Explosion prevention and mitigation in plants which process, generate and store combustible dusts

Combustible dusts which are present in workplaces are a significant hazard which cannot be ignored by the plant owners, managers and workers. Combustible dust deflagrations and explosions have caused large numbers of deaths and catastrophic property damages in various industries, ranging from pharmaceutical plants to sugar factories. One may say that dust explosions in process industries always start inside process equipment such as mills, dryers, filters. Such events may occur in any process in which a combustible dust is handled, produced or stored, and can be triggered by any energy source, including static electricity, friction and hot surfaces. For any combustible dust type, several important parameters have to be taken into account when designing and using protective systems: i.e. the ease with which dust clouds ignite and their burning rates, maximum explosion pressure, maximum rate of explosion pressure rise. These parameters vary considerably depending on the dust type, their knowledge being a first step for carrying out a proper explosion risk assessment in installations which circulate combustible dusts. The paper presents the main aspects concerning explosion protection which have to be taken into account when designing protective systems intended to be used in explosive atmospheres generated by combustible dusts and the importance of selecting the proper explosion protection technique.

Development of New Typhoon Rating to Predict Magnitude of Damage

For preparing damage from typhoons, the new typhoon rating system was developed that can predict the magnitude of damage by using the maximum wind speed and rainfall for duration 3 hrs at a specific location along the track. Existing forecasts predict typhoon’s characteristic values such as tack, minimum pressure, maximum wind speed and radiis, and issue typhoon advisories and typhoon warnings when danger or damage is expected. However, as it is difficult to prepare a response using this information alone, I developed new typhoon ratings that took the typhoon damage scale into account to aid disaster preparation. I divided typhoon grades into four classes based on the magnitude of damage. The grades were determined based on the maximum wind speed at a point near the 33° north latitude and rainfall for duration 3 hrs from the time at that point.

Urodynamic Values Role For Females With Different Types Of Urinary Incontinence

Aim — The aim of this study was to analyse how conventional urodynamic values differ between females with specific types of urinary incontinence (UI). Material and Methods — Cross-sectional study enrolled 666 females with UI. Based on patient history and questionnaires they were divided into three groups: stress (SUI), mixed (MixUI) and urgency (UUI). Physical investigation and urodynamics were performed. The continuous factors: age and urodynamic data were evaluated using Multinomial regression and ANOVA test using SUI, MixUI, UUI as outcome groups. Results — Analysing urodynamic parameters significant difference between at least two groups was shown by the cystometric capacity and maximum flow rate: both highest in the SUI group; residual urine, opening detrusor pressure, maximum urethral closure pressure at rest, functional urethral length at rest: all highest in the UUI group. Mainly all urodynamic data showed significant difference between SUI/UUI, and MixUI/UUI groups, while difference between SUI/MixUI were not significant. Conclusions — Most of urodynamic data for MixUI group patients do not differ from SUI group. UDS parameters like: maximum flow rate, residual urine, opening detrusor pressure, maximum urethral closure pressure at rest, functional urethral length at rest can help to distinguish SUI and MixUI groups from UUI group.

Sensitivity Analysis of PBL Physics Schemes of WRF-ARW Model in Simulating the Tropical Cyclone ‘TITLI’ (2018) Over the Bay of Bengal

Tropical Cyclone (TC) is the most destructive weather phenomenon in the Indian sub-continent. To mitigate the destruction due to TC better prediction is needed. So, the study of sensitivity of different physical schemes in WRF-ARW model with intensification and track of TC is important. In this study, sensitivity of Yonsei University (YSU), Asymmetric Convective Model version 2 (ACM2), Bougeault-Lacarrere (Boulac), Medium-Range Forecast (MRF), Mellor-Yamada Nakanishi and Niino Level 2.5 (MYNN2.5) and Level 3 (MYNN3) Planetary Boundary Layer (PBL) schemes are used to simulate the TC ‘Titli’ which made land fall near Palasa in North Andrha Pradesh and South Odhisha coasts at 0000 UTC of 11th October. National center for environmental prediction Global Final Reanalysis (FNL) data have been used as an initial and lateral boundary conditions. Variation of heat flux, latent heat flux and moisture flux with time for these schemes are shown which are responsible to intensify the TC. Model simulated intensity i.e., minimum central pressure, maximum sustained wind speed at the surface (10 m) and track are compared with the India Meteorological Department (IMD) estimated value. It can be specified that the Boulac, MYNN2.5 and MYNN3 schemes simulate the better intensity and track of TC ‘Titli’.

