Changes In Ambient Pressure Research Articles

Decompression Sickness Indicators in Traditional Divers in Bajo, Boalemo District

Decompression is a health problem due to changes in ambient pressure in the body due to the accumulation of nitrogen which forms bubbles in the body when the dive takes place. The bubbles are not released which leads to the clogging in the blood flow and the nervous system of the diver. This study aims to determine the indicators of decompressionoccurence in traditional divers in BajoVillage, Boalemo District. This was a cross sectional study with a population of 69 people (exhaustive sampling). Data collection is conducted through interviews and physical examinations on divers. The instruments used were questionnaires, history sheets, height and weight measurements. Multivariate data analysiswas carried out using smart PLS applications. The results of this study indicate that of 69 respondents, 41 people (59.4%) of them experienced symptoms of decompression sickness, both at mild and severe level. From the results of multivariate data analysis, it is obtained the results of variables that have a significant relationship (> 1.96) with the incidence of decompression problems, namely the duration of diving (2.453), rising to the surface attitude (3.703) and depth (3.516). It is concluded that the length of diving, the way the diver rise to the surface and depth of divingwere some of indicators of the incidence of decompression in traditional divers in Bajo Village, Boalemo District. It is suggested that divers carry out dives in accordance with safe procedures.

Fiber laser spot welding of molybdenum alloy in a hyperbaric environment.

The effect of the growth of ambient pressures on the penetration of laser welded molybdenum (Mo) alloy was explored. It was found that when ambient pressure rose from 0.1 MPa to 1.8 MPa, the penetration of base metal (BM) was significantly reduced, which was only 17% of that obtained under ambient pressure of 0.1 MPa. Moreover, the mechanism underlying the significant reduction of the penetration of BM was analyzed. At first, by using a high-resolution scanning electron microscope (SEM), the size and the number of nano-sized metallic particles generated during laser welding under different ambient pressures were surveyed. Furthermore, the scattering and absorption of the nano-sized metallic particles for laser energy under different ambient pressures were investigated; afterwards, by applying a high-speed camera and a spectrometer, the transient behaviors and spectral signals of plasmas during fiber laser spot welding under different ambient pressures were monitored. On this basis, the inverse bremsstrahlung absorption of plasmas for laser energy under different ambient pressures was explored; finally, fiber laser spot welding test was carried out on glass/metal composite samples under different ambient pressures to survey the influence of the change of ambient pressure on dynamic behaviors of the molten pool during the welding.

Reaction of inducible hsp70 form on different environmental conditions in Ommatogammarus flavus

The aim of the research was to estimate heat shock protein expression under the change in ambient temperature and hydrostatic pressure in Baikal deep-water amphipods Ommatogammarus flavus. The expression of the constitutive hsp70 transcript did not change in response to the influence of both environmental factors. The inducible hsp70 form did not differ after the change in hydrostatic pressure in amphipods captured from the depth of 50 and 750 m. High expression of inducible hsp70 transcript was shown during gradual increase in ambient temperature when it reached 22C. The detected increase in hsp70 expression is associated with the cells reaction to protein damage at the high temperature. Thus, the studied hsp70 inducible form is involved in the adaptation to change in ambient temperature in O. flavus despite the fact that this species inhabits the deep-water zone with stable temperature conditions. It is necessary to analyze other isoforms of hsp in the further studies to find those that participate in the adaptation to high hydrostatic pressure.

Semiconductor Sensor for Hydrogen Sulfide on the Basis of Tungsten and Copper Oxides

