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The physical properties and radiative role of ice clouds remain one of the uncertainties in the Earth–atmosphere system. In this study, we present a detailed analysis of ice cloud properties based on 4 years of surface millimeter-wavelength radar measurements in Beijing, China, where the summer monsoon from the ocean and the winter monsoon from the continent prevail alternately, resulting in various ice clouds. More than 6300 ice cloud clusters were studied to quantify the properties of ice clouds, such as the height, optical depth and horizontal extent, which can serve as a reference for parameterization and characterization in global climate models. In addition, comparison between ice cloud clusters formed under the summer monsoon and the winter monsoon indicates the different formation and evolution mechanisms of cirrus clouds. Statistically, temperatures of more than 95 % of ice radar bins are below −15 ∘C and more than 80 % of ice clouds are above 7 km. The dependence of the radar reflectivity of ice particles on height and temperature was also observed in this study, indicating that the reflectivity of ice bins increases (decreases) as the temperature (height) increases. In addition, it is found that there is a strong linear relationship between the mean reflectivity and the ice cloud depth. Due to various synoptic circumstances, the ice clouds in summer are warmer, higher and thicker, with larger reflectivity than that in winter; in particular, the mean cloud-top height of ice clouds in summer is 2.2 km higher than that in winter. Our analysis indicates that in spring, in situ-origin cirrus clouds are more common than liquid-origin cirrus clouds, while in summer liquid-origin cirrus clouds are more frequent; in autumn and winter, most cirrus clouds are of in situ origin.

The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards (STORM973) project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region (BMR) during the warm season from 2014 to 2018. The aim of the project was to understand how dynamical, microphysical and electrical processes interact in severe thunderstorms in the BMR, and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts. The platforms used in the field campaign included the Beijing Lightning Network (BLNET, consisting of 16 stations), 2 X-band dual linear polarimetric Doppler radars, and 4 laser raindrop spectrometers. The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region. Although diverse thunderstorm types were documented, it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area, influenced by the terrain and environmental conditions. The flash density maximums were found in eastern Changping District, central and eastern Shunyi District, and the central urban area of Beijing, suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing. In addition, the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions. The super (5% of the total), strong (35%), and weak (60%) thunderstorms contributed about 37%, 56%, and 7% to the total flashes in the BMR, respectively. Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms, the lightning flash rate can be used as an indicator of severe weather events, such as hail and short-duration heavy rainfall. Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale, through adjusting or correcting the thermodynamic and microphysical parameters of the model.

To better understand the accuracy of cloud top heights (CTHs) derived from passive satellite data, ground-based Ka-band radar measurements from 2016 and 2017 in Beijing are compared with CTH data inferred from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Himawari Imager (AHI). Relative to the radar CTHs, the MODIS CTHs are found to be underestimated by−1.10 ± 2.53 km on average and 49 % of CTH differences are within 1.0 km. The AHI CTHs are underestimated by −1.10 ± 2.27 km and 42 % are within 1.0 km. Both the MODIS and AHI CTH retrieval accuracy depends strongly on the cloud depth (CD). Large differences are mainly due to the retrieval of thin clouds of CD  km, especially when the cloud base height is higher than 4 km. For clouds with CD >1 km, the mean CTH difference decreases to -0.48±1.70 km for MODIS and to -0.76±1.63 km for AHI. It is found that MODIS CTHs with higher values (i.e. >6 km) show smaller discrepancy with radar CTH than those MODIS CTHs with lower values (i.e.  km). Statistical analysis illustrate that the CTH difference between the two satellite instruments is lower than the difference between the satellite instrument and the ground-based Ka-band radar. The monthly accuracy of both CTH retrieval algorithms is investigated and it is found that summer has the smallest retrieval difference.

