Low Target Temperature Research Articles

Targeted temperature management after cardiac arrest

Actively avoiding fever is the only possibility to improve neurological outcome after cardiac arrest. It is uncertain if and which patients benefit from a lower target temperature. The ERC Guidelines in 2021 recommended targeted temperature management (TTM) for all patients after in- and out-of-hospital cardiac arrest with a target temperature of 32-36 °C for at least 24 hours. These recommendations were updated in 2022 by the ERC/ESICM Guidelines suggesting to avoid fever only within the first 72 hours after the event. Divergent results of recent trials lead to these guideline changes. The large TTM2 Trial in 2021 did not show a benefit neither in survival nor in neurological outcome in the group of hypothermia at 33°C compared to normothermia. Although leading to the updated guidelines, applying these study results to the German population is restricted as the rate of bystander cardiopulmonary resuscitation (CPR) or shockable rhythms is much lower in Germany. Further studies are needed to allow a better differentiation of subpopulations and to implement a more individual classification und therapy.

Effect of different combinations of initial body temperature and target temperature on neurological outcomes in out-of-hospital cardiac arrest patients treated with targeted temperature management

We hypothesized that different combinations of initial and target temperatures during targeted temperature management (TTM) may be associated with neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors. Adult patients with OHCA who underwent TTM were enrolled. The study participants were divided into four groups: lower initial body temperature and lower target temperature (Low-Low group), lower initial body temperature and higher target temperature (Low-High group), higher initial body temperature and lower target temperature (High-Low group), and higher initial body temperature and higher target temperature (High-High group). Initial body temperature was dichotomized based on the median value (35.6 ◦C) as a cutoff, and the target temperature was dichotomized with a target temperature of 34 ◦C as a cutoff. The primary outcome was defined as a favorable 28-day neurological outcome. In total, 231 patients were included in the analysis, and 74 (32.0%), 43 (18.6%), 82 (35.5%), and 32 (13.9%) patients were classified into the Low-Low, Low-High, High-Low, and High-High groups, respectively. The proportion of patients with favorable 28-day neurological outcomes differed among the study groups (Low-Low, 14 (18.9%); Low-High, 7 (16.3%); High-Low, 37 (45.1%); High-High, 11 (34.4%); p = 0.001). In the multivariable analysis, the Low-High group was independently associated with a less favorable 28-day neurological outcome compared to the High-Low group (adjusted odds ratio, 0.22; 95% confidence interval, 0.06–0.91; p = 0.036). In conclusion, higher initial body temperature and lower target temperature during TTM were independently associated with a more favorable 28-day neurological outcome compared to the lower initial body temperature and higher target temperature in patients resuscitated from OHCA of medical etiology.

The role of plasma-molecule interactions on power and particle balance during detachment on the TCV tokamak

This paper shows experimental results from the TCV tokamak that indicate plasma-molecule interactions involving and possibly D− play an important role as sinks of energy (through hydrogenic radiation as well as dissociation) and particles (ions) during divertor detachment if low target temperatures (<3 eV) are achieved. Both molecular activated recombination (MAR) and ion source reduction due to a power limitation effect are shown to be important in reducing the ion target flux during a density ramp. In contrast, the electron–ion recombination (EIR) ion sink is too small to play an important role in reducing the ion target flux. MAR or EIR do not occur during N2 seeding induced detachment as the target temperatures are not sufficiently low. The impact of is shown to be underestimated in present (vibrationally unresolved) SOLPS-ITER simulations, which could result from an underestimated rate. The converged SOLPS-ITER simulations are post-processed with alternative reaction rates, resulting in considerable contributions of to particle and power losses as well as dissociation below the D2 dissociation area. Those findings are in quantitative agreement with the experimental results.

Targeted Temperature Management after Cardiac Arrest: A Systematic Review and Meta-Analysis with Trial Sequential Analysis.