Hydrogen sulfide is one of the main toxic and explosive components of atmospheric air, found in the waters of mineral springs, volcanic gases, and petroleum and natural gas fields. It is used in the production of sulfur, sulfuric acid, mineral fertilizers, sulfides, organosulfur compounds, in analytical chemistry and medicine. Н2S is an active poisonous substance of neuroparalytic action. Upon inhalation of 1.0 mg/l and higher hydrogen sulfide, poisoning with it can develop almost instantly: convulsions and loss of consciousness end in quick death from respiratory and cardiac attack. The maximum permissible concentration of hydrogen sulfide in the air of production zones is 10 mg/m3. The presence of hydrogen sulfide in environmental objects is a serious danger, both from an environmental and technical point of view. Its presence causes chemical and electrochemical corrosion, is easily ignited (at 346°C), and in a mixture with air explodes. Explosive concentrations in the mixture with air are at the level of 4.3-45.5%. With regards above mentioned the control of pre-explosion and fire-hazardous concentrations of hydrogen sulfide is one of the most important tasks of safety and solving various fire-fighting measures. A method for increasing the selectivity and sensitivity of semiconductor methods for determining hydrogen sulfide is proposed, based on the use of optimal values of the sensor temperature and the composition of the gas-sensitive material of catalysts with inadequate activity to different components of the gas mixture. As a result of the conducted experiments, a selective semiconductor hydrogen sulfide sensor was developed, which provides rapid determination of hydrogen sulfide in a wide range of its concentration in atmospheric air and process gases. The main metrological characteristics and operational parameters of the developed selective semiconductor sensors for the determination of hydrogen sulfide are evaluated. Selectivity, measurement range and basic errors, additional sensor errors due to changes in ambient temperature and pressure are studied. The change in the flow rate of the gas mixture in the studied interval (5-50 l/h) does not significantly affect the value of the sensor output signal. Scope of the developed sensors: environmental monitoring of atmospheric air and process gases. The developed semiconductor hydrogen sulfide sensors are not inferior in accuracy and reproducibility to well-known foreign analogues, while retaining the following characteristics: expressiveness, portability, ease of manufacture and operation. The value of the relative standard deviation (Sr) due to immutable components does not exceed 0.05. The output signal of the sensors also does not depend on the location in space and the angles of inclination, which makes it possible to classify the developed sensors (according to GOST-13320-82) as independent.

A Tunable Electrostatic MEMS Pressure Switch

In this article, we demonstrate a tunable air pressure switch. The switch detects when the ambient pressure drops below a threshold value and automatically triggers without the need for any computational overhead to read the pressure or trigger the switch. The switch exploits the significant fluid interaction of a microelectro-mechanical systems beam undergoing a large oscillation from electrostatic levitation to detect changes in ambient pressure. If the oscillation amplitude near the resonant frequency is above a threshold level, dynamic pull-in is triggered and the switch is closed. The pressure at which the switch closes can be tuned by adjusting the voltage applied to the switch. The use of electrostatic levitation allows the device to be released from their pulled-in position and reused many times without mechanical failure. A theoretical model is derived and validated with experimental data. It is experimentally demonstrated that the pressure switching mechanism is feasible.

Compensation of phase drifts caused by ambient humidity, temperature and pressure changes for continuously operating interferometers

Fusion experiments rely heavily on the measurement of the line-integrated electron density by interferometry for density feed-back control. In recent years the discharge length has increased dramatically and is continuing to rise, resulting in environmentally induced phase drifts to become an increasingly worrisome subject, since they falsify the interferometer's measurement of the density. Especially in larger Tokamaks the loss of density control due to uncontrolled changes in the optical path length can have a disastrous outcome. The control of environmental parameters in large diagnostic/experimental halls is costly and sometimes infeasible and in some cases cannot be retro-fitted to an existing machine. In this report we present a very cheap (ca. €100), easily retro-fitted, real-time capable phase compensation scheme for interferometers measuring dispersive media over long time scales. The method is not limited to fusion, but can be applied to any continuously measuring interferometer measuring a dispersive medium. It has been successfully applied to the Wendelstein 7-X density feed-back interferometer.

Horses for courses (or something much smaller!): The design, development and acoustic testing of sub-micron cavitation nucleation agents for biomedical applications

Lipid and protein-shelled microbubbles have been the mainstay of cavitation nucleation strategies for therapeutic applications for several decades. However, a growing number of therapeutic ultrasound applications require nuclei that (i) are significantly smaller in size, in order to overcome a particular biological barrier such as the leaky vasculature of tumours or the stratum corneum; (ii) offer greatly increased cavitation persistence, both during a single extended ultrasound pulse and in terms of extended circulation following intravenous administration; and (iii) have better resilience to sudden ambient pressure changes in order to enable direct injection without nuclei destruction into tissue targets via a needle and syringe. We will review a range of novel cavitation agents currently under development, including sub-micron gas-stabilizing solid particles and nanodroplets, and provide an overview of their known characteristics in terms of acoustic emissions, activation and cavitation thresholds, cavitation persistence, and circulation. Where possible, the relevant performance of these cavitation nucleation agents will be compared to microbubbles for applications ranging from drug delivery to nucleated tissue fractionation.

