Pump Size Research Articles

High power, high beam quality and narrow linewidth diode-end-pumped Nd:YAG seed laser at 1319 nm for a sodium guide star laser system

Abstract A high power, high beam quality and narrow linewidth Nd:YAG 1319 nm pulsed seed laser for sodium beacon is demonstrated, which was dual-end-pumped by the low quantum loss 885 nm quasi-continuous wave laser diodes (LDs). The resonator was based on a ring convex–convex structure with a dual-rod configuration. Adjusting the effective pump size in the crystal and the temperature of the LDs to realize the optimal size ratio of the pump beam and laser mode was analyzed finely. An output power of up to 25 W at 1319 nm has been obtained, operating at 800 Hz with a pulse duration of 140 μs, corresponding to a high optical-to-optical conversion efficiency of 18%. The average beam quality factor of M 2 was measured to be 1.25. To the best of our knowledge, this is both the highest output power and the highest beam quality at 1319 nm for the 885 nm LDs end-pumped with the pulse oscillator. This result provides a 1319 nm seed laser for a sodium guide star laser system, with high quality (high power, high beam quality and narrow linewidth), and also better stability.

Numerical Optimization of the Hydraulic and Hemolytic Performance of a Centrifugal Ventricular Assist Device Based on Impeller Flow Passage and Outlet Geometry

As technology continues to advance and modern lifestyles become increasingly mechanized, the prevalence of heart disease is steadily growing. On the other hand, donor hearts ready for transplantation are limited worldwide. Therefore, blood pumps are a suitable alternative to help the patient during the waiting period and even until the end of life. Blood pumps must meet biological requirements, including adequate output pressure and flow rate, within an acceptable margin of safety in the event of blood damage. Reduction of pump size, blood exposure time, and blood damage such as hemolysis have been mentioned as important challenges in the design of blood pumps. Statistics show that 30% of the patients who use a left ventricular blood pump need a right ventricular blood pump due to right ventricular failure. The purpose of this research is to determine the effect of the geometrical shape of the impellers (flow passage) and the thrust tube geometry of the volute chamber on the pump’s hydraulic performance, the amount of axial and radial forces, and the amount of blood damage. So, for this study, six blades and two types of geometry for the volute chamber thrust tube were designed. This pump has been simulated using computational fluid dynamics used the Ansys CFX 17. Finally, the appropriate pump has been selected for low hemolysis index (HI). The HI calculated using the Lagrangian method is 0.00279 in the pump with a flow rate of 5 L per minute and 1100 rpm.

Techno-Economic Comparative Assessment of High-Temperature Heat Pump Architectures for Industrial Pumped Thermal Energy Storage

Abstract The industrial sector is a key global source of wealth, but it is also recognized as a major challenge toward worldwide decarbonization. Today, the industrial sector requires more than 22% of the global energy demand as thermal energy and produces for this about 40% of the total CO2 emissions. Solutions to efficiently decarbonize the industrial sector are deemed. This work presents a comparative techno-economic performance assessment of a high-temperature heat pump (HTHP) integration within a molten salts (MSs) based power-to-heat system for industrial heat flexible generation. The main system performance is reported in terms of required working conditions and temperature for the heat pump and thermal demand size as well as reduction of the attainable levelized cost of heat (LCoH) against nonflexible electric boiler based systems. The impact of different industrial load profiles, electricity prices, heat pump capital cost, and heat pump real to Carnot efficiency ratio are also presented. The results highlight that the proposed system can be cost-competitive, particularly for thermal demand around 10 MW and waste heat temperatures above 80 °C. Under these conditions, LCoH reductions higher than 15%, with respect to the considered nonflexible electric boiler alternative, are attainable. These LCoH reductions are primarily driven by savings in electrical consumption as high as 30%. This study sets the ground for further power-to-heat techno-economic investigations addressing different industrial sectors and identifies main system and components design strategies, integrations, and targets.

