Explore the vast range of titles available.

The Basement Complex rocks of Akungba-Akoko, southwestern Nigeria, typically migmatites (M), biotite gneisses (BGN), granite gneisses (GGN), charnockites (Ch), biotite granites (BG) and pegmatites (P), were assessed using ground gamma-ray spectrometry (GRS). This study aimed at determining rocks’ radionuclides concentration, alterations, radionuclides mobilization, radiogenic heat production (RHP) rate (first report for the area) and environmental radiation risk to humans. The results of this study were integrated with previous data on the petrography and geochemistry of these rocks, for detailed interpretation. The results of average elemental and activity concentrations for Akungba-Akoko rocks, were 2.66%, 3.16 ppm and 13.98 ppm, and 831.35, 39.01 and 56.77 Bqkg-1 for 40K, 238U and 232Th, respectively; with increasing rock order of Ch < M < GGN < BGN < P < BG. High radionuclides concentration in the rocks, with exception of charnockites, were determined by high amount of K-feldspar, plagioclase, biotite and accessory minerals—zircon and monazites. On the other hand, the low radionuclides concentration in the rocks, especially in Ch and M, were aided by the variability of the naturally occurring radioactive elements (NORMs) caused by alterations and mobilization during metamorphism and crystallization processes as suggested by radioelements composite, K/eTh ratio and F-parameter of Efimov analyses. RHP average of 2.03 μWm-3 above the crustal average range of 0.8–1.2 μWm-3 may have significantly contributed to the heat flux in the studied area; however, the RHP of charnockites are lower than the crustal range. The absorbed dose rate average of 87.98 nGyh-1 was within the permissible range, and other estimated radiological parameters, namely annual effective doses, hazard indices, gamma activity and activity utilization index, were all far below the permissible limit of 1 mSvy-1 for these rocks. However, the annual gonad dose equivalent (618.874 μSvy-1) and excess life cancer risk (1.511 × 10− 3) were above their permissible limits. Due to the high gamma radiations from the pegmatitic and biotite-rich rocks in the studied area, their high usage should be reduced. Hence, periodic monitoring of the study area is advised.

This work aimed at characterizing the thermal balance of Nellore cattle from the system of indirect calorimetry using a facial mask. The study was conducted at the Animal Biometeorology Laboratory of the São Paulo State University, Jaboticabal, Brazil. Five male Nellore weighing 750 ± 62 kg, at similar ages and body conditions were distributed in four 5 × 5 Latin squares (5 days of records and five schedules) during 20 days. Physiological and environmental measurements were obtained from the indirect calorimetry system using a facial mask. Respiratory parameters, hair coat, skin, and rectal temperature were continuously recorded. From this, metabolic heat production, sensible and latent ways of heat transfer were calculated. Metabolic heat production had an average value of 146.7 ± 0.49 W m−2 and did not change (P > 0.05) over the range of air temperature (24 to 35 °C). Sensible heat flow reached 60.08 ± 0.81 W m−2 when air temperature ranged from 24 to 25 °C, being negligible in conditions of temperature above 33 °C. Most of the heat produced by metabolism was dissipated by cutaneous evaporation when air temperature was greater than 30 °C. Respiratory parameters like respiratory rate and ventilation remained stable (P > 0.05) in the range of temperature studied. Under shade conditions and air temperature range from 24 to 35 °C, metabolic heat production, respiratory rate, and ventilation of mature Nellore cattle remain stable, which is indicative of low energetic cost to the thermoregulation.