IN-FLIGHT BARODONTALGIA AMONG COMMERCIAL AND MILITARY PILOTS OF PAKISTANI ORIGIN

Background: Barodontalgia is defined as oral pain occurring due to changes in ambient pressure. It can be severe enough to cause inflight incapacitation and has a tendency to go undiagnosed in regular sickbays. There is a large variation in incidence of Barodontalgia in the literature and major fraction of epidemiological data on Barodontalgia has been compiled from military flight simulations. The aim of this study was to document the frequency of in-flight Barodontalgia in Pakistani military and civilian aircrew. Methods: A cross-sectional study was conducted on (non- patient) civilian as well as military pilots. Subjects were given standardized and anonymous questionnaires to complete regarding demographic and professional characteristics, occurrence of oral pain during flying, character of pain, treatment seeking and recurrence of the pain. Results: Out of the 100 subjects, 51 responded (response rate of 51%), with mean age 30.31 ± 5.634 Years; 17.6% (09) of these participants (All Civilian) reported at least one event of barodontalgia during their career. A total of 88 %( 8/9) of pilots visited their dentists after they had oral pain. The diagnosis rendered by their dental surgeons was always dental pain. None of the patients reported recurrence of the disease or premature mission termination due to dental pain. None of the military Pilots reported a n y e v e n t o f Barodontalgia. Conclusion: Barodontalgia was reported exclusively by commercial pilots, which was of a minor non-recurrent nature and did not disrupt their health or flight routines.

Design and Characterization of Capacitively Sensed Squeeze-Film Pressure Sensors

Compressed thin-film gas between the plates produces the squeeze-film damping force that comprises both dissipative and elastic effects. The latter is used in this paper as the mechanism to modify the structural resonance with respect to the change of ambient pressure. Capacitively sensed squeeze-film pressure sensors are implemented in a silicon-based fabrication platform. Nine designs with resonant plate sizes from $200\times 200$ to $800\times 800\,\,\mu \text{m}^{\mathbf {2}}$ , and different natural frequencies for the same size are comprehensively studied. Measured sensitivities range from 94 to 762 Hz/kPa. Both simulations and measurements show the design tradeoff between sensitivity and quality factor. Required critical dimensions such as gap spacing and structural thickness to increase the squeeze-film elastic effect are also analyzed.

Extension of Meyer-Neldel rule using chemical diffusion experiments in CdTe

The chemical diffusion coefficient D˜ in chlorine-doped CdTe with Cl concentration [Cl]≈4.3×1016cm−3 was determined by means of the high-temperature in-situ measurement of the relaxation of electrical conductivity after step-like changes of ambient Cd pressure for temperatures 600 °C, 700 °C and 800 °C. Weak dependence of D˜ on the ambient Cd pressure was found. Both D˜ and equilibrium conductivity for different Cl doping were calculated based on the defect model in which monovalent chlorine donors (ClTe) are compensated by divalent acceptors Cd vacancies (VCd) and monovalent acceptor-like complexes (ClTeVCd). It was shown that experimental D˜ can fit well for [Cl]=4×1016cm−3 assuming different diffusion coefficients for singly and doubly charged VCd. The temperature dependence of D˜ in the temperature interval 600–800 °C near Cd saturation was properly approximated by D˜(cm2s−1)=68exp(−1.38eV/kBT). Linear dependence of the pre-exponential term D0 on activation energy EA known as a Meyer-Neldel rule (MNR) was discussed in detail and its limited validity was proven based on experimental data and numerical simulations. It was shown that the standard MNR may be conveniently extended to a ”triangle Meyer-Neldel rule”, which conforms with theory and relevant experiment.

Influence of ambient air pressure changes on vestibular symptoms after stapes surgery

ObjectiveTo examine if vestibular irritation after stapes surgery may be provoked by pressure changes across the tympanic membrane, which consecutively results in displacements of the ossicular chain and the piston prosthesis suspended to it. MethodsIn this prospective study 15 patients (13 female, 2 male) received unilateral stapes surgery (4 left, 11 right ear) with stapedotomy (n=14) or stapedectomy (n=1) at an academic tertiary referral center. Surgery was performed under local anesthesia via a transmeatal approach with a piston prosthesis 0.4×4.5mm. The fixation of the stapes, the exclusion of a malleus head fixation, and the gliding capacity of the malleus-incus joint were examined intraoperatively. A pure tone audiogram at four frequencies, a tympanometry with simultaneous video-oculography (VOG), caloric testing, and posturography with and without simultaneous tympanometry were performed six days before surgery, six weeks and three months after surgery, respectively. ResultsThe mean air bone gap improved significantly from 25 (±8) dB preoperatively to 10 (±6) dB after surgery. In the tympanometry with simultaneous VOG only two patients showed nystagmus beats into the operated ears during only one of the two follow-up appointments. All other patients did not show any vestibular symptoms or nystagmus during any of the follow-up appointments. In the combined testing of posturography and tympanometry no patient showed any pathological findings. ConclusionIn patients who underwent stapes surgery with a piston prosthesis no vestibular symptoms can be provoked by pressure changes in the external auditory canal.

