Comparative Analysis of Domestic and International Test Guidelines for Various Concrete Repair Materials

The number of aged bridges among concrete structures is increasing. Therefore, to increase their lifespans, repair and reinforcement schemes ought to be implemented. This study selected various repair materials according to crack-surface treatment, crack-filling, and crack-injection methods. These repair materials were evaluated using various test methods proposed by the Korean Standards and the American Society for Testing and Materials for structure protection, structure restoration, and crack repair; the results were analyzed and compared. Consequently, the structure restoration material exhibited a similar freezing–thawing trend as that of chloride, while also exhibiting similar flexural, compressive, bond, and splitting-tensile strengths. However, chloride yielded performance differences (up to two-fold) depending on the type of material used for comparison. The crack-repair material yielded similar trends only for bond strength but yielded differences (up to 2–4-fold) in tensile, compressive, and flexural strengths depending on the material used for comparison. These results confirmed that crack-repair materials exhibit significant differences in performance depending on the manufacturer compared with structure protection and structure restoration materials. Therefore, it is expected that repair materials appropriate for usability, durability, and structure safety, while also being environmentally friendly, could be used in future bridge repairs based on these test evaluations.     

Study of mycotoxin calibration approaches on the example of trichothecenes analysis from flour

The aim of this study was to evaluate the applicability of different calibration approaches in trichothecenes analysis from wheat flour. Concretely eight trichothecenes (five type B trichothecenes and three type A trichothecenes) were analyzed by matrix solid-phase dispersion (MSPD) and liquid chromatography–tandem mass spectrometry (LC–MS/MS). In the first set of experiments the presence of matrix effects was evaluated; values ranged between 59% and 79%. In the second set of experiments, solutions to compensate these signal suppressions were examined. Different calibration methods showed to tackle matrix effects obtaining values between 69% and 85% for external matrix matched calibration and values from 76% to 111% and from 78% to 108% by analog and deuterated internal standard calibrations, respectively. Trueness of the method was studied using quality control material and certificated reference material (DON 1062 ± 110 μg kg⁻¹). The values were compared by matrix-matched, analog internal standard (deepoxydeoxynivalenol (DOM-1)) and deuterated internal standard (DON-d₁).     

Exact Solution of a Constraint Optimization Problem for the Thermoelectric Figure of Merit

In the classical theory of thermoelectricity, the performance integrals for a fully self-compatible material depend on the dimensionless figure of merit zT. Usually these integrals are evaluated for constraints z =  const. and zT =  const., respectively. In this paper we discuss the question from a mathematical point of view whether there is an optimal temperature characteristics of the figure of merit. We solve this isoperimetric variational problem for the best envelope of a family of curves z(T)T.     

Comparison of Two Automatic Devices and the Standard Mercury Sphygmomanometer in Hypertensive Patients

The standard mercury sphygmomanometer (SMS) and two automatic blood pressure recording devices, Dinamap 845 (D) and Sentron (S), were compared by means of a randomized 3-period cross-over experiment. Both devices recorded diastolic BP lower than SMS, on average and for most individual patients. Systolic BP was similar for SMS and S, and slightly lower for D, with variations for individual patients. A second study failed to detect effects of the physician's presence when BP was measured, whereas the difference between D and SMS was substantially confirmed.     

Investigation of Select Ergonomic Interventions for Farm Youth. Part 1: Shovels

ABSTRACT

There is some evidence that performing farm chores may place youth at risk of musculoskeletal injuries. However, actual investigations of interventions for farm youth have been sparse. The objective of the current study was to investigate two different types of interventions (add-on handles) for shovels, potentially reducing the risk of injury in farm youth. A lumbar motion monitor was used to capture trunk posture and motion while the youth performed a simulated shoveling task—removal of material from an animal stall. Ratings of perceived exertion and comfort of use were also assessed. The results indicate add-on handles decreased sagittal flexion but increased twisting as compared to regular shovels. Perceived ratings were worse for shovels with add-on handles. Overall, there appears to be a trade-off between sagittal and nonsagittal motion and appears to have minimal impact on risk of low back injury. However, further research is necessary to determine the complete ramifications of this trade-off with respect to the biomechanical load within the low back and on other joints.     

An Evaluation of the Nutrition Services for the Elderly

No abstract available for this article.     

