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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>First Flush of Organics in Highway Runoff</title>
      <link>https://trid.trb.org/View/2200870</link>
      <description><![CDATA[Stormwaters from three highway sites were monitored over two wet seasons for organics. Chemical oxygen demand, oil and grease and polyaromatic hydrocarbons (PAHs) were measured. The sites exhibited a first flush in most cases for most parameters. The mass first flush ratio (the ratio of the normalized transported mass of pollutant to the normalized runoff volume) generally was above 1.8 for the first 25% of the runoff volume, and in some cases as high as 2.8. Dissolved PAHs were generally at or below detection limits. Mass emission rates for particulate PAHs are reported. The results suggest that best management practices (BMPs) that address the initial runoff can have greater effectiveness than other types of BMPs.]]></description>
      <pubDate>Wed, 25 Oct 2023 10:14:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/2200870</guid>
    </item>
    <item>
      <title>Cabin Pressure Altitude Effect on Acceleration Atelectasis After Agile Flight Breathing 60% Oxygen</title>
      <link>https://trid.trb.org/View/2114827</link>
      <description><![CDATA[A flight trial was conducted to determine whether breathing 60% oxygen during high performance flight maneuvers using contemporary pilot flight equipment induces atelectasis and to explore whether cabin altitude had any influence on the extent of atelectasis identified. On 2 separate days, 14 male aircrew flew as passengers at High [14,500–18,000 ft (4420–5486 m)] and Low [4000–6000 ft (1219–1829 m)] cabin pressure altitude in a Hawk T Mk1 aircraft breathing 60% oxygen. Sorties comprised 16 maneuvers at +5 Gz, each sustained for 30 s. Lung volumes (spirometry), basal lung volume (electrical impedance tomography, EIT), and peripheral oxygen saturation during transition from hyperoxia to hypoxia (pulmonary shunt fraction) were measured in the cockpit immediately before (Pre) and after (Post) flight. Forced inspiratory vital capacity (FIVC) was significantly lower Postflight after High (−0.24 L) and Low (−0.38 L) sorties, but recovered to Preflight values by the fourth repeat (FIVC4). EIT-derived measures of FIVC decreased after High (−3.3%) and Low (−4.4%) sorties but did not recover to baseline by FIVC4. FIVC reductions were attributable to decreased inspiratory capacity. Spo2 was lower Postflight than Preflight in High and Low sorties. Breathing 60% oxygen during flight results in a 3.8–4.9% reduction in lung volume associated with a small decrease in blood oxygenation and an estimated pulmonary shunt of up to 5.7%. EIT measures suggest persisting airway closure despite repeated FIVC maneuvers. There was no meaningful influence of cabin pressure altitude. The operational consequence of the observed changes is likely to be small.]]></description>
      <pubDate>Wed, 22 Feb 2023 09:41:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2114827</guid>
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    <item>
      <title>Assessment of influence of anti-icing fluids based on ethylene and propylene glycol on environment and airport infrastructure</title>
      <link>https://trid.trb.org/View/1910650</link>
      <description><![CDATA[Snow, frost, and ice on the surface of aircraft negatively affect the aerodynamic and operational properties of aircraft. Ethylene glycol and propylene glycol are the most commonly used components of anti-icing fluids for aircraft, which have a significant impact on the environment. The paper presents complex analytical review of a large number of domestic and foreign technical and regulatory information, which made it possible to carry out a comprehensive comparison of physical-chemical and operational properties of propylene and ethylene glycol-containing materials, to investigate their influence on components of ecosystems, including the human body. Comparative analysis of studies shows that propylene glycol is inert for living organisms and people. Ethylene glycol negatively affects reproductive function, metabolism, immune system and leads to a decrease in haemoglobin concentration. LD50 value for ethylene glycol is more than 4 times lower than for propylene glycol. Propylene glycol fluid is more environmentally friendly due to low toxicity, increased biological decomposition under the same operating requirements. Basing on the systematised data the general strategy for minimising the negative effects of anti-icing and deicing fluids on the environment is considered and proposed.]]></description>
      <pubDate>Tue, 29 Mar 2022 10:20:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/1910650</guid>