Target temperature management (TTM) in cardiac arrest (CA) survivors is recommended after hospital admission for its possible beneficial effects on survival and neurological outcome. Whether a lower target temperature (i.e., 32–34 °C) improves outcomes is unclear. We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects on mortality and neurologic outcome of TTM at 32–34 °C as compared to controls (patients cared with “actively controlled” or “uncontrolled” normothermia). Results were analyzed via risk ratios (RR) and 95% confidence intervals (CI). Eight randomized controlled trials (RCTs) were included. TTM at 32–34 °C was compared to “actively controlled” normothermia in three RCTs and to “uncontrolled” normothermia in five RCTs. TTM at 32–34 °C does not improve survival as compared to normothermia (RR:1.06 (95%CI 0.94, 1.20), p = 0.36; I2 = 39%). In the subgroup analyses, TTM at 32–34 °C is associated with better survival when compared to “uncontrolled” normothermia (RR: 1.31 (95%CI 1.07, 1.59), p = 0.008) but shows no beneficial effects when compared to “actively controlled” normothermia (RR: 0.97 (95%CI 0.90, 1.04), p = 0.41). TTM at 32–34 °C does not improve neurological outcome as compared to normothermia (RR: 1.17 (95%CI 0.97, 1.41), p = 0.10; I2 = 60%). TTM at 32–34 °C increases the risk of arrhythmias (RR: 1.35 (95%CI 1.16, 1.57), p = 0.0001, I2 = 0%). TTM at 32–34 °C does not improve survival nor neurological outcome after CA and increases the risk of arrhythmias.

Outcome Related to Level of Targeted Temperature Management in Postcardiac Arrest Syndrome of Low, Moderate, and High Severities: A Nationwide Multicenter Prospective Registry.

The optimal target temperature during targeted temperature management for patients after cardiac arrest remains under debate. The aim of this study was to evaluate the association between targeted temperature management at lower target temperatures and the neurologic outcomes among patients classified by the severity of postcardiac arrest syndrome. A multicenter observational study from the out-of-hospital cardiac arrest registry of the Japanese Association for Acute Medicine, which is a nationwide prospective registry of out-of-hospital cardiac arrest patients. A total of 125 critical care medical centers or hospitals with an emergency care department across Japan. A total of 1,111 out-of-hospital cardiac arrest patients who had received targeted temperature management. We divided all 1,111 postcardiac arrest syndrome patients treated with targeted temperature management into two groups: those who received targeted temperature management at a lower target temperature (33-34°C) and those who received targeted temperature management at a higher target temperature (35-36°C). In regard to classification of the patients, we divided the patients into three categories of severity (low, moderate, and high severities) using the risk classification tool, post-Cardiac Arrest Syndrome for Therapeutic hypothermia, which was previously validated. The primary outcome was the percentage of patients with a good neurologic outcome at 30 days, and the secondary outcome was the survival rate at 30 days. Multivariate analysis showed that targeted temperature management at 33-34°C was significantly associated with a good neurologic outcome and survival at 30 days in the moderate severity (odds ratio, 1.70 [95% CI, 1.03-2.83] and 1.90 [95% CI, 1.15-3.16], respectively), but not in the patients of low or high severity (pinteraction = 0.033). Propensity score analysis also showed that targeted temperature management at 33-34°C was associated with a good neurologic outcome in the moderate-severity group (p = 0.022). Targeted temperature management at 33-34°C was associated with a significantly higher rate of a good neurologic outcome in the moderate-severity postcardiac arrest syndrome group, but not in the low- or high-severity group.

Temperature management on cardiopulmonary bypass: Is it standardised across Great Britain and Ireland?

