Gas explosion characteristics and spray control mechanism in underground square.

The spray system mechanism during a gas explosion in an underground square pipeline is complex. In this paper, the underground square of Fuxin City is selected as the research object. FLACS numerical simulation software is used to analyze the spatial and temporal distribution characteristics of a gas explosion in an underground square pipeline with an unopened spray system using combustion and combustion rate models. Different spray pressures were compared and analyzed to determine the optimal spray control pressure, and the spray system mechanism was clarified. The results revealed that the gas explosion overpressure is divided into the overpressure gentle, overpressure rising, and overpressure decay stages, corresponding to a trend of rapid growth and slow decline. The influence of spray pressure on the gas explosion exhibits a promotion-inhibition-promotion trend, corresponding to 0-0.2 MPa, 0.2-0.6 MPa, and 0.6-1.6 Mpa, respectively. The peak overpressure and overpressure propagation rates are the lowest at 0.6 MPa, and the explosion suppression effect is the most pronounced. The spray system mechanism varies with the explosion overpressure stages. Generally, the time to peak value, that is, the peak time, the overall duration of the explosion, and the duration of the explosion stage decrease, whereas the peak explosion overpressure decreases.

Encouraging Firework Safety Through Public Service Announcements.

A dramatic increase in firework-related blast injuries to the hand and upper extremity resulted in record-setting numbers at our institution over the July 4, 2018, holiday. This led our hand and upper extremity department to create a public service announcement (PSA) campaign regarding firework safety and injury prevention. This PSA was broadcast in advance of the next July 4 holiday via several media platforms including television, radio, and the internet. The following year only 4 patients required surgery for firework-related blast injuries to the hand and upper extremity over the same 10-day period, including the weekends before and after the July 4, 2019, holiday. This represented a considerable reduction compared with the 14 patients seen within the same time frame in 2018. The purpose of this article was to outline the process and report the impact of creating and disseminating a public service announcement for firework-related blast injury prevention.

Rehabilitación de trauma facial ocasionado por fuegos artificiales utilizando triamcinolona / Aesthetic and functional rehabilitation using triamcinolone on patient suffered by facial firework injury

Introduction: Facial injuries are a common occurrence at the emergency room. Treatment for this type of trauma is complex in terms of re-establishing good oral and facial function, plus aesthetics. Objective: This paper aims to report a clinical case of aesthetic and functional rehabilitation using triamcinolone in a patient affected on the face by a fireworks explosion. Case report: A 26-year-old man was admitted to the oral and maxillofacial surgery service of the Sergipe Urgency Hospital presenting trauma after the explosion of a "Firework rocket" in his face. The patient had extensive soft tissue injury in gingival mucosa, right labial commissure, and tongue. There was also inferior incisive avulsion and dentoalveolar fracture. His clinical and tomographic evaluation presented comminuted mandibular fracture. After eighteen days he was discharged and sent to the dentistry service of the Federal University of Sergipe for aesthetic and functional rehabilitation of his facial damages. Two months later, the patient attended a University dental service to begin aesthetic and postoperative functional rehabilitation. First, the necrotic bone was removed, following intralesional infiltration of hexacetonide triamcinolone 20mg/mL into the scar of the labial region and the commissure of the lips was performed. Each application was performed after twenty days of interval. Later, lingual frenectomy and glossosplasty were done for improving his lingual mobility and then hexacetonide triamcinolone 20mg/mL infiltrations were also done in the tongue base in the following sessions. Conclusions: After five infiltrations, it was observed an improvement in the scar appearance and texture, which also had a lower contracture, as well as a lingual motricity improvement(AU)

