High Pump Research Articles

Significant thermal upgrade via cascade high temperature heat pump with low GWP working fluids

High temperature heat pump is a promising solution for efficient high temperature heat supply. However, the poor performance when it operates in large temperature lift hinders it from utilizing low temperature waste heat. To solve this problem, a cascade high temperature heat pump with economized vapor injection was established and a simulation model was developed accordingly. The tests were conducted using R134a/R245fa and R1234ze(E)/HP-1 at heat source temperature from 5 to 30 °C and heat sink temperature from 90 to 120 °C, with the coefficient of performance (COP) varying in the range of 1.72–2.73 and 1.77–2.75, respectively. The COP about 2.20 was achieved with R1234ze(E)/HP-1 at optimal intermediate temperature and optimal economized vapor injection pressure when the temperature lift is 100 °C. In the simulated case study, the heat pump water boiler based on the experimental prototype decreases CO2 emission by 62.8 % compared to electric boiler. Moreover, using low GWP working fluids reduces 1.32 × 104 kg direct CO2 emission in TEWI. Under the current technological, pricing, and operational condition, it takes 16 years for heat pump to have economic benefit over electric boiler, but this duration can be shortened with reduced initial cost, improved COP, and increased operating hours and electricity price. In summary, this work presented a high-efficient, environmentally friendly, and economically viable cascade high temperature heat pump system which has potential to utilize the abundant environmental heat source and deliver high temperature heat, being an alternative to the conventional heat generation equipment such as boilers.

Reducing the specific energy use of seawater desalination with thermally enhanced reverse osmosis

This study investigates the concept of using heat to enhance reverse osmosis (RO) desalination. An analytical model is used to evaluate the effect of temperature on water permeate flux, specific energy, permeate quality, and applied operating pressures. When feed is heated from 20 to 50 °C, specific energy savings of up to 24 % are observed for high flux seawater desalination and up to 33 % for brackish water. Such improvements are consistent with the literature, but until now the thermal energy input required to heat feed has been mostly neglected from analysis. For the first time, the overall energy balance of thermally-enhanced RO is considered to evaluate the tradeoff between savings in mechanical pump work and thermal energy input. Results suggest that this tradeoff is favorable under the right conditions. In particular, there is a need for high thermal efficiencies including both a very high heat pump coefficient of performance and very high heat exchanger efficiency for recycling thermal energy. Under these conditions, overall energy savings of up to 12 % are observed for seawater desalination when feed is heated from 20 to 41 °C, and up to 18 % for brackish water with feed heated to 46 °C.

Innovative process integrating high temperature heat pump and direct air capture

Direct air capture (DAC) technology plays a crucial role in mitigating the effects of global warming by capturing carbon dioxide (CO2) directly from the atmosphere. A significant technical challenge for DAC is its high thermal energy consumption, which results in an unacceptable overall cost (600$tCO2–1). The combination of a high-temperature heat pump (HTHP) and DAC system offers a substantial reduction in thermal energy consumption, decreased reliance on renewable energy sources, and enhanced DAC system flexibility. This study presents three distinct thermal integration strategies that combine an HTHP with solid adsorbent-based DAC and verifies their effectiveness in reducing energy consumption and CO2 emissions compared to a traditional DAC system. Among them, the deeply integrated DAC-HTHP system (I-DAC) exploits low-grade adsorption heat and waste heat, providing direct heating and cooling energy to the DAC system via refrigerant condensation and evaporation processes. Simulation results indicate that the I-DAC system achieves an extremely low operating energy consumption of 2.77 GJtCO2–1, representing a 69.5% reduction than traditional DAC under the same conditions. Consequently, the I-DAC offers a cost-effective (32.0–46.2 $tCO2–1) negative emission solution. We also demonstrate that the I-DAC is promising for wide application in cities to recycle waste heat and remove CO2 from the air. The comprehensive implementation of the I-DAC in 105 cities could yield a net annual productivity of 980 MtCO2.

