Pad Thickness Research Articles

Immunity response of mice infected with laser irradiated protoscoleces of Echinococcus granulosus

The present study investigated the effect of the Neodymium- Doped Yttrium Aluminum Garnet (Nd: Y3AL5G12) Laser eradiation 1000 mw, against infection with secondary hydatid disease in BALB/c mice by inoculating the animals with protoscoleces of Echinococcus granulosus exposed to laser irradiation, for various periods 40,60,120 and 240 minutes, with viability of 70%,57%,50% and 40%, respectively, contrasted to the control set (mice inoculated with unexposed protoscoleces) along three months, depending on the evaluation of the total count of WBCs and assessment of acquired cell- mediated immunity, demonstrated by delayed type hypersensitivity test (DTH). The results showed considerable increase (p<0.01) in the total WBCs counting, in mice injected with irradiated protoscoleces, up to 13962 cell/cm3, in comparison to the control group 5420 cell/cm3, after 120 minutes, two months post infection. Moreover, there was considerable excess (p<0.01) in the foot pad thickness in treated mice, 2.94 mm after 120 minute (24hour post antigen injection), two months post infection, 2.86mm after 120 minutes (24 hours post antigen injection), 1 month post infection and 2.64 mm, 120 minutes (24 hours post antigen injection), three months post infection, compared with the control group 1.18mm, 1.80mm and 1.72mm, respectively. Results revealed that irradiation of Echinococcus granulosus protoscoleces with laser had a significant influence on the production of WBCs and stimulation of delayed-type hypersensitivity reaction in mice.

МОДЕЛИ ДРУКЕРА-ПРАГЕРА ДЛЯ ДИНАМИЧЕСКОГО АНАЛИЗА ГРАНУЛИРОВАННЫХ МЕТАМАТЕРИАЛОВ В ИНЖЕНЕРНОЙ СЕЙСМОЛОГИИ

Problem of developing methods for protecting buildings and structures from the vibrations transmitted to them from the soil under the action of seismic effects is extremely important to date. One of these modern methods is seismic pads. The purpose of this work was to study the effectiveness of adding a pad of granu-lar metamaterials under the foundation of the building to decrease influence of seismic shear waves. The Finite Element Analysis of Mohr-Coulomb models was used to achieve this goal. The FE model consists of a ten-story superstructure rested on the slab foundation, under which there is a layer of granular metamateri-als. The values of five variables that affect the mechanical properties of these metamaterials were analyzed (density – cohesion – internal friction angle – Young's modulus – Poisson's ratio) for two different pad thicknesses. The dynamic analysis performed using the software package Abaqus/CAE showed the effec-tiveness of the granular metamaterials in their ability to significantly reduce magnitudes of displacements, velocities and accelerations in the building compared to the same values in the absence of these metamateri-als. The analysis also revealed that among the studied variables, the cohesion is the parameter most influenc-ing the effectiveness of metamaterials in their ability to dissipate seismic waves, while no significant effect was observed for the other parameters

Hsa_circ_0044235 regulates the pyroptosis of rheumatoid arthritis via MiR-135b-5p-SIRT1 axis

ABSTRACT Studies have found that cell pyroptosis is involved in the occurrence and development of rheumatoid arthritis (RA). Hsa_circ_0044235 has been found to be significantly low-expressed in RA patients. The purpose of this research was to reveal the regulatory mechanism of hsa_circ_0044235 in the pyroptosis pathway of RA. Serum expressions of hsa_circ_0044235 and SIRT were detected by RT-qPCR, and the relationship of the two genes was analyzed by Pearson. Next, a collagen-induced arthritis (CIA) mouse model was constructed to examine the effect of hsa_circ_0044235 on knee joint injury. The number of apoptotic cells and the level of inflammatory cytokines in synovial tissue were detected by TUNEL and ELISA. Fibroblast-like synoviocytes (FLSs) were extracted as in vitro study subject. Functional assays including flow cytometry and immunofluorescence staining, molecular experiments including RT-qPCR, Western blot and dual luciferase assay, and bioinformatics analysis were performed to analyze the mechanism of hsa_circ_0044235 in pyroptosis in FLSs. Hsa_circ_0044235 and SIRT1 expressions were suppressed in RA patients and the two were positively correlated. Overexpressed hsa_circ_0044235 attenuated joint inflammation, cell apoptosis, and joint damage, reduced foot pad thickness, clinical case scores, inhibited the NLRP3-mediated pyroptosis pathway but promoted SIRT1 expression in CIA mice. Overexpressed hsa_circ_0044235 inhibited caspase-1 content and the NLRP3-mediated pyroptosis pathway. Moreover, hsa_circ_0044235 promoted SIRT1 expression by sponging miR-135b-5p in FLSs. Additionally, the effect of overexpressed hsa_circ_0044235 on FLSs was reversed by miR-135b-5p mimic and siSIRT1, while the effect of siSIRT1 was reversed by miR-135b-5p inhibitor. Hsa_circ_0044235 regulated NLRP3-mediated pyroptosis through miR-135b-5p-SIRT1 axis to regulate the development of RA.

