Biofuel-driven trigeneration systems for non-residential building applications: A holistic assessment from the energy, environmental and economic perspectives.

In the metropolises, it is unlikely to use merely solar and wind energy to pursue zero carbon building design. However, it would become possible if biofuel-driven trigeneration systems (BDTS) are adopted. It is thus essential to assess the application opportunity of BDTS in a holistic way. In this study, BDTS offered definite primary energy saving of up to 15% and carbon emissions reduction of at least 86% in different types of non-residential buildings as compared to the conventional systems. With 24/7 operation for the hotel and hospital buildings, the corresponding BDTS could even achieve zero carbon emissions. All the BDTS primed with compression-ignition internal combustion engine were not economically viable even in running cost due to the high local biodiesel price level. The BDTS primed with spark-ignition engine and fueled by biogas, however, would have economic merit when carbon price was considered for the conventional systems that fully utilize fossil fuels. Adoption of carbon tax and social cost could have the payback ceilings of 8 years and 2 years respectively for most of building types. Consequently, the results could reflect the application potential of BDTS for non-residential buildings, leading the pathway to carbon neutrality for sustainable sub-tropical cities.

Uniformity of stratum-ventilated thermal environment and thermal sensation.

Three human test series were conducted to evaluate the uniformity of the thermal environments in a stratum-ventilated chamber with dimensions of 8.8 m (L) × 5.1 m (W) × 2.4 m (H). In all, nineteen conditions were generated by adjusting the room temperature, supply airflow rate, and supply terminal type. An air diffuser performance index (ADPI) of at least 80% was achieved for most cases. This result shows that the air velocity and temperature in the occupied zone are reasonably uniform. Subjective assessments using the ASHRAE 7-point scale indicate that the thermal sensations of the subjects in stratum ventilation are also uniform. This study examines the applicability of the predicted mean vote (PMV) model for evaluating stratum ventilation. When compared to the actual mean thermal sensation votes (ATS), the PMV values are acceptable. The PMV results at a height of 1.1 m above the floor show better agreement with the ATS than at a height of 0.1 m.

Evaluation of thermal comfort conditions in a classroom with three ventilation methods.

UNLABELLED: Thermal sensation is studied experimentally under mixing ventilation, displacement ventilation, and stratum ventilation in an environmental chamber. Forty-eight subjects participated in all tests under the same boundary conditions but different ventilation methods in the classroom. Thermal comfort analysis was carried out according to the designated supply airflow rate, room temperature, and relative humidity for the three ventilation methods. The thermal neutral temperature under stratum ventilation is approximately 2.5 °C higher than that under mixing ventilation and 2.0 °C higher than that under displacement ventilation. This result indicates that stratum ventilation could provide satisfactory thermal comfort level to rooms of temperature up to 27 °C. The energy saving attributable to less ventilation load alone is around 12% compared with mixing ventilation and 9% compared with displacement ventilation. PRACTICAL IMPLICATIONS: The confirmation of the significantly elevated thermal neutral temperature can have a number of implications for both thermal comfort in an air-conditioned room and energy consumption of the associate air-conditioning system. With respect to the former, it provides scientific basis for the feasibility of elevated room temperatures, and with respect to the latter, it reveals considerable potentials for energy saving.

Antioxidative action of the beta-adrenoceptor antagonist bopindolol and its metabolite 18-502.

The antioxidative effects of beta-adrenoceptor antagonists and related compounds were investigated. Among the beta-adrenoceptor antagonists, the agents with a potent membrane-stabilizing activity such as bopindolol and propranolol strongly inhibited the hydrogen peroxide (H2O2)-induced lipid peroxidation of liver microsomes. Fifty percent inhibition concentration values for the lipid peroxidation of bopindolol, 18-502 (metabolite of bopindolol) and propranolol were calculated to be 1.8 microM, 10 microM and 2.3 microM, respectively. The same potency order of the agents for the inhibition of lipid peroxidation was observed in rat heart homogenates. Furthermore, cytochrome P-450-catalyzing lipid peroxidation in microsomes and H2O2-induced lipid peroxidation in coronary arteries or cardiac muscles of pigs were also inhibited by bopindolol, whereas propranolol was less effective. Bopindolol and 18-502, but not propranolol, scavenged a stable free radical 1,1-diphenyl-2-picrylhydrazyl. Thus it was concluded that bopindolol that has membrane-stabilizing and radical scavenging activities is a more potent antioxidant than propranolol and may produce a beneficial effect for the treatment of ischemic cardiac diseases.

Cardioprotective effects of hydrolyzed bopindolol against contractile dysfunction produced by coronary stenosis and reperfusion in dogs.

The effects of the active metabolite (18-502) of bopindolol, which is a new nonselective beta-adrenoceptor antagonist, were studied on the ischemic changes in myocardial segment shortening, cardiac lactate metabolism and S-T segment of subendocardial electrocardiogram during coronary stenosis and on their recoveries after reperfusion in anesthetized dogs, and were compared with those of propranolol at a dose exhibiting a comparable degree of beta 1-blocking activity. In the presence of coronary stenosis, intravenous administration of 18-502 (5 micrograms/kg) and propranolol (0.2 mg/kg), but not saline, produced significant improvements of regional myocardial dysfunction, lactate production and S-T segment elevations in the ischemic myocardium, which were associated with significant decreases in heart rate and cardiac contractility. After release of the stenosis, administration of 18-502, but not propranolol, resulted in a significantly accelerated recovery of the ischemic segment function as compared with the control group. In rat heart homogenates, 18-502 inhibited the lipid peroxidation approximately 4 times more potently than propranolol. These data show that 18-502 exerts favorable effects during myocardial ischemia produced by coronary stenosis and that it has a cardioprotective action against the contractile dysfunction following reperfusion.

Conjunctival biopsy in the diagnosis of sarcoidosis.

The diagnosis of sarcoidosis with ocular involvement is often difficult and accompanied by a certain measure of uncertainty due to a paucity of additional physical signs. In the ophthalmic literature, it is controversial as to whether biopsy of a clinically normal conjuctiva should be done if sarcoidosis is suspected. Many authors advocate biopsy only in the presence of conjunctival follicles or nodules. However, a positive biopsy from a clinically normal-appearing conjunctiva has been reported. Recently, we saw a patient with bilateral uveitis, evanescent cranial nerve palsies, and other clinical manifestations suggesting central nervous system and ocular sarcoidosis. Random biopsy of a normal-appearing conjunctiva revealed a noncaseating granuloma consistent with sarcoidosis. Since conjunctival biopsy is a simple office procedure with minimal morbidity, this diagnostic tool should be considered for patients with clinically suspected sarcoidosis, even in the absence of conjunctival follicles or nodules.