Sizing large-scale industrial heat pump for heat recovery from treated municipal sewage in coal-fired district heating system

Electrification of district heating and deep integration of sectors of national economies are fundamental elements of the future smart energy systems. This paper discusses the problem of optimal sizing of large-scale high-temperature heat pumps using treated sewage water as a heat source in a coal-fired district heating system. The study presents an approach to modelling of heat pump system that enables techno-economic analysis for investment decision making. Such analysis is enabled by a black-box-type identification model of the selected industrial heat pump. The model was developed based on the data generated by physical modelling of the heat pump using Ebsilon Professional software. In addition, it is proposed that the heat pump system is integrated with a dedicated photovoltaic power plant. The case study takes into consideration site-specific technical, economic, ecological, and legal constraints, weather conditions, hydraulic performance of the heat-ing network, and variability of loads within the sewage and the district heating systems. The results revealed that the proposed modelling approach is effective regarding multiple simulations and system optimisation. In addition, it was found that large-scale heat pump projects can be technically feasible and profitable if the heat pump is appropriately sized and operated. In the given case, the optimum size of the heat pump for a city of around 180 000 inhabitants is around 12 MW under maximum winter load.

ASSESSMENT AND TECHNICAL CONSTRAINT IDENTIFICATION OF SMALLHOLDER IRRIGATION PUMP IN ARSI AND EAST SHEWA ZONE, OROMIA

Efficient irrigation begins with properly installed and maintained pumps, motors, and engines. For this, the study was conducted on potential irrigation pump users of the Arsi and East Shewa zones with the objective of identifying the technical constraints of smallholder irrigation pump users. Doddota from Arsi and Dugda and Bora woreda from the East Shewa zone were selected. 211 samples size from 2321 pump users were used for data collection. The constraints listed by respondents, like pump damage, pump cost, long priming, and fuel, were the most common bottlenecks in pump irrigation schemes. Pump damage was positively correlation with use of un-recommended suction and delivery head, age of pump, long priming time and continues operation time but negatively correlation with pump maintenance, experience in irrigation farming and educational level of the household. Long priming and fuel consumption was positively (+Ve) correlation with use of un-recommended suction and delivery head, age of pump, operation time and pump size. From the existing pump type respondent responses, KAMA pumps were highly available on the market, vulnerable to damage, and had sufficient spare parts with values of 60.66, 64.45 and 44.08%, respectively. The lowest were Cushion their values were 1.42%, 3.32% and 3.78%, respectively. The respondents also reply, due to absence of governmental pump maintaining organization, cost of maintenance at local and private garage were very expensive (68.25%) and expensive (26.07%). This makes another problem on small holder irrigation pump. Therefore, it is recommended to government to add pump maintaining structure at engineering center which serves' closely to scheme users and providing regular training on maintenance checklist. It is also recommended for engineering and socio-economic researchers to conduct research collaboratively to assess the gap frequently for other kebele pump user and technical performance evaluation for pump that have problems.

Configurational Design of a Hybrid System Based on an Air–Water Heat Pump and Biomass Boiler for a Rural Dwelling

Hybrid energy systems combine multiple energy sources and storage technologies to enhance performance and meet diverse energy needs. Hybrid heat pump systems are particularly suitable for heating and cooling buildings in rural areas. Air-source heat pumps have two well-known disadvantages during the coldest period of the year, when the building’s heating load is at its peak: the heat pump’s capacity is reduced and it needs to perform defrost cycles. A potential solution is to size the heat pump to cover only a portion of the peak load and to use a second heat generator in a hybrid heat pump system. There is a gap in the literature regarding the configurational analysis of hybrid heat pump (HHP) systems, particularly in terms of combining heat pumps and biomass boilers, and evaluating their efficiency, economic aspects, and environmental impact. Thus, in this research, a dynamic model of a HHP system, consisting of an air-to-water heat pump paired with a biomass boiler as a backup, is presented. Various configurations of the HHP system have been developed to evaluate key performance indicators, such as efficiency, emissions, operational costs, and other relevant factors. The findings of this paper indicate that the energy performance of HHP systems is significantly affected by the system layout, heat pump size, cut-off temperature, and the control algorithm used to activate the heat generators. Moreover, series operation of HHP systems is not only more efficient than parallel operation but also results in lower emissions and reduced operation costs. As expected, the energy loss associated with defrost cycles significantly impacts the overall performance of a hybrid system based on an air-source heat pump. Finally, the impact of the cut-off temperature on the key parameters in the configuration analysis was examined, and the optimal performance of the HHP system, in terms of minimizing operational costs and emissions, was depicted using a heat map diagram.

