Dry Burning Research Articles

Influence of laser-processed surfaces on heat transfer performance of microflow channels

Microchannel heat dissipation systems are widely used in micro-electro mechanical systems owing to their high thermal conductivity and small size. Laser processing has the advantages of high efficiency and no tool contact, and is one of the best ways to process ceramic materials. However, the roughness of the machined surface will significantly affect the heat dissipation performance of the microchannel. In order to study the influence of roughness element characteristics on the heat dissipation efficiency of the micro-channel radiator, the surface roughness was simulated with typical shape, and the influence of different roughness element shape, height and spacing on the pressure field, velocity field and temperature field of the micro-channel radiator was analysed. The results indicate that the semi-circular roughness element has the highest heat transfer efficiency and that the overall flow is stable. With an increase in the height of the roughness element and a reduction in the spacing, the heat transfer efficiency and inlet/outlet pressure drop increased. When the height of the roughness element is 17.2 μm, the heat transfer ability was significantly improved and the pressure drop ratio is reduced by >20% compared with that for a height of 19.5 μm. When the distance between roughness elements is 33.5 μm, the maximum temperature of the heat dissipation system was only 331.85 K. Compared with other models, the temperature of the optimized model is reduced by 14.44K, and the heat transfer efficiency is the highest. The results of heat dissipation experiments show that compared with dry burning temperature, the optimized model can reduce the temperature of the micro-channel heat dissipation system by more than 73 K.

State of protective forest plantations in the Forest-Steppe zone of Ukraine

This paper analyzes approaches of scholars to the interpretation of the essence of protective forest plantations (PFP) and provides the most appropriate definition. The most significant functions of PFP are analyzed, and their peculiarities in certain regions of Ukraine are highlighted. PFP play an important role in preserving the stability of landscapes, including agricultural ecosystems. They are important for soil improvement and perform significant ecological functions, contributing to the creation and improvement of microclimate in agro-landscapes: reducing wind speed and intensity of wind erosion in the summer, preventing the blowing of the upper, most fertile layer of soil; snow retention and reducing surface runoff, including both snowmelt and rainwater, which helps to preserve soil moisture and prevent water erosion. Existing protective forest plantations in the Forest-Steppe zone of Ukraine are mainly formed from black locust (Robinia pseudoacacia), common oak (Quercus robur L.), common ash (Fraxinus excelsior L.), Canadian poplar (Populus canadensis Moench.), black poplar (Populus nigra L.), Norway maple (Acer platanoides L.), and sycamore maple (Acer pseudoplatanus L.). It is concluded that the Forest-Steppe zone of Ukraine is characterized by a rapid loss of protective forest plantations due to fires and military actions. During 11 months of the war with Russia, 425 cases of forest fires were recorded in PFP on a total area of 754 ha in the occupied Zaporizhia region and 287 ha in the Kherson region. This is three times more than during the same period in 2021, and the average area of one fire has increased by 16 times. Fires in the Forest-Steppe are characterized by the concept of temporary sterilization of the soil, during dry burning, as a result of which the death of worms, insects and microorganisms occurs in these areas. In the post-war period, the development of the forest industry requires scientific support for the implementation of the state policy on sustainable forest management, increasing the forest resource potential, as well as the forest cover of Ukraine to an optimal level, improving the efficiency of forest production through the application of modern scientifically-based methods for forest restoration and cultivation and rational use of forest resources, protecting forests from fires, illegal logging, pests, and diseases.