Experimental investigation of two-stage evaporative cooler powered by photovoltaic panels using underground water

Evaporative cooling systems are the most important techniques used in the hot and dry climates of the Middle East. Scorching summer months exist for about five months of the year in Iraq. The outside temperature in this period sometimes exceeding 50 °C. This study investigates an indirect/direct evaporative cooling system (IDEC) operated by PV panels utilizing underground water. Several parameters (number of cooling coils and pads, pad thickness, and different ranges of groundwater flow rate) were experimentally investigated to analyze the performance of the IDEC system. The IDEC consists of two cooling coils as an indirect evaporative cooler (IEC) followed by three cellulose pads as a direct evaporative cooler (DEC). Results indicated that IDEC system with 2 cooling coils and 3 cellulose pads (3 mm thickness with 5 L/min well water flow rate) leads to an increase in the temperature differences (14.9 °C, 18.5 °C, 26.2 °C) and increase the IEC efficiency by 81.88, 82.73, 86.57 and enhancement in the overall efficiency of the IDEC system 118%,125%, 167% respectively. Results demonstrated that using different pad thickness 3, 5, 8, and 10 cm leads to an increase in the IDEC efficiency by 118%, 121%, 146%, 155% respectively. Overall evaporative efficiency of the system (2 coils with 3 pads each pad 3 cm) reach 167% with the temperature difference is 26.2 °C. Using underground water decreases PV temperature by about 20 °C and improves power production by 24%. The proposed IDEC system can provide thermal comfort for the hot and dry regions with energy savings.

Pachydermoperiostosis: A Rare Masquerader of Acromegaly and Thyroid Acropachy

Background: Pachydermoperiostoasis is a rare disease of prostaglandin metabolism that presents with extensive clubbing, skin thickening, and enlargement of hands and feet, often misdiagnosed as acromegaly or thyroid acropachy. Clinical Case: A 29-year-old male presented with progressive enlargement of hands and feet for the past three years, with increased sweating, seborrhea, acne, arthralgia, and photophobia. On examination, facial furrowing and severe clubbing in all fingers and toes was noticed, with palmoplantar hyperhidrosis, tenderness and widening around distal forearms, and increased heel pad thickness. He had nodulocystic acne, injected right eye with ptosis, normal pupil, and visual field. Slit-lamp examination showed extensive pannus formation, with yellow nodules, suggestive of phlyctenular conjunctivitis, secondary to a systemic inflammatory process. No prominent supraorbital ridge, prognathism, proptosis, goiter, or pretibial myxedema. No family history of a similar condition. Labs showed normal cell counts and metabolic panel. Normal IGF-1 (112 ng/mL, n 84-250 ng/ml), TSH (3.82 mIU/L, n 0.27-4.2 mIU/L), fT4 (1.19 ng/dL, n 0.93-1.7 ng/dL), Testosterone (354 ng/dL, n 249-836 ng/dL) and Prolactin (15.2 ng/mL, n 2.1-17.7 ng/mL). Inflammatory markers were elevated with ESR of 54 mm/hr (n 0-15 mm/hr) and CRP of 12.45 mg/L (n 1-4 mg/L). ANA, RF, anti-CCP, and HLA-B27 were negative. C3 and C4 levels were normal as well. Interferon-gamma release assay was negative. Imaging showed a normal chest X-ray. Brain MRI showed normal pituitary gland and increased scalp skin thickness with cutis verticis gyrata “undulating skin sign.” X-ray of hands and feet showed diffuse periosteal reaction. A diagnosis of pachydermoperiostosis (PDP) was made based on clinical criteria (thickened skin, periosteal reaction, and finger clubbing). PDP is a genetic disorder of prostaglandin metabolism with variable expression and incomplete penetrance. It manifests after puberty and affects males more than females with a 7:1 ratio. PDP has been recently shown to go through an inflammatory phase, in which patients may benefit from immunosuppressants or NSAIDs. PDP should be distinguished from hypertrophic pulmonary osteoarthropathy, thyroid acropachy, and acromegaly. Our patient had a normal chest radiograph and normal hormone levels (TSH, T4, and IGF-1). The patient received topical steroids and antibiotics with artificial tears for his eyes, which resulted in a good response, and was referred to a rheumatology clinic for further management. Clinical Lesson: PDP can be mistaken for acromegaly or thyroid acropachy and should be considered in any patient with acromegaloid features with normal IGF-1 and no evident pituitary pathology. Awareness of this condition can help in reaching the diagnosis promptly.

