Effects of testosterone replacement and its pharmacogenetics on physical performance and metabolism

In men, testosterone （T） deficiency is associated with decreased physical performance, as defined by adverse traits in body composition, namely increased body fat content and reduced muscle mass. Physical abilities in androgen-deficient men are further attenuated by lower oxygen supply due to decreased hemoglobin concentrations and by poor glucose utilization. Dysthymia and a lack of necessary aggressiveness also contribute to deteriorate physical effectiveness. Substitution of T can improve lipid and insulin metabolism as well as growth of muscle fibers and decreasing fat depots, which consequently will result in changes of body composition. Increment of bone density will further contribute to increase physical fitness. The effects of T replacement therapy （TRT） are strongly influenced by age, training, and also pharmacogenetics： the CAG repeat polymorphism in exon 1 of the androgen receptor （AR） gene modulates androgen effects. In vitro, transcription of androgen-dependent target genes is attenuated with increasing length of triplet residues, Clinically, the CAG repeat polymorphism causes significant modulations of androgenicity in healthy eugonadal men as well as efficacy of TRT. Thresholds at which T treatment should be initiated, as well as androgen dosage, could be tailored according to this polymorphism.

Relationship of serum vitamin D level on geriatric syndromes and physical performance impairment in elderly hypertensive patients

Objective To investigate the relationship among serum vitamin D levels, physical performance impairment, and geriatric syndromes in elders with hypertension. Methods According to the concentration of vitamin D levels, a total of 143 elderly patients with hypertension were classified into vitamin D deficient group （vitamin D 〈 20 ng/mL, n = 94） and vitamin D appropriate group （vitamin D 〉 20 ng/rnL, n = 49）. Geriatric syndromes and physical performance were assessed by using comprehensive geriatric assessment （CGA）. Correlation among vitamin D levels, geriatric syndromes and physical performance was analyzed. Results No statistical differences were found in various aspects of geriatric syndromes between the two groups （P 〉 0.05）. While correlation analysis indicated that vitamin D levels had a positive association with ADL score （r = 0.235, P 〈 0.01） and a negative association with Morse fall scale score （r = 0.238, P 〈 0.01）. Patients with deficient vitamin D level had longer time both in the Five Time Sit to Stand Test （5tSTS）, （15.765 ± 5.593） and the four-meter walk test [7.440 （5.620, 9.200）], a weaker hand-grip in the grip strength test （28.049 ± 9.522）, and a lower Tinetti performance-oriented mobility assessment （Tinetti POMA） [26 （22, 27）] and Balance subscale of the Tinetti performance-oriented mobility assessment （B-POMA） score [ 14 （12, 16）], compared with appropriate vitamin D level [（13.275 ± 3.692）; 5.810 （4.728, 7.325）]; （31.989 ± 10.217）; [26.5 （25, 28）]; [15 （14, 16）, respectively, all P 〈 0.05]. Furthermore, results of logistic regression indicated that vitamin D was significantly associated with 5tSTS （OR = 1.2, 95% CI = 1.050-1.331, P 〈 0.01）, Tinetti POMA （OR = 3.7, 95% CI：1.284-10.830, P 〈 0.05） and B-POMA （OR = 0.8, 95% CI：0.643-0.973, P 〈 0.05）. Conclusions In elderly hypertensive patients, serum vitamin D deficient level is associated with physical performance impairment. However, no statistical significance was found between vitamin D and geriatric syndromes. Further study is required to investigate possible mechanisms for the association between vitamin D and physical performance.