Temperature management is an essential element of cardiopulmonary bypass (CPB), as indicated in the Guide to Good Practice in Clinical Perfusion, 'The safe conduct of CPB requires the clinical perfusionist to measure and control. . . blood temperature. . . during the period of bypass'. To review current practice, we have conducted a research survey into the management of temperature on CPB. Surveys were distributed to each centre in Great Britain and the Republic of Ireland, investigating numerous temperature management practices, to elucidate current practice and assess if recent research into temperature management marry routine clinical practice. Our results demonstrate that nasopharyngeal temperature is the most common (52%) temperature site used across the many centres, which correlates with previous research as a routine site for cerebral temperature management. The arterial outlet of the oxygenator temperature was used in 33% of centres, however, all centres lacked the knowledge to maintain this temperature below 37°C. There was significant variation between all centres, especially regarding rewarming times (20-40 minutes), demonstrating a lack of uniformity among perfusion centres. Interestingly, most centres have been using the same protocol that has been in place over the previous 10 years.To conclude, the practice of temperature management is changing with the awareness of new research. Lower target temperatures are recommended for rewarming, ensuring a lower temperature gradient and a longer mean rewarming time.

Zero Drift Infrared Radiation Thermometer Using Chopper Stabilised Pre-Amplifier

A zero-drift, mid–wave infrared (MWIR) thermometer constructed using a chopper stabilised operational amplifier (op-amp) was compared against an identical thermometer that utilised a precision op-amp. The chopper stabilised op-amp resulted in a zero-drift infrared radiation thermometer (IRT) with approximately 75% lower offset voltage, 50% lower voltage noise and less susceptibility to perturbation by external sources. This was in comparison to the precision op-amp IRT when blanked by a cover at ambient temperature. Significantly, the zero-drift IRT demonstrated improved linearity for the measurement of target temperatures between 20 °C and 70 °C compared to the precision IRT. This eases the IRT calibration procedure, leading to improvement in the tolerance of the temperature measurement of such low target temperatures. The zero-drift IRT was demonstrated to measure a target temperature of 40 °C with a reduction in the root mean square (RMS) noise from 5 K to 1 K compared to the precision IRT.

Risk factor for acute kidney injury in patients with chronic kidney disease receiving valve surgery with cardiopulmonary bypass

IntroductionAcute kidney injury (AKI) after cardiopulmonary bypass (CPB) in patients with pre-existing impaired renal function carries deleterious outcomes but is not frequently evaluated. The optimal CPB strategy for preventing AKI in this vulnerable patient group is still controversial. MethodsA total of 156 patients with preoperative estimated glomerular filtration rate (e-GFR) <30 ml/min but not on chronic dialysis receiving valve operation under CPB were included in the present study. Postoperative AKI was defined as KDIGO (Kidney Disease Improving Global Outcomes) stage 3. Hospital mortality and two-year renal function evolution were compared between patients with postoperative AKI and those without AKI. Risk factors for the development of postoperative AKI were also studied. ResultsThe incidence of postoperative KDIGO-3 was high (44.2%). Hospital mortality was higher in the AKI group (30.4%) than in the non-AKI group (8.0%). Among the hospital survivors, renal function deterioration to permanent dialysis at two years was also more common in AKI group (14.5%) than in non-AKI group (4.6%). Univariate logistic regression for postoperative AKI revealed male gender, increased age, height, weight, BSA, and BMI, high preoperative serum creatinine, prolonged CPB duration, and decreased CPB target temperature as risk factors. However, multivariate analysis revealed only high preoperative serum creatinine and decreased CPB target temperature as significant risk factors for postoperative AKI. ConclusionTo prevent postoperative AKI in CKD patients, low CPB target temperature is avoided, especially for those with high preoperative serum creatinine levels.