MRI-active inner regions of protoplanetary discs. I. A detailed model of disc structure

ABSTRACT Short-period super-Earth-sized planets are common. Explaining how they form near their present orbits requires understanding the structure of the inner regions of protoplanetary discs. Previous studies have argued that the hot inner protoplanetary disc is unstable to the magnetorotational instability (MRI) due to thermal ionization of potassium, and that a local gas pressure maximum forms at the outer edge of this MRI-active zone. Here we present a steady-state model for inner discs accreting viscously, primarily due to the MRI. The structure and MRI-viscosity of the inner disc are fully coupled in our model; moreover, we account for many processes omitted in previous such models, including disc heating by both accretion and stellar irradiation, vertical energy transport, realistic dust opacities, dust effects on disc ionization, and non-thermal sources of ionization. For a disc around a solar-mass star with a standard gas accretion rate ($\dot{M}\, \sim \, 10^{-8}$ M⊙ yr−1) and small dust grains, we find that the inner disc is optically thick, and the accretion heat is primarily released near the mid-plane. As a result, both the disc mid-plane temperature and the location of the pressure maximum are only marginally affected by stellar irradiation, and the inner disc is also convectively unstable. As previously suggested, the inner disc is primarily ionized through thermionic and potassium ion emission from dust grains, which, at high temperatures, counteract adsorption of free charges on to grains. Our results show that the location of the pressure maximum is determined by the threshold temperature above which thermionic and ion emission become efficient.

Normal Values and Associated Factors in High-resolution Anorectal Manometry in Healthy Vietnamese Adults

Introduction The present study aims to identify normal high-resolution anorectal manometry (HRAM) values and related factors in healthy Vietnamese adults. Methods The present cross-sectional study was conducted at the Viet Duc hospital, Hanoi, Vietnam, during April and May 2019. Healthy volunteers were recruited to participate in the study. Anorectal measurement values from the digestive tract, including pressure, were recorded. Results A total of 76 healthy volunteers were recruited. The mean functional anal canal length was 4.2 ± 0.5 cm, while the mean anal high-pressure zone length was 3.4 ± 0.5 cm. The mean defecation index was 1.4 ± 0.8, with values ranging from 0.3 to 5.0. The mean threshold volume to elicit the rectoanal inhibitory reflex (RAIR) was 18.1 mL. The mean rectal sensation values were 32.4 mL, 81.6 mL, and 159 mL for first sensation, desire to defecate, and urge to defecate, respectively. Dyssynergic patterns occurred in ∼ 50% of the study participants and included mainly types I (27.6%) and III (14.6%). There were significant differences between male and female patients in terms of maximum anal squeeze pressure, maximum anal cough pressure, maximum anal strain pressure, maximum rectal cough pressure, and maximum rectal strain pressure (all p < 0.01). Conclusions The present study establishes normal HRAM values in healthy Vietnamese adults, particularly regarding normal values of anorectal pressure and rectal sensation. Further studies that include larger sample sizes should be conducted to further confirm the constants and their relationships.

Assessment of structural bearing capacity in case of internal explosion

The work has developed a method for determining the deformation of bent rod structures during an internal explosion. When consideration of a quasi-stationary explosion, a model load is proposed, taking into account the pressure rise section to the maximum value at the beginning of the explosion, then a stationary section and then a decline. The pressure in the stationary area is equal to more of the two peaks. With a sufficiently long stationary section, the maximum deformation is realized here, and is also determined from the energy balance. In the case of a short section of stationary pressure, maximum deformation develops towards the end of the explosion after a pressure drop. The solutions are suitable for describing deformation of beams with different fastening at the ends and are limited to the case when the maximum value of the load does not exceed the resistance of the structure. The results of the work can be used in assessing the load capacity of elements of explosive industries, residential premises, taking into account the action of protective structures.

