scholarly journals Physical-and-chemical calculations of safe mode of propane transportation

2021 ◽  
Vol 2094 (5) ◽  
pp. 052056
Author(s):  
A A Katansky ◽  
N G Zhuravleva ◽  
M E Pankratova ◽  
M A Pastushkova ◽  
A A Trotsenko
Keyword(s):  
Ambient Temperature ◽  
Ignition Temperature ◽  
Storage Conditions ◽  
Spontaneous Ignition ◽  
Minimum Ignition Energy ◽  
Emergency Situations ◽  
Starting Point ◽  
Environment Temperature ◽  
Physical And Chemical ◽  
Initial Starting

Abstract The key criteria used to assess fire-and-explosive hazard of any facility are: flash point, self-ignition temperature and minimum ignition energy. This article addresses how fire-and-explosive hazard criteria can be used to forecast emergency situations while transporting great quantities of flammable substance – propane, based upon ambient environment temperature. Calculations that were made have led to a conclusion that fire-and-explosive safety concentration mode for propane handling will be: lower concentration value is equal to 1.27 % or under than that value; upper concentration value is equal to 13.96 % or greater than that value. When selecting safe transportation and storage conditions for self-igniting combustible substances, great attention is given to relationship between environment, mass of substance transported and time-period to spontaneous ignition. For propane, the safe self-ignition temperature is deemed to be less than 360°C. Calculations for theoretical experiment regarding propane transportation were made based upon three critical temperature values: 1) 25 °C+10 °C - initial starting point when ambient temperature is 25 °C (roadway temperature is disregarded because ambient temperature is not high enough); 2) 60 °C+10 °C – point of arrival where ambient temperature is 60 °C; 3) 470 °C – propane self-ignition temperature. This helped us to figure out that propane can be stored and transported safely if the minimal electric ignition source is under 4*10−6 Joule.

scholarly journals Insufficient Stability of Clavulanic Acid in Widely Used Child-Appropriate Formulations

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 225
Author(s):  
Ines Mack ◽  
Mike Sharland ◽  
Janneke M. Brussee ◽  
Sophia Rehm ◽  
Katharina Rentsch ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Clavulanic Acid ◽  
Storage Conditions ◽  
Essential Medicines ◽  
Active Components ◽  
Middle Income ◽  
Ambient Temperatures ◽  
Essential Medicines List ◽  
Dispersible Tablets ◽  
The Stability

Amoxicillin-clavulanic acid (AMC) belongs to the WHO Essential Medicines List for children, but for optimal antimicrobial effectiveness, reconstituted dry powder suspensions need to be stored in a refrigerated environment. Many patients in low- and middle-income countries who are sold AMC suspensions would be expected not to keep to the specified storage conditions. We aimed to assess the stability of both ingredients in liquid formulations and dispersible tablets, combined with nationally representative data on access to appropriate storage. Degradation of amoxicillin (AMX) and clavulanic-acid (CLA) was measured in suspensions and dispersible tablets commercially available in Switzerland at different ambient temperatures (8 °C vs. 28 °C over 7 days, and 23 °C vs. 28 °C over 24 h, respectively). Data on access to refrigeration and electricity were assessed from the USAID-funded Demographic and Health Survey program. In suspensions, CLA degraded to a maximum of 12.9% (95% CI −55.7%, +29.9%) at 8°C and 72.3% (95% CI −82.8%, −61.8%) at a 28 °C ambient temperature during an observation period of 7 days. Dispersible tablets were observed during 24 h and CLA degraded to 15.4% (95% CI −51.9%, +21.2%) at 23 °C and 21.7% (−28.2%, −15.1%) at a 28 °C ambient temperature. There is relevant degradation of CLA in suspensions during a 7-day course. To overcome the stability challenges for all active components, durable child-appropriate formulations are needed. Until then, prescribers of AMC suspensions or pharmacists who sell the drug need to create awareness for the importance of proper storage conditions regarding effectiveness of both antibiotics and this recommendation should be reflected in the WHO Essential Medicines List for children.

scholarly journals Physiological quality of Gliricidia sepium (Jacq.) Steud. (Leguminosae - Papilionoideae) seeds subjected to different storage conditions