Determination and Concentration of Adenine Nucleotides in Human Blood

Abstract

Background. The microdialysis technique is a method for sampling endogenous molecules from the interstitial compartments of varying tissues and relies on diffusion of molecules between the tissue and a perfusate via a membrane. Such samples do not allow determination of the true interstitial concentration but only a certain percentage. This gives rise to one of the most crucial parameter that needs to be considered for a dependable microdialysis; the relative recovery. Relative recovery states the efficiency of which an analyte is extracted from its external medium. Aim. To investigate the relative recovery of small molecules (< 20 kDa) such as lactate, fluid recovery and the reproducibility of the relative recovery at group and individual level of the microdialysis technique applied in muscle. Materials and methods. Using in vivo microdialysis of the trapezius muscle of 65 women from two separate occasions 4–6 months apart. Relative recovery of small molecules was measured from samples collected every 20 min during a period of 220 min. Results. Good reproducibility at group level of catheters with cut-offs 100 and 20kDa were found. Furthermore, there was a high and steady relative recovery with an overall good fluid recovery. Poor reproducibility was found at the individual level for both catheters. Conclusions. This study demonstrates that when using microdialysis in skeletal muscle relative recovery is stable over time and is not affected by low-force exercise. Although there is a good reproducibility at group level this is not the case at the individual level. Thus in vivo, the relative recovery should be determined for each test subject and at each test occasion.     

船用新型隔热绝缘材料(MBP)常温释放物、高温热解物测定及毒性评价

目的　为船舶舱室能否使用新型 (MBP)隔热绝缘材料作安全性评价。方法　定性、定量测定材料常温 (45℃ )释放物及高温 (煤气火焰 )热解物组份 ;动物急性吸入材料高温热解物毒性试验。结果　该材料常温释放物为一氟三氯甲烷 (氟里昂 - 1 1 ) ,其浓度低于水面船舶舱室空气组份容许浓度(GJB1 1 .2 - 91 ,1 992 )。该材料高温热解物 2 0种 ,7种为中等毒性物质 ,1 3种为低毒或微毒物。动物急性吸入高温热解物半数致死质量浓度 L C5 0 >5 0 mg/L。结论　该材料可以在水面船舶安全使用     

“劲润”牙本质保护膜的牙本质粘结性能探讨

目的：探讨“劲润”牙本质保护膜（Hybrid Coat,HyC）的牙本质粘结性能。方法：选取A组（HyC）和其他3组不同类型的牙本质粘结剂：B组（G-Bond）、C组（MegaBond）和D组（single Bond）,比较其对牛牙牙本质的剪切粘结强度,并用实体显微镜观察粘结界面断裂模式。各组试料数分别为n=10,结果通过Tukey-Kramer（P〈0．05）进行统计学分析。结果：B、C、D组均显示了较大的粘结强度,3组之间无统计学差异。A组（HyC）显示了较低的粘结强度,约10．08MPa,与其他3组之间存在显著性差异。断裂模式显示,A组（HyC）以界面破坏为主,而其他3组以凝集破坏和混合破坏为主。结论：本研究结果提示,“劲润”牙本质保护膜（HyC）的粘结强度弱于其他3组牙本质粘结剂。为了保证HyC长期稳定的防过敏效果及粘结性能,在今后的研究中有必要进一步探讨如何提高HyC的牙本质粘结性能。     

两种不同藻酸盐印模消毒效果对比研究

目的：比较两种不同藻酸盐印模消毒的效果。方法：使用不同的调拌方法制取3组藻酸盐印模样本各30个,共计90个（前两组用蒸馏水调拌,第3组用0．1％的洗必泰溶液调拌）。印模凝固后将3种不同菌液均匀涂布于印模表面。第1组为空白对照组,不做处理：第2组使用照射强度为100μW的紫外线照射5min;第3组用洗必泰溶液调拌,在空气中放置30min。3组印模洗脱表面残留的细菌进行培养,根据培养的细菌数量进行消毒效果的判定,并进行统计学分析（方差分析）。结果：与空白对照组相比,紫外线照射消毒与洗必泰消毒后印模表面细菌数量明显减少;用紫外线照射后的印模表面的细菌数少于用洗必泰调和消毒的印模,两者存在显著性差异。结论：紫外线照射的消毒效果优于洗必泰。