Values Of TP Research Articles

Development of low temperature cure hybrid benzoxazine-epoxy resins for thermally stable and moisture resistant applications

New type of diallyl bisphenol-A (ABA) based benzoxazines and benzoxazine resins tailored with epoxy groups for low-temperature curing, have been developed using various curatives for high performance applications. The molecular structure of the synthesized compounds was analyzed using HRMS, 1H NMR, 13C NMR and ATR-FTIR analytical techniques. The cure behavior (Tp) of benzoxazine (Bz) and benz-epoxy (Bz-Ep) resin in the absence and presence of different nature of curatives were studied using DSC to evaluate their applicability for advanced composite applications. The values of Tp obtained are 279 °C, 190 °C and 247 °C for ABA-a, ABA-dmapa and ABA-ipa respectively. The cure behavior has been further lowered by converting ally group present in the benzoxazine has been transformed into epoxy groups by appropriate mechanism. The curing (Tp) temperature observed for hybrid ABA-a-Ep, ABA-dmapa-Ep and ABA-ipa-Ep benz-epoxy resins are 151 °C, 226 °C and 160 °C, 187 °C and 150 °C, 211 °C respectively. The Tp of different benz-epoxy resin systems studied in the presence of catalysts were found to be in the range of 101-155 °C. With a Tmax of 484 °C and a char yield of 43 %, poly(ABA-a) exhibits impressive thermal stability when compared to other synthesized polybenzoxazines. Further, incorporating various curatives into the benz-epoxy matrix enhances its thermal stability and char yield compared to the neat matrices. Additionally, the developed samples exhibit excellent moisture resistant (0.75 %) and hydrophobic nature with the highest contact angle value of 152o for poly(ABA-a). The findings from various studies indicate that the hybrid benz-epoxy resins demonstrate characteristics such as low-temperature curability, thermal stability, hydrophobicity. These results render them appropriate for a diverse array of high-performance industrial and engineering uses.

Effects of training load on heart rate variability and blood pressure in track and field athletes and skiers

BACKGROUND: Adaptation of human body to the harsh conditions of the European North remains a topic of ongoing interest, despite numerous studies on the subject. There is a need to study population groups whose daily activities involve physical activity in extreme northern conditions. One such group includes athletes who participate in endurance sports. For athletes engaged in cyclical sports, competitive activities becomes can be particularly demanding, requiring sustained physical exertion and maximum power generation. Training and competing in harsh conditions place significant strain on the body’s cardiovascular regulation mechanisms. Over time, this may result in detrimental structural and biochemical changes in the cardiovascular system. AIM: To identify the patterns of changes in heart rate regulation among track and field athletes and skiers after a training load. MATERIAL AND METHODS: Athletes from the Arkhangelsk region, including skiers and track and field athletes in the mass sports categories, who regularly compete in regional events, took part in the study. The studies took place in the medical offices of sports complexes, where the UPFT-1/30“Psychophysiologist” device was used to record and analyze cardiointervalograms. Blood pressure was recorded before and after training sessions using the Criticare System 8100H monitor. RESULTS: The initial variational span (VR) values of the duration of cardio intervals before exercise were slightly lower than the reference values in both the group of skiers and the group of athletes. At the same time, the mean square deviation (SD) values initially fell within normal range. Following the training load, both groups experienced a statistically significant decrease in SD and VR values, falling below the lower limit of the permissible range. Furthermore, spectral analysis of the cardiac intervals before exercise indicated a high level of neurohumoral regulation. After exercise, there was a statistically significant decrease in the initial values of TP in both groups, aligning with the average level of neurohumoral regulation. CONCLUSION: The results obtained in track and field athletes with a predominant anaerobic training load and skiers with a predominant aerobic load suggest that the training load of a predominantly aerobic nature may lead to less pronounced stress on the regulatory systems. This hypothesis was further supported by the results of the changes in blood pressure.