Assessing the impacts of air-sealing on the sizing, operation, and economic feasibility of ground-source heat pumps for electrifying single-family houses in the US

According to recent studies and reports, in single-family houses (SFHs), air-sealing can significantly lower the thermal loads for space heating and cooling. Thus, air-sealing in SFHs could reduce the required size and cost of ground source heat pump (GSHP) systems for electrifying SFHs. This study investigated the costs and benefits of integrating air-sealing with GSHPs for retrofitting existing SFHs when compared with air-source heat pumps. A whole building energy simulation tool integrated with an advanced design tool for modeling ground heat exchangers was used to calculate changes in required GSHP capacity, total borehole length, and building energy consumption with and without air-sealing in SFHs in 16 US climatic regions. The results from this study showed that reducing outdoor air infiltration from 0.8 air changes per hour (ACH) to the minimum ventilation requirement (0.35 ACH) can significantly reduce borehole length (up to 55 %), GSHP capacity (up to 48 %), and total heating electricity reduction, especially in cold climates (up to 44 %). The results also showed that for airtight homes (0.03 ACH infiltration) with a direct outdoor air system, the minimum required borehole length, GSHP capacity, and total heating electricity consumption can be reduced up to 70 %, 68 %, and 67 %, respectively, when compared with SFHs with 0.8 ACH infiltration. Moreover, the life cycle cost analysis showed that air-sealing in conjunction with a GSHP is more profitable than replacing the existing system with an air-source heat pump, even without any incentives for most climatic regions in the US (except for some hot regions).

Heat pump and thermal energy storage: Influences of photovoltaic, the control strategy, and price assumptions on the optimal design

Combining heat pump, thermal energy storage, and photovoltaic is a common option to increase renewable energy usage in building energy systems. While research finds that optimal system design depends on the control, design guidelines neglect an influence of (1) photovoltaic, (2) the supervisory control, and (3) prices assumptions on the design of heat pump and thermal energy storage. We analyze how these influences may impact the optimal design. To analyze possible impacts, a pre-screening approach is used to identify relevant model input combinations with a potentially high influence on the optimal design. Applying a simulation-based design optimization with a detailed building energy system model, we optimize three cases: no photovoltaic, no supervisory control, and a state-of-the-art supervisory control. Results indicate that cost optimal design does not change with photovoltaic or the supervisory control, but heat pump size increases with higher electricity prices. For the storage, maximizing the size achieves high self-sufficiency degrees, but cost optimal design changes only for selected price assumptions. Overall, we find that neglecting photovoltaic and surplus control in the system design is a valid assumption. However, price assumptions should be included to allow simple but optimal design rules in current guidelines.

Performance assessment of residential heat pumps operating in extreme cold climates using zeotropic mixtures

Extremely cold climates subject residential heat pumps to significant temperature differences between the heat source and the ambient being heated, which may lead to system failure and reduced compressor performance. The present study considers the possibility of improving the performance of heat pump systems that are simultaneously used for residential space and domestic water heating while subjected to climates varying from -25 °C to 5 °C by exploring the use of zeotropic mixtures. CO2-based binary mixtures composed of low-GWP (global warming potential) refrigerants are considered – R32, R1234yf, and R290 – aiming to benefit from environmentally friendly and flame suppressants characteristics of CO2, as well as the improved thermal efficiency granted by the addition of a secondary refrigerant. A thermodynamic model was developed for a standard vapor-compression heat pump cycle and used to maximize the coefficient of performance limited by the minimum pinch point in the heat exchangers. Our analysis explores the effect of several parameters, such as, the mixture components, mass fractions, space and water heating demands, and heat source temperature on the heat pump's performance. For cold climates, the mixture of R32 (90%)/CO2 (10%) yields the highest COP and CO2-rich mixtures exhibit the lowest. However, by increasing the mass fraction of CO2 within the zeotropic mixture, the pressure ratio of the heat pump was improved. When considering combined performance criteria, such as the volumetric heating effect and the total heat delivered related to heat pump size, CO2-rich mixtures tend to allow more compact systems, especially in colder climates.

