THE EFFECT OF TILT ANGLE AND MASS FLOW RATE ON THE PERFORMANCE OF A PARABOLIC TROUGH SOLAR CONCENTRATOR VIA EXPERIMENTATION

Solar energy is widely regarded as a very promising alternative energy source due to its potential to satisfy a substantial portion of global energy demand. The efficacy of a solar concentrator is contingent upon operational and weather factors. This paper presents an experimental evaluation of the effect of tilt angle and mass flow rate on the effectiveness of a parabolic trough solar concentrator The parabolic trough solar collector was subjected to experimental testing in LAUTECH's Ogbomoso engineering facility. It has a collector length of 2.1m, an aperture width of 1.2m, an adjustable rim angle of 75o, 90o, and 105o, a focal length of 30 cm, a 10-liter storage reservoir with varying flow rates of  0.0004 m3/s, 0.0008m3/s, and 0.0012m3/s. The temperatures were measured with a 12-channel temperature recorder (SD data logger), while the solar radiation was measured with a solar meter and water was used as a working fluid. Thermal performance analysis was conducted to ascertain the impact of tilt angle, mass flow rate, and weather conditions on the solar concentrator's effectiveness. The results indicate that the system has a greater thermal efficacy with weather elements such as solar intensity and ambient temperature at higher mass flow rates and a 90o tilt angle. This concentrator aids the energy industry by decreasing reliance on electricity and pollution from fossil fuels, thereby minimizing environmental and health issues. Keywords: Alternative Energy, Concentrator, Effectiveness, Environment, Tilt Angle, DOI: 10.7176/APTA/88-01 Publication date: February 28th 202

Titin-truncating variants affect heart function in disease cohorts and the general population

Titin-truncating variants (TTNtv) commonly cause dilated cardiomyopathy (DCM). TTNtv are also encountered in ~1% of the general population, where they may be silent, perhaps reflecting allelic factors. To better understand TTNtv, we integrated TTN allelic series, cardiac imaging and genomic data in humans and studied rat models with disparate TTNtv. In patients with DCM, TTNtv throughout titin were significantly associated with DCM. Ribosomal profiling in rat showed the translational footprint of premature stop codons in Ttn, TTNtv-position-independent nonsense-mediated degradation of the mutant allele and a signature of perturbed cardiac metabolism. Heart physiology in rats with TTNtv was unremarkable at baseline but became impaired during cardiac stress. In healthy humans, machine-learning-based analysis of high-resolution cardiac imaging showed TTNtv to be associated with eccentric cardiac remodeling. These data show that TTNtv have molecular and physiological effects on the heart across species, with a continuum of expressivity in health and disease

Drivers of Change or Cut-Throat Competitors? Challenging Cultures of Innovation of Chinese and Nigerian Migrant Entrepreneurs in West Africa

L'afflux remarquable des entrepreneurs migrants chinois dans différents pays d'Afrique occidentale au cours des dernières années a été heurtée à une résistance de plus en plus farouche par des entrepreneurs locaux établis. Que le premiers ont un avantage concurrentiel sur ce dernier en raison de traits socio-culturels distinctifs, ou si l'efficacité supposée chinoise est juste une caractéristique de toutes les diasporas mercantiles, est ouvert à la question. Cette étude exploratoire des migrants entrepreneuriales chinois et nigérians au Ghana et au Bénin tente de répondre à cette question. Apparemment, les forces culturels des agents du changement migrants ne sont pas limités à des systèmes de valeurs héritées ou religions, comme une éthique protestante ou le confucianisme, mais ils sont adaptés en permanence et ont inventé de nouveau par des réseaux transnationaux de la migration dans un monde globalisé. Il n'y a aucune preuve d'une prétendue supériorité de la culture d’innovation chinois par rapport aux cultures d’innovation africains des migrants entrepreneuriales. Plutôt, il existe une capacité accrue d'innovation d'une diaspora mercantile en général vis à vis des entrepreneurs locaux, indépendamment de l'origine de la culture nationale dans lequel il est intégré. En outre, la rivalité des entrepreneurs migrants chinois et nigérians dans les marchés africains ne conduit pas nécessairement à la concurrence coupe-gorge souvent suspectée sous l'impact de la mondialisation. Souvent, les deux groupes agissent plutôt complémentaires. Cela contribue, sous certaines conditions, même à la réduction de la pauvreté dans le pays d'accueil