Impact of high-profile transvalvular pumps in heasrt failure related cardiogenic shock

Abstract Background Heart failure-related cardiogenic shock (HF-CS) not related to acute MI is a leading cause of CS.(1) Congestion is a major predictor of mortality among patients with HF-CS, for whom in-hospital mortality remains between 25-40%.(2,3) Both low-profile (Impella CP) and high-profile (Impella 5.0/5.5) transvalvular pumps are used to manage these patients. In the last few years, use of Impella 5.0/5.5 pumps in these patients is increasing, although it is often used as an escalation strategy from other temporary mechanical circulatory support (tMCS) devices. Purpose To assess the impact of LV unloading using high profile transvalvular pump (Impella 5.0/5.5) compared to a low-profile pump (Impella CP) on outcomes in HF-CS. Methods The Cardiogenic Shock Working Group (CSWG) is a large, multi-center international prospective registry of CS patients.(1) For this analysis, we retrospectively reviewed patients with HF-CS who underwent Impella 5.0/5.5 therapy for HF-CS and compared them to patients who underwent an Impella CP. Patients who received an Impella device as part of their escalation strategy from another device (IABP) or concomitant or de-escalation strategy with ECMO were excluded. Results Of the 2,755 patients with HF-CS, 125 patients received an Impella 5.0/5.5 while 152 patients received an Impella CP alone; 13 patients were escalated from an Impella CP to 5.0/5.5 pump. Of these 292 patients who either received an Impella CP or 5.0/5.5 or a combination of the two, 228(78%) were male, 208(71%) were white with a mean LVEF at presentation of 19%. About a third (n=78, 27%) presented with de-novo HF-CS while 214(73%) were acute on chronic HF-CS. In-hospital mortality in the entire HF-CS cohort was 717(26%). Unadjusted mortality was higher in those who underwent Impella CP alone (n= 57; 38%) compared to patients with Impella 5.0/5.5 (n=27, 23%; p=0.01). This improvement in mortality was seen in acute on chronic HF-CS with Impella 5.5/5.0 vs CP (41% vs 26%, p=0.02), and as a trend in de-novo HF-CS (30% vs 14%, p=0.13). More patients on Impella 5.0/5.5 went on to receive heart replacement therapies (durable LVAD or heart transplantation) compared to Impella CP (56% vs 9%, p<0.001). Conclusion(s) Use of a high-profile transvalvular pump (Impella 5.0/5.5) was associated with improved mortality compared to a low-profile transvalvular pump (Impella CP) in HF-CS.

Influence of High-Intensity Pumping on Gain Medium Temperature Increase and Laser Mode Tunability in a Hemispherical Short Cavity

To increase the efficiency of laser oscillators by overcoming losses, the unsaturated gain must be increased. For this purpose, high-intensity pumping, typically higher than 100 kW/cm2, is effective. However, the temperature increase and strong thermo-optic effects of the gain medium have been pointed out as obstacles to high efficiency in solid-state lasers. Therefore, the effect of high pump intensity on the laser mode tunability required for high efficiency is investigated by studying the dependence of the laser threshold on the cavity length using a continuous-wave hemispherical short-cavity laser. The results show that the laser mode can be tuned with sufficient range and precision for high efficiency under various loss conditions regardless of the high pump intensity and are in qualitative agreement with a simple theory. Furthermore, according to the heat transport theory, microchip Yb:YAG, the gain medium of this study, does not have a high cooling efficiency, but the maximum temperature increase is estimated to be only about 12 K despite the high pump intensity of about 110 kW/cm2. This is because it is the pump power, not the pump intensity, that is proportional to the temperature increase, as the maximum pump power is only 900 mW. These results indicate that high-intensity pumping is a promising approach to achieve efficient lasing at low cost.

