261 research outputs found
Characterization of flow rate and Heat Loss in Heating, Ventilation and Air Conditioning (HVAC) Duct System for Office Building
A building is an assemblage that is firmly attached to the ground and provides the performance of human
activities and need to be considered in the daily operation in that building. The improvements in building performance are
focused on improving the energy efficiency of buildings. This is approach by designing heating, ventilation and air
conditioning (HVAC) duct system due to one of the most utilized energy in maintaining building performance and
environment. The objectives of this research is to calculate the air (CFM) supply in office building, to characterize the
velocity and head loss in a round and rectangular HVAC ducting system at various duct thickness and to optimize the
thickness of the duct in HVAC system according to ASHRAE Standard. The increasing of velocity in duct system shows
the increasing of head loss. The round duct design gives the lowest velocity and head loss in HVAC system approximately
around 9.35% as compared to rectangular duct at 0.06 inches thickness. Hence, the trends of the head loss and duct thickness
has influenced in reducing noise in HVAC duct system in order to select the best design concepts which is round shape
design
Light storage protocols in Tm:YAG
We present two quantum memory protocols for solids: A stopped light approach
based on spectral hole burning and the storage in an atomic frequency comb.
These procedures are well adapted to the rare-earth ion doped crystals. We
carefully clarify the critical steps of both. On one side, we show that the
slowing-down due to hole-burning is sufficient to produce a complete mapping of
field into the atomic system. On the other side, we explain the storage and
retrieval mechanism of the Atomic Frequency Comb protocol. This two important
stages are implemented experimentally in Tm- doped
yttrium-aluminum-garnet crystal
A role of metallothionein in zinc regulation after oestradiol induction of vitellogenin synthesis in rainbow trout, Salmo gairdneri
Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology?
Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease
Comparative Assessment of the Bioremedial Potentials of Potato Resistant Starch-Based Microencapsulated and Non-encapsulated Lactobacillus plantarum to Alleviate the Effects of Chronic Lead Toxicity
Lead (Pb) is a well-recognized and potent heavy metal with non-biodegradable nature and can induce the oxidative stress, degenerative damages in tissues, and neural disorders. Certain lactic acid bacterial strains retain the potential to mitigate the lethal effects of Pb. The present work was carried out to assess the Pb bio-sorption and tolerance capabilities of Lactobacillus plantarum spp. Furthermore, potato resistant starch (PRS)-based microencapsulated and non-encapsulated L. plantarum KLDS 1.0344 was utilized for bioremediation against induced chronic Pb toxicity in mice. The experimental mice were divided into two main groups (Pb exposed and non-Pb exposed) and, each group was subsequently divided into three sub groups. The Pb exposed group was exposed to 100 mg/L Pb(NO3)2 via drinking water, and non-Pb exposed group was supplied with plain drinking water during 7 weeks prolonged in vivo study. The accumulation of Pb in blood, feces, renal, and hepatic tissues and its pathological damages were analyzed. The effect of Pb toxicity on the antioxidant enzyme capabilities in blood, serum, as well as, on levels of essential elements in tissues was also calculated. Moreover, KLDS 1.0344 displayed remarkable Pb binding capacity 72.34% and Pb tolerance (680 mg/L). Oral administration of both non- and PRS- encapsulated KLDS 1.0344 significantly provided protection against induced chronic Pb toxicity by increasing fecal Pb levels (445.65 ± 22.28 μg/g) and decreasing Pb in the blood up to 137.63 ± 2.43 μg/L, respectively. KLDS 1.0344 microencapsulated with PRS also relieved the renal and hepatic pathological damages and improved the antioxidant index by inhibiting changes in concentrations of glutathione peroxidase, glutathione, superoxide dismutase, malondialdehyde, and activated oxygen species, which were affected by the Pb exposure. Overall, our results suggested that L. plantarum KLDS 1.0344 either in free or encapsulated forms hold the potentiality to deliver a dietetic stratagem against Pb lethality
RELIABILITY OF DISSIMILAR METAL WELDS SUBJECTED TO SULFIDE STRESS CRACKING
Serious concerns have been raised in recent years in the Oil & Gas Industry about the reliability of Dissimilar Metal Welds (DMWs) in sour service. The primary reason for these concerns is because DMW joints exhibit small-localized hard zones that are susceptible to Sulfide Stress Cracking (SSC). In the open literature some methods such as preheating have been suggested to overcome the problem of hard zone formation. The objective of this study is to assess the effect of Sulfide Stress Cracking (SSC) on the reliability (mechanical integrity) of DMWs specimens fabricated with different preheat temperatures and electrodes exposed to sour service environment. The National Association of Corrosion Engineers (NACE) Standard Tensile Test TM 01-77-96 Method A was used to determine the influence of SSC on DMWs in a systematic manner. Test results show considerable improvement in the Time-To- Failure as a result of the preheating methods used. However, it does not appear that the hard zones can be reliably eliminated for manual welding methods, even with the nickel-base electrode, and the optimum preheat temperature. Metallographic Examination and Scanning Electron Microscope Characterization were also used to assess the susceptibility and the failure modes