2012 ◽  
Vol 36 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Renata Conduru Ribeiro Reis ◽  
Claudinéia Regina Pelacani ◽  
Cimille Gabrielle Cardoso Antunes ◽  
Bárbara França Dantas ◽  
Renato Delmondez de Castro
Keyword(s):  
Water Content ◽  
Seed Viability ◽  
Gliricidia Sepium ◽  
Storage Conditions ◽  
Physiological Processes ◽  
Plastic Bags ◽  
Starting Point ◽  
Cultivated Plant ◽  
Physiological Quality

Studies of seed physiological processes represent the starting point for the sustainable utilization of native or cultivated plant species from the caatinga biome for which germination studies are still scarce. In order to determine adequate methods for the conservation of Gliricidia sepium seeds, the physiological quality of propagules exposed to different conditions and times of storage were examined. Recently collected seeds of G. sepium were analyzed immediately, while the other sample was stored for three, six, nine, or twelve months in plastic or paper bags under refrigeration or at room temperature for further analysis. The germination rates of seeds from each storage regime were determined and these rates compared to their water content. It was observed that germination capacity was directly related to changes in seed humidity. Storing seeds in plastic bags yielded the best conservation, mainly when they were stored at low temperatures. However, even at temperatures near 25°C it was possible to prolong seed viability when their water content was controlled through the use of impermeable packing.

scholarly journals Scorpion Venom Antimicrobial Peptides Induce Siderophore Biosynthesis and Oxidative Stress Responses in Escherichia coli

mSphere ◽  
2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohamed M. Tawfik ◽  
Magnus Bertelsen ◽  
Mohamed A. Abdel-Rahman ◽  
Peter N. Strong ◽  
Keith Miller
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Venom Gland ◽  
Cation Transport ◽  
Content Type ◽  
Starting Point ◽  
Wide Range ◽  
Initial Starting ◽  
Increased Susceptibility

ABSTRACT The increasing development of microbial resistance to classical antimicrobial agents has led to the search for novel antimicrobials. Antimicrobial peptides (AMPs) derived from scorpion and snake venoms offer an attractive source for the development of novel therapeutics. Smp24 (24 amino acids [aa]) and Smp43 (43 aa) are broad-spectrum AMPs that have been identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus and subsequently characterized. Using a DNA microarray approach, we examined the transcriptomic responses of Escherichia coli to subinhibitory concentrations of Smp24 and Smp43 peptides following 5 h of incubation. Seventy-two genes were downregulated by Smp24, and 79 genes were downregulated by Smp43. Of these genes, 14 genes were downregulated in common and were associated with bacterial respiration. Fifty-two genes were specifically upregulated by Smp24. These genes were predominantly related to cation transport, particularly iron transport. Three diverse genes were independently upregulated by Smp43. Strains with knockouts of differentially regulated genes were screened to assess the effect on susceptibility to Smp peptides. Ten mutants in the knockout library had increased levels of resistance to Smp24. These genes were predominantly associated with cation transport and binding. Two mutants increased resistance to Smp43. There was no cross-resistance in mutants resistant to Smp24 or Smp43. Five mutants showed increased susceptibility to Smp24, and seven mutants showed increased susceptibility to Smp43. Of these mutants, formate dehydrogenase knockout (fdnG) resulted in increased susceptibility to both peptides. While the electrostatic association between pore-forming AMPs and bacterial membranes followed by integration of the peptide into the membrane is the initial starting point, it is clear that there are numerous subsequent additional intracellular mechanisms that contribute to their overall antimicrobial effect. IMPORTANCE The development of life-threatening resistance of pathogenic bacteria to the antibiotics typically in use in hospitals and the community today has led to an urgent need to discover novel antimicrobial agents with different mechanisms of action. As an ancient host defense mechanism of the innate immune system, antimicrobial peptides (AMPs) are attractive candidates to fill that role. Scorpion venoms have proven to be a rich source of AMPs. Smp24 and Smp43 are new AMPs that have been identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus, and these peptides can kill a wide range of bacterial pathogens. By better understanding how these AMPs affect bacterial cells, we can modify their structure to make better drugs in the future.