Diagnostic Analysis of the Response of Volume Transport through the Tsushima Strait to the Eddy-Induced Variations in the Kuroshio Region

Abstract The Tsushima Strait (TS) is the sole passage for volume transport from the East China Sea to the Sea of Japan. To date, the process underlying the interannual variability in volume transport remains unclear. In this study, 27-yr (1993–2019) reanalysis data from the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2M) system and in situ/satellite observations were employed to understand this process. The results suggest that TS transport was generally high in 1999, 2003/04, and 2010 and low in 1995/96, 2005/06, 2008, and 2014/15. The sea level anomaly (SLA) outside the entrance of the TS, that is, the upstream TS forcing, dominates the interannual TS transport variation. A high SLA pumps more water into the Sea of Japan via the TS, and vice versa. By synthesizing JCOPE2M reanalysis data and satellite observations, further analysis revealed that cyclonic mesoscale eddies from the subtropical countercurrent (STCC) could be responsible for this high SLA by reducing Kuroshio transport, enhancing Kuroshio intrusion across the shelf, and increasing the SLA around the upstream TS region. The reverse was true for anticyclonic STCC eddies. Variability in the Kuroshio intrusion southwest of Kyushu induces variations in the TS transport on an interannual time scale.

Pulsed stimulated Brillouin microscopy enables high-sensitivity mechanical imaging of live and fragile biological specimens

Brillouin microscopy is an emerging optical elastography technique capable of assessing mechanical properties of biological samples in a three-dimensional, all-optical and noncontact fashion. The typically weak Brillouin scattering signal can be substantially enhanced via a stimulated Brillouin scattering (SBS) process; however, current implementations require high pump powers, which prohibit applications to photosensitive or live imaging of biological samples. Here we present a pulsed SBS scheme that takes advantage of the nonlinearity of the pump–probe interaction. In particular, we show that the required pump laser power can be decreased ~20-fold without affecting the signal levels or spectral precision. We demonstrate the low phototoxicity and high specificity of our pulsed SBS approach by imaging, with subcellular detail, sensitive single cells, zebrafish larvae, mouse embryos and adult Caenorhabditis elegans. Furthermore, our method permits observing the mechanics of organoids and C. elegans embryos over time, opening up further possibilities for the field of mechanobiology.

Crucial Development Technologies for Volcanic Hydrocarbon Reservoirs: Lessons Learned from Asian Operations

Oil and gas reservoirs in volcanic rocks are a particular type of unconventional reservoir and present unique challenges for exploration and production engineers. To help the oil industry understand volcanic reservoirs and solutions to complex development problems, we reviewed their key engineering technologies as well as their geological characteristics. The distinctive geological characteristics of volcanic hydrocarbon reservoirs are strong heterogeneity, low porosity and permeability, complex fracture systems, etc. The volcanic reservoir rock types in order of hydrocarbon abundance are basalt (38.5%), andesite (15.9%), volcaniclastic (12.1%), and rhyolite (11.5%). The porosity ranges from 0.1 to 70%, and permeability ranges from 0.0007 to 762 md. In some commercially developed volcanic reservoirs of China, the average porosity is 7.7–13%; the average permeability is 0.41–3.4 md. Engineers have applied a variety of adapted technologies to produce volcanic reservoir economically. Horizontal wells can increase production and reserves by 4–6 times those of vertical wells, and longer wells are preferred. Specialized hydraulic fracturing techniques are suggested, including small or mixed proppant size, second HF treatment after proppant slugging, high-viscosity frac fluid with high-temperature resistance, special fluid loss reducer, high pump pressure, Extreme Overbalance Perforating, limited-entry fracturing, matrix acidizing, etc. Water control measures include producing below critical rates, partial perforation or penetration, controlling hydraulic fracture height, using horizontal wells, implementing complete cementing job, etc. Well productivity evaluation should be conducted to understand well performance and appropriately allocate production rates among wells, using the modified AOF method and other productivity prediction models considering breakdown fracture gradient, gas slippage effect, non-Darcy effect, etc. Well sites need to be selected based on recognizing profitable lithologies, lithofacies, high porosity and permeability, relatively developed fracture systems, thick net pay zones, etc. The critical questions for the industry are how to enhance volcanic reservoir recovery with more efficient and economic hydraulic fracturing and water control techniques. This is one of the first papers systematically summarizing the engineering technologies and unique solutions to develop volcanic reservoirs. Further and more complete reviews can be carried out in the future, and more novel and effective techniques can be explored and tested in the field.