AN ESTIMATION METHOD FOR GREENHOUSE TEMPERATURE UNDER THE INFLUENCE OF EVAPORATIVE COOLING SYSTEM

Temperature is one of the most important plant growth parameters that should be controlled in the greenhouses. The present study was aimed to assess the thermal behavior of a greenhouse with and without the fan and pad (FP) evaporative cooling system. A method was developed to approximate the greenhouse temperature based on the mass and energy balance equations. For this purpose, both of the fan and pad evaporative cooling system, and the greenhouse were studied. The results of the theoretical analysis were compared with those achieved by the experiments. Maximum deviations of 5.32, 5.56 and 4.53oC were observed between the theoretical and experimental temperatures of the inside air, the floor and the cover of the greenhouse without the cooling system, respectively. Whereas, the mean absolute error values associated with the predicted temperatures of the greenhouse with the FP system were ranged between 1.50 and 25.67%. Based on the obtained values for the correlation coefficient, root mean square error and mean absolute magnitude error, it was concluded that the models satisfactorily predicted the temperature of the greenhouse components. An air circulation system inside the greenhouse can be proposed to maintain the lumped condition even at the high temperatures, and lead to smaller errors. The results indicated that the inside air, the floor and the cover temperature of the greenhouse reduced by respectively 20.6, 13.0 and 20.6 oC when using the FP system with the air velocity of 4.4 ms-1 and the pad thickness of 6 cm.

Predictors of Whole-Body Vibration Exposure among Indian Bus and Truck Drivers

Heavy vehicle drivers in the Indian road transport industry are generally exposed to whole-body vibration (WBV) and shock loading resulting in musculoskeletal disorders (MSDs) in their different body parts. Not much work has been done in identifying the contribution of driver’s personal and vehicle/road-related factors in the enhancement of vibration and shock exposure. This study has been conducted on 10 bus and 10 truck drivers from Northern India to investigate the role of these factors. Based on previous studies, the factors or predictor variables included were driver’s age, body mass index (BMI), driving experience, age of vehicle, mileage, age of tyres, and seat pad thickness. 8-hours vector sum acceleration, i.e., (A(8)s) and vibration dose value, i.e., ( VDV(8)s) of 25% of the drivers were found to be more than upper limit values of ISO 2631-1. The WBV exposure magnitudes of acceleration and vibration dose value were much higher along the vertical z-axis than along the longitudinal x-axis and lateral y-axis. The results of univariate linear regression analysis found both vibrations and shocks to be related to the driver’s age, body mass index (BMI), driving experience, vehicle speed, and road roughness. Similar types of results were observed from multiple regression analyses with the only exception that no association was found between BMI and WBV exposure in this case. The results of the study may help the authorities in minimising the risks associated with the driver’s profession.

