Dynamometer Test Research Articles

Low-condensation diesel use contributes to winter haze in cold regions of China

The application of low-condensation diesel in cold regions with extremely low ambient temperatures (−14 to −29 °C) has enabled the operation of diesel vehicles. Still, it may contribute to heavy haze pollution in cold regions during winter. Here we examine pollutant emissions from low-condensation diesel in China. We measure the emissions of elemental carbon (EC), organic carbon (OC), and elements, including heavy metals such as arsenic (As). Our results show that low-condensation diesel increased EC and OC emissions by 2.5 and 2.6 times compared to normal diesel fuel, respectively. Indicators of vehicular sources, including EC, As, lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), and manganese (Mn), increased by approximately 20.2–162.5% when using low-condensation diesel. Seasonal variation of vehicular source indicators, observed at road site ambient environments revealed the enhancement of PM2.5 pollution by the application of low-condensation diesel in winter. These findings suggest that −35# diesel, a low-cetane index diesel, may enhance air pollution in winter, according to a dynamometer test conducted in laboratory. It raises questions about whether higher emissions are released if −35# diesel is applied to running vehicles in real-world cold ambient environments.

Butanol and selective catalytic reduction of gaseous emissions in a heavy-duty diesel engine

The impact of renewable fuels and their blends on vehicle exhaust emissions remains of high interest. In this study, we investigate the effect of butanol on the conversion efficiency of a Selective Catalytic Reduction (SCR) system installed on a commercial Euro V heavy-duty diesel engine (HDDE). Exhaust emissions were measured upstream and downstream of the SCR during dynamometer tests using diesel fuel and various butanol-diesel blends (5/95 %v, 10/90 %v, and 20/80 %v). Steady-state tests according to the World Harmonized Stationary Cycle (WHSC) on an engine bench were conducted including measurements of nitrogen oxides (NOX), total hydrocarbons (THC), and carbon monoxide (CO) emissions utilizing a portable emission measurement system (PEMS). The results showed a reduction in exhaust gas temperature (EGT) of around 4 % for a butanol content of 20 %. The use of butanol increased conversion efficiency of the SCR system by 4 % compared to diesel. The maximum SCR system conversion rate of around 96 % was obtained with a butanol content of 10 %. For all fuels, NOX conversion decreased at high engine loads (above 400 °C), while, as expected, was zero at low engine loads (below 200 °C). Reductions in CO and THC emissions were observed downstream of the SCR system. In general, this study shows that an SCR originally designed for a Euro V diesel engine can be equally effective when the engine is running on a partial blend of butanol.

Obscured Contribution of Oxygenated Intermediate-Volatility Organic Compounds to Secondary Organic Aerosol Formation from Gasoline Vehicle Emissions.

Secondary organic aerosol (SOA) formation from gasoline vehicles spanning a wide range of emission types was investigated using an oxidation flow reactor (OFR) by conducting chassis dynamometer tests. Aided by advanced mass spectrometric techniques, SOA precursors, including volatile organic compounds (VOCs) and intermediate/semivolatile organic compounds (I/SVOCs), were comprehensively characterized. The reconstructed SOA produced from the speciated VOCs and I/SVOCs can explain 69% of the SOA measured downstream of an OFR upon 0.5-3 days' OH exposure. While VOCs can only explain 10% of total SOA production, the contribution from I/SVOCs is 59%, with oxygenated I/SVOCs (O-I/SVOCs) taking up 20% of that contribution. O-I/SVOCs (e.g., benzylic or aliphatic aldehydes and ketones), as an obscured source, account for 16% of total nonmethane organic gas (NMOG) emission. More importantly, with the improvement in emission standards, the NMOG is effectively mitigated by 35% from China 4 to China 6, which is predominantly attributed to the decrease of VOCs. Real-time measurements of different NMOG components as well as SOA production further reveal that the current emission control measures, such as advances in engine and three-way catalytic converter (TWC) techniques, are effective in reducing the "light" SOA precursors (i.e., single-ring aromatics) but not for the I/SVOC emissions. Our results also highlight greater effects of O-I/SVOCs to SOA formation than previously observed and the urgent need for further investigation into their origins, i.e., incomplete combustion, lubricating oil, etc., which requires improvements in real-time molecular-level characterization of I/SVOC molecules and in turn will benefit the future design of control measures.