Location Information Services of Automated External Defibrillators (AEDs)

2021 ◽  
pp. 102-118
Author(s):  
Reima Suomi ◽  
Eila Lindfors ◽  
Brita Marianne Somerkoski
Keyword(s):  
Effective Means ◽  
Location Services ◽  
Automated External Defibrillators ◽  
Emergency Situations ◽  
Hospital Environments ◽  
Starting Point ◽  
Heart Operation ◽  
The World ◽  
Information And Communication ◽  
Normal Human

Cardiovascular diseases are a leading death cause in the world. Cardiac arrest is one of the most usual, and very quickly fatal, especially in out-of-hospital environments. Defibrillation, aside with cardiopulmonary resuscitation, is an effective means to restart blood circulation and heart operation, even though even these forms of treatment can help just in sadly few situations. Defibrillation was invented and first demonstrated already year 1899, but first in the 2000s portable defibrillators with good automatic functions started to penetrate daily environments of people, especially in urban settings. Nowadays the starting point is that every citizen with normal human functionality should be able to use automated defibrillators. The chapter discusses how modern information and communication technology, especially mobiles services, internet, and location services based on them, could help citizens in the first crucial step in implementing their safety competence in emergency situations by using automatic defibrillators if they could only find them.

scholarly journals Variation of ignition sensitivity characteristics of non-stick coal dust explosions

2020 ◽  
Author(s):  
Di Sha ◽  
Yucheng Li ◽  
Xihua Zhou ◽  
Ruiqing Li
Keyword(s):  
Ignition Temperature ◽  
Coal Dust ◽  
Dust Cloud ◽  
Particle Sizes ◽  
Ignition Energy ◽  
Minimum Ignition Energy ◽  
Dust Layer ◽  
Independent Variables ◽  
Minimum Ignition Temperature ◽  
Dust Explosions

Abstract The ignition and explosion of coal dust are significant hazards in coal mines. In this study, the minimum ignition temperature and energy of non-stick coal dust were investigated empirically at different working conditions to identify the key factors that influence the sensitivity and characteristics of coal dust explosions. The results showed that for a given particle size, the minimum ignition temperature of the coal dust layer was inversely related to the thickness of the coal dust layer. Meanwhile, when the layer thickness was kept constant, the minimum ignition temperature of the coal dust layer decreased with smaller coal dust particle sizes. Over the range of particle sizes tested (25–75 μm), the minimum ignition temperature of the coal dust cloud gradually increased when larger particles was used. At the same particle size, the minimum ignition temperature of the coal dust layer was much lower than that of the coal dust cloud. Furthermore, the curves of minimum ignition energy all exhibited a minimum value in response to changes to single independent variables of mass concentration, ignition delay time and powder injection pressure. The interactions of these three independent variables were also examined, and the experimental results were fitted to establish a mathematical model of the minimum ignition energy of coal dust. Empirical verification demonstrated the accuracy and practicability of the model. The results of this research can provide an experimental and theoretical basis for preventing dust explosions in coal mines to enhance the safety of production.

scholarly journals Semi-automated construction of patient individualised clinical target volumes for radiotherapy treatment of glioblastoma utilising diffusion tensor decomposition maps

2020 ◽  
Vol 93 (1108) ◽  
pp. 20190441 ◽  
Author(s):  
Roushanak Rahmat ◽  
Frederic Brochu ◽  
Chao Li ◽  
Rohitashwa Sinha ◽  
Stephen John Price ◽  
...  
Keyword(s):  
Level Set ◽  
Radiation Treatment ◽  
Diffusion Tensor ◽  
Tensor Decomposition ◽  
Data Set ◽  
Tumour Spread ◽  
Starting Point ◽  
Target Volumes ◽  
Initial Starting ◽  
Level Set Model