Hoffa\u2019s fat pad thickness: a measurement method with sagittal MRI sequences

BackgroundHoffa’s fat pad is a structure located within the fibrous joint capsule of the knee joint, but outside the synovial cavity. It plays an important biomechanical and metabolic role in knee joint, reducing the impact of forces generated by loading and producing cytokines. Changes in its size can induce modifications in the knee homeostasis. However, a great variability exists regarding its measurements. This work aims to evaluate the reliability of a measurement method of Hoffa’s fat pad dimensions through MRI.Methods3T sagittal IW 2D TSE fat-suppressed MRI sequences, taken from the OAI (Osteoarthritis initiative) database, of 191 male and female patients, aged between 40 and 80 years, were analysed; a manual measurement of the thickness of Hoffa’s fat pad of each subject was then performed by two different readers. The interobserver reliability and intraobserver reliability of the measurements were described by coefficient of variation (CV), Pearson correlation and Bland–Altman plots.ResultsAll statistical analyses have shown that not significant intra- or interobservers differences were evident (intraobserver CV % for the first observer was 2.17% for the right knee and 2.24% for the left knee, while for the second observer 2.31% for the right knee and 2.24% for the left knee; linear correlation was for the first observer r = 0.96 for the right knee and r = 0.96 for the left knee, while for the second observer r = 0.97 for the right knee and r = 0.96 for the left knee; in addition, the interobserver CV % was 1.25% for the right knee and 1.21% for the left knee and a high interobserver linear correlation was found: r = 0.97 for the right knee and r = 0.96 for the left knee).All results suggest that this manual measurement method of Hoffa’s fat pad thickness can be performed with satisfactory intra- and interobserver reliability.ConclusionsHoffa’s fat pad thickness can be measured, using sagittal MRI images, with this manual method that represents, for his high reliability, an effective means for the study of this anatomical structure.

Reliability Evaluation of Fan-Out Type 3D Packaging-On-Packaging.

The development of fan-out packaging technology for fine-pitch and high-pin-count applications is a hot topic in semiconductor research. To reduce the package footprint and improve system performance, many applications have adopted packaging-on-packaging (PoP) architecture. Given its inherent characteristics, glass is a good material for high-speed transmission applications. Therefore, this study proposes a fan-out wafer-level packaging (FO-WLP) with glass substrate-type PoP. The reliability life of the proposed FO-WLP was evaluated under thermal cycling conditions through finite element simulations and empirical calculations. Considering the simulation processing time and consistency with the experimentally obtained mean time to failure (MTTF) of the packaging, both two- and three-dimensional finite element models were developed with appropriate mechanical theories, and were verified to have similar MTTFs. Next, the FO-WLP structure was optimized by simulating various design parameters. The coefficient of thermal expansion of the glass substrate exerted the strongest effect on the reliability life under thermal cycling loading. In addition, the upper and lower pad thicknesses and the buffer layer thickness significantly affected the reliability life of both the FO-WLP and the FO-WLP-type PoP.

Multiejector CO2 cooling system with evaporative gascooler for a supermarket application in tropical regions

In the present study, the performance of a 33 kW multiejector trans-critical CO2 cooling system is experimentally evaluated for a supermarket application with/without internal heat exchanger and evaporative cooling. In order to enhance the overall performance of the system for tropical regions, the testing is carried out at high ambient temperature (up to 46 °C) with 5 cm, 10 cm and 15 cm cooling pad thickness arrangements. The experimental results clearly projects that the evaporative cooler capacity reaches a maximum of 10 cm pad thickness. However, a minor improvement is observed in terms of Coefficient of Performance and Power Input Ratio beyond 10 cm pad thickness. Maximum improvement in COP with internal heat exchanger and evaporative cooler is 11% and 40% respectively. On the other hand, a maximum reduction in the system Power Input Ratio with internal heat exchanger and evaporative cooler is 8.5% and 26% respectively. However, a minor enhancement in Coefficient of Performance and Power Input Ratio of 4% and 6% are observed respectively with 15 cm cooling pad thickness. Furthermore, a comparative analysis is carried out with the existing and present experimental study to project the compatibility of an evaporative condenser in the ejector based CO2 cooling system. From the study, it is evident that the evaporative cooling arrangement for the gascooler of the CO2 system is suggested as a potential solution to the supermarket application at a high ambient temperature context.

A Step in the Right Direction: A Prospective Randomized, Controlled Crossover Trial of Autologous Fat Grafting for Rejuvenation of the Heel.