Optimized Approach for Measuring Ethylene Oxide in Mobile Source Exhaust.

There is a growing awareness of the health impacts of ethylene oxide (EtO) and its role as a carcinogenic and mutagenic air contaminant of concern. Given the need to better understand EtO emissions and associated health effects, it is imperative to overcome the significant challenges associated with EtO measurement in complex air matrices, such as combustion emissions. This work focused on addressing these challenges by evaluating the utility of widely used canister-based EtO ambient measurement approaches, EPA Methods TO-15 and TO-15A, to investigate the presence of EtO in heavy-duty diesel vehicle (HDDV) exhaust. Chassis dynamometer testing was performed on two HDDVs and emissions samples were collected and analyzed following TO-15/TO-15A. Initial testing utilizing TO-15 led to the identification of a diesel exhaust constituent, ethyl nitrite, that coeluted with EtO during analysis and contributed large positive bias. An optimized TO-15A analytical approach was developed and utilized to measure EtO in diesel exhaust from two HDDVs in additional dynamometer tests. Using this optimized approach, EtO was not detected in HDDV exhaust in these tests. This work highlights the importance of utilizing this optimized approach to accurately quantify EtO in mobile source exhaust and may also be needed for testing other combustion sources.

The reliability of a Biometrics device as a tool for assessing hand grip and pinch strength, in a Polish cohort-A prospective observational study.

The aim of the study was to assess the external and internal compatibility of the Biometrics E-LINK EP9 evaluation system device in the area of hand grip and pinch strength in the Polish population. The testing of hand grip and pinch strength was carried out among 122 healthy students. Two examiners performed hand grip and pinch strength measurements with a Biometrics E-LINK EP9 evaluation system device. Measurements were made for the right and left hands. The same people were tested again two weeks later, under the same conditions. The scores of one rater on the first and second tests were compared for reproducibility, and the scores of the two raters were compared to assess the reliability of the instrument. The measurements were found to be highly consistent both between the investigators and between the tests in the hand grip dynamometer test. The findings show high values of the Pearson's correlation coefficient equal or close to 1, as well as the interclass correlation coefficient (ICC) >0.9. Analysis of pinch strength measurements performed using the pinchmeter also found high values of the Pearson's correlation coefficient close to 1, as well as the interclass correlation coefficient >0.9; this reflects high agreement between the measurements performed by two investigators as well as assessments performed by one investigator at time intervals. These findings were confirmed by analyses performed using Bland-Altman plots. The measurements made with the Biometrics E-link EP9 evaluation system show high internal and external consistency in hand grip and pinch strength assessment. Biometrics E-link EP9 can be recommended for daily clinical practice.

Effects on the Physical Functioning of Two Exercise Interventions in Patients with Multiple Myeloma: A Pilot Feasibility Study.

Because of the high prevalence of bone destruction in patients with multiple myeloma (MM), physical exercise is oftentimes discouraged by healthcare providers. The goal of this prospective trial was to investigate the feasibility of two six-month exercise interventions in patients with MM (N = 42): a remotely prompted home-based walking intervention or a supervised strength training intervention. Physical function and pain were assessed with the Activity Measure for Post-Acute Care (AM-PAC) Basic Mobility Short Form raw score, a six-minute walk test (6 MWT), a 30-second sit-to-stand test (30 SST), a timed up-and-go (TUG) test, a visual analog scale (VAS) for pain, handheld dynamometer tests, heart rate at rest, blood oxygen saturation at rest, and body mass index. No intervention-related serious adverse events were observed. Adverse events mostly affected the musculoskeletal system. In the resistance training group (n = 24), patients showed significant improvements in AM-PAC, TUG, 6 MWT, and 30 SST, with all effects but the 6 MWT sustained six months after the intervention. The walking group (n = 18) saw improvements in the AM-PAC, TUG, 6 MWT, and 30 SST, with a sustained change in the AM-PAC and TUG. This trial shows the feasibility of both exercise interventions with a sustained beneficial effect on the physical functioning of a six-month strength training intervention and, to a lesser extent, a six-month unsupervised walking intervention. A larger study building on these findings is currently underway.