The role of particle, energy and momentum losses in 1D simulations of divertor detachment

A new 1D divertor plasma code, SD1D, has been used to examine the role of recombination, radiation, and momentum exchange in detachment. Neither momentum or power losses by themselves are found to be sufficient to produce a reduction in target ion flux in detachment (flux rollover); radiative power losses are required to (a) limit and reduce the ionisation source and (b) access low-target temperature, Ttarget, conditions for volumetric momentum losses. Recombination is found to play a small role at flux rollover, but as Ttarget drops to temperatures around 1 eV, it becomes a strong ion sink. In the case where radiative losses are dominated by hydrogen, the detachment threshold is identified as a minimum gradient of the energy cost per ionisation with respect to Ttarget. This is also linked to thresholds in Ttarget and in the ratio of upstream pressure to power flux. A system of determining the detached condition is developed such that the divertor solution at a given Ttarget (or lack of one) is determined by the simultaneous solution of two equations for target ion current—one dependent on power losses and the other on momentum. Depending on the detailed momentum and power loss dependence on temperature there are regions of Ttarget where there is no solution and the plasma ‘jumps’ from high to low Ttarget states. The novel analysis methods developed here provide an intuitive way to understand complex detachment phenomena, and can potentially be used to predict how changes in the seeding impurity used or recycling aspects of the divertor can be utilised to modify the development of detachment.

Comparison of shear wave elastography and quasi-static elastography in the evaluation of radiofrequency ablation: ex vivo experiment

Objective To investigate the value of shear wave elastography (SWE) and quasi-static elastography in the evaluation of radiofrequency ablation of pork. Methods Twelve pieces of fresh pork were underwent radiofrequency ablation (RFA) with different target temperatures. Before and after RFA, conventional ultrasound (US), SWE and quasi-static elastography were conducted to visualize the boundaries of RFA zones. The size of ablation zones obtained from conventional ultrasound, SWE and quasi-static elastography measurement were observed and detected the correlativity with pathology findings. Moreover, the Young′s modulus and stain ratio of ablated zone were recorded. Results Most ablated boundaries were clearly delineated by both elastography techniques, except one with a low target temperature of 70 ℃. The sizes of ablated zones measured by SWE and quasi-static elastography were closely correlated with pathological findings. However, no ablated zones could be visualized by conventional US.Before and after RFA, the mean, minimum and maximum values of Young′s modulus were (24.2±3.8)kPa vs (97.6±29.1) kPa, (9.2±0.7)kPa vs (44.5±7.7)kPa and (29.9±3.8)kPa vs (181.5±36.7)kPa, respectively (all P<0.001). With the increase of target temperature of RFA, the Young′s modulus values and the mean strain ratio were significantly increased (all P<0.01). Conclusions Both SWE and quasi-static elastography are useful tools for evaluating the ablation, which are superior to conventional US. Moreover, SWE can be used to monitor the procedure of ablation. Key words: Elasticity imaging techniques; Radiofrequency ablation; Ex vivo experiment

TU‐H‐BRC‐06: Temperature Simulation of Tungsten and W25Re Targets to Deliver High Dose Rate 10 MV Photons

Purpose:To study the impact of electron beam size, target thickness, and target temperature on the ability of the flattening filter‐free mode (FFF) treatment head to deliver high‐dose‐rate irradiations.Methods:The dose distribution and transient temperature of the X‐ray target under 10 MeV electron beam with pulse length of 5 microseconds, and repetition rate of 1000 Hz was studied. A MCNP model was built to calculate the percentage depth dose (PPD) distribution in a water phantom at a distance of 100 cm. ANSYS software was used to run heat transfer simulations. The PPD and temperature for both tungsten and W25Re targets for different electron beam sizes (FHWM 0.2, 0.5, 1 and 2 mm) and target thickness (0.2 to 2 mm) were studied.Results:Decreasing the target thickness from 1 mm to 0.5 mm, caused a surface dose increase about 10 percent. For both target materials, the peak temperature was about 1.6 times higher for 0.5 mm electron beam compared to the 1 mm beam after reaching their equilibrium. For increasing target thicknesses, the temperature rise caused by the first pulse is similar for all thicknesses, however the temperature difference for subsequent pulses becomes larger until a constant ratio is reached. The target peak temperature after reaching equilibrium can be calculated by adding the steady state temperature and the amplitude of the temperature oscillation.Conclusion:This work indicates the potential to obtain high dose rate irradiation by selecting target material, geometry and electron beam parameters. W25Re may not outperformed tungsten when the target is thick due to its relatively low thermal conductivity. The electron beam size only affects the target temperature but not the PPD. Thin target is preferred to obtain high dose rate and low target temperature, however, the resulting high surface dose is a major concern.NIH funding:R21 EB015957‐01; DOD funding:W81XWH‐13‐1‐0165BL, PM, PB, and RF are founders of TibaRay, Inc. BL is also a borad member. BL and PM have received research grants from Varian Medical System, Inc. and RaySearch Laboratory. RF is an employee of Siemens Healthcare GmbH