The shock-absorbing soft tissues of the heel are composed of dermis and specialized fat pads. Heel fat pad atrophy is common and can be painful and debilitating. In our previous work, autologous fat grafting was effective for treating pain from forefoot fat pad atrophy. The authors hypothesized that autologous fat grafting to the heel would relieve pain and improve function in patients with heel fat pad atrophy. Patients with heel fat pad atrophy and associated pain were recruited and randomized into 2 groups. Group 1 received autologous fat grafting on enrollment and was followed for 2 years. Group 2 received offloading and activity modification for 1 year, then crossed over, underwent autologous fat grafting, and was followed for 1 year afterward. Outcome measures included ultrasound-measured fat pad and dermal thickness; pedobarograph-measured foot pressures and forces; and patient-reported outcomes as measured by the Manchester Foot Pain and Disability Index. Thirteen patients met the inclusion criteria and completed the study. Seven (12 affected feet) were randomized into Group 1; and 6 (9 affected feet) were randomized into Group 2. The average age was 55 years and BMI was 30.5 kg/m2. Demographics did not significantly differ between groups. Heel fat pad thickness increased after autologous fat grafting but returned to baseline at 6 months. However, autologous fat grafting increased dermal thickness significantly and also increased fat pad thickness under a compressive load compared with controls at 6 and 12 months. Foot pain, function, and appearance were also significantly improved compared with controls at 6 and 12 months. Autologous fat grafting improved patient-reported foot pain, function, and appearance and may rejuvenate local soft tissues in patients with heel fat pad atrophy.

Effects of hip protective clothing on thermal wear comfort of clothing ensembles

PurposeThis paper aims to examine the influence of hip protective clothing on ensemble performance attributes related to thermal comfort. It also explores the effect on protective pads of various materials and the arrangements of material. The thermal comfort characteristics are thermal insulation and moisture vapour resistance.Design/methodology/approachFor this research, four ensembles of clothing were used: one ensemble without hip protective clothing and three ensembles with hip protective clothing. A thermal manikin was used to test the thermal insulation and moisture vapour resistance of the ensembles.FindingsThe findings revealed that incorporating hip protective clothing into the clothing ensembles influenced the thermal resistance and moisture vapour resistance of the ensemble. In the “all zones group,” the influence of the hip protective clothing depended on clothing style, with hipster-style clothing producing insignificant changes. In the “hip zones group” and “stomach and hip zones group,” hip protective clothing strongly influenced the thermal comfort attributes of ensembles. Pad material and volume play important roles in these changes in thermal comfort attributes.Originality/valueThese outcomes are useful for the design and engineering of hip protective clothing, where maximizing protection while minimizing thermal and moisture vapour resistance is critical for wear comfort and adherence in warm or hot conditions. The designer should consider that material, volume and thickness of protective pad affect the overall thermal comfort attributes of the hip protective clothing.

Effective Particle Analysis on Wafer in the EKF-CMP System

This study aims to develop a three-dimensional electro-osmosis flow (3D-EOF) cell model for effective particle analysis on the wafer at steady-state under electro-kinetic force (EKF) assistance during chemical mechanical polishing/planarization (CMP). A simulation software is used to simulate the abrasive particle motion with three functional modules including the electric current, the laminar flow, and the particle trajectories. Parameter designs of various simulation conditions such as electrode gap spacing, direct current voltages, and polishing pad thickness have been investigated to analyze the motion of silica abrasive nanoparticles due to EOF. Simulation results of the EOF velocity of slurry flow circulation in different conditions have compared with theoretical calculation results. Results have shown that the total number of effective particles intensifies significantly with increasing electrode voltage, but decreases in both cases as raising electrode gap and larger pad thickness. Experimental results of EKF-CMP process can improve 25.03%, 2.52 nm, 1.39% for material removal rate (MRR), surface roughness, non-uniformity, respectively. It can explain that the wafer surface polishing qualification is significantly by motion of effectual abrasive particles. Results of this study can be extended to contribute to improvement and optimization of EKF-CMP process for Copper CMP process used in IC fabrication.

Splint Padding Thickness: Temperature Effects and X-ray Visualization.