Effective of exercise therapy on functional balance, physical performance and quality of life among patients undergoing hemodialysis: randomized controlled trial

Background:Patients undergoing hemodialysis suffer from deteriorating physical health,impaired physical function,and have a low quality of life,that explained by insufficient metabolic clearance.To overcome these obstacles,cost-effective strategies must be developed,including exercise as a complement to hemodialysis therapy.Objective:To determine the effectiveness of exercise therapy on functional balance,physical performance,and quality of life among patients undergoing hemodialysis:a randomized controlled trial.Methods:This randomized controlled trial study was carried out on 68 patients with chronic kidney disease undergoing hemodialysis for at least six months and had a medically stable condition who were randomly divided into training(n=32)exercise therapy and(n=31)control,groups.The training group participated in 8-week(3 sessions per week)resistance exercise therapy in three sets of 10 repetitions of knee extension,hip flexion,and hip abduction with the use of an elastic band under the supervision of a training physiotherapist and researcher during the first hour of the three routine hemodialysis treatment session per week.But the control group did not experience any intervention.To analyze the data,two-way analysis of variance and Bonferroni statistical tests were used at the significant level of(P=0.05).Results:6 Minute-Walk Test(6MWT)(0.013),and in the Physical Activity Scale for the Elderly(PASE)(0.014),and Short Survey Form 36(SF-36)questionnaires and health-related quality of life(HRQOL)(0.001)had significant improvements in the training group in comparison to the control group from pre to post-test,also physical performance(0.001)was improving as compared with control group(0.89)at(P=0.05).Conclusion:Resistance exercise therapy interventions for eight weeks effectively improve the physical function and performance,activity levels,and health-related quality of life of patients with chronic kidney disease and undergoing regular hemodialysis compared with a control group.

The Level of General Physical Performance and Physical Development of 10-Year-Old Pupils

This contribution deals with the level of general physical performance of 10-year-old male and female pupils attending primary schools. Fourth grade pupils attending primary schools in Banska Bystrica were tested in the number of 433 pupils （220 boys and 213 girls）. The following indicators of general physical performance were monitored： sit-and-reach, standing long jump, sit-ups, flexed arm hang, shuttle run 4 ×10 m, endurance shuttle run. Also basic somatic indicators such as body height, body weight and BM! were found out. 10-year-old boys achieve better level in five tests of general physical performance. The girls achieve statistically better level in one test. When comparing it with the previous researches in Slovakia, we noted a lower level of general physical performance but a higher level of indicators of physical development of boys and girls from Banska Bystrica. Used set of tests affects the whole range of general physical performance, and it is adequate to the temporal, spatial and material conditions of schools.

Impact of resistance exercise training on physical performance of patients undergoing hemodialysis

Background:Hemodialysis is the major treatment option for patients with chronic kidney disease.With the increase in the number of maintenance hemodialysis patients,debilitating conditions of muscle willing and atrophy and numerous health problems associated with chronic kidney disease and hemodialysis have become the most significant concerns.Methods:This randomized controlled trial study design will be conducted at Al-Najaf city in the southern region of Iraq and carried out on 68 patients with chronic kidney disease undergoing hemodialysis for at least six months and who had a medically stable condition,which will be randomly divided into training group;exercise therapy and control,groups.The training group participated in 8-week(3 sessions per week)resistance exercise therapy in three sets of 10 repetitions of knee extension,hip flexion,and hip abduction with the use of an elastic band under the supervision of a training physiotherapist and researcher during the first hour of the three routine hemodialysis treatment session per week.But the control group did not experience any intervention.To analyze the data,two-way analysis of variance and Bonferroni statistical tests will be used at the significant level of(P=0.05).Discussion:Important features of this study include the randomization procedures,double-blind,large sample size,and a standardized protocol for resistance exercise training on the physical performance of hemodialysis patients.This study aims to determine the effectiveness of resistance exercise for the patient with chronic kidney disease and undergoing hemodialysis.Therefore,our results will be useful for patients with chronic kidney diseases,medical staff,and healthcare decision-makers.