A cavalpulmonary assist device utilising impedance pumping enhanced by peristaltic effect.

Fontan procedure, the standard surgical palliation to treat children with single ventricular defects, causes systemic complications over years due to lack of pumping at cavopulmonary junction. A device developed specifically for cavopulmonary support is thus considered, while current commercial ventricular assist devices (VAD) induce high shear rates to blood, and have issues with paediatric suitability. To demonstrate the feasibility of a small, valveless, non-invasive to blood and pulsatile rotary pump, which integrates impedance and peristaltic effects. A prototype pump was designed and fabricated in-house without any effort to optimise its specification. It was then tested in vitro, in terms of effect of pumping frequency, background pressure differences and pump size on output performance. Net flow rate (NFR) and maximum pressure head delivery are both reasonably linearly dependent on pumping frequency within normal physiological range. Positive linearity is also observed between NFR and the extent of asymmetric pumping. The device regulates NFR in favourable pressure head difference and overcomes significant adverse pressure head difference. Additionally, performance is shown to be insensitive to device size. The feasibility of the novel rotary pump integrating impedance and peristaltic effects is demonstrated to perform in normal physiological conditions without any optimisation effort. It provides promising results for possible future paediatric cavopulmonary support and warrants further investigation of miniaturisation and possible haemolysis.

Peritoneal baclofen pump migration: a rare complication of subfascial placement. Illustrative cases.

The intrathecal baclofen pump is an effective treatment option for patients with severe spasticity. In children, subfascial pump placement is often preferred given concerns for infection and wound healing. However, this approach is not without risk, and rare complications, such as peritoneal pump migration, can occur. The authors describe three pediatric cases of peritoneal pump migration at their institution over the past 14 years (3/545, 0.5%). All three patients had low body weight (below the 39th percentile), and two had scoliosis requiring surgery. All pumps had been placed using the subfascial technique. The first case occurred 6 months postplacement, and the pump was not replaced. Cases 2 and 3 occurred at 2 and 3 years postplacement, respectively, and both pumps were replaced. The authors conclude that peritoneal pump migration, although uncommon, can occur in patients with subfascial pump placement, and providers should have a low threshold of suspicion for repeat imaging prior to refilling if the pump's location has migrated. Potential contributing factors to pump migration include a patient's small size, a larger pump size (40-mL pump), and scoliosis. All these factors should be considered during pump placement, and surgeons can consider using a 20-ml pump for smaller patients. https://thejns.org/doi/abs/10.3171/CASE24290.

Test Procedures and Mechanical Properties of Three-Dimensional Printable Concrete Enclosing Different Mix Proportions: A Review and Bibliometric Analysis

Three-dimensional printable concrete (3DPC) has become increasingly popular in the building and architecture industries due to its low cost and fast design. Currently, there is great interest in the mix design methods and mechanical properties of 3DPC, particularly in relation to yield stress analysis. The ability to extrude and build 3D-printed objects can be significantly affected by factors such as the rate of extrusion, nozzle size, and type of pumps used. It has been observed that a yield stress lower than 1.5 to 2.5 kPa is not sufficient to maintain the shape stability of concrete, while a yield stress above this range can limit the material’s extrudability. Furthermore, the strength properties of 3DPC are influenced by factors such as changes in yield stress and superplasticiser dosages. To meet the high mechanical strength and durability requirements of 3DPC in the construction industry, it is essential to analyse the material’s early-age mechanical properties. However, the development of standardised test methods for 3DPC is still deficient. To address this issue, a bibliometric analysis was conducted to comprehensively review the diverse test methods and mechanical characteristics of 3DPC with different mix proportions. To produce high-performance concrete from various additives and waste materials, it is critical to have a basic understanding of the hydration processes of 3DPC. Moreover, a detailed analysis of the environmental impact and energy efficiency of 3DPC is necessary for its widespread implementation. This review article will highlight the recent trends, upcoming challenges, and benefits of using 3DPC. It serves as a taxonomy to navigate the field of 3DPC towards sustainable development.