Intake of Dark and Milk Chocolate Differently Affects Autonomic Nervous Control of the Heart During Rest and Mental Stress

Objective Chocolate is a popular food that may affect the activity of the autonomic nervous system (ANS). The aim of this study was to determine the effect of a single dose of dark or milk chocolate on ANS cardiac control during rest and mental stress induced by the Stroop test (ST). Methods Healthy participants, divided into DARK or MILK chocolate groups, ingested corresponding type of chocolate (1 g/kg body weight). They underwent measurement of ANS during relaxation and ST before and 2 h after chocolate consumption. ANS control was assessed by determination of heart rate (HR) and heart rate variability using parameters related to complex autonomic modulation (TP, SDNN) or primary vagal modulation (HFnu, RMSSD). Results HR was always increased during ST in both groups. Relaxation HR values after chocolate ingestion were higher only in the DARK chocolate group. During ST, values of TP, SDNN and HFnu decreased before and after chocolate ingestion in the DARK group, but only before chocolate ingestion in the MILK group. RMSSD values decreased during ST before and after chocolate ingestion in both groups. Relaxation TP, RMSSD and HFnu values after chocolate ingestion were lower in the DARK but not in the MILK group. Conclusion The results suggest that even a single dose of milk chocolate attenuates changes in ANS cardiac control induced by mental stress, whereas a single dose of dark chocolate has an activating effect on the heart via modification of ANS cardiac control at rest. Different levels of sugars and cocoa biologically active compounds in the two types of chocolate could explain the observed effects.

Comprehensive approaches to diagnose thoracic cavity disorders (TCD) in cattle

The aim of the study was to document the prevalence and diagnosis of thoracic cavity disorders (TCD) in cattle. All the selected animals subjected to detailed anamnesis; physical, clinical haemato-biochemical, electrolytes, cardiac biomarker, thoracic radiography and ultrasonographic examination were performed. The prevalence of TCD was 0.76%, among these; cardiac disorders (CD) was in 37.0%, lung disorders (LD) in 22.0%, lung and cardiac disorders (LCD) in 22.0% and diaphragmatic hernia (DH) in 19.0%. Highest prevalence of thoracic cavity disorders was recorded in Jersey cross bred cattle (62.0%). More than 3 years of age and pregnant animals were the mostly affected. The most predominant clinical signs was recorded in the order of grunting, dyspnea, abduction of elbow, brisket edema, jugular vein engorgement, jowl edema, rumen hypo-motility and muffled heart sound. Haematology revealed significant reduction of Hb, PCV and RBC. Significant decrease in the mean values of serum TP, albumin, glucose, cholesterol and increases in ALP and AST levels were observed. Significant increase in the cardiac biomarkers (CK-MB, LDH and cTnI) was noticed. The presences of foreign body, DH and pericardial effusion were in radiographic examination. Ultrasound examination revealed anechoic fluid (37.50%), mixed echogenic fluid (18.75%), echogenic fibrinous strands (21.85%) on both of respiratory and cardiac disorders. Comprehensive approaches could facilitate early diagnosis of thoracic cavity disorders, as well as to assess the diseases status and to initiate appropriate therapeutic protocols in cattle.

Oil spill in an amazon blackwater environment: Biochemical and physiological responses of local fish species

The accidental spill of petroleum asphalt cement (PAC) in São Raimundo (SR Harbor, located on the Rio Negro (Manaus, Amazonas, Brazil) was monitored through the analysis of polyciclic aromatic hydrocarbons (PAHs) in water and a set of biomarkers in fishes (exposure biomarkes: PAHs-type metabolites concentrations in bile; the activities of ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in liver. Effect biomarkers: lipid peroxidation concentration (LPO) in liver, acetylcholinesterase activity in brain, and genotoxic DNA damage in erythrocytes). Two fish species, Acarichthys heckelii and Satanoperca jurupari, were collected 10, 45, and 90 days after the PAC spill in São Raimundo. At the same time, fish were collected from the Tupé Sustainable Development Reserve (Tupé) which served as a reference area. The sampling periods were related to the rising waters of the natural flood pulse of the Rio Negro. Higher concentrations of PAHs in water were observed at 10 and 45 days and returned to the values of TP 90 days after the PAC spill, a period in which harbor waters rose about 0.2 m. Unlike the PAHs in water, biomarker responses in both fish species significantly increased following the PAC spill in SR. Hepatic ethoxyresorufin-O-deethylase (EROD), PAH-like metabolites in bile, and erythrocyte DNA damage increases, together with inhibition of acetylcholinesterase (AChE) activity in the brain were the most evident responses for both fish species. The calculated pyrolytic index showed mixed sources of PAHs (petrogenic and pyrolytic). The applied PCA-FA indicated important relationships between dissolved organic carbon (DOC) and PAHs concentrations in water, where DOC and PAHs concentrations contributed to biomarkers responses for both fish species in all collection periods.

