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Thermal battery plays an important role in renewable energy utilization towards carbon neutrality. The novel absorption thermal battery (ATB) has excellent performance but suffers from serious capacity attenuation. To address this problem, two capacity regulation methods, i.e., variable solution flow and variable cooling water flow, are proposed to achieve a demanded discharging rate. The effects of the two regulation strategies on the dynamic discharging characteristics and overall storage performance are comparatively investigated. To demonstrate the adjustability of the output capacity, several stable discharging rates are successfully maintained by the proposed methods. To maintain a higher discharging rate, the stable discharging time has to be sacrificed. As the demanded output increased from 0.5 kW to 6.0 kW, the stable discharging time decreased from 781.8 min to 27.9 min under variable solution flow and from 769.9 min to 30.7 min under variable cooling water flow. With the increase of solution or water flow rate, the energy storage density is improved, while the energy storage efficiency is slightly increased first and decreased later. The regulation method of variable water flow shows relatively lower energy storage efficiency due to the larger pump power. This study could facilitate reasonable development and application of ATB cycles.

Reciprocating compressor stepless capacity control system in the petrochemical industry are widely used, unloading device as a key component of the system actuator, the action characteristics of the relationship between the quality of the system directly related to the efficiency of the air intake system and compressor valve life. In this paper, ANSYS/Ls-dyna explicit dynamics software is used to simulate the automatic opening process of the intake valve at the rated speed of the compressor. The displacement of the valve is measured by the eddy current displacement sensor. On the basis of this, the operation of the unloader under different oil supply pressure and different ejection time is simulated, the ideal hydraulic ejection force and the ejection phase are determined. It is concluded that the reasonable action of the unloader can effectively relieve the vibration of the valve plate and improve the force of the valve.

Compressor thermodynamics under varying capacity loads are difficult to predict due to the interaction between the valve-sealing element motion, unloader behavior, and fluid flow. In this paper, a new comprehensive mathematical model of piston compressor under various gas flow loads is established, which is combined with a reciprocating compressor, intake valves, hydraulic plunger cylinder, and unloader, and the model is validated by experimental data. Results show that the installation of finger-type unloaders clearly leads to an increase in flow loss. With a reduction in the flow load of compressed gas, the closing impact velocity of the suction valve plate increases, and the valve appears to oscillate under capacity regulation conditions, leading to premature fatigue damage of the valve component. The optimal combination of design parameters for a suction valve in the capacity regulation system is a 2.7 mm valve lift with a 2100 N/m spring stiffness, yielding a minimum valve resistance loss within admissible valve dynamic motion. The reset spring stiffness of 20 kN/m is chosen as the optimal parameter value by which the impact speed of the suction valve plate at the valve seat is clearly reduced, avoiding excessive impact stress in the reset process.

Cx43 has been documented to be involved in ischemic preconditioning (IPC). However, the participation of Cx43-formed hemichannels in IPC and the potential underlying mechanisms remain unclear. The present study focused on cardiomyocytes' volume regulation during IPC to investigate the role of hemichannels in the IPC-induced cardioprotection. In the study, mice cardiomyocytes were respectively treated with a hemichannel blocker, octanol or 18a-Glycyrrhizic acid (18a-GA), and a Cx43-silenced lentivirus. They were subsequently cultured in hypotonic solution to simulate ischemic reperfusion (SIR) and systemic ischemic preconditioning (SIP). Cell morphology and volumetric (area) change were detected by inverted microscopy at 30 min following the addition of hypotonic solution. Cardiomyocyte mortality was assessed by trypan blue stain assay. The analyses revealed that regardless of the treatments, hypotonic solution aggravated cell edema: Compared with the initial condition (the moment before the solution addition, 0 min), the volumetric area increased significantly 30 min later (for hypotonic+DMSO, 5,050±1,511 vs. 3,464±723 µm2; for hypotonic+scramble lentiviral vector, 5,517±1,128 vs. 2,331±536 µm2; P<0.05, respectively). Either treatment alleviated the edematous condition when a comparison was made between 30 min after the hypotonic addition and 0 min (for hypotonic+octanol, 2,990±765 vs. 2,821±773 µm2; for hypotonic+18a-GA, 4,817±1,306 vs. 4,762±1,271 µm2; for hypotonic+Cx43-silenced, 3,627±688 vs. 3,419±814 µm2; P>0.05 for all). Notably, results indicated that the SIP group had lower mortality rates compared with its SIR counterpart; the hypotonic+octanol, hypotonic+18a-GA, and hypotonic+Cx43-silenced group showed markedly-declined mortality when compared with their respective control groups (respectively, 35.70±1.02, 30.76±2.20 vs. 53.58±2.14%; 30.89±2.37 vs. 54.12±2.55%; P<0.05 for all). The results suggest that ischemic preconditioning may provide cardioprotection by blocking the opening of the hemichannels and further mediating the volume regulation of cardiomyocytes. [ABSTRACT FROM AUTHOR]