Research and Application of Intelligent Water Source Well Air Defense Pumping and Dry Burning Technology

The surface water injection technology for developing low permeability reservoirs comes from the water supply of water source wells. The groundwater resources in oil fields are limited, with high water consumption and a decrease in water level, lacking effective monitoring methods. In recent years, there have been frequent occurrences of unsafe waste of electrical energy due to dry burning during pumping in water source wells, which has seriously affected the normal water injection of oilfield formations. In order to prevent dry burning of water source wells by pumping air, research on intelligent air defense dry burning technology for water source wells has been carried out. The automatic pump stop alarm at low water level and the automatic pump start at high water level avoid the phenomenon of dry burning during pumping in the water source well, ensure the normal operation of the water source well, and ensure sufficient water injection from the source. Reduce employee labor intensity and achieve the goal of optimizing human resources. Associate the start and stop status of the water source well with the tank position of the water injection station to achieve automatic water distribution and inventory, achieve digital management and fine management, and achieve the goal of reducing costs and increasing efficiency, which has promotion value.

Authenticity discrimination of Pulsatillae Radix based on dry-process REIMS fingerprinting combined with machine learning

In this study, rapid evaporative ionization mass spectrometry(REIMS) fingerprints of 388 samples of roots of Pulsatilla chinensis(PC) and its common counterfeits, roots of P. cernua and roots of Anemone tomentosa were analyzed based on REIMS combined with machine learning. The samples were determined by REIMS through dry burning, and the REIMS data underwent cluster analysis, similarity analysis(SA), and principal component analysis(PCA). After dimensionality reduction by PCA, the data were analyzed by similarity analysis and self-organizating map(SOM), followed by modeling. The results indicated that the REIMS fingerprints of the samples showed the characteristics of variety differences and the SOM model could accurately distinguish PC, P. cernua, and A. tomentosa. REIMS combined with machine learning algorithm has a broad application prospect in the field of traditional Chinese medicine.

Aerosols optical and radiative properties in Indonesia based on AERONET version 3

Heterogeneity in seasonal aerosol types due to different sources, local characteristics, and meteorology lead to different optical and radiative properties from one place to another. This study analyzes the long-term averages of aerosol optical and radiative properties obtained by the Aerosol Robotic Network (AERONET) version 3 at four sites in Indonesia representing fire prone areas (Palangka Raya, Pontianak, Jambi: 2012–2020), and urban-industrial (Bandung: 2009–2018). We examined the seasonal variation of aerosol optical depth (AOD), Angstrom Exponent (AE), Precipitable Water Vapor (PWV), and Single Scattering Albedo (SSA) combined with meteorological parameters at these Indonesian sites. Multiple clustering techniques from different relationships among various aerosol optical and radiative parameters was employed to further study the aerosol type in respect to different seasonality. The results exhibited a distinct seasonal pattern at all sites except Bandung, whereas AOD increased owing to forest and peat fire outbreaks during the dry season. The trend in AOD annual depicts an increase in Bandung as emission from urban/industrial increases episodically, while it depicts a decrease at the three biomass burning sites. As AOD increased, Palangka Raya, Pontianak, and Jambi exhibited wider ranges of observed AE (1.2–1.8) and high FMF (>0.8) in the dry burning period (June to October). On the other hand, Bandung has more aerosol distribution in the range of FMF values 0.6–1 and AE 1–1.6, compared with other sites, suggesting contribution of complex aerosol emission from different sources and likely due to the formation of secondary aerosol production from trace gases. Palangka Raya, Pontianak, and Jambi exhibited non-absorbing characteristics, as indicated by high SSA (>0.95), high FMF, and high EAE values (1.2–1.7) with no discrepancy in seasonal patterns, implying that biomass burning aerosols in Indonesia tend to cool the atmosphere with strong scattering rather than absorbing. At Bandung, aerosols mixed with slightly absorbing and non-absorbing aerosols owing to urban and industrial emissions. This study lays a foundation for further research on the contribution of aerosol radiative forcing to climate within the complex aerosol and cloud environments in Indonesia.