The ability to determine total heat production (THP) in individual sows and litters can be logistically difficult and often requires the use of multiple animals to generate data on a per room basis. Furthermore, these systems may be costly to construct, precluding their use by many researchers. Therefore, the objective was to develop a low-cost indirect calorimetry system to determine THP in individual lactating sows and litters. Six indirect calorimeters were constructed to house 1 sow and litter in a crate throughout farrowing and a 21-d lactation period. Farrowing crates were placed within a high-density polyethylene pan filled with water and then a polyvinyl chloride frame was constructed around the crate. The frame provided a structure to hold the inlet and outlet air pipes, feed and water inlets, air circulation fans, and a polyethylene plastic sheet that was secured at the bottom of the frame and submerged under water to maintain an air tight seal. Chamber accuracies for O(2) and CO(2) were evaluated by ethanol combustion. One week pre-farrowing, 6 pregnant multiparous sows (parity 2.9 ± 0.9; 218.3 ± 38.6 kg BW) were housed individually in each farrowing crate and the calorimeters were maintained at thermoneutral conditions (20.9 ± 2.6°C and 43.7 ± 18.6% relative humidity) throughout lactation. On lactation day 4, 8, 14, and 18, indirect calorimetry was performed on all sows and their litters, as well as 2 piglets from a sentinel litter to determine THP and the respiratory quotient (RQ). Sentinel piglet data were used to estimate THP and RQ for the sows independent of the litter. Sow + litter THP (kcal/h) increased (P = 0.01; 16.6%) on day 8 compared to day 4 and was greater (27.3%) on day 14 and day 18 compared to day 4 and day 8. Sow THP was greater (P = 0.01) on day 8 (401.19 ± 17.15 kcal/h) and day 14 (430.79 ± 12.42 kcal/h) compared to day 4 (346.16 ± 16.62 kcal/h), and was greater on day 14 compared to day 8, and on day 18 (386.16 ± 20.02 kcal/h) compared to day 14. No sow + litter RQ differences (P = 0.21; 1.02 ± 0.04) were detected by day of lactation. However, sow RQ was reduced (P = 0.01) on day 14 (0.98 ± 0.02) compared to day 4 (1.03 ± 0.03), day 8 (1.02 ± 0.02), and day 18 (1.04 ± 0.03). In summary, this cost-effective system (total cost: $1,892 USD) can allow researchers to accurately evaluate THP in individual lactating sows and their litters.

The Gonghe Basin Complex is a pull-apart basin located in the Northeastern Qinghai–Tibet plateau (Qinghai, China) displaying several geothermal features, such as high geothermal gradients and hot springs. The adjacent mountain ranges and the basement are comprised of granitoid rocks, which, at sufficient depth and temperature, are suitable for deep enhanced geothermal systems. Nonetheless, the origin of the heat source mechanisms is not conclusively determined so far. The presented study provides insights of the radiogenic heat productions of the Gonghe Basin Complex and its surroundings. In total, 30 newly sampled Triassic, Silurian, Ordovician, and Devonian intrusive rocks were extracted from outcrops in the surroundings and within the Gonghe Basin Complex, of which one sample was retrieved from exploration well DR2 at c. 1800 m. Samples were analyzed by thin section analysis and a petrographic description is provided. To geochemically characterize the samples, X-ray fluorescence measurements were performed, and radiogenic heat productions were subsequently calculated. Additionally, analysis of 341 intrusive, 105 extrusive, 155 sedimentary, and 76 metamorphic rocks of the Qinling–Qilianshan–Kunlunshan were taken from the literature and compared to the data sampled in the Gonghe Basin Complex. As evidenced in the presented research, the radiogenic heat production values measured in the Gonghe Basin Complex are within the highest calculated for the Qinling-Qilianshan-Kunlunshan. However, radiogenic heat production rates in the Gonghe Basin Complex range from < 1 µW m−3 in tonalites to > 5 µW m−3 in two-mica granites and syenogranites. Nonetheless, average heat productions analyzed do not evidence large intrusions of HHP (high heat producing) granitoids as a source of the geothermal features in the Gonghe Basin Complex.

The current study analyzed and interpreted airborne radiometric data from Ilesha’s basement complex rock and its surroundings. At the surface, the concentrations of the most frequent primordial radionuclides notably K, elemental concentration of uranium eU, and elemental concentration of thorium eTh were measured. The weighted mean elemental and activity concentrations were 0.85%, 2.75 ppm, 10.22 ppm, and 267.54 Bq kg −1 , 34.41 Bq kg −1 , 41.51 Bq kg −1 for 40  K, 238 U, and 232 Th, respectively. The low concentration of 40  K was certainly due to the effects of weathering, kaolinization of granites, and pedogenesis activities. The abundance of uranium was ascribed to the availability of uranium minerals such as allanite, apatite, and sphene with accessories minerals, while that of thorium was due to minerals such as cheralite, thorite, uranothorite, thorianite, and uranothorianite with accessories minerals. The RPHR weighted mean 1.48 µWm −3 compared to the earth's crust mean between 0.8 and1.2 µWm −3 was higher due to significant presence of gneiss rocks in all the studied profiles. Radiological hazard, in particular, dose rates, external hazard index, internal hazard index, radium equivalent, annual gonadal dose, effective dose dispensed to various organs of the body were computed to determine the deleterious effects of rocks in the area. The weighted means of annual gonadal dose of 363.98 µSv y −1 and outdoor 0.91 × 10 ×3 and indoor 1.65 × 10 −3 excessive life cancer risks were more than the global average 300 µSv y −1 , 0.29 × 10 −3 and 1.16 × 10 −3 . As a result, proper surveillance is required in the area in order to prevent epidemics occurrence in future.