Comparison of the zooplankton-based RCC to Carlson’s trophic state indices and water quality parameters

Zooplankton is not included as a biological quality element, even though it is a key component of pelagic food webs. The data on zooplankton community structure can be used to evaluate the trophic state of lakes through an RCC Index, based on quantitative proportions between the main zooplankton groups. As previous investigations have related the index only to the Secchi disc transparency, the aim of this study was to compare the Index to a set of water quality parameters and trophic state indices. Two sandpit lakes with contrasting characteristics were selected as model lakes for the study. A total of 57 samples were collected simultaneously with the physicochemical water quality parameters between 2016 and 2020. Carlson’s trophic state indices were used to assess the trophic state of the lakes. Pearson correlation coefficient and Principal Component Analysis were used to assess the observed correlations between the measured parameters and to distinguish what factors regulate zooplankton community structure. Overall, 86 zooplankton taxa were identified. RCC Index ranged from 2 in the small sandpit lake to 87 in the big sandpit lake. A highly significant negative correlation was found between the RCC Index and the values of TP and COD. The results complement the arguments for the inclusion of zooplankton as a BQE for the assessment of the status of lakes.

Detection and quantification of wave trends in the Mediterranean basin

A study of a 42-year (1979–2020) long wave time series was performed for the Mediterranean Sea to detect and quantify trends in two relevant wave parameters adopted for coastal and offshore engineering purposes: significant wave height, Hs and peak period, Tp. The high resolution MeteOcean Re-Analysis database by the Department of Civil, Chemical and Environmental Engineering (DICCA) was used. At yearly and seasonal scales, the trends of the mean and maximum values were detected by the Mann–Kendall test, choosing a significance level equal to 90%. The slope or increase/decrease trends in Hs and Tp were assessed by the Theil–Sen estimator. For the mean values of Hs and Tp, increasing trends were detected for the Libyan, Levantine and Aegean seas, while for the maximum values this increasing trend was observed in a large part of the Mediterranean Sea. Finally, for the different marginal seas of the Mediterranean basin, a running trend analysis was applied in order to quantify the effect of the time window in the trend detection. The obtained results can be significant for flooding and erosion control strategies, ship and port operations, design and verification of structures, installations of Wave Energy Converters, in a hot spot for climate change such as the Mediterranean basin.

Discussions on Wave energy period in higher wave energy potential marine waters of Taiwan

For evaluating wave energy, wave energy period Te is commonly adopted. However, the in-charge government agencies in Taiwan traditionally provided with peak frequency Tp without giving information on the transferring relationship between Te and Tp. This results in difficulties on correctly evaluating wave energy potentials at certain marine waters. Thus, existing spectrum data need to be derived to calculate values of Tp and Te so as to derive representative transferring coefficient Cep for long-term evaluations on wave energy. This study aims at deriving values of Cep at relatively higher potential marine waters of Taiwan. As shown in Figure 1, the data were collected from two stations in Keelung marine waters and one station within marine waters for offshore wind of Changhua. By choosing different criteria for Cep, selected data were regressed for obtaining representative Cep in different seasons. For conservative point of views, the values of Cep ranging from 0.85~0.87 from data in northeaster monsoon months, as shown in Figure 2, being generally slightly smaller than those of the whole year, were adopted at the three stations. It is also found that the representative values of Cep were derived mainly from data comprising of exploitable wave power densities of between 2~80 kW/m2. Data collection instruments, selection criteria and associated outcomes shall be detailed in the full paper.