Associations between cardiac arrhythmia,incident disability in activities of daily living and physical performance:the ILSA study

Background Cardiac arrhythmias are common conditions in older people.Unfortunately,there is limited literature on associations between cardiac arrhythmias and physical performance or disability.We therefore aimed to prospectively investigate associations between cardiac arrhythmias and changes in disability and physical performance during 8 years of follow-up,using data from the Italian Longitudinal Study on Aging(ILSA).Methods Cardiac arrhythmias diagnosis was posed through a screening phase,confirmed by a physician.The onset of disability in activities of daily living(ADL)and the changes in several physical performance tests during follow-up were considered as outcomes.Fully-adjusted and propensity-score Cox Proportional Hazard models and mixed models were used for exploring associations between cardiac arrhythmia and the outcomes of interest.Results The prevalence of cardiac arrhythmia at baseline was 23.3%.People reporting cardiac arrhythmia at the baseline were significantly older,more frequently male,smokers and reported a higher presence of all medical conditions investigated(hypertension,heart failure,angina,myocardial infarction,diabetes,stroke),but no difference in dementia,Parkinsonism,cognitive or mood disorder.Cardiac arrhythmia at baseline was significantly associated with the incidence of disability in ADL(HR=1.23;95%:CI:1.01–1.50;P=0.0478 in propensity score analyses;HR=1.28;95%CI:1.01–1.61;P=0.0401 in fully adjusted models).Cardiac arrhythmia at baseline was also associated with a significant worsening in balance test(P=0.0436).Conclusions The presence of cardiac arrhythmia at baseline was associated with a significant higher risk of disability and of worsening in some physical performance tests,particularly those relating to balance.Screening and frequently assessing physical performance in older people affected by cardiac arrhythmia can be important to prevent a loss of physical performance,with further,potential,complications of medical management.

Physical-Rheological Properties and Performances of Rejuvenated(Styrene-Butadiene-Styrene)Asphalt with Polymerized-MDI and Aromatic Oil

Traditional asphalt rejuvenators,like aromatic oil(AO),are known to be effective in improving the low-temperature properties and fatigue performances of aged SBS(styrene-butadiene-styrene)modified asphalt(SBSMA)binders and mixtures.However,these rejuvenators inevitably compromise their high-temperature properties and deformation resistances because they dilute asphalt binder but do not fix the damaged structures of aged SBS.In this study,a highly-active chemical called polymerized 4,4-diphenylmethane diisocyanate(PMDI)was used to assist the traditional AO asphalt rejuvenator.The physical and rheological characteristics of rejuvenated SBSMA binders and the moisture-induced damage and rut deformation performances of corresponding mixtures were comparatively evaluated.The results showed that the increasing proportion of AO compromises the hightemperature property and hardness of aged SBSMA binder,and an appropriate amount of PMDI works to compensate such losses;3%rejuvenator at mass ratio of AO:PMDI=70:30 can have a rejuvenated SBSMA binder with a high-temperature performance similar to that of fresh binder,approximately at 71.4°C;the use of AO can help reduce the viscosity of PMDI rejuvenated SBSMA binder for improving its workability;PMDI can help improve the resistance of AO rejuvenated SBSMA binder to deformation,especially at elevated temperatures,through its chemical reactions with aged SBS;moisture induction can enhance the resistance to damage of rejuvenated mixtures containing AO/PMDI or only PMDI;and the rejuvenator with a mass ratio of AO:PMDI=70:30 can lead the rejuvenated mixture to meet the application requirement,with a rut depth of only 2.973 mm,although more PMDI can result in a higher resistance of rejuvenated mixtures to high-temperature deformation.

Physical and chemical performances of high Al steels

The effects of acid-soluble Al content on the physical and chemical performances of high Al steels were investigated. The results show that the distribution of acid-soluble Al in steel substrate is uniform. With increasing Al content, the strength and toughness of steels decrease a little but the hardness increases. The average yield strength and tensile strength are 425MPa and 570MPa, respectively, and the Rockwell hardness is 89.7. For non-Al steels the average oxidation rate is up to 0.421mg/(cm2·h) at 1373K. For high Al steels, when the mass fraction of Al is less than 5%, there is a thinner gray oxidized layer on surface and the oxidation rate is high; when the mass fraction of Al is more than 8.0%, the thin, close and yellow glossing film still exists, and the average oxidation rate is only 0.016mg/(cm2·h).