Partnership and Capacity Building of Local Governance
Partnership is about sharing of power, responsibility and achievements. According to the World Bank Public Private Partnership (PPP) promoting group, ―partnership refer to informal and shortterm engagements of non-governmental organizations, the private sector and/or government agencies that join forces for a shared objective; to more formal, but still short-term private sector engagements for the provision of specific services, for example, annual outsourcing arrangements for janitorial services for a school or operations of the school cafeteria; to more complex contractual arrangements, such as build, operate, transfer regimes, where the private sector takes on considerable risk and remains engaged long term; or to full privatizations‖ (World Bank Group 2014, 29).© Springer Nature Switzerland AG 2020. This is a post-peer-review, pre-copyedit version of an article published in Partnerships for the Goals. Encyclopedia of the UN Sustainable Development Goals. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-319-71067-9_21-1.fi=vertaisarvioitu|en=peerReviewed
Role of N-acetylcysteine in the management of COPD
The importance of the underlying local and systemic oxidative stress and inflammation in chronic obstructive pulmonary disease (COPD) has long been established. In view of the lack of therapy that might inhibit the progress of the disease, there is an urgent need for a successful therapeutic approach that, through affecting the pathological processes, will influence the subsequent issues in COPD management such as lung function, airway clearance, dyspnoea, exacerbation, and quality of life. N-acetylcysteine (NAC) is a mucolytic and antioxidant drug that may also influence several inflammatory pathways. It provides the sulfhydryl groups and acts both as a precursor of reduced glutathione and as a direct reactive oxygen species (ROS) scavenger, hence regulating the redox status in the cells. The changed redox status may, in turn, influence the inflammation-controlling pathways. Moreover, as a mucolytic drug, it may, by means of decreasing viscosity of the sputum, clean the bronchi leading to a decrease in dyspnoea and improved lung function. Nevertheless, as successful as it is in the in vitro studies and in vivo studies with high dosage, its actions at the dosages used in COPD management are debatable. It seems to influence exacerbation rate and limit the number of hospitalization days, however, with little or no influence on the lung function parameters. Despite these considerations and in view of the present lack of effective therapies to inhibit disease progression in COPD, NAC and its derivatives with their multiple molecular modes of action remain promising medication once doses and route of administration are optimized
Effects of Post-Resuscitation Treatment with N-acetylcysteine on Cardiac Recovery in Hypoxic Newborn Piglets
AIMS: Although N-acetylcysteine (NAC) can decrease reactive oxygen species and improve myocardial recovery after ischemia/hypoxia in various acute animal models, little is known regarding its long-term effect in neonatal subjects. We investigated whether NAC provides prolonged protective effect on hemodynamics and oxidative stress using a surviving swine model of neonatal asphyxia. METHODS AND RESULTS: Newborn piglets were anesthetized and acutely instrumented for measurement of systemic hemodynamics and oxygen transport. Animals were block-randomized into a sham-operated group (without hypoxia-reoxygenation [H-R, n = 6]) and two H-R groups (2 h normocapnic alveolar hypoxia followed by 48 h reoxygenation, n = 8/group). All piglets were acidotic and in cardiogenic shock after hypoxia. At 5 min after reoxygenation, piglets were given either saline or NAC (intravenous 150 mg/kg bolus + 20 mg/kg/h infusion) via for 24 h in a blinded, randomized fashion. Both cardiac index and stroke volume of H-R controls remained lower than the pre-hypoxic values throughout recovery. Treating the piglets with NAC significantly improved cardiac index, stroke volume and systemic oxygen delivery to levels not different from those of sham-operated piglets. Accompanied with the hemodynamic improvement, NAC-treated piglets had significantly lower plasma cardiac troponin-I, myocardial lipid hydroperoxides, activated caspase-3 and lactate levels (vs. H-R controls). The change in cardiac index after H-R correlated with myocardial lipid hydroperoxides, caspase-3 and lactate levels (all p<0.05). CONCLUSIONS: Post-resuscitation administration of NAC reduces myocardial oxidative stress and caused a prolonged improvement in cardiac function and in newborn piglets with H-R insults
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