Patient Satisfaction Survey on Portable Infusion Pumps for Colorectal Cancer Chemotherapy: Hard-Shelled or Soft-Shelled?

Elastomeric infusion pumps are widely used in colorectal cancer chemotherapy. However, no studies to date have investigated patient preferences regarding different infusion pump types. Twenty patients with unresectable colorectal cancer undergoing chemotherapy were initially treated with a portable hard-shelled continuous infusion pump, followed by a soft-shelled continuous infusion pump. The respondents used a numerical rating scale (0-10) to rate their comfort when using each pump, their ease of carrying it, the pump size and shape, its weight, their ease of reading its memory, and their overall satisfaction with it. They were then asked to determine which pump they would ultimately prefer. In terms of comfort, significantly higher user satisfaction was reported for the soft-shelled pump during the daytime and when going out (P < 0.001, P < 0.001, respectively). For pump portability, size, shape, and weight, the soft-shelled type also outperformed the hard-shelled one (P < 0.001, P=0.0011, P < 0.001, respectively). However, the hard-shelled pump scored significantly better in terms of ease of viewing memory (P < 0.001). Overall satisfaction was significantly higher for the soft-shelled pump than the hard-shelled type (P=0.0095). Finally, 13 patients (65%) indicated that they would prefer a soft-shelled pump for their next treatment, while only one patient (5%) preferred a hard-shelled alternative. A preference for soft-shelled pump was observed, particularly in female patients and those with a body mass index of < 22 kg/m2. The selection of portable elastomeric infusion pumps should consider the preferences of patients with colorectal cancer, as these devices have the potential to enhance their quality of life.

Study on the form of sealing ring and its sealing characteristics of centrifugal pump

Abstract The sealing ring, also known as the leakage relief ring, is usually composed of a fixed part and a rotating part, which is used to reduce the gap leakage between the rotating part of the pump and the fixed part, and its structural form and clearance value have a great impact on the stability and efficiency of the pump set. In this paper, the sealing ring between the top cover impeller of a centrifugal pump is used as the research object, and the empirical analysis method and numerical simulation method are used to analyse the water sealing characteristics of the sealing ring structure commonly used in five projects from the aspects of leakage amount and energy consumption, and compare. The results show that the labyrinth, stepped and comb tooth sealing rings have good water sealing effect. Aiming at the matching of different sealing gaps and diffusion domains of stepped sealing rings, the influence of sealing structure size on water sealing characteristics was explored, which provided a technical basis for the selection of sealing ring structure and the determination of matching size of centrifugal pump.

Analysis of the Use of Sand Pump Control Pumps in Overcoming Sand Problem in Sucker Rod Pump (SRP) in Sp Wells In the Kawengan Field

The sand problem is a common challenge in the oil and gas industry. PT Pertamina EP Asset 4 Cepu Field in the Kawengan Field has rock which is a ngrayoung formation and the type of sandstone can cause sand to enter into the well bour when oil is produced for a long time. Therefore, we need the right tool to be able to overcome the problem of sandiness. In this case PT Pertamina EP Asset 4 Cepu Field in the Kawengan Field uses a sand control pump in an effort to overcome the sand problem. Thus, this research was conducted by analyzing the appropriate pump size from the sand rate calculation, fluid flow rate before and after using the sand control pump, as well as economic analysis. The results of the pump size analysis show that the right pump size to use is 2 joint mud anchors. The results of the subsequent analysis show an increase in the rate of fluid production after using a sand control pump. The results of the economic analysis show that the use of a sand control pump on a sucker rod pump (SRP) in the SP well is feasible because it has economic value with an oil price of 45 US$ / bbl, an NPV of 221,709 USD is obtained, and project success (IRR) reaches 106 %, as well as the value of pay out time for 1.83 years. Keywords: Economy, Flow Rate, Sand Problem, Sand Control Pump, Sand Rate.