The Effects of a Unilateral Strength and Power Training Intervention on Inter-Limb Asymmetry and Physical Performance in Male Amateur Soccer Players

The aims of this study were(a)to investigate the effects of a unilateral training program in reducing inter-limb asymmetry in male soccer players;(b)to explore such effects on measures of physical performance and unilateral inter-limb asymmetry.Twenty-four soccer players,randomly assigned to a 6-week unilateral strength and power training(UNI)(n=12)or a control group(CON)(n=12),performed single countermovement jump(SLCMJ),single leg broad jump(SLBJ),single leg drop jump(SLDJ),10-m sprint,and 505 change of direction(COD)speed test.Raw jump scores revealed small to large improve-ments in SLCMJ,SLBJ,and SLDJ reactive strength index(RSI)(g=0.46 to 1.66)in the UNI group,whereas negligible changes were found in the CON group(g=−0.31 to 0.33).Asymmetry indexes showed a moderate significant reduction in the SLDJ(RSI)and in the SLDJ stiffness(K)(g=1.00 to 1.11)in the UNI group.The between-group comparison indicated a significant change in the SLDJ(RSI)and in the SLDJ(K)(g=1.01 to 1.07)in favour of the UNI group.Thus,a unilateral training program seems to be able to reduce between-limb imbalances and foster improvements in jump performance,without any detrimental effects on linear or COD speed times.Given the importance of these physical characteristics for soccer,it is suggested that unilateral strength and power training are incorporated into strength training routines for players of all levels.

Physical simulation of fluid flow and production performance in extra-low permeability porous media

For extra-low permeability reservoirs, with a permeability of about 0.3×10?3 μm2, fluid flow and production performance in cores were studied. A long core holder with a multi-location piezometric measurement was specially designed. An artificial long core, about 700 mm long and with a cross section of 45mm×45mm, was used. In the experiment, pressure distribution along the core can be measured in real time. Single phase flow in the core was investigated. Different modes of production in long cores were also simulated including natural depletion, water flooding, and advanced water flooding. Through physical simulation, flow parameters were collected and production characteristics in extra-low permeability cores were studied. From experimental results, it can be seen that fluid flow in extra-low permeability cores is different from that in high permeability cores. Transmission of pressure in extra-low permeability cores is very slow, and it needs a long time for the pressure to become stable. The distribution curve of pressure along the core is nonlinear and the production rate in extra-low permeability reservoirs decreases sharply. The development effects of different production modes in extra-low permeability cores were compared with one another. Among the production modes, advanced water flooding has much potential for effective development of extra-low permeability reservoirs. Natural depletion and conventional water flooding can also be used in early production periods. In addition, the countermeasures and some ideas especially for the potential development of extra-low permeability reservoirs are suggested.

The relationship between physical activity, body mass index, and academic performance and college-age students

Background: The purpose of this study was to determine if a relationship exists between physical activity or Body Mass Index (BMI) and academic performance in college-age students. Both physical activity and BMI have shown to impact academic performance in younger students, but data for college-age students is limited. Methods: Between October and December 2006, data were collected from 98 biochemistry students at the University of Nebraska-Lincoln. Analysis was performed on 77 students who had complete outcome data. Physical activity measures were categorized to reflect those who met and those who did not meet the Centers for Disease Control and Prevention (CDC) and American College of Sports Medicine (ACSM) recommendations for physical activity [1]. BMI was calculated from each student’s height and weight recordings. Academic performance was determined by each student’s cumulative college Grade Point Average (GPA) and score on the ACT examination. The means were compared using test for two groups and general linear models. Where statistically significant results existed, groups were compared using the Tukey multi-test procedure. A one-sample comparison of means was conducted for fitness between our sample and the age-matched American population as stated by the Healthy People 2010 Report [1]. Results: Students in the normal BMI category had significantly higher GPA and ACT scores than students in the overweight category. Juniors had significantly higher GPA and ACT scores than seniors. Our findings did not differ between our sample and the American population with regards to recommendations for fitness by the CDC and ACSM. Conclusions This study demonstrated that normal weight individuals, had higher GPA and ACT scores than their overweight counterparts, underscoring the need to intensify interventions focused on reducing and preventing obesity among school-age populace.

