6,730 research outputs found
A contribution to the discussion on the safety of air weapons
Firearms legislation in the UK stems from the Firearms Act 1968 with its definition of a firearm as a lethal barrelled weapon of any description. The Act allows certain exceptions to be held without licence, most notably air weapons although these are limited by The Firearms (Dangerous Air Weapons) Rules 1969 and related regulations to below 12 ft lb (16.3 J) for air rifles and below 6 ft lb (8.1 J) for air pistols. Despite this there are occasional fatalities, typically 1 or 2 each year in the UK, from legally owned air weapons. In the USA there are over 20,000 visits each year to emergency departments due to injuries from air weapons and paintball guns. Despite this, limited research appears to have been carried out into the safety of air weapons and the present study tries to address this.Fresh samples of animal tissue were obtained from an abattoir or butcher and were embedded in ballistic gelatin. Pig heart, lung, liver and shoulder were used. By firing pellets into gelatin alone and into the combination of the gelatin and animal tissue it was possible to compare gelatin as a model for these tissues. The depth of penetration was similar but the residual track appeared to remain more open in the animal tissue. Pellets penetrated completely through the organ, with total penetration of gelatin and organ being typically around 10ā15 cm.Samples of pig, cow and chicken skin were placed in contact with the gelatin or embedded in the gelatin to simulate the effect of skin on penetration into a body. Chicken skin had no effect, pig skin stopped the pellet and cow skin was perforated by the pellet. If cow skin was embedded in the gelatin there was little effect on the total amount of penetration, but cow skin on the front surface of the gelatin reduced penetration by about 30%.Computed tomography was used to examine the pellet track and to calculate the volume of damage produced. However, due to the similar densities of gelatin and organ a technique had to be developed to differentiate phases. A barium salt paste was applied to outer surfaces and iodine solution or barium nitrate solution containing red food colouring was injected into the pellet track to enhance the contrast of the track. The track through the gelatin tended to enclose itself whereas the track through the organ remained more open, presumably due to the inhomogeneity of the fibrous nature of the tissue.Pellets were also fired at construction materials (wood, plasterboard and brick) and computed tomography used to determine the volume of damage created. Pellets perforated single layers of wood and plasterboard and would embed in a second layer. However, if the two layers were in contact the pellet did not penetrate the first layer. An air rifle pellet could therefore perforate house construction materials, although the resultant kinetic energy would be low and further damage would be limited.Some of the possible physical parameters are discussed that might help predict the degree of damage caused, but from this study it is not possible to define a limit which could be proposed as safe
Wind data from the 250-foot /76.2-meter/ tower at Wallops Island, Virginia
Statistical evaluation of sampled wind data from anemometers mounted on meteorological tower on Wallops Islan
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Selective Laser Sintering of Polymer Nanocomposites
This paper describes the fabrication and characterization of polymer nanocomposite (PNC)
materials for use in the selective laser sintering (SLS) process. PNC materials are of great
interest generally because of their excellent physical properties, and offer excellent potential
in rapid manufacturing of structural polymeric parts. Three different nano additive materials
have been used: cerium oxide IV, yttrium stabilized zirconia, and layered Hectorite clay.