Research on Energy Loss of Optimization of Inducer–Impeller Axial Fit Dimensions Based on Wave-Piercing Theory

With the development of modern fluid machinery, the energy density of pumps is gradually being improved, and at the same time, higher demands are being placed on the cavitation performance, hence the introduction of the inducer and centrifugal impeller to form a dynamic–dynamic series structure. However, there are strict constraints on the axial size of pumps in fields such as firefighting and aerospace. The traditional empirical formula no longer satisfies the need to fit the axial dimensions between the induced wheel and the impeller at high velocities. Therefore, based on the wave-piercing theory, the drag reduction coefficient is introduced to explore the optimal axial fit size from the perspective of energy characteristics. This paper focuses on the influence of the inducer’s wake on the energy characteristics of downstream impellers, and conducts the following research: by adjusting the axial matching dimensions between the upstream inducer and the centrifugal impeller in the initial model, ten sets of axial distance models with matching dimensions of KD are designed, and the drag reduction coefficient is embedded to determine the optimal axial distance. The results show that the optimal axial distance is 0.2D, which is far lower than the axial distance value of 0.42D obtained from the traditional empirical formula for axial matching dimensions. Meanwhile, this paper uses tangential velocity, the inlet flow angle of the impeller, entropy production theory, and other indicators to analyze the internal energy loss of the high-speed vehicular fire pumps one by one. All of them confirm that the impeller in the high-speed vehicular fire pump has the lowest energy loss and optimal performance at an axial distance of 0.2D. Specifically, at this axial distance, the head can reach 259 m, and the hydraulic efficiency is as high as 83.62%. Thus, the feasibility of determining the axial placement of the impeller using the drag coefficient is validated. This research provides new insights into determining the axial coordination dimensions between the inducer and the impeller.

Assessment and Technical Constraint Identification of Smallholder Irrigation Pump in Arsi and East Shewa Zone, Oromia

Efficient irrigation begins with properly installed and maintained pumps, motors, and engines. For this, the study was conducted on potential irrigation pump users of the Arsi and East Shewa zones with the objective of identifying the technical constraints of smallholder irrigation pump users. Doddota from Arsi and Dugda and Bora woreda from the East Shewa zone were selected. 211 samples size from 2321 pump users were used for data collection. The constraints listed by respondents, like pump damage, pump cost, long priming, and fuel, were the most common bottlenecks in pump irrigation schemes. Pump damage was positively correlation with use of un-recommended suction and delivery head, age of pump, long priming time and continues operation time but negatively correlation with pump maintenance, experience in irrigation farming and educational level of the household. Long priming and fuel consumption was positively (+Ve) correlation with use of un-recommended suction and delivery head, age of pump, operation time and pump size. From the existing pump type respondent responses, KAMA pumps were highly available on the market, vulnerable to damage, and had sufficient spare parts with values of 60.66, 64.45 and 44.08%, respectively. The lowest were Cushion their values were 1.42%, 3.32% and 3.78%, respectively. The respondents also reply, due to absence of governmental pump maintaining organization, cost of maintenance at local and private garage were very expensive (68.25%) and expensive (26.07%). This makes another problem on small holder irrigation pump. Therefore it is recommended to government to add pump maintaining structure at engineering center which serves' closely to scheme users and providing regular training on maintenance checklist. It is also recommended for engineering and socio-economic researchers to conduct research collaboratively to assess the gap frequently for other kebele pump user and technical performance evaluation for pump that have problems.

Levodopa-Entacapone-Carbidopa Intestinal Gel Treatment in Advanced Parkinson's Disease: A Single-Center Study of 30 Patients.