Hydrodynamic Performance of a Newly-Designed Pelagic and Demersal Trawls Using Physical Modeling and Analytical Methods for Cameroonian Industrial Fisheries

This study proposed the newly-designed Pelagic and demersal trawls for the fishing vessels operating in Cameroonian waters in pelagic and demersal fishing grounds. The engineering performances of both trawls were investigated using physical modelling method and analytical method based on the predicted equations. In a flume tank, a series of physical model tests based on Tauti’s law were performed to investigate the hydrodynamic and geometrical performances of both trawls and to assess the applicability of the analytical methods based on predicted equations. The results showed that in model scale, the working towing speed and door spread for the pelagic trawl were 3.5 knots and 1.85 m, respectively, and for the bottom trawl net they were 4.0 knots and 1.8 m. At that speed and door spread, the drag force, net opening height, and wing-end spread of the pelagic model trawl were 36.73 N, 0.89 m, and 0.86 m, respectively, and the swept area was 0.76 m2. Bottom trawl speed and door spread were 30.43 N, 0.38 m, and 0.45 m, respectively, and the swept area was 0.25 m2. The maximum difference between the experimental and analytical results of hydrodynamic performances was less than 56.22% and 41.45%, respectively, for pelagic and bottom trawls, the results of the geometrical performances obtained using predicted equations were close to the experimental results in the flume tank with a maximum relative error less than 12.85%. The newly developed pelagic and bottom trawls had advanced engineering performance for high catch efficiency and selectivity and could be used in commercial fishing operations in Cameroonian waters.

Effects of a school-based karate intervention on academic achievement,psychosocial functioning,and physical fitness:A multi-country cluster randomized controlled trial

Purpose:To examine the effects of a school-based karate intervention on academic achievement,psychosocial functioning,and physical fitness in children aged 7-8 years.Methods:Twenty schools in 5 different European countries(2 second-grade classrooms per school)participated in a cluster randomized controlled trial(Sport at School trial).Participants were assigned to either a control group,which continued with their habitual physical education lessons,or to an intervention group,which replaced these lessons with a 1-year karate intervention(Karate Mind and Movement program).A total of 721 children(344 girls and 377 boys,7.4±0.5 years old,mean±SD)completed the study,of which 333 and 388 were assigned to the control group and intervention group,respectively.Outcomes included academic performance(average grade),psychosocial functioning(Strengths and Difficulties Questionnaire for parents),and different markers of physical fitness(cardiorespiratory fitness,balance,and flexibility).Results:The intervention provided small but significant benefits compared to the control group for academic achievement(d=0.16;p=0.003),conduct problems(d=-0.28;p=0.003),cardiorespiratory fitness(d=0.36;p<0.001),and balance(d=0.24;p=0.015).There was a trend towards significant benefits for flexibility(d=0.24;p=0.056).No significant benefits were observed for other variables,including psychosocial difficulties,emotional symptoms,hyperactivity/inattention,peer problems,or prosocial behaviour(all p>0.05).Conclusion:A 1-year school-based karate intervention was effective in improving academic achievement,conduct problems,and physical fitness in primary school children.The results support the inclusion of karate during physical education lessons.