Dynamics of TP, HF-, LF- and VLF- Waves of the Cardiointervalogram (in Clinostasis Conditions) of an Elite Ski Racer in the Preparatory, Competitive and Transitional Periods, Depending on the Volume and Intensity of Training Loads

In order to study the mechanisms of adaptation to loads requiring high endurance, the 27-year-old master of Sports of Russia in cross-country skiing repeatedly recorded a cardiointervalogram (CIG) under clinostasis conditions, estimating TP, absolute power (mc2) of LF-, HF- and VLF-waves and the relative (as a percentage of TP) power of these waves, i.e. LF%, HF% and VLF%. They were compared with the volume (Vkm, Vmin) and intensity (Nhr) of training loads. The volume of loads was maximum in the preparatory period (21 km/day) and it is minimal in the transition period (18 km/day), and their intensity throughout the annual cycle was stable (working pulse – 120–121 beats/min). With the change in the volume of loads, the values of the KIG indicators also changed. So, in the preparatory period, the medians of TP, the power of HF-, LF- and VLF-waves, as well as VLF% increase; in this period, with an increase in the volume of loads (Vkm), the values of VLF% increase. In the competitive period, the medians of TP, the power of HF-, LF- and VLF-waves and VLF% remain at a high level. In the transition period, the median of TP, the power HF-, LF- and VLF-waves, as well as LF% and VLF%, but the median of HF% increases. For the annual cycle, a direct dependence of the median of TP on the volume of loads (Vkm) and the median power of VLF waves on the volume (Vkm) and intensity (Nhr) of the load was revealed. It is postulated that the values of TP, HF-, LF-, and VLF-waves, as well as VLF% (in clinostasis) reflect the influence of the Cholinergic system on the heart, while VLF% probably reflects the intensity of synthesis of non-neuronal heart’s acetylcholine, and the values of LF% and HF% reflect the formation of anxiety in connection with upcoming starts.

Spatial and Temporal Analysis of Climatic Precursors before Major Earthquakes in Iran (2011–2021)

The present study provides a systematic assessment of the relationships between climatic variables and major earthquakes (M > 6) in Iran (2011–2021). These variables include total cloud cover (tcc), low cloud cover (lcc), total precipitation (tp), surface latent heat flux (slhf), and total column rainwater (tcrw). Based on a wider set of variables provided by a multidimensional global dataset (ERA5), the combination of a cross-correlation function (CCF) and receiver operating characteristic (ROC) was used to develop the spatial and temporal analytic relations. Covering maximal values from 0.42 to 0.92, the CCF plots revealed that an increase in climatic parameters could provide valuable information about impending earthquake activity within 8 to 20 days. The mean values of tcc, lcc, tp, slhf, and tcrw were found to increase by 95%, 60%, 80.0 mm, 105 W/m2, and 95 kg−3/m2, respectively. In fact, with the mean AUC (area under the curve) indices ranging from 0.677 (tcc) to 0.810 (tcrw) prior to major earthquakes, the ROC plots allowed for discrimination between seismic and climatic variables ranging from “acceptable” to “excellent”. The changes in the climatic variables under study were due to anomalous air ionization and water condensation in the atmosphere, which can be regarded as short-term precursors to major earthquakes.

Stormwater Quality Characteristics and Reuse Analysis of Different Underlying Surfaces at Wanzhou North Station

In response to the water shortage in Wanzhou North Station (WNS), the authors investigated the stormwater quality characteristics with different underlying surfaces of WNS and carried out stormwater reuse analysis in conjunction with the InfoWorks ICM model. The results show that during heavy, torrential, and moderate rainfall, the road stormwater runoff has the highest concentrations of pollutants, with an average EMC (event mean concentration) value of 206 mg/L for COD. For the square runoff, the average EMC values of COD, SS, TN, and TP are 108 mg/L, 395 mg/L, 2.113 mg/L, and 0.128 mg/L, in comparison, the average EMC values of the corresponding indexes for the roof runoff are 65 mg/L, 212 mg/L, 1.449 mg/L, and 0.086 mg/L, respectively, demonstrating their potential for reuse. The R2 (coefficient of determination) of SS and COD in both roof and square runoff is greater than 0.85, with a good correlation, indicating that SS removal is the key to stormwater purification. InfoWorks ICM analysis shows that the recyclable volume of rainwater from WNS in 2018 is 29,410 m3, accounting for 61.8% of the total annual rainfall. This study is expected to provide an ideal reference for the stormwater management of public buildings in mountainous areas.

Studies on the mechanism of energy metabolism via AMPK/PGC-1α signaling pathway induced by compatibility of Ligusticum chuanxiong Hort and Gastrodia.