Numerical modeling of heat generation process in a disk brake at three thermal contact conditions over an extended braking distance

The article examines the thermal behavior of five newly developed organic composite friction materials combined with a cast-iron railway brake disk during repeated braking. Bench tests were carried out in accordance with the established program, taking into account 15 braking and cooling cycles. In the next stage, the obtained braking parameters were implemented into a 3-D FE model of the brake. The main goal of the study was to determine an influence of important assumptions taken in computer simulations regarding contact conditions, cooling conditions, and the number of required brake components. The contact conditions included: 1) perfect thermal contact, 2) contact of rough surfaces taking into account thermal conductance, and 3) separate heating. The total duration of the analyzed multiple braking reached 7695 s, while the maximum distance covered during this time was 203.1 km. The results of numerical calculations were compared with experimental data obtained on the full-scale dynamometer test stand.

Reliability and Construct Validity of a Mobile Application for the Finger Tapping Test Evaluation in People with Multiple Sclerosis.

The finger tapping test (FTT) is a tool to evaluate the motor performance of the hand and fingers and eye-hand coordination with applicability in people with multiple sclerosis (pwMS). The aim of this study was to evaluate the intra- and inter-rater reliability of the TappingPro® mobile app and the construct validity between this app and validated clinical scales for motor performance in healthy subjects and pwMS. 42 healthy subjects (mean age 25.05) and 13 pwMS (mean age 51.69, EDSS between 3 and 7.5E) participated. FTT was performed with the TappingPro® mobile app. All participants were examined twice, with a one-week interval between the two appointments. For the analysis of construct validity, the Jamar® hydraulic hand dynamometer, Box and Blocks Test (BBT), and Nine Hole Peg Test (NHPT) were used. The intra-rater reliability showed a good correlation (Intraclass Correlation Coefficient, ICC > 0.787) for both upper limbs and both times of FTT for healthy subjects, and an excellent correlation (ICC > 0.956) for upper limbs and both times of FTT for pwMS. The ICC for the inter-rater reliability was good (ICC = 0.869) for the non-dominant upper limb in the FTT 10 s of the healthy subjects, and excellent (ICC > 0.904) for all the other measurements of the healthy subjects and pwMS. However, the Bland-Altman plots showed disagreement between observers and measurements that should be considered in the interpretation of clinical evaluations. The correlation analysis for healthy subjects showed poor associations between all variables, except for the association between hand grip strength and the FTT 60 s in the non-dominant upper limb, which had a moderate coefficient. For pwMS, there were moderate to excellent associations between BBT and the NHPT and FTT for both upper limbs. The correlations between hand grip strength and FFT were poor. This mobile app could be a useful and low-cost assessment tool in pwMS, allowing a simple evaluation and follow-up that has excellent correlation with clinical scales validated in this pathology.

Modelling CO2 Emissions from Vehicles Fuelled with Compressed Natural Gas Based on On-Road and Chassis Dynamometer Tests

In response to increasingly stringent global environmental policies, this study addresses the pressing need for accurate prediction models of CO2 emissions from vehicles powered by alternative fuels, such as compressed natural gas (CNG). Through experimentation and modelling, one of the pioneering CO2 emission models specifically designed for CNG-powered vehicles is presented. Using data from chassis dynamometer tests and road assessments conducted with a portable emission measurement system (PEMS), the study employs the XGBoost technique within the Optuna Python programming language framework. The validation of the models produced impressive results, with R2 values of 0.9 and 0.7 and RMSE values of 0.49 and 0.71 for chassis dynamometer and road test data, respectively. The robustness and precision of these models offer invaluable information to transportation decision-makers engaged in environmental analyses and policymaking for urban areas, facilitating informed strategies to mitigate vehicular emissions and foster sustainable transportation practices.