Do Lower Target Temperatures or Prolonged Cooling Provide Improved Outcomes for Comatose Survivors of Cardiac Arrest Treated With Hypothermia?

BackgroundOptimal protocols for targeted temperature management are still unclear. This study investigated whether lower target temperatures and/or prolonged cooling could provide improved outcomes in comatose survivors of cardiac arrest.Methods and ResultsThis observational study was conducted using the prospectively collected targeted temperature management database in Hiroshima, Japan. Between September 2003 and September 2014, 237 patients treated with TTM after cardiac arrest were enrolled in this study. The target temperatures and durations were assigned by the treating physicians regardless of the patients’ conditions. Favorable outcomes were defined as a cerebral performance category scale of 1 or 2 at the 90-day follow-up time point. The rate of favorable outcomes were similar between the patients whose protocols of target temperature were <34°C and ≥34°C (40% versus 35%, P=0.41), cooling durations were <28 and ≥28 hours (33% versus 44%, P=0.11), and rewarming durations were <28 and ≥28 hours (35% versus 41%, P=0.39). However, in patients treated with extracorporeal cardiopulmonary resuscitation, target temperatures <34°C were associated with more favorable outcomes (29% versus 8%, P=0.01). The cooling and rewarming durations >28 hours and target temperatures <34°C were associated with more frequent lethal arrhythmia, pneumonia, and/or bleedings.ConclusionsProlonged durations of cooling and rewarming ≥28 hours may not improve outcomes and may increase complications. Further studies are necessary to assess the hypothesis that target temperatures <34°C provide improved outcomes in patients treated with extracorporeal cardiopulmonary resuscitation.

Electron and recoil ion momentum imaging with a magneto-optically trapped target.

A reaction microscope (ReMi) has been combined with a magneto-optical trap (MOT) for the kinematically complete investigation of atomic break-up processes. With the novel MOTReMi apparatus, the momentum vectors of the fragments of laser-cooled and state-prepared lithium atoms are measured in coincidence and over the full solid angle. The first successful implementation of a MOTReMi could be realized due to an optimized design of the present setup, a nonstandard operation of the MOT, and by employing a switching cycle with alternating measuring and trapping periods. The very low target temperature in the MOT (∼2 mK) allows for an excellent momentum resolution. Optical preparation of the target atoms in the excited Li 2(2)P3/2 state was demonstrated providing an atomic polarization of close to 100%. While first experimental results were reported earlier, in this work, we focus on the technical description of the setup and its performance in commissioning experiments involving target ionization in 266 nm laser pulses and in collisions with projectile ions.

Abstract 161: Effectiveness of Lower Target Temperature Therapeutic Hypothermia for Post--Cardiac Arrest Victims Within 30 Minutes Resuscitation Interval