Micrometer-Scale Carrier Transport in the Solid Film of Giant CdSe/CdS Nanocrystals Imaged by Transient Absorption Microscopy.

For the practical applications in solar cells and photodetectors, semiconductor colloidal nanocrystals (NCs) are assembled into a high-concentration film with carrier transport characteristics, the full understanding and effective control of which are critical for the achievement of high light-to-electricity conversion efficiencies. Here we have applied transient absorption microscopy to the solid film of giant CdSe/CdS NCs and discovered that at high pump fluences the carrier transport could reach a long distance of ∼2 μm within ∼30 ps after laser pulse excitation. This intriguing behavior is attributed to the metal-insulator transition and the associated bandlike transport, which are promoted by the enhanced electronic coupling among neighboring NCs with extended wave functions overlap of the excited-state charge carriers. Besides providing fundamental transport information in the regime of high laser pump fluences, the above findings shed light on the rational design of high-power light detecting schemes based on colloidal NCs.

Portable light weight open tubular ion chromatograph for field determination of environmental anions

We report a battery powered non-suppressed open tubular ion chromatograph (NSOTIC) that weighs less than 3 kg with on-board rechargeable lithium-ion batteries that provide power for 18 h of operation. It is contained in an aluminum case measuring 30 × 25 × 16 cm. Separation relies on open tubular (OT) chromatographic columns which eliminate the need for high pressure pumps, drastically reducing weight and complexity. Eluent consumption is less than 100 µL per separation. Eluent is supplied from a pressurized vessel via a voltage-controlled electronic pressure controller. Flow rates are typically <200 nL/min which allows a single 16–20 g gas cartridge to perform hundreds of separations. Two anions, chloride and nitrate, in Atacama soil samples were field determined by running the portable NSOTIC. More samples were lab analyzed by commercial IC and IC/MS-MS (only perchlorate due to its low concentration level). To demonstrate the feasibility of running NSOTIC on sample analysis, samples were tested by both non-portable and portable NSOTIC.

Photon Energy‐Dependent Optical Spin‐Orbit Torque in Heavy Metal–Ferromagnet Bilayers

AbstractThe manipulation of magnetization through optically generated ultrafast spin currents is a fascinating area that needs a thorough understanding for its potential future applications. In this work, a comprehensive investigation of helicity‐driven optical spin‐orbit torque in heavy metal/ferromagnetic metal heterostructures is presented, specifically cobalt capped with gold or platinum, subject to laser pumping at different wavelengths. The results demonstrate up to tenfold enhancement in optical spin‐orbit torque quantum efficiency for gold compared to platinum of the same thickness when pumped with a visible laser. Additionally, the study provides the first experimental analysis of the photon energy dependence of optical spin‐orbit torque and derives the optical spin orientation spectra for both gold/cobalt and platinum/cobalt heterostructures. A key insight gained from the study is the impact of photon energy‐dependent spin transport in the system, which suggests the use of a high photon energy pump for efficient spin transport. These findings highlight the potential of spin current generation and manipulation in gold/ferromagnet heterostructures for a wide range of applications such as all‐optical magnetization switching, spin‐wave generation and control, and spintronic terahertz emission.

Techno-Economic Assessment of CO2-Based Power to Heat to Power Systems for Industrial Applications