Introducción: Las lesiones faciales son frecuentes en el servicio de emergencia. El tratamiento para este tipo de trauma es complejo en términos de restablecer una buena función bucal y facial, además de la estética. Objetivo: Reportar un caso clínico de rehabilitación estética y funcional a través del uso de hexacetónido de triamcinolona en un paciente afectado por una explosión de fuegos artificiales en su rostro. Caso clínico: Hombre de 26 años ingresado en el servicio de cirugía oral y maxilofacial del Hospital de Urgencia de Sergipe por presentar un traumatismo después de la explosión contra su rostro de un cohete de fuegos artificiales. El paciente tenía una lesión extensa de partes blandas en la mucosa gingival, comisura labial derecha y lengua. También hubo avulsión incisiva inferior y fractura dentoalveolar. A través de la evaluación clínica y de tomografía, fue posible observar fragmentación múltiple ósea en el sitio de la fractura, compatible con fractura mandibular conminuta. Después de dieciocho días fue dado de alta y enviado al servicio de odontología de la Universidad Federal de Sergipe para la rehabilitación estética y funcional de sus daños faciales. Dos meses después, el paciente asistió al servicio dental de la universidad para comenzar la rehabilitación funcional estética y posoperatoria. Primero, se retiró el hueso necrótico, luego se realizó la infiltración intralesional de hexacetónido de triamcinolona 20 mg/mL en la cicatriz de la región labial y se realizó la comisura de los labios; con un intervalo de 20 días entre cada aplicación. Posteriormente, se realizaron frenectomía lingual y glososplastia, para mejorar su movilidad lingual, y luego se realizaron infiltraciones de 20 mg/mL de hexacetónido de triamcinolona en la base de la lengua en las sesiones siguientes. Comentarios principales: Después de cinco infiltraciones se observó una mejora en el aspecto y la textura de la cicatriz, que también tenía una contractura más baja, así como una mejora de la motricidad lingual(AU)

A narrative review of hydrogen-oxygen mixture for medical purpose and the inhaler thereof.

Recent development regarding mixture of H2 (concentration of ~66%) with O2 (concentration of ~34%) for medical purpose, such as treatment of coronavirus disease-19 (COVID-19) patients, is introduced. Furthermore, the design principles of a hydrogen inhaler which generates mixture of hydrogen (~66%) with oxygen (~34%) for medical purpose are proposed. With the installation of the liquid blocking module and flame arresters, the air pathway of the hydrogen inhaler is divided by multiple isolation zones to prevent any unexpected explosion propagating from one zone to the other. An integrated filtering/cycling module is utilized to purify the impurity, and cool down the temperature of the electrolytic module to reduce the risk of the explosion. Moreover, a nebulizer is provided to selectively atomize the water into vapor which is then mixed with the filtered hydrogen-oxygen mix gas, such that the static electricity of a substance hardly occurs to reduce the risk of the explosion. Furthermore, hydrogen concentration detector is installed to reduce the risk of hydrogen leakage. Result shows that the hydrogen inhaler implementing the aforesaid design rules could effectively inhibit the explosion, even ignition at the outset of the hydrogen inhaler which outputs hydrogen-oxygen gas (approximately 66% hydrogen: 34% oxygen).

Preventing explosions of hydrogen gas inhalers.

Production and excretion of hydrogen (H2) gas in human was reported in 1969, since then it has been regarded as non-toxic molecule. For preventive and therapeutic medical uses, a possible treatment for cancer was reported and another article was published on how H2 acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. A variety of H2 gas inhalers have been available in the market for hospital and home uses. However, H2 is odorless and flammable or explosive ignited by static electricity. We have examined the safety of a variety of H2 gas concentrations from the viewpoint of flammability and explosion. We have also measured concentrations of H2 gas inhalers in the market respectively. This paper also details how to control H2 gas concentration for preventing explosions.

A systematic review of oil tanker truck disasters: Identifying prevention targets.

