A bulletproof vest should have high strength and durability to resist a bullet as vital war equipment. However, the cost of creating good quality bulletproof vest is expensive. Therefore, research ...about an alternative bulletproof vest with affordable cost and competitive quality is needed. This research aims to review and compare two alternative vest types with one commercial type IV vest. Both alternative vests have similar components, except the second one has an additional Ultra High Molecular Weight Polyethylene (UHMWPE) component. The ballistic test shows that alternative vests are still not enough to resist a 5.56 mm bullet, but it has the potency to handle a 9 mm bullet. Furthermore, the influence of UHMWPE to resist 9 mm bullets is shown in this research.
This paper investigates the effects of thermal referral and tactile masking illusions to achieve localized thermal feedback on the upper body. Two experiments are conducted. The first experiment uses ...a 2D array of sixteen vibrotactile actuators (4\times 4) with four thermal actuators to explore the thermal distribution on the user's back. A combination of thermal and tactile sensations is delivered to establish the distributions of thermal referral illusions with different numbers of vibrotactile cues. The result confirms that localized thermal feedback can be achieved through cross-modal thermo-tactile interaction on the user's back of the body. The second experiment is conducted to validate our approach by comparing it with thermal-only conditions with an equal and higher number of thermal actuators in VR. The results show that our thermal referral with a tactile masking approach with a lesser number of thermal actuators achieves higher response time and better location accuracy than thermal-only conditions. Our findings can contribute to thermal-based wearable design to achieve greater user performance and experiences.
Was the Soviet Union a superpower? Red Globalization is a significant rereading of the Cold War as an economic struggle shaped by the global economy. Oscar Sanchez-Sibony challenges the idea that the ...Soviet Union represented a parallel socio-economic construct to the liberal world economy. Instead he shows that the USSR, a middle-income country more often than not at the mercy of global economic forces, tracked the same path as other countries in the world, moving from 1930s autarky to the globalizing processes of the postwar period. In examining the constraints and opportunities afforded the Soviets in their engagement of the capitalist world, he questions the very foundations of the Cold War narrative as a contest between superpowers in a bipolar world. Far from an economic force in the world, the Soviets managed only to become dependent providers of energy to the rich world, and second-best partners to the global South.
Noble gases are chemically inert and variably soluble in crustal fluids. They are primarily introduced into hydrocarbon reservoirs through exchange with formation waters, and can be used to assess ...migration pathways and mechanisms, as well as reservoir storage conditions. Of particular interest is the role groundwater plays in hydrocarbon transport, which is reflected in hydrocarbon–water volume ratios. Here, we present compositional, stable isotope and noble gas isotope and abundance data from the Sleipner Vest field, in the Norwegian North Sea. Sleipner Vest gases are generated from primary cracking of kerogen and the thermal cracking of oil. Gas was emplaced into the Sleipner Vest from the south and subsequently migrated to the east, filling and spilling into the Sleipner Ost fields. Gases principally consist of hydrocarbons (83–93%), CO2 (5.4–15.3%) and N2 (0.6–0.9%), as well as trace concentrations of noble gases. Helium isotopes (3He/4He) are predominantly radiogenic and range from 0.065 to 0.116RA; reported relative to air (RA=1.4×10−6; Clarke et al., 1976; Sano et al., 1988), showing predominantly (>98%) crustal contributions, consistent with Ne (20Ne/22Ne from 9.70 to 9.91; 21Ne/22Ne from 0.0290 to 0.0344) and Ar isotopes (40Ar/36Ar from 315 to 489). Air-derived noble gas isotopes (20Ne, 36Ar, 84Kr, 132Xe) are introduced into the hydrocarbon system by direct exchange with air-saturated water (ASW). The distribution of air-derived noble gas species are controlled by phase partitioning processes; in that they preferentially partition into the gas (i.e., methane) phase, due to their low solubilities in fluids. Therefore, the extent of exchange between hydrocarbon phases and formation waters – that have previously equilibrated with the atmosphere – can be determined by investigating air-derived noble gas species. We utilize both elemental ratios to address process (i.e., open vs. closed system) and concentrations to quantify the extent of hydrocarbon–water exchange (i.e., volumetric gas–water ratios). These data are discussed within the framework of several conceptual models: (i) total gas-stripping model, which assumes all noble gases have been stripped from the water phase, thus defining the minimum volume of water to have interacted with the hydrocarbon phase; (ii) equilibrium model, which assumes equilibration between groundwater and hydrocarbon phase at reservoir P, T and salinity; and (iii) open and closed system gas-stripping models, using concentrations and elemental ratios. By applying these models to Ne–Ar data from Sleipner, we estimate volumetric gas–water ratios VgVw between 0.02 and 0.07, which are lower than standard geologic gas–water estimates of ∼0.24, estimated by combining gas-in-place estimates with groundwater porosity estimates. Sleipner Vest data can be best approximated by an open system model, which predicts more than an order of magnitude more groundwater interaction during migration than geologic estimates, indicating a dynamic aquifer system and/or a hydrous migration pathway. In an open system, the extent of gas loss can be estimated to be between 8 and 10 reservoir volumes, which have passed through the system and been lost (i.e., filled and spilled).
