Search

Tests of adsorption cooling prototypes with solar energy that use the silica gel–water​ pair have been reported in the literature; however, there is no work that analyzes, compares and integrates them to generate new knowledge from their data and results. In this context, our proposal consists comparing thermodynamic results, determining the characteristics of their parts and functions, and analyzing technical contradictions through the TRIZ methodology, for twelve identified adsorption refrigeration prototypes (including one where a co-author of this paper participated). The results and characteristics of the analyzed prototypes have been systematized, also a diversity of constructive forms was found in the studied prototypes, as well as in the non-standardized results and tests because some aspects were emphasized in each test. The results and simulations are compared using COP and refrigeration capacity as parameters to extrapolate new results consisting of a hybridized conceptual model and projected test results based on those found in the literature.

In this project an air conditioner was fabricated using R-410a as refrigerant and its COP is calculated. CFCs have been phased out, except for essential users, and HCFCs are to be eliminated by 2020, because of their ozone depletion potential.This generates a need for the investigation of zero ozone depletion potential (ODP) refrigerants or refrigerant blends.R410A is among newer brand of refrigerant blend, with zero ODP. The biggest difference to R22 is the pressure levels generated which are more than50% higher. The refrigerant R410A operates at higher pressure at the same saturated temperatures than R22, therefore system should be re designed. The overall COP of the system is 5 to 6% more than the R22. We also calculated the relative humidity of room air after it gets cooled, heat removed from the air by considering the input data from weather online which provides us the day to day climatic conditions. Present work provides us regarding performance of an self fabricated zeotropic air conditioner.

The paper presents 3E (energy, exergy and economic) analysis of a modified Kalina power-cooling vapour absorption cycles (KLPCCs) for better thermo-economic figures of merit to drive affordable energy access and climate change mitigation. The analysis presents a balanced technical and economic conclusion in view of resource management and sustainability. The system utilized a Kalina power-cooling system at the topping cycle and an embedded vapour absorption system (VAB) at the bottoming cycle, which is a novelty. In the modified KLPCC, a supplementary evaporator and heat exchangers are integrated with the bottoming cycle. The considered performance indicators include energy efficiency, exergy efficiency, cooling rate, turbine net output, COP, and cost rate. From the results, about 1077 kW cooling rate was produced, while the energy efficiency, exergy efficiency, COP, and turbine output were estimated at 16.97 %, 8.15 %, 0.706, and 291 kW, respectively. The LCC of $ 1.573 million was achieved, with the break-even point and unit energy cost calculated at five years and 0.0134 $/ kWh, respectively. The outcomes are holistic and adequate for policymakers in the field of energy access and environmental sustainability.

The aim of this project is to design a solar thermal absorption air conditioning system that operates under UAE climate conditions. In absorption system, compressor which is normally used in conventional AC system, replaced by a chemical cycle that consists of a generator, absorber, pump, and expansion valve, while the rest of the components such as the evaporator, condenser, and expansion valve remain the same as conventional AC system. In this design, the water and lithium bromide pair is used as a refrigerant and absorbent, respectively. The generator is driven by an evacuated solar collector to heat the lithium bromide in the chemical cycle, while a solar PV panel, which ensures that the system works 100% by solar energy, drives the pumps and fans. An energy storage device also incorporated in the system to run it round the clock. An experimental investigation of the proposed design is presented in the paper. Results suggest that the proposed design match well to meet the cooling load demand which was about 300 watts. Furthermore, the system able to provide a desired as well as uniform comforts temperature at about 23 °C inside the room. The system COP was calculated to be 0.51. Life cycle analyses were also carried out using Eco Audit CES Edu pack software to study the viability of the new design. The results showed that the proposed new system is economically viable and environmentally friendly. Keywords: Absorption cooling, Water–liBr, Solar energy, Solar PV, COP, Life cycle analysis

Compression of vaporized refrigerant is the essential process of the refrigeration cycle which is performed by using a compressor. The amount of power consumed by a refrigeration system is governed by the work input given to its compressor, which also determines the COP of the system. By reducing the work input given to the compressor, the power consumption of refrigerator is reduced along with the improvement in its COP. Nowadays, nanoparticles have emerged as the new generation additives in various working fluids because of their remarkable ability to improve the heat transfer, tribological and other thermophysical properties of the base fluid. In such a vein, we propose a compressor oil based nanofluid prepared by dispersing nanoparticles into the conventional compressor oil. In the present study, four samples of nanoadditive compressor oil were prepared by dispersing the nanoparticles like Al2O3, TiO2, and ZnO into the conventional mineral oil as a lubricant. The tribological properties of this four samples were studied, out of which one sample gave a better lubrication and heat transfer properties which are considered as one of the key parameters for reducing work input to the compressor, this can result in reduced power consumption, with enhancement of COP. These results are analyzed experimentally by carrying out performance and exergy analysis in a vapor compression refrigeration system, using R600a as a refrigerant. The experimental results show that, there is an improvement of COP by 14.61% and exergy efficiency by 7.51%. Also, the efficiency defect in the major components of vapor compression refrigeration system has been reduced effectively.