AMP-activated protein kinase (AMPK) regulates overall energy consumption and energy intake through cytokines. Ligusticum striatum DC (CX) combined with Gastrodia elata Blume (TM) has been used for migraine treatment for millennia. When used alone in clinical practice, CX causes symptoms of thirst, irritability, and yellow urine and has influenced the levels of cytokines such as AMP that activate the AMPK pathway of energy metabolism. However, relationships between this compatibility prescription, integral biological energy metabolism, and the AMPK pathway remain unclear. Studies were performed by treating normal rats with physiological saline, CX extract, CX coupled TM extract, and TM extracts separately for 4 weeks. Food intake, water intake, urine output, stool output, and body weight were monitored once a week by the metabolic cage method. Values of FBG, BUN, TP, TC and TG in blood samples were detected approaching the whole blood automatic detector from 1 to 4 weeks. Na+-K+-ATPase, Ca2+-Mg2+-ATPase, cAMP, and cGMP activity were determined by the enzyme-linked immunosorbent assay (ELISA); the biological samples that were obtained at 1, 2, 3, and 4 weeks after drug administration were tested by GC-TOF-MS. Then real-time PCR and Western Blot were applied to detect changes in expression of some substances involved in energy metabolism. The results demonstrated that administering CX alone increased energy input, mobility, and respiratory exchange ratio, accelerated energy consumption, and caused inflammatory infiltration in the liver. CX coupled with TM led to lower energy metabolism and liver damage in comparison with CX used alone. Moreover, CX-treated rats harbored higher levels of differential metabolites (including pyrophosphate, oxaloacetic acid, and galactinol). Glycerophospholipid metabolism and the citrate cycle are closely related to the differential metabolites above. In addition, CX-induced unbalanced energy metabolism depends on cAMP activation mediated by the AMPK/PGC-1α pathway in rats. Our findings suggest that CX-induced energy metabolism imbalance was corrected after coupling with TM by mediating the AMPK/PGC-1α pathway.

Comparison of Bagging and Adaboost Methods on C4.5 Algorithm for Stroke Prediction

Stroke is a non-communicable disease and is very dangerous because of functional disorders of the brain caused by blockage of blood circulation. This disease is classified as a cerebrovascular disease because it requires treatment for 24 hours, if not treated quickly it can cause death. The purpose of this research is to overcome this problem is to create a machine learning-based prediction model for medical experts in dealing with diseases to help reduce the risk of death. The method applied for this research is to apply the C4.5 algorithm classification method as well as the bagging and Adaboost methods from Ensemble Learning. Stroke data is processed using 2 stages of data processing, namely the data cleaning stage and the data transformation stage. In this study, a comparison will be made between the C4.5 algorithm, the bagging method + the C4.5 algorithm and the Adaboost method + the C4.5 algorithm using the confusion matrix, k-fold cross validation and validation test based on the values of TP, TN, FP, FN, recall, precision, F1-Score and accuracy. The results of the classification test using the Confusion Matrix and k-fold cross validation for the C4.5 algorithm resulted in an accuracy of 92.87%. Then the accuracy of the C4.5 algorithm with the bagging method increased to 95.02% and when combined with the Adaboost method the accuracy value also increased to 94.63%. From these results, it can be said that a single classifier algorithm, namely the C4.5 algorithm with the bagging and Adaboost methods, has been proven to improve classification performance.

Can the Physical Parameters with the Support Vector Machine (SVM) Method Able to Classify Benign and Malignant Breast Cancer?

Objective: Evaluating the diagnostic performance of SVM to classify benign and malignant by performing a meta-analysis.
 Methods: The data used for this study were secondary data. It consisted of 221 mammogram images (mean age 57.5 years) with 164 malignant and 57 benign, taken from a radiological database that has been examined by a radiologist with more than 20 years of experience. Also, histopathological record data that had been examined by an oncologist with more than 20 years of experience. Mammograms were taken from January 2022 to June 2022. In all, 221 mammograms consisting of 164 malignant and 57 benign were used as SVM method training, and 20 mammograms consisting of 10 malignant and 10 benign were used to test the performance of the SVM method. It was then evaluated using pathology results as the gold standard.
 Results: Benign had a significantly lower deviation (an average of 29.2661230 ± 10.14916673) than malignant (an average of 33.1841234 ± 11.70238757). The SVM method performance value obtained the values ​​of TP, FP, TN, FN, accuracy, sensitivity, Specificity, and Precision, respectively 7,7, 3, 3, 50%, 70%, 30%, and 50%.
 Conclusion: A proper performance to distinguish benign and malignant can be obtained using the physical deviation parameters with the SVM classification approach. However, these findings should be proven in larger datasets with different mammographic scanners. Our meta-analysis shows that the physical parameters and SVM have high sensitivity but low specificity. Of the nine physical parameters in the mammogram, only the parameter deviation was significant to distinguish between benign and malignant. The SVM method proved to be able to differentiate between benign and malignant.