Abstract
Scholars cite right-wing authoritarian and business-elite influences in their explanations of populist mobilization against climate reforms. The Yellow Vest movement in France, initially ...sparked by opposition to a carbon tax, defies the generalizations offered by scholars, the media, and politicians alike. This populist movement emerged from below rather than from elite sponsorship and was motivated by social justice concerns. Through in-depth interviews with 31 Yellow Vest activists as well as supplementary primary texts and data, I uncover how the activists frame carbon taxation and climate change within their political struggle. The findings are four-fold: 1) the Yellow Vests are concerned about global climate change and feel their anti-climate depictions in the media are rooted in a government strategy to divide and discredit the movement; 2) they view the government’s taxing them in order to fight climate change as corrupt and unfair; 3) they argue that the carbon tax is additionally unjust due to their precarity, which has increased over several decades; 4) they want to fight climate change on their own terms and argue for more direct forms of democracy to equalize decision making. I conclude with a framework for understanding how and why popular movements oppose climate reforms.
Personal cooling vests containing phase change material (PCM) are commonly used for outdoor workers. They cool the human torso and provide a better rating of overall thermal comfort in hot ...environments. However, PCM cooling vests become less effective at conditions where a high sweat secretion is present, and at very humid or very dry ambient conditions. Therefore, design variations have been used to justify the use of the PCM cooling vest in such conditions. These mainly include the hybrid PCM-Desiccant cooling vest, containing thin solid desiccant packets attached to the PCM packets, and the hybrid PCM-Fan vest, formed of PCM packets and ventilation fans.
The aim of this study is to develop criteria for comparing the performance of the three vests at different ambient conditions and human metabolic rates. The comparison used predicted values of torso skin temperature and overall thermal comfort using validated simulation models for heat and mass transfer in each of the vest layers, integrated with a validated bio-heat model. Steady state results were obtained at metabolic rates of 3 and 6 MET at ambient temperatures of 35, 40 and 45 °C with varying relative humidity (RH). Based on developed criteria, it was found that the use of the PCM-only vest is recommended at activity level of 3 MET in moderate ambient temperature of 35 °C and at ambient RH of 17% and 27%. At the higher ambient temperatures of 40 °C and 45 °C and low ambient RH, the use of the hybrid PCM-Fan vest is recommended. However, at moderate RH both hybrid vest types can be used while at higher ambient RHs, the use of hybrid PCM-Desiccant vest is justified. Similarly, it was shown that at higher metabolic rate of 6 MET, both hybrid vests can be used at moderate RH. However, at high RH, the hybrid PCM- Desiccant vest is recommended.
Schematic of the side back view of each of (a) the PCM-only cooling vest, (b) the hybrid PCM-Desiccant cooling vest and (c) the hybrid PCM-Fan cooling vest.
Plots of the steady state overall thermal comfort at 35 °C at 3 MET. Display omitted
•A performance criteria to compare effectiveness of different cooling vests was developed.•Integrated PCM-only and hybrid vest models with a bioheat model were utilized.•Steady-state predictions of heat losses, torso temperatures and thermal comfort were predicted.•Using PCM-only vest at 3 MET, Tamb of 35 °C and RH of 17% and 27% is appropriate.•Both hybrid vests at 40 and 45 °C and moderate RH are suitable, while at higher RH use PCM-Desiccant.