Wireless communication has become a very important part of our lives, and it is well known that meteorological factors affect the quality of communication links, especially at higher frequencies because the physical dimensions of raindrops, hail stones, and snowflakes are on a similar wavelength to the propagating radio frequency. Millimeter-waves are an important technology for fifth-generation cellular networks which are currently being deployed all over the world. Since atmospheric effects are challenging in millimeter-wave transmissions, in this paper, we conducted line-of-sight field measurements at 25 GHz and 38 GHz. We monitored the received signal during rainfall events and compared the theoretical attenuation and the recorded rain-induced attenuation. We also derived the rain-induced attenuation (A) and rainfall rate (R) relation for stratiform and convective rain, respectively, using local rain drop size distribution (DSD) information at our measurement site collected during the period of two years. Furthermore, opportunistic sensing of atmospheric phenomena using microwave or millimeter-wave communication links in commercial cellular networks has recently attracted more attention in meteorological research worldwide. The accuracy of calculating rainfall rates from microwave links highly depends on the retrieval model and values of coefficients in the model, i.e., a and b of the A-R relation model. Here, the coefficients a and b are estimated based on local DSD measurement, and the performance of the improved A-R model is evaluated using propagated signal power based on measurement data. Compared to the (a, b) coefficients in the International Telecommunication Union Recommendation (ITU-R) P.838 document, the derived coefficients achieved an improved rainfall rate estimation.

Accurate rainfall monitoring is important, and previously it has been shown that microwave backhaul link between adjacent base station towers can be used for rainfall estimation. However, with the deployment of 5G using millimeter technology, there is opportunity for dense rainfall monitoring network using both backhaul and data transmission links. This paper presents our millimeter-wave measurement results during rainy days in Beijing, China. Our measurement design is an exemplary line-of-sight transmission link. We show that it is possible to retrieve the path-averaged rain rate from the measurement and to use both millimeter-wave transmission link and backhaul link to assist rainfall monitoring. Compared to the local rain measurement from rain gauge and disdrometer, we show that the correlation value of millimeter-wave link retrieved average rain rate varies between 0.6 and 0.9 for different rainfall events. There is room for improvement, and we find that if we can monitor the received signal for a sufficiently long period of time, we can quantify the bias due to fading and work out a better estimate of the rain retrieval model's reference level.

A cloud clustering and classification algorithm is developed for a ground-based Ka-band radar system in the vertically pointing mode. Cloud profiles are grouped based on the combination of a time-height clustering method and the k-means clustering method. The cloud classification algorithm, developed using a fuzzy logic method, uses nine physical parameters to classify clouds into nine types: cirrostratus, cirrocumulus, altocumulus, altostratus, stratus, stratocumulus, nimbostratus, cumulus or cumulonimbus. The performance of the clustering and classification algorithm is presented by comparison with all-sky images taken from January to June 2014. Overall, 92% of the cloud profiles are clustered successfully and the agreement in classification between the radar system and the all-sky imager is 87%. The distribution of cloud types in Beijing from January 2014 to December 2017 is studied based on the clustering and classification algorithm. The statistics show that cirrostratus clouds have the highest occurrence frequency (24%) among the nine cloud types. High-level clouds have the maximum occurrence frequency and low-level clouds the minimum occurrence frequency.

A new dimeric quaternary protoberberine alkaloid, bispalmatrubine (1), and thirteen known compounds (2-14) were purified from the tubers of Tinospora dentata. Their structures were determined by spectroscopic and spectrometric analytical methods. Among the isolates, eight compounds were examined for their in vitro anti-inflammatory potential and several tested alkaloids displayed moderate inhibitory effects of N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release.

Millimeter waves have been recognized as carriers for 5G cellular networks. We carried out a series of millimeter-wave measurements in Beijing, China, and studied the atmospheric impacts on millimeter-wave transmission. Our measurement design is an exemplary LOS transmission link. We also studied a 3 km long commercial E-band millimeter-wave backhaul link in Göteborg, Sweden. We monitored the variation of received signal in the rain, and compared the theoretical rain-induced signal attenuation with the practically monitored signal attenuation. Our results show that there is 1.5-4.5 dB uncertainty between the practical and theoretical rain-induced signal attenuation. Assuming the prediction of rain intensity is available, we have proposed a novel rain-aware radio resource management strategy which adapts the modulation and coding schemes of an OFDM system to rainfall events. We have applied the proposed algorithm to an OFDM - based 5G system, and the throughput result is improved. The result shows that the throughput of a fixed modulation and coding scheme system is between 12%-95% of the system employing the proposed algorithm during rainfall events.