CO2 systems used in refrigeration are becoming more complex with the aim of improving their energy performance. Parallel compression is one of the implemented solutions to enhance the performance of the plants. However, an optimization process is required to operate this system at high performance and its operation is subjected to physical limitations in real plants. This work presents the experimental optimization of a transcritical CO2 plant working with parallel compression. The plant is tested at different discharge pressures and different secondary compressor speeds in order to optimize the COP of the plant and determine the optimal conditions for three gas-cooler exit temperatures 27.5ºC, 32.5ºC and 37.5ºC and three evaporation levels: -15.0ºC, -10.0ºC and -5.0ºC. The optimal working conditions that can be achieved in a real plant have been determined, obtaining COP from 1.71 to 2.63 for -5.0ºC, from 1.50 to 2.22 for -10.0ºC and from 1.25 to 1.84 for -15.0ºC. Cooling capacity ranges from 8.94 kW to 11.34 for -5.0ºC, from 7.71 kW to 9.47 kW for -10.0ºC and from 6.22 kW to 7.76 kW for -15.0ºC. The trends observed in theoretical results have been corroborated and the optimum gas-cooler and intermediate pressures have been determined and discussed.

Air-conditioning system notably contributes to global warming owing to the huge amount of energy consumption. Moreover, this system uses HFC based refrigerants, which have high global warming potential (GWP). This work investigates the direct and indirect impacts of GWP for commercial and residential air-conditioning systems considering the three widely used HFC based refrigerants. The warming impacts are assessed in terms of cooling load, co-efficient of performance (COP), evaporation temperature, and condensation temperature for three different locations in Japan. The indirect emission of the air-conditioning systems (commercial and residential) for different major cities of Japan is estimated in terms of energy demand and hours of operation. The results of this work indicate that the HFC based refrigerants such as R134a and R32 have lower warming impact compared to that of R410A refrigerant. Furthermore, the economic loss due to refrigerant leakage is also assessed.

In this study, a TRNSYS model for a solar‐assisted heat pump (SAHP) water heating system for a university bathroom in Xi'an was developed and validated through experimental measurements. Under the typical meteorological conditions in Xi'an, a comparative analysis of the performance of the serial indirect expansion SAHP (IDX‐SAHP) system and the parallel IDX‐SAHP system during different seasons was conducted using the validated model. The results demonstrated that for annual operation, the parallel IDX‐SAHP system showed better performance in the Xi'an district compared to the serial system. Under the same heating load, the average coefficient of performance (COP) of the serial IDX‐SAHP system was 3.23 and that of the parallel IDX‐SAHP system was 4.34. In particular, during summer and the transition season, the parallel IDX‐SAHP system showed large advantages, mainly owing to a larger part of the heating load being provided by the solar collector. However, the serial IDX‐SAHP system showed a higher efficiency than that of the parallel IDX‐SAHP system during winter conditions.

To evaluate the correlation between plasma protein concentration and colloid oncotic pressure (COP) and their influence on clinical symptom of edema, we studied 30 children with nephrotic syndrome (NS). Total plasma protein concentration (TP), albumm, globulin and COP were measured in all patients in edema forming state (EF) and m steady state phase (SS), except for COP, only 16 samples in SS phase. COP TP plasma albumin and globulin contents in EF group were 8. 7 ± 2. 7 mmHg, 4.07 '± 0.68 g/dl; 2.57 ± 0.50 g/dl and 1.51 ± 0.32 g/dl, respectively. In SS group these figures rose significantly to 16.7 ± 3.9 mmHg for COP; 5. 70 ± 0.99 g/dl for TP; 3.46 ± 0.52 g!dl and 2.06 ± 0.56 g/dl for plasma albumin and globulin, respectively. We also found the high correlation both between COP and albumin content (r= +0.58; p < 0.01) and between COP and TP (r= +0.54; P < 0.01) . A strong negative correlation was also found between COP and the degree of edema (r = _ 0.55; p 0.05). We conclude that COP has the highest correlation with plasma protein concentration and the degree of edema, and can be used as a diagnostic tool. It is even more sensitive and simple compared with the TP or albumin content determination.

Restrictive environmental regulations are driving the use of CO 2 as working fluid in commercial vapour compression plants due to its ultra-low global warming potential (GWP 100 = 1) and its natural condition. However, at high ambient temperatures transcritical operating conditions are commonly achieved causing low energy efficiencies in refrigeration facilities. To solve this issue, several improvements have been implemented, especially in large centralized plants where ejectors, parallel compressors or subcooler systems, among others, are frequently used. Despite their good results, these measures are not suitable for small-capacity systems due mainly to the cost and the complexity of the system. Accordingly, this work presents a new subcooling system equipped with thermoelectric modules (TESC), which thanks to its simplicity, low cost and easy control, results very suitable for medium and small capacity plants. The developed methodology finds the gas-cooler pressure and the electric voltage supplied to the TESC system that maximizes the overall COP of the plant taking into account the ambient temperature, the number of thermoelectric modules used and the thermal resistance of the heat exchangers included in the TESC. The obtained results reveal that, with 20 thermoelectric modules, an improvement of 20% in terms of COP and of 25.6% regarding the cooling capacity can be obtained compared to the base cycle of CO 2 of a small cooling plant refrigerated by air. Compared to a cycle that uses an internal heat exchanger IHX, the improvements reach 12.2% and 19.5% respectively. The authors would like to acknowledge the support of the Spanish Ministry of Science, Innovation and Universities for the funding under the FPU Program (FPU16/05203).