Turkey’s ecological footprint has recently been increasing, while its biocapacity has been decreasing. Furthermore, the country’s CO 2 emissions have been rising substantially in recent decades. Therefore, this study aims to identify the factors that are changing the CO2 emissions in Turkey, not only at the aggregated level but also for the sectors with the highest increases in CO 2 emissions, namely, electricity and heat production. Research into the aggregated CO 2 emissions and the sector-level analysis covered the period 1990–2017. The Shapley decomposition method was utilized, and the impacts of five factors, namely, scale effect, migration effect, population, energy intensity, and carbon intensity, were considered to examine the changes in total CO 2 emissions. Regarding the analysis of the electricity and heat production sectors, the roles of four factors, namely, income effect, electricity intensity, fuel structure, and pollution coefficient, were investigated by using the same decomposition approach. The results showed that the scale effect is the primary driver of acceleration of total CO 2 emissions in Turkey; population, migration, and carbon intensity effects follow the scale effect in this respect. Energy intensity significantly decreases Turkey’s total emissions. For the electricity and heat production sectors, the Shapley decomposition results showed that the income effect, electricity intensity, and fuel structure increase the country’s CO 2 emissions rapidly. The pollution coefficient was the only factor that decreased CO 2 in these sectors in the studied period. This study reveals that Turkey is still deficient in terms of green development processes, which are essential for a sustainable future.

Fasting heat production (FHP) is used for characterizing the basal metabolic rate of animals and the corresponding maintenance energy requirements and in the calculation of net energy value of feeds. In broilers, the most recent FHP estimates were obtained in the 1980s in slow-growing and fatter birds than nowadays. The FHP values (n=73; six experiments) measured in 3 to 6-week-old modern lines of broilers weighing 0.6 to 2.8 kg and growing at 80 to 100 g/day were used to update these literature values. Each measurement was obtained in a group of fasting broilers (5 to 14 birds) kept in a respiration chamber for at least 24 h. The FHP estimate corresponds to the asymptotic heat production corrected for zero physical activity obtained by modeling the decrease in heat production during the fasting day. The compilation of these data indicates that FHP was linearly related to the BW0.70 (in kg), which can be considered as the metabolic BW of modern broilers. The 0.70 exponent differs from the conventional value of 0.75 used for mature animals. The FHP per kg of BW0.70 ranged between 410 and 460 kJ/day according to the experiment (P<0.01). An experiment conducted with a shorter duration of fasting (16 h) indicated that FHP values are higher than those obtained over at least 24 h of fasting. Our values are similar to those obtained previously on fatter and slow-growing birds, even though the comparison is difficult since measurement conditions and methodologies have changed during the last 30 years. The FHP values obtained in our trials represent a basis for energy nutrition of modern broilers.

Genetic selection on residual feed intake (RFI) can be used as an alternative method to G:F to improve feed efficiency in pigs. The objective of this study was to determine the effects of selection for RFI on digestive and metabolic utilization of energy in 2 lines of purebred French Large White castrated male pigs obtained from a divergent selection experiment over 6 generations. The RFI⁺ (high RFI) line consumed more feed than predicted from performance compared with the RFI⁻ (low RFI) line. Digestibility of energy and nutrients, total heat production (HP), HP related to physical activity, and energy and N balance were measured in respiration chambers for a 6-d period in pigs offered feed ad libitum. Pigs remained in the chamber for an additional day and did not receive any feed to estimate the fasting HP and calculate the thermic effect of feeding. Five pairs of 2 littermates from the same farrowing batch were used in each line. Because 2 respiration chambers were available for the trial, pigs were measured regularly during the 25- to 95-kg growing period. Two pigs per chamber were used until pigs reached 45 kg of BW, and 1 pig per chamber was used thereafter. Individual feed intake and BW gain were measured continuously from weaning to the end of the trial. Pigs were fed 3 diets with decreasing CP contents during the 25 to 45 (period 1), 45 to 65 (period 2), and 65 to 95 (period 3) kg of BW periods. Average daily feed intake was greater in RFI⁺ pigs than in RFI⁻ pigs between 25 and 65 kg of BW (2,128 vs. 1,891 g/d; P < 0.01) and G:F was 8% greater in RFI⁻ pigs compared with RFI⁺ pigs (P < 0.01). There was no line effect on digestibility coefficients or N retention, irrespective of the experimental period studied. Nitrogen retention was 31.2, 28.7, and 20.8 g/d at periods 1, 2, and 3, respectively (P < 0.001). The HP was greater in RFI⁺ pigs than in RFI⁻ pigs (1,497 vs. 1,383 kJ·kg of BW⁻⁰.⁶⁰·d⁻¹; P < 0.01), with no subsequent line effect on energy retention. The activity-related HP tended to be greater in RFI⁺ pigs than in RFI⁻ pigs (250 vs. 218 kJ·kg of BW⁻⁰.⁶⁰·d⁻¹; P = 0.09), and the fasting HP was 10% greater (P = 0.04) in RFI⁺ pigs than in RFI⁻ pigs (846 vs. 771 kJ·kg of BW⁻⁰.⁶⁰·d⁻¹). The thermic effect of feeding, expressed as a percentage of ME intake, was the same for both lines of pigs (average, 14.7%). In conclusion, the RFI⁺ pigs are energetically less efficient because of their greater HP related to physical activity and basal metabolic rate.