Introduction: Therapeutic hypothermia (TH) for post cardiac arrest syndrome (PCAS) patients is standard strategy to reduce brain damage. However, current randomized control study (TTM: Target temperature management study, N Engl J Med 2013) suggested that simple target temperature did not improve outcome. Furthermore, there is no evidence, whether target temperature would be changed for each status of PCAS patients. Hypothesis: Lower target temperature could improve neurological outcome in PCAS patients. Methods: Participants with J-PULSE-Hypo study database were divided into the L group (32.0-33.9°C) and the M group (34-35°C). The favorable neurological outcomes (%, CPC 1-2 on 30th day) were compared between L and M groups in all and each subgroups with propensity score analysis with IPTW (inverse probability of treatment weighting) method as multivariate analysis. The subgroups were ages and interval from collapse to ROSC (return of spontaneous circulation). Results: 477 participants were analyzed. The comparison of each groups for favorable neurological outcome were that all groups (L: 64%, n = 42, vs M: 55%, n= 424, P = 0.234, multivariate: P = 0.452), age (≤60 y.o.) (L: 70% vs M: 67%, P = 0.717, multivariate: P = 0.657), age (&gt;60 y.o.) (L: 50% vs M: 44%, P = 0.665, multivariate: P = 0.061), interval from collapse to ROSC (≤30 min.) (L: 88% vs M: 64%, P = 0.022, multivariate: P = 0.007), and interval from collapse to ROSC (&gt;30 min.) (L: 21% vs M: 29%, P = 0.567, multivariate: P = 0.449). Conclusions: The PCAS victims within 30 min. from collapse to ROSC, would be treated by TH with less than 34°C target temperature.

A simple but accurate potential for the naphthalene-argon complex: Applications to collisional energy transfer and matrix isolated IR spectroscopy

An explicit polarizable potential for the naphthalene-argon complex has been derived assuming only atomic contributions, aiming at large scale simulations of naphthalene under argon environment. The potential was parametrized from dedicated quantum chemical calculations at the CCSD(T) level, and satisfactorily reproduces available structural and energetic properties. Combining this potential with a tight-binding model for naphthalene, collisional energy transfer is studied by means of dedicated molecular dynamics simulations, nuclear quantum effects being accounted for in the path-integral framework. Except at low target temperature, nuclear quantum effects do not alter the average energies transferred by the collision or the collision duration. However, the distribution of energy transferred is much broader in the quantum case due to the significant zero-point energy and the higher density of states. Using an ab initio potential for the Ar-Ar interaction, the IR absorption spectrum of naphthalene solvated by argon clusters or an entire Ar matrix is computed via classical and centroid molecular dynamics. The classical spectra exhibit variations with growing argon environment that are absent from quantum spectra. This is interpreted by the greater fluxional character experienced by the argon atoms due to vibrational delocalization.

Kinetics of aggregation in micellar solutions of thermoresponsive triblock copolymers – influence of concentration, start and target temperatures

In aqueous solution, symmetric triblock copolymers with a thermoresponsive middle block and hydrophobic end blocks form flower-like core–shell micelles which collapse and aggregate upon heating through the cloud point (CP). The collapse of the micellar shell and the intermicellar aggregation are followed in situ and in real-time using time-resolved small-angle neutron scattering (SANS), while heating micellar solutions of a poly((styrene-d8)-b-(N-isopropyl acrylamide)-b-(styrene-d8)) triblock copolymer in D2O rapidly through their CP. The influence of polymer concentration as well as of the start and target temperatures is addressed. In all cases, the micellar collapse is very fast. The collapsed micelles immediately form small clusters which contain voids. They densify which slows down or even stops their growth. For low concentrations and target temperatures just above the CP, i.e. shallow temperature jumps, the subsequent growth of the clusters is described by diffusion-limited aggregation. In contrast, for higher concentrations and/or higher target temperatures, i.e. deep temperature jumps, intermicellar bridges dominate the growth. Eventually, in all cases, the clusters coagulate which results in macroscopic phase separation. For shallow temperature jumps, the cluster surfaces stay rough; whereas for deep temperature jumps, a concentration gradient develops at late stages. These results are important for the development of conditions for thermal switching in applications, e.g. for the use of thermoresponsive micellar systems for transport and delivery purposes.