The physical properties and radiative role of cirrus clouds remain one of the uncertainties in the Earth–atmosphere system. In this study, we present a detailed analysis of cirrus properties based on four years of surface millimetre wavelength radar measurements in Beijing, China, where summer monsoon from the ocean and winter monsoon from the continent prevails alternately, resulting in various cirrus clouds. More than 6600 cirrus clusters were studied to quantify the properties of cirrus clouds, such as the height, optical depth and horizontal extent, which can serve as a reference for parameterization and characterization in global climate models. In addition, comparison between cirrus clusters formed under summer monsoon and winter monsoon indicates the different formation and evolution mechanisms of cirrus. Statistically, the temperature of more than 90 % of cirrus bins are below −15 °C. The dependence of the radar reflectivity of cirrus particles on the height and temperature was also observed in this study, indicating that the reflectivity of cirrus bins increases (decreases) as the temperature (height) increases. In addition, it was found that there is a strong linear relationship between the mean reflectivity and the cirrus cloud depth. Due to various synoptic circumstances, the cirrus clouds in summer are warmer, higher, and thicker, with larger reflectivity than that in winter; in particular, the mean cloud-top height of cirrus clouds in summer is 2.5 km higher than that in winter. It was found that most cirrus clusters in winter are likely to be the in situ origin type cirrus but some cirrus clusters in summer are the in situ origin cirrus and others are the liquid origin type cirrus.

A simple and highly efficient procedure for general synthesis of densely functionalized spiro[4H-pyran-3,3′-oxindole] derivatives from a wide range of carbonyl compounds, active methylenes and various kinds of enols catalyzed by Dabco-base ionic liquids has been successfully developed. All the reactions undergo an tandem Knoevenagel-Michael-cyclization process and afford the desired products in excellent yields within short times. The ionic liquid catalyst is inexpensive and which could be easily recycled and reused five times without significant loss of catalytic activity.

Millimeter-wave technology with its large bandwidth is the fastest growing small-cell backhaul solution for next generation wireless networks. E-band can provide twice 5 GHz bandwidth, offering 10 GHz aggregate spectrum (71-76 GHz and 81-86 GHz) and enable Gbps data rates. In this paper, E-band radio performance in line- of-sight (LOS) path conditions was recorded and correlated with weather statistic.

A new dimeric quaternary protoberberine alkaloid, bispalmatrubine (

Millimeter-wave channel modeling is an important topic for 5G research. As atmospheric changes are complicated, many of the existing studies are based on millimeter-wave measurements in sunny weather, and not many address the atmospheric loss in millimeter wave transmission in addition to propagation loss. In this study, we carried out line-of-sight signal transmission measurements at 28 GHz and 28 GHz, We monitored the variation of received signal during rain, and compared the theoretical rain-induced attenuation with the practically monitored attenuation.

A new dimeric quaternary protoberberine alkaloid, bispalmatrubine (1), and thirteen known compounds (2-14) were purified from the tubers of Tinospora dentata. Their structures were determined by spectroscopic and spectrometric analytical methods. Among the isolates, eight compounds were examined for their in vitro anti-inflammatory potential and several tested alkaloids displayed moderate inhibitory effects of N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release.