Objectives: Glioblastoma multiforme (GBM) is a highly infiltrative primary brain tumour with an aggressive clinical course. Diffusion tensor imaging (DT-MRI or DTI) is a recently developed technique capable of visualising subclinical tumour spread into adjacent brain tissue. Tensor decomposition through p and q maps can be used for planning of treatment. Our objective was to develop a tool to automate the segmentation of DTI decomposed p and q maps in GBM patients in order to inform construction of radiotherapy target volumes. Methods: Chan-Vese level set model is applied to segment the p map using the q map as its initial starting point. The reason of choosing this model is because of the robustness of this model on either conventional MRI or only DTI. The method was applied on a data set consisting of 50 patients having their gross tumour volume delineated on their q map and Chan-Vese level set model uses these superimposed masks to incorporate the infiltrative edges. Results: The expansion of tumour boundary from q map to p map is clearly visible in all cases and the Dice coefficient (DC) showed a mean similarity of 74% across all 50 patients between the manually segmented ground truth p map and the level set automatic segmentation. Conclusion: Automated segmentation of the tumour infiltration boundary using DTI and tensor decomposition is possible using Chan-Vese level set methods to expand q map to p map. We have provided initial validation of this technique against manual contours performed by experienced clinicians. Advances in knowledge: This novel automated technique to generate p maps has the potential to individualise radiation treatment volumes and act as a decision support tool for the treating oncologist.

scholarly journals The Core-Mantle Model of Interstellar Grains and the Cosmic Dust Connection

1989 ◽  
Vol 135 ◽  
pp. 345-356
Author(s):  
J. Mayo Greenberg
Keyword(s):  
Chemical Properties ◽  
Morphological Structure ◽  
Infrared Emission ◽  
Dynamical Theory ◽  
Interstellar Space ◽  
The Core ◽  
Starting Point ◽  
Far Ultraviolet ◽  
Trace Constituents ◽  
Physical And Chemical

Historically there have been two different types of grain modelling: One of these basically uses particle populations which evolve essentially by coagulation (e. g., the MRN model: Mathis, Rumpl and Nordsieck, 1977); the other considers the physical and chemical evolution of the particles with a particular emphasis on changes not only in sizes but also in chemical and morphological structure (e. g. Greenberg, 1978; Williams, 1989). The model of Oort and van de Hulst (1946) was the first to consider that grains must evolve in interstellar space by treating both growth and destruction in clouds. The chemical properties had already been derived by van de Hulst (1946) and then later described as the dirty ice model which consisted of the saturated molecules H2O, CH4 and NH3 with trace constituents of other atoms and molecules resulting from surface reactions of atoms on the grains. How such grains could nucleate was left as an unsolved problem but the fact that, once formed, there did not seem to be any reason why they should not grow until they exhausted the condensable atoms in the gas led to the suggestion that a limiting destructive mechanism must be provided. This was assumed to be by grain-grain collisions within clouds moving at relative speeds of 10 km s−1. We thus had the first dynamical theory leading to a steady state distribution of grain sizes. This model provided for me the starting point of the core-mantle model of grains. The observations of the 60's and henceforth clearly showed the existence of other types of small particles, which have been invoked to explain the 2200 å hump (Stecher and Donn, 1965), the far ultraviolet (FUV) extinction (Greenberg and Chlewicki, 1983), and now certain infrared emission features. These other components notwithstanding, grains still account for the major fraction of the solid particle mass in space.

Ocean ecosystem discrete time dynamics generated by ℓ-Volterra operators

2019 ◽  
Vol 12 (02) ◽  
pp. 1950015 ◽  
Author(s):  
U. A. Rozikov ◽  
S. K. Shoyimardonov
Keyword(s):  
Dynamical System ◽  
Fixed Points ◽  
Discrete Time ◽  
Volterra Operator ◽  
Saddle Points ◽  
Time Dynamics ◽  
Discrete Time Dynamical System ◽  
Starting Point ◽  
Ocean Ecosystem ◽  
Initial Starting

We consider a discrete-time dynamical system generated by a nonlinear operator (with four real parameters [Formula: see text]) of ocean ecosystem. We find conditions on the parameters under which the operator is reduced to a [Formula: see text]-Volterra quadratic stochastic operator mapping two-dimensional simplex to itself. We show that if [Formula: see text], then (under some conditions on [Formula: see text]) this [Formula: see text]-Volterra operator may have up to three or a countable set of fixed points; if [Formula: see text], then the operator has up to three fixed points. Depending on the parameters, the fixed points may be attracting, repelling or saddle points. The limit behaviors of trajectories of the dynamical system are studied. It is shown that independently on values of parameters and on initial (starting) point, all trajectories converge. Thus, the operator (dynamical system) is regular. We give some biological interpretations of our results.

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