Levodopa-entacapone-carbidopa intestinal gel (LECIG) is a novel device assisted treatment option for advanced Parkinson's disease (PD). It has been available in Finland since 2020. There is paucity of scientific studies considering LECIG treatment in clinical practice. Objectives of this study were to evaluate the changes in medication, adverse events and early discontinuations of LECIG treatment in real life clinical practice. The records of 30 consecutive patients, who received LECIG between years 2020 and 2022 in Helsinki University Hospital, were retrospectively analyzed. Data considering changes in medication, discontinuations, and adverse events during the first six months of LECIG treatment was collected. Mean levodopa equivalent daily dose (LEDD) rose significantly between baseline before LECIG and six months with treatment (1230 mg vs. 1570 mg, P = 0.001). Three patients were discarded during nasojejunal tube test phase and seven discontinued the treatment during six-month follow-up. Most common reasons for discontinuation were difficulty in finding suitable infusion rate and neuropsychiatric problems. Safety issues encountered were similar to those reported with levodopa-carbidopa intestinal gel (LCIG) treatment. One case of rhabdomyolysis due to severe dyskinesia during LECIG treatment was observed. Patients were satisfied with the small size of the pump system. LEDD seems to increase during the first months of LECIG treatment. When compared to studies on LCIG, safety profile of LECIG appears similar, but early discontinuation rate is higher than expected. However, long-term studies are lacking. Only clear advantage to LCIG appears to be the smaller LECIG pump size.

The Use of Renewable Energy and Capillary Heat Exchangers for Energy Savings in the Existing Apartment

Abstract The use of capillary heat exchangers with a large area means the lowest heat carrier temperature – typically less than 30 °C for heating. This determines the very efficient use of the installed heat pump due to an increase in the coefficient of performance (COP) with a decrease in the provided water temperature. The aim of the study was to find out whether renewable energy sources and radiant capillary heat exchangers increase energy efficiency. In order to achieve the maximum energy efficiency during the renovation of the existing apartment, a combination of two green approaches was used. One of them is the replacement of the existing high-temperature radiator heating system with radiant capillary mats. The same system is also used for cooling, which was not possible with the existing system. The necessary energy is provided from renewable aerothermal energy by installing a heat pump together with PV panels to ensure electricity consumption. The measurements were made in the apartment to determine the thermal transmission properties of all boundary structures and an air exchange rate using long-term monitoring. Experimental data were used to create the heat balance, to estimate the heating and cooling powers, as well as the seasonal energy needs. The amount of capillary heat exchangers and the size of the heat pump were chosen accordingly. The very first energy consumption data allow concluding that the planned improvement of the energy efficiency has been successfully achieved by using technology combination described without improvement of the thermal properties.

Abstract 16713: Pre-Clinical 30-day Survival Results of the BiVACOR TAH

Introduction: The BiVACOR Total Artificial Heart (TAH) replaces the failing heart with a durable and physiologically adaptive pump, which combines magnetic levitation and rotary blood pump technology. The pump has large clearances to minimize shear stress, generates pulse pressure via cyclic changes in pump speed, and modulates total outflow based on physiological conditions. A single rotor design enables a small pump size. Aim: Primary endpoint was survival at 30 days with normal end-organ function and absence of device related thromboembolism at necropsy. Methods: Five calves (82 - 108 kg) were implanted with the BiVACOR TAH and underwent continuous hemodynamic monitoring for 30 days. The pumps ability to generate a pulse pressure, balance outflow to the systemic and pulmonary circulations and to increase outflow in response to increased physical activity was assessed. Hemocompatibility and end-organ function were routinely monitored. Necropsy was performed on day 30 to evaluate for evidence of thromboembolism and end organ damage. Explanted pumps were examined. Results: All five calves survived to 30 days with normal end-organ function. Stable hemodynamics were achieved with normal pressures in the aorta and left and right atrium (MAP 111 ± 6 mmHg, CVP 12 ± 5 mmHg, LAP of 20 +/- 5 mmHg). Average estimated pump output was 12 ± 2 L/min with average pulse pressure of 30 mmHg. Pump output increased during changes in daily physiological condition (10 to 14 L/min). No device-related thromboembolism or other end organ pathologies were detected at necropsy. All explanted pumps were free of internal pump thrombus. Hemocompatibility was demonstrated (pfHb 4.34 ± 0.74 mg/dL). Bypass time decreased by 34 minutes over the entire study cohort. Conclusion: The BiVACOR TAH demonstrates normal hemodynamics including left/right balance. Pump design allows for a normal pulse pressure, increased pump output in response to exercise, and excellent hemocompatibility without device-related thromboembolism. Operative time markedly improves with surgeon experience. The small pump size may expand the use of TAH to smaller patients. This device may address the need for select patients with advanced heart failure who require biventricular support.