Community-police relations in Pakistan are often intricate, as are their reforms. Mistrust, political intervention, meager financial resources, lack of educated/trained human resources, over-expectations and miscommunication are some of the factors contributing to weak policing and poor community-police relations. The police as a service-oriented public institution has been a demand of the public and the dream of consecutive governments. In this study, we explore the political, institutional and technical reforms taken by the government of Khyber Pakhtunkhwa (KP) and the police department to improve their police and policing. The Police Act 2017 and Community-Oriented Policing, Dispute Resolution Councils (DRCs), and Information and Communications Technology (ICT) initiatives are critically analyzed in terms of their intentions and contribution to improved police-community relations. Politicians, police, civil society organizations and community members from KP were interviewed for their perceptions of police reforms and community-police relations. The study finds strong political will to empower and depoliticize police, and to shift its focus from purely crime fighting into community service provision, including pro-active engagement of police with the community. The study also finds that most of the new initiatives of the government of KP are in the spirit of community--oriented policing, and community members see visible improvement in policing and community-police relations.

In this study, a branched GAX absorption cycle operating with NH3-H2O pair has beeninvestigated to assess its performance under steady state conditions. The cycle modeling isimplemented using Engineering Equation Solver (EES) software. Analysis includesequations of mass, species and energy conservation. The analysis is used to simulate a GAXabsorption chiller utilization for air conditioning applications with a nominal capacity of 95TR. This chiller uses solar collectors as heat source. The operating parameters are selected atdifferent values of the heat source temperature (140 - 185°C), condenser exit temperature(30 to 48°C), evaporator exit temperature (2 to 11°C) ; split ratio (0 to 0.18); the difference inammonia concentration(0.25-036), mass flow rate in solution pump mr=1 kg/s; heatexchanger effectiveness ? ? 0.8. The results showed that the average COP is sensitive tooperating conditions where the average COP and cooling capacity of the branched GAXabsorption chiller increase with increasing generator and evaporator temperature whereasthey decrease with increasing condenser temperature. Simulation results also show that thesplit ratio and ammonia concentration difference have a significant impact on theperformance of absorption chiller.

This work presents an experimental study of an ammonia-water absorption refrigeration system using the exhaust of an internal combustion engine as energy source. The exhaust gas energy availability, the performance of the absorption refrigeration system and the engine performance are evaluated. A commercial turbocharged Diesel engine has been tested in a bench test dynamometer, with the absorption refrigeration system adapted to the exhaust system. The maximum COP obtained from the refrigeration system is 0.136 and it has been shown that heat energy available with exhaust gas is capable of producing sufficient cooling capacity for air conditioning the vehicle without requiring any energy input from the engine.

[Purpose] The general motor strategy for gait initiation is achieved by the difference between the center of gravity and center of pressure; it be as bigger under speed optimization. This study aimed to investigate the motor pattern in rapid gait initiation under conditions of limited backward displacement of center of pressure. [Participants and Methods] The participants were 30 healthy young males (mean age, 19.7 ± 1.0 years). They performed a gait initiation task at three center of pressure start positions (anterior, middle, and posterior) and two speed conditions (normal and rapid). The gait initiation motion was measured using a video camera and motor pattern in the images was classified. The center of pressure position was continuously monitored using a pressure distribution measurement system. [Results] Forward tilt pattern was the most common under no limited center of pressure control and normal speed. The backward tilt pattern was the most preferred in the posterior position under limited center of pressure control and rapid speed. Displacement of the center of pressure showed a significant decline when the center of pressure start position was displaced backward. [Conclusion] The backward tilt pattern is the most effective motor strategy to increase the forward speed of the center of gravity.

Introduction An optimal hip implant is biocompatible, durable, and resistant to chemical and mechanical wear. This analysis aimed to compare failure (revision) and complication rates between ceramic-on-ceramic (CoC) and ceramic-on-highly-crosslinked-polyethylene (CoHXLPE) implants. Methods This review comprised of scientific literature published between 1995 and 2019. We included randomized controlled trials in adults (>18 years) that presented results of CoC and CoHXLPE total hip arthroplasty (THA) with more than two years of mean follow-up and drafted in English. The primary outcomes for this analysis were complications, revision rates, and loosening rates. Results Eight studies (1,689 hips) were included in this systematic review. There was no significant differences between COC and CoHXLPE for the risk of post-surgical complications (relative risk [RR]: 1.98, 95% confidence interval [CI]: 0.83-4.69, P = 0.12). Revision rates (RR: 1.25, 95% CI: 0.71-2.20, P = 0.43] and loosening rates between the two implants were not significantly different (RR: 1.17, 95% CI: 0.30-4.52, P = 0.82). Conclusion We report no significant differences between CoHXLPE and CoC in adults undergoing primary THA. Although introduced relatively recently, CoHXLPE is a cost-effective bearing that can be used for younger patients with no risk of increased complications in comparison to CoC. Further studies with longer follow-up periods are recommended to confirm the findings of this meta-analysis.