Brain Mapping – Neuromuscular correlations in long-term Postsurgical rehabilitation of Adult Brachial Plexus Palsies

Abstract: Background: Correlations of Transcranial magnetic stimulation (TMS) mapping of the cortical area and electromyography (EMG) + dynamometric testing may demonstrate active neuroplas-ticity events that are reliant on rehabilitation therapy (RT) compliance in adult postsurgical brachial plexus (BP) injuries. Material and Methods: On the right (dominant) arm of two patients with chronic operated BP lesions, we evaluated the progress of functional recovery. The trau-matic event was dated more than 10 years ago for both patients. The first patient (male, 50 years old) and the second one (female, 58 years old) had a history of several microsurgical neurotiza-tion and muscle transfer procedures, with less amelioration of the motor deficit, especially re-lated to elbow flexion (MRC 1/5 and 2/5, respectively). We followed up their evolution by EMG parameters, dynamometry, MRC scaling, and TMS. The motor region of the limb was mapped using TMS to assess the amplitudes of the motor evoked potentials (MEP), on a 4-axis protocol. The patients were assessed twice, with the second examination performed after RT had just fin-ished. TMS findings were compared with EMG and dynamometric results. Results: Higher MEP amplitudes were associated with improved MEP latency during stimulation of the left cerebral hemisphere's cortical area, as well as at the cervical level. EMG findings, both nerve conduction and needle EMG studies showed nonsignificant improvements, as well as muscle strength (as measured by the hydraulic dynamometer). The best results for the first patient showed an in-crease in MEP’s amplitude increase from 1.08 mV to 1.49 mV (in the hotspot), which correlated with measurable latencies, as compared to the first TMS (when no response was obtained at cer-vical stimulation). The second patient also had improvements in latencies: from 37.1 msec. to 36.3 msec. (cervical stimulation with recording at bicipital level) and from 39.2 msec. to 37.9 (cervical stimulation recording at the first interosseous), with a hotspot increase from 1.35 mV to 1.98 mV. The results demonstrate cortical region reactivity in regard to therapeutic techniques. Central modifications do not correlate with visible EMG and dynamometric improvements. Pa-tients with traumatic BP palsy may receive several microsurgical reconstructive procedures, nevertheless, the rehabilitation of the upper limb’s functionality may sometimes still be limited. This increases the risk of discontinuity of the neuromotor RT. We aim to prove that in spite of little correlations with clinical and EMG findings, mapping the cortical area using TMS provides proof of ongoing neuroplasticity phenomena, dependent on adherence to RT. Conclusion: The evidence of continued brain activity supports the requirement for long-term adherence to treatment guidelines and long-term study protocols.

Augmented Reality Training on Combat Sport: Improving the Quality of Physical Fitness and Technical Performance of Young Athletes

This study aims to analyze the effects of augmented reality (AR) training in improving physical fitness and technical performance. An 11-week randomized controlled design was adopted in this study. This research involved sixty female athletes in Pencak Silat and Karate from Sriwijaya University (Indonesia). Participants were allocated into the experimental group, namely AR (Pencak silat: n=15, Karate: n=15) and control group (Pencak silat: n=15, Karate: n=15). Handgrip dynamometer, leg dynamometer test, medicine ball, standing long jump test, hexagon agility test, sit and reach test and multi stage test are used to measure physical fitness levels while the target punching test and target kick test are used to measure technical performance. The results of Student's t showed that there was a change in the mean value of AR (all, p < 0.05) and control only in MBT (p < 0.05) from baseline to final-test, ANOVA analysis we observed that there was an effect of Time on physical fitness (all, p < .001), there was a Group effect related to HDT (p < .001), MBT (p = 0.043), SART (p < .001), and MST (p < .001) and there was a Time * Group interaction related to HDT (p < .001), LDT ( p = 0.029), SLJT (p < .001), HAT ( p < .001), SART (p < .001), and MST (p < .001), there was an effect of Time on technical performance (all, p < .001), Group effect related to TPT (p = 0.004), and Time * Group interaction related to TPT (p = 0.001) and TKT (p < .001). Thus, we conclude that using AR for 11 weeks is an effective training method for improving the quality of physical fitness and technical performance of young athletes in combat sports. Keywords: Combat sport, Athlete performance, Technology training.

Assessment of Isokinetic Trunk Muscle Strength and Fatigue Rate in Individuals after Bariatric Surgery.