Numerical Simulation of Localized Bulging in an Inflated Hyperelastic Tube with Fixed Ends

When a hyperelastic tube is inflated, the inflation pressure has a maximum for almost all rubber material models, but has no maximum for commonly used arterial models. It is generally believed that the pressure having a maximum is a necessary condition for localized bulging to occur, and therefore aneurysms cannot be modeled as a mechanical bifurcation phenomenon. However, recent theoretical studies have shown that if the axial stretch is fixed during inflation, localized bulging may still occur even if a pressure maximum does not exist in uniform inflation. In this paper, numerical simulations are conducted to confirm this theoretical prediction. It is also demonstrated that if the axial pre-stretch is not sufficiently large, unloading near the two ends can reduce the axial stress to a value close to zero and Euler-type buckling then occurs.

PARALISIA BULBAR PROGRESSIVA (PBP): relato de caso

Motor neuron disease is a term used in several clinical syndromes, among them Progressive Bulbar Paralysis, a rare degenerative and progressive disease of rapid evolution and loss of early respiratory muscle strength. The characteristics are dysphonia, dysphagia, dysarthria, inability in bronchial hygiene, wheezing breaths and atrophy of the tongue musculature, affecting chewing, the grinding of food is increasingly difficult, affecting chewing, causing a potentially disabling and debilitating disease. This study aimed to describe a clinical case of an individual with a clinical diagnosis of Progressive Bulbar Paralysis in Propaedeutics at the Clinical School of the Faculty of the Alto Paranaíba-MG region. The object of study was a 57-year-old male, who underwent an initial physical therapy evaluation and was collected with maximum physiological pressure: maximum inspiratory pressure, maximum expiratory pressure, Borg CR-10 scale, heart rate (HR), respiratory pressure (RF), systolic blood pressure (SBP), diastolic blood pressure (DBP), peripheral oxygen saturation (SPO2). Then, follow a course of action in accordance with the provisions of the literature on the performance of the disease. The results found in this study are satisfactory, for all eight variables analyzed, with the possibility of highlighting the variable Borg CR-10 as the most satisfactory variable compared.

Geological conditions of generation and distribution of abnormal high formation pressure in Ninotsminda and Manavi fields sedimentary cover (near Tbilisi oil and gas region)

Abnormal high formation pressure (AHFP) zones are widely spread in sedimentary cover of numerous oil and gas regions of the world and our fields are among them. A lot of money and time are spent on elimination of some drilling complications of relevant intervals and that makes well costs more expensive. Therefore, study of forecast abnormal pressure generation and distribution zones is one of the current problems of deep well drilling activities. According to the drilling, geological and geophysical data analyzes and references, the generation of abnormal pressure in the sedimentary cover of the studied territory is mainly caused by: the existence of long submerged sedimentary basin, wide distribution of thick plastic clayey formations enriched with bentonite, primate of submersion velocity against persistence of hardening of faeces, intense folding of formations and frequent network of fault dislocations. Stratigraphically AHFP zone corresponds mainly with Middle Sarmatian-Maikopian-Upper Eocene clayey-sandstone suit distribution intervals. Formation pressure maximum gradient within the region varies from 1.75-1.85 to 2.00-2.20, intervals of distribution AHFP zones - from 600-2200m to 3700-4500m, thicknesses - from 700-2100m to 2500-3000m. Indicators of the given parameters generally increase roughly from South-West to North-East towards the thicknesses of plastic clayey formations, their submersion depth and tectonic tense growth factor. Besides, geological characteristics of some particular areas cause some adjustments: AHFP zone is hypsometrically aroused in the hinge lines of fault anticlines and is sunk in syncline depressions, thickness and formation pressure gradients are less in anticlines than in synclines.