    </item>
    <item>
      <title>Effects of Acceleration-Induced Reductions in Retinal and Cerebral Oxygenation on Human Performance</title>
      <link>https://trid.trb.org/View/1764418</link>
      <description><![CDATA[Ischemic hypoxia induced by suprathreshold G-force loading can adversely affect vision, cognition, and lead to loss of consciousness (LOC). The purpose of this study was to determine whether reductions in cerebral oxygenation, caused by subthreshold G-forces (up to 4 Gz and of limited durations that do not lead to LOC), would affect visual perception and working memory performance. Sixteen subjects performed visual perception and working memory tasks both before and during Gz exposures (1, 2.2, 3, 4 with leg pressurization, 4 with leg and abdomen pressurization) within a human-use centrifuge. As measured using near-infrared spectroscopy, blood oxygenation over medial prefrontal cortex was similar in the 1 and 2.2 Gz conditions, but was reduced to a similar extent in the 3 and 4 Gz conditions. In parallel, visual perception accuracy was reduced in the 3 and 4 Gz conditions, with no difference between the 3 and 4 Gz conditions. No change in reaction time was seen. Conversely, neither accuracy nor reaction time changes were observed for the visual working memory task. These results indicate that although visual working memory is not affected, the ability to visually discriminate between stimuli is reduced at G-forces as low as 3 and 4 Gz. This may have important ramifications for pilots who are routinely subjected to such forces.]]></description>
      <pubDate>Mon, 19 Apr 2021 17:20:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1764418</guid>
    </item>
    <item>
      <title>Chest Compression Duration May Be Improved When Rescuers Breathe Supplemental Oxygen</title>
      <link>https://trid.trb.org/View/1754665</link>
      <description><![CDATA[At sea level, performing chest compressions is a demanding physical exercise. On a commercial flight at cruise altitude, the barometric pressure in the cabin is approximately equal to an altitude of 2438 m. This results in a Po2 equivalent to breathing an FIo2 of 15% at sea level, a condition under which both the duration and quality of cardiopulmonary resuscitation (CPR) may deteriorate. The authors hypothesized that rescuers will be able to perform fewer rounds of high-quality CPR at an FIo2 of 15%. In this crossover simulation trial, 16 healthy volunteers participated in 2 separate sessions and performed up to 14 2-min rounds of chest compressions at an FIo2 of either 0.15 or 0.21 in randomized order. Subjects were stopped if their Spo2 was below 80%, if chest compression rate or depth was not achieved for 2/3 of compressions, or if they felt fatigued or dyspneic. Fewer rounds of chest compressions were successfully completed in the hypoxic than in the normoxic condition, (median [IQR] 4.5 [3,8.5]) vs. 5 [4,14]). The decline in arterial Spo2 while performing chest compressions was greater in the hypoxic condition than in the normoxic condition [mean (SD), 6.19% (4.1) vs. 2% (1.66)]. The findings suggest that the ability of rescuers to perform chest compressions in a commercial airline cabin at cruising altitude may be limited due to hypoxia. One possible solution is supplemental oxygen for rescuers who perform chest compressions for in-flight cardiac arrest.]]></description>
      <pubDate>Mon, 14 Dec 2020 17:40:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1754665</guid>
    </item>
    <item>
      <title>BOD and COD Reduction Using Porous Concrete Pavements</title>
      <link>https://trid.trb.org/View/1715225</link>
      <description><![CDATA[Many places in the world suffer from a shortage in potable water because of the population growth, contamination of water supplies and the problems related with global warming issue. The contamination of drinking water is a considerable problem in the world. In this study, the possibility of using a Pervious Concrete Pavement (PCP) in wastewater clarification was studied. Twenty-four Portland cement mixtures were prepared and tested in order to estimate the effect of coarse aggregate size, water-to-cement ratio and cement content as well as the relationships between compressive strength, porosity, and permeability. Two gravel grades were used (G1 and G2), G1 includes the aggregate size between 4.75 to 9 mm, while the aggregate size between 9-19 mm was represented by G2. Three water cement ratios (W1 = 0.28, W2 = 0.30, W3 = 0.32) and four cement contents (C1 = 275, C2 = 300, C3 = 325 and C4 = 350 kg/m3) were used. The maximum compressive strength obtained in this study was 17.75 Mpa, which resulted from gravel size of G1 and the highest W/C ratio and cement content. The evaluation of water treatment properties