Sampling methods are important factors that can potentially limit the accuracy of predictions of spatial distribution patterns. A 10 ha tobacco-planted field was selected to compared the accuracy in predicting the spatial distribution of soil properties by using ordinary kriging and cross validation methods between grid sampling and simple random sampling scheme (SRS). To achieve this objective, we collected soil samples from the topsoil (0-20 cm) in March 2012. Sample numbers of grid sampling and SRS were both 115 points each. Accuracies of spatial interpolation using the two sampling schemes were then evaluated based on validation samples (36 points) and deviations of the estimates. The results suggested that soil pH and nitrate-N (NO 3 -N) had low variation, whereas all other soil properties exhibited medium variation. Soil pH, organic matter (OM), total nitrogen (TN), cation exchange capacity (CEC), total phosphorus (TP) and available phosphorus (AP) matched the spherical model, whereas the remaining variables fit an exponential model with both sampling methods. The interpolation error of soil pH, TP, and AP was the lowest in SRS. The errors of interpolation for OM, CEC, TN, available potassium (AK) and total potassium (TK) were the lowest for grid sampling. The interpolation precisions of the soil NO 3 -N showed no significant differences between the two sampling schemes. Considering our data on interpolation precision and the importance of minerals for cultivation of flue-cured tobacco, the grid-sampling scheme should be used in tobacco-planted fields to determine the spatial distribution of soil properties. The grid-sampling method can be applied in a practical and cost-effective manner to facilitate soil sampling in tobacco-planted field.

Background In patients with hypertension, psychosocial factors, such as depressive symptoms and anxiety, are associated with reduced quality of life and triple the risk of nonadherence with medical treatment regimens. Thus, screening tests are crucial to identify patients who may require further assessment and treatment. Objectives The objective of the current study was to test the psychometric properties of the Chinese version of the Mood and Anxiety Symptoms Questionnaire-Short Form (MASQ-SF-C) in patients with essential hypertension. Methods The MASQ-SF-C, the Center for Epidemiologic Studies Depression Scale (CES-D), and the State-Trait Anxiety Inventory (STAI) were administered to a convenience sample of 869 hypertensive patients in 4 hospitals. A confirmatory factor analysis was used to test the tripartite model. We evaluate the internal consistency of the MASQ-SF-C and we used the Bland-Altman approach to evaluate convergent validity between the MASQ-SF-C t score and symptoms of (1) depressive symptoms and (2) anxiety. Results Cronbach's α coefficient for the total MASQ-SF-C was .95, and Cronbach's α coefficients for the 3 subscales were .83 for anhedonic depression (AD), .91 for anxiety arousal (AA), and .94 for general distress (GD), indicating adequate internal consistency reliability. The mean interitem correlation coefficients were as follows: MASQ-SF-C, 0.29; AD, 0.28; AA, 0.38; and GD, 0.40. The 1-month test-retest reliability for the MASQ-SF-C was 0.72. Confirmatory factor analyses indicated that the 3 first-order factors (GD, AD, and AA) fit the data well (nonnormed fit index = 0.953, comparative fit index = 0.936, incremental fit index = 0.936, root-mean-square error of approximation = 0.038). Conclusions This study supported the reliability and validity of the MASQ-SF-C, indicating that it can be used for assessing depressive symptoms and anxiety concurrently in Chinese-speaking patients with hypertension.