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

Purpose This paper aims to study the impact of intentionally developed communities of practice (CoPs) on knowledge sharing and practice improvement in an administrative public sector organisation (PSO). Design/methodology/approach A case study approach was used to analyse the impact of the CoPs intentionally developed by four different teams at a Danish PSO. The study applied a CoP development framework suggested by the literature to develop the CoPs. Findings Three out of the four CoPs were successfully developed, and they positively affected knowledge sharing and practice improvement. CoP participants engaged in conversations to explore individual ways of working, share knowledge and ultimately improve practice. Standardisation and boundary spanning were identified as contextual factors influencing the CoP activities. Research limitations/implications The findings verify the framework and contribute to a better understanding of the factors affecting the development of CoPs that positively impact knowledge sharing and practice improvements in a PSO context. Practical implications The study provides operations managers in PSOs with a framework for developing CoPs to improve work performance through better knowledge sharing among employees. Originality/value The paper provides case study evidence for the relevance of CoPs in PSO settings and highlights the necessity of investing resources in employee knowledge-sharing interactions.

The number of large-scale heat pumps (HP) implemented in Danish district heating networks has increased in recent years. The installations are often custom-made solutions designed carefully to obtain a high Coefficient of Performance (COP). This study aims at quantifying and compare five approaches for improving the COP of a heat pump, with a one-stage ammonia cycle used as the reference case with sink temperatures of 50 °C/80 °C (in/out) and source temperatures of 10 °C/3 °C. The approaches include increased complexity of cycle layout, optimization of intermediate pressure in two-stage cycles, a connection of HP cycles in series, optimization of load share between heating capacity for HPs in series, and optimal design of heat exchanger networks (HEN). The latter is based on an implementation of pinch analysis to HP HENs. The results revealed an improvement in COP by +15.8% obtained with increased complexity of cycle layout (two-stage cycle with a low-stage desuperheater) compared to a COP of 2.98 for the reference case. Connecting up to three one-stage HPs and two-stage cycles in series improved COP by 4.42% and 24.5%, respectively. The benefit of optimal load share and intermediate pressure was less than 0.5 % points for all configurations compared to reference values based on theoretical approaches. Exploiting the potential for optimal HEN increased the potential to 10.4% for one-stage cycles in series and nearly 29% for two-stage cycles increasing the COP to a maximum of 3.84.

This research was performed experimentally and determined the first and second law performance (energetic and exergetic) of a split type air conditioner. A blend of R22 and R600a (80:20 by mass) was used as a refrigerant with TiO2/Mineral oil (MO) as a lubricant for a varied concentration of TiO2 (0.1–0.4%) as a drop-in replacement of R22/POE. The obtained data were analyzed to investigate the thermodynamic performance including compression work, compressor discharge temperature, cooling effect, coefficient of performance (COP), and exergy destroyed in the compressor, total exergy destruction, sustainability, and exergy efficiency. The analysis was based on temperature, pressure readings recorded from the appropriate gauge, and the physical and thermal properties of the refrigerants were extracted from REFRPROP 7.0 software. Experimental outcomes showed that both energetic and exergetic performance was improved for a blend with nanolubricants compared to R22. The compressor outlet temperature was found to be decreased by 15 ​°C for the blend with 0.4% TiO2/MO nanolubricant. Again, COP was improved by 10–19.5% for the various concentration of nanolubricant. The exergetic performance was also increased with the increase of concentration of nanolubricants and exergy destruction was reduced by 20.1–37.4% for the nanolubricant. It was found that exergy efficiency was also increased by 38–42.88% compared to R22. Also, exergy destruction and entropy generation were found to be maximum for the compressor compared to other components. Based on this experimental work, it can be concluded that nanolubricant and refrigerant blends worked safely without any modification in this system.

