Study of Crater in the Gobi Desert Induced by Ground Explosion of Large Amounts of TNT Explosive up to 10 Tons

Explosion craters on the ground surface induced by contact or near-field explosions have important implications, which can be used to assess blast consequences, guide the design of the explosion, or develop a protective strategy. In this study, to understand the crater characteristics induced by the contact explosion of large weight explosives, four field contact explosion tests were conducted on the surface of the Gobi Desert with large TNT charge weights of 1 ton, 3 tons, and 10 tons (test conducted twice). Cratering on the ground surface generated by large amounts of explosives was measured and evaluated, including the shape, depth, and diameter. A fine-mesh numerical model was developed and validated on the AUTODYN software platform, and a detailed parametric study was performed on the resulting craters. The effects of sand and gravel density, initiation method, shear modulus, and failure criteria were analyzed and discussed. An energy conversion coefficient was determined, and the corresponding theoretical equations were derived to predict the dimensions of the craters resulting from the large weight contact explosion. The calculated cratering characteristics were consistent with previous data and hence can be used in future engineering applications.

P367 Weight patterns in biologicals treated Inflammatory bowel disease cohort

Background Biologic therapies are effective at inducing and maintaining remission in patients with inflammatory bowel disease (IBD). Previous studies have associated TNF-a inhibitors with weight gain, however it is unclear if this is a class-related effect or a manifestation of clinical remission. We performed this retrospective study to compare weight changes from baseline across different biological classes, examine weight patterns over time and assess characteristics and associations within each (sub)groups. Methods Adult patients with IBD who received any biological therapy for at least 12 months, between 2008 and 2020, were identified from prospectively maintained records at two IBD units in Australia. Data collected included demographics; weight and BMI at baseline, 6, 12, 24 and 48 months; IBD type and phenotype; baseline endoscopy, baseline haemoglobin, C-reactive protein (CRP) and albumin; combination or monotherapy; initial steroid therapy and frequency of biologic infusion. Patients with missing data were excluded. A linear mixed-effects model was performed for the outcome of weight change from baseline, including the interaction of treatment group and time period. A latent class analysis was then performed, assigning patients to weight trajectory groups, and univariate ordinal logistic regressions were used to explore possible associations between membership of each group (the outcome) against various predictive factors. Results Of 294 patients (156 females), 165 received Infliximab (IFX), 68 Adalimumab (ADA), 36 Vedolizumab (VDZ) and 25 Ustekinumab (UST). There was a statistically significant interaction between time and treatment group with a significant weight gain over time in both the IFX and VDZ groups. After adjusting for baseline weight and inflammatory markers, significant weight gain was found for IFX vs ADA and VDZ vs ADA at most time points (Fig.1). Significantly less weight gain was seen in those with a higher initiation weight. Each 10kg increase in baseline weight resulted in 0.5kg less weight gain. This effect also held true for BMI. Latent class analysis identified three weight trajectories: 57.4% of patients had small weight loss (-2.3kg), 37.8% small weight gain (6.6 kg) and 4.8% large weight gain (24.3 kg). Baseline BMI inversely influenced weight gain; with every 1 unit increase in BMI, reducing the odds of large weight gain by 8%. Being female, having an initiation CRP£5 or albumin>35 also reduced the odds of large weight gain. Conclusion Weight gain in biological-treated IBD patients appears to be associated with male gender, active baseline inflammation and the type of drug used.

A New Global Variance Reduction Technique Based on Geometry and Energy Splitting/Roulette

With the increase of computer resources and the application of global variance reduction (GVR) method, it is a trend to obtain global distribution using the Monte Carlo (MC) method in deep-penetration shielding calculation. GVR technique uses biased source and weight window to decrease the MC calculation tally error for deep-penetration problems. However, excessive splitting of large weight particles out of the source region is time-consuming for problems with significant fluence rate variation. A new GVR technique, which performs space and energy splitting/roulette based on the importance of the phase space, is proposed in this paper to avoid excessive splitting of large weight particles. The improved GVR technique is applied to the H. B. Robinson Unit 2 (HBR-2) benchmark and CAP1400 dose rate distribution calculation. Numerical results show that the new GVR technique shows excellent performance for deep-penetration shielding calculation.

Ultra-processed foods, incident overweight and obesity, and longitudinal changes in weight and waist circumference: the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Objective:To evaluate the association of ultra-processed food (UPF) consumption with gains in weight and waist circumference, and incident overweight/obesity, in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort.Design:We applied FFQ at baseline and categorized energy intake by degree of processing using the NOVA classification. Height, weight and waist circumference were measured at baseline and after a mean 3·8-year follow-up. We assessed associations, through Poisson regression with robust variance, of UPF consumption with large weight gain (1·68 kg/year) and large waist gain (2·42 cm/year), both being defined as ≥90th percentile in the cohort, and with incident overweight/obesity.Setting:Brazil.Participants:Civil servants of Brazilian public academic institutions in six cities (n 11 827), aged 35–74 years at baseline (2008–2010).Results:UPF provided a mean 24·6 (sd 9·6) % of ingested energy. After adjustment for smoking, physical activity, adiposity and other factors, fourth (>30·8 %) v. first (<17·8 %) quartile of UPF consumption was associated (relative risk (95 % CI)) with 27 and 33 % greater risk of large weight and waist gains (1·27 (1·07, 1·50) and 1·33 (1·12, 1·58)), respectively. Similarly, those in the fourth consumption quartile presented 20 % greater risk (1·20 (1·03, 1·40)) of incident overweight/obesity and 2 % greater risk (1·02; (0·85, 1·21)) of incident obesity. Approximately 15 % of cases of large weight and waist gains and of incident overweight/obesity could be attributed to consumption of >17·8 % of energy as UPF.Conclusions:Greater UPF consumption predicts large gains in overall and central adiposity and may contribute to the inexorable rise in obesity seen worldwide.