COWSLIP (PRIMULA VERIS L.) CHEMICAL COMPOSITION DEPENDENCE ON THE SOIL PROPERTIES

It is known that perennial herbaceous plants growing in harsh conditions in unfertilized soils accumulate large amounts of valuable substances. The aim of the study was to investigate the main chemical composition of wild growth cowslip (Primula veris L.) leaves and inflorescences. Plants samples were collected in April–May of 2019 in different regions of Lithuania (area No. 1 and area No. 2). The plant samples were analyzed immediately after harvesting. Dry matter, soluble solids, ascorbic acid content, titratable acidity was determined by standard methods. Total carotenoid content, chlorophyll a, and b were analyzed by spectrophotometer. The total phenolic content was established by using the Folin–Ciocalteu reagent. The amount of crude ash was determined by the dry burning of samples at a temperature of 500 °C. Phosphorus was measured photometrically, calcium content was established according to Commission Directive. The potassium was determined by flame photometry, magnesium, iron, copper, manganese, zinc, and boron contents were identified by atomic absorption spectrophotometry. The results were analyzed by using a two-way analysis of variance. Our research data analysis showed the different chemical compositions of cowslip samples collected from different areas. Higher amounts of dry matter, ascorbic acid, chlorophyll a and b, total carotenoids, and total phenolics were found in the plants from area No. 1. In the plants from area No. 2 were established higher content of crude ash. The amounts of mineral elements in plants varied unequally. The correlations showed the dependence of the chemical composition of cowslip aerial parts on the soil composition.

Experimental Study on the Heat Transfer Performance of a Stainless-Steel Heat Pipe With Sintered Fiber Wick

Abstract A kind of stainless-steel heat pipe with sintered fiber wick is investigated with the aim to improve the heat dissipation when it is used in spent fuel pools in nuclear power plants. The effects of test angle, porosity, and the filling rate on the heat transfer performance of the heat pipe are studied. At a test angle of 90 deg, the permeability plays an important role in the power limit since gravity can provide the necessary driving force. Larger porosity involves poor heat conductivity although it results in better permeability. When the test angle is zero, gravity is no longer the driving force. In this case, the evaporation section can still avoid dry burning because part of the evaporation section is dipped in deionized water. Therefore, permeability and filling ratio are two important factors influencing the power limit. Filling rate determines the vapor-flowing space. When the test angle is smaller than zero, gravity becomes a resistance force. Then, the lag tension and the filling rate exert the greatest influence on the performance of the heat pipe. Smaller porosity corresponds to a smaller contact angle.

Experimental research on falling film flow and heat transfer characteristics outside the vertical tube

• Flow and heat transfer characteristics of falling film are studied experimentally. • The experimental data show large differences with values of existing correlations. • Correlations of heat transfer coefficient and dry burning condition are developed. • The study provides a reference for the research on evaporator of MVR. The falling film flow has attracted much attention recently due to its advantages of low temperature difference, low flow rate, high heat transfer coefficient and high heat flux density. In this paper, a series of experiments were carried out to investigate the falling film flow and heat transfer characteristics outside the vertical tube based on the established experimental system. Flow patterns, the trend of heat transfer coefficients along the tube as well as the falling film breakdown phenomenon were described. Two new correlations were obtained to predict the heat transfer coefficient and falling film dry burning based on experimental data, and the maximum deviation between the experimental data and predicted values were −13.36% and 16.81%, respectively. The new correlations can provide a reference for the design of the heater in the Mechanical vapor recompression systems.

Dry Burning Lips

ABSTRACT Teledermatology is a term to describe the provision of dermatologic medical services through telecommunication technology. This is a teledermatology case of dry burning lips.

Critical and optimal inclination angles of two-phase closed thermosyphon under different operating conditions

Two-phase closed thermosyphon (TPCT) is widely used and usually installed vertically, but the inclination angle has significant effects on TPCT performance. This work presents an experimental study of TPCT with water as working fluid. The critical and optimal inclination angles of TPCT under non-forced convection cooling conditions are investigated from three aspects of start-up, operating, and heat transfer characteristics at different operating temperatures. The results show that TPCT has the critical inclination angle and the optimal inclination angle. A critical inclination angle of 45° is obtained under different operating conditions. The optimal inclination angle of TPCT is 60° at the operating temperature of 80–150 °C, but it is 90° (vertical) at 150–185 °C. Furthermore, the start-up and heat transfer performance of TPCT gradually improves with the augment of heating power. This study provides a reference for future research on heat pipe performance enhancement methods and related applications, and presents experimental basis for performance changes in TPCT applications when accidental dry burning occurs.