Abstract The industrial sector is a major source of wealth, producing about one-quarter of the global gross product. However, industry is also a major emitter of CO2 and it represents a key challenge toward achieving the worldwide CO2 emission reduction targets. Nowadays, about 22% of the overall energy demand is heating for the industrial sector, generating about 40% of the global CO2 emissions. Additionally, 30% of the final energy demand of the industrial sector is electricity. Solutions to decarbonize the industrial sector are needed. This work presents the techno-economic assessment of four different molten salts-based power-to-heat-to-heat and power solutions aiming at decarbonizing the industrial sector, requiring medium temperature heat. The systems are studied under different electric markets. Dispatch strategies and system sizing are identified to ensure optimal techno-economic performance. The main performance indicators investigated are the levelized cost of heat and electricity (LCoH and LCoE), the operational expenditure, and the attainable savings with respect to alternative business as usual solutions. The results highlight that the proposed system can be cost-competitive, particularly in markets characterized by low electricity prices and high daily price fluctuations, such as Finland. In these locations, LCoE as low as 100 €/MWh and LCoH lower than 55 €/MWh can be attained by the base system configuration. The introduction of high temperature heat pumps can provide further LCoH reduction of about 50%. This study sets the ground for further power-to-heat-to-heat and power techno-economic investigations addressing different industrial sectors and identifies main system design strategies.

Experimental study on the diffusion characteristics of nonaqueous reactive expansive polymers in sand and gravel media under dynamic water conditions

Grouting is an effective method to solve water inrush from sand and gravel. However, due to the self-expandability of nonaqueous reactive expandable polymers, the diffusion behaviour of polymers in injected media becomes more complex, which brings great uncertainty to the selection of grouting parameters in grouting practice. For this reason, a series of diffusion experiments of nonaqueous reactive expansive polymers in sand and gravel media under dynamic water conditions were carried out using a homemade experimental device. The effects of grouting parameters such as dynamic pump pressure, mass fractal dimension, and grouting volume on the effective diffusion length and water plugging rate of the slurry were revealed. The results show that (1) the diffusion behaviour of nonaqueous reactive expansive polymers in sand and gravel media can be summarized as edge dispersion, downstream diffusion, and expansion diffusion. (2) The diffusion consolidated bodies of nonaqueous reactive expansive polymers mostly exhibit a hemispherical or columnar shape with a wide top and a narrow bottom. (3) The greater the pressure of the moving water pump is, the smaller the effective diffusion length of the slurry. Under the same grouting volume, with increasing mass fractal dimension, the effective diffusion length of the slurry first increases and then decreases. (4) Under the conditions of high dynamic water pump pressure and low mass fractal dimension, increasing the grouting volume has a better water plugging effect.

Application of deep learning modelling of the optimal operation conditions of auxiliary equipment of combined cycle gas turbine power station

Reasonable condition adjustment of the auxiliary machinery can optimize the operation performance of the Combined Cycle Gas Turbine (CCGT) power station. In this paper an optimization method for the operation control of the auxiliary equipment based on deep learning is proposed and applied to an F-class gas turbine generation unit. A database of the optimal operating conditions is established to achieve the best economic benefit based on the analysis of two years of historical operation data. The control optimization models are built using the machine learning algorithms including the Multi-Layer Perceptron (MLP), Supporting Vector Machine (SVM), Gaussian process regression and linear regression methods and their accuracy has been compared. The input parameters of these models consist of the load rate, the heating output and the ambient temperature, with the output parameters including the electrical currents for the mechanical draft cooling tower, the high pressure feed pump, the medium pressure feed pump and the condensate pump. The MLP model is designed with different network hidden layer structures and provides the highest calculation accuracy with the least average error of 1.82 %. Different training data sizes are compared and the optimal control trajectory is analyzed. The result can provide useful references for the optimization of auxiliary equipment operations.

Numerical Analysis of Dual-Wavelength Tungsten-Tellurite Fiber Raman Lasers with Controllable Mode Switching