These materials have been used to reinforce PA6 polymer using solution blending and spray
drying to create powder with particle sizes in the range of 5-40 Āµm. The mechanical
properties and microstructure of the PNC materials have been evaluated and the results
compared to those of unfilled polymer.Mechanical Engineerin
The 2011 Nucleic Acids Research Database Issue and the online Molecular Biology Database Collection
The current 18th Database Issue of Nucleic Acids Research features descriptions of 96 new and 83 updated online databases covering various areas of molecular biology. It includes two editorials, one that discusses COMBREX, a new exciting project aimed at figuring out the functions of the āconserved hypotheticalā proteins, and one concerning BioDBcore, a proposed description of the āminimal information about a biological databaseā. Papers from the members of the International Nucleotide Sequence Database collaboration (INSDC) describe each of the participating databases, DDBJ, ENA and GenBank, principles of data exchange within the collaboration, and the recently established Sequence Read Archive. A testament to the longevity of databases, this issue includes updates on the RNA modification database, Definition of Secondary Structure of Proteins (DSSP) and Homology-derived Secondary Structure of Proteins (HSSP) databases, which have not been featured here in >12 years. There is also a block of papers describing recent progress in protein structure databases, such as Protein DataBank (PDB), PDB in Europe (PDBe), CATH, SUPERFAMILY and others, as well as databases on protein structure modeling, proteināprotein interactions and the organization of inter-protein contact sites. Other highlights include updates of the popular gene expression databases, GEO and ArrayExpress, several cancer gene databases and a detailed description of the UK PubMed Central project. The Nucleic Acids Research online Database Collection, available at: http://www.oxfordjournals.org/nar/database/a/, now lists 1330 carefully selected molecular biology databases. The full content of the Database Issue is freely available online at the Nucleic Acids Research web site (http://nar.oxfordjournals.org/)
Understanding the scale and nature of outcome change in area-regeneration programmes: evidence from the New Deal for Communities Programme in England
The New Deal for Communities (NDC) Programme is one of the most intensive area-based initiatives (ABIs) launched in England. Between 1998 and 2010, 39 NDC Partnerships were charged with improving conditions in relation to six outcomes within deprived neighbourhoods, each accommodating around 9,800 people. Data point to only modest change, much of which reflected improving attitudes towards the area and the environment. There are problems in identifying positive people-based outcomes because relatively few individuals benefit from relevant initiatives. Few positive benefits leak out of NDC areas. Transformational change was always unlikely bearing in mind the limited nature of additional resources, and because only a minority of individuals directly engage with NDC projects. This evidence supports perspectives of ABIs rooted in 'local-managerialism'
Indentation-based characterization of creep and hardness behavior of magnesium carbon nanotube nanocomposites at room temperature
The time-dependent plastic deformation response of magnesium/carbon nanotube (CNT) nanocomposites containing 0.25, 0.5, and 0.75 vol% of carbon nanotubes is investigated through depth nanoindentation tests against monolithic pure magnesium in the present study. The Mg-CNT nanocomposite materials were successfully synthesized via a powder metallurgy technique coupled with microwave sintering followed by hot extrusion to produce 8-mm diameter, long solid bars. All depth-sensing indentation creep tests were conducted at ambient (room) temperature employing a diamond Berkovich pyramidal indenter. These tests are dual-stage, i.e., loading to a prescribed peak load of 50 mN, holding the peak load constant for a dwell period of 500 s, and finally unloading. Various strain rates of 0.01, 0.1, 1, and 10 sā1were performed to assess the effects of strain rate and dwell time on the ambient temperature creep response of the Mg-CNT nanocomposites. The outcomes of these tests are explained through material hardness, microstructure, the extent of CNT content in each material, and strain rate sensitivity. Upon analyzing the nanoindentation creep tests, the dominant creep mechanism at room temperature was found to be a dislocation creep mechanism. It is also found that CNTs increase the creep resistance of magnesium. Findings of this study can be used as a starting point for a high-temperature creep study on Mg-CNT nanocomposites. This paper is a continued study from our group on time-dependent plastic deformation of Mg nanocomposites (i.e., see Haghshenas et al., Journal of Composite Materials, https://doi.org/10.1177/0021998318808358). The short-term goal is to provide a compressive picture of the controlling creep mechanisms and their dependency upon, time, temperature, strain rate, volume fraction of the nanoparticles, and the type of the nanoparticles. Mg, in general, is a notorious material for high-temperature application; therefore, the long-term objective is to propose Mg nanocomposite as reliable replacements for Mg when lightweight and creep resistance are needed. However, to be able to confidently suggest such a replacement detailed understanding on the controlling phenomena, mention as short-term goals, are required
Predictive Validity of the SAVRY With Indigenous and Caucasian Female and Male Adolescents on Probation
Indigenous people and the courts have emphasized that it is important to examine whether violence risk assessment tools are valid and appropriate for Indigenous youth. However, studies are scarce. Therefore, we examined the predictive validity of youth probation officersā SAVRY ratings for 744 Canadian youth, including 299 Indigenous youth (219 male, 80 female), and 445 Caucasian youth (357 male, 88 female) in a prospective field study. The SAVRY summary risk ratings and risk total scores significantly predicted violent and any reoffending for Indigenous female and male youth with medium effect sizes. Relatively few significant differences in the predictive validity emerged for Indigenous and Caucasian youth. However, Historical, Protective, and Risk Total scores predicted any recidivism better for Caucasian males than Indigenous males. Also, Indigenous youth scored significantly higher on all risk domains than Caucasian youth. Opposite to predictions, the rates of false positives were higher for Caucasian youth than for Indigenous youth. Based on the results, the SAVRY appears to be a reasonable tool to use for assessing risk in youth who are Indigenous. However, assessors should take steps to ensure that they use the SAVRY in a culturally appropriate manner, such as considering cultural factors in case formulations and treatment planning as the SAVRY does not ground assessments in an understanding of factors such as colonialism. In addition, future research should examine culturally salient risk factors (e.g., discrimination) and examine potential causes of higher risk scores in Indigenous youth, particularly the role of both past and present-day colonialism
Oil palm land conversion in ParĆ”, Brazil, from 2006-2014: evaluating the 2010 Brazilian Sustainable Palm Oil Production Program.