Cultivation of Oyster Mushroom (Pleurotus ostreatus) from Agro-waste and Dry Leaf Litter in used Plastic Bottles: Community Waste Management Model targeting Stubble and Dry leaf burning

In recent years, solid waste management has developed from early approaches of burning or dumping to reuse, recycle, regain, and retain various alternative technologies. The present study aims at developing an effective community waste management model with a solution to multiple issues. It aims to provide an alternative to widespread stubble burning, burning dry leaf litter and promoting plastic reuse. The present novel technology involved the cultivation of Oyster Mushroom (Pleurotus ostreatus) in used plastic bottles to convert agricultural and urban waste into a highly nutritional end product. In this direction, the effect of different wheat straw and dry leaves’ ratios was assessed on the spawn run time, primordial formation, final harvesting time, mean yield per plastic bottle, and the % biological efficiency per gram of the substrate. Both the combinations of L30:WS70 and L50:WS50 represented ideal options for using the two waste substrates to cultivate the mushroom species. This model will help recycle agro-waste and serve as an effective method of generating nutritious food for fighting food security while decreasing the plastic load and trash thrown for disposal.

Моніторинг ландшафтних пожеж Транскордонної Рамсарської території «Ольмани-Переброди» за даними дистанційного зондування Землі

Зміни клімату, землекористування та зростання відвідуваності лісів населенням зумовили суттєве загострення проблеми охорони лісів від пожеж, зокрема на заповідних та суміжних територіях. Транскордонна Рамсарська територія «Ольмани-Переброди», в яку входить Рівненський природний заповідник, характеризується високим рівнем ландшафтного та біологічного різноманіття за рахунок видів птахів, тварин і рослин, які знаходяться під загрозою зникнення, тому задача охорони таких територій від пожеж є однією з пріоритетних. Зважаючи на те, що в останні роки на території України почастішали випадки великих лісових пожеж, слід бути готовим до можливих випадків таких пожеж і на території Рівненського природного заповідника, до якого входить українська частина Транскордонної Рамсарської території. У статті наводиться аналіз динаміки пожеж, які відбулися в природних ландшафтах Транскордонної Рамсарської території «Ольмани-Переброди» упродовж 2006–2016 рр., на основі даних дистанційного зондування Землі. Отримані результати щодо часового та просторового розподілу пожеж на досліджуваній території за багаторічний період дозволять у майбутньому спрогнозувати ймовірність виникнення та поширення пожеж.

Influence of filling ratio and working fluid thermal properties on starting up and heat transferring performance of closed loop plate oscillating heat pipe with parallel channels

Using ethanol or acetone as the working fluid, the performance of starting up and heat transfer of closed-loop plate oscillating heat pipe with parallel channels (POHP-PC) were experimentally investigated by varying filling ratio, inclination, working fluids and heating power. The performance of the tested pulsating heat pipe was mainly evaluated by thermal resistance and wall temperature. Heating copper block and cold water bath were adopted in the experimental investigations. It was found that oscillating heat pipe with filling ratio of 50% started up earlier than that with 70% when heating input was 159.4 W, however, it has similar starting up performance with filling ratio of 50% as compared to 70% on the condition of heat input of 205.4 W. And heat pipe with filling ratio of 10% could not start up but directly transit to dry burning. A reasonable filling ratio range of 35%‒70% was needed in order to achieve better performance, and there are different optimal filling ratios with different heating inputs - the more heating input, the higher optimal filling ratio, and vice versa. However, the dry burning appeared easily with low filling ratio, especially at very low filling ratio, such as 10%. And higher filling ratio, such as 70%, resulted in higher heat transfer ( dry burning ) limit. With filling ratio of 70% and inclination of 75°, oscillating heat pipe with acetone started up with heating input of just 24W, but for ethanol, it needed to be achieved 68 W, Furthermore, the start time with acetone was similar as compared to that with ethanol. For steady operating state, the heating input with acetone was about 80 W, but it transited to dry burning state when heating input was greater than 160 W. However, for ethanol, the heating input was in vicinity of 160 W. Furthermore, thermal resistance with acetone was lower than that with ethanol at the same heating input of 120 W.