Dental and Temporomandibular Joint Problems among SCUBA Divers in Jeddah, KSA

The recent increase in the popularity of scuba diving has emphasized the role of the dentist in the prevention and treatment of oralbarotrauma. Barotrauma is a physical injury that results from ambient pressure changes during flying, diving or hyperbaric oxygen therapy [1]. Pressure changes can induce otitis-media, sinusitis, headache or can be manifested as pain to the oral region [2]. Dental barotrauma can happen while ascending; upon surfacing after completing the dive, the diver may report that a tooth broke or has shattered [4]. Divers may also suffer from signs of tempromandibular disorder such as pain in tempromandibular joint (TMJ) and ears, TMJ clicking or crepitus, trismus and impaired TMJ mobility, headache and facial pain [5]. Hence, this article aims to Assessment of dental and TMJ problems in a sample of SCUBA divers in Jeddah Saudi Arabia,Assessment of dental complaints of divers, Assessment of TMJ problems associated with SCUBA diving and relate the previous problems to diving related characteristics such as the duration of practice, the number of dives and the frequency of diving per month. Material and methods: Divers at four dive centers at the Northern coast of Jeddah (Obhur) asked to complete a questionnaire that requested information regarding diving experience and facial pain and dental symptoms experienced during diving. Cross sectional study assessing the prevalence of dental and TMJ problems among divers. The total number was 60 SCUBA divers. Results: most of divers did not complain of sinusitis (75%). More than have of the sample complained of headache (65%). While facial pain was reported by (46.7%) of the sample. More than half did not experience dental pain (65%) while (35%) had dental pain during diving. More than half of the sample did not experience TMJ pain 70% while (30%) reported having TMJ pain during diving. Conclusions: Scuba diving is one of the fastest growing sports in the world. Since Jeddah is the main port of Saudi Arabia, diving has become an occupation as well a popular sport for many people. This attracted our attention to the importance of evaluating the oral problems related to this activity. It is inevitable that the general dental practitioner will have patients who participate in this sport and they should be aware of a number of problems that a diver can experience that are associated with the teeth and related structures. The dental team must educate the diver patient of the infectious potential of the mouthpiece and recommend using only a private one, and encourage maintenance by hygiene procedures after each use, similar to other removable oral devices. The diver should not dive in times of illness. Diving related TMD symptoms should be differentiated from barotitis symptoms.

Constraining the origin of the Mesozoic Xishimen Fe deposit in the Taihang Mountain Range, North China using geochemistry of magnetite

The Xishimen (XSM) iron (Fe) deposit located in the Taihang Mountain Range in North China is one of the largest known Mesozoic skarn Fe deposits in China. Recent research suggests that the Fe deposit exhibits some magmatic features. Here, we report new major and trace element, mineral assemblage and Fe isotope data of magnetite from the XSM Fe deposit in the Han-Xing Fe metallogenic belt, which allows for the identification of four distinct types of magnetite (Type I, II, III and IV). Magnetite type I is characterized by anhedral shape with vesicles in the ores, and consists of minerals diopside (Di), tremolite (Tr), ±garnet (Gt) and/or augite (Aug), spreading over diopside, tremolite, phlogopite and/or Aug as an interstitial mineral, which can dissolve or melt pre-existing minerals (such as Di and Tr). Magnetite type I also contains high content of TiO2 (0.25–1.21 wt.%) and Al2O3 + MnO (0.24–0.72 wt.%). These features suggest that magnetite type I is of magmatic origin. Magnetite type IV is marked by euhedral shape, consists of Cc, Ap and/or Py, enriched in SiO2, CaO, Sr, Ba, Rb, Nb, and total REE, and depleted in TiO2. These properties suggest that magnetite type IV is of hydrothermal origin. The features of magnetite types II and III fall in between magnetite I and magnetite IV. The δ56Fe value also differs for the four types of magnetite: δ56Fe is the highest for type I magnetite (average 0.085‰); and the lowest for magnetite type IV (average 0.016‰). We also find that δ56Fe value tends to be higher under high temperature environment and in lower part of the main orebody. Statistical analysis shows that δ56Fe and altitudes are negatively correlated.In order to constrain the origin of the XSM Fe deposit, we present a new conceptual model based on our new geochemistry data. This model suggests a stepwise pattern of Fe ore genesis, including (1) “melt-fluid bearing Fe” forms in the deep magma chamber; (2) “melt-fluid bearing Fe” rises along the magmatic conduit due to fluid overpressure in the deep magma chamber; (3) changes in ambient temperature, pressure, and oxygen fugacity cause the different composition of magnetite along the magmatic conduit; and (4) Fe isotope fractionation occurs during the rising and settlement of “melt-fluid bearing Fe” in response to changes in temperature and oxygen fugacity. This model explains the magmatic characteristics of magnetite formed under high temperature in the lower part of the conduit, and the hydrothermal characteristics of magnetite occurred under low temperature in the upper part of the conduit.