Background: A halo vest is an immobilization device widely used to stabilize the cervical spine. Pain and infection at the skull pin insertion site are common complications, but skull perforation is ...rare, and most published studies are case reports. This study aimed to identify risk factors for skull perforation by comparing patients who did and did not develop perforation.Methods: Overall thickness and the thicknesses of the internal and external laminae of the skull at the skull pin insertion sites were measured on cranial computed tomography scans of 66 patients fitted with a halo vest. The results were compared between patients who did and did not develop perforation.Results: Four patients developed perforations. All patients with perforation were older women, and their external and internal laminae were significantly thinner than those of patients who did not develop perforation.Conclusion: The reported causes of skull pin perforation include infection around the pin, osteoporosis, and an enlarged frontal sinus. However, most patients with perforation in the present study were older women, and the cause was the thinning of the external and external laminae.
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•Novel ventilated vest add-on to chair-based comfort system is proposed for elderly.•The vest ventilates cool air extracted from microclimate for enhanced body heat ...removal.•Performance is assessed with models of ventilated vest, microclimate, and thermal sensation (TS).•Elderly TS reached acceptable level of 0.5 in room at 33 °C with the vest add-on.•20% less energy use by the vest with the chair comfort system at the same TS.
This study proposes using a personal comfort system (PCS) with a ventilated vest to improve the thermal comfort of older people in hot conditions with low energy requirements. A chair-based PCS that establishes a cool microclimate around body parts influential for thermal comfort is used with a ventilated vest that draws cool air from the established microclimate. The vest acts as an additional heat removal measure to provide adequate elderly thermal sensation (TS) with the chair PCS.
The research methodology incorporates a ventilated vest model integrated with an elderly bioheat and TS models, as well as computational fluid dynamics for predicting the flow and thermal fields of microclimate and space. Models are validated by i) conducting experiments on a chair-based PCS with a vest on thermal manikin in a climatic chamber and ii) comparing predictions with published data on elderly TS. The validated models are used to evaluate the effect of combining the vest and the chair PCS on improving elderly TS. The combined system reduced the elderly TS from 0.8 to 0.5 (between neutral and slightly warm) at 33 °C microclimate with a chair PCS supply flow rate of 21 l/s and a vest suction fan flow rate of 11 l/s. In contrast, achieving a TS of 0.5 using the chair PCS alone necessitate a supply flow rate of 34 l/s, which results in 19 % higher energy consumption compared to the combined mode. Using the vest with the chair PCS is a viable solution for elderly individuals in hot conditions.
There is a steadily growing number of mobile communication systems that provide spatially encoded tactile information to the humans’ torso. However, the increased use of such hands-off displays is ...currently not matched with or supported by systematic perceptual characterization of tactile spatial discrimination on the torso. Furthermore, there are currently no data testing spatial discrimination for dynamic force stimuli applied to the torso. In the present study, we measured tactile point localization (LOC) and tactile direction discrimination (DIR) on the thoracic spine using two unisex torso-worn tactile vests realized with arrays of 3 × 3 vibrotactile or force feedback actuators. We aimed to, first, evaluate and compare the spatial discrimination of vibrotactile and force stimulations on the thoracic spine and, second, to investigate the relationship between the LOC and DIR results across stimulations. Thirty-four healthy participants performed both tasks with both vests. Tactile accuracies for vibrotactile and force stimulations were 60.7% and 54.6% for the LOC task; 71.0% and 67.7% for the DIR task, respectively. Performance correlated positively with both stimulations, although accuracies were higher for the vibrotactile than for the force stimulation across tasks, arguably due to specific properties of vibrotactile stimulations. We observed comparable directional anisotropies in the LOC results for both stimulations; however, anisotropies in the DIR task were only observed with vibrotactile stimulations. We discuss our findings with respect to tactile perception research as well as their implications for the design of high-resolution torso-mounted tactile displays for spatial cueing.
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The outer shell of the bulletproof fabric is one of the important parts that help the shield in performing its function of protection in the best way. In this paper, there are two ...types of high-performance materials used as the outer shell and finished with knife coating with fluorocarbon and polyurethane coating to improve the performance of the two materials. Five laboratory tests were conducted for both materials to show their functional performance efficiency, the ballistic test was applied using two types of calibers 7.62x54MSC and 7.62x54API. A scanning electron microscope was conducted to show the coating effect on samples. Paired sample T-tests were used to show the differences between variables. An improvement was shown in the performance for both ballistic nylon and Cordura after treatment. Finally cordura is more durable, as it recorded the highest value in Puncture test and less damaged, while ballistic nylon recorded the highest value in the abrasion resistance after the same treatment.
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