of PCP involved pavement samples of 300 × 300 mm with three different thicknesses of 100, 150 and 200 mm that subjected to synthetic wastewater flow with volume of 5 liters. Removal efficiencies of several pollutants such as the chemical oxygen demand (COD), biological oxygen demand (BOD) were inspected. The removal percentage of such pollutants increased with the increment of gravel size and pavement thickness. Maximum removal for COD and BOD were 54% and 68%, respectively, they were obtained using the aggregate size of G2, water cement ratio of W3 and pavement thickness of 20 cm. The modification in pollutants removal percentages can be done depending on the enhancement and refreshment of the bacterial growth by adding the required feed for the bacteria in wastewater in form of mineral salt solution MSM. The resulted removals due to this process also occurred when the large gravel size of G2, water cement ratio of 0.32 and pavement thickness of 20 cm were used, the removal percentages were increased in this case to be 61% and 79% for COD and BOD, respectively.]]></description>
      <pubDate>Thu, 23 Jul 2020 16:10:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1715225</guid>
    </item>
    <item>
      <title>Influence of salinity on the biological treatment of domestic ship sewage using an air-lift multilevel circulation membrane reactor</title>
      <link>https://trid.trb.org/View/1676201</link>
      <description><![CDATA[Recently, strict standards for ship domestic sewage discharge have been implemented by the International Maritime Organization (IMO). The high salinity of ship sewage was considered a key factor influencing the removal efficiency of ship sewage treatment systems. In the present study, the salinity effect on the removal of chemical oxygen demand (COD) and ammonia nitrogen (NH₄⁺-N) from ship domestic sewage was investigated by using a novel air-lift multilevel circulation membrane reactor (AMCMBR). Enzyme activity analysis and wavelet neural network (WNN) models were built to determine the mechanisms of the process. The experimental results indicate that high salinity levels (> 21 g/L) had a negative impact on COD and NH₄⁺-N removal efficiencies, and low saline concentrations (≤ 21 g/L) caused a negligible effect. The COD and NH₄⁺-N removal efficiencies were 84% and 97%, respectively, at a salinity of 21 g/L, which were higher than those at low salinities (i.e., 7 g/L and 14 g/L). Invertase and nitrate reductase had a close relationship with removal performance, and they can be considered important indicators reflecting the operation effort under saline environments. With high predictive accuracies, the constructed WNN models simulated the complex COD and NH₄⁺-N removal processes well under different saline concentrations, ensuring the long-term stable operation of the AMCMBR under different salinities.]]></description>
      <pubDate>Tue, 28 Jan 2020 09:47:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1676201</guid>
    </item>
    <item>
      <title>Nutrient removal from urban stormwater runoff by an up-flow and mixed-flow bioretention system</title>
      <link>https://trid.trb.org/View/1629176</link>
      <description><![CDATA[Bioretention is one of the most popular technical practices for urban runoff pollution control. However, the efficiency of nutrient removal from urban stormwater runoff by bioretention systems varies significantly. To improve the nutrient removal performance, innovative up-flow and mixed-flow bioretention systems were proposed in this study, and a laboratory study was conducted to investigate the runoff retention and nutrient removal performance. During the leaching experiment using tap water as the inflow, turbidity, chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) leaching phenomenon was obvious. COD and TN leaching controls were obviously improved when the up-flow and mixed-flow bioretention systems were adopted comparing with the conventional bioretention. During the semi-synthetic runoff experiments, after the leaching experiments’ performance (accumulated 2.78 times of empty bed volume), there were no significant differences in COD mass removal efficiencies of conventional and up-flow bioretention processes (p > 0.05); however, the COD mass removal efficiencies of the mixed-flow bioretention processes increased by 10% when compared with conventional bioretention. The TN mass removal efficiencies of the up-flow and mixed-flow bioretention increased obviously from 17% ± 13% (conventional) to 41% ± 23% (up-flow) and 31% ± 16% (mixed-flow). However, there were no significant differences in TP mass removal or runoff reduction among the three bioretention columns (p > 0.05). Both up-flow and mixed-flow bioretention can effectively improve TN mass removal, and the mixed-flow bioretention did not show a better TN removal performance than the up-flow bioretention because these two bioretention had almost the same volume of the saturated zone. Overall, the results indicate the mixed-flow bioretention proposed in this study can effectively improve TN mass removal and slightly improve COD mass removal relative to conventional methods via increases in hydraulic retention time and in-flow paths, respectively.]]></description>