Fiber laser sources in the spectral range near 1.7–1.8 μm are in highly demand for a lot of applications. We propose and theoretically investigate a dual-wavelength switchable Raman tungsten-tellurite fiber laser in the 1.7–1.8 µm range which can produce two stable modes at frequencies separated by ~7 THz with a pump at 1.55 µm. The Raman waves shifted by 19.8 THz (mode 1) and 27.5 THz (mode 2) from the pump frequency can be generated near two different maxima of the Raman gain spectrum (gain is higher at 19.8 THz and twice lower at 27.5 THz). We numerically simulate two-mode Raman lasing with allowance for energy transfer from the pump wave to modes 1 and 2, and from mode 1 to mode 2 due to inelastic Raman scattering. Diagrams of generation regimes depending on system parameters are constructed. We demonstrate controlled switching between two modes by changing the pump power. For the same intracavity losses for both Raman modes at relatively low pump powers, only mode 1 is generated. At medium pump power, generation occurs simultaneously in both modes. At relatively high pump power, only mode 2 is generated near the weaker maximum. This effect seems surprising, but a rigorous explanation with allowance for the nonlinear interaction between mode 1 and mode 2 is found. When losses for one of the modes change, switching of the generated regimes is also predicted.

Carbon sequestration reservoir at Rock Springs Uplift, Wyoming, USA

The Rock Springs Uplift (RSU) located in southwest Wyoming USA as indicated in Figure 1 is one of several sites across the country to be characterized for suitability for CO2 sequestration. The RSU was identified for several reasons: proximity to a large CO2 emissions point source, the overall geometry of the RSU structure, and geologic formations recognized to have properties required for long term storage of CO2. Original rock cores of the Weber Sandstone formation and the dolomite facies of the Madison Limestone formation from the RSU were prepared into 25-mm diameter rock samples. These samples were vacuum-saturated to 100% saturation with synthetic brine, aged with brine for 800 hours at in-situ temperatures and initial confining pressure of 3.5 MPa, and aged with CO2-rich brine (400 hours first with brine and another 400 hours with compressed CO2-saturated brine) at in-situ temperatures and initial confining pressure of 3.5 MPa. During the aging process, the pore and confining pressure were increased in small steps, typically 0.69 to 1.38 MPa at a time using high precision syringe pumps (Teledyne ISCO 260D, Lincoln, NE, USA) until the test conditions were met without fluid flow. Laboratory hydrostatic and triaxial experiments were performed at in-situ reservoir conditions with the temperatures of 90°C for Weber Sandstone and and 93°C for Madison Limestone under three differential pressures of 6.9 MPa, 34.5 MPa and 55.2 MPa.&#x0D; Geomechanical results of the aged rock samples are presented and discussed. Under the triaxial compression, Weber Sandstone exhibited brittle failure strengths while Madison Limestone exhibited a brittle-ductile transition behavior. For the sandstone samples with similar initial porosity, the Young’s moduli increased and Poisson’s ratios decreased as the result of CO2 under the linear elastic regime. No relationship between stress (or strain) data and CO2 in the nonlinear plastic regime was observed. However, the confining pressure has a greater effect than CO2 on geomechanical behaviors. For the limestone samples, the change of elastic constants due to CO2 is more significant than that of sandstone samples. However, no consistent trend was observed on the limestone samples,&#x0D; and the effect of CO2 is not the dominant factor influencing the plastic properties of rocks. DH1c with the lowest initial porosity and differential pressure exhibits the highest peak strength, Young’s modulus and Poisson’s ratio, indicating the effect of initial porosity. Considering the effect of CO2 on Mohr failure envelopes, the decreasing trend of cohesion and increasing friction angle was observed in both sandstone and limestone samples. Table 1 summarizes the maximum deviatoric stress, elastic properties, and shear strength parameters of Weber Sandstone and Madison Limestone samples.

Experimental Study on Electromagnetic Interference on control cable from two unbalanced 10 kV Power Cables

The occurrence of unpredicted and sudden failures in power cables seriously threatened the nearby control cables. Two cases of unbalance in the three-phase current load originate from a high horsepower pump and a sudden power off in an MW pump, resulting in an error signal detected in the adjacent control cable. However, these two cases just occurred once during the plant operation; no more history records can be a reference. In this paper, a typical power cable and control cable structure was constructed, typical accidents in power cables were considered, and electromagnetic interference was considered. The results show that the unbalance of the three-phase load results in a fold increase in interference current. Compared with the two-phase unbalance, the one-phase would bring a higher current. In other words, power off in a sudden situation brought a higher current than three-phase unbalance, especially a faster drop in current load. Finally, more attention should be given to the power cable operation, including unbalance in the power cable and an urgent power off.