The purpose of this study was to determine if the thickness of splint padding could be determined on X-rays, and whether increasing layers of splint padding have an effect on temperature at the skin after placement. Both in vitro and in vivo testing was performed. Ten cadaveric lower extremities were used. A thermocouple was placed on the posterior calf for temperature determination. Cadavers were used with short leg posterior splints with sidebars placed using various thicknesses of padding: (1) 2 layers of Webril, (2) 4 layers of Webril, (3) 2 × 2 padding (Webril followed by kerlix, then repeated), and (4) bulky cotton padding. A splint with no padding was used as a control. Lateral X-rays of the ankle were obtained. The padding thickness was measured. The change in temperature at the level of the skin was measured throughout the process. The test was then repeated in vivo to correlate the cadaver findings with a live subject. The mean thickness of the 5 padding types could be reliably determined on X-ray. Our cadaver temperature data shows that all padding thickness tested decreased temperature change after plaster curing, with no significant difference between wraps. Live subject testing showed similarities between the 2-layer Webril and 2 × 2 padding, and between the 4-layer Webril and bulky padding. Padding thickness can be consistently determined on X-ray. We determined that at least 2 layers of Webril significantly decrease temperature change at the level of the skin caused by plaster curing. Two layers of Webril can be identified on X-ray by measuring at least 1 mm of padding.

Application of Taguchi and ANOVA methods in the optimisation of a direct evaporative cooling pad

ABSTRACT The evaporative cooling pad system permits to cool buildings with less consumption of the electricity and without any use of refrigerant gases. A good evaporative cooling pad system must have a higher coefficient of performance and a lower rate of water consumption. In this study, the Taguchi method is used to investigate the effect of the velocity, the thickness of the pad, and the type of pads on the performances of cellulosic cooling pads. It was found that the velocity has more influence on the coefficient of performance and the water consumption while the pad thickness is the more significant parameter on the outlet temperature. For the three indicators, the best combinations of the influencing parameters are identified. The obtained results are confirmed by ANOVA analysis, and for fast sizing of the considered cooling pads, a regression model was presented for the aforementioned performance indicators.

Anatomical insights into posterior wall isolation in patients with atrial fibrillation: A hypothesis to protect the esophagus.

Left atrial posterior wall (LAPW) isolation may be performed as an additional atrial fibrillation (AF) ablation strategy based on pulmonary vein isolation. A modified posterior-inferior line (MPL) was proposed for reducing esophageal injury. The aim of this study was to evaluate the anatomical characteristics of the MPL, compared with the conventional posterior line (CPL). Multidetector computed tomography was performed in 102 consecutive AF patients (male/female = 60/42) preoperative, and the parameters were evaluated as follows: the distance from MPL and CPL to the esophagus, fat pad presence and thickness in the course of MPL and CPL, and the esophageal route below CPL. The average distance from the MPL to the esophagus was longer than from CPL to the esophagus (3.7 ± 1.5 vs. 1.7 ± 0.4 mm, p < .001). Proportion of fat pad was higher in the course of MPL than CPL. The myocardium tissue and fat pad under MPL was thicker than under CPL (2.9 ± 1.1 vs. 1.6 ± 0.3 mm, p < .001; 1.4 ± 0.6 vs. 0.9 ± 0.2 mm, p < .001), respectively. In patients whose esophagus was unconfined in a triangular space at the left inferior pulmonary vein level, the average distance from MPL to esophagus was longer than the confined patients (4.0 ± 1.7 vs. 3.2 ± 1.0 mm, p = .001). The MPL was far away from the esophagus with thicker myocardium tissue and more fat pad than the CPL; thus, MPL could serve as a favorable alternative in linear ablation for LAPW isolation.

The effects of gel pad thickness on the evaluation of skin structures using ultrasonography in normal dogs

Gel pads are commonly used in skin ultrasonography; however, the effects of their thickness are unknown. This study investigated the effects of pad thickness on measurements of skin thickness in 10 beagle dogs. Sonograms to measure neck skin thickness were captured without pads and using pads with thicknesses of 3, 5, 10, and 20 mm. Without pads, acoustic shading was observed due to air bubbles in the coupling gel. With 20-mm pads, echogenic artifacts were observed on the skin surface. Entry echo with 20-mm pads was significantly higher than with 3-mm pads. This suggests that visibility of the skin structure could be affected when a gel pad is not used or when a thick gel pad is selected.