An Analysis of Physical Fitness Differences in Soccer,Handball,and Basketball

This study focuses on the evaluation of the differences of physical fitness among soccer players, handball players, and basketball players, and the investigation of the physical fitness structures of those players. The participants consisted of 160 elite players selected from university teams. Fourteen tests related to health and motor fitness were conducted. The results were subjected to a multivariate analysis of variance (MANOVA) to test the mean vector differences among the three groups of different sport. Nine out of the fourteen tests were of significantly discriminating results regarding to different group, which include side step, abdominal strength, shuttle running, 100m running, pull-up, 1,500m running, trunk flexion, grip strength and broad jump, as determined by a stepwise regression approach. MANOVA showed that there was a significant difference (p<0.001) of the mean vectors of the 9 tests among the three events. Discriminant function analysis showed that three discriminant functions were significant, whose correctness was testified by the classification analysis to be over 80.2%. It is demonstrated that elite handball players are good at agility, elite soccer players are speedy, and successful basketball players apparently possess preeminent muscular strength and endurance.

一种新型压配式腰椎椎间融合器的机械性能

背景:行经皮微创椎间孔腰椎椎间融合置入椎间融合器时,由于入路操作范围狭窄,有牵拉神经根损伤或置入融合器位置不良等风险,为了解决以上问题作者课题组发明了一种新型机械结构可变形压配式cage(Press-fit cage,YP-cage)。目的:对新型腰椎融合器YP-cage的机械强度特性进行初步评估。方法:对不同尺寸9,11,13 mm高度的新型YP-cage(n=9)和聚醚醚酮-cage(n=9)进行了静态轴向压缩实验和静态轴向扭转实验,分别采集力-位移曲线计算屈服位移及载荷、极限载荷位移及刚度,屈服角位移及扭矩、极限载荷角位移扭矩及刚度,并进行对比分析。结果与结论:(1)在静态轴向压缩测试中,YP-cage在3组测试中(9,11,13 mm),其刚度、屈服载荷、极限位移和载荷极限方面均优于聚醚醚酮-cage(P <0.01),但YP-cage的屈服位移小于聚醚醚酮-cage(P <0.05);(2)在静态扭转测试中,除了9 mm组的YP-cage和聚醚醚酮-cage在极限扭转角度上差异无显著性意义,YP-cage在屈服扭矩、屈服扭转角度及极限扭矩均小于聚醚醚酮-cage(P <0.01),而YP-cage扭转刚度在9 mm组和11 mm组大于聚醚醚酮-ccage(P <0.01);(3)结果表明新型压配式机械结构椎间融合器相较于聚醚醚酮材质cage具有更高的抗压强度,但抗扭强度不如聚醚醚酮-cage。

CEE-Gr:A Global Router with Performance Optimization Under Multi-Constraints

A global routing algorithm with performance optimization under multi constraints is proposed,which studies RLC coupling noise,timing performance,and routability simultaneously at global routing level.The algorithm is implemented and the global router is called CEE Gr.The CEE Gr is tested on MCNC benchmarks and the experimental results are promising.

The association between Tai Chi exercise and safe driving performance among older adults： An observational study

Background: Age-related cognitive and physical decline can impair safe driving performance. Tai Chi exercise benefits cognitive and physical function and may influence safe driving performance in older adults. The primary aim of this observational study was to compare cognitive processes and physical function related to safe driving performance among older adult Tai Chi practitioners to normative reference values.Secondary aims were to examine relationships between Tai Chi exercise habits, cognitive processes, and physical function related to safe driving performance and to explore potential predictors of safe driving performance.Methods: The Driving Health Inventory, the Driving Scenes Test, other driving-related cognitive and physical measures, and self-reported measures including the Mindful Attention Awareness Scale(MAAS) and the Vitality Plus Scale(VPS) were collected from current Tai Chi practitioners(n = 58; age 72.9 ± 5.9 years, mean ± SD) with median >3 years Tai Chi practice.Results: Compared to normative reference values, participants performed better on numerous cognitive measures including the Driving Scenes Test(p < 0.001, d = 1.63), maze navigation(p = 0.017, d = 0.27), the Useful Field of View Test(p < 0.001, r = 0.15), and on physical measures including the Rapid Walk Test(p < 0.001, r = 0.20), and the Right Foot Tapping Test,(p < 0.001, r = 0.35). Participants scored higher than normative reference values on MAAS and VPS(p < 0.001, d = 0.75; p = 0.002, d = 0.38, respectively). Statistically significant correlations were found between several study measures. The digit span backward test was the strongest predictor of safe driving performance(β = 0.34,p = 0.009).Conclusion: Tai Chi exercise has the potential to impact cognitive processes and physical function related to safe driving performance. Further study using randomized controlled trials, structured Tai Chi exercise doses, and driving simulator or on-road driving performance as outcome measures are warranted.