To explore the effect and difference of percutaneous coronary intervention (PCI) and medical therapy on quality of life and cognitive function in patients with coronary heart disease (CHD), and to investigate the relationship between quality of life and cognitive function. Methods: A total of 320 patients with CHD, who underwent coronary angiography and PCI (PCI group, n=160), or underwent coronary angiography and medical therapy (drug therapy group, n=160), were selected. The quality of life was assessed by using the Health Survey Form SF-36 (SF-36) and the Seattle Angina Questionnaire (SAQ), and the cognitive function was assessed by using the Mini-Mental State Examination (MMSE). General data of patients were collected on the day of coronary angiography. Telephone follow-up was conducted in 1 month after treatment, and the outpatient review was carried out in 3 and 6 months after treatment. Results: A total of 309 valid questionnaires were collected. The scores of quality of life in the PCI group and the drug therapy group after treatment were both increased compared with those before treatment (both P0.05). The SF-36 scores of four dimensions (role physical, bodily pain, vitality and mental health) in the PCI group were all significantly greater than those in the drug therapy group (all P0.05). The SAQ scores of two dimensions (angina stability and angina frequency) were both higher in the PCI group than those in the drug therapy group in 6 months of post-operation (all P0.05). There was no significant difference in cognitive function before and after the treatment in the 2 groups (P0.05). There was no significant difference in cognitive function between the PCI group and the drug therapy group (P0.05). In the PCI group, physical function, role physical, bodily pain, and role emotional were positively correlated with cognitive function (r=0.207, 0.182, 0.184, 0.176 respectively, all P0.05). In the drug therapy group, there was no correlation between quality of life and cognitive function. Conclusion: The quality of life for the patients is improved in the PCI group and the drug therapy group, but the improvement degree in the PCI group is more obvious. Both PCI and drug therapy do not result in the decrease of cognitive function, and there is no difference between the 2 groups. There is positive correlation between quality of life and cognitive function in the PCI group, there is no correlation between quality of life and cognitive function in the drug therapy group.目的：探讨经皮冠状动脉介入(percutaneous coronary intervention，PCI)和药物治疗对冠心病(coronary heart disease，CHD)患者生活质量和认知功能的影响及其区别，以及生活质量与认知功能的关系。方法：从冠状动脉造影患者中选取PCI的CHD患者160例(PCI组)，药物治疗的CHD患者160例(药物治疗组)。采用健康调查表SF-36(Short-form-36 Health Survey)和西雅图心绞痛问卷(Seattle Angina Questionnaire，SAQ)评估患者的生活质量，采用简易智能精神状态检查量表(Mini-Mental State Examination，MMSE)评估患者的认知功能。在完成冠状动脉造影术当天收集患者的一般资料。治疗后1个月进行电话随访，3个月和6个月通知门诊复查。结果：共收回有效问卷309份。PCI组和药物治疗组生活质量评分均比治疗前高(均P0.05)。PCI组生理职能、躯体疼痛、精力、精神健康这4个维度的SF-36评分均比药物治疗组高(均P0.05)。术后6个月PCI组心绞痛稳定状态、心绞痛发作频率这2个维度的SAQ评分均比药物治疗组高(均P0.05)。两组患者治疗前后认知功能差异均无统计学意义(均P0.05)。两组之间的认知功能差异亦无统计学意义(P0.05)。PCI组生理机能、生理职能、躯体疼痛、情感智能与认知功能呈正相关关系(分别r=0.207，0.182，0.184，0.176，均P0.05)，药物治疗组生活质量与认知功能无相关关系。结论：PCI组和药物治疗组患者的生活质量均得到改善，但PCI组改善更明显。PCI和药物治疗均未出现认知功能下降，且两组间无差异。PCI组生活质量与认知功能呈正相关关系，药物治疗组生活质量与认知功能无相关关系。.

Communication at millimeter-wave frequencies represents the most recent game-changing development for wireless systems. Provided the significant increase in bandwidth and new capabilities offered by millimeter wave frequencies, the base station-to-device links, as well as backhaul links between base stations, will be able to handle much greater capacity than today's cellular networks in populated areas. Governments around the world have allowed operations in the millimeter bands for backhaul, often as little or no licensing fee. In addition to 6–42 GHz, 50 GHz, 60 GHz bands, and recently, the E-bands at 71-76, 81-86, and 92–95 GHz in the USA have become popular, as the spectrum is made available at very little cost to carriers.

Currently, efficient and cost-efficient methods are needed to manage fields in order to maximize economic return, minimize environmental impact, and improve soil and crop site-specific management. Management zones (MZs) of uniform production potential may offer a solution to the problems associated with grid soil sampling while still effectively describing variability in soil properties. In this study, a hillside field of 4 ha was selected as the study site and 111 soil samples were taken from the topsoil (0–20 cm), on an ∼20-m grid. Soil samples were analyzed for pH, organic matter, active soil organic matter, total nitrogen, alkalytic nitrogen, available phosphorous, available potassium and cation-exchange capacity. Their spatial variability was analyzed and spatial distribution maps were constructed using geostatistical techniques. Principal component analysis (PCA) and fuzzy c-means clustering algorithm were then performed to delineate MZs, and eigenvalues were used to select the principal components ...