Global models of biophysical suitability for oil palm consistently rank Brazil as having the greatest potential for expansion, with estimates as high as 238 Mha of suitable lands. In 2010, Brazil launched the Sustainable Palm Oil Production Program (SPOPP) to incentivize oil palm development without deforestation on as much as 30Mha. Here we examine oil palm expansion before and after the SPOPP?s launch. In ParĀ“a, the major oil palm producing state in Brazil, we analyze the extent and change in oil palm cultivation from 2006−2014 using satellite imagery, ground-truthed verification, site-based interviews, and rural environmental (land) registration data. Between 2006−2014, oil palm area (≥9 ha) expanded >200% to ∼219 000 ha. Of the ∼148 000 ha of oil palm developed, ∼91% converted pasturelands while ∼8% replaced natural vegetation, including intact and secondary forests. Although >80% of all oil palm parcels rest <0.5 km from intact forests, direct conversion of intact forests declined from ∼4% pre-SPOPP (2006−2010) to <1% post-SPOPP (2010−2014). Despite low and declining deforestation rates associated with oil palm expansion in ParĀ“a, our results also show a low area of oil palm development overall compared with reported land suitability. To explore potential contributing factors, we conducted semi-structured interviews with researchers, company representatives, and government officials involved in the sector to characterize the perceived factors influencing oil palm development and the role of agro-ecological suitability mapping among them. Interviews indicated that: (1) individual effects of suitability mapping efforts to encourage oil palm expansion on cleared areas, i.e. without deforestation, cannot be disentangled from pre-existing public and private deforestation reduction initiatives; and, (2) socio-economic constraints, e.g. high relative production costs and limited familiarity with this crop, appear to partially explain the major discrepancy between estimated potential suitable areas with realized oil palm development
The Natural Product Lepidiline A as an N-Heterocyclic Carbene Ligand Precursor in Complexes of the Type [Ir(cod)(NHC)PPh3)]X: Synthesis, Characterisation, and Application in Hydrogen Isotope Exchange Catalysis
A range of iridium(I) complexes of the type [Ir(cod)(NHC)PPh3)]X are reported, where the N-heterocyclic carbene (NHC) is derived from the naturally-occurring imidaozlium salt, Lepidiline A (1,3-dibenzyl-4,5-dimethylimidazolium chloride). A range of complexes were prepared, with a number of NHC ligands and counter-ions, and various steric and electronic parameters of these complexes were evaluated. The activity of the [Ir(cod)(NHC)PPh3)]X complexes in hydrogen isotope exchange reactions was then studied, and compared to established iridium(I) complexes
Evaluation of Four Recovery Communities across England: Interim report for the Give it Up project
The Comic Relief: Give it Up Fund is a programme that aims to develop and build abstinence based recovery communities and learn more about their value. The Give it Up Fund supports the development of recovery communities in four geographical locations in England. It is
expected that the recovery communities will be sustainable and continue to operate after the two years of funding is complete. The aim of this research is to evaluate the operational processes of the pilot programmes and better understand how they might contribute to ambitions of improved and sustained recovery.
Abstinence-based recovery communities aim to ensure that people with addictions are supported to meet their personal, social and economic needs in order to enable long-term recovery and reintegration back into society. Abstinence-based recovery complements the UK Drug Strategy (2010) objective of supporting people to live abstinence-based, ādrug-freeā lives.
The large grants programme element of the Give it Up Fund is supporting the development of recovery communities in Durham, Birmingham, Gloucester and London by creating partnerships offering collaborative working with approaches that aim to sustain recovery.
This work explores how each of the projects contribute to recovery outcomes over time, and aims to embed processes to ensure that projects are able to measure and evidence their outcomes once the commissioned evaluation has finished
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