Diurnal decline in the photosynthetic capacity of uppermost leaves in an eggplant canopy grown in a horticultural greenhouse

Parameters representing leaf photosynthetic capacity, namely, the maximal carboxylation rate (Vcmax), maximal electron transport rate (Jmax), and triose phosphate-utilization rate (Tp), can vary depending on various factors. The present study investigated diurnal variations in Vcmax, Jmax, and Tp of uppermost leaves of soil-grown, well-watered eggplant in a greenhouse based on the simultaneous measurements of leaf gas exchange and chlorophyll fluorescence. The values of net photosynthetic rates and electron transport rates plotted against intercellular CO2 concentrations were noticeably higher in the morning than in the afternoon. Significant differences were detected among the values of Vcmax, Jmax, and Tp obtained at different times of day (08:30, 11:00, 13:30, and 16:00 h). All three parameters tended to decline as the time of day advanced; compared to the values at 08:30 h, Vcmax, Jmax, and Tp declined by approximately 15% at 16:00 h. Among the three parameters, Tp appeared to be the most sensitive to time.

Clinical Efficacy of Imeglimin (Twymeeg) for Elderly Patient with Type 2 Diabetes Mellitus (T2DM)

Background: As an oral hypoglycaemic agent (OHA), imeglimin (Twymeeg) has been recently introduced to clinical practice for patients with type 2 diabetes mellitus (T2DM) as Twymeeg. It has beneficial pharmacological mechanisms, which are improving insulin secretion, increasing insulin sensitivity, and decreasing insulin resistance. Case Presentation: The case is 84-year-old man with mild cognitive impairment (MCI) for 3 years. He visited late August, 2021 our clinic for general malaise and was pointed out to have post-prandial blood glucose 336 mg/dL and HbA1c 8.6%. He was diagnosed with T2DM. Results: He was started to be given imeglimin 1000mg twice a day, and then HbA1c value was decreased to 7.3% in 4 weeks and 5.7% in 8 weeks. During 9-12 weeks, he felt loss of appetite and reduced food intake. Biochemical examination on 12 weeks showed decreased values of TP, Alb, HbA1c, glucose, free T3, and normal values of TSH, free T4. Doses of imeglimin were 500 mg twice a day for 9-12 weeks and discontinued after 12 weeks. Discussion: Regarding appetite loss, possible causes may include MCI, previous history of gallbladder dyskinesia, adverse effect of imeglimin, and so on. Further development of research will be expected for imeglimin in the future.

Wave Parameters Prediction for Wave Energy Converter Site using Long Short-Term Memory

Forecasting the behaviour of various wave parameters is crucial for the safety of maritime operations as well as for optimal operations of wave energy converter (WEC) sites. For coastal WEC sites, the wave parameters of interest are significant wave height (Hs) and peak wave period (Tp). Numerical and statistical modeling, along with machine and deep learning models, have been applied to predict these parameters for the short and long-term future. For near-future prediction of Hs and Tp, this study investigates the possibility of optimally training a Long Short-Term Memory (LSTM) model on historical values of Hs and Tp only. Additionally, the study investigates the minimum amount of training data required to predict these parameters with acceptable accuracy. The Root Mean Square Error (RMSE) measure is used to evaluate the prediction ability of the model. As a result, it is identified that LSTM can effectively predict Hs and Tp given their historical values only. For Hs, it is identified that a 4-year dataset, 20 historical inputs, and a batch size of 256 produce the best results for three, six, twelve, and twenty-four-hour prediction windows at half-hourly step. It is also established that the future values of Tp can be optimally predicted using a 2-year dataset, 10 historical inputs, and a 128-batch size. However, due to the much dynamic nature of the peak wave period, it is discovered that the LSTM model yielded relatively low prediction accuracy as compared to Hs.