Impact attenuation provided by older adult protective headwear products during simulated fall-related head impacts.

IntroductionWhile protective headwear products (PHP) are designed to protect older adults from fall-related head injuries, there are limited data on their protective capacity. This study’s goal was to assess the impact attenuation provided by commercially available PHP during simulated head impacts.MethodsA drop tower and Hybrid III headform measured the decrease in peak linear acceleration (g atten ) provided by 12 PHP for front- and back-of-head impacts at low (clinically relevant: 3.5 m/s) and high (5.7 m/s) impact velocities.ResultsThe range of g atten across PHP was larger at the low velocity (56% and 41% for back and frontal impacts, respectively) vs. high velocity condition (27% and 38% for back and frontal impacts, respectively). A significant interaction between impact location and velocity was observed (p < .05), with significantly greater g atten for back-of-head compared to front-of-head impacts at the low impact velocity (19% mean difference). While not significant, there was a modest positive association between g atten and product padding thickness for back-of-head impacts (p = .095; r = 0.349).ConclusionThis study demonstrates the wide range in impact attenuation across commercially available PHP, and suggests that existing products provide greater impact attenuation during back-of-head impacts. These data may inform evidence-based decisions for clinicians and consumers and help drive industry innovation.

Experimental investigation of air-conditioning and HDH desalination hybrid system using new packing pad humidifier and strips-finned helical coil

A low energy HDH (humidification-dehumidification) and AC (air-conditioning) hybrid system using an efficient design of dehumidifier (strips-finned helical coil) and packing pad material (cellulose paper in bee-hive structure) is proposed. An experimental investigation of the performance of the proposed system is conducted for wide ranges of air and water flow rates and temperatures and packing pad thickness. The results showed that (i) the proposed hybrid system can produce fresh water and remove space cooling load to maintain the required comfort conditions, (ii) the fresh water production rate, cooling load capacity and the system performance increase with increasing air and water flow rates and temperatures and cooling pad thickness, (iii) the proposed HDH system with the new humidification-dehumidification sections has better productivity and performance compared to other systems, (vi) daily production cost of the system increases with increasing inlet air and water flow rates and decreasing cooling pad thickness and air and water temperatures, and (v) production cost per kg of fresh water decreases by increasing cooling pad thickness and air and water flow rates and temperatures. The system performance parameters (fresh water productivity, cooling load capacity, space supply air temperature and coefficient of performance) can reach to 17.42 kg/h, 3.9 kW and 16 °C, and 4.35, respectively. Moreover, the lowest specific cost of fresh water production can be obtained is 0.7 ¢/kgFW, respectively. Finally, empirical correlations of system productivities and performance parameters in terms of operating conditions and system geometric parameters were predicted within acceptable errors.

Review and experimental study on performance improvement of split air conditioner by reducing inlet air temperature to the ODU

Split Air Conditioners (ACs) are more commonly use now a days in residential and commercial buildings for achieving thermal comfort in all seasons. Split ACs works on well-known VCR (Vapour Compression Refrigeration) cycle. Split ACs used more in summer season and due to high outside temperature condenser pressure in a VCR cycle and ultimately result in to high electricity consumption. One of the way to reduce energy consumption of Split ACs and increase cooling capacity is reduce air temperature entering to the condenser in ODU using evaporative cooling principle. In this paper detailed review have been carried out for the improvement of split air conditioner performance and experimental study conducted on Split AC (0.8 TR cooling capacity) with and without evaporative cooling pad at ODU. Evaporative cooling pad material and thickness have been varied to analyse their effects on cooling capacity and coefficient of performance (COP) of Split AC. Out of the PVC, Grass and Cellulose cooling pad of same thickness 150 mm, cellulose cooling pad at ODU of Split AC results about 2 bar reduction in condenser pressure and 1.5 KWH energy saving for 10 hours of operation in a day. Split AC with 100 mm thick cooling pad of cellulose material at ODU results in to approximately 16% increase in overall COP, 10.8 % increase in cooling capacity and 4.6 % reduction in power consumption and at 32°C DBT and about 35% RH outdoor weather condition.