      <pubDate>Thu, 01 Aug 2019 09:18:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/1629176</guid>
    </item>
    <item>
      <title>A Systematic Review and Meta-Analysis of Decompression Sickness in Altitude Physiological Training</title>
      <link>https://trid.trb.org/View/1565737</link>
      <description><![CDATA[A review of decompression sickness (DCS) cases associated with the NASA altitude physiological training (APT) program at the Johnson Space Center (JSC) motivated us to place the findings into the larger context of DCS prevalence from other APT centers. The authors reviewed JSC records from 1999 to 2016 and 14 publications from 1968 to 2004 about DCS prevalence in other APT programs. The authors performed a meta-analysis of 15 APT profiles (488 cases / 385,116 exposures). The authors used meta-regression to evaluate the relation between estimated exposures and probability of DCS in a test group, accounting for the heterogeneity between studies. The in-house review identified 6 Type I DCS (1 from an inside observer) and 1 Type II DCS. There were 6 cases in 9560 student hypobaric exposures from 3 NASA training flights; a student pooled prevalence rate of 0.44 cases / 1000 exposures compared to 1.44 cases / 1000 from 12 published APT profiles. The overall pooled DCS prevalence rate was 1.16 cases / 1000 exposures. There was substantial heterogeneity in DCS prevalence across studies. Denitrogenation time, exposure pressure, and exposure time were associated with probability of DCS in the meta-regression model. While the overall DCS prevalence rate is relatively low, there is marked heterogeneity among profiles. The pooled DCS prevalence rate estimate for the NASA profiles was lower than the overall rate. Variability in APT profile DCS prevalence could be further explained given student level and additional test-level covariates.]]></description>
      <pubDate>Tue, 20 Nov 2018 10:20:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1565737</guid>
    </item>
    <item>
      <title>Working Memory Capacity and Surgical Performance while Exposed to Mild Hypoxic Hypoxemia</title>
      <link>https://trid.trb.org/View/1484004</link>
      <description><![CDATA[Medical Emergency Response Team (MERT) helicopters fly at altitudes of 3000 m in Afghanistan (9843 ft). Civilian hospitals and disaster-relief surgical teams may have to operate at such altitudes or even higher. Mild hypoxia has been seen to affect the performance of novel tasks at flight levels as low as 5000 ft. Aeromedical teams frequently work in unpressurized environments; it is important to understand the implications of this mild hypoxia and investigate whether supplementary oxygen systems are required for some or all of the team members.  Ten UK orthopedic surgeons were recruited and in a double blind randomized experimental protocol, were acutely exposed for 45 min to normobaric hypoxia [fraction of inspired oxygen (FIo2) ∼14.1%, equivalent to 3000 m (10,000 ft)] or normobaric normoxia (sea-level). Basic physiological parameters were recorded. Subjects completed validated tests of verbal working memory capacity (VWMC) and also applied an orthopedic external fixator (Hoffmann® 3, Stryker, UK) to a plastic tibia under test conditions.  Significant hypoxia was induced with the reduction of FIo2 to ∼14.1% (Spo2 87% vs. 98%). No effect of hypoxia on VWMC was observed. The pin-divergence score (a measure of frame asymmetry) was significantly greater in hypoxic conditions (4.6 mm) compared to sea level (3.0 mm); there was no significant difference in the penetrance depth (16.9 vs. 17.2 mm). One hypoxic frame would have failed early.  The authors believe that surgery at an altitude of 3000 m, when unacclimated individuals are acutely exposed to atmospheric hypoxia for 45 min, can likely take place without supplemental oxygen use but further work is required.]]></description>
      <pubDate>Tue, 28 Nov 2017 09:28:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1484004</guid>
    </item>
    <item>
      <title>Pulmonary Effects from a Simulated Long-Duration Mission in a Confined Cockpit</title>
      <link>https://trid.trb.org/View/1484007</link>