Background and Objectives: Lean body mass loss after bariatric surgery (BS) is remarkable, despite an effective long-term mass reduction and significant declines in comorbidities. A person's functional capacity is adversely affected when their skeletal muscle strength declines by up to 30%. This study aimed to assess the isokinetic trunk muscle strength and fatigue rate in individuals after BS. Materials and Methods: This study included fifty-eight patients, both male and female, ranging in age from 19 to 45. Twenty-seven individuals had BS and twenty-seven healthy people served as the control group. The primary outcomes were the measurement of the concentric and eccentric isokinetic muscle strength of the trunk flexor and extensor muscles. An isokinetic dynamometer (Biodex Rehabilitation and Testing System 3) was used for the assessment of the isokinetic muscle strength. Noraxon EMG was used to determine a secondary outcome, which was the median frequency slop (MF/time) and root mean square slop (RMS/time) of the lumbar erector spinea muscle at 50% of the Maximum Voluntary Isometric Contraction (MVIC). Outcome measures were assessed for both groups. Results: Compared to the control group, the bariatric group showed a lower mean value of both concentric and eccentric isokinetic muscle strength for the flexor and extensor trunk muscles (p < 0.05). In terms of the EMG fatigue rate, the RMS slope increased significantly more than that of the control group, while the MF slope decreased (p > 0.05). Conclusions: The current study found that, in comparison to the healthy subjects, the BS group showed reduced levels of fatigue and isokinetic strength in the trunk muscles. Based on these results, it is recommended that individuals who underwent BS take part in tailored rehabilitation programs to avoid potential musculoskeletal issues in the future.

Factors Associated With Knee Extension Strength Symmetry After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft.

Diminished postoperative knee extension strength may occur after anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) autograft. Factors influencing the restoration of knee extensor strength after ACLR with QT autograft remain undefined. To identify factors that influence knee extensor strength after ACLR with QT autograft. Case-control study; Level of evidence, 3. The authors performed a retrospective review of patients who underwent primary ACLR with QT autograft at a single institution between 2010 and 2021. Patients were included if they completed electromechanical dynamometer testing at least 6 months after surgery. Exclusion criteria consisted of revision ACLR, <6 months of follow-up, concomitant procedure (osteotomy, cartilage restoration), and concomitant ligamentous injury requiring surgery. Knee extension limb symmetry index (LSI) was obtained by comparing the peak torque of the operated and nonoperated extremities. Univariable and multivariable analyses were performed to identify factors associated with knee extension LSI in the patient, injury, rehabilitation, and preoperative patient-reported outcomes score domains. A total of 107 patients (58 male; mean age, 22.8 years) were included. Mean knee extension LSI of the overall cohort was 0.82 ± 0.18 at 7.5 ± 2.0 months; 35 patients (33%) had a value of ≥0.90. Multivariable analysis demonstrated significant negative associations between knee extension LSI and female sex (-0.12; P < .001), increased age at the time of surgery (-0.01; P = .018), and larger QT graft width (-0.049; P = .053). Factors influencing knee extensor LSI after ACLR with QT autograft in this study population spanned patient and surgical factors, including female sex, older age at the time of surgery, and wider graft harvest. Surgeons should consider the association between these factors and lower postoperative knee extensor LSI to optimize patient outcomes.

Secondary Organic Aerosol Formation Potential from Vehicular Non-tailpipe Emissions under Real-World Driving Conditions.

Traffic emissions are a dominant source of secondary organic aerosol (SOA) in urban environments. Though tailpipe exhaust has drawn extensive attention, the impact of non-tailpipe emissions on atmospheric SOA has not been well studied. Here, a closure study was performed combining urban tunnel experiments and dynamometer tests using an oxidation flow reactor in situ photo-oxidation. Results show a significant gap between field and laboratory research; the average SOA formation potential from real-world fleet is 639 ± 156 mg kg fuel-1, higher than the reconstructed result (188 mg kg fuel-1) based on dynamometer tests coupled with fleet composition inside the tunnel. Considering the minimal variation of SOA/CO in emission standards, we also reconstruct CO and find the critical role of high-emitting events in the real-world SOA burden. Different profiles of organic gases are detected inside the tunnel than tailpipe exhaust, such as more abundant C6-C9 aromatics, C11-C16 species, and benzothiazoles, denoting contributions from non-tailpipe emissions to SOA formation. Using these surrogate chemical compounds, we roughly estimate that high-emitting, evaporative emission, and asphalt-related and tire sublimation share 14, 20, and 10% of the SOA budget, respectively, partially explaining the gap between field and laboratory research. These experimental results highlight the importance of non-tailpipe emissions to atmospheric SOA.