Purpose To determine the sensorimotor and clinical function of patients with confirmed successful outcome after either undergoing acromioclavicular joint (ACJ) stabilization, Bankart repair (BR), or rotator cuff repair (RC), and to compare these measures to the contralateral, healthy side without history of previous injuries or surgeries of the upper extremity. It was hypothesized that patients of each interventional group would have inferior sensorimotor function of the shoulder joint compared to the contralateral, healthy side, while presenting with successful clinical and functional outcomes. Methods Three intervention groups including ten patients who had confirmed successful clinical and functional outcomes after either undergoing ACJ stabilization, BR, or RC were evaluated postoperatively at an average follow-up of 31.7 ± 11.6 months. Additionally, a healthy control group (CG) of ten patients was included. Clinical outcomes were assessed using the Constant–Murley (CM) and American Shoulder and Elbow Surgeons (ASES) Score. Pain was evaluated using the visual analogue scale (VAS). Sensorimotor function was assessed by determining the center of pressure (COP) of the shoulder joint in a one-handed support task in supine position on a validated pressure plate. Results Each interventional group demonstrated excellent clinical outcome scores including the CM Score (ACJ 83.3 ± 11.8; BR 89.0 ± 10.3; RC 81.4 ± 8.8), ASES Score (ACJ 95.5 ± 7.0; BR 92.5 ± 9.6; RC 96.5 ± 5.2), and VAS (ACJ 0.5 ± 0.9; BR 0.5 ± 0.8; RC 0.5 ± 0.8). Overall, the CG showed no significant side-to-side difference in COP, whereas the ACJ-group and the BR-group demonstrated significantly increased COP compared to the healthy side (ACJ 103 cm vs. 98 cm, p = 0.049; BR: 116 cm vs. 102 cm, p = 0.006). The RC-group revealed no significant side-to-side difference (120 cm vs. 108 cm, n.s.). Conclusion Centre of pressure measurement detected sensorimotor functional deficits following surgical treatment of the shoulder joint in patients with confirmed successful clinical and functional outcomes. This may indicate that specific postoperative training and rehabilitation protocols should be established for patients who underwent surgery of the upper extremity. These results underline that sensorimotor training should be an important component of postoperative rehabilitation and physiotherapeutic activities to improve postoperative function and joint control. Level of evidence IV.

Central nervous system (CNS) uses vision, vestibular, and somatosensory information to maintain body stability. Research has shown that there is more lumbar proprioception error among low back pain (LBP) individuals as compared to healthy people. In this study, two groups of 20 healthy people and 20 non-specific low back pain (NSLBP) participants took part in this investigation. This investigation focused on somatosensory sensors and in order to alter proprioception, a vibrator (frequency of 70 Hz, amplitude of 0.5 mm) was placed on the soleus muscle area of each leg and two vibrators were placed bilaterally across the lower back muscles. Individuals, whose vision was occluded, were placed on two surfaces (foam and rigid) on force plate, and trunk angles were recorded simultaneously. Tests were performed in eight separate trials; the independent variables were vibration (four levels) and surface (two levels) for within subjects and two groups (healthy and LBP) for between subjects (4 × 2 × 2). MANOVA and multi-factor ANOVA tests were done. Linear parameters for center of pressure (COP) [deviation of amplitude, deviation of velocity, phase plane portrait (PPP), and overall mean velocity] and non-linear parameters for COP and trunk angle [recurrence quantification analysis (RQA) and Lyapunov exponents] were chosen as dependent variables. Results indicated that NSLBP individuals relied more on ankle proprioception for postural stability. Similarly, RQA parameters for the COP on both sides and for the trunk sagittal angle indicated more repeated patterns of movement among the LBP cohort. Analysis of short and long Lyapunov exponents showed that people with LBP caused no use of all joints in their bodies (non-flexible), are less stable than healthy subjects. ispartof: FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY vol:8 ispartof: location:Switzerland status: published

Energy is at the basis of any social or economic development. The fossil energy is the most used energy source in the world due to the cheap building cost of the power plants. In 2017, fossil fuels generated 64.5% of the world electricity. Since, on the one hand, these plants produce large amount of carbon dioxide which drives climate change, and on the other hand, the storage of existing world fossil resources is in continuous decrease, safer and highly available energy sources should be considered. Hence, for human well-being, and for a green environment, these fossil plants should be switched to cleaner ones. Renewable energy resources have begun to be used as alternatives. These resources have many advantages such as sustainability and environmental protection. Nevertheless, they require higher investment costs. In addition, the reliability of many planted systems is poor. In most cases these systems are not sufficient to ensure a continuous demand of energy for all in needy regions because most of their resources are climate dependent. The main contributions of this research are (i) to propose a natural formalisation of the renewable energy distribution problem, based on COP (Constraint Optimisation Problem), that takes into consideration all the constraints related to this problem; (ii) to propose a novel multi-agent dynamic (A-RESS for Agent based Renewable Energy Sharing System) to solve this problem. The proposed system was implemented and the obtained results show its efficiency and performance in terms of produced, consumed and lost energy.

The role of optic flow in the control of balance in persons with Parkinson's disease (PD) has yet to be studied. Since basal ganglia are understood to have a role in controlling ocular fixation, we have hypothesized that persons with PD would exhibit impaired performance in fixation tasks, i.e., altered postural balance due to the possible relationships between postural disorders and visual perception. The aim of this preliminary study was to investigate how people affected by PD respond to optic flow stimuli presented with radial expanding motion, with the intention to see how the stimulation of different retinal portions may alter the static postural sway. We measured the body sway using center of pressure parameters recorded from two force platforms during the presentation of the foveal, peripheral and full field radial optic flow stimuli. Persons with PD had different visual responses in terms of fixational eye movement characteristics, with greater postural alteration in the sway area and in the medio-lateral direction than the age-matched control group. Balance impairment in the medio-lateral oscillation is often observed in persons with atypical Parkinsonism, but not in Parkinson's disease. Persons with PD are more dependent on visual feedback with respect to age-matched control subjects, and this could be due to their impaired peripheral kinesthetic feedback. Visual stimulation of standing posture would provide reliable signs in the differential diagnosis of Parkinsonism.