INTRODUCTION: Oil tanker truck disasters have been reported worldwide; however, the circumstances, causes, and health effects of these disasters have not been described. To address this gap, we performed a systematic review using PRISMA criteria to better understand this public health problem and identify prevention targets. METHODS: The academic and lay literatures were systematically searched for terms related to oil tanker truck disasters. Reports about civilian oil tanker truck disasters that occurred from 1997-2017 were included. Details about the disasters were summarized, including circumstances, identifiable causes, and health effects. RESULTS: The search yielded 4713 Nexis Uni articles, 199 Google results, and one PubMed article; 951 records met inclusion criteria, describing 224 oil tanker truck explosions or fires. At least 2909 people died as a result of these disasters, and 3038 additional people were hospitalized. Almost all deaths (94%) occurred in low- and low-middle-income countries (LMIC). This may largely be due to scooping - the practice of collecting spilled oil from disabled tanker trucks for use or resale. Using the Haddon matrix, potential targets for future disaster prevention were identified. CONCLUSIONS: These data highlight the circumstances, causes, and health burden related to oil tanker truck disasters. Most began as collisions or rollovers, but nearly half of the fatalities involved scooping. The findings suggest opportunities to promote road safety, improve scene safety and security protocols used by drivers and first responders, and promote public understanding of the dangers of scooping to prevent mass casualty disasters from disabled tanker trucks, particularly in LMIC.

Is There a Threat Towards Medical Institutions, and What to Do?

Unfortunately the reality of today is that a terrorist threat in Europe has become evident. With increasing frequency we are confronted with attacks all across Europe, at least this is the perception. So is there a Threat? If look at the paper of Wolf et al (1), this describes an increase of terrorist attacks from 1999- 2006, the amount of victims due to these attacks increased exponentially. This means the attacks are getting more effective. The perpetrators are getting better and are learning how to injure or kill more victims. The techniques are getting more sophisticated. For example if we look at the Bali Bombing in 2002, here a second hit technique is used. The terrorist placed first a small bomb in a tourist area, knowing that this eventually will attract many people who rush in to help the victims. Then a second hit was done with a much larger bomb killing and wounding even a larger group of people. This is the goal of the terrorist, introducing terror, shocking the world, introduce fear. If we look at the attack in Nice, South France. They used a truck driving through a large tourist crowd, knowing that there would be many children and young people. This is their ultimate goal, shock the world. With that mindset, just imagine how shocking would it be to primary attack a medical institution. Our weakness as medical people is that we want to help people, In fact we gave a Hippocratic oath that we will always help other people, that is our job. We find it hard to believe that medical relief institutions will be attacked. If we look at the London bombing in 2005, one of the terrorists detonated the bomb in a bus. By coincidence this happened right in front of the British Medical Association with many doctors in the building at that time. All of them immediately went to the exploded bus to provide medical relieve, did they even think for a second that there maybe would be a second hit? We are to nice, and the terrorists know this. Historyhas proven to us that medical institutions are a potential goal. 2008 a terror attack in Mumbai, eight series of attacks were done between 26-29th of November. Eventually the terrorist where heading for the CAMA hospital. However because the hospital was alerted and were able to perform a complete lock down they were able to prevent additional casualties in the hospital itself. Are these rare incidents?

The simulation of air recirculation and fire/explosion phenomena within a semiconductor factory.

The semiconductor industry is the collection of capital-intensive firms that employ a variety of hazardous chemicals and engage in the design and fabrication of semiconductor devices. Owing to its processing characteristics, the fully confined structure of the fabrication area (fab) and the vertical airflow ventilation design restrict the applications of traditional consequence analysis techniques that are commonly used in other industries. The adverse situation also limits the advancement of a fire/explosion prevention design for the industry. In this research, a realistic model of a semiconductor factory with a fab, sub-fabrication area, supply air plenum, and return air plenum structures was constructed and the computational fluid dynamics algorithm was employed to simulate the possible fire/explosion range and its severity. The semiconductor factory has fan module units with high efficiency particulate air filters that can keep the airflow uniform within the cleanroom. This condition was modeled by 25 fans, three layers of porous ceiling, and one layer of porous floor. The obtained results predicted very well the real airflow pattern in the semiconductor factory. Different released gases, leak locations, and leak rates were applied to investigate their influence on the hazard range and severity. Common mitigation measures such as a water spray system and a pressure relief panel were also provided to study their potential effectiveness to relieve thermal radiation and overpressure hazards within a fab. The semiconductor industry can use this simulation procedure as a reference on how to implement a consequence analysis for a flammable gas release accident within an air recirculation cleanroom.