Register and discovery of education resource is the key to effective share education resources. Only based on resource register and discovery, other applications may be realized . Based on the existing discovery mechanisms, this paper proposed the model of hierarchy education resource classified register and discovery in grid. Puts forward to the register and discovery algorithm of education resources, and made a simulation test using GridSim.

The inhibition effect of nitrotetrazolium blue chloride (NTBC) on the corrosion of cold rolled steel (CRS) in 1.0-5.0 mol·L - 1 HCl solution was investigated by weight loss method, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results show that NTBC is a good inhibitor for CRS in 1.0 mol·L - 1 HCl solution and the adsorption of NTBC on the CRS surface obeys the Langmuir adsorption isotherm. Inhibition efficiency increases with inhibitor concentration while it decreases with hydrochloric acid concentration and temperature. The adsorption thermodynamic parameters (adsorption free energy ΔG 0 , adsorption enthalpy ΔH 0 , adsorption entropy ΔS 0 ) and corrosion kinetic parameters (corrosion rate constant k, kinetic reaction constant B) were also calculated. Based on these parameters the inhibitive mechanism is discussed. Potentiodynamic polarization curves show that NTBC acts a mixed-type inhibitor. EIS spectra exhibit one capacitive loop at high frequency and this is followed by a small inductive loop at low frequency, and the charge transfer resistance increases with inhibitor concentrations. SEM clearly shows that the addition of NTBC can drastically retard the corrosion of steel in hydrochloric acid media.

Hypercholesterolemia contributes to cardiovascular diseases, but its direct effect on lung is little known. 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have been shown to exert numerous effects that are dependent and independent of their cholesterol-lowering property. The authors hypothesized that atorvastatin would attenuate hypercholesterolemia-induced lesion in lung. Fifteen rabbits were randomly divided into control group, high-cholesterol forage group, and atrovastatin treatment group. Body weight and blood lipid were measured. All lung tissue and pulmonary arteries were collected for histopathology and immunohistochemistry. Alveolar macrophages (AMs) were cultured and activation of nuclear factor (NF)-κB was detected. Concentrations of interleukin (IL)-6 were measured in serum, bronchoalveolar lavage fluid (BALF), and culture supernatants of AMs. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) of high-cholesterol forage group were higher than control group (P < .05). There were infiltrating of AMs and lymphocytes in lung tissue of high-cholesterol forage group. NF-κB activity in AMs and concentrations of IL-6 in serum, BALF, and culture supernatants of AMs were higher than those of control group (P < .01), and so were all vascular remodeling indexes. TC and LDL-C and other indexes of atrovastatin treatment group were decreased (P < .05). Hypercholesterolemia induced pulmonary inflammatory Infiltration and vascular remodeling. Atorvastatin attenuated inflammatory infiltration and vascular remodeling in lung of hypercholesterolemia rabbits.

The first example of an iron-mediated direct Suzuki-Miyaura reaction between N-heterocyclic compounds and arylboronic acids is described, and both electron-rich and electron-deficient heteroarenes can be successfully used for the coupling reaction.

The chemical compatibility of the Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) with the yttria-stabilized zirconia (YSZ) electrolyte or Gd-doped ceria electrolyte (GDC), as well as that of the GDC with the YSZ electrolyte were examined. It was found that BSCF had a good compatibility with the GDC electrolyte but a poor chemical compatibility with the YSZ electrolyte. The BSCF cathode was adopted for anode-supported YSZ electrolyte cells with and without the application of a 1 μm thick GDC buffering layer between the cathode and the YSZ electrolyte. The interfacial reactions of the BSCF with the YSZ electrolyte surface and the GDC coated YSZ surfaces were investigated. The single cells were evaluated by using I–V curve measurements and AC impedance spectroscopy. The results depicted a great improvement in cell performance and a significant decrease in polarization resistance after adding the GDC buffer layer. The optimum firing temperature of the GDC film onto the YSZ film was around 1250 °C, which led to the maximum power density of 1.56 W cm−2 at 800 °C using air as oxidant and hydrogen as fuel.