Reduction in Chassis Dynamometer Test Time for Evaluating Energy Economy and Range of Light-Duty Battery Electric Vehicles

Reduction in Chassis Dynamometer Test Time for Evaluating Energy Economy and Range of Light-Duty Battery Electric Vehicles

EFFECT OF CYLINDER HEAD GASKET ADDITION AND VARYING OCTANE NUMBER GASOLINE TO INTERNAL COMBUSTION ENGINE PERFORMANCE

The aim of this research was to investigate the different impacts of compression pressure on power and torque outputs using gasoline RON 92, RON 95, and RON 100. The study involved experiments using a single-cylinder motorcycle engine with a capacity of 125 cm. The selection of this type of engine is based on the popularity of vehicles in Indonesia that use a single-cylinder engine with a capacity of 125 cm. To modify the compression pressure, variations in the number of gaskets were applied to the cylinder head, with quantities of 1 and 3 gaskets. Dynamometer tests were conducted to measure the engine's performance differences. Throughout the testing, the settings for the main jet, pilot jet, and the number of idle screw rotations on the carburetor remain constant. The findings indicate that the engine with the highest compression pressure of 11.8 Kg/cm, using RON 100 gasoline, produces the highest power output at 7.9 kW, with the highest torque at 10 Nm.

Risk of sarcopenia in subjects with osteoporosis and osteoarthritis

The study aimed to determine the relationship between the risk of sarcopenia (SP) and common age-related diseases of the musculoskeletal system, such as osteoporosis (OP) and osteoarthritis (OA). There were examined 460 women aged 50-85 years (mean age 66.4 ± 8.8 years) and they were divided into 4 groups. Group I included 176 women without bone and joint diseases (BJD); Group II included 137 persons with a diagnosis of systemic OP; Group III included 95 subjects with knee and/or hip OA (2nd-3rd degree of Kellgren-Lawrence grades); IV group included 52 females with OP and large joints OA (2nd-3rd degree of Kellgren-Lawrence grades). Bone mineral density (BMD) and trabecular bone score (TBS) were determined in all patients using dual-energy X-ray absorptiometry (DXA), which was subsequently taken into account in the calculation of the 10-year probability of the major osteoporotic fractures according to the Ukrainian version of FRAX®. The following questionnaires were used: SARC-F, IADL, Desmond Fall Risk Questionnaire, and KOOS-12. Also, we used the chair stand test (5 times sit-to-stand) and hand grip dynamometer test. The frequency of persons with risk of SP in Group I was 20.3 %, and it was significantly higher in women with OP (33.5 %, χ2= 6.9 [3.4 – 23.0], p &lt; 0.05), subjects with OA (34.7 %, χ2= 6.7 [3.4 – 25.7], p &lt; 0.05), and women with combined pathology (44.2 %, χ2= 12.1 [9.8 – 38.2], p &lt; 0.05). In patients with OA and risk of SP, pain intensity was significantly higher (43.7 [31.3 – 62.5] points compared to patients with OA without risk of SP - 68.8 [50.0 – 93.8] points, Z = 3.6, p &lt; 0.05), as well as function, and daily living (43.8 [31.3 – 68.8] and 75.0 [56.3 – 100.0] points, respectively, Z = 4.1, p &lt; 0.05 and quality of life 43.8 [37.5 – 62.8] and 75.0 [43.8 – 87.5] points, respectively (Z = 3.0, p &lt; 0.05) according to the KOOS-12. The probability of the major OP fracture was significantly higher in the group of OP and risk of SP (11.0 [8.5 – 12.0] % compared to patients with OP without risk of SP - 8.1 [5.4 – 10.0] %, Z = - 3.8, p &lt; 0.05). The same differences were found for the 10-year probability of hip fracture (5.0 [2.8 – 7.3] and 2.1 [1.5 – 3.5] %, respectively, Z = - 4.9, p &lt; 0.05). High Risk of SP, falls and the need for external assistance were recorded significantly more often in women with OP pathology, and their skeletal muscle strength was significantly lower. Women with a high risk of SP had significantly lower skeletal muscle strength (according to hand grip dynamometry), a higher risk of falls and fractures, and a greater need for assistance. The combination of a risk of SP and OA was associated with more severe joint pain intensity, lower function, and quality of life, and the risk of SP and OP combination was associated with a higher risk of OP fracture. _________________________________________________________________________________________ Keywords: sarcopenia; osteoporosis; osteoarthritis; FRAX; fracture; fall; pain; quality of life.

