biosynthesis and metabolism under each treatment. In addition, heat shock proteins, zinc finger proteins, serine/threonine-protein kinases, and antioxidase were differentially expressed between the different treatments. The results of the q-RT PCR showed that the expression levels of these genes increased with increasing temperature and over treatment time. Our findings provide a general expression profile of the adaptive expression of heat-resistance genes responding to high temperature and high humidity in A. mellifera, including the expression patterns of several DEGs. Our data provide a basis for future research on the mechanisms underlying the adaptation of insects to high temperature and humidity.

High Voltage Temperature Humidity Bias Test (THB) customized system and methodologies for reliability assessment of power semiconductor devices

High Voltage Temperature Humidity Bias Test (THB-HV) is currently the state of the art test method for reliability evaluation of power devices in high humidity environments at high voltage. These conditions have become especially significant in the case of power modules for the automotive industry and other applications in harsh environments. In this research work, a custom system for active monitoring of THB-HV testing is developed and customized, in order to evaluate different testing methodologies, intercept device degradation in real time, and allow for a controlled and more accurate failure analysis of the DUTs.

P‐5.10: Lifetime Prediction Model for Microcapsule Electrophoretic Display Device Based on High Temperature and High humidity Test

The failure mode of electronic paper display under different temperature and humidity conditions is studied in this paper. Nine high temperature and high humidity conditions are designed for the verification, it is found that the Arrehenius accelerated life model and the Peck accelerated life model are not suitable for the lifetime prediction of Microcapsule Electrophoretic Display Device. Therefore, based on these two accelerated life models, the new model is proposed, which is a new acceleration method for Predicting the lifetime of Microcapsule Electrophoretic Display Device, and the feasibility of this model has been theoretically confirmed.

Copper electrochemical migration growth in an air HAST

High performance electronics require printed circuit boards (PCBs) with an extremely narrow pitch between adjacent copper patterns. However, copper electrochemical migration in these fine-pitch PCBs is a major source of failure. This phenomenon is typically identified using a highly accelerated temperature and humidity stress test (HAST) in which the water vapor pressure inside a chamber is increased along with the temperature and humidity. However, a side effect of this is that little air remains in the chamber despite air being required when replicating actual environments. This can be overcome by using an air HAST system that includes air inputs in its chamber. In our experiments, we analyzed the copper electrochemical migration on coupon samples with a 125 μm pitch at temperatures above 120 °C under various air pressures. We then compared the results for the air HAST, HAST, and high temperature and high humidity (85 °C/85% R.H.) tests by plotting each lifetime in the form of a Weibull distribution. Upon inspection, the cross-sectional microstructures of the copper electrochemical migration were seen to vary between the HAST and air HAST methods due to differences in the growth mechanism of the copper electrochemical migration.

Effect of Side Chain Length in Phosphoric Acid Based Membranes on Nanophase-Segregation and Transport

Due to the high conductivity and stability, perfluorinated sulfonic acid (PFSA) proton exchange membranes such as Nafion are currently the standard for polymer electrolyte membranes (PEMs). While boasting superior conductive properties at standard conditions, Nafion dehydrates at high temperature and low humidity, drastically compromising its performance. While functionalization of PFSA membranes with phosphoric acid has been shown to improve conductivity under low-humidity conditions, these membranes still require optimization as they lack a practical level of conductivity. In this study, we use computational methods to investigate the nanophase-segregation and transport in phosphoric acid membranes in comparison to Nafion membranes, and analyze the effect of side chain length on these two properties. It is found that, as in sulfonic acid membranes, larger water clusters are formed in phosphoric acid membranes with longer side chains. However, unlike in sulfonic acid membranes, the phosphoric acid groups associate closely with one another via hydronium bridging, which suppresses proton hopping. Therefore, it is inferred that the proton transport is decreased with increasing the phosphoric acid side chain length. Based on these results, we recommend opting for shorter side chain lengths when designing phosphoric acid membranes.

(Invited) Harsh Environments Treatment and Detection: Piezocatalysis and Wireless Triboelectric Vibration Sensor

The rapid growth of materials and science technology yields miniaturized and stretchable electronics, with a various revolutionary technology on multifunctional devices. However, without the self-powered function, it is difficult to make the sensor to be deployed in harsh environments. Thus, considering the sustainable operation for most of the internet of things (IoT) devices, which have become challenges, especially for the inconvenience of having to replace batteries in devices such as environmental monitoring for high temperature and high humidity regions, deep ocean areas, the implanted biomedical sensor, and the complexly industry-treatment system. Moreover, one of the major problems is the emission of all sorts of organic compounds in water, such as textile dyeing, industrial food waste, printing industries, which cause severe health issue and environmental contamination. Such problems become more difficult when there is no obvious solution and strategies. In this work, we will report the piezocatalysis could deliver the powerful technologies for decomposing the waste water while the wireless self-powered triboelectric sensor is successful developed for operating in an underwater environment at various temperatures through the enzymatically treated process.

P‐8.4: A Novel Non‐barrier‐film Quantum Dot Diffusion Plate in Backlight System

Compared with traditional LED backlight source, the quantum dot‐based backlight module has recently attracted extensive interest owing to their wider color gamut. Generally, quantum dots are sensitive to the external environment, and quantum dots in current commercial quantum dot film are usually protected by two barrier film layers to isolate the influence of external factors such as water and oxygen. In this report, a new quantum dot plate strategy was developed by a three‐layer co‐extrusion method without the use of any expensive barrier film. Quantum dots were homogeneous embedded in the polymeric matrix of the middle layer, and the upper and lower layer act as protective layers to avoid the destruction of external environment to quantum dots. Reliability tests demonstrate that this non‐barrier‐film quantum dot plate shows satisfactory stability comparable to the high‐barrier‐material‐based quantum dot films under conditions of blue‐LED irradiation, high temperature and high humidity.

P‐6.10: Study on the mechanism and method of improving around mura

In this article, we study how to improve the irregular Mura in the surrounding and corner of GOA (Gate Driver on Array) product in high temperature and high humidity HTHHO (60/90) environment, because of the influence of PI Halo area. This article illustrates that by adjusting the PI phase separation ,adjusting the PI drop position and adjustment of coating position of Seal ,which can reduce the influence of PI and improve the around mura. The experimental results show that increasing PPO (PI prebake oven) temperature can accelerate the separation of PI phase, allow PI to form faster and improve the around mura. By modifying the Pattern coated by PI, the PI is expanded and the around mura. can be improved. Adjusting Seal location also improves Mura around the site.