Nucleation on Heating/Loading Path and Its Effects on the Evaluation of Nucleation Rate

AbstractWe investigate the nucleation on heating/loading paths and its effects on the olivine phase transformation and the determinations of nucleation rate in in‐situ experiments by the numerical simulation based on the kinetic parameters from low temperature experiments in of Ni2SiO4 olivine phase transformation[1]. Results show that the high temperature experiments, of which samples are first loaded and then heated to the experimental conditions after annealing, are greatly affected by the nucleation during heating. The predicted nucleation rates based on these experiments are obviously overrated. Especially in the case that most of experiments have high target temperatures, the predicted nucleation rates will significantly deviate from their true values, which will have influences on the evaluations of olivine grain size and the rheological structures of subduction zones. Although there are many growth data of Mg2SiO4 olivine and a rough evaluation on the nucleation rate of (Mg0.89Fe0.11)2SiO4 olivine based on the feature of grain impingement, only Ref.[2] showed some nucleation rates of Mg2SiO4 olivine from in‐situ high temperature experiments, in which the sample is finally heated to the target experimental condition. The results in present study suggest that the experiments with low target temperature or those reached their experimental condition finally by loading are needed to derive the correct nucleation parameters of mantle olivine.

Radiofrequency ablation of retained placenta accreta after conservative management: preliminary evaluation in the pregnant ewe and in normal human placenta in vitro

To evaluate radiofrequency (RF) efficiency and safety for the ablation of retained placenta in humans, using a pregnant sheep model. Experimental study. Laboratory of Surgery School, Nancy, France. Three pregnant ewes/ten human placentas. Various RF procedures were tested in pregnant ewes on 50 placentomes (individual placental units). Reproducibility of the best procedure was then evaluated in a further 20 placentomes and on ten human term placentas in vitro after delivery. Placental tissues destruction, lesions' size, myometrial lesions. Low power (100 W) and low target temperatures (60 degrees C) lead to homogenous tissue destruction, without myometrial lesion. No significant difference was observed in terms of lesion size and procedure duration for in the placentomes of pregnant ewe in vivo and in human placentas in vitro. The diameter of the ablation could be correlated with the tines deployment. The placental tissue structure is very permissive to RF energy, which suggests that RF could be used for the ablation of retained placenta, providing optimal control of tissue destruction. These results call for further experimental evaluations.

The screening effect of D–D fusion in Sm in a sub-low energy region (⩽20 keV)

The fusion reaction may be significantly changed in a solid target due to electron screening on target nuclei while the projectile energy is very low. The electron screening effect of the D(d, p)T reaction in the deuterated metal Sm at low target temperature (T ∼ 133.2 K) has been studied in a deuteron energy region from 10 to 20 keV. The thick target yields of protons emitted in the D(d, p)T reaction were measured and compared with those data extrapolated from cross sections and stopping power data at higher energies. It is found that the reaction rates in Sm are enhanced over those of the bare nuclei. The screening potential in Sm under cooled conditions is deduced to be 520 ± 56 eV, which cannot be simply interpreted by the electron screening. The enhanced screening potential might be roughly interpreted with the classical plasma model of Debye, in which the screening potential decreases with increasing temperature while quasi-free metallic electrons are applied.

Influence of reflected radiation of high velocity oxy-fuel spraying torch on long wavelength IR pyrometry temperature measurement

High velocity oxy-fuel (HVOF) torch radiations were measured in the 8–14 μm spectral band as a function of successively oxygen and methane (CH 4) flow rates. Experienced flow rates were varied respectively from 250 to 450 Nl/min for oxygen and from 100 to 150 Nl/min for methane. Prediction about the effects of the reflected HVOF torch radiation on the measured temperature was detailed. Extraneous radiant energy coming from the HVOF torch was found to have drastic effects on temperature measurement under some special input conditions. In such a case, a correction of the measured temperature for reflected HVOF radiant energy has to be performed for low target temperature or low target emissivity.