      <description><![CDATA[A recent U-2 fatigue study, in which 10 subjects completed 2 simulated long-duration missions breathing either 100% oxygen or air in a hypobaric chamber, offered an opportunity to compare subjects' pulmonary function before and after remaining seated in a confined cockpit for 12 h.  In one U-2 mission configuration, the subject wore a full pressure suit and breathed aviator's breathing oxygen while chamber pressure was maintained at 4572 m (15,000 ft) above mean sea level. In the second mission configuration, subjects wore standard aircrew flight equipment and breathed air while chamber pressure was maintained at 2438 m (8000 ft) above mean sea level. Subjects' pulmonary function was assessed before and after the mission using four metrics: forced vital capacity, forced expiratory volume in 1 s, peak expiratory flow, and forced expiratory volume in 1 s/forced vital capacity ratio.  Subjects showed significant declines for all four pulmonary metrics (2.7%, 6.4%, 13.9%, and 3.5%, respectively) after 12 h seated in the cockpit in both full pressure suit and aircrew flight equipment conditions.  While the declines at both altitudes amounted to modest percentages of subjects' total pulmonary capacities, they emerged after a single, acute sedentary exposure and appear to be unrelated to the percentage of oxygen in the breathing gas. This might have operational implications in confined mission environments where physiological demands are interspersed with long periods of inactivity.]]></description>
      <pubDate>Tue, 28 Nov 2017 09:28:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1484007</guid>
    </item>
    <item>
      <title>Determining Airfield Pavement Deicer and Anti-Icer Contributions to Airport Stormwater</title>
      <link>https://trid.trb.org/View/1478081</link>
      <description><![CDATA[ACRP Project 02-61 identified and ranked research needs related to airport stormwater management. One of the conclusions of this review was that the National Pollutant Discharge Elimination System (NPDES) stormwater permit compliance requirements increasingly include pavement deicer constituents in stormwater discharges. As controls on aircraft deicing runoff have become more widespread and effective, focus on the relative contribution and influence of pavement deicing runoff has increased. Yet airports face significant challenges when attempting to parse out the relative contribution of airfield deicers, because the sources contributing to oxygen demand (i.e., biochemical oxygen demand [BOD] and chemical oxygen demand [COD]) cannot be easily measured. Airports therefore need a method to determine the contribution of pavement deicers and anti-icers to the total oxygen demand in stormwater.
The objective of this research is to develop a method to estimate the contributions of airfield pavement deicers and anti-icers to overall oxygen demand (BOD and COD) in stormwater discharges.
The method should:
(1) Account for sources, fate and transport of airfield pavement deicers and anti-icers;
(2) Identify and quantify airfield pavement deicers and anti-icers contained in discharged waters;
(3) Account for contributions from other non-airfield pavement-related deicers and anti-icing activities;
(4) Be adaptable to background water chemistry, various geographies, airport configurations, soils, topography, climate, weather, and hydrology;
(5) Be scalable to levels of resource availability (e.g., data, time, money, personnel, expertise); and
(6) Produce output expressed as a percentage of overall BOD and COD attributable to airfield pavement deicers and anti-icers with levels of confidence, and identify uncertainties.]]></description>
      <pubDate>Mon, 31 Jul 2017 12:26:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1478081</guid>
    </item>
    <item>
      <title>Propranolol Effects on Decompression Sickness in a Simulated DISSUB Rescue in Swine</title>
      <link>https://trid.trb.org/View/1461206</link>
      <description><![CDATA[Disabled submarine (DISSUB) survivors may face elevated CO2 levels and inert gas saturation, putting them at risk for CO2 toxicity and decompression sickness (DCS). Propranolol was shown to reduce CO2 production in an experimental DISSUB model in humans but its effects on DCS in a DISSUB rescue scenario are unknown. A 100% oxygen prebreathe (OPB) reduces DCS incidence and severity and is incorporated into some DISSUB rescue protocols. We used a swine model of DISSUB rescue to study the effect of propranolol on DCS incidence and mortality with and without an OPB. In Experiment 1, male Yorkshire Swine (70 kg) were pressurized to 2.8 ATA for 22 h. Propranolol 1.0 mg · kg-1 (IV) was administered at 21.25 h. At 22 h, the animal was rapidly decompressed and observed for DCS type, onset time, and mortality. Experimental animals (N = 21; 69 ± 4.1 kg), PROP1.0, were compared to PROP1.0-OPB45 (N = 8; 69 ± 2.8 kg) with the same dive profile, except for a 45 min OPB prior to decompression. In Experiment 2, the same methodology was used with the following changes: swine pressurized to 2.8 ATA for 28 h; experimental group (N = 25; 67 ± 3.3 kg), PROP0.5 bis, propranolol 0.5 mg · kg-1 bis (twice) (IV) was administered at 22 h and 26 h. Control animals (N = 25; 67 ± 3.9 kg) received normal saline. OPB reduced mortality in PROP1.0-OBP45 compared to PROP1.0 (0% vs. 71%). PROP0.5 bis had increased mortality compared to CONTROL (60-% vs. 4%). Administration of beta blockers prior to saturation decompression appears to increase DCS and worsen mortality in a swine model; however, their effects in bounce diving remain unknown.]]></description>