District heating systems are gaining an increasing importance in the space heating and the production of Domestic Hot Water. Focusing on the geothermal energy as the energy supply of these systems, an optimal design could involve an increased number of geothermal district heating installations. This research presents two different designs of a groundwater heat pump system from the application of initial real data. Both designs differ in the heat pumps: 1 installation in scenario 1 and 3 installations in scenario 2. The procedure includes the calculation of all the required geothermal parameters in both assumptions. Optimization of the drilling schema is carried out using COMSOL Multiphysics software. Technical and economic results reveal that scenario 1 is the most suitable option for the study case here presented. Global initial investment is lower in scenario 1 the same as the annual operational costs since the coefficient of performance of the heat pumps in this scenario 1 is slightly higher than the one of each module of scenario 2.

Cryptogenic organizing pneumonia is a rare idiopathic interstitial lung disease, with a well-defined clinical-radiological and pathological entity. It may also be secondary to several causes. Rapid clinical and imaging improvement is usually obtained with corticosteroid therapy. We report here, to the best of our knowledge, a unique case of organizing pneumonia associated with Sertraline, a selective serotonin reuptake inhibitor, commonly used in antidepressant therapy.

Background/objective: Standing balance has become an important clinical measure in patient populations who are at risk of falls or have osteoarthritis. With custom-written software, the Wii Balance Board (WBB) has been shown to be a valid and reliable force platform that can be used to assess standing balance. However, no studies to date have assessed the use of the more readily available Wii Stillness Score (WSS) as a measure of balance. Methods: Twenty-four individuals without lower limb pathology performed a combination of unilateral and double leg standing balance tests with eyes open or closed on two separate occasions. At each session, data from the WBB were acquired on a laptop computer running custom software and then by Wii-Fit software on a Wii console. The reliability of the WSS was determined by assessing reproducibility, while the validity of the WSS was determined by comparing the results of the WSS to that of the custom-written software. Results: We found that the WSS exhibited excellent intra and inter device reliability in three out of four stances tested. The Bland-Altman plots also showed good concurrent validity for the three analysed stances. However, there remain significant limitations with the use of the WSS such as its rigid thirty-second time parameter and single score result. Conclusion: The readily available WBB may be a used as a portable and inexpensive device to assess standing balance with custom written software. However, with the current limitations of the WSS, we would discourage its use as a clinical measure of balance. Keywords: Wii-fit, Standing, Balance, Stillness score, Wii balance board, CoP

Background Falling is the most common accident of daily living and the second most prevalent cause of accidental death in the world. The complex nature of risk factors associated with falling makes those at risk amongst the elderly population difficult to identify. Commonly used clinical tests have limitations when it comes to reliably detecting the risk of falling, but existing laboratory tests, such as force platform measurements, represent one method of overcoming this lack of a test. Despite their widespread use, however, Center of Pressure (COP) signal analysis techniques vary and there is currently no consensus on which features should be used diagnostically. Our objective is to identify, through a systematic review and meta-analysis, the COP characteristics of older adults (≥ 60 years old) during quiet bipedal stance which will allow fallers to be distinguished from non-fallers. Methods The systematic review will include both prospective and retrospective articles. Five databases will be searched: PubMed, Cochrane CENTRAL, EMBASE, and ScienceDirect. In addition, a search of gray literature will be performed using Google Scholar and ClinicalTrials.gov. Searches will be circumscribed to include only older adults (aged over 60 years) who underwent a bipedal quiet standing measure of their balance and for whom the number of falls was reported. Two authors will independently assess the risk of bias for each included article using a 26-item checklist. Funnel plots will be drawn to attest of possible publication biases for each COP parameters. The results will be synthesized descriptively and a meta-analysis will be undertaken. When trial methodological heterogeneity is too great for pooling of the data into a meta-analysis, evidence strength will be evaluated using best evidence analysis. Discussion Despite the numerous advantages of posturography, the diversity of studies exploring balance in older fallers has led to uncertainty regarding the method’s ability to reliably identify fall-prone older adults. It is expected that the findings from this systematic review will help clinicians use bipedal quiet standing measures as a diagnostic test and allow researchers to explore COP characteristics to create better models for fall prevention care. Systematic review registration PROSPERO CRD42018098671 Electronic supplementary material The online version of this article (10.1186/s13643-019-1147-9) contains supplementary material, which is available to authorized users.