Colonic gas explosion during therapeutic colonoscopy with electrocautery.

Therapeutic colonoscopy with electrocautery is widely used around the world. Adequate colonic cleansing is considered a crucial factor for the safety of this procedure. Colonic gas explosion, although rare, is one of the most frightening iatrogenic complications during colonoscopy with electrocautery. This complication is the result of an accumulation of colonic gases to explosive concentrations, but may be prevented by meticulous bowel preparation. The purpose of this review is to discuss the indications and the types of bowel preparations for therapeutic colonoscopy, and to contribute recommendations for the adequate bowel preparation for colonoscopy with electrocautery.

The detection of landmines by neutron backscattering: exploring the limits of the technique.

Neutron backscattering (NB) sensors have been proposed for Humanitarian De-mining applications. Recently, a prototype hand-held system integrating a NB sensor in a metal detector has been developed within the EU-funded DIAMINE Project. The results obtained in terms of performance of the NB systems and limitations in its use are presented in this work. It is found that the performance of NB sensors is strongly limited by the presence of the soil moisture and by its small-scale variations. The use of the neutron hit distribution to reduce false alarms is explored.

Reflecting on theatre explosion danger.

Risk of explosion and fire in operating theatres used to be significant. For this Health Estate Journal 'Then and now' feature, Mike Arrowsmith BSc (Hons) CEng FIMechE FIHEEM, technical editor, provides commentary on an article which was published in December 1945 in the second issue of The Hospital Engineer, a publication then taking the form of a newsletter--of The Institution of Hospital Engineers. The 1945 article was formed from a short paper read at an Institution branch meeting, and a slightly amended version of the article text follows the commentary.

Application of neutron generators for high explosives, toxic agents and fissile material detection.

The portable pulsed neutron generators developed and designed by VNIIA are presented. The neutron methods are good tools for non-destructive assay of dangerous materials. The samples of various systems for the detection of high explosives in luggage, identification of toxic agents in chemical munitions, and also for the prevention of illicit trafficking of fissile elements in passengers' luggage are discussed.

Small threat and contraband detection with TNA-based systems.

The detection of small threats, such as explosives, drugs, and chemical weapons, concealed or encased in surrounding material, is a major concern in areas from security checkpoints to UneXploded Ordnance (UXO) clearance. Techniques such as X-ray and trace detection are often ineffectual in these applications. Thermal neutron analysis (TNA) provides an effective method for detecting concealed threats. This paper shows the effectiveness of Ancore's SPEDS, based on TNA, in detecting concealed liquid threats and differentiating live from inert mortar shells.

DUNBID, the Delft University neutron backscattering imaging detector.

In the search for low-metallic land mines, the neutron backscattering technique may be applied if the soil is sufficiently dry. An advantage of this method is the speed of detection: the scanning speed may be made comparable to that of a metal detector. A two-dimensional position sensitive detector is tested to obtain an image of the back scattered thermal neutron radiation. Results of experiments using a radionuclide neutron source are presented. The on-mine to no-mine signal ratio can be improved by the application of a window on the neutron time-of-flight. Results using a pulsed neutron generator are also presented.

Increasing the capability of MNBRP for the detection of anti-personnel landmines.

Monte Carlo simulations were used to show that even very small explosives (<100g) can be detected by monoenergetic neutron backscattering with resonance penetration (MNBRP) at a depth well beyond 30 cm when time slicing is used for background suppression. At the present state of technology no other nuclear method appears to have a comparable sensitivity or penetration capability. This method has been successfully tested experimentally at a depth of 16.5 cm. A substantial simplification of the detection procedure could be achieved either by taking advantage of the time shadow rather than the geometric shadow or by applying neutron threshold detectors. Using a threshold detector could simplify the application, too.