Specifics of Explosion-Venting Structures Providing Acceptable Indoor Explosion Loads

This article experimentally and theoretically demonstrates that the presence of blast-relief openings (windows) equipped with explosion-venting structures (EVS) allows explosive pressure to be reduced to a safe level (2–4 kPa). We provide results of model and full-scale experiments aimed at studying the influence of EVS parameters of blast-relief openings in explosion-hazardous buildings on the intensity of explosive loads. It was demonstrated that the maximum explosive-pressure value inside EVS-equipped buildings depends on the EVS start-to-open pressure, the structure’s response rate (lag), and characteristic dimension of the premises. Thus, each particular building requires individual selection of EVS parameters, which provide a safe level of excessive pressure in case of an explosive accident. This aspect, however, prevents the widespread use of EVS at explosion-hazardous sites. This article offers an modest upgrade of the explosion-venting structure that provides an indoor pressure equal to the EVS start-to-open pressure. The suggested innovation excludes the possibility of a significant increase in explosive pressure due to an EVS response delay. The efficiency of the suggested technical upgrade was proven by numerical experiments and indirectly by experimental studies aimed at exploring the physical processes associated with the opening of EVSs after an explosion accident. The use of upgraded EVSs will allow for provision of a known maximum level of the explosion load should an explosion event occur in an EVS-equipped room.

Spectrum of Clinical, Neuroimaging, and Cerebrospinal Fluid Features of Adult Neurocutaneous Melanocytosis

Background: Neurocutaneous melanocytosis (NCM) is a poorly understood disease due to its rarity. This study aimed to summarize the characteristics of adult NCM and improve the awareness of this disease. Methods: The clinical data of 13 adult patients with NCM were retrospectively reviewed, including neuroimages, cerebrospinal fluid (CSF), and histological features. Results: There were 9 males and 4 females. The mean age at symptom onset was 36.5 years. The initial symptoms included intracranial hypertension in 8 patients and seizure in 4 patients. Ten patients had large and/or multiple congenital melanocytic nevi. MRI revealed hydrocephalus and diffuse thickening of the leptomeninges with T1 shortening in all patients. Post-contrast T1-weighted images showed diffuse linear enhancement of the leptomeninges. Lumbar punctures showed increased open pressure, and elevated protein levels and decreased glucose concentrations in CSF. Cells with intracytoplasmic coarse black granules were found in the CSF and were positive for S100, HMB45, and vimentin. Histopathology of the cutaneous lesions and meninges showed melanocytes but no evidence of malignant melanoma. Conclusion: Adult NCM patients present a diversity of clinical manifestations. Brain MRI showing diffuse thickening of the leptomeninges with T1 shortening is useful in diagnosing NCM. Heterocellular melanin may be of great value for early diagnosis of NCM in challenging cases.

Study on Numerical Simulation of Gas Explosion inside Compression Compartment of Gas Filling Station

For the compression compartment safety design in gas filling station, hazards of gas explosion inside compression compartment should be assessed, and explosion energy as well as influence factors should be determined. In this paper, numerical simulation was adopted to build 3D model of compression compartment and simulate gas explosion pressure and flame propagation behavior under different ignition point location, open-pressure and weight of relief panels. The results show that the ignition point location relative to the location of the vent opening and relief panel’s characteristics is very important for gas explosion inside compression compartment. The nearer the ignition point location is away from the venting opening location, the smaller the caused explosion pressure will be. For the relief panel, explosion pressure is proportional with the open-pressure and the weight of relief panel. Besides the rational distribution of ignition source and the adoption of relief panel with less unit weight and relief pressure, the crushing material damage and secondary hazard of flame should also be noticed in order to mitigate the hazard of gas explosion.

Experimental Research of Granular Silica Pneumatic Conveying System in Tyre Factory

Through the experimental research of granular silica in dense phase pneumatic conveying in the tyre plants, the characteristic parameters of granular silica pneumatic conveying have been obtained. By adjusting the main and bypass pipe pressure values, the stable plug flow conveying of granular silica can be realized, which considerably reduces the broken ratio of the granular silica. The plug flow conveying will be even more stable, when the opening blow tank pressure is set at zero. Additionally the same research has also proven that bypass valves open pressure in the end of pipeline will affect the stability of the entire conveying system as well.

Study on the Dense Phase Pneumatic Conveying Property of Carbon Black

The dense phase pneumatic conveying system of carbon black and the experimental process are introduced in the paper. According to the test data, the factors that influence the carbon black conveying performance are analysed. This paper points out that the higher of air flow rate will increase the conveying capacity of carbon black, but will approach to a critical value. The open pressure of the blow pot has a optimal extent, in which the carbon black conveying time will be the shortest. This paper also points out that the longer the conveying distance, the higher the carbon black fragmentation rate.

Idiopathic Intracranial Hypertension With and Without Papilloedema in a Consecutive Series of Patients With Chronic Migraine

Chronic migraine (CM) has been associated with idiopathic intracranial hypertension without papilloedema (IIHWOP), a significant percentage of these cases occurring in obese patients with intractable headache. A prospective study from February 2005 to June 2006 was made of 62 CM patients who fulfilled International Headache Society diagnostic criteria and had cerebral magnetic resonance venography (MRV) and lumbar puncture (LP) done. Two patients were excluded, six (10%) with elevated cerebrospinal fluid (CSF) open pressure (OP), five with body mass index (BMI) > 25. None of the patients had papilloedema or abnormal MRV. BMI and CSF OP were significantly correlated ( r = 0.476, P < 0.001, Pearson's correlation test). Obesity (defined as BMI > 30) was a predictor of increase in intracranial pressure (defined as OP > 200 mmH2O) ( f = 17.26, 95% confidence interval 6.0, 8.6; P < 0.001). From our study we strongly recommend that not only intractable CM patients with high BMI, but also first diagnosed patients with BMI > 30 should be systematically evaluated by a LP to rule out IIHWOP.

Effect of tension therapy in the management of pressure ulcers a case report

The purpose of this case study was to determine the therapeuticeffect of tension on the healing of an open pressure sore. An in-patient of the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria was chosen for the study. The patient had paraplegia secondary to Burkitt’s lymphoma and subsequently developed pressure ulcers on the sacrum and right ischium. The right ischial ulcer was randomly chosen as experimental and the other ulcer as the control. Tension therapy was administered to the experimental ulcer for 20 minutes for four days a week. This was achieved by applying passive mobilization exercises to the right hip joint. The tension was maintained for about 5 minutes and released for 1 minute. The process was repeated 4 times per treatment session. The control wound did not receive tension therapy. Both the experimental and control ulcers received conventional dressing. The study lasted for five weeks. The experimental sore reduced to 60.5% of the original surface area while the control ulcer did not show any appreciable healing but rather expanded by 19.6% of its original size. This finding indicates that tension therapy could be effectively used to accelerate healing of pressure ulcers.