Outcome Measures for Baro-Challenge-Induced Eustachian Tube Dysfunction: A Systematic Review.

Baro-challenge-induced Eustachian tube dysfunction (baro-induced ETD) is characterized by failure of the Eustachian tube (ET) to open adequately to permit middle-ear pressure regulation during ambient pressure changes. There are no well-characterized tests for identifying the condition, which makes both patient diagnosis and research into treatment efficacy challenging. This systematic review evaluates ET function tests as potential outcome measures for baro-induced ETD. MEDLINE and CENTRAL were searched (database inception to March 2017) and reference lists reviewed for all relevant English Language articles. Tests in included studies were required to measure ET function in patients reporting baro-induced ear symptoms or barotrauma. Data were extracted in a standardized manner, and studies assessed according to Standards for Reporting of Diagnostic Accuracy Studies (STARD) criteria. The primary outcome of interest was the accuracy of ET function tests. Heterogeneity of subject demographics, ET function test methodology, and reference standards only permitted narrative systematic review. Sixteen studies involving seven different types of ET function tests were identified. The nine-step test was the most commonly used outcome measure, with overall test sensitivity and specificity ranges of 37 to 100% and 57 to 100%, respectively. Tympanometry test sensitivity was consistently poor (0-50%) while specificity was higher (52-97%). Published accuracy data for other ET function tests and test combinations were limited. Currently, no single test can be recommended for use in clinical practice. A combination of the nine-step test with other objective tests or patient-reported measures appears most promising as a core set of outcome measures for baro-induced ETD.

On Study of AFFF Performance Parameter in Altitude Low Pressure Environment

Abstract In view of special low pressure environment in high-altitude plateau, the paper carries out simulation and field experiment of AFFF in high-altitude low pressure environment. The results show that: when ambient pressure changes from 101kPa to 24kPa, with the reduction of ambient pressure, the foam expansion of AFFF decreases, and drainage time of AFFF decreases first and increases later; the 59kPa is the extreme point of whole change process and the drainage time of AFFF fire extinguishing agent reaches a minimum under this ambient pressure. During the stage from 101kPa to 59kPa, the drainage time of AFFF decreases with the reduction of ambient pressure. It shows through field test that in the stage from 101 kPa to 59kPa, the performance parameters of AFFF foam are consistent with those in simulation experiment.

A conservative, thermodynamically consistent numerical approach for low Mach number combustion. Part I: Single-level integration

We present a numerical approach for low Mach number combustion that conserves both mass and energy while remaining on the equation of state to a desired tolerance. We present both unconfined and confined cases, where in the latter the ambient pressure changes over time. Our overall scheme is a projection method for the velocity coupled to a multi-implicit spectral deferred corrections (SDC) approach to integrate the mass and energy equations. The iterative nature of SDC methods allows us to incorporate a series of pressure discrepancy corrections naturally that lead to additional mass and energy influx/outflux in each finite volume cell in order to satisfy the equation of state. The method is second order, and satisfies the equation of state to a desired tolerance with increasing iterations. Motivated by experimental results, we test our algorithm on hydrogen flames with detailed kinetics. We examine the morphology of thermodiffusively unstable cylindrical premixed flames in high-pressure environments for confined and unconfined cases. We also demonstrate that our algorithm maintains the equation of state for premixed methane flames and non-premixed dimethyl ether jet flames.

A new type of vacuum sensors with sensitive elements based on multicomponent oxide nanomaterials with fractal structures

A new type of vacuum sensors with sensitive elements based on two- and three-component oxide nanomaterials with fractal structures is proposed. It is shown that a sensory response for two-component oxide systems based on SiO2-SnO2 is determined by their quantitative composition – mass fraction of tin dioxide. An increase in sensitivity to changes in ambient pressure for three-component oxide nanomaterials has been demonstrated.

