7 research outputs found
The Development of explosives competencies, training and education in the UK
Competent explosives workers in the Armed Forces and in the civil sector are
critical to the safe production, testing and use of explosives. Moreover we need
competent explosives specialists to combat the challenge from terrorism and
clean up the planet from the explosive hazards that are the legacy of past
conflicts. Unfortunately many countries are witnessing a significant loss of
capability in this area and are looking at ways of replenishing vital expertise.
This paper describes the work done in recent years by the authors and others in
the UK to establish numbers of people working in the sector and to consider the
skills and knowledge required to carry out their work. It outlines the concept
of national occupational standards and the framework of professional and
vocational qualifications that are available or are being developed for
explosives specialists. It also describes some of the educational and e-learning
programmes designed to support this initiative. Ultimately the aim is to address
the professionalism of all personnel who deal with explosives in order to reduce
the incidence and consequence of accidents and maintain national capability
Low hazard small-scale synthesis and chemical analysis of high purity nitroglycerine (NG)
A previously reported two-phase (99.5% fuming nitric acid/dichloromethane) batch method to prepare high purity 1,2,3-propanetriyl trinitrate (nitroglycerine, NG) was evaluated, simplified and adapted specifically for low hazard small-scale synthesis. The purity of the product, as determined by NMR spectroscopy, HPLC and IR spectroscopic analysis was found to be greater than 99%. The quick synthetic method is highly recommended when small amounts of highly pure NG are required for analytical and related purposes in the absence of a microreactor
An estimate of the TNT-equivalent net explosive quantity (NEQ) of the Beirut port explosion using publicly-available tools and data
Publicly available video recordings of the explosion in Beirut on August 4, 2020, were examined and from them it was possible, in conjunction with the wellâknown Google Maps website, to obtain estimates for the locations of the observersâ cameras with respect to the blast, and estimates for the blast wave arrival time. A publiclyâavailable blast wave calculator was then used to estimate the size of the explosion in terms of the equivalent quantity of TNT that would produce the same blast wave arrival time at the observersâ distance. This work estimates the Beirut explosion to have been equivalent to 637 tons TNT, with a lower bound estimate of 407 tons and an upper bound estimate of 936 ton
Further insights into the discoloration of TATB under ionizing radiation
To determine degradation products formed by exposure of TATB to ionizing radiation, a computational and experimental study is presented. Thermochemical and spectral data have been calculated using DFT at the MH06-HF/aug-cc-pVTZ level which suggest the formation of the cation radical derivative of TATB. Irradiated TATB samples showed the widely reported yellow-to-green discoloration, with measured CIE L*, a*, b* and RGB values correlating with total dose. Trace quantities of a mono-furazan derivative were detected by HPLC-MS; the discoloration is not attributed to this, but rather to the presence of a paramagnetic species (i.e., the cation), as detected by ESR measurements. Recrystallized irradiated TATB samples reverted to their original color, further suggesting it is the cation radical that is responsible for color change
Cross-linking of hydroxyl-terminated polyols with triethyleneglycol diglycidyl ether: an alternative to toxic isocyanates
Isocyanates are highly reactive and toxic substances with severe health effects. Certain diisocyanates are restricted under REACH â The European Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals. Triethyleneglycol diglycidyl ether (TEGDGE) was used as an alternative to toxic isocyanates for the cross-linking of hydroxyl-terminated pre-polymers at 70oC. The effect of three curing accelerators was determined while following the reaction kinetics by 1H-NMR spectroscopy and differential scanning calorimetry (DSC). Polybutadiene (Poly BD R45HT-LO) and acrylic ester (HyTemp 4454) successfully cross-linked in 7â10 days to produce thermally stable networks with low glass transition temperatures, as observed by DSC. Pre-aging the polybutadiene resin promoted cross-linking with TEGDGE. Four energetic compositions were then prepared using cyclotrimethylenetrinitramine (RDX) and pentaerythritoltetranitrate (PETN) as fillers, and polybutadiene (Poly BD R45HT-LO) and acrylic ester (HyTemp 4454) as binders. Both binders successfully cross-linked with TEGDGE in the presence of RDX and PETN, but only PETN was found to be chemically compatible with the cross-linked polymers. These results show that TEGDGE is suitable as a replacement for toxic isocyanates for the cross-linking of hydroxyl-terminated polyols
Low Grade Lymphoma Mimicking Metastatic Urothelial Carcinoma: When Do We Need Further Histologic Staging?
Introduction. Patients with urothelial carcinoma of the bladder often present with metastases to regional lymph nodes, with lymphadenopathy on physical examination or radiographic imaging. Case Presentation. We present the case of a 73-year-old Caucasian man with presumed metastatic urothelial carcinoma of the bladder to regional pelvic and retroperitoneal lymph nodes. He underwent systemic chemotherapy for treatment of urothelial carcinoma and was discovered on restaging to have findings suggestive of disease progression but ultimately was found to have a concurrent secondary malignancy. Conclusion. Our case suggests that in patients with urothelial carcinoma, the concurrent presentation of regional lymphadenopathy may not be metastatic urothelial carcinoma and may warrant further investigation