Toward a solid microneedle patch for rapid and enhanced local analgesic action.

Analgesic creams find widespread application as adjuncts for localized anesthesia prior to surgical procedures. Nevertheless, the onset of analgesic action is protracted due to the skin barrier's inherent characteristics, which necessitates prolonged intervals of patient and clinician waiting, consequently impinging upon patient compliance and clinician workflow efficiency. In this work, a biodegradable microneedles (MNs) patch was introduced to enhance the intradermal administration of lidocaine cream to achieve rapid analgesia through a minimally invasive and conveniently accessible modality. The polylactic acid (PLA) MNs were mass-produced using a simple hot-pressing method and served the purpose of creating microchannels across the skin's surface for rapid absorption of lidocaine cream. Optical and electron microscopes were applied to meticulously scrutinize the morphology of the fabricated MNs, and the comprehensive penetration tests involving dynamometer tests, evaluation on porcine cadaver skin, artificial film, optical coherence tomography (OCT), transepidermal water loss, and analysis on rats' skins, demonstrated the robust mechanical strength of PLA MNs for successful intradermal penetration. The behavioral pain sensitivity tests on living rats using Von Frey hair filaments revealed that the MN-assisted lidocaine treatment expeditiously accelerated the onset of action from 40 to 10min and substantially enhanced the efficacy of localized anesthesia. Furthermore, different treatment protocols encompassing the sequence of drug application relative to MN treatment, MN dimensions, and the frequency of MN insertions exhibited noteworthy influence on the resultant local anesthesia efficacy. Together, these results demonstrated that the lidocaine cream followed by diverse PLA MN treatments would be a promising strategy for rapid clinical local anesthesia with wide-ranging applications.

Alloy selection for wear-resistant lightweight aluminium brake disc

Brake discs for the rear axle of a high-performance sports car have been manufactured in three different lightweight materials; AA6082, AA7075 and AA2024 aluminium alloys. These were subsequently coated with a Keronite plasma electrolytic oxidation (PEO) ceramic layer. Full-scale dynamometer tests have been conducted against a standard low-met brake pad using a modified AK master test at increasing levels of braking temperature until a physical limit is reached. Microstructural characterisation of coating and brake pad wear and tribo-layer have been studied using SEM and EDX. In addition, post-dynamometer-test friction discs have been exposed to salt fog testing. Dynamometer tests give confidence that PEO-coated aluminium brake discs are a viable technical solution for vehicle lightweighting. In particular, compelling performance with respect to good coefficient-of-friction (CoF), extremely high coating adhesion, minimal disc and pad wear, low disc run-out, good heat dissipation, and good corrosion resistance has been demonstrated for Mat A (AA6082) alloy discs. Despite higher room temperature strength, the resulting performances of Mat B (AA7075) and Mat C (AA2024) are poor at higher braking temperatures, resulting in excessive coating spallation and subsequent grain boundary attack followed by severe intergranular corrosion.

Low emission stepped piston engine for marine outboard motor application

Separating the scavenging process from the lubrication methodology in conventional two-stroke engines is an effective method of reducing emissions. Segregation of scavenging by use of stepped pistons is one such method providing significant improvements in engine durability, and reduced lubricant consumption, together with reduced production cost. The study discusses the approaches used together with those applied to conventional engines. This paper focusses on a marine outboard motor application and cross-comparisons with a comparable four-stroke outboard motor are drawn within the study. One-dimensional computational fluid dynamics models of the engine types have allowed performance and emissions simulations. Where possible, data from experimental dynamometer testing is compared with the theoretical models. A reasonable level of correlation in terms of performance has been observed. Two-stroke cycle engines are able to demonstrate reduced oxides of nitrogen emissions when compared with conventional four-stroke engines. Models of the stepped piston engine have confirmed the lower NOx emission evident with operation on the two-stroke cycle.