Infusion Pump in UH60L/M Flight in Afghanistan: Why Failures Occur

The ALARIS MSIII Infusion Pump (CareFusion, San Diego, CA) uses 3 separate alarms designed to prevent air emboli: “check air sensor,” “air in lower tubing,” and “air in line.” It is assumed that ambient pressure changes cause air emboli that lead to pump failure although evidence to support this is limited. In this small study, the MSIII proved to be highly resilient and able to maintain function even after large repetitive emboli. Although unproven, it is more likely that these alarms are usually caused by loosening of the intravenous tubing within the pump’s collar. This disjointing of the tubing and the ultrasonic sensor can be perceived as an air embolus leading to severe consequences. If the user attempts the clear air function, the pump will not resume function. Problems such as this may have been related to at least 1 reported patient death. More research is needed to determine the cause of these alarms and determine the exact cause. Patient safety can potentially be improved at all levels including manufacturer modifications and operator training. It seems reasonable that the manufacturer should design a mode (“transport mode”) that allows the pump to function even with air emboli.

Barosinusitis: Comprehensive review and proposed new classification system.

Background:Barosinusitis, or sinus barotrauma, may arise from changes in ambient pressure that are not compensated by force equalization mechanisms within the paranasal sinuses. Barosinusitis is most commonly seen with barometric changes during flight or diving. Understanding and better classifying the pathophysiology, clinical presentation, and management of barosinusitis are essential to improve patient care.Objectives:To perform a comprehensive review of the available literature regarding sinus barotrauma.Methods:A comprehensive literature search that used the terms “barosinusitis,” “sinus barotrauma,” and “aerosinusitis” was conducted, and all identified titles were reviewed for relevance to the upper airway and paranasal sinuses. All case reports, series, and review articles that were identified from this search were included. Selected cases of sinus barotrauma from our institution were included to illustrate classic signs and symptoms.Results:Fifty-one articles were identified as specifically relevant to, or referencing, barosinusitis and were incorporated into this review. The majority of articles focused on barosinusitis in the context of a single specific etiology rather than independent of etiology. From analysis of all the publications combined with clinical experience, we proposed that barosinusitis seemed to fall within three distinct subtypes: (1) acute, isolated barosinusitis; (2) recurrent acute barosinusitis; and (3) chronic barosinusitis. We introduced this terminology and suggested independent treatment recommendations for each subtype.Conclusion:Barosinusitis is a common but potentially overlooked condition that is primed by shifts in the ambient pressure within the paranasal sinuses. The pathophysiology of barosinusitis has disparate causes, which likely contribute to its misdiagnosis and underdiagnosis. Available literature compelled our proposed modifications to existing classification schemes, which may allow for improved awareness and management strategies for barosinusitis.

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate the ignition delay of n-dodecane and n-heptane in a constant volume combustion chamber (CVCC), which is archived in the engine combustion network (ECN) library (http://www.ca.sandia.gov/ecn). A detailed chemical kinetic model for gasoline surrogates from the Lawrence Livermore National Laboratory (LLNL) was utilized for the simulation of n-heptane and isooctane. Additional simulations were performed using an optimized gasoline surrogate mechanism from RWTH Aachen University. Validations of the simulated data were also performed with experimental results from an IQT at KAUST. For simulation of n-dodecane in the CVCC, two n-dodecane kinetic models from the literature were utilized. The primary aim of this study is to test the ability of TSL to replicate ignition timings in the IQT and the CVCC. The agreement between the model and the experiment is acceptable except for isooctane in the IQT and n-heptane and n-dodecane in the CVCC. The ability of the simulations to replicate observable trends in ignition delay times with regard to changes in ambient temperature and pressure allows the model to provide insights into the reactions contributing towards ignition. Thus, the TSL model was further employed to investigate the physical and chemical processes responsible for controlling the overall ignition under various conditions. The effects of exothermicity, ambient pressure, and ambient oxygen concentration on first stage ignition were also studied. Increasing ambient pressure and oxygen concentration was found to shorten the overall ignition delay time, but does not affect the timing of the first stage ignition. Additionally, the temperature at the end of the first stage ignition was found to increase at higher ambient pressure and oxygen concentration.Sensitivity analysis was performed using the TSL model to elucidate the reactions that control the overall ignition process. The present TSL modeling approach demonstrates the suitability of using detailed chemical kinetic models to provide insights into spray combustion processes.