Background Reduced protein diet manifested potential to mitigate heat production based on the concept of ideal amino acid profile. The hypothesis of this study was that lactating sows fed a low crude protein (LCP) diet with supplemental amino acid produce less heat compared to those fed a high crude protein (HCP) diet under both thermal neutral (TN) and heat stress (HS) conditions. Methods Thirty-two lactating sows were allotted to HCP (193 g CP/kg) and LCP (140 g CP/kg) diets under thermal neutral (TN, 21 ± 1.5 °C) or cycling heat stress (HS, 32 ± 1.5 °C daytime and 24 ± 1.5 °C nighttime) conditions. Diets contained 0.90% SID lysine and 10.8 MJ/kg net energy. Positive pressure indirect calorimeters were used to measure gas exchange in individual sows with litters, and individual piglets on days 4, 8, 14 and 18. Sow and litter weights were recorded on days 1, 10 and 21. Results Sow total heat production (THP) was calculated by subtracting litter THP from sow + litter THP based on BW 0.75 . Sow BW and body protein (BP) loss was greater for LCP diet compared to HCP diet in peak lactation ( P  < 0.05 and P  < 0.01, respectively) and throughout the entire lactation period ( P  < 0.05 and P  = 0.056, respectively) under HS conditions. Heat-stressed sows fed HCP diet had higher ( P  < 0.05) rectal temperature at 13:00 ( P  < 0.05) and 19:00 ( P  < 0.01), and higher respiration rate at 07:00 ( P  <  0.05), 13:00 ( P  < 0.05) and 19:00 ( P  < 0.05) compared to TN sows fed HCP diet. In sows fed LCP diet, those under HS tended to have higher ( P  = 0.098) rectal temperature at 13:00 and had higher ( P  <  0.05) respiration rate at 07:00, 13:00 and 19:00 compared to TN sows. The relationship between daily THP and days in lactation of sows fed LCP diet was quadratic ( P  < 0.05), with an ascending trend until day 14 and a descending trend from days 14 to 18. Sows fed LCP diet had lower daily THP at day 18 ( P  < 0.001) compared to those fed the HCP diet under HS conditions. Conclusion Reduction in THP in sows fed LCP diet was largely associated with THP on day 18 of lactation under HS conditions. Feeding LCP diets alleviated the increased body temperature in sows under HS conditions throughout lactation, which was accompanied by a reduction in respiration rate. Total heat production is associated with days in lactation, in particular under HS conditions with THP appearing to peak between days 14 and 18.

In this work, the effect of hydrological spatial variability on the heat production performance of a naturally fractured geothermal reservoir was investigated. Using the geological information of an abandoned natural gas exploration well in northern Songliao Basin, northeast China, the hydraulic properties of the fractured reservoir were studied based on DFN models. The heterogeneous distribution of reservoir hydrological properties was simulated using random field method. Evolution characteristics of production temperature, heat extraction rate, injection pressure, reservoir flow impedance, and the spatio-temporal distribution of temperature and pressure were studied. A sensitivity analysis was performed on correlation distance and coefficient of variation for the random field model. The results indicate that spatial variability of the hydrological parameters has significant influence on the heat production performance. Besides, correlation distance and coefficient of variation are two key parameters that influence the distributions of reservoir parameters and cause the variation of heat production performance in random field models.