Highly Efficient O-Band Rectangular Pulse Emission in a Figure-of-Nine Bismuth-Doped Fiber Laser

Highly efficient rectangular pulse emission is significant in high energy O-band applications due to the zero dispersion of standard telecom optical fiber in the second telecommunication window. The rectangular pulse emission offers the peak power clamping, which avoids wave-breaking and maintains the fundamental repetition frequency with arbitrarily widened temporal pulse width of ultrafast laser at high pump powers. The current technology in the O-band rectangular pulse emission achieves the maximum pulse energy of ∼30 nJ with an efficiency of ∼1.06%. Here, we fabricated a single-mode bismuth-doped phosphosilicate optical fiber by the modified chemical vapour deposition technique. The Bi-doped phosphosilicate optical fiber was characterized by a peak absorption of ∼0.6 dB/m at 1250 nm and a high gain coefficient of ∼0.22 dB/m at 1320 nm. These parameters contribute to the generation of rectangular pulse with a pump power threshold of ∼227.7 mW in a figure-of-nine laser cavity. The maximum pulse energy was achieved as ∼197.7 nJ, whereas the laser efficiency is ∼14.3%. We presented an O-band rectangular pulse emission with the highest pulse energy and efficiency as compared to previous studies, whilst its all-fiber laser setup is robust and feasible for high pulse energy applications.

Measurement of Activity of the Ca2+_Mg2+ ATPase in Membranous Vesicles Isolated from Smooth Muscle of Ileum in Rats Treated with Ultraviolet Radiation

The Ca2+_Mg2+ ATPase are high attraction calcium pump, that contributes in maintaining plasma membrane of cytoplasm Ca2+, Mg2+ homeostasis by source to the outside of cell. The aim of the study is to evaluate the effect of the ultraviolet radiation on the activity of the Ca2+_Mg2+ ATPase in the membranous vesicles of ileum in rats. Thirty adult Sprague–Dawley rats (age, 3-4 months, weight range, 180 – 200 g) were used in this experiment, which divided in to 5 groups (n = 6 / group). The membrane vesicles isolated from smooth muscles of rats showed high activity Ca2+_Mg2+ ATPase. All isolated membranous vesicles are irradiated with Ultraviolet radiation of 250 nanometers except control group. The irradiation period for each group was (5, 10, 30 and 45) minutes, respectively. The activity of Ca2+_Mg2+ ATPase was decreased with increased time of irradiation. In conclusion, the increased time of irradiation inhibited Ca2+_Mg2+ ATPase activity isolated from ileum smooth muscles of rats. The recommendations are to expose other organs like liver and kidney to UV radiation to explain its effect or using other range of UV radiation to reflect its effect.

High temperature transcritical CO2 heat pump with optimized tube-in-tube heat exchanger

CO2 heat pump operating on tanscritical cycle is widely adopted to provide hot water whose temperature is as high as about 90 °C. Recently, it is recognized that high temperature heat pump has promising application in various industries such as papermaking, chemical, automotive, and metallurgical. Then, in this paper a model of a tube-in-tube heat exchanger was established, and its parameters including tube length, fin height, fin number, fin thickness and helix angle are optimized through simulation to enhance its heat transfer performance, Accordingly, a transcritical CO2 heat pump system which can provide about 100 °C pressurized hot water is proposed and investigated. Subsequently, an experimental setup is constructed and operated under ambient temperatures, inlet and outlet temperatures of cooling water to demonstrate the feasibility of obtaining hot water at 100 °C. When the ambient temperature and inlet water temperatures are 40 °C and 9 °C respectively, the highest COP of 3.64 is obtained in experiments and the corresponding simulated value is 3.87. When the ambient temperature is 40 °C, inlet and outlet water temperatures are 9 °C and 85 °C, respectively, the study recorded the highest COP of 4.47. It is worth noting that both the heating capacity and COP increase with rising ambient temperature.