Experiment investigation on visualization and operating characteristics of closed loop plate oscillating heat pipe with parallel channels

Using ethanol or acetone as the working fluid, visualization of oscillations in steady state was observed visually by high-speed cameras, and temperature oscillating and heat transfer characteristics of closed-loop plate oscillating heat pipe with parallel channels (POHP-PC) were experimentally investigated by varying liquid filled ratios (50%, 70%, 85%), section scales (1 mm×1 mm and 1 mm×1.5 mm), inclination angles, working fluids and heating inputs. It was found that during operating there was mixed flow consisting of plug flow and annular flow in channels of oscillating heat pipe at steady-state. There was an equilibrium position for working fluid of condenser during oscillating, and periodic oscillations occurred up and down in the vicinity of equilibrium position. With heat input increasing, equilibrium position rose slowly as a result of vapor pressure of evaporation. Evaporation temperature oscillating amplitude possessed a trend of small-large-small and frequency trend was of small-large during steady-state. It may be generally concluded that temperature, whether evaporator or condenser, fluctuated sharply or rose continuously when oscillating heat pipe coming to dry burning state. Simultaneously, it was found that temperature difference of cooling water possibly dropped with heat input rising during dry burning state. Thermal resistance of No. 2 with acetone was lower than that of No. 1 during experiments, but No. 2 achieving heat transfer limit was earlier than No. 1. However, with ethanol, thermal resistance of No. 1 and No. 2 were similar with the heating input less than 110–120 W and filling ratios of 50% and 70%. And with filling ratio of 85%, heating transfer performance of No. 2 was better compared to No. 1 during all the experiments.

Dry eye findings worsen with anticholinergic therapy in patients with urge incontinence.

To evaluate the effects of oral anticholinergic (OAC) drugs on tear secretion in women with overactive bladder over a 3-month follow-up period. In this prospective study, 108 women with a diagnosis of overactive bladder were evaluated. All patients were examined ophthalmologically at baseline (day 0), and after 1month (day 30) and 3months (day 90) of OAC treatment. Tear film break-up time (BUT) and Schirmer 1 test results were recorded. The subjective complaints of the patients including dry mouth, and burning, dryness and foreign body sensation in the eyes, were also recorded. The chi-squared test or the paired sample t test as appropriate, was used for statistical analysis. The mean age of the patients was 51.8 ± 9.2years (30-69years). The most frequent subjective complaints were dry mouth and dry eyes and both complaints were significant on both day 30 and day 90. Both tear film BUT and Schirmer 1 test results were significantly lower on day 30 and day 90. Dry eye measurement values worsened with prolongation of OAC treatment (p = 0.037 and p = 0.012 for BUT, and p = 0.046 and p = 0.035 for Schirmer 1 test, on day 30 and day 90, respectively). OAC treatment in women with overactive bladder significantly and progressively affects tear secretion.

