Hierarchical porous carbon derived from animal bone as matric to encapsulated selenium for high performance Li-Se battery

Animal bone was employed as raw material to prepare hierarchical porous carbon by KOH activation. Rare metal selenium（Se） was encapsulated into hierarchical porous carbon successfully for the cathode material of Li–Se battery, achieving the transformation of waste into energy,protecting environment and reducing the spread of the disease. Animal bone porous carbon（ABPC） acquires a specific surface area of 1244.7903 m^2·g^-1 and a pore volume of 0.594184 cm^3·g^-1. The composite Se/ABPC with 51 wt%Se was tested as a novel cathode for Li–Se batteries. The results show that Se/ABPC exhibits high specific capacity,good cycling stability and current-rate performance; at 0.1C,the composite Se/ABPC delivers a high reversible capacity of 705 mAh·g^-1 in the second cycle and 591 mAh·g^-1 after 98 cycles. Even at the current density of 2.0C, it can still maintain at a reversible capacity of 485 mAh·g^-1. The excellent electrochemical properties benefit from the high electron conductivity and the carbon with unique hierarchical porous structure. ABPC can be a promising carbon matrix for Li–Se batteries.

Study of the circumstance influence on the elemental distribution in ancient animal bone using μ-XRF

Elemental analysis of archaeological bone plays an important role in the study of the dietary habits of ancient animals. The elemental characteristic of diagenetic skeletons depends on the surrounding circumstance. The study of environmental influence on the elemental concentration of ancient bone is significant. In this paper, the diagenetic influence on archaeological skeletons is analyzed by microbeam X-ray fluorescence （p.-XRF）. The results show that the enamel is an excellent barrier to the diagenesis and the element Sr in bone isn＇t susceptible to contamination from the buried environment.

THE ANIMAL BONES FROM A FURTHER GROUP OF EARLY BRONZE AGE PITS AT OSTIANO, S. SALVATORE (Cremona)

The faunal remains from a group of pits excavated at Ostiano, S. Salvatore (Cremona- Northern Italy) are represented by bones of cattle, sheep/goat, pig and hare. Together with the archaeo-botanical and archaeological data, they reveal a well balanced, mixed subsistence strategy, combiningcereal agriculture and stock raising, adapted to the geographical and environmental location of this EarlyBronze Age settlement. I resti faunistici di un altro gruppo di pozzetti del sito del Bronzo antico di Ostiano,S. Salvatore (Cremona). I reperti faunistici di Ostiano, S. Salvatore sono rappresentati da resti di bovini,capra/pecora, maiale e lepre. Unitamente ai reperti archeobotanici ed archeologici, questi docmnentanouna strategia di sussistenza ben bilanciata fra allevamento ed agricoltura che concorda con la localizza-zione geografico-ambientale del sito dell’età del Bronzo antica.

Optimization of a new animal glue binder system cured by CO_2 for use in foundry

A new sand binder system cured by CO2 was prepared based on the animal bone glue.To overcome the disadvantages of animal glue such as agglomeration at room temperature,high energy consumption and low efficiency,an alkaline decomposition process was selected,and certain modifier was used to modify the performance of the animal glue binder.For the alkaline decomposition,NaOH was used as the catalyst with an addition of 4wt.% to the animal glue.A modifier was determined through the orthogonal experiment with a weight ratio of glycerin:glycol:dextrin:animal glue = 9:16:15:100,and the optimal modification reaction should be performed at 75 ℃ with a reaction time of 90 min.Ca(OH)2 was used as a promoter;the optimal CO2 gas flux blowing into the sand was 0.7 m3.h-1 for a duration of 60s under the experimental conditions.Results show that an original strength above 0.7 MPa and a final strength about 4.2 MPa can be achieved,which could meet the requirement of rapid moulding and core-making for foundry.The new binder was characterized and analyzed by means of IR,and the modification and CO2-cured mechanisms of this animal glue binder were also discussed.

The impact on alpha emission rates of varying distances between a CR-39 detector and alpha-emitting bone samples

Background Changing the distance between a sample and an exposed solid-state nuclear track detector affects the number of alpha tracks recorded by the detector.This concept had been used to distinguish high-energy alpha particles by computing the alpha emission rate at two distances(0 and 2 cm)from animal bone ash.Materials and methods Two Cr-39 detectors were placed in a container with bone ash inside to measure the alpha emission rate when the detectors were in contact with the ash and hung at a distance of 2 cm from the ash.Results The alpha emission rate was found to be 62.7×10^(−4) Bq cm^(−2) when the detector was in contact with the sample(a small exposure area)and 324.4×10^(−4) Bq cm^(−2) when the sample was placed 2 cm away(a larger exposure area).A mathematical equalization of the exposure areas was conducted(the area of the detector exposed to the alpha emitter sample at a distance of 2 cm was equalized to the area exposed when in contact with the sample).After equalization,a reduction in the average value of the alpha emission rate from 324.4×10^(−4) to 17.4×10^(−4) Bq cm^(−2) was observed.Conclusion The increase in distance between the sample and the detector allowed only high-energy alpha particles with a range greater than the traveled distance to reach the detector.Thus,this system can distinguish the type and number of nuclides in the sample by changing the distance between the detector and the sample according to each nucleus range.Additionally,the results show that the alpha emission rates in these bone samples are higher than the local values.