In steam pipeline pressure energy recovery application, twin-screw expander is a promising approach to recover waste pressure energy dissipated in the throttling process. Since the expander operates at off-design condition in most circumstances, regulating expander capacity under fluctuating operating conditions appears to be an urgent problem. In this paper, a thermodynamic mathematical model is developed to study the performance of twin-screw steam expander under fluctuating operating conditions. In the modeling, suction pressure loss is taken into account, as well as leakage and heat transfer during the two-phase expansion process. Simulation results show that the filling factor varies 0.82–0.88 and isentropic efficiency varies 0.73–0.83, which proves twin-screw expander an efficient technology in steam pipeline pressure recovery application. Compared to suction pressure and back pressure, rotational speed affects the suction pressure loss more significantly. Increasing rotational speed has a negative effect on filling factor and larger expansion ratio leads to higher isentropic efficiency. In addition, over-expansion results in more energy loss than under-expansion. Therefore, the built-in volume ratio should be elaborately designed to ensure the expander operating at an under-expansion condition. Furthermore, rotational speed adjustment is recommended as the currently most convenient and efficient way for expander capacity regulation. [ABSTRACT FROM AUTHOR]

Linijske konferencije su u mnogim zakonodavstvima uživale određene oblike izuzeća ili imuniteta od primjene prava tržišnog natjecanja. U EU Vijeće ministara je 1986. godine donijelo Uredbu 4056/86 kojom se određivanje cijena i reguliranje upotrebe kapaciteta linijskih konferencija, uz ispunjavanje određenih uvjeta, izuzima od primjene čl.81 i 82. Ugovora o osnivanju Europske zajednice. Opravdanje za donošenje Uredbe 4056/86 temeljilo se na pretpostavci kako određivanje vozarinskih stavova i druge aktivnosti linijskih konferencija dovode do stabilnih vozarina, osiguravajući tako prijevoznicima pouzdane prijevozne usluge prema redovitom rasporedu. Međutim, u posljednje vrijeme imunitet linijskih konferencija je podvrgnut reviziji u nekoliko dijelova svijeta, jedan od njih je i EU. Komisijin prijedlog za ukidanje skupnog izuzeća za linijske konferencije rezultat je njenog trogodišnjeg istraživanja tijekom kojeg su održane mnogobrojne konzultacije s prijevoznicima i korisnicima prijevoza. Vijeće ministara je u rujnu 2006. usvojilo Komisijin prijedlog za ukidanje izuzeća od primjene pravila tržišnog natjecanja na linijske konferencije koje djeluju na pravcima iz i prema EU. Ukidanje izuzeća će stupiti na snagu u listopadu 2008. Vijeće je također ovlastilo Komisiju da primjenjuje pravila tržišnog natjecanja na kabotažu i slobodnu plovidbu, tako što je proširilo područje primjene Uredbe 1/2003, koja sadrži provedbena pravila tržišnog natjecanja. Kako bi se olakšao prelazak na potpuno kompetitivni sustav, Komisija će donijeti Smjernice o primjeni prava tržišnog natjecanja na pomorski prijevoz, u dogovoru sa svim zainteresiranim stranama. U radu se analiziraju recentne izmjene materijalno-pravnih i procesno-pravnih pravila tržišnog natjecanja, koji se odnose na linijske konferencije, kabotažu i slobodnu plovidbu, a na različite prijedloge i argumente zainteresiranih strana kritički se osvrće.