Interconnected silicon hollow nanospheres for lithium-ion battery anodes with long cycle life

Silicon is a promising candidate for the anode material in lithium-ion batteries due to its high theoretical specific capacity. However, volume changes during cycling cause pulverization and capacity fade, and improving cycle life is a major research challenge. Here, we report a novel interconnected Si hollow nanosphere electrode that is capable of accommodating large volume changes without pulverization during cycling. We achieved the high initial discharge capacity of 2725 mAh g(-1) with less than 8% capacity degradation every hundred cycles for 700 total cycles. Si hollow sphere electrodes also show a Coulombic efficiency of 99.5% in later cycles. Superior rate capability is demonstrated and attributed to fast lithium diffusion in the interconnected Si hollow structure.     

Effect of diet on animal performance, lipid composition of subcutaneous adipose and liver tissue of beef cattle

Two trials were carried out with Brahman beef cattle to study animal performance and carcass characteristics as well as fatty acid composition of subcutaneous adipose and hepatic tissue, as influence by length of grain feeding period or a pasturing regimen. In trial 1, steers were allotted to three feedlot finishing periods (76, 104 and 146 days) after being backgrounded on pasture. Steers fed 76 days had greater average daily gains (P < 0·05) than steers fed 146 and 104 days, respectively. Carcasses of steers slaughtered after 146 days on feed had higher (P < 0·05) marbling scores, quality grades, fat over ribeye, quality yield and per cent kidney, pelvic and heart (KPH) fat than steers fed for 104 and 76 days. The proprortions of certain fatty acid of subcutaneous fat and liver tissue were influenced by the length of grain feeding. There was a marked increased in the proportion of oleic acid in both tissues as the steers remained longer in the feedlot and a higher percentage of total saturated fatty acids at 76 days than at the other two times. Quantitative separation of hepatic lipid classes by the Iatroscan revealed that phosphatidylcholine and phosphatidylethanolamine were the main components of the phospholipids. Presents as minor components were cardiolipin and sphingomyelin. No differences (P > 0.·05) in these individual subclasses of liver lipids or in triglycerides were observed between the feedlot groups. Liver polyunsaturated fatty acids (PUFA) were higher (P < 0·001) at 104 than 76 days. In trial 2, steers fed a concentrate diet gained faster (P < 0·05) than the pasture group after 138 days. Marbling scores, yield grade, quality grade, fat over ribeye and per cent KPH were higher (P < 0·01) for the concentrate group while fat color scores were higher (P < 0·01) for the pasture group. Liver fatty acid analysis of summed ω6 PUFAs of triglyceride, phosphatidylcholine, phosphatidylethanolamine were higher for the feedlot than the pasture group. Linoleic acid was higher (P < 0·05) in the TG and PC liver subclass of the feedlot animals while higher (P < 0·05) linolenic acid occurred in the pasture group.     

Effect of a commercial freeze/tempering process on the viability of Cryptosporidium parvum oocysts on lean and fat beef trimmings

Lean and fat beef trimmings (25 cm⁻²) were inoculated with approximately 250,000 Cryptosporidium parvum oocysts, placed in commercial packages (28 kg boxes) and subjected to normal commercial processes i.e. blast frozen (to −20 °C within 60 h), stored (−20 °C, 21 days), tempered (48 h at −3 °C), and held at 0 °C for 10 h. Inoculated areas were then excised, pulsified (30 s in 50 ml PBST), and centrifuged (2500×g, 15 min). The resultant pellet was resuspended in 10 ml water and subjected to immunomagnetic separation and viability dye assay. Following the commercial freeze/tempering process the viability of the oocysts had decreased from 90.6% viable in the working stock suspension to 7.17% and 9.46% viable on lean and fat trimmings, respectively. The results of this study indicate that if C. parvum oocysts were present on beef trimmings their viability would be substantially reduced as a result of the freeze/tempering process.     

Analyzing the occurrence of foaming in batch fermentation processes using multiway partial least square approaches

This article presents an application of multiway partial least squares (MPLS) methods to develop interpretative correlation models to monitor the foaming occurrence and improve batch fermentation. We choose the exhaust differential pressure as a quality variable to quantify the foaming occurrence and consider three-dimensional datasets of different batches, process variables, and measurements. We integrate batch-wise unfolding (BWU) and observation-wise unfolding (OWU) of plant datasets with standard, dynamic, and kernel PLS methods. We find that dynamic PLS (DPLS) with OWU and time-lagged quality variables to be the most efficient, accurate, and easy to implement. The BWU approach is useful for analyzing the differences between batches and identifying abnormalities and outliers, while the OWU quantifies the variation within a given batch. With OWU, the DPLS method with one unit of time lag in the quality variable is the most effective, accurate, and easy to implement. With both BWU and OWU, we identify the quantitative effects of process variables on the quality variable and providence guidance to improve fermentation performance.