35LBA Supersaturated calcium-phosphate rinse reduces dry mouth and burning sensation in cancer patients treated with TKI and mTORi – Results of a double-blind, randomised phase III trial (NCT01265810)

35LBA Supersaturated calcium-phosphate rinse reduces dry mouth and burning sensation in cancer patients treated with TKI and mTORi – Results of a double-blind, randomised phase III trial (NCT01265810)

Response of Soil Denitrifying Communities to Long-Term Prescribed Burning in Two Australian Sclerophyll Forests

Low-intensity prescribed burning is a common forest management tool and plays a major role in modifying biogeochemical cycling through the alteration of substrate availability and microbial communities. In this study, we assessed the response of microbial community to repeated prescribed burning in two sclerophyll forests (the Bauple site, dry, annual rainfall 1000 mm; and the Peachester site, wet, 1711 mm) in southeast Queensland, Australia. At the dry sclerophyll forest (the Bauple site), annual and triennial burning did not significantly alter the soil carbon (C) and nitrogen (N) content, while at the wet scleophyll forest (the Peachester site), two yearly burnings resulted in significantly lower soil total C and N contents compared to the long unburnt treatment. In spite of these different responses, prescribed burning regimes did not significantly influence the abundance of 16S rRNA or denitrifying gene (narG, nirK, nirS, nosZ) at both sites. These results indicated that, long-term prescribed burning has little effect on the denitrifying communities, while it has varying effects on soil chemical properties at the two sites, which are likely to be explained by differences in vegetation type and soil moisture regime.

Characterization of black deposits in karst caves, examples from Slovenia

Karst caves are important tourism and natural heritage destinations. Within dry cave passages otherwise notable for their rich flowstone decoration, areas with a characteristic black color can sometimes be observed on cave walls and floors and on speleothems. To determine the origin of these black deposits, mineralogical and chemical analyses were carried out in two caves (Postojna Cave and Crna Jama (Kocevje), Slovenia). Qualitative chemical composition was obtained by scanning electron microscopy in conjunction with energy dispersive X-ray spectrometry (SEM/EDS). Organic matter in black deposits was confirmed by the Walkley–Black (wet burning) and loss-on-ignition (LOI, dry burning) methods. Results showed that black deposits from the caves studied could be attributed to natural and anthropogenic causes. Natural causes are related to Mn–Fe oxide precipitation and are probably dependent on microorganism activity. Anthropogenic sources are related to historic (or/and prehistoric) human activities such as cave visitors using torches and fires, events outside the caves such as forest and settlement fires, and recent air pollution. Black deposits show the effect of long-term environmental impact on karst caves and could be included in guided tours of show caves along with a scientific explanation of their causes and origin.

Effect of environment factors on ac flashover performance of 3 units of polluted insulator strings under natural fog condition

The electrical characteristics of contaminated insulators wetted by natural fog are rarely reported at home and abroad. Based on natural fog observations for 4 years at Xuefeng Mountain testing station, the AC flashover performance of three units of polluted insulator strings wetted by natural fog was studied. The results show that there are some differences on the flashover voltage stress between results of field test and Baker et al. The AC flashover process of the polluted insulators mainly includes wetness of the contamination, formation of dry bands, burning and elongation of partial arc and flashover. Moreover, the wind velocity has influence the flashover performance of insulator strings.

How do A‐train sensors intercompare in the retrieval of above‐cloud aerosol optical depth? A case study‐based assessment

AbstractWe intercompare the above‐cloud aerosol optical depth (ACAOD) of biomass burning plumes retrieved from A‐train sensors, i.e., Moderate Resolution Imaging Spectroradiometer (MODIS), Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP), Polarization and Directionality of Earth Reflectances (POLDER), and Ozone Monitoring Instrument (OMI). These sensors have shown independent capabilities to retrieve aerosol loading above marine boundary layer clouds—a kind of situation often found over the southeast Atlantic Ocean during dry burning season. A systematic comparison reveals that all passive sensors and CALIOP‐based research methods derive comparable ACAOD with differences mostly within 0.2 over homogeneous cloud fields. The 532 nm ACAOD retrieved by CALIOP operational algorithm is underestimated. The retrieved 1064 nm AOD however shows closer agreement with passive sensors. Given the different types of measurements processed with different algorithms, the reported close agreement between them is encouraging. Due to unavailability of direct measurements above cloud, the validation of satellite‐based ACAOD remains an open challenge. The intersatellite comparison however can be useful for the relative evaluation and consistency check.