Background Reducing greenhouse gas emissions is a vital step in limiting climate change and meeting the goals outlined in the COP 21 Paris Agreement of 2015. Studies have suggested that agriculture accounts for around 11% of total greenhouse gas emissions and the industry has a significant role in meeting international and national climate change reduction objectives. However, there is currently little consensus on the mechanisms that regulate the production and assimilation of greenhouse gases in arable land and the practical factors that affect the process. Practical advice for farmers is often overly general, and models based on the amount of nitrogen fertiliser applied, for example, are used despite a lack of knowledge of how local conditions affect the process, such as the importance of humus content and soil types. Here, we propose a systematic map of the evidence relating to the impact on greenhouse gas flux from the agricultural management of arable land in temperate regions. Methods Using established methods for systematic mapping in environmental sciences we will search for, collate and catalogue research studies relating to the impacts of farming in temperate systems on greenhouse gas emissions. We will search 6 bibliographic databases using a tested search string, and will hand search a web-based search engine and a list of organisational web sites. Furthermore, evidence will be sought from key stakeholders. Search results will then be screened for relevance at title, abstract and full text levels according to a predefined set of eligibility criteria. Consistency checking will be employed to ensure the criteria are being applied accurately and consistently. Relevant studies will then be subjected to coding and meta-data extraction, which will be used to populate a systematic map database describing each relevant study’s settings, methods and measured outcomes. The mapping process will help to identify knowledge gaps (subjects lacking in evidence warranting further primary research) and knowledge clusters (subjects with sufficient studies to allow a useful full systematic review), and will highlight best and suboptimal research methods.

The refrigerants used in conventional vapor-compression air conditioning systems have detrimental effects on the global environment. Phasing-down hydrofluorocarbon (HFC) refrigerants for HVAC equipment over the next 20 years has been proposed. A thermoelectric air conditioning system that directly converts electrical energy to thermal energy using a simple solid-state semiconductor device, has the advantages of environmentally friendly, no refrigerant, very compact, high reliability, no moving parts (except for small fans), and it can be easily integrated into the building structure. However, the existing thermoelectric air conditioning systems have the problem of low Coefficient of Performance (COP), which limits its applications for domestic air conditioning. With the development of the thermoelectric technologies, the above problem is prospected to be solved. The paper presents an overview of recent advances in thermoelectric materials, thermoelectric module design and thermoelectric heating and cooling system design which would provide the potential to greatly improve the COP of the thermoelectric air conditioner. In addition, utilizing the waste heat of the thermoelectric system for domestic applications to improve the overall COP of the system would be an ideal way to promote public adoption of the TE air conditioner, which is discussed in this paper. The paper also presents an overview of the existing building integrated thermoelectric air conditioning systems and proposes a novel building integrated thermoelectric system that integrates a thermoelectric heat pump unit into a double-skin ventilated facade to provide heating and cooling, heat recovery ventilation and domestic hot water or drying services for buildings, based on the thermoelectric waste heat utilization. Several building integration methods of the proposed system are presented.

An analysis of design configurations is proposed for a 5 kW residential space heating split system comparing several low GWP refrigerants (R32, R290, R1234yf, R1234ze, XL41, XL55) as potential alternatives to the most common refrigerants actually used (R410A, R407C, R134a). By means of an ad-hoc model, the system performance has been estimated for several geometrical configurations among those possible according to the current compressor and heat exchangers technology. The configurations complying with geometric and thermodynamic constraints are discussed in terms of opposing criteria: economic (set-up and total costs), thermodynamic (COP) and environmental ones (LCCP). With R32 it is possible to define design configurations that are able to reach the best energetic performances for fixed set-up costs. In the range of low set-up costs solutions, R32 and R410A design options are able to work with the same performance. Particularly, R32 can reach the minimum LCCP value as propane with 15% lower total costs.

International audience; Adaptation to climate change and its mitigation are some of the biggest challenges facing agriculture. In the global South, these challenges are associated with the need for food security. The arrival of climate change on the international agenda has prompted the recycling of a multitude of initiatives to address this problem, leading inevitably to the emergence of numerous controversies. However, although the scales and actors targeted may differ, all of these initiatives are trying in one way or another to provide technical, social, economic and political options to increase the climate resilience of agriculture. There is heated debate about three approaches, which focus on these relationships between agriculture and climate: climate-smart agriculture, agroecology and the 4 per 1000 Initiative on soil carbon. Beyond the conceptual differences and the sometimes partisan interpretations of these three approaches, agriculture in the Southern countries needs to take advantage of their potential synergies.