Thermal behaviour of benzoxazine blends based on epoxy and cyanate ester

In the present work, an attempt has been made to develop high-performance polymeric hybrid binary blends of epoxy/benzoxazine and benzoxazine/cyanate ester with varying weight percentages (25/75, 50/50 and 75/25 wt%) of resins, namely, bisphenol-F epoxy resin (DGEBF), benzoxazines [bisphenol–F/aniline (BF-a) and imidazole core-based bisphenol/aniline (IBP-a)] and cyanate ester [bisphenol-F bifunctional cyanate ester (BF-CE)]. The molecular structure, polymerisation temperature/cure behaviour, glass transition temperature (Tg) and thermal stability of the neat polymeric matrices and binary hybrid blends of polymeric matrices were characterised using different analytical techniques, viz. Fourier Transform infra-red spectroscopy (FTIR), Nuclear Magnetic Resonance spectroscopy (NMR), Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA). Among the binary hybrid blends, the lowest polymerisation temperatures (Tp) were noticed in the case of blends of epoxy/benzoxazine were 219°C for DGEBF/BF-a (25/75 wt%) and 170°C for DGEBF/IBP-a (25/75 wt%). Similarly, in the case of blends of benzoxazine/cyanate ester, the lowest values of Tp observed were 155°C and 153°C for BF-a/BF-CE (75/25 wt%) and IBP-a/BF-CE (75/25 wt%), respectively. The highest values of Tg observed for the blends of epoxy/benzoxazine were 175°C and 254°C for DGEBF/BF-a (25/75 wt%) and DGEBF/IBP-a (25/75 wt%), respectively. Whereas, the highest values of Tg observed in the case of blends of benzoxazine/cyanate ester were 234°C and 278°C for BF-a/BF-CE (25/75 wt%) and IBP-a/BF-CE (75/25 wt%), respectively. From the TGA results of blends, the maximum degradation temperature (Tmax) and limiting oxygen index (LOI) value calculated from the char yield, which ascertain that almost all the binary hybrid blends of epoxy/benzoxazine and benzoxazine/cyanate ester possess good flame retardant behaviour.

Spatial Patterns of Nitrogen and Phosphorus in Soil and Their Influencing Factors in a Typical Agro-pastoral Ecotone

Soil nitrogen and phosphorus influence physical, chemical, and biological processes in soil, therefore, clarifying their contents and spatial patterns is of great significance for soil resource management and utilization. The spatial patterns of soil total nitrogen (TN) and phosphorus (TP) and the influencing factors in Jungar Banner were studied using classical statistical and geostatistical methods. The results showed that soil TN and TP contents decreased with soil depth, and the weighted mean values of TN and TP were 0.29 g·kg-1 and 0.26 g·kg-1, respectively. The nugget effect values of soil TN and TP were concentrated in the ranges 0.15-0.43 and 0.34-0.53, respectively, indicating that soil TN (except in the 0-10 cm and 80-100 cm zones) and TP were moderately spatially dependent, dominated by structural and random factors. The spatial distributions of soil nutrients were related to soil layers and elements, even in same layer, while the distributions of TN and TP were not consistent. Soil total nitrogen was mainly affected by soil organic carbon, while TP was mainly affected by latitude, altitude, vegetation, and soil texture.

Looking forward to a decarbonized era: Geothermal potential assessment for oil & gas fields in Italy

The target of this work is to produce a vision of the geothermal potential stored in the depleted oil & gas fields in Italy, by using the available information provided by the Ministry of Economic Development, the published data on hydrocarbon fields, and the estimated temperature at depth from the Italian National Geothermal Database. Five most promising fields have been selected and the volume method has been applied to assess their geothermal potential. Then a probabilistic approach has been adopted to obtain not a single value but a distribution of values of the technical potential TP. The results indicate that the available heat in hydrocarbons fields is encouraging and it is fundamental to analyze the production capacities of the existing wells to have a clearer idea of the possible uses of this existing and wasted heat.