      <pubDate>Wed, 19 Jul 2017 15:44:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1461206</guid>
    </item>
    <item>
      <title>Blood-Injection-Injury (B-I-I) Specific Phobia Affects the Outcome of Hypoxic Challenge Testing</title>
      <link>https://trid.trb.org/View/1465084</link>
      <description><![CDATA[Blood-injection-injury (B-I-I) phobia is capable of producing inaccurate hypoxic challenge testing results due to anxiety-induced hyperventilation. CASE REPORT: A 69-yr-old woman with a history of hypersensitivity pneumonitis, restrictive spirometry, exercise desaturation requiring supplementary oxygen on mobilizing, reduced DLco, and B-I-I phobia was referred for hypoxic challenge testing (HCT) to assess in-flight oxygen requirements. HCT was performed by breathing a 15% FIo2 gas mixture, simulating the available oxygen in ambient air onboard aircraft pressurized to an equivalent altitude of 8000 ft. Spo2 fell to a nadir value of 81% during HCT, although it rapidly increased to 89% during the first of two attempts at blood gas sampling. A resultant blood gas sample showed an acceptable Po2 outside the criteria for recommending in-flight oxygen and a reduced Pco2. Entering the nadir Spo2 value into the Severinghaus equation gives an estimated arterial Po2 of 6 kPa (45 mmHg), which was felt to be more representative of resting values during HCT, and in-flight oxygen was recommended. While hyperventilation is an expected response to hypoxia, transient rises in Spo2 coinciding with threat of injury are likely to be attributable to emotional stress-induced hyperventilation, characteristic of B-I-I specific phobia and expected during the anticipation of exteroceptive threat, even in normal subjects. In summary, should excessive hyperventilation be detected during HCT and coincide with transient increases in Spo2, HCT should be repeated using Spo2 only as a guide to the level of hypoxemia, and Spo2 maintained using supplementary oxygen in accordance with alternative methods described in guidelines.]]></description>
      <pubDate>Wed, 19 Jul 2017 15:43:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1465084</guid>
    </item>
    <item>
      <title>Mathematical Model of Mixing in New Haven Harbor</title>
      <link>https://trid.trb.org/View/1389269</link>
      <description><![CDATA[A mathematical model of New Haven Harbor, a shallow embayment with approximately 8 square nautical miles of water surface within boundaries established by Long Island Sound and the mouths of the Quinnipiac, West and Mill Rivers, has been developed. The Harbor has extensive tidal flats and dredged channels which help to produce large lateral variations of velocity and mixing over a tidal cycle. In order to adequately consider these lateral variations, a two-dimensional model of mixing, dispersion, pollutant reactions, and re-aeration is made by linking together 28 segments of the Harbor, using a series of mass-balance equations. Mixing, or dispersion, is a complex function of reversing tidal currents, salinity-induced circulation patterns, fresh-water inflow, and the physical boundaries of the Harbor. Field measurements of salinity, dissolved oxygen, biochemical oxygen demand (BOD), and tidal and hydraulic factors are used, in conjunction with laboratory studies, to evaluate coefficients and rate constants for the model. The linked system of equations is solved by matrix inversion procedures on a large computer. After verification, the model was used to predict the effect of treatment levels, outfall locations, and hydrologic parameters on oxygen levels and water quality m the Harbor. An important aspect of the work is that it presents a rational evaluation of estuarine water quality as a function of tidal mixing, outfall location, and the degree of BOD removal by proposed treatment plants, rather than the acceptance of arbitrary treatment standards.]]></description>
      <pubDate>Wed, 30 Mar 2016 09:47:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1389269</guid>
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