The refrigeration and air-conditioning system contribute significantly to building energy consumption. Therefore, it is necessary to develop new technologies that can achieve a higher coefficient of performance (COP). Employing a magnetic field (MF) on the condenser tube (between the condenser outlet and the capillary tube) is a new technique that helps in improving efficiency and cooling capacity of air-cooled vapour compression cycle (VCC) water chiller. In this work, four pairs of the permanent magnet of 3000 G field strength were installed on the condenser tube (between exit of the condenser and inlet of the capillary tube) of the VCC water chiller test setup. The performance of the test setup was compared by applying and removing an MF from the condenser tube to estimate an enhancement in the VCC water chiller system with an MF. Experiments were carried out using R404A as a primary refrigerant in the VCC system. This work discusses the outcomes of magnetic flux applied to the condenser tube at various locations of VCC on COP and power consumption of the water chiller unit. The percentage growth in refrigeration effect ranged between 0.58 and 8.82, and a higher value of the refrigeration effect of 8.82 was found by using the first magnet pair. Experimental outcomes show that compressor power consumption decreased by 4.43% with an increase in the number of magnet pairs from 1 to 4. The VCC system performance was improved by 8.94%. (C) 2017 Elsevier B.V. All rights reserved.

In this study, theoretical investigation of two evaporator ejector refrigeration system was carried out based on energy and exergy analysis using R134a and low global warming potential refrigerants (namely R1234yf and R1234ze(E)). In order to perform the analyses, a simulation model was developed and then the influence of different parameters on the COP, COP increase rate and exergy destructions were discussed for each refrigerant. The model was validated with experi¬mental data for R134a and later used to predict the behavior with R1234yf and R1234ze(E). It was found that the highest exergy destruction occurs in the R1234yf system and the increase rate in the COP with respect to the conventional system by using ejector as an expansion device are 15% for R134a, about 17% for R1234yf and about 15% for R1234ze(E), respectively.

This paper presents the performance assessment and working fluid selection for a novel integrated vapor compression cycle-organic Rankine cycle system (i-VCC-ORC), which recovers ultra-low-temperature waste heat rejected (50 °C) by the condenser of a vapor compression cycle (VCC). The analyses are carried out for a vapor compression cycle of a refrigeration capacity (heat input) of 35kW along with the component sizing of the organic Rankine cycle (ORC). The effects of the operational parameters on integrated system performance were investigated. The integrated system performance is estimated in terms of net COP, cycle thermal efficiency and exergy efficiency by completely utilizing and recovering the heat rejected by the condenser of the VCC system. R600a-R141b with COPnet (3.54) and ORC thermal efficiency (3.05%) is found to be the most suitable VCC-ORC working fluid pair. The integration of the vapor compression refrigeration cycle with the organic Rankine cycle increases the COP of the system by 12.5% as compared to the standalone COP of the vapor compression system. Moreover, the sensitivity analysis results show that there exists an optimum operating condition that maximizes the thermal performance of the integrated system.

Magnetic refrigeration is a fascinating superior choice technology as compared with traditional refrigeration that relies on a unique property of particular materials, known as the magnetocaloric effect (MCE). This paper provides a thorough understanding of different magnetic refrigeration technologies using a variety of models to evaluate the coefficient of performance (COP) and specific cooling capacity outputs. Accordingly, magnetic refrigeration models are divided into four categories: rotating, reciprocating, C-shaped magnetic refrigeration, and active magnetic regenerator. The working principles of these models were described, and their outputs were extracted and compared. Furthermore, the influence of the magnetocaloric effect, the magnetization area, and the thermodynamic processes and cycles on the efficiency of magnetic refrigeration was investigated and discussed to achieve a maximum cooling capacity. The classes of magnetocaloric magnetic materials were summarized from previous studies and their potential magnetic characteristics are emphasized. The essential characteristics of magnetic refrigeration systems are highlighted to determine the significant advantages, difficulties, drawbacks, and feasibility analyses of these systems. Moreover, a cost analysis was provided in order to judge the feasibility of these systems for commercial use.

&nbsp, Evaporative systems are probably the oldest technology for thermal comfort. However, they are still an essential technology in the food industry, environments for thermal comfort, and even for cooling data centers. Standards have been improved to compare the energy efficiency of this type of equipment. Using AHRI concepts with temperature data from the 29 most populous cities in the world, an EvaCOP index was created from temperatures that are easier to simulate than current parameters. The index parameters were tested in a laboratory located in Curitiba (Brazil). EvaCOP values of 45.58 and 25.77 W/W were found in the calculation in two different simulated equipment and compared with the compression cycle systems that in the most efficient machines is around 6.29 W/W.&nbsp

This paper reports a theoretical study of a conventional vapor compression air conditioner combined with a solar energy source. This system comprises two parts: the cooling mechanism and the solar heat source to operate it. Only the cooling machine part will be considered here, in which the refrigerant temperature leaving the immersed coil inside the storage tank can be calculated directly from the pressure–enthalpy diagram of the operating refrigerant. The investigation has been made using a new low global warming potential refrigerant that belongs to HFO family as an alternative to two high global warming potential refrigerants that belong to HFC family. These are R-1234ze(E) as an alternative to R-134a and R-410A. Comparisons between the classical vapor compression air conditioner and the solar assisted air conditioner and also between the selected refrigerants are investigated. The effects of the refrigerant temperature leaving the storage tank on the main performance parameters such as the coefficient of performance, the gain based on compression work, and the required condenser surface area are discussed.

Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene) is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP) for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%), which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle). Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.