Teaching the User By Learning From the User:Personalizing Movement Control in Physical Human-robot Interaction

This paper proposes a novel approach for physical human-robot interactions(pHRI), where a robot provides guidance forces to a user based on the user performance. This framework tunes the forces in regards to behavior of each user in coping with different tasks, where lower performance results in higher intervention from the robot. This personalized physical human-robot interaction(p2HRI) method incorporates adaptive modeling of the interaction between the human and the robot as well as learning from demonstration(LfD) techniques to adapt to the users' performance. This approach is based on model predictive control where the system optimizes the rendered forces by predicting the performance of the user. Moreover, continuous learning of the user behavior is added so that the models and personalized considerations are updated based on the change of user performance over time. Applying this framework to a field such as haptic guidance for skill improvement, allows a more personalized learning experience where the interaction between the robot as the intelligent tutor and the student as the user,is better adjusted based on the skill level of the individual and their gradual improvement. The results suggest that the precision of the model of the interaction is improved using this proposed method,and the addition of the considered personalized factors to a more adaptive strategy for rendering of guidance forces.

Hydrodynamic Performance and Power Absorption of A Coaxial DoubleBuoy Wave Energy Converter

As an important wave energy converter(WEC),the double-buoy device has advantages of wider energy absorption band and deeper water adaptability,which attract an increasing number of attentions from researchers.This paper makes an in-depth study on double-buoy WEC,by means of the combination of model experiment and numerical simulation.The Response Amplitude Operator(RAO)and energy capture of the double-buoy under constant power take-off(PTO)damping are investigated in the model test,while the average power output and capture width ratio(CWR)are calculated by the numerical simulation to analyze the influence of the wave condition,PTO,and the geometry parameters of the device.The AQWA-Fortran united simulation sy stem,including the secondary developme nt of AQWA software coupled with the flowchart of the Fortran code,models a new dynamic system.Various viscous damping and hydraulic friction from WEC system are measured from the experimental results,and these values are added to the equation of motion.As a result,the energy loss is contained in the final numerical model the by united simulation system.Using the developed numerical model,the optimal period of energy capture is identified.The power capture reaches the maximum value under the outer buoy's natural period.The paper gives the peak value of the energy capture under the linear PTO damping force,and calculates the optimal mass ratio of the device.

Study on Influence of Functional Composition Distribution on Combustion Performance of a Modified Single Base Propellant

The modified single base propellant samples were prepared by impregnating blasting oil into single base grains and deactivating deterrent in water medium. The concentration distribution of functional compositions in this propellant was determined by using FTIR micro-spectroscopy. Its combustion performance was investigated by means of closed-bomb and interior ballistic tests. The results show that the concentration of NG distributes parabolically along the radius and the concentration of NA decreases from the surface to the centre exponentially. The deeper the NG impregnates, the slower the NA concentration decreases, the stronger the progressive combustion is and the better the interior ballistic performance is. When the depth corresponding to maximum NG concentration is about 1/2 of the web and the NA decreases slowly, the progressive combustion is the strongest and the interior ballistic performance is the best.