An Experimental Investigation of Influence of Relative Humidity on Thermal Performances of a Parabolic Trough Solar Concentrator

Solar energy is considered by many as a highly prospective alternative energy source due to its ability to meet a significant portion of the world's energy demand. The effectiveness of a solar concentrator depends on operational and atmospheric conditions. This paper presents an experimental analysis of the influence of humidity coupled with inclination angle and mass flow rate on the performance of a parabolic trough solar concentrator.  The parabolic trough solar collector underwent experimental testing at the LAUTECH engineering facility in Ogbomoso. It possesses a collector length of 2.1m, an aperture width of 1.2m, an adjustable rim angle of 75o, 90o, and 105o, a focal length of 30 cm, a 10-liter storage reservoir, and variable flow rates of 0.0004 m3/s, 0.0008 m3/s, and 0.0012 m3/s. Temperatures were measured using a 12-channel temperature recorder (SD data logger), solar radiation was measured using a solar meter, relative humidity was measured using an environment meter,  and water was used as the working fluid. Thermal performance analysis was conducted to ascertain the impact of relative humidity coupled with tilt angle, mass flow rate, and weather conditions on the solar concentrator's effectiveness. The findings reveals that at higher mass flow rates and a 90° tilt angle, the system has a greater thermal efficacy with weather elements such as solar intensity and relative humidity. Parabolic trough concentrators' performance is determined by the amount of solar intensity focused onto a receiver tube and high humidity in the air reduces the quantity of direct solar radiation that reaches the concentrator and high relative humidity reduces the thermal effectiveness of the system. While relative humidity may not be the main factor influencing the performance of a parabolic trough concentrator, its effects on thermal efficiency and heat exchange should be taken into account when designing and operating such solar thermal systems, especially in environments with varying humidity levels. Keywords Parabolic Trough Collector, Heat loss, Thermal efficiency, Humidity. DOI: 10.7176/JEES/14-2-05 Publication date:March 31st 202

Influence of Relative Humidity on Thermal Performances of a Parabolic Trough Solar Collector

Solar energy is considered by many as a highly prospective alternative energy source due to its ability to meet a significant portion of the world's energy demand. The effectiveness of a solar concentrator depends on operational and atmospheric conditions. This paper presents an experimental analysis of the influence of humidity coupled with inclination angle and mass flow rate on the performance of a parabolic trough solar concentrator. The parabolic trough solar collector underwent experimental testing at the LAUTECH engineering facility in Ogbomoso. It possesses a collector length of 2.1m, an aperture width of 1.2m, an adjustable rim angle of 75o, 90o, and 105o, a focal length of 30 cm, a 10-liter storage reservoir, and variable flow rates of 0.0004 m3/s, 0.0008 m3/s, and 0.0012 m3/s. Temperatures were measured using a 12-channel temperature recorder (SD data logger), solar radiation was measured using a solar meter, relative humidity was measured using an environment meter,  and water was used as the working fluid. Thermal performance analysis was conducted to ascertain the impact of relative humidity coupled with tilt angle, mass flow rate, and weather conditions on the solar concentrator's effectiveness. At higher mass flow rates and a 90° tilt angle, the system has a greater thermal efficacy with weather elements such as solar intensity and relative humidity. This concentrator assists the energy industry by reducing its dependence on electricity and pollution from fossil fuels, thereby mitigating environmental and health concerns. Keywords Parabolic Trough Collector, Heat loss, Thermal efficiency, Humidity. DOI: 10.7176/JEES/14-1-06 Publication date: February 28th 202